CA2226194A1 - A high resolution intravascular ultrasound transducer assembly having a flexible substrate and method for manufacture thereof - Google Patents
A high resolution intravascular ultrasound transducer assembly having a flexible substrate and method for manufacture thereof Download PDFInfo
- Publication number
- CA2226194A1 CA2226194A1 CA002226194A CA2226194A CA2226194A1 CA 2226194 A1 CA2226194 A1 CA 2226194A1 CA 002226194 A CA002226194 A CA 002226194A CA 2226194 A CA2226194 A CA 2226194A CA 2226194 A1 CA2226194 A1 CA 2226194A1
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- Prior art keywords
- transducer
- ultrasound transducer
- transducer assembly
- ultrasound
- assembly
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Links
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Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B1/00—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor
- A61B1/00064—Constructional details of the endoscope body
- A61B1/0011—Manufacturing of endoscope parts
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B8/00—Diagnosis using ultrasonic, sonic or infrasonic waves
- A61B8/12—Diagnosis using ultrasonic, sonic or infrasonic waves in body cavities or body tracts, e.g. by using catheters
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B8/00—Diagnosis using ultrasonic, sonic or infrasonic waves
- A61B8/44—Constructional features of the ultrasonic, sonic or infrasonic diagnostic device
- A61B8/4483—Constructional features of the ultrasonic, sonic or infrasonic diagnostic device characterised by features of the ultrasound transducer
- A61B8/4488—Constructional features of the ultrasonic, sonic or infrasonic diagnostic device characterised by features of the ultrasound transducer the transducer being a phased array
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
- B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
- B06B1/06—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction
- B06B1/0607—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements
- B06B1/0622—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements on one surface
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
- B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
- B06B1/06—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction
- B06B1/0607—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements
- B06B1/0622—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements on one surface
- B06B1/0633—Cylindrical array
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B8/00—Diagnosis using ultrasonic, sonic or infrasonic waves
- A61B8/44—Constructional features of the ultrasonic, sonic or infrasonic diagnostic device
- A61B8/4444—Constructional features of the ultrasonic, sonic or infrasonic diagnostic device related to the probe
- A61B8/445—Details of catheter construction
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K1/00—Printed circuits
- H05K1/18—Printed circuits structurally associated with non-printed electric components
- H05K1/189—Printed circuits structurally associated with non-printed electric components characterised by the use of a flexible or folded printed circuit
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/42—Piezoelectric device making
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/49005—Acoustic transducer
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/49117—Conductor or circuit manufacturing
- Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
- Y10T29/4913—Assembling to base an electrical component, e.g., capacitor, etc.
Abstract
An ultrasound transducer assembly of the present invention includes a flexible circuit to which an ultrasound transducer array and integrated circuitry are attached during fabrication of the ultrasound transducer assembly. Integrated circuitry and transducer elements are attached to the flexible circuit while the flexible circuit is in a substantially flat shape. The contacts of the transducer elements are positioned on substantially the same plane such that electrical contact with signal and ground lines on the flexible circuit is established without the need for conductive bridges to physically remote electrodes. In an embodiment of the invention wherein the transducer elements are arranged in a cylindrical array, gaps are entirely filled with backing material having a relatively low acoustic impedance. Structure integrity is enhanced and a path to ground facilitated by electrically conductive disks attached to the ends of the transducer assembly.
Description
A HIGH RESOLUTION INTRAVASCULAR ULTRASOUND TRANSvu~
ASSEMBLY HAVING A FT~TRTR SUBSTRATE AND
h~r~O~ FOR M~NUFACTUR~ TH~REOF
rN~O~rOKATION ~Y K~N OE
The applicants hereby expressly incorporate by reference in their entirety the description of an I~Apparatus and Method for Imaging S B 11 CaVitie8n described in Prou~An et al. U.S. Patent 4,917,097, the description of a ~Dilating and Imaging Apparatus n described in Bberle et al. U.S. Patent 5,167,233, the description of an ~Ultrasound Catheter~ described in Eberle et al. U.S. Patent 5,368,037, the description of an "Apparatus And Method For Detecting Blood Flow In Intravascular Ultrasonic Imaging~ in O'Donnell et al.
U.S. Patent 5,453,575, and the description of a "High Resolution Intravascular Ultrasound Transducer Having a Flexible Substrate~ in Eberle et al. U.S. Serial No.
08/712,576 filed on September 13, 1996 which is a continuation of U.S. Serial No. 08/578,226 filed on December 26, 1995.
FI~LD OP IE~ INVENTION
This invention relates to ultrasound imaging apparatuse~ pl~ce~ within a cavity to provide images thereof of the type described in Pron~;An et al. U.S.
Patent 4,917,097 and ~ re specifically, to ultrasound imaging apparatuses and methods for fabricating such devices on a scale such that the tr~n~Al7c~r assembly portion of the imaging apparatus may be placed within a vasculature in order to produce images of the vasculature.
R~ JND 0~ T~e INY~rION
In the United States and many othe~ countries, heart disease is a le~ ng cause of death and disability. One particular kind of heart disease is atherosclerosis, which involves the degeneration of the walls and lumen of the arteries throughout the body.
Scientific studies have ~mon~trated the thi~ken; ng of an arterial wall and eventual encroachment of the tissue into the lumen as fatty material builds upon the vessel walls. The fatty material i8 known as "plaque." As the pla~ue builds up and the lumen narrows, blood flow is restricted. If the artery narrows too much, or if a s blood clot forms at an injured plaque site (lesion), flow is severely reduced, or cut off and consequently the muscle that it su~oLLs may be injured or die due to a lack of o~yye~. Atherosclerosis can occur throughout the human body, but it is most life threatening when it involves the coronary arteries which supply o~yye,- to the heart. If blood flow to the heart is significantly reduced or cut off, a myocardial infarction or ~heart attack~ often occurs. If not treated in sufficient time, a heart attack often leads to death.
- 15 The medical profession relies upon a wide variety of tools to treat coronary disease, ranging from drugs to open heart ~bypas~ surgery. Often, a lesion can be diagnose~ and treated with minimal intervention through the use of catheter-based tools that are threaded into the coronary arteries via the femoral artery in the groin. For example, one treatment for lesions is a procedure known as percutAneoll~ transl~lnAl coronary angioplasty (PTCA) whereby a catheter with an ~YpAn~Ahle balloon at its tip is threaded into the lesion and 2s inflated. The underlying le~ion is re-shaped, and hopefully, the lumen diameter is increased to improve - blood flow.
In recent years, a new technique has been developed for obtAin~ng infonmation about coronary vessels and to view the effects of therapy on the form and structure of a site within a vessel rather then merely determining that blood is flowing through a vessel. The new technique, known as Intracoronary/Intravascular UltrA~olln~ (Icus/rvus)~ employs very small transducers arranged on the end of a catheter which provide electronic trAn~nce~ echo signals to an external imaging system in order to produce a two or three-dimensional image of the lumen, the arterial tissue, and tissue surrolln~i ng the artery. These images are generated in 8ubstantially real time and provide images of superior quality to the known x-ray imaging methods s and apparatuses. Imaging technigues have been developed to obtain detailed images of vessels and the blood flowing through them. An example of such a method is the flow imaging method and apparatus described in O'~onnell et al. U.S. patent 5,453,575, the t~Ach;ngs of which are e~rëssly incoL~oL~ted in their entirety herein by reference. Other ~mAging methods and intravascular ultrasound imaging applications would also benefit from ~nhAnce~ image resolution.
Transducer backing materials having relatively low acoustic impe~Ance improve signal quality in transducer assemblies comprising PZT or PZT composites. The advantages of such backing materials are ~YplAine~ in Eberle et al. U.S. patent 5,368,037 the teAch~ngs of which are ex~le~sly incoL~o-ated in their entirety herein by reference. It is also important to select a matching layer for m7Y;~zing the acoustic perform~nce of the PZT transducers by min~m~zing echoes arising from the ultrA~olln~ assembly/blood-tissue interface.
When designing a very small device for manufacture in large quantities it is important to take into consideration practical limitations such as manufacturability, reliability, resiliency and perfonmance. The ultrasound catheter assembly must produce high quality raw image signals for the signal processing system located outside the body within which the intravascular ultrasound trAn~ cer asse~mbly i8 inserted for imaging. However, there is an interest in limiting the nl~ber of parts since added complexity can increase the manufacturing costs and reduce the yield of the intravascular ultrasound catheter assemblies. The devices must be sufficiently rêsilient to withstand handling during manufacture and use.
Sn~MARY OF TEB I~N~ION
It is a general ob~ect of the present invention to i~LV~e the manufacturability of an intravascular ultrasound transducer assembly.
S It is another ob~ect of the present invention to decrease the per-unit cost for manufacturing ultrasound trAna~lcer assemblies.
If is yet another ob~ect of the present invention to increase the yield of manufactured ultrasound - 10 tr~nQ~l~)cer ass~mhlie8.
It is a related ob;ect to provide ~nhAnce~
structural integrity of the electrical connections in the transducer assembly.
It is another ob~ect of the present invention to decrease the complexity of the ultrasound transducer assembly.
The above mentioned and other ob~ects are met in a new ultrasound trAnq~cer assembly, and method for fabricating the ultrasound trAn~ cer assembly including a PZT substrate with metallic contacts formed directly on the PZT substrate during a pre-fabrication step.
The ultrasound trAnq~C r assembly of the present invention includes a flexible substrate having an inner surface to which transducer signal lines and a ground line are attached to form a flexible circuit. In a preferred embodiment of the present inv~nt~Qn, the - flexible substrate provides the quarter-wave matching layer for the ultrasound tr~n~)c~rs.
An ultrasound trAna~cer array and integrated circuitry are attached during fabrication of the ultrasound trAn~nc~r assembly while the flexible substrate is substantially pl~AnAr (i.e., flat). In accordance with an aspect of the present invention, the signal electrode and ground electrode for transducer elements at least partially extend to the surface of the tr~ns~lcer elements that establishes contact with the inner surface plane of the flexible circuit. As a consequence both the ground and signal electrodes can establish direct electrical contact with corre8p~nA; ng signal and ground pads on the flexible surface.
Therefore, conductive bridges between flexible circuit lines and electrodes located on a physically remote surface of the transducer elements are no longer required.
In a particular embodiment of the invention, after the tr~nq~l)cer array and integrated circuit chips are attached to the flexible substrate, the flexible substrate is re~h~re~ into a subst~nt~lly non-planar shape around a lumen tube to form a substantially cylindrical shape. In accordance with another, more particular, aspect of the present invention, the spaces within the ultrasound transducer assembly between the lumen tube, the flex circuit, the transducer array and the integrated circuits are all filled with a backing material characterized by relatively low acoustic i~re~nce. While the use of backing material in the area of the integrated circuits m.~ay reduce the physical rigidity of the ultrasound transducer aqsembly, in accordance with yet another aspect of the present invention, metal discs are placed upon the lumen~tube of the assembly and ~nhAnce the physical integrity of the device. The metal discs also form part of a path from a ground wire to the ground electrodes of the ultrasound - tr~n~cer array elements.
The integrated circuitry is housed within integrated circuit chips on the ultrasound transducer assembly. The integrated circuitry is coupled via a cable to an imaging computer which controls the tr~nam~sion of ultrasound emission ~ignals transmitted by the integrated circuitry to the ultrasound transducer array elements. The imaging computer also constructs im~ages from electrical signals transmitted from the integrated circuitry correspon~;ng to ultrasound echoes received by the transducer array elements.
The above described new ultrasound transducer assembly and method for mAk~ng such a device retains a two-dimensional aspect to the early stages of ultrasound trAn~ c~r assembly fabrication which will ultimately yield a three-dimensional, cylindrical device.
Furthermore, the flexible circuit and method for fabricating an ultrasound transducer assembly according to the present invention facilitate the construction of individual, physically separate transducer ele~ent~ in a trAn~ cer array. Finally, the present device el~m;nates a number of structures which contributed to the complexity of the ultrasound transducer assembly and the method for making such a device.
BRI~F ~ PTPTION OF TE~ DRA~INGS
The app~ndP~ cl~mq set forth the features of the presPnt invention with particularity. The invention, together with its objects and advantages, may be best understood from the following detailed description taken in conjunction with the accompanying drawings of which:
Figure 1 is a perspective view of the flat sub-assembly of an ultrasound tr~n~ cer assembly incorporating a 64 element ultrasound transducer array and integrated circuits mounted to a flexible circuit;
Fig. 2 is a schematic perspective view of the assembled ultrasound transducer assembly from the end cont~n;ng the cable attachment pad;
Fig. 3 is a cross-section view of the ultrasound lS transducer assembly illustrated in Fig. 2 sectioned along line 3-3 in the integrated circuit portion of the ultrasound transducer assembly;
Fig. 4 is a cross-section view of the ultrasound transducer assembly illustrated in Fig. 2 sectioned along line 4-4 in the transducer portion of the ultrasound transducer assembly;
Fig. S is a longitn~nAl cross-section view of the ultrasound tr~n~ cer assembly illustrated in Fig. 2 sectioned along line S-5 and rl~nn~ng along the length of the ultr~o~nA tr~nQ~cer assembly;
Fig. Sa is an enlarged view of the outer layers of - the section~ view of the ultr~o~)n~ tr~n~cer assembly illustratively depicted in Fig. S;
Fig. 6 is an enlarged and more detailed view of the transducer region of the ultrasound transducer assembly illustratively depicted in Fig. S;
Fig. 6a is a further enlarged view of a portion of the transducer region cont~n~ng a cross-sectioned transducer;
Fig. 6b is a side view of a single transducer element in accordance with a preferred ~mho~m~nt of the invention;
Fig. 7 is a perspective ~iew of a lumen tube and discs assembly in accordance with a preferred embodiment of ~he present invention;
Fig. 8 is an outline of the generally circular disc which is pressed onto the lumen tube at the transducer array portion of the ultrasound trAnQ~l~cer assembly;
Fig. 9 is an outline of the generally pentagonal disc which i9 pressed onto the lumen tube at the - electronics portion of the ultrasound transducer assembly;
Fig. 10 is a flowchart summarizing the steps for fabricating a cylindrical ultrasound transducer assembly embodying the present invention;
Fig. 11 is a schematic drawing showing a longit~ nAl cross-section view of a mandrel used to form a mold within which a'partially assembled ultrasound trAn~ cer assembly is drawn in order to re-shape the flat, partially assembled transducer assembly into a substantially cylindrical shape and to thereafter finish the ultrasound catheter assembly in accordance with steps 59-61 of Fig. 10;
Fig. 12 is a schematic drawing of an illustrati~e example of an ultrasound imaging system including an ultrasound transducer assembly Pmhodying the present invention and demonstrating the use of the device to image a coronary artery; and Fig. 13 18 an enlarged and partially sectioned view of a portion of the coronary artery in Fig. 12 showing the ultrasound transducer assP~hly incorporated within an ultrasound transducer probe located in a catheter proximal to a balloon and inserted within a coronary artery.
D~T~ Tt.ln'l nR.C ~ TpTION O~ DRAMINGS
Turning now to Fig. 1, an ultrasound transducer asse~mbly is illustratively depicted in its flat form in which it i8 assembled prior to forming the device into its final, cylindrical form. The ultrasound transducer assembly comprise~ a flex circuit 2, to which the other illustrated compon~ntP of the ultr~o~ln~ transducer assembly are attached. The flex circuit 2 preferably comprises a flexible polyimide film layer (sub~trate) such as KAPTON (TM) by DuPont. However, other suitable flexible and relatively strong materials, such as MYLAR
(Registered trademark of B.I. ~uPont) may comprise the film layer of the flex circuit 2. The flex circuit 2 further comprises metallic interconnection circuitry formed from a m~lleable metal (such as gold) deposited by means of known sputtering, plating and etching techniques employed in the fabrication of microelectronic circuits upon a chromium adhesion layer on a surface of the flex circuit 2.
The interconnection circuitry comprises conductor lines deposited upon the surface of the flex circuit 2 between a set of five (5) integrated circuit chips 6 and a set of sixty-four (64) transducer elPm~nts 8 made from PZT or PZT composites; between adjacent ones of the five (5) integrated circuit chips; and between the five (5) integrated circuit chips and a set of cable pads 10 for - communicatively coupling the ultrasound catheter to an image signal processor via a cable (not shown). The cable comprises, for example, seven (7) 43 AWG insulated magnet wires, spirally cabled and jacketed within a thin plastic sleeve. The connection of these seven cables to the integrated circuit chips 6 and their function are ~YP1A~ne~ in Pro~ n (deceased) et al. U.S. Patent No.
4,917,097.
The width ~W~ of the individual cQnA~lctor lines of the metallic circuitry (on the order of one-thonq~n~th of an inch) is relatively thin in cQmrArison to the typical width of metallic circuitry deposited upon a film or other flexible substrate. On the other hand, the width of the individual con~ctor lines is relatively large in comparison to the width of s transmission lines in a typical integrated circuit. The layer thickne~ ~T~ of the conductor lines between the chips 6 and the transducer elements 8 is preferably 2-5~m. This selected magnitude for the thickn~s and the width of the conductor lines enables the con~tor lines to be sufficiently conductive while ma;nt~in;ng relative flexibility and resiliency 80 that the conductor lines do not break during re-shaping of the flex circuit 2 into a cylindrical shape.
The thickness of the flex circuit 2 substrate is preferably on the order of 12.5~m to 25.0~m. However, the thickness of the substrate i8 generally related to the degree of curvature in the final assembled transducer assembly and its acoustic perfor~2nre. The thin substrate of the flex circuit 2, as well as the relative flexibility of the substrate material, enables the fle~x circuit 2 to be wrapped into a generally cylindrical shape after the integrated circuit chips 6 and the transducer elements 8 have been mounted and formed and then att~che~ to the metallic conductors of the flex circuit 2. Therefore, in other configurations, designs, and applications requiring less or more substrate flexibility such as, for eY~mrle, the various ~ e~bodiments shown in Eberle et al. U.S. Patent 5,368,037, the substrate thickne~ may be either greater or smaller than the above mentioned range. Thus, a flexible substrate thi~kness may be on the order of several (e.g. 5) microns to well over 100 microns (or even greater) -- ~epPn~ng upon the flexibility requirements of the particular transducer assembly configuration.
The flex circuit is typically formed into a very small cylindrical shape in order to accommodate the space limitationg of blood vessels. In such instances the range of diameters for the cylindrically 9h;3p~
ult~asound tr~n~ucer assembly is typically within the range of 0.5 mm. to 3.0 mm. in an ultrasound catheter for blood vessel imaging. FurthermQre, the flex circuit 2 may also be incorporated into larger cylindrical transducer assemblies or even transducer assemblies having alternative sh~rP~ including planar tr~nq~cer ass~mblies where the flexibility requirements imposed upon the flex circuit 2 are significantly rel~Ye~. A
production source of the flex circuit 2 in accordance with the present invention i9 Metrigraphics Corporation, 80 Concord Street, W~lm~ngton, Massachusetts 01887.
The integrated circuit chips 6 are preferably of a type described in the Proudian et al. U.S. Patent 4,917,097 (incorporated herein by reference) and include the modifications to the integrated circuits described in the O'Donnell et al. U.S. Patent 5,453,575 (also incorporated herein by reference). However, both simpler and more complex integrated circuits may be attached to the flex circuit 2 embodying the present invention. Furthermore, the integrated circuit arrangement illustrated in Fig. 1 is intended to be illustrative. Thus, the present invention may be incorporated into a very wide variety of integrated circuit designs and arrangements contemplated to fall within the scope of the invention.
Finally, the flex circuit 2 illustratively depicted in Fig. 1 includes a tapered lead portion 11. As will be expl~ne~ further below, this portion of the flex circuit 2 provides a lead into a TEF~ON (registered tr~e~-rk of E.I. DuPont) mold when the flex circuit 2 and attached comron~n~ are re-shaped into a cylindrical shape. Thereafter, the lead portion 11 is cut from the re-shaped flex circuit 2.
Tllrn~ng to Fig. 2, an illustrative ultrasound transducer assembly is shown in a re-~hAr~ state. This CA 02226l94 l997-l2-3l shape is generally obt~; ne~ by wrapping the flat, partially asgembled ultrasound transducer assembly shown in Fig. 1 into a cylindrical shape by means of a molding process described below. A transducer portion 12 of the ultrasound transducer assem~bly cont~;n;ng the transducer elements 8 is shaped in a cylinder for transmitting and receiving ultrasound waves in a generally radial direction in a side-loa~;ng cylindrical transducer array arrangement. The tr~n~Al~cer portion 12 on which the transducer elements 8 are placed may alternatively be sh~pe~ or oriented in a ~nner different from the cylinder illustratively depicted in Fig. 2 in accordance with alternative fields of view such as side-fire planar arrays and forward look; ng pl ~nAr or curved arrays.
- 15 An electronics portion 14 of the ultrasound transducer ~ mhly is not constrained to any particular shape. However, in the illustrative example the portions of the flex circuit 2 su~olLing the integrated circuit chips 6 are relativeIy flat as a result of the electrical connections between the flex circuit 2 and the integrated circuit chips 6. Thus the portion of the flex circuit 2 carrying five (5) integrated circuit chips 6 has a pentagon cross-section when re-shaped (wrapped) into a cylinder. In an alternative embo~m~nt of the present invention, a re-~h~pe~ flex circuit having four (4) integrated circuits has a rectangular - cross-section. Other numbers of integrated circuits and resulting cross-sectional shapes are also contemplated.
Fig. 2 also shows the set of cable pads 10 on the flex circuit 2 exten~ng from the portion of the flex circuit 2 su~o~Ling the integrated circuit chips 6. A
lumen 16 in the center of the ultrasound transducer assembly (within which a guidewire is threaded during the use of a catheter upon which the transducer assembly has been mounted) is defined by-a lumen tube la made of a thin radiopaque, con~nctive material such as Platinum/Iridium. The radiopaque material assists in CA 02226l94 l997-l2-3l locating the ultrasound transducer assembly within the body during a medical procedure incorporating the use of the ultrasound transducer assembly. As will be ~Ypl~ne~ further below, the conductive property of the lumen tube 18 offers a means for connecting the transducer ground electrodes to a ground wire included in at least one of the wires connected to the cable pads 10 .
Spaces in the re-formed ultrasound transducer assembly between the integrated circuit chips 6, the transducer elements 8 and the lumen tube 18 are filled with a backing material 30. In contrast to earlier ultrasound catheter assembly designs including a relatively hard carrier material such as a rigid Pnc~pqulating epoxy, the backing material 30 that fills the spaces between the lumen tube 18 and the integrated circuit chips 6 is relatively soft. This ensures proper acoustic perfor~nc~ in the transducer portio~ 12 of the ultrasound transducer assembly. While the backing material 30 does not exhibit the rigidity of the previously used epoxy, other structures (disks) incorporated into the new transducer assembly design, described herein below, provide additional structural support for the integrated circuit chips 6 and reduces manufacturing complexity.
Turning now to Fig. 3, a cross-section view is - provided of the ultr~ollnA transducer assembly taken along line 3-3 and look~ng toward the transducer portion 12 in Fig. 2. The outside of the electronics portion 14 has a pentagon shape. The circular outline 26 repre~nts the outside of the tr~n~llc~r portion 12.
The flex circuit 2 Pncomr~es the cylindrically shaped - ultr~aol~n~ tr~nq~ucer assPmhly. The b~ck~ng material 30 fills the spaces between the integrated circuit chips 6 and the lumen tube 18. While relatively soft, the backing material 30 provides a satisfactory measure of structural 8U~YOL~ to the integrated circuit chips 6 in the final assembly of the ultrasound transducer assembly. A disk (not shown in Fig. 3) inserted in one end of the ultrasound transducer assembly housing the integrated circuits 6 further Pnh~ncP~ the structural integrity of the ultrasound transducer assembly.
Turning now to Fig. 4, a view i9 provided of a cross-section of the ultrasound trAna~ncPr assembly taken along line 4-4 and look;ng toward the electronics portion 14 in Fig. 2. The five corners of the~pentagon outline comprising the electronics portion 14 are illustrated in the bachyLo~,d of the cross-sectional view at line 4-4. The set of sixty-four (64) transducer elPm~nt~ 8 are displayed in the foLeyLound of this cross-sectional view of the transducer portion 12 of the ultrasound transducer assembly. The backing material 30, characterized by relatively low acoustic~impe~AncP, fills the space between the lumen tube 18 and the transducer elements ~ as well as the gaps between ad~acent ones of the sixty-four (64) transducer elements 8.
The determlnation of desirable materials for the backing material 30 i8 inflllPncptl by a number of considerations. The hAck;ng material 30 preferably possesses the ability to highly attenuate ultrasound energy emitted-by the tr~nq~vcer elements 8. The hA~k~ng material 30 also provides sufficient support for - ma~n~sA~ ~n~ng the array of transducer elements 8 in their - desired configuration. A suitable material for the h;~ck;ng material 30 cures in a sufficiently short period of time to meet manufacturing needs. A n~ er of known materials meeting the above described criteria for a good backing material will be known to those skilled in the art. An example of such a preferred h~rk; ng material comprises a ~Yture of epoxy, hardener and phenolic microballoons providing high ultrasound signal attenuation and satisfactory support for the ultrasound transducer assembly.
Having generally described an ultrasound tran~ducer assembly incorporating the flex circuit in accordance with the present invention, the advantages provided by the flex circuit will now be described in con~unction with the illustrative 2r~0~;ment. The flex circuit 2 provides a number of ad~antages over prior ultrasound transducer assembly designs. The RAPTON substrate of the flex circuit 2 provides acoustic (guarter-wave) matching for the PZT transducer elements 8.
The ease with which the flex circuit 2 may be re-~h~pe~ facilitates mounting, formation and connection of the integrated circuit chips 6 and tr~nqA~)c~r elements a while the flex circuit 2 is flat, and then re-shaping the flex circuit 2 into its final state after the - 15 compon~nt~ have been mounted, formed and connected. The flex circuit 2 is held within a frame for improved handling and positioning while the PZT and integrated circuits are hon~e~ to complete the circuits. The single sheet of PZT or PZT composite transducer material is diced into sixty-four (64) discrete transducer elements by sawing or other known cutting methods.
After dicing the transducer sheet, kerfs exist between ad~acent tr~nq~ncer elements while the flex circuit 2 is in the flat state. After the integrated circuit chips 6 and transducer elements 8 have been mounted, formed and connected, the flex circuit 2 is re-sh~pe~ into its final, cylindrical shape by drawing the flex circuit 2 and the ~ unted elements into a TEF~ON mold (described further below).
Also, because the integrated circuits and transducer elements o$ the ultrasound transducer assembly may be assembled while the flex circuit 2 is in the flat state, the flex circuit 2 may be manufactured by batch processing techniques wherein transducer assemblies are assembled side-by-side in a multiple-stage assembly process. The flat, partially assembled tr~n~t3ncer agge~mblies are then re-shaped and fabrication completed.
Furthermore, it is also possible to incorporate strain relief in the catheter asse~bly at the set of s cable pads 10. The strain relief involves flexing of the catheter at the cable pads 10. Such flexing improves the durability and the positionability of the assembled ultrasound catheter within a patient.
Another important advantage provided by the flex 10 circuit 2, is the relatively greater amount of surface area provided in which to lay out connection circuitry between the integrated circuit chips 6 and the tr~nq~ cer elements 8. In the illustrated embodiment of the present invention, the tr~nq~cer array includes 15 sixty-four (64) individual transducer elements. This i9 twice the number of tr~n~)cer elements of the transducer array described in the Pro~ n '097 patent.
Doubling the ml~r of tr~n~ lcer el~ments without increasing the circumference of the cylindrical 20 transducer array doubles the density of the transducer el~mentq. If the same circuit layout described in the Proudian l097 was employed for connecting the electronic comronents in the sixty-four (64) transducer element design, then the density of the connection circuitry 25 between the integrated circuit chips 6 and the transducer elements 8 must be doubled.
Ho~e~e, the flex circuit 2 occupies a relatively outer circumference of: (1) the tr~nq~ cer portion 12 in comparison to the transducer elements 8 and, (2) the 30 electronics portion 14 in comparison to the integrated circuit chips 6. The relatively outer circumference provides substantially more area in which to lay out the connection circuitry $or the sixty-four (64) transducer element design in comparison to the area in which to lay 35 out the connection circuitry in the design illustratively depicted in the Proudian ~097 patent. As a result, even though the number of conductor lines between the integrated circuit chips 6 and the transducer elements 8 doubles, the density of the conductor lines is increased by only about fifty percent (50~) in comparison to the previous carrier design disclosed in the Proudian '097 patent having a substantially same transducer assembly diameter.
Yet another advantage provided by the flex circuit 2 of the present invention is that the interconnection solder bumps, connecting the metallic pads of the integrated circuit chips 6 to matching pads on the flex circuit 2, are distributed over more of the chip surface, 80 the solder bumps only have to be slightly smaller than the previous design having only thirty-two (32) transducer elements.
The integrated circuit chips 6 are preferably hon~e~ to the flex circuit 2 using known infrared alignment and heating methods. However, since the flex circuit 2 can be translucent, it is also possible to perfonm alignment with less ~Ypenqive optical methods which include viewing the align~nt of the integrated circuit chips 6 with the connection circuitry deposited upon the substrate of the flex circuit 2 from the side of the flex circuit 2 opposite the surface to which the integrated circuit chips 6 are to be bonded.
Turning now to Figs. 5 and 5a, a cross-sectional view and enlarged partial cross-sectional view are - provided of the ultrasound tr~n~ cer ass~mhly illustrated in ~ig. 2 sectioned along line 5-5 and running along the length of the ultrasound transducer assembly embodying the present invention. A KAPTON
substrate 33 portion of the flex circuit 2, a~ o~lmately 13 ~m in thickness,-completely surrounds the ultrasound transducer assembly, acts as an acoustic matching layer and protects the electronic comron~nts of the ultrasound tr~nq~l)cer assembly. Metallic transducer signal lines 34, a~Lo~lmately 2-5~m in thickness, are h-~nAeA to the ~CAPTON substrate 33 with a chromium adhesion layer to form the flex circuit 2.
The trAn~A--cer signal lines 34 of the flex circuit 2 are illustrated as a solid layer in Fig. 5. However, s it will be appreciated by those skilled in the art that the transducer signal lines 34 are fabricated from a solid layer (or layers) of deposited metal using well known metal layer selective etching techniques such as - m:~qk~ng or selective plating techniques.
A cable 35 of the type disclosed in the Proudian '097 patent is connected to the cable pads 10 for carrying control and data signals transmitted between - the ultrasound transducer assembly and a processing unit. A set of solder bumps such as solder bump 36 connect the contacts of the integrated circuit chips 6 to the transducer signal lines 34 of the flex circuit 2.
Two-part epoxy 38 bonds the integrated circuit chips 6 to the flex circuit 2.
Fig. 5 also shows the backing ntaterial 30 which fills the gaps between the integrated circuits and the lumen tube 18. The lumen tube 18 has a diameter of approximately 0.024~ and is approxintately 25~m thick.
The space between the trAnqA~tcers 8 and the lumen tube 18 in transducer portion 12 of the ultrasound transducer ass~mhly is filled by the bAr~ng material 30 having a low acoustic imp~AAnc~ and therefore well suited for attenuating ringing in the ultra80und transducer ; assentbly by absorbing ultrasound waves emitted by the trAn~A-~cer elements toward the lumen tube 18. The transducer portion 12 of the-ultrasound transducer assembly of the present invention is described in greater detail below in conjunction with Figs. 6 and 6a.
A pair of gro~nA~ng discs 37 and 39 are located on each end of the ultrA~o~nA tr~An~A~cer assembly. The primary function of the discs 37 and 39 is to provide a ground contact between a ground wire on the cable 35, the lumen tube 18, and the transducer ground electrode leads. In the preferred embodiment of the present invention, merhAn~cal contacts (rather than solder) exi~t between the tr~An~l)cer ground electrode pads and the disc 37, the disc 37 and the lumen tube 18, the s lumen tube 18 and disc 39, and disc 39 and a pad on the flex circuit 2 to a ground wire in the cable 35.
The ground contact i8 established by press-fitting the discs 37 and 39 onto the lumen tube 18 as shown in Fig. 7. Thereafter, the flex circuit 2 is wrapped around the discs 37 and 39 and the resulting cylindrical device is filled with the h~Ac~ng material 30 in order to create a device having a cross-section illustratively depicted in Fig. S after final assPmhly. As illustratively depicted in Figs. 8 and 9, the disc 37 i8 generally circular (to provide a round cylinder shape to the transducer portion 12 of the ultrasound transducer assembly), and the disk 39 i8 generally pentagonal (to provide a five-sided cylinder shape to accommodate the arrany~E~t of the five (5) integrated circuit chips 6 attached to flex circuit 2 in the electronics portion 14). FurthPr~ore, the discs 37 and 39 are formed with through holes to facilitate a step of injecting backing material into the ultrasound trAn~ cer assembly during a preferred fabrication process described herein below.
Turning now to Figs. 6, 6a and 6b, the transducer elements 8 comprise PZT or PZT composite 40 appr~Y~-tely 90~m in thickn~s and, ~ep~n~ng on frequency, a~p~oAimately 40~m wide and 700~m long. Each s transducer element includes a Cr/Au ground electrode 42 and a Cr/Au signal electrode 46 which are approximately O.l~m in thickness. As illustratively depicted in Fig.
6b, the electrodes are constructed by ~nc~p~ulating the PZT or PZT composite 40 in Cr/Au. Thereafter,-the electrodes 42 and 46 are defined as two separate metal sheets by cutting (or etching) a first yLoove at point X
- on a first surface primarily cont~;ning the signal electrode 46 and cutting a second y~Go~e at point Y on a second surface primarily cnnt~ ~ n~ ng the ground electrode lS 42. The yLoove~ at points X and Y define the active region 45 of the tr~n~ cers 8. The re~ce~ active region 45, that does not include the ends of the transducer elements 8 provides edge damping and potentially improved image quality.
As illustratively depicted in Fig. 6b, the positions of the grooves X and Y establish electrical isolation between the electrodes 42 and 46 in a ~nner such that connections between electrical lines 44 (ground) and 34 (signal) and correspon~ng transducer electrodes 42 and 46 are achieved without fabricating bridges between lead lines on the flex circuit 2 and the - upper surface of the transducers 8 defining the signal electrode 46. As a consequence of positioning all electrode cont~cts on a single plane, connections between electrodes 42 and 46, and correspon~ ng lines 44 and 34 on the flex circuit 2 are preferably achieved by means of pressure and adhesive materials rather than soldering or csn~nctive glues. More particularly, in a preferred embodiment, a two-part epoxy S0, a~.o~imately 2-5~m in thicknes occupies the space between the ground electrode 42 and the gAPTON substrate 33 of the flex circuit 2. The two-part epoxy 50 holds the transducer CA 02226l94 l997-l2-3l elements 8 in signal contact with the transducer signal linee 34 of the flex circuit 2 while the relative rough surfaces of the PZT or PZT composite 40 establish several points of contact between the transducer S electrodes 42 and 46, and correspon~; ng electrical lines 44 and 34.
The thicknesq of the two-part epoxy 50 between the substrate 33 and the ground electrode 42 is controlled by spacer bars 49. The spacer bars 49 run the entire width of the flat flex circuit. However, the continuous spacer bar material is separated into discrete bars by a saw during the step of dicing the transducer material into discrete trAn~ cer elements 8. Additional two-part epoxy 50 is applied at the ends of the transducers 8.
Finally, it is noted that the transducer signal lines 34 are separate, electrically isolated conductors which terminate at signal cont~3cts 48. The transducer signal lines 34 couple the trAnl~l)cer el~m~nt~ 8 to correspon~l~ ng I/0 ~hAnn~l8 of the integrated circuit chips 6. The ground line 44 comprises a continuous conductor is not cut through since the integrated circuits and the distal portion of the ground line 44 are fixtured at a lower elevation than the transducer array during dicing and maintains the trAn~ucer ground electrode 42 for each of the transducer elements 8 at a - common electrical potential established by a ground wire within the cable 35. This ground connection is achieved through the metallic disc 37 which conducts a ground signal via the lumen tube 18 and disc 39. The disc 39 is connected directly to the yLOu~d signal which originates from the cable 35.
Turning now to Fig. 10, the steps are summarized for fabricating the above-described ultrA~o~n~l 35 transducer assembly embodying the present invention. It will be appreciated by those skilled in the art that the steps may be modified in alternative embo~;mPnts of the invention.
At step 52, the flex circuit 2 is formed by depositing conductive materials such as Chromium/Gold (Cr/Au) on a surface of the KAPTON substrate 33.
Chromium is first deposited as a thin adhesion layer, typically 50-100 Angstroms thick, followed by the gold conA~cting layer, typically 2-5~m thick. Using well known etching techniques, portions of the Cr/A~ layer are removed from the surface of the RAPTON substrate 33 in order to form the transducer signal lines 34, the ground line 44, and the spacer bars 49 of the flex circuit 2. Also during step 52 gold bumps, used to form the signal contacts 48, are formed on the flex circuit 2.
In a separate and ~n~epPn~Pnt procedure with re~pect to the above-described step for fabricating the flex circuit 2, at step 53 a thin metal layer, on the order of O.l~m to 5.0~m is applied to a single PZT or PZT composite crystal. In contrast to an alternative metalization procedure, during step 53 the metal layer covers the top, bottom and ends of the PZT crystal.
Next, during step 54, the metal layer is divided into two separate metal layers by cutting the two ylooves identified previously by the X and Y in Fig. 6a. These two metal layers will later comprise the separate ground - electrode 42 and signal electrode 46 for each of the ; transducer ele~ents.
Next, at step 55, the metallized PZT or PZT
composite 40 is honAeA under pressure to the flex circuit 2 by means of two-part epoxy 50, and cured for a reasonable period. This is typically done overnight.
The pressure exerted during hQn~ ng re~lce~ the thickne~ of the two-part epoxy 50 to a thickness of approximately 2-5~m, ~epPn~ng on the chosen thickness of the spacer bars 49 and signal contacts 48. The very thin layer of two-part epoxy 50 provides good adhesion of the metallized PZT or PZT composite to the flex circuit 2 without ~ignificantly affecting the acoustic perform~nce of the transducer elements 8. During exertion of pressure during step 55, a portion of the 5 two-part epoxy 50 squeezes out from between the flex circuit 2 and the transducer sheet from which the transducer elements 8 will be formed. That portion of the two-part epoxy 50 also forms a fillet at each end of the honrle~ tr~nqtlllcer sheet (See Fig. 6). The fillets 10 of the two-part epoxy 50 provide additional support for the tr~n~ c~r elements 8 during sawing of the PZT or PZT composite 40 into physically discrete transducer el~m~nt~. Additional two-part epoxy 50 may be added around the PZT to make the fillet more uniform.
In order to obtain good performance of the elements and to facilitate re-shaping the flex circuit 2 into a cylinder after the integrated circuit chips 6 and transducer elements 8 are attached, the transducer sheet is diced to form physically discrete tr~nq~ cer elements 8 during step 56. Dicing is accomplished by means of a well known high precision, high speed disc sawing apparatus, such as those used for sawing silicon wafers.
It i8 desirable to make the saw kerfs (i.e., the spaces between the adjacent tr~n~ducer elements) on the order of 15-25~m when the flex circuit is re-shaped into a cylindrical shape. Such separation ~l~m~n~ions are achieved by known high precision saw h~ e~ having a thickness of 10-15~m.
Continuing with the description of the dicing step 56, after the two part epoxy 50 i9 fully cured, the flex circuit 2 is fixtured to facilitate dicing of the transducer sheet into sixty-four (64) discrete el~m~nt~.
The flex circuit 2 i8 fixtured by pl~c~ng the flex circuit 2 onto a vacuum chuck (of well known design for precision dicing of very small objects such as semiconductor wafers) which is raised by 50-200~m in the region of the transducer elements 8 in order to enable a saw blade to penetrate the flex circuit 2 in the region of the trAn~A~-cer elements 8 without affecting the integrated circuit region and without sawing through the distal portion of the ground line proximate to the disc 3-7. The saw height i8 carefully controlled 80 that the cut extends completely through the PZT or PZT composite 40 and partially into the KAPTON substrate 33 of the flex circuit 2 by a few microns. RYt~n~ng the cut further into the flex circuit 2 further reduces the conduction of ultrasound to ad~acent transducer elem~t~R. The resulting transducer element pitch (width) is on the order of SO~m. In alternative embo~me~ts this cut may extend all the way through the flex circuit 2 in order to provide full physical Reparation of the transducer elements.
Alternatively a laser performs the step of dicing the transducer elements. However, a drawback of using a laser to dice the transducer sheet is that the laser energy may depolarize the PZT or PZT compQsite 40. In view of present difficulties associated with polarization of the separated PZT transducer elements, the sawing method i8 presently preferred.
After the PZT or PZT composite 40 has been diced into discrete trAnQ~cer elements and cleaned of dust arising from the sawing of the PZT or PZT composite 40, at step 57 the integrated circuit chips 6 are flip-chip bonded in a known manner to the flex circuit 2 using - pressure and heat to melt solder bumps such as solder bump 36 forming the electrical contacts between the flex circuit 2 and the pads of the integrated circuit chips 6. The integrated circuit chips 6 are aligned by means of either infrared or visible light alignment techniques 90 that the Indium solder bumps on the integrated circuits 6 align with the pads on the flex clrcuit 2.
These alignment methods are well known to those skilled in the art. The partially assembled ultrasound trAnR~cer assembly is now ready to be formed into a substantially cylindrical shape as shown in Figs 2, 3 and 4.
-- Be~ore re-shaping the flat flex circuit 2 (as shown in Fig. 1) into a cylindrical shape around the lumen tube 18, at step 58 the ~Lo~ ng discs 37 and 39 are pressed onto the ends of the lumen tube 18 (see Fig. 7).
The tolerances of the inner sprockets of the disc 37 and the inner diameter of the disc 39 and the outer diameter of the lumen tube 18 are such that the discs 37 and 39 frictionally engage the outer surface of the lumen tube 18. The discs 37 and 39 shown in Figs. 8 and 9 respectively, ensure concentricity of the transducer portion 12 of the assembled ultrasound trAnCAl~cer device around the lumen tube 18 and facilitates even distribution of the backing material 30 within the spaces of the ultrA~o~ trAnC~llcer apparatus between the lumen tube and the ultrA~oll~A trAncAl~c~rs 8.
At step 59, the yLo~ ing assembly, consisting of the lumen tube 18 and discs 37 and 39, and the partially assembled flex circuit 2, are carefully matched up and then drawn into a preformed TEFLON mold having very precise dimensions. The TEFLON mold is formed by heat shrin~ng TEPLON tubing over a precision machine~
mandrel (as shown in Fig. 11 and described below). The heat shrinkable TEFLON tubing is removed and ~i~cArded after fabrication of the ultrasound transducer assembly ~ is complete. As a result, distortion of a mold through multiple uses of the same mold to complete fabrication of several ultra~c~ln~ transducer assemblies is not a problem, and there is no clean up of the mold required.
The TEFLON molds incor~orate a gentle lead-in taper enabling the sides of the flex circuit 2 to be carefully aligned, and the gap between the first and last elements to be ad~usted, as the flex circuit 2 is pulled into the mold. In the region of the trAn~llc~r, the mold and the disc 37 are held to a diametric precision of 2-3~m.
Since the flex circuit 2 dimensions are formed with precision optical techniques, the ~;m~n~ions are repeatable to less than l~m, the gap between the first and last elements (on the outer edges of the flat flex circuit 2) can be repeatable and s~lAr to the kerf s width between ad;acent elements.
A TEPLON bead is placed within the lumen tube 18 in order to prevent filling of the lumen 16 during the steps described below for completing fabrication of the ultrasound transducer assembly.
After drawing the flex circuit into the mold, at step 60 backing material 30 is in~ected into the distal end of the ultrasound tr~n~ cer assembly in order to fill the kerfs between transducer el~m~ntq and any gaps between the preformed portion of the hA~king material 30 and the transducer elements 8. The hA~king material is injected by means of the through holes in the grounding disc 37. The air occupying the space between the lumen tube 18 and comron~nt~ of the flex circuit assembly escapes through holes in the disc 39. This ensures that there are no air gaps in the region of the ultrasound transducer assembly having the transducer array since air gaps degrade the performAnce of the ultrasound transducer assembly and degrade the mechanical integrity of the device. In contrast to prior fabrication methods employing separate and distinct chip carrier and backing materials, the present design utilizes the backing material 30 to support the integrated circuits. This modification re~ceq manufacturing complexity while providing sufficient 8u~po~ for the integrated circuits.
At step 61, after the backing material 30 cures, the ultrasound trAn~ c~r assembly is removed from the mold by either pll~h~ng the device out of the mold or carefully cutting the TEFLON mold and peeling it from the ultrasound transducer assembly. The TEFLON bead i8 removed from the lumen tube 18. Stray h~cking material is L ~..~ed from the device.
Having degcribed one method for fabricating an ultrasound transducer assembly incorporating the flex circuit 2, it is noted that the order of the steps is not necessArily important. For exA~mple, while it is s preferred to attach the integrated circuits 6 to the flex circuit 2 after the trAn~ c~rs 6 have been bon~e~
to the flex circuit 2, such an order for assembling the ultrasound transducer assembly is not essential.
Similarly, it will be appreciated by those ski~led in the art that the order of other steps in the described method for fabricating an ultrasound transducer assembly can be re-arranged without departing from the spirit of the present invention.
Turning briefly to Fig. 11, a longit~ nAl cross-section view is provided of the mandrel previously mentioned in connection with the description of step 59 above. The mandrel enables a TFFLON tube to be re-formed into a mold (shown generally by a ghost outline~
having very precise inside ~im~n~ions by heat shrinking the TEFLON tube onto the mandrel. The TEFLON mold is thereafter used to re-shape the partially assembled ultrasound trAn~ncer assembly during step 59. While precise dimensions and tolerances are provided on the drawing, they are not intended to be limiting since they 2s are associated with a particular size and shape for an ultrA~o~n~ trAn~ncer assembly embodying the present - invention.
The mandrel and resulting inside surface of the TEFLON mold generally display certain characteristics.
First, the mandrel incorporates a taper from a maximum diameter at the end where the flex circuit enters the mold to a min~m diameter at the portion of the mold COrre8pQn~ ng to the trAn~llcer portion of the ultrasound transducer assembly. This first characteristic facilitates drawing the flex circuit into the mold.
Second, the mold has a region of constant diameter at the region where the integrated circuit portion will be ~ormed during step 59. This diameter is slightly greater than the diameter of the trAn~lcer region of s the mold where the diameter of the inside surface is precisely formed into a cylinder to ensure proper mating of the two sides of the flex circuit when the flat, partially assembled transducer assembly is re-shaped into a cylindrical transducer assembly. The greater diameter in the integrated circuit region accommodates the points of the pentagon cross-section created by the integrated circuit chips 6 when the flat flex circuit is re-~h~re~ into a cylinder.
Finally, a second taper region is provided between the integrated circuit and transducer portions of the mold in order to provide a smooth transition from the differing diameters of the two portions.
The above description of the invention has focused primarily upon the structure, materials and steps for constructing an ultrasound trAn~ cer assembly ~odying the present invention. Turning now to Figs. 12 and 13, an illustrative ~Y~rle of the typical envirG~..cnt and application of an ultrasound device embodying the present invention is provided. Referring to Figs. 12 and 13, a buildup of fatty material or plaque 70 in a coronary artery 72 of a heart 74 may be treated in - certain situations by inserting a balloon 76, in a deflated state, into the artery via a catheter assembly 78. As illustrated in Fig. 12, the catheter assembly 78 is a three-part assembly, having a guide wire 80, a guide catheter 78a for threA~i ng through the large arteries such as the aorta 82 and a smaller diameter catheter 78b that fits inside the guide catheter 78a.
After a surgeon directs the guide catheter 78a and the guide wire 80 through a large artery leA~ ng via the aorta 82 to the coronary arteries, the smaller catheter 78b is inserted. At the beginning of the coronary artery 72 that is partially blocked by the plaque 70, the guide wire 80 is first extended into the artery, followed by catheter 78b, which includes the balloon 76 at its tip.
After the balloon 76 ha~ entered the coronary artery 72, as in Fig. 13, an ultrasonic imaging device including a probe assembly 84 housed within the proYi sleeve 86 of the balloon 76 provides a surgeon with a cross-sectional view of the artery on a video display 88. In the illustrated embodiment of the invention, the transducers emit 20 MHz ultrasound excitation waveforms.
However, other suitable eYcitation waveform frequencies would be known to those skilled in the art. The transducers of the probe assembly 84 receive the reflected ultrasonic wavefor~ and convert the ultrAqo~-n~ echoes into echo waveforms. The amplified - -echo waveforms from the probe assembly 84, indicative of reflected ultrasonic waves, are transferred along a microcable 90 to a signal processor 92 located outside the patient. The catheter 78b ends in a three-part junction 94 of conventional construction that couples the catheter to an inflation source 96, a guide wire lumen and the signal processor 92. The inflation and guide wire ports 94a and 94b, respectively, are of conve~tional PTCA catheter construction. The third port 94c provides a path for the cable 90 to connect with the - signal pLoce_~or 92 and video display 88 via an electronic connector 98.
It should be noted that the present invention can be incorporated into a wide variety of ultrasound imaging catheter assem~blies. For example, the present invention may be incG.~oLated in a probe assembly mounted upon a diagnostic catheter that does not include a balloon. In addition, the probe assembly may also be mounted in the manner taught in Proll~t~n et al. U.S.
Patent 4,917,097 and Eberle et al. U.S. Patent 5,167,233, the teachings of which are explicitly incorporated, in all respects, herein by reference.
These are only examples of various mounting configurations. Other configurations would be known to those skilled in the area of catheter design.
S Furthen~Qre, the preferred ultrasound transducer assembly embodying the present invention is on the order of a fraction of a millimeter to several millimeters in order to fit within the relatively small cross-section of blood vessels However, the structure and nethod for manufacturing an ultr~o~ln~ tr~n~cer assembly in accordance with present invention may be incorporated within larger ultr~qo~n~ devices such as those used for lower gastrointestinal ~Y~m~nAtions.
Illustrative embodiments of the present invention have been provided. However, the scope of the present invention is intended to include, without limitation, any other m~difications to the described ultrasound transducer device and methods of pro~c;ng the device falling within the fullest legal scope of the present invention in view of the description of the invention and/or various preferred and alternative ~mho~;ments described herein. The ;ntent is to cover all alternatives, modifications and equivalents included within the spirit and scope of the invention as defined by the ~pp~n~e~ claims.
ASSEMBLY HAVING A FT~TRTR SUBSTRATE AND
h~r~O~ FOR M~NUFACTUR~ TH~REOF
rN~O~rOKATION ~Y K~N OE
The applicants hereby expressly incorporate by reference in their entirety the description of an I~Apparatus and Method for Imaging S B 11 CaVitie8n described in Prou~An et al. U.S. Patent 4,917,097, the description of a ~Dilating and Imaging Apparatus n described in Bberle et al. U.S. Patent 5,167,233, the description of an ~Ultrasound Catheter~ described in Eberle et al. U.S. Patent 5,368,037, the description of an "Apparatus And Method For Detecting Blood Flow In Intravascular Ultrasonic Imaging~ in O'Donnell et al.
U.S. Patent 5,453,575, and the description of a "High Resolution Intravascular Ultrasound Transducer Having a Flexible Substrate~ in Eberle et al. U.S. Serial No.
08/712,576 filed on September 13, 1996 which is a continuation of U.S. Serial No. 08/578,226 filed on December 26, 1995.
FI~LD OP IE~ INVENTION
This invention relates to ultrasound imaging apparatuse~ pl~ce~ within a cavity to provide images thereof of the type described in Pron~;An et al. U.S.
Patent 4,917,097 and ~ re specifically, to ultrasound imaging apparatuses and methods for fabricating such devices on a scale such that the tr~n~Al7c~r assembly portion of the imaging apparatus may be placed within a vasculature in order to produce images of the vasculature.
R~ JND 0~ T~e INY~rION
In the United States and many othe~ countries, heart disease is a le~ ng cause of death and disability. One particular kind of heart disease is atherosclerosis, which involves the degeneration of the walls and lumen of the arteries throughout the body.
Scientific studies have ~mon~trated the thi~ken; ng of an arterial wall and eventual encroachment of the tissue into the lumen as fatty material builds upon the vessel walls. The fatty material i8 known as "plaque." As the pla~ue builds up and the lumen narrows, blood flow is restricted. If the artery narrows too much, or if a s blood clot forms at an injured plaque site (lesion), flow is severely reduced, or cut off and consequently the muscle that it su~oLLs may be injured or die due to a lack of o~yye~. Atherosclerosis can occur throughout the human body, but it is most life threatening when it involves the coronary arteries which supply o~yye,- to the heart. If blood flow to the heart is significantly reduced or cut off, a myocardial infarction or ~heart attack~ often occurs. If not treated in sufficient time, a heart attack often leads to death.
- 15 The medical profession relies upon a wide variety of tools to treat coronary disease, ranging from drugs to open heart ~bypas~ surgery. Often, a lesion can be diagnose~ and treated with minimal intervention through the use of catheter-based tools that are threaded into the coronary arteries via the femoral artery in the groin. For example, one treatment for lesions is a procedure known as percutAneoll~ transl~lnAl coronary angioplasty (PTCA) whereby a catheter with an ~YpAn~Ahle balloon at its tip is threaded into the lesion and 2s inflated. The underlying le~ion is re-shaped, and hopefully, the lumen diameter is increased to improve - blood flow.
In recent years, a new technique has been developed for obtAin~ng infonmation about coronary vessels and to view the effects of therapy on the form and structure of a site within a vessel rather then merely determining that blood is flowing through a vessel. The new technique, known as Intracoronary/Intravascular UltrA~olln~ (Icus/rvus)~ employs very small transducers arranged on the end of a catheter which provide electronic trAn~nce~ echo signals to an external imaging system in order to produce a two or three-dimensional image of the lumen, the arterial tissue, and tissue surrolln~i ng the artery. These images are generated in 8ubstantially real time and provide images of superior quality to the known x-ray imaging methods s and apparatuses. Imaging technigues have been developed to obtain detailed images of vessels and the blood flowing through them. An example of such a method is the flow imaging method and apparatus described in O'~onnell et al. U.S. patent 5,453,575, the t~Ach;ngs of which are e~rëssly incoL~oL~ted in their entirety herein by reference. Other ~mAging methods and intravascular ultrasound imaging applications would also benefit from ~nhAnce~ image resolution.
Transducer backing materials having relatively low acoustic impe~Ance improve signal quality in transducer assemblies comprising PZT or PZT composites. The advantages of such backing materials are ~YplAine~ in Eberle et al. U.S. patent 5,368,037 the teAch~ngs of which are ex~le~sly incoL~o-ated in their entirety herein by reference. It is also important to select a matching layer for m7Y;~zing the acoustic perform~nce of the PZT transducers by min~m~zing echoes arising from the ultrA~olln~ assembly/blood-tissue interface.
When designing a very small device for manufacture in large quantities it is important to take into consideration practical limitations such as manufacturability, reliability, resiliency and perfonmance. The ultrasound catheter assembly must produce high quality raw image signals for the signal processing system located outside the body within which the intravascular ultrasound trAn~ cer asse~mbly i8 inserted for imaging. However, there is an interest in limiting the nl~ber of parts since added complexity can increase the manufacturing costs and reduce the yield of the intravascular ultrasound catheter assemblies. The devices must be sufficiently rêsilient to withstand handling during manufacture and use.
Sn~MARY OF TEB I~N~ION
It is a general ob~ect of the present invention to i~LV~e the manufacturability of an intravascular ultrasound transducer assembly.
S It is another ob~ect of the present invention to decrease the per-unit cost for manufacturing ultrasound trAna~lcer assemblies.
If is yet another ob~ect of the present invention to increase the yield of manufactured ultrasound - 10 tr~nQ~l~)cer ass~mhlie8.
It is a related ob;ect to provide ~nhAnce~
structural integrity of the electrical connections in the transducer assembly.
It is another ob~ect of the present invention to decrease the complexity of the ultrasound transducer assembly.
The above mentioned and other ob~ects are met in a new ultrasound trAnq~cer assembly, and method for fabricating the ultrasound trAn~ cer assembly including a PZT substrate with metallic contacts formed directly on the PZT substrate during a pre-fabrication step.
The ultrasound trAnq~C r assembly of the present invention includes a flexible substrate having an inner surface to which transducer signal lines and a ground line are attached to form a flexible circuit. In a preferred embodiment of the present inv~nt~Qn, the - flexible substrate provides the quarter-wave matching layer for the ultrasound tr~n~)c~rs.
An ultrasound trAna~cer array and integrated circuitry are attached during fabrication of the ultrasound trAn~nc~r assembly while the flexible substrate is substantially pl~AnAr (i.e., flat). In accordance with an aspect of the present invention, the signal electrode and ground electrode for transducer elements at least partially extend to the surface of the tr~ns~lcer elements that establishes contact with the inner surface plane of the flexible circuit. As a consequence both the ground and signal electrodes can establish direct electrical contact with corre8p~nA; ng signal and ground pads on the flexible surface.
Therefore, conductive bridges between flexible circuit lines and electrodes located on a physically remote surface of the transducer elements are no longer required.
In a particular embodiment of the invention, after the tr~nq~l)cer array and integrated circuit chips are attached to the flexible substrate, the flexible substrate is re~h~re~ into a subst~nt~lly non-planar shape around a lumen tube to form a substantially cylindrical shape. In accordance with another, more particular, aspect of the present invention, the spaces within the ultrasound transducer assembly between the lumen tube, the flex circuit, the transducer array and the integrated circuits are all filled with a backing material characterized by relatively low acoustic i~re~nce. While the use of backing material in the area of the integrated circuits m.~ay reduce the physical rigidity of the ultrasound transducer aqsembly, in accordance with yet another aspect of the present invention, metal discs are placed upon the lumen~tube of the assembly and ~nhAnce the physical integrity of the device. The metal discs also form part of a path from a ground wire to the ground electrodes of the ultrasound - tr~n~cer array elements.
The integrated circuitry is housed within integrated circuit chips on the ultrasound transducer assembly. The integrated circuitry is coupled via a cable to an imaging computer which controls the tr~nam~sion of ultrasound emission ~ignals transmitted by the integrated circuitry to the ultrasound transducer array elements. The imaging computer also constructs im~ages from electrical signals transmitted from the integrated circuitry correspon~;ng to ultrasound echoes received by the transducer array elements.
The above described new ultrasound transducer assembly and method for mAk~ng such a device retains a two-dimensional aspect to the early stages of ultrasound trAn~ c~r assembly fabrication which will ultimately yield a three-dimensional, cylindrical device.
Furthermore, the flexible circuit and method for fabricating an ultrasound transducer assembly according to the present invention facilitate the construction of individual, physically separate transducer ele~ent~ in a trAn~ cer array. Finally, the present device el~m;nates a number of structures which contributed to the complexity of the ultrasound transducer assembly and the method for making such a device.
BRI~F ~ PTPTION OF TE~ DRA~INGS
The app~ndP~ cl~mq set forth the features of the presPnt invention with particularity. The invention, together with its objects and advantages, may be best understood from the following detailed description taken in conjunction with the accompanying drawings of which:
Figure 1 is a perspective view of the flat sub-assembly of an ultrasound tr~n~ cer assembly incorporating a 64 element ultrasound transducer array and integrated circuits mounted to a flexible circuit;
Fig. 2 is a schematic perspective view of the assembled ultrasound transducer assembly from the end cont~n;ng the cable attachment pad;
Fig. 3 is a cross-section view of the ultrasound lS transducer assembly illustrated in Fig. 2 sectioned along line 3-3 in the integrated circuit portion of the ultrasound transducer assembly;
Fig. 4 is a cross-section view of the ultrasound transducer assembly illustrated in Fig. 2 sectioned along line 4-4 in the transducer portion of the ultrasound transducer assembly;
Fig. S is a longitn~nAl cross-section view of the ultrasound tr~n~ cer assembly illustrated in Fig. 2 sectioned along line S-5 and rl~nn~ng along the length of the ultr~o~nA tr~nQ~cer assembly;
Fig. Sa is an enlarged view of the outer layers of - the section~ view of the ultr~o~)n~ tr~n~cer assembly illustratively depicted in Fig. S;
Fig. 6 is an enlarged and more detailed view of the transducer region of the ultrasound transducer assembly illustratively depicted in Fig. S;
Fig. 6a is a further enlarged view of a portion of the transducer region cont~n~ng a cross-sectioned transducer;
Fig. 6b is a side view of a single transducer element in accordance with a preferred ~mho~m~nt of the invention;
Fig. 7 is a perspective ~iew of a lumen tube and discs assembly in accordance with a preferred embodiment of ~he present invention;
Fig. 8 is an outline of the generally circular disc which is pressed onto the lumen tube at the transducer array portion of the ultrasound trAnQ~l~cer assembly;
Fig. 9 is an outline of the generally pentagonal disc which i9 pressed onto the lumen tube at the - electronics portion of the ultrasound transducer assembly;
Fig. 10 is a flowchart summarizing the steps for fabricating a cylindrical ultrasound transducer assembly embodying the present invention;
Fig. 11 is a schematic drawing showing a longit~ nAl cross-section view of a mandrel used to form a mold within which a'partially assembled ultrasound trAn~ cer assembly is drawn in order to re-shape the flat, partially assembled transducer assembly into a substantially cylindrical shape and to thereafter finish the ultrasound catheter assembly in accordance with steps 59-61 of Fig. 10;
Fig. 12 is a schematic drawing of an illustrati~e example of an ultrasound imaging system including an ultrasound transducer assembly Pmhodying the present invention and demonstrating the use of the device to image a coronary artery; and Fig. 13 18 an enlarged and partially sectioned view of a portion of the coronary artery in Fig. 12 showing the ultrasound transducer assP~hly incorporated within an ultrasound transducer probe located in a catheter proximal to a balloon and inserted within a coronary artery.
D~T~ Tt.ln'l nR.C ~ TpTION O~ DRAMINGS
Turning now to Fig. 1, an ultrasound transducer asse~mbly is illustratively depicted in its flat form in which it i8 assembled prior to forming the device into its final, cylindrical form. The ultrasound transducer assembly comprise~ a flex circuit 2, to which the other illustrated compon~ntP of the ultr~o~ln~ transducer assembly are attached. The flex circuit 2 preferably comprises a flexible polyimide film layer (sub~trate) such as KAPTON (TM) by DuPont. However, other suitable flexible and relatively strong materials, such as MYLAR
(Registered trademark of B.I. ~uPont) may comprise the film layer of the flex circuit 2. The flex circuit 2 further comprises metallic interconnection circuitry formed from a m~lleable metal (such as gold) deposited by means of known sputtering, plating and etching techniques employed in the fabrication of microelectronic circuits upon a chromium adhesion layer on a surface of the flex circuit 2.
The interconnection circuitry comprises conductor lines deposited upon the surface of the flex circuit 2 between a set of five (5) integrated circuit chips 6 and a set of sixty-four (64) transducer elPm~nts 8 made from PZT or PZT composites; between adjacent ones of the five (5) integrated circuit chips; and between the five (5) integrated circuit chips and a set of cable pads 10 for - communicatively coupling the ultrasound catheter to an image signal processor via a cable (not shown). The cable comprises, for example, seven (7) 43 AWG insulated magnet wires, spirally cabled and jacketed within a thin plastic sleeve. The connection of these seven cables to the integrated circuit chips 6 and their function are ~YP1A~ne~ in Pro~ n (deceased) et al. U.S. Patent No.
4,917,097.
The width ~W~ of the individual cQnA~lctor lines of the metallic circuitry (on the order of one-thonq~n~th of an inch) is relatively thin in cQmrArison to the typical width of metallic circuitry deposited upon a film or other flexible substrate. On the other hand, the width of the individual con~ctor lines is relatively large in comparison to the width of s transmission lines in a typical integrated circuit. The layer thickne~ ~T~ of the conductor lines between the chips 6 and the transducer elements 8 is preferably 2-5~m. This selected magnitude for the thickn~s and the width of the conductor lines enables the con~tor lines to be sufficiently conductive while ma;nt~in;ng relative flexibility and resiliency 80 that the conductor lines do not break during re-shaping of the flex circuit 2 into a cylindrical shape.
The thickness of the flex circuit 2 substrate is preferably on the order of 12.5~m to 25.0~m. However, the thickness of the substrate i8 generally related to the degree of curvature in the final assembled transducer assembly and its acoustic perfor~2nre. The thin substrate of the flex circuit 2, as well as the relative flexibility of the substrate material, enables the fle~x circuit 2 to be wrapped into a generally cylindrical shape after the integrated circuit chips 6 and the transducer elements 8 have been mounted and formed and then att~che~ to the metallic conductors of the flex circuit 2. Therefore, in other configurations, designs, and applications requiring less or more substrate flexibility such as, for eY~mrle, the various ~ e~bodiments shown in Eberle et al. U.S. Patent 5,368,037, the substrate thickne~ may be either greater or smaller than the above mentioned range. Thus, a flexible substrate thi~kness may be on the order of several (e.g. 5) microns to well over 100 microns (or even greater) -- ~epPn~ng upon the flexibility requirements of the particular transducer assembly configuration.
The flex circuit is typically formed into a very small cylindrical shape in order to accommodate the space limitationg of blood vessels. In such instances the range of diameters for the cylindrically 9h;3p~
ult~asound tr~n~ucer assembly is typically within the range of 0.5 mm. to 3.0 mm. in an ultrasound catheter for blood vessel imaging. FurthermQre, the flex circuit 2 may also be incorporated into larger cylindrical transducer assemblies or even transducer assemblies having alternative sh~rP~ including planar tr~nq~cer ass~mblies where the flexibility requirements imposed upon the flex circuit 2 are significantly rel~Ye~. A
production source of the flex circuit 2 in accordance with the present invention i9 Metrigraphics Corporation, 80 Concord Street, W~lm~ngton, Massachusetts 01887.
The integrated circuit chips 6 are preferably of a type described in the Proudian et al. U.S. Patent 4,917,097 (incorporated herein by reference) and include the modifications to the integrated circuits described in the O'Donnell et al. U.S. Patent 5,453,575 (also incorporated herein by reference). However, both simpler and more complex integrated circuits may be attached to the flex circuit 2 embodying the present invention. Furthermore, the integrated circuit arrangement illustrated in Fig. 1 is intended to be illustrative. Thus, the present invention may be incorporated into a very wide variety of integrated circuit designs and arrangements contemplated to fall within the scope of the invention.
Finally, the flex circuit 2 illustratively depicted in Fig. 1 includes a tapered lead portion 11. As will be expl~ne~ further below, this portion of the flex circuit 2 provides a lead into a TEF~ON (registered tr~e~-rk of E.I. DuPont) mold when the flex circuit 2 and attached comron~n~ are re-shaped into a cylindrical shape. Thereafter, the lead portion 11 is cut from the re-shaped flex circuit 2.
Tllrn~ng to Fig. 2, an illustrative ultrasound transducer assembly is shown in a re-~hAr~ state. This CA 02226l94 l997-l2-3l shape is generally obt~; ne~ by wrapping the flat, partially asgembled ultrasound transducer assembly shown in Fig. 1 into a cylindrical shape by means of a molding process described below. A transducer portion 12 of the ultrasound transducer assem~bly cont~;n;ng the transducer elements 8 is shaped in a cylinder for transmitting and receiving ultrasound waves in a generally radial direction in a side-loa~;ng cylindrical transducer array arrangement. The tr~n~Al~cer portion 12 on which the transducer elements 8 are placed may alternatively be sh~pe~ or oriented in a ~nner different from the cylinder illustratively depicted in Fig. 2 in accordance with alternative fields of view such as side-fire planar arrays and forward look; ng pl ~nAr or curved arrays.
- 15 An electronics portion 14 of the ultrasound transducer ~ mhly is not constrained to any particular shape. However, in the illustrative example the portions of the flex circuit 2 su~olLing the integrated circuit chips 6 are relativeIy flat as a result of the electrical connections between the flex circuit 2 and the integrated circuit chips 6. Thus the portion of the flex circuit 2 carrying five (5) integrated circuit chips 6 has a pentagon cross-section when re-shaped (wrapped) into a cylinder. In an alternative embo~m~nt of the present invention, a re-~h~pe~ flex circuit having four (4) integrated circuits has a rectangular - cross-section. Other numbers of integrated circuits and resulting cross-sectional shapes are also contemplated.
Fig. 2 also shows the set of cable pads 10 on the flex circuit 2 exten~ng from the portion of the flex circuit 2 su~o~Ling the integrated circuit chips 6. A
lumen 16 in the center of the ultrasound transducer assembly (within which a guidewire is threaded during the use of a catheter upon which the transducer assembly has been mounted) is defined by-a lumen tube la made of a thin radiopaque, con~nctive material such as Platinum/Iridium. The radiopaque material assists in CA 02226l94 l997-l2-3l locating the ultrasound transducer assembly within the body during a medical procedure incorporating the use of the ultrasound transducer assembly. As will be ~Ypl~ne~ further below, the conductive property of the lumen tube 18 offers a means for connecting the transducer ground electrodes to a ground wire included in at least one of the wires connected to the cable pads 10 .
Spaces in the re-formed ultrasound transducer assembly between the integrated circuit chips 6, the transducer elements 8 and the lumen tube 18 are filled with a backing material 30. In contrast to earlier ultrasound catheter assembly designs including a relatively hard carrier material such as a rigid Pnc~pqulating epoxy, the backing material 30 that fills the spaces between the lumen tube 18 and the integrated circuit chips 6 is relatively soft. This ensures proper acoustic perfor~nc~ in the transducer portio~ 12 of the ultrasound transducer assembly. While the backing material 30 does not exhibit the rigidity of the previously used epoxy, other structures (disks) incorporated into the new transducer assembly design, described herein below, provide additional structural support for the integrated circuit chips 6 and reduces manufacturing complexity.
Turning now to Fig. 3, a cross-section view is - provided of the ultr~ollnA transducer assembly taken along line 3-3 and look~ng toward the transducer portion 12 in Fig. 2. The outside of the electronics portion 14 has a pentagon shape. The circular outline 26 repre~nts the outside of the tr~n~llc~r portion 12.
The flex circuit 2 Pncomr~es the cylindrically shaped - ultr~aol~n~ tr~nq~ucer assPmhly. The b~ck~ng material 30 fills the spaces between the integrated circuit chips 6 and the lumen tube 18. While relatively soft, the backing material 30 provides a satisfactory measure of structural 8U~YOL~ to the integrated circuit chips 6 in the final assembly of the ultrasound transducer assembly. A disk (not shown in Fig. 3) inserted in one end of the ultrasound transducer assembly housing the integrated circuits 6 further Pnh~ncP~ the structural integrity of the ultrasound transducer assembly.
Turning now to Fig. 4, a view i9 provided of a cross-section of the ultrasound trAna~ncPr assembly taken along line 4-4 and look;ng toward the electronics portion 14 in Fig. 2. The five corners of the~pentagon outline comprising the electronics portion 14 are illustrated in the bachyLo~,d of the cross-sectional view at line 4-4. The set of sixty-four (64) transducer elPm~nt~ 8 are displayed in the foLeyLound of this cross-sectional view of the transducer portion 12 of the ultrasound transducer assembly. The backing material 30, characterized by relatively low acoustic~impe~AncP, fills the space between the lumen tube 18 and the transducer elements ~ as well as the gaps between ad~acent ones of the sixty-four (64) transducer elements 8.
The determlnation of desirable materials for the backing material 30 i8 inflllPncptl by a number of considerations. The hAck;ng material 30 preferably possesses the ability to highly attenuate ultrasound energy emitted-by the tr~nq~vcer elements 8. The hA~k~ng material 30 also provides sufficient support for - ma~n~sA~ ~n~ng the array of transducer elements 8 in their - desired configuration. A suitable material for the h;~ck;ng material 30 cures in a sufficiently short period of time to meet manufacturing needs. A n~ er of known materials meeting the above described criteria for a good backing material will be known to those skilled in the art. An example of such a preferred h~rk; ng material comprises a ~Yture of epoxy, hardener and phenolic microballoons providing high ultrasound signal attenuation and satisfactory support for the ultrasound transducer assembly.
Having generally described an ultrasound tran~ducer assembly incorporating the flex circuit in accordance with the present invention, the advantages provided by the flex circuit will now be described in con~unction with the illustrative 2r~0~;ment. The flex circuit 2 provides a number of ad~antages over prior ultrasound transducer assembly designs. The RAPTON substrate of the flex circuit 2 provides acoustic (guarter-wave) matching for the PZT transducer elements 8.
The ease with which the flex circuit 2 may be re-~h~pe~ facilitates mounting, formation and connection of the integrated circuit chips 6 and tr~nqA~)c~r elements a while the flex circuit 2 is flat, and then re-shaping the flex circuit 2 into its final state after the - 15 compon~nt~ have been mounted, formed and connected. The flex circuit 2 is held within a frame for improved handling and positioning while the PZT and integrated circuits are hon~e~ to complete the circuits. The single sheet of PZT or PZT composite transducer material is diced into sixty-four (64) discrete transducer elements by sawing or other known cutting methods.
After dicing the transducer sheet, kerfs exist between ad~acent tr~nq~ncer elements while the flex circuit 2 is in the flat state. After the integrated circuit chips 6 and transducer elements 8 have been mounted, formed and connected, the flex circuit 2 is re-sh~pe~ into its final, cylindrical shape by drawing the flex circuit 2 and the ~ unted elements into a TEF~ON mold (described further below).
Also, because the integrated circuits and transducer elements o$ the ultrasound transducer assembly may be assembled while the flex circuit 2 is in the flat state, the flex circuit 2 may be manufactured by batch processing techniques wherein transducer assemblies are assembled side-by-side in a multiple-stage assembly process. The flat, partially assembled tr~n~t3ncer agge~mblies are then re-shaped and fabrication completed.
Furthermore, it is also possible to incorporate strain relief in the catheter asse~bly at the set of s cable pads 10. The strain relief involves flexing of the catheter at the cable pads 10. Such flexing improves the durability and the positionability of the assembled ultrasound catheter within a patient.
Another important advantage provided by the flex 10 circuit 2, is the relatively greater amount of surface area provided in which to lay out connection circuitry between the integrated circuit chips 6 and the tr~nq~ cer elements 8. In the illustrated embodiment of the present invention, the tr~nq~cer array includes 15 sixty-four (64) individual transducer elements. This i9 twice the number of tr~n~)cer elements of the transducer array described in the Pro~ n '097 patent.
Doubling the ml~r of tr~n~ lcer el~ments without increasing the circumference of the cylindrical 20 transducer array doubles the density of the transducer el~mentq. If the same circuit layout described in the Proudian l097 was employed for connecting the electronic comronents in the sixty-four (64) transducer element design, then the density of the connection circuitry 25 between the integrated circuit chips 6 and the transducer elements 8 must be doubled.
Ho~e~e, the flex circuit 2 occupies a relatively outer circumference of: (1) the tr~nq~ cer portion 12 in comparison to the transducer elements 8 and, (2) the 30 electronics portion 14 in comparison to the integrated circuit chips 6. The relatively outer circumference provides substantially more area in which to lay out the connection circuitry $or the sixty-four (64) transducer element design in comparison to the area in which to lay 35 out the connection circuitry in the design illustratively depicted in the Proudian ~097 patent. As a result, even though the number of conductor lines between the integrated circuit chips 6 and the transducer elements 8 doubles, the density of the conductor lines is increased by only about fifty percent (50~) in comparison to the previous carrier design disclosed in the Proudian '097 patent having a substantially same transducer assembly diameter.
Yet another advantage provided by the flex circuit 2 of the present invention is that the interconnection solder bumps, connecting the metallic pads of the integrated circuit chips 6 to matching pads on the flex circuit 2, are distributed over more of the chip surface, 80 the solder bumps only have to be slightly smaller than the previous design having only thirty-two (32) transducer elements.
The integrated circuit chips 6 are preferably hon~e~ to the flex circuit 2 using known infrared alignment and heating methods. However, since the flex circuit 2 can be translucent, it is also possible to perfonm alignment with less ~Ypenqive optical methods which include viewing the align~nt of the integrated circuit chips 6 with the connection circuitry deposited upon the substrate of the flex circuit 2 from the side of the flex circuit 2 opposite the surface to which the integrated circuit chips 6 are to be bonded.
Turning now to Figs. 5 and 5a, a cross-sectional view and enlarged partial cross-sectional view are - provided of the ultrasound tr~n~ cer ass~mhly illustrated in ~ig. 2 sectioned along line 5-5 and running along the length of the ultrasound transducer assembly embodying the present invention. A KAPTON
substrate 33 portion of the flex circuit 2, a~ o~lmately 13 ~m in thickness,-completely surrounds the ultrasound transducer assembly, acts as an acoustic matching layer and protects the electronic comron~nts of the ultrasound tr~nq~l)cer assembly. Metallic transducer signal lines 34, a~Lo~lmately 2-5~m in thickness, are h-~nAeA to the ~CAPTON substrate 33 with a chromium adhesion layer to form the flex circuit 2.
The trAn~A--cer signal lines 34 of the flex circuit 2 are illustrated as a solid layer in Fig. 5. However, s it will be appreciated by those skilled in the art that the transducer signal lines 34 are fabricated from a solid layer (or layers) of deposited metal using well known metal layer selective etching techniques such as - m:~qk~ng or selective plating techniques.
A cable 35 of the type disclosed in the Proudian '097 patent is connected to the cable pads 10 for carrying control and data signals transmitted between - the ultrasound transducer assembly and a processing unit. A set of solder bumps such as solder bump 36 connect the contacts of the integrated circuit chips 6 to the transducer signal lines 34 of the flex circuit 2.
Two-part epoxy 38 bonds the integrated circuit chips 6 to the flex circuit 2.
Fig. 5 also shows the backing ntaterial 30 which fills the gaps between the integrated circuits and the lumen tube 18. The lumen tube 18 has a diameter of approximately 0.024~ and is approxintately 25~m thick.
The space between the trAnqA~tcers 8 and the lumen tube 18 in transducer portion 12 of the ultrasound transducer ass~mhly is filled by the bAr~ng material 30 having a low acoustic imp~AAnc~ and therefore well suited for attenuating ringing in the ultra80und transducer ; assentbly by absorbing ultrasound waves emitted by the trAn~A-~cer elements toward the lumen tube 18. The transducer portion 12 of the-ultrasound transducer assembly of the present invention is described in greater detail below in conjunction with Figs. 6 and 6a.
A pair of gro~nA~ng discs 37 and 39 are located on each end of the ultrA~o~nA tr~An~A~cer assembly. The primary function of the discs 37 and 39 is to provide a ground contact between a ground wire on the cable 35, the lumen tube 18, and the transducer ground electrode leads. In the preferred embodiment of the present invention, merhAn~cal contacts (rather than solder) exi~t between the tr~An~l)cer ground electrode pads and the disc 37, the disc 37 and the lumen tube 18, the s lumen tube 18 and disc 39, and disc 39 and a pad on the flex circuit 2 to a ground wire in the cable 35.
The ground contact i8 established by press-fitting the discs 37 and 39 onto the lumen tube 18 as shown in Fig. 7. Thereafter, the flex circuit 2 is wrapped around the discs 37 and 39 and the resulting cylindrical device is filled with the h~Ac~ng material 30 in order to create a device having a cross-section illustratively depicted in Fig. S after final assPmhly. As illustratively depicted in Figs. 8 and 9, the disc 37 i8 generally circular (to provide a round cylinder shape to the transducer portion 12 of the ultrasound transducer assembly), and the disk 39 i8 generally pentagonal (to provide a five-sided cylinder shape to accommodate the arrany~E~t of the five (5) integrated circuit chips 6 attached to flex circuit 2 in the electronics portion 14). FurthPr~ore, the discs 37 and 39 are formed with through holes to facilitate a step of injecting backing material into the ultrasound trAn~ cer assembly during a preferred fabrication process described herein below.
Turning now to Figs. 6, 6a and 6b, the transducer elements 8 comprise PZT or PZT composite 40 appr~Y~-tely 90~m in thickn~s and, ~ep~n~ng on frequency, a~p~oAimately 40~m wide and 700~m long. Each s transducer element includes a Cr/Au ground electrode 42 and a Cr/Au signal electrode 46 which are approximately O.l~m in thickness. As illustratively depicted in Fig.
6b, the electrodes are constructed by ~nc~p~ulating the PZT or PZT composite 40 in Cr/Au. Thereafter,-the electrodes 42 and 46 are defined as two separate metal sheets by cutting (or etching) a first yLoove at point X
- on a first surface primarily cont~;ning the signal electrode 46 and cutting a second y~Go~e at point Y on a second surface primarily cnnt~ ~ n~ ng the ground electrode lS 42. The yLoove~ at points X and Y define the active region 45 of the tr~n~ cers 8. The re~ce~ active region 45, that does not include the ends of the transducer elements 8 provides edge damping and potentially improved image quality.
As illustratively depicted in Fig. 6b, the positions of the grooves X and Y establish electrical isolation between the electrodes 42 and 46 in a ~nner such that connections between electrical lines 44 (ground) and 34 (signal) and correspon~ng transducer electrodes 42 and 46 are achieved without fabricating bridges between lead lines on the flex circuit 2 and the - upper surface of the transducers 8 defining the signal electrode 46. As a consequence of positioning all electrode cont~cts on a single plane, connections between electrodes 42 and 46, and correspon~ ng lines 44 and 34 on the flex circuit 2 are preferably achieved by means of pressure and adhesive materials rather than soldering or csn~nctive glues. More particularly, in a preferred embodiment, a two-part epoxy S0, a~.o~imately 2-5~m in thicknes occupies the space between the ground electrode 42 and the gAPTON substrate 33 of the flex circuit 2. The two-part epoxy 50 holds the transducer CA 02226l94 l997-l2-3l elements 8 in signal contact with the transducer signal linee 34 of the flex circuit 2 while the relative rough surfaces of the PZT or PZT composite 40 establish several points of contact between the transducer S electrodes 42 and 46, and correspon~; ng electrical lines 44 and 34.
The thicknesq of the two-part epoxy 50 between the substrate 33 and the ground electrode 42 is controlled by spacer bars 49. The spacer bars 49 run the entire width of the flat flex circuit. However, the continuous spacer bar material is separated into discrete bars by a saw during the step of dicing the transducer material into discrete trAn~ cer elements 8. Additional two-part epoxy 50 is applied at the ends of the transducers 8.
Finally, it is noted that the transducer signal lines 34 are separate, electrically isolated conductors which terminate at signal cont~3cts 48. The transducer signal lines 34 couple the trAnl~l)cer el~m~nt~ 8 to correspon~l~ ng I/0 ~hAnn~l8 of the integrated circuit chips 6. The ground line 44 comprises a continuous conductor is not cut through since the integrated circuits and the distal portion of the ground line 44 are fixtured at a lower elevation than the transducer array during dicing and maintains the trAn~ucer ground electrode 42 for each of the transducer elements 8 at a - common electrical potential established by a ground wire within the cable 35. This ground connection is achieved through the metallic disc 37 which conducts a ground signal via the lumen tube 18 and disc 39. The disc 39 is connected directly to the yLOu~d signal which originates from the cable 35.
Turning now to Fig. 10, the steps are summarized for fabricating the above-described ultrA~o~n~l 35 transducer assembly embodying the present invention. It will be appreciated by those skilled in the art that the steps may be modified in alternative embo~;mPnts of the invention.
At step 52, the flex circuit 2 is formed by depositing conductive materials such as Chromium/Gold (Cr/Au) on a surface of the KAPTON substrate 33.
Chromium is first deposited as a thin adhesion layer, typically 50-100 Angstroms thick, followed by the gold conA~cting layer, typically 2-5~m thick. Using well known etching techniques, portions of the Cr/A~ layer are removed from the surface of the RAPTON substrate 33 in order to form the transducer signal lines 34, the ground line 44, and the spacer bars 49 of the flex circuit 2. Also during step 52 gold bumps, used to form the signal contacts 48, are formed on the flex circuit 2.
In a separate and ~n~epPn~Pnt procedure with re~pect to the above-described step for fabricating the flex circuit 2, at step 53 a thin metal layer, on the order of O.l~m to 5.0~m is applied to a single PZT or PZT composite crystal. In contrast to an alternative metalization procedure, during step 53 the metal layer covers the top, bottom and ends of the PZT crystal.
Next, during step 54, the metal layer is divided into two separate metal layers by cutting the two ylooves identified previously by the X and Y in Fig. 6a. These two metal layers will later comprise the separate ground - electrode 42 and signal electrode 46 for each of the ; transducer ele~ents.
Next, at step 55, the metallized PZT or PZT
composite 40 is honAeA under pressure to the flex circuit 2 by means of two-part epoxy 50, and cured for a reasonable period. This is typically done overnight.
The pressure exerted during hQn~ ng re~lce~ the thickne~ of the two-part epoxy 50 to a thickness of approximately 2-5~m, ~epPn~ng on the chosen thickness of the spacer bars 49 and signal contacts 48. The very thin layer of two-part epoxy 50 provides good adhesion of the metallized PZT or PZT composite to the flex circuit 2 without ~ignificantly affecting the acoustic perform~nce of the transducer elements 8. During exertion of pressure during step 55, a portion of the 5 two-part epoxy 50 squeezes out from between the flex circuit 2 and the transducer sheet from which the transducer elements 8 will be formed. That portion of the two-part epoxy 50 also forms a fillet at each end of the honrle~ tr~nqtlllcer sheet (See Fig. 6). The fillets 10 of the two-part epoxy 50 provide additional support for the tr~n~ c~r elements 8 during sawing of the PZT or PZT composite 40 into physically discrete transducer el~m~nt~. Additional two-part epoxy 50 may be added around the PZT to make the fillet more uniform.
In order to obtain good performance of the elements and to facilitate re-shaping the flex circuit 2 into a cylinder after the integrated circuit chips 6 and transducer elements 8 are attached, the transducer sheet is diced to form physically discrete tr~nq~ cer elements 8 during step 56. Dicing is accomplished by means of a well known high precision, high speed disc sawing apparatus, such as those used for sawing silicon wafers.
It i8 desirable to make the saw kerfs (i.e., the spaces between the adjacent tr~n~ducer elements) on the order of 15-25~m when the flex circuit is re-shaped into a cylindrical shape. Such separation ~l~m~n~ions are achieved by known high precision saw h~ e~ having a thickness of 10-15~m.
Continuing with the description of the dicing step 56, after the two part epoxy 50 i9 fully cured, the flex circuit 2 is fixtured to facilitate dicing of the transducer sheet into sixty-four (64) discrete el~m~nt~.
The flex circuit 2 i8 fixtured by pl~c~ng the flex circuit 2 onto a vacuum chuck (of well known design for precision dicing of very small objects such as semiconductor wafers) which is raised by 50-200~m in the region of the transducer elements 8 in order to enable a saw blade to penetrate the flex circuit 2 in the region of the trAn~A~-cer elements 8 without affecting the integrated circuit region and without sawing through the distal portion of the ground line proximate to the disc 3-7. The saw height i8 carefully controlled 80 that the cut extends completely through the PZT or PZT composite 40 and partially into the KAPTON substrate 33 of the flex circuit 2 by a few microns. RYt~n~ng the cut further into the flex circuit 2 further reduces the conduction of ultrasound to ad~acent transducer elem~t~R. The resulting transducer element pitch (width) is on the order of SO~m. In alternative embo~me~ts this cut may extend all the way through the flex circuit 2 in order to provide full physical Reparation of the transducer elements.
Alternatively a laser performs the step of dicing the transducer elements. However, a drawback of using a laser to dice the transducer sheet is that the laser energy may depolarize the PZT or PZT compQsite 40. In view of present difficulties associated with polarization of the separated PZT transducer elements, the sawing method i8 presently preferred.
After the PZT or PZT composite 40 has been diced into discrete trAnQ~cer elements and cleaned of dust arising from the sawing of the PZT or PZT composite 40, at step 57 the integrated circuit chips 6 are flip-chip bonded in a known manner to the flex circuit 2 using - pressure and heat to melt solder bumps such as solder bump 36 forming the electrical contacts between the flex circuit 2 and the pads of the integrated circuit chips 6. The integrated circuit chips 6 are aligned by means of either infrared or visible light alignment techniques 90 that the Indium solder bumps on the integrated circuits 6 align with the pads on the flex clrcuit 2.
These alignment methods are well known to those skilled in the art. The partially assembled ultrasound trAnR~cer assembly is now ready to be formed into a substantially cylindrical shape as shown in Figs 2, 3 and 4.
-- Be~ore re-shaping the flat flex circuit 2 (as shown in Fig. 1) into a cylindrical shape around the lumen tube 18, at step 58 the ~Lo~ ng discs 37 and 39 are pressed onto the ends of the lumen tube 18 (see Fig. 7).
The tolerances of the inner sprockets of the disc 37 and the inner diameter of the disc 39 and the outer diameter of the lumen tube 18 are such that the discs 37 and 39 frictionally engage the outer surface of the lumen tube 18. The discs 37 and 39 shown in Figs. 8 and 9 respectively, ensure concentricity of the transducer portion 12 of the assembled ultrasound trAnCAl~cer device around the lumen tube 18 and facilitates even distribution of the backing material 30 within the spaces of the ultrA~o~ trAnC~llcer apparatus between the lumen tube and the ultrA~oll~A trAncAl~c~rs 8.
At step 59, the yLo~ ing assembly, consisting of the lumen tube 18 and discs 37 and 39, and the partially assembled flex circuit 2, are carefully matched up and then drawn into a preformed TEFLON mold having very precise dimensions. The TEFLON mold is formed by heat shrin~ng TEPLON tubing over a precision machine~
mandrel (as shown in Fig. 11 and described below). The heat shrinkable TEFLON tubing is removed and ~i~cArded after fabrication of the ultrasound transducer assembly ~ is complete. As a result, distortion of a mold through multiple uses of the same mold to complete fabrication of several ultra~c~ln~ transducer assemblies is not a problem, and there is no clean up of the mold required.
The TEFLON molds incor~orate a gentle lead-in taper enabling the sides of the flex circuit 2 to be carefully aligned, and the gap between the first and last elements to be ad~usted, as the flex circuit 2 is pulled into the mold. In the region of the trAn~llc~r, the mold and the disc 37 are held to a diametric precision of 2-3~m.
Since the flex circuit 2 dimensions are formed with precision optical techniques, the ~;m~n~ions are repeatable to less than l~m, the gap between the first and last elements (on the outer edges of the flat flex circuit 2) can be repeatable and s~lAr to the kerf s width between ad;acent elements.
A TEPLON bead is placed within the lumen tube 18 in order to prevent filling of the lumen 16 during the steps described below for completing fabrication of the ultrasound transducer assembly.
After drawing the flex circuit into the mold, at step 60 backing material 30 is in~ected into the distal end of the ultrasound tr~n~ cer assembly in order to fill the kerfs between transducer el~m~ntq and any gaps between the preformed portion of the hA~king material 30 and the transducer elements 8. The hA~king material is injected by means of the through holes in the grounding disc 37. The air occupying the space between the lumen tube 18 and comron~nt~ of the flex circuit assembly escapes through holes in the disc 39. This ensures that there are no air gaps in the region of the ultrasound transducer assembly having the transducer array since air gaps degrade the performAnce of the ultrasound transducer assembly and degrade the mechanical integrity of the device. In contrast to prior fabrication methods employing separate and distinct chip carrier and backing materials, the present design utilizes the backing material 30 to support the integrated circuits. This modification re~ceq manufacturing complexity while providing sufficient 8u~po~ for the integrated circuits.
At step 61, after the backing material 30 cures, the ultrasound trAn~ c~r assembly is removed from the mold by either pll~h~ng the device out of the mold or carefully cutting the TEFLON mold and peeling it from the ultrasound transducer assembly. The TEFLON bead i8 removed from the lumen tube 18. Stray h~cking material is L ~..~ed from the device.
Having degcribed one method for fabricating an ultrasound transducer assembly incorporating the flex circuit 2, it is noted that the order of the steps is not necessArily important. For exA~mple, while it is s preferred to attach the integrated circuits 6 to the flex circuit 2 after the trAn~ c~rs 6 have been bon~e~
to the flex circuit 2, such an order for assembling the ultrasound transducer assembly is not essential.
Similarly, it will be appreciated by those ski~led in the art that the order of other steps in the described method for fabricating an ultrasound transducer assembly can be re-arranged without departing from the spirit of the present invention.
Turning briefly to Fig. 11, a longit~ nAl cross-section view is provided of the mandrel previously mentioned in connection with the description of step 59 above. The mandrel enables a TFFLON tube to be re-formed into a mold (shown generally by a ghost outline~
having very precise inside ~im~n~ions by heat shrinking the TEFLON tube onto the mandrel. The TEFLON mold is thereafter used to re-shape the partially assembled ultrasound trAn~ncer assembly during step 59. While precise dimensions and tolerances are provided on the drawing, they are not intended to be limiting since they 2s are associated with a particular size and shape for an ultrA~o~n~ trAn~ncer assembly embodying the present - invention.
The mandrel and resulting inside surface of the TEFLON mold generally display certain characteristics.
First, the mandrel incorporates a taper from a maximum diameter at the end where the flex circuit enters the mold to a min~m diameter at the portion of the mold COrre8pQn~ ng to the trAn~llcer portion of the ultrasound transducer assembly. This first characteristic facilitates drawing the flex circuit into the mold.
Second, the mold has a region of constant diameter at the region where the integrated circuit portion will be ~ormed during step 59. This diameter is slightly greater than the diameter of the trAn~lcer region of s the mold where the diameter of the inside surface is precisely formed into a cylinder to ensure proper mating of the two sides of the flex circuit when the flat, partially assembled transducer assembly is re-shaped into a cylindrical transducer assembly. The greater diameter in the integrated circuit region accommodates the points of the pentagon cross-section created by the integrated circuit chips 6 when the flat flex circuit is re-~h~re~ into a cylinder.
Finally, a second taper region is provided between the integrated circuit and transducer portions of the mold in order to provide a smooth transition from the differing diameters of the two portions.
The above description of the invention has focused primarily upon the structure, materials and steps for constructing an ultrasound trAn~ cer assembly ~odying the present invention. Turning now to Figs. 12 and 13, an illustrative ~Y~rle of the typical envirG~..cnt and application of an ultrasound device embodying the present invention is provided. Referring to Figs. 12 and 13, a buildup of fatty material or plaque 70 in a coronary artery 72 of a heart 74 may be treated in - certain situations by inserting a balloon 76, in a deflated state, into the artery via a catheter assembly 78. As illustrated in Fig. 12, the catheter assembly 78 is a three-part assembly, having a guide wire 80, a guide catheter 78a for threA~i ng through the large arteries such as the aorta 82 and a smaller diameter catheter 78b that fits inside the guide catheter 78a.
After a surgeon directs the guide catheter 78a and the guide wire 80 through a large artery leA~ ng via the aorta 82 to the coronary arteries, the smaller catheter 78b is inserted. At the beginning of the coronary artery 72 that is partially blocked by the plaque 70, the guide wire 80 is first extended into the artery, followed by catheter 78b, which includes the balloon 76 at its tip.
After the balloon 76 ha~ entered the coronary artery 72, as in Fig. 13, an ultrasonic imaging device including a probe assembly 84 housed within the proYi sleeve 86 of the balloon 76 provides a surgeon with a cross-sectional view of the artery on a video display 88. In the illustrated embodiment of the invention, the transducers emit 20 MHz ultrasound excitation waveforms.
However, other suitable eYcitation waveform frequencies would be known to those skilled in the art. The transducers of the probe assembly 84 receive the reflected ultrasonic wavefor~ and convert the ultrAqo~-n~ echoes into echo waveforms. The amplified - -echo waveforms from the probe assembly 84, indicative of reflected ultrasonic waves, are transferred along a microcable 90 to a signal processor 92 located outside the patient. The catheter 78b ends in a three-part junction 94 of conventional construction that couples the catheter to an inflation source 96, a guide wire lumen and the signal processor 92. The inflation and guide wire ports 94a and 94b, respectively, are of conve~tional PTCA catheter construction. The third port 94c provides a path for the cable 90 to connect with the - signal pLoce_~or 92 and video display 88 via an electronic connector 98.
It should be noted that the present invention can be incorporated into a wide variety of ultrasound imaging catheter assem~blies. For example, the present invention may be incG.~oLated in a probe assembly mounted upon a diagnostic catheter that does not include a balloon. In addition, the probe assembly may also be mounted in the manner taught in Proll~t~n et al. U.S.
Patent 4,917,097 and Eberle et al. U.S. Patent 5,167,233, the teachings of which are explicitly incorporated, in all respects, herein by reference.
These are only examples of various mounting configurations. Other configurations would be known to those skilled in the area of catheter design.
S Furthen~Qre, the preferred ultrasound transducer assembly embodying the present invention is on the order of a fraction of a millimeter to several millimeters in order to fit within the relatively small cross-section of blood vessels However, the structure and nethod for manufacturing an ultr~o~ln~ tr~n~cer assembly in accordance with present invention may be incorporated within larger ultr~qo~n~ devices such as those used for lower gastrointestinal ~Y~m~nAtions.
Illustrative embodiments of the present invention have been provided. However, the scope of the present invention is intended to include, without limitation, any other m~difications to the described ultrasound transducer device and methods of pro~c;ng the device falling within the fullest legal scope of the present invention in view of the description of the invention and/or various preferred and alternative ~mho~;ments described herein. The ;ntent is to cover all alternatives, modifications and equivalents included within the spirit and scope of the invention as defined by the ~pp~n~e~ claims.
Claims (22)
1. An ultrasound transducer assembly for facilitating providing images from within a cavity, the ultrasound transducer assembly comprising:
integrated circuitry;
an ultrasound transducer array including a set of ultrasound transducer elements comprising a transducer material, a signal electrode and a ground electrode;
a flexible circuit to which the ultrasound transducer array and the integrated circuitry are attached during fabrication of the ultrasound transducer assembly, the flexible circuit comprising:
a flexible substrate, providing a re-shapable platform, to which the integrated circuitry and transducer elements are attached;
transducer signal lines on an inner surface of the flexible substrate, the transducer signal lines providing an electrical signal path between the integrated circuitry and the transducer element signal electrodes; and a ground line on the inner surface of the flexible substrate; and wherein a first contact on the signal electrode and a second contact on the ground electrode contact for each transducer element are arranged upon substantially a same physical plane as the inner surface of the flexible substrate.
integrated circuitry;
an ultrasound transducer array including a set of ultrasound transducer elements comprising a transducer material, a signal electrode and a ground electrode;
a flexible circuit to which the ultrasound transducer array and the integrated circuitry are attached during fabrication of the ultrasound transducer assembly, the flexible circuit comprising:
a flexible substrate, providing a re-shapable platform, to which the integrated circuitry and transducer elements are attached;
transducer signal lines on an inner surface of the flexible substrate, the transducer signal lines providing an electrical signal path between the integrated circuitry and the transducer element signal electrodes; and a ground line on the inner surface of the flexible substrate; and wherein a first contact on the signal electrode and a second contact on the ground electrode contact for each transducer element are arranged upon substantially a same physical plane as the inner surface of the flexible substrate.
2. The ultrasound transducer assembly of claim 1 wherein the transducer elements are covered by a substantially continuous metal layer having first and second discontinuities thereby defining the signal electrode and ground electrode.
3. The ultrasound transducer assembly of claim 2 wherein the first discontinuity is located on a surface of each transducer element primarily comprising the signal electrode and the second discontinuity is located on a surface of each transducer element primarily comprising the ground electrode.
4. The ultrasound transducer assembly of claim 1 wherein the ultrasound transducer array is substantially cylindrical in shape.
5. The ultrasound transducer assembly of claim 4 wherein the spaces within the ultrasound transducer assembly between a lumen tube, the flex circuit, the transducer array and the integrated circuits are filled with a backing material characterized by relatively low acoustic impedance.
6. The ultrasound transducer assembly of claim 5 further comprising at least a first disc attached to the lumen tube and wherein the outer edges abut the reshaped flexible substrate thereby enhancing the structural integrity of the ultrasound transducer assembly.
7. The ultrasound transducer assembly of claim 6 wherein the first disc comprises a conductive material and wherein the first disc provides a portion of an electrically conductive path between the ground electrodes and an external ground signal.
8. The ultrasound transducer assembly of claim 6 wherein the first disc is positioned at an end of the transducer assembly housing the transducer array, and a second disc attached to the lumen tube positioned at an opposite end of the transducer assembly housing the integrated circuitry, and wherein the outer edges abut the re-shaped flexible substrate.
9. The ultrasound transducer assembly of claim 1 wherein the transducer elements are covered by a substantially continuous metal layer having first and second discontinuities thereby defining an active region of each transducer element which terminates before an end of the transducer material.
10. The ultrasound transducer assembly of claim 1 wherein the transducer material comprises a PZT
material.
material.
11. The ultrasound transducer assembly of claim 1, having suitable dimensions for providing images of a blood vessel from within a vasculature, and wherein the diameter of the substantially cylindrical ultrasound transducer assembly is on the order of 0.3 to 5.0 millimeters.
12. A method for fabricating an ultrasound transducer assembly comprising a flexible circuit, integrated circuitry, and a set of transducer elements for facilitating providing images of a blood vessel from within a vasculature, the method comprising the steps:
fabricating the flexible circuit comprising a flexible substrate and a set of electrically conductive lines formed on an inner surface of the flexible substrate;
fabricating a transducer sheet comprising a transducer material, a signal electrode and a ground electrode, wherein a first contact on the signal electrode and a second contact on the ground electrode contact for each transducer element are arranged upon substantially a same physical plane; and attaching the transducer sheet to the flexible circuit while the flexible circuit is in a substantially flat shape such that the first contact and second contact for each transducer element abuts corresponding pads of the electrically conductive lines on the inner surface of the flexible circuit.
fabricating the flexible circuit comprising a flexible substrate and a set of electrically conductive lines formed on an inner surface of the flexible substrate;
fabricating a transducer sheet comprising a transducer material, a signal electrode and a ground electrode, wherein a first contact on the signal electrode and a second contact on the ground electrode contact for each transducer element are arranged upon substantially a same physical plane; and attaching the transducer sheet to the flexible circuit while the flexible circuit is in a substantially flat shape such that the first contact and second contact for each transducer element abuts corresponding pads of the electrically conductive lines on the inner surface of the flexible circuit.
13. The method of claim 12 further comprising the step of re-shaping the flexible circuit into a substantially non-flat shape after the steps of fabricating a transducer sheet and attaching the transducer sheet to the flexible circuit.
14. The method of claim 12 wherein the fabricating step comprises the sub-step of creating first and second discontinuities in a continuous metal layer thereby defining the signal electrode and ground electrode for each transducer element.
15. The method of claim 14 wherein the first discontinuity is located on a surface of each transducer element primarily comprising the signal electrode and the second discontinuity is located on a surface of each transducer element primarily comprising the ground electrode.
16. The method of claim 13 wherein the re-shaping step comprises reforming the flexible circuit into a cylindrical shape.
17. The method of claim 16 further comprising the step of filling the spaces within the ultrasound transducer assembly between a lumen tube, the flex circuit, the transducer array and the integrated circuits with a backing material characterized by relatively low acoustic impedance.
18. The method of claim 17 further comprising the step of fabricating a subassembly comprising the lumen tube and at least a first disc attached to the lumen tube and wherein the outer edges of the first disc abut the re-shaped flexible substrate thereby enhancing the structural integrity of the ultrasound transducer assembly.
19. The method of claim 18 wherein the first disc comprises a conductive material and wherein the first disc provides a portion of an electrically conductive path between the ground electrodes and an external ground signal.
20. The method of claim 19 wherein the first disc is positioned at an end of the transducer assembly housing the transducer array, and further comprising the step of attaching a second disc to the lumen tube positioned at an opposite end of the transducer assembly housing the integrated circuitry, and wherein the outer edges of the second disc abut the re-shaped flexible substrate.
21. The method of claim 13 wherein the resulting ultrasound transducer assembly has suitable dimensions for providing images of a blood vessel from within a vasculature, and wherein the diameter of the substantially cylindrical ultrasound transducer assembly is on the order of 0.3 to 5.0 millimeters.
22. The method of claim 12 further comprising the step of dicing the transducer sheet into a set of discrete transducer elements.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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US08/780,437 US5857974A (en) | 1997-01-08 | 1997-01-08 | High resolution intravascular ultrasound transducer assembly having a flexible substrate |
US08/780,437 | 1997-01-08 |
Publications (1)
Publication Number | Publication Date |
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CA2226194A1 true CA2226194A1 (en) | 1998-07-08 |
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Application Number | Title | Priority Date | Filing Date |
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CA002226194A Abandoned CA2226194A1 (en) | 1997-01-08 | 1997-12-31 | A high resolution intravascular ultrasound transducer assembly having a flexible substrate and method for manufacture thereof |
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US (5) | US5857974A (en) |
EP (1) | EP0853919B1 (en) |
JP (1) | JPH10192281A (en) |
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CA (1) | CA2226194A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2014083283A (en) * | 2012-10-25 | 2014-05-12 | Seiko Epson Corp | Ultrasonic measuring device, head unit, probe, and diagnostic system |
CN108618805A (en) * | 2017-03-22 | 2018-10-09 | 精工爱普生株式会社 | Ultrasonic device unit, ultrasonic probe and ultrasonic unit |
Families Citing this family (230)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5655538A (en) * | 1995-06-19 | 1997-08-12 | General Electric Company | Ultrasonic phased array transducer with an ultralow impedance backfill and a method for making |
US5857974A (en) * | 1997-01-08 | 1999-01-12 | Endosonics Corporation | High resolution intravascular ultrasound transducer assembly having a flexible substrate |
EP1059878B1 (en) | 1998-03-05 | 2005-11-09 | Gil M. Vardi | Optical-acoustic imaging device |
US6113546A (en) * | 1998-07-31 | 2000-09-05 | Scimed Life Systems, Inc. | Off-aperture electrical connection for ultrasonic transducer |
US6277077B1 (en) | 1998-11-16 | 2001-08-21 | Cardiac Pathways Corporation | Catheter including ultrasound transducer with emissions attenuation |
US7232433B1 (en) * | 1999-09-22 | 2007-06-19 | Siemens Medical Solutions Usa, Inc. | Medical diagnostic ultrasound catheter with dielectric isolation |
AU2619301A (en) * | 1999-10-25 | 2001-06-06 | Therus Corporation | Use of focused ultrasound for vascular sealing |
US6626855B1 (en) * | 1999-11-26 | 2003-09-30 | Therus Corpoation | Controlled high efficiency lesion formation using high intensity ultrasound |
WO2001045550A2 (en) * | 1999-12-23 | 2001-06-28 | Therus Corporation | Ultrasound transducers for imaging and therapy |
US6457365B1 (en) * | 2000-02-09 | 2002-10-01 | Endosonics Corporation | Method and apparatus for ultrasonic imaging |
US6310427B1 (en) * | 2000-05-03 | 2001-10-30 | Bae Systems Aerospace Inc. | Connecting apparatus for electro-acoustic devices |
US6467138B1 (en) | 2000-05-24 | 2002-10-22 | Vermon | Integrated connector backings for matrix array transducers, matrix array transducers employing such backings and methods of making the same |
US6392330B1 (en) * | 2000-06-05 | 2002-05-21 | Pegasus Technologies Ltd. | Cylindrical ultrasound receivers and transceivers formed from piezoelectric film |
GB2365127A (en) * | 2000-07-20 | 2002-02-13 | Jomed Imaging Ltd | Catheter |
US6437487B1 (en) * | 2001-02-28 | 2002-08-20 | Acuson Corporation | Transducer array using multi-layered elements and a method of manufacture thereof |
US6497667B1 (en) * | 2001-07-31 | 2002-12-24 | Koninklijke Philips Electronics N.V. | Ultrasonic probe using ribbon cable attachment system |
US6572547B2 (en) * | 2001-07-31 | 2003-06-03 | Koninklijke Philips Electronics N.V. | Transesophageal and transnasal, transesophageal ultrasound imaging systems |
US6582371B2 (en) * | 2001-07-31 | 2003-06-24 | Koninklijke Philips Electronics N.V. | Ultrasound probe wiring method and apparatus |
CA2459921C (en) * | 2001-09-06 | 2009-12-22 | Pegasus Technologies Ltd. | Cylindrical ultrasound receivers and transceivers formed from piezoelectric film |
WO2003039350A2 (en) * | 2001-11-09 | 2003-05-15 | Cardio-Optics, Inc. | Direct, real-time imaging guidance of cardiac catheterization |
US6793829B2 (en) * | 2002-02-27 | 2004-09-21 | Honeywell International Inc. | Bonding for a micro-electro-mechanical system (MEMS) and MEMS based devices |
US20040054287A1 (en) * | 2002-08-29 | 2004-03-18 | Stephens Douglas Neil | Ultrasonic imaging devices and methods of fabrication |
US6712767B2 (en) | 2002-08-29 | 2004-03-30 | Volcano Therapeutics, Inc. | Ultrasonic imaging devices and methods of fabrication |
US7289837B2 (en) * | 2002-10-01 | 2007-10-30 | Nellcor Puritan Bennett Incorpoated | Forehead sensor placement |
US7698909B2 (en) * | 2002-10-01 | 2010-04-20 | Nellcor Puritan Bennett Llc | Headband with tension indicator |
US7245789B2 (en) | 2002-10-07 | 2007-07-17 | Vascular Imaging Corporation | Systems and methods for minimally-invasive optical-acoustic imaging |
EP1575429A1 (en) * | 2002-12-11 | 2005-09-21 | Koninklijke Philips Electronics N.V. | Miniaturized ultrasonic transducer |
EP1614389A4 (en) * | 2003-04-01 | 2017-06-14 | Olympus Corporation | Ultrasonic vibrator and method of producing the same |
JP4323487B2 (en) * | 2003-04-01 | 2009-09-02 | オリンパス株式会社 | Ultrasonic vibrator and manufacturing method thereof |
US7335052B2 (en) * | 2003-06-05 | 2008-02-26 | Koninklijke Philips Electronics N.V. | Method and system for determining and controlling a contrast opacification in an ultrasonic examination |
US20040254471A1 (en) * | 2003-06-13 | 2004-12-16 | Andreas Hadjicostis | Miniature ultrasonic phased array for intracardiac and intracavity applications |
US7047056B2 (en) * | 2003-06-25 | 2006-05-16 | Nellcor Puritan Bennett Incorporated | Hat-based oximeter sensor |
US7180736B2 (en) * | 2003-07-10 | 2007-02-20 | Visteon Global Technologies, Inc. | Microelectronic package within cylindrical housing |
US20050043627A1 (en) * | 2003-07-17 | 2005-02-24 | Angelsen Bjorn A.J. | Curved ultrasound transducer arrays manufactured with planar technology |
US8412297B2 (en) | 2003-10-01 | 2013-04-02 | Covidien Lp | Forehead sensor placement |
US20050251127A1 (en) * | 2003-10-15 | 2005-11-10 | Jared Brosch | Miniature ultrasonic transducer with focusing lens for intracardiac and intracavity applications |
US20050085731A1 (en) * | 2003-10-21 | 2005-04-21 | Miller David G. | Ultrasound transducer finger probe |
JP4913601B2 (en) * | 2003-11-26 | 2012-04-11 | イマコー・インコーポレーテッド | Transesophageal ultrasound using a thin probe |
JP4773366B2 (en) * | 2003-12-04 | 2011-09-14 | コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ | Ultrasonic transducer and method for performing flip-chip two-dimensional array technology on curved array |
US20070222339A1 (en) * | 2004-04-20 | 2007-09-27 | Mark Lukacs | Arrayed ultrasonic transducer |
CA2563775C (en) * | 2004-04-20 | 2014-08-26 | Visualsonics Inc. | Arrayed ultrasonic transducer |
EP1765175B1 (en) * | 2004-05-17 | 2019-01-16 | Humanscan Co., Ltd. | Ultrasonic probe and method for the fabrication thereof |
JP4621452B2 (en) * | 2004-08-20 | 2011-01-26 | 富士フイルム株式会社 | Ultrasound endoscope and ultrasound endoscope apparatus |
US20080045882A1 (en) * | 2004-08-26 | 2008-02-21 | Finsterwald P M | Biological Cell Acoustic Enhancement and Stimulation |
WO2006030355A1 (en) * | 2004-09-13 | 2006-03-23 | Koninklijke Philips Electronics, N.V. | Integrated circuit for implementing high-voltage ultrasound functions |
EP1808130A4 (en) * | 2004-09-24 | 2018-02-14 | Olympus Corporation | Ultrasonic transducer, ultrasonic array and ultrasonic endoscope system |
JP4647968B2 (en) * | 2004-11-09 | 2011-03-09 | オリンパス株式会社 | Ultrasound endoscope |
JP4969456B2 (en) * | 2005-01-11 | 2012-07-04 | コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ | Redistribution interconnect for microbeamformers and medical ultrasound systems |
WO2006076409A2 (en) * | 2005-01-11 | 2006-07-20 | Volcano Corporation | Vascular image co-registration |
US20060173350A1 (en) * | 2005-01-11 | 2006-08-03 | Scimed Life Systems, Inc. | Systems and methods for three dimensional imaging with an orientation adjustable array |
JP4516451B2 (en) * | 2005-03-09 | 2010-08-04 | 富士フイルム株式会社 | Ultrasonic probe and method for producing ultrasonic probe |
US20060253028A1 (en) * | 2005-04-20 | 2006-11-09 | Scimed Life Systems, Inc. | Multiple transducer configurations for medical ultrasound imaging |
US8796901B2 (en) * | 2005-06-17 | 2014-08-05 | Kolo Technologies, Inc. | Micro-electro-mechanical transducer having an insulation extension |
US20070194658A1 (en) * | 2005-07-13 | 2007-08-23 | Jimin Zhang | Systems and methods for performing acoustic hemostasis of deep bleeding trauma in limbs |
US8237335B2 (en) * | 2005-07-20 | 2012-08-07 | Ust, Inc. | Thermally enhanced ultrasound transducer means |
US8446071B2 (en) * | 2005-07-20 | 2013-05-21 | Ust, Inc. | Thermally enhanced ultrasound transducer system |
KR20080058402A (en) * | 2005-10-19 | 2008-06-25 | 코닌클리케 필립스 일렉트로닉스 엔.브이. | 2d ultrasound transducer for radial application and method |
US20070213616A1 (en) * | 2005-10-20 | 2007-09-13 | Thomas Anderson | Systems and methods for arteriotomy localization |
JP5630958B2 (en) | 2005-11-02 | 2014-11-26 | ビジュアルソニックス インコーポレイテッド | High frequency array ultrasound system |
US7599588B2 (en) | 2005-11-22 | 2009-10-06 | Vascular Imaging Corporation | Optical imaging probe connector |
US20070167826A1 (en) * | 2005-11-30 | 2007-07-19 | Warren Lee | Apparatuses for thermal management of actuated probes, such as catheter distal ends |
US20070167824A1 (en) * | 2005-11-30 | 2007-07-19 | Warren Lee | Method of manufacture of catheter tips, including mechanically scanning ultrasound probe catheter tip, and apparatus made by the method |
US20070167821A1 (en) * | 2005-11-30 | 2007-07-19 | Warren Lee | Rotatable transducer array for volumetric ultrasound |
US20070167825A1 (en) * | 2005-11-30 | 2007-07-19 | Warren Lee | Apparatus for catheter tips, including mechanically scanning ultrasound probe catheter tip |
US20070232921A1 (en) * | 2006-04-03 | 2007-10-04 | General Electric Company | Transducer assembly having a wide field of view |
EP2001359B1 (en) * | 2006-04-04 | 2018-06-27 | Volcano Corporation | Ultrasound catheter and hand-held device for manipulating a transducer on the catheter's distal end |
US8187189B2 (en) * | 2006-04-28 | 2012-05-29 | The Invention Science Fund I, Llc | Imaging via blood vessels |
US8442281B2 (en) | 2006-04-28 | 2013-05-14 | The Invention Science Fund I, Llc | Artificially displaying information relative to a body |
JP4351229B2 (en) * | 2006-06-28 | 2009-10-28 | ジーイー・メディカル・システムズ・グローバル・テクノロジー・カンパニー・エルエルシー | Manufacturing method of ultrasonic probe |
US9867530B2 (en) | 2006-08-14 | 2018-01-16 | Volcano Corporation | Telescopic side port catheter device with imaging system and method for accessing side branch occlusions |
US20080221448A1 (en) * | 2007-03-07 | 2008-09-11 | Khuri-Yakub Butrus T | Image-guided delivery of therapeutic tools duing minimally invasive surgeries and interventions |
US7557489B2 (en) | 2007-07-10 | 2009-07-07 | Siemens Medical Solutions Usa, Inc. | Embedded circuits on an ultrasound transducer and method of manufacture |
US9596993B2 (en) | 2007-07-12 | 2017-03-21 | Volcano Corporation | Automatic calibration systems and methods of use |
WO2009009799A1 (en) | 2007-07-12 | 2009-01-15 | Volcano Corporation | Catheter for in vivo imaging |
US10219780B2 (en) * | 2007-07-12 | 2019-03-05 | Volcano Corporation | OCT-IVUS catheter for concurrent luminal imaging |
US8702609B2 (en) * | 2007-07-27 | 2014-04-22 | Meridian Cardiovascular Systems, Inc. | Image-guided intravascular therapy catheters |
WO2009073753A1 (en) | 2007-12-03 | 2009-06-11 | Kolo Technologies, Inc. | Cmut packaging for ultrasound system |
US8517990B2 (en) | 2007-12-18 | 2013-08-27 | Hospira, Inc. | User interface improvements for medical devices |
US20090183350A1 (en) * | 2008-01-17 | 2009-07-23 | Wetsco, Inc. | Method for Ultrasound Probe Repair |
EP2114085A1 (en) | 2008-04-28 | 2009-11-04 | Nederlandse Centrale Organisatie Voor Toegepast Natuurwetenschappelijk Onderzoek TNO | Composite microphone, microphone assembly and method of manufacturing those |
US8140146B2 (en) * | 2008-05-30 | 2012-03-20 | General Electric Company | Catheter tip device and method for manufacturing same |
US8197413B2 (en) * | 2008-06-06 | 2012-06-12 | Boston Scientific Scimed, Inc. | Transducers, devices and systems containing the transducers, and methods of manufacture |
US7641480B1 (en) * | 2008-06-18 | 2010-01-05 | Volcano Corporation | Axial multi-wire barrel connector for interconnecting a controller console to catheter including a distally mounted ultrasound transducer assembly |
EP2345066B1 (en) * | 2008-09-18 | 2018-10-31 | FUJIFILM SonoSite, Inc. | Methods for manufacturing ultrasound transducers and other components |
US9184369B2 (en) | 2008-09-18 | 2015-11-10 | Fujifilm Sonosite, Inc. | Methods for manufacturing ultrasound transducers and other components |
US9173047B2 (en) | 2008-09-18 | 2015-10-27 | Fujifilm Sonosite, Inc. | Methods for manufacturing ultrasound transducers and other components |
US8257274B2 (en) * | 2008-09-25 | 2012-09-04 | Nellcor Puritan Bennett Llc | Medical sensor and technique for using the same |
US8364220B2 (en) | 2008-09-25 | 2013-01-29 | Covidien Lp | Medical sensor and technique for using the same |
US20100081904A1 (en) * | 2008-09-30 | 2010-04-01 | Nellcor Puritan Bennett Llc | Device And Method For Securing A Medical Sensor to An Infant's Head |
WO2010039950A1 (en) * | 2008-10-02 | 2010-04-08 | Eberle Michael J | Optical ultrasound receiver |
CA2778218A1 (en) | 2008-10-31 | 2010-05-06 | Vascular Imaging Corporation | Optical imaging probe connector |
JP5377957B2 (en) * | 2008-12-26 | 2013-12-25 | ジーイー・メディカル・システムズ・グローバル・テクノロジー・カンパニー・エルエルシー | Piezoelectric vibrator of ultrasonic probe, ultrasonic probe, ultrasonic diagnostic apparatus, and method of manufacturing piezoelectric vibrator in ultrasonic probe |
US9366938B1 (en) | 2009-02-17 | 2016-06-14 | Vescent Photonics, Inc. | Electro-optic beam deflector device |
JP5580994B2 (en) * | 2009-02-20 | 2014-08-27 | 日本オクラロ株式会社 | Optical module |
US8515515B2 (en) | 2009-03-25 | 2013-08-20 | Covidien Lp | Medical sensor with compressible light barrier and technique for using the same |
US8781548B2 (en) | 2009-03-31 | 2014-07-15 | Covidien Lp | Medical sensor with flexible components and technique for using the same |
US20100256502A1 (en) * | 2009-04-06 | 2010-10-07 | General Electric Company | Materials and processes for bonding acoustically neutral structures for use in ultrasound catheters |
WO2011014567A1 (en) | 2009-07-29 | 2011-02-03 | Imacor Inc. | Ultrasound imaging transducer acoustic stack with integral electrical connections |
US8986211B2 (en) | 2009-10-12 | 2015-03-24 | Kona Medical, Inc. | Energetic modulation of nerves |
US9174065B2 (en) | 2009-10-12 | 2015-11-03 | Kona Medical, Inc. | Energetic modulation of nerves |
US20110118600A1 (en) * | 2009-11-16 | 2011-05-19 | Michael Gertner | External Autonomic Modulation |
US20110092880A1 (en) * | 2009-10-12 | 2011-04-21 | Michael Gertner | Energetic modulation of nerves |
US20160059044A1 (en) | 2009-10-12 | 2016-03-03 | Kona Medical, Inc. | Energy delivery to intraparenchymal regions of the kidney to treat hypertension |
US8469904B2 (en) | 2009-10-12 | 2013-06-25 | Kona Medical, Inc. | Energetic modulation of nerves |
US8986231B2 (en) | 2009-10-12 | 2015-03-24 | Kona Medical, Inc. | Energetic modulation of nerves |
US8517962B2 (en) | 2009-10-12 | 2013-08-27 | Kona Medical, Inc. | Energetic modulation of nerves |
US8295912B2 (en) | 2009-10-12 | 2012-10-23 | Kona Medical, Inc. | Method and system to inhibit a function of a nerve traveling with an artery |
US9119951B2 (en) | 2009-10-12 | 2015-09-01 | Kona Medical, Inc. | Energetic modulation of nerves |
US9907534B2 (en) * | 2009-12-15 | 2018-03-06 | St. Jude Medical, Atrial Fibrillation Division, Inc. | Self-aiming directable acoustic transducer assembly for invasive medical device applications |
US20110255249A1 (en) * | 2010-04-20 | 2011-10-20 | General Electric Company | High density flexible foldable interconnect |
US8857269B2 (en) | 2010-08-05 | 2014-10-14 | Hospira, Inc. | Method of varying the flow rate of fluid from a medical pump and hybrid sensor system performing the same |
JP5826478B2 (en) * | 2010-10-28 | 2015-12-02 | 日立アロカメディカル株式会社 | Tissue insertion type ultrasonic probe |
IN2013CN03726A (en) | 2010-11-18 | 2015-08-07 | Koninkl Philips Electronics Nv | |
US11141063B2 (en) | 2010-12-23 | 2021-10-12 | Philips Image Guided Therapy Corporation | Integrated system architectures and methods of use |
US11040140B2 (en) | 2010-12-31 | 2021-06-22 | Philips Image Guided Therapy Corporation | Deep vein thrombosis therapeutic methods |
US9310485B2 (en) | 2011-05-12 | 2016-04-12 | Georgia Tech Research Corporation | Compact, energy-efficient ultrasound imaging probes using CMUT arrays with integrated electronics |
US9295447B2 (en) | 2011-08-17 | 2016-03-29 | Volcano Corporation | Systems and methods for identifying vascular borders |
AU2012299169B2 (en) | 2011-08-19 | 2017-08-24 | Icu Medical, Inc. | Systems and methods for a graphical interface including a graphical representation of medical data |
US9360630B2 (en) | 2011-08-31 | 2016-06-07 | Volcano Corporation | Optical-electrical rotary joint and methods of use |
US8936553B2 (en) | 2011-12-08 | 2015-01-20 | Volcano Corporation | Devices, systems, and methods for visualizing an occluded vessel |
US10022498B2 (en) | 2011-12-16 | 2018-07-17 | Icu Medical, Inc. | System for monitoring and delivering medication to a patient and method of using the same to minimize the risks associated with automated therapy |
US9995611B2 (en) | 2012-03-30 | 2018-06-12 | Icu Medical, Inc. | Air detection system and method for detecting air in a pump of an infusion system |
CA3088574C (en) | 2012-05-25 | 2023-01-17 | Phyzhon Health Inc. | Optical fiber pressure sensor |
ES2743160T3 (en) | 2012-07-31 | 2020-02-18 | Icu Medical Inc | Patient care system for critical medications |
JP6261581B2 (en) * | 2012-08-09 | 2018-01-17 | ダルハウジー ユニバーシティー | Ultrasound endoscope and manufacturing method thereof |
US9511393B2 (en) * | 2012-08-17 | 2016-12-06 | The Boeing Company | Flexible ultrasound inspection system |
WO2014055729A1 (en) | 2012-10-04 | 2014-04-10 | Vascular Imaging Corporatoin | Polarization scrambling for intra-body fiber optic sensor |
US9367965B2 (en) | 2012-10-05 | 2016-06-14 | Volcano Corporation | Systems and methods for generating images of tissue |
EP2904671B1 (en) | 2012-10-05 | 2022-05-04 | David Welford | Systems and methods for amplifying light |
US9292918B2 (en) | 2012-10-05 | 2016-03-22 | Volcano Corporation | Methods and systems for transforming luminal images |
US9324141B2 (en) | 2012-10-05 | 2016-04-26 | Volcano Corporation | Removal of A-scan streaking artifact |
US11272845B2 (en) | 2012-10-05 | 2022-03-15 | Philips Image Guided Therapy Corporation | System and method for instant and automatic border detection |
US9307926B2 (en) | 2012-10-05 | 2016-04-12 | Volcano Corporation | Automatic stent detection |
US10070827B2 (en) | 2012-10-05 | 2018-09-11 | Volcano Corporation | Automatic image playback |
US9858668B2 (en) | 2012-10-05 | 2018-01-02 | Volcano Corporation | Guidewire artifact removal in images |
US9286673B2 (en) | 2012-10-05 | 2016-03-15 | Volcano Corporation | Systems for correcting distortions in a medical image and methods of use thereof |
US10568586B2 (en) | 2012-10-05 | 2020-02-25 | Volcano Corporation | Systems for indicating parameters in an imaging data set and methods of use |
US9840734B2 (en) | 2012-10-22 | 2017-12-12 | Raindance Technologies, Inc. | Methods for analyzing DNA |
US9925354B2 (en) | 2012-10-24 | 2018-03-27 | Evergreen Medical Technologies, Inc. | Flex circuit ribbon based elongated members and attachments |
JP6205704B2 (en) * | 2012-10-25 | 2017-10-04 | セイコーエプソン株式会社 | Ultrasonic measuring device, head unit, probe and diagnostic device |
JP6186696B2 (en) * | 2012-10-25 | 2017-08-30 | セイコーエプソン株式会社 | Ultrasonic measuring device, head unit, probe and diagnostic device |
JP6322210B2 (en) | 2012-12-13 | 2018-05-09 | ボルケーノ コーポレイション | Devices, systems, and methods for targeted intubation |
CA2895770A1 (en) * | 2012-12-20 | 2014-07-24 | Jeremy Stigall | Locating intravascular images |
US10942022B2 (en) | 2012-12-20 | 2021-03-09 | Philips Image Guided Therapy Corporation | Manual calibration of imaging system |
US11406498B2 (en) | 2012-12-20 | 2022-08-09 | Philips Image Guided Therapy Corporation | Implant delivery system and implants |
EP2934310A4 (en) | 2012-12-20 | 2016-10-12 | Nathaniel J Kemp | Optical coherence tomography system that is reconfigurable between different imaging modes |
WO2014099899A1 (en) | 2012-12-20 | 2014-06-26 | Jeremy Stigall | Smooth transition catheters |
US10939826B2 (en) | 2012-12-20 | 2021-03-09 | Philips Image Guided Therapy Corporation | Aspirating and removing biological material |
CA2896006A1 (en) | 2012-12-21 | 2014-06-26 | David Welford | Systems and methods for narrowing a wavelength emission of light |
US9612105B2 (en) | 2012-12-21 | 2017-04-04 | Volcano Corporation | Polarization sensitive optical coherence tomography system |
EP2934653B1 (en) | 2012-12-21 | 2018-09-19 | Douglas Meyer | Rotational ultrasound imaging catheter with extended catheter body telescope |
WO2014100530A1 (en) | 2012-12-21 | 2014-06-26 | Whiseant Chester | System and method for catheter steering and operation |
EP2934280B1 (en) | 2012-12-21 | 2022-10-19 | Mai, Jerome | Ultrasound imaging with variable line density |
US10058284B2 (en) | 2012-12-21 | 2018-08-28 | Volcano Corporation | Simultaneous imaging, monitoring, and therapy |
CA2895940A1 (en) | 2012-12-21 | 2014-06-26 | Andrew Hancock | System and method for multipath processing of image signals |
US9486143B2 (en) | 2012-12-21 | 2016-11-08 | Volcano Corporation | Intravascular forward imaging device |
US9615878B2 (en) | 2012-12-21 | 2017-04-11 | Volcano Corporation | Device, system, and method for imaging and tissue characterization of ablated tissue |
WO2014099763A1 (en) | 2012-12-21 | 2014-06-26 | Jason Spencer | System and method for graphical processing of medical data |
WO2014100162A1 (en) | 2012-12-21 | 2014-06-26 | Kemp Nathaniel J | Power-efficient optical buffering using optical switch |
US10226597B2 (en) | 2013-03-07 | 2019-03-12 | Volcano Corporation | Guidewire with centering mechanism |
CN105103163A (en) | 2013-03-07 | 2015-11-25 | 火山公司 | Multimodal segmentation in intravascular images |
EP2967391A4 (en) | 2013-03-12 | 2016-11-02 | Donna Collins | Systems and methods for diagnosing coronary microvascular disease |
US11154313B2 (en) | 2013-03-12 | 2021-10-26 | The Volcano Corporation | Vibrating guidewire torquer and methods of use |
US20140275996A1 (en) * | 2013-03-12 | 2014-09-18 | Volcano Corporation | Systems and methods for constructing an image of a body structure |
US11026591B2 (en) | 2013-03-13 | 2021-06-08 | Philips Image Guided Therapy Corporation | Intravascular pressure sensor calibration |
US9301687B2 (en) | 2013-03-13 | 2016-04-05 | Volcano Corporation | System and method for OCT depth calibration |
EP2967488B1 (en) | 2013-03-13 | 2021-06-16 | Jinhyoung Park | System for producing an image from a rotational intravascular ultrasound device |
US10426590B2 (en) | 2013-03-14 | 2019-10-01 | Volcano Corporation | Filters with echogenic characteristics |
US10175421B2 (en) | 2013-03-14 | 2019-01-08 | Vascular Imaging Corporation | Optical fiber ribbon imaging guidewire and methods |
US10219887B2 (en) | 2013-03-14 | 2019-03-05 | Volcano Corporation | Filters with echogenic characteristics |
US10292677B2 (en) | 2013-03-14 | 2019-05-21 | Volcano Corporation | Endoluminal filter having enhanced echogenic properties |
US9592027B2 (en) | 2013-03-14 | 2017-03-14 | Volcano Corporation | System and method of adventitial tissue characterization |
WO2014190264A1 (en) | 2013-05-24 | 2014-11-27 | Hospira, Inc. | Multi-sensor infusion system for detecting air or an occlusion in the infusion system |
CA2913918C (en) | 2013-05-29 | 2022-02-15 | Hospira, Inc. | Infusion system and method of use which prevents over-saturation of an analog-to-digital converter |
AU2014274146B2 (en) | 2013-05-29 | 2019-01-24 | Icu Medical, Inc. | Infusion system which utilizes one or more sensors and additional information to make an air determination regarding the infusion system |
DE102013211596A1 (en) | 2013-06-20 | 2014-12-24 | Robert Bosch Gmbh | Method for electrically contacting a piezoceramic |
WO2015028311A1 (en) * | 2013-08-26 | 2015-03-05 | Koninklijke Philips N.V. | Ultrasound transducer assembly and method for manufacturing an ultrasound transducer assembly |
JP6221582B2 (en) * | 2013-09-30 | 2017-11-01 | セイコーエプソン株式会社 | Ultrasonic device and probe, electronic apparatus and ultrasonic imaging apparatus |
US10327645B2 (en) | 2013-10-04 | 2019-06-25 | Vascular Imaging Corporation | Imaging techniques using an imaging guidewire |
US10537255B2 (en) | 2013-11-21 | 2020-01-21 | Phyzhon Health Inc. | Optical fiber pressure sensor |
WO2015116944A1 (en) | 2014-01-30 | 2015-08-06 | Volcano Corporation | Devices and methods for treating fistulas |
EP3110474B1 (en) | 2014-02-28 | 2019-12-18 | ICU Medical, Inc. | Infusion system and method which utilizes dual wavelength optical air-in-line detection |
KR102205505B1 (en) * | 2014-03-04 | 2021-01-20 | 삼성메디슨 주식회사 | Method for manufacturing ultrasonic probe and ultrasonic probe |
WO2015164301A1 (en) * | 2014-04-23 | 2015-10-29 | Koninklijke Philips N.V. | Catheter with integrated controller for imaging and pressure sensing |
JP2017513643A (en) * | 2014-04-28 | 2017-06-01 | コーニンクレッカ フィリップス エヌ ヴェKoninklijke Philips N.V. | Pre-doped solid substrates for intravascular devices |
AU2015266706B2 (en) | 2014-05-29 | 2020-01-30 | Icu Medical, Inc. | Infusion system and pump with configurable closed loop delivery rate catch-up |
US10107645B2 (en) * | 2014-05-30 | 2018-10-23 | Fujifilm Dimatix, Inc. | Piezoelectric transducer device with flexible substrate |
US9789515B2 (en) | 2014-05-30 | 2017-10-17 | Fujifilm Dimatix, Inc. | Piezoelectric transducer device with lens structures |
US10022751B2 (en) | 2014-05-30 | 2018-07-17 | Fujifilm Dimatix, Inc. | Piezoelectric transducer device for configuring a sequence of operational modes |
WO2016009689A1 (en) | 2014-07-14 | 2016-01-21 | オリンパス株式会社 | Ultrasound observation device |
JP6400826B2 (en) | 2014-07-15 | 2018-10-03 | コーニンクレッカ フィリップス エヌ ヴェKoninklijke Philips N.V. | Device and method for intrahepatic shunt |
JP6670292B2 (en) * | 2014-07-17 | 2020-03-18 | コーニンクレッカ フィリップス エヌ ヴェKoninklijke Philips N.V. | Ultrasonic transducer assembly, ultrasonic probe and ultrasonic imaging system |
WO2016027198A1 (en) | 2014-08-21 | 2016-02-25 | Koninklijke Philips N.V. | Device and methods for crossing occlusions |
US10512449B2 (en) * | 2014-09-19 | 2019-12-24 | Volcano Corporation | Intravascular device for vessel measurement and associated systems, devices, and methods |
US10925579B2 (en) | 2014-11-05 | 2021-02-23 | Otsuka Medical Devices Co., Ltd. | Systems and methods for real-time tracking of a target tissue using imaging before and during therapy delivery |
US10258240B1 (en) | 2014-11-24 | 2019-04-16 | Vascular Imaging Corporation | Optical fiber pressure sensor |
US11344668B2 (en) | 2014-12-19 | 2022-05-31 | Icu Medical, Inc. | Infusion system with concurrent TPN/insulin infusion |
WO2016130713A1 (en) | 2015-02-10 | 2016-08-18 | Cathprint Ab | Low profile medical device with integrated flexible circuit and methods of making the same |
US20160228061A1 (en) * | 2015-02-10 | 2016-08-11 | Cathprint Ab | Low profile medical device with integrated flexible circuit and methods of making the same |
US20160270732A1 (en) * | 2015-03-17 | 2016-09-22 | Cathprint Ab | Low profile medical device with bonded base for electrical components |
US10850024B2 (en) | 2015-03-02 | 2020-12-01 | Icu Medical, Inc. | Infusion system, device, and method having advanced infusion features |
JP6960860B2 (en) | 2015-06-24 | 2021-11-05 | コーニンクレッカ フィリップス エヌ ヴェKoninklijke Philips N.V. | Transducer transfer stack |
JP6526925B2 (en) | 2016-03-30 | 2019-06-05 | コーニンクレッカ フィリップス エヌ ヴェKoninklijke Philips N.V. | Imaging assembly for intravascular imaging device and related devices, systems and methods |
JP6998317B2 (en) * | 2016-03-30 | 2022-01-18 | コーニンクレッカ フィリップス エヌ ヴェ | Conductive Support Members and Related Devices, Systems and Methods for Intravascular Imaging Devices |
EP3435880B1 (en) * | 2016-03-30 | 2020-08-19 | Koninklijke Philips N.V. | Flexible support member for intravascular imaging device and associated devices, systems, and methods |
AU2017264784B2 (en) | 2016-05-13 | 2022-04-21 | Icu Medical, Inc. | Infusion pump system and method with common line auto flush |
US20190090856A1 (en) | 2016-05-20 | 2019-03-28 | Koninklijke Philips N.V. | Devices and methods for stratification of patients for renal denervation based on intravascular pressure and cross-sectional lumen measurements |
EP3468635A4 (en) | 2016-06-10 | 2019-11-20 | ICU Medical, Inc. | Acoustic flow sensor for continuous medication flow measurements and feedback control of infusion |
WO2018060369A1 (en) * | 2016-09-29 | 2018-04-05 | Koninklijke Philips N.V. | Flexible imaging assembly for intraluminal imaging and associated devices, systems, and methods |
US20210282742A1 (en) * | 2016-09-29 | 2021-09-16 | Koninklijke Philips N.V. | Electrical grounding for imaging assembly and associated intraluminal devices, systems, and methods |
EP3600699B1 (en) * | 2017-03-31 | 2021-06-09 | Koninklijke Philips N.V. | Annular integrated circuit controller for intraluminal ultrasound imaging device |
US10188368B2 (en) | 2017-06-26 | 2019-01-29 | Andreas Hadjicostis | Image guided intravascular therapy catheter utilizing a thin chip multiplexor |
US11109909B1 (en) | 2017-06-26 | 2021-09-07 | Andreas Hadjicostis | Image guided intravascular therapy catheter utilizing a thin ablation electrode |
US10492760B2 (en) | 2017-06-26 | 2019-12-03 | Andreas Hadjicostis | Image guided intravascular therapy catheter utilizing a thin chip multiplexor |
CN111212606B (en) * | 2017-08-15 | 2024-03-01 | 皇家飞利浦有限公司 | Frequency tunable intravascular ultrasound device |
US11883235B2 (en) * | 2017-08-15 | 2024-01-30 | Philips Image Guided Therapy Corporation | Phased array imaging and therapy intraluminal ultrasound device |
JP6999350B2 (en) * | 2017-10-05 | 2022-01-18 | 株式会社ディスコ | Package substrate processing method |
CN107736900A (en) * | 2017-11-09 | 2018-02-27 | 深圳先进技术研究院 | A kind of dual transducers intravascular ultrasound imaging device |
US10089055B1 (en) | 2017-12-27 | 2018-10-02 | Icu Medical, Inc. | Synchronized display of screen content on networked devices |
EP4275609A2 (en) | 2018-03-15 | 2023-11-15 | Koninklijke Philips N.V. | Variable intraluminal ultrasound transmit pulse generation and control devices, systems, and methods |
CN110553676B (en) * | 2018-05-30 | 2022-02-01 | 南昌欧菲显示科技有限公司 | Sensor with a sensor element |
WO2020002061A1 (en) | 2018-06-27 | 2020-01-02 | Koninklijke Philips N.V. | Dynamic resource reconfiguration for patient interface module (pim) in intraluminal medical ultrasound imaging |
US20210345989A1 (en) | 2018-10-04 | 2021-11-11 | Koninklijke Philips N.V. | Fluid flow detection for ultrasound imaging devices, systems, and methods |
US20220061805A1 (en) * | 2019-01-07 | 2022-03-03 | Koninklijke Philips N.V. | Increased flexibility substrate for intraluminal ultrasound imaging assembly |
CN113924045A (en) * | 2019-03-25 | 2022-01-11 | 艾科索成像公司 | Hand-held ultrasonic imager |
WO2021069216A1 (en) | 2019-10-10 | 2021-04-15 | Koninklijke Philips N.V. | Vascular tissue characterization devices, systems, and methods |
EP3824817A1 (en) | 2019-11-22 | 2021-05-26 | Cairdac | Catheter with ultrasound imaging sensors |
US11278671B2 (en) | 2019-12-04 | 2022-03-22 | Icu Medical, Inc. | Infusion pump with safety sequence keypad |
WO2022020184A1 (en) | 2020-07-21 | 2022-01-27 | Icu Medical, Inc. | Fluid transfer devices and methods of use |
US11135360B1 (en) | 2020-12-07 | 2021-10-05 | Icu Medical, Inc. | Concurrent infusion with common line auto flush |
Family Cites Families (68)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2173115B1 (en) * | 1972-02-22 | 1977-09-02 | Univ Erasmus | |
US3938502A (en) * | 1972-02-22 | 1976-02-17 | Nicolaas Bom | Apparatus with a catheter for examining hollow organs or bodies with the ultrasonic waves |
JPS5918051B2 (en) * | 1976-02-29 | 1984-04-25 | 三菱油化株式会社 | catheter |
JPS54149615A (en) * | 1978-05-17 | 1979-11-24 | Oki Electric Ind Co Ltd | Production of ultrasonic oscillator of curved arrangement type |
US4211949A (en) * | 1978-11-08 | 1980-07-08 | General Electric Company | Wear plate for piezoelectric ultrasonic transducer arrays |
US4456013A (en) * | 1981-09-08 | 1984-06-26 | Brown University Research Foundation | Catheter |
JPS58118739A (en) * | 1982-01-05 | 1983-07-14 | テルモ株式会社 | Ultasonic probe and production thereof |
US4582067A (en) * | 1983-02-14 | 1986-04-15 | Washington Research Foundation | Method for endoscopic blood flow detection by the use of ultrasonic energy |
US4576177A (en) * | 1983-02-18 | 1986-03-18 | Webster Wilton W Jr | Catheter for removing arteriosclerotic plaque |
US4645961A (en) * | 1983-04-05 | 1987-02-24 | The Charles Stark Draper Laboratory, Inc. | Dynamoelectric machine having a large magnetic gap and flexible printed circuit phase winding |
EP0145429B1 (en) * | 1983-12-08 | 1992-02-26 | Kabushiki Kaisha Toshiba | Curvilinear array of ultrasonic transducers |
JPS60140153A (en) * | 1983-12-28 | 1985-07-25 | Toshiba Corp | Preparation of ultrasonic probe |
JPS61161446A (en) * | 1985-01-10 | 1986-07-22 | Terumo Corp | Ultrasonic wave probe and its production |
JPS61180560A (en) * | 1985-02-01 | 1986-08-13 | Kangiyou Denki Kiki Kk | Dc brushless micromotor |
US4728834A (en) * | 1985-05-28 | 1988-03-01 | Autotech Corporation | Compact digital resolver/encoder assembly with flexible circuit board |
US4665925A (en) * | 1985-09-13 | 1987-05-19 | Pfizer Hospital Products Group, Inc. | Doppler catheter |
US4794931A (en) * | 1986-02-28 | 1989-01-03 | Cardiovascular Imaging Systems, Inc. | Catheter apparatus, system and method for intravascular two-dimensional ultrasonography |
US4821731A (en) * | 1986-04-25 | 1989-04-18 | Intra-Sonix, Inc. | Acoustic image system and method |
FR2607591B1 (en) * | 1986-11-28 | 1989-12-08 | Thomson Cgr | CURVED BAR PROBE FOR ECHOGRAPH |
US4841977A (en) * | 1987-05-26 | 1989-06-27 | Inter Therapy, Inc. | Ultra-thin acoustic transducer and balloon catheter using same in imaging array subassembly |
GB2208138B (en) * | 1987-06-19 | 1991-08-07 | Circulation Res Ltd | Tubular probe |
US4917097A (en) * | 1987-10-27 | 1990-04-17 | Endosonics Corporation | Apparatus and method for imaging small cavities |
GB2212267B (en) * | 1987-11-11 | 1992-07-29 | Circulation Res Ltd | Methods and apparatus for the examination and treatment of internal organs |
US4951677A (en) * | 1988-03-21 | 1990-08-28 | Prutech Research And Development Partnership Ii | Acoustic imaging catheter and the like |
JP2502685B2 (en) * | 1988-06-15 | 1996-05-29 | 松下電器産業株式会社 | Ultrasonic probe manufacturing method |
US4975607A (en) * | 1988-07-11 | 1990-12-04 | Kabushiki Kaisha Sankyo Seiki Seisakusho | Frequency generator with superimposed generation coil |
US5046503A (en) * | 1989-04-26 | 1991-09-10 | Advanced Cardiovascular Systems, Inc. | Angioplasty autoperfusion catheter flow measurement method and apparatus |
GB2233094B (en) * | 1989-05-26 | 1994-02-09 | Circulation Res Ltd | Methods and apparatus for the examination and treatment of internal organs |
US5240003A (en) * | 1989-10-16 | 1993-08-31 | Du-Med B.V. | Ultrasonic instrument with a micro motor having stator coils on a flexible circuit board |
NL8902559A (en) * | 1989-10-16 | 1991-05-16 | Du Med Bv | INTRA-LUMINAL DEVICE. |
US5418691A (en) * | 1990-02-07 | 1995-05-23 | Canon Kabushiki Kaisha | Two printed circuit boards superiposed on one another both having position registry marks |
US5117831A (en) * | 1990-03-28 | 1992-06-02 | Cardiovascular Imaging Systems, Inc. | Vascular catheter having tandem imaging and dilatation components |
JPH03280939A (en) * | 1990-03-29 | 1991-12-11 | Fujitsu Ltd | Ultrasonic probe |
US5044053A (en) * | 1990-05-21 | 1991-09-03 | Acoustic Imaging Technologies Corporation | Method of manufacturing a curved array ultrasonic transducer assembly |
NL9001755A (en) * | 1990-08-02 | 1992-03-02 | Optische Ind De Oude Delft Nv | ENDOSCOPIC SCANNER. |
US5167233A (en) | 1991-01-07 | 1992-12-01 | Endosonics Corporation | Dilating and imaging apparatus |
US5243988A (en) * | 1991-03-13 | 1993-09-14 | Scimed Life Systems, Inc. | Intravascular imaging apparatus and methods for use and manufacture |
JPH06292669A (en) * | 1991-04-17 | 1994-10-21 | Hewlett Packard Co <Hp> | Ultrasonic probe |
JPH04347147A (en) * | 1991-05-23 | 1992-12-02 | Fujitsu Ltd | Ultrasonic diagnostic apparatus |
US5183048A (en) * | 1991-06-24 | 1993-02-02 | Endosonics Corporation | Method and apparatus for removing artifacts from an ultrasonically generated image of a small cavity |
GB2258364A (en) * | 1991-07-30 | 1993-02-03 | Intravascular Res Ltd | Ultrasonic tranducer |
US5199437A (en) * | 1991-09-09 | 1993-04-06 | Sensor Electronics, Inc. | Ultrasonic imager |
JPH0685341B2 (en) * | 1991-09-27 | 1994-10-26 | 帝国通信工業株式会社 | Flexible board terminal structure |
US5186177A (en) * | 1991-12-05 | 1993-02-16 | General Electric Company | Method and apparatus for applying synthetic aperture focusing techniques to a catheter based system for high frequency ultrasound imaging of small vessels |
GB2263974B (en) * | 1992-01-30 | 1995-11-08 | Intravascular Res Ltd | Ultrasound imaging and catheters for use therein |
JPH05259604A (en) * | 1992-03-16 | 1993-10-08 | Murata Mfg Co Ltd | Electronic circuit board and manufacture thereof |
JPH05335821A (en) * | 1992-05-28 | 1993-12-17 | Tdk Corp | Dielectric resonator and its manufacture |
JPH06131919A (en) * | 1992-10-19 | 1994-05-13 | Murata Mfg Co Ltd | Flexible wiring cable |
US5423220A (en) * | 1993-01-29 | 1995-06-13 | Parallel Design | Ultrasonic transducer array and manufacturing method thereof |
US5368037A (en) * | 1993-02-01 | 1994-11-29 | Endosonics Corporation | Ultrasound catheter |
US5453575A (en) * | 1993-02-01 | 1995-09-26 | Endosonics Corporation | Apparatus and method for detecting blood flow in intravascular ultrasonic imaging |
JP3399474B2 (en) * | 1993-03-30 | 2003-04-21 | 株式会社村田製作所 | Electronic component manufacturing method |
US5375321A (en) * | 1993-03-30 | 1994-12-27 | United States Department Of Energy | Method for fabricating fan-fold shielded electrical leads |
US5359760A (en) * | 1993-04-16 | 1994-11-01 | The Curators Of The University Of Missouri On Behalf Of The University Of Missouri-Rolla | Method of manufacture of multiple-element piezoelectric transducer |
JP2630241B2 (en) * | 1993-06-17 | 1997-07-16 | 日本電気株式会社 | Electronics |
KR970003448B1 (en) * | 1993-07-21 | 1997-03-18 | 대우전자 주식회사 | An optical path regulating apparatus and an manufacturing method |
DE4427798C2 (en) * | 1993-08-06 | 1998-04-09 | Toshiba Kawasaki Kk | Piezoelectric single crystal and its use in an ultrasonic probe and ultrasonic array probe |
US5403202A (en) * | 1993-10-07 | 1995-04-04 | Hewlett-Packard Company | Low insertion force/low profile flex connector |
US5402793A (en) * | 1993-11-19 | 1995-04-04 | Advanced Technology Laboratories, Inc. | Ultrasonic transesophageal probe for the imaging and diagnosis of multiple scan planes |
JP3162584B2 (en) * | 1994-02-14 | 2001-05-08 | 日本碍子株式会社 | Piezoelectric / electrostrictive film element and method of manufacturing the same |
DE69516444T2 (en) * | 1994-03-11 | 2001-01-04 | Intravascular Res Ltd | Ultrasonic transducer arrangement and method for its production |
US5467779A (en) * | 1994-07-18 | 1995-11-21 | General Electric Company | Multiplanar probe for ultrasonic imaging |
US5493541A (en) * | 1994-12-30 | 1996-02-20 | General Electric Company | Ultrasonic transducer array having laser-drilled vias for electrical connection of electrodes |
US5655276A (en) * | 1995-02-06 | 1997-08-12 | General Electric Company | Method of manufacturing two-dimensional array ultrasonic transducers |
US5651365A (en) * | 1995-06-07 | 1997-07-29 | Acuson Corporation | Phased array transducer design and method for manufacture thereof |
US5655538A (en) * | 1995-06-19 | 1997-08-12 | General Electric Company | Ultrasonic phased array transducer with an ultralow impedance backfill and a method for making |
US7226417B1 (en) | 1995-12-26 | 2007-06-05 | Volcano Corporation | High resolution intravascular ultrasound transducer assembly having a flexible substrate |
US5857974A (en) * | 1997-01-08 | 1999-01-12 | Endosonics Corporation | High resolution intravascular ultrasound transducer assembly having a flexible substrate |
-
1997
- 1997-01-08 US US08/780,437 patent/US5857974A/en not_active Expired - Lifetime
- 1997-11-19 US US08/974,677 patent/US6049958A/en not_active Expired - Lifetime
- 1997-12-31 CA CA002226194A patent/CA2226194A1/en not_active Abandoned
-
1998
- 1998-01-07 EP EP98200020A patent/EP0853919B1/en not_active Expired - Lifetime
- 1998-01-07 AT AT98200020T patent/ATE538879T1/en active
- 1998-01-08 JP JP10002577A patent/JPH10192281A/en active Pending
-
2000
- 2000-04-17 US US09/550,864 patent/US6618916B1/en not_active Expired - Lifetime
-
2003
- 2003-09-12 US US10/661,269 patent/US6899682B2/en not_active Expired - Lifetime
-
2005
- 2005-05-02 US US11/120,257 patent/US20050197574A1/en not_active Abandoned
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2014083283A (en) * | 2012-10-25 | 2014-05-12 | Seiko Epson Corp | Ultrasonic measuring device, head unit, probe, and diagnostic system |
CN108618805A (en) * | 2017-03-22 | 2018-10-09 | 精工爱普生株式会社 | Ultrasonic device unit, ultrasonic probe and ultrasonic unit |
Also Published As
Publication number | Publication date |
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US20050197574A1 (en) | 2005-09-08 |
US6049958A (en) | 2000-04-18 |
US5857974A (en) | 1999-01-12 |
US6899682B2 (en) | 2005-05-31 |
JPH10192281A (en) | 1998-07-28 |
EP0853919A3 (en) | 2001-05-09 |
US20040054289A1 (en) | 2004-03-18 |
ATE538879T1 (en) | 2012-01-15 |
US6618916B1 (en) | 2003-09-16 |
EP0853919A2 (en) | 1998-07-22 |
EP0853919B1 (en) | 2011-12-28 |
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