DE10356315B4 - Endoscopes with balloon attachment and their manufacture - Google Patents

Abstract

endoscope (100) with an outer shell (7), at least one distal region of the endoscope (100) light afferent Element (18), at least one for transmitting image information an object in the distal region suitable element (20), at least one gas or liquid-conducting Element (13) and a balloon attachment (14a, 14b) in the distal region with an inflatable, transparent balloon element (6), characterized that the balloon attachment (14a, 14b) in the distal region at least a plate-shaped Holder (1) with at least one hole (5) passing through the holder (1) having at least two opposite flat sides of disc-shaped Holders (1), which are interspersed by at least one hole (5), as surfaces are configured and as at least one plate-shaped holder (1) one or more such are used, in which or each one a balloon element (6) on only one flat side of the plate-shaped holder (1) the hole (s) (5) overlapping applied and so as just this flat side of the holder whole or partially covering stretchy Layer applied ...

Description

The The invention relates to an endoscope having an outer shell, at least one distal Area of the endoscope light-feeding Element, at least one for transmission suitable for image information of an object in the distal region Element, at least one gas or liquid-conducting element and a balloon attachment in the distal region with an expandable, transparent balloon element and method for its production.

diseases the vessels and the Heart belong the main causes of death or disability. A main focus in at The diagnosis and treatment of these diseases is directed minimally invasive surgical methods, such as the dilation narrowed Vessels with balloon endoscopes or the removal of intraluminal deposits, for example with Lasers. This requires suitable methods for the representation of Inside of the vascular system. Main problem here, as well as in applications with liquids in other cavities, like Heart, digestive tract or joint space, is the very strong absorption and / or scattering of UV, IR and in particular visible light in liquids with appropriate electromagnetic waves absorbing and / or especially scattering (clouding) Components, such as red blood cells in Blood or leukocytes in inflammatory Synovial fluid, so the use of ordinary optical endoscopes (use of visible light) is impossible because not big enough Field of view can be realized.

The Today's standard methods for displaying the vascular system, Radiography is unsuitable for direct examination of the vessel surface.

A Series of endoscopes for introduction into cavities containing with (particularly hindering) scattering components and / or IR, UV and / or visible light-absorbing liquids filled are but are known.

Thus, endoscopes with an ultrasound transmitting and receiving unit are proposed for image acquisition, as in US 3,938,502 or US 4,917,097 described. The low resolution can be improved by using higher frequencies, which in turn reduces the penetration depth of the waves and thus the visibility. This requires integration of the transmit and receive modules as well as the signal processing in the catheter tip, which in turn increases endoscope size. The limited number of ultrasound transducers in the catheter tip and a useful signal strength near the noise limit also make it difficult to produce a sharp image.

Another method utilizes the irradiation of turbid fluids such as blood with infrared rays less scattered in red blood cells as the wavelength increases (eg US 6,178,346 B1 round US 6,529,770 B1 ) Described. However, the absorption of water in the IR range requires strong light sources. Therefore, wavelengths are used in which the absorption spectrum has local minima. Tissue damage is avoided by pulsed laser sources with very short pulses. Despite advantages (no fluid channels, no blocking of blood vessels), there is still no marketable product. The development costs of suitable light sources and detectors are high.

In particular, the use of intravascular endoscopes with white light sources, however, requires a temporary displacement of blood from the area in front of the optical fiber bundle end. This can be done by administering optically transparent liquids. However, in order to maintain the field of view for a long time, liquid must be constantly replenished via fluid channels in the endoscope, for example physiological saline solution (cf. US 4,204,528 or US 4,576,146 ) or fluorocarbon-based liquids such as perftorane (see WO 02/34297 A2). To increase the residence time of transparent liquids beat US 4,681,093 and US 6,522,913 B2 to eliminate the blood flow by inflating one or more balloons in the area of interest and / or quasi clamp the endoscopes there. A use of transparent balloons to increase the field of view by displacing the cloudy liquids is here and in the DE 284 84 84 A1 as in US 3,690,769 and DE 37 90 493 C2 (the latter with additional distal protective foil), the balloons being secured by means of sections and adhesive or tying means which are cylindrically pushed over other parts of the endoscope. Particularly suitable are such balloon endoscopes for examinations of the inner heart wall, since a complete suppression of blood flow is not necessary here. The inflatable balloon is placed in front of the end of the optical fibers and completely encloses them. After dilation, the balloon attaches to the heart wall and the area between the fiber end and heart wall is kept free of blood. However, the production of the corresponding endoscopes from many individual components is expensive. Moreover, although the dimensions and fluid expense of such endoscopes are advantageous over those described in the last paragraph, the resulting endoscopes are still relatively large, which reduces patient compliance and makes it difficult for the surgeon to handle and, for example, angiography even in narrower blood vessels reduced. Also, they are not very well suited for industrial production in large numbers, since their production requires a wealth of mechanical, chemical and / or physical steps and parallel production of multiple endoscopes is difficult, which can lead to quality variations.

task Therefore, the present invention is simple and particularly easy and / or in big Number and with consistently high quality producible and small dimensionable Endoscopes available to put, which also with dyed or especially cloudy liquids optical investigations in the field of ultraviolet, infrared or above all to make visible light possible and also more avoid the above-mentioned disadvantages of the prior art. For the rest, should inexpensive Manufacturability and ease of use are possible.

The Invention relates in this context to the abovementioned endoscopes, which are characterized in that the balloon attachment in the distal Area at least one plate-shaped holder with at least a hole passing through the holder, wherein at least two opposing Flat sides of the plate-shaped Halters, which are interspersed by at least one hole, designed as surfaces are and as at least one plate-shaped holder one or more those are used in which or at each of which a balloon element on one side of the holder covering the hole or holes and so only one Side of the holder completely or partially covering the stretchable layer is applied.

• a) in ein Substrat zur Herstellung mindestens eines entsprechenden plattenförmigen Haltes ein oder mehrere durchgehende Löcher eingebracht werden und das Material für mindestens ein transparentes, aufweitbares Ballonelement auf nur einer Seite des Substrates für den plattenförmigen Halter, die der Flach-Seite des plattenförmigen Halters entspricht, das oder die Löcher überdeckend aufgebracht wird oder (vorzugsweise)
• b) ein Material für ein transparentes, aufweitbares Ballonelement auf nur einer Seite des Substrates für mindestens einen entsprechenden plattenförmigen Halter, die der Flach-Seite des plattenförmigen Halters entspricht, das oder die Löcher überdeckend aufgebracht wird und anschließend ein oder mehrere bis zum genannten transparenten, aufweitbaren Ballonelement reichende Löcher auf dem Substrat für den plattenförmigen Halter eingebracht oder schon bestehende Vertiefungen zu bis zum Ballonelement durchgehenden Löchern vervollständigt werden;

und jeweils anschließend ein oder mehrere der so mit mindestens einem transparenten, aufweitbaren Ballonelement versehenen plattenförmigen Halter, erforderlichenfalls nach Vereinzelung, mit weiteren Bauteilen zu einem Ballonaufsatz vervollständigt und am distalen Ende des Endoskops befestigt werden.The invention also relates to a manufacturing method for such an endoscope according to the invention with a balloon attachment, which has one or more plate-shaped holders, each with at least one hole passing through the holder, wherein

• a) one or more through holes are introduced into a substrate for producing at least one corresponding plate-shaped support, and the material for at least one transparent inflatable balloon element on only one side of the substrate for the plate-shaped holder, which corresponds to the flat side of the plate-shaped holder, the cover or holes is applied overlapping or (preferably)
• b) a material for a transparent expandable balloon element on only one side of the substrate for at least one corresponding plate-shaped holder which corresponds to the flat side of the plate-shaped holder, which is applied overlapping the holes and then one or more transparent, expandable balloon element reaching holes on the substrate for the plate-shaped holder introduced or already existing wells to be completed to the balloon element through holes;

and then one or more of the thus provided with at least one transparent, expandable balloon element plate-shaped holder, if necessary, after isolation, completed with other components to a balloon attachment and attached to the distal end of the endoscope.

These embodiments enable the simple production of balloon attachments for fiber endoscopes with very small Dimensions, as that covering the holes Balloon element, made of transparent, elastic material to balloons can be expanded, for example, to microballoons, preferably as small as 1 to 2 mm, in particular 1.5 to 2 mm, but also larger, for example to to 5 mm, can be. The possible parallel manufacturing process of a variety of balloon elements, in particular through the use of microsystem technology is greatly simplified a consistently high quality and simple production. Due to the simultaneous manufacturability of many such balloon elements are the cost of the individual balloon attachment low. Thus, the ones used in the endoscopes according to the invention are suitable balloon essays for use as a disposable tool, resulting in a complex preparation (Sterilization, for example by autoclaving or chemical treatment) can be omitted, and there are very small endoscope diameter possible, what again very small cavities (e.g., narrow blood vessels).

The invention also allows the use of the endoscopes according to the invention for the examination of cavities in objects or living beings, in particular in the body of animals or humans, for example in angioscopy, cardioscopy or arthroscopy, characterized in that the endoscopes are inserted into the cavity in question, the transparent elastic balloon element is expanded by means of gas or liquid supply for the displacement of absorbing or in particular scattering liquids and, if necessary, examined under light supply areas within the cavity in the infrared, ultraviolet or in particular visible light. The invention involves the use of plate-shaped holders (in particular as described below) with at least one hole passing through the holder, to which at least one balloon element on one side of the holder covering the hole (s) is applied on only one side of the holder for manufacture of balloon attachments for endoscopes.

Especially It is advantageous if the balloon element by a in the Balloon element initiated by the gas or liquid-conducting element Medium like gas or liquid is expandable. As a result, the balloon element can be practically inflated be by the pressure within the balloon element on the Pressure in the external environment of the Balloon element increases becomes.

At the Applying the balloon element on the plate-shaped holder is - especially because of the ease of manufacture - part of the invention, that the balloon element as one the one side of the holder completely or partially covering stretchy Layer is formed. Such layers are in different Thickness or strength can be applied quickly and in particular with constant thickness or thickness.

there For example, the layer forming the balloon element can be placed directly on the plate-shaped holder be applied or it may vary depending on the material combination used be advantageous when between the holder and the balloon element layer an adhesive layer is provided. Through this additional Adhesive layer can increase the adhesion between the holder and the balloon element elevated become. However, it is particularly advantageous because of the so on simplified production and structure of the endoscope, if none additional Adhesive layer is present.

A advantageous embodiment the balloon attachment provides that the plate-shaped holder transversely to the longitudinal axis of the endoscope is arranged and that the distal area of the Endoscope side facing away from the holder wearing the balloon element layer and that the balloon element is transparent at least on expansion to a balloon. In this way it is possible Objects or areas in the longitudinal direction before the distal end of the endoscope with the help of the image-transmitting Receive elements and by means of a to the image-transmitting Play elements connected observation unit. there repressed the expanded balloon present, wholly or partially opaque Media such as liquids around the area to be imaged, thus allowing the view to this area. The opaque or used for illustration Radiation absorbing and / or scattering components in liquids in the first case electromagnetic waves are in the range of the IR, UV or especially visible light absorbing components, such as dyes, in the second primarily opacifying (e.g., corpuscular or droplet-shaped) components, like cells or cell parts (e.g., red blood cells), emulsion droplets or the like, in the common case both.

Is appropriate it if the balloon element at least for part of the (visible) Light spectrum is transparent. Transparent means that the balloon element and / or its material at least in the balloon expanded state for UV, IR or visible light of the desired wavelength is transparent, without the desired Image too much to scatter or distort. For those not used for picture Parts of the spectrum may make the balloon element opaque. Through the transparent balloon element can thus be Areas outside the balloon element, for example objects on which the balloon element rests, with the help of image-transmitting Imaging elements, wherein the medium within the balloon element also for the part of the light spectrum used for imaging is transparent.

For the easy Applying and good adhesion of the balloon element on the plate-shaped holder it is a constituent of the invention that at least two opposite Flat sides of the plate-shaped Halters, which are penetrated by at least one hole, as preferred (in particular parallel to each other) plane surfaces designed are. On such flat surfaces can be particularly apply well layers by methods such as knife or spin coating, these layers are comparatively simple in uniform thickness or strength can be applied. By overstretching the hole in the plate-shaped Holder through the flexible layer of the balloon element is characterized a movable membrane formed in this area.

Advantageous it is when at or before the distal end of the image transmitting Elements a lens, preferably a wide-angle lens, which in particular is designed as gradient index lens, attached or in the image-transmitting Element is integrated. Such a lens can change or improve the image information serve, then through the image-transmitting elements is transmitted to an observation unit. In particular, a reduction, enlargement and / or Ver- or equalization the image information is possible.

For a particularly space-saving design, in particular for a small diameter of the endoscope, it is expedient if the image-transmitting element and the light-guiding elements in the distal region of the endoscope directly adjacent, in particular in the form of a common optical fiber bundle, preferably the light-guiding elements concentric around the Image-transmitting element are arranged, and when preferably a lens at the common distal end of the image-transmitting member and the light-guiding elements is arranged. As a result, the area to be imaged can be illuminated particularly effectively and in particular with little shadow, since the light is radiated very close to the location of the objective, and thus the shadows generated by the light in the thus-illuminated area do not appear or appear only very slightly in the recorded image. The optical fiber bundle can be displaceable in the longitudinal direction within the endoscope, in order in particular to be able to change the distance of the distal end of the fiber bundle with the objective to the region to be imaged.

A another embodiment the balloon attachment according to the invention provides that the plate-shaped Holder parallel to the longitudinal axis At the distal end of the endoscope is arranged that the balloon element on the plate-shaped Holder applied to the outside relative to the endoscope side is and that a reflection element is provided, which for reflection or coupling an image of the object into the distal end of the image-transmitting Element, in particular in a lens at or before this end, and / or for reflection of light from the light-supplying Elements of the endoscope in the area of the object to be imaged is trained. With the help of such a attached balloon attachment can also images of objects or areas to the side of distal end of the endoscope, so for example along the Endoscope extending vessel walls of a Blood vessel, in which introduced the endoscope is, recorded or viewed.

to Illustration of two different areas, which are in the longitudinal direction located next to the distal end of the endoscope, it is beneficial if the balloon attachment at least two plate-shaped holder, each with a Hole and each having a balloon element, if the two holders opposite arranged at the distal end and parallel to the longitudinal axis of the endoscope and if the reflective element is the distal end of the endoscope longitudinal opposite is arranged. Thereby can for example, two opposite ones Areas of a vessel wall or at a rotation of the endoscope about the longitudinal axis also piecewise successively an annular area imaged in a container become. The image of the two areas is thereby through the reflection element to the distal end of the image-transferring element or its lens reflected back.

For that, the Balloon essay expediently be formed so that the reflection element on or on a Middle part is arranged, which between the plate-shaped holders arranged and from these outside is acted upon, that at least one side of the middle part is a continuous receiving opening which has the light-supplying and image transmitting Is facing elements and that of this receiving opening opposite Region of the central part is designed as a reflection element, which two bevelled, the light-conducting and image-transmitting Having elements facing reflective surfaces, the side by side are arranged to make an angle greater than 180 ° (preferably from the not the material of the middle part facing side of the reflective surfaces from). Through the opening in the Middle part can on the one hand, the light-supplying and image transfer Elements led or penetrate the image information and / or the supplied light. On the other hand, through this opening also flow the medium required to expand the balloon elements. The Reflection surfaces are designed so that the incident rays approximately perpendicular to the endoscope longitudinal axis (for example, at an angle of 90 ° to 120 °, for example, about 110 °), that is, from / to distal end of the fiber bundle from light-supplying and image transmitting Elements and from / to be imaged area through the hole in the plate-shaped holder be deflected, the reflective surfaces preferably preferably level are. Possible for special arrangements of the two balloon elements or the areas to be imaged is that the reflection element may have asymmetrically arranged reflection surfaces or that the reflection surfaces a curved one surface have the image of the area to be imaged when redirecting enlarge or shrink or otherwise distort or equalize. The (in the preferred embodiment roof-shaped) Arrangement of two reflection surfaces can also be designed such that in the region of the roof edge an opening is provided by the addition a limited area in the longitudinal direction in front of the distal end of the endoscope without deflection by the lens can be included. Preferably, the middle part is in shape a rectangular, open on one side frame, with roof-shaped reflective surfaces on the inside of the frame sections.

For a simple Production of the middle part, in particular with the aid of microtechnical Method, it is advantageous if the middle part of two (preferably mirror-symmetrically arranged) interconnected Layers is built up.

The terms used above and below preferably have the meanings given below, wherein more general terms can be replaced individually or in groups by more specific terms, which leads to preferred embodiments of the invention:
The endoscope components defined below are designed such that the endoscopes according to the invention are rigid or preferably semi-flexible or in particular fully flexible.

The Outer shell of the Endoscopes can be made from usual Materials such as plastics, silicone rubber (also called laminate) or Rubber, insist. If desired, can the outer shell or also the rest Components of the endoscope wholly or partially with anticoagulant Be coated with agents such as heparin or hirudin.

the distal region of the endoscope light-guiding or light-guiding elements are primarily IR, UV or primarily visible light conductive (= optically conductive) single fibers or groups of such Single fibers, the light from a light source, which forms part of a preferred embodiment an endoscope according to the invention is, to the desired distal location, in particular to the object to be considered, on, in front or next to the endoscope.

light sources can e.g. Light-emitting diodes, diode lasers, lasers, xenon lamps, halogen lamps, other annealing or discharge lamps, or others for generating IR, UV or in particular visible light sources. They are located usually at the proximal end of the endoscope. Is the place of use sufficiently bright, can be on the light-emitting elements and a light source be waived.

For transmission an image of an object in the distal region suitable image-transmitting Elements are primarily of a variety of strictly ordered fiber bundles constructed of optical fibers; for example, anyone can Fiber of an imaging unit, for example a pixel or pixel correspond. The image-transmitting Lead elements into a viewing device preferably located at the proximal end of the endoscope. or image capture unit.

When Observation unit can For example, for direct visualization eyepieces or indirect Visualizing cameras, such as video cameras, their images if desired can still be processed (for example, by computer), in particular, if no visible light is used, used.

When gas or liquid-conducting Elements are primarily one or more lines or hoses, which allow the supply of gases or liquids in particular. By these become transparent fluids, i. Gases or liquids, for varying the expansion state of the balloon element (s) added or removed. In particular, inert gases, such as nitrogen or in particular, come as gases the readily soluble carbon dioxide, as liquids (to risks from damage the balloon elements or leakage at the endoscope to avoid) desired Wavelength range transparent, in particular physiologically compatible liquids, such as suitable buffers, physiological saline or liquids based on fluorohydrocarbon polymers such as perftorane (JSC SPF Perftoran, Moscow region, Russia).

One Balloon attachment in the distal region comprises in particular one or several plate-shaped Holder with at least one hole passing through the holder, wherein an expandable, transparent balloon element on one side of the Holders as described above, covering the holes, and a holding device for mounting the plate-shaped holder to the rest of the endoscope.

expandable especially means expandable to a balloon. Preferably lies the expandable, transparent balloon element in the unexpanded Condition as one side of the plate-shaped holder all or at least partially covering stretchy Layer before.

When Material for the balloon element comes in particular a transparent, elastic Material in consideration, preferably transparent rubber (in particular Natural) rubber, (e.g., single or multi-component polyurethane resin producible) transparent polyurethane or in particular silicone rubber (to obtain from single or multi-component silicone rubbers) in Consider, as well as any other sufficiently well on plate-shaped holder be applied with at least one hole and in particular directly, but if necessary also over an adhesive layer adhering, sufficiently elastic and transparent Material.

The one or more plate-shaped holder having at least one hole made from conventional materials, in particular in microsystems technology usual materials, such as plastics, particularly polymers, such as polymethylmethacrylate (PMMA), polycarbonate, polyester, polyamides, polytetrafluoroethylene (TEFLON ^®), polyvinyl chloride (PVC ), Polydimethylsiloxane (PDMS), polysulfone, polystyrene, polyolefins such as polymethylpentene, polypropylene or polyethylene, polyvinylidine fluoride, acrylonitrile-butadiene copolymer (ABS), block copolymers or mixtures of two or more thereof; or, in particular, silicon-based materials such as silicon (particularly preferred), silica, glass, quartz, silicone or polysilicone, or further other semiconductor materials such as gallium arsenide. As the glass, for example, photo-structurable glass such as FOTURAN ^® (microglass Technik AG, Mainz, Germany) or in particular borosilicate glass such as Pyrex ^® (Corning, USA) is suitable. In the case of semiconductor materials, it may often be desirable to layer an insulating layer, for example of silicon dioxide, over the material. Polymeric substrate and cover layers can be prepared by known microfabrication methods, or by microfabricated parent molds using known molding methods, such as injection molding, embossing or stamping, or by polymerization of the mono- or oligomeric precursor material within the mold (prototype). Such polymeric materials are advantageous because they are easy to manufacture, inexpensive and disposable. However, silicon or glass based holders are particularly preferred.

The Manufacturing process for Endoscopes according to the invention uses in particular microsystem production methods, such as deposition, ablation, modification or connection.

The introduction of holes in the base material for the plate-shaped holder, in particular as mentioned above in the microsystem technology common material, which is in plate, eg wafer form and preferably the substrate for the production of more than one balloon element and in whole or in part with one or more materials, in particular silicon dioxide, silicon nitride or photoresist, coated or can be during the process, carried out by drilling, in particular ultrasonic drilling, irradiation eg with lasers or preferably by etching methods such as (especially selective) dry or wet etching or Combinations of it. Preferably, for dry etching, for example, reactive ion etching (RIE) or (since the flank angles are particularly easy to adjust and eg round holes can be achieved) is an advanced silicon etch (ASE) process (cf the disclosure of which is incorporated herein by reference) DE 424 10 45 C1 ), for example with SF ₆ , used for wet etching eg KOH etching, with ASE methods being particularly preferred.

The Substrate for production can also be oxidized on the surface (im Case of a silicon substrate, for example as a thermally produced oxide).

Where necessary, for example for fixing and making the holes by etching, one or more removable protective layers are applied (at least partially), for example silicon nitride (Si ₃ N ₄ ) or in a second case photoresists or the like, or both, for example first case by (in particular chemical) vapor deposition from the gas phase (eg LPCVD) or in the second case by spin-coating or other application. In the first case by etching, for example by dry etching, in the second case by photolithography layers, where necessary, in whole or in part, for example, in the first case before etching holes, in the second case to expose layers are removed.

The Coating with the material for at least one transparent, expandable balloon element is by means of conventional Methods, such as printing, spraying or in particular doctoring or especially spin-on. In multi-component systems, the mixture of components happens before or during the application.

For example, the preferred variant b) of the production process is preferably carried out as follows:
A wafer made of a base material, preferably of (in particular {100} -) silicon or borosilicate glass, in particular with inertized surfaces, for example in the case of silicon preferably by thermal oxidation coated at the top and bottom with an oxide layer, if desired already with (for example photolithographically generated) depressions at the top, which lie in the region of the holes or holes to be introduced is covered at the top and bottom with a suitable, removable material layer, in particular silicon nitride, for example by chemical vapor deposition (CVD), for example LPCVD. At least on the back of the wafer, photoresist is applied. Photolithographically (for example rectangular) mask openings are produced on the wafer back side and superfluous photoresist is removed. The mask openings are transferred to the wafer material by an etching process, preferably RIE dry etching, Advanced Silicon Etch (ASE), and / or KOH etching, with the removable front material layer (eg, silicon nitride) forming an etch stop. Thus, the substrate for the plate or the holder is made. Their removable material layer (on the front side of the wafer) is coated (e.g., by knife coating or spin coating) with a transparent, inflatable balloon member material such as silicone rubber or, if present, is placed in recesses in the front of the wafer, preferably by knife coating , Then the removable material layer in the area of the mask openings transferred into the wafer material is removed from the rear side by an etching process (in the case of a silicon nitride coating, for example by RIE dry etching and / or here or generally by means of Advanced Silicon Etch (ASE) method), so that one or several holes resul animals that are consistent to the one or more transparent balloon element materials.

Examples of corresponding methods of preparation can be found in Yang et al., J. Micromech. Systems 8 (4), 393 (1999).

variant a) of the method according to the invention may preferably by the or the holes overlapping applying a already prefabricated layer (preferably stabilized on a support material directly or on a coating to facilitate its detachment such a carrier material, For example, of polyimide, applied, the prefabricated Then layer by pressing transferred to the substrate is) of a transparent material for at least one transparent rent, expandable balloon element (in particular one of the above corresponding materials, for example silicone rubber or silicone rubber) on one side of a substrate in wafer form (preferably out one of those mentioned above as preferred in microsystem technology Materials, e.g. Borosilicate glass or silicon) with at least one through hole for the plate-shaped holder, if necessary using an adhesive, what a uniform layer thickness also over the hole (s) allows.

Either in the preferred variant a) as well as in the preferred variant b) as described in the immediately preceding paragraph Procedure, can subsequently, if necessary, in a preferred embodiment with multiple holes in the Substrate from the resulting substrate with holes and deposited material for transparent, expandable balloon elements by separation, for example by Sawing, cutting (e.g., by laser) or break, single with at least one transparent, expandable balloon element provided plate-shaped holder according to the invention be won. One or more of the like or directly without singling obtained with at least one transparent, expandable balloon element provided plate-shaped holder be with other components (especially holding devices) completed to a balloon essay and at the distal end of a thus obtained endoscope according to the invention attached.

In a further preferred embodiment The invention is additionally incorporated as one of the other components Middle part with a reflection element in combination with a or more plate-shaped Holders with one or more holes and balloon attachment in built in an endoscope, which is preferably made as follows: A (preferably on both sides with an inerting layer, such as an oxide layer (obtained, for example, by thermal oxidation)) Wafer (preferably from a customary in microsystem technology Material as defined in particular above, e.g. Borosilicate glass or preferably (in particular {100} -) silicon) is on both sides with a suitable, removable material layer, in particular Silicon nitride, coated, for example, by chemical vapor deposition from the gas phase (CVD), e.g. LPCVD. At least on the back of the wafer, photoresist is applied. On the wafer back become photolithographically (for example rectangular) mask openings generated and superfluous photoresist away. about the mask openings is by means of an etching process, preferably RIE dry etching to remove the removable material layer and etching with KOH, the wafer material etched away to the opposite inert layer (in the preferred Silicon in particular to form {111} surfaces). If desired, the removable ones Layers (eg, silicon nitride removed by etching, such as RIE dry etching) and, if desired, two so obtained wafers so over their front sides joined that the holes come to lie one above the other, and (for example, by anodic bonding or bonding) with each other connected. By means of applied stencils, if the reflectivity is to be increased, the areas around the holes covered and their insides (e.g., {111} faces) are mirrored, for example wet-chemically or by vapor deposition of metal layers, e.g. With Aluminum and / or silver. Are the precursors of several such Middle parts on a (single or double) wafer before, so be By separating corresponding middle parts won, on one obtained from one or more of the reflective or mirrored surfaces Reflection element facing away directly by corresponding Singling open be open or, for example, by drilling, sawing or the like can, so a for light-feeding and / or image-transmitting Elements or light and light emitted from images, and if necessary gas or liquid continuous area (for feeding to the balloon elements) is formed. These middle parts will be then with one or more plate-shaped elements with one or more holes and Ballonaufsatz applied and by means of a holder and if necessary completed further components to an endoscope according to the invention.

The Invention will now be illustrated by the following examples which are given by way of illustration of the invention, without limiting their scope, however also preferred embodiments represent the invention, and described in more detail with reference to the drawings. It shows in partly schematized representation:

1 in cross-section an example of a plate-shaped holder according to the invention with a hole on which a balloon element, here in the form of a transparent elastic material, covering the hole is applied,

2 an endoscope with a balloon attachment with a frontal viewing window with a plate-shaped holder as a component at the distal end of the endoscope,

3 an endoscope attachment for continuous vascular examination with lateral viewing windows (view from the fiber bundle end),

4 the endoscope attachment according to 3 in cross-section from the side as well

5 schematically a central part with a reflection element according to 3 and 4 ,

Example 1: Endoscope 100 with an endoscope attachment 14a with a frontal viewing window and a plate-shaped holder 1 silicon-based

2 shows such an endoscope 100 with a plate-shaped holder 1 with balloon element 6 as well as in 1 shown.

The plate-shaped holder 1 consists of a substrate 2 , here made of silicon, on a flat side with a transparent material 3 , here made of silicone rubber, coated. Between the substrate 2 and the transparent material 3 is an etch stop layer 4 , here a silicon nitride layer, applied. A hole 5 penetrates the substrate 2 and the etch stop layer 4 but not the transparent material 3 ,

The production of this plate-shaped holder 1 takes place in this example by depositing a 100 nm thick layer of Si ₃ N ₄ on both sides on a 380 μm thick {100} silicon wafer by means of LPCVD. After back-coating of photoresist, photolithographically rectangular mask openings are produced on the wafer back side and transferred into the silicon by means of RIE dry etching and etching with KOH. The Si ₃ N ₄ layer of the front thereby forms a natural Ätzstopp. Before or after the KOH treatment, a film of silicone rubber (for example based on siloxanes such as, in particular, polydimethylsiloxane or of two-component systems of, for example, polydimethylsiloxane and .alpha.,. Omega.-divinyl-polymethyldisiloxane) about 100 to 150 .mu.m thick with a spin is applied to this layer Coater spun on and crosslinked at about 125 ° C in the oven for silicone rubber. Finally, the Si ₃ N _{4 is} removed from the backside by RIE dry etching to form a self-supporting silicone rubber membrane. By subsequent separation can be in this way hundreds of individual plate-shaped carrier with (micro) balloons 6 on each wafer.

The the balloon element 6 carrying plate-shaped holder 1 is then at the rear end of an outer endoscope shell 7 of the endoscope 100 attached so that the opening of the outer shell 7 is tightly closed. This can be done by bonding the substrate 2 with the outer shell 7 happen. But preferred is a mechanical holding device 8th providing a simple replacement of the balloon-carrying plate-shaped holder 1 allows. The holding device 8th has on one side a socket 9 for fixing the outer shell 7 , on the other side a section 10 holding the plate-shaped holder 1 firmly clamped. In between there is a passage 11 which is sufficiently large to light-supplying and image-transmitting elements 18 and 20 , here as a common optical fiber bundle 12 designed to pass through. The holding device 8th seals the coupling point between endoscope outer sheath 7 and balloon-carrying plate-shaped holder 1 liquid and gas tight, so that when expanding the balloon element 6 over the outer shell 7 or gas or liquid-conducting elements contained therein 13 (Channels) no gas and / or liquid can escape to the outside. The size of the holding device 8th exceeds the diameter of the outer shell 7 not essential to not affect the maneuverability of the endoscope system, for example in the blood vessel. For this purpose, it may, in particular in the field of the version 9 , also a smaller diameter than the outer shell 7 and be secured within this. The holding device 8th and the balloon-carrying plate-shaped holder 1 together make up the endoscope attachment 14a , Optionally, the end of the common, the light-supplying and image-transmitting elements 18 and 20 containing fiber bundle 12 as a lens 15 be formed or it can be a lens 15 at the distal end of the fiber bundle 12 be arranged here in the form of a Gradientenindexlinse.

Other possible components of an endoscope 100 with an endoscope attachment 14a are for example a gas or liquid reservoir 16 , here trained as a hypodermic syringe; as well as an observation unit 17 , here formed as an eyepiece, and a light source to which the light-supplying elements 18 preferably coupled at the proximal end (not shown).

Example 2: Endoscope 100 with endoscope attachment 14a with frontal window and plate-shaped holder 1 on pyrex basis

As an alternative to Example 1, pyrex is used as the base material instead of silicon. (Kapton ^®, EI du Pont de Nemours and Company, USA) for this purpose, a thin polyimide layer is applied to a substrate and then doctored it as a transparent elastic material of silicone rubber. In a Pyrex wafer holes are first drilled for an optical fiber or by anisotropic etch introduced. Subsequently, the Pyrex wafer is pressed and annealed on the silicone rubber layer of the above-mentioned substrate. Due to the low adhesion strength of the silicone rubber on the polyimide, the Pyrex wafer with the elastomer adhered to it can easily be peeled off. By separating balloon-carrying plate-shaped holder 1 won, analogous to the corresponding plate-shaped holders 1 with holding devices 8th from Example 1 to corresponding Endoskopaufsätzen 14a be assembled.

Example 3: Endoscope attachment 14b for continuous vascular examination with two balloon elements 6

3 and 4 show schematically an endoscope attachment 14b for continuous vascular examination with two balloon elements 6 , The end 19 of the endoscope 100 is through the two balloon elements 6 in the dilated state to the blood vessel wall 20 rich, held in the blood vessel. About the reflection surfaces 21 becomes light from the optical fiber bundle 12 on the blood vessel wall 20 passed approximately perpendicular to the longitudinal axis of the endoscope and radiated therefrom light back to the image-transmitting elements 20 within the optical fiber bundle 12 reflected back.

The two halves of a central, in this embodiment about horseshoe-shaped or on the side of the fiber bundle 12 for receiving it with a receiving opening 22 pierced or perforated middle section 23 be outside by two plate-shaped holder 1 made of Pyrex glass or silicon applied to the (here in the above holes 5 expanded state shown) balloon element 6 made of transparent transparent material 3 , here on the outside, are coated and held by a holder 24 together with the halves of the middle section 23 are held, which the entire assembly on the endoscope outer shell 7 attached.

About a cavity 25 and the receiving opening 22 in the holder 24 is by means of the gas or liquid-conducting elements 13 Gas or liquid to control the expansion state of the balloon element 6 fed.

Opposite the end of the optical fiber bundle, the middle part 23 a reflection element 26 with two reflective surfaces 21 on which of the light-supplying elements 18 radiated light reflected thereby approximately at right angles in the area to be imaged through one of the holes 5 and through the wall of the balloon element 6 radiates through. The image of the brightened area located on the outside of the balloon element also becomes on the reflection element 26 and its reflective surfaces 21 reflected and from the lens 15 at the end of the image-transmitting elements 20 added. The reflection surfaces 21 are convex and roof-shaped, wherein the roof edge in the longitudinal direction of the endoscope 100 in the direction of the lens 15 protrudes. The reflection surfaces 21 are designed to be level, so that in particular the imaging area largely undistorted from the lens 15 can be included.

The production of this endoscope attachment 14b First, a {100} silicon wafer with a thickness of 380 μm polished on both sides is thermally provided with a 300 nm thick oxide layer on both sides of the surface. In each case, a 100 nm thick Si ₃ N ₄ layer is applied to these oxide layers by means of LPCVD. Thereafter, photoresist is spin coated on both sides. On either side (back side), rectangular holes are made in the photoresist layer by photolithography, and then the Si ₃ N ₄ layer and the oxide layer within these holes are etched away by RIE. By KOH etching, the Si layer is etched away to the opposite oxide layer of the front to form [111] surfaces. The front oxide and nitride layers are etched away using the RIE process, and the nitride layer on the backside is also removed. Two thus obtained wafers are connected in such a way over their front sides that the holes come to lie one above the other, and connected together by anodic bonding. Using masks applied on both sides (Advanced Silicon Etch (= ASE ^™ ) etched wafers with the same mask as the two bonded wafers) covers the areas around the holes and the [111] faces of the Si wafers by vapor deposition of a silver / aluminum layer for fabrication of reflection surfaces 21 mirrored and removed the templates again. By singling become middle parts 23 made, which are either cut so that each one of the sides for receiving the optical fiber bundles 12 and the passage of gas or liquid from the gas or liquid-conducting element 13 to the balloon elements 6 open and so is the receiving opening 22 forms (the middle part 23 with the reflection surfaces 21 then has horseshoe shape, cf. to 5 ), or it will, provided that of the reflecting surfaces 21 bordered holes are closed laterally, in each case from one of the edge sides along the bonding plane between the two middle part halves the corresponding receiving opening 22 introduced, for example by drilling or milling.

By means of the holder 24 then become the middle parts 23 , each with a holder on the outside 1 with transparent elastic material 3 and hole 5 provided at the distal end of the endoscope 19 so fastened that over the receiving opening 22 Gas or liquid over the gas or liquid carrying elements 13 fed and the patency for the optical fiber bundle 12 can be guaranteed.

Claims (15)

Endoscope ( 100 ) with an outer shell ( 7 ), at least one distal portion of the endoscope ( 100 ) Light-feeding element ( 18 ), at least one element suitable for transmitting image information of an object in the distal region ( 20 ), at least one gas or liquid-conducting element ( 13 ) and a balloon attachment ( 14a . 14b ) in the distal region with an inflatable, transparent balloon element ( 6 ), characterized in that the balloon attachment ( 14a . 14b ) in the distal region at least one plate-shaped holder ( 1 ) with at least one holder ( 1 ) passing through hole ( 5 ), wherein at least two opposite flat sides of the plate-shaped holder ( 1 ) of at least one hole ( 5 ) are interspersed, are designed as surfaces and as at least one plate-shaped holder ( 1 ) one or more such are used, in which one or each balloon element ( 6 ) on only one flat side of the plate-shaped holder ( 1 ) the hole or holes ( 5 ) applied covering and as only this flat side of the holder is covered in whole or partially covering stretchable layer. Endoscope according to claim 1, characterized in that the balloon element ( 6 ) by a in the balloon element ( 6 ) through the gas or liquid-conducting element ( 13 ) introduced medium such as gas or liquid is expandable. Endoscope according to claim 1, characterized in that between the holder ( 1 ) and the balloon element layer ( 6 ) An adhesive layer is arranged. Endoscope according to one of claims 1 to 3, characterized in that the plate-shaped holder ( 1 ) transverse to the longitudinal axis of the endoscope ( 100 ) and that the distal region of the endoscope ( 100 ) facing away from the holder ( 1 ) the balloon element layer ( 6 ) wearing. Endoscope according to one of claims 1 to 4, characterized in that the balloon element ( 6 ) is transparent at least on expansion to a balloon. Endoscope according to one of claims 1 to 5, characterized in that the balloon element ( 6 ) is transparent at least to part of the light spectrum. Endoscope according to one of claims 1 to 6, characterized in that the two opposite flat sides of the plate-shaped holder ( 1 ) of at least one hole ( 5 ) are interspersed, are designed as flat surfaces. Endoscope according to one of claims 1 to 7, characterized in that at or in front of the distal end of the image-transmitting element ( 20 ) a lens ( 15 ) or in the image-transmitting element ( 20 ) is integrated. Endoscope according to one of claims 1 to 8, characterized in that the image-transmitting element ( 20 ) and the light-guiding element (s) ( 18 ) in the distal region of the endoscope ( 100 ) are arranged directly adjacent and that a lens ( 15 ) at the common distal end of the image-transmitting element ( 20 ) and the light-guiding elements ( 18 ) is arranged. Endoscope according to one of claims 1 to 9, characterized in that the plate-shaped holder ( 1 ) parallel to the longitudinal axis at the distal end of the endoscope ( 100 ) is arranged that the balloon element ( 6 ) on the plate-shaped holder ( 1 ) on the relative to the endoscope ( 100 ) outer side is applied and that a reflection element ( 26 ) is arranged, which for the reflection or coupling of an image of the object in the distal end of the image-transmitting element ( 20 ) and / or for reflection of light from the light-guiding elements ( 18 ) of the endoscope ( 100 ) is formed in the region of the object to be imaged. Endoscope according to claim 10, characterized in that the balloon attachment ( 14b ) at least two plate-shaped holder ( 1 ) each with a hole ( 5 ) and one balloon element each ( 6 ), that the two holders ( 1 ) opposite the distal end and parallel to the longitudinal axis of the endoscope ( 100 ) are arranged and that the reflection element ( 26 ) the distal end of the endoscope ( 100 ) is arranged opposite in the longitudinal direction. Endoscope according to claim 10 or 11, characterized in that the reflection element ( 26 ) on or on a middle section ( 23 ), which between the plate-shaped holders ( 1 ) and is acted upon by these on the outside, that at least one side of the middle part ( 23 ) a continuous receiving opening ( 22 ), which the light-supplying (18) and image-transmitting elements ( 20 ) and that of this receiving opening ( 22 ) opposite region of the middle part ( 23 ) as a reflection element ( 26 ) is formed, which two bevelled, the light-conducting (18) and image-transmitting elements ( 20 ) facing reflecting surfaces ( 21 ), which are arranged side by side so as to enclose an angle greater than 180 °. Endoscope according to one of claims 10 to 12, characterized in that the middle part ( 23 ) is composed of two interconnected layers. Method for producing an endoscope with a balloon attachment ( 14a . 14b ), one or more plate-shaped holder ( 1 ) each with at least one holder ( 1 ) passing through hole ( 5 ) according to any one of claims 1 to 13, wherein a) in a substrate ( 2 ) for producing at least one corresponding plate-shaped holder ( 1 ) one or more through holes ( 5 ) and the material for at least one transparent, expandable balloon element ( 6 ) on only one side of the substrate ( 2 ) for the plate-shaped holder ( 1 ) corresponding to the flat side of the plate-shaped holder, the hole (s) ( 5 ) or b) a material for a transparent, inflatable balloon element ( 6 ) on only one side of the substrate ( 2 ) for at least one corresponding plate-shaped holder ( 1 ) corresponding to the flat side of the plate-shaped holder, the hole (s) ( 5 ) is applied and then one or more up to the transparent, expandable balloon element ( 6 ) reaching holes ( 6 ) on the substrate ( 2 ) for the plate-shaped holder ( 1 ) or already existing depressions to the balloon element ( 6 ) through holes ( 5 ) to be completed; and then each one or more of the so with at least one transparent, expandable balloon element ( 6 ) provided plate-shaped holder ( 1 ) with further components to a balloon attachment ( 14a . 14b ) and at the distal end of the endoscope ( 100 ) are attached. A method according to claim 14, characterized in that the production of the plate-shaped holder ( 1 ) with at least one hole ( 5 ) microsystem technology takes place.