WO2003053492A2 - Expandable device to profile the wall of a hollow body organ - Google Patents

Abstract

An expandable device (40) for profiling the wall of a hollow body organ includes a flexible, expandable member (42) capable of conforming to the wall of a cavity or hollow body organ. A temperature sensor (48) within the interior of the expandable member can move about and measure the temperature at different locations. One expandable member can be an elastomeric balloon for conforming to the walls of the hollow body organ and which can be coated or doped with a material (46) that responds to a change of temperature of the cavity wall. This change can be assessed by the sensor, e.g., a fiberoptic that can transmit light and collect the reflected light. The fiberoptic can have a reflection mechanism (50) at its tip to direct the angle of incidence. The controller can measure and process the collected signal to produce a graph representing, the temperature profile.

Description

EXPANDABLE DEVICE TO PROFILE THE WALL OF A HOLLOW BODY

ORGAN

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of priority to U.S. Patent

Application Serial No. 60/333,598 filed November 27, 2001, which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION [0002] The present invention relates generally to cavity wall profiling apparatus and more specifically it relates to an expandable device to profile the wall of a hollow body organ for assessing and graphing a condition of the wall of a cavity or a hollow body organ.

BACKGROUND OF THE INVENTION [0003] It can be appreciated that cavity wall profiling apparatus have been in use for years. Typically, cavity wall profiling apparatus are comprised of temperature indicating probes such as thermocouples, thermistors, fluorescence lifetime measurement systems, resistance thermal devices and infrared measurement devices. Other examples of existing products include temperature indicating labels and liquid crystal materials.

[0004] One problem with conventional cavity wall profiling apparatus are that these devices usually exert an undue amount of force on the subject which its property is being measured. If a given subject cannot withstand these forces, it may be damaged or even torn. One such subject vulnerable to damage is the inside walls of a human artery. Another problem with conventional cavity wall profiling apparatus are that they can only measure the temperature of an object at one specific location. One example of such a device is a thermocouple. In order to get a map of the object's temperature, one will need to move the sensing probe from location to location; this can be very tedious and may not resolve temporal characteristics of the profile with sufficient resolution or use an array of sensors that can become very big and heavy. Another problem with conventional cavity wall profiling apparatus involve using infrared energy for measuring the temperature of an object. The energy must pass through a medium that contains materials, which may include water. Water absorbs significant amounts of infrared energy and may make the sensor ineffective or inaccurate.

[0005] While these devices may be suitable for the particular purpose to which they address, they are not as suitable for assessing and graphing a condition of the wall of a cavity or a hollow body organ. Another problem is that these devices typically only measure the temperature of an object at one specific location. One example of such a device is a thermocouple. In order to get a map of the object's temperature, one will need to move the sensing probe from location to location; this can be very tedious and may not resolve temporal characteristics of the profile with sufficient resolution. Otherwise, a device may use an array of sensors that can become, relatively, very big and heavy.

[0006] In these respects, the expandable device to profile the wall of a hollow body organ according to the present invention substantially departs from the conventional concepts and designs and in so doing provides an apparatus primarily developed for the purpose of assessing and graphing a condition of the wall of a cavity or a hollow body organ.

SUMMARY OF THE INVENTION [0007] In view of the foregoing disadvantages inherent in the known conventional types of cavity wall profiling apparatus, the present invention provides a new expandable device to profile the wall of a hollow body organ construction wherein the same can be utilized for assessing and graphing a condition of the wall of a cavity or a hollow body organ.

[0008] The present invention, which will be described subsequently in greater detail, provides, in part, a new expandable device to profile the wall of a hollow body organ that has many of the advantages of the cavity wall profiling apparatus mentioned heretofore and many novel features that result in a new expandable device to profile the wall of a hollow body organ which is not anticipated, rendered obvious, suggested, or even implied by any of the prior art cavity wall profiling apparatus, either alone or in any combination thereof.

[0009] To attain this, the present invention generally comprises a flexible, expandable member capable of conforming to the wall of a cavity or hollow body organ doped or at least coated in part with an agent that changes its state proportionally to a change in the condition of the wall of the cavity or hollow body organ within which a sensing apparatus for measuring the said change of state and correlating the change of state to the location on the wall of the cavity or hollow body organ. An expandable member such as an elastomeric balloon that can conform to the walls of the cavity or hollow body organ and substantially cover the wall of the said cavity or hollow body organ. This balloon is coated or doped with a material that can respond to a change of state of the wall of the cavity. This change of state can be assessed by a sensor. A fiberoptic or other energy transferring structure that can emit electromagnetic radiation and collect the reflected radiation to perform spectral radiometry may be incorporated into the expandable member. This element has incorporated at its tip a reflection mechanism to direct the angle of incidence toward the walls of the cavity or hollow body organ. A controller performs the task of moving the sensor about within the expandable member to poll the change of state from different locations on the inside wall of the hollow body organ. The controller also measures and processes the collected signal to produce a point-by-point graph indicating the measure of the change of state. A treatment device may be used to heat the walls of the expandable member to effect thermotherapy of the walls of the hollow body organ.

[0010] There has thus been outlined, rather broadly, some of the features of the invention in order that the detailed description thereof may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter. [0011] In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of the description and should not be regarded as limiting. [0012] The present invention provides an expandable device to conform to and profile the wall of a hollow body organ that overcomes the shortcomings of conventional devices. It also provides an expandable device to profile the wall of a hollow body organ for assessing and graphing a condition of the wall of a cavity or a hollow body organ and further provides an expandable device to profile the wall of a hollow body organ that can expand within the cavity or lumen of an object or a living being and conform to the wall of said cavity in order to measure a parameter of this wall. This expandable member can be constructed from a hollow guidewire with preshaped expandable features.

[0013] Alternatively, this expandable member can be constructed out of an elastomeric material forming a balloon. In measuring parameters of the wall, one such parameter that can be measured is the temperature profile of the inside of a lumen or hollow body organ. One such lumen may be the blood vessels including veins or arteries, the intestines or the nasal passage. An example of a hollow body organ may include the human uterus, stomach, brain, and arteries and ventricles of the heart.

[0014] The device may also be used to profile the wall of a hollow body organ for generating a two or three dimensional parameter map of the inside of a cavity such as a hollow body organ. This map may be pseudo-color coded for ease of interpretation. Furthermore, the device may also be used to heat the wall of the hollow body organ to treat inflammation. This heating can take place by electromagnetic irradiation or simply by conduction of heat from a hot fluid inside the expandable member and into the wall.

[0015] The device may also be configured such that it is capable of measuring and profiling the radiation emitted from the wall of a hollow body organ. This radiation may be emitted from the tissues contained in the wall that have previously absorbed a radiation-emitting tracer injected into the body. Alternatively, the device may be configured to measure the radiation transmitted through the walls of the hollow body organ such as a blood vessel. The source of this radiation in this case can be a radioactive material outside the organ.

[0016] The device may further alternatively be configured to be capable of measuring fluorescence decay times of the inside wall of a hollow body organ. The fluorescence signal can be generated from material adjacent the wall of a hollow body organ such as a blood vessel or intestines.

[0017] Other aspects of the present invention will become obvious to the reader and it is intended that these variations are within the scope of the present invention. [0018] To the accomplishment of the above, this invention may be embodied in the form illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that changes may be made in the specific construction illustrated.

BRIEF DESCRIPTION OF THE DRAWINGS [0019] Various other features and attendant advantages of the present invention will become fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:

[0020] FIG. 1 is a cross section of an artery containing a length of vulnerable plaque.

[0021] FIG. 2 is a section of a temperature sensitive liquid crystal sheet with a range of 30-35 degrees Celsius.

[0022] FIG. 3 shows the principle of operation of this device in which a balloon material is doped with the agent that can change color upon getting heated. Within this balloon a sensing member detects the changes in the color of the balloon to correspond it with the temperature of the said balloon.

[0023] FIG. 4 shows one of the principles of scanning the wall of the balloon in which the optical fiber carries light energy into the balloon and measures the reflected light from the walls to detect a temperature change in this wall. This is the colorimetry apparatus. The polarizer polarizes the white light incident upon it, which in turn gets reflected from the beam splitter and enters the fiber. The reflected light from the inside of the balloon is no longer polarized and is readily transmitted through the beam splitter for measurement.

[0024] FIG. 5 shows the spectral distribution of reflected light from which the peak wavelength and the corresponding temperature can be detected. [0025] FIG. 6. Shows a dual fiber concept where one fiber may be used for injection of light and the other may be used to collect the reflected light. [0026] FIG. 7 shows an array of fiberoptics that extend longitudinally into the expandable member and would be able to image the wall of the expandable member by a single rotation about the axis of the fiberoptic. [0027] FIG. 8 shows a plurality of strips of the temperature sensitive material placed upon or within the expandable member's walls. The strips provide the advantage of indexing the location as the fiberoptic images the wall.

[0028] FIG. 9 shows a collimating lens used to narrow the angle of view of the fiberoptic. A reflector such as gold or silver is used to deflect the path of light by

90 degrees.

[0029] FIG. 10 shows a dual fiber approach in which there is a light emitting fiber, a light collecting fiber are used for the data collection and a proximal occlusion balloon is used to occlude the blood vessel while the temperature is being read.

[0030] FIG. 11 shows a balloon with a through hole for the blood to flow while the temperature is being read.

[0031] FIG. 12 shows an embodiment of this invention where there is an alternating low and high temperature strips on the wall to increase the range of temperatures that the system can read or to increase the resolution of the system.

[0032] FIG. 13 shows the current invention with the addition of a treatment means that carries warm water into and out of the balloon to cause heating of the wall of the vessel and apoptosis of the same. Alternatively, electrodes placed on the surface of the balloon can be used to inject radio frequency energy into the wall and the temperature can be again profiled using the temperature sensitive material of the wall.

[0033] FIG. 14 shows a three dimensional representation of the temperature inside a blood vessel.

[0034] FIG. 15 shows the interrelation of the scanning and control means. A linear motor (M2) works in cooperation with a rotational motor (Ml) to rotate and withdraw the fiberoptic from inside the balloon. There may be only one rotation involved if the linear fiber bundle is used or there may be a helical pattern of scanning if only a single fiberoptic may be used.

[0035] FIGS. 16A-16C show two different scanning modes, helical and longitudinal, to scan all points of interest on the wall of the expandable member.

[0036] FIG. 17 shows a linear-circumferential fiberoptic bundle that can image the inside of the expandable member without needing any physical movement.

[0037] FIG. 18 shows a potential image of the proximal end of the image bundle of figure 17. [0038] FIG. 19 shows an annular bundle that only needs linear movement to image the wall of the expandable member.

[0039] FIG. 20 shows another longitudinally moving bundle with a flow through hole.

[0040] FIG. 21 shows a needle coated with the thermochromic material and a single fiberoptic inside to scan the wall for temperature variations.

[0041] FIGS. 22A and 22B show two variations of the circumferential light collecting fiberoptic.

[0042] FIG. 23 shows a dielectric material such as glass coated with the thermochromic material of the present invention.

[0043] FIG. 24 shows the preferred embodiment of the present invention where a guidewire is preshaped into a helix and it expands to conform to the wall of the lumen or hollow body organ and through it a sensing member senses the temperature.

[0044] FIG. 25 shows an LCD material responsive to a change in temperature that changes its opacity as a result of a change in temperature. The reflector is used to reflect the light through the medium and the difference in amplitude between the incident and reflected light is an indication of the opacity of the LCD medium and therefore the temperature of the LCD material.

[0045] FIGS. 26 A and 26B show a linearly everting balloon within which the sensing element is located. The everting balloon is made out of a thin elastomeric material that can quickly deploy into the vessel and move down the vessel. As the sensing element is withdrawn from the balloon, the scanning of the wall can take place to assess the temperature profile.

[0046] FIG. 27 shows a schematic of spectrum modulating system. In order to have an incident light spectrum that has relatively equal amplitude at different component frequencies, a series of notch filters are used to homogenize the amplitude over the spectrum of light that is used to measure the color of the wall.

[0047] FIG. 28 A to 28C show the potential reflected spectrum of light at different temperatures. There will be a peak corresponding to a given color that represents a given temperature at a given peak wavelength from which the temperature can be inferred. [0048] FIG. 29 shows another means to homogenize the spectrum of the light incident upon the thermochromic material. Here, a series of neutral density filters are used to convert discrete colors of fight at varying amplitudes generated by the different color filters into a homogenous amplitude pattern.

[0049] FIG. 30 shows a cross section of an artery containing a lipid pool and inflammatory cells all covered by a fibrous cap.

[0050] FIGS. 31 A-31 C show different ways to deliver glutaraldehyde to the vessel wall to fix the collagen in the thin fibrous cap thereby strengthening it and preventing its rupture.

[0051] FIG. 32 shows the preferred embodiment of this invention where a preshaped guidewire is used as the expandable means that conforms to the wall. A thermocouple or other sensor within the guidewire is movable between the distal end of the wire and the proximal end. As it passes through these different sections, it equalizes its temperature with that of the wire and readings are taken at different points to generate a graph. A mechanism pulls the wire out of the guidewire at a constant rate and measurements are then taken at discrete intervals.

[0052] FIG. 33A shows how the guidewire is deployed in a blood vessel.

Initially, the guidewire has a straight shape and is inserted into the blood vessel within the sheet and advanced to a desirable location. Upon reaching that location, the guidewire is advanced out of the sheath as the sheath is slowly retracted. In this manner, the guidewire will take a helical shape against the wall of the artery. As the guidewire is pushed out of the sheath, it takes on its memory shape and becomes a helix. Various pre-sizes can be used to adapt to vessels of different sizes.

[0053] FIG. 33B shows how the guidewire is positioned after deployment into a blood vessel. The temperature of the wall at all contact points on the vessel wall can be measured and mapped by knowing the approximate diameter of the vessel.

[0054] FIG. 34 shows the guidewire embodiment having in it a nitinol tube to enhance its memory shape features.

[0055] FIG. 35 shows another variation of the guidewire where many sensors are located at the tip of a multi-tipped guidewire to place the least amount of pressure on the wall of the vessel.

[0056] FIG. 36 shows another variation of the guidewire, where the guidewire material itself is one leg of the thermocouple. This guidewire may have a PTFE coating that will be scraped off the inside section. The outside section and where the loops touch one another is still coated to provide lubricity in the case of the first and thermal isolation from the adjacent loops in the case of the second feature. The advantage of this embodiment is that a single strand of a conductor can be used to measure the temperature as represented by the potential difference between the guidewire and that single conductor.

[0057] FIG. 37 shows a fluid delivery mechanism to a section of the blood vessel containing the hot plaque. The two balloons isolate the section while glutaraldehyde or other fixing agents as well as warm or hot water can be injected through the ports to induce apoptosis. Ethyl alcohol is another candidate for this method of treatment. Warm water at the temperature of 40-44 degrees Celsius can be used to passivate the hot plaque.

[0058] FIG. 38 shows a heating means located at the entry point of an artery through which blood flows. Blood flowing over and through this heating means is heated to a desired temperature, which is sufficient for the treatment of the vulnerable plaque in the walls of the artery receiving the heated blood.

DETAILED DESCRIPTION OF THE INVENTION [0059] Turning now descriptively to the drawings, in which similar reference characters denote similar elements throughout the several views, the attached figures illustrate an expandable device to profile the wall of a hollow body organ, which comprises a flexible, expandable member capable of conforming to the wall of a cavity or hollow body organ.

[0060] In profiling the wall of the hollow body organ, various parameters of the organ may be measured. For instance, temperature of the wall may be sensed and measured to identify regions of instability, such as areas where unstable plaque may be located within the walls. Diseases such as unstable plaque may lead to rupture of the plaque and possibly death of the patient if left untreated. An example of unstable plaque is shown in FIG. 1. Hollow body organ 10 may be seen in cross-section where a region of unstable plaque 16 is located within the walls 12. Such regions of unstable plaque 16 are typically indicated by regions of higher temperature than surrounding areas of tissue. Temperature increases over unstable plaque 16 may generally range anywhere from 0.5° C up to 4.0° C, or higher. In this instance, the unstable plaque 16 is shown harboring lipids 18 therewithin while plaque 16 has ruptured. At the point of rupture 20, these lipids are shown escaping into lumen 14, where they may form potential vessel-occluding thrombi.

[0061] A material which may be utilized to facilitate detection of temperature changes within the vessel walls is shown in FIG. 2, which in one variation is a conventional temperature sensitive liquid crystal sheet 30. Such liquid crystal sheets are well known in the art and may be used to indicate temperature variations through color changes 32 within the sheet 30. These liquid crystal sheets generally comprise a plurality of micron-sized crystals (e.g., 3-5 μm) dispersed within a polymer matrix and are configured to exhibit total color spectrum response with temperature change. The example of sheet 30 shown in FIG. 2 is configured to detect temperature changes within a range of 30-35° C, however, other sheets may be configured to detect different temperature ranges and the sheets may further be variously sized or configured than shown here.

[0062] A variation of the temperature sensing material may be incorporated into a compliant balloon, as shown in FIG. 3. As seen, inflatable compliant balloon assembly 40 may be comprised of an inflatable balloon 42 which may be coated on the interior of the balloon 42, or the exterior of the balloon 42, or the temperature sensitive material may be incorporated or laminated within the balloon material. The balloon 42 may be an elastomeric balloon which allows it to cover and conform to the wall of a hollow body organ. The balloon 42 itself may be made from a biocompatible compliant material such as silicone, latex, polyurethane, polyethylene, polypropylene, etc. A detail 44 of the balloon wall cross-section is shown in this variation as having an emulsion of the temperature sensitive liquid crystal doped within the balloon material 46. For example, one such dopant is a cholesteryl ester based liquid crystal that changes color as temperature changes. One supplier of this type of material is Edmond Industrial Optics. Other dopants which may be used may include scintillation material such as gamma or beta radiation scintillation material. For gamma rays, a sodium iodide salt doped with Thallium would be useful. This particular scintillation material produces light at about the waveleng of 413 nm upon detecting gamma radiation. For beta radiation, an appropriate phosphor scintillation material may be used.

[0063] As the balloon 42 is inflated within a vessel lumen and comes into contact against the vessel walls, the heat from the walls are conducted into the balloon 42 and the balloon material 46 may change its color to accordingly reflect the temperature of the portion of the vessel wall in which the balloon 42 contacts. Various regions of the vessel wall being measured may reflect different relative temperatures. In order to measure the temperature profile of the vessel wall over the length and surface area of the balloon 42, an optical measurement device located within the balloon 42 may be utilized. In this variation, a fiber optic reflectometer 48 may be placed within the balloon 42 interior along its longitudinal axis (the reflectometer 48 may be placed in different areas within the balloon 42 interior in other variations, depending upon the desired results). The reflectometer 48 may be used to measure the variations in color indicated by the balloon wall 46 by emitting a light through an emission region 50, which may be located at or near the distal end of the fiber optic. The emission region 50 may also be utilized to receive the reflected light from the balloon 42 walls, as described in further detail below. Furthermore, the reflectometer 48 may be configured to transmit the light in various directions, and since the fiber optic can transmit light in either direction without bias, the angle of incidence may be the same as the angle of collection. To further facilitate temperature measurement, the outer surface of balloon 42 may optionally be coated with a reflective coating or alternatively with a black, non-glossy coating. [0064] FIG. 4 shows a representative illustration of one variation of the reflectometer assembly 60 (the balloon has been removed for clarity). As shown, an incident surface 64 may have located at a proximal end of the fiber optic 62 through which light may be transmitted into the fiber optic 62. This light may be transmitted through the body, which is preferably flexible, of the fiber optic 62 to the distal end or proximal to the distal end along the body of the fiber optic 62. At or near the distal end is a reflecting surface 66 which may be beveled or angled, e.g., at 45°, relative to the longitudinal axis of the fiber optic 62 to reflect the light perpendicularly. Surface 66 may alternatively be angled through a range of values depending upon the desired degree of light transmittance and reflectance. Surface 66 may also be used to receive the transmitted and reflected light 68 from the balloon wall. [0065] To supply the measurement light, light source 72, which may be a white light, laser diode, etc., may be used to produce emitted light 74. A polarizer 76 may optionally be used to filter the emitted light 74, particularly if a white light source is used. This filtered light 78 may then be directed into the proximal end of the fiber optic 62 using, e.g., beam splitter 70. Beam splitter 70 may also be used to receive the reflected light 80, which has been transmitted back through the fiber optic 62 from reflected light 68. This reflected light 80 may be passed through beam splitter 70 and received upon a charge-coupled diode (CCD) device, which may then transmit the reflected light 80 information into a signal 84 for processing by, e.g., a computer. Because the emitted and reflected light 52 gathers information from a portion of the balloon wall, the fiber optic 62 may be pulled or pushed through the balloon interior while also be rotated to achieve a 360° mapping of the balloon wall interior along the entire length of the balloon. The longitudinal and rotational direction of travel is indicated by arrows 86. During the rotational advancement or withdrawal of fiber optic 62 through balloon, the light may be continuously or intermittantly transmitted and received. The fiber optic 62 itself may be advanced or withdrawn continuously or only along specified regions of the balloon interior. Furthermore, rather than rotating the fiber optic 62, it may simply be advanced or withdrawn only translationally to obtain measurements along selected portions of the balloon, and hence the vessel. During the translation and/or rotation, the fiber optic 62 may also be stopped intermittantly to measure a scan at a specific location. FIG. 5 shows an example of a plot 90 of a spectral reflection received from the reflected light. Plot 90 shows the example of the measured wavelength, λ, versus the amplitude over a range of, e.g., 400 nm to 2000 nm.

[0066] FIGS. 6 and 7 show alternative variations of the optical fibers which may be used within the balloons. As seen in FIG. 6, a dual fiber optic variation 100 is shown where one fiber 102 may be used for transmitting light and a second fiber 104 may be used for receiving the reflected light. Alternatively, fiber optic 102 may be used for receiving the reflected light while fiber optic 104 may be used for transmitting the light. In either case, reflecting/receiving surface 106 may be configured to either transmit and/or receive the transmitted/reflected light 108. Another alternative variation may have both optical fibers 102, 104 both emitting and receiving the reflected light. Such a variation may reduce the distance that fiber optic assembly 100 is translated as well as increase the area scanned. Another variation 110 is shown in FIG. 7 in which multiple optical fibers may be employed. Assembly 110 may be comprised of a plurality of optical fibers 112_I-112_N offset from one another each having a corresponding refecting/receiving surface 114_I-114_N for each emitting and/or receiving light 116_I-116_N. Alternatively, a single optical fiber, e.g., 112ι, may be used to emit the light and the remaining fibers 112₂-112_N may be used to receive the reflected signals. Additional optical fibers may be used to emit the light while the remaining optical fibers may be used to receive the signals. Although only four optical fibers 112_I-112_N are shown in the figure, fewer or additional optical fibers may be utilized depending upon the desired results and practicability. In variations where multiple optical fibers are utilized, the diameters of these fibers are preferably small enough, e.g., 50 μm, to allow the adequate placement and positioning of the fiber optics while still allowing access into a hollow body organ. [0067] Another variation 120 on the balloon material may be seen in FIG. 8, which shows a portion of a balloon wall section 122. Rather than having a uniform coating of temperature sensitive material upon the balloon or integral to the balloon material, strips of the material 124 may be placed longitudinally along the length of the balloon to allow for positional encoding, e.g., analagous to optical shaft encoding in digital design. The strips of material 124 may be uniform in length with one another, alternatively, individual lengths of the temperature sensitive material 124 be varied in length. Inbetween each strip of material 124, a coating 126 having a color, e.g., black or reflective, not indicated or different from the range of possible colors indicated by the sensing material 124 may be placed therebetween. Coating 126 may also be a color-insensitive material.

[0068] To facilitate the resolution of the light being emitted or received by a fiber optic member, an optional lens 134, such as a collimating lens, may be placed adjacent to the reflective surface 132 of the fiber optic 130, as shown in FIG. 9. Such a collimating lens 134 may facilitate the resolution of the light by at least decreasing the amount of scattered light by focusing the emitted light against the balloon wall. Another option to facilitate light resolution and intensity is to place a highly reflective coating on reflective surface 132. Such a coating may include a variety of biocompatible reflective materials, e.g., silver, gold, etc. [0069] An alternative balloon assembly 140 may optionally include an occlusive balloon or member to temporarily occlude the flow of blood within the vessel lumen to facilitate accurate temperature measurement against the vessel wall. Balloon 142 is shown in FIG. 10 along with a layer of the temperature sensitive 144. Within balloon 142 are light emitting fiber 146 and light receiving or sensing fiber 148; the emitting and receiving fibers may be alternated. As shown in balloon assembly 140, an additional occlusion balloon 152 may be placed proximally, as shown here, or distally of balloon 142 along a length of catheter 150. Occlusion balloon 152 may be independently inflated relative to the inflation of balloon 142 or both balloons 142, 152 may be inflated through a common inflation lumen within catheter 150. Furthermore, both balloons 142, 152 may be inflated simultaneously or sequentially, i.e., either occlusion balloon 152 is inflated before balloon 142 or balloon 142 is inflated before occlusion balloon 152.

[0070] Rather than occluding the blood flow through the vessel, another alternative device 160 is shown in FIG. 11 which allows blood or fluids to pass through the device itself. As shown, balloon assembly 160 has balloon member 162 with a coating of temperature sensitive material 164 surrounding emitting fiber optic 166 and receiving fiber optic 168. The fiber optic assembly 166, 168 may be retained within balloon 162 by fastening band 170, which may fasteningly hold fiber optic assembly 166, 168 relative to one another and relative to the assembly 160. Fastener 170 may be configured to be translationally as well as rotatably slidable over an outer surface of flow-through channel 178 within balloon 162 while maintaining the positioning of fibers 166, 168. When a temperature measurement is made, balloon 162 may be inflated into contact with the vessel walls. Once balloon 162 is inflated, blood or fluid flow through the vessel may be occluded by balloon 162 but the blood or fluid may still flow into one or several entrance ports 176 defined along catheter body 172 proximally (or distally) of balloon 162. The blood or fluid flow is shown by flow path 174. The blood or fluid entering entrance port(s) 176 may then flow within flow-through channel 178 defined within catheter body 172 through the length of balloon 162 and exit through one or several exit ports 180 defined near or at the distal end of the assembly 160.

[0071] Another variation of the balloon device is seen in balloon assembly

190 in FIG. 12. In this variation, dual temperature sensitive strips having different temperature ranges may be used for temperature indication at both low and high temperature differences. For instance, a first set of temperature sensitive strips 194 may be disposed longitudinally while uniformly spaced apart from one another upon the balloon wall 192. These strips 194 may be configured to indicate a temperature difference in the vessel walls within a range of, e.g., 25°-30° C. A second set of temperature sensitive strips 196 may be interspersed longitudinally and inbetween each of the first set of strips 194 upon balloon wall 192. The second set of strips 196 may be configured to indicate a temperature difference in the vessel walls within a range of, e.g., 30°-35° C. The adjacent placement of each of the strips 194 or 196 relative to one another may be uniform or varied, depending upon the desired measurement results. Furthermore, the temperature ranges indicated by the strips 194, 196 may also be varied depending upon the range of temperature increase to be indicated. For instance, first set of strips 194 may be configured to detect temperatures within a range of, e.g., 30°-35° C, while second set of strips 196 may be configured to detect temperatures within a range of, e.g., 35°-40° C. [0072] In addition to sensing and mapping temperature differences within hollow body organs, the devices described herein may also be optionally configured to provide hyperthermic or thermal therapy to ablate diseased tissue. Such diseased tissue is generally heated to elevated temperatures, e.g., above 41° C and up to 44" C, while adjacent healthy cells are maintained at lower temperatures to prevent damage. Alternatively, cryogenic fluid may be used to freeze the walls of the vessel or even laser or ultrasonic energy may be utilized. The balloon variation 200 shown in FIG. 13 is one variation in which the temperature profile of a tissue region may be first measured to indicate whether a diseased region exists by expanding balloon 202 and placing the temperature sensitive coating 204 against the tissue wall. The tissue region may be mapped by emitting fiber 206 and receiving fiber 208 receiving the reflected light 210. If a diseased region of tissue is determined to exist adjacent to the balloon walls 202, a heated biocompatible fluid 216, e.g., water, saline, etc., may be pumped or urged into the balloon lumen through fluid entry port 212. Entry port 212 may be located centrally within the balloon 202 or it may also be located distally or proximally (as shown) within the balloon 202. The charged fluid 216 may enter the balloon interior and heat the walls of balloon 202, which in turn heats the walls of the contacted vessel tissue. The discharged or spent fluid 218 may then be pumped out of balloon 202 via fluid exit port 214, which may be located distally (as shown) or proximally within the balloon 202. The entry port 212 and exit port 214 may be located adjacently to one another, however, they are preferably located one proximally and the other distally, or vice versa, to optimize the amount of heat transferred to the tissue. The fluid delivery channels for entry port 212 and exit port 214 may be disposed within the catheter and balloon as integral fluid tubes or as separate tubes made, e.g., of polymeric materials.

[0073] FIG. 14 shows a computer-generated image 220 showing one example of a 3 -dimensional representation of a temperature profile 222. This temperature profile 222 is merely one representation based upon readings from the color-indicated temperature-sensitive material placed in contact against a vessel wall. The profile 222 may be displayed in one of a variety of ways, e.g., color-coded temperature profiles, contour lines indicating temperature differences, temperature values on the figure, etc. [0074] In order to control the fiber optic drive mechanisms and measurement processing, various control methodologies may be employed. One variation on a control system is shown in FIG. 15, which is a representation of controller system 230. Light may be generated by light source 238, e.g., a white light source such as a xenon light, laser diode, etc., which provides the light energy for transmission through lens 240 and entry through proximal end 234 of emitting fiber optic 232. Light source 238 may also be a strobed light source for reducing the amount of heat generated. This light energy is transmitted through fiber optic 232 and emitted through, e.g., diffusing distal end 236, much as described above. The reflected light may be received by sensing fiber optic 242 through receiving portion 244. In this variation, emitting fiber optic 232 may remain stationary relative to the balloon within which it may be positioned and receiving fiber optic 242 may be translationally and rotationally withdrawn or advanced within the balloon device. Alternatively, both emitting fiber optic 232 as well as receiving fiber optic 242 may both be translationally and rotationally withdrawn or advanced. In order, for instance, to withdraw receiving fiber optic 242, fiber optic 242 may be operably connected to drive screw 246 via rotational motor 252 and threaded coupler 250. Drive screw 246 in turn may be rotatingly connected to linear motor 248. Rotational motor 252 may be used to rotate fiber optic 242 about its own longitudinal axis for receiving the reflected signal through 360° within the balloon interior. Linear motor 248 may be used to selectively rotate drive screw 246 such that its rotational motion is translated into linear motion by coupler 250. Thus, as drive screw 246 is rotated, rotational motor 242 and fiber optic 242 is advanced or withdrawn within the balloon depending upon the direction of rotation of drive screw 246. [0075] As fiber optic 242 is advanced or withdrawn, a proximal portion of fiber optic 242 may be looped once or several times to provide slack for the translational motion of fiber optic 242. Additionally, to accommodate the rotational motion of fiber optic 242 about its longitudinal axis, the proximal end of fiber optic 242 may be connected to rotatable coupler 254, which may provide for rotation of the assembly while maintaining a fixed position relative to a receiving lens or prism 258. A lens or prism 258 may be used for dispersing the received light signals 260 upon a detector, such as CCD 262. The received signals from CCD 262 may be transmitted via electrical line 266 and the control signals to and feedback from motors 248, 252 may be transmitted via electrical line 268. The signals from both lines 266, 268 may be transmitted via signal line 270 to controller 264, e.g., a CPU, for not only controlling the motors but also for processing the received signals for displaying upon, e.g., a video display 272 showing a 3-dimensional representation of the results, as discussed above. The assembly 230 may be integrated into a single unit 276 which incorporates many of the features described above.

[0076] In controlling the withdrawal and/or advancement of the optical fibers within the balloon, a scanning algorithm may be used which ensures a complete scanning area. One variation of a scanning algorithm 280 is seen in FIG. 16A, which shows spiral scanning pattern 282 within balloon 284. The pitch of the spiral scan pattern 282 may be uniform or varied; furthermore, it may be a relatively tighter pitch to ensure higher resolution of the reflected signals. FIG. 16B shows another scanning variation 290 having a linear scanning pattern 292 over balloon 294. In this variation, the optical fiber may be advanced or withdrawn linearly, rotated slightly, and then advanced or withdrawn linearly in the opposite direction, and so on, until the entire balloon 294, or a desired portion thereof, has been scanned. [0077] During a scanning algorithm, the temperature measurement may be timed by the processor or CPU to take a measurement simultaneously as the light is pulsed on, as shown in the representative chart 300 in FIG. 16C. A light source may be continuously on during a scanning procedure, but to reduce the power and to minimize the amount of heat generated by the light being emitted into the balloon interior, the light may be strobed or pulsed. Accordingly, to facilitate the temperature measurement, the control assembly may be configured to take readings during periods when the light is pulsed on. [0078] A further variation on the optical fibers may be seen in FIGS. 11, which shows a portion of optical fiber bundle 310. Fiber bundle 310 is a fiber optic variation which may remain stationary within the balloon, thereby eliminating the need for any rotational or linear motors. Because it may be comprised of several dozen to several hundred fibers, it may be stepped into a number of corresponding body segments 312_I-312_N where each step may correspond to a region where light is emitted and/or received 314_I-314_N. Each successive body segment 312_I-312_N may have a diameter which is smaller than a proximally located segment. Moreover, the number of segments may correspond to the number of individual optical fibers included within fiber bundle 310. FIG. 18 shows a representative 2-dimensional convoluted image 320 which may be generated by a CCD in communication with a proximal end of fiber bundle 310. Image 320 may further represent temperature differences 322 through colored profiles or through any of the other methods described above. The resolution of image 320 may vary depending upon the number optical fibers in fiber bundle 310.

[0079] Another variation on the optical fibers is shown in FIG. 19 in fiber variation 330, which is configured to utilize only linear withdrawal or advancement and to eliminate the need for rotational motion of the optical fiber. This variation also comprises a fiber bundle 332 of a plurality, i.e., two or more, individual optical fibers 334 which may be arranged circumferentially within bundle 332. A reflector 336, which may be conically-shaped or faceted, may be placed at the distal end of fiber bundle 332 to correspondingly reflect the emitted or reflected light 338 in a "halo" or circumferential pattern. Accordingly, fiber bundle 332 does not need to be rotated in order to obtain a full 360° scan, but need only be advanced or withdrawn within the balloon to scan along the length of the balloon.

[0080] Yet another variation on the optical fibers is shown in FIG. 20 in variation 340. In this variation, two or more optical fibers 342, 344 each having a corresponding reflector 346, 348 at each distal end may be placed circumferentially about lumen 354 to emit and receive light signals 350, 352. Lumen 354 may act as a flow-through channel to allow fluid flow 356 through the device while allowing the optical fibers to take measurements unobstructed and without having to rotate a single optical fiber about lumen 354 to obtain a full scan of the balloon interior. [0081] Another variation on a temperature measurment device is shown in

FIG. 21, which is a cross-sectional view of a thermochromic needle suitable for insertion into tissue. The needle assembly 360 may include an elongate needle or trocar body 362 in which the temperature sensitive material 364 may be coated on the interior surface of body 362. Needle body 362 may be made of a biocompatible material having sufficient strength, e.g., stainless steel, etc., for insertion into tissue and may define a lumen throughout the length of needle body 362. Material 364 may alternatively be coated onto the exterior of needle body 362 but needle body 362 would preferably be made of a translucent material, e.g., plastics, polymers, etc. A closed piercing tip 366 may be placed at the distal end of needle body 362 to facilitate insertion of needle assembly 360 into the tissue. Optical fiber 368 having a reflective end 370, of the type described above which is configured to simultaneously take a 360° measurement, may be disposed within needle body 362 and advanced or withdrawn 372 through needle body 362 to effect temperature measurement. FIGS. 22A and 22B show fiber optic variations which may be used within needle assembly 360. As shown in FIG. 22 A, optical fiber 380 shows fiber body 382 having a reflector 384 disposed distally of fiber 382 for reflecting both emitted and reflected light 386. The distal end of fiber 382 may be flat or perpendicularly formed relative to the optical fiber body 382 and reflector 384 may be conically-shaped or faceted, as described above. In FIG. 22B, optical fiber 390 shows fiber body 392 having a conically-shaped reflective distal end, as described above, for emitting and receiving reflected light 396. Both variations 380, 390 may be used with needle assembly 360 to produce the halo or circumferential scanning effect.

[0082] FIG. 23 shows another variation 400 which utilizes a glass tube 402 upon which temperature sensitive material 404 may be coated. The material 404 may be coated on the interior or upon the exterior of tube 402. In this variation, light may transmitted through the glass tube 402 itself to provide the illumination and optical fiber 410 may be translated within lumen 408 for scanning the temperature indications. Glass tube assembly 400 may further include a piercing tip 406 to facilitate entry into tissue. The glass tubing 402 may be made from conventional glass material, but it may also be made of translucent plastics or polymers. [0083] Another alternative may be seen in FIG. 24, which shows a coiled guidewire device 420 having multiple radially configurable coils 422. A thermochromic coating 424 may be lined within the interior of guidewire 420. A shape memory alloy wire 428, e.g., nitinol, or a spring steel wire, e.g., stainless spring steel, may be positioned within the length of guidewire 420 along with sensor 426. In operation, guidewire 420 may be delivered into and through the body as a straightened member. Upon deployment and once in contact with the temperature of the vessel environment, shape memory alloy wire 428 may reconfigure itself into a series of coils 222 for urging guidewire 420 into contact with the walls of the vessel. Once guidewire 420 is fully reconfigured and is in contact with the vessel walls, sensor 426 may be withdrawn through guidewire 420 while taking temperature measurements therethrough. Further details of the apparatus and methods are described in commonly owned and co-pending U.S. Patent Application Serial Nos. 09/904,012 and 09/904,080, both of which were filed July 12, 2001 and both of which are incorporated herein by reference in their entirety. [0084] Another alternative is shown in FIG. 25 in which temperature measurement assembly 430 may utilize a liquid crystal emulsion 442. Such an emulsion 442 may be configured to change its opacity as a function of temperature. Thus, the emitted light 438 transmitted from light source 436 through emitting fiber optic 432 passes through emulsion 442. As the light is reflected from reflecting surface 444, it passes through emulsion 442 and the absorption of the reflected light causes modulation of the light 440 as a function of temperature. This modulated light 440 may then be received by sensing fiber 434 for detection by CCD detector 446. [0085] An alternative balloon which may be used with most, if not all, of the variations described above is shown in FIGS. 26A and 26B. A linearly everting balloon 450 is shown which may be used to obtain a thermal profile of a long section of a vessel, e.g., a coronary artery. Such an everting balloon may be made from various polymers or latex. Balloon 450 may be made of a balloon wall 452 which everts inwardly upon itself during delivery and deployment. When desirably deployed within a vessel, a pressured gas or fluid, e.g., saline, water, etc., may be pumped into the balloon 450 cause it to linearly expand, as indicated by direction 454 in FIG. 26A. Once fully expanded and desirably positioned within a vessel, e.g., coronary artery section 466, fiber optic 460 may be advanced into the expanded balloon 450 for taking measurements 462 while fiber optic 460 is advanced or withdrawn 464 within the balloon. [0086] To improve the quality of the light signals emitted and subsequently reflected over any incident light, a spectrum modulating system 470, such as the example shown in FIG. 27, may be used. In this variation, light source 472 may emit light which is passed through collimating lens 474. The light emitted and passed through lens 474 is unfiltered light with multiple infrared (IR) peaks throughout its spectrum, as demonstrated by the wavelength-amplitude plot 480. IR filter 476 may be used to filter out the IR spectrum from the emitted light to result an IR free spectrum, as evidenced by the wavelength-amplitude plot 482. Additional filters 478 may be used as frequency equalizers to filter out various wavelengths λi-λ to result in filtered light 488 having a spectrum which is fairly constant over a broad range of wavelengths and which has amplitude variations 486 of preferably less than 10%, as shown by the wavelength-amplitude plot 484. Filtered light 488 may then be passed through lens 490 for transmission through fiber optic 492 and through distal end 494. The number and type of filters may be varied depending upon the type of light spectrum that is desired.

[0087] The numerical aperture (angle of the cone of light acceptance) or the field of view of the catheter is determined by the inherent numerical aperture of the fiberoptic or by a collimating optics system. The collimation of the light entering the fiberoptic will reduce the area on the inside of the balloon that is "looked at" by the fiberoptic (pixel size) and therefore increase the "resolution of the system". The fiberoptic 's numerical aperture can be chosen by selecting its core/clad indices of refraction and applying the appropriate formulas.

[0088] In determining the temperature value associated with a certain color,

FIGS. 28A to 28C demonstrate the temperature-color correlation for a temperature range of 35°-40° C, in this example. As seen in the figures, a temperature of 35° C may correlate to an indicated color of red, as in plot 500, a temperature of 37° C may correlate to an indicated color of green-yellow, as in plot 502, while a temperature of 40° C may correlate to an indicated color of blue, as in plot 504. Alternatively, a system of discrete, individually adjusted colors may be used to produce an equalized spectrum, as shown in the spectrum equalizer assembly 510 in FIG. 29. As shown, several separate light sources 512_I-512_N may be used to emit light, which may be passed through corresponding collimating lenses 514_I-514_N. The light from each light source 512I-512_N may then be passed through a corresponding color filter 516ι- 516_N to filter out specific wavelengths of light and allow only certain wavelengths to pass therethrough. Each individual filter 516_I-516_N may be configured to filter specified wavelengths different from each of the other filters. Once the light has been filtered, they may be passed through corresponding neutral density filters 518_I-518_N and finally to corresponding beam splitters 520_I-520_N which may direct the individual beams of light through a lens 522 and into fiber optic 524 to emitter 526. The emitted light is thus composed of discrete, individually adjusted colors having a fairly equalized spectrum for comparison to the reflected light, as shown in the plot 528. [0089] Prior to or after temperature measurement of a vessel region, areas where unstable plaque are located may be vulnerable to rupture, either naturally or through agitation by physical contact by a measurement device. Therefore, a region of unstable plaque may be artificially covered by a fibrous cap, e.g., a hydrogel- cohesive material optionally incorporating glutaraldehyde, having a thickness of, e.g., 60-80 μm, to lend some stability and to lower the chances of rupture. FIG. 30 shows an area of a vessel 530 having inflammatory cells 536 within a region of vulnerable plaque 534 within the walls of vessel 532. There are various methods for delivering and covering vulnerable plaque with a fibrous cap. For instance, FIG. 31 A shows one variation in which delivery catheter 540 may be configured with one or more delivery ports 542 near or at the distal end for deliverying hydrogel 544 therethrough. FIG. 3 IB shows another variation in which catheter 546 may simply be coated with a layer of hydrogel 548 along the outer surface of the catheter near or at the distal end of catheter 546. Yet another variation may be seen in FIG. 31C, which is a balloon catheter 550 which may have a hydrogel coating 554 on an outer surface of inflatable balloon 552. When catheter 550 is desirably positioned adjacent to a region to be coated, balloon 552 may be simply inflated such that it come into contact with the vessel and thereby transfers the hydrogel 554 directly onto the vessel walls and onto the vulnerable plaque.

[0090] Another variation on a device for stabilizing a region of vulnerable plaque is shown in FIG. 37. Stabilization catheter assembly 640 is shown positioned within a vessel 642 having a region of vulnerable plaque 644. Catheter assembly 640 comprises catheter 646 which may have two or more stabilization balloons 648, 650 for isolating vulnerable plaque 644 therebetween. The vulnerable plaque 644 to be treated may first be isolated by advancing catheter 646 adjacent to the tissue such that balloons 648, 650 are located proximally and distally of the tissue. Balloons 648, 650 may then be inflated to temporarily block the flow of blood between the inflated balloons 648, 650. Once the region of plaque 644 has been isolated from the rest of the vessel 642, the hydrogel cohesive material or glutaraldehyde may be pumped through catheter 646 and into the region of vessel 642 between balloons 648, 650 via delivery tube 656 and through delivery port 658, which is located between balloons 648, 650. The pumped-in hydrogel may then be utilized to coat plaque 644 with fibrous cap 664 to stabilize it until further treatment may be effected. The hydrogel may be removed from the region via a vacuum force through aspiration port 654, also located between balloons 648, 650, and carried away through catheter 646 via aspiration tube 652. During this procedure, the hydrogel may be isolated from the remainder of vessel 642 by balloons 648, 650. To enable blood flow to continue during this particular procedure, a flow-through channel may be provided through catheter 646. Blood or fluids may enter catheter 646 through port 660, which is defined proximally of balloon 648, and continue to flow through catheter 646 for exit through exit port 662, which is located distally of balloon 650. Although this variation shows the use of two balloons for isolating a single region of tissue, other variations may utilize multiple balloons for selectively isolating multiple regions of tissue.

[0091] FIGS. 32, 33A, and 33B show yet another alternative variation of the invention where a wound spring guidewire assembly 560 is used for the purpose of temperature profiling. This guidewire assembly 560 has a guidewire 564 which may be coiled to form a tubular structure which is hollow and which terminates in distal end 566. Guidewire 564 itself may then be wound into larger coils 562 for contacting the walls of the hollow body organ. As shown in FIG. 33 A, delivery catheter assembly 580 may be used to deliver guidewire assembly 584 through the body with delivery catheter 582. Guidewire 584 may be made from a shape memory alloy such as nitinol, as described above, and it may be pre-configured to form a helical or spiral structure for reconfiguring itself from a straightened configuration into its helical or spiral configuration upon deployment from catheter 582.

[0092] The shaping of the guidewire can take place in two fashions. It can either be made out of spring steel or nitinol and contained within a sheath and then released. Upon release, the guidewire will take the preshape representing the lowest energy state and become a length of repeating loops.

[0093] The other way shaping can take place is to use the martensitic transformation properties of nitinol. The guidewire may be inserted into a sheath in its straight form and kept cool within the sheath by the injection of cold saline through the sheath and over the guidewire. Upon release of the guidewire into the bloodstream, it will warm up and change to its austenite memory shape based on the well known martensitic transformation by application of heat and putting the material through its transformation temperature.

[0094] The guidewire can also be made out of a composite such as a nitinol tube within the guidewire structure. In this fashion, the martensitic or superelastic properties of nitinol can be combined with the spring steel characteristics of the spring and lead to a desirable composition.

[0095] Within the guidewire lumen, a temperature sensor 568, e.g., a thermistor, thermocouple, thermoresistive detector such as a resistance temperature detector (RTD), etc., coupled to signal line 570 can be placed therewithin to measure the wall temperature. By moving the temperature sensor 568 from one location to another, as shown by the direction of travel 572, the temperature of the guidewire wall, which should be in substantial equilibrium with the vessel wall, can be measured. If there is any gradient between the vessel wall and the guidewire wall, the difference between the temperatures at different locations along the guidewire wall can be used to map the profile by looking at the deltas of temperature rather than the absolute temperatures. The predominant temperature, which is the temperature of the body or close to that, can then form the baseline and the hyperthermic areas can be distinguished from that. FIG. 33B shows an example of device deployment 586 where guidewire assembly 560 is deployed within vessel 588. Guidewire 560 may be deployed from delivery catheter 594 within vessel lumen 592 over a region of vulnerable plaque 590. To deploy guidewire assembly 560, the distal end of catheter 594 may be first positioned distally of plaque 590 while guidewire 560 is initially deployed. As guidewire 560 is urged out of the distal end and into lumen 592, catheter 594 may be slowly pulled back proximally such that guidewire assembly 560 is deployed along the vessel wall 588 over plaque 590 or tissue region of interest. As the guidewire assembly 560 is ejected from catheter 594, it may slowly reconfigure itself into the helical or spiral shape and come into gentle contact against the vessel wall 588. Additional details on the deployment of this variation may be seen in U.S. Patent Application Serial Nos. 09/904,012 and 09/904,080, both of which have been incorporated herein by reference above.

[0096] As shown in guidewire assembly 600 in FIG. 34, the temperature sensor may be placed inside of another tube 604 to give guidewire 602 and the temperature sensor added structural strength. The second tube 604 may be made out of a very thin layer of a lubricous polymer such as Teflon, polyethylene or other lubricious polymers as known in the art. Alternatively, tube 604 may be made from a shape memory alloy, such as nitinol, or a thin spring stainless steel tube. The guidewire's 602 loops may also be coated with a lubricous material such as PTFE to aid its use and aid the insertion and removal of the thermocouple. The coating on the adjacent loops of the guidewire 602 helps to thermally isolate the adjacent loops from one another and make the thermal mapping more precise. In other words, it will reduce the spread of heat from a hot zone to a normothermic zone. [0097] A sensing and control mechanism may be provided on the proximal end of the guidewire 602 where the sensor can be pulled out of the guidewire at a controlled rate, which may be constant or variable. These types of mechanisms are well explained in the prior art. As the sensor is pulled out towards the proximal end, the controller will know the position of the temperature sensor relative to the position of the tip of the guidewire and therefore the difference. It can then assign that point a temperature and can therefore create a two dimensional map of the temperature distribution of the guidewire which includes the temperature values along the guidewire's length. By knowing the approximate diameter of the loops that the guidewire has made inside the vessel, an approximate, cylindrical three-dimensional map of the inner temperature of the vessel wall can be generated. Further details may be found in U.S. Patent Application Serial Nos. 09/904,012 and 09/904,080. [0098] A variation of the guidewire can be made in the form of a multipronged guidewire 610 in which a guidewire 614 may have a plurality, i.e., two or more, radially extending prongs or arms 616 where the tip of each prong contains a sensor 618. This structure 610 may be pulled proximally through a vessel 612 while the prongs 616 are gently touching the walls and sensing the temperature of the wall. [0099] The guidewire variations described above can also be used to detect radiation emitted from the wall from a radioactive tracer taken up previously by the cells within the inflammatory region. In this case, the guidewire or a tube within it may be doped with a scintillation material and the fiberoptic sensor within the guidewire may transmit the photons out of the immediate region and block the adjacent region. Again a three dimensional map of the radiation intensity can be generated in an analogous way as described earlier.

[0100] Various methods may be utilized to ensure intimate contact of the sensor with the wall of the guidewire. FIG. 36 shows one variation in guidewire assembly 620. Guidewire 622 itself may be utilized as a portion of a thermocouple measurement device where spring 624 extends from thermocouple joint 628 and contacts guidewire 622 at contact point 626. Thermocouple lead 630 extends from joint 628 while the guidewire 622 is then able to act as the corresponding lead for the thermocouple.

[0101] Another method of treating areas with vulnerable plaque 674, 676 is by heating the blood entering the artery to up to 40°-44° C, as shown by catheter heating assemlby 670 in FIG. 38. One variation of accomplishing this is by inserting a heating element 680 into the lumen 678 of vessel 672. The heating member 680, having a large blood contacting area, will be placed inside the vessel 672 and blood flowing over it is heated to the desired temperature. Heating member 680 can be in electrical communication through transmission line 682 with power generator and CPU 684, which is located outside the patient. Another way to heat the arterial wall is by using a special angiographic catheter where blood is sucked into the catheter at a location proximal to its tip, which is located inside the coronary artery. A heating element located inside the angiographic catheter is used to heat the blood as it passes through the catheter and enters the coronary artery or other arteries. In this fashion, a long heating time (e.g., more than 30 minutes) can be used without compromising the patient.

[0102] With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.

[0103] Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

Claims

CLAIMS What is claimed is:

1. An apparatus for measuring the temperature of a region of tissue comprising: an inflatable balloon member having a proximal end and a distal end and being capable of conforming to the region of tissue, wherein at least a portion of the balloon member is adapted to exhibit a predetermined color change when the balloon member contacts an area having a predetermined temperature; and at least one optical fiber extending from within the balloon member to a proximal end of the apparatus, wherein the optical fiber is adapted to be moved relative to the balloon member and receive a light reflected within an interior of the balloon member.

2. The apparatus of claim 1 wherein the balloon member further comprises a temperature sensitive liquid crystal material disposed at least partially over an exterior or interior surface of the balloon member.

3. The apparatus of claim 2 wherein the liquid crystal material is disposed longitudinally upon the balloon member in strips.

4. The apparatus of claim 1 wherein the portion of the balloon member is further adapted to exhibit a second predetermined color change when the balloon member contacts the area having a second predetermined temperature.

5. The apparatus of claim 4 wherein the balloon member further comprises a second temperature sensitive liquid crystal material.

6. The apparatus of claim 1 wherein the temperature sensitive liquid crystal material is incorporated into the balloon member.

7. The apparatus of claim 1 wherein the predetermined color change corresponds to a specifiable temperature range.

8. The apparatus of claim 1 wherein the balloon member further comprises an outer surface having a reflective or black coating.

9. The apparatus of claim 1 wherein the balloon member is an evertable balloon.

10. The apparatus of claim 1 wherein a distal end of the at least one optical fiber comprises an angled surface for reflecting the emitted light and the reflected light.

11. The apparatus of claim 10 wherein the angled surface is angled at 45° relative to a longitudinal axis of the optical fiber.

12. The apparatus of claim 1 wherein the distal end is coated with a highly reflective material.

13. The apparatus of claim 1 further comprising at least one additional optical fiber adjacently positioned with the at least one optical fiber.

14. The apparatus of claim 1 wherein the inflatable balloon member is attached to a catheter having a proximal end, a distal end, and defining a lumen therebetween.

15. The apparatus of claim 14 wherein the catheter defines a flow-through lumen partially therethrough extending from an opening defined in the catheter proximally of the balloon member to the distal end of the catheter.

16. The apparatus of claim 14 further comprising a second inflatable balloon member positioned along the catheter proximally of the inflatable balloon member.

17. The apparatus of claim 1 further comprising a heat exchanger positioned within the balloon member for passing a heated fluid through an interior of the balloon member for heating a wall of the balloon member.

18. The apparatus of claim 1 wherein a distal end of the optical fiber is adapted to reflect an emitted light onto an interior surface of the balloon member and wherein the distal end is further adapted to receive a reflected light from the interior surface

19. The apparatus of claim 18 wherein the optical fiber is adapted to reflect the emitted light in a circumferential pattern onto the interior surface of the balloon member.

20. The apparatus of claim 1 further comprising a light source for producing an emitted light.

21. The apparatus of claim 20 wherein the light source is selected from the group consisting of white lights, lasers, and LEDs.

22. The apparatus of claim 20 wherein the emitted light is pulsed.

23. The apparatus of claim 20 further comprising a lens for collimating the emitted light.

24. The apparatus of claim 20 further comprising at least one filter for filtering a predetermined wavelength of light from the emitted light.

25. The apparatus of claim 1 comprising an actuator adapted to move the optical fiber longitudinally within the balloon member.

26. The apparatus of claim 1 comprising an actuator adapted to move the optical fiber rotationally about a longitudinal axis of the balloon member.

27. The apparatus of claim 26 further comprising a rotational coupler attached to a proximal end of the optical fiber.

28. The apparatus of claim 1 further comprising a detector adapted to receive the reflected light and transmit an electrical signal corresponding to the reflected light.

29. The apparatus of claim 28 wherein the detector comprises a CCD.

30. The apparatus of claim 1 further comprising a processor adapted to control a movement of the optical fiber within the balloon member.

31. The apparatus of claim 30 wherein the processor is in communication with the optical fiber.

32. The apparatus of claim 1 wherein the optical fiber is adapted to scan the interior of the balloon member in a spiral or helical pattern.

33. The apparatus of claim 1 wherein the optical fiber is adapted to scan the interior of the balloon member in a linear pattern.

34. A method of measuring the temperature of a region of tissue comprising: inflating a balloon member against the region of tissue to be measured, wherein at least a portion of the balloon member is adapted to exhibit a predetermined color change when the balloon member contacts an area having a predetermined temperature; emitting a light onto an interior surface of the balloon member; receiving the light reflected from the balloon member with an optical fiber located within the balloon member, wherein the optical fiber is adapted to be moved relative to the balloon member; and transmitting the reflected light proximally through the optical fiber.

35. The method of claim 34 wherein inflating the balloon member against the region of tissue comprises inflating the balloon member within a hollow body organ.

36. The method of claim 34 wherein emitting the light onto the interior surface comprises emitting the light with the optical fiber located within the balloon member.

37. The method of claim 34 wherein emitting the light onto the interior surface comprises emitting the light with an LED located within the balloon member.

38. The method of claim 34 wherein emitting the light onto the inerior surface comprises emitting the light in a pulsed pattern.

39. The method of claim 34 further comprising moving the optical fiber relative to the balloon member while transmitting the reflected light.

40. The method of claim 39 wherein the optical fiber is moved longitudinally.

41. The method of claim 39 wherein the optical fiber is moved rotationally about a longitudinal axis of the balloon member.

42. The method of claim 34 further comprising filtering the light prior to emitting the light onto the interior surface.

43. The method of claim 34 further comprising controlling a position of the optical fiber within the balloon member with a processor.

44. The method of claim 34 further comprising heating the region of tissue.