Claims
- 1. A method of detecting along a vessel wall an atherosclerotic plaque at risk of reducing fluid flow within said vessel, the method comprising determining whether said plaque or a region thereof exhibits an elevated temperature compared to the temperature of at least one adjacent vessel wall site.
- 2. A method of identifying an atherosclerotic plaque at risk of rupture or thrombosis in a living vessel, the method comprising measuring the temperature of at least two sites along the lumen wall of said vessel and detecting a temperature elevation of about 0.4 to 4° C. at one said site compared to the temperature of at least one other said site.
- 3. The method of claim 1 or 2 further comprising determining average vessel wall temperature and measuring a temperature difference of about 0.4 to 4° C. between at least one vessel wall site and said average temperature.
- 4. The method of claim 3 wherein said measuring comprises measuring a temperature difference of at least about 1.5° C. between at least one said site and said average vessel wall temperature.
- 5. The method of claim 1 or 2 further comprising obtaining an intravascular ultrasound image of said atherosclerotic plaque.
- 6. The method of claim 1 or 2 further comprising introducing a heat detecting catheter into a vessel of a living subject.
- 7. The method of claim 6 wherein said step of introducing a heat detecting catheter comprises:
inserting an infrared imaging catheter into said vessel, said infrared imaging catheter having a flexible housing enclosing
a flexible imaging bundle containing a plurality of coherent optical fibers, a circumferential window in said housing adapted for contacting said vessel wall, and a guidewire lumen.
- 8. The method of claim 7 further comprising inserting into a vessel lumen of a living subject a guiding catheter having an inflatable occluding balloon, an inflation lumen and a catheter receiving lumen.
- 9. The method of claim 6 wherein said step of introducing a heat detecting catheter comprises introducing a thermocouple basket catheter having a point of maximum outer diameter when deployed, at least one channel containing a pair of electrically insulated thermocouple wires, and a thermocouple junction situated at said maximum diameter point and disposed inside said channel between a thermally conductive layer and a thermally insulating layer.
- 10. The method of claim 6 wherein said step of introducing a heat detecting catheter comprises introducing a thermistor basket catheter having a point of maximum outer diameter when deployed and at least one channel containing a resistive temperature device situated at said maximum diameter point.
- 11. The method of claim 6 wherein said step of introducing a heat detecting catheter comprises introducing a introducing a catheter chosen from the group consisting of an intravascular ultrasound catheter, an intravascular magnetic resonance imaging catheter, a liquid crystal thermometry catheter and a near-infrared spectroscopy catheter.
- 12. The method of claim 11 wherein said non-invasive temperature measuring step comprises employing magnetic resonance imaging.
- 13. The method of claim 1 or 2 wherein said determining or measuring step comprises non-invasively measuring the temperature of said at least two sites using infrared, microwave, or magnetic resonance imaging.
- 14. An infrared imaging catheter comprising a flexible housing enclosing
a flexible imaging bundle containing a plurality of coherent optical fibers, said bundle disposed about a guidewire lumen extending longitudinally through said catheter, a circumferential IR transmissive window in said housing adapted for contacting said vessel wall; and a guidewire lumen.
- 15. The catheter of claim 14 further comprising a reflective surface in optical communication with said window and said optical fibers.
- 16. The catheter of claim 14 wherein said plurality of fibers have tips bent radially outward and terminating adjacent said window.
- 17. The catheter of claim 14 further comprising a flushing lumen.
- 18. The catheter of claim 14 wherein said guidewire lumen is also a flushing lumen.
- 19. The catheter of claim 14 further comprising an inflatable occluding balloon and an inflation lumen.
- 20. An infrared imaging catheter comprising a flexible housing enclosing
a flexible imaging bundle containing a plurality of coherent optical fibers, said bundle disposed about a guidewire/flushing lumen extending longitudinally through said catheter; a circumferential window in said housing adapted for contacting said vessel wall; and a reflective surface in optical communication with said window and said optical fibers.
- 21. An intravascular infrared imaging catheter assembly for detecting temperature heterogeneity along a vessel wall, said assembly comprising:
the infrared imaging catheter of claim 20; and a guiding catheter having an inflatable occluding balloon, an inflation lumen in communication with said balloon, and a guiding lumen adapted for slidingly receiving said infrared imaging catheter.
- 22. The catheter assembly of claim 21 further comprising means for applying 38° to 45° C. heat to said vessel wall.
- 23. An infrared imaging catheter assembly comprising:
the catheter of claim 14;an infrared array detector; a signal processor; a microcontroller programmed for receiving, storing, analyzing and reporting temperature information obtained from a plurality of sites along a vessel wall; a display system; and a user interface, said infrared imaging bundle being in optical contact with said infrared array detector, said detector being in electrical contact with said signal processor, said signal processor being in electrical contact with said display system and microcontroller, and said microcontroller being in electrical contact with said user interface.
- 24. The catheter assembly of claim 23 further comprising a source of infrared radiation operatively connected to said imaging bundle.
- 25. A thermocouple basket catheter for detecting temperature heterogeneity along a vessel wall, the catheter comprising
an expandable basket formed by at least four hollow channels and having proximal and distal ends, each said channel having a distal terminus and comprising a thermally conductive material and having a vessel wall-contacting side and a vessel lumen facing side; a hollow shaft joined to said proximal end; a tip joined to said distal end and enclosing each said channel terminus; a thermocouple junction disposed inside each said channel, said junction being longitudinally disposed within each said channel at a point about mid-way between said basket proximal and distal ends, and said junction disposed within each said channel in thermal contact with said vessel wall contacting side and thermally insulated from said lumen facing side; and a pair of insulated thermocouple wires disposed inside each said channel and extending from said junction through said hollow shaft.
- 26. The thermocouple basket catheter of claim 25 wherein each said channel terminus is fixedly enclosed in said tip.
- 27. The thermocouple basket catheter of claim 25 wherein at least one said terminus is moveably enclosed inside said tip.
- 28. An intravascular thermocouple catheter assembly for detecting temperature heterogeneity along a vessel wall, said assembly comprising:
the thermocouple basket catheter of claim 25; and a guiding catheter having a guiding lumen adapted for slidingly receiving said thermocouple basket catheter.
- 29. The assembly of claim 28 wherein said guiding catheter further comprises an inflatable occluding balloon and an inflation lumen in communication with said balloon.
- 30. The catheter assembly of claim 28 further comprising an intravascular ultrasound wire.
- 31. The assembly of claim 28 further comprising a thermally insulating material disposed inside each said channel between said junction and said lumen facing side.
- 32. A thermistor basket catheter for detecting temperature heterogeneity along a vessel wall, the catheter comprising
an expandable basket formed by at least four hollow channels and having proximal and distal ends, each said channel having a vessel wall-contacting side and a lumen facing side; a hollow shaft joined to said proximal end; a tip joined to said distal end; a thermistor disposed on the outside of each said channel, said thermistor being longitudinally disposed on each said channel at a point about mid-way between said basket proximal and distal ends on said vessel wall contacting side of each said channel; a pair of insulated wires in electrical contact with each said thermistor and extending from said thermistor through said proximal end and through said hollow shaft.
- 33. The catheter of any one of claims 14, 25 or 32 having an outer diameter of no more than about 6 mm.
- 34. The catheter of claim 33 having an outer diameter of no more than about 3 mm.
- 35. An assembly for identifying vulnerable atherosclerotic plaque, the assembly comprising:
the catheter of claim 14 having an external diameter of no more than 6 mm; an infrared array detector; a signal processor; a microcontroller programmed for receiving, storing, analyzing and reporting temperature information obtained from a plurality of sites along a vessel wall; a display system; and a user interface, said fibers being in optical contact with said infrared array detector, said detector being in electrical contact with said signal processor, said signal processor being in electrical contact with said display system and microcontroller, and said microcontroller being in electrical contact with said user interface.
- 36. The assembly of claim 35 further comprising:
an infrared radiation source in optical communication with an infrared fiber multiplexer, said multiplexer also being in electrical contact with said microcontroller.
- 37. An assembly for identifying vulnerable atherosclerotic plaque, the assembly comprising:
the catheter of claim 25 or 32; a temperature display system; a microprocessor programmed for receiving, storing, analyzing and reporting temperature information; and a user interface, each said thermocouple or thermistor being in electrical contact with said display system and said microprocessor, said microprocessor being in electrical contact with said user interface.
- 38. A method of detecting and monitoring inflammation in a transplanted arteriovenous graft in a living subject, the method comprising:
using an infrared camera, non-invasively imaging said arteriovenous graft to obtain an initial infrared thermogram of said graft; subsequent to obtaining said initial thermogram, repeating said infrared imaging to obtain a second infrared thermogram of said graft; subsequent to obtaining said second thermogram, optionally repeating said infrared imaging to obtain at least one subsequent infrared image of said arteriovenous graft; comparing said initial, second and subsequent infrared images to identify temperature changes in a region of said graft; from said temperature changes, determining an increase, decrease or no change in inflammation in at least one region of said arteriovenus graft.
- 39. A method of evaluating an anti-atherosclerotic interventional therapy in a flowing mammalian artery, the method comprising:
feeding cholesterol to a Watanabe hypercholesterolemic rabbit such that visible, palpably warm atherosclerotic lesions extending along the central ear artery develop in said rabbit, whereby an animal model of human atherosclerosis is produced; non-invasively measuring the temperature of at least one region of said ear artery in at least one said animal model to obtain at least one baseline temperature measurement: administering an anti-atherosclerotic interventional treatment to at least one said animal model; administering a suitable control treatment to at least one said animal model; subsequent to said treatments, non-invasively measuring the temperature of at least one region of said artery in at least one said treated animal model to obtain at least one post-treatment temperature measurement; comparing said baseline, control and post-treatment temperature measurements; and detecting any temperature differences in an artery attributable to said interventional treatment.
- 40. The method of claim 39 wherein said temperature measuring steps comprise employing an infrared imaging camera.
- 41. A method of monitoring the progression or amelioration of an atherosclerotic plaque in a flowing mammalian artery, the method comprising:
breeding genetically hypercholesterolemic animals characterized by development of atherosclerotic lesions that are histologically similar to human atherosclerotic plaques, whereby an animal model of human atherosclerosis is produced; using the catheter of any one of claims 14, 25 or 32, measuring the temperature of a multiplicity of sites along a vessel wall of said animal to obtain a baseline temperature measurement for each said site and recording the physical location of sites alone the vessel wall corresponding to each said temperature measurement; removing said catheter; at a later time, reinserting said catheter and repeating said temperature measurement and recording of physical location steps; and determining a temperature difference between adjacent sites of said vessel wall, and/or determining a temperature difference between each said site and its corresponding baseline temperature.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. pat. app. Ser. No. 08/717,449 filed Sep. 20, 1996, now U.S. Pat. No. ______, which claims the benefit of U.S. Provisional Pat. App. No. 60/004,061 filed Sep. 20, 1995. The present application also claims the benefit of U.S. Provisional Pat. App. Nos. 60/090,712 and 60/090,846, both filed Jun. 26, 1998. These patents and applications are incorporated herein by reference for all purposes.
Provisional Applications (3)
|
Number |
Date |
Country |
|
60090712 |
Jun 1998 |
US |
|
60090846 |
Jun 1998 |
US |
|
60004061 |
Sep 1995 |
US |
Continuations (2)
|
Number |
Date |
Country |
Parent |
09340089 |
Jun 1999 |
US |
Child |
10033731 |
Dec 2001 |
US |
Parent |
08717449 |
Sep 1996 |
US |
Child |
10033731 |
Dec 2001 |
US |