Method and apparatus for detecting vulnerable atherosclerotic plaque

• US 6,763,261 B2
• Filed: 12/26/2001
• Issued: 07/13/2004
• Est. Priority Date: 09/20/1995
• Status: Expired due to Term

• Current Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Original Assignee: Texas Heart Institute, Board of Regents of the University of Texas System (University of Texas System)
• Inventors: Naghavi, Morteza, Willerson, James T., Guo, Bujin, Casscells, S. Ward III
• Primary Examiner(s): Jastrzab, Jeffrey R.
• Application Number:
  US10/033,731
• Publication Number:
  US 20030028114A1
• Time in Patent Office: 930 Days
• Field of Search: 600/473-475, 600/478, 600/479, 600/549
• US Class Current: 600/474
• CPC Class Codes: A61B 2017/00084 Temperature
• CPC Class Codes: A61B 2017/22001 Angioplasty, e.g. PCTA
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 5/0071 by measuring fluorescence emission
• CPC Class Codes: A61B 5/0075 by spectroscopy, i.e. measuring spectra, e.g. Raman spectroscopy, infrared absorption spectroscopy A61B5/0071 takes precedence
• CPC Class Codes: A61B 5/0077 Devices for viewing the surface of the body, e.g. camera, magnifying lens
• CPC Class Codes: A61B 5/0086 using infrared radiation
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/015 By temperature mapping of body part
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• CPC Class Codes: A61B 5/0507 using microwaves or terahertz waves
• CPC Class Codes: A61B 5/413 Monitoring transplanted tissue or organ, e.g. for possible rejection reactions after a transplant
• CPC Class Codes: A61B 5/415 the glands, e.g. tonsils, adenoids or thymus
• CPC Class Codes: A61B 5/418 lymph vessels, ducts or nodes
• CPC Class Codes: A61B 5/6853 with a balloon
• CPC Class Codes: A61B 5/6858 with a distal basket, e.g. expandable basket
• CPC Class Codes: A61B 5/6885 Monitoring or controlling sensor contact pressure
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61B 8/445 Details of catheter construction
• CPC Class Codes: A61B 8/5223 for extracting a diagnostic or physiological parameter from medical diagnostic data for algorithms to analyse biomedical images G06T7/0012
• CPC Class Codes: A61B 8/5238 : for combining image data of patient, e.g. merging several images from different acquisition modes into one image for image registration algorithms G06T7/30

Abstract

Methods and devices are disclosed for detecting vulnerable atherosclerotic plaque, or plaque at risk of reducing blood flow in a vessel, by a identifying a region of elevated temperature along a living vessel wall. The disclosure that human atherosclerotic plaque with measurable temperature heterogeneity has the morphological characteristics of plaque that is likely to ulcerate provides a new and sensitive technique for detecting and treating these dangerous plaques before myocardial infarction and its consequences occur. The disclosed methods are advantageous over conventional plaque detection techniques because they are capable of differentiating between those plaques that are at great risk of rupture, fissure, or ulceration, and consequent thrombosis and occlusion of the artery and those that are not presently at risk. Infrared heat-sensing catheters useful for identifying potentially fatal arterial plaques in patients with disease of the coronary or other arteries are also described. In some embodiments a coherent infrared fiber optic bundle is employed to radially and longitudinally explore a luminal wall to identify inflamed, heat-producing, atherosclerotic plaque. Certain other methods and devices are disclosed which are particularly suited for non-invasively identifying and then monitoring the progression or amelioration of an inflamed plaque in a patient, and for monitoring for onset of inflammation in an implanted arteriovenous graft. Also disclosed are thermocouple basket catheters and thermistor basket catheters which are also capable of detecting temperature heterogeneity along a vessel wall.

Claims

1. A system for differentiating different types of plaque in a vessel and thereby detecting vulnerable plaque in vivo, comprising:

a catheter having a proximal end and a distal end;

an expandable member at said distal end of said catheter;

one or more thermal sensors at said distal end of said catheter;

a detector coupled to said proximal end of said catheter and in communication with said one or more thermal sensors, said detector being capable of receiving thermal information from said one or more thermal sensors and differentiating the different types of plaque based upon the thermal information received.

2. The system of claim 1 wherein said expandable member comprises a balloon.

3. The system of claim 2 wherein said thermal sensors comprise one or more optical fibers passing through said balloon.

4. The system of claim 3 wherein said thermal sensors comprise one or more optical fibers capable of transmitting optical radiation indicative of temperature.

5. The system of claim 4 wherein said optical fibers are capable of transmitting infrared radiation indicative of temperature.

6. The system of claim 1 wherein said expandable member comprises a basket.

7. The system of claim 6 wherein said thermal sensors comprise one or more thermistors mounted on said basket.

8. The system of claim 6 wherein said thermal sensors comprises one or more thermocouples mounted on said basket.