Microwave balloon angioplasty

• US 5,057,106 A
• Filed: 07/09/1990
• Issued: 10/15/1991
• Est. Priority Date: 02/27/1986
• Status: Expired due to Term

• Current Assignee: Kasevich Associates Incorporated
• Original Assignee: Kasevich Associates Incorporated
• Inventors: McQueeney, James F., Crooker, Ronald H., Kasevich, Raymond S.
• Primary Examiner(s): Cohen, Lee S.
• Application Number:
  US07/550,341
• Time in Patent Office: 463 Days
• Field of Search: 606/33, 128/736, 128/784, 128/786, 128/804, 128/401
• US Class Current: 606/33
• CPC Class Codes: A61B 18/18 by applying electromagnetic radiation, e.g. microwaves radiation therapy A61N5/00
• CPC Class Codes: A61B 18/1815 using microwaves
• CPC Class Codes: A61B 2017/00057 Light
• CPC Class Codes: A61B 2017/00084 Temperature
• CPC Class Codes: A61B 2017/00853 low friction, hydrophobic and corrosion-resistant fluorocarbon resin coating (ptf, ptfe, polytetrafluoroethylene)
• CPC Class Codes: A61B 2017/22001 Angioplasty, e.g. PCTA
• CPC Class Codes: A61B 2017/22051 with an inflatable part, e.g. balloon, for positioning, blocking, or immobilisation A61B2017/22048, A61B2017/3486 take precedence
• CPC Class Codes: A61B 2017/22062 to be filled with liquid
• CPC Class Codes: A61B 2018/00285 Balloons
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00738 Depth, e.g. depth of ablation
• CPC Class Codes: A61B 2018/1861 with an instrument inserted into a body lumen or cavity, e.g. a catheter
• CPC Class Codes: A61M 25/104 used for angioplasty
• CPC Class Codes: H01Q 21/08 the units being spaced along or adjacent to a rectilinear path waveguide fed H01Q21/0037

Abstract

A microwave catheter system used for heating arterial plaque and including a catheter member adapted for positioning in the artery and an inflatable balloon supported at the distal end of the catheter member. Microwave energy is coupled by means of a transmission line to an antenna means. An optic fiber extends through the catheter member and may be used for temperature sensing or other purposes. A channel is provided through the catheter member for coupling a fluid to the balloon for inflation thereof.

Claims

1. A microwave catheter system for heating arterial plaque, comprising:

a flexible catheter member having a distal end and a proximal end, and adapted for positioning in an artery, an inflatable balloon supported at the distal end of the catheter member, a microwave signal generator at the proximal end of the catheter member, transmission line means for transmitting energy coupled from said signal generator through said catheter member and including at the distal end thereof an antenna means for radiating energy substantially uniformly and controllably into said artery, optic fiber means for transmitting optical energy extending through said catheter member between proximal and distal ends thereof and having one end thereof disposed in said balloon in juxtaposition with said antenna means, and channel means extending through said catheter member between proximal and distal ends thereof for coupling a fluid to said balloon for inflation thereof.

2. A microwave catheter system for heating arterial plaque as set forth in claim 1, wherein said channel means has an entrance port to said balloon, and further including a pressurized fluid source coupled to said channel means for introducing the fluid to the balloon under pressure.

3. A microwave catheter system for heating arterial plaque as set forth in claim 2 further including means for exciting the signal generator for a predetermined period of time upon injection of said inflating fluid.

4. A microwave catheter system for heating arterial plaque as set forth in claim 3 wherein said optic fiber means has a sensor at the distal end within the balloon to measure temperature in the balloon or at the surface of the balloon.

5. A microwave catheter system for heating arterial plaque as set forth in claim 4 including a pair of sensors coupled to said fiber means for measuring temperature at two locations within the balloon.

6. A microwave catheter system for heating arterial plaque as set forth in claim 1 wherein said antenna means comprises a collinear array of antennae.

7. A microwave catheter system for heating arterial plaque as set forth in claim 6 wherein the collinear array antennae is disposed inside the balloon.

8. A microwave catheter system for heating arterial plaque as set forth in claim 6 wherein said balloon has a skin and the collinear array antennae is disposed within the skin forming the balloon.

9. A microwave catheter system for heating arterial plaque as set forth in claim 6 wherein the collinear array antennae is formed in a spiral to provide full balloon circumferential coverage.

10. A microwave catheter system for heating arterial plaque as set forth in claim 6 wherein the collinear array antennae is formed in a helix to provide full balloon circumferential coverage.

11. A microwave catheter system for heating arterial plaque as set forth in claim 6 wherein said collinear array antennae includes separate antenna sections and further includes power divider means for intercoupling from the transmission line means to the separate antenna sections.

12. A microwave catheter system for heating arterial plaque as set forth in claim 11 wherein said balloon has a skin and the separate antenna sections are disposed in opposite locations in the balloon skin.

13. A microwave catheter system for heating arterial plaque as set forth in claim 1 wherein said antenna means comprises a plurality of collinear array antennae.

14. A microwave catheter system for heating arterial plaque as set forth in claim 13 wherein said transmission line means further comprises separate transmission lines in the catheter member for delivering electrical energy to each of the collinear array antennae.

15. A microwave catheter system for heating arterial plaque as set forth in claim 1 wherein said antenna means comprises a microstrip radiator.

16. A microwave catheter system for heating arterial plaque as set forth in claim 15 wherein said microstrip radiator is comprised of a conductive strip and a ground plane inter-separated by a dielectric substrate.

17. A microwave catheter system for heating arterial plaque as set forth in claim 15 wherein said radiator is of annular configuration, having an outer radiating strip.

18. A microwave catheter system for heating arterial plaque as set forth in claim 15 wherein said radiator includes a hollow member coated with a thin conductive film to form a ground plane, a thin dielectric film over the ground plane, and a conductive antenna pattern printed over the dielectric film surface.

19. A microwave catheter system for heating arterial plaque as set forth in claim 18 wherein said antenna pattern is in a spiral form.

20. A microwave catheter system for heating arterial plaque as set forth in claim 1 wherein said transmission line means has a center conductor of sufficient stiffness to form a guide wire.

21. A microwave catheter system for heating arterial plaque as set forth in claim 20 including impedance matching means along said center conductor at the location where the center conductor enters and leaves the balloon.

22. A microwave catheter system for heating arterial plaque as set forth in claim 21 wherein the transmission line means has an outer conductor except at positions within the balloon, a tip of the center conductor extending beyond said balloon.

23. A microwave catheter system for heating arterial plaque as set forth in claim 1 wherein said antenna means comprises a plurality of metallic filaments each having a resonant length at the microwave frequency of operation.

24. A microwave catheter system for heating arterial plaque as set forth in claim 23 including an active antenna in the balloon for exciting the filaments.

25. A microwave catheter system for heating arterial plaque as set forth in claim 24 wherein the filaments are disposed inside the balloon.

26. A microwave catheter system for heating arterial plaque as set forth in claim 24 wherein the filaments are disposed within the skin of the balloon.

27. A microwave catheter system for heating material plaque as set forth in claim 1 wherein said balloon has an inside surface and said antenna means is comprised of a plurality of spacedly disposed antenna wires arranged about the balloon near the inside surface thereof and commonly coupled to said transmission line means.

28. A microwave catheter system for heating arterial plaque as set forth in claim 1 wherein said optic fiber means comprises a fiber core and said transmission line means comprises multiply deposited layers on said core including a conductive layer defining an inner conductor, a dielectric coating defining an insulating layer and an outer conductive layer defining an outer conductor.

29. A microwave catheter system for heating arterial plaque as set forth in claim 1 wherein said balloon has a skin and is constructed of a compliant material loaded with a lossy material to allow the balloon skin to absorb microwave energy directly.

30. A microwave catheter system for heating arterial plaque as set forth in claim 1 wherein said balloon is coated with a lossy material to absorb microwave energy.

31. A microwave catheter system for heating arterial plaque as set forth in claim 29 wherein the lossy material includes ferrite or graphite material.

32. A microwave catheter system for heating arterial plaque as set forth in claim 1, wherein said antenna means comprises a helical antenna.

33. A microwave catheter system for heating arterial plaque as set forth in claim 32, wherein said helical antenna is tapered.

34. A microwave catheter system for heating arterial plaque as set forth in claim 1, wherein said antenna means comprises a segment of transmission line within said balloon.

35. A microwave catheter system for heating arterial plaque as set forth in claim 34, wherein a section of said transmission line within the balloon is comprised of a center conductor, a dielectric material disposed about the center conductor and a thin metallic film deposited over the dielectric material and forming an outer conductor.

36. A microwave catheter system for heating arterial plaque as set forth in claim 35, wherein the thin metallic film is deposited by physical vapor deposition.

37. A microwave catheter system for heating arterial plaque as set forth in claim 35, wherein the thin metallic film is deposited by chemical vapor deposition.

38. A device for heating arterial plaque having a proximal section adapted to be coupled to a source of electromagnetic energy and a distal section for radiating said energy, comprising:

a collinear array antenna formed by a continuous inner conductor, and a distal end in the distal section surrounded by dielectric material and an interrupted coaxial outer conductor longitudinally extending at one end from the proximal section to another end at the distal section and wherein the interruptions are in the form of circumferential gaps periodically spaced along the coaxial conductor at interrelated harmonic wavelengths to radiate a substantially uniform beam pattern of electromagnetic energy about the periphery of the antenna and an impedance matching means at the proximal section for matching the impedance of the antenna to the impedance of the source of electromagnetic energy,

a catheter member supporting at a catheter member distal end an inflatable balloon and further comprising an impedance matching means at a distal side of said balloon for reducing current leakage outside said balloon at said catheter member distal end, said balloon enclosing said collinear array antenna.