LOW PROFILE ELECTRODES FOR AN ANGIOPLASTY SHOCK WAVE CATHETER

• US 20140039513A1
• Filed: 03/14/2013
• Published: 02/06/2014
• Est. Priority Date: 08/06/2012
• Status: Active Grant

• Current Assignee: Shockwave Medical, Incorporated
• Original Assignee: Shockwave Medical, Incorporated
• Inventors: ADAMS, John M., HAKALA, Doug, LE, Khoi T., WU, Show-Mean Steve
• Granted Patent: US 8,888,788 B2
• Time in Patent Office: Days
• US Class Current: 606/128
• CPC Class Codes: A61B 17/2202 the ultrasound transducer being inside patient's body at the distal end of the catheter
• CPC Class Codes: A61B 17/22022 using electric discharge
• CPC Class Codes: A61B 2017/22001 Angioplasty, e.g. PCTA
• CPC Class Codes: A61B 2017/22021 electric leads passing through the catheter
• CPC Class Codes: A61B 2017/22025 applying a shock wave A61B2017/22091 takes precedence
• CPC Class Codes: A61B 2017/22028 arrays, e.g. phased arrays
• 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

Abstract

Described herein are low-profile electrodes for use with an angioplasty shockwave catheter. A low-profile electrode assembly may have an inner electrode, an insulating layer disposed over the inner electrode such that an opening in the insulating layer is aligned with the inner electrode, and an outer electrode sheath disposed over the insulating layer such that an opening in the outer electrode sheath is coaxially aligned with the opening in the insulating layer. This layered configuration allows for the generation of shockwaves that propagate outward from the side of the catheter. In some variations, the electrode assembly has a second inner electrode, and the insulating layer and outer electrode may each have a second opening that are coaxially aligned with the second inner electrode. An angioplasty shockwave catheter may have a plurality of such low-profile electrode assemblies along its length to break up calcified plaques along a length of a vessel.

Claims

1. A device for generating shockwaves comprising:

an axially extending catheter;

a balloon surrounding a portion of the catheter, said balloon being fillable with a conductive fluid;

an insulating layer wrapped around a portion of the catheter within the balloon, said layer having a first aperture therein;

a first inner electrode carried within the catheter and aligned with the first aperture of the insulating layer; and

an outer electrode mounted on the insulating layer and having a first aperture coaxially aligned with the first aperture in the insulating layer and arranged so that when the balloon is filled with fluid and a voltage is applied across the electrodes, a first shockwave will be initiated from a first side location of the catheter.

2. A device as recited in claim 1, wherein said insulating layer is an insulating sheath and said outer electrode is in the form of a sheath that is circumferentially mounted around the insulating sheath.

3. A device as recited in claim 1, wherein the size of the first aperture in the outer electrode is larger than the size of the first aperture in the insulating sheath.

4. The device of claim 1, further comprising a first wire, and a second wire, wherein the first and second wires extend along the length of the catheter, and wherein the first wire is connected to the first inner electrode, and the second wire is connected to the outer electrode.

5. The device of claim 4, wherein the catheter has first and second grooves that extend along the length of the catheter, and the first wire is slidably disposed within the first groove and the second wire is slidably disposed within the second groove.

6. The device of claim 4, wherein the first inner electrode and the outer electrode are crimped over an electrically conductive portion of the first and second wires, respectively.

7. The device of claim 6, wherein the first inner electrode is a hypotube that is crimped over the first wire.

8. A device as recited in claim 2, wherein:

the insulating sheath has a second aperture circumferentially opposite the first aperture in the insulating sheath;

the device further comprises a second inner electrode aligned with the second aperture in the insulating sheath; and

the outer electrode sheath has a second aperture coaxially aligned with the second aperture in the insulating sheath and arranged so that when the balloon is filled with a fluid and a voltage is applied across the second inner electrode and the outer electrode, a second shockwave will be initiated from a second side location of the catheter that is opposite to the first side location.

9. The device of claim 8, further comprising a first wire, a second wire, and a third wire, wherein the first, second and third wires extend along the length of the catheter, and wherein the first wire is connected to the first inner electrode, the second wire is connected to the outer electrode, and the third wire is connected to the second inner electrode.

10. The device of claim 9, wherein the catheter has first, second and third grooves that extend along the length of the catheter, and the first wire is slidably disposed within the first groove, the second wire is slidably disposed within the second groove, and the third wire is slidably disposed within the third groove.

11. The device of claim 9, wherein the first inner electrode and the second inner electrode are crimped over an electrically conductive portion of the first and third wires, respectively.

12. The device of claim 11, wherein the first inner electrode and the second inner electrode are first and second hypotubes that are each crimped over the first and third wires, respectively.

13. The device of claim 12, wherein the surface of the first and second crimped hypotubes each circumferentially spans a portion of the elongate member.

14. The device of claim 13, wherein the first and second crimped hypotubes each circumferentially span at least ⅙

of the way around the circumference of the elongate member.

15. A device as recited in claim 8, wherein:

the insulating sheath has a third aperture circumferentially 90 degrees from the first aperture in the insulating sheath;

the device further comprises a third inner electrode aligned with the third aperture in the insulating sheath; and

the outer electrode sheath has a third aperture coaxially aligned with the third aperture in the insulating sheath and arranged so that when the balloon is filled with a fluid and a voltage is applied across the third inner electrode and the outer electrode, a third shockwave will be initiated from a third side location that is 90 degrees offset from the first side location.

16. A device as recited in claim 15, wherein:

the insulating sheath has a fourth aperture circumferentially opposite the third aperture in the insulating sheath;

the device further comprises a fourth inner electrode aligned with the fourth aperture in the insulating sheath; and

the outer electrode sheath has a fourth aperture coaxially aligned with the fourth aperture in the insulating sheath and arranged so that when the balloon is filled with a fluid and a voltage is applied across the fourth inner electrode and the outer electrode, a fourth shockwave will be initiated from a fourth side location that is opposite to the third side location.

17. A device for generating shockwaves comprising:

an axially extending catheter;

a balloon surrounding a portion of the catheter, said balloon being fillable with a conductive fluid;

a first inner electrode mounted on the side of the catheter;

an insulating layer having an aperture disposed over the first inner electrode such that the aperture is coaxially aligned with the first inner electrode; and

an outer electrode having an aperture disposed over insulating layer such that the outer electrode aperture is coaxially aligned with the insulating layer aperture.

18. The device of claim 17, wherein the first inner electrode, insulating layer and outer electrode do not protrude more than 0.015 inch from the outer surface of the catheter.

19. The device of claim 17, further comprising a second inner electrode mounted on the side of the catheter at a location that is circumferentially opposite to the first inner electrode, and wherein the insulating layer has a second aperture coaxially aligned with the second inner electrode and the outer electrode has a second aperture that is coaxially aligned with the second aperture of the insulating layer.

20. A system for generating shockwaves comprising:

an axially extending catheter;

a balloon surrounding a portion of the catheter, said balloon being fillable with a conductive fluid;

a first electrode assembly at a first location along the length of the catheter, the first electrode assembly comprising a first inner electrode, a second inner electrode, and an outer electrode and configured to initiate shockwaves at two circumferentially opposite locations;

a second electrode assembly at a second location along the length of the catheter, the second electrode assembly comprising a first inner electrode, a second inner electrode, and an outer electrode and configured to initiate shockwaves at two circumferentially opposite locations;

a third electrode assembly at a third location along the length of the catheter, the third electrode assembly comprising a first inner electrode, a second inner electrode, and an outer electrode and configured to initiate shockwaves at two circumferentially opposite locations;

a fourth electrode assembly at a fourth location along the length of the catheter, the fourth electrode assembly comprising a first inner electrode, a second inner electrode, and an outer electrode and configured to initiate shockwaves at two circumferentially opposite locations;

a fifth electrode assembly at a fifth location along the length of the catheter, the fifth electrode assembly comprising a first inner electrode, a second inner electrode, and an outer electrode and configured to initiate shockwaves at two circumferentially opposite locations; and

a voltage pulse generator, wherein the channels of the voltage pulse generator are connected to one or more of the electrode assemblies.

21. The device of claim 20, wherein:

the first inner electrode of the first electrode assembly is connected is a first output of the voltage pulse generator,

the second inner electrode of the first electrode assembly is connected to the first inner electrode of the second electrode assembly,

the first inner electrode of the third electrode assembly is connected to a second output of the voltage pulse generator,

the second inner electrode of the third electrode assembly is connected to a third output of the voltage pulse generator,

the first inner electrode of the fourth electrode assembly is connected to a fourth output of the voltage pulse generator,

the second inner electrode of the fourth electrode assembly is connected to the first inner electrode of the fifth electrode assembly, and

the second inner electrode of the second electrode assembly, the outer electrode of the third electrode assembly, and the second inner electrode of the fifth electrode assembly are all connected to a fifth output of the voltage pulse generator.

22. A device for generating shockwaves comprising:

an elongate member;

a first electrode assembly located along the side of the elongate member at a first longitudinal location, wherein the first electrode assembly is configured to initiate shockwaves at a first side location on the elongate member;

a second electrode assembly circumferentially opposite the first electrode assembly, wherein the second electrode assembly is configured to initiate shockwaves at a second side location that is circumferentially opposite the first side location of the elongate member; and

a balloon surrounding a portion of the elongate member, the balloon being fillable with a conductive fluid.

23. A system for generating shockwaves comprising:

a high voltage pulse generator having a plurality of high voltage output channels;

a catheter;

a plurality of shockwave sources located along a length of the catheter, wherein the number of high voltage output channels driving the plurality of shockwave sources is less than the number of shockwave sources; and

a balloon surrounding the length of the catheter that has the shockwave sources, the balloon being fillable with a conductive fluid.