Shockwave catheter system with energy control

• US 9,333,000 B2
• Filed: 09/13/2012
• Issued: 05/10/2016
• Est. Priority Date: 09/13/2012
• Status: Active Grant

• Current Assignee: Shockwave Medical, Incorporated
• Original Assignee: Shockwave Medical, Incorporated
• Inventors: Hakala, Doug, Adams, John M., Holmberg, Randy
• Primary Examiner(s): Nguyen, Tuan V
• Application Number:
  US13/615,107
• Publication Number:
  US 20140074113A1
• Time in Patent Office: 1,335 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: A61B 17/22 Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for dilators A61M29/00
• CPC Class Codes: A61B 17/22022 using electric discharge
• CPC Class Codes: A61B 17/225 for extracorporeal shock wave lithotripsy [ESWL], e.g. by using ultrasonic waves
• CPC Class Codes: A61B 2017/00039 Electric or electromagnetic phenomena other than conductivity, e.g. capacity, inductivity, Hall effect
• CPC Class Codes: A61B 2017/00084 Temperature
• CPC Class Codes: A61B 2017/00154 pulsed
• CPC Class Codes: A61B 2017/22025 applying a shock wave A61B2017/22091 takes precedence
• CPC Class Codes: A61B 2017/22038 with a guide wire
• 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 2017/22065 Functions of balloons dilating A61M29/02

Abstract

A system that breaks calcium in a liquid includes a catheter including first and second electrodes arranged to receive there-across a high electrical voltage at an initial low current. The high electrical voltage causes an electrical arc to form across the electrodes creating a gas bubble within the liquid, a high current to flow through the electrodes, and a mechanical shock wave. A power source provides the electrodes with the high electrical voltage at the initial current and terminates the high electrical voltage in response to the high current flow through the electrodes.

Claims

1. A system comprising:

a catheter including an elongated carrier, a balloon about the carrier in sealed relation thereto, the balloon being arranged to receive a fluid therein that inflates the balloon, and first and second electrodes within the balloon arranged to receive there-across a high electrical voltage pulse at an initial low current, the high electrical voltage pulse causing an electrical arc to form within the balloon, the electrical arc creating a gas bubble within the liquid, a high current to flow through the first and second electrodes, and a mechanical shock wave within the balloon; and

a power source that provides the first and second electrodes with the high electrical voltage pulse at the initial low current, said power source including a sensor for monitoring a parameter that varies during each voltage pulse and wherein the high electrical voltage pulse is terminated when the monitored parameter reaches a predetermined value.

2. The system of claim 1, wherein the power source includes a current sensor that senses current flowing through the first and second electrodes.

3. The system of claim 2, wherein the current sensor causes the power source to terminate the high electrical voltage pulse when the current flowing through the first and second electrodes reaches a predetermined limit.

4. The system of claim 3, wherein the predetermined limit is on the order of fifty amperes.

5. The system of claim 1, further including a temperature sensor within the balloon that senses temperature of the fluid within the balloon, and wherein the power source is further responsive to the temperature sensor.

6. The system of claim 5, wherein the temperature sensor causes the power source to decrease energy applied to the first and second electrodes responsive to the temperature of the fluid within the balloon increasing to control the temperature of the fluid.

7. The system of claim 6, wherein the temperature sensor causes the power source to decrease energy applied to the first and second electrodes responsive to the temperature of the fluid within the balloon increasing to above two degrees Celsius above ambient temperature.

8. The system of claim 6, wherein the energy applied to the first and second electrodes by the power source is in the form of serial electrical high voltage pulses and wherein the temperature sensor causes the power source to decrease the energy applied to the first and second electrodes by temporarily terminating the serial electrical high voltage pulses.

9. The system of claim 6, wherein the energy applied to the first and second electrodes by the power source is in the form of serial electrical high voltage pulses, wherein the serial electrical high voltage pulses have a pulse rate, and wherein the temperature sensor causes the power source to decrease the energy applied to the first and second electrodes by decreasing the pulse rate of the serial electrical high voltage pulses.

10. The system of claim 1, wherein the balloon is a dilation balloon.

11. The system of claim 10, wherein the dilation balloon is an angioplasty balloon.

12. The system of claim 1, further comprising a timer that times a delay time in response to the high current flow through the first and second electrodes and wherein the power source terminates the high electrical voltage pulse after the delay time is timed.

13. The system of claim 12, wherein the power source includes a current sensor that senses current flowing through the first and second electrodes and wherein the current sensor causes the timer to time the delay time when the current flowing through the first and second electrodes reaches a predetermined limit.

14. The system of claim 13, wherein the predetermined limit is on the order of fifty amperes.

15. A system comprising:

a catheter including an elongated carrier, the carrier having a guide wire lumen, a balloon having an inner surface about the carrier in sealed relation thereto, the balloon forming with the carrier, a channel arranged to receive a fluid that inflates the balloon, and first and second electrodes, within the balloon between the carrier and the inner surface of the balloon, arranged to receive there-across a high electrical voltage pulse at an initial low current to cause an electrical arc to form within the balloon, the electrical arc creating a gas bubble within the liquid, a high current to flow through the first and second electrodes, and a mechanical shock wave within the balloon; and

a power source that provides the first and second electrodes with the high electrical voltage at the initial low current, said power source including a sensor for monitoring a parameter that varies during each voltage pulse and wherein the high electrical voltage pulse is terminated when the monitored parameter reaches a predetermined value.

16. The system of claim 15 wherein the sensor senses current flowing between the first and second electrodes.

17. A method comprising:

providing a catheter including an elongated carrier, a balloon about the carrier in sealed relation thereto, the balloon being arranged to receive a fluid therein that inflates the balloon, and first and second electrodes within the balloon;

introducing the fluid into the balloon to inflate the balloon;

applying an electrical voltage pulse across the first and second electrodes to form an electrical arc allowing current to flow across the first and second electrodes;

sensing current flow through the first and second electrodes; and

terminating the application of the electrical voltage pulse across the first and second electrodes in response to sensed current flow through the first and second electrodes after the electrical arc is formed.

18. The method of claim 17, wherein the application of the high electrical voltage pulse is terminated when the current flowing through the first and second electrodes reaches a predetermined limit.

19. The method of claim 18, wherein the predetermined limit is on the order of fifty amperes.

20. The method of claim 17, including the further steps of sensing temperature of the fluid within the balloon, and varying the application of the electrical voltage across the first and second electrodes in response to sensed temperature of the fluid.

21. The method of claim 20, wherein the varying step includes decreasing energy applied to the first and second electrodes responsive to the temperature of the fluid within the balloon increasing to control the temperature of the fluid.

22. The method of claim 21, wherein the energy applied to the first and second electrodes is decreased responsive to the temperature of the fluid within the balloon increasing to above two degrees Celsius above ambient temperature.

23. The method of claim 20, wherein the applying step includes applying energy in the form of serial electrical high voltage pulses and wherein the varying step further includes decreasing the energy applied to the first and second electrodes by temporarily terminating the serial electrical high voltage pulses.

24. The method of claim 20, wherein the applying step includes applying energy in the form of serial electrical high voltage pulses, wherein the serial electrical high voltage pulses have a pulse rate, and wherein the varying step further includes decreasing the energy applied to the first and second electrodes by decreasing the pulse rate of the serial electrical high voltage pulses.

25. The method of claim 17 including the further step of timing a delay time in response to sensed current flow through the first and second electrodes prior to terminating the application of the electrical voltage across the first and second electrodes.

26. The method of claim 25, wherein the delay time is timed when the current flowing through the first and second electrodes reaches a predetermined limit.

27. The method of claim 26, wherein the predetermined limit is on the order of fifty amperes.

28. A system that treats obstructions within bodily fluid comprising:

a catheter including first and second electrodes arranged to receive there-across a high electrical voltage pulse at an initial low current, the high electrical voltage causing an electrical arc to form allowing current to flow across the first and second electrodes within the bodily fluid, the electrical arc creating a gas bubble within the bodily fluid, a high current to flow through the first and second electrodes, and a mechanical shock wave within the bodily fluid; and

a power source that provides the first and second electrodes with the high electrical voltage pulse at the initial current, said power source including a sensor for monitoring a parameter that varies during each voltage pulse and wherein the high electrical voltage pulse is terminated when the monitored parameter reaches a predetermined value.

29. The system of claim 28, wherein the energy applied to the first and second electrodes by the power source is in the form of serial electrical high voltage pulses, wherein the serial electrical high voltage pulses have a pulse rate, and wherein the power source further controls the energy applied to the first and second electrodes by varying the pulse rate of the serial electrical high voltage pulses.

30. The system of claim 28, wherein the energy applied to the first and second electrodes by the power source is in the form of serial electrical high voltage pulses, wherein each pulse of the serial electrical high voltage pulses has an amplitude, and wherein the power source further controls the energy applied to the first and second electrodes by varying the amplitude of the serial electrical high voltage pulses.

31. The system of claim 28, further comprising a timer that times a delay time in response to the high current flow through the first and second electrodes and wherein the power source terminates the high electrical voltage after the delay time is timed.

32. The system of claim 31, wherein the power source includes a current sensor that senses current flowing through the first and second electrodes and wherein the current sensor causes the timer to time the delay time when the current flowing through the first and second electrodes reaches a predetermined limit.

33. The system of claim 32, wherein the predetermined limit is on the order of fifty amperes.

34. The system of claim 28 wherein the sensor senses current flowing between the first and second electrodes.

35. A method of producing a mechanical shcok wave to treat calcified lesion in a human body comprising:

providing a catheter including first and second electrodes;

applying an electrical voltage pulse across the first and second electrodes to form an electrical arc allowing current to flow across the first and second electrodes;

sensing current flow through the first and second electrodes; and

terminating the application of the electrical voltage pulse across the first and second electrodes in response to sensed current flow through the first and second electrodes after the electrical arc is formed.

36. The method of claim 35 including the further step of timing a delay time in response to sensed current flow through the first and second electrodes prior to terminating the application of the electrical voltage pulse across the first and second electrodes.

37. The method of claim 36, wherein the delay time is timed when the current flowing through the first and second electrodes reaches a predetermined limit.

38. The method of claim 37, wherein the predetermined limit is on the order of fifty amperes.