Shockwave catheter system with energy control

• US 9,522,012 B2
• Filed: 03/18/2014
• Issued: 12/20/2016
• Est. Priority Date: 09/13/2012
• Status: Active Grant

• Current Assignee: Shockwave Medical, Incorporated
• Original Assignee: Shockwave Medical, Incorporated
• Inventors: Adams, John M.
• Primary Examiner(s): Anderson, Gregory
• Assistant Examiner(s): DANG, PHONG SON H
• Application Number:
  US14/218,858
• Publication Number:
  US 20140288570A1
• Time in Patent Office: 1,008 Days
• US Class Current: 1/1
• CPC Class Codes: A61B 17/22022 using electric discharge
• CPC Class Codes: A61B 2017/22025 applying a shock wave A61B2017/22091 takes precedence
• CPC Class Codes: A61B 2017/22062 to be filled with liquid
• CPC Class Codes: A61B 2017/22081 Treatment of vulnerable plaque

Abstract

A system includes 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 carry a voltage there-across including an initial high electrical voltage at an initial low current. The initial high electrical voltage causes an electrical arc to form across the first and second electrodes within the balloon. The electrical arc causes a gas bubble within the liquid, a high current to flow through the first and second electrodes, a decrease in the initial high electrical voltage, and a mechanical shock wave within the balloon. The system further includes a power source that provides the first and second electrodes with a drive voltage that creates the initial high electrical voltage at the initial current and that terminates the drive voltage in response to the decrease in the initial high electrical voltage.

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 carry a voltage there-across including an initial high electrical voltage at an initial low current, the initial high electrical voltage causing an electrical arc to form within the balloon, the electrical arc causing a gas bubble within the liquid, a high current to flow through the first and second electrodes, a decrease in the initial high electrical voltage, and a mechanical shock wave within the balloon; and

a power source that provides the first and second electrodes with a drive voltage pulse that creates the initial high electrical voltage at the initial current and that terminates the drive voltage pulse in response to the decrease in the initial high electrical voltage.

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

3. The system of claim 2, wherein the voltage sensor causes the power source to terminate the drive voltage pulse when the voltage across the first and second electrodes decreases by more than a predetermined amount of voltage within less than a predetermined amount of time.

4. The system of claim 3, wherein the predetermined amount of voltage is on the order of one-hundred volts and the predetermined time is on the order of about 0.1 microseconds.

5. The system of claim 3, wherein the predetermined amount of voltage is on the order of five-hundred volts and the predetermined time is on the order of about 0.5 microseconds.

6. 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.

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 control the temperature of the fluid.

8. The system of claim 7, 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.

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

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

11. The system of claim 1, further comprising a timer that times a delay time in response to the decrease in the initial high electrical voltage and wherein the power source terminates the drive voltage after the delay time is timed.

12. The system of claim 11, wherein the power source includes a voltage sensor that senses voltage across the first and second electrodes and wherein the voltage sensor causes the timer to time the delay time when the voltage across the first and second electrodes decreases by more than a predetermined amount of voltage within less than a predetermined amount of time.

13. The system of claim 12, wherein the predetermined amount of voltage is on the order of one-hundred volts and the predetermined time is on the order of about 0.1 microseconds.

14. The system of claim 12, wherein the predetermined amount of voltage is on the order of five-hundred volts and the predetermined time is on the order of about 0.5 microseconds.

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, 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, the first and second electrodes within the balloon being arranged to carry a voltage there-across including an initial high electrical voltage at an initial low current, the initial high electrical voltage causing an electrical arc to form within the balloon, the electrical arc causing a gas bubble within the liquid, a high current to flow through the first and second electrodes, a decrease in the initial high electrical voltage, and a mechanical shock wave within the balloon; and

a power source that provides the first and second electrodes with a drive voltage pulse that creates the initial high electrical voltage at the initial current and that terminates the drive voltage pulse in response to the decrease in the initial high electrical voltage.

16. A balloon catheter for delivering shock waves to a calcified lesion comprising:

an elongated carrier;

a flexible balloon mounted on the elongate carrier, said balloon being fillable with a conductive fluid;

a pair of electrodes on the elongated carrier within the balloon; and

a power source coupled to the electrodes for supplying voltage pulses to the electrodes, each voltage pulse resulting in an initial high voltage across the electrodes that generates an arc in the fluid within the balloon and causes current to flow between the electrodes and producing a shock wave;

wherein the power source includes a voltage sensor for detecting the voltage across the electrodes during each voltage pulse, and wherein when the voltage is reduced by a predetermined voltage value after the initial high voltage, the sensor generates a signal that causes the power source to terminate the voltage supplied to the electrodes for that pulse.

17. The balloon catheter of claim 16, wherein the power source is configured to terminate the voltage supplied to the electrodes when the initial high voltage drops by the predetermined value within a predetermined time interval.

18. The balloon catheter of claim 17, wherein the predetermined voltage value is about 100 V and the predetermined time interval is about 0.1 microseconds.

19. The balloon catheter of claim 17, wherein the predetermined voltage value is about 500 V and the predetermined time interval is about 0.5 microseconds.

20. The balloon catheter of claim 16, wherein the predetermined voltage value is from about 100 V to about 500 V.

21. The balloon catheter of claim 16, wherein the carrier has a guidewire lumen.

22. A balloon catheter for delivering shock waves to a calcified lesion comprising:

an elongated carrier;

a flexible balloon mounted on the elongate carrier, said balloon being fillable with a conductive fluid;

a pair of electrodes on the elongated carrier within the balloon; and

a power source coupled to the electrodes for supplying voltage pulses to the electrodes, each voltage pulse resulting in an initial high voltage across the electrodes that generates an arc in the balloon producing a shock wave, wherein the power source includes a voltage sensor configured to detect the voltage across the electrodes during each pulse;

wherein the power source is configured to terminate the supplied voltage pulse after the voltage across the electrodes for that pulse is reduced by a predetermined voltage value during a predetermined time interval.

23. The balloon catheter of claim 22, wherein the predetermined voltage value is about 100 V and the predetermined time interval is about 0.1 microseconds.

24. The balloon catheter of claim 22, wherein the predetermined voltage value is about 500 V and the predetermined time interval is about 0.5 microseconds.

25. The balloon catheter of claim 22, wherein the carrier has a guidewire lumen.

26. A catheter for delivering shock waves to a calcified lesion comprising:

an elongated carrier;

a pair of electrodes carried by the carrier, said electrodes being immersed in a conductive fluid; and

a power source with a circuit coupled to the electrodes for supplying voltage pulses to the electrodes, each voltage pulse generating an arc in the fluid and causing current to flow between the electrodes and producing a shock wave;

wherein the power source includes a voltage sensor for monitoring the voltage across the electrode pair and wherein when the voltage drops by a predetermined value during each voltage pulse, a signal is generated that causes the power source to terminate the voltage supplied to the electrodes for that pulse.

27. The catheter of claim 26, wherein the power source further includes a delay timer with a predetermined delay time, the delay timer being triggered in response to the generated signal and wherein the voltage supplied to the electrodes is terminated after the predetermined delay time has expired.