Apparatus and method for ablating tissue

• US 7,674,257 B2
• Filed: 06/28/2004
• Issued: 03/09/2010
• Est. Priority Date: 10/22/1996
• Status: Expired due to Fees

• Current Assignee: St. Jude Medical, Atrial Fibrillation Division, Inc. (Abbott Laboratories)
• Original Assignee: St. Jude Medical, Atrial Fibrillation Division, Inc. (Abbott Laboratories)
• Inventors: Ciciarelli, Timothy, Ulstad, Jack E. Jr., Vaska, Matthias, Richman, Roxanne L., Anderson, Scott C., Gallup, David A., Podmore, Jonathan L., Pless, Benjamin, Crowe, John E.
• Primary Examiner(s): PEFFLEY, MICHAEL F
• Application Number:
  US10/879,996
• Publication Number:
  US 20050033274A1
• Time in Patent Office: 2,080 Days
• Field of Search: 600/439, 600/459, 600/461, 600/462, 606/27, 606/28, 606 32- 34
• US Class Current: 606/27
• CPC Class Codes: A61B 17/22012 in direct contact with, or very close to, the obstruction or concrement for removing obstructions in blood vessels by laser A61B18/245
• 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 18/00 Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body eye surgery A61F9/007; ear surgery A61F11/00
• CPC Class Codes: A61B 18/02 by cooling, e.g. cryogenic techniques devices for cooling specific reflex points of the body within cell-life limits A61H39/06
• CPC Class Codes: A61B 18/1402 Probes for open surgery
• CPC Class Codes: A61B 18/148 having a short, rigid shaft for accessing the inner body transcutaneously, e.g. for neurosurgery or arthroscopy
• CPC Class Codes: A61B 18/1482 having a long rigid shaft for accessing the inner body transcutaneously in minimal invasive surgery, e.g. laparoscopy
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 2017/00039 Electric or electromagnetic phenomena other than conductivity, e.g. capacity, inductivity, Hall effect
• CPC Class Codes: A61B 2017/00243 cardiac
• CPC Class Codes: A61B 2017/00247 Making holes in the wall of the heart, e.g. laser Myocardial revascularization
• CPC Class Codes: A61B 2017/00252 for by-pass connections, i.e. connections from heart chamber to blood vessel or from blood vessel to blood vessel
• CPC Class Codes: A61B 2017/003 Steerable
• CPC Class Codes: A61B 2017/22077 with a part piercing the tissue A61B2017/22044 takes precedence
• CPC Class Codes: A61B 2017/3419 Sealing means between cannula and body
• CPC Class Codes: A61B 2018/00023 closed, i.e. without wound contact by the fluid
• CPC Class Codes: A61B 2018/0016 Energy applicators arranged in a two- or three dimensional array
• CPC Class Codes: A61B 2018/00232 having an irregular shape
• CPC Class Codes: A61B 2018/00261 arranged in a line
• CPC Class Codes: A61B 2018/00285 Balloons
• CPC Class Codes: A61B 2018/00291 : using suction
• CPC Class Codes: A61B 2018/00351 : Heart
• CPC Class Codes: A61B 2018/00363 : Epicardium
• CPC Class Codes: A61B 2018/00392 : Transmyocardial revascularisation
• CPC Class Codes: A61B 2018/00577 : Ablation
• CPC Class Codes: A61B 2018/00654 : with individual control of each of a plurality of energy emitting elements
• CPC Class Codes: A61B 2018/00797 : measured by multiple temperature sensors
• CPC Class Codes: A61B 2018/00839 : Bioelectrical parameters, e.g. ECG, EEG
• CPC Class Codes: A61B 2018/142 : at least partly surrounding the target, e.g. concave, curved or in the form of a cave
• CPC Class Codes: A61B 2018/1467 : using more than two electrodes on a single probe
• CPC Class Codes: A61B 2018/1472 : for use with liquid electrolyte, e.g. virtual electrodes
• CPC Class Codes: A61B 2090/3614 : using optical fibre
• CPC Class Codes: A61B 2090/3782 : transmitter or receiver in catheter or minimal invasive instrument
• CPC Class Codes: A61B 2090/395 : with marking agent for marking skin or other tissue
• CPC Class Codes: A61B 2218/002 : Irrigation
• CPC Class Codes: A61B 2218/007 : Aspiration
• CPC Class Codes: A61B 34/20 : Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 5/287 : Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• CPC Class Codes: A61N 1/06 : for high-frequency therapy
• CPC Class Codes: A61N 1/3629 : in combination with non-electric therapy
• CPC Class Codes: A61N 2007/0065 : Concave transducers
• CPC Class Codes: A61N 2007/0078 : with multiple treatment transducers
• CPC Class Codes: A61N 2007/027 : with multiple foci created simultaneously
• CPC Class Codes: A61N 7/02 : Localised ultrasound hyperthermia hyperthermia in general A61F7/00

Abstract

A control system alters one or more characteristics of an ablating element to ablate tissue. In one aspect, the control system delivers energy nearer to the surface of the tissue by changing the frequency or power. In another aspect, the ablating element delivers focused ultrasound which is focused in at least one dimension. The ablating device may also have a number of ablating elements with different characteristics such as focal length.

Claims

1. A system for ablating tissue with ultrasound energy, the system comprising:

a plurality of ablating elements adapted to emit ultrasound energy; and

a control system coupled to the plurality of ablating elements,

wherein the control system is programmed to automatically vary a frequency and at least one other operating characteristic of at least one of the plurality of ablating elements independent of other ablating elements, the at least one other operating characteristic selected from the group consisting of, a power setting, an ablation time period, a direction of a focus of the at least one of the plurality of ablating elements and a focal length of the at least one of the plurality of ablating elements, to output ultrasound energy at at least a first treatment setting and a second treatment setting different from the first setting.

2. The system of claim 1, wherein the control system is programmed to automatically change a frequency and a power setting of the at least one of the plurality of ablating elements.

3. The system of claim 1, wherein the plurality of ablating elements are adapted to emit focused ultrasound which is focused in at least one direction.

4. The system of claim 3, wherein the focused ultrasound has a focal length, and wherein the control system is programmed to automatically change the location of the focus relative to the tissue structure being ablated.

5. The system of claim 4, wherein the control system is programmed to decrease the focal length relative to a near surface of the tissue structure being ablated.

6. The system of claim 1, wherein the control system includes means for assessing the adequacy of contact between the at least one of the plurality of ablating elements and the tissue structure being ablated.

7. The system of claim 6, wherein the assessing means is adapted to measure an electrical impedance.

8. The system of claim 1, wherein the at least one of the plurality of ablating elements includes an inflatable member having a deflated state and an inflated state, the at least one of the plurality of ablating elements having a first focal length in the deflated state and a second focal length in the inflated state.

9. The system of claim 8, wherein the inflatable member is configured to contact the tissue being ablated.

10. The system of claim 1, wherein the control system is programmed to automatically control activation of the at least one of the plurality of ablating elements to ablate the tissue at a first frequency and a first power setting for a first ablation time period, and subsequently, to ablate the same tissue at a second frequency equal to or higher than the first frequency and a second power setting lower than the first power setting for a second ablation time period equal to or greater than the first ablation time period, wherein the second frequency, the second power setting, and the second ablation time period are predetermined.

11. The system of claim 10, wherein the first ablation time period is about 0.01 to 1.0 second and the second ablation time period is about 1.1 to 4 seconds.

12. The system of claim 10, wherein the first frequency is about 2-7 MHz and the second frequency is about 2-14 MHz.

13. The system of claim 10, wherein the first power setting is about 80-140 watts and the second power setting is about 20-60 watts.

14. The system of claim 10, wherein the control system is programmed to control activation of the at least one of the plurality of ablating elements to ablate the same tissue, subsequent to the second ablation time period, at a third frequency equal to or higher than the second frequency and a third power setting lower than the second power setting for a third ablation time period.

15. The system of claim 14, wherein the third frequency is about 6-16 MHz and the third power setting is about 2-10 watts.

16. The system of claim 1 comprising a first ablating element having a first focal length and a second ablating element having a second focal length, wherein the first focal length and the second focal length are different.

17. The system of claim 1, wherein the control system is programmed to activate the plurality of ablating elements in a predetermined sequence.

18. The system of claim 1, wherein the control system is programmed to control activation of the at least one of the plurality of ablating elements to ablate the tissue at a first focal length, and subsequently, to ablate the same tissue at a second focal length, wherein the second focal length is predetermined.

19. The system of claim 18, wherein the first focal length is greater than the second focal length.

20. The system of claim 1, wherein the control system includes a sensor adapted to assess the adequacy of contact between the at least one of the plurality of ablating elements and the tissue.

21. The system of claim 20, wherein the sensor is adapted to measure an electrical impedance.

22. The system of claim 1, wherein the control system is programmed to control pressure of a substance coupled to a part of at least one of the plurality of ablating elements.

23. The system of claim 22, wherein the substance is a fluid.

24. The system of claim 23, wherein the substance is one of a liquid and a gas.

25. The system of claim 22, wherein the substance is coupled to an inflatable member, which is coupled to the at least one of the plurality of ablating elements.

26. The system of claim 25, wherein the inflatable member is a balloon.

27. The system of claim 1, wherein at least one of the plurality of ablating elements further comprises one or more suction ports coupled to a suction lumen.

28. They system of claim 1, further comprising one or more temperature monitoring elements located on or near at least one of the plurality of ablating elements.

29. The system of claim 28, wherein the one or more temperature monitoring elements comprises one of a thermocouple and a thermistor.

30. A system for ablating tissue with ultrasound energy, the system comprising:

a plurality of ablating elements, each of the plurality of ablating elements including a transducer adapted to emit ultrasound energy; and

a control system coupled to the plurality of ablating elements,

wherein the control system is programmed to automatically change a treatment setting of two or more operating characteristics of the transducer of at least one of the plurality of ablating elements, the operating characteristics selected from the group consisting of a frequency, a power setting, an ablation time period, a direction of a focus of the at least one of the plurality of ablating elements and a focal length of the at least one of the plurality of ablating elements,

such that the transducer of the at least one of the plurality of ablating elements is individually activated to ablate a tissue at a first treatment setting of the two or more operating characteristics and, subsequently, is individually activated to ablate the same tissue at a second treatment setting of the two or more operating characteristics, the second setting being different from the first setting, and

wherein the second treatment setting produces localized heating closer to a near surface of the tissue than the first treatment setting.

31. The system of claim 30, wherein the control system is programmed to automatically control activation of the transducer of at least one of the plurality of ablating elements to ablate the tissue at a first frequency and a first power setting for a first ablation time period, and subsequently, to ablate the same tissue at a second frequency equal to or higher than the first frequency and a second power setting lower than the first power setting for a second ablation time period equal to or greater than the first ablation time period, wherein the second frequency, the second power setting, and the second ablation time period are predetermined.

32. The system of claim 31, wherein the first ablation time period is about 0.01 to 1.0 second and the second ablation time period is about 1.1 to 4 seconds.

33. The system of claim 31, wherein the first frequency is about 2-7 MHz and the second frequency is about 2-14 MHz.

34. The system of claim 31, wherein the first power setting is about 80-140 watts and the second power setting is about 20-60 watts.

35. The system of claim 31, wherein the control system is programmed to control activation of the transducer of at least one of the plurality of ablating elements to ablate the same tissue at a third treatment setting of the two or more operating characteristics subsequent to the second treatment setting, the third setting being a predetermined setting different from the second setting,

wherein the third treatment setting produces localized heating closer to the near surface of the tissue than the second treatment setting.

36. The system of claim 35, wherein the control system is programmed to control activation of the transducer of at least one of the plurality of ablating elements to ablate the same tissue, subsequent to the second ablation time period, at a third frequency equal to or higher than the second frequency and a third power setting lower than the second power setting for a third ablation time period.

37. The system of claim 36, wherein the third frequency is about 6-16 MHz and the third power setting is about 2-10 watts.

38. The system of claim 30, wherein the control system is programmed to activate the transducers of the plurality of ablating elements in a predetermined sequence.

39. The system of claim 30, wherein the control system is programmed to control pressure of a substance coupled to a part of at least one of the plurality of ablating elements.

40. The system of claim 39, wherein the substance is a fluid.

41. The system of claim 40, wherein the substance is one of a liquid and a gas.

42. The system of claim 39, wherein the substance is coupled to an inflatable member, which is coupled to the at least one of the plurality of ablating elements.

43. The system of claim 42, wherein the inflatable member is a balloon.

44. The system of claim 30, wherein the plurality of ablating elements further comprise one or more suction ports coupled to a suction lumen.

45. They system of claim 30, further comprising one or more temperature monitoring elements located on or near the plurality of ablating elements.

46. The system of claim 45, wherein the one or more temperature monitoring elements comprises one of a thermocouple and a thermistor.