METHOD AND APPARATUS FOR TREATING TISSUES WITH HIFU

• US 20100210976A1
• Filed: 10/05/2009
• Published: 08/19/2010
• Est. Priority Date: 10/03/2008
• Status: Active Grant

• Current Assignee: Mirabilis Medica, Inc.
• Original Assignee: Mirabilis Medica, Inc.
• Inventors: Connolly, Michael J., Horth, Roland, Reed, Justin A., Murkowski, John, Parsons, Jessica E., Darlington, Gregory P.
• Granted Patent: US 8,845,559 B2
• Time in Patent Office: Days
• US Class Current: 601/2
• CPC Class Codes: A61B 2090/378 using ultrasound
• CPC Class Codes: A61N 2007/0082 Scanning transducers
• CPC Class Codes: A61N 7/02 Localised ultrasound hyperthermia hyperthermia in general A61F7/00

Abstract

A method for treating a desired volume of tissue using HIFU or other energy modality to ablate a pattern of elemental treatment volumes each having a volume that is greater than that of the focal zone of the HIFU transducer but smaller than the overall volume of the desired treatment volume. In one embodiment, the pattern of elemental treatment volumes are arranged to form a shell which partially or wholly encapsulates the desired volume of tissue, which then necroses in situ due to effects other than direct HIFU damage (including some combination of ischemia, thermal conduction, inflammation, apoptosis, etc.). The necrosed tissue remains in the body and is subsequently resorbed and/or healed via normal body mechanisms.

Claims

1. A system for treating a desired treatment volume of tissue with high intensity focused ultrasound (HIFU), comprising:

a HIFU transducer configured to deliver treatment energy to a focal zone; and

a processor programmed to repeatedly position the focal zone over a perimeter of or along an elemental treatment volume as treatment energy is applied.

2. The system of claim 1, wherein the elemental treatment volume has size selected such that an interior region is treated by indirect heating as the treatment energy is applied to the perimeter of the elemental treatment volume.

3. The system of claim 1, wherein the processor is programmed to position the focal zone of the HIFU transducer in a pattern to create a number of elemental treatment volumes within the desired treatment volume.

4. The system of claim 1, wherein the processor is programmed to position the focal zone of the HIFU transducer in a pattern to create a shell of elemental treatment volumes around the desired treatment volume of tissue.

5. The system of claim 4, wherein the processor is programmed to position the focal zone of the HIFU transducer to create the shell of elemental treatment volumes around a tumor or uterine fibroid in a body.

6. The system of claim 1, wherein the treatment energy is non-linear at the focal zone.

7. The system of claim 1, wherein the elemental treatment volume is cylindrical and has a diameter approximately equal to a length of the focal zone.

8. The system of claim 1, wherein the processor is programmed to control a mechanical linkage that adjusts the position of the HIFU transducer.

9. The system of claim 1, wherein the processor is programmed to control an electronic beam steerer.

10. The system of claim 1, wherein the processor is programmed to position the focal zone of the HIFU transducer around the perimeter of the elemental treatment volume and control the application of treatment energy such that the tissue of the elemental treatment volume is partially ablated with each pass of the focal zone around the perimeter of the elemental treatment volume.

11. A system for treating a desired treatment volume of tissue with high intensity focused ultrasound (HIFU), comprising:

a HIFU transducer configured to deliver treatment energy to a focal zone; and

means for creating one or more elemental treatment volumes within the desired treatment volume of tissue by repeatedly positioning the focal zone of the HIFU transducer around a perimeter of the elemental treatment volume as treatment energy is being delivered such that the perimeter is directly treated by the treatment energy and an interior region of the elemental treatment volume is indirectly treated.

12. The system of claim 11, wherein each elemental treatment volume is a cylinder having a diameter substantially equal to a length of the focal zone.

13. The system of claim 11, wherein each elemental treatment volume is a cylinder having a diameter that is larger than twice the diameter of the focal zone.

14. The system of claim 13, wherein each elemental treatment volume has a height substantially equal to the length of the focal zone.

15. The system of claim 11, wherein the means for creating the one or more elemental treatment volumes includes a mechanical linkage to move the transducer such that the focal zone is repeatedly positioned around the perimeter of the elemental treatment volume.

16. The system of claim 11, wherein the means for creating the one or more elemental treatment volume includes an electronic beam steerer that electronically orients the focal zone of the HIFU transducer such that the focal zone is repeatedly positioned around the perimeter of the elemental treatment volume.

17. The system of claim 11, wherein the means for creating one or more elemental treatment volumes creates a pattern of elemental treatment volumes within the desired treatment volume of tissue.

18. The system of claim 17, wherein the pattern of elemental treatment volumes defines a shell that encompasses a portion of the desired treatment volume of tissue.

19. The system of claim 18, wherein the shell encompasses a tumor in a body.

20. The system of claim 18, wherein the shell encompasses a uterine fibroid in a body

21. The system of claim 11, wherein the treatment energy is a HIFU signal that is non-linear in tissue at the focal zone.

22. A method of operating a HIFU ultrasound device to treat a desired tissue volume, comprising:

selectively controlling the position of a focal zone of a HIFU transducer such that the focal zone is repeatedly positioned around a perimeter of an elemental treatment volume; and

applying treatment energy to the tissue while the focal zone is oriented at a number of positions around the perimeter of the elemental treatment volume such that the perimeter is repeatedly ablated by direct exposure to the treatment energy and an interior of the elemental treatment volume is indirectly treated by heat due to the direct ablation of the perimeter of the elemental treatment volume.

23. The method of claim 22, further comprising selectively controlling the focal zone of the HIFU transducer to create a pattern of elemental treatment volumes within the desired tissue volume.

24. The method of claim 23, wherein the pattern of elemental treatment volumes defines a shell that partially or completely encapsulates the desired tissue volume.

25. The method of claim 24, wherein position of the focal zone is controlled to create a pattern of elemental treatment volumes that are sufficiently close together to form the shell.

26. The method of claim 22, wherein the focal zone of the HIFU transducer is selectively positioned over a diameter that is approximately equal to a length of the focal zone to create each elemental treatment volume.

27. The method of claim 24, further comprising selectively controlling the focal zone of the HIFU transducer to create two or more shells within the desired tissue volume.

28. The method of claim 22, wherein applying the treatment energy includes delivering HIFU signals that are non-linear at the focal zone to the tissue.

29. The method of claim 22, further comprising:

producing an image of the desired tissue volume;

displaying the image of the tissue on a video display screen;

receiving input from a user that indicates a boundary of the desired tissue volume; and

determining a required pattern for moving the focal zone to create a number of adjacent elemental treatment volumes to form an ablated shell which encapsulates some or all of the desired tissue volume, based on the input from the user.

30. The method of claim 22, wherein the focal zone of the HIFU transducer is positioned around the perimeter of the elemental treatment volume and treatment energy is applied such that the tissue of the elemental treatment volume is partially ablated with each pass of the focal zone around the perimeter of the elemental treatment volume.

31. The method of claim 22, wherein the treatment energy is a pulsed HIFU signal.

32. The method of claim 24, wherein the shell is created to encompass all or a portion of a tumor or uterine fibroid.

33. A system for treating a tumor or uterine fibroid within a body with high intensity focused ultrasound (HIFU), comprising:

a HIFU transducer configured to deliver treatment energy in a controllable direction to a focal zone; and

a processor programmed to direct the focal zone as treatment energy is applied to create an ablated shell that encompasses all or a portion of the tumor or uterine fibroid.

34. The system of claim 33, wherein the processor is programmed to direct the focal zone in pattern that forms the shell from a number of elemental treatment volumes.

35. The system of claim 34, wherein the processor is programmed to repeatedly direct the focal zone on the perimeter of each elemental treatment volume.

36. The system of claim 33, wherein the processor is programmed to direct the focal zone in pattern of annular rings that are stacked to encompass all or a portion of the tumor or uterine fibroid.