Lesion generation through bone using histotripsy therapy without aberration correction

• US 9,144,694 B2
• Filed: 08/09/2012
• Issued: 09/29/2015
• Est. Priority Date: 08/10/2011
• Status: Active Grant

• Current Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Original Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Inventors: Cain, Charles A.
• Primary Examiner(s): Peffley, Michael
• Application Number:
  US13/570,708
• Publication Number:
  US 20130041293A1
• Time in Patent Office: 1,146 Days
• Field of Search: 606/27
• US Class Current: 1/1
• CPC Class Codes: A61B 2017/320069 for ablating tissue
• CPC Class Codes: A61B 2018/00642 with feedback, i.e. closed loop control
• CPC Class Codes: A61B 2018/00702 Power or energy
• CPC Class Codes: A61B 2090/378 using ultrasound
• CPC Class Codes: A61B 8/0816 using echo-encephalography
• CPC Class Codes: A61B 8/13 Tomography A61B8/10, A61B8/12 take precedence; tomography for radiation diagnosis A61B6/02
• CPC Class Codes: A61N 2007/003 Destruction of nerve tissue
• CPC Class Codes: A61N 2007/0039 using microbubbles
• CPC Class Codes: A61N 2007/0052 using the same transducer for therapy and imaging
• CPC Class Codes: A61N 7/00 Ultrasound therapy lithotripsy A61B17/22, A61B17/225; massage using supersonic vibration A61H23/00 ; using ultrasound for introducing media into the body A61M37/0092
• CPC Class Codes: A61N 7/02 Localised ultrasound hyperthermia hyperthermia in general A61F7/00

Abstract

A medical imaging and therapy device is provided that may include any of a number of features. The device may include a Histotripsy transducer, a generator and controller configured to deliver Histotripsy energy from the transducer to target tissue, and an imaging system. In some embodiments, a method of treating tissue with Histotripsy energy comprises positioning a focus of a histotripsy transducer on a target tissue, delivering histotripsy energy from the histotripsy transducer through a bone aberrator, forming a histotripsy bubble cloud on the focus, and preventing the formation of secondary histotripsy bubble clouds without implementing an aberration correction algorithm.

Claims

1. A method of treating tissue with ultrasound energy, comprising:

positioning a focus of a histotripsy transducer on a target tissue;

delivering histotripsy energy from the histotripsy transducer through a bone aberrator;

forming a histotripsy bubble cloud on the focus; and

preventing the formation of secondary histotripsy bubble clouds due to the bone aberrator without implementing an aberration correction algorithm; and

in the event that a secondary histotripsy bubble cloud develops away from the focus due to the bone aberrator, decreasing a power level of the histotripsy transducer until the secondary bubble cloud disappears.

2. The method of claim 1 further comprising imaging the focus with an ultrasound imaging system.

3. The method of claim 1, further comprising damaging the target tissue at the focus.

4. The method of claim 1, wherein the delivering histotripsy energy step comprises delivering short (<

20 μ

sec), high pressure (peak negative pressure >

10 MPa) shockwave ultrasound pulses at a duty cycle <

5%.

5. The method of claim 1, wherein the bone aberrator comprises a rib cage.

6. The method of claim 1, wherein the bone aberrator comprises a skull.

7. The method of claim 1, wherein the bone aberrator comprises a pelvic bone.

8. The method of claim 1, further comprising:

adjusting a position of the focus to a different portion of the target tissue;

delivering histotripsy energy from the histotripsy transducer through the bone aberrator; and

forming a histotripsy bubble cloud on the focus at the different portion of the target tissue.

9. A method of treating tissue with ultrasound energy, comprising:

positioning a focus of a histotripsy transducer on a target tissue;

delivering histotripsy energy from the histotripsy transducer through a bone aberrator; and

increasing a power level of the histotripsy transducer until a histotripsy bubble cloud develops at the focus without developing a secondary histotripsy bubble cloud away from the focus; and

in the event that a secondary histotripsy bubble cloud develops away from the focus, decreasing the power level of the histotripsy transducer until the secondary bubble cloud disappears.

10. The method of claim 9 further comprising imaging the focus with an ultrasound imaging system.

11. The method of claim 10 wherein the increasing step further comprises increasing the power level of the histotripsy transducer until a histotripsy bubble cloud is imaged at the focus.

12. The method of claim 9, further comprising damaging the target tissue at the focus.

13. The method of claim 9, wherein the delivering histotripsy energy step comprises delivering short (<

20 μ

sec), high pressure (peak negative pressure >

10 MPa) shockwave ultrasound pulses at a duty cycle <

5%.

14. The method of claim 9, further comprising:

adjusting a position of the focus to a different portion of the target tissue;

delivering histotripsy energy from the histotripsy transducer through the bone aberrator; and

forming a histotripsy bubble cloud on the focus at the different portion of the target tissue.

15. A method of treating tissue with ultrasound energy, comprising:

positioning a focus of a histotripsy transducer on a target tissue;

delivering histotripsy energy from the histotripsy transducer through a bone aberrator;

forming a histotripsy bubble cloud on the focus;

observing formation of a secondary histotripsy bubble cloud positioned away from the focus; and

decreasing a power level of the histotripsy transducer to eliminate the secondary histotripsy bubble cloud.

16. The method of claim 15, wherein the observing step further comprises observing formation of the secondary histotripsy bubble cloud positioned away from the focus due to the bone aberrator.

17. A method of treating tissue with ultrasound energy, comprising:

delivering histotripsy energy from the histotripsy transducer through a bone aberrator;

forming a histotripsy bubble cloud on a focus of the histotripsy transducer;

forming a secondary histotripsy bubble cloud away from the focus of the histotripsy transducer; and

decreasing a power level of the histotripsy transducer to eliminate the secondary histotripsy bubble cloud.

18. The method of claim 17, wherein the forming a secondary histotripsy bubble cloud step further comprises forming the secondary histotripsy bubble cloud away from the focus of the histotripsy transducer due to the bone aberrator.