Closed-Loop Clot Lysis

• US 20100125193A1
• Filed: 11/17/2009
• Published: 05/20/2010
• Est. Priority Date: 11/19/2008
• Status: Active Grant

• Current Assignee: InSightec Ltd.
• Original Assignee: InSightec Ltd.
• Inventors: Zadicario, Eyal
• Granted Patent: US 8,425,424 B2
• Time in Patent Office: Days
• US Class Current: 600/411
• CPC Class Codes: A61B 5/0263 using NMR
• CPC Class Codes: A61B 90/37 Surgical systems with images on a monitor during operation
• CPC Class Codes: A61N 7/02 Localised ultrasound hyperthermia hyperthermia in general A61F7/00
• CPC Class Codes: A61N 7/022 intracavitary

Abstract

The present invention provides procedures and systems that use a closed-loop approach for directing ultrasound energy at a clot while monitoring blood flow and/or liquification of the clot tissue so as to allow automated and/or manual adjustments to various treatment parameters.

Claims

1. A system for delivering acoustic energy to a clot within a blood vessel, the system comprising:

a. a focused-ultrasound phased-array transducer;

b. means for monitoring blood flow in a vicinity of the blood vessel as ultrasound energy is directed at the blood vessel; and

c. a controller for operating the transducer and adjusting transducer operation based on the monitored blood flow.

2. The system of claim 1 wherein the means for monitoring blood flow comprises a visual display.

3. The system of claim 1 further comprising a beam former for driving the transducer elements based on the monitored blood flow.

4. The system of claim 1 further comprising a processor for generating correction factors based on the monitored blood flow and wherein the controller is responsive to the processor, thereby implementing the correction factors and influencing the application of acoustic energy to the clot.

5. The system of claim 2 wherein the controller further assesses a focal quality of images used to monitor the blood flow applying phase correction factors to adjust alter the focus.

6. The system of claim 1 wherein the treatment effect is monitored based on an oxygen level within the vicinity of the blood vessel blood.

7. The system of claim 4 wherein the controller permits a user to override one or more of the correction factors.

8. The system of claim 1 wherein the phased-array transducer comprises a plurality of transducer elements, each element configured to deliver ultrasound energy independently of the others.

9. The system of claim 1 wherein the images comprise one or more of a magnetic resonance image, a computer tomography image, and an ultrasound image.

10. The system of claim 1 wherein the images provide an indication of blood flow about the blood vessel.

11. The system of claim 10 wherein the monitored blood flow includes blood flow through the blood vessel containing the clot.

12. The system of claim 1 wherein the controller comprises a phase adjuster for adjusting phases of excitation signals provided to transducer elements based upon phase correction factors for respective transducer elements.

13. The system of claim 12, wherein the controller comprises one or more amplifiers coupled to the phase adjuster for amplifying the excitation signals provided to the respective transducer elements based upon amplitude correction factors.

14. The system of claim 13 where the amplitude adjustments result in a uniform temperature distribution about the patient'"'"'s skull.

15. The system of claim 13 where the amplitude adjustments are determined at least in part on a predefined temperature map.

16. The system of claim 1 wherein the processor constructs an acoustic transmission regime comprising a plurality of treatment parameters optimized to perform clot lysis, the correction factors influencing one or more of the treatment parameters.

19. The system of claim 1 further comprising a processor for generating correction factors based on the liquefaction information and wherein the controller is responsive to the processor, thereby implementing the correction factors and influencing the application of acoustic energy to the clot.

17. A system for delivering acoustic energy to a clot within a blood vessel, the system comprising:

a. a focused-ultrasound phased-array transducer;

b. means for monitoring liquid content of the clot as ultrasound energy is directed at the clot; and

c. a controller for operating the transducer and adjusting transducer operation based on the monitored liquid content.

18. The system of claim 17 wherein the means for monitoring liquefaction compromise a visual display.

20. A method for treating a clot within a blood vessel, the method comprising the steps of:

a. applying focused ultrasound energy to the blood vessel using a focused-ultrasound phased-array transducer;

b. monitoring blood flow in a vicinity of the blood vessel as ultrasound energy is directed at the blood vessel; and

c. operating the transducer including adjusting transducer operation based on the monitored blood flow.

21. The method of claim 20 further comprising obtaining subsequent images of the cranial blood vessel during the application of the ultrasound energy.

22. The method of claim 20 further compromising

(d) assessing a focal quality in situ and applying phase correction factors to adjust alter the focus.

23. The method of claim 22 further comprising:

(e) generating respective correction factors for one or more transducer elements of the transducer array based on the images.

24. The method of claim 20 wherein the images comprise at least one of a magnetic resonance image, a computer tomography image, and an ultrasound image.

25. The method of claim 20 wherein the indication of blood flow indicates blood flow through the blood vessel in which the clot lies.

26. The method of claim 23 wherein the correction factors comprise phase correction factors associated with respective transducer elements, and further comprising adjusting phases of excitation signals provided to the transducer based upon the phase correction factors.

27. The method of claim 23 further comprising driving the phased-array transducer with excitation signals based upon the correction factors to focus acoustic energy from the transducer elements at the clot.

28. The method of claim 26, wherein the excitation factors comprise amplitude correction factors associated with respective transducer elements, and further comprising amplifying the excitation signals provided to the respective transducer elements based upon the amplitude correction factors.

29. The method of claim 23 further comprising constructing an acoustic transmission regime comprising a plurality of treatment parameters optimized to perform clot lysis and wherein the correction factors influence one or more of the treatment parameters.

30. The method of claim 23 further comprising repeating steps (b)-(e) until the clot is substantially ablated.

31. A method for treating a clot within a blood vessel, the method comprising the steps of:

a. applying focused ultrasound energy to the clot using a focused-ultrasound phased-array transducer;

b. monitoring liquid content of the clot as ultrasound energy is directed at the blood vessel; and

c. operating the transducer including adjusting transducer operation based on the monitored liquid content.

32. The method of claim 31 further comprising obtaining subsequent images of the clot during the application of the ultrasound energy.

33. The method of claim 32 further comprising generating respective correction factors for each transducer element of the transducer array based on the images.