ADAPTIVE ACTIVE COOLING DURING FOCUSED ULTRASOUND TREATMENT

• US 20120101412A1
• Filed: 10/22/2010
• Published: 04/26/2012
• Est. Priority Date: 10/22/2010
• Status: Active Grant

• Current Assignee: InSightec Ltd.
• Original Assignee: InSightec Ltd.
• Inventors: Vortman, Kobi, Vitek, Shuki, Levy, Yoav
• Granted Patent: US 9,981,148 B2
• Time in Patent Office: Days
• US Class Current: 601/3
• CPC Class Codes: A61B 2017/00084 Temperature
• CPC Class Codes: A61B 2018/00023 closed, i.e. without wound contact by the fluid
• CPC Class Codes: A61B 2090/0472 against ultrasound energy
• CPC Class Codes: A61B 2090/374 NMR or MRI
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 90/04 Protection of tissue around surgical sites against effects of non-mechanical surgery, e.g. laser surgery protection of eyes against laser radiation A61F9/022
• 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

Disclosed are thermal treatment methods that involve monitoring and/or actively adjusting the temperature of targeted and/or non-targeted tissues.

Claims

1. A thermal treatment method comprising:

heating a target tissue;

monitoring a temperature field in a region encompassing the target tissue and a non-target tissue; and

based, at least in part, on the monitored temperature field, actively adjusting the temperature of the non-target tissue.

2. The method of claim 1, wherein heating the target tissue comprises focusing ultrasound into the target tissue.

3. The method of claim 2, further comprising adjusting the ultrasound focusing based, at least in part, on the monitored temperature field.

4. The method of claim 3, wherein adjusting the ultrasound focusing comprises adjusting at least one of a location or an intensity of the ultrasound focus.

5. The method of claim 4, wherein adjusting the location of the ultrasound focus comprises cycling the location between different targets at different distances from the non-target tissue.

6. The method of claim 5, wherein the different targets have different thermal properties.

7. The method of claim 6, wherein the different targets have different thermal time constants.

8. The method of claim 1, wherein actively adjusting the temperature of the non-target tissue comprises actively cooling the non-target tissue.

9. The method of claim 8, wherein the heating of the target tissue and the active cooling of the non-target tissue are repeated in cycles.

10. The method of claim 8, wherein actively adjusting the temperature of the non-target tissue further comprises, following cooling, actively heating the non-target tissue.

11. The method of claim 1, wherein the target tissue and the non-target tissue have different thermal time constants, and the step of actively adjusting the temperature of the non-target tissue is based at least in part on the difference between the thermal time constants.

12. The method of claim 1, wherein actively adjusting the temperature of the non-target tissue comprises flowing a fluid in thermal contact with the non-target tissue.

13. The method of claim 12, wherein adjusting the temperature further comprises changing a flow rate of the fluid.

14. The method of claim 12, wherein adjusting the temperature further comprises changing a temperature of the fluid.

15. The method of claim 1, wherein monitoring the temperature field comprises magnetic resonance imaging thermometry.

16. The method of claim 1, wherein monitoring the temperature field comprises computing a time-evolution of the temperature field.

17. The method of claim 16, wherein the computation is based on calibrated parameters.

18. The method of claim 17, wherein the calibrate parameters relate tissue thermal response to a thermal stimulus applied thereto.

19. An ultrasound treatment method comprising:

monitoring a temperature difference between a first non-target tissue and a first target tissue proximate thereto;

directing an ultrasound focus into the first target tissue so as to heat the first target tissue while cooling a second non-target tissue proximate to a second target tissue; and

when the temperature difference exceeds a specified threshold, re-directing the ultrasound focus into the second target tissue so as to heat the second target tissue.

20. An ultrasound treatment method comprising a plurality of treatment cycles, each cycle comprising:

activating cooling of a non-target tissue;

focusing ultrasound into a target tissue proximate the non-target tissue so as to heat the target tissue; and

deactivating cooling of the non-target tissue.

21. The method of claim 20, wherein a thermal time constant of the target tissue is greater than a thermal time constant of the non-target tissue.

22. The method of claim 20, wherein the cooling is deactivated when the target tissue is heated.

23. The method of claim 20, wherein the cooling is deactivated after heating of the target tissue has ceased.

24. The method of claim 20, wherein a temporal cycle of activating and deactivating cooling is established based on thermal properties of the target and non-target tissue.

25. A controller for use in conjunction with a thermal treatment apparatus and temperature control equipment, the controller comprising:

a module for processing monitored data indicative of a temperature field in a region encompassing the target tissue and a non-target tissue; and

a module for controlling the temperature control equipment so as to adjust a temperature of the non-target tissue based, at least in part, on the monitored temperature field.

26. A thermal treatment system, comprising:

a thermal treatment apparatus for heating a target tissue;

temperature control equipment for adjusting a temperature of a non-target tissue; and

a controller for driving the thermal treatment apparatus and controlling the temperature control equipment based, at least in part, on a monitored temperature field in a region encompassing the target tissue and the non-target tissue.