MULTI-SEGMENT ULTRASOUND TRANSDUCERS

• US 20110270075A1
• Filed: 04/28/2010
• Published: 11/03/2011
• Est. Priority Date: 04/28/2010
• Status: Active Grant

• Current Assignee: InSightec Ltd.
• Original Assignee: InSightec Ltd.
• Inventors: Vitek, Shuki, Medan, Yoav, Hertzberg, Yoni
• Granted Patent: US 9,852,727 B2
• Time in Patent Office: Days
• US Class Current: 600/411
• CPC Class Codes: A61B 2090/374 NMR or MRI
• CPC Class Codes: A61N 2007/0065 Concave transducers
• CPC Class Codes: A61N 2007/0078 with multiple treatment transducers
• CPC Class Codes: A61N 2007/0091 with moving parts, e.g. transducers, lenses, reflectors
• CPC Class Codes: A61N 2007/0095 by modifying an excitation signal
• CPC Class Codes: A61N 7/02 Localised ultrasound hyperthermia hyperthermia in general A61F7/00
• CPC Class Codes: G10K 11/346 using phase variation
• CPC Class Codes: G10K 11/352 by moving the transducer

Abstract

Disclosed are systems and methods for focusing ultrasound transducers that include multiple separate, independently movable transducer segments.

Claims

1. A method of focusing an ultrasound transducer arrangement comprising a plurality of separate, independently movable segments, each transducer segment comprising a plurality of transducer elements, the method comprising, for each of the plurality of transducer segments:

driving the segment so as to generate an ultrasound focus;

measuring a total phase associated with the focus relative to a phase of a global focus; and

determining whether the focus is in phase with the global focus and, if not, adjusting the total phase of the focus to a phase of the global focus.

2. The method of claim 1 wherein measuring the total phase of the focus relative to the phase of the global focus comprises (i) driving the segment at a variable phase while driving the other segments at a constant phase, thereby varying an intensity of the global focus;

(ii) determining a phase difference, if any, between the constant and variable phases where the intensity is maximized; and

(iii) if the phase difference is non-zero, adjusting the total phase of the segment based thereon.

3. The method of claim 2 wherein determining the phase difference comprises imaging the focus.

4. The method of claim 3 wherein imaging the focus is accomplished using magnetic-resonance acoustic radiation force imaging.

5. The method of claim 1 wherein adjusting the total phase of the focus comprises applying phase shifts of equal magnitude to all of the transducer elements of the segment generating that focus.

6. The method of claim 1 further comprising measuring a location of the focus relative to a location of the global focus, determining whether the focus is co-located with the global focus, and, if not, shifting the focus to the global focus.

7-12. -12. (canceled)

13. A method of focusing an ultrasound transducer arrangement comprising a plurality of separate, independently movable segments, each transducer segment comprising a plurality of transducer elements, the method comprising, for each of the plurality of transducer segments:

driving the segment so as to generate an ultrasound focus;

measuring a location of the focus relative to a location of a global focus; and

determining whether the focus is co-located with the global focus and, if not, shifting the focus to the global focus.

14. The method of claim 13 wherein measuring the location of the focus relative to the global focus comprises imaging the focus.

16. The method of claim 14 wherein imaging the focus is accomplished using thermal imaging.

17. The method of claim 13 wherein shifting the focus comprises physically moving the segment.

18. The method of claim 13 wherein shifting the focus comprises applying a phase gradient across the transducer elements of the segment.

15. (canceled)

19. A system for focusing ultrasound, the system comprising:

an ultrasound transducer arrangement comprising a plurality of separate, independently movable segments, each transducer segment comprising a phased array of transducer elements for generating an ultrasound focus associated therewith;

a magnetic resonance imaging system for imaging the ultrasound foci associated with the segments; and

in communication with the magnetic resonance imaging system and the ultrasound transducer arrangement, a control facility configured to (i) drive each segment to generate the associated ultrasound focus, (ii) based at least in part on an image of the ultrasound focus, determine whether the focus is co-located and in phase with a global focus, and, if not, (iii) adjust at least one of a position, a total phase, or a phase gradient of the segment so as to co-locate and bring the focus in phase with the global focus.

20. The system of claim 19 wherein the transducer segments are mechanically uncoupled.

21. The system of claim 19 wherein the transducer segments are mechanically coupled.

22. The system of claim 21 wherein the transducer segments form a linkage mechanism with a single degree of freedom.

23. The system of claim 19 wherein the magnetic resonance imaging system, ultrasound transducer arrangement, and control facility are collectively configured to image the ultrasound foci using magnetic-resonance acoustic radiation force imaging.

24. A method of treating a target using ultrasound, the method comprising:

arranging a plurality of separate, independently movable transducer segments, each comprising a plurality of transducer elements, around the target;

calibrating the arrangement of the transducer segments by (i) driving each segment to generate an ultrasound focus, (ii) imaging the ultrasound focus of each segment to determine whether it coincides with a global focus at the target and, if not, adjusting the segment to bring the ultrasound focus in coincidence with the global focus; and

simultaneously driving the transducer segments to focus ultrasound into the target, thereby treating the target.

25. The method of claim 24 wherein determining whether the ultrasound focus coincides with the global focus comprises determining whether the ultrasound focus is co-located with the global focus.

27. The method of claim 24 wherein determining whether the ultrasound focus coincides with the global focus comprises determining whether the ultrasound focus is in phase with the global focus.

26. (canceled)

28-29. -29. (canceled)

30. A control system for operating an ultrasound system used in conjunction with a magnetic resonance imaging system, the ultrasound system comprising an arrangement of separate, independently movable transducer segments, each transducer segment comprising a phased array of transducer elements for generating an ultrasound focus associated therewith, the control system comprising circuitry for (i) driving each segment to generate an associated ultrasound focus, (ii) based at least in part on an image of the ultrasound focus, determining whether the focus is co-located and in phase with a global focus, and, if not, (iii) adjusting at least one of a position, a total phase, or a phase gradient of the segment so as to co-locate and bring the focus in phase with the global focus.