Asymmetric ultrasound phased-array transducer for dynamic beam steering to ablate tissues in MRI

• US 9,177,543 B2
• Filed: 08/26/2010
• Issued: 11/03/2015
• Est. Priority Date: 08/26/2009
• Status: Active Grant

• Current Assignee: InSightec Ltd.
• Original Assignee: InSightec Ltd.
• Inventors: Vitek, Shuki, Vortman, Kobi
• Primary Examiner(s): Jung, Unsu
• Assistant Examiner(s): Akar, Serkan
• Application Number:
  US12/869,024
• Publication Number:
  US 20110066032A1
• Time in Patent Office: 1,895 Days
• Field of Search: 600/437, 601/2
• US Class Current: 1/1
• CPC Class Codes: A61B 8/4483 characterised by features of the ultrasound transducer
• 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: B06B 1/0629 Square array
• CPC Class Codes: B06B 1/0633 Cylindrical array
• CPC Class Codes: G01S 15/8925 the array being a two-dimensional transducer configuration, i.e. matrix or orthogonal linear arrays
• CPC Class Codes: G01S 15/8952 using discrete, multiple frequencies
• CPC Class Codes: G10K 11/345 using energy switching from one active element to another
• CPC Class Codes: G10K 11/346 using phase variation

Abstract

An asymmetric ultrasound transducer array may include multiple regions or groups of transducer elements. The regions may be configured to generate respective ultrasound beams with different capabilities, such as, e.g., focusing at varying focal depths and lateral steering, and/or focusing into different volumes.

Claims

1. An asymmetric ultrasound transducer comprising:

(a) the asymmetric ultrasound transducer arranged in a plurality of ultrasound transducer elements in a two-dimensional phased array comprising at least a first region of a first plurality of rows and columns of grouped transducer elements extending over a first contiguous area and including only transducer elements of the first region and a second region of a second plurality of rows and columns of grouped transducer elements extending over a second contiguous area, wherein the second contiguous area is different from and not overlapping with the first contiguous area, and the second contiguous area including only transducer elements of the second region;

(b) a first plurality of signal channels connected to and collectively driving the transducer elements of the first region, and the signal channels are configured to generate a first ultrasound beam and a first focus, the elements within each group being connected to the same signal channel and the elements configured to be driven together with the same drive signal; and

(c) a second plurality of signal channels connected to and collectively driving the transducer elements of the second region and the signal channels are configured to generate a second ultrasound beam and a second focus, the elements within each group being connected to the same signal channel and the elements configured to be driven together with the same drive signal,

wherein (i) the first region, by virtue of the grouping of transducer elements, is configured to continuously vary focal depths of the first focus along a focal path in the direction of propagation of the first beam via adjusting relative phases between the drive signals of different groups of elements,

(ii) the second region, by virtue of the grouping of transducer elements, is configured to laterally shift the second focus of the second ultrasound beam in a direction perpendicular to propagation of the second beam by laterally steering the second beam, whereby a direction of propagation of the second beam relative to the ultrasound transducer is changed and

(iii) the first and second foci are generated simultaneously;

(d) the asymmetric ultrasound transducer configured to ablate tissues [0003], [00051] and configured to provide simultaneous treatment with other treatment equipment [0024].

2. The asymmetric ultrasound transducer of claim 1, wherein the two-dimensional phased array is planar.

3. The asymmetric ultrasound transducer of claim 1, wherein the two-dimensional phased array is non-planar.

4. The asymmetric ultrasound transducer of claim 1, wherein the first region is configured to steer the first ultrasound beam into a first selected volume and the second region is configured to steer the second ultrasound beam into a second selected volume.

5. The asymmetric ultrasound transducer of claim 4, wherein the first and second regions generate a third ultrasound beam and a third focus thereof and steer the third beam into a third volume, the third volume being different from the first and second volumes.

6. The asymmetric ultrasound transducer of claim 1, wherein the first region is configured to focus the first ultrasound beam at a tissue depth beneath a patient'"'"'s skin line of less than 4 cm.

7. The asymmetric ultrasound transducer of claim 1, wherein the second ultrasound beam has a lateral steerability greater than 0.1 radians.

8. The asymmetric ultrasound transducer of claim 1, wherein the connections of the first plurality of signal channels to the grouped transducer elements of the first region and the connections of the second plurality of signal channels to the grouped transducer elements of the second region are hardwired.

9. An asymmetric ultrasound transducer, comprising:

(a) the asymmetric ultrasound transducer arranged in a plurality of ultrasound transducer elements in a two-dimensional phased array, each transducer element having at least one switch associated therewith;

(b) a plurality of signal channels connected to the transducer elements via the switches, at least some of the signal channels being connected to multiple transducer elements; and

(c) a computer is configured to set the switches to group the transducer elements, the computer is further configured to form a first region and a second region of grouped transducer elements, wherein the first region comprising a first plurality of rows and columns of grouped transducer elements extending over a first contiguous area and including only transducer elements of the first region and the second region comprising a second plurality of rows and columns of grouped transducer elements extending over a second contiguous area, wherein the second contiguous area is different from and not overlapping with the first contiguous area, and the second contiguous area including only transducer elements of the second region, wherein the elements within each group being connected to the same signal channel and thereby driven together with the same drive signal,

wherein (i) the first region is configured, by virtue of the groupings, to generate a first ultrasound beam and a first focus thereof and continuously vary focal depths of the first focus along a focal path in the direction of propagation of the first beam via adjusting relative phases between the drive signals of different groups of elements,

(ii) the second region is configured, by virtue of the groupings, to generate a second ultrasound beam and a second focus thereof and laterally shift the focus in a direction perpendicular to propagation of the second beam by laterally steering the second beam, whereby a direction of propagation of the second beam relative to the ultrasound transducer is changed, and

(iii) the first and second foci are generated simultaneously

(d) the asymmetric ultrasound transducer configured to ablate tissues and configured to provide simultaneous treatment with other treatment equipment.

10. The asymmetric ultrasound transducer of claim 9, wherein the two-dimensional phased array is planar.

11. The asymmetric ultrasound transducer of claim 9, wherein the two-dimensional phased array is non-planar.

12. The asymmetric ultrasound transducer of claim 9, wherein the first region is configured to steer the first beam into a first selected volume and the second region is configured to steer the beam into a second selected volume.

13. An ultrasound transducer system, comprising:

(a) the asymmetric ultrasound transducer arranged in a plurality of ultrasound transducer elements in a two-dimensional phased array, each transducer element having at least one switch associated therewith;

(b) a plurality of signal channels connected to the transducer elements via the switches;

(c) a controller configuring the switches so as to group the transducer elements, the elements within each group being connected to the same signal channel and thereby driven together with the same drive signal;

(d) a hard drive for storing data sets where each data sets corresponds to a configuration of the switches; and

(e) user interface for facilitating user selection of one of the stored data sets, the controller being responsive to the selection and configuring the switches in accordance therewith,

wherein (i) a first set of grouped elements, comprising a first plurality of rows and columns of grouped elements extending over a first contiguous area of the array and including only transducer elements of the first contiguous area, is configured to generate a first ultrasound beam and a first focus thereof and continuously vary focal depths of the first focus within a first range of focal depths via adjusting relative phases between the drive signals of different groups of elements,

(ii) a second set of grouped elements, comprising a second plurality of rows and columns of grouped elements extending over a second contiguous area, wherein the second contiguous area is different from and not overlapping with the first contiguous area, of the array and the second contiguous area including only transducer elements of the second contiguous area, the grouped elements is configured to generate a second ultrasound beam and a second focus thereof and continuously vary focal depths of the second focus within a second range of focal depths via adjusting relative phases between the drive signals of different groups of elements, the second range being different from the first range, and

(iii) the first and second foci are generated simultaneously

the asymmetric ultrasound transducer configured to ablate tissues and configured to provide simultaneous treatment with other treatment equipment.

14. The system of claim 13 wherein at least one of the data sets specifies a configuration of the switches that configures the first set of grouped transducer elements to steer an ultrasound beam into a selected volume.

15. The system of claim 13 wherein the first range of focal depths corresponds to tissue depth beneath a patient'"'"'s skin line of less than 4 cm.

16. The system of claim 15 wherein at least one of the data sets specifies a configuration of the switches that configures the second set of grouped transducer elements to laterally steer the beam.

17. A method of configuring an asymmetric ultrasound transducer, the method comprising:

(a) the asymmetric ultrasound transducer arranged in providing a plurality of ultrasound transducer elements in a two-dimensional phased array;

(b) dynamically configuring, in response to geometric constraints associated with a patient'"'"'s anatomy and an equipment configuration, a plurality of signal channels connected to the transducer elements and the signal channels configured to produce a plurality of groups of transducer elements, the elements within each group being connected to the same signal channel and thereby driven together with the same signal; and

(c) separately driving the groups of transducer elements,

whereby (i) a first set of grouped elements, comprising a first plurality of rows and columns of grouped elements extending over a first contiguous area of the array and including only transducer elements of the first contiguous area, is configured to generate a first ultrasound beam and a first focus thereof and continuously vary focal depths of the first focus within a first range of focal depths via adjusting relative phases between the drive signals of different groups of elements,

(ii) a second set of grouped elements, comprising a second plurality of rows and columns of grouped elements extending over a second contiguous area, wherein the second contiguous area is different from and not overlapping with the first contiguous area, of the array and the second contiguous area including only transducer elements of the second contiguous area, the grouped elements is configured to generate a second ultrasound beam and a second focus thereof and continuously vary focal depths of the second focus within a second range of focal depths via adjusting relative phases between the drive signals of different groups of elements, the second range being different from the first range, and

(iii) the first and second foci are generated simultaneously

the asymmetric ultrasound transducer configured to ablate tissues and configured to provide simultaneous treatment with other treatment equipment.

18. The method of claim 17, wherein step (a) comprises providing the plurality of ultrasound transducer elements arranged in a planar two-dimensional phased array.

19. The method of claim 17, wherein step (a) comprises providing the plurality of ultrasound transducer elements arranged in a non-planar two-dimensional phased array.

20. The method of claim 17, wherein the first set of grouped elements is configured to steer the beam into a first selected volume and the second set of grouped elements is configured to steer the beam into a second selected volume.