Ultrasound transducers for imaging and therapy

• US 20060235300A1
• Filed: 06/19/2006
• Published: 10/19/2006
• Est. Priority Date: 12/23/1999
• Status: Abandoned Application

• Current Assignee: Otsuka Medical Devices Co., Ltd. (Otsuka Holdings Company Limited)
• Original Assignee: Otsuka Medical Devices Co., Ltd. (Otsuka Holdings Company Limited)
• Inventors: Zhang, Jimin, Perozek, David M., Weng, Lee
• Application Number:
  US11/471,052
• Publication Number:
  US 20060235300A1
• Time in Patent Office: Days
• US Class Current: 600/439
• CPC Class Codes: A61B 17/0057 Implements for plugging an opening in the wall of a hollow or tubular organ, e.g. for sealing a vessel puncture or closing a cardiac septal defect sutures A61B17/04; closing rectum or urethra near body surface A61F2/0009
• CPC Class Codes: A61B 2017/00504 Tissue welding
• CPC Class Codes: A61B 2017/00907 for light
• CPC Class Codes: A61B 2090/062 penetration depth
• CPC Class Codes: A61B 2090/378 using ultrasound
• CPC Class Codes: A61B 2090/3904 specially adapted for marking specified tissue
• CPC Class Codes: A61B 2090/3937 Visible markers
• CPC Class Codes: A61B 2562/164 the sensor is mounted in or on a conformable substrate or carrier
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61B 8/445 Details of catheter construction
• CPC Class Codes: A61B 8/4461 Features of the scanning mechanism, e.g. for moving the transducer within the housing of the probe
• CPC Class Codes: A61H 23/0245 with ultrasonic transducers, e.g. piezoelectric
• CPC Class Codes: A61N 2007/0052 using the same transducer for therapy and imaging
• CPC Class Codes: A61N 2007/0065 Concave transducers
• CPC Class Codes: A61N 2007/0078 with multiple treatment transducers
• CPC Class Codes: A61N 7/02 Localised ultrasound hyperthermia hyperthermia in general A61F7/00
• CPC Class Codes: G10K 11/32 characterised by the shape of the source
• CPC Class Codes: G10K 11/346 using phase variation

Abstract

Ultrasound applicators able to both image a treatment site and administer ultrasound therapy include an array of transducer elements that can be focused. In several embodiments, an electronically phased array is used for controlling the focal point of an ultrasound beam. The ultrasound beam produced thereby can also be electronically steered. To reduce the quality factor or Q of the array when the array is used for imaging, an electronic switch is selectively closed, placing a resistance in parallel with each of the array elements. A flexible array is employed in several embodiments and is selectively bent or flexed to vary its radius of curvature and thus control the focal point and/or a direction of focus of the array. In another embodiment, each of the transducer elements comprising the array are individually mechanically pivotable to steer the ultrasonic beam produced by the transducer elements.

Claims

1. An ultrasound applicator, comprising:

a plurality of ultrasound transducer elements configured in an array;

a control system configured to energize the transducer elements; and

a first damping network configured to be electrically coupled to the transducer elements during use of the transducer elements for ultrasound imaging and configured to be electrically decoupled from the transducer elements during use of the transducer elements for ultrasound therapy.

2. The ultrasound applicator of claim 1, comprising an electronic switch configured to selectively electrically couple or decouple the damping network to the transducer elements.

3. The ultrasound applicator of claim 1, wherein the damping network is configured such that the transducer elements have a substantially greater quality factor when the damping network is electrically coupled to the transducer elements than when the damping network is electrically decoupled from the transducer elements.

4. The ultrasound applicator of claim 1, wherein the control system is configured to provide a signal to at least one of the transducer elements that has a different phase than a signal provided to at least one other of the transducer elements.

5. The ultrasound applicator of claim 1, wherein the plurality of ultrasound transducer elements are configured in a concave array.

6. The ultrasound applicator of claim 1, wherein when the damping network is electrically coupled to the transducer elements, the applicator comprises an impedance matched, highly damped transducer configuration.

7. The ultrasound applicator of claim 1, comprising a second damping network configured to be electrically coupled to the transducer elements during use of the transducer elements for ultrasound therapy and configured to be electrically decoupled from the transducer elements during use of the transducer elements for ultrasound imaging.

8. The ultrasound applicator of claim 7, comprising an electronic switch configured to selectively electrically couple either the first damping network or the second damping network to the transducer elements.

9. The ultrasound applicator of claim 7, wherein the first and second damping networks are configured such that the transducer elements have a substantially greater quality factor when the first damping network is electrically coupled to the transducer elements than when the second damping network is electrically coupled to the transducer elements.

10. The ultrasound applicator of claim 7, wherein when the second damping network is electrically coupled to the transducer elements, the applicator comprises an impedance matched, weakly damped transducer configuration.

11. An ultrasound applicator, comprising:

a flexible array of ultrasound transducer elements comprising a plurality of ultrasound transducer elements supported by a thermally and electrically conductive layer, each transducer element separated from adjacent elements by a kerf that is filled with a deformable material, wherein the flexible array is deformed into a concave shape; and

a control system configured to energize at least one of the transducer elements with a different phase than at least one other of the transducer elements.

12. The ultrasound applicator of claim 11, further comprising a housing in which the flexible array is mounted.

13. The ultrasound applicator of claim 11, wherein each of the plurality of ultrasound transducer elements comprises a composite mixture that includes a piezo-ceramic, an adhesive binder, and thermally conductive particles.

14. An ultrasound applicator, comprising:

means for generating ultrasonic energy have a first quality factor; and

means for reducing the first quality factor to generate ultrasonic energy having a second quality factor.

15. The ultrasound applicator of claim 14, wherein the generating means comprises at least on ultrasound transducer.

16. The ultrasound applicator of claim 14, wherein the reducing means comprises a damping network.