Dual-Mode Piezocomposite Ultrasonic Transducer

• US 20130060140A1
• Filed: 05/20/2011
• Published: 03/07/2013
• Est. Priority Date: 05/21/2010
• Status: Active Grant

• Current Assignee: Misonix OPCO LLC
• Original Assignee: Misonix Incorporated (Smith & Nephew PLC)
• Inventors: Sinelnikov, Yegor
• Granted Patent: US 8,698,377 B2
• Time in Patent Office: Days
• US Class Current: 600/439
• CPC Class Codes: A61B 2018/0016 Energy applicators arranged in a two- or three dimensional array
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2090/378 using ultrasound
• CPC Class Codes: A61B 8/4483 characterised by features of the ultrasound transducer
• CPC Class Codes: A61B 8/4494 characterised by the arrangement of the transducer elements devices for short-range imaging using particular transducer elements arrangements under G01S15/8909; arrangements of transducers in generation of mechanical vibrations of infrasonic, sonic or ultrasonic frequency B06B1/0607
• CPC Class Codes: A61B 8/485 involving measuring strain or elastic properties
• CPC Class Codes: A61N 2007/0078 with multiple treatment transducers
• CPC Class Codes: A61N 7/00 Ultrasound therapy lithotripsy A61B17/22, A61B17/225; massage using supersonic vibration A61H23/00 ; using ultrasound for introducing media into the body A61M37/0092
• 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: H10N 30/20 with electrical input and mechanical output, e.g. functioning as actuators or vibrators

Abstract

A compact, high power, dual mode, emitting and receiving ultrasound transducer and method for applying ultrasonic energy within a living subject and for monitoring the effects it induces in tissue comprises a set of piezoelectric polymeric transducer elements and a set of piezoelectric ceramic elements, bonded together. The polymeric transducer elements have electrodes enabling their use for low power diagnostic imaging interrogation of the tissue and the ceramic transducer elements have electrodes enabling their use for high power therapy applications.

Claims

1. An ultrasonic transducer device comprising at least one imaging transducer element made of a piezoelectric polymeric material and at least one therapeutic transducer element made of a piezoelectric ceramic material, said at least one imaging transducer element and said at least one therapeutic transducer element being bonded to one another.

2. The device defined in claim 1 wherein said at least one therapeutic transducer element is one of a plurality of piezoelectric ceramic transducer elements, said ceramic transducer elements being embedded in said imaging transducer element so that each of said ceramic transducer elements is spaced from the others of said ceramic transducer elements by said piezoelectric polymeric material.

3. The device defined in claim 2, further comprising an electrical circuit connecting said ceramic transducer elements in parallel to said imaging transducer element.

4. The device defined in claim 2, further comprising an electrical circuit connecting each of said ceramic transducer elements to an alternating voltage source.

5. The device defined in claim 2 wherein said piezoelectric ceramic transducer elements are electrically independent from each other and at least a subset of said piezoelectric ceramic transducer elements can be operated as a phased array while cross talk between members of said subset is minimized.

6. The device defined in claim 1 wherein said at least one imaging transducer element is one of a plurality of piezoelectric polymeric transducer elements, said piezoelectric polymeric transducer elements being embedded in said therapeutic transducer element so that each of said piezoelectric polymeric transducer elements is spaced from the others of said piezoelectric polymeric transducer elements by said piezoelectric ceramic material.

7. The device defined in claim 6, further comprising an electrical circuit connecting said piezoelectric polymeric transducer elements in parallel to said therapeutic transducer element.

8. The device defined in claim 6, further comprising an electrical circuit connecting said piezoelectric polymeric transducer elements to an ultrasound signal processor.

9. The device defined in claim 6 wherein said piezoelectric polymeric transducer elements are electrically independent from each other and at least a subset of said piezoelectric polymeric transducer elements can be operated as a receiving array while acoustical and electrical cross talk between members of said subset is minimized.

10. The device defined in claim 1 wherein said at least one imaging transducer element is one of a plurality of piezoelectric polymeric transducer elements and wherein said at least one therapeutic transducer element is one of a plurality of piezoelectric ceramic transducer elements, said piezoelectric polymeric transducer elements and said piezoelectric ceramic transducer elements being bonded to one another so that each of said piezoelectric polymeric transducer elements is spaced from the others of said piezoelectric polymeric transducer elements by one or more of piezoelectric ceramic transducer elements and so that each of said piezoelectric ceramic transducer elements is spaced from others of said piezoelectric ceramic transducer elements by one or more of said piezoelectric polymeric transducer elements.

11. The device defined in claim 10, further comprising an electrical circuit connecting each of said ceramic transducer elements to an alternating voltage source, also comprising an electrical circuit connecting each of said piezoelectric polymeric transducer elements to an ultrasound signal processor.

12. The device defined in claim 1 wherein said at least one imaging transducer element includes a plurality of first finger parts and wherein said at least one therapeutic transducer element includes a plurality of second finger parts, said first finger parts and said second finger parts being interdigitated or interleaved with one another so that each of said first finger parts is partially spaced from the others of said first finger parts by one or more of said second finger parts and so that each of said second finger parts is partially spaced from others of said second finger parts by one or more of said first finger parts.

13. The device defined in claim 1 wherein said at least one therapeutic transducer element includes a plurality of recesses, grooves, holes, cuts, dimples, or indentations filled with said piezoelectric polymeric material.

14. The device defined in claim 1 wherein said at least one imaging transducer element includes a plurality of recesses, grooves, holes, cuts, dimples, or indentations filled with said piezoelectric ceramic material.

15. The device defined in claim 1 wherein said at least one imaging transducer elements and said at least one therapeutic transducer element constitute a dual-mode transducer module, said at least one imaging transducer element and said at least one therapeutic transducer element being electrically and acoustically independent of one another.

16. The device defined in claim 15, further comprising an electrical circuit connecting the elements of said dual mode transducer module, further comprising means for operating the elements of said module as an emitting and receiving array.

17. The device defined in claim 15 wherein said at least one therapeutic transducer element is one of a multiplicity of therapeutic transducer elements electrically connected in parallel to one another and having respective resonance frequencies different from one another so as to permit selective activation of said therapeutic transducer elements.

18. The device defined in claim 15 wherein said at least one imaging transducer element is one of a multiplicity of imaging transducer elements electrically connected in parallel to one another and having respective frequency envelopes different from one another so as to permit selective processing of received ultrasound signals.

19. The device defined in claim 15 wherein said dual-mode transducer module includes at least one layer of piezoelectric polymeric material and at least one layer of piezoelectric ceramic substantially overlapping in a direction of ultrasound propagation.

20. The device defined in claim 19 wherein said layer of piezoelectric polymeric material and said layer of piezoelectric ceramic are separated by a water layer.

21. The device defined in claim 19 wherein said layer of piezoelectric polymeric material and said layer of piezoelectric ceramic collectively have a substantially planar or concave shape to produce a geometric focusing of ultrasound beam.

22. The device defined in claim 19 wherein said layer of piezoelectric polymeric material and said layer of piezoelectric ceramic are mechanically held together by means of an open cell metallic foam structure that permits water flow and efficient cooling.

23. The device defined in claim 19 wherein said layer of piezoelectric polymeric material and said layer of piezoelectric ceramic are poled in the same direction that permits an emission and reception of substantially unidirectional ultrasonic waves.

24. The device defined in claim 23 wherein said layer of piezoelectric polymeric material and said layer of piezoelectric ceramic are both poled in the direction normal to a surface comprising individual emitting and receiving element surfaces.

25. The device defined in claim 19 wherein said layer of piezoelectric polymeric material and said layer of piezoelectric ceramic are poled in different directions to enable a simultaneous emission and reception of substantially different ultrasonic waves to simultaneously monitor and induce the lesion formation.

26. The device defined in claim 25 wherein said layer of piezoelectric ceramic material is poled in the thickness mode normal to a surface comprising individual emitting and receiving elements surfaces and said layer of piezoelectric polymeric material is poled in a perpendicular direction radial to the center of said device in order to maximize the ability to perform multiwave imaging.

27. The device defined in claim 1 wherein said at least one imaging transducer elements and said at least one therapeutic transducer element are integral parts of a unitary transducer module, further comprising means in contact with said module for deforming said module to thereby alter a focal point of said at least one therapeutic transducer element.

28. The device defined in claim 27 wherein said means for deforming includes at least one bladder member.

29. The device defined in claim 27, further comprising an electrical circuit connecting said at least one therapeutic transducer element to an alternating voltage source, also comprising an electrical circuit connecting said at least one imaging transducer element to an ultrasound signal processor.