Ultrasound transducer array

• US 6,974,417 B2
• Filed: 10/04/2002
• Issued: 12/13/2005
• Est. Priority Date: 10/05/2001
• Status: Expired due to Fees

• Current Assignee: Queen's University At Kingston
• Original Assignee: Queen's University At Kingston
• Inventors: Morton, Christine E., Lockwood, Geoffrey R.
• Primary Examiner(s): Jaworski, Francis J.
• Application Number:
  US10/263,683
• Publication Number:
  US 20030067249A1
• Time in Patent Office: 1,166 Days
• Field of Search: 600/443, 600/447, 600/459, 128/916, 73625-626, 340/334, 340/336, 340366-368
• US Class Current: 600/459
• CPC Class Codes: B06B 1/0622 on one surface
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48 of an individual wire connector
• CPC Class Codes: H01L 24/45 of an individual wire connector
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01012 Magnesium [Mg]
• CPC Class Codes: H01L 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01019 Potassium [K]
• CPC Class Codes: H01L 2924/0102 Calcium [Ca]
• CPC Class Codes: H01L 2924/01038 Strontium [Sr]
• CPC Class Codes: H01L 2924/01078 Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/12042 LASER
• CPC Class Codes: H01L 2924/3011 Impedance

Abstract

This invention relates to an ultrasonic transducer array for non-destructive imaging and inspection of materials, suitable for applications such as bio-medical imaging. According to the invention, the transducer has at least one electrode comprising an array of electrode elements, wherein the elements are not separated by a grooves or kerfs. The grooveless transducer design simplifies transducer construction and permits very high operating frequencies, and hence very high resolution. In one embodiment suitable for producing real-time high resolution 3-dimension images, the invention provides a hybrid transducer comprising two opposed electrodes, one electrode being a grooveless linear array and the second electrode being a grooved linear phased array.

Claims

1. A transducer for transmitting and/or receiving ultrasound energy, comprising:

a hard substrate having first and second opposed faces;

a first electrode disposed on said first substrate face, said first electrode comprising an array of electrode elements and lacking grooves in the substrate between electrode elements; and

a second electrode disposed on said second substrate face, said second electrode comprising an array of electrode elements and having grooves in the substrate between electrode elements.

2. The transducer of claim 1, wherein said arrays of elements on said first and second substrate faces have different patterns.

3. The transducer of claim 1, wherein said first electrode on the first substrate face comprises a linear array and said second electrode on the second substrate face comprises a linear phased array.

4. The transducer of claim 1, wherein said substrate is of a material selected from piezoelectric ceramic, ferroelectric ceramic, and single crystal relaxor ferroelectric material.

5. The transducer of claim 1, wherein said substrate is of PZT material.

6. The transducer of claim 1, further comprising at least one matching layer disposed on at least one of said first and second electrodes.

7. An ultrasonic imaging system comprising the transducer of claim 1 and ultrasound transmitting and receiving circuitry.

8. The system of claim 7 further comprising means for processing signal information.

9. A method for producing a transducer for transmitting and/or receiving ultrasound energy, comprising:

providing a hard substrate having first and second opposed faces;

disposing a first electrode on said first substrate face, said first electrode comprising an array of electrode elements and lacking grooves in the substrate between electrode elements; and

disposing a second electrode on said second substrate face, said second electrode comprising an array of electrode elements and having grooves in the substrate between electrode elements.

10. A method for producing a 3-D ultrasound image of a material under investigation, comprising:

(a) providing a transducer for transmitting and receiving ultrasound energy which includes a hard substrate having first and second opposed faces, a first electrode disposed on said first substrate comprising an array of electrode elements and lacking grooves in the substrate between the electrode elements and a second electrode disposed on said second substrate face comprising an array of electrode elements and having grooves in the substrate between electrode elements, and where said first electrode on the first substrate face comprises a linear array and said second electrode on the second substrate face comprises a linear phased array,

(b) activating a first subset of said linear array elements to create a first 2-D image;

(c) activating a second subset of said linear array elements to create a second 2-D image, wherein said second image is spatially adjacent to said first 2-D image;

(d) repeating steps (b) and (c) n times to create n spatially adjacent 2-D images; and

(e) assembling said n 2-D images to produce a 3-D image of said material under investigation.

11. The method of claim 10, wherein the material under investigation is biological tissue.

12. The method of claim 11, wherein the biological tissue is cardiac tissue.

13. A method for transmitting and/or receiving ultrasound energy, comprising providing a hard substrate having first and second opposed faces;

disposing a first electrode on said first substrate face, the first electrode comprising a first array of electrode elements, said first array of electrode elements lacking grooves in the substrate between electrode elements;

disposing a second electrode on said second substrate face, the second electrode comprising a second array of electrode elements, said second array of electrode elements lacking grooves in the substrate between electrode elements; and

focusing electronically said first array of electrode elements at a fixed steering angle to transmit and/or receive ultrasound energy and focusing electronically said second array of electrode elements at a fixed steering angle to transmit and/or receive ultrasound energy.

14. A method for producing an ultrasound image of a material under investigation, comprising

transmitting at least one ultrasonic pulse into a material under investigation and receiving an echo of said at least one pulse using the method of claim 13;

and

processing information corresponding to said pulse and said echo to generate an image of said material.

15. The method of claim 14, wherein the material under investigation is biological tissue.

16. The method of claim 15, wherein the biological tissue is cardiac tissue.

17. The method of claim 13, wherein providing a hard substrate comprises providing a substrate of a material selected from piezoelectric ceramic, ferroelectric ceramic, single crystal relaxor ferroelectric material, and composite transducer materials.

18. The method of claim 13, wherein providing a hard substrate comprises providing a substrate of PZT material.

19. The method of claim 13, wherein providing a hard substrate comprises providing a substrate selected from PZN-PT and PMN-PT material.

20. The method of claim 13, further comprising disposing at least one matching layer on said second electrode.

21. The method of claim 13, further comprising disposing at least one silver epoxy matching layer on said second electrode.

22. The method of claim 13, wherein said second electrode is also a matching layer.

23. The method of claim 13, further comprising disposing at least one backing layer on said first electrode.

24. The method of claim 13, further comprising disposing at least one tungsten-loaded epoxy backing layer on said first electrode.

25. The method of claim 13, wherein disposing said first electrode comprises providing an array of electrode elements in an array pattern selected from annular, linear, curved linear, 1.5-D, and 2-D.

26. The method of claim 13, further comprising providing, for said a second array of electrode elements on the second substrate face, grooves in the substrate between electrode elements.

27. The method of claim 13, wherein said first and second arrays of electrode elements on said first and second electrodes have different patterns.

28. A method for producing an ultrasound image of a material under investigation, comprising:

transmitting at least one ultrasonic pulse into a material under investigation and receiving an echo of said at least one pulse using the method of claim 13; and

processing information corresponding to said pulse and said echo to generate an image of said material.

29. The method of claim 28, wherein the material under investigation is biological tissue.

30. The method of claim 29, wherein the biological tissue is cardiac tissue.

31. A method for producing a 3-D ultrasound image of a material under investigation, comprising:

(a) providing a transducer comprising a substrate having first and second opposed faces, said first opposed substrate face comprising an electrode having a first array of electrode elements, and said second opposed substrate face comprising an electrode having a second array of electrode elements, said first and second arrays of electrode elements lacking grooves in the substrate between electrode elements;

(b) focusing electronically a subset of said first array of electrode elements at a fixed steering angle to transmit an ultrasound signal into the material under investigation;

(c) receiving an ultrasound signal from the material under investigation using said second array of electrode elements;

(d) processing the signal received in (c) to produce a 2-D image;

(e) repeating steps (b) to (d) n times to create n spatially adjacent 2-D images; and

(e) assembling said n 2-D images to produce a 3-D image of said material under investigation.

32. The method of claim 31, wherein the material under investigation is biological tissue.

33. The method of claim 32, wherein the biological tissue is cardiac tissue.