High frequency synthetic ultrasound array incorporating an actuator

• US 20020050169A1
• Filed: 08/13/2001
• Published: 05/02/2002
• Est. Priority Date: 08/30/2000
• Status: Active Grant

• Current Assignee: Penn State Research Foundation
• Original Assignee: Penn State Research Foundation
• Inventors: Shung, K. Kirk, Ritter, Timothy Adam, Shrout, Thomas R.
• Granted Patent: US 6,679,845 B2
• Time in Patent Office: Days
• US Class Current: 73/606
• CPC Class Codes: G01S 15/8915 using a transducer array
• CPC Class Codes: G01S 15/8945 using transducers mounted for linear mechanical movement
• CPC Class Codes: G01S 15/8956 using frequencies at or above 20 MHz
• CPC Class Codes: G01S 15/8997 using synthetic aperture techniques
• CPC Class Codes: G01S 7/52046 Techniques for image enhancement involving transmitter or receiver image enhancement by image data processing G06T5/00

Abstract

The present invention discloses a method and apparatus for ultrasound imaging with improved spatial sampling. The device includes a plurality of ultrasound imaging elements each having a pitch defined by the center to center spacing of the ultrasound imaging elements; and a motion mechanism operatively connected to the plurality of ultrasound imaging elements and adapted to move the plurality of ultrasound imaging elements over a distance to increase the spatial sampling of the plurality of ultrasound imaging elements. The method of the present invention includes transducing a signal from one or multiple ultrasound imaging elements within an array of ultrasound imaging elements; moving the array of ultrasound imaging elements a distance less than the pitch; and transducing at least one additional signal from the ultrasound imaging element.

Claims

1. A device for ultrasound imaging at a frequency with improved spatial sampling comprising:

a plurality of ultrasound imaging elements each having a center and the ultrasound imaging elements having a pitch defined by a center to center spacing of the ultrasound imaging elements; and

a motion mechanism operatively connected to the plurality of ultrasound imaging elements and adapted to move the plurality of ultrasound imaging elements over a distance to increase the spatial sampling of the plurality of ultrasound imaging elements.

2. The device of claim 1 wherein the distance is a series of incremental steps.

3. The device of claim 1 wherein the motion mechanism is adapted for continuous movement over the distance.

4. The device of claim 1 wherein the distance is approximately the pitch.

5. The device of claim 1 wherein the distance is less than the pitch.

6. The device of claim 1 wherein the frequency is greater than approximately 30 MHz.

7. The device of claim 1 wherein the frequency is greater than approximately 50 MHz.

8. The device of claim 1 further comprising a control unit operatively connected to the motion mechanism for controlling the movement of the motion mechanism and to the plurality of ultrasound imaging elements for communicating pulse and echo information.

9. The device of claim 8 wherein the control unit is adapted to apply a synthetic aperture algorithm.

10. The device of claim 1 wherein the motion mechanism is an actuator.

11. The device of claim 1 wherein the plurality of imaging elements is an array of imaging elements.

12. The device of claim 11 wherein the array of imaging elements is a linear array of imaging elements.

13. The device of claim 11 wherein the array of imaging elements is a multi-dimensional array of imaging elements.

15. The method of claim 14 wherein the distance comprises one or more incremental distances.

16. The method of claim 15 wherein the step of transducing is simultaneous with the step of moving.

17. The method of claim 15 further comprising applying synthetic aperture reconstruction.

18. The method of claim 14 wherein the distance is less than the pitch.

20. The apparatus of claim 19 wherein the motion mechanism is an actuator.

21. The apparatus of claim 20 wherein the actuator is a piezoelectric stack.

22. The apparatus of claim 21 wherein the actuator is a bimorph.

23. The apparatus of claim 19 wherein the motion mechanism is adapted to incrementally move the array from spatial sampling location to spatial sampling location.

24. The apparatus of claim 19 wherein the motion mechanism is adapted to continuously move the array.

25. The apparatus of claim 19 wherein each element has a width maximized for the high frequency.

26. The apparatus of claim 19 wherein the motion mechanism is adapted to incrementally move the array less than an overall sampling aperture used for imaging with the array.

27. The apparatus of claim 19 wherein the motion mechanism is adapted to incrementally move the array a distance less than the element-to-element pitch.

29. The apparatus of claim 19 wherein the motion mechanism is adapted to continuously move the array so that the resulting pulse-echo dataset represents spatial locations separated by less than the element-to-element pitch.

30. The apparatus of claim 19 further comprising a processor having software to control pulse/echo of the elements through a channel.

31. The apparatus of claim 19 further comprising a processor having software to apply a synthetic aperture algorithm on the echoes received from the array when forming the image from the array.

32. The apparatus of claim 19 further comprising a

(a) coaxial cable in electrical communication with each element of the array,

(b) a multiplexer attached to the coaxial cable,

(c) an ultrasound pulser,

(d) an ultrasound receiver,

(e) an actuator control, and

(f) a processing device.

33. The apparatus of claim 19 wherein the high frequency is approximately 30 MHz or greater.

34. The apparatus of claim 19 wherein the high frequency is approximately 50 MHz or greater.

14. A method of ultrasound imaging comprising:

(a) transducing a signal from an ultrasound imaging element within an array of ultrasound imaging elements, the ultrasound imaging element having a pitch defined by a center to center spacing of the ultrasound imaging element with an adjacent ultrasound imaging element;

(b) moving the array of ultrasound imaging elements a distance to increase the spatial sampling of the array; and

(c) transducing at least one additional signal from the ultrasound imaging element.

19. An ultrasound imaging apparatus for high spatial resolution at a high frequency comprising:

(a) an array comprising a plurality of linearly arranged ultrasound transducer elements, the elements having an element-to-element pitch that is larger than 0.5 wavelengths;

(b) a motion mechanism operatively associated with the array and adapted to move the array for the expressed purpose of increasing the spatial sampling.