High-frequency ultrasound imaging system
A high frequency ultrasound analog beamformer comprises a linear array of surface acoustic wave (SAW) devices formed on a single crystal piezoelectric substrate, such as a PMN-PT single crystal piezoelectric substrate. Each SAW device comprises ultrasound input and output electrode structures separated by a variable delay structure. The beamformer further comprises a delay controller operably connected to each variable delay structure to control the delay of each SAW device to dynamically focus signals received at each input electrode.
1. A high frequency ultrasound analog beamformer, comprising:
a linear array of surface acoustic wave (SAW) devices formed on a single crystal piezoelectric substrate, each SAW device of the linear array comprising ultrasound input and output electrode structures separated by a respective variable delay structure; and
a delay control circuit operably connected to each variable delay structure to control, in the acoustic analog domain, a delay of each SAW device to dynamically focus signals received at each input electrode.
2. The beamformer of claim 1 , wherein each respective variable delay structure is formed of a set of two planar electrodes comprising one planar electrode on each of two opposite surfaces of the substrate.
3. The beamformer of claim 2 , wherein the delay control circuit applies a voltage across each respective set of planar electrodes to control the length of each respective variable delay structure.
4. The beamformer of claim 1 , wherein each respective variable delay structure is formed of a photoconductive layer on a surface of the respective SAW device.
5. The beamformer of claim 1 , further comprising an adder to add the output signals of each SAW device of the linear array.
6. The beamformer of claim 1 , wherein the ultrasound output electrode structure of all SAW devices in the linear array is formed as a single electrode pair to sum the variably delayed signals received from the input electrode structures of all SAW devices in the linear array.
7. The beamformer of claim 1 , wherein the input and output electrode structures are interdigital electrode structures.
8. The beamformer of claim 1 , wherein the single crystal piezoelectric substrate is a PMN-PT single crystal piezoelectric substrate.
9. A high-frequency ultrasound imaging system comprising:
an imaging array;
a high-frequency ultrasound transmit beamformer to focus signals transmitted by the imaging array to a target;
a high-frequency ultrasound analog receive beamformer to focus signals received by the imaging array, the beamformer comprising:
a linear array of surface acoustic wave (SAW) devices formed on a single crystal piezoelectric substrate, each SAW device of the linear array comprising ultrasound input and output electrode structures separated by a respective variable delay structure; and
a delay control circuit operably connected to each variable delay structure to control, in the acoustic analog domain, a delay of each SAW device to dynamically focus signals received at each input electrode; and
processing circuitry to image the focused signals.
10. A high frequency endoscopic ultrasound probe comprising:
an imaging array;
a high-frequency ultrasound transmit beamformer to focus signals transmitted by the imaging array to a target;
a high-frequency ultrasound analog receive beamformer to focus signals received by the imaging array from the target, the beamformer comprising:
a linear array of surface acoustic wave (SAW) devices formed on a single crystal piezoelectric substrate, each SAW device of the linear array comprising ultrasound input and output electrode structures separated by a respective variable delay structure; and
a delay control circuit operably connected to each variable delay structure to control, in the acoustic analog domain, a delay of each SAW device to dynamically focus signals received at each input electrode; and
processing circuitry to image the focused signals.
11. The probe of claim 10 having a size suitable for in-vivo imaging of inner ear structures.
12. The probe of claim 11 , wherein the size of the probe is suitable for imaging inner ear structures through a round window membrane of an inner ear.
13. The beamformer of claim 2 , wherein the input and output electrode structures are interdigital electrode structures.
14. The beamformer of claim 3 , wherein the input and output electrode structures are interdigital electrode structures.
15. The beamformer of claim 4 , wherein the input and output electrode structures are interdigital electrode structures.
16. The beamformer of claim 5 , wherein the input and output electrode structures are interdigital electrode structures.
17. The beamformer of claim 6 , wherein the input and output electrode structures are interdigital electrode structures.
18. The beamformer of claim 2 , wherein the single crystal piezoelectric substrate is a PMN-PT single crystal piezoelectric substrate.
19. The beamformer of claim 3 , wherein the single crystal piezoelectric substrate is a PMN-PT single crystal piezoelectric substrate.
20. The beamformer of claim 4 , wherein the single crystal piezoelectric substrate is a PMN-PT single crystal piezoelectric substrate.
21. The beamformer of claim 5 , wherein the single crystal piezoelectric substrate is a PMN-PT single crystal piezoelectric substrate.
22. The beamformer of claim 6 , wherein the single crystal piezoelectric substrate is a PMN-PT single crystal piezoelectric substrate.
23. The beamformer of claim 7 , wherein the single crystal piezoelectric substrate is a PMN-PT single crystal piezoelectric substrate.
24. The system of claim 9 , wherein each respective variable delay structure is formed of a set of two planar electrodes comprising one planar electrode on each of two opposite surfaces of the substrate.
25. The system of claim 24 , wherein the delay control circuit applies a voltage across each respective set of planar electrodes to control the length of each respective variable delay structure.
26. The system of claim 9 , wherein each respective variable delay structure is formed of a photoconductive layer on a surface of the respective SAW device.
27. The system of claim 9 , further comprising an adder to add the output signals of each SAW device of the linear array.
28. The system of claim 9 , wherein the ultrasound output electrode structure of all SAW devices in the linear array is formed as a single electrode pair to sum the variably delayed signals received from the input electrode structures of all SAW devices in the linear array.
29. The system of claim 9 , wherein the input and output electrode structures are interdigital electrode structures.
30. The system of claim 9 , wherein the single crystal piezoelectric substrate is a PMN-PT single crystal piezoelectric substrate.
31. The probe of claim 10 , wherein each respective variable delay structure is formed of a set of two planar electrodes comprising one planar electrode on each of two opposite surfaces of the substrate.
32. The probe of claim 31 , wherein the delay control circuit applies a voltage across each respective set of planar electrodes to control the length of each respective variable delay structure.
33. The probe of claim 10 , wherein each respective variable delay structure is formed of a photoconductive layer on a surface of the respective SAW device.
34. The probe of claim 10 , further comprising an adder to add the output signals of each SAW device of the linear array.
35. The probe of claim 10 , wherein the ultrasound output electrode structure of all SAW devices in the linear array is formed as a single electrode pair to sum the variably delayed signals received from the input electrode structures of all SAW devices in the linear array.
36. The probe of claim 10 , wherein the input and output electrode structures are interdigital electrode structures.
37. The probe of claim 10 , wherein the single crystal piezoelectric substrate is a PMN-PT single crystal piezoelectric substrate.