Ultrasound imaging of the anterior segment, posterior segment and the full lens contour is important in diagnosis of glaucoma, cataracts, etc. eye disease, eye surgery guidance and post surgery assessment. High resolution, large field of depth and rapid electronic scanning are necessary to obtain accurate images of eye as a whole. Blatek, NCSU and USC team proposes to integrate the innovative single crystal piezo composite micromachined ultrasound transducer (PC-MUT) technology with the novel concept of bi-frequency co-linear array technology to develop broad band, highly sensitive PC-MUT bi-frequency collinear arrays for advanced ophthalmic imaging. In Phase I, a novel dual-layer, co-linear array interconnect fabrication technique will be developed first, demonstrating the functionality of a low frequency co-linear array (7.5/15 MHz) using diced PMN-PT 1-3 composites. A high frequency (17.5/35 MHz) co-linear array will then be developed using micromachined PMN-PT single crystal 1-3 composites. The prototyped bi-frequency PC-MUT co-linear arrays will be evaluated using phantom wires in terms of beam scanning and dynamic focusing using the USC high frequency linear array imaging system. In Phase II, optimized 192/128-element bi-frequency co-linear arrays will be developed and extensive eye imaging experiments will be performed using the USC digital beamforming system. In Phase III, Blatek and the phase II partners will seek to commercialize this technology.
The state of art commercial ultrasonic ophthalmic imaging technologies use 10-20 MHz probes with fixed focus and mechanical scanning to obtain ultrasound images with poor resolution in anterior segments. High frequency UBM is helpful in obtaining high resolution, but lack of field of depth and still requires mechanical scanning. Annular arrays addressed field of depth concern, but requires mechanical scanning and the resolution needs to be improved. High frequency linear arrays showed high resolution in azimuth and field of depth control via electronic scanning, but with poor resolution in elevation axis. To overcome these issues Blatek and the team proposes to integrate the novel piezo-crystal micromachined ultrasound transducer (PC-MUT) technology with the novel bi-frequency collinear array technology to develop broad band, highly sensitive PC-MUT bi-frequency collinear arrays for advanced ophthalmic imaging. The bi- frequency design considers both the high resolution requirements for anterior segment imaging and the field depth requirements for posterior and lens imaging. The novel co- linear configuration allows for electronic scanning and dynamic focusing at both azimuth and elevation directions. The proposed technology will also facilitate improved resolution of imaging and increased field of depth for pre-operative analysis of corrective procedures of the lens. In Phase I, a novel dual-layer, co-linear array interconnect fabrication technique will be developed to demonstrate the feasibility of a 64/64-element 17.5/35 MHz co-linear array for ophthalmic imaging. In Phase II, optimized 192/128- element bi-frequency (17.5/35 MHz) co-linear arrays will be developed and extensive eye imaging experiments will be performed using the USC digital beamforming system. In Phase III, Blatek and the phase II partners will seek to commercialize this technology.
| Wang, Zhuochen; Li, Sibo; Czernuszewicz, Tomasz J et al. (2016) Design, Fabrication, and Characterization of a Bifrequency Colinear Array. IEEE Trans Ultrason Ferroelectr Freq Control 63:266-74 |
