A hand-held, high frequency ultrasound scanner

A new real-time high frequency ultrasound scanner has been developed to easily image superficial structures and estimate blood flow, with several major improvements. A great limitation of previous high frequency systems has been the requirement to water-couple the mechanically-scanned transducer to the object to be imaged, and slowly scan the transducer using a fixed motion system. In this system, we have integrated a high-speed actuator used in conjunction with a low mass transducer enclosed in a hand-held scanhead, which allows direct placement on the eyelid or skin. The design of this system is optimized for high frame rates and clinical versatility. Implemented on this system are B-scan, M-mode, and swept-scan imaging modes, with velocity estimation in the latter two. A series of experiments were performed to characterize system performance. The system provides a frame rate of 10 fps, which is partially limited by the execution time of the software. Phantom images from the scanner have 8-bit resolution with a SNR in excess of 35 dB, providing sharp, high-resolution images. Using these results, a variety of experiments were performed on tissue and vessel phantoms to demonstrate the versatility of the scanner. The resulting B-scan, M-mode, and swept-scan structural and colorflow images will be presented.