Vessel navigation algorithm for single beam ultrasound Doppler

Pulsed wave ultrasound Doppler with single element transducer has a potential for being developed as portable forms due to having simple imaging systems. Since the single element transducer does not provide ultrasound images, manual adjustment of the Doppler gate is required for locating the Doppler gate in a targeted vessel. Therefore, optimal vessel navigation is required in using a single element transducer for pulsed wave Doppler. In this research, we developed a vessel navigator integrating an optically transparent single element transducer with photoplethysmography, and a three-dimensional vessel navigation algorithm. An optically transparent 5 MHz transducer was fabricated by loading indium-tin-oxide on a lead magnesium niobate-lead titanate and attached to a reflective pulse oximetry sensor. The offset and pulsation amplitude of the optical signal were analyzed for lateral navigation. Furthermore, Doppler velocity and power Doppler signal calculated from acoustic signal were employed for axial navigation. The proposed vessel navigator and navigation algorithm were evaluated by flow phantom, successfully detected the vessel, and acquired Doppler signals successfully.