Three-dimensional vascular reconstruction and Doppler flow measurement using PMUTs

Piezoelectric Micromachined Ultrasonic Transducer (PMUT) has been studied a lot in the past decades since the merit of easily integrating with IC to develop 2-D array for 3-D imaging applications. However, there are tremendous work and high costs in both time and investment to establish the final goal. In this paper, we propose a low cost approach to achieve 3-D imaging using two 1-D arrays by introducing binocular stereo vision method. The imaging system with two PMUTs is designed to conduct 3-D reconstruction of the vessel in vitro, and the flow velocity can be measured much more accurately comparing to traditional 2-D method. To decrease the requirement of imaging system, especially the number of independence T/R channels, B-mode imaging of the vessel is performed by analogy with Synthetic Aperture Focusing Technique (SAFT) technique. Two images in different directions are collected individually, and then combined and compensated into 3-D imaging. After that, the blood flow velocity is measured using pulsed Doppler. With the combination of 3-D imaging of the vessel and Doppler measurement, the position and morphology of vessel could be obtained, and then the flow velocity can be calculated accurately.