Pulsed-Wave Doppler Measurement Based on a PMUT Array

Doppler ultrasound is widely used for cardiovascular disease diagnosis. However, the large size and high power consumption of conventional ultrasound transducers limit their applicability for long-term blood flow monitoring. Piezoelectric micromachined ultrasonic transducer (PMUT) technology offers a promising solution to address these challenges. In this study, a 128-element linear PMUT array, comprising a total of 20,736 PMUT cells, was designed and fabricated. Performance tests demonstrated resonant frequencies of 4.3 MHz in air and 3 MHz in water, with a transmit sensitivity of 426 Pa/V at 6.5 mm and a receive sensitivity of 10.58 mV/MPa at 11 mm. Integrated with a Verasonics Vantage 256 system, the array enabled B-mode imaging of human tissue and pulsed-wave Doppler measurement of a blood flow phantom. The results indicate the potential of PMUT arrays for future portable and wearable blood flow imaging systems.