A Flexible Ultrasound Array for Local Pulse Wave Velocity Monitoring

• Published in: Biosensors (Basel) Vol. 12; no. 7; p. 479
• Main Authors: Xu, Lirui, Wang, Peng, Xia, Pan, Wu, Pang, Chen, Xianxiang, Du, Lidong, Liu, Jiexin, Xue, Ning, Fang, Zhen
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 30.06.2022; MDPI
• Subjects: Acoustics; Arrays; arterial stiffness; Arteries; Blood flow; Coefficient of variation; Design and construction; Diagnosis, Ultrasonic; Distension; Elastomers; Electrodes; Equipment and supplies; flexible ultrasound array; Flow velocity; local PWV; Materials; Mathematical analysis; Measurement; Mechanical properties; Monitoring; Piezoelectric transducers; Position sensing; pulse wave velocity; Regression analysis; Silicones; Skin; Sphygmomanometer; Stiffness; Transducers; Ultrasonic imaging; Ultrasonic transducers; Ultrasound; Veins & arteries; Velocity; Wave velocity; Waveforms; China; United States > US; Texas
• ISSN: 2079-6374; 2079-6374
• DOI: 10.3390/bios12070479

Pulse wave velocity (PWV) measured at a specific artery location is called local PWV, which provides the elastic characteristics of arteries and indicates the degree of arterial stiffness. However, the large and cumbersome ultrasound probes require an appropriate sensor position and pressure maintenance, introducing usability constraints. In this paper, we developed a light (0.5 g) and thin (400 μm) flexible ultrasound array by encapsulating 1–3 composite piezoelectric transducers with a silicone elastomer. It can capture the distension waveforms of four arterial positions with a spacing of 10 mm and calculate the local PWV by multi-point fitting. This is illustrated by in vivo experiments, where the local PWV value of five normal subjects ranged from 3.07 to 4.82 m/s, in agreement with earlier studies. The beat-to-beat coefficient of variation (CV) is 12.0% ± 3.5%, showing high reliability. High reproducibility is shown by the results of two groups of independent measurements of three subjects (the error between the mean values is less than 0.3 m/s). These properties of the developed flexible ultrasound array enable the bandage-like application of local PWV monitoring to skin surfaces.