An accelerometer probe for local pulse wave velocity measurement

Abstract

The velocity of propagation of arterial blood pulse signals obtained from a smaller arterial section referred as local pulse wave velocity (PWV) is an index of cardiovascular events of a particular artery. In this work, we introduce a novel design of accelerometer probe for local PWV measurement from the carotid artery. The proposed probe was developed using highly sensitive dual MEMS accelerometers. The probe design with tiny dual element sensors was capable of simultaneously acquiring acceleration signals generated due to arterial wall displacement towards the skin surface. Measurements were performed from carotid artery over a smaller arterial section of length 24 mm. The ability of the probe to acquire continuous arterial waveforms and cycle-to-cycle local PWV measurement was verified by conducting an in-vivo test in multiple subjects (11 volunteers aged between 20 – 60 years) under controlled settings. Reliable as well as repeatable signals (maximum beat-to-beat variation was less than 13%) and carotid PWV measurement with high reproducibility was obtained. A correlation examination of the local PWV with heartrate and BP was conducted during the same study. A statistically significant correlation was observed with the correlation coefficient greater than 0.78 for BP parameters and 0.66 for heartrate. In-vivo validation study promising the potential use of the developed accelerometer probe for cuffless evaluation of BP parameters and heartrate as a confounder of local PWV assessment was obtained.