Probing blood pressure and arterial stiffness noninvasively by guided axial waves

TL;DR

This study demonstrates a noninvasive ultrasound-based method using guided axial waves to simultaneously measure blood pressure and arterial stiffness, potentially aiding early cardiovascular disease diagnosis.

Contribution

It introduces a novel approach combining guided elastic wave detection and wavelet analysis for in vivo arterial stiffness and blood pressure assessment.

Findings

Group velocity varies with blood pressure (~20% change)

Linear relationship between squared group velocity and blood pressure

Wavelet analysis effectively extracts dispersion relation for stiffness measurement

Abstract

The clinical and economic burden of cardiovascular diseases (CVDs) poses a global challenge. Growing evidence suggests an early assessment of arterial stiffness can provide insights into the pathogenesis of CVDs. However, it remains difficult to quantitatively characterize the arterial stiffness in vivo. Here we utilize the guided elastic waves continuously excited and detected by ultrasound as a tool to probe the blood pressure (BP) and mechanical properties of the common carotid artery (CCA) simultaneously. In a pilot study of 17 healthy volunteers, we obverse a ~20% variation in the group velocity (5.16 m/s in systole and 4.31 m/s in diastole) induced by variation of the BP. A linear relationship between the square of the group velocity and the BP is revealed by our experimental data and finite element analysis, which enables us to measure the waveform of the BP. Furthermore, we propose to use the wavelet analysis to extract the dispersion relation of the guided waves, which provides a quantitative measurement of the arterial stiffness. The results and methods reported in this study show the group velocity and dispersion relation of the guided waves can be adopted to probe BP and arterial stiffness noninvasively and thus promising for early diagnosis of the CVDs.