Real-time beat-to-beat pulse wave velocity estimation: a quality-driven approach using laser Doppler vibrometry

Area of Science:

• Biomedical Engineering
• Cardiovascular Physiology
• Medical Diagnostics

Background:

• Arterial stiffness is a critical indicator of cardiovascular risk.
• Carotid-femoral pulse wave velocity (cf-PWV) is the gold standard for assessing arterial stiffness.
• Current cf-PWV assessment methods can be time-consuming and require specialized expertise.

Purpose of the Study:

• To introduce and evaluate Continuous Automatic PWV Estimation (CAPE), an innovative framework for real-time cf-PWV measurement.
• To assess the reliability and precision of CAPE using laser-Doppler vibrometry (LDV) signals.
• To demonstrate CAPE's suitability for clinical applications demanding rapid cardiovascular risk assessment.

Main Methods:

• Developed CAPE, a framework integrating automatic fiducial point detection and signal quality control for cf-PWV estimation from LDV signals.
• Utilized a multichannel laser vibrometry system to acquire signals from 100 hypertensive patients.
• Calculated cf-PWV by dividing carotid-femoral distance by pulse transit time (PTT), derived from template-matching on the second derivative of LDV signals.

Main Results:

• CAPE demonstrated high reliability and precision when validated against applanation tonometry, with a mean bias of 0.25 ± 0.77 m/s.
• The framework provides confidence scores (acceptable or excellent) for PWV measurements based on automated quality assessment.
• CAPE achieves cf-PWV estimation in just 3 seconds, enabling near real-time analysis.

Conclusions:

• CAPE offers a reliable, automated, and rapid method for estimating cf-PWV using LDV signals.
• The speed and accuracy of CAPE make it highly suitable for real-time clinical cardiovascular risk assessment.
• This technology has the potential to significantly improve the monitoring and management of arterial stiffness in patient populations.