An In-Ear Pulse Wave Velocity Measurement System Using Heart Sounds as Time Reference

TL;DR

This paper presents an in-ear pulse wave velocity measurement system that uses heart sounds as a time reference, combining sensor development, signal processing algorithms, and embedded hardware for medical diagnostics.

Contribution

It introduces a novel in-ear sensor and MATLAB algorithm for pulse wave measurement using heart sounds as a timing reference, with an embedded system implementation.

Findings

Successful detection of pressure variations in the ear canal

Effective extraction of heart sounds from pressure data

Accurate calculation of pulse wave transit time

Abstract

Pulse wave measurements provide vital information in medical diagnosis. For this reason, a measurement system is developed for determining the transient time of the pulse wave between the heart and the ear. To detect pressure variations in the sealed ear canal, caused by the arriving pulse wave, an in-ear sensor is developed which uses heart sounds as time reference. Furthermore, for extracting the heart sounds from the pressure measurements and calculating the pulse wave transient time, a MATLAB-based algorithm is described. An embedded microcontroller based measurement board is presented, which realizes an interface between the sensor and the computer for signal processing.