Deformation of Heartbeat Pulse Waveform Caused by Sensor Binding Force

TL;DR

This paper investigates how the force of sensor attachment affects the shape of heartbeat pulse waveforms in PPG signals, highlighting potential impacts on the reliability of wearable health devices.

Contribution

It provides an experimental analysis of waveform deformation caused by varying sensor binding forces, which was previously underexplored.

Findings

Increased sensor binding force reduces pulse width.

Sensor force influences waveform shape and reliability.

Results inform design considerations for wearable PPG devices.

Abstract

Photoplethysmography (PPG) is a method of detecting variation in blood volume commonly through contact with the skin and involving the usage of one or multiple sensors. PPG is typically used in health-related fields and one of its most popular uses is heart rate monitoring. Recent developments in technology have introduced wearable smart devices that can detect PPG signals. These devices mostly rely on signals that are detected at a single location, indicating that such devices require the signal waveform to be immensely reliable. In further detail, the properties of the blood circulation system are being deducted from the heartbeat signal profile. One disadvantage is that the waveform can be affected by tissues that surround the blood vessels. This may result in the unreliability of the methods utilized by many wearable smart devices. This paper introduces an experimental study on the deformation of waveform change caused by sensor binding force. The results of the study are that an increase in sensor binding force decreases the width of the pump strength-related pulse.