Wearable chemical sensors: characterization of heart rate electrodes using electrochemical impedance spectroscopy

摘要

Wearable monitoring systems have become very popular in the health and sports industry in recent years. Noninvasive measurements, such as speed, direction, acceleration, strain, impact and heart rate, are being utilized across countless different monitoring platforms. Heart rate monitoring is of particular interest, since this one diagnostic can provide descriptive information about the health of the user in all levels of activity. In addition, there is a recent exploration of different acquisition techniques and placement of sensors on the body in order to increase ease of use and comfort of the device. Optimizing these factors is a high priority as they will ultimately determine the extent to which device is used. However, it is important that accuracy does not suffer for the sake of comfort. \ud\udHerein, a series of measurements comparing heart rate monitoring electrodes is presented. Using electrochemical impedance spectroscopy, textile electrodes are compared to disposable Ag/AgCl electrodes. Equivalent circuit modeling is used to understand the reaction kinetics occurring within both types of electrodes and how they differ from each other. In addition, nonmotion on-body measurements are performed to observe the practical differences between the electrodes. This work will provide a foundation to assess future generations of heart rate monitoring electrodes. \ud