A Portable Electrical Impedance Measurement System for Flexible Electrodes

This paper introduces a new portable impedance measurement system for Electrical Impedance Spectroscopy (EIS) and continuous impedance monitoring of various flexible-wearable electrodes and sensors. The system comprises a low-power, highly sensitive Electrochemical Front End and a Bluetooth Low Energy (BLE) enabled microcontroller. Impedance measurements are conducted on-chip and transmitted wirelessly via BLE to a nearby mobile device or PC application. As a case study, the implemented prototype interfaces flexible sensors' designed for measuring changes in impedance. Preliminary results demonstrate the sensors ability to perform EIS and detect impedance variations caused by sensor stretching,

I. Introduction

Wireless embedded biosensors and measurement systems are gaining wide interest in healthcare monitoring applications, especially in Wireless Body Area Networks (WBANs) [1]. Unlike traditional clinical-based monitoring that relies on fixed infrastructure and is applied during specific periods, wearable and implantable WBAN biosensors provide continuous real-time monitoring of the user's health without disturbing daily activities [2], [3]. However, the development of portable measurement systems still faces many challenges in terms of their lifetime, sensitivity, selectivity, stability, and robustness [4]. Practical aspects also affect the success of such systems, including their installation and maintenance requirements, transmission range, data security, and reliability [5].