Wireless Embedded Microcontroller System for Bioimpedance Measurements

Abstract

In this thesis the design and prototype of a bioimpedance measurement system is described. The system is wireless and battery powered. A custom analog front-end has been made to be able to do bioimpedance measurements. It uses a two or three electrode setup to do the measurements. It does most of the signal processing in the digital domain and two different techniques has been discussed. A common ARM microcontroller has been used to do the processing. The measurement data is transferred from the system to a desktop computer or Android device over Bluetooth. The system has been tested and verified to work in the 1 kHz to 140 kHz frequency range. It measures the impedance modulus and phase correctly when tested with an electrical circuit. The egg white, egg yolk and the boundary between has been successfully discriminated by using a needle electrode as the measurement electrode.