Abstract:
High accuracy in measurement of physiological signals like skin impedance is critical and is more difficult to achieve in biomedical systems with very limited power budge...Show MoreMetadata
Abstract:
High accuracy in measurement of physiological signals like skin impedance is critical and is more difficult to achieve in biomedical systems with very limited power budget. A new method for accurate bio-impedance measurement using square wave demodulation is proposed in this paper. An error correction algorithm has been derived from the analysis of a generic impedance model with multiple poles, which reduces the estimation error in square wave demodulation from 9.3% to 1.3% for a simple tissue model. Simulation results in Matlab using ideal RC values show an accuracy of <;0.14% for single pole and <;0.67% for two pole RC networks. Measurements from saline phantom solution gives an accuracy <;0.72%. The results indicate that the algorithm can be used as a postprocessing technique for error correction or even incorporated into wearable signal monitoring SoCs since modulation and demodulation using square waves consumes less power compared to sine waves.
Date of Conference: 19-23 May 2013
Date Added to IEEE Xplore: 01 August 2013
ISBN Information: