Multiple lead recordings improve accuracy of bio-impedance plethysmographic technique

We have developed the theory and instrumentation of multiple multi-electrod e bio-impedance (BI) measurements based on lead field theoretical approach, To derive reliable information based on BI data, a quantity of measurement s should be taken with electrode configurations possessing regional measure ment sensitivity. An apparatus has been developed with an eye to the requir ements imposed by the theoretical aspects of achieving multiple multi-elect rode BI measurements, It has features compensating electrode-contact relate d errors and errors due to imbalance between the conductive pathways when m ultiple electrodes are utilised for BI measurement. The proposed design all ows simultaneous multi-electrode BI and bioelectric recording with the same electrode system. Initial operation experiences in clinical environment in dicate that the device functions as intended, and allows user-friendly util isation of multiple BI measurements. Contributions presented to BI methodol ogy and instrumentation improve the reliability of BI measurements. (C) 199 9 IPEM. Published by Elsevier Science Ltd. All rights reserved.