Decentralized Multi-channel Digitizing of Bioimpedance Signals

Abstract

As bioimpedance data more often than not have to be acquired from a number of signal sources scattered over some area, multi-channel data acquisition scheme has to be implemented and that typically is realized on the basis of multiplexers. However connecting a multitude of distanced analog signal sources to a multiplexer causes a number of problems. To avoid them, an alternative approach to decentralized bioimpedance data acquisition is suggested and discussed. It is shown that the centralized multiplexing of input signals can be replaced by decentralized remote sampling of the bioimpedance signals performed in the close proximity of the respective signal sources. That leads to a number of advantages, including reductions in design complexity and power consumption of the front-end remote sampling devices. The suggested digitizing of bioimpedance signals is based on application of a distributed analog/digital converter containing a number of remote samplers that might be placed near to the signal sources. The functions of sampling and data acquisition from multiple sources then are performed specifically. The algorithms for processing the data acquired in this way, matched to these specifics, and the significant benefits achievable in the described way are described and discussed.