多路独立人体阻抗测量和信号分析

Multi-channel Independent Source Bio-impedance Measurement and Signal Analysis.

目的测量多路阻抗信号 ,使用分解多路阻抗信号信源方法分析阻抗信号。方法本文提出的阻抗测量系统采用独立电流源设计 ,可以同时采集多路阻抗信号。使用基于锁相环的相敏相干检测技术 ,可以直接得到阻抗信号的幅度变化。利用奇异值分解方法分解胸部阻抗信号 ,得到产生阻抗变化的源信号—心、肺阻抗信号。然后把经过频谱甄别的源信号重新投影在测量电极位置上。结果对系统实测得到的阻抗信号成功地进行了分解和投影处理 ,取得了较好的结果。结论多路阻抗系统能够提供单导测量系统无法提供的信息。在阻抗信号分析具有良好应用价值。

Objective To separate source components of the thoracic electrical impedance, and to establish a novel multi channel measurement and signal analysis method. Method The measuring hardware was able to obtain multi channel impedance signals at the same time. It was a phase sensitive coherent measurement system based on phase lock loop, which could get the impedance amplitude directly. It also had independent current sources to provide uniform electrical field in the body. By Singular Value Decomposition method, the 'bio impedance source' was detected from multi channel signals measured on the skin. At last, the source signals were projected to the positions of the electrode to get more tangible meaning. Result Three channel thoracic impedance signals were obtained and processed. It was proved to be better than the one channel system. Conclusion Multi channel measurement and signal processing method provideds better properties than one channel system. It provides a new way to analyze thoracic impedance signals.