Equalization filters for multiple-channel electromyogram arrays.
Equalization filters for multiple-channel electromyogram arrays.
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用于多通道肌电图阵列的均衡滤波器。
DOI：
10.1016/j.jneumeth.2007.05.025
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发表时间：
2007
影响因子：
3
通讯作者：
Kamen,Gary
中科院分区：
文献类型：
--
作者：
Clancy,EdwardA;Xia,Hongfang;Christie,Anita;Kamen,Gary
多通道的肌电图活动通常通过电极进行转换，然后以电子方式组合以形成一个电生理记录，例如双极、线性双差和拉普拉斯蒙太奇。对于高质量的记录，在硬件中实现各个电极电势的精确增益和频率响应匹配（例如，用于双极记录的仪表放大器）。当导出的信号的数量很小时，并且蒙太奇是预先确定的，这种技术工作得很好。然而，对于采用各种蒙太奇的阵列电极，硬件通道匹配可能是昂贵且繁琐的，并且限制了所监测的导出信号的数量。本文介绍了一种基于均衡滤波器概念的信道匹配方法。在没有精确硬件匹配的情况下，从每个部位记录单极电位。在校准阶段，时变线性啁啾电压同时施加到每个部位并记录。根据校准记录，对每个单极通道进行数字滤波，以“校正”（均衡）各个通道中的差异，然后创建任何衍生导联。在硬件演示系统中，双极导联的共模抑制比（60 Hz）从35.2± 5.0 dB（信道均衡前）提高到69.0± 5.0 dB（均衡后）。
Multiple-channels of electromyogram activity are frequently transduced via electrodes, then combined electronically to form one electrophysiologic recording, e.g. bipolar, linear double difference and Laplacian montages. For high quality recordings, precise gain and frequency response matching of the individual electrode potentials is achieved in hardware (e.g., an instrumentation amplifier for bipolar recordings). This technique works well when the number of derived signals is small and the montages are pre-determined. However, for array electrodes employing a variety of montages, hardware channel matching can be expensive and tedious, and limits the number of derived signals monitored. This report describes a method for channel matching based on the concept of equalization filters. Monopolar potentials are recorded from each site without precise hardware matching. During a calibration phase, a time-varying linear chirp voltage is applied simultaneously to each site and recorded. Based on the calibration recording, each monopolar channel is digitally filtered to “correct” for (equalize) differences in the individual channels, and then any derived montages subsequently created. In a hardware demonstration system, the common mode rejection ratio (at 60Hz) of bipolar montages improved from 35.2±5.0dB (prior to channel equalization) to 69.0±5.0dB (after equalization).