Platt R S, Hajduk E A, Hulliger M, Easton P A
Department of Medicine, University of Calgary, Alberta, Canada.
J Appl Physiol (1985). 1998 Jan;84(1):378-88. doi: 10.1152/jappl.1998.84.1.378.
We studied a device that is commonly used for amplitude demodulation of respiratory muscle electromyograms (EMG). This device contains a rectifier and a low-pass filter called a modified third-order Paynter filter. We characterized this filter and found that it has good transient characteristics that suit its task as an EMG demodulator, but it has poor high-frequency attenuation that passes interfering, higher frequency components to the output waveform. Therefore, we designed and constructed a new filter with transient characteristics that are comparable to those of the modified Paynter filter but with superior high-frequency attenuation. This new filter is a modified seventh-order Bessel filter. We also identified a simple technique to convert an existing modified Paynter filter back to an original Paynter filter. The original Paynter filter has a wider pass band than the modified Paynter filter but superior stop-band attenuation.
我们研究了一种常用于呼吸肌肌电图（EMG）幅度解调的设备。该设备包含一个整流器和一个称为改进型三阶佩因特滤波器的低通滤波器。我们对该滤波器进行了特性分析，发现它具有良好的瞬态特性，适合作为EMG解调器的任务，但它的高频衰减较差，会让干扰性的高频成分通过并进入输出波形。因此，我们设计并构建了一种新的滤波器，其瞬态特性与改进型佩因特滤波器相当，但具有更好的高频衰减。这种新滤波器是一种改进型七阶贝塞尔滤波器。我们还确定了一种简单的技术，可以将现有的改进型佩因特滤波器转换回原始的佩因特滤波器。原始的佩因特滤波器比改进型佩因特滤波器具有更宽的通带，但阻带衰减更好。
