KP351 Lecture Notes - Lecture 4: Moving Average, Long Term Ecological Research Network, Signal Processing
20 Mar 2020
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Document Summary
Integrated emg (area) **not for timing data. How much is the muscle ring and what is the magnitude. Evaluation of the frequency spectrum of the signal. Activation magnitude (low pass lter through signal) Raw emg has baseline value of zero. Easier visualization of amplitude characteristics of signal. Emg signal is a time-varying signal, has zero mean, therefore the signal at any insant is not a good indicator of overall emg activity. Linear envelope provides an estimate of the magnitude of muscle activity. Low pass lter through fwr signal (10hz cut-o is common) Provides moving average indicator of emg magnitude. Linear envelop and integrated emg are same. Allows comparison of data (multiple time points / multiple people) Normalize emg magnitude as a percentage of mvc (maximum voluntary contraction) Purpose: attenuate speci c sections of the frequency spectrum and to maximize the signal- to-noise ratio. Low pass: low frequencies are unchanged higher frequencies are attenuated.
