Fig. 7
From: A compact system for simultaneous stimulation and recording for closed-loop myoelectric control
300 ms windows of EMG recorded while the stimulation was delivered at three different frequencies: a shows a recording made using 20 Hz frequency, level 2 amplitude, 300 µs pulse width and four active channels, while in b the frequency was changed to 50 Hz and in c to 80 Hz. The red lines indicate blanked segments of the signal. In these segments, the EMG value was constant since it was “frozen” by the sample-and-hold (see Section Dynamic blanking)