PMC

Filtering performance when a real EMG with added simulated stimulation and m-wave artefacts was filtered with the short adaptive, and the comb filter. (a) Original EMG. (b) The original EMG with simulated stimulation and m-wave artefacts added. (c) Spectrum of the original EMG and, the original EMG with stimulus and m-wave artefacts. (d) Coherence between the original EMG and, the original EMG with the added artefacts. (e) Extracted signal with both the adaptive and comb filter. (f) Spectrum of the original and the signal extracted with both the adaptive and comb filter. (g) Coherence between the original signal and the signal extracted with both the adaptive and comb filter. (h) Extracted signal with only the adaptive filter. (i) Spectrum of the original and the signal extracted with only the adaptive filter. (j) Coherence between the original and the signal extracted with only the adaptive filter. (k) Extracted signal with comb filter. (l) Spectrum of the original and the signal extracted with comb filter, (m) Coherence between the original signal and the signal extracted with comb filter.

(a) Left: original signal composed of 800-Hz carrier modulated at 20 Hz. Right: Spectrum of the original signal. (b) Left: envelope of the original signal. Right: Spectrum of the modulator of the original signal. (c) Left: Fine structure (i.e. carrier) of the original signal. Right: Spectrum of the carrier of the original signal. (d) Left: spectrogram of the original signal. Right: joint acoustic/modulation frequency representation of the original signal. Colors indicate energy over an 80 dB range, where red represents high energy and blue low energy.

Four different types of human motion original 2D echo signals and reconstructed 2D echo signals. (The above figure shows the original human motion radar 2D echo signal, the blow figure shows the reconstructed 2D radar echo signal.) (a) Walk forward of human motion original 2D echo signal and reconstructed 2D echo signal; (b) fall forward of human motion original 2D echo signal and reconstructed 2D echo signal; (c) walk around of human motion original 2D echo signal and reconstructed 2D echo signal; and (d) jump forward of human motion original 2D echo signal and reconstructed 2D echo signal.

A) waveform of original simulated signal; B) spectrum of the original simulated signal.