“…where denotes the n th input sample, denotes n th output sample, b0, b1, bM, a1, a2, aN are the filter coefficients, and P=Q is the filter order. Previous studies used this filtering technique to smooth the estimation [17,42]. In this study, the coefficients of low pass filter, the feature extraction, and low pass filtering was performed using MATLAB (Student version, Math Works, Inc., USA).…”