Fig. 3
From: Fast time-varying linear filters for suppression of baseline drift in electrocardiographic signals
Graphical representation of the ratio of a couple of frequencies with transfers 1 and 0.9441 (−0.5 dB). The amplitude frequency response G HP (H HP ) of the derived HP filter G HP (z) = z −τ − G LP (z) for fs = 500 Hz and f c ≈ 1 Hz