Removal of Cardiopulmonary Resuscitation Artifacts with an Enhanced Adaptive Filtering Method: An Experimental Trial

Table 1

Estimated signal-to-noise ratio (SNR) for pulseless electrical activity (PEA), ventricular fibrillation (VF), and asystole (ASY) before and after filtering.

	Unfiltered	Adaptive filter	High-pass filter
Medians (dB) (25/75 percentiles)
VF	−9.3 (−14.9/−3.6)^△△	0.2 (−5.1/4.5)**	0.1 (−4.2/0.9)**
PEA	−6.2 (−9.0/−1.12)^△△	0.1 (−3.6/3.4)**	−2.0 (−7.4/−0.6)**
ASY	−21.2 (−24.2/−18.5)^△△	−12.7 (−15.0/−4.4)**	−7.1 (−10.7/−6.3)**
Range (dB) (min./max.)
VF	−26.1/9.6	−18.2/20.0	−19.7/20.4
PEA	−16.0/9.9	−7.6/19.9	−14.0/14.7
ASY	−31.6/−10.0	−20.6/2.4	−18.4/1.7

∗∗Compared with unfiltered signal, 𝑃<0.001; △△comparison among rhythm types, 𝑃<0.001.