Fig. 4From: A novel method for the detection of R-peaks in ECG based on K-Nearest Neighbors and Particle Swarm OptimizationResult after performing each stage of the proposed method for the ECG with high frequency noise and artifact (ECG recording 200). a) Original signal. b) Filtering. c) Differentiation. d) Absolute value. e) Backward cumulation. f) Detected peaksBack to article page