R Peak Detection Method Using Wavelet Transform and Modified Shannon Energy Envelope

Figure 5

Example flow of the proposed R peak detection methods using WT and modified SEE. (a) Input ECG signal of record 121, (b) resized ECG after wavelet transform, (c) output of 1st-order differential, (d) squared differential, (e) normalized differential, (f) calculated Shannon energy (SE), (g) extracted Shannon energy envelope (SEE) after moving average, (h) normalized difference of SEE, (i) calculated peak energy (PE) after square operation, (j) extracted peak energy envelope (PEE) after moving average, (k) estimated peaks in PEE (red circles), and (l) true detected R peaks in ECG signal (red circles).

(a) Input ECG signal of record 121

(b) Result of the wavelet transform

(c) 1st‐order differential

(d) Squared differential

(e) Normal differential

(f) Shannon energy (SE)

(g) Shannon energy envelope (SEE)

(h) Normalized differential of SEE

(i) Peak energy (PE)

(j) Peak energy envelope (PEE)

(k) Estimated peak in PEE

(l) Detected real R peaks