Digital signal processing, Find peaks on ECG using threshold

ECG waveform generator for MATLAB [s, ipeaks] = ecgsyn(sfecg,N,Anoise,hrmean,hrstd,lfhfratio,sfint,ti,ai,bi) Produces synthetic ECG with the following outputs: s: ECG (mV) ipeaks: labels for PQRST peaks: P(1), Q(2), R(3), S(4)