ECG Signal Analysis - ECG Acquisition and Automated Remote Processing - page 44

35. if end of array skip step 36
36. go to step 13 for next search
37. stop

Appendix 4

The algorithm steps for Q and Q-onset:
i = ECG data array index; y = magnitude; y(blp) = baseline voltage;
slp(i) = 8-point average slope; slp_mn = minimum average slope
k1 = 1; % R-peak index

1. i = r(k1) % R-peak index
2. if y(i) B y(blp) go to step 6% baseline cross
3. i = i-1
4. if i = r(k1)-50 go to step 11% no defined Q peak exits
5. go to step 2
6. k = i
7. if (slp(i+4) [ 0) & (slp(i-4) \ 0) go to step 11
8. i = k-1;
9. if i = k-30 go to step 13
10. go to step 7
11. k = Q_indx(k1); % Q peak obtained
12. go to step 14 for Q-onset detection
13. consider Q peak as slope with minimum average slope in R to R-50 zone

(i) i = r(k1)
(ii) slp_mn = abs[slp(i)]; % initialization
(iii) if abs[slp(i)] C slp_mn skip step (iv)
(iv) slp_mn = slp(i); indx = i
(v) i = i-1;
(vi) if i = r(k1)-50 skip step (vii)
(vii) i = i-1; go to step (iii)
(viii) Q_indx(k1) = indx; % accept index with absolute minimum slope
(

ix) Qon_indx(k1) = indx;
(x) go to step 22

14. k2 = Q_indx(k1)
15. slp_mn = abs[slp(k2)]; % initialization
16. if abs[slp(k2)] [ slp_mn skip step 17
17. slp_mn = slp(k2); indx = k2
18. k2 = k2-1;
19. if i = r(k1)-50 skip step 20
20. i = i-1; go to step 16