Chun-Cheng Lin Medical Engineering & Physics 30 (2008) 834–842, ELSEVIER

1. Enhancement of accuracy and reproducibility of parametric modeling for estimating abnormal intra-QRS potentials in signal-averaged electrocardiograms Chun-Cheng Lin Medical Engineering & Physics 30 (2008) 834–842, ELSEVIER Presenter Chia-Cheng Chen

2. Outline • Introduction • Materials and methods • Results • Conclusions

3. Introduction • Enhance the accuracy and reproducibility of parametric modeling in the discrete cosine transform (DCT)domain for the estimation of abnormal intra-QRS potentials (AIQP). • 100 independent sets ofwhite noise to simulate the broadband, unpredictable AIQP.

4. Introduction(Cont.) • The estimated AIQP has obvious estimation errors in the low-frequency DCT coefficients. • Eliminates some low-frequency DCT coefficients with estimation errors to define a high-frequency AIQP parameter.

5. Materials and methods • Materials • Group I (the normal group) consisted of 42 normal Taiwanese (20 men and 22 women, aged 58±14 years old) • Group II (the VT group) consisted of 30 patients (15 men and 15 women, aged 63±16 years old)

6. Materials and methods(Cont.)

7. Materials and methods(Cont.) • ARMA(2M,2M)

8. Materials and methods(Cont.) • The cross-correlation coefficient p between the original signal x(n) and the QRS estimate

9. Materials and methods(Cont.)

10. Materials and methods(Cont.) • Definition of the high-frequency AIQP parameter q% indicates the percentage of the total DCT coeffi- Cients

11. Results • Used 100 independent sets of normallydistributed white noise with zero mean to simulate the broad-band, unpredictable AIQP. • TheAIQP was estimated under different values of q% (100%,90% and 80%) and magnitudes (AIQP l(q%) = 0–10 V).

12. Results(Cont.)

13. Results(Cont.)

14. Results(Cont.)

15. Conclusions • This study has successfully demonstrated that the high-frequency AIQP parameter, while neglecting some low-frequency DCT coefficients with estimation errors.