I propose an integrated approach to investigations of issues connected with long-term ambulatory ECG monitoring. I envisage my research culminating in the development of microprocessor-based ambulatory and intra-cardiac arrhythmia monitors. Signal processing: I plan to carry out frequency and time domain analysis of ECG and noise signals. I will identify optimal QRS filter and detector parameters, and signal processors for high resolution ECG. ECG interpretation: I propose a significant-point extraction algorithm that carries out data reduction and pattern recognition. This technique promises to help identify P and T-waves, and S-T segments. Also, R-R and P-R interval predictors will aid in arrhythmia analysis. Electrode studies; I propose experiments on new electrode designs-including a guard-ring ECG electrode, optimal placement, study origins of skin potentials and artifacts, and skin preparations to reduce them. Intracardiac ECGs and defibrillation: In connection with pacemaker and defibrillator developments, I plan to characterize intra-cardiac ECG (including ventricular fibrillation- VFIB) signals, develop algorithms, and investigate other sensors for VFIB recognition. For effective defibrillation, I plan to study current distributions in the thorax. Evaluation: I will develop quantitative measures of performance of arrhythmia detectors (analysis of contingency table, detection curves, utility theoretic analysis, etc.). For evaluation of arrhythmia systems, studies with annotated database, volunteers, and patients are proposed. Long term goals: I hope to design patient monitors utilizing microprocessor and VLSI (very large scale integration) technologies. This research should benefit the development of Holter event-recorders, pacemakers and defibrillators with ECG interpretation capabilities, long-term monitoring and (when necessary) resuscitation of critically ill cardiac patients in their homes. Through the use of intelligent ambulatory and implantable monitors I hope to develop solutions to identification and prevention sudden death in ambulatory population.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Modified Research Career Development Award (K04)
Project #
5K04HL001509-03
Application #
3073830
Study Section
Surgery and Bioengineering Study Section (SB)
Project Start
1985-07-01
Project End
1990-06-30
Budget Start
1987-07-01
Budget End
1988-06-30
Support Year
3
Fiscal Year
1987
Total Cost
Indirect Cost
Name
Johns Hopkins University
Department
Type
Schools of Medicine
DUNS #
045911138
City
Baltimore
State
MD
Country
United States
Zip Code
21218
Thakor, N V; Zhu, Y S (1991) Applications of adaptive filtering to ECG analysis: noise cancellation and arrhythmia detection. IEEE Trans Biomed Eng 38:785-94
Gliner, B E; Murakawa, Y; Thakor, N V (1990) The defibrillation success rate versus energy relationship: Part II--Estimation with the ""bootstrap"". Pacing Clin Electrophysiol 13:425-31
Thakor, N V; Zhu, Y S; Pan, K Y (1990) Ventricular tachycardia and fibrillation detection by a sequential hypothesis testing algorithm. IEEE Trans Biomed Eng 37:837-43
Gliner, B E; Murakawa, Y; Thakor, N V (1990) The defibrillation success rate versus energy relationship: Part I--Curve fitting and the most efficient defibrillation energy. Pacing Clin Electrophysiol 13:326-38
Laguna, P; Thakor, N V; Caminal, P et al. (1990) Low-pass differentiators for biological signals with known spectra: application to ECG signal processing. IEEE Trans Biomed Eng 37:420-5
Vaz, C A; Thakor, N V (1989) Adaptive Fourier estimation of time-varying evoked potentials. IEEE Trans Biomed Eng 36:448-55
Murakawa, Y; Gliner, B E; Thakor, N V (1989) Success rate versus defibrillation energy: temporal profile and the most efficient defibrillation threshold. Am Heart J 118:451-8
Murakawa, Y; Gliner, B E; Shankar, B et al. (1989) The effect of an unsuccessful subthreshold shock on the energy requirement for the subsequent defibrillation. Am Heart J 117:1065-9
Thakor, N V (1987) Adaptive filtering of evoked potentials. IEEE Trans Biomed Eng 34:6-12
Thakor, N V; Moreau, D (1987) Design and analysis of quantised coefficient digital filters: application to biomedical signal processing with microprocessors. Med Biol Eng Comput 25:18-25

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