PMID- 12046695 OWN - NLM STAT- MEDLINE DCOM- 20020719 LR - 20091111 IS - 0018-9294 (Print) IS - 0018-9294 (Linking) VI - 49 IP - 6 DP - 2002 Jun TI - Use of the ventricular propagated excitation model in the magnetocardiographic inverse problem for reconstruction of electrophysiological properties. PG - 509-19 AB - A novel magnetocardiographic inverse method for reconstructing the action potential amplitude (APA) and the activation time (AT) on the ventricular myocardium is proposed. This method is based on the propagated excitation model, in which the excitation is propagated through the ventricle with nonuniform height of action potential. Assumption of stepwise waveform on the transmembrane potential was introduced in the model. Spatial gradient of transmembrane potential, which is defined by APA and AT distributed in the ventricular wall, is used for the computation of a current source distribution. Based on this source model, the distributions of APA and AT are inversely reconstructed from the QRS interval of magnetocardiogram (MCG) utilizing a maximum a posteriori approach. The proposed reconstruction method was tested through computer simulations. Stability of the methods with respect to measurement noise was demonstrated. When reference APA was provided as a uniform distribution, root-mean-square errors of estimated APA were below 10 mV for MCG signal-to-noise ratios greater than, or equal to, 20 dB. Low-amplitude regions located at several sites in reference APA distributions were correctly reproduced in reconstructed APA distributions. The goal of our study is to develop a method for detecting myocardial ischemia through the depression of reconstructed APA distributions. FAU - Ohyu, Shigeharu AU - Ohyu S AD - Medical Systems Research and Development Center, Toshiba Corporation, Tochigi, Japan. shigeharu.ohyu@toshiba.co.jp FAU - Okamoto, Yoshiwo AU - Okamoto Y FAU - Kuriki, Shinya AU - Kuriki S LA - eng PT - Journal Article PL - United States TA - IEEE Trans Biomed Eng JT - IEEE transactions on bio-medical engineering JID - 0012737 SB - IM MH - Action Potentials/*physiology MH - Body Surface Potential Mapping/*methods MH - Computer Simulation MH - Electric Conductivity MH - Electrocardiography/*methods MH - Heart Conduction System/physiology MH - Humans MH - Magnetic Resonance Imaging/*methods MH - Magnetics MH - *Models, Cardiovascular MH - Reproducibility of Results MH - Sensitivity and Specificity MH - Stochastic Processes EDAT- 2002/06/06 10:00 MHDA- 2002/07/20 10:01 CRDT- 2002/06/06 10:00 PHST- 2002/06/06 10:00 [pubmed] PHST- 2002/07/20 10:01 [medline] PHST- 2002/06/06 10:00 [entrez] AID - 10.1109/TBME.2002.1001964 [doi] PST - ppublish SO - IEEE Trans Biomed Eng. 2002 Jun;49(6):509-19. doi: 10.1109/TBME.2002.1001964.