Direct Inference of the Spectra of Pericardial Potentials using the Boundary-Element Method
New methods, based on Tikhonov regularization, were developed to infer the magnitude and phase of pericardial potentials directly. These methods were tested in an adult-male torso model using measured human epicardial potentials. With 1% noise added to body-surface potentials, regularization with an optimal parameter at each frequency from 1 to 100 Hz gave an average relative error (RE) in inferred spectral magnitudes of 0.44. Regularization with the composite-residual-smoothing-operator (CRESO) parameter increased the RE slightly to 0.47. With 10% additive noise, 10 mm overestimation of heart radius, and a 10 mm error in heart position, the average CRESO parameter from 1 to 100 Hz gave an average RE of 0.71. Performance was frequency dependent. The smallest REs occurred at low frequencies. With 1% noise, optimal regularization gave average REs of 0.20, 0.40, and 0.53 in the 1-15, 15-46, and 46-100 Hz bands, respectively. Direct inference of spectral magnitudes was more accurate than Fourier transformation of inferred time-domain waveforms. Results suggest that when heart size and location are not known, minimum REs in spectral estimates are found using an overestimated heart size and a regularization parameter which is the average value over the frequency band of interest.
D. G. Beetner and R. M. Arthur, "Direct Inference of the Spectra of Pericardial Potentials using the Boundary-Element Method," Annals of Biomedical Engineering, vol. 27, no. 4, pp. 498-507, Kluwer Academic Publishers-Plenum Publishers, Jul 1999.
The definitive version is available at http://dx.doi.org/10.1114/1.223
Electrical and Computer Engineering
Keywords and Phrases
Frequency Components; Human Data; Inverse Electrocardiology; Tikhonov Regularization
International Standard Serial Number (ISSN)
Article - Journal
© 1999 Kluwer Academic Publishers-Plenum Publishers, All rights reserved.