Publications [#61020] of Roger C. Barr

Papers Published

1. Di Persio, D.A. and Barr, R.C., A prototype inverse solution in one-dimension to find the origin of excitation, strand radius, intracellular resistivity, or distance from the surface, IEEE Trans. Biomed. Eng. (USA), vol. BME-34 no. 9 , pp. 681 - 91
   (last updated on 2007/04/12)

   Abstract:
   A computer simulation of a strand 11.8 mm long was used to examine whether extracellular waveforms from a one-dimensional strand can be used to find the site of origin of excitation (x_s0), strand radius (a₀), intracellular resistivity (R_i0), or distance of the electrodes from the strand (b₀). The Ebihara-Johnson equations were used to model the membrane's behavior. Extracellular waveforms simulated at two of 60 points along the strand were used as `measurements'. The inverse calculations had the objective of finding one or two of the variables x<sub>s0</sub>, a<sub>0</sub>, R<sub>i0</sub>, or b<sub>0</sub> with the others known. The solution procedure compared the `measured' waveforms to trial waveforms obtained by varying all unknown parameters through their physiological range. The error curves were frequently found to have several relative minima. In general, however, no combination of unknowns other than the correct one led to rms errors within experimental noise levels, a result in marked contrast to that of most other inverse calculations in electrocardiography

   Keywords:
   bioelectric phenomena;cardiology;cellular biophysics;