A scheme to correct for electric field non-uniformity in right ventricular volume measurement using a conductance catheter

A finite element model of a right ventricle and a conductance catheter was developed to understand the effects of electric field non-uniformity in conductance volumetry. Simulations showed that the measured volumes were underestimated by non-uniformity of the electric field. Volume underestimation diminished at smaller ventricular volumes and larger catheter curvatures. Correction factors to adjust for field non-uniformity were established for different ventricular volumes and catheter positions. These factors when applied to conductance volumes in in vitro canine hearts reduced the measurement error from 8.3+/-18.6% before correction to -1.3+/-6.3% after correction.