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Baan, J., Aouw Jong, T. T., Kerkhof, P. L., Moene, R. J., van Dijk, A. D., van der Velde, E. T., and Koops, J., (1981) Con-tinuous stroke volume and cardiac output from in-tra-ventricular dimensions obtained with an impedance catheter. Cardiovascular Research, 15, 328–334.

has been cited by the following article:

• TITLE: Calibrating volume measurements made using the dual-field conductance catheter

  AUTHORS: Simon P. McGuirk, David Barron, Dan Ewert, John H. Coote

  KEYWORDS: Conductance Catheter; Calibration; Volume Measurement

  JOURNAL NAME: Journal of Biomedical Science and Engineering, Vol.2 No.7, November 19, 2009

  ABSTRACT: The conductance catheter technique allows real- time measurements of ventricular volume based on changes in the electrical conductance of blood within the ventricular cavity. Conductance volume measurements are corrected with a calibration coefficient, α, in order to improve accuracy. However, conductance volume measurements are also affected by parallel conductance, which may confound cali-bration coefficient estimation. This study was un-dertaken to examine the variation in α using a physical model of the left ventricle without parallel conductance. Calibration coefficients were calculated as the conductance-volume quotient (αV(t)) or the stroke conductance-stroke volume quotient (αSV). Both calibration coefficients varied as a non-linear function of the ventricular volume. Conductance volume measurements calibrated with αV(t) estimated ventricular volume to within 2.0 ± 6.9%. By contrast, calibration with αSV substantially over-estimated the ventricular volume in a volume-dependent manner, increasing from 26 ± 20% at 100ml to 106 ± 36% at 500ml. The accuracy of conductance volume measurements is affected by the choice of calibration coefficient. Using a fixed or constant calibration coeffi-cient will result in volume measurement errors. The conductance-stroke volume quotient is associated with particularly significant and volume-dependent measurement errors. For this reason, conductance volume measurements should ideally be calibrated with an alternative measurement of ventricular vol-ume.