Areas under thermal-dilution curves assuming log-normal distribution

Journal/Book: Am. J. Physiol. 207(1): 144-148. 1964. 1964;

Abstract: Cardiovascular Research Department Research Laboratorium Dr. C. Janssen Beerse Belgium Received for publication 28 March 1963. Graphical methods are described for the calculation of areas under dilution curves. Replotting of the original curve and subsequent planimetry can be avoided by assuming log-normal distribution of the transit times. The validity of the assumption is indicated. Relative accuracies of the proposed methods are discussed. A comparison is drawn between the log-normal assumption and the negative exponential law of Hamilton and a systematic deviation between the procedures is observed for higher values of the cardiac output. The log-normal assumption has a trend to yield higher values for the cardiac output than the classical method of Hamilton. ___MH

Keyword(s): cardiac output - quadrature - distribution of transit times - extrapolation - Hamilton's method - random walk - triangle approximation

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