A Mathematical Representation of the Thermodilution Curve


  • Sven Budwill M.H.Sc. P.Eng. Memorial University of Newfoundland
  • Jason Rhinelander B. Eng. Memorial University of Newfoundland


The primary purpose of this study was to develop a mathematical representation of the thermodilution cardiac output curve. Further work focused on the development of an empirical model and a software implementation to measure cardiac output with improved patient diagnostic efficiency (speed) by area prediction. The empirical model is equivalent to a second-order over-damped system with a rectangular pulse as input. The output of the system represents the thermal response. The curve is constrained in that it follows the area criterion assumed by many cardiac output units. A software implementation of this model used to predict cardiac output takes in measured values of a thermal response up to the curve’s peak and matches time constants with the model to derive a predicted curve. In matching the curve, the software also produces data that assesses the error between the two curves (measured and predicted).




How to Cite

S. Budwill and J. Rhinelander, “A Mathematical Representation of the Thermodilution Curve”, CMBES Proc., vol. 27, no. 1, Dec. 2002.