Continuous measurement of cardiac output with the use of stochastic system identification techniques

J Clin Monit. 1990 Oct;6(4):322-32. doi: 10.1007/BF02842492.


The limitations of developing a technique to measure cardiac output continuously are given. Logical explanations are provided for the economic, technical, and physiologic benefits of a stochastic system identification technique for measuring cardiac output. Heat is supplied by a catheter-mounted filament driven according to a pseudorandom binary sequence. Volumetric fluid flow is derived by a cross-correlation algorithm written in the C language. In vitro validation is performed with water in a flow bench. The computed flow (y) compared with the in-line-measured flow (x) yields the linear regression y = 1.024x - 0.157 (r = 0.99). The average coefficient of variation is less than 2% over a volumetric fluid flow range of 2 to 10 L/min.

MeSH terms

  • Analog-Digital Conversion
  • Blood Physiological Phenomena
  • Body Temperature / physiology
  • Cardiac Catheterization
  • Cardiac Output* / physiology
  • Hot Temperature
  • Humans
  • Indicator Dilution Techniques
  • Models, Cardiovascular
  • Monitoring, Physiologic*
  • Pulmonary Artery / physiology
  • Signal Processing, Computer-Assisted*
  • Stochastic Processes*