Skip to main content

Advertisement

Log in

Noninvasive cardiac output estimation: a preliminary study

  • Published:
Biological Cybernetics Aims and scope Submit manuscript

Abstract.

 The availability of a simple-to-use, automatic measurement system for noninvasive flow estimation is imperative, given the clinical demand for an acceptable noninvasive procedure rather than the standard invasive procedure of thermodilution. A method for calculating cardiac output from noninvasively derived pressure pulses has been developed, and the results of a preliminary evaluation study on post-cardiac surgery patients for whom invasive flow measures were readily available for comparison are provided in this report. The proposed method relies on fast Fourier transform (FFT) analysis of pulses measured externally at the carotid and femoral pressure points. A transfer function of the aorta is computed from digitally filtered pulse measurements, and a tapered model of the aorta is parametrically adapted using a simplex optimization algorithm so that its transfer function matches that derived experimentally. An aortic input impedance term is obtained from the optimized model and utilized along with the carotid pulse (analogous to input voltage) to compute aortic flow. In addition to its automation, attractive features of this method include the requirement for relatively few pulses for analysis as well as considerable resistance to noise artifact. For 59 data records collected from 54 post-cardiac surgery patients, the average flow measurements computed over several pulses compare well with the standard, invasive method of thermodilution. Preliminary results also indicate a strong potential for tracking changes in cardiac output over time, and invite further use of the method in monitoring hemodynamically unstable patients.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

Author information

Authors and Affiliations

Authors

Additional information

Received: 18 February 1997 / Accepted in revised form: 12 May 1997

Rights and permissions

Reprints and permissions

About this article

Cite this article

Redling, J., Akay, M. Noninvasive cardiac output estimation: a preliminary study. Biol Cybern 77, 111–122 (1997). https://doi.org/10.1007/s004220050372

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1007/s004220050372

Keywords

Navigation