Estimation of ventricular volume and elastance from the arterial pressure waveform.

We propose that it is possible to estimate cardiovascular parameters from the arterial pressure waveform, including ventricular maximal elastance and end-diastolic volume, if cardiac output is also known. We tested this hypothesis by means of a parameter estimation algorithm applied to simulated arterial pressure signals. The program first estimated three coefficients representing products of passive parameters from the diastolic part of the simulated arterial pressure waveform. Second, it estimated three parameter products pertaining to the ventricular function from the systolic part of the waveform. Third, mean blood flow was entered, enabling the program to compute individual parameters. This program was tested on 200 computer-generated arterial pressure signals, obtained by simulating the model with random but bounded parameters. Correlation between estimated parameters with those actually used in the simulations was excellent. Even though the value of this computer simulation is limited to the simplified model used and requires experimental validation, it demonstrates that the technique is theoretically feasible.