Baroreflex sensitivity evaluation by Volterra Wiener model and the Laguerre expansion technique

This paper presents a Volterra-Wiener model and the Laguerre expansion technique to analyze the changes in heart rate interval, as modelpsilas output to the corresponding changes in systolic arterial blood pressure, as modelpsilas input. This new technique can not only find the baroreflex sensitivity (BRS) but also can assess the nonlinear and dynamic behavior of baroreflex from the identified model parameters. The performance of this new technique was compared with the measurements by sequence technique (SEQ) and alpha coefficient technique (Alpha) in 5 normal and 11 hypertension subjects. The BRS of hypertension subjects was 4.4 plusmn 2.0 ms/mmHg for SEQ, 4.6 plusmn 1.9 ms/mmHg for Alpha, and 2.9 plusmn 1.6 ms/mmHg for the new technique. For normal subjects, the BRS was 30.4plusmn12.4 ms/mmHg for SEQ, 25.8 plusmn 10.2 ms/mmHg for Alpha, and 17.5 plusmn 7.7 ms/mmHg for the new technique. The proposed new technique yielded a reasonable lower BRS estimation than existing noninvasive BRS techniques.