Model selection for pressure-flow velocity relationships of cerebral arteries

Five different mathematical models of pressure-flow velocity relationships of the middle cerebral artery have been studied using 93 records of data obtained from 35 newborn babies. The models considered are based on a general autoregressive/moving average structure which can be translated into physical/haemodynamic analogs. Each model was fitted to individual heart beats of a sequence of 200 cardiac cycles and mean values, variability estimates, and model statistics were obtained for each record. Although all models studied are highly significant and accurate, considerations of parameter significance, variability and the nature of the clinical problem should determine the final choice of the most appropriate model for each application