Time series methods in the monitoring of intracranial pressure. Part 2: Comparative study and initial assessment

The primary objective of monitoring intracranial pressure (ICP) is to detect a reduction in brain compliance at an early stage in order to be able to initiate corrective therapy and thus ensure that an adequate cerebral perfusion is maintained. This paper describes studies aimed at assessing the value of several time series analysis techniques as a basis for a scheme of monitoring ICP. The theoretical foundations for this work were laid in part 1. The paper begins with the outline of a suite of computer programs that were written to implement the techniques selected. Early results from studies with the programs are presented and the discussion is directed towards explaining practical aspects and limitations of the methods that were experienced. It is concluded that the most promising avenue for future development is the use of a dynamic linear model with a recursive parameter estimator within an adaptive framework. The direction of this future work is presented.