A computer system for the identification of the cerebrospinal compensatory model

Abstract

A computer system, based on IBM PC, was designed for the cerebrospinal compensatory model identification. The intracranial pressure (ICP) signal, registered during the lumbo-lumbar infusion test is analyzed by means of the spectral analysis algorithm in order to measure precisely the pulse wave amplitude. The amplitude and the mean ICP level, calculated repetetively within the period of about 8 seconds, are stored on the disk and form the basis for further model identification. Three different methods of identification were applied. They enable one to estimate the fundamental model parameters, such as: resistance to the cerebrospinal fluid resorption, pressure-volume index, baseline pressure, rate of formation of the cerebrospinal fluid. Statistical evaluation of the results of the infusion test analysis obtained by means of the system described in two groups of hydrocephalic patients (children and adults) is presented.

Infusion technique can be used to distinguish between dysfunction of a hydrocephalus shunt system and a progressive dementia

“…Lumbar infusion tests for CSF dynamic investigations were first presented in 1970 (KATZMAN and 14USSEY, 1970) and have since been improved (CzoSNYKA et al, 1990;EKSTEDT, 1977;LUNDKVIST et al, 2001). The main focus has been to find a test, based on the CSF dynamics, for selecting hydrocephalus patients who are likely to benefit from a shunt operation.…”

A computing system for the clinical and experimental investigation of cerebrovascular reactivity

“…Specialised programs enable data acquisition and pro- [20][21][22]. Similar computer support has been reported for individual tests of cerebrovascular reactivity [7,18,23].…”

Spectral analysis of intracranial pressure signals recorded during infusion studies in patients with hydrocephalus

“…Computerised infusion tests [11,12] are a modification of the conventional constant rate infusion test, originally described by Katzman [13].…”

“…ICP signals have been also studied in the frequency domain using very different strategies. The FT of ICP signals was analysed in the context of the pulse amplitude of ICP, as a means of characterising ICP waveform [11,19]. Other researchers tried to reconstruct the ICP signal from the information in the first harmonic of the FT of the signal [20].…”

“…In this study, data were recorded during infusion studies for patients with hydrocephalus. However, signals in [11,18,20,38] did not come from infusion tests. Thus, a direct comparison with our study is not straightforward.…”