Real-time estimation of cerebrospinal fluid system parameters via oscillating pressure infusion
2010 (English)In: Medical and Biological Engineering and Computing, ISSN 0140-0118, E-ISSN 1741-0444, Vol. 48, no 11, 1123-1131 p.Article in journal (Refereed) Published
Hydrocephalus is related to a disturbed cerebrospinal fluid (CSF) system. For diagnosis, lumbar infusion test are performed to estimate outflow conductance, C (out), and pressure volume index, PVI, of the CSF system. Infusion patterns and analysis methods used in current clinical practice are not optimized. Minimizing the investigation time with sufficient accuracy is of major clinical relevance. The aim of this study was to propose and experimentally evaluate a new method, the oscillating pressure infusion (OPI). The non-linear model of the CSF system was transformed into a linear time invariant system. Using an oscillating pressure pattern and linear system identification methods, C (out) and PVI with confidence intervals, were estimated in real-time. Forty-two OPI and constant pressure infusion (CPI) investigations were performed on an experimental CSF system, designed with PVI = 25.5 ml and variable C (out). The ARX model robustly estimated C (out) (mean C (out,OPI) - C (out,CPI) = 0.08 μl/(s kPa), n = 42, P = 0.68). The Box-Jenkins model proved most reliable for PVI (23.7 ± 2.0 ml, n = 42). The OPI method, with its oscillating pressure pattern and new parameter estimation methods, efficiently estimated C (out) and PVI as well as their confidence intervals in real-time. The results from this experimental study show potential for the OPI method and supports further evaluation in a clinical setting.
Place, publisher, year, edition, pages
Springer, 2010. Vol. 48, no 11, 1123-1131 p.
normal pressure hydrocephalus, system identification, outflow resistance, outflow conductance, intracranial pressure, infusion test
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:umu:diva-36898DOI: 10.1007/s11517-010-0670-6ISI: 000282830000007PubMedID: 20690044OAI: oai:DiVA.org:umu-36898DiVA: diva2:356591