A comparison of pressure-volume models in hydrocephalus

R. H. Simon, R. A W Lehman, Sean O'Connor

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Traditional descriptions of the pressure-volume properties of the craniospinal axis have expressed pressure as a function of volume. This study develops a theoretical and practical rationale for expressing volume as a function of pressure. We tested the rationale by comparing the two functions using pressure and volume data collected from 37 hydrocephalic patients during ventricular fluid removal. Two equivalent expressions were evaluated, one expressing pressure as an exponential function of volume and one relating volume as an exponential function of pressure. Each expression had three parameters, adjustable to the specific case. We used a nonlinear curve-fitting algorithm to determine the best estimate of the parameters. We could fit three-parameter exponential functions of either type to the data in all cases. We found a superior goodness-of-fit to aggregated data when expressing volume as a three-parameter exponential function of pressure changes. This finding is discussed in the context of the preferable number of parameters in a model and the interpretation of the terms in the models. This 'reversed' volume-pressure relationship has importance in the development of more complicated models involving these same relationships.

Original languageEnglish (US)
Pages (from-to)694-699
Number of pages6
JournalNeurosurgery
Volume15
Issue number5
StatePublished - 1984
Externally publishedYes

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Hydrocephalus
Pressure

ASJC Scopus subject areas

  • Clinical Neurology
  • Surgery

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Simon, R. H., Lehman, R. A. W., & O'Connor, S. (1984). A comparison of pressure-volume models in hydrocephalus. Neurosurgery, 15(5), 694-699.

A comparison of pressure-volume models in hydrocephalus. / Simon, R. H.; Lehman, R. A W; O'Connor, Sean.

In: Neurosurgery, Vol. 15, No. 5, 1984, p. 694-699.

Research output: Contribution to journalArticle

Simon, RH, Lehman, RAW & O'Connor, S 1984, 'A comparison of pressure-volume models in hydrocephalus', Neurosurgery, vol. 15, no. 5, pp. 694-699.
Simon, R. H. ; Lehman, R. A W ; O'Connor, Sean. / A comparison of pressure-volume models in hydrocephalus. In: Neurosurgery. 1984 ; Vol. 15, No. 5. pp. 694-699.
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