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Field calculations in the head of a newborn infant and their application to the interpretation of transcephalic impedance measurements

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Abstract

A spherical model, of five regions, has been applied to the head of a typical premature baby for the purpose of computing the potential and current density fields, with a constant total current applied via small electrodes at opposite poles. The results have been compared within vivo transcephalic impedance measurements, and the model has been used to determine the magnitudes of the impedance effects to be expected in various clinical situations. The model predictions are found to agree well with impedance measurements as a function of the distance between the potential and current electrodes. It is calculated that a large intracranial haemorrhage would produce an increase in the transcephalic impedance of the order of 1 Ω. The model predicts a decrease of up to 20% in the impedance for a change in head circumference of 2 cm due to increased cerebrospinal fluid content. This confirms the conclusion ofReigel et al. (1977) that transcephalic impedance is a sensitive indicator of developing hydrocephalus.

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  1. University Department of Paediatrics, John Radcliffe Hospital, Headington, Oxford, England

    P. W. Murray

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  1. P. W. Murray
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Murray, P.W. Field calculations in the head of a newborn infant and their application to the interpretation of transcephalic impedance measurements. Med. Biol. Eng. Comput. 19, 538–546 (1981). https://doi.org/10.1007/BF02442766

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  • DOI: https://doi.org/10.1007/BF02442766

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