UCL logo

UCL Discovery

UCL home » Library Services » Electronic resources » UCL Discovery

Impedance changes during evoked nervous activity in human subjects: implications for the application of applied potential tomography (APT) to imaging neuronal discharge.

Holder, DS; (1989) Impedance changes during evoked nervous activity in human subjects: implications for the application of applied potential tomography (APT) to imaging neuronal discharge. Clin Phys Physiol Meas , 10 (3) pp. 267-274.

Full text not available from this repository.

Abstract

Impedance changes were measured with scalp electrodes in human subjects during physiologically evoked responses to assess whether such changes could form the basis for imaging of neuronal discharge by applied potential tomography (APT). Conventional methods were employed to measure cortical sensory and visual evoked responses, and the sensory action potential of the ulnar nerve at the elbow. In each case impedance was measured across the appropriate tissue of origin using a high sensitivity four-electrode method. No consistent changes larger than 0.002 or 0.02% (depending on electrode configuration and period of measurement) of the resting impedance were obtained. Changes within these limits appeared to be due to variations in pulse related impedance changes. This suggests that currently available APT devices could not be used to obtain images of neuronal discharge, and research into APT imaging in the adult head might more profitably be directed at imaging the relatively large impedance changes during stroke or spreading depression.

Type: Article
Title: Impedance changes during evoked nervous activity in human subjects: implications for the application of applied potential tomography (APT) to imaging neuronal discharge.
Location: England
Keywords: Action Potentials, Adult, Brain, Electric Conductivity, Evoked Potentials, Somatosensory, Evoked Potentials, Visual, Humans, Neurons, Tomography, Ulnar Nerve
UCL classification: UCL > School of BEAMS
UCL > School of BEAMS > Faculty of Engineering Science
URI: http://discovery.ucl.ac.uk/id/eprint/39203
Downloads since deposit
0Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item