Recording and physical characteristics of disposable concentric needle EMG electrodes.

Journal Article

There is currently considerable interest in using disposable concentric needle (CN) electrodes for clinical electromyography (EMG). To determine how these electrodes compare with reusable CN electrodes, we have compared signals recorded by these two electrode types from the same muscle in normal subjects. We also made similar recordings with two groups of reusable electrodes. There was no difference in the features of motor unit action potentials (MUAPs) recorded by the two groups of reusable electrodes. Disposable electrodes performed satisfactorily in conventional EMG examination. However, compared to reusable electrodes, the disposable electrodes recorded MUAPs with smaller amplitude and area but with the same area:amplitude ratio and MUAP duration. The physical and electrical properties of the CNE groups were also investigated. Disposable electrodes had lower electrical resistance and greater capacitance than reusable electrodes when measurements were made in saline. Photomicrographs showed that the disposable electrodes had smaller recording surfaces and that the central wire was frequently eccentric in the cannula. The differences in electrical recording characteristics could be due to differences in the size of the recording surface, eccentric placement of the central wire in the cannula or differences in the metal used for the central wire. We conclude that electrical and physical testing may not predict the recording characteristics of needle electrodes. Electrophysiologic testing is necessary to determine how EMG signals recorded by new types of electrodes compare with those recorded by currently used electrodes.

Full Text

Duke Authors

Cited Authors

  • Nandedkar, SD; Tedman, B; Sanders, DB

Published Date

  • October 1990

Published In

Volume / Issue

  • 13 / 10

Start / End Page

  • 909 - 914

PubMed ID

  • 2233847

International Standard Serial Number (ISSN)

  • 0148-639X

Digital Object Identifier (DOI)

  • 10.1002/mus.880131004

Language

  • eng

Conference Location

  • United States