Affordable Access

Publisher Website

Concentric/monopolar needle electrode modeling: spatial recording territory and physiologic implications

Electroencephalography and Clinical Neurophysiology/Electromyography and Motor Control
Publication Date
DOI: 10.1016/s0924-980x(97)00045-3
  • Volume Conduction
  • Motor Unit Action Potential
  • Concentric Needle Electrode
  • Monopolar Needle Electrode
  • Instrumentation
  • Biology


Abstract Scaled 20:1 physical models of monopolar and standard concentric needle electrodes are investigated with a constant current bipolar generator to determine the amplitude versus radial distance characteristics of these two electrodes. Each model is examined at three scaled and simulated tissue penetration depths (4, 10 and 20 mm) with measurements documented from 20 to 9000 /Am radially in front and behind the models. The monopolar compared to concentric electrode has a smaller response to a standardized stimuli but a flatter response curve at distances of less than 1500 μm The cannula of the concentric needle also has a flatter response than that of its core. When compared to a remote reference such as that at scaled depths of tissue penetration approximating 4 mm or less the cannula-to-remote reference potential exceeds the amplitude of the core-to-remote reference, recording a net negative potential at 6500 μm in front and 3500 um behind the core. This study offers an explanation for the clinically observed larger magnitude potentials detected with monopolar compared to concentric electrodes resulting from a larger recording cross-sectional area with more fibers contributing to the potential even though the magnitude of potential at any one location is comparatively smaller in magnitude than that for the concentric electrode. Additionally, the physiologic duration of a motor unit is anticipated to be considerably longer than presently measured clinically with automated methods because of the electrodes' ability to detect such small signals from a large region of the volume conductor.

There are no comments yet on this publication. Be the first to share your thoughts.


Seen <100 times

More articles like this

Concentric/monopolar needle electrode modeling: sp...

on Electroencephalography and cli... October 1997

Motor unit action potential duration recorded by m...

on American journal of physical m... 1997

Comparison of recording characteristics of monopol...

on Electroencephalography and Cli... Jan 01, 1993

Comparison of recording characteristics of monopol...

on Electroencephalography and cli... August 1993
More articles like this..