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Concentric and single fiber electrode spatial recording characteristics
Author(s) -
King John C.,
Dumitru Daniel,
Nandedkar Sanjeev
Publication year - 1997
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/(sici)1097-4598(199712)20:12<1525::aid-mus7>3.0.co;2-a
Subject(s) - concentric , perpendicular , electrode , materials science , fiber , sensitivity (control systems) , core (optical fiber) , optics , physics , geometry , composite material , mathematics , quantum mechanics , electronic engineering , engineering
A better appreciation of the specific spatial recording characteristics of the single fiber and concentric needle electrode can result in more accurate physiologic and theoretical interpretations of single fiber and quantitative motor unit action potential analysis. We demonstrate by physical modeling that the 90% and 99% amplitude sensitivity envelopes are not simple hemispherical shapes. The 90% sensitivity concentric electrode volume does not extend beyond the insulated portion of the 15° beveled surface between the core and cannula and extends only 280 μm perpendicularly from the center of the core's surface. The 99% envelope extends approximately 830 μm perpendicularly from the core's center. This is a much smaller volume of sensitivity than exists for a similarly modeled monopolar electrode. The 90% and 99% envelopes extend to 110 and 320 μm perpendicularly from the exposed single fiber core. Both the single fiber and concentric needle volumes of sensitivity have specific asymmetries described. © 1997 John Wiley & Sons, Inc. Muscle Nerve 20: 1525–1533, 1997