Open AccessReduced Heat Generation During Magnetic Stimulation of Rat Sciatic Nerve Using Current Waveform Truncation
Author(s) -
Zachary Kagan,
John Mize,
Pragya Kosta,
Gianluca Lazzi,
Richard A. Normann,
David J. Warren
Publication year - 2019
Publication title -
ieee transactions on neural systems and rehabilitation engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.093
H-Index - 140
eISSN - 1558-0210
pISSN - 1534-4320
DOI - 10.1109/tnsre.2019.2911054
Subject(s) - vagus nerve stimulation , waveform , stimulation , sciatic nerve , stimulus (psychology) , electromagnetic coil , transcranial magnetic stimulation , pulse (music) , peripheral nervous system , physics , nuclear magnetic resonance , biomedical engineering , materials science , medicine , vagus nerve , voltage , anatomy , central nervous system , psychology , quantum mechanics , psychotherapist
Current truncating circuit designs used in some controllable pulse width transcranial magnetic stimulation systems can be adapted for use with the peripheral nervous system. Such a scaled-down stimulator produces neuromuscular activation using less stimulus energy than described in previous reports of sciatic nerve stimulation. To evaluate the energy reductions possible with current truncation, we performed six in vivo experiments in rats where the magnetic stimulating coil abutted the sciatic nerve. We used electromyographic data to quantify neuromuscular response, with a criterion level of 20%-of-maximum to indicate a useful level of neuromuscular activation. The energy required to evoke this criterion response from muscles innervated by the sciatic nerve was reduced by approximately 34% from 10.7J with a stimulus waveform lasting 300 [Formula: see text] to 7.1J with a waveform lasting 50 [Formula: see text]. In water, the 300 [Formula: see text] pulse heated the coil by 0.30°C whereas the 50 [Formula: see text] pulse heated the coil by 0.15°C. Truncated-waveform magnetic stimulation systems can be used in basic research and clinical applications not requiring rapidly pulsed stimuli. An example of such a clinical application is left vagus nerve stimulation, a treatment that is reported to reduce epileptic partial-onset seizures.