Experimental thresholds of magnetically induced currents via a figure-of-eight coil up to 25 kHz.
Magnetic particle imaging, uses magnetic fields of frequencies in the kilo-hertz range. Little research has been carried out upon effects on excitable tissue caused by time-varying magnetic fields in that frequency range. To learn about magnetic stimulation thresholds, a system that is capable of generating a very focused magnetic field strong enough to induce a muscular reaction was built. Stimulation thresholds at 7.38, 12.04, 16.5, and 25.27 kHz have been recorded in 31 trial participants. It has been proved that magnetic stimulation is possible up to even 25 kHz, and respective thresholds have been determined. This article presents the trial setup, procedure, and evaluation of field quantities.
Institute of Biomedical Engineering, Karlsruhe Institute of Technology, Germany. publications@ibt.uni-karlsruhe.de
Julia
J
Bohnert
Matthias
M
Gräser
Bernhard
B
Gleich
Olaf
O
Dössel
D004056:Differential Threshold / Q000502:physiology / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D004558:Electric Stimulation / Q000379:methods*; D005260:Female; D006801:Humans; D060526:Magnetic Fields; D008297:Male; D009119:Muscle Contraction / Q000502:physiology* / Q000528:radiation effects*; D018482:Muscle, Skeletal / Q000502:physiology* / Q000528:radiation effects*; D011829:Radiation Dosage; D055815:Young Adult