Institute of Biomedical Engineering

Entwicklung eines Spulensystems zur Abschätzung der muskelstimulierenden Wirkung von Magnetfeldern im kHz-Bereich

The effect of magnetic field gradients below 1 kHz on ionic current density inside the human body and the stimulation of nerves and muscles involved have been tested many times. Beyond this threshold the results have been perpetuated linearly. Hardly any further tests were done.


Figure 1: Asymptotic strength-frequency model for excitation by uniform electric field within the biological medium; continued sinusoidal stimulus.

The aim of this project is to investigate the effect of alternating magnetic fields, generated by a figure-8-coil. The main question is whether it is possible to stimulate muscles inductively. Therefore, numerical methods are being used in order to calculate the induced fields in the Visible Man’s arm. To do this we use properties like permitivity and conductivity published by Gabriel & Gabriel. Simultaneously, a circuit shall be composed, which provides sufficient current in order to generate a magnetic field that is able to induce a muscle stimulating field.
Real characteristics like maximum currents, shapes, parasitic characteristics, and inductivity have to be considered in terms of feasibility. Finally the coil setup is to be built according to the simulation results and tested on real human arms.


Figure 2: left: Model of the human arm and figure-8-coil.
Right: Induced current density in the muscle tissue below the coil.