[Improvement of coils used in functional magnetic stimulation].
OBJECTIVE
Functional magnetic stimulation (FMS) is a new technique for stimulating the excitable tissue. But the difficulty to locate the activation point and the poor capability of focusing limit the further progress of FMS. A new stimulation method using 8-shaped coil and a combinatorial coil were presented to improve coils performance.


METHODS
The distribution of the induced electrical field was calculated based on Faraday law.


RESULTS
When the nerve was perpendicular to the handle of 8-shaped coil and tangential to the coil edge, the position with the maximum of first spatial gradient of the field did not change with the varying of the radius of coil and the excitation depth; the values of the first spatial gradient of field above the stimulation target decreased obviously using the combinatorial coils.


CONCLUSIONS
Comparing with the current stimulation method of 8-shaped coil, the new method gave a fixed activation point. The capability of focusing was improved using the presented combinatorial coil.
Wang
Y
Y
Institute of Biomedical Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
Shen
Q
Q
Jiang
D
D
D004558:Electric Stimulation / Q000295:instrumentation*; D004574:Electromagnetic Fields; D005069:Evaluation Studies as Topic; D006801:Humans; D008280:Magnetics / Q000627:therapeutic use*; D009474:Neurons / Q000502:physiology*