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Biomedical subjects

J Ruohonen

Publications and source records attributed to J Ruohonen.

20 records · Page 2Linked to original sources

Coil optimization for magnetic brain stimulation.

Further development of magnetic brain stimulation requires smaller coils, smaller power consumption, and less coil heating. This study addresses the optimization of the complete stimulator and in particular the coil. We describe the coil structure in terms of simple mathematical functions and examine the influence of changes in the structure on several figures of merit. A few optimal coil geometries suitable for repetitive brain stimulation are depicted. It is demonstrated that today's coils are far from optimal and that, for instance, the power consumption can be reduced remarkably from the level of today's equipment. Improvements may act as a springboard toward new applications.

Biomedical Engineering↗

Magnetic stimulation of the nervous system: induced electric field in unbounded, semi-infinite, spherical, and cylindrical media.

Knowledge of the electric field that is induced in the brain or the limbs is of importance in magnetic stimulation of the nervous system. Here, an analytical model based on the reciprocity theorem is used to compare the induced electric field in unbounded, semi-infinite, spherical, and cylinder-like volume conductors. Typical stimulation coil arrangements are considered, including the double coil and various orientations of the single coil. The results can be used to determine when the influence of the boundaries is negligible enough to allow the use of more simplified geometries.

Brain↗