Neuromagnetic focusing for selective transcranial stimulation of muscles

A focusing method for spatially selective, fast and efficient neuromagnetic stimulation is described that is using novel excentric coil systems. Electrolytic tank phantoms indicate good subcutaneous focusing without surface stimulation at cutaneous and shallow subcutaneous levels. Preliminary in vivo tests in humans indicate that selective transcranial stimulation of such closely adjoining muscle group areas as the ones of the musculus abductor pollicis brevis (thumb) and the musculus interosseous I (index finger) is possible with at least 50% less power than with conventional systems, with higher repetition rates and with limited electronic tuning of the subcutaneous focusing depth. Use of this method might lead to new applications in neurology and rehabilitation medicine.