A waveform-controlled energy-recycling monophasic repetitive transcranial magnetic stimulation device

A waveform-controlled, power-efficient, monophasic repetitive transcranial magnetic stimulation (rTMS) device is presented. Unlike conventional designs, the power efficiency is improved by recycling the energy used to generate monophasic stimulation pulses. Such enhanced power efficiency enables a monophasic rTMS device to eliminate an extra cooling system. The slope and width of the stimulation pulse is made programmable in the digital domain for user-friendliness. The energy-recycling circuitry is reconfigured to function as a buck-boost converter with a single additional switch, allowing the proposed device to be low-voltage battery operated. In addition, the pulse width in the DC-DC conversion process is adjusted dynamically to eliminate current accumulation in the inductor, which reduces ohmic dissipation in parasitic resistors and further improves the power efficiency.