Novel non-resonant, low-frequency pulse–current circuit for energy-efficient, low-noise transcranial magnetic stimulation

Three variants of non-resonant, low-frequency TMS circuits were implemented based on the optimized pulse-current waveforms. Theoretical expressions for the optimal waveforms, including the IGBT-controlled voltage-dividing system, were presented. Each optimized triangular pulse-current waveform was modeled and simulated in MATLAB Simulink using these expressions. Moreover, by employing a low-frequency PWM controller, high-frequency switching is entirely avoided. The proposed circuit architecture, which combines a finite series of cascaded modules with the voltage-dividing network, can reproduce any of the optimized pulse-current waveforms as required.