The amount of electrical energy transmitted to the patient while inducing a seizure during electroconvulsive therapy (ECT) may vary considerably depending on the waveform of the electrical stimulus. The majority of ECT equipment used in the past employed a sinusoidal waveform for the stimulus. Advances in waveform technology have led to the development of pulsatile waveforms which are effective convulsants requiring a fraction of the electrical energy transmitted by the sinusoidal waveform. This paper summarizes the clinically relevant advances in waveform technology. The therapeutic principle of using the minimum effective dosage is emphasized.
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