Method and apparatus for defibrillation using a multiphasic truncated exponential waveform

DETAILED DESCRIPTION It is an object of this invention to provide a method and apparatus for improving the efficacy of defibrillators which provide biphasic truncated exponential waveforms.
It is a further object of the method of this invention to provide biphasic defibrillation pulses to a heart wherein the relative durations of the phases have a predetermined relationship to each other, such that the energy, voltage, and current required for defibrillation is reduced from that required prior to the applicant's invention.
It is a further object of this invention provide a defibrillator which generates biphasic defibrillation pulses in accordance with the applicant's invention wherein the energy, voltage, and current required for defibrillation is reduced from that which has previously been considered necessary.
In accordance with this invention, a method and apparatus of defibrillation is provided in which multiphasic pulses are applied to a heart with the first pulse being of a shorter duration than the second pulse.
More particularly, in accordance with this invention, a defibrillator is provided wherein a biphasic, truncated exponential waveform is generated from a single capacitor discharge in which the first pulse is shorter in duration than the subsequent phase or phases.
Further, a method of defibrillation is provided wherein a defibrillator provides a biphasic pulse, the duration ratio of the first pulse to the subsequent pulse in a preferred embodiment being approximately 40 to 60.
In its broader aspects; the method and apparatus of this invention is generally applicable to converting arrhythmias of the heart, particularly both atrial and ventricular tachycardia arrhythmias.