n. the apparatus used for *defibrillation, which may be internal (see implantable cardiovertor defibrillator) or external. External defibrillators may be fully automated (see automated external defibrillator), semiautomated, or manual and usually deliver the electric current via two defibrillation paddles. They are now all manufactured to deliver a biphasic current waveform (until recently they were all monophasic). The efficacy of the first shock during *cardiac arrest is higher with biphasic systems, which also use less battery power per shock.
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