Patent ID: 7200434

Claim:
A system for controlling a slow-rise, ramp-type defibrillation output waveform to deliver constant energy from a device to terminate a cardiac fibrillation condition, comprising: means for delivering an initial portion of energy to a load impedance of a subsystem between at least a pair of electrodes with a voltage-controlled or current-controlled slow-rise, ramp-type defibrillation output waveform; means for measuring a length of time it takes a storage capacitor voltage to decay by a certain percentage during delivery of the initial portion of energy; means for calculating a real-time value of the load impedance that a voltage-controlled or current-controlled slow-rise, ramp-type defibrillation output waveform is delivered into based on the length of time; and means for extending the voltage-controlled or current-controlled slow-rise, ramp-type defibrillation output waveform to deliver a pre-programmed level of energy irrespective of the load impedance.