Defibrillation method and system

PURPOSE: To yield the highest probability of successful defibrillation while minimizing the risk of damage to the myocardium and nerve system for a defibrillation system adding defibrillation pulse to a patient to restore normal cardioalmus by controlling impedance-normalized delivered energy (joule unit per ohm). CONSTITUTION: This defibrillation system 10 includes a condenser 12 which is an energy storage device, and poles 14 for exerting an electric shock of the storied electric charge to a patient 16. The electric charge of the condenser 12 is detected by a detector 20. The charge of the condenser 12 is controlled by a comparator/charge control circuit 22. Also provided is an impedance sensing system 24 generating corresponding signals inversely proportional to the patient's transthoracic impedance. The output signal is input to a computer 28. Then a first table memory is searched to determine the value of the patient's transthoracic impedance by the computer 28. A second table memory is searched on the basis of the minimum impedance value to select and output the target voltage value. COPYRIGHT: (C)1994,JPO