25 may also directly interface to analog to digital converter 40 and use internal timing to interrupt microprocessor 25 for sampling frequency additionally microprocessor 25 may be a microcontroller and have memory analog to digital converter 40 and other peripherals on a single chip the defibrillator also contains lcd screen 50 as well as a voice synthesizer and speaker for instructing the rescuer defibrillator 15 also contains all the necessary components for defibrillation including but not limited to charger circuit 60 battery pack 10 capacitors 65 and an h bridge circuit 70 the defibrillator data acquisition system samples the battery voltage once every 45 ms 22 22 hz and stores the data into random access memory ram the data acquisition system may also store the battery data onto a removable multi media flash card for post incident review defibrillator 15 is also capable of storing the battery data into eeprom flash or other types of memory well known in the art defibrillator 15 does not need to implement a digital filter however a digital filter such as but not limited to an averaging filter smoothing filter low pass filter or other filters well known in the art may easily be implemented defibrillator 15 may also store historical information into ram such data may contain information about the period of time since the device was last used the number of times the device has been used the operational mode of the device and the number of shocks that have been delivered the device may additionally store its historical information onto a removable multi media.