Inspection and Testing of Defibrillators

Over the last 50 years of use, defibrillation has been proved to be safe and efficient method to terminate lethal arrhythmias like ventricular fibrillation and ventricular tachycardia without pulse. However, in order to ensure safety and efficacy of this therapy, it is necessary to have a defibrillator which has been tested and proved to be fully functional. Preventive maintenance of all medical devices is highly important to ensure correct diagnosis and therapy, but for defibrillators it is even more important, because a defibrillator is a life-saving device and it is used in the case when a patient life is in danger. Any failure or partial failure of a defibrillator functionality may result in death of a patient. Therefore, there is a zero-tolerance on discrepancies between full functionality of defibrillator, as described in device documentation and actual functionality of defibrillator. Preventive maintenance of defibrillator consists of series of tests which need to be done on the device, with use of special measuring equipment. The most important tests include measurement of output energy which is being delivered from a defibrillator, at all energy levels, to a certain testing impedance. It is also possible to repeat this testing on variable impedance values, and that is highly recommended, because actual patient impedance values will also vary. The documentation for each defibrillator defines tolerance of the delivered energy value, so the actual value must be within prescribed tolerance values, in order to declare the device fully functional. In this chapter, the principles of operation are described too, as well as related standards and the simplest to use kind of defibrillators, called automatic external defibrillators (AEDs).