That is called "defibrillator" (also known as defibrillator or electric cardioversion machine), it is a kind of application of electric shock to rescue and treatment of cardiac arrhythmia of a medical electronic equipment. It has the advantages of high efficacy, fast action, easy operation and safer compared with drugs, etc. It is widely used in all levels of medical units to save the patient's heart stop beating when the instrument.
Principle:
The method of eliminating arrhythmia and restoring sinus rhythm with a strong pulse current through the heart is known as defibrillation or electrical cardioversion.