Annually, 350000 Sudden cardiac arrests happen outside the hospital and there is a window of 5 minutes between the arrest and the shock to resuscitate the patient and these minutes are golden. With every passing minute, the chances of survival drops by 7-10% and that precisely is the reason Public Access Defibrillator comes into picture. These automated external defibrillators can be installed in public places such as movie theatres, malls, airports etc and they come with instructions on how they can be operated.  
By automatically analyzing the ECG of the patient,it prepares for a shock. Simply put, it can make anyone a saviour of life.