One of the most important recent advances in prehospital emergency care is the

Is the use of external automatic defibrillator. this is a portable device that is used to detect any abnormal rhythms in the heart. in addition, it can also be used to send electric shock to the heart to try and restore normal rhythm in case of abnormalities. this device is used in treatment of sudden cardiac arrest where heart unexpectedly stops beating.  

The answer is The use of Automated external defibrillator. It is a portable device which could detect the problem in heartbeat automatically with the help of electrodes and built in computer and calculates if the defibrillation is necessary. If necessary it gives the option to give the shock which stops all heart activity.

The answer is observations and interpreting.