Automated External Defibrillator (AED) AED’s are a lightweight battery-operated, portable device that can be a critical early life-saving piece of equipment that does not require any training. When applied to the chest, this device is an intelligent machine that can evaluate and determine a lethal heart rhythm that has caused a cardiac arrest and correct the abnormal rhythm with an electrical shock. When an AED is used during a cardiac arrest in conjunction with CPR, it can increase the cardiac arrest survival rate by 40-70%.