What is the main purpose of an AED?

The primary purpose of an Automated External Defibrillator (AED) is to restore a normal heart rhythm in individuals experiencing sudden cardiac arrest. During this critical situation, the heart can become uncoordinated and ineffective in pumping blood, potentially leading to death if not addressed immediately. The AED analyzes the heart's rhythm and, if necessary, delivers a controlled electric shock to reset the heart's electrical activity, allowing it to regain a normal rhythm. This essential function is why AEDs are vital tools in emergency settings, as quick access and use can significantly increase the chances of survival for someone in cardiac arrest.

The other options pertain to different aspects of medical response and care. Monitoring heart rate during exercise is a distinct function that is important but unrelated to cardiac arrest. Providing oxygen to the lungs serves a critical role in respiratory emergencies but does not directly correct cardiac rhythm. Controlling bleeding during trauma is crucial in situations involving significant blood loss, but it does not relate to the management of cardiac arrest. Each of these functions is important in their own right but does not align with the specific purpose of an AED.