What is the primary function of an automated external defibrillator (AED)?

The primary function of an automated external defibrillator (AED) is to deliver a controlled electric shock to the heart in order to restore a normal rhythm when the heart is experiencing a fatal arrhythmia, such as ventricular fibrillation or pulseless ventricular tachycardia. These arrhythmias are life-threatening conditions where the heart is unable to pump blood effectively, leading to cardiac arrest.

When a person is in cardiac arrest, the AED is designed to analyze the heart's rhythm and determine whether a shock is needed. If the device indicates that a shock is appropriate, it delivers a precise electrical shock intended to reset the heart's electrical system, allowing it to resume normal function. This action can significantly increase the chances of survival if performed quickly after cardiac arrest occurs.

The other options pertain to functions that an AED does not perform. Continuous monitoring of vital signs is typically done by other medical devices, providing oxygen is a function of respiratory support systems or methods, and stimulation of consciousness is not a direct function of an AED, as its primary purpose is to correct heart rhythms rather than to awaken a patient.