A manual defibrillator is a medical device used to restore a normal heart rhythm in patients experiencing life-threatening heart conditions, such as ventricular fibrillation or pulseless ventricular tachycardia. Unlike automated external defibrillators (AEDs), manual defibrillators require trained medical personnel to analyze the heart's rhythm and deliver an electric shock if necessary. These devices typically consist of a monitor and a set of paddles or pads that are placed on the patient's chest. The operator can adjust the energy level of the shock and choose the timing, making manual defibrillators essential tools in emergency situations, particularly in hospitals and advanced life support settings.