The monitor defibrillator is used to: - Monitor vital signs such as heart rate, blood pressure, oxygen saturation, respiratory rate, and end-tidal carbon dioxide. - Treat cardiac arrhythmias by delivering an electric shock through paddles or pads placed on the chest to depolarize the heart and restore a normal rhythm. - It displays the ECG rhythm and detects shockable rhythms like ventricular fibrillation to guide treatment.