In a method to control a medical apparatus of an installation having: a contact device for a patient, at least one electrical potential sensor that can be coupled to the body of said patient is integrated into the contact device. A signal evaluation device is provided with measurement signals generated with the electrical potential sensor for evaluation. The medical apparatus is connected with the signal evaluation device, and measurement signals that relate to the breathing and/or cardiac activity of the patient are acquired with the at least one electrical potential sensor coupled to the body of said patient upon contact of the patient with the contact device. Trigger signals are generated with the signal evaluation device based on the measurement signals that relate to the breathing cycle and/or the cardiac cycle of the patient. Operation of the medical apparatus is controlled based on the trigger signals.
