The invention relates to a system of a plurality of medical treatment units that are respectively associated with a patient, and a plurality of peripheral appliances also respectively associated with a patient. The peripheral appliances transmit control signals and patient signals to the treatment units, while the treatment units receive the control signals and patient signals from the peripheral appliances. The present invention ensures that the treatment units do not receive patient signals from other peripheral appliances that are not associated with the particular patient. The operating staff allocate a peripheral appliance to a patient and confirm the successful association of the peripheral appliance with the treatment unit allocated to the patient.