Medical device with selective Broadcasting

The medical device (1) for performing and / or monitoring of a medical procedure with a patient's blood with a blood treatment unit (20) is treated in an extracorporeal circuit, with a plurality of microprocessor units (11a-11f) for carrying out and / or the monitoring of the medical procedure, each with suitable actuators (26; 31, 32, 33) or sensors (27a, 27b; 28a, 28b; 34a, 34b) are connected . with a connecting the microprocessor units (11a-11f) CAN data bus (10), wherein at least a first of the microprocessor units in the first regular time intervals the data packets (40) having a first identifier (41, 41a) via the data bus (10) in broadcast mode, sends selectively to a first group of the other microprocessor units and wherein at least a second of said microprocessor units in the second regular time intervals the data packets with a second identifier via the data bus (10) in broadcast mode sent selectively to a second group of the other microprocessor units, which is different from the first group.