Reliable first-fault-safety detection of collisions in medical devices

An operating method for a medical device, the method comprising:

• moving, by a control apparatus of the medical device and in a normal mode of the medical device, a moving element of the medical device in a controlled manner via a drive when corresponding movement commands are issued to the control apparatus;
• monitoring, by an evaluation apparatus and in the normal mode, a first-fault-safety contact element on the medical device for actuation and, if actuation is detected, transmitting a respective normal collision signal via respective lines to the control apparatus and a monitoring apparatus of the medical device, the monitoring apparatus being different from the control apparatus;
• and
• in response to a normal collision signal being transmitted,
• ending, by the control apparatus, the movement of the moving element at least in a current direction of travel, and
• preventing, by the monitoring apparatus, the drive from acting on the moving element,
• wherein
• the control apparatus or the monitoring apparatus transmits a check command to the evaluation apparatus on an occurrence of a checking condition,
• in response to a check command being transmitted, the evaluation apparatus transmits a respective special collision signal to the control apparatus and the monitoring apparatus via the lines, and
• in the absence of a special collision signal expected based on the check command, the control apparatus blocks movement of the moving element at least in the current direction of travel and the monitoring apparatus prevents the drive from acting on the moving element.