Touch sensor apparatus for a medical device, medical device and method for operator control of a touch sensor apparatus for a medical device

A touch sensor apparatus for a medical device, comprising:

• a touch sensor;
• a controller configured to detect an operator control event at a user interface of the touch sensor apparatus by evaluating sensor data of the touch sensor;
• and
• a fault detector configured to detect a fault relating to the controller, the fault detector configured to at least one of,
• (a) measure a common mode interference directly if the fault is caused by the common mode interference, the fault detector configured to measure the common mode interference by detecting a voltage dipping between a first reference potential referenced to a ground of the controller and a second reference potential referenced to a ground of an insulated power supply unit of the touch sensor apparatus;
• or
• (b) generate an alternating current voltage signal if the fault is caused by a defect in the controller, apply the generated alternating current voltage signal to the touch sensor via an insulated section of the touch sensor apparatus, detect an influence on the applied alternating current voltage signal caused by the operator control event, and check whether the operator control event is detectable via the fault detector and not via the controller, wherein the defect in the controller is identified if the operator control event is detectable via the fault detector and not via the controller.