The present invention relates to a medical coupling unit for electrical signal transmission between the medical coupling unit (1, 1a, 1b) and a medical sensor (2, 2a) coupled to the medical coupling unit. The medical coupling unit comprises a coupling-side connector (10) comprising a plurality of first electrical contacts (11) in or on a first surface (12) and a plurality of second electrical contacts (13) in or on a second surface (14) opposite the first surface, and a connector interface (15) for analyzing electrical signals available at one or more of the plurality of first and second electrical contacts (11, 13) to detect one or more of presence of a medical sensor coupled to the medical coupling unit, the type of medical sensor coupled to the medical coupling unit, and the orientation of a sensor-side connector of a medical sensor coupled to the medical coupling unit. The present invention relates further to a sensor-side connector (20).