The present invention relates to an extracorporeale interface unit (8), for an intravascular measurement system for measuring at least one physiological, or other, variable in a living body, adapted to generate a sensor signal in response of the variable. The interface unit (8) comprises a sensor interface circuitry (6) adapted to interface a sensor wire configured to be inserted into the living body and provided with one or many sensor element (s) at its distal region. The sensor interface circuitry (6) comprises a measurement unit (9) adapted to generate the measured data of the variable as a sensor signal. The interface unit (8) further comprises a control unit (1) adapted to control and supervise the different functions of the interface unit (8), wherein the different functions are performed by predefined tasks (T1, T2... TN) during consecutive control periods CP having the same time duration.
