An extracorporeale interface unit, for an intravascular measurement system formeasuring a variable in a living body, adapted to generate a sensor signal inresponse to said variable, which interface unit includes: a sensor interfacecircuitry adapted to interface a sensor wire provided with one or more sensorelement(s), the circuitry comprises a measurement unit adapted to generatemeasured data of said variable as a sensor signal. The sensor interfacecircuitrycomprises two current source units adapted to energize said sensor element(s)viaat least two connection points, and a switching unit. The switching unit isadaptedto alternately switch connection between said current source units and atleast twoof said connection points using a preset switching frequency havingessentiallythe same connection time period for each connection. The measurement unit isadapted to determine a sensor variable value related to said variable at twoof saidconnection points.
