A control unit for a medical device wherein the control unit comprises a pump, a conduit and control means for controlling the flow of fluid from the pump through the conduit; and wherein the conduit is a rigid internal passage located in the control unit.一種用於一醫療裝置之控制單元總成,其中該總成包含一控制單元及一對接單元,該對接單元位於該醫療裝置內,其中該控制單元包含一泵、一導管及用於控制流體從該泵流過該導管之控制構件;及該對接單元包含一可卸離之流體轉移連接器,用於將該導管連接於該裝置之一可膨脹室。