Medical fluid-flow regulating devices are provided. Such medical fluid-flow regulating devices typically include a rotor and a flow-regulator element engaged or engageable with each other via a coupling that below a torque and/or fluidic-pressure threshold value allows the flow-regulator element to move upon rotation of the rotor and thereby regulate fluid flow. The medical fluid-flow regulating devices also include a blocking unit that above the torque and/or fluidic-pressure threshold value irreversibly blocks the rotor or the flow-regulator element or the coupling between the rotor and the flow-regulator element resulting in irreversible inactivation of the medical fluid-flow regulating device. Systems incorporating such medical fluid-flow regulating devices are also provided. Methods for detecting inactivation of such devices are also provided.