A flow rate control device having features for selectively controlling the flow rate of a fluid over a continuous range of flow rates is provided. In particular, a flow rate control device including an inflatable flow restrictor is provided, where the flow restrictor is selectively inflatable to occlude a flow path of a fluid to thereby control the flow rate of the fluid. A flow rate control mechanism comprising a flow restrictor also is provided, the flow restrictor having an inflatable balloon for occluding a flow path of a fluid to selectively control the flow rate of the fluid.