Pump cassettes, infusion systems, and methods are described. An example pump cassette may include a rigid body comprising a frame portion, a base portion, a compliant membrane disposed substantially therebetween, and two opposing longitudinal edge sections. The rigid body may include a controllable fluid pathway defined in part by the compliant membrane and extending from an inlet port to an outlet port. The pump cassette may include a slider coupled to the two opposing longitudinal edge sections and longitudinally articulable with respect to the rigid body.
