Disposable fluid infusion pumping chamber cassette and drive mechanism thereof

The pump cassette (10) is adapted to be driven by a pump driver having a plunger and valve actuators and comprises a cassette inlet (64), a cassette outlet, and a fluid path therebetween. The cassette (10) has a rigid back member (14) having a recess forming a pumping chamber along the fluid path, a rigid face member (12) having a plunger opening therethrough opposite the pumping chamber to permit passage of the plunger and valve actuator openings to permit valve actuators to control the flow of fluid through the fluid chamber and an elastomeric member (16) positioned between the face and back members (12, 14). Air detection means project from the face member (12) to detect the presence of air in the cassette (10).