A medical fluid infusion system includes a peristaltic pump system configured to deliver a fluid drug to a patient. The peristaltic pump system can include a peristaltic pump in communication with a pressure source. In some embodiments, the peristaltic pump system can include a valve body positioned between the peristaltic pump and pressure source for controlling the delivery of pressurized fluid (e.g., air, liquid) to the peristaltic pump. The peristaltic pump can include more than one occluder, with each occluder having a flexible member that can form a collapsed and extended configuration based on a pressure provided to the flexible member.