Roller or peristaltic pumps have many uses in the medical field. For example, roller pumps may be used in medical devices, such as automated apheresis and blood processing devices, to push fluid (e.g., blood or blood components) through flexible tubing. The operation of a roller pump is to pump fluid by positive displacement using revolving rollers that occlude the flexible tubing. Generally, roller pumps may be simply structured, generate a consistent flow, and use disposable tubing through which a fluid medium is transferred.
Roller pumps generally comprise a pump drive and a pump head. The pump drive causes rotation of the pump head to pump a fluid medium. The pump head often comprises a pump stator and a pump rotor. The pump stator may be a chamber or housing having an inner circumferential surface (or “raceway”) against which one or more tubes are compressed by the pump rotor. The pump rotor, which may be rotatable relative to the stator and raceway, may be arranged in the pump stator in such a manner that the pump rotor engages tubing loops positioned in the pump stator with one or more rollers. Upon rotation of the pump rotor by a rotating shaft that is otherwise part of the pump drive, the roller(s) may compress the tubing loop against the inner circumferential surface of the pump stator as it is rolled along the tubing. The fluid medium contained in the tubing may then be transported in a direction of the pump rotor rotation.