A peristaltic pump drives fluid forward based on peristalsis. Peristalsis is originally a physiological term depicting the involuntary constriction and relaxation of the muscles of the intestine or another canal, which creates wave-like movements pushing the contents in the canal forward. Similarly, peristalsis associated with a peristaltic pump is passively generated in a flexible hose by rotating rollers along the hose. This procedure creates alternating compression and relaxation of the hose, propelling fluid forward and drawing fluid in, respectively.

A peristaltic pump rotor drives shoes or rollers to pass along a hose thus creating a positive displacement fluid with the temporary seal between the suction and discharge sides of the hose. The movement of shoes or rollers generates a positive pressure forcing fluid to flow into the discharge hose side; simultaneously, the hose relaxation due to the hose elasticity results in a negative pressure drawing fluid into the suction side of the hose. To maintain a continuous flow while preventing back flow, at least two rollers located at 180 degrees apart are usually required to alternately rotate along the inside of an arc track in which a hose sits. Three or more rollers uniformly distributed may generate more stable flows.