US Patent 7591639 Peristaltic pump

A peristaltic pump includes a plurality of occlusion surfaces and a plurality of rotors. The plurality of occlusion surfaces include a first occlusion surface and a second occlusion surface. The plurality of rotors includes a first rotor configured to be rotated about an axis and carrying a first set of occluding surfaces and a second rotor configured to be rotated about the axis and carrying a second set of occluding surfaces. The first set of occluding surfaces and the second set of occluding surfaces have a staggered pitch.