Patent ID: 9163623
Filing Date: 2015-10-20
Classification: A61M,F04B

Abstract:
1. A pumping mechanism comprising: a plurality of peristaltic pumping actuators configured to sequentially compress adjacent sections of a first portion of an at least partially compressible pumping element having an inlet and an outlet that is downstream of the inlet, the plurality of pumping actuators further configured to reciprocate with a motion comprising a fundamental drive frequency, wherein a last pumping actuator of the plurality of pumping actuators is nearest to the outlet; at least one compensation actuator arranged to selectively compress a second portion of the at least partially compressible pumping element that is disposed between the first portion and the outlet of the at least partially compressible pumping element, the at least one compensation actuator configured to reciprocate with a motion comprising the fundamental drive frequency at a phase shift relative to the last pumping actuator; a drive shaft; a plurality of pumping cams fixedly coupled to the drive shaft, the plurality of pumping cams configured to respectively cause the plurality of pumping actuators to reciprocate; and at least one compensation cam fixedly coupled to the drive shaft, the at least one compensation cam configured to respectively cause the at least one compensation actuator to reciprocate, wherein the drive shaft rotates at an angular rate that varies over a 360° rotation, wherein the fundamental drive frequency is determined by the inverse of a time period required for the drive shaft to complete one 360° rotation, and wherein the angular rate of the drive shaft which varies comprises one or more integer harmonics of the fundamental drive frequency.