Patent ID: 9506457
Filing Date: 2016-11-29
CPC Classification: A61M,F04B

Claim Text:
1. A fluid pump apparatus comprising: a housing configured to accept a disposable portion having an internal cavity with an input port and an output port, a movable wall having a variable position that includes a first position at which the internal cavity has a first volume and a second position at which the internal cavity has a second volume, and a planar magneto-sensitive element coupled to the movable wall and oriented perpendicular to a direction of motion between the first and second positions at all positions of the movable wall between the first and second positions; a stopping element disposed in the housing and configured to prevent a volume of the internal cavity formed by the movable wall from reducing below the second volume; a position sensor coupled to the housing and configured to detect the position of the movable wall and provide a position signal; a first actuator and a second actuator coupled to the housing and positioned within the housing such that the magneto-sensitive element is disposed between the first and second actuators when the disposable portion is accepted, wherein the first actuator is configured to selectably create a first magnetic field to attract the magneto-sensitive element so as to draw the movable wall toward the first position and the second actuator is configured to selectably create a second magnetic field to attract the magneto-sensitive element so as to draw the movable wall toward the second position; and a controller communicatively coupled to the position sensor and the first and second actuators, the controller configured to receive the position signal and cause the first actuator to attract the magneto-sensitive element until the movable wall reaches the first position during an input cycle lasting for a first period of time, and then cause the second actuator to attract the magneto-sensitive element until the movable wall reaches the second position during an output cycle lasting for a second period of time, wherein the second period of time is longer than the first period of time to provide a laminar fluid flow downstream from the output port.