Pumping devices, systems including multiple pistons and methods for use with medical fluids

A system for delivery of a medical fluid to a patient, the system comprising:

• a pump system comprising a plurality of at least three chambers, each of the plurality of chambers comprising a piston slidably disposed therein, an inlet through which fluid is drawn into each of the chambers, and an outlet from which fluid is expelled from each of the chambers, the outlet of each of the plurality of chambers being in fluid connection with a common outlet channel,
• a cam shaft comprising a plurality of at least three cam lobes, each of the plurality of pistons being in operative connection with one of the plurality of cam lobes via one of a plurality of at least three cam lobe followers;
• and
• a fluid intake system in fluid connection with the inlets of the plurality of chambers, the fluid intake system comprising at least two fluid inlet ports, a control member to adjust the volumetric ratio of fluid delivered from the fluid inlet ports, and an extending channel in fluid connection with each of the at least two fluid inlet ports of the fluid intake system,
• wherein the at least two fluid inlet ports are spaced along the extending channel and the control member comprises a sealing member in sealing engagement with the extending channel, and wherein the sealing member is movable within the extending channel between the at least two fluid inlet ports to adjust the volumetric ratio of fluid delivered from the fluid inlet ports.

A system for delivery of a medical fluid to a patient, the system comprising:

• a pump system comprising:
• a plurality of at least three chambers, each of the plurality of chambers comprising an inlet through which fluid is drawn into each of the chambers and an outlet from which fluid is expelled from each of the chambers;
• a common outlet channel in fluid communication with the outlet of each of the plurality of chambers;
• and
• a plurality of at least three pistons, each of which is slidably disposed within a respective one of the plurality of chambers;
• and
• a drive system comprising:
• a cam shaft comprising a plurality of at least three cam lobes, each of the plurality of cam lobes having a profile;
• a plurality of at least three cam lobe followers, each of which is in operative connection with a respective one of the plurality of cam lobes and is adapted to be placed in operative connection with a respective one of the plurality of pistons;
• a plurality of at least three cam lifters, each having a first end and a second end wherein the first end of each of the cam lifters is in removable connection with a respective one of the plurality of at least three pistons and the second end of each of the cam lifters is connected to a respective one of the plurality of at least three cam lobe followers;
• a plurality of at least three biasing elements, each in operative connection with a respective cam lifter to retain the connected cam lobe followers in contact with the associated cam lobe during a chamber filling phase of the cam lobe profile;
• and
• a first abutment member which passes through the plurality of at least three cam lifters through respective extending slots defined in each of the cam lifters to limit rotation of each of the cam lifters about a longitudinal axis thereof, and each of the cam lifters is movable relative to the first abutment member in the direction of the longitudinal axis of the cam lifter
• wherein the profile of each of the plurality of cam lobes comprise a fluid delivery phase comprising an acceleration portion, a constant velocity portion and a deceleration portion and are adapted to provide a positive spike in calculated theoretical output of the pump system to reduce periodic variation in measured output thereof.