Reciprocating pump
A pump suitable for use in a wearable medical device, such as a patch pump, comprises an axially translatable chamber with an inlet and an outlet, a piston or a diaphragm rotatably received in the chamber, a first valve between the inlet and the chamber, a second valve between the outlet and the chamber, a cam affixed to the chamber, a follower affixed to the piston and in contact with the cam for axially translating the chamber, and a biasing means acting on the chamber for applying a force on the chamber in an axial direction of the chamber to maintain such contact.
1 . A pump system for the pumping of a liquid, the pump system comprising:
an axially translatable chamber having a cam surface, an inlet valve and an outlet valve;
a diaphragm received in the chamber;
a follower coupled to the diaphragm and in contact with the cam surface for axially translating the chamber by rotation of said follower relative to said chamber; and
where said chamber is biased in an axial direction of the chamber with respect to the pump system to maintain contact between the follower and the cam surface of the chamber;
wherein said diaphragm is flexible and has an outer edge rotatably coupled to an inner surface of said chamber, and said pump system further comprises a post, said diaphragm covering an axial end of said post.
2 . The pump system according to claim 1 , wherein the inlet valve and the outlet valve comprise check valves.
3 . The pump system according to claim 1 , wherein the inlet valve and the outlet valve comprise externally controlled valves that are operated by a mechanical linkage or operated an electrical control system.
4 . The pump system according to claim 1 , wherein the inlet valve and said outlet valve comprise pinch valves.
5 . The pump system according to claim 1 , wherein the chamber is biased by a biasing member comprising a spring.
6 . The pump system according to claim 1 , wherein the cam surface is on an axial surface of the chamber.
7 . The pump system according to claim 1 , wherein said diaphragm is flexible and has an outer edge coupled to an inner radial surface of said chamber, said diaphragm forming an axial barrier of said chamber.
8 . The pump system according to claim 1 , wherein said follower extends radially outward from said post and is oriented for contacting the cam surface of the chamber.
9 . The pump system of claim 1 , wherein rotation of said follower and said post relative to said chamber moves said center portion of said diaphragm between a first configuration and a second configuration.