Patent ID: 8382460

Claim:
A pump comprising: a) a flexible tube, wherein said pump is configured to provide an output constriction of said flexible tube, wherein said output constriction is at a fixed output location on said flexible tube during operation of said pump; b) a pump body; c) a pump member, wherein said pump member is moveable relative to said pump body; wherein said pump member is capable of moving to at least a refill position, a seal position, and an expel position, all relative to said pump body; wherein said pump member and pump body at said seal position and at said expel position form an input constriction of said flexible tube at a fixed input location, wherein said input constriction impedes flow through said flexible tube more than said output constriction; wherein part or all of said flexible tube between said input constriction and said output constriction defines a pump chamber having a pump chamber volume; wherein said pump member and pump body at said expel position cause said pump chamber volume to be substantially less than said pump chamber volume when said pump member and pump body are at said seal position; and wherein said pump member and pump body at said refill position allow flow through said flexible tube past said fixed input location.