Patent ID: 9533093
Date: 2017-01-03
CPC Classifications: A61M

Claim:
1. A mobile medical pump comprising: a tubular cartridge unit comprising a first end having an interface to an infusion line and a second, open end having a first engagement interface, with a piston inserted in the cartridge and engaging an inner diameter of the cartridge, such that translation of the piston within the cartridge will draw in or expel liquid to or from the cartridge, wherein the piston comprises an embedded steel plate oriented such that a surface of the plate is orthogonal to a longitudinal axis of the cartridge and an opening leading to and exposing the steel plate; a case housing having an opening for inserting the cartridge within the case and an internal second engagement interface at a depth that, with the cartridge fully inserted and the first and second engagement interfaces joined, an infusion line may be connected to the first end external to the case; and a piston rod within the case housing, the piston rod having a permanent magnet at a first end with a planar surface orthogonal to a longitudinal axis of the piston rod, and a threaded opening at an opposite end engaging a rotatable translation screw driven by a translation drive system including an electric motor; characterized in that, with the piston rod set at a preprogrammed position corresponding to a volume of liquid charged in the cartridge, inserting the cartridge charged with the volume of liquid into the case to engage the first and second engagement interfaces causes the magnet end of the piston rod to be held within the opening of the piston and to securely contact the steel plate embedded in the piston, such that translation of the piston rod by the translation drive system will expel liquid from the cartridge, and holding the piston rod motionless will hold the piston motionless, preventing any discharge of liquid from the cartridge; and wherein the piston rod further comprises a mechanism to prevent the piston rod from rotating in the case housing while the rotatable translation screw rotates, wherein the mechanism to prevent the piston rod from rotating comprises: