Fluid infusion pump driver
First Claim
1. An infusion pump driver for pumping liquid from a cassette adapted to be selectively engaged with said driver and having a pumping chamber therein with an exposed wall thereof being formed by a flexible diaphragm, said driver comprising a frame structure, a motor mounted to said frame structure and including a drive shaft, a plunger adapted to engage said diaphragm for pumping liquid from the cassette pumping chamber, said plunger having an axially extending shaft, means for securing the plunger to said frame structure so as to permit movement thereof generally along the axis of the plunger shaft but preventing rotational movement thereof about said shaft axis, and means for coupling the plunger shaft to the drive shaft, said last named means providing a threaded connection between the drive shaft and the plunger shaft wherein rotation of the drive shaft results in movement of the plunger generally along the plunger shaft axis and including a universal joint for permitting relative pivotal movement between said plunger shaft axis and the axis of the drive shaft.
2 Assignments
0 Petitions
Accused Products
Abstract
A fluid infusion pump driver device for pumping fluid from the chamber of a disposable cassette. The pump driver includes a reciprocatable plunger which is driven by a stepping motor. The motor and plunger are coupled through a universal joint which provides a threaded connection translating the incremental angular movements of the motor into incremental linear movements of the plunger, and the plunger is coupled directly to the frame through a flexible leaf spring to prevent wear in the threaded connection from generating undue noise or creating accuracy problems.
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Citations
14 Claims
- 1. An infusion pump driver for pumping liquid from a cassette adapted to be selectively engaged with said driver and having a pumping chamber therein with an exposed wall thereof being formed by a flexible diaphragm, said driver comprising a frame structure, a motor mounted to said frame structure and including a drive shaft, a plunger adapted to engage said diaphragm for pumping liquid from the cassette pumping chamber, said plunger having an axially extending shaft, means for securing the plunger to said frame structure so as to permit movement thereof generally along the axis of the plunger shaft but preventing rotational movement thereof about said shaft axis, and means for coupling the plunger shaft to the drive shaft, said last named means providing a threaded connection between the drive shaft and the plunger shaft wherein rotation of the drive shaft results in movement of the plunger generally along the plunger shaft axis and including a universal joint for permitting relative pivotal movement between said plunger shaft axis and the axis of the drive shaft.
- 8. In an infusion pump drivr for pumping liquid from a cassette adapted to be selectively engaged with said driver and having a pumping chamber therein with an exposed wall thereof being formed by a flexible diaphragm, said driver comprising a frame structure, a motor mounted to said frame structure and including a drive shaft, the improvement comprising a plunger adapted to engage said diaphragm for pumping liquid from the cassette pumping chamber, said plunger having an axially extending shaft, means for securing the plunger to said frame structure so as to permit movement thereof generally along the axis of the plunger shaft but preventing rotational movement thereof about said shaft axis, and means for coupling the plunger shaft to the drive shaft, said last named means providing a threaded connection between the drive shaft and the plunger shaft wherein rotation of the drive shaft results in movement of the plunger generally along the plunger shaft axis and including a universal joint for permitting relative pivotal movement between said plunger shaft axis and the axis of the drive shaft.
Specification