Infusion pump latch mechanism and associated free-flow protection device
An infusion pump apparatus includes a length of resilient tubing removably loadable in an infusion pump having a housing, a pumping mechanism, and a pump door. A latch member is pivotally mounted to the pump door and cooperates with a latch pin fixed on pump housing. A free-flow protection device is biased to pinch the tubing closed to stop fluid flow. The latch member has a first range of pivotal motion in a latching direction for causing the latch member to engage with the latch pin to secure the door in a closed position and a second range of pivotal motion in the latching direction for causing the latch member to actuate the free-flow protection device to unpinch the tubing and allow flow. The latch member pivots through at least a portion of the first range of pivotal motion before beginning to pivot through the second range of pivotal motion.
1. A free-flow protection device comprising:
a body defining a tubing guideway and a plunger channel intersecting the tubing guideway;
a plunger slidably received by the plunger channel, the plunger defining a tubing passageway through the plunger, the plunger being movable relative to the body to vary a degree of alignment between the tubing passageway and the tubing guideway;
a spring biasing the plunger in a direction reducing the degree of alignment between the tubing passageway and the tubing guideway;
wherein the plunger includes a curved actuating surface protruding from the plunger channel;
wherein the tubing passageway of the plunger extends along a first axis, and the curved actuating surface includes an arc segment profile residing in a plane which is normal to a second axis;
wherein the second axis is orthogonal to the first axis; and
wherein the second axis is orthogonal to the direction in which the plunger is biased by the spring.
2. An administration set comprising:
a free-flow protection device including (i) a body defining a tubing guideway and a plunger channel intersecting the tubing guideway, (ii) a plunger defining a tubing passageway through the plunger, wherein the plunger is slidably received by the plunger channel and is movable relative to the body to vary a degree of alignment between the tubing passageway and the tubing guideway, and (iii) a spring biasing the plunger in a direction reducing the degree of alignment between the tubing passageway and the tubing guideway; and
a length of resilient tubing extending through the tubing guideway and the tubing passageway;
wherein the plunger includes a curved actuating surface protruding from the plunger channel;
wherein the tubing passageway of the plunger extends along a first axis, and the curved actuating surface includes an arc segment profile residing in a plane which is normal to a second axis;
wherein the second axis is orthogonal to the first axis; and
wherein the second axis is orthogonal to the direction in which the plunger is biased by the spring.
3. The administration set according to claim 2 , wherein the body of the free-flow protection device is attached to the length of resilient tubing.