Infusion pump cassette and cassette interface configured to assist cassette removal

A cassette apparatus for an infusion pump includes a cassette for operatively connecting administration set tubing to the infusion pump and a cassette interface a cassette interface on the infusion pump for removably receiving the cassette. The cassette includes a press tab having an upwardly facing press surface and an undersurface, and the cassette interface includes at least one fulcrum member, wherein the undersurface of the press tab engages the fulcrum member(s) when the cassette is received by the cassette interface. As a result, the cassette is pivotable relative to fulcrum member(s) by pressing the press surface of the press tab to assist in removing the cassette from the cassette interface.

FIELD OF THE INVENTION

The present invention relates generally to infusion pumps for controlled delivery of liquid food and medications to patients. More specifically, the present invention relates to a removable cassette apparatus by which an administration tubing set is operatively connected to an infusion pump, wherein the cassette apparatus is configured to assist a user in removing the cassette from the pump.

BACKGROUND OF THE INVENTION

Programmable infusion pumps are used to carry out controlled delivery of liquid food for enteral feeding and medications for various purposes, for example pain management. In a common arrangement, an infusion pump receives a disposable administration set comprising a cassette removably received by the pump and flexible tubing connected to the cassette for providing a fluid delivery path through the pump.

The administration set may include a pumping segment of tubing that wraps around a rotor mechanism of the pump, and the cassette may include a pair of tubing connectors to which opposite ends of the tubing segment are connected. The rotor mechanism may have pinch rollers or fingers that deform the tubing segment as the rotor rotates to progressively urge fluid through the tubing in a peristaltic manner. The cassette may have another pair of tubing connectors for connecting inflow tubing carrying fluid from a fluid source and outflow tubing leading to a patient. As a result, a flow path is provided from the inflow tubing, through the tubing segment, to the outflow tubing.

The pump may have a cassette interface configured to provide a nesting region for receiving the cassette when it is loaded into the pump. In prior art designs, such as that shown in U.S. Pat. No. 7,070,575, the cassette interface defines a shaped recess into which the cassette fits when the cassette is loaded in the pump. As a result, some users have difficulty removing the cassette and administration set tubing from the pump after use.

What is needed is a cassette and a corresponding cassette interface that facilitate removal of the cassette and administration set tubing from the pump.

SUMMARY OF THE INVENTION

A cassette apparatus for an infusion pump is configured so that a user may load and remove the cassette quickly and easily. The cassette apparatus generally comprises a cassette for operatively connecting administration set tubing to the infusion pump, and a cassette interface on the infusion pump for removably receiving the cassette.

In accordance with the present invention, the cassette includes a press tab having an upwardly facing press surface and an undersurface, and the cassette interface includes at least one fulcrum member, wherein the undersurface of the press tab engages the at least one fulcrum member when the cassette is received by the cassette interface. As a result, the cassette is pivotable relative to the at least one fulcrum member by pressing the press surface of the press tab to assist in removing the cassette from the cassette interface.

In one embodiment of the invention, the cassette includes a vertical rib extending downwardly from the undersurface of the press tab, and the cassette interface includes a pair of fulcrum members laterally spaced from one another to define a slot therebetween. When the cassette is loaded, the vertical rib of the cassette is received in the slot of the cassette interface between the pair of fulcrum members, and the undersurface of the press tab engages each of the pair of fulcrum members, such that the cassette is pivotable relative to the pair of fulcrum members by pressing the press surface of the press tab.

The cassette may also include an inflow tubing connector, an outflow tubing connector, an upstream pumping segment connector in flow communication with the inflow tubing connector, and a downstream pumping segment connector in flow communication with the outflow tubing connector. The downstream pumping segment connector may include an in-line occluder for restricting flow through the downstream pumping segment connector.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1shows an infusion pump10in which an administration set12is removably received. Administration set12includes a cassette14, which is shown by itself inFIGS. 2 and 3. Cassette14may include an inflow connector16, an upstream pumping segment connector18in flow communication with inflow connector16, a downstream pumping segment connector20, and an outflow connector22in flow communication with downstream pumping segment connector20. Administration set12may further include inflow tubing24having one end mated to inflow connector16and an opposite end (not shown) connected to a fluid source, and outflow tubing26having one end connected to outflow connector22and an opposite end (not shown) connected to a patient. Finally, administration set14may further include a pumping segment of tubing28having one end mated to upstream pumping segment connector18and an opposite end mated to downstream pumping segment connector20.

In the illustrated embodiment, pump10is a rotary peristaltic pump having a rotor30, wherein pumping segment28is wrapped around rotor30and is engaged by angularly spaced rollers on rotor30as the rotor rotates to provide peristaltic pumping action forcing liquid through the tubing of administration set12. As may be understood by reference toFIG. 1, when rotor30rotates in a counter-clockwise direction, liquid is moved from inflow tubing24through inflow connector16and upstream pumping segment connector18to pumping segment28, and then from pumping segment28through downstream pumping segment connector20and outflow connector22to outflow tubing26. Although the present invention is described in the context of a rotary peristaltic pump, the invention is not limited to this type of infusion pump. The invention may be practiced with any type of infusion pump that receives an administration set having a cassette.

Cassette14also includes a press tab32having an upwardly facing press surface32A and an undersurface32B. Cassette14may further include a vertical rib34extending downwardly from undersurface32B. In a particular embodiment, cassette14may include an in-line occluder36which may be incorporated into downstream pumping segment connector20. In-line occluder36prevents flow when pump door38is open. An actuator39on an underside of pump door38engages pumping segment28in a manner which opens a flow path around occluder36when door38is closed.

As seen inFIG. 1, infusion pump10includes a cassette interface40for removably receiving cassette14.FIG. 4shows cassette interface40without a loaded administration set. In the illustrated embodiment, cassette interface40includes a pair of fulcrum members42laterally spaced from one another to define a slot44therebetween. Fulcrum members42extend upward from a base surface46of the cassette interface. Cassette14and cassette interface40may be formed of molded plastic.

As may be understood fromFIGS. 1, 5 and 6, when cassette14is received by cassette interface40, the vertical rib34of cassette14is received in slot44of cassette interface40and the undersurface32B of press tab32engages a top portion of each of the pair of fulcrum members42. As shown in the drawings, the undersurface32B of press tab32may be convexly curved in a downward direction and the pair of fulcrum members42may be convexly curved in an upward direction. Vertical rib34of cassette14may be in a central plane of the cassette between the upstream pumping segment connector18and the downstream pumping segment connector20, whereby insertion of rib34into slot44centers the cassette with respect to the rotational axis of rotor30.

FIGS. 5 and 6illustrate an initial step according to the present invention that facilitates removal of cassette14from cassette interface40of infusion pump10(tubing of administration set12is omitted inFIG. 5for clarity). InFIG. 5, cassette14is shown in its loaded or installed state, nested in the cassette interface40. As will be understood fromFIG. 6, cassette14is pivotable relative to fulcrum members42by pressing the press surface32A of press tab32. This action assists a user in removing cassette14from cassette interface40by lifting inflow connector16and outflow connector22away from base surface46of cassette interface40.

One skilled in the art will recognize that modifications to the depicted embodiment are possible without straying from the invention. For example, press tab may be flat instead of curved, and vertical rib34may have an inclined outer edge that is straight instead of curved. Other modifications are also possible. Instead of a pair of fulcrum members42, only a single, centrally located fulcrum member may be provided as part of cassette interface40. Under such a modification, cassette14may be provided with a pair of laterally-spaced vertical ribs34arranged to straddle the single fulcrum member. As another alternative, the undersurface32B of press tab32may include a recess contoured to pivotally receive a top surface of the single fulcrum member. As yet another alternative, the top of the single fulcrum member may include a laterally extending grooved for receiving a rounded, laterally extending rib on undersurface32B in the manner of a hinge.

While the invention has been described in connection with exemplary embodiments, the detailed description is not intended to limit the scope of the invention to the particular forms set forth. The invention is intended to cover such alternatives, modifications and equivalents of the described embodiment as may be included within the scope of the invention.