Discriminating fluid connection system

A discriminating connector system for medical use. The connector system includes a male connector and a female connector. A standoff of the male connector forms a sealed, fluid connection with a receptacle of the female connector for fluid flow between conduits connected to the male and female connectors. The construction of the connector system prevents connection of either the male or female connector to other non-conforming connectors or syringes commonly found in medical environments, such as male and female luer-lock connectors and syringes.

FIELD OF INVENTION

The present invention generally relates to fluid connection systems and more particularly to a discriminating fluid connection system.

BACKGROUND OF THE INVENTION

Tubing and catheter misconnections are a serious problem in hospitals. One type of tube and catheter misconnection error involves enteral feeding tubes and intravenous catheters. Enteral feeding tubes are used to administer liquid nutritional solutions and medications directly to a patient's gastrointestinal system. In contrast, intravenous catheters are used to administer medications and the like directly to a patient's vascular system. Patients may be harmed if feeding solutions are administered intravenously and vice versa. Errors such as this occur because of medical professionals using similar or identical tubing for different purposes. For example, luer tips, including luer-lock components, contribute to many of these errors because they enable functionally dissimilar tubes or catheters to be connected. In other words, a luer tip may be inserted improperly into a connector or adaptor of a feeding tube, with potentially harmful results.

SUMMARY OF THE INVENTION

In one aspect of the present invention, a connection system for forming a sealed fluid connection generally comprises a first connector that comprises a floor and an annular wall extending from the floor. The first connector also comprises a standoff projecting from the floor within the annular wall and disposed for blocking nonconforming connectors from entering into fluid connection with the annular wall of the first connector. The first connector also comprises at least one opening in at least one of the standoff and the floor. The system also comprises a second connector that comprises a floor and an annular wall adapted to form a sealed fit connection with the annular wall of the first connector to provide a fluid tight passage between the first and second connectors. The second connector also comprises a receptacle projecting from the floor of the second connector to receive the standoff of the first connector and to permit the annular wall of the first connector to come into sealing engagement with the annular wall of the second connector to form the fluid tight passage. At least one opening in the floor of the second connector is disposed radially outward from the receptacle.

In another aspect of the present invention, a discriminating connector for use in inhibiting incorrect fluid connections in a medical environment generally comprises a floor and an annular wall extending from the floor. The connector also comprises a discriminating structure projecting from the floor within the annular wall and disposed for blocking nonconforming connectors from entering into fluid connection with the annular wall of the connector. The connector also comprises at least one opening in at least one of the discriminating structure and the floor to permit passage of fluid through the connector around the discriminating structure.

In yet another aspect of the present invention, a connection system for forming a sealed connection between a first conduit and a second conduit generally comprises a first connector adapted for connection to the first conduit. The first connector defines a passage having an axis and a first surface having a plane with a first angular orientation with respect to said axis. The first surface comprises one or more subsurfaces, each subsurface having a plane with a different angular orientation to said axis than the first angular orientation. The system also comprises a tip connector continuous with the second conduit and comprising a second surface that is shaped to be complementary to the first surface.

In yet another aspect of the present invention, a connector system for forming a sealed connection between fluid delivery lines. The connector system comprises a first connector having a longitudinal axis and a connection surface having a fluid opening therein. The connection surface is arranged at an angle to the longitudinal axis of the first connector. The system also comprises a second connector having a longitudinal axis and a connection surface having a fluid opening therein. The connection surface of the second connector is arranged at an angle to the longitudinal axis of the second connector. The connection surface of the second connector is arranged to be complementary to the connection surface of the first connector. Upon connection of the first connector with the second connector, the connection surfaces are in face to face position with the fluid openings of the first and second connectors in general alignment for passage of fluid through the fluid openings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring toFIGS. 1-3, a discriminating connection system according to this invention is designated generally by the reference10. In general, system10comprises a male threaded locking connector18coupled to a first conduit28, and a female threaded locking connector14coupled to a second conduit22. More specifically, and as best illustrated inFIG. 3, a standoff34of the connector18includes external threads that thread into a threaded receptacle38of the female connector14to form a sealed, fluid connection. The standoff34and the receptacle38may be broadly considered to be a ‘discriminating structure’. As will be discussed later, the construction of the male connector18prevents connection to other non-conforming connectors or syringes commonly found in medical environments, such as male and female luer-lock connectors and syringes. Similarly, female connector14cannot be connected to a wide range of common, non-conforming connectors and syringes. System10is configured, when the male connector18and the female connector14are connected, to permit fluid communication between conduits22and28in an interior space42surrounding the locking mechanism formed by the standoff34and the receptacle38.

As illustrated inFIGS. 3-4, the male connector18includes a generally frustoconical outer annular wall46, preferably formed with a tapered exterior surface54for purposes of custom fit with the female connector14. Other forms of the annular wall46, as well as variations in the extent of taper of the surface54, are within the scope of the invention. The threaded, concentric standoff34enclosed within the outer annular wall46extends from a floor50of the outer member. Though preferably of circular cross section, any suitable thread configuration (form, handedness, thread angle, pitch, etc.) or other type of connection such as a bayonet style connection may be chosen. Moreover, there may be no locking connection between the standoff34and the receptacle38. The floor50provides fluid communication between the interior space42and the conduit28via an arrangement of two openings72formed on the floor, as best seen inFIG. 4. Openings72are disposed radially outward from the standoff34. Variations in numbers, design and layout of openings72are within the scope of the invention.

As illustrated inFIGS. 3 and 5, the female connector14includes a generally cylindrical outer annular wall60. The annular wall60is preferably formed with a tapering interior surface64that receives the tapered outer surface54of the frustoconical annular wall46of the male connector18to form a sealed connection and define an interior space42. The receptacle38extends from a base68of the female connector14. In a preferred embodiment, an inner surface of the receptacle38is threaded and sized, complementary to the threading on standoff34, to thread onto the standoff34of the connector18. As illustrated inFIG. 5, two openings76formed on the base68of the female connector14provide fluid communication between the interior space42and the conduit22. Openings76are formed radially outward of the receptacle38. Variations in numbers, design and layout of openings76are within the scope of the invention. In this embodiment, connector system10provides separate sealing (tapering surfaces54,64) and locking mechanisms (standoff34, projection38).

Conduits22,28may be of any suitable form, preferably for medical use. By way of example and not limitation, conduits22,28are associated with enteral feeding sets and/or devices, and the system10is used for enteral delivery of medication or nutritional fluids while preventing connectivity with common connectors used for other delivery routes, such as luer lock/slip syringes for intravenous delivery.

Conduits22,28are connected to the female14and male connector18respectively by any suitable sealing means. Preferably, connectors14,18have strain reliefs20a,20brespectively formed thereon for connecting and sealing the respective conduits (seeFIGS. 1-3). Advantageously, strain reliefs20a,20ballow conduits22,28respectively to flex without breaking away or detaching from the respective connectors14,18. In the illustrated embodiment, strain reliefs20a,20bare a series of interconnected ridges formed where each conduit meets its respective connector. Other designs of strain relief20a,20bare within the scope of the invention. In an embodiment, a tethered cap (not shown) may be formed on each strain relief20a,20bfor closing off the respective connector during non-use. Each tethered cap may be integrally formed or molded with its respective strain relief. Alternatively, the tethered cap may be formed on the connector itself.

Strain reliefs20a,20bare formed of any suitable flexible material. In contrast, connectors14,18are preferably rigid and not flexible or conformable, thereby preventing forced accommodation of non-conforming connectors. This permits the connectors to form a tapering, interference fit of a sealing nature as described below.

FIG. 6illustrates fluid flow through the mated female and male connectors14,18. To mate the connectors, they are pushed together to bring standoff34into the receptacle38. One or both of the connectors14,18are rotated to engage the threads of the standoff34and receptacle38and to draw the annular walls60,46into sealing engagement. In a typical medical application, fluid flows from the feeding set via a source line22, through openings76of the female connector14and into the interior space42. Flow continues through openings72of the connector18and into a delivery line28for delivery to the patient. By virtue of positioning of openings72and76, the fluid flows around the centrally located standoff34and receptacle38.

FIG. 7illustrates how connections of either the male connector18or the female connector14discriminate non-conforming connectors and in particular luer-type connectors.FIG. 7Ashows a failed connection between the female connector14and a male luer-lock syringe80. The luer tip engages but cannot enter the receptacle38, so that connection is not achieved.FIG. 7Bshows a failed connection between the male connector18and the male luer-lock syringe80. This time, the standoff34engages the luer tip of the syringe80, preventing mating.FIGS. 7C and 7Dshow how a female luer connector84abuts the receptacle38and the annular wall46, and is unable to connect to the female connector14or the male connector18, respectively.FIGS. 7E and 7Fillustrate a mismatch between the female connector14and a stepped connector86having a luer tip and between the male connector18and the stepped connector, respectively.

In another embodiment of a connection system100shown (as separate components) inFIG. 8, the floor of the connector118is modified to provide a web-like structure190for holding the threaded standoff134in place. The base of the female connector114is similarly modified with a web-like structure194to hold threaded receptacle138in place. A fluid path198is then formed upon sealed connection between connectors114and118.

In yet another embodiment (seeFIG. 9), the locking mechanism of the connection system210is a tapered-locking mechanism. Male connector218has an unthreaded tapered standoff234, generally conical, that forms a sliding interference fit with an unthreaded and tapered receptacle238of the female connector214. The other components of the tapered-locking connection system may or may not be similar to that of the threaded-locking connection system.

In yet another embodiment conceptually illustrated inFIG. 10, male connector218has a tapered, cross-shaped standoff234b, instead of the solid standoff234. Openings236are formed on the floor240within the footprint of the cross-shaped standoff234b. Standoff234bis sized to provide a sliding interference fit with receptacle238(FIG. 9B) without the receptacle touching the floor240, thereby preventing blockage of openings236. Other variations of the shape of standoff234bthat permit access to openings236when in a sealed configuration are within the scope of the invention.

The conduits22and28, male connector18and female connector14are formed of generally biocompatible and non-reactive materials. The conduits22,28are preferably flexible medical tubing, while male connector18and female connector14are preferably semi-rigid and formed of suitable materials. Different materials may be used to form the locking mechanism and the sealing mechanism, providing some freedom of selecting design, rigidity, etc.

FIGS. 11-13illustrate still another embodiment of a connector system310for enteral delivery that incorporates anti-luer, discriminating connector concepts of the invention. A female connector314has a passage376that mates with a tip322of a syringe318. The female connector314also has a sculpted mating surface326that mates with a complementary sculpted surface330surrounding the tip322. Desirably, and as illustrated, the plane of the surface326is angled with respect to an axis AX of passage376. Angle θ1is generally obtuse, and desirably selected to provide non-conformance with luer-lock and luer-slip syringes. Surface326may include variations in plane, such as subsurfaces333and335, to require custom connectors for proper fit. Accordingly, surface330is shaped to complement surface326for proper fit as best illustrated inFIGS. 12A and 12B. The sculpted shapes warn the user that standard syringes and connectors should not be used.

In another embodiment illustrated inFIGS. 14-16, a connector system410comprises a port418and a syringe414. Port418has a generally rectangular opening462in a projecting part463at the end of the port. The opening462allows for passage of fluid into or out of the port418. Shapes of the port opening462other than rectangular are within the scope of the invention. Projecting part463has a surface that is preferably angled away from the axis of the port418. This angle θ2may be selected such that a standard luer-type syringe would need to be presented in an angular fashion to access the opening462, although the opening is not sized or shaped to receive a luer tip. Port418further comprises an annular port wall466defining a receptacle467for receiving and sealing with the syringe414. Port wall466also restricts access to the opening462in a manner that prevents angular insertion of luer-type syringes as described above. Port wall466tapers towards its free edge. A recess470is cut into the port wall466, the use of which is described hereinafter.

The syringe414has an end that is shaped in a manner complementary to that of the port418. The syringe414is broadly ‘a connector’. The end of the syringe414is radially inset for being received in the receptacle467of the port418. The end has a semicircular recess474sized and shaped to receive the projecting part463of the port414. An opening475in an angled wall in the recess474is aligned with the opening462in the projecting part463when the port418and syringe414are connected for fluid communication. A bump482on the end of the syringe414snaps into the recess470on the port418for secure, temporary connection and sealing (seeFIG. 14B).

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained. The invention significantly reduces the risk of using erroneous (especially intravenous) routes of administration, as none of the components of the connector systems of the invention are compatible with luer-lock or luer-slip syringes.