US20080303267A1

US20080303267A1 - Fluid flow connector permitting forceful lateral separation

Info

Publication number: US20080303267A1
Application number: US11/810,427
Authority: US
Inventors: William J. Schnell; David S. Utterberg
Original assignee: Individual
Current assignee: NxStage Medical Inc
Priority date: 2007-06-05
Filing date: 2007-06-05
Publication date: 2008-12-11
Also published as: WO2008150781A1

Abstract

A fluid flow connector comprises a connector body which carries a first connector tube having a lumen for receiving a second connector tube when the connectors are joined. The first connector tube has a lumen and a lumen wall. The first connector tube typically has an end portion that carries a plurality of circumferentially spaced, outerwardly extending lugs to engage the second connector tube when connected. The fluid flow connector is made of a plastic having a flexural modulus that is low enough to allow deformation, permitting a connected, engaging second connector to pop loose from connection with the fluid flow connector when laterally struck, rather than breaking the fluid flow connector. Also, the first, fluid flow connector may optionally be frictionally retained in a retracted position where fluid flow is blocked through the connectors by a skirt of the second connector, which skirt has an inner diameter in frictional engagement with radially outer surfaces of the lugs of the first connector, for frictional retention of the connectors.

Description

BACKGROUND OF THE INVENTION

Extracorporeal blood sets are used for conveying blood from a patient to an extracorporeal blood treatment device, such as a dialyzer. These blood sets conventionally contain various components for obtaining access to an intermediate portion of the blood set, such as an injection site access port, a Y connector access port, or the like. Also, an access port may be carried on a flow-through chamber positioned in the set between the ends thereof. Such a chamber may be a pressure chamber having rigid walls for pressure measurement, and may carry a fluid flow connector access site, for example a needleless access site of a known type, such as a needleless access site of the type disclosed in U.S. Pat. No. 7,025,744.
This access site may be connected with a syringe, or a tube set having a luer or luer lock connector, for the administration of parenteral solution or other medicament, or for venting air, or for administration of blood, or the like.
During use, for example in a hemodialysis procedure, a needleless access site or the like may be carried on a rigid chamber in the dialysis set. A syringe containing heparin or the like may be carried during the procedure in the needleless access site. If the syringe is somehow accidentally, laterally struck, a great deal of torque is exerted on the needleless access site, with the syringe acting as a lever arm. Conventional needle access sites may break off in such a circumstance, if the rigid chamber that carries them is firmly held in an immovable position. This, of course, is a serious problem, requiring immediate action and causing great inconvenience and possibly loss of blood.
By this invention, a fluid flow connector, which may be a needleless access site, is provided in which a sharp, lateral blow to a second connector or the like which is laterally connected to the fluid flow connector is not likely to cause breakage. Rather, the fluid flow connector is designed so that the second connector will pop out of connection with the fluid flow connector when it is struck with a severe, lateral blow, which might otherwise cause breakage. This may be of much less serious consequence, and is more easily corrected than the situation where the fluid flow connector is actually broken, which generally requires termination of the extracorporeal blood flow procedure, replacement of the set, breach of sterility, and repriming.
Furthermore, by this invention, the fluid flow connector which is provided can be of a proportion allowing swabbing with an antiseptic such as isopropyl alcohol prior to use, particularly when comprising a tubular access site and connector which contains an internal, perforated sealing diaphragm which may be opened by a male luer or other tubular connector member. This may be accomplished in part by typically enlarging the inner diameter of the fluid flow connector, above and beyond typical connectors that conform to ANSI specifications.

DESCRIPTION OF THE INVENTION

By this invention, a first fluid flow connector comprises: a connector body which carries a first connector tube having a lumen for receiving a second connector tube of a second connector when said connectors are joined. The first connector tube may have a lumen and a lumen wall, for example of angled cone shape, in at least a major outer portion thereof, to the longitudinal axis of the first connector. The first connector tube carries a plurality of circumferentially spaced, outwardly extending lugs, to engage inwardly extending threads or lugs of the second connector tube when connected.
The first fluid flow connector may be made of a plastic which has a dimensions (especially thickness) and a flexural modulus that is low enough to allow deformation, permitting a connected, engaging second connector to pop loose from connection with the fluid flow connector when laterally struck, rather than breaking the first fluid flow connector.
The lugs of the first connector tube may comprise interrupted screw threads that occupy a spiral section, or they may comprise lugs that occupy essentially a single, longitudinal position along the length of the first connector tube. Typically, the lugs in question are diametrically opposed and extend in an arc about the connector tube ranging from essentially 40 to about 180°. In some embodiments, only a pair of said lugs are present, the lugs being substantially diametrically opposed to each other.
In some embodiments, the first fluid flow connector described above may be connected to the second connector, with the connector tubes being together in telescoping relation but radially spaced from each other at least at an outer portion of the lumen wall, or essentially completely radially spaced from each other, to avoid substantial frictional retention between the connector tubes. Thus, without added retention, the connectors would tend to fall apart, a 360 degree gap between the connector tubes being present, in some embodiments, on the order of at least 0.1 mm.
Typically the conical lumen wall shape is at an angle of greater than three degrees to the lumen axis, thus providing lateral movability or rotatability to the engaging first and second connector tubes.
Alternatively, the second connector tube may define an outer wall of lesser angle to the longitudinal axis of the first connector than the angle of the first lumen wall major outer portion described above. In this embodiment, a zone of contact between the first connector tube and the second connector tube may be present as a relatively short zone along the length of the respective tubes, and remaining portions of the tubes are laterally (radially) spaced.
The above embodiments allow a measure of lateral movement between the first and second connector tubes, to facilitate the popping loose of the second connector if forcefully and laterally struck.
When the fluid flow connector carries an elastomeric, slit diaphragm, in a manner similar to that disclosed in U.S. Pat. No. 7,025,744, (the disclosures of which are incorporated by reference herein), the second connector tube can effectively open the diaphragm by opening the perforation, to open flow through the connected system. Then, when the second connector tube is withdrawn again out of engagement with the perforated diaphragm, the elastomeric diaphragm reseals again to block fluid flow.
In another embodiment, the second connector tube can be completely, laterally spaced from the inner wall that defines the lumen, while positioned in the lumen so that the second connector tube is typically only in contact with the fluid flow connector by its engagement with the diaphragm, when in connected, flow permitting position.
Further by this invention, the second connector threads or lugs may be carried by a skirt that surrounds the lugs of the first connector. The skirt has an inner diameter less than the maximum diameter of the diametrically opposed lugs, to be in frictional engagement with radially outer surfaces of the lugs of the first connector, for frictional retention of said connectors together. In this circumstance, it can be possible for the fluid flow connector and the second connector to be frictionally retained in a retracted position, in which the second connector tube is spaced from the perforated diaphragm, so that fluid flow is blocked through the connectors by the perforated diaphragm, but the two connectors are held together in a retained condition.
Thus, a syringe which carries a second connector may be brought into connection with the first fluid flow connector, and advanced so that the second connector tube of the second connector penetrates and opens the diaphragm, or the second connector can be in a retracted position, but is still frictionally retained with the first fluid flow connector, with the second connector tube being spaced from the diaphragm, so that the diaphragm is closed, and flow through the system is prevented.
Thus, the syringe may be held on an extracorporeal blood flow set by an attached fluid flow connector during a procedure, with flow being closed between the syringe and the set. Then, as desired, the syringe can be advanced, and flow is opened for administration of medicament or the like, or the taking of a blood sample. Then the syringe may retract again, while remaining in retained condition.
As stated above, the first fluid flow connector may be made of plastic having a flexural modulus that is low enough to allow deformation permitting a connected, engaging second connector to pop loose from connection with the fluid flow connector when laterally struck. In some embodiments, this flexural modulus may be no more than about 370,000 psi, for example from about 250,000 to 350,000 psi, as determined by ASTM D 790. As stated, this popping away, rather than breaking of the fluid flow connector, is facilitated by the low flexural modulus as indicated for the plastic, as well as by a space defined between the first and second connector tubes permitting some lateral motion, with or without pivoting, between the first and second connector tubes when laterally struck. Also, momentary deformation of at least a portion of the first connector tube from cylindrical to a substantially oval cross section may take place upon the lateral striking, to facilitate spontaneous disconnection rather than breakage.
In some embodiments, the first connector tube may have an inner diameter of at least 5.5 mm along its entire length, less than a conventional ANSI connector. This inner diameter may vary, since, typically, the first connector tube defines at least a portion of lumen wall of angled cone shape.
In some embodiments, the first connector tube may have a length of 3.5-6 mm, which is less than a conventional ANSI connector, and which facilitates spontaneous disconnection upon lateral striking.
In some embodiments, the wall thickness of the first connector tube may be from essentially 0.6 to 1.1 mm, which is typically less than conventional-ANSI tubular connection sites, to further facilitate the above-described, spontaneous disconnection on lateral striking.
In some embodiments, the fluid flow connector of this invention may be carried on a generally rigid pressure sensing chamber, and the connector and chamber may comprise an integrally molded, single piece. If desired, a portion of the chamber may be comolded with the fluid flow connector of this invention and then attached to another chamber component. Thus, the fluid flow connector may be carried on the substantially rigid pressure sensing chamber.
Thus there is provided a medical connector which comprises: a connector body which carries a first connector tube having a lumen for receiving a second connector tube of a second connector when the connectors are joined; the medical connector having a perforated diaphragm carried by the connector body and sealingly occluding flow through the first connector tube. A locking member is provided for locking connection with a second connector having a second connector tube that enters into the lumen. The first connector tube may be made of a material and dimensions to permit deformation thereof when the first connector tube is forcefully and laterally struck, causing disconnection of the first and second connector tubes rather than breakage of the connector body or first connector tube.

DESCRIPTION OF THE DRAWINGS

In the drawings, FIG. 1 is an elevational view of two connectors, prior to connection with each other, in accordance with this invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1.

FIG. 3 is an enlarged, longitudinal sectional view of a portion of the female connector of FIGS. 1-2 that defines a conical lumen.

FIG. 4 is a perspective view of the component of FIG. 3.

FIG. 5 is a plan view of the component of FIG. 3, showing a section of the second connector skirt in connected relation.

FIG. 6 is an elevational view of the component of FIG. 3.

FIG. 7 is a longitudinal sectional view of the component of FIG. 3.

FIG. 8 is an elevational view of the respective connectors of FIGS. 1-2, shown in connected form.

FIG. 9 is a sectional view taken along line 9-9 of FIG. 8.

FIG. 10 is an enlarged view of a portion of FIG. 9, showing a fully forward, different, connected position.

FIG. 11 is a longitudinal, sectional view showing the connected system of FIG. 10, in which the male connector has been laterally struck and is in the process of popping out of connection from the female connector.

DESCRIPTION OF SPECIFIC EMBODIMENTS

Referring to the drawings, FIGS. 1-11 disclose a first embodiment of a fluid flow connector 10, which is shown to be a female connector, having a connector body comprising a forward component 12 and a rearward component 14. Between the two connector components there is a peripherally secured, elastomeric diaphragm 16, which defines a perforation 18, such as a slit which provides sealing against fluid flow at a substantially predetermined range of pressures. Sleeve 17 of forward component 12 sealingly engages annular enlargement 19 of rearward component 14 by a conventional sealing process.
Connector body component 12 carries a first connector tube 20, which has a lumen 21, defined by conical wall 22, wall 22 being of cone shape that, in some embodiments, defines an angle to the longitudinal axis 24 of connector 10 that is greater than about 3 degrees, such as 5° to 10°.
First connector tube 20 has an end portion that carries a plurality of circumferentially spaced, outwardly extending lugs 26, for engaging inwardly extending threads 28 (or lugs) of a skirt 30 of a second connector 32. Second connector 32 may comprise a conventional syringe 33 having a conventional male luer lock connector on its end. The male luer second connector tube 34 of second connector 32 may have a conventional taper that is less than the taper of conical wall 22, with respect to axis 24. Thus, when the two connectors 10, 32 are connected, as shown in FIG. 10, the lesser angle of the male luer second connector tube 34, compared with the lumen angle of conical wall 22, causes the respective connector tubes 20, 34 to be spaced from each other, as at space 36 (FIG. 10) at least at an outer portion of first connector tube 20, or tubes 20, 34 are entirely radially spaced, optionally. The respective connector tubes 20, 32 may be frictionally joined together at an inner junction area 36, if desired.
Also, it can be seen from FIG. 10 that when the connectors 10, 32 are joined together, in the fully advanced position of threaded skirt 30 and lugs 26, perforation 18 of diaphragm 16 is stretched by male luer 34 to be greatly enlarged, to connect with aperture 18 a that can be large enough to permit laminar flow from male luer second connector 34 into and through lumen 38 of connector 10.
Threads or lugs 26 of first fluid flow connector 10 are helically arranged like an interrupted screw thread, and are substantially diametrically opposed to each other. It can also be seen from FIG. 5 that the radially outer edge 39 of lugs or threads 26 defines an arc, so that ends 40 of arc 39 (FIG. 5) merge with the outer surface of first connector tube 20, while central portions of lug outer surface 38 are radially outwardly spaced from the outer surface of first connector tube 20. This shape facilitates the “pop-off” characteristic of the respective connectors 10, 32.
Second connector threads 28 are carried by skirt 30 that surrounds lugs 26 of first connector tube 20. In this embodiment, skirt 30 has an inner surface 43 between threads 28 that is in frictional engagement with radially outer surfaces of lugs 26, so that the position of the respective connectors 10, 32 may be maintained by frictional retention between lugs 26 and inner surface 43 of skirt 30, as in FIGS. 5 and 9. The radially outermost outer surface 42 of lugs 26 are slightly radially larger in diameter than the inner diameter 43 of skirt 30, typically by about 0.1 to 0.7 mm. to make this happen .
Thus, if the connectors 10, 32 are relatively withdrawn so that second connector tube 34 is no longer in contact with diaphragm 16, which diaphragm closes again to its original sealing position of FIG. 2, the two connectors may still be retained together by the frictional retention between lugs 26 and the inner surface 43 of skirt 30, as shown particularly in FIG. 9. Thus, second connector 32 and the syringe 33 that carries it may be retained in connection with connector 10, while flow is blocked through the respective connectors 10, 32 by closed diaphragm 16. Thus, the first and second connectors may be frictionally retained in a retracted position while fluid flow is blocked through the connectors. The inner diameter of skirt 30 may, for example, be about 8.0 mm, with the maximum diameter of lugs 26 being about 8.3 mm.
The plastic material of particularly forward component 12 of first connector 10 may have a flexural modulus that is low enough to allow deformation at the dimensions used, permitting a connected, engaging second connector to pop loose from first connector 10 when laterally struck rather than breaking connector 10, so that first connector tube 20 can be briefly pushed into an oval shape or the like. Specifically, a particular plastic that may be used is a poly(styrene-methylmethacrylate) such as Zylar 530 having a flexural modulus of about 285,000 psi. Also, first connector tube 20 may have an inner diameter of at least 5.5 mm along its entire length so that its inner diameter is larger than the outer diameter of second connector male luer tube 34 along their lengths in their most advanced engaging position where skirt 30 abuts upper surface 45 (FIG. 10) of forward component 12 of connector 10.
Fluid flow connector 10 may, for example, be carried on a substantially rigid, pressure sensing chamber wall 44 (FIG. 1 1) for an extracorporeal blood line or the like, with the pressure sensing chamber and connector 10 comprising an integrally molded, single piece, if desired.
First connector tube 20 also has a length of about 4.1 mm, which is less than the length of the corresponding tapered bore component of a conventional luer lock connector. This facilitates the “pop-off” characteristic of the connector of this invention, as illustrated in FIG. 11.
Also, first connector tube 20 has a wall thickness of about 0.8 mm which is thinner than typical luer lock connectors in accordance with ANSI specifications. Thus, first connector tube 20 has more flexibility because of the thinner wall than a corresponding component of a conventional female luer lock connector of ANSI specification, and also because of the material of relatively low flexural modulus from which first connector tube 20 is made. The entire connector 10 may be made of such material of limited flexural modulus as described above, or rearward connector body component 14 may be made of a different material, with forward connector body component 12, and first connector tube 20 which comprises a part thereof, being made of the plastic material described above.
In FIG. 11, the results of lateral striking of syringe 33 is shown, with connector 10 being attached to a stationary element, for example wall 44 of substantially rigid pressure sensing chamber for an extracorporeal blood line, or the like. It can be seen that, because of the increased taper of the lumen of first connector tube 20, second connector tube (male luer) 34 can easily tip to an extent, as shown. Also because of the preferred lack of frictional connection between first and second connector tubes 20, 34, the thinner wall of first connector tube 20, and the plastic material from which it is made, under lateral pressure 41, by an inadvertent striking, syringe 33 can tip and even separate without breaking first connector tube 20 or second connector 32.
Syringe 33 can be tilted even further by pressure-distortion of the lumen 21 of first connector tube 20 into an oval shape, which can serve to facilitate disengagement of threads 28 from lugs 26, further facilitating the resultant pop-off, and separation of the connection between connectors 10 and 32. Elastomeric diaphragm 16 spontaneously closes back through its original configuration, providing sealing of the system from first, female connector 10 at predetermined pressures, which typically include the operating pressures of the system.
As a further advantage, because of the lesser wall thickness of first connector tube 20, when compared with conventional luer connectors of ANSI specification, the lumen within first connector tube 20 may be wider than a conventional ANSI female luer connector, which facilitates sterilization using an antiseptic-soaked pad or the like. Similarly, second connector tube 34 may have sufficient exposure to permit swabbing with an antiseptic-soaked cotton swab, so that the system may be manually resterilized, and then reconnected in the event of an accidental separation.
The above has been offered for illustrative purposes only, and it is not intended to limit the scope of the invention of this application, which is as defined in the claims below.

Claims

1. A fluid flow connector, which comprises:

a connector body which carries a first connector tube having a lumen for receiving a second connector tube of a second connector when said connectors are joined;

said first connector tube having a lumen and a lumen wall;

said first connector tube carries a plurality of circumferentially spaced, outwardly extending lugs to engage the second connector when connected;

the first connector tube being made of a plastic having dimensions and a flexural modulus that is low enough to allow deformation, permitting a connected, engaging second connector to pop loose from connection with the fluid flow connector when laterally struck, rather than breaking the fluid flow connector.

2. The fluid flow connector of claim 1, connected to said second connector, with said connector tubes being together in telescoping relation but essentially radially spaced from each other to avoid substantial frictional retention between said connector tubes.

3. The fluid flow connector of claim 2 in which only a pair of said lugs are present, said lugs being substantially diametrically opposed to each other.

4. The fluid flow connector of claim 3 in which second connector threads are carried by a second connector skirt that surrounds the lugs of the first connector when connected, said skirt having an inner diameter that is in frictional engagement with radially outer surfaces of said lugs of the first connector, for frictional retention of said connectors.

5. The fluid flow connector of claim 4 in which the first and second connectors are frictionally retained in a retracted position in which fluid flow is blocked through the connectors by a perforated diaphragm carried within the first connector and spaced from the second connector tube.

6. The fluid flow connector of claim 1 in which said deformation comprises the momentary deformation of at least a portion of said first connector tube from cylindrical to substantially oval cross-section.

7. The fluid flow connector of claim 1 in which said plastic has a flexural modulus of no more than essentially 370,000 psi.

8. The fluid flow connector of claim 1 in which said first connector tube has an inner diameter of at least 5.5 mm along its entire length.

9. The fluid flow connector of claim 1, carried on a substantially rigid, pressure sensing chamber for an extracorporeal blood line.

10. The fluid flow connector of claim 9 in which said pressure sensing chamber and said fluid flow connector comprise an integrally molded, single piece.

11. The fluid flow connector of claim 3 in which said plastic has a flexural modulus of no more than essentially 370,000 psi.

12. The fluid flow connector of claim 11 in which said first connector tube has an inner diameter of at least 5.5 mm along its entire length.

13. The fluid flow connector of claim 1 in which said first connector tube has a length of 3.5 to 6 mm.

14. The fluid flow connector of claim 1 in which said first connector tube has a wall thickness of 0.6 to 1.1 mm.

15. The fluid flow connector of claim 1 in which the first connector tube has a conical lumen wall having an angle of greater than three degrees to the lumen axis.

16. A medical connector which comprises:

a connector body which carries a first connector tube having a lumen for receiving a second connector tube of a second connector when the connectors are joined;

said medical connector having a perforated diaphragm carried by the connector body and controlling flow through the first connector tube;

a locking member provided for locking connection with a second connector having a second connector tube that enters into the lumen;

said first connector tube being made of a material and dimensions to permit deformation thereof when the first connector tube is forcefully and laterally struck, causing disconnection of the first and second connector tubes rather than breakage of the connector body or first connector tube.

17. A fluid flow connector which comprises:

a connector body which carries a first connector tube having a lumen receiving a second connector tube of a second connector when the connectors are joined;

said first connector tube having a lumen of an inner diameter that is greater than the greatest outer diameter of the second connector tube; and a lumen wall of angled cone shape defining an angle, at least in a major outer portion thereof, to the longitudinal axis of the first connector, that is from 5 to 100;

said first connector tube being made of a plastic having a dimensions and flexural modulus that is low enough to allow deformation permitting said connected, engaging second connector tube to pop loose from connection with the fluid flow connector when laterally struck, rather than breaking the fluid flow connector.

18. The fluid flow connector of claim 17 in which said first connector tube has an end portion that carries a plurality of circumferentially spaced, outwardly extending lugs engaging inwardly extending threads or lugs of the second connector when connected, said lugs of the first connector tube being substantially diametrically opposed to each other.

19. The fluid flow connector of claim 17 said second connector defining at least a pair of connector arms having free ends with retention hooks, proportioned to snap-engage said connector body for retention of the connectors together.

20. The fluid flow connector of claim 18 in which said plastic of the first connector tube has a flexural modulus of no more than essentially 370,000 psi.

21. The fluid flow connector of claim 20 in which a perforated diaphragm is carried within said first connector to be opened by said second connector tube.

22. A fluid flow connector, which comprises:

a perforated diaphragm carried within said first connector;

said second connector carrying a skirt that surrounds the lugs of the first connector, said skirt having an inner diameter that is in frictional engagement with radially outer surfaces of said lugs of the first connector, said first and second connectors being positioned by said frictional engagement with the second connector tube within the first connector tube, with the second connector in a retracted position with the second connector tube being spaced from the perforated diaphragm, and in which fluid flow is blocked through the connectors by said perforated diaphragm, said second connector being capable of being advanced farther into said first, fluid flow connector to cause the perforated diaphragm to open said perforation, to permit fluid flow through said joined connectors.