DEVICE INJECTION SITE FOR INFUSION

Abstract: A self-priming injection site (10) having a stopper (14) that resists dislocation or removal from the injection site. The stopper is positioned within the plastic housing between a top (30) with an open center (38) and an intermediate ledge (34) having an upturned lip (40). The stopper includes an annular groove (42) that receives the upturned lip of the intermediate ledge, to assist in holding the stopper in compression within the housing. An arm portion (54) allows the intravenous fluid to enter the injection site on a path approximately parallel to an immediately adjacent to the ledge and the bottom of the stopper. A check valve (16) may be positioned within the arm portion.

Description: This invention relates to a self-priming injection site. More particularly, this invention relates to a combination injection site and check valve for use in a parenteral solution administration apparatus whereby the apparatus is constructed so that the fluid flowing through the check valve automatically primes the injection site. Presently, injection sites are generally ′Y′ shaped with one of the top arms of the ′Y′ being covered by a sleeve stopper formed of a latex compound. The sleeve stopper known in the prior art surrounds both the inside and the outside of the upper portion of the hollow arm. The sleeve stopper has a center that extends across the hollow arm of the injection site to prevent contaminants from entering the intravenous administration set. The closed center surface is generally located adjacent to the end of the hollow arm. To add medication or other solutions to the fluids already passing though the administration set, medical personnel use a syringe or other injection apparatus to pierce through the center surface of the sleeve stopper. Upon the needle being inserted into and removed from the sleeve stopper, the sleeve stopper may be damaged, rearranged, or even removed from the injection site. The sleeve-type stopper is particularly susceptible to being pulled from the injection site by large gauge needles since the sleeve-type stopper depends solely on the friction between itself and the arm of the injection site to retain the stopper in proper position. Since the friction alone is often insufficient, a vinyl heat seal band may be placed around the outside of the sleeve stopper and the adjacent portion of the arm. Although the heat seal band has improved the retention of the stopper in the arm, the results have still not been totally satisfactory. The stoppers are generally formed of latex or a similar material that substantially reseals upon the needle being removed. However, repeated piercings damage the stopper, especially piercings done in such a manner that they create substantially larger openings. Once the stopper has been damaged by piercing, the stopper develops an even greater propensity to being moved from its proper position. The removal of the stopper from the injection site causes an assortment of problems including fluids leaking from the administration set and the introduction of contaminants and air into the intravenous solution. The problem of stoppers that do not remain in their proper position on the injection site is particularly troublesome since the injection site is not independently removable from the administration set. The entire administration set must be changed to allow a new injection site to be put into place. It would be an advantage to provide an injection site which can withstand a large number of needle piercings and removals even when subjected to high pressures often associated with injections from small syringes, which may exceed 8.5 × 10⁵ Pa (125 p.s.i.). It is an object of this invention to provide an improved injection site which can withstand a number of needle piercings and removals without the stopper being repositioned or removed from the injection site. It is a further object of this invention to provide an injection site that is self-priming or easily primed. One additional object of this invention is to provide minimal amounts of internal residual volume within the injection site lumen. US-A-4294249 and EP-A-0109903 each disclose an injection site having a disc-shaped stopper positioned between a top of a housing and an O-shaped ledge in the housing, the top having a central opening. In EP-A-0109903, the top and the ledge are on separate parts secured together, whereas in US-A-4294249, the top and ledge are parts of a single moulding, the top being swaged over the edge of the stopper. The pre-characterising part of Claim 1 is based on these documents and the distinguishing features of the invention are as set out in the characterising part of the claim. Figure 1 is a perspective view of an injection site that is a first embodiment of the subject invention. Figure 2 is a side view of the injection site of Figure 1. Figure 3 is a top view of the injection site of Figure 1. Figure 4 is cross-sectional view of the injection site of Figure 1 taken along the lines 4--4 of Figure 3. Figure 5 is an exploded view of the injection site of Figure 1. Figure 6 is a second embodiment of the injection site that is the subject of the instant invention. Figure 7 is a third embodiment of the injection site that is the subject of the instant injection. Figure 8 is a perspective view of a parenteral administration set utilizing the injection site of Figure 1. The injection site of the instant invention can be seen by reference to the figures. In general, the injection site, indicated generally as 10, includes a housing, a stopper 14, and a valve 16. As shown in Figure 8, the injection site 10 is connected between tubing 18 and tubing 20 in an apparatus for administering a parenteral solution to a patient. Generally, the injection site constitutes a portion of the passageway of the intravenous fluid continually administered to the patient. As the patient's therapy requires supplemental intravenous medication or other intermittant administration of a second fluid, a syringe or other injection apparatus is used to insert medication into the intravenous fluid. The needle is inserted and then withdrawn through stopper 14. Since the intravenous solution may be administered to the patient for lengthy periods of time, it is desirable to have a stopper that can withstand numerous piercings and removals of the needle, even under high pressure. Housing 12 may be a combination housing of a stopper housing 24 and valve housing or second housing 26, as shown in Figure 4, or may be a single housing as shown in Figure 6. The stopper housing or stopper portion 24 includes an approximately cylindrical portion 28, a top 30, an intermediate ledge 34, and a cone-shaped outlet portion 32. Cone-shaped outlet portion 32 helps deflect a needle into the center of the injection site to prevent the needle from piercing the sidewall of the injection site. Top 30 has an open center 38, while the ledge 34, which extends the entire 360° around the circumference of cylindrical portion 28, has an upwardly turned lip 40. The stopper 14 is approximately disc-shaped with its bottom surface having an annular groove 42 that receives ledge lip 40. Top 30 and ledge 34 hold stopper 14 in vertical and/or diametric compression to securely retain the stopper within the housing 12. Groove 42 creates an ear 44 around the circumference of the stopper 14. At least one dimension of the ear 44, such as the height, must be larger than the distance from the lip 40 to the top 30 to deter the repositioning or removal of the stopper when the needle is inserted and removed therefrom. Because the stopper is held in compression, its center 46 extends through the open center 38 of the housing. Raised center 46 facilitates the sterilization of the stopper, by providing easier accessibility for wiping with an anti-microbial agent, such as isopropal alcohol, with abrasive action. Prior art injeciton sites having a stopper that is recessed below the remainder of the top of the injection site allow the anti-microbial agent to accumulate in a puddle on the top of the stopper. Particulate matter may also collect on the top of the stopper, and may be transmitted inside the injection site to the I.V. solution when a needle pierces the stopper. The raised or flush stopper design of the instant invention permits a clean drain of the anti microbial agent from the stopper, as well as facilitating the cleaning of the stopper. Raised center 46 has an embossed ring 48 that defines the preferred target area for insertion of the needle. A needle inserted within the embossed ring 48 exerts a force that is small enough that it generally does not reposition or remove the stopper from the housing. The target area is at least 3.8 mm (.15 inches in diameter), large enough to accept large bore needles, such as 16 or 18 gauge needles, and multiple simultaneous needles. The stopper housing 24 is molded as one unit. Immediately after molding, the top 30 of the housing is a vertical extension of the sides 50 of the cylindrical portion 28, as shown in Figure 5. After the stopper 14 is positioned on the ledge 34, the top edge of the cylinder sides 50 is bent inwards to form the top 30 either by ultrasonic deformation, by heating or by cold forming. The unitary molded housing holding stopper 14 in compression provides for lower cost, easier assembly and more stable assembly dimensions. Because the dimensions are more precise, the performance of the injection site is more reliable. The stopper housing 34 has an arm portion 54 joined to the cone-shaped outlet portion 32 immediately below ledge 34. Arm portion 54 provides for the main flow of fluid through the injection site. In the embodiment of the invention shown in Figures 1-5, the arm portion includes an enlarged section 54 that houses the valve 16. The valve in the embodiment shown is a duckbill type as will be described briefly herein and is described in more detail in U.S. Patent No. 4,566,493. A variety of other valves may also be used. A valve housing portion 26 is joined to the stopper housing 24 by one of a variety of methods. Adhesive may be applied between the two parts or ultrasonic welding may be used to cause the two parts to merge together. Valve 16 includes sides 56 extending to an annular collar 58. Valve sides 56 are positioned at an angle to form a slit 60 through which the fluid passes. The sides 56 are connected to one another through curved walls 62. Valve 16 also has tabs 64 positioned on the sides 56 adjacent the annular collar 58. The end of the valve at slit 60 is positioned very close to cone shaped outlet portion 32 of the housing, approximately 7 mm (.272 inches) from the end of the valve to the outlet passageway in the embodiment described herein. By combining the injection site and the check valve instead of positioning the check valve upstream from the injection site a number of advantages are achieved. The close proximity of the two components prevents any retrograde flow up the I.V. tubing. This is important for drugs that require minimum diluent or that must be administered quickly to the patient. In particular, viscous highly dense drugs that flow up the I.V. tubing require considerable time and fluid for purging the drug out of the tubing. The present design also minimizes the stagnant area where drugs can collect, to reduce the portion of the drug that is not administered to the patient. Enlarged section 52 of the housing includes a flange 70 that surrounds and mates with the annular collar 58 of valve 16, while valve tabs 64 are received in notches 68 of the arm portion 54 of the housing. This arrangement helps to ensure that valve 16 does not twist within the housing. Since the clearance between valve sides 56 and sides 66 of the housing arm protion is very small, any twisting of valve 16 within the housing would disturb the proper operation of the valve. Valve housing 26 includes a sleeve 72 that surrounds the flange 70 of the housing arm portion. Passageway 74 of valve housing portion 26 includes an approximately right angle turn. Fluid through the valve flows vertically downward through passageway 74, then horizontally through arm portion 54, then downward again through cone-shaped outlet 32. Thus, the tubing attached to the valve housing and to the outlet of the stopper housing 24 are approximately parallel to one another. Since this tubing generally hangs vertically, stopper 14 will generally be positioned on the top of the injection site where it is easily accessible to medical personnel, as shown in the figures. The vertical inlet of valve housing 26 has its outer edge positioned at least.75 inches from the center of stopper 14. This allows for easy access with the large bore needles and multiple simultaneous needles, as discussed above. As the intravenous solution enters the valve housing 26, it makes an approximately right angle turn as shown in the embodiment of Figures 1-5, moves through the valve and directly across the bottom of the housing ledge 34 and across the bottom of the stopper 14. The fluid flow forces substantially all air within the stopper housing towards the outlet 78. The injection site is thus self-priming. In the prior art injection sites utilizing the sleeve stopper, the cavity located within the center of the sleeve stopper prevented a self-priming feature. Using the sleeve stopper, even a stream of liquid directed across the bottom of the rubber part could not force out the air located within the cavity. Air was removed by inverting the injection site while manually tapping on the housing. The second and third embodiments of the invention, shown in Figures 6 and 7, respectively, also direct the fluid across the bottom of the stopper 14. The arm portion 54 of the embodiment shown in Figure 6 joins the cylindrical portion 28 of the housing at an angle other than 90°. The intravenous solution enters the inlet 76 of the stopper housing 24 and flows down the passageway 74 of the arm portion. At the end of the arm portion is a ramp 84 which adjusts the direction of flow of the intravenous fluid to be approximately parallel to the bottom of the ledge 34 and the bottom of the stopper 14. This arrangement produces a self-priming injection site. The stopper housing 24 that is shown in Figure 6 may be molded of one piece since each opening in the housing forms a straight line from outside the housing to the center of the housing. The angle between the arm portion 54 and the cylindrical portion 28 was chosen as an angle other than 90° to utilize the benefit of a molded one-piece housing while creating an arrangement in which the injection site 10 hangs from vertical tubing in a manner so that the stopper 14 is generally on the top of the injection site. The angle between arm portion 54 and cylindrical portion 28 may be either greater or less than 90°. The third embodiment shown in Figure 7 is similar to that shown in Figure 6. The inlet 76 of the injection site is vertical and parallel to the outlet 78. The third embodiment has a housing arm portion that forms with inlet 74 an angle greater than 90°, so that the housing may be molded from one piece. The embodiment shown in Figure 7 is also one which has a self-priming or easy-priming feature. The device shown in Figure 7 also utilizes a ramp 84 to modify the direction of the intravenous fluid so that it runs approximately parallel to and immediately adjacent to the bottom of the stopper 14. Again, the injection site hangs from vertical tubing in a manner such that the stopper 14 is generally on the top of the injection site. It will thus be seen that through the present invention there is now provided a self-priming injection site which is simple in construction. The injection site also has the advantage of being capable of accepting many needle insertions and withdrawals without leaking or otherwise functioning improperly. The vertical and/or diametric compression of stopper 14, as well as the thickness of the latex stopper enhance the resalability of stopper 14. While the invention has particularly been shown and described with reference to a number of preferred embodiments, it will be understood by those skilled in the art that variations in form, construction, and arrangement may be made therein without departing from the scope of the invention, as defined by the following claims.

Claims: 1. An injection site for use in an apparatus for administering a parenteral solution to a patient comprising a stopper housing (24) including a top (30) with a center opening (38), a cylindrical portion (28) having an O-shaped ledge (34) positioned therein, and an outlet portion (78) extending away from the top (30); and an approximately disc-shaped stopper (14) positioned in said center opening (38) between the top (30) and the ledge (34), the ledge (34) being provided with a lip (40) extending towards the top (30) characterised in that the stopper (14) is formed with an annular groove (42), an annular ear (44) is delineated around the groove, the lip is received in the groove so that the ear extends around the lip, and the height of the ear is greater than the distance between said housing top (30) and said lip (40). 2. An injection site as claimed in Claim 1, wherein the outlet portion (32) is cone-shaped and reduces in diameter away from the ledge (34). 3. An injection site as claimed in Claim 1 or 2, adapted for the insertion of a needle, wherein a portion (46) of said stopper (14) protrudes from said center opening (38) and has a means (48) defining a target location for the insertion of the needle. 4. An injection site as claimed in Claim 3 wherein the target location of said stopper is large enough to accept two needles. 5. An injection site as claimed in Claim 3, the target location of said stopper being at least.15 inches (3.8 mm) in diameter. 6. An injection site according to any one of claims 1 to 5, wherein the stopper housing (24) is part of a unitary moulding including an arm portion (54) for conveying fluid to the cylindrical portion (28), wherein the stopper (14) has a substantially flat bottom surface and wherein the arm portion is positioned to direct fluid across the flat bottom surface of said stopper into the cylindrical portion to provide a substantially self-priming injection site. 7. An injection site as claimed in Claim 6 wherein the portion (54) is substantially perpendicular to the cylindrical portion (28). 8. An injection site as claimed in Claim 6 wherein the arm portion (54) includes a ramp (84) that directs the fluid across the flat bottom surface of the stopper. 9. An injection site as claimed in Claim 8 wherein the arm portion has an inlet portion (76) leading to the ramp (84) and extending substantially parallel to the outlet portion (78). 10. An injection site as claimed in any one of claims 6 to 9, wherein the bottom of the substantially flat bottom surface of the stopper is co-extensive with the ledge (34) when the groove (42) received the lip (40). 11. An injection site as claimed in any one of claims 1 to 5 additionally comprising a valve (16) with an oulet (54) producing an output into the housing (24) below the ledge (34). 12. An injection site as claimed in Claim 11 wherein said valve outlet (54) is directly connected to said housing (24). 13. An injection site according to claim 12 and including the features of Claim 6, wherein the valve (16) is accommodated in the arm portion (54) of the unitary moulding. 14. An injection site as claimed in Claim 13 additionally comprising a second housing (26) of a unitary moulded construction, the second housing being connected to the stopper housing (24) and providing an inlet (74) to the valve. 15. An injection site as claimed in any preceding claim wherein the stopper (14) is in compression within the housing (24). 16. An injection site as claimed in any one of claims 11 to 15 wherein said valve (16) has an input (74) that is approximately parallel to the outlet portion (32) of the housing. 17. An injection site as claimed in any one of Claims 11 to 16 wherein the distance between the outlet portion (78) and the adjacent end (60) of the valve is less than.5 inches (12.7 mm). 18. An injection site as claimed in any preceding claim wherein the housing top (30) comprises an inside surface that is rough.

Inventors: DESECKI, VINCE, HESS, JOHN, M., III, KULLE, LEE
Applicants: BAXTER INTERNATIONAL INC. (A DELAWARE CORPORATION)
Application year: 1988
Main classification: A61M5
IPC codes: A61M5, A61M39