United States Patent 3670727

A medical infusion set for administering parenteral liquid into a patient's veins in which the set is in the form of a continuous flexible loop that is manually broken apart before venipuncture at a frangible section (this section comprising an indication of the sterile integrity of the set to subsequent users), the set providing means for flushing air therefrom while maintaining the set in a sterile condition by either running the liquid through the loop before effecting the venipuncture, or flushing the air from the set by using the patient's blood flowing therethrough and before connection to the liquid being administered; the set including means protecting either a connector to the parenteral liquid or the needle against contamination while air is flushed from the set; and the needle of the set including a pair of flexible plastic wings generally diametrically opposed and including manually interengageable portions comprising interengageable upstanding ribs manually interlockable when manually pinched together to form a dual purpose temporary handle in which the wings can be subsequently spread apart adjacent the venipuncture in the patient for securement to the patient to stabilize the implanted needle or cannula.

Application Number:
Publication Date:
Filing Date:
Primary Class:
Other Classes:
International Classes:
A61M5/158; (IPC1-7): A61M5/14; A61M5/158; A61m005/00; A61m005/32
Field of Search:
128/214,214.2,215,218N,221 206
View Patent Images:
US Patent References:
3538915INFUSTION DEVICE AND METHOD1970-11-10Frampton et al.
3064648Intravenous needle assembly1962-11-20Bujan
2737951Clinical cannula or tubule device1956-03-13Braun
2452643Disposable venoclysis set1948-11-02Fields
1564499Hypodermic needle1925-12-08Tropp

Foreign References:
Primary Examiner:
Truluck, Dalton L.
I claim

1. A medical infusion set comprising in combination:

2. The combination as claimed in claim 1 in which said hub has handle means connected thereto and said protector sleeve is optionally removable from said adapter for flushing liquid therethrough to remove residual air while the sleeve is still connected to said hub and protects said cannula subsequent to manual rupture of the thinned wall section, or alternatively manually separable from said hub whereby the cannula can be immediately administered so that the patient's blood will flush residual air from the set prior to administration of a liquid to a patient through the set.

3. The combination as set forth in claim 2 in which said handle means includes normally generally diametrically opposed, flexible wings integral with the hub and foldable into juxtaposed relation to form a temporary, radially extending handle for facilitating administration of the cannula or rupture of said thinned wall section between said hub and protector sleeve, said wings being flexible for generally overlying the portion of a patient into which the cannula has been emplaced for securement to the patient and stabilizing the implanted cannula.

4. The combination as claimed in claim 3 in which said wings included interlockable structural portions interengageable when adjacent surfaces of the wings are manually juxtaposed for preventing relative movement therebetween when implanting the cannula or rupturing the protector sleeve and hub.

5. The combination as set forth in claim 4 in which the sharpened end of said cannula comprises an angular bevel defining a thin transverse sharpened edge relative to the direction toward which said cannula extends, said wings extending generally diametrically from said hub substantially parallel to the transverse direction of said angular bevel whereby the formation of the temporary radial handle orients the sharpened edge of the cannula in an optimum position for implantation.

6. The combination as claimed in claim 1 in which said cannula includes a collar permanently secured in abutting relation to a rear end portion of said hub for preventing the cannula from being accidentally pulled out of the hub, said flexible tube being telescoped over said collar and said hub and being permanently secured thereto.

7. The combination as claimed in claim 1 in which said flexible tube comprises at least one continuous loop portion internally sterilized, and a packaging band circumposed about said loop transversely to said loop for facilitating manipulation of the infusion set during administration.

8. The combination as claimed in claim 1 in which said vent passage means comprises a tortuous sterilizing gas vent formed by cooperating portions between said protector sleeve and said adapter for internally sterilizing the infusion set while said set is formed as a continuous loop.

9. For use in a medical infusion set, a cannula having a sharpened end; a hub integrally joined to the cannula in spaced relation from said sharpened end, said hub including diametrically opposed wings integrally and flexibly connected thereto, said wings having a permanent set normally disposing them in generally coplanar relation for flexible engagement on a patient's body for securement thereto after the cannula has been implanted, said wings being pivotal about the hub on an axis substantially parallel to said needle for forming juxtaposed, radially extending portions forming a temporary radial handle to assist in implanting the cannula in a patient, the improvement wherein said wings include portions forming mechanically interengageable portions for preventing relative movement between the wings when the wings are manually juxtaposed to form the temporary radial handle, said wings returning to generally diametrical opposed relation after no longer being manually juxtaposed; a flexible tube connected at one end to the cannula at the end opposite said sharpened end, said flexible tube including a tubular element at the end opposite that connected to said cannula; and a tubular protector sleeve having one end telescopically connected to said element and including an extension receiving said cannula therein, the terminal end of said protector sleeve in said hub including a manually rupturable, frangible portion whereby said protector sleeve can be manually separated from the hub to expose said cannula.

10. The structure as claimed in claim 9 including portions forming a tortuous vent passage communicating between the interior and exterior of said protector sleeve whereby the cannula, flexible tube and tubular element can be interiorally sterilized with a gaseous medium or the like and will so remain until the frangible portion is ruptured.

11. A medical infusion set comprising: a metal cannula with a passage extending between a sharpened front end and a rear end; a thermoplastic hub injection molded around and forming a firm joint with the cannula behind its sharpened end and presenting a rearwardly facing shoulder spaced forward of the cannula's rear end; a pair of flexible thermoplastic wings integrally molded with the hub and extending outwardly from opposite sides of the hub and adapted to be pinched together to form a handle; these wings having opposed faces with a series of upstanding ribs that are approximately parallel to the cannula and are formed in at least three rows approximately perpendicular to the cannula, the middle row of ribs being offset from the two adjoining rows of ribs, so the ribs can interlock when pinched together to prevent sliding of the wings relative to each other in either their longitudinal or lateral directions; a separate metal safety collar permanently swaged to the cannula's outer surface adjacent its rear end; a flexible tube in the form of a loop with one end portion telescoped over the safety collar and bonded to the hub, so the safety collar can abut the hub's shoulder to prevent the cannula from being pulled out of the hub in a forward direction even if the joint between the cannula and hub should loosen; a rigid hollow adapter connected to an opposite end portion of the flexible tube, with this adapter being of a substantially larger diameter than the cannula and positioned adjacent the sharpened front end of the cannula; a thermoplastic protector sleeve integrally molded with and joined at a frangible groove structure to the hub, the protector sleeve's end at the groove structure having an internal diameter approximately the same as the cannula's outer diameter, and the other end of the protector sleeve having a substantially larger opening wedgingly receiving the rigid adapter, there being a tortuous sterilizing gas vent between the protector sleeve and adapter for gas sterilizing internal surfaces of the infusion set while so connected; and the protector sleeve being removable from one of the adapter or cannula portions fitting within it, so such portion can connect to a liquid source to flush air out of the infusion set through the protector sleeve still fitting over the other portion.

This invention relates to a medical device, sometimes called a "small vein infusion set" or a "scalp vein infusion set". It is used to make a venipuncture into a patient's vein and to then administer parenteral solution, blood, etc. from a suspended bottle or plastic bag. These liquids are generally infused into an arm, hand, or scalp vein--the latter site frequently employed in infants, because it is one of the most highly developed veins in an infant.

Infusion sets for administering medical liquids have been known for years. They include an intravenous needle connected to one end of a flexible plastic tube. This tube is connected by means of a spike or adapter at its other end to a medical liquid source. There is a sterility protector fitting over a sharpened end portion of the needle's cannula, and a separate sterility protector fitting over the spike or adapter at the tube's other end. These protectors are removed before connecting the set to the liquid source and the patient.

These separate protectors on opposite ends of the infusion set made it cumbersome to perform a very vital procedure with the infusion set before administering the liquid. In intravenous infusion it is very important to flush out all the air from the system so the infused liquid will not push a hazardous air bubble or embolism into the patient's vein. If both protectors ere removed, there was the problem of trying to simultaneously control both ends of the infusion set without contaminating them. If one of the protectors was removed, there was a problem of what to do with it while air was flushed out of the system. Also, a protector fitting over the sharpened end portion of the cannula could be removed, the needle contaminated, and then the protector replaced without any indication that the protector had been removed.

With my invention I have overcome these problems with an infusion set having a unique structure providing two simple methods of flushing air from the set. The infusion set is in the form of a loop with the sharpened front end portion of the cannula and the adapter facing each other and temporarily joined together by a plastic protector sleeve. This protector sleeve is integrally connected at a frangible groove structure to a plastic hub molded onto the cannula. Once the protector sleeve is removed from the hub, the broken groove structure gives a visual indication that the set could have been contaminated and should not be used. For ease of handling, the hub has integral flexible wings that fold up and lock together with interfitting ribs to form a firm handle.

The infusion set of this invention is very simple to use, particularly in the air flushing procedure just prior to liquid infusion. In one method, the looped infusion set is broken apart at the frangible groove, thus exposing the cannula for venipuncture and air is flushed out by filling the set with the patient's blood. In another method the loop is broken apart by removing an adapter on one end of a flexible tube from the protector sleeve and connecting the adapter to a liquid source to flush out air prior to venipuncture.

My invention can be better understood with reference to the drawings in which:

FIG. 1 is a top plan view of the looped infusion set and protector sleeve;

FIG. 2 is a perspective view of the set after venipuncture has been made in a patient's arm;

FIG. 3 is a fragmentary top plan view of the set showing the protector sleeve in cross section;

FIG. 4 is an enlarged fragmentary view taken along line 4--4 of FIG. 3;

FIG. 5 is a fragmentary top plan view showing the protector sleeve remaining on the adapter after it has been broken at the frangible groove structure;

FIG. 6 is a fragmentary top plan view with the protector sleeve remaining around the cannula after the adapter has been removed;

FIG. 7 is an enlarged perspective view of the cannula, hub and wing portions of the infusion set;

FIG. 8 is an enlarged front view of the wings folded up and interlocked by rib structure to form a handle; and

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

Referring in detail to these drawings, the same numerals are used to indicate the same parts in the various views.

Beginning with FIGS. 1 and 3, the infusion set of my invention has a metal cannula 1 with a passage extending between a sharpened front end 2 and a rear end 3. Spaced a distance behind the sharpened end 2 is a thermoplastic hub 4 injection molded around the cannula and firmly bonded to its outer surface. As an added precautionary feature of the hub and cannula joint a metal collar 5 is swaged on the cannula's outer surface near its rear end 3. This collar abuts a rear shoulder 6 of the hub and keeps the cannula from being pulled out of the hub even if the bond between the cannula and hub should be broken.

Fitting over collar 5 and rear of the hub is an end portion of a flexible thermoplastic tube 7 which is bonded by cement, solvent sealing, or heat sealing to the hub. This flexible tube is formed into one or two loops with an opposite end portion 8 facing the sharpened forward end of the cannula. In describing the opposite end portion of the flexible tube it is understood that this portion can include a hollow adapter 9 having a plug section 10, and handle section 11. This adapter is rigid and capable of connecting to a liquid source.

The end portion of the flexible tube, i.e. adapter 9, as shown in FIG. 3, is temporarily joined with the cannula by a thermoplastic protector sleeve 13 that wedgingly receives the adapter 9. This protector sleeve is integrally molded with hub 4 and joined to the hub by a circumferential frangible groove structure 14 that has an internal diameter approximately equal to the cannula's outside diameter, which groove structure has a wall thickness of about 0.005 to 0.010 inch. Inside the protector sleeve are two longitudinal ribs 15 and 16, shown enlarged in FIG. 4, and there are also two notches 17 and 18 at the end of the protector sleeve 13 fitting over the adapter. This structure provides a small tortuous path for sterilizing gases, such as ethylene oxide, to enter the internal areas of the looped infusion set; but protects the internal areas from contamination by bacteria which might subsequently contact the exterior of the set.

FIG. 1 shows the infusion set with two loops and a paper band 19 encircling its center portion including the protector sleeve 13 to hold the loops in an oval configuration. This is for easy handling and packaging. The paper loop does not extend over the flexible wings 20 and 21 so indicia on the wings showing cannula size is clearly visible. For quick identification, the wings can also be color coded for cannula size if desired. In the example "21 TW" means there is a thin wall 21 gauge cannula inside the protector sleeve. In addition to having cannula size indicia, these flexible wings also have a unique locking structure which will be discussed in more detail later.

The looped infusion set of FIG. 1 is supplied to the hospital in sterile condition inside a conventional package such as a plastic bag, peel open paper pouch, etc. When ready to infuse liquid into a patient, a nurse opens the package and takes out the infusion set and removes band 19. It is noted that after the band is removed the infusion set is still in a looped configuration with cannula 1 and adapter 9 still inside protector sleeve 13. The unbroken frangible groove structure 14 shows that the set has not been previously used.

Next comes the critical procedure of flushing air from the system. With my infusion set the nurse can do this by either of two methods. In the first method, she opens up the loop by breaking the protector sleeve 13 at frangible groove 14. She does this by grasping ribs on the protector sleeve and the wings on the hub and twistingly rotating them relative to each other until they break apart as in FIG. 5. A venipuncture is made as in FIG. 2 with protector sleeve 13 still remaining on adapter 9. The broken groove structure 14 of the protector sleeve provides an exit port 22 large enough for flushing out air with little resistance as a patient's blood pressure causes his blood to fill the set. When the transparent flexible tube 7 is filled with blood, it can be pinched or clamped shut and protector sleeve 13 removed from the adapter after which it is connected to a liquid source. The adapter might connect directly to a liquid filled bottle or to a connecting tube leading from it.

A second method of flushing air from the system involves breaking apart the loop by removing adapter 9 from protector sleeve 13 illustrated in FIG. 6 with the protector sleeve remaining around the cannula 1. This opens up a chamber 23, substantially larger than the cannula, at one end of the protector sleeve. Now, the adapter is connected to a liquid source and liquid slowly drained into the set until it drips off the cannula's sharpened end 2 inside the protector sleeve 13 and is observed inside the enlarged chamber 23. Finally, the protector sleeve is broken off at the frangible groove, a venipuncture made, and infusion started.

During the venipuncture step of the above procedure, the wings 20 and 21 are very helpful in providing a firm handle for gripping. Flexible wings have been used before to provide a large grasping surface, but there were problems with these wings. The wings were difficult to hold and when they slid against each other they caused the cannula to roll. Such cannula rolling could cause additional pain to the patient during venipuncture and also decreases control over the cannula bevel direction. As shown in FIG. 7, the beveled surface 24 of the sharpened cannula is directed upwardly. This orientation is preferred by many in making a venipuncture, because it causes less damage to the vein.

Wings 20 and 21 of my infusion set have interlocking or interengageable rib structures that give very good control over bevel orientation by keeping the wings from sliding against each other. Referring to FIG. 7, the wings are elongated and rectangular in shape and extend outwardly in their longitudinal directions from opposite sides of hub 4. The top surface of each wing has a series of short upstanding ribs represented by 25, 26, and 27 that are approximately parallel to the cannula. These ribs are formed into three rows that are approximately perpendicular to the cannula with the outer rows being offset from the middle row. Such structure causes the ribs to temporarily interlock when manually folded together to form a handle as in FIG. 8, and keeps them from sliding against each other in their longitudinal directions to roll the cannula. The wings are also kept from sliding against each other in their lateral directions by ends 28, 29, 30, and 31 of the ribs in the offset rows abutting each other as shown in FIG. 9. After a venipuncture has been made with the manually interengaged interlocking wings, they can be flattened again and taped to the patient as in FIG. 2 to keep the cannula from moving in the vein.

The preferred materials used in my improved infusion set are: a stainless steel cannula; a plasticized polyvinyl chloride flexible tube; an adapter of acrylonitrile-butadiene-styrene (ABS); and a one-piece injection molded part of plasticized polyvinyl chloride forming the hub, wings, and protector sleeve. This latter part greatly decreases the labor cost of assembly and makes for an economical infusion set that is used only once and then discarded.

In the foregoing description of my invention, I have used specific examples to describe my invention. However, persons skilled in the art will understand how to make certain modifications to these examples without departing from the spirit and scope of the invention.