Field of the Invention
This invention relates generally to hypodermic syringes, and is particularly related to a hypodermic syringe which can be used to obtain a fluid specimen, serve as a safe transport container for the specimen, and facilitate removal of a specimen from within the syringe.
Background of the Invention
Hypodermic syringes are well known, and are routinely used to obtain fluid or liquid specimens for diagnostic testing. For example, body fluids so collected include absess fluids, peritoneal fluids, bone joint fluids and so forth. Likewise, certain types of urine samples such as superpubic aspirates and urine samples from indwelling Foley catheters are collected by means of hypodermic syringes. The specimen must be first obtained from the patient through the insertion of the hypodermic needle of the syringe into the fluid containing area, with the fluid specimen then drawn into the interior chamber of the syringe through withdrawing action of the syringe plunger. Next, the specimen obtained must be somehow transported to the examining laboratory for analysis. Lastly, the specimen must be removed from its transport container for testing.
Specimens collected through the use of a hypodermic syringe are oftentimes expressed into a second container for transport to the laboratory for testing. In some instances, the fluid specimens are transported in the syringe itself. The transportation of specimens in the syringe is advantageous for several reasons. First, and most obvious, the sample does not need to be expressed into a second container. This transferring process of course requires extra time for the physician, as well as the expense of a second container. Secondly, when fluids from closed or air-isolated spaces are transported to the laboratory in the syringe, such fluids are obviously maintained in a closed or substantially closed environment. This is important particularly where it is necessary to prevent any anaerobic bacteria from being exposed to atmospheric oxygen. Expressing the fluid into a second container increases the risk that the specimen will be exposed to contaminating atmosphere.
Hypodermic syringes which are presently used for obtaining such routine fluid specimens are not suitably adapted for the relatively rough handling which they are subjected to during transportation. For instance, the close conforming tubular sheath which is typically used to protect the needle during transport is usually only loosely attached about the needle, and can be easily flexed. Since the base of the needle itself is typically only loosely attached to the neck of the barrel of syringe in a friction fit, such flexing can cause the needle to become loosened, with the result that fluid may leak or be exposed to contamination. Furthermore, once the plunger has been partially withdrawn from the barrel in obtaining the specimen, there is no means for preventing the plunger from being reinserted. Handling or jostling during transport can thereby express some of the specimen and expose handlers to potentially hazardous matter.
Another difficulty in using the ordinary hypodermic syringe as a transport container for the specimen presents itself once the specimen has arrived at the laboratory. Ordinarily, the fluid will have to be expressed for purposes of examination. In some instances, the fluid may have clotted and thus will obstruct its exit from the syringe. In other instances, excessive fluid may be expressed out, particularly in larger diameter syringes, due to control problems inherent in manually expressing small volumes of fluid.
Particular problems are presented by urines which are transported to the laboratory in the syringes in which they were collected. Standard laboratory procedures require that a calibrated or dairy loop be placed into the urine so that a specific volume will adhere to the loop. Thus, a loop with an overall diameter of about 5 mm will typically be placed directly into a volume of the urine. When the urine arrives at a laboratory in a syringe, it must be either expressed into a second container, or the plunger must be removed to allow access to the volume of urine contained within the syringe barrel. When the plunger is removed, however, urine can leak out of the needle, creating an unpleasant and hazardous condition for the handler.
Summary of the Invention
In light of these shortcomings of using conventional hypodermic syringes for transport of the specimens obtained with the syringe, and the difficulties in removing certain specimens from the syringe once it is at the examining laboratory, it is the general object of this invention to provide an improved syringe for the safe transport of specimens in the syringe in which the specimen was originally obtained, and which facilitates the access to and/or removal of the specimen from the syringe when desired.
It is a more specific object of this invention to provide a port in the side of the barrel of a hypodermic syringe which is proximate the neck or narrowed portion upon which the hypodermic needle is received, the port communicating with the interior of the chamber, and through which port sampling instruments can be introduced with little difficulty directly into the interior of the chamber, and further providing a fluid-tight closure for the port.
It is another object of the invention to provide a protective cover surrounding the hypodermic needle which is firmly secured to the barrel of the syringe to thereby prevent any flexing or loosening of the needle during transport. Commensurate with this object is to provide this cover in a manner which will insure a fluid-tight fit of the cover on the barrel to thereby prevent the escape of any specimen leaking from the syringe in the event that the needle is dislodged during transport.
Yet another object of the invention is to provide a mechanism for preventing the inadvertent or accidental reinsertion of a syringe plunger within the barrel to thereby prevent inadvertent or accidental expression of fluid specimen.
These and other objects are accomplished by this invention which includes a hypodermic syringe having an enlarged port in the side of the syringe barrel proximate the narrowed opening of the syringe communicating with the hypodermic needle. The port communicates with the interior of the chamber, and is of a sufficient width such that sampling instruments, such as a 5 mm loop, can be easily introduced into the interior of the chamber and into specimen fluid contained therein.
Syringes with side ports have of course been known in the prior art, such as U.S. Pat. No. 1,456,469 and U.S. Pat. No. 2,541,621. These patents, however, are merely illustrative and it is not intended to suggest that they are the only or most pertinent background patents. Such patents do not disclose in a syringe an enlarged port which is located proximate the narrowed needle opening for accessing the interior chamber of the syringe with sampling instruments to thereby withdraw fluid samples from the syringe.
The port is further provided with a fluid-tight closure or cap, which may be of a screw on or snap on fit. The improved syringe further includes an elongated boss spaced inwardly along the exterior of the barrel near the plunger opening of the syringe which serves to incline the syringe on a flat surface to promote pooling of specimen fluids in the area of the port.
In a preferred embodiment of the invention, the barrel of the syringe is provided with an annular shaped extension or collar which surrounds and is radially spaced from the neck of the syringe which receives the hypodermic needle. A rigid elongated cover is detachably received on the collar in a fluid-tight fit, the cover having an interior recess sufficiently long to receive the needle therein without the needle contacting the cover interior. Being rigidly attached to the barrel of the syringe and spaced from the needle, the cover serves to adequately protect the hypodermic needle during transport, as well as contain any fluid which might escape should the needle become dislodged or should fluid otherwise leak from or be accidentally expressed from the syringe.
A preferred form of the invention also provides for a mechanism for preventing the plunger of the syringe from being accidentally or inadvertently reinserted into the barrel, such as during transport of the specimen containing syringe. This mechanism comprises a series of spaced detents or notches extending longitudinally along the elongated body portion of the plunger. For example, where the plunger has an elongated body portion which has a pair of opposed longitudinally extending ribs, each of such ribs has a regular series of notches spaced along a portion of its length. One-way movement of the plunger permitting withdrawal of the plunger from the chamber and preventing reinsertion movement of the plunger within the chamber is accomplished by a resilient member carried on the exterior of the syringe barrel and adjacent to the plunger opening.
The resilient member has a portion which, in one embodiment, is in the form of a finger which is angled radially inwardly relative to the axis of the barrel and extending in the direction of withdrawal of the plunger from the barrel. The tip of the resilient member is biased to engage the detents of the body portion of the plunger seriatim as the plunger is withdrawn from the chamber, by alternatingly riding along the body portion of the plunger and then dropping into and engaging a detent. Due to the bias and angularity of the resilient member, the plunger can only be withdrawn from the barrel and cannot be pushed back in. In its preferred form, the resilient member is carried on a flexible clip which is removably attached to the barrel, such that the clip can be simply removed to depress or reinsert the plunger, if desired.
The foregoing objectives, features and advantages of the present invention will be more readily understood upon consideration of the following detailed description of the invention taken in conjunction with the accompanying drawings, in which:
Brief Description of the Drawings
FIG. 1 is an elevational view of the improved syringe of this invention with the protective needle cover and port cap disassembled for clarity.
FIG. 2 is a partial elevational view of a hypodermic syringe including the one-way plunger mechanism.
FIG. 3 is a cross-sectional view taken along the line 3--3 of FIG. 2.
Detailed Description of the Invention
The improved hypodermic syringe of this invention is designed to be used to gather a fluid specimen, to safely transport the specimen to the laboratory for testing, and to facilitate the removal of the specimen from the syringe once at the testing facility. The improved syringe advantageously reduces the cost of obtaining and analyzing the specimen through the elimination of the need for an intermediate transport container, as well as improving the efficiency of those personnel who must obtain the specimens and those who must thereafter examine the specimens.
Referring now more particularly to FIG. 1, the improved hypodermic syringe comprises a conventional hypodermic syringe having a hollow cylindrical barrel 10 and a plunger piston 11. A hollow hypodermic needle 12 is received on a neck 13 of the barrel surrounding a narrowed opening 13'. The end of the barrel 10 opposite from the narrowed opening 13' has an enlarged opening 15 into which the plunger 11 is slidably received. The hypodermic needle 12 is provided with a collar or bowl 14 around the base, which bowl is received on the neck 13, such as by a simple friction fit thereon. The neck 13 has a passage through which fluid from the barrel interior 16 can flow on its way to the needle, such as when the plunger 11 is inserted in the barrel and moved in the direction of the narrowed opening 13'.
The plunger 11, being conventional in form, has an elongated body portion 17, which herein consists of a beam having an X-shaped cross section presenting four joined ribs 17a, 17b, 17c and 17d which are normal to each other. The rearward end of the plunger 17 has a portion 18 which facilitates pushing and pulling of the plunger within the barrel 10. The forward end of the plunger 17 carries a plunger head 19 which includes resilient gasket portion 20. Gasket portion 20 engages the interior side walls of the barrel 10 to thereby provide a fluid tight fit of the plunger head within the barrel.
Surrounding the plunger opening is a flange 21 which extends radially from the exterior of the barrel around at least a portion of the circumference of the barrel. The flange provides a leverage surface for use of the plunger 17.
The barrel 10 and the plunger 11 may be of any suitable material, such as glass or plastic, and the exterior thereof may be provided with gradations to indicate the quantity of fluid within the interior chamber. The hollow hypodermic needle 12 will typically be formed of metal. The hypodermic syringe as heretofore described is of course well known in the art.
Where a hypodermic syringe is used to obtain a fluid specimen, such as absess fluids or urine specimens, the needle 12 will be inserted into a fluid containing area, and the plunger withdrawn from the barrel an appropriate distance to thereby cause a desired amount of fluid to be drawn through the hollow needle and into the interior chamber 16. To facilitate access to a fluid specimen so drawn, such as when the specimen has been transported to the testing laboratory, a port generally designated at 25 is provided in the side wall of the barrel 10.
The port 25 is of an enlarged diameter to permit ready access to the interior of the chamber 16 for the introduction of sampling instruments directly into the fluid contained therein. For example, in the testing of urine specimens, a 5 mm loop is typically employed which must be inserted directly into a volume of the urine to be tested. Provision of a port 25 in the side of the barrel 10 which is wide enough to permit the loop to pass therethrough and into the chamber 16 thus advantageously permits such sampling without the need to either express urine into another container or remove the plunger 17 completely from the barrel 10 to thereby access the chamber 16 through the plunger opening 15.
The port 25 has a tubular extension 26 of small vertical height which extends generally radially from the barrel 10. The extension 26 is canted at a slight angle for reasons which will be explained hereafter. Location of the port proximate the narrowed opening of the neck 13 is deemed to be of significance, particularly for access to small quantities of specimen fluids which might not otherwise be obtainable, and further for pooling of fluids at this end of the barrel.
The port is provided with a fluid-tight closure 27, which in this illustrated embodiment takes the form of a cap which is threadably received on the tubular extension 26. A snap-on or other type cap might of course be utilized with the same effect. The cap 27 herein is additionally provided with an interior protuberance 28 which projects downwardly from the underside of the cap and which is sized to be slidably received in the shaft 26' formed by the tubular extension 26 and tightly embraced therein to further ensure a fluid-tight fit.
A boss 30 is located on the exterior of the barrel 10 on the side of the barrel opposite of the port 25. The boss is elongated and extends generally tangentially to the side of the barrel, and has a flattened lower portion 31. The boss 30 is spaced inwardly from the flange 21 a sufficient distance to permit easy manipulation of the syringe in obtaining or expressing fluid without interference from the boss 30. The boss 30 has a small vertical height so that, when the syringe is placed on a level surface on the flattened lower portion 31, the small vertical height of the boss serves to raise the rearward portion of the syringe barrel 10 inclining the syringe. This serves to pool liquid specimen in the forward portion of the chamber 16 and in the vicinity of the port 25.
Since the barrel 10 will be inclined with respect to the horizontal due to the presence of the boss 30, the tubular extension 26 of the port 25 is consequently canted with respect to the barrel side, such that the shaft 26' of the port is substantially vertical with respect to the horizontal surface upon which the syringe rests.
The hypodermic syringe will ordinarily be provided with a protective sheath 33 for the needle 12. The sheath, typically made of a rigid plastic, is formed to closely surround the needle 12 and slide over the bowl 14 of the needle in a friction fit. Since the sheath 33 so closely surrounds the needle 12, deflection of the sheath, such as might occur during transport or rough handling, in turn causes deflection of the bowl 14 of the needle. This can loosen the bowl 14 on the neck 13 of the syringe, and cause the bowl 14 to become separated from the neck 13. Fluid contained within the syringe can consequently leak out, contaminating both the specimen being transported as well as the handlers of the syringe. A protective cap 34 is therefore provided to prevent any deflection of the needle and sheath 33, to protect the needle during transport and provide the additional safety feature of a fluid tight cap surrounding the needle. The rigid plastic cover 34 is generally conical in shape in this embodiment, and is provided with an interior space 35 sufficiently long to easily surround the needle 12 and sheath 33.
A collar 36, which herein is an annular extension of the forward portion of the syringe barrel 10, receives the protective cover 34. The interior wall 37 of the collar is radially spaced from the neck 13, bowl 14 and base of the sheath 33 to prevent any contact between the protective cover 34 and the needle and sheath which might cause the needle to become dislodged from the neck 13. The collar 36 is provided with screw threads 38 on at least a portion of its exterior for receiving matched screw threads 39 of the protective cover 34 in a fluid-tight engagement. This fluid-tight seal surrounding the needle provides an extra measure of protection in the event that the needle does become dislodged and leakage from the syringe occurs.
It will of course be recognized that although a screw engagement of the protective cover 34 is described herein, a snap-on cover could be used with equal effectiveness. Further, although a collar 36 which is an extension of the syringe barrel is shown herein, the protective cover 34 could be adapted to attach directly to the syringe barrel 10. The use of the collar 36 is considered to be particularly advantageous, however, due to the need to place the port 25 in as close proximity to the neck 13 of the syringe as possible.
In obtaining a specimen with the syringe, the plunger 11 will be partially withdrawn within the barrel 10 to thereby draw fluid material into the chamber 16. The plunger 11 will obviously have to remain in this partially withdrawn configuration during transport of the syringe to the testing laboratory. In order to prevent the plunger 11 from being accidentally or inadvertently reinserted within the barrel 10 and thereby causing undesired expression of specimen from the syringe, a one-way plunger mechanism is provided for the syringe, and is depicted in the modified embodiment shown in FIGS. 2 and 3.
With particular reference to those figures, this one-way mechanism comprises a one-way clip generally indicated at 44. As shown here, the clip 44 includes a generally C-shaped base member 45 which is adapted to conform to a portion of the circumference of the syringe barrel 10. The C-shaped base 45 snap-fits about the barrel 10, preferably being located in abutting relationship with the flange 21 of the syringe.
Extending from the base 45 of the one-way clip are opposed resilient members 46, which herein are in the form of fingers. The fingers 46 extend perpendicularly from the base 45 and then angle inwardly and toward each other. With respect to the one-way clip 44 when mounted on the syringe barrel 10, the fingers 46 extend rearwardly and then angle radially inwardly relative to the axis of the barrel 10, extending in the direction of withdrawal of the plunger from the barrel. Each of the fingers in this embodiment is provided with a notch 47, for reasons which will be made immediately apparent The clips 44 can advantageously be made of rigid or semi-rigid plastic.
The conventional plunger 11 is modified to provide for a series of spaced detents or notches 48 along a substantial portion of at least two opposed ribs of the plunger 11, such as 17a and 17c. A notch 48 need be only of a small depth.
In use, the plunger 11 will be oriented with respect to the clip 44 so that the notched ribs 17a and 17c will be respectively received within the notches of one of the opposed fingers 46. The resilient fingers 46 are sufficiently biased so that finger notches 47 will be caused to drop into and engage the notches 48 of the respective ribs. It will thus be seen that as the plunger 11 is withdrawn from the syringe 10, the fingers 46 will alternately ride along the surface of the ribs 17a, 17c and engage rib notches 48 seriatim The angled fingers 46 thus permit only withdrawal movement of the plunger 11, and prevent the plunger from being reinserted within the barrel 10. Inadvertent or accidental reinsertion of the plunger such as might occur during transport of the syringe is thus prevented. If it is desired to reinsert the plunger, such as for expression of the specimen at the testing laboratory, the snap-on clip 44 is removed and the plunger operated.
The one-way clip 44 as previously described is of course a presently preferred embodiment of the invention. Any kind of a resilient member which is biased to engage within detents provided along the syringe plunger to provide such one-way movement is considered to be within the scope of this invention.
Thus, while the invention has been described in connection with certain presently preferred embodiments, it will be immediately obvious to those skilled in the art that many modifications to the structure, arrangement, portions, elements, materials, and components can be used in the practice of the invention without departing from the principles of this invention.