ASSEMBLY OF SYRINGE
BACKGROUND OF THE INVENTION
Field of the invention. The present invention relates to syringe assemblies and more particularly concerns syringe assemblies for use in jet wash procedures
Background. An IV catheter is a commonly used therapeutic device Many patients, according to their therapy, have an IV catheter connected to a vein ready for use in various procedures or in fluid communication with an IV system to infuse fluids and medication Many IV sets have IV ports which are in fluid communication with a catheter and allow access for the purpose of injecting medication into the patient, and for use in jet washing techniques to maintain integrity and lack of catheter obstruction. health have jet wash protocols, which depend on the amount of time the catheter will remain in the patient and the type of catheter being used. For example, a peripherally inserted central catheter (PICC) is a long flexible catheter, the which is normally inserted into the central venous system (optimally with the tip ending in the superior vena cava ) via the superficial veins of the antecubital fossa The PICC lines are designed to be used when long or medium term therapy is prescribed These catheter lines should be flushed
periodically with saline jet solution and / or solution of jet of closing of hepapna depending on the protocol Among other things, the saline solution of washing to jet removes blood from the catheter and the hepapna helps to prevent the formation of future blood clots. the most common iv ports are covered by perforable septums or pre-split septums, and are known in the art and are sometimes referred to as "PN" from the Latin pro re nata, which means "as the need arises" The septum is preferably made of rubber or other elastomeric material, which allows the insertion of an acute needle cannula, in order to infuse fluids into, or withdraw fluids from, the catheter Upon removal of the water cannula, the septum seals by itself The same ports are used having pre-split septums with blunt cannula Normally, the blunt cannula is attached to a syringe, and the syringe moves to place a soft pressure on the septum m pre-split, which is forced to open by the blunt cannula to establish fluid communication In addition, some iv assemblies have access valves, which respond to the truncated-conical tip of a syringe barrel to allow the fluid communication between the inside of the syringe and the catheter Catheters are flushed using syringe assemblies filled with various fluids In some cases, different fluids are injected sequentially according to the protocol For example, a saline solution followed by an anticoagulant , such as, hepapna The size of the syringe used for flushing IV lines varies by various factors including the size and length of the catheter
Typically, syringes of volume 1 ml, 3 ml, 5 ml and 10 ml are used. A commercially available 1 ml syringe can have a barrel inner diameter of about 6 6 mm, a 3 ml syringe can have an internal diameter of barrel of approximately 8 6 mm, while a 10 ml syringe can have a barrel inner diameter of approximately 14 5 mm Unfortunately, during the jet wash of vascular access devices, syringes of different nominal size generate substantially different pressures in the Solution being injected by the same force being applied to the syringe plunger rod For example a force of 0 703 kg / cm2 on the plunger rod can cause a 10 ml syringe to generate 2 812 kg / cm2 of liquid pressure, while a 3 ml syringe generates 7 733 kg / cm2 and a 1 ml syringe generates 13 357 kg / cm2 Pressure control is very important during jet washing procedures for detection No resistance to flow or occlusion catheter, and to avoid overpressure due to the danger of dislodging a clot or breaking the catheter According to this, many practitioners believe that they prefer the syringe of 1 0 ml in size, because when using the 10 ml syringe it is easier to observe the possible occlusion of the catheter and it is less likely to provide excessive pressures, which could dislodge a blood clot or damage the catheter Furthermore, it is important in the jet wash procedure not to draw blood back to the catheter where it can be coagulated and seal the catheter In order to prevent blood reflux into the catheter, the user is encouraged to maintain positive pressure on the line
during the jet wash procedure This may involve slowly removing the syringe and cannula from port IV, while still applying pressure to the syringe plunger rod When a syringe with an elastomer plug is used, if the cap is compressed by the action of the plunger rod, the release of the plunger rod causes the plug to expand and may cause blood to enter the catheter line. Although a wide variety of iv port catheters and ports may be adequately flushed using Currently available syringe assemblies, there is still a need for simple, direct, easy-to-manufacture syringe assemblies, which eliminate the substantial variations in pressure possible with the present syringes and minimize the potential to accidentally draw blood into the catheter during the procedure. flushing
BRIEF DESCRIPTION OF THE INVENTION A syringe assembly comprises a syringe barrel having an elongate body defining a fluid retaining chamber, an open proximal end, a distal end and a truncated-conical tip extending from the distal end having a pointed passageway through it in fluid communication with the chamber The chamber has an internal diameter of at least 13 5 mm The chamber has a distal end defined by a distal wall through which the passageway passes A stopper is in fluid communication with the inside of the barrel A rigid, elongated plunger rod extends in a manner
proximal from the cap through the open proximal end of the barrel and contains a flange at its proximal end. The flange is configured and positioned to limit the distal movement of the plunger rod in the barrel by contacting the proximal end of the barrel. A tip cap is releasably connected to the tip to seal the passageway and the chamber contains injectable liquid In another embodiment, the plug and the plunger rod are dimensioned so that when the plunger rod tab contacts the proximal end of the barrel, there is a space between at least a portion of the distal end of the plug and the distal wall of the syringe barrel In another embodiment, a syringe assembly comprises a syringe barrel having an elongate body defining a chamber for holding the fluid, an open proximal end , a distal end and a truncated-coma shaped tip extending from the distal end and having a phantom passageway. Through it in fluid communication with the camera The camera has an internal diameter of at least about 13 5 mm The camera has a distal end defined by a distal wall through which the passage passes The length of the camera does not is more than about 57 mm A plug is in close fluid communication with the inside of the barrel An elongated piston rod extends proximally from the plug through the open proximal end of the barrel In this embodiment, the plunger rod does not necessarily have a tab at its proximal end, and the plunger rod flange does not necessarily limit the distal movement of the plunger rod in the barrel
BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view illustrating a prior art syringe assembly and needle assembly. Fig. 2 illustrates a syringe and needle assembly of the prior art being used to jet wash an ivy site. a catheter Fig 3 illustrates the prior art syringe of Fig 1 with the plunger rod and plug in its most proximal position simulating a syringe filled with liquid for injection Fig 4 illustrates the syringe assembly of the present invention
Fig. 5 is a partially elongated cross-sectional view of the syringe assembly of Fig. 4 Fig. 6 illustrates the syringe assembly of Fig. 4 being used to jet wash an iv site and a catheter. Fig. 7 is a sectional view. elongate cross section of the syringe assembly of the present invention illustrating the syringe assembly after use Fig. 8 illustrates a family of syringes of the present invention having three volumes of 3 ml, 5 ml and 10 ml Fig. 9 illustrates a set containing two syringe assemblies of the present invention in a package that acts as a sterile barrier
DETAILED DESCRIPTION Although this invention is satisfied by embodiments in many different forms, they are shown in the drawings and will be described in detail.
herein, preferred embodiments of the invention with the understanding that the present disclosure will be considered exemplary of the principles of the invention and is not intended to limit the invention to the illustrated embodiments. The scope of the invention will be measured by the appended claims and their equivalents. Referring to Figs. 1-7, the syringe assembly of the prior art 20 includes a barrel 21 having an elongated body 22 defining a chamber 23 for holding fluid. The barrel includes an open proximal end 25, having a flange 26 and a distal end 27 including a tip 28 having a passageway 29 therethrough in fluid communication with the chamber The distal end of the barrel also includes, preferably but not necessarily, a luer-type closure collar 30 concentrically surrounding a tip 28 The luer collar has an internal thread 33 A needle assembly of prior art includes a cannula 38 which There is a proximal end 39, a distal end 40 and a lumen therethrough. The distal end of the cannula can include a sharp tip 43 or a blunt tip (not shown). A hub 44 includes an open proximal end 45 that contains a cavity. and a distal end 47 attached to the proximal end 39 of the cannula 38, such that the lumen of the cannula is in fluid communication with the cavity in the hub. The needle assembly is attached to the syringe through a friction coupling. of the inner surface of the cavity and the outer surface of the tip 28 The hub also includes radial projections 42 at its proximal end for coupling the thread 33 to keep it secured to the barrel Mounting
Prior art syringe 20 further includes a resilient plug 31 connected to an elongated plunger rod 32 having a flange 34 at its proximal end The 3 ml syringe most commonly used in the United States has a barrel inner diameter of approximately 8 6 mm As best illustrated in Fig. 1, the length of its plunger rod and plug is larger than the chamber in the barrel, so that portions of the plunger rod and plunger rod flange extend proximally from the barrel. open proximal end of the barrel when the stopper has reached its maximum distal position and is resting on the inner distal wall of the chamber Furthermore, the barrel flange is not configured non-circularly, while the plunger rod flange is circularly configured , so that the piston rod flange extends radially beyond the outside of the barrel flange to facilitate the dragging of the bar. plunger and plug in a proximal direction for filling the syringe using known methods In use, the prior art 3 ml syringe assembly is connected to a hypodermic needle assembly and filled with jet wash solution using methods known per se. For example, the syringe with the attached needle assembly is used to pierce the pierceable stopper of a bottle containing a jet wash solution and the wash solution is drawn into the syringe barrel by pulling the plunger rod flange 34. in a proximal direction, while holding the barrel 21, to draw fluid through the needle cannula into the chamber of the syringe barrel
The sets iv can be very complicated and include multiple injection ports, a valve and other components. For the purpose of illustrating the present invention, a simplified iv set 48 is illustrated in Fig. 2 Set iv 48 comprises a site iv 51, the which includes a housing 50 having a hollow interior duct 52 and a septum 53 at its proximal end A catheter 49 having a lumen therethrough, extends from the distal end of the housing The filled syringe of the prior art is now ready for use in the flushing of a catheter With the illustrated modality, a sharp tip 43 of the cannula 38 moves to perforate the septum 53 to establish fluid communication between the hollow interior duct 52 of a housing 51 and the barrel chamber of the syringe The syringe is maintained so that the liquid in the syringe the chamber can be forced into the hollow interior passage of the housing and through the catheter by applying digital pressure, such as with the use of the thumb, to the flange 34 to move the plunger rod in a direction distal to the barrel. Because of the relatively small diameter of the barrel of the syringe, the user must be careful not to exert excessive pressure, which could dislodge a blood clot or damage the catheter. In addition, it is important to maintain a positive pressure during the jet wash procedure, in a manner that when the syringe is almost empty, the user should begin to remove the cannula from the septum as the fluid is being expelled. The syringe The previous one has a disadvantage when it is being used with a jet wash syringe, because the length of the plunger rod is so long that the elastomeric plug can be compressed
When the distal end of the chamber is contacted in the barrel If the user compresses the stopper and then releases the pressure on the plunger bar flange, the stopper will expand back to its normal size by withdrawing liquid from the catheter into the barrel of the syringe. is undesirable because this case can cause blood to undesirably enter the catheter at the distal end of the catheter A syringe assembly 55 of the present invention preferably includes a syringe barrel 56 having an elongate body 57 that defines a chamber 58 for retaining fluid The syringe barrel includes an open proximal end 59 having a barrel flange 61, a distal end 62 and a frustum-conical shaped tip 64 extending from the distal end and having a passageway of tip 65 therethrough in fluid communication with the chamber The inside diameter A of the chamber is at least 13 5 mm The chamber 58 includes a distal end defined p The wall of the distal chamber 68 The length of the chamber is illustrated as element C in FIG. 5 and is measured approximately between the distal chamber wall and the proximal end of the chamber. The chamber is the generally constant diameter of the portion of the chamber. constant cross section of the interior of the barrel Although a wide variety of chamber lengths are within the purview of the present invention, the preferred embodiment has a chamber length C, which is not more than about 57 mm with a chamber length of no more than about 44 5 to 38 1 mm being desirable for many applications A plug 70 is in close fluid coupling within the barrel An elongated plunger rod 73 having a distal end 75
and a proximal end 76 defining a longitudinal axis 74, extends proximally from the stopper through the open proximal end of the barrel. In this embodiment, the plunger rod and the stopper are separate elements. The stopper is preferably made of a elastomeric material selected from the group of natural rubber, synthetic rubber, thermoplastic elastomers or combinations thereof The piston is preferably made of a rigid thermoplastic material The piston rod 73 includes a distally directed threaded extension 74, which is coupled to a threaded recess 71 in the cap 70 In this embodiment, the syringe can be assembled without the plunger rod for purposes such as conserving space or reducing the packing material, and the plunger rod can be mounted to the cap at the time of use by simply screwing the plunger rod into the plug There are many ways to connect the plug to a plunger rod including the structure of a Pressure adjustment, adhesives, welding and two-shot molding, where a plug of a material is molded with a plunger rod of another material The screwed-in arrangement described above is considered an example of these many possibilities It is also within the scope of this invention, including a plunger rod assembly and a one-piece plug, wherein the plug and the plunger rod are made of the same material. As will be explained in more detail below, it is preferred that the tab 77 be configured and positioned to limit the distal movement of the plunger rod in the barrel when contacting the proximal end of the barrel instead of having the run of the plunger rod and stopper limited by the cap that is compressed against the chamber wall
distal 68 Ideally, the flange should stop the forward movement of the plug as soon as the distal face 72 of the plug contacts the distal chamber wall 68 When there is a space between at least a portion of the distal end or distal face of the distal end. plug and the distal barrel wall Since manufacturing tolerances will vary, it will be up to the manufacturer to choose whether there should be an opening between the plug and the distal barrel wall or a slight plug deviation when the plunger rod tab contacts the end proximal syringe barrel In any case, it is not desirable to have excessive compression of the plug, which, upon release of the plunger rod, can draw blood to a catheter during a jet wash procedure. A tip cap 80 is releasably connected to the tip. sealing the passageway 29 It is preferred that the tip cap be formed of material selected from the group of thermoplastic material and elastomeric material, the elastomeric material being preferred The syringe assembly of the present invention may contain fluid volumes from about 1ml to 10ml , wherein the preferred embodiment contains no more than 3 ml of injectable liquid 82 in the chamber. It is preferred that the injectable liquid be selected from the group consisting of saline jet wash solution and hepapillary jet wash solution. Solutions are known in the art and are readily available. An example of a jet wash solution is chlorur or sodium 0 9% USP An example of a hepap closure jet wash solution is sodium chloride 0 9% with 100
USP units of hepapna sodium per ml or 10 units USP of hepapna sodium per ml The materials for the barrel of syringe, cap tip and cap will have to be chosen based not only on the performance but on the compatibility with the injectable liquid In this preferred embodiment, the syringe assembly is pre-filled with injectable liquid. There may be a substantial amount of time between when the syringe assembly is filled and when the contents of the syringe assembly are delivered. Accordingly, the materials chosen from the syringe assembly may have to be stable under long-term storage The syringe assembly contains volume metering indications 83 in the elongate body 57 The volume metering indications in the preferred embodiment show volumes up to 30 ml However, because the syringe assembly is pre-filled preferably, the indications can be limited to the exact amount of liquid in the syringe, by axis 0.3 ml One important feature of the present invention over the prior art syringes of 3 ml smaller diameter is that the larger diameter barrel provides a satisfactory area for printed or marked instructions or a description of the contents of the syringe. syringe The syringe assembly 55 can be used to flush catheters having IV sites in a similar manner as that described above for the prior art syringe. However, there are several major differences and advantages when using the syringe assembly of the present invention. using the syringe assembly 55 in a washing procedure to
The user first removes the tip cap and applies a needle assembly so that the needle assembly 37 or a needle assembly having a blunt tip if the IV site has a pre-split septum. Also in IV sites having a valve the user removes the tip cap and applies the syringe directly to the valve. The syringe assembly 55 is illustrated in Fig. 6 as being used with the needle assembly 37 and the iv site. 50 When the needle assembly is applied to the barrel The mounted unit is moved in position so that the sharp point 43 of the needle penetrates the septum 53 and enters the hollow internal conduit 52 of the housing 51. The usapo now advances the plunger rod in the distal direction by applying digital pressure to the syringe. the flange 77 for ejecting the contents of the syringe into and through the catheter A major advantage of the syringe assembly of the present invention is that the fluid pressure will be only about one third of Fluid pressure if a 3 ml syringe of the prior art was being used by applying the same force to the plunger rod The reduced pressure makes it easier for the user to determine if the catheter is open and reduces the possibility of dislodging a clot or breaking the catheter Also if syringes of larger volumes are used having the same diameter the general feeling of the syringe and the technique will remain consistent from syringe to syringe so that the sensation and the touch and forces applied to wash the catheter with the syringe of 3 ml of the present invention are the same as a 10 ml syringe having the same diameter
A further advantage of the present invention, as best illustrated in FIGS. 6 and 7 is that the distal movement of the plunger rod is limited by the flange 77 contacting the distal end 59 of the barrel. As previously mentioned, it is important to maintain a positive pressure in the intravenous line to prevent the reflux of blood in the catheter lumen. This can be conveniently achieved by partial removal of the septum cannula during injection of the final volume of injectable liquid. It is an important advantage of the present invention that maintains positive pressure in the line for two reasons. First, at the end of the delivery of fluid, the plunger rod flange 77 is in contact with the proximal end of the syringe barrel and is not exiting or detached from the proximal end of the barrel as the syringe of the prior art as illustrated in Fig. 1 Therefore, an inadvertent or accidental movement of the bar of embo is avoided it in a proximal direction, to create negative pressure in the line In this preferred embodiment, the plunger rod flange 77 is dimensioned and configured to be smaller than the barrel flange 61 in all dimensions measured radially from the longitudinal axis of the plunger rod Accordingly, the plunger rod tab can not be pulled again at the end of its run. Many syringes of the prior art contain a round plunger bar flange and an oblong or noncircular barrel flange, so that When the plunger rod flange is near the barrel flange it is still larger in a radial direction to facilitate the movement of the piston rod in a proximal direction with respect to the barrel. However, since the
syringe assembly of the present invention is pre-filled preferably, there is no need to have such easy access to the plunger rod flange Secondly, it can be seen in Fig 7 when plunger rod flange 77 is in contact with its proximal end 56 of the distal end of syringe barrel or distal face 72 of the cap separated from the distal chamber wall 68 of the syringe barrel This configuration prevents the cap from being compressed excessively against the distal chamber wall If the bar The plunger is long enough to allow substantial compression of the plug, the release of force on the plunger rod will allow the plug to expand and possibly pull fluid from the catheter and allow blood to enter the tip of the catheter. it is preferred that the effective length B of the plug and the plunger rod is measured from the distal side of the plunger rod flange 77 to the distal end 72 of the plug to be 51 mm or smaller
Accordingly, the syringe assembly of the present invention has two major advantages over syringes of the prior art, since its large diameter, never again available in a 3 ml syringe, reduces the pressures associated with jet washing a catheter iv, making it easier for the user to detect a clot and less likely that fluid pressures will damage the catheter Additionally, reflux is prevented or minimized substantially by having a plunger bar flange, which limits the stroke of the bar of plunger and plug assembly so that the plug can not be substantially compressed
on the barrel wall of distal syringe, which can cause reflux of fluid and blood to the catheter Syringe assembly 55 can be provided in a tear or brittle package, which provides an obvious barrier to alterations surrounding the syringe assembly Materials such as paper, coated paper, plastic film, sheet and combinations thereof, can be used for such purposes. Tearing of the package can be evidence that the syringe has been used or altered. The syringe assembly 55 can also be provided at a package that provides a sterile barrier surrounding the syringe assembly A package, which constitutes a sterile barrier, which provides substantial resistance to the passage of microorganisms, can be made of many known materials, such as paper, coated paper, plastic film , sheet, non-woven materials and combinations thereof If the package is made of tear-off materials or suitable fragile, it can function as a sterile barrier and as a package in which alterations are evident To assemble the packaged syringe, the syringe assembly 55 can be sterilized after filling and can be placed in the package or placed in the package and sterilize, or be sterilized, placed in the package and sterilized a second time. In addition to the preferred syringe assembly 55 of the present invention, as illustrated in FIG. 8, other embodiments of the present invention include a syringe assembly 85 which they have a capacity of approximately 5 ml and a syringe assembly 95 that has a capacity
of about 10 ml The three syringe assemblies have an inner diameter of at least about 13 5 mm Referring to Fig 9, a catheter jet wash assembly comprises a first syringe assembly 1 00 and a second syringe assembly 1 01 Each of the syringe assemblies includes a syringe barrel (102, 103) having an elongate body (104, 105), which defines a chamber 1 06, 107 to retain fluid. Each barrel of the syringe includes an open proximal end 1 1 0, 1 1 1, a distal end 1 12, 1 13 and a truncated-conical tip extending from the distal end and having a tip passage 1 16 and 1 17, through which it is in communication of fluid with the chambers 106 and 1 07 Each chamber has an inner diameter of at least 13 5 mm and a distal end defined by a distal wall 1 1 8 and 1 19 through which pass the passageways A plug 120 and 121 is in tight fluid coupling inside each barrel The elongated piston rods 122, 123 define longitudinal axes and extend proximally from the plugs through the open ends of the barrels The flanges 1 24 and 125 are positioned at the proximal ends of plunger rods 122 and 123 The flanges 124 and 125 are placed at the ends proximal plunger rods 122 and 123 A tip cap 126 and 127 seals the passageway of each syringe The first syringe 100 has no more than about 3 3 ml of a first injectable liquid 1 30 in chamber 106 The second syringe assembly does not it has more than about 10 ml of a second injectable liquid 1 31 in the chamber 107 The injectable liquids are selected from the group consisting of saline jet wash solution
hepapna The syringe assemblies 100 and 101 are contained in a package 132, which preferably provides an obvious barrier to alterations surrounding the syringe assemblies The piston rod flange in at least one of the syringe assemblies, is configured and positioned to limit the distal movement of the plunger rod in the barrel by contacting the proximal end of the barrel