SEALANT GUARD OF SEALING OF CANNULAFIELD OF THE INVENTION The present invention relates to a cannula and a protective assembly for use with fluid delivery devices such as a hypodermic syringe and more particularly, it relates to a protector having cannula sealing characteristics.
DESCRIPTION OF THE PREVIOUS TECHNIQUEA typical hypodermic syringe includes a syringe barrel with a tapered tip extending from its distal end. The syringe is generally used in combination with a needle assembly having a hub and a needle cannula. The hub is configured to attach the tip of the syringe barrel so that the syringe combination and the needle assembly can be used to fill the syringe barrel with medicament or other liquid for direct delivery to a patient or other fluid delivery apparatus connected to the patient. The prior art teaches a wide variety of needle shields that can be used to re-protect a hypodermic needle after the syringe is filled with medication and prior to delivery to the patient. These shields protect the needle between filling and delivery of the needle. The prior art teaches also prefilled syringes having a needle guard aligned with the elastomeric material which seals the contents of the syringe so that the medicament can not leave the syringe through the needle cannula during storage. These needle shields are especially useful in the commercial environment where pharmaceutical manufacturers fill syringes that are not used for long periods afterwards. However, there is still a need for a simple cannula and the protective assembly that will protect a cannula before use, to be attached to an empty syringe barrel, wherein the shield has cannula sealing features that can be activated manually by the cannula. user after the syringe cylinder is filled with the medication or other liquid.
BRIEF DESCRIPTION OF THE INVENTIONThe present invention relates to a cannula sealing protective assembly comprising a cannula, a shield and a seal plug. A cannula assembly includes the cannula having a proximal end, a distal end and a lumen between them, and a hub having an open proximal end and a distal end attached to the proximal end of the cannula so that the lumen is in the proximal end. fluid communication with the open close end of the hub. The protector has an open proximal end, an open distal end and a side wall between them that defines a recess in the protector. The shield is removably connected to the cannula assembly so that the distal end of the cannula is contained within the recess. The seal plug has a proximal end and a distal end. The seal plug has a distal portion wherein the seal plug projects distally outward from the distal end of the telescope movement guard from the distal portion toward the proximal position. The seal plug includes the structure for sealing the cannula to prevent communication of non-pressurized fluid between the lumen of the cannula and the exterior of the seal plug when the seal plug is in the proximal position. Another embodiment of the present invention includes a cannula sealing shield and the syringe assembly comprising a syringe barrel, a cannula, a shield and a seal plug. The syringe barrel has an elongate body defining a chamber for holding fluid, an open proximal end and a distal end having a tip extending therefrom. The tip includes a passage through it in fluid communication with the camera. The cannula has a proximal end, a distant end and a lumen between them. The proximal end of the cannula is connected to the tip of the syringe barrel so that it is in fluid communication with the chamber. The protector has an open close end, a distant open end and a side wall between them that defines a recess in the protector. The protector is removably connected to the tip of the syringe barrel so that the distal end of the cannula is contained within the recess. The seal plug has a proximal end and a distal end. The seal plug has a position distant from the guard where the seal plug projects outwardly from the remote end of the telescope movement guard from the distant position to a proximal position. The cap includes the structure for sealing the cannula to prevent communication of non-pressurized fluid between the lumen and the exterior of the protector when the cap is in the proximal position.
BRIEF DESCRIPTION OF THE DRAWINGSFig. 1 is an exploded perspective view of the cannula sealing protective assembly of the present invention and a hypodermic syringe. Fig. 2 is a side elevational view of the cannula sealing protective assembly of the present invention affixed to a hypodermic syringe. Fig. 3 is a cross-sectional view of the cannula assembly and the syringe of Fig. 2 taken along line 3-3. Fig. 4 is the cannula assembly and syringe of Fig. 3 illustrating the seal plug in the proximal cannula sealing position. Fig. 5 illustrates an alternative needle cannula assembly.
Fig. 6 illustrates a standard hypodermic needle. Figs. 7 and 8 are cross-sectional side elevational views of an alternative embodiment of the cannula sealing protective assembly of the present invention. Figs. 9 and 10 are cross-sectional side elevation views of another alternative embodiment of the cannula sealing protective assembly of the present invention. Figure 11 is a cross-sectional side elevational view of an alternative embodiment of the present invention wherein the seal plug is capable of sealing the lumen of the cannula. Fig. 12 is a side elevational view of a cannula sealing protective assembly of the present invention that is used with a syringe barrel having a permanently mounted needle cannula.
DETAILED DESCRIPTION While this invention is satisfactory for the embodiments in the different forms, the preferred embodiments of the invention are described in the drawings and will be described in detail herein with the knowledge that the present disclosure is to be considered as illustrative of the principles of the invention and is not intended to limit the scope of the invention to those illustrated embodiments. The scope of the invention will be measured by the appended claims and their equivalents.
With reference to Figs. 1-4, a cannula sealing protective assembly 20 comprises a cannula assembly comprising a cannula 22 having a proximal end 23, a distal end 25 and a lumen 27 therebetween. A hub having an open proximal end 29 and a distal end 31 attached to the proximal end 23 of the cannula so that the lumen is in fluid communication with the open proximal end of the hub. The hub 28 preferably includes radial projections 32 for coupling the "luer" type collar of the syringe barrel or other fluid delivery device, as will be explained in greater detail hereinafter. In this embodiment, the distal end 25 of the cannula preferably includes a blunt tip 33, and the cannula and hub are preferably integrally formed of a thermoplastic material. However, the cannula and the mallet can be formed by. separate and then connect mechanically or bond with adhesives such as epoxy. A guard 35 includes an open proximal end 37, an open distal end 38 and a side wall 39 therebetween defining a recess 40 in the guard. The shield is removably connected to the cannula assembly so that the distal end 25 of the cannula is contained within the recess 40 of the shield. A seal plug 43 includes a proximal end 44 and a distal end 45. The seal plug has a distal position, as illustrated in FIG. 3, wherein the seal plug projects distally outwardly from the end. Distant 38 of shield 35 for telescope movement from the distal position to a proximal position, illustrated in Fig. 4. The seal plug includes means for sealing the cannula to prevent communication of the non-pressurized fluid between lumen 27 of the cannula and the exterior of the protector when the seal plug is in the proximal position. In this modality, the sealing means include the holding conduit 46 extending remotely from the proximal end 44 of the seal plug. The retaining conduit includes an internal surface 47 for sealing engagement with the distal end of the cannula when the seal plug is in the proximal position as illustrated in Fig. 4. It is preferable to include a tapered portion 46 at the proximal end of the seal plug for guiding the distal end of the cannula into the retention conduit when the seal plug moves from the distal position toward the proximal sealing position. In some applications it is preferable to provide the structure or configure the components so that, in normal use of the cannula sealing protective assembly, the seal plug can not be moved from its proximal sealing position through its distal position. Means for preventing the seal plug from moving from the near sealing position to the distal position can be obtained by means of a variety of structures and configurations. The preferred structure includes configuring the seal plug 43 so that it is pushed over the distal position of Fig. 3 towards the proximal sealing position of Fig 4 by applying digital pressure to the contact surface of the finger 50, the The plug comes to rest substantially within the open distal end 38 of the protector 35 In that position, the user is prevented from holding the plug to pull it back to its distal position. Also, the interaction structure can be provided between the shield and the seal plug. to assist in locking the seal plug in the proximal sealing position. Such a structure may include projections and / or recesses on the protector for coupling the projections and / or recesses on the seal plug when the seal plug is in its position. next seal, as will be explained in more detail below in the present seal cap can be held in its distant position to through the mechanical interaction between the protector and the seal plug such as interference structures, friction, threads or the like In this embodiment, the protector includes an annular projection directed inwardly 41 and an annular recess 51 in the seal plug When the The seal plug is in its distal position, as illustrated in FIG. 3, the annular projection 41 in the protector engages the annular recess 51 in the seal plug, to hold the seal plug in its desired axial position with respect to the protector The projection can be of any size from a discrete protrusion to a complete annular ring or, a segmented ring depending on the structural shapes and the selection of materials for the stopper on the shield Likewise, the recess on the seal plug can take a variety of configurations to interact properly with the projection on the protector The structure can also be reversed so that the cap contains the projection and the protector contains the recess The cannula sealing protective assembly of the present invention is suitable for use with a wide variety of fluid delivery devices such as syringes. For purposes of illustration, the protective sealing assembly of cannula 20 is connected to a hypodermic syringe 70 comprising a syringe barrel 71 having a distal end 73, a proximal end 74 and a circular side wall 75 defining a chamber 76 for holding the fluid. The volume measurement indications 72 are on the syringe barrel for measuring the amount of fluid to be delivered or received The distal end of the syringe barrel is connected to the hub 28 so that the lumen of the cannula 22 is in fluid communication with the chamber 76 of the syringe barrel In this embodiment, the distal end 73 of the syringe barrel includes a tip of preferably truncated shape. conical 77 having a conduit 78 therethrough that provides a fluid path between the cannula and the chamber The truncated-conical tip of the syringe barrel fpccionally couples a surface of preferably trunco-conical shape 30 at the proximal end open 29 of the hub The distal end of the syringe barrel also preferably, but not necessarily, includes a luer-type collar 79 that concentrically surrounds the tip 77. The luer collar has an internal threading 80 that couples the projections Radials 32 on the hub 28 to hold the hub secured to the cylinder. It is within the scope of the present invention to include various hub configurations for attachment to a variety of medical fluid handling devices. The club configuration described below in this, which has a truncated-conical inner cavity, reflects one of those diverse possibilities. Many syringes and fluid handling devices, such as robinets and adapters, contain a "luer" strip or "luer" -type accessories to which a hub having an internal truncated-conical cavity will fit. It is within the scope of the present invention to provide a cannula and syringe seal protective assembly wherein the cannula assembly is integrally molded with the syringe barrel. It is also within the scope of the present invention to provide such an assembly wherein the cannula is permanently attached to the tip of the syringe barrel. A detent 82 is placed in the chamber 76 in fluid-tight engagement with the circular side wall 75. An elongate piston plug 83 is connected to the retainer and extends proximally through the proximal end of the cylinder 71. The retainer and the plunger plug can be made in one piece unitary construction. The force applied to the plunger plug causing the sliding movement of the detent in a proximal direction draws the fluid through the conduit 78 into the chamber 76. Conversely the sliding movement of the detent 82 in a distal direction drives the fluid from the chamber 76 through conduit 78 In use, syringe 70 can be filled with medicament or other liquid through a variety of known methods with the cannula assembly attached or removed After filling, the syringe and cannula assembly, without the protector, can be used immediately to deliver the medication or other liquid to a patient either directly or through the skin or through a pierceable septum of an IV equipment or other device if the distal end of the cannula is sharp When the distant end of the cannula is blunt, the medication or other liquid can be delivered through various fluid transfer devices that include equipment IV having previously divided septa that are known in the art The protector, in the embodiment of Figs 1-4, can be removed and installed as many times as necessary between the filling of the syringe and the supply of medicament or other liquid to the patient. It is an important feature of the present invention that the user has the option of sealing the cannula by moving the seal plug from the distal position to the proximal position. This movement can be achieved by pressing the contact surface of the seal plug to move the cap of the seal. seal in a proximal direction There may be a prolonged period between the filling of the syringe and the supply of the medication or liquid During that time the user may wish that the unpre- dicted fluid does not exit through the distal end of the cannula. seal towards the next position the cannula is sealed to avoid communication of non-pressurized fluid between the lumen n and the exterior of the protector. At the time of use, the protector is removed to expose the cannula. Fig. 5 illustrates an alternative cannula assembly 121 that includes a metal cannula 122, preferably made of metal with stainless steel and the hub 128 preferably made of thermopiped material. Cannula 122 includes a proximal end 123 and a distal end 125, having a lumen therebetween. The distal end 125 includes a blunt tip 133. The cannula assembly 121 operates in a manner similar to the cannula assembly 21, in the embodiment of Figs. 1-4. Stainless steel cannulas are desirable because of their strength advantage over thermoplastic cannulas that allow such cannulas to be made of smaller diameters and having a large lumen diameter while still having substantial strength. Fig. 6 illustrates a needle assembly of the prior art 221 that is commonly used to inject medicament into a patient or to transfer fluid through perforable septa such as septa found in medication containers and I V equipment. the needle assembly 221 includes the needle cannula 222 having the proximal end 223, the distant end 225 and a lumen between them. The needle assembly 221 also includes a hub 228 having an open proximal end 229 and a distal end 231 attached to the proximal end of the cannula. The distal end 225 of the cannula further includes a sharp edge 233 capable of penetrating the skin, seals and septa. The preferred embodiment of the cannula sealing protective assembly of the present invention includes a cannula assembly having a blunt cannula. However, it is within the scope of the present invention to include a cannula sealing protective assembly containing a cannula assembly having a cannula with a sharp distal tip such as the cannula assembly 221. FIGS. 7-8 illustrate an alternative cannula sealing protector assembly 320 that is functionally similar to the embodiment of Figs. 1-4. For purposes of illustration, the cannula sealing protective assembly 320 is connected to the syringe 370 having an elongated cylindrical body 375 that defines a chamber 376 for holding the fluid, a proximal end, a distal end 372. A truncated tip -conical 377 extends from the distal end and has a conduit 378 therethrough in fluid communication with chamber 376. A cannula assembly 321 includes a cannula 322 having a distal end 325 that includes a sharp edge 333. A guard 335 having an open proximal end 337, an open distal end 338 and a side wall 339 therebetween defining a recess 340 in the guard. The shield is removably connected to the cannula assembly so that the distal end of the cannula is contained within the recess.
A seal plug 343 includes a proximal end 344, which has a proximal surface 348 and a distal end 345. The seal plug has a distal position where the seal plug projects outwardly from the distal end of the protector for telescope movement from the distal position, as illustrated in Fig. 7, to a proximal position, as illustrated in Fig. 8, where the seal plug seals the distal end of the cannula to prevent fluid communication not pressurized between the passage and the exterior of the protector. In this embodiment, the components are configured so that the cannula 322 is sufficiently long so that when the seal plug 343 is in the proximal position, as illustrated in FIG. 8, the distal end of the cannula is embedded in the the proximal end 344 of the seal plug. Depending on the shape of the sharp edge 333 of the distal end of the cannula and the configuration and material of the seal plug, embedding the needle portion within the seal plug will cause the seal plug to seal the outer surface of the seal Distant from the cannula, the lumen or both are occluded, to prevent communication of non-pressurized fluid between the lumen and the exterior of the shield. The cannula sealing protective assembly is used in a manner similar to the embodiment of Figs. 1-4. Although a wide variety of materials can be used to manufacture the seal plug of the present invention, such as natural rubber, synthetic rubber, thermoplastic elastomer and thermoplastic, softer materials such as natural rubber, synthetic rubber and thermoplastic elastomers are preferred for the stopper of seal 343 of the present embodiment A softer, more elastic material will more easily allow the distal end of the cannula to be embedded within the proximal end of the seal plug. The seal plug can be made of two materials, for example, thermoplastic with an insert elastomeric for the proximal surface Figs. 9 and 10 illustrate an alternative cannula and syringe seal protector assembly. This mode operates in a manner similar to that of Figs. 1-4 except that the cannula 422 and the hub 428 are integrally formed with the cylinder. of syringe 471 A shield 435 has an open proximal end 437, one end is distal open 438 and a side wall 439 therebetween defining a recess 440 in the shield A seal plug 434 includes a proximal end 444 and a distal end 445 The seal plug has a distal position where the seal plug is projected to distance outwardly from the distant open end 438 of the shield, as illustrated in FIG. 9, for telescope movement from the distant position to a proximal position, as illustrated in FIG. 10 FIG. 11 illustrates another alternative embodiment of an assembly. cannula sealing protector of the present invention This embodiment includes the protector 535 having an open proximal end 537, an open distal end 538 and a side wall 539 therebetween defining a recess 540 in the protector A seal plug 543 also includes the projection directed proximally 552 on the proximal end of the seal plug. The projection 552 is configured so that when the seal plug is in the proximal position a portion of the projection 552 is in the lumen 527 of the cannula 522. The embodiment of Fig. 11 also includes means to prevent movement of the plug. seal from the close sealing position to the distant position. In this embodiment the means for preventing such movement include the annular rib projecting inwardly 542 in the protector and the annular recess 553 in the seal plug. When the seal plug moves to its proximal cannula sealing position, by applying pressure to the finger contact surface 550, the annular rib projecting inward 542 fits within annular recess 553 to lock the seal plug in the proximal position. Fig. 12 illustrates another reciprocating syringe and cannula sealing assembly wherein hypodermic syringe 670 includes a syringe barrel 671 having an elongated cylindrical body or side wall 675 defining a chamber 676 for retaining fluid. The cylinder 671 includes a distal end 673 having a distance projecting tip 677 including a tip passage 681 therethrough in communication with the chamber 676. A cannula 622 includes a distal end 625 and a proximal end 623 which is fixedly secured to tip 677 of the syringe barrel. In this embodiment the proximal end of the cannula is positioned within the tip passage 681 and held there by mechanical means or adhesive such as epoxy. In this modalityThe syringe barrel is preferably made of metal such as stainless steel and includes a sharp tip 633. In use, the assembly of this embodiment operates in a manner similar to the assembly of FIG. 11.