Tip shield for needle stick prevention

A vascular access system for preventing needle sticks includes a needle, a tip shield, and a housing. The needle may be a hypodermic needle or other conventional needle having a needle shaft terminating at a needle tip. The tip shield provides an enclosure defining a chamber. The enclosure includes a closed distal end and a proximal end that slidably engages the needle shaft. The enclosure further includes at least one side wall configured to slidably engage the needle shaft. The housing defines a passageway with respective proximal and distal openings through which the needle extends. The tip shield is also disposed in the passageway and is releasably retained therein. The needle and/or the tip shield is adapted to prevent the needle shaft from being completely withdrawn from the tip shield. The tip shield further secures the needle tip in the chamber upon withdrawal of the needle tip into the chamber.

BACKGROUND OF THE INVENTION

This disclosure relates generally to vascular access systems and methods, including hypodermic needles, needle assemblies, catheter assemblies, and devices used with catheter assemblies. Generally, vascular access systems are used for communicating fluid with the vascular system of patients and may include one or more vascular access devices. For example, catheters are used for infusing fluid, such as saline solution, various medicaments, and/or total parenteral nutrition, into a patient, withdrawing blood from a patient, and/or monitoring various parameters of the patient's vascular system.

Intravenous (IV) catheter assemblies are among the various types of vascular access systems, and over-the-needle peripheral IV catheters are a common IV catheter configuration. As its name implies, an over-the-needle catheter is mounted over an introducer needle having a sharp distal tip. The introducer needle is generally a hypodermic needle forming a part of a needle assembly to help guide the needle and to facilitate its cooperation with the catheter. At least the inner surface of the distal portion of the catheter tightly engages the outer surface of the needle to prevent peelback of the catheter and thus facilitates insertion of the catheter into the blood vessel. The catheter and the introducer needle are assembled so that the distal tip of the introducer needle extends beyond the distal tip of the catheter with the bevel of the needle facing up away from the patient's skin. The catheter and introducer needle are generally inserted at a shallow angle through the patient's skin into a blood vessel.

In order to verify proper placement of the needle and/or catheter in the blood vessel, the clinician generally confirms that there is “flashback” of blood in a flashback chamber, which is generally associated with a needle assembly. Once proper placement of the distal tip of the catheter into the blood vessel is confirmed, the clinician may apply pressure to the blood vessel by pressing down on the patient's skin over the blood vessel distal of the introducer needle and the catheter. This finger pressure occludes the vessel, minimizing further blood flow through the introducer needle and the catheter.

The clinician may then withdraw the introducer needle from the catheter. The introducer needle may be withdrawn into a needle tip shield or needle shield that covers the needle tip and prevents accidental needle sticks. In general, a needle tip shield includes a housing, a sleeve, or other similar device that is designed such that when the needle is withdrawn from the patient, the needle tip will be trapped/captured within the needle tip shield. The purpose of the needle tip shield is to house the tip of the needle in a secure location, thereby reducing the possibility of needle sticks when the needle and needle tip shield are separated properly from the catheter, which is left in place to provide intravenous access to the patient.

The separation of the needle assembly from the catheter portions of the catheter assembly presents numerous potential hazards to the clinicians and others in the area. As indicated above, there is a risk of accidental needle sticks if the needle tip is not secured properly in a needle tip shield. Additionally, because the needle has been in contact with blood in the patient's vasculature, blood is often present on the exterior of the needle and is often present inside the lumen of the needle. As the needle is withdrawn, there is a risk that this blood will drip from the needle tip or come into contact with other surfaces to expose clinicians and equipment to blood. The present disclosure presents systems and methods to significantly limit and/or prevent needle sticks, and in some implementations, blood exposure.

SUMMARY OF THE INVENTION

The systems and methods of the present disclosure have been developed in response to problems and needs in the art that have not yet been finally resolved by currently available vascular access systems and methods. Thus, these systems and methods are developed to provide safer vascular access systems, methods of manufacturing the same, and methods of using the same to reduce needle sticks.

A vascular access system within the scope of the present invention includes a hypodermic needle, a tip shield, and a housing. The needle includes a needle shaft that terminates at a needle tip. The tip shield includes an enclosure defining a chamber. The enclosure includes at least one side wall configured to slidably engage the needle shaft, a closed distal end, and a proximal end slidably engaging the needle shaft. Accordingly, the tip shield may be disposed at an angle with respect to the needle when the needle extends through both the side wall and the proximal end of the tip shield. The housing of the vascular access system defines a passageway with respective proximal and distal openings through which the needle slidably extends. The proximal opening of the housing releasably retains the tip shield in the passageway. Through a variety of possible implementations, at least one of the needle and the tip shield are adapted to prevent the needle shaft from being completely withdrawn from the tip shield. Additionally, the tip shield is adapted to secure the needle tip in the chamber upon withdrawal of the needle tip into the chamber.

In some implementations, vascular access systems within the scope of the present invention include a needle having an enlarged shaft region proximate to the needle tip. The enlarged shaft region cooperates with and engages an opening in the proximal end of the tip shield adapted to slidably engage the needle shaft without allowing the enlarged region to pass proximally through the opening. Additionally or alternatively, some implementations may include a tip shield having an elongate hollow body defining the chamber and a needle shaft port, which may be in a side wall of the elongate body. In such implementations, the needle shaft extends through the opening in the proximal end of the tip shield and the needle shaft port when the needle is disposed in the housing, which disposes the tip shield at an angle with the needle shaft. The opening in the proximal end of the tip shield may be configured as a pivot hole that engages the enlarged shaft region during proximal movement of the needle relative to the housing and further proximal movement of the needle relative to the housing causes the tip shield to pivot at the pivot hole drawing the needle tip into and through the needle shaft port and into the chamber.

These and other features and advantages of the present disclosure may be incorporated into certain embodiments and will become more fully apparent from the following description and appended claims, or may be learned by the practice of the methods and use of the systems as set forth hereinafter. The present disclosure does not require that all the advantageous features and all the advantages described herein be incorporated into every embodiment.

DETAILED DESCRIPTION

The presently preferred embodiments of the present disclosure will be best understood by reference to the drawings. It will be readily understood that the components of the present disclosure, as generally described and illustrated in the figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description, as represented in the figures, is not intended to limit the scope of the claims, but is merely representative of presently preferred embodiments.

Referring toFIG. 1, the perspective view illustrates an example of an extravascular system10, or vascular access system, including multiple vascular access devices12. In this example, the extravascular system10includes a catheter assembly14and a needle assembly16. The catheter assembly14has a proximal end20and a distal end22and includes a catheter24having an opening28at the distal end22of the catheter assembly14and a catheter hub26disposed at the proximal end20of the catheter assembly14. The catheter assembly14also defines a lumen30extending from the proximal end20to the distal end22.

Proximal end20of catheter assembly14may be configured in any suitable manner to facilitate its cooperation with other vascular access devices. Two exemplary configurations are illustrated inFIG. 1. Shown in solid lines inFIG. 1, the catheter assembly proximal end20may be configured with positioning ridges and grooves32adapted to coordinate with similar features on adjoining devices. The positioning ridges and grooves32are examples of coupling systems that may be used to position and/or retain another vascular access device, such as adapters, flow control plugs, dead-ender caps, or other devices (not shown), attached to the catheter hub26in a desired orientation. Other suitable coupling and positioning systems may be used. For example, traditional Luer lock features may be included, which may be male or female Luer lock configurations.FIG. 1further illustrates, in dotted lines, that the catheter assembly14may optionally be configured with an activating housing34adapted to cooperate with particular aspects of the present vascular access systems. The activating housing34will be described in greater detail below, including at least with reference toFIG. 3. The activating housing34is one example of a housing36within the scope of the present disclosure.

Continuing withFIG. 1, the vascular access system10includes a needle assembly16includes a hypodermic needle40having a needle shaft42adapted to extend through the lumen30of the catheter assembly14. The needle tip44and other aspects of the needle40are obscured inFIG. 1by the position of the tip shield60and will be illustrated and described in connection with subsequent figures. The illustrated needle assembly16includes a needle hub46, which may be provided in some implementations to facilitate the insertion, removal, and control of the needle40and the needle assembly16generally. The proximal end of the needle assembly16may be adapted to cooperate with yet additional vascular access devices12, such as a flow control plug48as illustrated inFIG. 1.

While the needle assembly16illustrated inFIG. 1is configured for use with the catheter assembly14, other needle assemblies and vascular access systems within the scope of the present invention may include hypodermic needles (not shown) adapted for other applications. For example, the needle assembly16may or may not include the needle hub46of the configuration illustrated. Additionally or alternatively, the vascular access systems of the present disclosure and invention may be adapted for use in injections rather than in cooperation with catheters.

FIG. 1further illustrates that the extravascular system10may include an optional adapter housing50. The adapter housing50, when included, may be configured to cooperate with the tip shield60, such as to accommodate the tip shield60during use of the extravascular system10and to activate the tip shield60when the needle40is being withdrawn from the catheter assembly14. The adapter housing50is illustrated schematically inFIG. 1representative of the variety of configurations the adapter housing may take in cooperating with aspects of the needle assembly16and the catheter housing14. For example, the distal end52of the adapter housing50may be configured with Luer lock features (not shown) to cooperate with mating Luer lock features on the catheter hub26. Similarly, the proximal end54of the adapter housing50may be adapted to coordinate with the needle hub46or other aspect of the needle assembly16. The adapter housing50is yet another example of a suitable housing36within the scope of the present disclosure.

With continuing reference toFIG. 1, the needle tip44is illustrated as being housed within the tip shield60. The tip shield60shown inFIG. 1is representative of needle shield60within the scope of the present disclosure. As used herein, the term tip shield60shield refers to a structure that is adapted to be positioned adjacent to the needle tip44when the needle tip has been withdrawn, such as withdrawn from the catheter assembly14or a patient's vascular system, to encapsulate the needle tip42.

FIG. 2provides an illustrative cross-sectional view of a portion of the extravascular system10, including the catheter assembly14, the adapter housing50, and the needle assembly16. As seen inFIG. 2, the catheter assembly14and the adapter housing50are adapted to associate proximal end20to distal end52. Additionally, the proximal end of the adapter housing50associates with the distal end of the needle hub46. The adapter housing50defines a passageway54having a proximal opening56and a distal opening58. As shown inFIG. 3, the adapter housing50accommodates the tip shield60within the passageway54.

Moreover, the proximal opening56of the housing50is configured to releasably retain the tip shield60within the housing. The retention of the tip shield60may be accomplished by disposing the side walls of the proximal opening56close enough together to create a frictional fit between the tip shield60and the proximal opening of the housing, as illustrated. Other suitable configurations may be utilized to releasably retain the tip shield60in the housing50, such as disposing a yielding finger or other extension member into the path of the proximal opening56that allows the tip shield60to pass only under a certain minimum force. The releasable retention of the tip shield60may be implemented to limit or prevent the inadvertent separation of the needle assembly from the catheter assembly14. Additionally or alternatively, the releasable retention of the tip shield60may be configured to assist in the activation or transition of the tip shield from a use position (as seen inFIG. 2) to a protection position (as seen inFIG. 1).

FIG. 2further illustrates that extravascular system10may include one or more blood stabilizing materials38to further limit the risk of blood exposure. As seen inFIG. 2, the blood stabilizing material38is disposed inside the passageway54of the housing50. Additionally or alternatively, blood stabilizing materials may be disposed inside or outside the adapter housing50, inside and/or outside the tip shield60, or in any other suitable location to control the spillage or flow of blood. The blood stabilizing material38is shown schematically to represent the variety of manners in which such material may be incorporated into the present vascular access systems and devices. The blood stabilizing material38may be a coagulant, an absorbent, or another material for stabilizing the blood to reduce the exposure risk. Similarly, the blood stabilizing material38may be a liquid, a solid, a gel, a powder, granular, or any other consistency appropriate for its use. The blood stabilizing material38may be disposed in a porous membrane or container (not shown) that allows the blood to enter while preventing the exit of the blood stabilizing material38.

Once the blood has been stabilized by absorption and/or coagulation by contact with the blood stabilizing material38, the risk of blood being splattered is significantly reduced and the exposure risk is still further minimized due to the stability of the blood (i.e., being coagulated or absorbed, the blood does not contaminate other objects or persons). The clinician is then left with a single, defined source of blood exposure risk at a distal exterior surface of the needle tip shield60. The implementation of blood stabilizing material38together with the housing36configured to allow the tip shield to close before the needle40is completely withdrawn may further reduce the risk of blood exposure.

As suggested, the housing36, whether implemented as part of a catheter assembly, as a separate adapter, or as part of a needle assembly, may be adapted to allow the tip shield60to close or otherwise entrap the needle tip44before the needle is fully withdrawn.FIG. 2provides an exemplary illustration of a tip shield60including needle trap means configured to allow the needle shaft42to slide within the trap means while securing the needle tip44once it is withdrawn into the tip shield. For example, and as illustrated inFIG. 2, the tip shield60may include an enclosure62including at least one side wall64, a closed distal end66, and a proximal end68. The proximal end may be adapted to slidingly engage the needle shaft42, such as through an opening (not shown inFIG. 2). Similarly, at least a portion64of the side wall of the enclosure62may be adapted to slidingly engage the needle shaft42. For example, a side wall may be provided with a needle shaft port72adapted to slidingly engage the needle shaft42.

To prevent the needle40from being withdrawn proximally from the tip shield60, thereby exposing the needle tip44, at least one of the needle40and the tip shield60may be configured to retain the needle. For example, the needle shaft42may be provided with an enlarged shaft region74(seen inFIG. 3) proximate the needle tip44or the needle tip itself and the opening in the proximal end68of the enclosure62may be configured to prevent the complete withdrawal of the needle tip44from the tip shield60in the proximal direction. Additionally, the closed distal end66of the tip shield60prevents distal exit of the needle tip44from the tip shield60once the needle tip is disposed within the chamber76defined by the enclosure62.

As will be described in further detail in connection withFIGS. 7-12, the tip shield60is configured to allow the needle shaft to extend through a sidewall64of the enclosure62. Accordingly, with the needle shaft extending through the proximal end of the enclosure and the sidewall of the enclosure, the needle shaft is disposed at an angle with respect to the needle shaft. Depending on the configuration of the needle shaft port72, the angle between the needle shaft and the tip shield may vary. One exemplary relationship is shown inFIG. 2.

Referring now toFIGS. 3-5and13collectively, a cross-sectional view of a needle assembly16and a housing36are illustrated having the needle tip44and the tip shield60in various states of relationship with the housing36. As illustrated, the housing36is representative of both an activating housing34as may be part of a catheter assembly14and an adapter housing50, as well as other housing configurations that may be implemented. One exemplary manner through which the present tip shields60and vascular access systems10reduce and/or prevent needle sticks is illustrated inFIGS. 3-5. Other suitable methods and configurations may similarly be used implementing the principles of the present disclosure. As just one example, the tip shield60may be retained on the needle shaft42through use of a tether (not shown) coupled to the tip shield and the needle hub46where the tether is dimensioned to be shorter than the needle shaft.

FIG. 3illustrates an exemplary relationship between the housing36, the tip shield60, and the needle40when the needle is being withdrawn but before the enlarged shaft region74has entered the tip shield. As discussed above, the needle tip44is being withdrawn proximally and is positioned adjacent the distal opening58of the housing36. The needle shaft42extends through the proximal opening56of the housing36, the proximal end68of the tip shield60, and the sidewall64of the tip shield.

Referring now toFIG. 4, the needle40is shown being further withdrawn in the proximal direction. The enlarged shaft region74, here illustrated as a ferrule, near the needle tip42has passed through the sidewall64of the tip shield and is shown engaged with the proximal end68of the tip shield. It is noted that the enlarged shaft region74may be provided by a ferrule or by other means. As the enlarged shaft region74engages the proximal end of the tip shield, the needle shaft is no longer able to slide through the tip shield and the tip shield position changes from the disposition shown inFIG. 3. As the needle is continually moved proximally relative to the housing, the needle shaft42and the tip shield60will try to move together. However, the proximal opening56of the housing36does not allow such movement without first moving the tip shield60relative to the needle shaft42. As illustrated, the tip shield60rotates becoming more coaxial with the needle shaft. As the needle40and the tip shield60are drawn through the proximal opening56of the housing36, the needle tip44is pressed further into the chamber76of the tip shield60. The length of the tip shield60and the distance from the enlarged shaft region74to the needle tip44may be coordinated to allow the needle tip to be seated in or received by the tip shield. Any suitable length may be used while shorter lengths may be preferred for the convenience of the users and the costs of materials.

It should be noted by comparing the illustrations inFIGS. 3 and 4that the needle shaft port72and the opening in the proximal end68may be configured to allow some movement of the needle shaft to accommodate the rotation of the tip shield relative to the needle shaft. For example, the opening in the proximal end of the tip shield may be configured as a slot having sufficiently narrow width to retain the needle tip in the chamber76and a length sufficient to accommodate the rotation of the tip shield. Similarly, the needle shaft port72or other opening in the sidewall64of the tip shield may be sized to allow such movement.

As the needle40and the tip shield60are further drawn through the proximal opening56of housing36, the tip shield60continues to move relative to the needle shaft to a final position in which the needle tip44is pressed completely through the needle shaft port72into the chamber76of the tip shield to encapsulate the needle tip44, which is best seen inFIG. 5. As illustrated inFIG. 5, the tip shield60is longer than the length of the needle42from the needle tip44to the enlarged shaft region74. Thus, the needle tip44is fully encased within the tip shield60.

The enlarged shaft region74together with the proximal end of the tip shield prevent the needle tip44from exiting the tip shield proximally while the closed distal end66of the tip shield prevents the need tip from exiting distally. As will be seen in the discussion ofFIGS. 7-12, the opening in the sidewall64is configured to prevent exit of the needle shaft42and/or needle tip44once the needle tip is drawn into the chamber76.

The releasable retention of the tip shield60by the housing36may be configured to ensure that the needle tip44is completely received into the chamber76before the needle is separated from the housing. Such a configuration ensures that the needle tip44is not exposed and thereby prevents needle sticks. Additionally, enclosing the needle tip44in the tip shield60before the needle tip44exits the housing may reduce the risk of blood exposure as well.

FIG. 13illustrates essentially the same device as illustrated inFIGS. 3-5, however, the device is provided with a leaf spring150. Leaf spring150biases the tip shield60upwardly as the needle is withdrawn. The leaf spring150simply provides additional force in an upward direction to assure that the needle is ultimately encased within the tip shield60.

FIG. 6presents a cross-sectional view similar to the view ofFIG. 3.FIG. 6schematically illustrates a housing36configured as an activating housing34that is formed as part of the catheter assembly14, or more particularly as part of the catheter hub26. The elements and the relative positions of the elements are the same inFIG. 6as they are inFIG. 3and little more description is necessary. It should be noted that the proximal opening56of the activating housing34may be configured to releasably retain the tip shield and to cause the tip shield to move into a protecting position that is at least substantially coaxial with the needle shaft.FIG. 6is merely a schematic representation of a catheter hub26adapted to cooperate with tip shields of the present disclosure. Other suitable and more developed configurations may be used as well.

Turning now toFIGS. 7-12, additional details of the tip shield are provided along with various examples of methods of constructing the tip shield. For example,FIGS. 7-9provide top plan and perspective views of the tip shield60at various stages of the manufacturing process. The tip shield may be made of any suitable material that is resistant to penetration by a needle tip. In the illustrated configuration ofFIGS. 7-9, the tip shield60is made from a stamped sheet80(FIG. 7) of stainless steel or other suitable, non-corroding metal or plated metal. The sheet80includes a rectangular body82, a dependent proximal disk84with a slot86or other opening of a length sufficient to allow the tip shield60to pivot relative to the needle shaft42, as discussed above, and a width to closely slidably receive the shaft42of needle40but to not pass the enlarged shaft region74. The sheet80further includes a dependent distal disk88, a pair of proximal tabs90, and a pair of distal tabs92. The tabs90,92are optional, but may be used to facilitate the formation of the tip shield60, as seen inFIG. 9. Alternatively, the proximal and distal disks may be coupled and joined to the body through other means.

The body82of sheet80is rolled to form a substantially cylindrical shape, as seen inFIG. 8. The opposing longitudinal edges94and96(shown inFIG. 7) are brought together and rolled inward into the cylinder forming what may be referred to as having a rounded heart-shaped cross-section. The inwardly rolled opposing longitudinal edges are one manner of forming an opening in the sidewall64through which the needle shaft42may extend. The opposing longitudinal edges may form one example of a needle shaft port72. The longitudinal edges94,96may be disposed to be touching or at a spacing that is smaller than the diameter of the needle shaft42. Accordingly, the needle40cannot pass through the needle shaft port72without deforming the body82of the tip shield60. The material and thickness thereof from which the sheet80is made, material properties, bending/forming geometry, the spacing of the edges94,96, heat treatment or temper of the material, and contour (sharp, tapered, or rounded) of the edges94,96can be varied as desired to control resistance due to drag as the needle40is drawn through the needle shaft port72.

While opposing longitudinal edges94,96may be used to form the needle shaft port72, other suitable configurations may be used. For example, the needle shaft port72may include deforming or biased materials, such as plastics, that allow the needle shaft to move in one direction (e.g. to allow the needle tip to be drawn in to the chamber) but not in the other direction (e.g. to allow the needle tip to be moved out of the chamber).

The proximal end68and distal end66of the tip shield are closed by the respective proximal and distal disks84and88, which may be as seen inFIG. 9. This may be accomplished by bending the proximal and distal disks84,88ninety degrees and securing using the proximal and distal tabs90,92. Additionally or alternatively, the disks84,88may be secured to the body82through other means. As illustrated inFIG. 9, the tip shield60defines a tip-receiving chamber76of a length slightly larger than the distance from the enlarged shaft region74to the needle tip44to receive the needle tip44and enlarged shaft region74therein.

While the opening in the proximal end68of the tip shield60is illustrated as a relatively narrow slot86, the opening may be configured in any suitable manner. For example, to facilitate assembly of the needle assembly, the opening in the proximal end68and/or the enlarged shaft region74may be configured to facilitate the passage of the enlarged shaft region distally and to retain or prevent the enlarged shaft region during proximal movement. Additionally or alternatively, the construction or assembly of the needle assembly16may be facilitated through strategic order of operations, such as inserting the needle in the reverse direction so that the enlarged shaft region does not have to pass through the tip shield in a distal direction. Other suitable methods for assembling the components of the present disclosure are available.

Referring toFIG. 10, an exploded perspective view of an alternative tip shield60that includes a body102, a proximal end cap104, and a distal end cap106each molded from a suitable medical grade plastic material. The body102is extruded or otherwise formed to provide a hollow cylinder108of the substantially cylindrical construction illustrated. The substantially cylindrical cross-section includes an opening in the sidewall thereof, which may be provided by a pair of opposing longitudinal edges110. Additionally or alternatively, the plastic tip shield may be molded to provide a more customized needle shaft port73. Due to the flexibility and customizability of plastics, a variety of options may be available for use of plastic as tip shields. For example, the plastic materials may be adapted to provide a better seal against re-emergence of the needle tip and/or to facilitate the operation of the present extravascular systems10.

The proximal end68and the distal end66of the tip shield may be capped by adhesively or ultrasonically affixing the proximal and distal end caps104and106thereto. In addition, the body102may be constructed of two halves which are joined together by sonic welding, adhesives, snap fitting, or any other attachment mechanism. The plastic material and thickness(es) of the material from which the body102is made, material properties, bending/forming geometry, the spacing between edges, any filler materials added to the plastic material, and the contour (sharp, tapered, or rounded) of the edges can be varied as desired to control resistance due to drag as the needle40is drawn through the valve needle shaft port73.

FIGS. 11 and 12provide a schematic illustration of yet another variation on the inventive concepts described herein.FIG. 11is comparable toFIG. 7illustrating that the tip shield60may be formed from a sheet80of metal or other suitable material. However, it should be noted that the body82of the tip shield60shown inFIG. 11includes shaped regions112adjacent the proximal end cap104. Referring toFIG. 12, which illustrates the tip shield60formed from the sheet80ofFIG. 11, it can be seen that the shaped regions112cooperate to form an enlarged opening114in the needle shaft port72. The enlarged opening114may be sized to reduce the frictional resistance against movement of the needle shaft in the needle shaft port72. Accordingly, the shaped regions112may be configured in any suitable manner to create an enlarged opening114suitable for the needle assembly being used (e.g., the enlarged opening114may be larger for larger diameter needle shafts).

Various modifications to the needle tip shields of the present invention are possible while staying within the same inventive concept. For example, the tip shields can be used to protect the tip of any type of sharp, including a cannula in an IV catheter, the tip of a stylet in a long anesthesia needle, a hypodermic needle, surgical blade and other such medical devices. Additionally, the cross-section of the tip shield can be of other shapes such as square, rectangular, triangular, oval, polygonal, and the like.

Still additionally or alternatively, the needle shaft port in the tip shield body can be formed by slitting a pliable tube. In some configurations, the needle shaft port may be held open by a tab or a post-like feature, such as adjacent to the proximal end of the tip shield. The tab or post-like feature may be used in connection with any of the tip shields described above and may be associated with the housing36or other component of the vascular access system. The use of a tab feature to hold the needle shaft port open may reduce the frictional drag on the needle shaft as it is being withdrawn and may enable the tip shield to more completely seal once the tip is received in the chamber and the tab feature is disengaged from the tip shield allowing the needle shaft port to close.

Additionally or alternatively, the enlarged shaft region of the needle may be non-symmetrical and/or may be formed other than by crimping the shaft or affixing a ferrule. Moreover, the enlarged shaft region can be retained to prevent proximal movement beyond the tip shield proximal end by means other than the restricted width of the slot.

As still further variations on the inventive principles of the present application, the means for activating the tip shield may be varied in any suitable manner. For example, in addition to or as an alternative to the restricted opening of the housing and cooperating inclined slope (seeFIGS. 2-6), the needle tip can be pressed or introduced into the chamber of the tip shield by pressure from a biasing member encouraging the tip shield towards the needle shaft.

It is believed that the disclosure set forth above encompasses multiple distinct methods and/or apparatus with independent utility. While each of these methods and apparatus has been disclosed in its preferred form, the specific embodiments thereof as disclosed and illustrated herein are not to be considered in a limiting sense as numerous variations are possible. The subject matter of the disclosures includes all novel and non-obvious combinations and sub-combinations of the various elements, features, functions and/or properties disclosed herein. The principles of the present disclosure may be embodied in other specific forms without departing from its structures, methods, or other essential characteristics as broadly described herein, The described embodiments are to be considered in all respects only as illustrative, and not restrictive. The scope of the disclosure is, therefore, not limited by the foregoing description or the following claims, and all changes that come within the meaning and range of equivalency of the foregoing description and/or the following claims are to be embraced within its scope. Similarly, where the description and/or the claims recite “a” or “a first” element or the equivalent thereof, such description should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements.

It is believed that the following claims are directed to certain combinations and sub-combinations that correspond to disclosed examples and that are believed to be novel and non-obvious. Other combinations and sub-combinations of features, functions, elements and/or properties may be claimed through amendment of the present claims or presentation of new claims in this or a related application. Such amended or new claims, whether they are directed to a different combination or directed to the same combination, whether different, broader, narrower or equal in scope to the original claims, are also regarded as included within the subject matter of the present disclosure.