Safety needle apparatus

A safety needle apparatus having a needle is provided that includes a first cylinder extending from a proximal end to a distal end thereof and defining a longitudinal axis. The first cylinder further defines at least one longitudinal keyway in a side wall thereof and at least one keyslot disposed adjacent the distal end of the first cylinder. The keyslot is rotationally spaced apart from the at least one keyway relative to the longitudinal axis. The keyway includes a raised surface relative to and disposed adjacent the distal end of the first cylinder. A second cylinder is mounted for relative movement with the first cylinder and defines at least one radially projecting key adjacent a proximal end thereof. The key is configured for axial movement along the keyway such that the second cylinder is movable between an activated position, whereby the key is releasably engaged with a proximal end of the keyway to expose the needle, and a transport position, whereby the key is releasably disposed adjacent the distal end of the first cylinder via an interference engagement with the raised surface of the first cylinder to releasably enclose the needle within the second cylinder. The second cylinder is further movable from the transport position to a locked position, whereby the key is rotated relative to the first cylinder for fixed disposal within the keyslot to fixedly enclose the needle within the second cylinder.

BACKGROUND

1. Technical Field

The present disclosure generally relates to the field of medical needle assemblies for the administration of fluids, and more particularly, to safety shields that prevent hazardous exposure to a needle during use and transport.

2. Description of the Related Art

Problems associated with inadvertent needle sticks are well known in the art of fluid sampling, percutaneous medication injection and other medical procedures involving the use of medical needles. Significant attention is focused on health risks associated with hazardous needle exposure due to the contemporary sensitivity of exposure to AIDS, Hepatitis and other serious blood-borne pathogen exposures. These risks are some of the most prevalent occupational health hazards among healthcare professionals. These professionals are in danger of contracting such blood-borne pathogens from infected patients by inadvertent needle sticks from a contaminated needle employed during dental, medical, laboratory, etc. procedures.

Many known needle shielding devices have been used in an attempt to overcome the health hazards associated with inadvertent or undesired needle stick from a contaminated needle. Some of these devices utilize a separate shielding cap mounted over the needle after use, while other devices employ pivoting, spring activated telescoping shields, etc. These type of structure, however, can require button or lever activation that is prone to accidental engagement resulting in hazardous needle exposure.

In an exemplary dental needle application, a syringe dispenses medication from a medical cartridge that is supported by a barrel or the like. A double-ended needle is mounted to the barrel and has a proximal end that penetrates a seal of the medical cartridge. Medication is delivered by the needle through a distal end thereof to a patient via manipulation of a plunger. Upon removal of the distal end of the needle from the patient, a shield mounted to the barrel is slid from a retracted position to an extended position to cover the needle. Some devices allow the shield to freely slide between the extended and the retracted positions. These configurations, however, may disadvantageously interfere with a procedure or expose the distal end of the needle after use resulting in hazardous exposure to the needle.

Other shield devices employ locking structure to permanently lock the shield in the extended position. See, e.g., U.S. Pat. No. 5,024,660. These type devices, however, do not allow re-exposure of the distal end of the needle for multiple injection procedures, during transport, etc. Further, these devices may disadvantageously require complex relative movements of the barrel and shield to effect locking.

The above mentioned devices may suffer from additional drawbacks such as needle bending during use and moisture buildup on the shield, which can prevent visual inspection of needle travel during a procedure.

Therefore, it would be desirable to overcome the disadvantages and drawbacks of the prior art with a safety needle apparatus that is easily employed to prevent hazardous exposure to a needle during use, transport and upon completion of a procedure to facilitate disposal thereof. It would be highly desirable if the safety needle apparatus was designed to prevent needle bending during use and moisture buildup on a shield of the safety needle apparatus. It is contemplated that the safety needle apparatus is easily and efficiently fabricated.

SUMMARY

Accordingly, a safety needle apparatus is provided that is easily employed to prevent hazardous exposure to a needle during use, transport and upon completion of a procedure to facilitate disposal thereof for overcoming the disadvantages and drawbacks of the prior art. Desirably, the safety needle apparatus is designed to prevent needle bending during use and moisture buildup on a shield of the safety needle apparatus. The safety needle apparatus is easily and efficiently fabricated. The present disclosure resolves related disadvantages and drawbacks experienced in the art.

One of the advantages of the present disclosure is the ability to manipulate the safety needle apparatus to a transport position. For example, during administration of anesthetic medication during a dental procedure, a clinician may desire to set the needle aside and subsequently use the needle to administer additional injections. The safety needle apparatus allows the clinician to slide a shield of the safety needle apparatus in the distal direction into the transport position to perform multiple injections.

The transport position is a releasably retained position and the needle is protected from inadvertent exposure. It is contemplated that an arrow will be molded into a barrel of the safety needle apparatus and universal lock or unlock symbols will be molded on the shield. In the transport position, the arrow of the barrel will be lined up with the unlocked symbol indicating that the safety needle apparatus is in the transport position and not a permanent final lock position. The shield can be moved between the transport position to an active position as deemed necessary by the clinician for additional injections.

During the administration of the medication, additional medication cartridges may be required. By placing the shield in the transport position the safety needle apparatus can be safely removed from a syringe holder and the used cartridge removed and replaced with a new cartridge. The safety needle apparatus is reattached and employed for subsequent injections.

Another advantage of the present disclosure is the ability to manipulate the safety needle apparatus to a final lock position. Upon completion of the desired injections, the shield can be manipulated to the permanent final lock position. Once in the final lock position, the shield can no longer be retracted to expose the needle and the safety needle apparatus is safe for removal and disposal. In the transport position, the clinician can place the safety needle apparatus in the final lock position by grasping the shield and rotating, for example, approximately 45° in either the clockwise or counter clockwise direction.

The clinician may receive confirmation that the safety needle apparatus is in the final lock position by tactile and visual attributes. Tactilely, the clinician will feel the snap as keys of a lock ring of the shield enter the final lock position. Visually, the arrow on the barrel will be aligned with one of the locked symbols disposed adjacent to the unlocked symbol. It is contemplated that there will also be an audible sensation as the keys snap into the final locked position.

It is contemplated that the safety needle apparatus is available in various lengths for adaptability to a standard barrel. It is further contemplated that the needle lengths may vary.

Other advantages of the present disclosure include manipulation of the safety needle apparatus to the transport and final lock positions without the use of buttons or levers. This configuration avoids associated risks that could result in hazardous exposure to the needle. The shield can be designed with a small inner diameter cylindrical surface at its distal end. Needles that are intentionally or unintentionally bent by the user during injections will be contained within this inner diameter cylindrical surface. This feature maintains the point of the needle facing forward and minimizes piercing of the side wall of the shield. This feature also allows the clinician to re-enter the active position without causing additional bending of the needle or puncturing of the shield.

A cylindrical section can be molded on the barrel near the distal end. The cylindrical section is designed to create a contact fit with the inner diameter surface of the distal end of the shield. This contact fit serves as a moisture barrier when the shield is retracted and the needle is exposed. By blocking the path of the moisture from the patient's mouth to the inside of the shield, the occurrence of shield fogging can be eliminated. Desirably, the safety needle apparatus has a narrow, low profile design allowing minimally restricted access to the patient's mouth and gum areas and allows a clear line of site for injections.

Another advantage of the safety needle apparatus of the present disclosure is avoidance of a clinician's hands being in the direct path of an exposed needle. This is particularly beneficial when the clinician attempts to remove a cap or sheath from a distal end of the safety needle apparatus. For example, the sheath may engage the shield of the safety needle apparatus in an interference fit. The clinician can manipulate the sheath in the distal direction such that the shield slides forward with the sheath and into the transport position. Once the shield is in the transport position, continued application of force on the sheath will detach the sheath from the shield and allow removal. The distal end of the needle will be surrounded by the shield to avoid accidental needlesticks. In another example, the clinician can slide the shield into the transport position by grasping the shield and sliding it in the distal direction. Once in the transport position, the sheath can be safely removed because the protective shield surrounds the needle.

In one particular embodiment, in accordance with the principles of the present disclosure, a safety needle apparatus having a needle is provided that includes a first cylinder extending from a proximal end to a distal end thereof and defining a longitudinal axis. The first cylinder further defines at least one longitudinal keyway in a side wall thereof and at least one keyslot disposed adjacent the distal end of the first cylinder. The keyslot is rotationally spaced apart from the at least one keyway relative to the longitudinal axis. The keyway includes a raised surface relative to and disposed adjacent the distal end of the first cylinder. A second cylinder is mounted for relative movement with the first cylinder and defines at least one radially projecting key adjacent a proximal end thereof. The key is configured for axial movement along the keyway such that the second cylinder is movable between an activated position, whereby the key is releasably engaged with a proximal end of the keyway to expose the needle, and a transport position, whereby the key is releasably disposed adjacent the distal end of the first cylinder via an interference engagement with the raised surface of the first cylinder to releasably enclose the needle within the second cylinder. The second cylinder is further movable from the transport position to a locked position, whereby the key is rotated relative to the first cylinder for fixed disposal within the keyslot to fixedly enclose the needle within the second cylinder.

In an alternate embodiment, the first cylinder includes a barrel and the second cylinder includes a shield mounted to an outer surface of the barrel. The second cylinder may include an elongated shield configured to enclose the needle and a locking ring mounted to a proximal end of the shield. The locking ring defines the key about an inner circumferential surface thereof. The shield may include at least one proximally extending tab that facilitates mounting of the shield within the lock ring. The shield can include a plurality of proximally extending tabs that facilitate mounting of the shield within the lock ring. The tab may be flexibly cantilevered from the shield.

The locking ring may define a plurality of keys about the inner circumferential surface thereof and the first cylinder further defines a plurality of keyslots for disposal of the keys therein. The locking ring may mount with the shield via disposal of the plurality of keys within a plurality of axial slots defined by the proximal end of the shield. The plurality of keys may be equidistantly spaced for corresponding disposal within the plurality of axial slots of the shield.

Alternately, the second cylinder is movable from the transport position to the locked position such that the plurality of keys are rotatable in a clockwise direction and a counter clockwise direction relative to the first cylinder for fixed disposal within the plurality of keyslots to fixedly enclose the needle within the second cylinder.

The proximal end of the shield can include a radial lip that engages the lock ring to facilitate retention therewith. The first cylinder may define a reduced diameter cylindrical portion extending from the distal end thereof. A distal end of the second cylinder is configured and dimensioned to receive an outer surface of the cylindrical portion of the first cylinder in a contacting engagement. The cylindrical portion of the first cylinder may have a circumferential lip that engages the distal end of the second cylinder in an interference fit configured to form a moisture barrier.

Alternately, the first cylinder and the second cylinder include visual indicia that cooperate to provide a visual indication that the second cylinder is in the locked position.

The proximal end of the first cylinder can include at least one radially projecting tab. The tab of the first cylinder is configured for receipt within a cammed slot of a syringe plunger adapter for mounting therewith.

In another alternate embodiment, a dental safety needle apparatus having a double-ended needle cannula includes a barrel extending from a proximal end to a distal end thereof and defining a longitudinal axis. The barrel further defines a pair of diametrically disposed longitudinal keyways in a sidewall thereof and a plurality of keyslots disposed adjacent the distal end of the barrel. The keyslots are rotationally spaced apart from the keyways relative to longitudinal axis. The keyways include a raised surface relative to and disposed adjacent to the distal end of the barrel. The barrel have a reduced diameter barrel tip extending from the distal end thereof.

A shield is mounted for relative movement with the barrel and includes a lock ring mounted to a proximal end thereof. The lock ring has a pair of diametrically disposed radially projecting keys. The keys are configured for axial slidable movement along the keyways of the barrel such that the shield is movable between an activated position, whereby the keys are releasably engaged with proximal ends of the keyways to expose the double-ended needle cannula, and a transport position, whereby the keys are releasably disposed adjacent the distal end of the barrel via an interference engagement with the raised surface of the barrel to releasably enclose the double-ended needle cannula within the shield. The shield is further movable from the transport position to a locked position such that the keys are rotatable in a clockwise direction and a counter clockwise direction relative to the barrel for fixed disposal within the plurality of keyslots to fixedly enclose the double-ended needle cannula within the shield. The lock ring includes raised longitudinal ribs circumferentially disposed thereabout.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The exemplary embodiments of the safety needle apparatus and methods of operation disclosed are discussed in terms of medical needle assemblies for the administration of fluids, and more particularly, in terms of a dental safety needle apparatus that is easily employed to prevent hazardous exposure to a needle during use, transport and upon completion of a procedure to facilitate disposal thereof. It is contemplated that the needle may be shielded during use including storage, transport, fluid infusion and/or collection, subsequent thereto, etc. It is envisioned that the present disclosure, however, finds application to a wide variety of cannula needles and devices for the infusion of preventive medications, medicaments, therapeutics, etc. as well as injections employed during procedures relating to phlebotomy, orthopedic, digestive, intestinal, urinary, veterinary types, etc., to a subject. It is also envisioned that the present disclosure may be employed for collection of body fluids including those employed during procedures relating to phlebotomy, digestive, intestinal, urinary, veterinary, etc. It is contemplated that the safety needle apparatus may be utilized with other medical needle applications including phlebotomy devices, catheters, catheter introducers, guide wire introducers, spinal and epidural, biopsy, aphaeresis, dialysis, blood donor, Veress needles, Huber needles, etc.

In the discussion that follows, the term “proximal” refers to a portion of a structure that is closer to a clinician, and the term “distal” refers to a portion that is further from the clinician. As used herein, the term “subject” refers to a patient that receives infusions or has blood and/or fluid collected therefrom using the safety needle apparatus. According to the present disclosure, the term “clinician” refers to an individual administering an infusion, performing fluid collection, installing or removing a safety needle apparatus and may include support personnel.

The following discussion includes a description of the safety needle apparatus, followed by a description of an exemplary method of operating the safety needle apparatus in accordance with the principles of the present disclosure. Reference will now be made in detail to the exemplary embodiments of the disclosure, which are illustrated in the accompanying figures.

The component parts of the safety needle apparatus are fabricated from materials suitable for medication injections, such as, for example, polymerics or metals, such as stainless steel, depending on the particular medical needle application and/or preference of a clinician. Semi-rigid and rigid polymerics are contemplated for fabrication, as well as resilient materials, such as molded medical grade polypropylene. One skilled in the art, however, will realize that other materials and fabrication methods suitable for assembly and manufacture, in accordance with the present disclosure, also would be appropriate.

Turning now to the figures, wherein like components are designated by like reference numerals throughout the several views. Referring initially toFIGS. 1-11, there is illustrated a dental safety needle apparatus20including a double-ended needle cannula26, constructed in accordance with the principals of the present disclosure. Needle cannula26is suitably configured for medical, dental, laboratory, etc. applications to perform infusion, fluid collection, etc. Dental safety needle apparatus20is advantageously configured to prevent hazardous exposure to needle cannula26during use, transport and upon completion of a procedure to facilitate disposal thereof, as will be discussed below.

Dental safety needle apparatus20includes a first cylinder, such as, for example, barrel22extending from a proximal end21to a distal end23and defining a longitudinal axis x. Barrel22further defines keyways32in a side wall25thereof. It is contemplated that one or a plurality of keyways32may be employed. Keyslots36are disposed adjacent distal end23of barrel22and rotationally spaced apart from keyways32relative to longitudinal axis x. It is contemplated that one or a plurality of keyslots36may be employed. Keyways32include a raised surface, such as, for example, releasable stop40relative to and disposed adjacent distal end23. It is envisioned that releasable stop40may be variously positioned with keyway32.

A second cylinder, such as, for example, shield28is mounted to an outer surface of barrel22for relative movement therewith and includes a lock or locking ring24mounted to a proximal end29of shield28. Lock ring24defines radially projecting keys, including long keys46and short keys48. Long keys46are configured for axial movement along keyways32such that shield28is movable between an activated position (FIG.17), whereby long keys46are releasably engaged with releasable stop40to expose a distal end72of needle26, and a transport position (FIG.18), whereby long keys46are releasably disposed adjacent distal end23of barrel22via an interference engagement with releasable stop40to releasably enclose distal end72of needle26within shield28. Shield28is further movable from the transport position to a final locked position (FIG.19), whereby long keys46are rotated relative to barrel22for fixed disposal within keyslots36to fixedly enclose distal end72of needle26within shield28. It is envisioned that one or a plurality of keys may be employed. It is further envisioned that the first cylinder and the second cylinder may interchangeably include the barrel or the shield.

Dental safety needle apparatus20is advantageously configured to shield dental needles and protect clinicians, including dentists and their assistants from inadvertent needle sticks during the attachment and removal of dental safety needle apparatus20from a syringe adaptor during use, including multiple injections and transport, as discussed. Additionally, dental safety needle apparatus20includes a final lock position to ensure that needle26is not inadvertently exposed after use. Dental safety needle apparatus20device presented can be used with reusable plastic syringe adaptors.

Referring toFIGS. 3-5, barrel22includes keyways32diametrically disposed along a length thereof. Keyways32may be variously disposed about barrel22. Keyways32receive long keys46to facilitate relative slidable movement of lock ring24and barrel22. Keyways32provide sufficient frictional resistance to maintain long keys46adjacent a proximal end thereof such that shield28is held in the active position. It is contemplated that long keys46may be frictionally maintained at various positions along keyways32or that short keys48may be frictionally held therewith.

A radial stop34prevents shield28from traveling beyond a designated position so that shield28cannot be removed. Radial stop34prevents travel of shield28beyond stop34via engagement with shield28, discussed below.

Locking slots36are formed in a distal end of barrel22and configured to receive long keys46, which become trapped therein to lock shield28in the final lock position. From the transport position, shield28and lock ring24are manipulated such that long keys46are rotated about barrel22at an angle α relative to longitudinal axis x, which spans from keyway32to keyslot36. For example, shield28is manipulated such that keys46are rotated approximately 45 degrees, in the clockwise or counter-clockwise direction. After long key46moves distally beyond releasable stop40, long key46engages a key surface47. As shield28and lock ring24are manipulated, key46travels along key surface47and is fixedly disposed in keyslot36for locking shield28in the final locked position. Key surface47has a uniform arcuate surface to facilitate free sliding of long keys46therealong. It is contemplated that key surface47may provide resistance to movement of long keys46by, for example, friction, a raised surface, etc.

Barrel22includes visual indicia, such as, for example an arrow42that cooperates with visual indicia of shield28to indicate whether shield28is in the transport position or the final lock position, as will be discussed. Tabs44are diametrically disposed about proximal end21of barrel22to facilitate attachment with a syringe adaptor, as discussed below.

Referring toFIGS. 6-8, long keys46and short keys48of lock ring24are equidistantly spaced about an inner circumferential surface thereof and guided within axial slots58of shield28for attachment therewith. Shield28may include one or a plurality of slots58. Raised longitudinal ribs50are disposed about an outer circumferential surface of lock ring24. Ribs50are configured to facilitate handling and manipulation of shield28. Universal lock symbols52and unlocked symbols54are disposed on the outer circumferential surface of lock ring24to provide a visual indicia to a clinician in cooperation with arrow42, that shield28is in the transport position or the final lock position. It is contemplated that lock ring24may have other geometric configurations, such as, for example, rectangular, elliptical, etc.

Referring toFIGS. 9 and 10, shield28includes tabs56that extend from proximal end29thereof to facilitate mounting with lock ring24. Tabs56are flexibly cantilevered and compressible to facilitate attachment with lock ring24. Upon compression of tabs56, lock ring24slides onto shield28. Axial slots58are disposed between tabs56and are configured to guide long keys46and short keys48of lock ring24during attachment. Axial slots58have closed distal ends60that interfere with long keys.46and short keys48to restrict distal movement of lock ring24upon attachment to shield28.

Shield28includes an external lip62configured to interfere with a proximal edge of lock ring24restricting proximal movement of lock ring24upon attachment. An internal lip64is configured to prevent removal of shield28from barrel22upon attachment. Raised longitudinal ribs66are disposed about the circumference and along the longitudinal length of shield28to facilitate handling and manipulation of lock ring24and shield28.

Barrel22defines a reduced diameter cylindrical portion90extending from distal end23, as shown inFIGS. 20 and 21. A distal end31of shield28, such as, for example, cylindrical portion91is configured and dimensioned to receive an outer surface of cylindrical portion90in a contacting engagement. Cylindrical portion90has a circumferential lip38that engages cylindrical portion91in an interference fit configured to form a moisture barrier. This configuration advantageously blocks the path of moisture from a subject's mouth to the interior of shield28. In the event that shield28is fabricated from a transparent or semi-transparent material, fogging is substantially avoided or eliminated.

Dental safety needle apparatus20is assembled by compressing tabs56of shield28and sliding lock ring24thereon. Keys46,48of lock ring24slide within slots58of shield28. Lock ring24is disposed about shield28and movement of lock ring24is prevented in the distal direction by interference between keys46,48and distal end60of slots58. Lock ring24is prevented from proximal movement by interference with external lip62. Shield28and lock ring24are attached to barrel22by guiding long keys46within keyways32of barrel22. Internal lip64slides over radial stop34for retention of shield28with barrel22. Shield28and lock ring24are slid into the furthest proximal position for insertion of needle26. Needle26is inserted into barrel22and bonded therein by, for example, a crimped metal insert or epoxy.

Referring toFIGS. 11 and 12, a proximal end70of needle26protrudes within barrel22for attachment to a drug containing cartridge, discussed below. Distal end72of needle26is exposed for injection. Needle sheath30(FIG. 1) is attached to cylindrical portion91of shield28and maintained by interference fit. A clinician is initially protected from proximal end70of needle26by barrel22and from distal end72by needle sheath30.

A medication cartridge74is inserted with proximal end21of barrel22. Medication cartridge74is forced in the distal direction until travel is prevented due to interference with distal end23of barrel22. Proximal end70of needle26penetrates a diaphragm93of medication cartridge74, which prepares cartridge74for use. Dental safety needle apparatus20is manipulated such that proximal tabs44of barrel22are slid into slots76of a syringe adaptor78. Tabs44radially project from barrel22and are configured for receipt within cammed slots76of syringe adaptor78for mounting therewith. A retaining ring80secures dental safety needle apparatus20to syringe adaptor78.

Referring toFIG. 13, in an alternate embodiment, a syringe adaptor178is shown, which is configured for mounting with dental safety needle apparatus20. Dental safety needle apparatus20and cartridge74(FIG. 12) are attached to an adaptor180by sliding tabs44of barrel22into slot182formed in a distal end of adaptor180. Tabs44enter an open portion183of slot182and are rotated clockwise through a base portion184and released. A spring member186, attached to a plunger188, maintains dental safety needle apparatus20and cartridge74under compression.

Spring member186also maintains tabs44within slots182. With tabs44within slots182, shield28and lock ring24can be rotated clockwise or counter clockwise without disengaging dental safety needle apparatus20from adaptor180. To remove dental safety needle apparatus20from adaptor180, plunger188is pulled in a proximal direction to disengage a harpoon190from cartridge74. Dental safety needle apparatus20is moved in the proximal direction and rotated counter clockwise until tabs44align with open portion183. Dental safety needle apparatus20can be removed and discarded or a new cartridge74may be inserted for additional injections.

Referring toFIGS. 15 and 16, another alternate embodiment of syringe adaptor178is shown. Syringe adaptor178includes a plunger280having a blunt end282. Blunt end282is configured for a self aspirating syringe whereby barrel22includes a projection284. Projection284is configured to stretch a diaphragm of cartridge74upon injection to create back pressure for aspiration when plunger280is released. It is contemplated that this embodiment may be employed with harpoon, self aspirating, etc. syringe adaptors. It is contemplated that a flexible adaptor is attachable over a harpoon syringe adaptor to form a self aspirating device.

Referring to FIGS.14and17-19, dental safety needle apparatus20, similar to that described above, is assembled as discussed, sterilized and otherwise prepared for storage, shipment and use. Dental safety needle apparatus20is attached to syringe adaptor78and medication cartridge74, as discussed above. The clinician manipulates the needle sheath30in the distal direction. Needle sheath30engages shield28in an interference fit such that shield28slides forward with needle sheath30into the transport position (FIG.18).

In the transport position, continued application of force on needle sheath30detaches needle sheath30from shield28. Distal end72of needle26is protected by shield28to avoid hazardous exposure. Alternately, the clinician slides shield28into the transport position by manipulating shield28or lock ring24in the distal direction. In the transport position, needle sheath30is safely removed because shield28surrounds needle26.

In use, a clinician (not shown) performs a medication (contained in medication cartridge74) infusion to a subject (not shown) by manipulating shield28in a proximal direction such that long keys46(FIG. 11) of lock ring24overcome the interference of releasable stop40and slide inside keyways36of barrel22. Long keys46slide to a frictional engagement with the proximal end of keyway36such that shield28and dental safety needle apparatus20are disposed in the activated position (FIG.17). Distal end72of needle26is exposed for medication infusion to the subject.

Shield28may be returned to the transport position, for example, for administration of additional injections, transport, etc. by sliding shield28in the distal direction. The transport position is a releasably retained position and needle26is protected from hazardous exposure. In the transport position of dental safety needle apparatus20, arrow42is aligned with unlocked symbol54of lock ring24indicating that shield28is releasably retained to enclose distal end72and not in the final lock position. Shield28can be moved back and forth between the transport position and the active position.

For example, in a dental procedure for administering anesthetic medication the clinician may set dental safety needle apparatus20aside and subsequently administer additional injections. Recapping needle26with needle sheath30is not required when dental safety needle apparatus20is the transport position. It is contemplated that arrow42may be molded with shield28and universal lock52or unlock54symbols can be molded with lock ring24.

Upon completion of all injections, dental safety needle apparatus20is manipulated to the final lock position, as shown inFIG. 19, for safe removal and disposal thereof. Shield28and/or lock ring24are manipulatively rotated approximately 45° in the clockwise or counter-clockwise direction, as discussed, until long keys46become fixedly disposed in locking slots36. Tactilely, the clinician feels a snap as keys46enter slots36. Visually, arrow42on shield28is aligned with lock symbol52. An audible sensation is heard upon snapping of long keys46.

In the final lock position, shield28can not be retracted to expose distal end72needle26and dental safety needle apparatus20is safe for removal from syringe adaptor78and disposal. Other methods of employing dental safety needle apparatus20are also envisioned.