Patent ID: 12251543

DETAILED DESCRIPTION OF THE EMBODIMENTS

The syringe assembly of the invention refers to a syringe having a needle or cannula for injecting a medication or other substance into a patient. The terms needle and cannula are used herein interchangeably to refer to a thin tubular member having a sharp end for insertion into an injection site on a subject. A distal direction is in the direction toward the injection end of the syringe assembly, and the proximal direction is the opposite direction. The axial direction refers to a direction along or parallel to the longitudinal axis of the needle and the needle hub and the radial direction refers to a direction perpendicular to the axial direction.

The syringe is configured to injecting a medication into a patient at a selected depth depending on the medication and the intended depth of penetration. The intradermal layer in adults generally has a thickness of around 2 to 3 mm, so that intradermal injection depth is in a range of up to about 3 mm as measured from the outer surface of the skin. The thickness of the subcutaneous layer varies depending on the age of the patient, gender, body mass index (BMI), and the part of the body where the injection is administered. The subcutaneous region has an average thickness of about 7 mm to about 15 mm. Insulin can be delivered to the subcutaneous region.

The syringe is suitable for use in a method for injections and for injecting a drug to a patient. The description of the embodiments is not to be deemed as limiting. The disclosure is intended to enable the artisan of ordinary skill to practice variants of the syringe described without departing from the scope of the invention. Numerical limitations herein, in the specification and in the claims, are understood to be limited by the modifier “about,” such that minor departures yielding equivalent results is within the scope of the invention. Features or dependent claim limitations disclosed in connection with one embodiment or independent claim may be combined in another embodiment or with a different independent claim without departing from the scope of the invention.

This disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The embodiments herein are capable of being modified, practiced or carried out in various ways. Also, it will be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless limited otherwise, the terms “connected,” “coupled,” and “mounted,” and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings. In addition, the terms “connected” and “coupled” and variations thereof are not limited to physical or mechanical connections or couplings. Further, terms such as up, down, bottom, and top are relative, and are to aid illustration, but are not limiting. The embodiments are not intended to be mutually exclusive so that the features of one embodiment can be combined with other embodiments as long as they do not contradict each other. Terms of degree, such as “substantially”, “about” and “approximately” are understood by those skilled in the art to refer to reasonable ranges around and including the given value and ranges outside the given value, for example, general tolerances associated with manufacturing, assembly, and use of the embodiments. The term “substantially” when referring to a structure or characteristic includes the characteristic that is mostly or entirely present in the structure. Distal refers to a direction or position toward the patient end of the needle and proximal refers to a direction or position away from the patient end of the needle and toward the user of the syringe.

Referring to the drawings, the syringe10includes a syringe barrel12having a proximal end14and a distal end16. The proximal end14receives a movable plunger18and stopper for dispensing the substance contained in the syringe assembly.

A needle hub20is coupled to the distal end16of the syringe barrel12as shown inFIG.1. The needle hub20includes a needle22extending axially from the needle hub and the syringe. The needle hub20is configured for coupling to the distal end of the syringe barrel12. In the embodiment shown, the needle hub20has a substantially cylindrical body24with a proximal end26having outwardly extending radial flange28and a distal end30.

A needle shield assembly32is coupled to the syringe for sliding from an initial retracted position shown inFIG.5to an intermediate position shown inFIG.7, and to an extended position to cover the distal end of the needle after use to prevent re-use of the syringe and prevent inadvertent needle stick shown inFIG.8. The needle shield assembly32includes a base34for coupling to the syringe and a movable shield36for covering the needle after use. In the embodiment shown, the movable shield36slides relative to the base34and with relative to the syringe12.

Referring toFIGS.3and4, the base34is configured for coupling to the syringe and for enabling the shield36to slide with respect to the base34and with respect to the syringe and needle. The base34in the embodiment shown is coupled to the syringe hub20by snapping onto the radial flange28. The base34forms a mounting structure for the shield and for coupling the shield to the syringe for sliding movement to different positions on the syringe and with respect to the needle. The base34includes a body38and a mounting member shown as a cylindrical sleeve40. The body38is configured for receiving and attaching to the shield so that the shield can slide in a longitudinal direction with respect to the syringe and the base. The sleeve40has a configuration for coupling to the syringe barrel12. In the embodiment shown, the sleeve40has a substantially cylindrical shape with a central opening with a dimension for coupling with the syringe barrel. The sleeve40is attached to the syringe barrel to resist axial movement and separation of the sleeve with respect to the syringe barrel12during normal use. The sleeve40can be coupled directly to the syringe in a manner where the shield can rotate on the syringe to a position selected by the user. In one embodiment, the sleeve40is fixed to the syringe barrel12by a suitable mechanical mechanism or by bonding such as by an adhesive or welding.

The base34includes a pair of spaced apart side walls42forming a longitudinal passage43or gap for receiving the shield and allowing the shield to slide longitudinally in the passage43. The side walls42have a top end with inwardly projecting flanges44extending in the longitudinal direction. A bottom wall46extends between the side walls42forming the passage43to form an open portion between the side walls42that is open to a top end of the base. The flanges44, side walls42and bottom wall46capture the shield36for sliding movement relative to the syringe and needle.

A locking mechanism is included in the base34for retaining the shield in one or more selected positions with respect to the base and the syringe. In the embodiment shown, the locking mechanism is in the form of a latch to retain the shield36in a selected position where the latch can be released to allow the shield to slide to another position in the proximal direction. The locking mechanism in the embodiment shown is a spring biased finger48having a proximal end connected to the base34by a spring hinge50to enable the finger48to bend inwardly toward the bottom wall46of the base34and bias the finger48outwardly away from the bottom wall of the base. The finger48has a distal end with a tab52having a distal face54and proximal face56. As shown inFIG.4, the distal face54defines a leading face of the finger48. The proximal face56in the embodiment shown is inclined relative to the longitudinal axis of the base34and inclined outwardly in a distal direction. A substantially flat end face56of the tab52is shown substantially parallel to the longitudinal axis of the finger48and the longitudinal axis of the base34.

The sleeve40is configured for coupling the base34to the syringe and mounting the shield36for sliding movement with respect to the base and the syringe. The sleeve40has a center opening60extending longitudinally with a dimension for receiving the distal end of the syringe. A coupling mechanism is included in the central opening60shown inFIG.4for coupling the sleeve40to the syringe. The coupling mechanism can be one or more detents62on the inner surface of the sleeve that project inwardly to engage and capture the flange28on the needle hub. The detents62are spaced longitudinally from an end wall63to form a recess65to receive and capture the flange28on the syringe barrel12. In one embodiment, the coupling mechanism can be a snap connection that inhibits or prevents separation of the base34from the syringe barrel12and the needle hub20. The detent62as shown inFIG.4can have an angled or slanted proximal face to slide over the radial flange28of the syringe. In other embodiments, coupling mechanism can be an annular ring that can form a snap or interference connection.

The sleeve40in the embodiment shown has an open proximal end to receive the distal end of the needle hub and radial flange28when the base34is coupled to the needle hub or syringe. In one embodiment, the sleeve has a shape and dimension to receive the distal end of the needle hub where the needle can extend distally from the distal end of the sleeve. The passage60can be open at the distal end as shown inFIG.4where the distal end30of the needle hub can project from the distal end of the sleeve40. In one embodiment, the sleeve40has a longitudinal length complementing the length of the needle hub so that the distal end30of the needle hub is aligned with the distal end of the sleeve. Alternatively, the distal end30of the needle hub can be recessed slightly with respect to the distal end of the sleeve. In other embodiments the sleeve can have an end wall with an opening having a dimension to allow the needle to pass through and contact the distal end of the needle hub.

The shield36as shown inFIG.2has a shield body37with a substantially cylindrical shape and an open axial passage64having an open proximal end66and a distal end wall68. The end wall68has a central opening70with a dimension to allow the needle to extend through the shield36a sufficient length to fill and aspirate the syringe and to inject the medication into the patient. The open proximal end66has a dimension to receive the distal end of the sleeve40where the end of the sleeve40can slide into the open proximal end66as shown inFIG.5.

The shield36includes an arm72attached to a side of the shield36and extending in the proximal direction of the shield and spaced radially outward from the wall of the shield with respect to the center axis of the shield36. The arm72is configured for coupling with the base34and sliding relative to the base and the syringe to guide the shield during longitudinal movement of the shield. In the embodiment shown, the arm72has distal end74coupled to the side wall of the shield36and a proximal end76. A thumb tab78is formed on the proximal end76for manipulating the shield and manually pushing the shield in a distal direction relative to the syringe and needle. Ribs80project from opposite sides of the arm and extend longitudinally for mating with the flanges44on the side walls42of the base34. The flanges44contact the top face of the ribs80to capture the arm72in the open passage43of the base formed by the side walls42, the flanges44, and the bottom wall46. The arm is able to slide in the passage43with respect to the base in a longitudinal direction relative to the syringe and the needle. In the embodiment shown, the arm72has a substantially straight distal portion82and an angled proximal portion84.

The arm72includes a locking member to mate with the locking member on the base34to retain the shield in selected positions with respect to the base and the syringe and to lock the shield in an extended position to cover the distal end of the needle after use and prevent re-use of the syringe. The locking member includes a mechanism that mates with the spring finger48of the base34. A locking mechanism is positioned at the distal end of the arm72near the shield36for retaining the shield in a first position and releasing the shield when a force is applied to the end of the arm to allow the arm to slide in the base in a distal direction. The locking mechanism in the embodiment shown has a recessed portion86for mating with the tab52on the spring finger48. The recessed portion86in one embodiment is formed by a first detent88and a second detent90spaced from the first detent88. In other embodiments the recessed portion can be formed in a surface of the arm. The locking mechanism is formed by the detent88, recess86, and detent90.

The first detent88is spaced from a distal surface91of a radial rib93extending from the shield36as shown inFIG.2to form a recessed area95. The first detent88has a leading distal face92that is inclined relative to the longitudinal axis of the arm72and a trailing proximal face94. The proximal face94is shown as being at an incline complementing the incline of the surface54of the spring finger48, although the proximal face can be substantially perpendicular to the face of the arm. The proximal face94has a shape and configuration for mating with the distal face54of the finger48. The second detent90has a configuration to form the recessed portion86and is spaced from the first detent88a distance to receive the tab52of the finger. The second detent90has a leading distal face96and a proximal face98.

The second detent90can have a suitable configuration to allow the tab52of the finger48to slide over the second detent90by applying sufficient force to the arm in the distal direction. The leading distal face96of the detent90has a surface with a configuration to allow the finger to slide over the detent in the distal direction. The trailing proximal face98of the detent90can have a suitable configuration to limit the sliding of the arm over the finger48in a proximal direction toward the proximal end of the base to resist sliding in the proximal direction. In the embodiment shown, the second detent90has a rounded distal face96and a rounded proximal face98to slide over the spring finger48when a force is applied in the distal direction. The recessed portion86is configured to receive the tab52of the spring finger48when the shield36and arm72are in an intermediate position with respect to the base and syringe as shown inFIG.7relative to the initial position shown inFIG.6.

A second locking member on the arm mates with the spring finger48to lock the arm in an extended position to cover the distal end of the needle after use. The second locking member includes a projection or detent100spaced from the first locking mechanism and is positioned toward the proximal end of the arm and proximal to the first locking mechanism. The detent100has an inclined distal face102and proximal face104. The inclined distal face102has a length to enable the spring finger48to slide upward onto the surface of the distal face by applying an axial force to the proximal end of the arm72. The proximal face104in the embodiment shown is angled to engage the tab52of the spring finger48and prevent the arm72from sliding rearward in a proximal direction relative to the base34and the syringe to lock the shield in the extended position to cover the tip of the needle. The arm72has a longitudinal length to slide distally with respect to the syringe a distance to cover the distal end of the needle.

During use, the base34is coupled to the syringe as shown inFIG.5where the base34is connected to the distal end of the syringe and the shield36is in the retracted position. In the retracted position, the distal end of the body of the sleeve40is received in the proximal open end of the shield36. The needle projects from the distal end of the shield as shown inFIG.5andFIG.6a distance for filling the syringe and injecting the medication to the patient. The tab56of the spring finger48is received in the recessed area95of the shield when the shield36is the proximal position relative to the syringe. In one embodiment, the needle has an exposed length of about 6-8 mm extending from the distal end of the shield36when the shield is in the initial retracted, proximal position shown inFIG.5andFIG.6. In one embodiment, the needle has an exposed length of about 6 mm when the shield is in the proximal retracted position. In the retracted position, the tab52of the spring finger48is positioned forward or distally of the detent88to retain the shield in the retracted position. The syringe can be used in the configuration ofFIGS.5and6where the shield36forms a limiter to limit the depth of penetration of the exposed length of the needle. The needle22has an exposed length extending from the shield when the shield is in the proximal position shown inFIG.6to enable the syringe to be filled by piercing a septum of a vial. Needle length less than 6 mm are general difficult to fill from a vial since the needle length may not be sufficient to pierce the septum, particularly when the needle penetrates the septum at an angle. Thus, in the embodiment shown, the needle has an exposed length of at least 6 mm when the shield is in the proximal position.

After filling the syringe, the shield36can slide to the second intermediate position shown inFIG.7by the user pushing in a distal direction on the proximal end of the arm72. The inclined leading surface92of the detent88slides over the proximal face56of the tab52of the spring finger48thereby deflecting the spring finger toward the base where the tab52snaps into the recess86. Sliding the tab52into the recess86can produce an audible or tactile sensation to the user to provide an indication that the shield is in the second intermediate position shown inFIG.7. In one embodiment, the exposed length of the needle extending from the shield is about 4 mm to about 5 mm and typically about 4 mm when the shield is in the intermediate position ofFIG.7. In other embodiments, the needle has an exposed length of about 3-5 mm when the shield is in the intermediate position ofFIG.7. The exposed length of the needle is determined by the position of the recess86with respect to the arm. The needle shield also forms a limiter to limit the axial length of the exposed portion of the needle during the injection. The recessed portion86captures the tab52on the finger48with sufficient resistance to retain the shield and the arm in the intermediate position during use.

After the injection, the arm72is pushed forward in the distal direction with respect to the syringe where the tab52separates from the recess position86and slides over the second detent90. The detent100slides over the tab52of the spring finger to the position shown inFIG.8and the shield slides to a position to cover the distal end of the needle. The proximal portion84of the arm72is at an angle relative to the distal portion82to move the shield off center from the needle as shown inFIG.8so that distal tip of the needle is no longer aligned with the opening66in the end wall of the shield. The distal face54of the tab52engages the proximal face of the detent100to lock the shield in the extended position to cover the end of the needle and prevent re-use of the syringe.

Another embodiment shown inFIG.9includes a shield110that is similar to the shield of the previous embodiment. The shield110includes an arm112and sleeve114coupled to the arm for covering the end of the needle as in the previous embodiment. The shield110is coupled to a base34as in the previous embodiment for sliding movement on the base in a linear direction relative to the syringe and the needle. The sleeve114has an open proximal end116with a dimension for receiving the distal end of the needle hub of the syringe and an open distal end118for allowing the needle to project a distance for injecting the medication to the patient.

The arm112in the embodiment ofFIG.9is similar to the arm of the previous embodiment except for including more than one set of detents forming locking mechanisms for positioning the shield at selected locations with respect to the needle hub and needle for exposing different lengths of needle depending on the intended depth of penetration of the needle. The arm112has a first locking mechanism120at the distal end of the arm112and a second locking mechanism122spaced proximally from the first locking mechanism120. The first locking mechanism and the second locking mechanism are configured for mating with the spring finger48to retain the shield in a selected position relative to the base34and the syringe. The first locking mechanism120includes a distal detent124and proximal detent126that are spaced apart to form a recess128. The distal detent124has an inclined leading distal face130for sliding over the spring finger and a trailing proximal face to prevent the shield from sliding proximally relative to the base. The recess128has a dimension sufficient to receive the tab of the spring finger to retain the shield in a selected position during use. The second locking mechanism122is similar and includes a distal detent132and a proximal detent134forming a recess136. The detents are substantially similar to capture the tab of the spring finger and retain the shield in a selected position relative to the base and the syringe.

During use, the shield110is received in the opening in the base34and positioned in a retracted position to expose a first length of the needle where the syringe can be aspirated and filled with the medication. The syringe can be used by inserting the needle into the patient to inject the medication to a depth corresponding to the exposed length of the needle. The shield can be retracted to a first extended position by sliding the shield distally with respect to the syringe until the spring finger snaps into the recess128to retain the shield in the partially extended position to expose a length of the needle that is shorter than the initial exposed length. By way of example, the initial exposed length of the needle can be about 6 mm and exposed length of the needle can be about 4 mm in the partially extended position. The shield can be extended to a second position where the finger is received in the recess128of the second locking mechanism122to expose a shorter length of the needle that is less than the initial length and less than the length when the spring finger is received in the recess of the first locking mechanism120. The exposed length of the needle when the spring finger is received in the recess of the second locking mechanism can be, for example, about 2 mm. After use, the shield slides to the extended distal position where shield covers the end of the needle and the proximal locking detent138locks the arm and shield in the extended position to prevent re-use in a manner similar to the previous embodiment.

The foregoing embodiments and advantages are exemplary and are not intended to limit the scope of the invention. The description of alternative embodiments are intended to be illustrative, and not to limit the scope of the present invention. Various modifications, alternatives, and variations will be apparent to those skilled in the art, and are intended to fall within the scope of the invention. It is particularly noted that the features of different embodiments and claims may be combined with each other as long as they do not contradict each other. Accordingly all such modifications are intended to be included within the scope of this invention as defined in the appended claims and their equivalents.