BACKGROUND OF THE INVENTION

[0002] The present invention relates generally to a needle safety mechanism and, more particularly, to a device that simplifies and improves the safety and reliability of a protective rigid needle shield.

[0003] Rigid needle shields are well known and are used in numerous medical facilities to prevent healthcare providers from suffering a needle stick injury, in which the healthcare provider accidentally sticks himself or herself with a needle intended for use with a patient. The rigid needle shield is typically mounted on or over a needle or syringe so that before use with a patient, at least the distal, sharp end of the needle is enclosed or covered so that accidental needle stick injuries are reduced or avoided.

[0004] Conventional rigid needle shields are made from a rigid polymeric material such as a plastic and are formed in a generally cylindrical shape having a closed distal end and an open proximal end for receiving the needle and at least a portion of the syringe. The needle shield is mounted over the distal end of a needle or syringe and held securely thereon, for example, by an interference or friction fit such that the open proximal end of the needle shield engages and grips a portion of the syringe. The user must grasp the cylindrical needle shield with his or her fingers in a pinching fashion and pull the needle shield away from the needle or syringe to expose the needle. Upon asserting enough force to overcome the gripping force retaining the needle shield to the needle or syringe, the needle shield abruptly breaks free. Grasping the needle shield in the pinching fashion with sufficient force to overcome the gripping force can be challenging for a user having limited dexterity, for example, a patient with rheumatoid arthritis.

[0005] Therefore, there is a need for a rigid needle shield which can be more easily grasped by users with limited dexterity so that the users can more easily remove the needle shield from a needle or syringe without compromising the needle shield's protective properties. The present invention accomplishes this need.

BRIEF SUMMARY OF THE INVENTION

[0006] Briefly stated, one aspect of the present invention is directed to a rigid needle shield having an open proximal end, a closed distal end, and a sidewall extending between the open proximal end and the closed distal end, forming an elongated chamber therein. The sidewall contains at least one elongated member which moves between a closed, first position and an open, second position extending generally radially outwardly from the sidewall. The elongated member has a first end pivotally connected to the rigid needle shield proximate the closed distal end, a second end, and a buttress extending radially outwardly from the elongated member proximate the first end of the elongated member. The buttress allows the elongated member to move from the closed, first position to the open, second position upon receipt of sufficient distally upward and radially inward force.

[0007] A second aspect of the present invention is directed to a syringe assembly wherein the syringe has a barrel, the barrel having a shoulder, a needle hub extending from the shoulder, and a needle extending from the needle hub. A rigid needle shield is releasably connected to the needle hub to cover the needle hub and the needle, the rigid needle shield having an open proximal end, a closed distal end, and a sidewall extending between the open proximal end and the closed distal end, forming an elongated chamber therein. The sidewall contains at least one elongated member which moves between a closed, first position and an open, second position extending generally radially outwardly from the sidewall. The elongated member has a first end pivotally connected to the rigid needle shield proximate the closed distal end, a second end, and a buttress extending radially outwardly from the elongated member proximate the first end of the elongated member. The buttress allows the elongated member to move from the closed, first position to the open, second position upon receipt of sufficient distally upward and radially inward force.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0008] The foregoing summary, as well as the following detailed description of a preferred embodiment of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings an embodiment which is presently preferred. It should be understood, however, that the invention is not limited to the precise arrangement and instrumentalities shown. In the drawings:

[0009] Fig. 1 is a perspective view of a syringe assembly including a rigid needle shield according to a preferred embodiment of the present invention in a closed, first position;

[0010] Fig. 2 is a perspective view of the syringe assembly of Fig. 1 with the needle shield in the open, second position prior to removal; [0011] Fig. 3 is a cross-sectional view of a portion of the syringe assembly shown in Fig. 2 taken along line 3-3 of Fig. 2.

DETAILED DESCRIPTION OF THE INVENTION

[0012] Certain terminology is used in the following description for convenience only and is not limiting. The words "right", "left", "lower", and "upper" designate directions in the drawings to which reference is made. The words "inwardly" and "outwardly" refer to directions toward and away from, respectively, the geometric center of the device, and designated parts thereof, in accordance with the present invention. Unless specifically set forth herein, the terms "a", "an", and "the" are not limited to one element, but instead should be read as meaning "at least one." The terminology includes the words noted above, derivatives thereof, and words of similar import.

[0013] Referring to the drawings in detail, wherein like numerals are used to indicate like elements throughout, Figs. 1-3 show a syringe assembly 10 in accordance with a preferred embodiment of the present invention. The syringe assembly 10 includes a rigid needle shield 12 and a syringe 14. As shown in Figs. 1 and 3, the syringe 14 includes a barrel 16, a shoulder 18 on the barrel 16, a needle hub 20 extending from the shoulder 18, and a needle 22 extending from the needle hub 20. The syringe 14 is typical of a syringe well known in the art. The rigid needle shield 12 is releasably connected to a portion of the syringe 14, such as the needle hub 20, to enclose and cover at least the sharp distal end of the needle 22 for protection before injection of a patient or user. Also shown in Figs. 1-2 is a piston 24 within the barrel 16 of the syringe 14 which is connected to a plunger (not shown) for injecting a medicament (not shown) within the barrel 16 through the needle 22 and into a patient in a manner well known in the art. The piston 24 is preferably made from a rubber or polymeric material but is not limited to such a material. The syringe 14 is preferably a glass or plastic syringe of standard type, which is intended for a single use, but the syringe 14 is not limited to such a type or functionality. The rigid needle shield 12 can be made from any rigid material, but is preferably made from a single piece of a rigid polymeric material such as plastic.

[0014] Referring to Figs. 1-3, the generally cylindrical rigid needle shield 12 includes an open proximal end 26, a closed distal end 28, a sidewall 30 extending between the open proximal end 26 and the closed distal end 28 forming an elongated chamber 32 therein, and a pair of arms or elongated members 34. It will be appreciated by one skilled in the art that the rigid needle shield 12 need not be generally cylindrical, but could also be hexagonal, conical, or any like shape which sufficiently encloses the needle 22. The elongated members 34 are movable between a closed, first position adjacent the sidewall 30, as shown in Fig. 1 , and an open, second position extending generally radially outwardly from the sidewall 30 at an angle of

approximately 90 degrees, as shown in Figs. 2-3.

[0015] Referring to Figs. 2-3, the sidewall 30 includes a pair of generally axially extending elongated slots 36 formed therein. As shown in Fig. 1 , when the elongated members 34 are in a closed first position, the elongated members 34 are positioned substantially within the elongated slots 36. As shown in Fig. 2, the elongated slots 36 have a distal end and a proximal end, wherein a first end 34a of each of the elongated members 34 is connected to the sidewall 30 proximate the distal end of the elongated slots 36. As shown in Fig. 1, the second end 34b of each of the elongated members 34 is received within the proximal end of the elongated slots 36 when the elongated members 34 are in the first, closed position. The elongated members 34 are preferably made of the same rigid material as the remainder of the rigid needle shield 12.

[0016] As shown in Fig. 3, the syringe assembly 10 includes a resilient needle sheath 40 positioned within the elongated chamber 32 of the rigid needle shield 12. The resilient needle sheath 40 contains an open proximal end 42, a closed distal end 44, and a sidewall 46 which define a chamber 48 therein. The resilient needle sheath 40 may be formed of any suitable, preferably elastomeric material, such as rubber, for supporting the needle 22 within the rigid needle shield 12 while being stored or transported. In some applications, the needle sheath 40 may be eliminated.

[0017] The rigid needle shield 12 is mounted over the distal end of the syringe 14 to completely cover at least the sharp end of the needle 22. The open, proximal end 26 of the rigid needle shield 12 engages and grips a portion of the syringe 14 with an interference or friction fit to remain securely mounted thereon until the user removes the rigid needle shield 12. It will be appreciated by one skilled in the art that the rigid needle shield 12 can be mounted to the syringe 14 through a connection other than an interference or friction fit.

[0018] As shown in Figs. 1-3, the first end 34a of each of the elongated members 34 is hingedly connected to at least one of the closed distal end 28 and the sidewall 30 of the rigid needle shield 12. In the present embodiment, the first end 34a is hingedly connected to the sidewall 30 proximate the closed distal end 28 of the rigid needle shield 12. The hinged connection is preferably a living or flex point hinge 35. As shown in Figs. 1-3, the elongated members 34 are preferably generally flat or curved and are sized and shaped to correspond to the elongated slots 36 in the sidewall 30 along the axis stretching from the first end 34a to the second end 34b. However, the elongated members 34 need not extend the entire distance between the first end 34a and second end 34b of the sidewall 30.

[0019] Referring to Figs. 1-3, each of the elongated members 34 includes a lug or buttress 54 which, as shown in Fig. 1, extends generally radially outwardly proximate the first end 34a to facilitate movement of the elongated members 34 from the first to the second position. The buttress 54 preferably includes a stop surface 56 which preferably at least partially engages at least one of the sidewall 30 and the closed distal end 28 when the elongated members 34 are in the open second position, as shown in Figs. 2-3.

[0020] As shown in Figs. 1-3, the needle shield 12 preferably includes two elongated members 34 positioned diametrically opposite each other. Both elongated members 34 are independently movable between the closed, first position adjacent the sidewall 30, as shown in Fig. 1 , and the open, second position extending generally radially outwardly from the sidewall 30, as shown in Figs. 2-3. In certain applications, the needle shield 12 may include only a single elongated member 34 or more than two elongated members 34.

[0021] In operation, the rigid needle shield 12 is shipped or stored on the syringe 14 in the first, closed position, as shown in Fig. 1, so that it takes up as little space as possible. Operation of the preferred embodiment is described below with respect to two elongated members 34, but the below method of operation is equally applicable with respect to any embodiment with at least one elongated member 34. When a healthcare provider wishes to use the syringe 14, he or she removes the rigid needle shield 12. To do so, the user actuates the buttresses 54 around the hinged first ends 34a of the elongated members 34 by pressing the buttresses 54 upwardly (distally) and radially inwardly, thereby pivoting the elongated members 34 about the hinge connection 35 to place the elongated members 34 into the open, second position as shown in Figs. 2-3, in which the stop surfaces 56 of the buttresses 54 are engaged with at least one of the sidewall 30 and the closed distal end 28. In the open, second position, the elongated members 34 extend approximately 90 degrees radially outwardly from the sidewall 30 to place the rigid needle shield 12 generally in a "T" shape. The user then hooks his or her fingers under the elongated members 34 to grasp the rigid needle shield 12 and pull the elongated members 34 upwardly (distally) while holding the syringe 14 with sufficient force to disengage the rigid needle shield 12 from the syringe 14. The "T" shape of the rigid needle shield 12 in the open, second position allows a more natural and comfortable grip for the user than the pinching grip required by a rigid needle shield that does not contain the elongated members 34. The "T" shape thereby allows the rigid needle shield 12 to be used by a user with less dexterity than would be required if the user were required to pinch the needle shield 12. The syringe 14 is then ready for use on a patient.

[0022] It will be appreciated by those skilled in the art that changes could be made to the embodiment described above without departing from the broad inventive concept thereof.

Therefore, it is understood that this invention is not limited to the particular embodiment disclosed, but is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.