Safety pen needle assembly

Abstract

In one aspect, a safety pen needle assembly is provided herein which includes a hub with a needle fixed to the hub, the needle having a distal end, formed for insertion into a patient, and a proximal end. The assembly further includes a shield and a biasing member disposed between the hub and the shield configured to urge the shield distally. A protrusion extends from at least one of the hub and the shield with a channel being formed in at least the other of the hub and the shield. The channel is formed to accommodate the protrusion. The shield is movable from a first position to a second position. In the first position, the shield is spaced from the distal end of the needle such that the distal end of the needle is exposed. In the second position, the shield covers the distal end of the needle. The channel guides the protrusion as the shield moves from the first position to the second position. With this arrangement, a shield may be directed to move in a desired path with stability. In addition, the distal end of the needle may be initially exposed to permit visual confirmation of priming, while allowing the shield to cover a majority of the needle to minimize any needle-related anxiety.

1 . A safety pen needle assembly comprising:
 a hub;   a needle fixed to said hub, said needle having a distal end, formed for insertion into a patient, and a proximal end;   a shield; and,   a biasing means disposed between said hub and said shield configured to urge said shield distally,   wherein, a protrusion extends from at least one of said hub and said shield, a channel is formed in at least the other of said hub and said shield, said channel formed to accommodate said protrusion,   wherein said shield is movable from a first position to a second position, wherein, in said first position, said shield is spaced from said distal end of said needle such that said distal end of said needle is exposed, wherein, in said second position, said shield covers said distal end of said needle, and wherein said channel guides said protrusion as said shield moves from said first position to said second position;   whereby when said shield is in said first position, a user may visually confirm proper priming and needle placement during use.   
     
     
         2 . The needle assembly of  claim 1 , wherein said channel is generally U-shaped, V-shaped, J-shaped, or hook-shaped. 
     
     
         3 . The needle assembly of  claim 1 , wherein said channel has a proximal and a distal end, and wherein under force of said biasing means, said protrusion is urged towards said distal end of said channel. 
     
     
         4 . The needle assembly of  claim 1 , further comprising a locking means to lock said shield in said second position. 
     
     
         5 . The needle assembly of  claim 4 , wherein said shield may be locked in said second position through manual manipulation by said patient. 
     
     
         6 . The needle assembly of  claim 4 , wherein a locking tab extends from at least one of said hub and said shield, a locking window is formed in at least the other of said hub and said shield, wherein said locking tab engages said locking window when said shield is in said second position. 
     
     
         7 . The needle assembly of  claim 1 , wherein said channel comprises a first part and a second part, wherein said protrusion is located in said first part of said channel prior to use and wherein said protrusion is located in said second part of said channel after use. 
     
     
         8 . The needle assembly of  claim 7 , wherein a flexible finger extends into said channel which extends across an axis extending from said first part of said channel. 
     
     
         9 . The needle assembly of  claim 8 , wherein during use, said flexible finger deflects said protrusion into said second part of said channel. 
     
     
         10 . The needle assembly of  claim 7 , wherein the distalmost portion of said second part of said channel is located distally of the distalmost portion of said first part of said channel. 
     
     
         11 . The needle assembly of  claim 10 , wherein a locking tab extends from at least one of said hub and said shield, a locking window is formed in at least the other of said hub and said shield, wherein said locking tab engages said locking window when said shield is in said second position, and wherein said locking window is located more distally than the distalmost portion of said first part of said channel. 
     
     
         12 . The needle assembly of  claim 7 , wherein a locking tab extends from at least one of said hub and said shield, a locking window is formed in at least the other of said hub and said shield, wherein said locking tab engages said locking window when said shield is in said second position, and wherein said locking window is located more distally than the distalmost portion of said first part of said channel. 
     
     
         13 . A safety pen needle assembly comprising:
 a hub;   a needle fixed to said hub, said needle having a distal end, formed for insertion into a patient, and a proximal end;   a shield; and,   a biasing means disposed between said hub and said shield configured to urge said shield distally,   wherein a protrusion extends from at least one of said hub and said shield, a channel is formed in at least the other of said hub and said shield, said channel formed to accommodate said protrusion,   wherein said shield is movable from a first position to a second position, wherein, in said first position, said shield covers said distal end of said needle, wherein, in said second position, said distal end of said needle is exposed, and wherein said channel guides said protrusion as said shield moves from said first position to said second position; and,   wherein said shield is initially in a locked state with said protrusion being spaced from said channel, said shield being manually movable out of said locked state to urge said protrusion into said channel thereby allowing said shield to move from said first position to said second position.   
     
     
         14 . The needle assembly of  claim 13 , wherein a locking aperture is formed in at least one of said hub and said shield formed to accommodate in snap engagement said protrusion in said locked state, said locking aperture being spaced from said channel. 
     
     
         15 . The needle assembly of  claim 13 , wherein said shield is rotatable out of said locked state. 
     
     
         16 . The needle assembly of  claim 13 , wherein said shield is axially displaceable out of said locked state. 
     
     
         17 . A safety pen needle assembly comprising:
 a hub;   a needle fixed to said hub, said needle having a distal end, formed for insertion into a patient, and a proximal end;   an axially-displaceable shield for covering said distal end of said needle, said shield having an angled engagement surface defined thereon;   a secondary shield for covering said proximal end of said needle, said secondary shield having at least one detent with a ramped surface formed thereon in axial alignment with said angled engagement surface; and,   a biasing means disposed to urge said secondary shield proximally,   wherein, said detent releasably retains said secondary shield in a first state with said proximal end of said needle being exposed, and,   wherein, with sufficient proximal movement of said shield, said engagement surface engages said ramped surface and causes displacement of said detent thereby releasing said secondary shield from said first state and allowing said biasing means to urge said secondary shield proximally.   
     
     
         18 . The needle assembly of  claim 17 , wherein said secondary shield includes one or more elongated locking arms, said detent being formed on said locking arm. 
     
     
         19 . The needle assembly of  claim 18 , wherein one or more locking tabs being configured on said locking arms so as to collectively snap receive a portion of said hub. 
     
     
         20 . A safety pen assembly comprising:
 a hub;   a needle fixed to said hub, said needle having a distal end, formed for insertion into a patient, and a proximal end; and,   a leafspring secured to said hub by a frangible connection, said frangible connection being rupturable, wherein, with rupture of said frangible connection, a free end of said leafspring is urged to cover said proximal end of said needle.   
     
     
         21 . A medical injector comprising:
 a needle; and,   a slidable body disposed adjacent to said needle, said body having depth marks defined thereon, wherein during an injection of said needle into a patient, said slidable body is depressed by the patient's skin, said depth marks indicating the extent of depression of said body during the injection thereby providing an indication of depth of injection by said needle.