Passively activated safety needle assemblies and methods of use

Abstract

Described are passively activated safety needle assemblies and methods for use. The assemblies comprise an elongate hollow outer shield, an elongate hub slidably engaged within the outer shield and biased to move proximally with respect to the outer shield. A locking ring in the hub has a ring element that cooperates with an activation element on the outer shield rotate the locking ring and disable the assembly.

What is claimed is: 
     
       1. A passively activated safety needle assembly comprising:
 a hub having an elongate cylindrical body with an outer surface, a distal end and a proximal end defining a length, an aperture extending through the length of the hub, at least two longitudinal grooves extending at least partially along the length of the hub, and a circumferential channel; 
 a locking ring having a cylindrical body rotatably positioned in the circumferential channel and coaxial with the hub, the locking ring including at least one ring element extending outwardly from an outside surface of the locking ring, the at least one ring element having a proximal end, a distal end and a ramped face extending from the proximal end to the distal end, and at least one ramp-shaped locking tab extending outwardly from the outside surface of the locking ring, the at least one locking tab having a proximal locking face extending from the outside surface of the cylindrical body; 
 an outer shield coaxial to and slidable around the hub and locking ring, the outer shield including an elongate hollow cylindrical body with an open distal end and a closed proximal end with an aperture to permit a needle to move therethrough, at least one activation element projecting inwardly from an interior surface of the outer shield that engages the at least one ring element, the at least one activation element sized to slidably move within a longitudinal groove on the hub and having a shape that cooperatively interacts with the at least one ring element on the locking ring, and at least one finger projecting inwardly from the outer shield and sized to slidably move within a longitudinal groove on the hub; 
 a spring element positioned adjacent the proximal end of the hub within the outer shield; and 
 a needle extending from the proximal end of the hub within the outer shield and the spring element, wherein proximally directed force on the hub causes compression of the spring element, extends a tip of the needle through the aperture in the outer shield, and causes the activation element to exert distally directed force onto the ring element to rotate the locking ring such that the at least one finger on the outer shield aligns with the at least one ramped surface. 
 
     
     
       2. The assembly of  claim 1 , wherein subsequent release of the proximally directed force allows the spring element to expand causing distal movement of the hub with respect to the outer shield so that the at least one finger slides over the at least one ramped surface and that additional proximal movement of the hub is prevented by interaction of the at least one finger with the proximal locking face. 
     
     
       3. A passively activated safety needle assembly comprising:
 an elongate, hollow outer shield having a distal end, a proximal end, an outer surface and an inner surface, an activation element protruding inwardly from the inner surface, and at least one finger biased radially inwardly; 
 an elongate hub having a distal end and a proximal end, the hub slidably engaged with the outer shield and biased to move in proximal direction, the hub including a longitudinal groove that guides the activation element during relative sliding motion between the hub and the outer shield; 
 a spring element positioned within the elongate, hollow outer shield adjacent the proximal end of the elongate hub 
 a locking ring on the hub having a ring element complementary to the activation element and at least one ramped surface radially spaced from the ring element and providing a proximal facing edge, wherein distal movement of the outer shield with respect to the hub causes the activation element and ring element to rotate the locking ring such that the at least one finger aligns with the ramped surface and subsequent proximal movement of the outer shield causes the at least one finger to engage the proximal facing edge, preventing further relative movement of the outer shield and hub. 
 
     
     
       4. The assembly of  claim 3 , wherein the hub includes a circumferential channel and the locking ring is rotatably seated within the circumferential channel. 
     
     
       5. The assembly of  claim 3 , wherein the ring element is a substantially triangular wedge with a proximal end and a distal end, the proximal end being narrower than the distal end. 
     
     
       6. The assembly of  claim 3 , wherein the activation element is a substantially triangular wedge with a proximal end and distal end, the proximal end being wider than the distal end. 
     
     
       7. The assembly of  claim 3 , wherein there are two activation elements. 
     
     
       8. The assembly of  claim 3 , wherein the locking ring further comprises a longitudinal opening. 
     
     
       9. The assembly of  claim 3 , further comprising a needle positioned within the hub so that distal movement of the outer shield with respect to the hub compresses the spring element and causes the needle to extend from the distal end of the hub. 
     
     
       10. The assembly of  claim 3 , wherein the activation element is a substantially triangular wedge with a proximal end and distal end narrower than the proximal end and the ring element if a complementary triangular wedge with a proximal end and distal end wider than the proximal end. 
     
     
       11. The assembly of  claim 10 , wherein the activation elements are positioned on opposite sides of the outer shield. 
     
     
       12. The assembly of  claim 3 , wherein there are two ring elements. 
     
     
       13. The assembly of  claim 12 , wherein the ring elements are on opposite sides of the locking ring. 
     
     
       14. The assembly of  claim 3 , wherein the locking ring further comprises a projection extending one or more of proximally and distally from the locking ring. 
     
     
       15. The assembly of  claim 14 , wherein the elongate hub further comprises at least one complementary recess that engages the projection. 
     
     
       16. The assembly of  claim 3 , wherein the elongate, hollow outer shield further comprises an aperture that permits a needle to extend therethrough. 
     
     
       17. The assembly of  claim 16 , further comprising a needle extending from the proximal end of the elongate hub within the spring element and the outer shield such that proximal movement of the hub with respect to the outer shield compresses the spring element and causes the needle to project through the aperture. 
     
     
       18. The assembly of  claim 17 , wherein the needle is connected to the elongate hub using a Luer connector on the proximal end of the elongate hub. 
     
     
       19. The assembly of claim 1, wherein there are two activation elements. 
     
     
       20. The assembly of claim 3, wherein the locking ring further comprises an opening extending through a thickness of the cylindrical body.