Intravitreal injector

Abstract

Provided herein are needle assemblies for intravitreal injection of an implant into an eye of a patient through an unsheathed state and a sheathed state. Such needle assemblies are precise and accurate for proper treatment and prevent further damage to the eye.

What is claimed is: 
     
         1 . An injector system for injecting an implant into an eye of a patient having an unsheathed state and a sheathed state, the system comprising:
 (a) a plunger assembly comprising:
 (i) a plunger housing; and 
 (ii) a plunger slidably disposed within the plunger housing, wherein a distal end of the plunger being engaged with the push pin of the needle assembly when in a distal position within the plunger housing; and 
   (b) a needle assembly comprising:
 (i) a needle housing having a proximal end and a distal end; 
 (ii) a needle having a proximal end attached to the distal end of the needle housing or within the needle housing, a distal end extending beyond the distal end of the needle housing, and a needle lumen at the distal end of the needle; 
 (iii) the needle lumen being configured to receive an implant positioned therewithin; and 
 (iv) a push pin having a head and a push rod, wherein a distal end of the push rod is disposed within the needle lumen, and wherein translating the push pin in a distal direction ejects the implant from the needle lumen and into the eye of the patient. 
   
     
     
         2 . The injector system of  claim 1 , wherein the distal end of the plunger engages the head of the push pin. 
     
     
         3 . The injector system of  claim 1 , wherein the plunger is manually actuated to translate distally within the plunger housing. 
     
     
         4 . The injector system of  claim 1 , wherein a proximal end of the plunger assembly protrudes beyond the plunger housing. 
     
     
         5 . The injector system of  claim 1 , wherein the plunger is mechanically actuated to translate distally within the plunger housing. 
     
     
         6 . The injector system of  claim 1 , wherein the plunger assembly further comprises a compression spring biasing the plunger towards a proximal end of the plunger housing. 
     
     
         7 . The injector system of  claim 6 , wherein the compression spring has a distal end connected to the plunger housing and a proximal end connected to the plunger. 
     
     
         8 . The injector system of  claim 1 , wherein the plunger comprises a first stop feature, wherein the plunger housing comprises a second stop feature engageable with the first stop feature. 
     
     
         9 . The injector system of  claim 8 , wherein the second stop feature comprises a primary second stop and a secondary second stop. 
     
     
         10 . The injector system of  claim 1 , wherein the needle assembly further comprises a resilient member disposed within the needle housing. 
     
     
         11 . The injector system of  claim 10 , wherein the resilient member proximally biases the push pin. 
     
     
         12 . The injector system of  claim 1 , wherein the needle assembly further comprises a needle sheath having a proximal portion surrounding the distal end of the needle housing, and a distal portion surrounding the distal end of the needle. 
     
     
         13 . The injector system of  claim 12 , wherein the needle sheath is removable from the needle housing by translating in a distal direction away from the needle housing to expose the needle. 
     
     
         14 . The injector system of  claim 12 , wherein the needle sheath translates proximally to the unsheathed state where the distal end of the needle extends beyond the distal portion of the needle sheath. 
     
     
         15 . The injector system of  claim 1 , further comprising a needle seal at the distal end of the needle that seals the distal end of the needle lumen. 
     
     
         16 . The injector system of  claim 15 , wherein the needle seal is within a distal portion of the needle sheath. 
     
     
         17 . The injector system of  claim 15 , wherein the needle seal is pierced by translating the needle sheath in a proximal direction. 
     
     
         18 . The injector system of  claim 15 , wherein the needle has a length such that the distal end of the needle is within the needle seal when the system is in a sheathed state. 
     
     
         19 . The injector system of  claim 15 , wherein the needle assembly further comprises a removable push pin retainer that prevents movement of the needle housing relative to the needle sheath when engaged. 
     
     
         20 . The injector system of  claim 19 , wherein the removable push pin retainer removably couples the push pin to the needle housing.