Intravitreal injector

Abstract

Provided herein are needle assemblies for intravitreal injection of an (e.g., one or more) implant(s) 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 (e.g., one or more) implant(s) 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 a 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 (e.g., one or more) implant(s) positioned therewithin; and 
 (iv) the 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 (e.g., one or more) implant(s) from the needle lumen and into the eye of the patient. 
   
     
     
         2 . The injector system of  claim 1 , wherein the needle assembly further comprises a needle sheath and a needle seal secured by the needle sheath, wherein the distal end of the needle lumen is within and sealed by the needle seal when the system is in the sheathed state, and wherein the distal end of the needle extends beyond the needle seal when the system is in the unsheathed state. 
     
     
         3 . The injector system of  claim 2 , wherein a distal surface of the needle seal is pierced by translating the needle sheath in a proximal direction. 
     
     
         4 . The injector system of  claim 2 , 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. 
     
     
         5 . The injector system of  claim 2 , wherein at least a portion of the needle seal and the needle sheath are separated by a gap. 
     
     
         6 . The injector system of  claim 5 , wherein the portion of the needle seal is a mesial portion of the needle seal. 
     
     
         7 . The injector system of  claim 2 , wherein at least a distal portion of the needle seal extends beyond at least a distal portion of the needle sheath. 
     
     
         8 . The injector system of  claim 2 , further comprising the implant in the needle lumen between the push pin and the seal. 
     
     
         9 . The injector system of  claim 1 , wherein the distal end of the plunger engages the head of the push pin. 
     
     
         10 . The injector system of  claim 1 , wherein the plunger is manually actuated to translate distally within the plunger housing. 
     
     
         11 . The injector system of  claim 1 , wherein a proximal end of the plunger assembly protrudes beyond the plunger housing. 
     
     
         12 . The injector system of  claim 1 , wherein the plunger is mechanically actuated to translate distally within the plunger housing. 
     
     
         13 . 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. 
     
     
         14 . The injector system of  claim 12 , wherein the compression spring has a distal end connected to the plunger housing and a proximal end connected to the plunger. 
     
     
         15 . 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. 
     
     
         16 . The injector system of  claim 15 , wherein the second stop feature comprises a primary second stop and a secondary second stop. 
     
     
         17 . The injector system of  claim 1 , wherein the needle assembly further comprises a resilient member disposed within the needle housing. 
     
     
         18 . The injector system of  claim 17 , wherein the resilient member proximally biases the push pin. 
     
     
         19 . 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. 
     
     
         20 . The injector system of  claim 19 , 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. 
     
     
         21 . The injector system of  claim 19 , 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.