Wearable automatic injection device for controlled delivery of therapeutic agents

Abstract

Exemplary embodiments provide wearable automatic injection devices for subcutaneously injecting a therapeutic agent into a patient's body at controlled rates, for example, in a single bolus. Exemplary embodiments provide methods for assembling wearable automatic injection devices for subcutaneously injecting a therapeutic agent into a patient's body at controlled rates. Exemplary embodiments provide methods for using wearable automatic injection devices for subcutaneously injecting a therapeutic agent into a patient's body at controlled rates.

1 - 43 . (canceled) 
     
     
         44 . A wearable automatic injection device for injecting a therapeutic agent into a patient, the wearable automatic injection device comprising:
 a housing having a patient contact portion securable to a patient;   a vessel in the housing for holding a therapeutic agent;   a bung disposed in the vessel;   a syringe needle fluidically couplable to the vessel;   an injection assembly moveably disposed in the housing having an injection needle for insertion into the patient and fluidically couplable with the syringe needle; and   a fluid-based plunger actuation mechanism having one or more fluid circuits to transport a working fluid to provide a force to the bung to eject the therapeutic agent from the vessel.   
     
     
         45 . The wearable automatic injection device of  claim 44 , wherein the plunger actuation mechanism comprises a pressure element storing an incompressible working fluid for providing a hydraulic pressure to eject the therapeutic agent from the vessel. 
     
     
         46 . The wearable automatic injection device of  claim 44 , wherein the plunger actuation mechanism further comprises:
 a fluid conduit provided between the pressure element and the plunger.   
     
     
         47 . The wearable automatic injection device of  claim 46 , wherein the plunger actuation mechanism further comprises:
 a damping mechanism coupled to the vessel and the pressure element to regulate the ejection of the therapeutic agent from the vessel.   
     
     
         48 . The wearable automatic injection device of  claim 47 , wherein the damping mechanism comprises a flow restrictor for maintaining the hydraulic pressure downstream of the flow restrictor toward the vessel at a lower pressure that the hydraulic pressure upstream of the flow restrictor toward the source of the working fluid. 
     
     
         49 . The wearable automatic injection device of  claim 48 , wherein the pressure element is coupled to the flow restrictor using a tubing. 
     
     
         50 . The wearable automatic injection device of  claim 44 , wherein the working fluid includes one of water or oil. 
     
     
         51 . The wearable automatic injection device of  claim 44 , wherein the pressure element includes one of an elastic bladder, a master cylinder, or a spring-loaded syringe. 
     
     
         52 . The wearable automatic injection device of  claim 44 , further comprising a delivery trigger that when activated releases the working fluid into fluid communication with the bung and generates a fluid pressure to advance the bung within the vessel. 
     
     
         53 . The wearable automatic injection device of  claim 44 , wherein the vessel is moveably disposed within the housing. 
     
     
         54 . The wearable automatic injection device of  claim 44 , further comprising:
 a pierceable septum separating the syringe needle from the sterile fluid conduit in a pre-injection state.   
     
     
         55 . The wearable automatic injection device of  claim 54 , wherein the vessel moves in an injection state causing the syringe needle to pierce the septum and establishing fluid communication between the syringe needle and the injection needle. 
     
     
         56 . The wearable automatic injection device of  claim 55 , further comprising:
 a vessel actuator for automatically actuating the vessel from a first position in the pre-injection state to a second position in the injection state.   
     
     
         57 . The wearable automatic injection device of  claim 44 , wherein the plunger actuation mechanism and the patient contact portion are non-sterile. 
     
     
         58 . The wearable automatic injection device of  claim 44 , wherein the housing is non-sterile. 
     
     
         59 . The wearable automatic injection device of  claims 44 , further comprising:
 an inspection window disposed in the housing that allows the user to inspect the therapeutic agent held by the vessel from outside the housing.   
     
     
         60 . The wearable automatic injection device of  claim 44 , wherein the plunger actuation mechanism includes a flow restrictor to regulate a rate of delivery of the therapeutic agent into the patient. 
     
     
         61 . The wearable automatic injection device of  claim 44 , further comprising:
 a needle locking mechanism for automatically locking the injection needle in a retracted position within the housing in a post-injection state.   
     
     
         62 . The wearable automatic injection device of  claim 61 , wherein the needle locking mechanism comprises:
 a barrier mechanism moveably disposed over an injection needle aperture in the housing;   wherein the injection needle aperture is open and allows the injection needle to protrude outside the housing when the barrier mechanism is in a first position; and   wherein the injection needle aperture is closed and prevents the injection needle from protruding outside the housing when the barrier mechanism is in a second position.   
     
     
         63 . The wearable automatic injection device of  claim 62 , wherein the needle locking mechanism comprises:
 a needle lock release mechanism responsive to retraction of the injection assembly from an extended position in the injection state to a retracted position in the post-injection state; and   a pivoting member coupled to the injection needle and to the needle lock release mechanism;   wherein activation of the needle lock release mechanism causes the pivoting member to pivot the injection needle away from an injection needle aperture in the housing.   
     
     
         64 . The wearable automatic injection device of  claim 44 , wherein the therapeutic agent comprises a protein in a solution. 
     
     
         65 . The wearable automatic injection device of  claim 64 , wherein the protein comprises any of a fusion protein, an enzyme, an antibody, or an antigen-binding fragment thereof in a solution. 
     
     
         66 . The wearable automatic injection device of  claim 64 , wherein the antibody is a dual specificity antibody. 
     
     
         67 . The wearable automatic injection device of  claim 44 , wherein the therapeutic agent comprises is a TNFα inhibitor. 
     
     
         68 . The wearable automatic injection device of  claim 44 , further comprising a transfer mechanism defining a sterile fluid conduit between the syringe needle and the injection needle 
     
     
         69 . The wearable automatic injection device of  claim 68 , further comprising:
 an injection button including the transfer mechanism.   
     
     
         70 . The wearable automatic injection device of  claim 44 , wherein the transfer mechanism comprises an adapter coupled to the syringe needle and the injection needle establishing the sterile fluid conduit between the syringe needle and the injection needle. 
     
     
         71 . The wearable automatic injection device of  claim 70 , wherein a first portion of the adapter extends from the vessel substantially parallel to a longitudinal axis. 
     
     
         72 . The wearable automatic injection device of  claim 71 , wherein a second portion of the adapter extends from the first portion of the adapter substantially perpendicular to the longitudinal axis. 
     
     
         73 . The wearable automatic injection device of  claim 72 , wherein the second portion of the adapter couplable to the injection needle. 
     
     
         74 . The wearable automatic injection device of  claim 72 , wherein the first portion of the adapter and the second portion of the adapter are formed integrally. 
     
     
         75 . The wearable automatic injection device of  claim 70 , wherein the first portion of the adapter substantially envelopes a distal end of the vessel. 
     
     
         76 . The wearable automatic injection device of  claim 70 , wherein the adapter enables the injection needle to extend at approximately 90 degrees relative to the longitudinal axis. 
     
     
         77 . The wearable automatic injection device of  claim 76 , wherein the sterile fluid conduit is a centrally extending channel in the transfer mechanism through which the therapeutic agent flows from the syringe needle to the injection needle. 
     
     
         78 . The wearable automatic injection device of  claim 77 , wherein the fluid conduit comprises raised wall portions extending along the edges of the centrally extending channel to constrain the therapeutic agent to the channel. 
     
     
         79 . The wearable automatic injection device of  claim 44 , wherein the wearable automatic injection device is operable without electrical power. 
     
     
         80 . The wearable automatic injection device of  claim 44 , wherein the therapeutic agent is delivered in a linear delivery profile at a constant linear flow rate.