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 . A wearable automatic injection device for providing a subcutaneous injection of a therapeutic agent into a patient, the wearable automatic injection device comprising:
 a housing comprising a patient contact portion securable to the patient;   an injection assembly moveably disposed in the housing holding a hypodermic injection needle for insertion into the patient, the injection assembly moveable between a retracted position in which the injection needle does not protrude outside the housing and an extended position in which the injection needle protrudes outside the housing;   a vessel provided in the housing for holding the therapeutic agent;   a plunger moveably disposed in the vessel for ejecting the therapeutic agent from the vessel into the injection assembly;   a plunger actuation mechanism for actuating the plunger within the vessel;   a retraction trigger responsive to a change of state of the wearable automatic injection device from an injection state to a post-injection state; and   a retraction mechanism for automatically retracting the injection assembly from the extended position in the injection state to the retracted position in the post-injection state upon triggering by the retraction trigger.   
     
     
         2 .- 7 . (canceled) 
     
     
         8 . The wearable automatic injection device of  claim 1 , wherein the vessel comprises a syringe. 
     
     
         9 . The wearable automatic injection device of  claim 8 , wherein the syringe comprises:
 a barrel portion for holding the therapeutic agent; and   a syringe needle coupled to a distal end of the barrel portion for establishing fluid communication between the barrel portion of the syringe and the injection needle.   
     
     
         10 .- 11 . (canceled) 
     
     
         12 . The wearable automatic injection device of  claim 1 , wherein the vessel comprises a cartridge. 
     
     
         13 . The wearable automatic injection device of  claim 12 , wherein the cartridge comprises:
 a barrel portion for holding the therapeutic agent; and   a septum that is pierceable by a piercing needle.   
     
     
         14 .- 16 . (canceled) 
     
     
         17 . The wearable automatic injection device of  claim 1 , wherein the vessel is moveably disposed within the housing. 
     
     
         18 . The wearable automatic injection device of  claim 17 , wherein the vessel is moveable between a first position in a pre-injection state and a second position in the injection state. 
     
     
         19 .- 21 . (canceled) 
     
     
         22 . The wearable automatic injection device of  claim 1 , wherein the plunger actuation mechanism comprises a biasing mechanism. 
     
     
         23 . The wearable automatic injection device of  claim 22 , wherein the plunger actuation mechanism further comprises:
 a fusee; and   a tether coupling the biasing mechanism to the fusee and the plunger.   
     
     
         24 .- 31 . (canceled) 
     
     
         32 . The wearable automatic injection device of  claim 1 , wherein the plunger actuation mechanism further comprises:
 a source of a working fluid for providing a hydraulic pressure to eject the therapeutic agent from the vessel; and   a fluid conduit provided between the source of the working fluid and the plunger.   
     
     
         33 . The wearable automatic injection device of  claim 32 , wherein the plunger actuation mechanism further comprises:
 a damping mechanism coupled to the vessel and the source of the working fluid to regulate the ejection of the therapeutic agent from the vessel.   
     
     
         34 .- 42 . (canceled) 
     
     
         43 . A method for subcutaneously injecting a therapeutic agent into a patient, the method comprising:
 providing a wearable automatic injection device, comprising:
 a housing comprising a patient contact portion securable to the patient, 
 an injection assembly moveably disposed in the housing holding a hypodermic injection needle for insertion into the patient, the injection assembly moveable between a retracted position in which the injection needle does not protrude outside the housing and an extended position in which the injection needle protrudes outside the housing, 
 a vessel provided in the housing for holding the therapeutic agent, 
 a plunger moveably disposed in the vessel for ejecting the therapeutic agent from the vessel into the injection assembly, 
 a plunger actuation mechanism for actuating the plunger within the vessel, 
 a retraction trigger responsive to a change of state of the wearable automatic injection device from an injection state to a post-injection state, and 
 a retraction mechanism for automatically retracting the injection assembly from the extended position in the injection state to the retracted position in the post-injection state upon triggering by the retraction trigger; 
 securing the wearable automatic injection device to the skin of the patient or an article of clothing on the patient using the patient contact of the housing; and 
 administering the therapeutic agent into the skin of the patient using the wearable automatic injection device. 
   
     
     
         44 .- 47 . (canceled) 
     
     
         48 . The method of  claim 43 , wherein the vessel comprises a cartridge. 
     
     
         49 . The method of  claim 48 , wherein the cartridge comprises:
 a barrel portion for holding the therapeutic agent; and   a septum that is pierceable by a piercing needle.   
     
     
         50 .- 52 . (canceled) 
     
     
         53 . The method of  claim 43 , wherein the vessel is moveably disposed within the housing. 
     
     
         54 . The method of  claim 53 , wherein the vessel is moveable between a first position in a pre-injection state and a second position in the injection state. 
     
     
         55 .- 56 . (canceled) 
     
     
         57 . The method of  claim 43 , wherein the plunger actuation mechanism ejects the therapeutic agent into the patient at a controlled rate. 
     
     
         58 . The method of  claim 43 , wherein the plunger actuation mechanism comprises a biasing mechanism. 
     
     
         59 . The method of  claim 58 , wherein the plunger actuation mechanism further comprises:
 a fusee; and   a tether coupling the biasing mechanism to the fusee and the plunger.   
     
     
         60 . The method of  claim 59 , wherein the plunger actuation mechanism further comprises:
 a damping mechanism coupled to the fusee for regulating the movement of the fusee; and   a gear train including one or more gears for coupling the fusee to the damping mechanism.   
     
     
         61 .- 78 . (canceled)