In an embodiment, a resettable injection training device and a method embodiment for resetting the device is provided herein. The device may include a housing having a proximal end and a distal end, the housing defining a cavity there within. A plunger may be slidable relative to the housing between the proximal end and the distal end. A releasably locking shield having a proximal end and a distal end, and being slidably engaged with the housing is also provided. The shield may be slidable between a retracted, pre-use position an extended, locked, post-use position. The device may further include a flat biasing member for locking the shield in the extended position, and a compressing component slidable relative to the housing, wherein pressure on the flat biasing member from the compressing component deforms the flat biasing member, and unlocks the shield, and wherein a release of pressure by the compressing component on the flat biasing member locks the shield in an extended, post-use position.

A safety syringe (100; 700; 1200) comprising: a barrel (104; 704; 1204) having an opening at an end thereof; a syringe plunger (108; 708; 1208) configured to move within the barrel such that an inward stroke of the syringe plunger causes a substance within the barrel to be expelled from the opening; and a sheath (112; 712; 1212) configured to cover at least partially the opening in the barrel after use of the syringe, wherein the sheath is coupled to the syringe plunger and is configured to decouple from the syringe plunger at a point on the inward stroke such that the sheath is moveable independently of the syringe plunger and further movement of the sheath after decoupling at least partially covers the opening in the barrel.

A safety syringe (100; 700; 1200) comprising: a barrel (104; 704; 1204) having an opening at an end thereof; a syringe plunger (108; 708; 1208) configured to move within the barrel such that an inward stroke of the syringe plunger causes a substance within the barrel to be expelled from the opening; and a sheath (112; 712; 1212) configured to cover at least partially the opening in the barrel after use of the syringe, wherein the sheath is coupled to the syringe plunger and is configured to decouple from the syringe plunger at a point on the inward stroke such that the sheath is moveable independently of the syringe plunger and further movement of the sheath after decoupling at least partially covers the opening in the barrel.

An injector comprising an outer housing, a generally longitudinally extending keyway formed in the outer housing, an inner housing located interiorly of the outer housing, a guide member mounted at one end of the inner housing, the guide member having at least one protrusion adapted to engage the keyway, a spring member, the spring member having a first end abutting the outer housing, a second end of the spring member abutting the guide member, a syringe mounted interiorly of the inner housing, a needle mounted on one end of the syringe, the syringe having a plunger and a plunger rod, a finger rest member mounted over the outer housing, the finger rest member being opaque to thereby prevent visual access to the keyway.

A safety syringe (100; 700; 1200) comprising: a barrel (104; 704; 1204) having an opening at an end thereof; a syringe plunger (108; 708; 1208) configured to move within the barrel such that an inward stroke of the syringe plunger causes a substance within the barrel to be expelled from the opening; and a sheath (112; 712; 1212) configured to cover at least partially the opening in the barrel after use of the syringe, wherein the safety plunger is decoupled from the sheath and is configured to couple to the sheath at a first point on the inward stroke and to decouple from the syringe plunger at a second point on the inward stroke such that the sheath is moveable independently of the syringe plunger and further movement of the sheath after decoupling at least partially covers the opening in the barrel.

A system with a needle head that attaches to a syringe assembly. The syringe assembly contains a barrel and a plunger. The plunger has a bore opening that is accessible from within the barrel. A tubular spacer is disposed within the barrel. The tubular spacer defines a central opening. The needle head has a needle that extends from a needle base. The needle base extends into the central opening of the tubular spacer. A plug is provided that blocks access to the needle. The plug is displaced out of the central opening of the tubular spacer and into the opening in the plunger as the plunger contacts and displaces the tubular spacer in the barrel. As the plug is displaced from the tubular spacer, the plug transfers into the bore opening within the plunger. This enables the plunger to press flush against the tubular spacer.