Abstract: A needle retraction medical device including a hollow body (10) and a plunger (20). The hollow body (10) has a first end (11) provided with a needle mounting hub (13) and a plurality of releasable latches (15) holding the needle mounting hub (13) against spring (14) bias. The latches (15) are formed integrally with the hollow body (10) and project longitudinally inside the hollow body (10) from a proximal end at or adjacent the first end (11) of the hollow body (10) to a free end. A respective opening (35) is provided in the body (10) radially inwards of each of the latches (15). The plunger (20) has a forward end insertable into the body (10) from a second end thereof, a hollow interior and a closed rear end.

Abstract: To eliminate needle-stick risk by encapsulating the needle of a syringe immediately after discharge of syringe contents, the entire syringe is housed in a device comprising a hollow body, a spring and a plunger. The barrel of the syringe is held in the body interior against the force of the spring by latching formations internal to the body. The plunger is hollow to provide a chamber to receive the syringe piston and at least part of the barrel. The plunger has deflectable engagement elements at its forward end so it is pushed into the body, it reliably displaces the syringe piston/rod to discharge the syringe contents via a hollow needle, the elements ultimately being deflected outwards as the contents are fully discharged so as not to impede syringe retraction into the hollow plunger. The plunger also has latch opening projections at its forward end.

Abstract: A fluid filled cartridge having a fixed needle and a piston assembly for expression of its contents is mounted inside an applicator. In order to extend the needle from the body prior to cartridge contents expression and without premature leakage of fluid therefrom, an actuator is mounted in the body to drive the cartridge forwards. This is accomplished by co-operating driving and driven parts of the actuator and the cartridge (or any carrier it may have) which are decoupled by release formations in the applicator body after the cartridge has been moved sufficiently to extend the needle. The applicator also includes provision for automatic needle retraction after cartridge contents expression. A separate inventive feature is the deformability of the piston so that force transmission to the trigger means to initiate needle retraction only occurs upon full content expression when the piston has “bottomed out” within the cartridge.

Abstract: First and second hollow needles extend from opposing sides of a common hub which is formed in one piece of transparent material. Proximal ends of the respective needles are in communication with each other by a narrow passageway through the hub. The projecting portion of the second needle is covered by an elastomeric sheath. The hub preferably includes a magnifying formation overlying the passageway portion between the proximal ends of the needles. In use, once the point of the first needle penetrates a vein, the patient's blood pressure is sufficient to displace air from the entire first needle and at least part of the passageway through the hub. The sheath over the second needle is sufficiently elastic to allow this and expand accordingly. The blood flows into the piercing needle and the passageway between the needles, thus being viewable through the surrounding transparent material and the magnifying portion, if present.