| abstract |
A device (10) for rapid vascular drug delivery, particularly through the adult sternum or the pediatric tibia, incorporates a cylindrical syringe body (12), fitted with a needle (14). The syringe body is held in a cylindrical main housing (16) having a front barrel (18) with an orifice (20) through which the needle (14) may be extended. A cylindrical actuation handle (22) fits over end (24) of the main housing (16) for sliding movement along the main housing. A syringe plunger (26) contacts drive plunger (28) and extends into the syringe body (12) from end (30) to confine liquid medication (32) in the syringe body (12). A main spring (34) extends between the drive plunger (28) and the actuation handle (22) to bias the actuation handle (22) in its extended position. A needle return spring (38) extends between the front barrel (18) and the syringe body (12) to bias the needle to its retracted position. The drive plunger (28) has an annular peripheral socket (42) for one or more lock balls (44) which engage one or more openings (45) on the main housing (16) to lock the drive plunger in position with respect to the syringe body (12). A mating annular lock ball trip pocket (46) is positioned on inside surface (48) of the actuation handle to allow the device (10) to be fired when the lock ball(s) in socket (42) reach the pocket (46). |