Syringe with automatically triggered safety sleeve

摘要

A medical injection device is provided which includes a shield system and a syringe. The shield system includes a housing, a shield telescopically received in the housing and slidably coupled to the housing and a driver that pushes the syringe stopper to cause drug injection. The driver is equipped with sensing elements that automatically detect empty syringe. A spring resiliently urges the shield from a retracted position to an extended position shielding the needle. The syringe is coupled to the housing. The shield is positioned externally to the syringe and the driver. The shield includes flexible latches to keep its position relative to the housing during storage and use. The axial movement of the driver in respect to the syringe causes an automatic release of the spring by sensors when the syringe is empty, allowing the spring to move and lock the shield in the extended position after use.

主权项

1. An injection device comprising:
a housing having a proximate end and a distal end, the distal end having an opening therein; a cartridge barrel within the housing, the cartridge barrel having proximate and distal ends; a needle cannula fixed to the distal end of the cartridge barrel; a stopper within the cartridge barrel; a driver coupled to the stopper; a shield coupled to the housing and slidable between a retracted and an extended position; a spring activateable to urge the shield from the retracted position to the extended position; and at least one deformable side arm forming a portion of said driver and releasably retaining the spring in a compressed state, wherein the at least one side arm is biased into slidable contact with an exterior surface of said cartridge barrel and deflects radially inwardly at an end profile of the distal end of the cartridge barrel and, in turn, release the spring such that the spring slides past the at least one side arm and applies a force to the shield to urge the shield into the extended position.