| 摘要 |
This invention consists of a syringe (10) with a thin walled plastic reservoir (26) lodged under a collapsible roof (22) that is located at the distal end of the syringe barrel adjacent the needle (42). Hermetically stored in the thin walled reservoir is a local anesthetic. Depression of the syringe plunger (18) applies pressure to the collapsible roof (22) which compresses sharp projections (28) through the walls of the plastic reservoir. The sharp projections rupture the plastic reservoir (26) and the continued depression of the plunger induces flow of the anesthetic through a filter (64) and one way valve (68) into a porous needle (42). The porous needle projects forward of a second needle (20). This second needle is coupled to the syringe cylinder for passage of fluids. The openings (44) along the length of the porous needle provide for flow of the local anesthetic in multiple directions which results in anesthetization of the region through which the needles are passed in search of a vein or body cavity. |
