| 摘要 |
The invention generally relates to a needle assembly of the kind having a needle, an elongate blunting device, a shifting member, and a flash chamber. The needle is of the kind that has a needle proximal end, a sharp needle distal end and a needle canula extending therethrough. The elongate blunting device is at least partially located within the needle canula. The elongate bluntin g device is of the kind that has a blunting device proximal end, a blunting device distal end, and a blunting device blood flow passage therethrough, through which blood can flow from the blunting device distal end to the blunting device proximal end. The shifting member can be actuated to move relative to the needle and, upon movement relative to the needle, causes movement to the elongate blunting device from a retracted position wherein the blunting devi ce distal end is retracted into the needle canula so that the sharp needle dist al end can penetrate the body, to an extended position wherein the blunting device distal end extends out of the needle canula so as to prevent the sharp needl e distal end from penetrating the body. The flash chamber is of the kind that has an internal volume which is in communication with the blunting device blood flow passage so that the blood can flow from the blunting device blood flowpassag e into the internal volume. The flash chamber is at least partially made of a material through which blood can be seen when located in the internal volume . |
