| 摘要 |
An intravenous catheter (10) with a self-locating needle guard (51). The intravenous catheter comprises a catheter assembly including a catheter attached to a hollow catheter hub (50), and an introducer needle assembly (56). The introducer needle assembly includes a hollow needle (54) with a distal tip (57), with the needle being affixed near its proximal end to a needle hub, the distal end of which is suitable for engagement with the hollow catheter hub (50). The needle has a substantially round diameter (59) outer shape extending along the distal end thereof, and a nonround deformed outer shape (58) at a given distance from the distal end thereof for engaging a needle guard. The needle guard includes a distal portion having a longitudinal length greater than the given distance and a proximal portion having the same nonround deformed outer shape as the needle to allow the nonround deformed portion of the needle to pass therethrough, but to engage and prevent the round distal end of the needle from passing therethrough. The needle guard is mounted for relative movement with respect to said needle as the needle is withdrawn from the catheter until the nonround deformed shape of the needle guard engages the round distal portion of the needle, at which position the distal portion of the needle guard extends over and guards the needle tip. The nonround deformed outer shape of the needle guard also rotationally orients the nonround deformed portion of the needle, and the needle guard further includes a latch mechanism to engage the lumen of the needle to prevent the needle guard from travelling back toward the proximal end of the needle when the latch mechanism (52) is engaged. |
