| 摘要 |
A protective device for enclosing the scarf of a cannula used to draw blood includes an elongate sheath (14) open at one end and having a stop (18) at the other end. A piston (22) is disposed in the sheath (14) to be slidable between an extended position against the stop (18) and a retracted position away from the stop (18). The piston (22) has a bore extending through it in the direction in which the piston slides. A nipple (36) is provided for securing an elongate, double-ended cannula (34) in the piston bore so the cannula (34) extends longitudinally through the bore with one end of the cannula (34) in the sheath (14) and the other end of the cannula (34) extending outwardly away from the sheath (14) when the piston (22) is in the extended position. Means are provided for sliding the piston (22) away from the stop (18) to the retracted position to retract the outwardly extending end of the cannula (34) into the sheath (14). |
