| 摘要 |
A blood extraction device is disclosed herein, which is an improvement over similar devices having a cylindrical extraction tube enclosing an air-tight piston and sealed with a closure cap having an axial projection which contains a self-sealing puncturable plug and is received within a movable tubular guide sleeve containing a double-ended cannula the rear end of which is enclosed by a deformable but resilient thin hose with a closed self-sealing rear end. The improvement resides in the inclusion of one or more slots on the guide sleeve and cooperating lugs on the projection, or vice versa, each slot having an axially extending portion and a peripherally extending portion, such that rotation of the rear cutting edge of the cannula is prevented during penetration of both the rear end of the hose and the plug, and rotation is possible only when penetration is complete. In this way, the self-sealing properties of both the hose and the plug are retained, and the resilience of the hose secures each lug in position in the peripherally extending portion of each slot. |
