| 摘要 |
<p>There is disclosed a cannula device of the kind referred to characterised by a radially protruding stud on the needle hub slidable along an axially extending slot in the cylindrical shield and inwardly directed barbs at the rearward end of the slot which after resilient deformation of the shield close behind the stud when the needle is retracted into the shield to prevent redeployment of the needle.</p> |
