套管
Cannula \Can"nu*la\, n. [L. cannula a small tube of dim. of
canna a reed, tube.] (Surg.)
A small tube of metal, wood, or India rubber, used for
various purposes, esp. for injecting or withdrawing fluids.
It is usually associated with a trocar. [Written also
{canula}.]
cannula
n : a small flexible tube inserted into a body cavity for
draining off fluid or introducing medication