| 摘要 |
<p>An echogenic cannula (7) includes a hole (5) provided at the distal end (17). Preferably the hole (5) is positioned through a centerline (8) which is spaced from the centerline (6) of the stylet (9) in order to form a concave surface (11) from which sound waves (10) are reflected in order to locate the distal tip end (17). An echogenic needle (410) includes a hole (42) provided at the distal tip end. Preferably, the hole (42) is positioned through a centerline (413) which is spaced from the centerline (414) of the stylet (411) in order to form a concave surface (43) from which sound waves are reflected in order to locate the distal tip end.</p> |
