Sicherheitstrokar.

摘要

A safety trocar (10) is provided in which the cutting tip (12) is withdrawn into the cannula (14) in response to counterforce being removed from the cutting tip, e.g., by the tip entering a body cavity. The cutting tip is maintained in the exposed positioned by a mechanism associated with the obturator shaft, and is automatically withdrawn into the cannula under the force of a spring (64) when the first mechanism is released by a second mechanism associated with the obturator. Penetration force is maintained at a minimum and safe and efficacious trocar entry is facilitated.