| 摘要 |
An automatic retractable safety trocar instrument includes a portal sleeve, a trocar disposed within the portal sleeve and a safety shield disposed between the portal sleeve and the trocar. The trocar is movable automatically from an operative position wherein a sharp distal end of the trocar protrudes from the portal sleeve to a retracted position wherein the sharp distal end is protected within the instrument upon penetration into a cavity in the body. The safety shield is automatically movable proximally from an extended position during penetration of tissue and distally toward the extended position upon introduction of a distal end of the portal sleeve in an anatomical cavity such that a distal end of the safety shield contacts tissue within the cavity and moves the tissue away from the cavity wall. A method of creating a space between a wall of an anatomical cavity and a layer of tissue within the cavity includes penetrating the cavity wall with the sharp tip of a penetrating member disposed within a portal sleeve to position a distal end of the portal sleeve within the cavity and extending a safety shield to protrude beyond the sharp tip and the cavity wall whereby a blunt distal end of the safely shield moves the tissue away from the wall maintaining a space between the tissue and the wall. |
