| 摘要 |
<p>A trocar (10) having a cannula (22) and housing (28) which define an access channel, is configured to receive a surgical instrument (26). A flexible valve (36) disposed in the channel includes first portions (37) which define an orifice (38) through the valve (36) and second portions (39) which are disposed outwardly of the first portions. The second portions (39) are provided with a greater flexibility so that when the instrument (26) is inserted off axis, the second portions (39) of the valve (38) will deform before the first portions (39) causing the orifice (38) to move without substantial deformation, to the off axis location. Alternatively, levers (54) engaging the first portions (37) of the valve (35) can be pivotally mounted on a floating ring (180) to move the substantially undeformed orifice (38) to the off axis location. An associated method includes the steps of deforming the second portions (30) of the valve (36) without substantially deforming the first portions (37) of the valve (36) to move the orifice (38) into axial alignment with the instrument (26). A mechanism (81) is provided for protecting the valve (36) from instruments having pointed distal tips.</p> |
