| 摘要 |
Trocar for thoracic surgery, comprising a guide duct (T) for surgical instruments adapted to be inserted in a body opening of access to the thoracic cavity. The duct (T) is formed by a plurality of sectors (11) arranged around its axis (12) and articulated to a support frame (13). Sector expansion means (14) are associated with the duct (T) for opening out the sectors from an initial insertion position in the body opening to a final maximum expansion position in which they are moved away from the axis (12) to a greater extent than in the configuration assumed in said initial position. The expansion means (14) comprise a control ring nut (26) movably connected with the sectors (11) and with the support frame (13) such that a rotation of the ring nut (26) in one direction, results in the sectors (11) away of the axis (12). Associated with the ring nut (26) are means for locking the rotation (29) in the direction opposite that of the expansion direction. The rotation locking means (29) comprise a device (32) for temporarily removing the rotation hindrance of the ring nut (26) in the direction opposite the expansion direction, whereby the sectors can move backwards to the initial position. |
