Trocar with floating septum seal

A trocar adapted to form an access channel across a body wall, the channel being sized and configured to receive a surgical instrument having an outer surface and a first axis, the trocar comprising:

• a cannula having a second axis extending between a proximal end and a distal end of the trocar;
• a seal housing disposed at the distal end of the cannula and forming with the cannula the access channel of the trocar;
• a flexible valve disposed relative to the housing and across the access channel, the valve having elastomeric properties for forming a seal with the instrument when the instrument is disposed in the access channel;
• portions of the valve defining an orifice having a third axis which is normally aligned with the second axis of the cannula, the valve portions being sized and configured to receive the instrument and to form the seal with the outer surface of the instrument;
• and
• means disposed circumferentially outwardly of the valve portion and responsive to the instrument being inserted with the first axis non-aligned with the second axis of the cannula, for moving the valve portions so that the third axis of the orifice is substantially aligned with the first axis of the instrument.

A method for forming a seal around an instrument introduced off-axis through an access device, includes the steps of:

• providing a valve in the access device, the valve having an axis and including first portions defining an aperture sized and configured to receive the instrument, and second portions having a greater flexibility than the first portions;
• inserting the instrument into the access device;
• contacting the valve with the instrument at a location off-axis relative to the aperture;
• pushing the instrument through the aperture to form the seal around the instrument;
• and
• during the pushing step deforming the second portions of the valve, without substantially deforming the first portions of the valve to move the aperture into axial alignment with the instrument.

A trocar adapted to form an access channel across a body wall and configured to receive a surgical instrument, the trocar comprising:

• a cannula having an axis;
• a housing disposed relative to the cannula and defining with the cannula the access channel of the trocar, the housing having an annular recess with a first diameter;
• a ring disposed in the recess and having a second diameter;
• a flexible valve disposed relative to the housing and across the access channel, the valve having an orifice and elastomeric properties for forming a seal with the instrument when the instrument is disposed in the access channel;
• a plurality of levers connected to the ring and engaging the valve in proximity to the orifice;
• the second diameter of the ring being less than the first diameter of the recess so that the ring and levers are free to float radially of the access of the cannula;
• whereby
• movement of the ring and levers cause the orifice to move without substantial deformation from the axis of the cannula.

An access device adapted to form an access channel across a body wall, and configured to receive a surgical instrument in the access channel, the access device comprising:

• a cannula having an axis extending between a proximal end and a distal end of the device;
• a seal housing disposed at the distal end of the cannula and forming with the cannula the access channel of the device;
• a flexible valve disposed relative to the housing and across the access channel, the valve having elastomeric properties for forming a seal with the instrument when the instrument is disposed in the access channel;
• portions of the valve defining an orifice which is sized and configured to receive the instrument and to form the seal with an outer surface of the instrument;
• and
• means disposed circumferentially outwardly of the valve portions for supporting the valve portions within the seal housing, the supporting means being movable relative to the housing to permit the valve portions to float relative to the axis of the cannula.

An access device adapted to form an access channel across a body wall, and configured to receive a surgical instrument in the access channel, the access device comprising:

• a cannula having an axis extending between a proximal end and a distal end of the device;
• a seal housing disposed at the distal end of the cannula and forming with the cannula the access channel of the device;
• a flexible valve disposed relative to the housing and across the access channel, the valve having elastomeric properties for forming a seal with the instrument when the instrument is disposed in the access channel;
• portions of the valve defining an orifice which is sized and configured to receive the instrument and to form the seal with an outer surface of the instrument, the valve portions being located along a normal axis when the instrument is not present in the access channel;
• and
• means for preventing deformation of the valve portions when the instrument is inserted through the valve along an axis displaced from the normal axis of the valve portions.