Seal assembly for accommodating introduction of surgical instruments

• US 5,657,963 A
• Filed: 12/15/1994
• Issued: 08/19/1997
• Est. Priority Date: 06/16/1993
• Status: Expired due to Term

• Current Assignee: United States Surgical Corporation (Medtronic Plc)
• Original Assignee: United States Surgical Corporation (Medtronic Plc)
• Inventors: Hinchliffe, Peter W. J., Gresham, Richard D., Smith, Robert C.
• Primary Examiner(s): CHAMBERS, A MICHAEL
• Application Number:
  US08/356,436
• Time in Patent Office: 978 Days
• Field of Search: 251/149.1, 604/167, 604/256
• US Class Current: 251/149.1
• CPC Class Codes: A61B 17/3462 with means for changing the diameter or the orientation of the entrance port of the cannula, e.g. for use with different-sized instruments, reduction ports, adapter seals expandable cannulas A61B17/3417
• CPC Class Codes: A61B 2017/3464 with means acting on inner surface of valve or seal for expanding or protecting, e.g. inner pivoting fingers
• CPC Class Codes: A61B 2090/0811 for the position of a particular part of an instrument with respect to the rest of the instrument, e.g. position of the anvil of a stapling instrument
• CPC Class Codes: A61M 2039/0626 used with other surgical instruments, e.g. endoscope, trocar
• CPC Class Codes: A61M 2039/0633 the seal being a passive seal made of a resilient material with or without an opening
• CPC Class Codes: A61M 2039/0646 Duckbill-valve
• CPC Class Codes: A61M 2039/0666 Flap-valve
• CPC Class Codes: A61M 2039/0686 comprising more than one seal
• CPC Class Codes: A61M 39/06 Haemostasis valves, i.e. gaskets sealing around a needle, catheter or the like, closing on removal thereof

Abstract

A seal assembly is provided which includes a housing and resilient first seal member associated with the housing. The first seal member is preferably a gasket having an aperture formed therein for receiving surgical instrumentation adapted to cooperate with a dilating means having an exterior face associated with the housing for dilating the aperture of the gasket. The first seal member and the dilating member are adapted for relative movement therebetween, the first seal member and the dilating member assuming a first position wherein the aperture of the first seal member is spaced from the dilating member and assuming a second position wherein the aperture of the first seal member is stretched around the exterior face of the dilating member. A flexible member may also be provided to help maintain a seal between the first seal member and an instrument inserted therethrough, in particular when the instrument is moved in a transverse direction.

Claims

1. A seal assembly which comprises:

(a) a unitary housing defining a cavity therein;

(b) a deformable gasket positioned within the housing and defining an aperture to receive surgical instrumentation;

(c) a dilating member positioned at least partially within the housing cavity in coaxial alignment with the deformable gasket for movement between a first position adjacent the gasket and a second position in engagement with the gasket whereby the aperture is expanded; and

(d) a biasing mechanism mounted in the housing cavity and accessible through the housing, the biasing mechanism being positioned to urge the dilating member to the first position.

5. The seal assembly of claim 1, wherein the housing includes a seal mechanism, the seal mechanism being configured and dimensioned to provide a substantially fluid-tight seal in the absence of an instrument passing therethrough.

6. The seal assembly of claim 5, wherein the seal mechanism comprises a distally directed duckbill member.

7. The seal assembly of claim 5 further comprising a latching mechanism disposed within the housing for retaining the dilating member in the second position.

8. The seal assembly of claim 1, wherein the biasing mechanism comprises at least one spring member.

9. The seal assembly of claim 8, wherein the at least one spring member comprises a circumferential resilient spring disposed about the dilating member.

10. The seal assembly of claim 8, wherein the at least one spring member comprises at least one substantially planar, flexible spring member positioned to act upon the dilating member.

11. The seal assembly of claim 1 further comprising an actuating mechanism in communication with the dilating member, for moving the dilating member between the first position and the second position.

12. The seal assembly of claim 11 wherein the actuating mechanism is manually actuable.

13. The seal assembly of claim 1 further comprising a door assembly transverse the housing, wherein longitudinal movement of the door assembly from a rest position to a predetermined displaced position results in corresponding movement of the dilating member from the first position to the second position.

14. The seal assembly of claim 13 wherein the door assembly comprises a slidable door, slidable between a first, closed position and a second, opened position.

15. The seal assembly of claim 14 wherein the door assembly comprises a door return spring for biasing the door to the first, closed position.

16. The door assembly of claim 15 further comprising a door opening spring in communication with a spring winding gear for winding the door opening spring.

17. The seal assembly of claim 16 wherein the door return spring maintains a greater tensile force on the door than the door opening spring when the door assembly is at the proximal position, the greater tensile force maintaining the door in the first, closed position.

18. The seal assembly of claim 16 further comprising a spring winding rack disposed within the housing and in communication with the spring winding gear.

19. The seal assembly of claim 18 wherein the spring winding rack is longitudinally disposed within the housing.

20. The seal assembly of claim 18 wherein the spring winding rack and the spring winding gear are a rack and pinion assembly.

21. The seal assembly of claim 18 wherein longitudinal movement of the door assembly from the proximal position to the distal position results in rotational movement of the spring winding gear, distally along the spring winding rack, thereby causing corresponding movement of the door opening spring about the spring winding gear resulting in increased tensile force on the door by the door opening spring wherein the increased tensile force causes the door to open when the spring reaches the distal position.

22. The seal assembly of claim 15 further comprising a door latch mechanism pivotally disposed within the housing, adjacent the door, for maintaining the door in the first, closed position.

23. The seal assembly of claim 22 further comprising a latch release disposed distally within the housing, wherein movement of the door from the rest position to the predetermined displaced position causes the latch release to engage the door latch mechanism thereby disengaging the latch mechanism and releasing the door.

2. In combination:

(a) an elongated cannula having proximal and distal ends and a throughbore; and

(b) a sealing mechanism operably associated with the proximal end of the cannula, the sealing mechanism including;

(i) housing;

(ii) deformable sealing member having a body with a passage formed through the body;

(iii) a dilator member supported within the sealing mechanism housing, the dilator member having a central bore having a diameter substantially equal to the diameter of the cannula throughbore, the dilator member being movable from a first position in which the sealing member is in a predeformed position to a second position in which the sealing member is deformed to increase the area of the sealing member passage.

3. A cannula assembly which comprises:

(a) a housing;

(b) a resilient first gasket disposed within the housing, wherein the first gasket includes an aperture formed therein to receive surgical instrumentation;

(c) a biasing mechanism positioned within the housing;

(d) a cannula having a throughbore operatively associated with the housing;

(e) a dilating member having an exterior face associated with the housing and having a bore with a diameter substantially the same as the diameter of the cannula throughbore;

wherein the first gasket and the dilating member are adapted for relative movement therebetween, the dilating member assuming a first position spaced from the first gasket, and assuming a second position wherein the aperture of the first gasket is stretched around the exterior face of the dilating member to allow free passage of surgical instrumentation of varying diameter with minimal insertion force into the cannula, the biasing mechanism returning the dilating member to the first position spaced from the first gasket after insertion of the instrument thereby allowing the first gasket to sealingly engage the surgical instrumentation.

4. The seal assembly of claim 3, wherein the first gasket is substantially planar and is mounted transverse with respect to the housing.

24. The seal assembly of claim 3 comprising a block assembly disposed about the dilating member, said block assembly comprises a cut-out ramp having a pin slidably disposed therethrough, the pin operatively communicating with the dilating member, wherein movement of the block assembly causes the pin to move within the cut-out ramp thereby causing the dilating member to move from the first position to the second position.

25. The seal assembly of claim 24, wherein the housing includes a seal mechanism, the seal mechanism being configured and dimensioned to provide a substantially fluid-tight seal in the absence of an instrument passing therethrough.

26. The seal assembly of claim 25 further comprising a latching mechanism disposed within the housing for retaining the dilating member in the second position.

27. The seal assembly of claim 26 further comprising a latch release mechanism disposed within the housing, distal the first gasket, wherein actuation of the release mechanism releases the latching mechanism thereby allowing the dilating member to return to the first position.

28. The seal assembly of claim 27 wherein the release mechanism is disposed distally of the seal mechanism.