GB2332627A

GB2332627A - Variably sized port for medical instrument

Info

Publication number: GB2332627A
Application number: GB9727154A
Authority: GB
Inventors: Ian James Broome
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-12-23
Filing date: 1997-12-23
Publication date: 1999-06-30
Also published as: GB9727154D0

Abstract

The port, which may provide a gas and/or liquid tight seal around a scope or other instrument placed through it, comprises an open-ended tube 1 of elastic material which is held at or near its two open ends by clamping between respective pairs of rings 2,3 and 4,5 so that rotation of one pair of rings relative to the other has the effect of twisting the tube to thereby alter the size of its central hole. The size of the aperture may be set by turning one end of the tube relative to the other and then fixing in this position, the tube end being held by friction or by a locking mechanism. Alternatively, the seal may be held partly or fully closed by a rotational force applied to one end of the tube by a spring. A guard device may prevent passsage of an object through the port when it is partially or completely closed.

Description

2332627 THE TWIST SEAL This invention relates to a port with a variable

sized aperture.

It is common practice to pass viewing scopes and other instruments through ports to enable surgery or investigations to take place. Many currently available ports use elastic diaphragms, which have a small hole in them to allow the passage of these scopes or instruments. When pushed through this hole the instrument or scope blocks it to form a seal, which allows gas to be supplied to one side which will not leak to the other side of the seal.

One disadvantage of the above system is that the diaphragm cannot be fully closed except by the use of an obturator or separate sealing mechanism. Another disadvantage is that there is a limit to the distensibility of the diaphragm, meaning that it may not be possible to pass large scopes or instruments though the hole and then subsequently obtain an adequate gas seal when small scopes or instruments are used. It is also difficult to pass an irregular shaped object through this type of seal, as it is prone to catch on the diaphragm.

According to the present invention a variably sized port is provided where adjustment of the size of the port's aperture can be made using an open ended tube of elastic material. This tube is held at or near to the two open ends. Rotation of one end of the tube relative to the other causes the size of the tube's central hole to alter. The size of the hole through the port can be adjusted to permit the passage of objects or reduced until fully closed. The diameter of the hole through the port can be adjusted so that it may provide a gas and / or liquid tight seal around many objects placed so as to extend through it.

1 In some variations of this port the size of the hole through the tube may be set by turning one end of the tube in relation to the other and then fixing it in this position. This tube end may be held in position by frictional forces or by the use of a locking mechanism. Alternatively, in other variations of the port, the seal may be held either partly or fully closed by a rotational force applied to one end of the tube (by a spring for example). The end of the tube may then be turned against the action of this force to open it and released to partly or fully close it. In a variation of this port, the tube may be held either partly or fully open by a rotational force applied to one end of the tube (by a spring for example). The end of the tube may ther, be turned against the action of this force to close it and released to partly or fully open it. In some circumstances it may be appropriate to incorporate an associated guard device (which may or may not itself prevent the passage of gas or liquid through the port) that prevents objects from being passed through the port in certain situations (for example when the port is partially or completely closed). The action of this guard may or may not be linked to work with any action or actions required to adjust the aperture size of the port.

Specific embodiments of the invention will now be described by way of examples, with reference to the accompanying drawings.

Figure 1 shows a cross section of the port with if s adjustable seal in the open position. The seal consists of an open-ended tube of thin elastic material (for example latex rubber) (1). The edge of one open end of this tube is clamped between two rings (2) and (3). Rings (2) and (3) do not move in relation to each other. The edge of the other open end of the tube is clamped between two more 2 rings (4) and (5) forming an outer collar. Again, rings (4) and (5) do not move in relation to each other. It is possible, however, to rotate rings (4 and 5) in relation to rings (2 and 3). Doing this has the effect of twisting the tubular piece of elastic material and causing the size of the hole through its centre to start to get smaller. In this manner, it is possible to adjust the size of the hole through the port as may be necessary to provide a gas and / or liquid proof seal around many objects placed through the port. Further rotation of rings (4 and 5) in relation to rings (2 and 3) causes the hole through the centre of the elastic tube to occlude completely. In this example there is sufficient friction between rings (3) and (4) to ensure that the size of the hole through the port can be set and will remain fixed when the collar (4 and 5) is released.

Figure 2 shows a cross section of the port with it's adjustable seal in a partially closed position. It provides a gas and / or liquid tight seal (6) around the instrument that can be seen to be extending through the port (7).

Figure 3 shows a cross section of the port with it's adjustable seal in the closed position.

Figure 4 shows a plan view of the port shown in figure 1. The central aperture of the open port can be seen (8).

Figure 5 is a schematic diagram of the open ended tube of elastic material that is used to form the seal. It shows the edges of the open ends of the tube that are clamped by rings 2 and 3 and 4 and 5.

3 Figure 6 shows a cross section and plan view of the port with ifs adjustable seal (1) in a partially opened position. In this example a locking mechanism (9) is provided which can be used to fix the aperture of the port at a desired size. Figure 7 shows a cross section and plan view of one example of how a spring (10) can be used to alter the aperture size of the port as described above. Release of the outer ring (5) after rotation in the direction shown (11) will allow the spring ( 10) to pull the outer ring (5) back towards its starting position. Figure 8 shows a cross section and plan view of one example of how the action of a guard (12) as described above could be linked to the actions required to alter the size of the aperture through the port. The guard (12) is fixed to bar (13) that is held in position by piece (14). Bar (13) has teeth which engage teeth on the outer surface of ring (5). It can be seen that movement of bar 13 will simultaneously move the guard (12) and adjust the aperture of the port.

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Claims

1) A variably sized port is provided where adjustment of the size of ifs aperture can be made using an open ended tube of elastic material. This tube is held at or near to the two open ends. Rotation of one end of the tube relative to the other causes the size of the tube's central hole to alter.

2) A port as claimed in 1 where it is possible to fully close the port by rotation of one end of the tube of elastic material relative to the other.

3) A port as claimed in 1 or 2 where the elastic material is impermeable to gas and / or liquid. This enables the port to be adjusted to form a seal that is impermeable to gas and / or liquid. The port may be adjusted to form an impermeable seal around objects of certain shapes that extend through the port.

4) A port as claimed in any preceding claim where adjustment of the size of the hole through the port is made by the turning of a collar fixed at or near to one end of the open ended tube which forms the seal. This causes rotation of one end of the tube relative to the other.

5) A port as claimed in any preceding claim where rotation of one end of the open ended tube, relative to the other, is sufficiently stiff to ensure that the size of the hole through the port can be set and will remain fixed when that end is released.

6) A port as claimed in 1 or 2 or 3 or 4 where a locking mechanism is used to fix the aperture of the port in any set position.

7) A port as claimed in 1 or 2 or 3 or 4 where the aperture through the port is held either partly or fully closed by a rotational force applied to one end of the tube. The collar may then be turned against the action of this force to open it and released to partly or fully close it.

8) A port as claimed in 1 or 2 or 3) or 4 where the seal is held either partly or fully open by a rotational force applied to one end of the tube. The collar may then be turned against the action of this force to close it and released to partly or fully open it.

9) A port as claimed in any preceding claim that has an associated guard device that can prevent the port form being used. This guard device may or may not prevent the passage of gas or liquid through the port. The action of this guard may or may not be linked to work with any action or actions required to adjust the aperture size of the port.

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