Cleaning adaptor for an endoscope

Abstract

A cleaning adaptor 100 for engagement with an endoscope’s air / water cylinder (62, Fig 1b). The cleaning adaptor is a unitary element comprising a sealing plug 104 having a head portion 114, 108 config

Description

FIELD OF THE INVENTION This invention relates to a cleaning adaptor for engagement in an air-water port of a control section of an endoscope during a cleaning procedure. The cleaning adaptor is configured to replace an airwater valve of the endoscope to permit flushing of the air-water channel of the endoscope. This invention also relates to methods of using such a cleaning adaptor and to methods of flushing an airwater channel of an endoscope. BACKGROUND TO THE INVENTION Endoscopes are now widely used in a number of medical procedures. An endoscope typically includes a light source connector, a control section, an umbilical cord connecting the light source connector to the control section, and an insertion tube terminating at a distal tip. The light source connector provides connections to a light source, an air pump, and a water bottle. During use of the endoscope, an operator is able to use an air / water valve in the control section to control the delivery of air (from the air pump) or water (from the water bottle) to the distal tip through an air / water channel of the endoscope. A small metal nozzle is generally disposed at the distal tip of the endoscope to deflect air or water from the air / water channel across an image lens of the endoscope. It will be appreciated that the air / water channel is necessarily of a small diameter. Furthermore, the air / water channel is actually formed by the two separate small diameter channels that only combine into a single channel proximate the distal tip of the endoscope. After use of an endoscope it is essential that the endoscope is properly cleaned and sterilised before it is used again. Cleaning refers to the removal of visible debris, which may include both inorganic and organic substances. Cleaning usually involves a mechanical process, together with the application of water and detergent. Following cleaning, sterilisation of the endoscope destroys microorganisms present on or in the endoscope. Sterilisation processes usually involve steam or a chemical sterilant. Following sterilisation, the endoscope undergoes high-level disinfection. The presence of the metal nozzle at the distal tip means that it is not possible to brush the air / water channel. This, together with the small diameter of the air / water channel, as well as other factors, makes it difficult to clean and decontaminate the air / water channel. Additionally, the air / water nozzle is the point of smallest internal diameter of the air / water channel system such that it can easily become blocked or obstructed by debris. During an endoscopic procedure, air infused into the organ being examined can force debris to back up into the nozzle and into the air / water channels. This debris can travel some distance back into the channels. It is currently recommended that a preliminary cleaning routine is undertaken immediately after use of the endoscope and before the light source connector is detached from the light source / video processor. Current pre-clean practice is to flush air and water through the air / water channel. It is also recommended that the air and water channels (and any auxiliary channel) are also irrigated with detergent, not only to expel any blood, mucus and other debris, but also to check for blockages. It has been found, however, that routine pre-cleaning procedures for endoscopes do not remove biofilm reliably from endoscope channels. This leads to failures in the subsequent decontamination processes. To enable this pre-clean or flushing of the air / water channel it is necessary to replace the air / water valve that is used during the procedure with a dedicated cleaning valve or adaptor. These cleaning valves allow a user to direct a flow of air or water (or detergent solution) down each of the separate smaller channels of the air / water channel. Some of these cleaning valves are reusable and must, therefore, be designed to be thoroughly cleaned and sterilised after use to avoid cross-contamination between endoscopes. There is therefore significant cost involved in providing a suitable reusable cleaning valve. To overcome this problem, a number of disposable or single-use cleaning valves have been developed. These disposable valves are, however, still relatively expensive to manufacture due to the complex arrangement of seals and passageways that must be provided to control the flow of air and water during the pre-clean procedure. It is an aim of the present invention to provide an improved cleaning adaptor for use in pre-clean procedures for flushing the air / water channel of an endoscope. In particular it is an object of the present invention to provide an improved cleaning adaptor that is easier to use during the pre-clean procedure and provides greater efficacy of the cleaning procedure. SUMMARY OF THE INVENTION A first aspect of the invention provides a cleaning adaptor for engagement with an air / water cylinder of an endoscope, said cylinder having an air inlet disposed in a circumferential wall of the cylinder and said circumferential wall extending between a base of the cylinder and an opening, the cleaning adaptor being a unitary element comprising a sealing cap configured to seal said opening of the air / water cylinder and a sealing plug having: a distal sealing portion having an end surface; and a stem portion extending between the head portion and the distal sealing portion, an axis of the stem portion defining a longitudinal axis of the sealing plug, the distal sealing portion comprising a sealing surface arranged to align with the air inlet and contact the circumferential wall of the cylinder immediately surrounding the air inlet around the full perimeter of the air inlet to form a fluid-tight seal at the air inlet, and the distal sealing portion having a cross-sectional shape transverse to the longitudinal axis providing a fluid flow path between an outer surface of the distal sealing portion and the circumferential wall of the cylinder, the fluid flow path fluidly connecting a first region beyond the end surface of the distal sealing portion and a second region between an outer surface of the stem portion and the circumferential wall of the cylinder. The fluid-tight seal at the air inlet is preferably a liquid-tight seal. In preferred embodiments the distal sealing portion comprises a radially recessed portion that provides the fluid flow path. The sealing cap may include an upper plate and an annular retainer configured to engage with a collar surrounding the opening of the air / water cylinder. The stem portion preferably extends from the sealing cap such that the first annular retainer surrounds a proximal end of the stem portion. In some embodiments the first annular retainer comprises a retaining wall, a plurality of spacing ribs disposed on an inner surface of the retaining wall, and a sealing lip. The sealing lip is preferably configured to seal against a first surface of the collar, which may be a lower surface or underside of a flange of the collar. The spacing ribs are preferably configured to space the retaining wall from a second surface of the collar, which may be a circumferential outer surface of a flange of the collar. The spacing ribs are preferably spaced apart to define flow passages between the ribs allowing fluid to flow over the second surface of the collar. In preferred embodiments an outer surface of the stem portion includes a helical groove. The helical groove may increase the turbulence of the fluid flow within the air / water cylinder to increase the cleaning action of the fluid over the circumferential wall of the cylinder. In other embodiments the outer surface of the stem portion may include other features to increase turbulence of the fluid flow, such as projections, bumps, fins, or a textured surface. In some embodiments the sealing portion may comprise a plurality of radially projecting sealing ribs that extend longitudinally along the sealing portion. In some embodiments the sealing portion has a cruciform cross-section in a plane perpendicular to the longitudinal axis. The stem portion may also have a cruciform cross-section in a plane perpendicular to the longitudinal axis. In other embodiments the stem portion and sealing portion may both have a generally rectangular cross-sectional shape in a plane perpendicular to the longitudinal axis. The cleaning adaptor may be used together with a separate adaptor or plug that engages with the suction port and suction cylinder of the endoscope. The cleaning adaptor may include a mating feature that is configured to engage with a part of the suction port adaptor. In preferred embodiments the sealing cap includes a mating feature in the form of a planar surface, a protrusion or a recess configured to engage with a complimentary feature to prevent rotation of the cleaning adaptor about the longitudinal axis. The mating feature is configured to engage with the suction port adaptor to fix the orientation of the cleaning adaptor with respect to the suction port adaptor. In some embodiments of the invention the sealing cap may extend over an opening of a suction cylinder of the endoscope. A part of the sealing cap is therefore configured to form a fluid-tight seal over the opening of the suction cylinder. The cleaning adaptor may further comprise a flow modifying stem for insertion into the suction cylinder of the endoscope. The flow modifying stem preferably extends from the sealing cap. A longitudinal axis of the flow modifying stem may be generally parallel to the longitudinal axis of the sealing plug. In preferred embodiments including a flow modifying stem, the sealing cap includes an upper plate and an annular retainer configured to engage with a collar surrounding the opening of the suction cylinder. The flow modifying stem preferably extends from the sealing cap such that the annular retainer surrounds a proximal end of the flow modifying stem. In some embodiments the annular retainer may comprise a retaining wall, a plurality of spacing ribs disposed on an inner surface of the retaining wall, and a sealing lip. The sealing lip is preferably configured to seal against a first surface of the collar, which may be a lower surface or underside of a flange of the collar. The spacing ribs are preferably configured to space the retaining wall from a second surface of the collar, which may be a circumferential outer surface of a flange of the collar. The spacing ribs are preferably spaced apart to define flow passages between the ribs allowing fluid to flow over the second surface of the collar. In preferred embodiments an outer surface of the flow modifying stem includes a helical groove. The helical groove may increase the turbulence of the fluid flow within the suction cylinder to increase the cleaning action of the fluid over the circumferential wall of the cylinder. In other embodiments the outer surface of the flow modifying stem may include other features to increase turbulence of the fluid flow, such as projections, bumps, fins, ora textured surface. In preferred embodiments the cleaning adaptor further comprises a pull tab that extends from the sealing cap. The pull tab is configured to be gripped by a user to disengage the cleaning adaptor from the air / water cylinder. In some embodiments the sealing cap may include a weakened portion at a proximal end of the pull tab, the weakened portion being configured to rupture a part of the sealing cap when a force is applied to the pull tab so that the sealing cap no longer forms a seal over the opening of the air / water cylinder. In some embodiments in which the cleaning adaptor a flow modifying stem for insertion into a suction cylinder of the endoscope, the sealing cap preferably includes a weakened portion at a proximal end of the pull tab. The weakened portion is preferably configured, when a force is applied to the pull tab, to rupture a first part of the sealing cap so that the sealing cap no longer forms a seal over the opening of the air / water cylinder and to rupture a second part of the sealing cap so that the sealing cap no longer forms a seal over the opening of the suction cylinder. In preferred embodiments the cleaning adaptor is made from silicone. A second aspect of the invention provides an assembly comprising: an endoscope having an air / water port connected to air and water channels and including an air / water cylinder having an air inlet, an air outlet, a water inlet and a water outlet; and a cleaning adaptor according to the first aspect of the invention, the sealing plug being disposed in the air / water cylinder such that the water inlet and water outlet are in direct fluid communication via the first region beyond the end surface of the distal sealing portion, the air outlet is in fluid communication with the second region and with the water inlet via the fluid flow path between the first region and the second region, and the sealing surface forms a fluid-tight seal at the air inlet. In embodiments in which the endoscope further comprises a suction port including a suction cylinder having an opening, and the cleaning adaptor includes a flow modifying stem, the assembly preferably comprises the sealing cap engaged with the suction port to seal the opening of the suction cylinder. A third aspect of the invention provides a method ofcleaning air and water channels of an endoscope using a cleaning adaptor according to the first aspect of the invention, the endoscope having an air / water port connected to the air and water channels and including an air / water cylinder having an air inlet, an air outlet, a water inlet and a water outlet, and the method comprising: engaging the sealing cap with the air / water port to seal an opening of the air / water cylinder; inserting the sealing plug of the cleaning adaptor into the air / water cylinder so that the sealing portion aligns with the air inlet and the sealing surface contacts an inner circumferential wall of the air / water cylinder around the air inlet to form a fluid-tight seal at the air inlet; and providing a flow of liquid to the air / water cylinder through the water inlet, the fluid flow path between an outer surface of the distal sealing portion and the circumferential wall of the cylinder allowing the liquid entering the air / water cylinder to flow out of both the air outlet and the water outlet simultaneously. In embodiments in which the cleaning adaptor includes a flow modifying stem, and the endoscope has a suction port including a suction cylinder connected to a suction channel, and the method preferably further comprises: engaging the sealing cap with the suction port to seal an opening of the suction cylinder; inserting the flow modifying stem into the suction cylinder; and flushing liquid through the suction channel and the suction cylinder. In embodiments in which the cleaning adaptor has a sealing cap including a weakened portion configured to rupture a part of the sealing cap when a force is applied to the pull tab so that the sealing cap no longer forms a seal over the opening of the air / water cylinder, the method preferably comprises: gripping the pull tab and applying a force to the cleaning adaptor to pull the sealing plug out of the air / water cylinder; and breaking or rupturing a part of the sealing cap so that the sealing cap no longer forms a seal over the opening of the air / water cylinder. In embodiments in which the cleaning adaptor has a sealing cap including a weakened portion configured, when a force is applied to the pull tab, to rupture a first part of the sealing cap so that the sealing cap no longer forms a seal over the opening of the air / water cylinder and to rupture a second part of the sealing cap so that the sealing cap no longer forms a seal over the opening of the suction cylinder, the method preferably comprises: gripping the pull tab and applying a force to the cleaning adaptor to pull the sealing plug out of the air / water cylinder; breaking or rupturing a first part of the sealing cap so that the sealing cap no longer forms a seal over the opening of the air / water cylinder; and breaking or rupturing a second part of the sealing cap so that the sealing cap no longer forms a seal over the opening of the suction cylinder. Preferred and / or optional features of each aspect and embodiment described above may also be used, alone or in appropriate combination, in the other aspects and embodiments also. BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be further described by way of example only and with reference to the accompanying drawings, in which like reference signs are used for like features, and in which: Figure 1a illustrates the internal fluid channels of a known endoscope; Figure 1b is a cross-sectional diagram illustrating an air / water port and a suction port of a control section of a known endoscope; Figure 2 is a perspective view of a cleaning adaptor according to a first preferred embodiment of the invention, showing an underside or insertion side of the adaptor and showing a sealing plug for insertion into an air / water port of an endoscope and a flow modifying stem for insertion into a suction port of an endoscope; Figure 3 is a section view showing the cleaning adaptor of Figure 2 engaged with the air / water port and suction port of Figure 1; Figure 4 is a perspective view of the cleaning adaptor of Figure 2, showing a sealing cap and a single use feature of the adaptor; Figure 5 is a further perspective view of the cleaning adaptor of Figure 2, showing a top side of the adaptor; Figure 6 is a top view of the cleaning adaptor of Figure 2; Figure 7 is a cross-sectional view of the cleaning adaptor of Figure 2 engaged with the air / water port and suction port of Figure 1, along the line VII-VII of Figure 3; Figure 8 is a cross-sectional view of the cleaning adaptor of Figure 2 engaged with the air / water port and suction port of Figure 1, along the line VI ll-VI 11 of Figure 3; Figure 9 is a bottom view of the cleaning adaptor of Figure 2; Figure 10 is a cross-sectional view of the cleaning adaptor of Figure 2 engaged with the air / water port and suction port of Figure 1, along the line X-X of Figure 8; Figure 11 is a cross-sectional view of a part of the cleaning adaptor of Figure 2 showing the sealing plug engaged with the air / water port of Figure 1; Figure 12 is a perspective view of a cleaning adaptor according to a second preferred embodiment of the invention, showing an underside or insertion side of the adaptor and showing a sealing plug for insertion into an air / water port of an endoscope and a flow modifying stem for insertion into a suction port of an endoscope; Figure 13 is a cross-sectional view showing the cleaning adaptor of Figure 12 engaged with the air / water port and suction port of Figure 1; Figure 14 is a perspective view of a cleaning adaptor according to a third preferred embodiment of the invention, showing a sealing plug for insertion into an air / water port of an endoscope and a flow modifying stem for insertion into a suction port of an endoscope; Figure 15 is a section view showing the cleaning adaptor of Figure 14 engaged with the air / water port and suction port of Figure 1; Figure 16 is a side view of the cleaning adaptor of Figure 14; Figure 17 is a bottom view of the cleaning adaptor of Figure 14; Figure 18 is a cross-sectional view of the cleaning adaptor of Figure 14 engaged with the air / water port and suction port of Figure 1, along the line XVIll-XVIII of Figure 15; Figure 19 is a perspective view of a cleaning adaptor according to a fourth preferred embodiment of the invention, showing an underside or insertion side of the adaptor and showing a sealing plug for insertion into an air / water port of an endoscope and a flow modifying stem for insertion into a suction port of an endoscope; Figure 20 is a section view showing the cleaning adaptor of Figure 19 engaged with the air / water port and suction port of Figure 1; Figure 21 is a further perspective view of the cleaning adaptor of Figure 19; Figure 22 is a further perspective view of the cleaning adaptor of Figure 2, showing a sealing cap and a single use feature of the adaptor; Figure 23 is a cross-sectional view of a part of the cleaning adaptor of Figure 19 showing the sealing plug engaged with the air / water port of Figure 1; Figure 24 is a cross-sectional view of the cleaning adaptor of Figure 19 engaged with the air / water port and suction port of Figure 1, along the line XXIV-XXIV of Figure 20; Figure 25 is a cross-sectional view of the cleaning adaptor of Figure 19 engaged with the air / water port and suction port of Figure 1, along the line XXV-XXV of Figure 20; Figure 26 is a perspective view of a cleaning adaptor according to a fifth preferred embodiment of the invention, showing an underside or insertion side of the adaptor and showing a sealing plug for insertion into an air / water port of an endoscope and a flow modifying stem for insertion into a suction port of an endoscope; Figure 27 is a perspective view of the cleaning adaptor of Figure 26, showing a sealing cap and a single use feature of the adaptor; Figure 28 is a top view of the cleaning adaptor of Figure 26; Figure 29 is a section view of the cleaning adaptor of Figure 26 along the line XXIX-XXIX of Figure 28; Figure 30 is a perspective view of a cleaning adaptor according to a sixth preferred embodiment of the invention, showing an underside or insertion side of the adaptor and showing a sealing plug for insertion into an air / water port of an endoscope and a flow modifying stem for insertion into a suction port of an endoscope; Figure 31 is a perspective view of the cleaning adaptor of Figure 30, showing a sealing cap and a single use feature of the adaptor; Figure 32 is a top view of the cleaning adaptor of Figure 30; Figure 33 is a section view of the cleaning adaptor of Figure 30 along the line XXXIII-XXXIII of Figure 32; Figure 34 is a side view of a cleaning adaptor according to a seventh embodiment of the invention, showing a sealing plug for insertion into an air / water port of an endoscope and a flow modifying stem for insertion into a suction port of an endoscope; Figure 35 is a cross-sectional view of the sealing plug of Figure 34 along the line XXXV-XXXV; Figure 36 is a cross-sectional view of the sealing plug of Figure 34 along the line XXXVI-XXXVI; Figure 37 is a side view of a cleaning adaptor according to an eighth embodiment of the invention, showing a sealing plug for insertion into an air / water port of an endoscope and a flow modifying stem for insertion into a suction port of an endoscope; and Figure 38 is a cross-sectional view of the sealing plug of Figure 37 along the line XXXVIII-XXXVIII. DESCRIPTION OF THE PREFERRED EMBODIMENTS Figures 1a and 1b illustrate a known air / water system of an endoscope 2. The endoscope 2 includes a light source connector 4, a control section 6, an umbilical cord 8 connecting the light source connector 4 to the control section 6, and an insertion tube 10. The light source connector 4 comprises a connector 12 for connection to a light source and a connector 14 for connection to an air pump. The light source connector 4 also includes a connector 16 for attachment of a water bottle. This water bottle connector 16 includes an air port 18 and a water port 20. The light source connector 4 further includes a connection 22 to a suction pump and a connection 24 to a waterjet. The endoscope 2 includes a suction / biopsy channel 26 that extends from the connection 22 to the suction pump to a distal end or tip 28 of the insertion tube 10. A first or proximal section of the suction / biopsy channel 26 extends from the light source connector 4 to a suction valve housed within a suction port 30 of the control section 6. A second or distal section of the suction / biopsy channel 26 extends from the suction port 30 to the tip 28 of the insertion tube 10. A branch off the second section of the suction / biopsy channel 26 terminates at a biopsy valve 32. An air channel 34 of the endoscope extends from the connector 14 for connection to an air pump to the distal tip 28 of the insertion tube 10. A first section of the air channel 34 extends from the light source connector 4 to an air / water valve 35 housed within an air / water port 36 of the control section 6. A second section of the air channel 34 extends from the air / water port 36 to the tip 28 of the insertion tube 10. Within the light source connector 4, a branch extends from the first section of the air channel 34 to the air port 18 of the water bottle connector 16 to permit a flow of air from the air channel 34 to a water bottle connected to the connector 16. A water channel 38 of the endoscope extends from the water port 20 of the water bottle connector 16 to the distal tip 28 of the insertion tube 10. A first section of the water channel 38 extends from the light source connector 4 to the air / water valve housed within the air / water port 36 of the control section 6. A second section of the water channel 38 extends from the air / water port 36 to the tip 28 of the insertion tube 10. Proximate the distal tip 28 of the insertion tube 10 the air and water channels 34, 38 combine into a single channel. Typically the air and water channels 34, 38 are referred to collectively as the air / water channel 40 of the endoscope 2. Referring now to Figure 1 b, the suction port 30 comprises a cylindrical recess or cavity 42 (referred to as a suction cylinder) for receiving the suction valve. The suction cylinder 42 creates an opening 44 in a surface 46 of the control section 6 that is, in this example, surrounded by a raised collar 48. The first section of the suction / biopsy channel 26 enters the suction cylinder 42 at a suction inlet 50 and the second section of the suction / biopsy channel 26 extends from a suction outlet 52 of the suction cylinder 42. In this example the collar 48 of the suction port 30 comprises a radially protruding lip or flange 54. The collar flange 54 includes a lower annular surface 56, opposite upper annular surface 58 and an outer circumferential surface 60. The air / water port 36 comprises a cylindrical recess or cavity 62 (referred to as an air / water cylinder) for receiving the air / water valve. The air / water cylinder 62 creates an opening 64 in the surface 46 of the control section 6 that is surrounded, in this example, by a raised collar 66. In this example the collar 66 of the air / water port 36 comprises a radially protruding lip or flange 68. The collar flange 68 includes a lower annular surface 70, opposite upper annular surface 72 and an outer circumferential surface 74. The openings 44, 64 of the suction port 30 and air / water port 36 are disposed adjacent each other in the control section 6. The first section of the air channel 34 enters the air / water cylinder 62 at an air inlet 76 and the second section of the air channel 34 extends from an air outlet 78 of the air / water cylinder 62. The first section of the water channel 38 enters the air / water cylinder 62 at a water inlet 80 and the second section of the water channel 38 extends from a water outlet 82 of the air / water cylinder 62. During use of the endoscope in a medical procedure an air / water valve is seated in the air / water cylinder. Similarly, a suction valve is seated in the suction cylinder. Following use of the endoscope, the air / water valve is removed and replaced by a cleaning adaptor before pre-clean of the endoscope. A known cleaning adaptor is similar in construction to the air / water valve. Known cleaning adaptors comprise a stem surrounded by a plurality of annular seals extending radially from the stem and being spaced along an axis of the stem. The annular seals seal against a wall of the air / water cylinder to divide the cylinder into a set of separate chambers. The air inlet is fluidly connected to a first chamber, the air outlet is fluidly connected to a second chamber, and the water inlet and water outlet are fluidly connected to a third chamber. A passage in the stem of the cleaning adaptor fluidly connects the third chamber to the second chamber. This allows water or detergent solution to flow from the water inlet to both the water outlet and the air outlet concurrently to flush the second sections of both the air channel and the water channel, while preventing water entering the first chamber. This arrangement of seals, however, blocks a significant volume of the air / water cylinder from interaction with the water or detergent solution used to flush the air / water channel. Accordingly, the use of known cleaning adaptors results in a significant portion of the surfaces of the air / water cylinder not being flushed or cleaned during the pre-clean procedure. This reduces the efficacy of subsequent decontamination processes (sterilisation and disinfection). The present invention therefore provides a cleaning adaptor for an air / water cylinder of an endoscope that may be utilised in a pre-clean process to flush the air / water channel of the endoscope with water or a detergent solution which minimises contact with the surfaces of the air / water cylinder. Figures 2 to 11 show a cleaning adaptor 100 according to a first preferred embodiment of the present invention. The cleaning adaptor 100 is a unitary, one-piece element. The cleaning adaptor 100 has no moving parts other than due to the inherent flexibility of some parts of the adaptor 100 as described further below. The cleaning adaptor is preferably made from a suitable polymeric material, having a degree of elasticity or flexibility. The cleaning adaptor may be made from silicone. The cleaning adaptor is preferably made from a single material. The cleaning adaptor may be injection moulded. The cleaning adaptor 100 comprises a sealing cap 102 for engagement with and sealing of both the air / water port 36 and the suction port 30 of the endoscope 2, a sealing plug 104 extending from the sealing cap 102 for insertion into the air / water cylinder 62 of the air / water port 36 of the endoscope 2, and a flow modifying stem 106 extending from the sealing cap 102 for insertion into the suction cylinder 42 of the suction port 30 of the endoscope 2. The sealing cap 102 comprises an upper plate 108 having a top face 110 and an opposite sealing face 112. Extending from the sealing face 112 is a first annular retainer 114 that is configured to engage with the collar 66 surrounding the opening 64 of the air / water cylinder 62 and a second annular retainer 116 that is configured to engage with the collar 48 surrounding the opening 44 of the suction cylinder 42. In this embodiment the first retainer 114 comprises an annular retaining wall 118 extending from the sealing face 112 of the upper plate 108. A sealing lip 120 is disposed at a free edge of the retaining wall 118 furthest from the upper plate 108. The sealing lip 120 comprises a radially inwardly extending protrusion configured to locate under the collar flange 68 of the air / water port 36, as described further below. A plurality of spacing ribs 122 are disposed on an inner surface of the retaining wall 118. In this example each of the spacing ribs 122 extends longitudinally between the sealing face 112 of the upper plate 108 and the sealing lip 120. The spacing ribs 122 project from the inner surface of the retaining wall 118 and are spaced apart around the retaining wall 118. In this way a corresponding plurality of grooves or passages are defined between the spacing ribs 122. A depth of each of the spacing ribs 122 in a radial direction is less than a depth of the sealing lip 120 in a radial direction. In this way a minimum internal diameter of the first retainer 114 is defined by the sealing lip 120 and a maximum internal diameter of the first retainer 114 is defined by the inner surface of the retaining wall 118. In this embodiment the second retainer 116 comprises an annular retaining wall 124 extending from the sealing face 112 of the upper plate 108. A sealing lip 126 is disposed at a free edge of the retaining wall 124 furthest from the upper plate 108. The sealing lip 126 comprises a radially inwardly extending protrusion configured to locate under the collar flange 54 of the suction port 30, as described further below. A plurality of spacing ribs 128 are disposed on an inner surface of the retaining wall 124. In this example each of the spacing ribs 128 extends longitudinally between the sealing face 112 of the upper plate 108 and the sealing lip 126. The spacing ribs 128 project from the inner surface of the retaining wall 124 and are spaced apart around the retaining wall 124. In this way a corresponding plurality of grooves or passages are defined between the spacing ribs 128. A depth of each of the spacing ribs 128 in a radial direction is less than a depth of the sealing lip 126 in a radial direction. In this way a minimum internal diameter of the second retainer 116 is defined by the sealing lip 126 and a maximum internal diameter of the second retainer 116 is defined by the inner surface of the retaining wall 124. The sealing plug 104 comprises an elongate tubular stem 130 extending from the sealing face 112 of the upper plate 108. The stem 130 extends longitudinally between a proximal end 132 at the sealing cap 102 and a distal end 134. In this embodiment the stem 130 is axially aligned with the first annular retainer 114 so that the stem 130 extends centrally from the first annular retainer 114 and the first annular retainer 114 surrounds the proximal end 132 of the stem 130. An outer diameter of the stem 130 at the proximal end 132 is less than a minimum internal diameter of the sealing lip 120 such that an annular gap 136 is defined between the stem 130 and the first retainer 114 for receiving the raised collar 66 of the air / water port 36. The first retainer 114 and part of the upper plate 108 between the first retainer 114 and the stem 130 may be considered to form a head portion of the sealing plug 104. An outer surface of the stem 130 includes a helical groove or channel 138. A first end of the helical channel 138 is disposed at the distal end 134 of the stem 130. The helical channel 138 extends substantially fully along the stem 130, but may not extend fully to the proximal end 132 of the stem 130. In the illustrated embodiment the helical channel 138 extends through a single 360° turn over the length of the stem 130. In other embodiments the helical channel 138 may turn through more than 360° along the length of the stem 130. The sealing plug 104 further comprises a sealing portion 140 at the distal end 134 of the stem 130. The sealing portion 140 includes a distal end surface 142 of the sealing plug 104. The sealing portion 140 further comprises a sealing surface 144. In this embodiment the sealing portion 140 comprises a core 146 which is generally cylindrical and extends longitudinally from the distal end 134 of the stem 130. The sealing portion 140 further comprises a plurality (in this example four) sealing ribs 148 that project radially from the core 146. Each of the sealing ribs 148 extend longitudinally along the core 146 between the stem 130 and the distal end surface 142. An outer circumferential surface of each of the sealing ribs 148 provides a sealing surface 144 of the sealing portion 140. When the sealing plug 104 is inserted into the air / water cylinder 62 of an endoscope 2, the sealing surface 144 is arranged to contact an internal wall of the air / water cylinder 62 to form a seal against the internal surface of the air / water cylinder 62. In particular, the dimensions of the sealing plug 104 are such that a part of the sealing surface 144 aligns with the air inlet 76 in the internal wall of the air / water cylinder 62. The sealing surface 144 is arranged to contact the wall of the cylinder 62 immediately surrounding the air inlet 76, and to contact the wall around the full perimeter of the air inlet 76, such that the sealing surface 144 forms a water-tight seal at the air inlet 76. In this example, one of the sealing ribs 148a has a larger width (in a circumferential direction) than the other three sealing ribs 148. The sealing plug 104 is oriented with respect to the sealing cap 102 so that this wider or primary sealing rib 148a aligns with the air inlet 76. In this example a second sealing rib 148b is disposed diametrically opposite to the primary sealing rib 148a. This second sealing rib 148b presses against the wall of the air / water cylinder 62 opposite the air inlet 76 and helps to retain the primary sealing rib 148a in sealing contact with the wall of the air / water cylinder 62 around the air inlet 76. In this example the sealing portion 140 includes two further sealing ribs 148c, 148d that project from the core 146 in directions perpendicular to the primary sealing rib 148a. These centralising sealing ribs 148c, 148d assist in centralising the sealing portion 140 of the sealing plug 104 in the air / water cylinder 62 so that an even sealing pressure is applied by the primary sealing rib 148a. In this example, therefore, the arrangement of the four sealing ribs 148 means that the transverse cross-sectional shape of the sealing portion is generally cross-shaped. A plurality (in this example four) gaps or flow passages 150 are defined between the sealing ribs 148. These flow passages 150 provide a path for fluid flow between a region beyond the distal end surface 142 of the sealing plug 104 and a region surrounding the outer surface of the stem 130 when the sealing plug 104 is seated in an air / water cylinder. In this embodiment a passage or bore 152 extends longitudinally through the sealing portion 140 and the stem 130 of the sealing plug 104. A first end of the bore 152 terminates at an opening 154 in the distal end surface 142. A second end of the bore 152 is a closed end proximate the sealing cap 102. A branch passage extends radially from the bore 152 in the stem 130 and terminates at an opening 156 in the outer surface of the stem 130. In this example the opening 156 is disposed in the helical groove 138. The flow modifying stem 106 extends from the sealing face 112 of the upper plate 108. The stem 106 is elongate and extends longitudinally between a proximal end 158 at the sealing cap 102 and a distal end 160. A longitudinal axis of the flow modifying stem 106 is substantially parallel to the longitudinal axis of the sealing plug 104. In this embodiment the flow modifying stem 106 is a separate component that is joined to the sealing cap 102. As such, the flow modifying stem 106 comprises a connector portion 162 at the proximal end 158 of the flow modifying stem 106. In this embodiment the connector portion 162 comprises a plug that engages with an aperture in the sealing cap 102 to attach the flow modifying stem 106 to the sealing cap 102. It will be appreciated that in other embodiments the flow modifying stem 106 may be integrally formed with the sealing cap 102. In this embodiment the flow modifying stem 106 is axially aligned with the second annular retainer 116 so that the stem 106 extends centrally from the second annular retainer 116 and the second annular retainer 116 surrounds the proximal end 158 of the stem 106. An outer diameter of the stem 106 at the proximal end 158 is less than a minimum internal diameter of the sealing lip 126 such that an annular gap 164 is defined between the stem 106 and the second retainer 116 for receiving the raised collar 48 of the suction port 30. The flow modifying stem 106 has a generally cylindrical outer surface 166 including a spiral channel or helical groove 168 extending along the length of the flow modifying stem 106. In the illustrated embodiment the helical groove 168 extends through a single 360° turn over the length of the flow modifying stem 106. In other embodiments the helical groove 280 may turn through more than 360° along the length of the flow modifying stem 106. The outer surface 166 of the flow modifying stem 106 further comprises, in a region proximate the proximal end 158, a planar deflection surface 170. The planar deflection surface 170 preferably extends for less than half of the length of the flow modifying stem 106. In this example the planar deflection surface 170 is formed by a surface of a cylindrical segment oriented parallel to the longitudinal axis of the flow modifying stem 106. A grip element or grip portion 172 projects from the top face 110 of the sealing cap 102. In this embodiment the grip element 172 is disposed in a region of the top face 110 opposite the second retainer 116. The grip element 172 has a generally semicircular shape. In this example the grip element 172 is semi-annular. In other embodiments the cleaning adaptor 100 may not include a grip element or the grip element may have a different shape or configuration. It is advantageous if the cleaning adaptor 100 of the present invention is disposable or single use. Accordingly, in preferred embodiments, the cleaning adaptor 100 includes a single use feature that prevents subsequent re-use of the adaptor 100. The single use feature may comprise a part of the cleaning adaptor 100 that ruptures or breaks when the cleaning adaptor 100 is removed from the endoscope 2 after use. The single use feature may comprise a part of the cleaning adaptor that is disabled upon first use of the adaptor such that the adaptor cannot be reinserted into the air / water port of a second endoscope or cannot otherwise be reused. In this embodiment, the cleaning adaptor 100 includes a pull tab 174 that extends from the sealing cap 102. The pull tab 174 has a free distal end, which in this embodiment includes an annular ring pull 176 through which a user’s thumb or finger may be inserted. At a proximal end 178 of the pull tab 174 the sealing cap 102 includes a weakened portion 180. As shown most clearly in Figures 5 and 6, a first line of weakness 180a extends along a first side of the pull tab 174 at its proximal end 178 and a second line of weakness 180b extends along a second side of the pull tab 174 at its proximal end 178. The lines of weakness 180 are provided by regions of the sealing cap 102 having a reduced thickness of material. Use of the cleaning adaptor 100 will now be described with particular reference to Figures 3, 7, 8, 10 and 11. After use of an endoscope during a medical procedure the air / water valve and the suction valve are removed to allow pre-cleaning of the endoscope. The cleaning adaptor 100 of the present invention is then engaged with the air / water port 36 and the suction port 30 of the control section 6 of the endoscope 2. The sealing cap 102 is pressed over the openings 64, 44 of the air-water port 36 and the suction port 30 so that the stem 130 and sealing portion 140 of the sealing plug 104 are received in the air / water cylinder 62 and the first retainer 114 is engaged with the collar 66 of the air / water port 36, and the flow modifying stem 106 is inserted into the suction cylinder 42 and the second retainer 116 is engaged with the collar 48 of the suction port 30. The first retainer 114 engages with the collar 66 of the air / water port 36 such that the sealing lip 120 locates under the collar flange 68 in a space between the lower annular surface 70 of the flange 68 and the surface 46 of the control section 6. The retaining wall 118 surrounds the collar flange 68 with the spacing ribs 122 contacting the outer circumferential surface 74 of the flange 68. Furthermore, a height of the retaining wall 118, between the upper plate 108 and the sealing lip 120, is such that there is a clearance gap between a top surface 67 of the collar 66 and the sealing face 112 of the upper plate 108. With the sealing plug 104 inserted fully into the air / water cylinder 62, the sealing portion 140 is in contact with the inner surface of the air / water cylinder 62 proximate and surrounding the air inlet 76. In particular, the sealing surface 144 of the primary sealing rib 148a forms a water-tight seal at the air inlet 76. A length of the sealing plug 104, between the sealing face 112 of the upper plate 108 and the distal end surface 142, is smaller than the depth of the air / water cylinder 62 so that there is a region of the air / water cylinder 62 beyond or below the distal end surface 142. The water inlet 80 and water outlet 82 are preferably both disposed in this region. In this example, the sealing surface 144 of the sealing portion 140 is continuous with the outer surface of the stem 130. In this way, a maximum diameter of the stem 130 is equal to a maximum diameter of the sealing portion 140. Furthermore, the internal diameter of the air / water cylinder 62 increases in an upper portion of the air / water cylinder 62 between the air inlet 76 and the opening 64 of the air / water cylinder 62. There is, therefore, an annular flow region 182 defined around the stem 130, between the outer surface of the stem 130 and the inner surface of the air / water cylinder 62. The air outlet 78 is aligned with a part of the stem 130 of the sealing plug 104 so that the air outlet 78 is fluidly connected with the annular flow region 182 around the stem 130. The flow passages 150 disposed between the sealing ribs 148 form a fluid flow path fluidly connecting the region beyond the distal end surface 142 of the sealing portion 140 and the region between the outer surface of the stem 130 and the circumferential wall of the air / water cylinder 62. In this embodiment the bore 152 and branch passage form a second fluid flow path between the region beyond the distal end surface 142 of the sealing portion 140 and the region between the outer surface of the stem 130 and the circumferential wall of the air / water cylinder 62. The second retainer 116 engages with the collar 48 of the suction port 30 such that the sealing lip 126 locates under the collar flange 54 in a space between the lower annular surface 56 of the flange 54 and the surface 46 of the control section 6. The retaining wall 124 surrounds the collar flange 54 with the spacing ribs 128 contacting the outer circumferential surface 60 of the flange 54. Furthermore, a height of the retaining wall 124, between the upper plate 108 and the sealing lip 126, is such that there is a clearance gap between a top surface 49 of the collar 48 and the sealing face 112 of the upper plate 108. With the second retainer 116 engaged in this way, the flow modifying stem 106 extends into the suction cylinder 42. An external diameter of the flow modifying stem 106 is smaller than an internal diameter of the suction cylinder 42 such that there is a cylindrical tubular gap 184 between the outer surface 166 of the flow modifying stem 106 and an inner surface of the suction cylinder 42. There is also a gap or region 84 between the distal end 160 of the flow modifying stem 106 and the suction outlet 52 in the base of the suction cylinder 42. Furthermore, the planar deflection surface 170 of the flow modifying stem 106 is disposed opposite the suction inlet 50. With the cleaning adaptor 100 fully engaged with the air / water port 36 and the suction port 30, a liquid is then introduced into the first section of the water channel 38. The liquid may be water, but preferably the liquid is a detergent solution. The liquid enters the air / water cylinder 62 through the water inlet 80. As there are no seals between the water inlet 80 and the water outlet 82, the liquid is free to flow out of the water outlet 82 and into the second section of the water channel 38. The liquid is also able to flow through the flow passages 150, through the annular flow region 182 between the outer surface of the stem 130 and the circumferential wall of the air / water cylinder 62, through the air outlet 78 and into the second section of the air channel 34. In this way, water or detergent solution may be flushed through the second section of both the air and water channels 34, 38 at the same time. It will be appreciated that as the liquid flows through the flow passages 150 and through the annular flow region 182 the liquid contacts and flows over inner surfaces of the air / water cylinder 62. As the only contact between the sealing plug 104 and the inner surface of the air / water cylinder 62 is at the sealing surface 144, the liquid is able to contact and flow over substantially all of the inner surface of the air / water cylinder 62 thereby assisting in the pre-cleaning of this part of the endoscope 2. Furthermore, the helical channel 138 in the outer surface of the stem 130 causes the liquid flowing through the annular flow region 182 to swirl around the stem 130. This increases the turbulence of the flow of the liquid creating a greater cleaning action. Additionally, the liquid may flow through the bore 152 and branch passage and enter the annular flow region 182 through the opening 156 in the outer surface of the stem 130, creating further turbulence in this region. As noted above, the arrangement of the first retainer 114 is such that a further fluid flow path is created from the annular flow region 182, through the clearance gap between the top surface 67 of the collar 66 and the sealing face 112 of the upper plate 108, and to the passages defined between the spacing ribs 122 around the outer circumferential surface 74 of the collar flange 68. In this way, the liquid is also able to contact and flow over the top surface 67 of the collar 66, the upper annular surface 72 of the collar flange 68 and the outer circumferential surface 74 of the flange 68. This allows these surfaces to also be cleaned or flushed during the pre-clean procedure. To flush the suction / biopsy channel 26 with a liquid (preferably water or a detergent solution) the liquid is drawn up through the second section of the suction / biopsy channel 26 and into the suction cylinder 42 through the suction inlet 50. As the liquid enters the suction cylinder 42 at least a part of the volume of the liquid strikes the planer deflection surface 170 and is deflected upwardly towards the opening 44 of the suction port 30. As noted above, the arrangement of the second retainer 116 is such that a fluid flow path is created from the tubular gap 184 surrounding the outer surface 166 of the flow modifying stem 106, through the clearance gap between the top surface 49 of the collar 48 and the sealing face 112 of the upper plate 108, and to the passages defined between the spacing ribs 128 around the outer circumferential surface 60 of the collar flange 54. In this way, the liquid is also able to contact and flow over the top surface 49 of the collar 48, the upper annular surface 58 of the collar flange 54 and the outer circumferential surface 60 of the flange 54. This allows these surfaces to also be cleaned or flushed during the pre-clean procedure. The liquid flows towards the suction outlet 52 through the cylindrical tubular gap 184 between the outer surface 166 of the flow modifying stem 106 and the inner surface of the suction cylinder 42. The helical groove 168 in the outer surface 166 causes the liquid to flow around the flow modifying stem 106 thereby creating a vortex flow. This more turbulent flow in the suction cylinder 42 increases the ability of the liquid to clean or scour the inner surfaces of the suction cylinder 42. The turbulence of the flow of the liquid may be increased further by providing a textured outer surface 166 of the flow modifying stem 106, including surfaces of the helical groove 168. The liquid exits the suction cylinder 42 through the suction outlet 52. While in the above embodiment the flow modifying stem included a helical groove in an outer surface, in other embodiments the stem may not include such a groove. The presence of a cylindrical stem within the suction cylinder 42 may be sufficient to create more turbulent fluid flow within the suction cylinder 42 and / or to force the flow of fluid in the suction cylinder 42 generally towards or against the inner surfaces of the suction cylinder 42. In other embodiments the outer surface of the generally cylindrical stem may be textured to provide a more turbulent fluid flow within the suction cylinder. In further embodiments the flow modifying stem may comprise fins or other protrusions extending radially outwardly from a central rod or shaft. The fins or protrusions may have a helical arrangement. After completion of the pre-clean procedure the cleaning adaptor 100 is removed from the air / water port 36 and suction port 30. It is desirable to make the cleaning adaptor 100 single use to remove the need to clean and sterilise the cleaning adaptor 100 between uses, and to reduce the risk of cross-contamination between endoscopes. In this embodiment the user disengages the cleaning adaptor 100 from the air / water port 36 and suction port 30 by pulling on the pull tab 174 by gripping ring pull 176. Pulling the ring pull 176 in a direction away from the control section 6 of the endoscope 2 withdraws the sealing plug from the air / water cylinder 62 and withdraws the flow modifying stem from the suction cylinder. The force exerted by the user on the pull tab 174 causes the sealing cap 102 to tear or rupture along the regions of weakness 180. The arrangement of the weakened portions 180 is such that the pull tab 174 remains connected to the rest of the sealing cap 102, but partially separates from the upper plate of the sealing cap 102 at its proximal end 178. The tearing or rupturing of the sealing cap 102 creates a hole or opening in the upper plate that extends within the boundary of the first retainer 114. In this way, once the sealing cap has been ruptured, it is not possible to form a water-tight seal over the opening 64 of the air / water port 36 and the cleaning adaptor cannot, therefore, be reused. Figures 12 and 13 show a cleaning adaptor 200 according to a second preferred embodiment of the present invention. The cleaning adaptor 200 is substantially identical to the cleaning adaptor 100 of the first embodiment and like features will not be described further in relation to this embodiment. In this embodiment, the stem 230 of the sealing plug 204 includes a passage or bore 252 that extends longitudinally through the sealing portion 240 and the stem 230 of the sealing plug 204. A first end of the bore 252 terminates at an opening 254 in the distal end surface 242 of the sealing plug 204. A second end of the bore 252 is a closed end proximate the sealing cap 202. In this embodiment the bore 252 is only present to decrease the amount of material used to form the cleaning adaptor 200. In this embodiment the stem 230 does not include a branch passage extends radially from the bore 252, such that an upper end of the bore 252 is not directly fluidly connected to the annular flow region 282 between the outer surface of the stem 230 and the circumferential wall of the air / water cylinder 62. Figures 14 to 18 show a cleaning adaptor 300 according to a third preferred embodiment of the present invention. The cleaning adaptor 300 is identical to the cleaning adaptor 100 of the first embodiment except that the outer surface of the stem 330 of the sealing plug 304 does not include a helical channel. In this embodiment the outer surface of the stem 330 is simply cylindrical, having a generally constant diameter along its length. In this embodiment the stem 330 still includes a passage or bore 352 that extends longitudinally through the sealing portion 340 and the stem 330 of the sealing plug 304. A first end of the bore 352 terminates at an opening 354 in the distal end surface 342 of the sealing plug 304. A second end of the bore 352 is a closed end proximate the sealing cap 302. A branch passage extends radially from the bore 352 in the stem 330 and terminates at an opening 356 in the outer surface of the stem 330. This opening 356 is disposed proximate the proximal end 332 of the stem 330 and proximate the first retainer 314. Accordingly, when liquid is flushed through the air / water cylinder 62 as described above, the liquid flows from the region beyond the distal end surface 342 of the sealing plug 304, through the flow passages 350, and into the annular flow region 382 between the outer surface of the stem 330 and the circumferential wall of the air / water cylinder 62. At the same time liquid flows through the bore 352 and branch passage and enters the annular flow region 382 through the opening 356 in the outer surface of the stem 330. As liquid enters the annular flow region 382 from two different directions, turbulent flow is created around the stem 330 that increases the ability of the liquid to clean or scour the inner surfaces of the air / water cylinder 62. Figures 19 to 25 show a cleaning adaptor 400 according to a fourth preferred embodiment of the present invention. The cleaning adaptor 400 is substantially identical to the cleaning adaptor 100 of the first embodiment and like features will not be described further in relation to this embodiment. The cleaning adaptor 400 comprises a sealing cap 402 for engagement with and sealing of both the air / water port 36 and the suction port 30 of the endoscope 2, a sealing plug 404 extending from the sealing cap 402 for insertion into the air / water cylinder 62 of the air / water port 36 of the endoscope 2, and a flow modifying stem 406 extending from the sealing cap 402 for insertion into the suction cylinder 42 of the suction port 30 of the endoscope 2. The sealing cap 402 is identical to the sealing cap 102 of the first embodiment and comprises a first annular retainer 414 and a second annular retainer 416. The flow modifying stem 406 is also identical to the flow modifying stem 106 of the first embodiment and extends from a region of the sealing cap 402 surrounded by the second retainer 416. In this embodiment the sealing plug 404 comprises stem 430 extending from the sealing face 412 of the upper plate 408 of the sealing cap 402. The stem 430 extends longitudinally between a proximal end 432 at the sealing cap 402 and a distal end 434. In this embodiment the stem 430 is axially aligned with the first annular retainer 414 so that the stem 430 extends centrally from the first annular retainer 414 and the first annular retainer 414 surrounds the proximal end 432 of the stem 430. The stem 430 has a cruciform cross-section in a plane perpendicular to a longitudinal axis 486 of the sealing plug 404. The stem 430 therefore comprises four arms or ribs 488 that extend radially from the axis 486 and extend along the length of the stem 430. A first pair of ribs 488 (first rib and second rib 488a, 488b) extend in opposite directions away from the axis 486, and a second pair of ribs 488 (third rib and fourth rib 488c, 488d) extend in opposite direction away from the axis 486 and in directions perpendicular to the first pair of ribs 488. In this embodiment a width of each of the four ribs 488, in a circumferential direction, is substantially the same. The sealing plug 404 further comprises a sealing portion 440 at the distal end 434 of the stem 430. The sealing portion 440 includes a distal end surface 442 of the sealing plug 404. The sealing portion 440 further comprises a sealing surface 444. In this embodiment the sealing portion 440 also has a cruciform cross-section in a plane perpendicular to the longitudinal axis 486 of the sealing plug 404. The sealing portion 440 therefore comprises four sealing arms or sealing ribs 490 that extend radially from the axis 486. In this embodiment a first or primary sealing rib 490a is continuous with the first rib 488a of the stem 430. A width of the first sealing rib 490a, in a circumferential direction, is the same as the width of the first rib 488a of the stem 430, so that opposite side surfaces of the first ribs 490a, 488a are continuous. Furthermore, a radial dimension of the first sealing rib 490a is equal to a radial dimension of the first rib 488a of the stem 430 such that an outer circumferential sealing surface 444 of the first sealing rib 490a is continuous with an outer circumferential surface of the first rib 488a of the stem 430. Similarly, a second sealing rib 490b of the sealing portion 440 is continuous with the second rib 488b of the stem 430, a third sealing rib 490c of the sealing portion 440 is continuous with the third rib 488c of the stem 430, and a fourth sealing rib 490d of the sealing portion 440 is continuous with the fourth rib 488d of the stem 430. A radial dimension of the second sealing rib 490b is equal to a radial dimension of the second rib 488b of the stem 430 such that an outer circumferential sealing surface 444 of the second sealing rib 490b is continuous with an outer circumferential surface of the second rib 488b of the stem 430. A radial dimension of the third sealing rib 490c is equal to a radial dimension of the third rib 488c of the stem 430 such that an outer circumferential sealing surface 444 of the third sealing rib 490c is continuous with an outer circumferential surface of the third rib 488c of the stem 430. A radial dimension of the fourth sealing rib 490d is equal to a radial dimension of the fourth rib 488d of the stem 430 such that an outer circumferential sealing surface 444 of the fourth sealing rib 490d is continuous with an outer circumferential surface of the fourth rib 488d of the stem 430. In this embodiment, however, a width of each of the second, third and fourth sealing ribs 490b, 490c, 490d, in a circumferential direction, is less than a width of the corresponding second, third and fourth ribs 488b, 488c, 488d of the stem 430. Accordingly, a step is formed between the corresponding side surfaces of each of the second, third and fourth ribs 488b, 488c, 488d of the stem 430 and the second, third and fourth sealing ribs 490b, 490c, 490d. When the sealing plug 404 is inserted into the air / water cylinder 62 of an endoscope 2, the sealing surfaces 444 are arranged to contact an internal wall of the air / water cylinder 62 to form a seal against the internal surface of the air / water cylinder 62. In particular, the dimensions of the sealing plug 404 are such that a part of the sealing surface 444 aligns with the air inlet 76 in the internal wall of the air / water cylinder 62. The sealing surface 444 is arranged to contact the wall of the cylinder 62 immediately surrounding the air inlet 76, and to contact the wall around the full perimeter of the air inlet 76, such that the sealing surface 444 forms a water-tight seal at the air inlet 76. In this example, the sealing plug 404 is oriented with respect to the sealing cap 402 so that the wider primary sealing rib 490a aligns with the air inlet 76. The second sealing rib 490b is disposed diametrically opposite to the primary sealing rib 490a. This second sealing rib 490b presses against the wall of the air / water cylinder 62 opposite the air inlet 76 and helps to retain the primary sealing rib 490a in sealing contact with the wall of the air / water cylinder 62 around the air inlet 76. The third and fourth sealing ribs 490c, 490d act as centralising sealing ribs 490c, 490d and assist in centralising the sealing portion 440 of the sealing plug 404 in the air / water cylinder 62 so that an even sealing pressure is applied by the primary sealing rib 490a. A plurality (in this example four) gaps or flow passages 450 are defined between the sealing ribs 490. These flow passages 450 provide a path for fluid flow between a region beyond the distal end surface 442 of the sealing plug 404 and a region surrounding the outer surface of the stem 430 when the sealing plug 404 is seated in an air / water cylinder. As shown most clearly in Figure 25, the decreased width of the second, third and fourth sealing ribs 490b, 490c, 490d means that there is a smaller area of contact between the sealing surfaces 444 and the inner surface of the air / water cylinder. This allows fluid to contact and flow over a greater proportion of the inner surface of the air / water cylinder. It also maximises the rate of fluid flowthrough the flow passages 450 between the sealing ribs 490 while still maintaining the required sealing of the air inlet 76. In use, with the cleaning adaptor 400 fully engaged with the air / water port 36 and the suction port 30, liquid is introduced into the first section of the water channel 38. The liquid may be water, but preferably the liquid is a detergent solution. The liquid enters the air / water cylinder 62 through the water inlet 80. As there are no seals between the water inlet 80 and the water outlet 82, the liquid is free to flow out of the water outlet 82 and into the second section of the water channel 38. The liquid is also able to flow through the flow passages 450, through the annular flow region 482 between the outer surface of the stem 430 and the circumferential wall of the air / water cylinder 62, through the air outlet 78 and into the second section of the air channel 34. In this way, water or detergent solution may be flushed through the second section of both the air and water channels 34, 38 at the same time. It will be appreciated that as the liquid flows through the flow passages 450 and through the annular flow region 482 the liquid contacts and flows over inner surfaces of the air / water cylinder 62. As the only contact between the sealing plug 404 and the inner surface of the air / water cylinder 62 is at the sealing surface 444, the liquid is able to contact and flow over substantially all of the inner surface of the air / water cylinder 62 thereby assisting in the pre-cleaning of this part of the endoscope 2. The arrangement of the first retainer 414 is such that a further fluid flow path is created from the annular flow region 482, through the clearance gap between the top surface 67 of the collar 66 and the sealing face 412 of the upper plate 408, and to the passages defined between the spacing ribs 422 around the outer circumferential surface 74 of the collar flange 68. In this way, the liquid is also able to contact and flow over the top surface 67 of the collar 66, the upper annular surface 72 of the collar flange 68 and the outer circumferential surface 74 of the flange 68. This allows these surfaces to also be cleaned or flushed during the pre-clean procedure. To flush the suction / biopsy channel 26 with a liquid (preferably water or a detergent solution) the liquid is drawn up through the second section of the suction / biopsy channel 26 and into the suction cylinder 42 through the suction inlet 50. As the liquid enters the suction cylinder 42 at least a part of the volume of the liquid strikes the planer deflection surface 470 and is deflected upwardly towards the opening 44 of the suction port 30. As noted above, the arrangement of the second retainer 416 is such that a fluid flow path is created from the tubular gap 484 surrounding the outer surface 466 of the flow modifying stem 406, through the clearance gap between the top surface 49 of the collar 48 and the sealing face 412 of the upper plate 408, and to the passages defined between the spacing ribs 428 around the outer circumferential surface 60 of the collar flange 54. In this way, the liquid is also able to contact and flow over the top surface 49 of the collar 48, the upper annular surface 58 of the collar flange 54 and the outer circumferential surface 60 of the flange 54. This allows these surfaces to also be cleaned or flushed during the pre-clean procedure. The liquid flows towards the suction outlet 52 through the cylindrical tubular gap 484 between the outer surface 466 of the flow modifying stem 406 and the inner surface of the suction cylinder 42. The helical groove 468 in the outer surface 166 causes the liquid to flow around the flow modifying stem 406 thereby creating a vortex flow. This more turbulent flow in the suction cylinder 42 increases the ability of the liquid to clean or scour the inner surfaces of the suction cylinder 42. The turbulence of the flow of the liquid may be increased further by providing a textured outer surface 466 of the flow modifying stem 406, including surfaces of the helical groove 468. The liquid exits the suction cylinder 42 through the suction outlet 52. Figures 26 to 29 show a cleaning adaptor 500 according to a fifth preferred embodiment of the present invention. The cleaning adaptor 500 is substantially identical to the cleaning adaptor 100 of the first embodiment. The cleaning adaptor 500 comprises a sealing cap 502 for engagement with and sealing of both the air / water port 36 and the suction port 30 of the endoscope 2, a sealing plug 504 extending from the sealing cap 502 for insertion into the air / water cylinder 62 of the air / water port 36 of the endoscope 2, and a flow modifying stem 506 extending from the sealing cap 502 for insertion into the suction cylinder 42 of the suction port 30 of the endoscope 2. The sealing plug 504 and flow modifying stem 506 of this embodiment are identical to the sealing plug 104 and flow modifying stem 106 of the first embodiment and will not be described further in relation to this embodiment. The sealing cap 502 comprises an upper plate 508 having a top face 510 and an opposite sealing face 512. Extending from the sealing face 512 is a first annular retainer 514 that is configured to engage with the collar 66 surrounding the opening 64 of the air / water cylinder 62 and a second annular retainer 516 that is configured to engage with the collar 48 surrounding the opening 44 of the suction cylinder 42. The first annular retainer 514 and the second annular retainer 516 of this embodiment are identical to the first annular retainer 114 and the second annular retainer 116 of the first embodiment and will not be described further in relation to this embodiment. In this embodiment the sealing plug 504 extends from the sealing cap 502 and is axially aligned with the first annular retainer 514 so that the stem 530 of the sealing plug 504 extends centrally from the first annular retainer 514 and the first annular retainer 514 surrounds the proximal end 532 of the stem 530. Similarly, the flow modifying stem 506 extends from the sealing cap 502 and is axially aligned with the second annular retainer 516 so that the stem 506 extends centrally from the second annular retainer 516 and the second annular retainer 516 surrounds the proximal end 558 of the stem 506. It is advantageous if the cleaning adaptor 500 of the present invention is disposable or single use to remove the need to clean and sterilise the cleaning adaptor 500 between uses, and to reduce the risk of cross-contamination between endoscopes. Accordingly, in preferred embodiments, the cleaning adaptor 500 includes a single use feature that prevents subsequent re-use of the adaptor 500. The single use feature may comprise a part of the cleaning adaptor 500 that ruptures or breaks when the cleaning adaptor 500 is removed from the endoscope after use. The single use feature may comprise a part of the cleaning adaptor that is disabled upon first use of the adaptor such that the adaptor cannot be reinserted into the air / water port of a second endoscope or cannot otherwise be reused. In this embodiment, the cleaning adaptor 500 includes a pull tab 574 that extends from the sealing cap 502. The pull tab 574 has a free distal end, which in this embodiment includes an annular ring pull 576 through which a user’s thumb or finger may be inserted. In the first embodiment described above, the pull tab 174 extends from a part of the sealing cap proximate or adjacent the first annular retainer 114. A user disengages the cleaning adaptor 100 from the air / water port 36 and suction port 30 by pulling on the pull tab 174 and pulling the ring pull 176 in a direction away from the control section 6 of the endoscope 2. Weakened portions 180 of the sealing cap 102 extend into an area bounded by the first annular retainer 114 such that the force exerted by the user on the pull tab 174 causes the sealing cap 102 to tear or rupture along the regions of weakness 180 and create a hole or opening in the upper plate that extends within the boundary of the first retainer 114. In this way, once the sealing cap 102 has been ruptured, it is not possible to form a water-tight seal over the opening 64 of the air / water port 36 and the cleaning adaptor cannot, therefore, be reused. In this embodiment the pull tab 574 includes two leg portions 592, 594 that connect the annular ring pull 576 to the sealing cap 502. A first one of these leg portions 592 has a proximal end 578a that extends into a region of the sealing cap 502 that is bounded by the first annular retainer 514. A second one of these leg portions 594 has a proximal end 578b that extends into a region of the sealing cap 502 that is bounded by the second annular retainer 516. At the proximal end 578a of the first leg portion 592 the sealing cap 502 includes a weakened portion 580. A first line of weakness 580a extends along a first side of the first leg portion 592 and a second line of weakness 580b extends along a second side of the first leg portion 592. The lines of weakness 580 are provided by regions of the sealing cap 502 having a reduced thickness of material. Similarly, at the proximal end 578b of the second leg portion 594 the sealing cap 502 includes a weakened portion 580. A first line of weakness 580c extends along a first side of the second leg portion 594 and a second line of weakness 580d extends along a second side of the second leg portion 594. The lines of weakness 580 are provided by regions of the sealing cap 502 having a reduced thickness of material, as shown most clearly in Figure 29. After completion of the pre-clean procedure the cleaning adaptor 500 is removed from the air / water port 36 and suction port 30. In this embodiment the user disengages the cleaning adaptor 500 from the air / water port 36 and suction port 30 by pulling on the pull tab 574 by gripping ring pull 576. Pulling the ring pull 576 in a direction away from the control section 6 of the endoscope 2 withdraws the sealing plug from the air / water cylinder 62 and withdraws the flow modifying stem from the suction cylinder. The force exerted by the user on the pull tab 574 causes the sealing cap 502 to tear or rupture along the regions of weakness 580. The arrangement of the weakened portions 580 is such that the pull tab 574 remains connected to the rest of the sealing cap 502, but partially separates from the upper plate of the sealing cap 502 at the proximal ends 578 of the first and second leg portions 592, 594. In particular, the sealing cap 502 tears or ruptures along each of the lines of weakness 580 along the sides of the first and second leg portions 592, 594 thereby creating a hole or opening in the upper plate that extends within both the boundary of the first retainer 114 and the boundary of the second retainer 116. In this way, once the sealing cap 502 has been ruptured, it is not possible to form a water-tight seal over either the opening 64 of the air / water port 36 or the opening 44 of the suction port 30, and the cleaning adaptor cannot, therefore, be reused. Figures 30 to 33 show a cleaning adaptor 600 according to a sixth preferred embodiment of the present invention. The cleaning adaptor 600 is substantially identical to the cleaning adaptor 500 of the fifth embodiment, except that the cleaning adaptor 600 includes a sealing plug 604 having a shape and configuration that is identical to the sealing plug 404 of the fourth embodiment described above. In this embodiment the cleaning adaptor 600 includes a pull tab 674 that extends from the sealing cap 602. The pull tab 674 has a free distal end, which in this embodiment includes an annular ring pull 676 through which a user’s thumb or finger may be inserted, the pull tab 674 includes two leg portions 692, 694 that connect the annular ring pull 676 to the sealing cap 602. A first one of these leg portions 692 has a proximal end 678a that extends into a region of the sealing cap 602 that is bounded by the first annular retainer 614. A second one of these leg portions 694 has a proximal end 678b that extends into a region of the sealing cap 602 that is bounded by the second annular retainer 616. At the proximal end 678a of the first leg portion 692 the sealing cap 602 includes a weakened portion 680. A first line of weakness 680a extends along a first side of the first leg portion 692 and a second line of weakness 680b extends along a second side of the first leg portion 692. The lines of weakness 680 are provided by regions of the sealing cap 602 having a reduced thickness of material. Similarly, at the proximal end 678b of the second leg portion 694 the sealing cap 602 includes a weakened portion 680. A first line of weakness 680c extends along a first side of the second leg portion 694 and a second line of weakness 680d extends along a second side of the second leg portion 694. The lines of weakness 680 are provided by regions of the sealing cap 602 having a reduced thickness of material, as shown most clearly in Figure 33. In this embodiment the sealing plug 604 comprises a stem 630 extending from the sealing cap 602 and a sealing portion 640 at the distal end 634 of the stem 630. The stem 630 has a cruciform crosssection in a plane perpendicular to a longitudinal axis of the sealing plug 604. The stem 630 therefore comprises four arms or ribs 688 that extend radially from the axis and extend along the length of the stem 630. The sealing portion 640 includes a distal end surface 642 of the sealing plug 604. The sealing portion 640 further comprises a sealing surface 644. In this embodiment the sealing portion 640 also has a cruciform cross-section in a plane perpendicular to the longitudinal axis of the sealing plug 604. The sealing portion 640 therefore comprises four sealing arms or sealing ribs 690 that extend radially from the axis 686. Figures 34 to 36 show a cleaning adaptor 700 according to a seventh preferred embodiment of the present invention. The cleaning adaptor 700 of this embodiment is substantially identical to the cleaning adaptor 100 of the first embodiment and like features will not be described further in relation to this embodiment. The cleaning adaptor 700 comprises a sealing cap 702 for engagement with and sealing of both the air / water port 36 and the suction port 30 of the endoscope 2, a sealing plug 704 extending from the sealing cap 702 for insertion into the air / water cylinder 62 of the air / water port 36 of the endoscope 2, and a flow modifying stem 706 extending from the sealing cap 702 for insertion into the suction cylinder 42 of the suction port 30 of the endoscope 2. The sealing cap 702 is identical to the sealing cap 102 of the first embodiment and comprises a first annular retainer and a second annular retainer. A pull tab 774 extends from a part of the sealing cap 702 proximate or adjacent the first annular retainer. Weakened portions of the sealing cap 702 extend into an area bounded by the first annular retainer such that a force exerted by a user on the pull tab 774 causes the sealing cap 702 to tear or rupture along the regions of weakness and create a hole or opening in the sealing cap 702 that extends within the boundary of the first retainer. In this way, once the sealing cap 702 has been ruptured, it is not possible to form a water-tight seal over the opening 64 of the air / water port 36 and the cleaning adaptor cannot, therefore, be reused. The flow modifying stem 706 is also identical to the flow modifying stem 106 of the first embodiment and extends from a region of the sealing cap 702 surrounded by the second retainer. In this embodiment the sealing plug 704 comprises a stem 730 extending from the sealing face of the upper plate of the sealing cap 702. The stem 730 extends longitudinally between a proximal end 732 at the sealing cap 702 and a distal end 734. In this embodiment the stem 730 is axially aligned with the first annular retainer so that the stem 730 extends centrally from the first annular retainer and the first annular retainer surrounds the proximal end 732 of the stem 730. The stem 730 is generally cylindrical and in this embodiment is in the form of a straight rod. The sealing plug 704 further comprises a sealing portion 740 at the distal end 734 of the stem 730. The sealing portion 740 includes a distal end surface 742 of the sealing plug 704. The sealing portion 740 is generally disc-shaped having an outer circumferential sealing surface 744. A diameter of the sealing portion 740 is greater than a diameter of the stem 730. The sealing portion 740 includes a recess or channel 796 formed in the outer surface 744. The channel 796 extends longitudinally between the distal end surface 742 of the sealing plug 704 and an upper surface 743 of the sealing portion 740. In use, the sealing surface 744 contacts an internal wall of the air / water cylinder 62 to form a seal against the internal surface of the air / water cylinder 62. In particular, the dimensions of the sealing plug 704 are such that a part of the sealing surface 744 aligns with the air inlet 76 in the internal wall of the air / water cylinder 62. The sealing surface 744 is arranged to contact the wall of the cylinder 62 immediately surrounding the air inlet 76, and to contact the wall around the full perimeter of the air inlet 76, such that the sealing surface 744 forms a water-tight seal at the air inlet 76. The location of the channel 796 is at a distance from the region of contact between the sealing surface 744 and the wall around the full perimeter of the air inlet 76. In some embodiments the channel 796 may be disposed in the sealing portion 740 at a point diametrically opposite to the air inlet 76 when the sealing plug is inserted into the air / water cylinder. In this embodiment, the channel 796 is slightly offset from this diametrically opposite point, so that the channel 796 does not lessen the force with which the sealing surface 744 is pressed against the wall of the air / water cylinder 62 around the air inlet 76. The channel 796 provides a passage for fluid flow between a region beyond the distal end surface 742 of the sealing plug 704 and a region surrounding the outer surface of the stem 730 when the sealing plug 704 is seated in an air / water cylinder. It will be appreciated that, during pre-cleaning of the endoscope 2, the smaller diameter of the stem 730 means that water or detergent solution is able to contact and flow over substantially all of the inner surface of the air / water cylinder 62, as there is no contact between the stem 730 of the sealing plug and the inner surface of the air / water cylinder. Figures 37 and 38 show a cleaning adaptor 800 according to an eighth preferred embodiment of the present invention. The cleaning adaptor 800 of this embodiment is substantially identical to the cleaning adaptor 100 of the first embodiment and like features will not be described further in relation to this embodiment. The cleaning adaptor 800 comprises a sealing cap 802 for engagement with and sealing of both the air / water port 36 and the suction port 30 of the endoscope 2, a sealing plug 804 extending from the sealing cap 802 for insertion into the air / water cylinder 62 of the air / water port 36 of the endoscope 2, and a flow modifying stem 806 extending from the sealing cap 802 for insertion into the suction cylinder 42 of the suction port 30 of the endoscope 2. The sealing cap 802 is identical to the sealing cap 102 of the first embodiment and comprises a first annular retainer and a second annular retainer. A pull tab 874 extends from a part of the sealing cap 802 proximate or adjacent the first annular retainer. Weakened portions of the sealing cap 802 extend into an area bounded by the first annular retainer such that a force exerted by a user on the pull tab 874 causes the sealing cap 802 to tear or rupture along the regions of weakness and create a hole or opening in the sealing cap 802 that extends within the boundary of the first retainer. In this way, once the sealing cap 802 has been ruptured, it is not possible to form a water-tight seal over the opening 64 of the air / water port 36 and the cleaning adaptor cannot, therefore, be reused. The flow modifying stem 806 is also identical to the flow modifying stem 106 of the first embodiment and extends from a region of the sealing cap 802 surrounded by the second retainer. In this embodiment the sealing plug 804 comprises a stem 830 extending from the sealing cap 802. The stem 830 extends longitudinally between a proximal end 832 at the sealing cap 802 and a distal end. In this embodiment the stem 830 is axially aligned with the first annular retainer so that the stem 830 extends centrally from the first annular retainer and the first annular retainer surrounds the proximal end 832 of the stem 830. The sealing plug 804 further comprises a sealing portion 840 at the distal end of the stem 830 and continuous with the stem 830. The sealing portion 840 includes a distal end surface 842 of the sealing plug 804. In this embodiment both the stem 830 and the sealing portion 840 have the same cross-sectional shape perpendicular to a longitudinal axis of the sealing plug 804. The stem 830 and sealing portion 840 both have a generally rectangular cross-sectional shape, having two opposite side faces 898 and two opposite end faces 899. A distance between the two opposite side faces 898 defines a minor or smaller dimension of the sealing plug 804 and a distance between the two opposite end faces 899 defines a major or larger dimension of the sealing plug 804. These dimensions are the same for the full length of the sealing plug 804 between the proximal end 832 of the stem 830 and the distal end surface 842. The larger dimension is generally equal to the internal diameter of the air / water cylinder 62 so that, when the sealing plug 804 is inserted into the cylinder, the end faces 899 contact the inner wall of the air / water cylinder. The end faces 899 therefore form sealing surfaces 844 of the sealing plug 804. Furthermore, the sealing plug 804 is oriented so that one of the end faces 899 contacts the inner wall of the cylinder 62 immediately surrounding the air inlet 76, and contacts the inner wall around the full perimeter of the air inlet 76, such that the sealing surface 744 forms a water-tight seal at the air inlet 76. It will be understood that the other end face 899 contacts the inner surface at a point diametrically opposite to the air inlet 76 so that the first end face 899 is pressed into tight sealing contact with the inner wall of the cylinder. During pre-cleaning of the endoscope 2, fluid, such as water or detergent solution, is able to flow from a region beyond the distal end surface 842 either side of the sealing plug 804, between the side faces 898 and the inner wall of the air / water cylinder. The water or detergent solution is therefore able to contact and flow over a larger proportion of the inner surface of the air / water cylinder 62. In the present invention, the relative positions of the sealing plug and flow modifying stem are known and fixed by the sealing cap. Furthermore, the sealing cap fits in a known and fixed position onto the collars 66, 48 surrounding the openings 64, 44 of the air / water port 36 and suction port 30. As the location of the air inlet 76 in the inner wall of the air / water cylinder 62 is also known and fixed, it is possible to know the position of the air inlet 76 in relation to a surface of the sealing plug. In the cleaning adaptor of the present invention, therefore, it is not necessary for the sealing plug to include annular seals or fully cylindrical sealing surfaces. The sealing plug can be designed with minimal contact between the sealing portion and the inner wall of the air / water cylinder 62 as it is only necessary to form a liquid-tight seal at and around the air inlet 76. This allows a greater area of the surface of the air / water cylinder 62 to be contacted by the water or detergent solution during cleaning of the endoscope 2, as described above. This more selective contact between the sealing plug and the inner wall of the air / water cylinder 62 is not possible in sealing plugs that attach only to the collar 66 of the air / water port 36 as it is not possible to reliably ensure that the sealing plug is in the correct orientation to form the necessary water-tight seal at the air inlet 76. By contrast, in the present cleaning adaptor, because the first annular retainer attaches to the collar 66 of the air / water port 36 and the second annular retainer attaches to the collar 48 of the suction port 30, the orientation of the sealing plug with respect to the air / water cylinder 62 is fixed. A number of preferred embodiments of a cleaning adaptor according to the present invention have been described above. It will be appreciated that in all of these embodiments the cleaning adaptor comprises a sealing cap having a first annular retainer that attaches to the collar 66 of the air / water port and a second annular retainer that attaches to the collar 48 of the suction port 30, a sealing plug that extends into the air / water cylinder 62 including a sealing surface to form a water-tight seal at the air inlet, and a flow modifying stem that extends into the suction cylinder. In some embodiments the cleaning adaptor may not include the second annular retainer or the flow modifying stem, such that the cleaning adaptor only engages with the air / water port. In these embodiments the cleaning adaptor preferably includes an alignment feature so that a user can insert the sealing plug into the air / water cylinder 62 in the correct orientation to seal the air inlet. The alignment feature may be in the form of a protrusion from the sealing cap, for example. In further embodiments, the cleaning adaptor does not engage with the suction port. In particular, the cleaning adaptor may not include the second annular retainer or the flow modifying stem. In these embodiments, the cleaning adaptor may be used together with a separate adaptor or plug that engages with the suction port and suction cylinder. In these embodiments the cleaning adaptor may include a mating feature that is configured to engage with a part of the suction port adaptor. The mating feature is configured to engage with the suction port adaptor to fix the orientation of the cleaning adaptor with respect to the suction port adaptor. In some embodiments the mating feature may comprise a planar surface that contacts a corresponding planar surface of the suction port adaptor to prevent rotation of the cleaning adaptor with respect to the suction port adaptor. In other embodiments the mating feature of the cleaning adaptor may include a protrusion or a recess that engages with a corresponding recess or protrusion of the suction port adaptor. For example a protrusion may extend from the sealing cap of the cleaning adaptorthat engages with a recess in a sealing cap of the suction port adaptor thereby preventing rotation of the cleaning adaptor with respect to the suction port adaptor. Furthermore, the inclusion of the single use feature in the form of weakened areas of the sealing cap is also preferable, but may not be present in all embodiments of the cleaning adaptor. In some embodiments no single use feature may be included, in other embodiments a different single use feature may be included, such as a weakened section at the proximal end of either or both of the stem of the sealing plug and the flow modifying stem. Other modifications and variations not explicitly disclosed above may also be contemplated without departing from the scope of the invention as defined in the appended claims.

Claims

1. A cleaning adaptor for engagement with an air / water cylinder of an endoscope, said cylinder having an air inlet disposed in a circumferential wall of the cylinder and said circumferential wall extending between a base of the cylinder and an opening, the cleaning adaptor being a unitary element comprising a sealing cap configured to seal said opening of the air / water cylinder and a sealing plug having:a distal sealing portion having an end surface; anda stem portion extending between the head portion and the distal sealing portion, an axis of the stem portion defining a longitudinal axis of the sealing plug,the distal sealing portion comprising a sealing surface arranged to align with the air inlet and contact the circumferential wall of the cylinder immediately surrounding the air inlet around the full perimeter of the air inlet to form a fluid-tight seal at the air inlet, andthe distal sealing portion having a cross-sectional shape transverse to the longitudinal axis providing a fluid flow path between an outer surface of the distal sealing portion and the circumferential wall of the cylinder, the fluid flow path fluidly connecting a first region beyond the end surface of the distal sealing portion and a second region between an outer surface of the stem portion and the circumferential wall of the cylinder.

2. A cleaning adaptor according to Claim 1, in which the distal sealing portion comprises a radially recessed portion that provides the fluid flow path.

3. A cleaning adaptor according to Claim 1 or Claim 2, in which the sealing cap includes an upper plate and an annular retainer configured to engage with a collar surrounding the opening of the air / water cylinder, and in which the stem portion extends from the sealing cap such that the first annular retainer surrounds a proximal end of the stem portion.

4. A cleaning adaptor according to Claim 3, in which the first annular retainer comprises a retaining wall, a plurality of spacing ribs disposed on an inner surface of the retaining wall, and a sealing lip, and wherein the sealing lip is configured to seal against a first surface of the collar and the spacing ribs are configured to space the retaining wall from a second surface of the collar.

5. A cleaning adaptor according to any preceding claim, in which an outer surface of the stem portion includes a helical groove.

6. A cleaning adaptor according to any preceding claim, in which the sealing portion comprises a plurality of radially projecting sealing ribs that extend longitudinally along the sealing portion.

7. A cleaning adaptor according to any one of Claims 1 to 4, in which the sealing portion has a cruciform cross-section in a plane perpendicular to the longitudinal axis.

8. A cleaning adaptor according to Claim 7, in which the stem portion has a cruciform crosssection in a plane perpendicular to the longitudinal axis.

9. A cleaning adaptor according to any one of Claims 1 to 4, in which the stem portion and sealing portion both have a generally rectangular cross-sectional shape in a plane perpendicular to the longitudinal axis.

10. A cleaning adaptor according to any preceding claim, in which the sealing cap includes a mating feature in the form of a planar surface, a protrusion or a recess configured to engage with a complimentary feature to prevent rotation of the cleaning adaptor about the longitudinal axis.

11. A cleaning adaptor according to any one of Claims 1 to 9, in which the sealing cap extends over an opening of a suction cylinder of the endoscope, a part of the sealing cap being configured to form a fluid-tight seal over the opening of the suction cylinder.

12. A cleaning adaptor according to Claim 11, further comprising a flow modifying stem extending from the sealing cap and the flow modifying stem being configured to extend into the suction cylinder.

13. A cleaning adaptor according to Claim 12, in which a longitudinal axis of the flow modifying stem is generally parallel to the longitudinal axis of the sealing plug.

14. A cleaning adaptor according to Claim 12 or Claim 13, in which the sealing cap includes an upper plate and an annular retainer configured to engage with a collar surrounding the opening of the suction cylinder, and in which the flow modifying stem extends from the sealing cap such that the annular retainer surrounds a proximal end of the flow modifying stem.

15. A cleaning adaptor according to Claim 14, in which the annular retainer comprises a retaining wall, a plurality of spacing ribs disposed on an inner surface of the retaining wall, and a sealing lip, and wherein the sealing lip is configured to seal against a first surface of the collar and the spacing ribs are configured to space the retaining wall from a second surface of the collar.

16. A cleaning adaptor according to any one of Claims 12 to 15, in which an outer surface of the flow modifying stem includes a helical groove.

17. A cleaning adaptor according to any preceding claim, further comprising a pull tab that extends from the sealing cap, the pull tab configured to be gripped by a user to disengage the cleaning adaptor from the air / water cylinder.

18. A cleaning adaptor according to Claim 17, in which the sealing cap includes a weakened portion at a proximal end of the pull tab, the weakened portion configured to rupture a part of the sealing cap when a force is applied to the pull tab so that the sealing cap no longer forms a seal over the opening of the air / water cylinder.

19. A cleaning adaptor according to Claim 17 when dependent on any one of Claims 12 to 16, in which the sealing cap includes a weakened portion at a proximal end of the pull tab, the weakened portion configured, when a force is applied to the pull tab, to rupture a first part of the sealing cap so that the sealing cap no longer forms a seal over the opening of the air / water cylinder and to rupture a second part of the sealing cap so that the sealing cap no longer forms a seal over the opening of the suction cylinder.

20. A cleaning adaptor according to any preceding claim, in which the cleaning adaptor is made from silicone.

21. An assembly comprising:an endoscope having an air / water port connected to air and water channels and including an air / water cylinder having an air inlet, an air outlet, a water inlet and a water outlet; anda cleaning adaptor according to any one of Claims 1 to 20, the sealing plug being disposed in the air / water cylinder such that the water inlet and water outlet are in direct fluid communication via the first region beyond the end surface of the distal sealing portion, the air outlet is in fluid communication with the second region and with the water inlet via the fluid flow path between the first region and the second region, and the sealing surface forms a fluid-tight seal at the air inlet.

22. An assembly according to Claim 21, in which the endoscope further comprises a suction port including a suction cylinder having an opening, the cleaning adaptor is according to any one of Claims 12 to 16, and the sealing cap is engaged with the suction port to seal the opening of the suction cylinder.

23. A method of cleaning air and water channels of an endoscope using a cleaning adaptor as claimed in any one of Claims 1 to 20, the endoscope having an air / water port connected to the air and water channels and including an air / water cylinder having an air inlet, an air outlet, a water inlet and a water outlet, and the method comprising:engaging the sealing cap with the air / water port to seal an opening of the air / water cylinder; inserting the sealing plug of the cleaning adaptor into the air / water cylinder so that the sealing portion aligns with the air inlet and the sealing surface contacts an inner circumferential wall of the air / water cylinder around the air inlet to form a fluid-tight seal at the air inlet; andproviding a flow of liquid to the air / water cylinder through the water inlet, the fluid flow path between an outer surface of the distal sealing portion and the circumferential wall of the cylinder allowing the liquid entering the air / water cylinder to flow out of both the air outlet and the water outletsimultaneously.

24. A method according to Claim 23, in which the cleaning adaptor is according to any one of Claims 11 to 16, the endoscope has a suction port including a suction cylinder connected to a suction channel, and the method further comprises:engaging the sealing cap with the suction port to seal an opening of the suction cylinder; and flushing liquid through the suction channel and the suction cylinder.

25. A method according to Claim 24, in which the cleaning adaptor is according to any one of Claims 12 to 16, and the method further comprises inserting the flow modifying stem into the suction cylinder.

26. A method according to Claim 23, in which the cleaning adaptor is according to Claim 18 and the method comprises:gripping the pull tab and applying a force to the cleaning adaptor to pull the sealing plug out of the air / water cylinder; andbreaking or rupturing a part of the sealing cap so that the sealing cap no longer forms a seal over the opening of the air / water cylinder.

27. A method according to Claim 24 or Claim 25, in which the cleaning adaptor is according to Claim 19 and the method comprises:gripping the pull tab and applying a force to the cleaning adaptor to pull the sealing plug out of the air / water cylinder;breaking or rupturing a first part of the sealing cap so that the sealing cap no longer forms a seal over the opening of the air / water cylinder; andbreaking or rupturing a second part of the sealing cap so that the sealing cap no longer forms a seal over the opening of the suction cylinder.36

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