Insufflating apparatus and a method for insufflating a cavity in the body of a human or animal subject

Abstract

An insufflating apparatus (1) for insufflating a stomach of a subject comprises an insufflator (7) and an access device (10) for engaging in the mouth of the subject for accommodating an endoscope (9) through an instrument channel (18) of the access device to the stomach. The insufflator comprises a flow controller (39) connected to an insufflating channel (57) of the endoscope for insufflating the stomach. A pressure sensor (50) monitors stomach pressure through an instrument channel (60) of the endoscope. A vacuum control valve (47) applies a first vacuum at an extraction vacuum level to an outlet port (29) of the access device which is applied to the instrument channel thereof for drawing insufflating and other gases and smoke from the stomach. The outlet port communicates with an annular manifold (31) extending around and within the access device, and first inlet ports (27) communicate the manifold with the instrument channel.

Description

[0001] Insufflating apparatus and a method for insufflating a cavity in the body of a human or animal subject

[0002] The present invention relates to insufflating apparatus for insufflating a cavity in the body of a human or animal subject, and in particular, to such insufflating apparatus adapted to draw gases from the cavity, such as smoke. The invention also relates to a method for insufflating a cavity in the body of a human or animal subject, and also for drawing gases, such as smoke from the cavity. Additionally, the invention relates to an access device for accommodating an instrument through a bodily orifice into a cavity in the body of a human or animal subject.

[0003] Endoscopic and colonoscopy investigative and surgical procedures are well known, in general, such procedures are carried out through an endoscope, or a colonoscope, as the case may be. In the case of endoscopic procedures, an endoscope, in general, is entered orally through a subject to the lumen, vessel, organ or cavity in which the endoscopic procedure is being carried out. Typically, endoscopic procedures are carried out in the stomach and the oesophagus, although, in some cases, a procedure may be carried out in the intestine of a subject. In such procedures an endoscope is entered orally through the subject and in turn through the alimentary canal into the stomach or the relevant part of the intestine. In the case of colonoscopy investigative and surgical procedures, in general, a colonoscope is entered anally into a subject to the lumen, vessel, organ or cavity in which the procedure is to be carried out. Such colonoscopy procedures in general, are carried out in the rectum, the colon and the intestine. A colonoscope in such cases, is entered anally into the subject to the rectum, colon or intestine.

[0004] Additionally, a procedure may be carried out endoscopically in the abdominal cavity or in a lumen, vessel, organ or cavity in the abdominal cavity, in which case an endoscope is entered orally into a subject through the alimentary canal, and the endoscope is entered into the abdominal cavity through an incision formed in an appropriate part of the alimentary canal, for example, in the stomach, in order to provide access to the endoscope from the alimentary canal into the abdominal cavity.

[0005] For convenience, throughout this specification, the term "cavity’’ will be used to mean any lumen, vessel, organ or cavity in the body of a human or animal subject in which a procedure may be carried out.

[0006] Due to limitations on the maximum outer diameter of an endoscope or a colonoscope, in order that the endoscope or colonoscope may be entered either orally or anally to the cavity, the number of channels which may be provided through an endoscope or a colonoscope is limited. In general, in many cases, there is only sufficient room for an insufflating channel and an instrument channel. While such limitations do not present major problems for the insufflating of a cavity in which a procedure is being carried out, significant problems arise when a surgeon or clinician is carrying out a cauterising procedure, for example, an argon plasma coagulation procedure, or other such procedure which generates smoke and / or increases the pressure in the cavity.

[0007] During such procedures, it is essential that the smoke be drawn from the cavity in the shortest possible time, in order to provide adequate visibility for a surgeon or a clinician in the cavity. This, thus, requires the application of a vacuum through the endoscope or colonoscope to draw the smoke from the cavity. Additionally, in order to effectively draw the smoke from the cavity, it is essential that insufflating gas also be delivered into the cavity while the vacuum is applied thereto in order to maintain the pressure in the cavity at a set pressure value, and to provide a flow of insufflating gas through the cavity for the removal of the smoke. Accordingly, two channels of the endoscope are required to remove smoke from a cavity in which a procedure is being carried out, one channel to accommodate the insufflating gas to the cavity, and another channel for applying a vacuum to the cavity for drawing the smoke and insufflating gas from the cavity.

[0008] Additionally, in general, it is desirable to be able to monitor the pressure accurately in a cavity while a vacuum is being applied to the cavity in order to avoid collapsing of the cavity which would result if the pressure in the cavity suddenly dropped. It is therefore important to be able to accurately monitor the pressure in the cavity during withdrawal of the smoke therefrom. Ideally, this requires three channels through the endoscope or colonoscope, one to accommodate the insufflating gas into the cavity, another to apply a vacuum to the cavity to draw smoke and insufflating gas from the cavity, and a third to allow the pressure in the cavity to be continuously monitored. Otherwise, the only feasible way of monitoring the pressure in the cavity is to monitor the pressure in the cavity through the channel through which the insufflating gas is being delivered to the cavity, or through the channel to which the vacuum is being applied to the cavity, and this requires interruption of the flow of insufflating gas to the cavity or interruption of the vacuum applied to the cavity during monitoring of the pressure in the cavity.

[0009] This is quite problematical, and since in general three channels are not available in an endoscope or a colonoscope, delays in removing smoke from a cavity in which a procedure is being carried out regularly arise. Substantially similar problems arise when pressurised gas resulting from a procedure being carried out in a cavity, for example, a cryogenic procedure, is to be drawn quickly from a cavity in order to reduce the cavity pressure to a set pressure value.

[0010] There is therefore a need for an insufflating apparatus and a method for insufflating a cavity in a human or animal subject which addresses at least some of these problems.

[0011] The present invention is directed towards providing such an insufflating apparatus and a method for insufflating a cavity in a human or animal subject which addresses some of the problems. The invention is also directed towards an access device for accommodating an instrument through a bodily orifice into a cavity in the body of a human or animal subject.

[0012] According- to the invention there is provided an insufflating apparatus for insufflating a cavity in the body of a human or animal subject, the insufflating apparatus comprising an access device adapted for engaging in a bodily orifice of the subject through which the cavity is accessible, the access device extending between a proximal end and a distal end and having an instrument channel extending therethrough from the proximal end to the- distal end thereof for accommodating an instrument therethrough to the cavity, a communicating means adapted to communicate with the cavity through the access device, and an insufflator, the insufflator comprising a flow controller for controlling delivery of insufflating gas to the cavity, a pressure sensor for monitoring pressure in the cavity (cavity pressure) and for producing a signal indicative of the cavity pressure, a vacuum applying means adapted for applying vacuum to the communicating means, and a signal processor programmed to read the signal from the pressure sensor and / or to read a smoke evacuate signal, the signal processor being programmed to be responsive to the signal read from the pressure sensor being indicative of the cavity pressure exceeding a set pressure value, or to the smoke evacuate signal to operate the vacuum applying means in a first state to produce a first vacuum at an extraction vacuum level for applying to the communicating means for drawing gases and / or smoke from the cavity through the access device.

[0013] In one embodiment of the invention the signal processor is programmed to operate the vacuum applying means in the first state for applying the first vacuum to the communicating means until the signal read from the pressure sensor is indicative of the cavity pressure having fallen to or below the set pressure value, or until termination of the smoke evacuate signal. In another embodiment of the invention the signal processor is programmed to operate the flow controller to control delivery of insufflating gas to the cavity while the vacuum applying means is being operated in the first state for applying the first vacuum to the communicating means, and preferably, the signal processor is programmed to operate the flow controller to control delivery of insufflating gas to the cavity while the signal processor is operating the vacuum applying means in the first state thereof in response to the smoke evacuate signal,

[0014] Preferably, the signal processor is programmed to operate the flow controller to control delivery of insufflating gas to the cavity while the signal processor is operating the vacuum applying means in the first state thereof in response to the smoke evacuate signal for maintaining the cavity pressure substantially at the set pressure value.

[0015] In another embodiment of the invention the vacuum applying means is operable in the first state thereof under the control of the signal processor for applying the first vacuum at at least two selectable extraction vacuum levels.

[0016] Preferably, the vacuum applying means is operable in the first state thereof under the control of the signal processor for applying the first vacuum at a plurality of selectable extraction vacuum levels.

[0017] In one embodiment of the invention the signal processor is responsive to the smoke evacuate signal to operate the vacuum applying means to apply the first vacuum at a selected one of the selectable extraction vacuum levels of the first vacuum.

[0018] In another embodiment of the invention the smoke evacuate signal is produced by a smoke evacuate signal producing means, and preferably, the smoke evacuate signal producing means is adapted to produce the smoke evacuate signal indicative of the selectable extraction vacuum level at which the vacuum applying means is to apply the first vacuum in the first state thereof.

[0019] In one embodiment of the invention the smoke evacuate signal producing means comprises at least one smoke evacuate signal generating electrical switch or at least one smoke evacuate signal generating electronic switch. Preferably, the at least one smoke evacuate signal generating switch comprises a bistate switch, and preferably, a mono-stable bi-state switch, and advantageously, the mono-stable bi-state switch is stable in an open circuit state, and is unstable in a closed circuit state.

[0020] In one embodiment of the invention the mono-stable bi-state switch is adapted to produce the smoke evacuate signal when operated in one of a closed circuit state or an open circuit state, and preferably, to indicate termination of the smoke evacuate signal when the at least one smoke evacuate signal generating switch is operated in the other one of the closed circuit state or the open circuit state.

[0021] Preferably, the at least one smoke evacuate signal generating mono-stable bi-state switch is adapted to produce the smoke evacuate signal when operated in the closed circuit state.

[0022] In one embodiment of the invention the signal processor is responsive to the smoke evacuate signal generating switch being operated once from the stable state to the unstable state and back to the stable state to operate the vacuum applying means in the first state to produce the first vacuum and to maintain the vacuum applying means in the first state producing the first vacuum until the smoke evacuate signal generating switch is again operated once from the stable state to the unstable state and back to the stable state.

[0023] In one embodiment of the invention the smoke evacuate signal is indicative of the selectable extraction vacuum level at which the vacuum applying means is to produce the first vacuum.

[0024] In one embodiment of the invention the smoke evacuate signal producing means comprises an analogue switch, and preferably, the analogue switch is adapted to produce an analogue signal of varying value in response to the degree to which the switch is operated, the analogue signal produced by the switch being proportional to the selectable extraction vacuum levels.

[0025] Preferably, the signal processor is responsive to the value of the analogue signal produced by the analogue switch to operate the vacuum applying means in the first state to produce the first vacuum at the selectable extraction vacuum level corresponding to the value of the analogue signal.

[0026] In an alternative embodiment of the invention the signal processor is responsive to the number of operations of the mono-stable bi-state switch from the stable state through the unstable state and back to the stable state in quick succession to determine the selectable extraction vacuum level at which the vacuum applying means is to produce the first vacuum, the greater the number of operations of the mono- stable bi-state switch, the greater will be the selectable extraction vacuum level at which the vacuum applying means is operated to produce the first vacuum,

[0027] In one embodiment of the invention the at least one smoke evacuate signal generating switch comprises a foot pedal operated switch.

[0028] In another embodiment of the invention the at least one smoke evacuate signal generating switch comprises a button operated electrical or an electronic switch.

[0029] In another embodiment of the invention the at least one smoke evacuate signal generating switch comprises a voice operated electrical or an electronic switch.

[0030] In one embodiment of the invention the signal processor is adapted to read the smoke evacuate signal produced by the at least one smoke evacuate signal generating switch.

[0031] In another embodiment of the invention the signal processor is responsive to the signal read from the pressure sensor being indicative of the cavity pressure exceeding the set pressure value for operating the flow controller to reduce the rate at which insufflating gas is being delivered to the cavity, or to pause delivery of insufflating gas to the cavity.

[0032] In one embodiment of the invention the signal processor when operating the flow controller in response to the signal read from the pressure sensor being indicative of the cavity pressure exceeding the set pressure value is programmed to operate the flow controller to reduce the rate at which insufflating gas is being delivered to the cavity or to pause delivery of insufflating gas to the cavity until the cavity pressure has fallen to the set pressure value.

[0033] In another embodiment of the invention the signal processor is responsive to the amount by which the cavity pressure exceeds the set pressure value for determining the extraction vacuum level at which the first vacuum is to be produced by the vacuum applying means in the first state thereof, so that the greater the amount by which the cavity pressure exceeds the set pressure value, the greater will be the extraction vacuum level of the first vacuum produced by the vacuum applying means in the first state thereof.

[0034] In another embodiment of the invention the signal processor is programmed to operate the vacuum applying means in the first state thereof to produce the first vacuum at the selectable extraction vacuum levels in proportion to the amount by which the cavity pressure exceeds the set pressure value, so that the greater the amount by which the cavity pressure exceeds the set pressure value, the greater will be the extraction vacuum level at which the first vacuum is produced by the vacuum applying means.

[0035] In one embodiment of the invention when the vacuum applying means is being operated in the first state thereof to produce the first vacuum at the extraction vacuum level in response to the cavity pressure exceeding the set pressure value, the vacuum applying means is sequentially and alternately operated to produce the first vacuum for a predefined vacuum on time period and to pause producing the first vacuum for a predefined vacuum off time period. Preferably, each predefined vacuum off time period commences immediately upon termination of the immediately previous predefined vacuum on time period, and advantageously, each predefined vacuum on time period commences immediately upon termination of the immediately preceding predefined vacuum off time period.

[0036] In one embodiment of the invention each predefined vacuum on time period lies in the range of 1 second to 3 seconds, and preferably, each predefined vacuum on time period is approximately 1.5 seconds.

[0037] In another embodiment of the invention each predefined vacuum off time period lies in the range of 0.10 seconds to 0.75 seconds, and advantageously, each predefined vacuum off time period is approximately 0.5 seconds.

[0038] In another embodiment of the invention the signal processor is programmed in response to the signal produced by the pressure sensor being indicative of the cavity pressure being at or below the set pressure value or the termination or the absence of the smoke evacuate signal to operate the vacuum applying means in a second state to produce a second vacuum at a collecting vacuum level less than the extraction vacuum level or less than the lowest level of the selectable extraction vacuum levels of the first vacuum for applying to the communicating means for collecting gases and / or smoke escaping from the cavity through or adjacent the access device.

[0039] Preferably, the collecting vacuum level of the second vacuum is insufficient to draw gases and / or smoke from the cavity but sufficient to draw gases and / or smoke escaping from the cavity through the access device. In one embodiment of the invention the collecting vacuum level of the second vacuum is at a level less than any of the extraction vacuum levels of the first vacuum.

[0040] In one embodiment of the invention the communicating means communicates with the cavity through the instrument channel of the access device.

[0041] In one embodiment of the invention the collecting vacuum level of the second vacuum lies in the range of lOOmmHg to 500mmHg below atmospheric pressure. Preferably, the collecting vacuum level of the second vacuum lies in the range of 200mmHg to 400mmHg below atmospheric pressure. Advantageously, the collecting vacuum level of the second vacuum is approximately 300mmHg below atmospheric pressure.

[0042] In another embodiment of the invention the extraction vacuum level of the first vacuum lies in a range that when applied to the communicating means insufflating gas is drawn from the cavity through the communicating means at a flow rate in the range of 1 Litre per minute to 20 Litres per minute, and preferably, at a flow rate in the range of 2 Litres per minute to 10 Litres per minute, and advantageously, at a flow rate of 3 Litres per minute to 5 Litres per minute.

[0043] In another embodiment of the invention the vacuum applying means comprises a vacuum control valve, and preferably, the vacuum control valve is adapted for connecting to the vacuum source, and advantageously, the vacuum control valve is adapted for connecting to the communicating means.

[0044] Preferably, the vacuum control valve is operable in at least two states, and in one embodiment of the invention in one of the at least two states the vacuum control valve is operable in an isolating state isolating the communicating means from the vacuum source, and preferably, in the other one of the at least two states the vacuum control valve is operable in the first state producing the first vacuum at the extraction vacuum level.

[0045] In another embodiment of the invention the vacuum control valve comprises a three-state valve operable in the isolating state and in the first state, and operable in the second state for applying the second vacuum at the collecting vacuum level to the communicating means.

[0046] In one embodiment of the invention the vacuum control valve comprises a multi-state vacuum control valve operable in a plurality of the first states for producing the first vacuum at the respective selectable extraction vacuum levels for applying to the communicating means.

[0047] In another embodiment of the invention the multi-state vacuum control valve is operable in a plurality of second states for producing the second vacuum at a plurality of second states for producing the second vacuum at respective selectable collecting vacuum levels.

[0048] In another embodiment of the invention the vacuum applying means comprises a vacuum pump, and preferably, the vacuum pump is adapted for connecting to the communicating means.

[0049] Preferably, the vacuum pump is operable in at least a non-vacuum generating state and the first state to produce the first vacuum at the extraction vacuum level.

[0050] Advantageously, the vacuum pump is operable in the second state to produce the second vacuum at the collecting vacuum level.

[0051] In one embodiment of the invention the vacuum pump is operable to produce the first vacuum at a plurality of the selectable extraction vacuum levels.

[0052] In one embodiment of the invention the communicating means comprises a manifold, an outlet port communicating with the manifold, the outlet port being adapted for connection to the vacuum applying means for applying the first vacuum or the second vacuum to the manifold, and at least one first inlet port communicating with the manifold for applying the first vacuum or the second vacuum adjacent the access device.

[0053] In another embodiment of the invention the manifold is located in the access device, and the at least one first inlet port for applying the first vacuum or the second vacuum adjacent the access device extends from the manifold and terminates in the instrument channel communicating with the instrument channel, or terminates adjacent a distal end of the access device with the at least one first inlet port facing distally from the access device.

[0054] Preferably, a plurality of the first inlet ports are provided spaced apart circumferentially around the access device. Preferably, the first inlet ports are equi-spaced apart circumferentially around the access device. In one embodiment of the invention at least one second inlet port extends from the manifold and terminates in an outer surface of the access device. Preferably, a plurality of the second outlet ports are spaced apart circumferentially around the outer surface of the access device.

[0055] Preferably, the manifold extends circumferentially around and within the access device. Advantageously, the manifold extends completely around the access device.

[0056] In one embodiment of the invention the manifold comprises an annular chamber extending around and within the communicating access device.

[0057] In one embodiment of the invention a sealing means is located in the instrument channel of the access device, the sealing means being adapted to slideably and sealably engage the instrument extending through the instrument channel. Preferably, the sealing means comprises a sealing membrane extending into the instrument channel, and terminating in an instrument accommodating opening for slideably and sealably engaging an instrument extending through the instrument channel. Advantageously, the sealing membrane comprises a resilient material. Preferably, the sealing membrane comprises a flexible material.

[0058] In one embodiment of the invention the sealing means is located in the instrument channel intermediate the proximal and distal ends thereof. Preferably, the sealing means is located proximally of the at least one first inlet port.

[0059] Advantageously, a proximal flange extends sidewardly outwardly from and circumferentially around the access device adjacent the proximal end thereof.

[0060] Preferably, a pair of radially sidewardly outwardly extending proximal side flanges extend from the access device adjacent the proximal end thereof.

[0061] In one embodiment of the invention the sealing means comprises a sealing disc.

[0062] In another embodiment of the invention the access device is adapted for locating in the mouth of a subject, and defines a bite portion for enabling a subject to bite thereon. In another embodiment of the invention the outlet port from the manifold extends from one of the proximal side flanges of the access device.

[0063] Preferably, the side flanges are adapted for engaging a head-strap for securing the access device in the mouth of a subject.

[0064] Preferably, a distal flange extends sidewardly outwardly from and circumferentially around the access device adjacent a distal end thereof.

[0065] In another embodiment of the invention the access device is adapted for locating in the anus of a subject, and the access device comprises an anus engaging element for engaging the anus of a subject.

[0066] Preferably, the proximal flange is engageable with the buttocks of the subject extends sidewardly outwardly from the access device adjacent the proximal end thereof for parting the buttocks of a subject.

[0067] In another embodiment of the invention the proximal flange diverges outwardly proximally from the proximal end of the access device.

[0068] In another embodiment of the invention the outlet port from the manifold extends from the proximal flange.

[0069] In one embodiment of the invention the outlet port from the manifold extends from the access device adjacent the proximal end thereof.

[0070] In an alternative embodiment of the invention the access device comprises a distal part and a proximal part, the proximal part comprising the communicating means located therein. Preferably, the proximal part of the access device is secured to the distal part thereof.

[0071] In one embodiment of the invention the proximal part is secured to the distal part with the instrument channel extending through the proximal and distal parts aligned with each other.

[0072] In another embodiment of the invention the proximal flange of the access device extends from a proximal end of the proximal part of the access device. Alternatively, the proximal flange of the access device extends from a distal end of the proximal part of the access device.

[0073] In one embodiment of the invention an instrument extends through the instrument channel of the access device into the cavity, or through one or more vessels or lumens into the cavity. Preferably, the instrument comprises an endoscope or a colonoscope.

[0074] In one embodiment of the invention the flow controller is connected to one of the channels extending through the endoscope or the colonoscope for insufflating the cavity.

[0075] In another embodiment of the invention the pressure sensor is connected to one of the channels extending through the endoscope or the colonoscope for monitoring the cavity pressure. Preferably, the flow controller is connected to an insufflating channel, an instrument channel or a vacuum channel of the insufflator or the colonoscope, and the pressure sensor is connected to the other one of the insufflating channel, the instrument channel or the vacuum channel.

[0076] In another embodiment of the invention the flow controller is connected to the insufflating channel or the instrument channel of the endoscope or the colonoscope, and the pressure sensor is connected to the other one of the insufflating channel and the instrument channel of the endoscope or the colonoscope. Alternatively, the flow controller and the pressure sensor are connected to the same channel of the endoscope or the colonoscope.

[0077] In one embodiment of the invention the flow controller is connected to an insufflating channel of the endoscope or the colonoscope.

[0078] In another embodiment of the invention the pressure sensor is connected to the instrument channel of the endoscope or the colonoscope.

[0079] In another embodiment of the invention the signal processor is programmed to control the flow controller in response to the signal produced by the pressure sensor to maintain the cavity pressure at the set pressure value.

[0080] In one embodiment of the invention the cavity comprises the stomach of the subject. In another embodiment of the invention the cavity comprises the rectum or the colon of the subject.

[0081] In one embodiment of the invention the set pressure value lies in the range of 2mmHg to 20mmHg, and preferably, the set pressure value lies in the range of 7mmHg to 15mmHg, and advantageously, the set pressure value is approximately lOmmHg.

[0082] In another embodiment of the invention the set pressure is selectable in the range of 2mmHg to 20mmHg.

[0083] In one embodiment of the invention the flow controller is adapted for connecting to an external source of insufflating gas, and preferably, to a hospital supply of insufflating gas.

[0084] In another embodiment of the invention the vacuum applying means is adapted for connecting to an external vacuum source, and preferably, to a hospital vacuum source.

[0085] In one embodiment of the invention the insufflator comprises a first inlet port and a first outlet port, the flow controller being located in a path between the first inlet port and the first outlet port.

[0086] Preferably, the first inlet port is adapted for connecting to a pressurised source of insufflating gas.

[0087] Advantageously, the first outlet port is adapted for connecting to one of the channels of the endoscope or the colonoscope.

[0088] In another embodiment of the invention the insufflator comprises a second inlet port, and the vacuum applying means is connected to the second inlet port. Preferably, the second inlet port is adapted for connecting to the outlet port of the communicating means.

[0089] In another embodiment of the invention the insufflator comprises a second outlet port, the second outlet port being adapted for connecting to an external vacuum source.

[0090] In one embodiment of the invention the vacuum applying means is located in a path between the second inlet port and the second outlet port.

[0091] In another embodiment of the invention the insufflator comprises a third inlet port, the pressure sensor being connected to the third inlet port.

[0092] Preferably, the third inlet port is adapted for connecting to one of the channels of the endoscope or the colonoscope.

[0093] In another embodiment of the invention the vacuum applying means comprises a vacuum pump or a vacuum control valve, the vacuum pump or the vacuum control valve being infinitely variable, to produce a vacuum at infinitely variable vacuum levels.

[0094] The invention also provides an access device for accommodating an instrument through a bodily orifice into a cavity in the body of a human or animal subject during carrying out of a minimally invasive procedure therein, the access device being engageable in the bodily orifice and extending between a proximal end and a distal end and having an instrument channel extending therethrough from the proximal end to the distal end thereof for accommodating the instrument therethrough to the cavity, and comprising a communicating means adapted to receive a first vacuum at an extraction vacuum level and to apply the first vacuum to the cavity for drawing insufflating gas and smoke from the cavity.

[0095] Additionally, the invention also provides a method for insufflating a cavity in the body of a human or animal subject, the method comprising: inserting an access device into a bodily orifice of the subject through which the cavity is accessible, the access device extending between a proximal end and a distal end and having an instrument channel extending therethrough between the proximal and distal ends thereof for accommodating an endoscope or a colonoscope therethrough to the cavity, the access device comprising a communicating means adapted to communicate with the cavity through the access device, inserting the endoscope or the colonoscope through the instrument channel of the access device into the cavity, insufflating the cavity by delivering insufflating gas to the cavity through a channel extending through the endoscope or the colonoscope, and applying a first vacuum at an extraction vacuum level to the cavity through the communicating means in response to the cavity pressure exceeding a set pressure value or in response to a smoke evacuate signal for drawing gases and / or smoke from the cavity through the access device.

[0096] In one embodiment of the invention the first vacuum at the extraction vacuum level is applied to the cavity through the communicating means until the cavity pressure has fallen to the set pressure value, or until termination of the smoke evacuate signal.

[0097] In another embodiment of the invention the delivery of insufflating gas to the cavity is controlled while the first vacuum at the extraction vacuum level is being applied to the cavity through the communicating means.

[0098] Preferably, the delivery of insufflating gas to the cavity is controlled while the first vacuum at the extraction vacuum level is being applied to the cavity through the communicating means in response to the smoke evacuate signal for maintaining the cavity pressure substantially at the set pressure value.

[0099] Advantageously, delivery of insufflating gas to the cavity is increased in response to the cavity pressure falling below the set pressure value when the first vacuum at the extraction vacuum level is being applied to the cavity through the communicating means in response to the smoke evacuate signal to maintain the cavity pressure at the set pressure value.

[0100] In one embodiment of the invention delivery of insufflating gas to the cavity is reduced or paused in response to the cavity pressure exceeding the set pressure value when the first vacuum at the extraction vacuum level is being applied to the cavity in response to the cavity pressure exceeding the set pressure value.

[0101] In one embodiment of the invention the first vacuum is produced by a vacuum applying means, and the vacuum applying means is operable in a first state thereof to produce the first vacuum at at least two selectable extraction vacuum levels.

[0102] In another embodiment of the invention the vacuum applying means is operable in the first state thereof to produce the first vacuum at a plurality of selectable extraction vacuum levels.

[0103] Preferably, the extraction vacuum level at which the first vacuum is applied to the cavity through the communicating means is selected from the selectable extraction vacuum levels thereof in response to the cavity pressure when the first vacuum is being applied to the cavity in response to the cavity pressure exceeding the set pressure value, so that the greater the amount by which the cavity pressure exceeds the set pressure value, the greater will be the extraction vacuum level of the first vacuum. Preferably, the smoke evacuate signal is produced by a smoke evacuate signal producing means.

[0104] Advantageously, the smoke evacuate signal producing means is adapted to produce the smoke evacuate signal indicative of the selectable extraction vacuum level at which the vacuum applying means operating in the first state thereof is to produce the first vacuum.

[0105] In another embodiment of the invention the smoke evacuate signal is indicative of the selectable extraction vacuum level at which the first vacuum is to be applied to the cavity through the communicating means, and the extraction vacuum level at which the first vacuum is applied to the cavity through the communicating means is selected from the selectable extraction vacuum levels thereof in response to the smoke evacuate signal.

[0106] In another embodiment of the invention a second vacuum at a collecting vacuum level of value less than the extraction vacuum level or the lowest level of the selectable extraction vacuum levels of the first vacuum is applied to the communicating means for collecting gases and / or smoke escaping from the cavity through or adjacent the access device in response to the signal produced by the pressure sensor being indicative of the cavity pressure being at or below the set pressure value or the termination or the absence of the smoke evacuate signal.

[0107] Preferably, the collecting vacuum level of the second vacuum comprises a vacuum level insufficient to draw gases and / or smoke from the cavity but sufficient to draw gases and / or smoke escaping from the cavity through or adjacent the access device.

[0108] In another embodiment of the invention the communicating means comprises a manifold, an outlet port communicating with the manifold, the first vacuum or the second vacuum being applied to the outlet port, and at least one first inlet port communicating with the manifold for applying the first vacuum or the second vacuum adjacent the access device.

[0109] Preferably, the manifold is located in the access device, and the at least one first inlet port for applying the first vacuum or the second vacuum adjacent the access device extends from the manifold and terminates in the access device in the instrument channel communicating with the instrument channel, or terminates adjacent a distal end of the access device with the at least one first inlet port facing distally from the access device.

[0110] Advantageously, a plurality of the first inlet ports are provided spaced apart circumferentially around the access device.

[0111] In one embodiment of the invention at least one second inlet port extends from the manifold and terminates in an outer surface of the access device.

[0112] Preferably, the manifold extends circumferentially around the access device within the access device.

[0113] Advantageously, a sealing means is located in the instrument channel of the access device, the sealing means being adapted to slideably and sealably engage the endoscope or the colonoscope extending through the instrument channel.

[0114] Preferably, the sealing means comprises a sealing membrane extending into the instrument channel, and terminating in an instrument accommodating opening for slideably and sealably engaging the endoscope or the colonoscope.

[0115] Advantageously, the sealing means is located proximally of the at least one first inlet port.

[0116] In one embodiment of the invention the access device is adapted for locating in the mouth of a subject, and defines a bite portion for enabling a subject to bite thereon.

[0117] Preferably, the access device is secured to the mouth of the subject by a head-strap.

[0118] Advantageously, the access device is engageable with the anus of a subject for accommodating an endoscope or a colonoscope through the anus.

[0119] In another embodiment of the invention the access device comprises a distal part and a proximal part, and the proximal part comprises the communicating means located therein.

[0120] Preferably, the proximal part is secured to the distal part with the instrument channel extending through the proximal and distal parts aligned with each other. In one embodiment of the invention the endoscope or the colonoscope is inserted into the cavity through the instrument channel of the access device, or through the instrument channel in the access device and through one or more vessels or lumens into the cavity.

[0121] In another embodiment of the invention the insufflating gas is delivered to the cavity through an insufflating channel, an instrument channel or a vacuum channel of the endoscope or the colonoscope.

[0122] In a further embodiment of the invention the cavity pressure is monitored through the insufflating channel, the instrument channel or the vacuum channel of the endoscope or the colonoscope.

[0123] In another embodiment of the invention the insufflating gas is delivered to the cavity through the insufflating channel or the instrument channel of the endoscope or the colonoscope, and the cavity pressure is monitored through the other one of the insufflating channel or the instrument channel.

[0124] In another embodiment of the invention the vacuum applying means is operated under the control of a signal processor to produce the first and second vacuum at the respective extraction vacuum level and the collecting vacuum level in response to the cavity pressure and the smoke evacuate signal.

[0125] Preferably, the insufflating gas is delivered to the cavity by a flow controller under the control of the signal processor in response to the cavity pressure or in response to the smoke evacuate signal.

[0126] Further, the invention provides an access device for use in the insufflating apparatus according to the invention.

[0127] Additionally, the invention provides an access device for use in the method according to the invention for insufflating a cavity in the body of a human or animal subject.

[0128] The advantages of the invention are many. By virtue of the fact that the first vacuum to draw gases and smoke from the cavity which is being insufflated in order to reduce the pressure in the cavity is applied through the access device, the number of channels in an endoscope or a colonoscope required to adequately insufflate the cavity, to monitor the pressure in the cavity and to control the pressure in the cavity is reduced. In particular, by virtue of the first vacuum being applied to the cavity through the access device, only two channels of the endoscope are required, one channel to insufflate the cavity, and one channel to monitor the pressure in the cavity. This is a particularly important advantage, in that it reduces the number of channels required in the endoscope or a colonoscope, and where only two channels are available, in the endoscope or in a colonoscope, for example, an insufflating channel and an instrument channel, the insufflating of the cavity and the monitoring of the pressure in the cavity may be accurately controlled due to the fact that the cavity pressure may be continuously monitored through one of the channels in the endoscope or the colonoscope, for example, insufflating of the cavity may be carried out through the insufflating channel and the cavity pressure may be monitored through the instrument channel of the endoscope or the colonoscope, or vice versa.

[0129] Another important advantage of the invention is that there is no interruption of insufflating of the cavity during smoke being evacuated from the cavity.

[0130] A further advantage of the invention is that any gases, smoke and pathogens and the like which would otherwise escape through the mouth or anus of a subject while the cavity is being insufflated and maintained at or below the set pressure value are collected by applying the second vacuum at the collecting vacuum level to the access device. This is a particular advantage, when a minimally invasive procedure is being carried out on a subject who may be infected with an infection or a virus, whereby pathogens associated with the infection or virus carried in insufflating and other gases escaping from the cavity being insufflated, which would otherwise escape through the mouth or anus, as the case may be, into the environment, are drawn by the second vacuum through the first and / or second inlet ports into the manifold of the access device, and are in turn drawn by the second vacuum into the insufflator where the insufflating gas and / or smoke is filtered where any pathogens associated with an infection or a virus are filtered out of any insufflating and other gasses before being returned to the environment.

[0131] The invention will be more clearly understood from the following description of some preferred embodiments thereof which are given by way of example only with reference to the accompanying drawings, in which:

[0132] Fig. 1 is a block representation of insufflating apparatus according to the invention for insufflating a cavity in the body of a human or animal subject,

[0133] Fig. 2 is a side elevational view of an access device also according to the invention of the insufflating apparatus of Fig. 1 ,

[0134] Fig. 3 is a top plan view of the access device of Fig. 2 of the insufflating apparatus of Fig. 1,

[0135] Fig. 4 is a cross-sectional front elevational view of the access device of Fig. 2 on the line IV-IV of Fig. 3 of the insufflating apparatus of Fig. 1,

[0136] Fig. 5 is a cross-sectional top plan view of the access device of Fig. 2 on the line V-V of Fig. 4 of the insufflating apparatus of Fig. 1,

[0137] Fig. 6 is a cross-sectional top plan view of the access device of Fig. 2 on the line VI-VI of Fig. 4 of the insufflating apparatus of Fig. 1,

[0138] Fig. 7 is a front view of a part of a subject illustrating the insufflating apparatus of Fig. 1 in use,

[0139] Fig. 8 is a block representation of insufflating apparatus according to another embodiment of the invention,

[0140] Fig. 9 is a front elevational view of an access device according to another embodiment of the invention of the insufflating apparatus of Fig. 8,

[0141] Fig. 10 is a top plan view of the access device of Fig. 9 of the insufflating apparatus of Fig. 8,

[0142] Fig. 11 is a cross-sectional side elevational view of the access device of Fig. 9 on the line XI-XI of Fig. 9 of the insufflating apparatus of Fig. 8,

[0143] Fig. 12 is a cross-sectional side elevational view of the access device and a colonoscope of the insufflating apparatus of Fig. 8 in use,

[0144] Fig. 13 is a front elevational view of an access device according to another embodiment of the invention of insufflating apparatus also according to another embodiment of the invention,

[0145] Fig. 14 is a top plan view of the access device of Fig. 13, Fig. 15 is a cross-sectional side elevational view of the access device of Fig. 13 on the line XV-XV of

[0146] Fig. 13,

[0147] Fig. 16 is a block representation of insufflating apparatus according to another embodiment of the invention,

[0148] Fig. 17 is a cross-sectional front elevational view of an access device according to another embodiment of the invention for use in insufflating apparatus also according to the invention,

[0149] Fig. 18 is a cross-sectional side elevational view of an access device according to a further embodiment of the invention for use in insufflating apparatus also according to the invention,

[0150] Fig. 19 is a perspective view of an access device according to a further embodiment of the invention,

[0151] Fig. 20 is a cross-sectional side elevational view of the access device of Fig. 19 on the line XX-XX of Fig. 19,

[0152] Fig. 21 is a perspective view of a portion of the access device of Fig. 19,

[0153] Fig. 22 is a cross-sectional side elevational view of the portion of Fig. 21 of the access device of Fig.

[0154] 19 on the line XXII-XXII of Fig. 21,

[0155] Fig. 23 is a perspective view of another part of the access device of Fig. 19, and

[0156] Fig. 24 is a block representation of insufflating apparatus according to a further embodiment of the invention.

[0157] Referring to the drawings and initially to Figs. 1 to 7 thereof, there is illustrated insufflating apparatus according to the invention indicated generally by the reference numeral 1 for insufflating a cavity in the body of a human or animal subject, in which a minimally invasive investigative or surgical procedure is being carried out through an endoscope or a colonoscope. In this embodiment of the invention the insufflating apparatus 1 is adapted for insufflating the stomach 3 of a subject 5 in which an endoscopic investigative or surgical procedure is being carried out. The insufflating apparatus 1 comprises an insufflator 7 for supplying insufflating gas to an endoscope 9, which is inserted orally into the stomach 3 through the oesophagus 8, for delivering the insufflating gas into the stomach 3 for insufflating thereof through the endoscope 9. The insufflating apparatus 1 also comprises an access device also according to the invention and indicated generally by the reference numeral 10. The access device 10 is adapted for locating in a bodily orifice of the subject to accommodate an instrument, for example, an endoscope or a colonoscope therethrough to the cavity in a subject. In this embodiment of the invention the access device 10 comprises a mouth engaging access device 10 for locating in the mouth 12 of the subject 5 for accommodating the endoscope 9 through the mouth 12 of the subject 5, and in turn into the oesophagus 8 to the stomach 3.

[0158] The mouth engaging access device 10 comprises a tubular member 14 extending between a proximal end 15 and a distal end 16. An instrument channel 18 extends through the tubular member 14 from the proximal end 15 to the distal end 16 for accommodating the endoscope 9 therethrough. The instrument channel 18 is of generally oval or elliptical cross-section and diverges outwardly from a position substantially midway between the proximal and distal ends 15 and 16 towards the proximal end 15 and the distal end 16 of the tubular member 14. A proximal flange 19 extends around and outwardly from the tubular member 14 adjacent the proximal end thereof. A pair of proximal side flanges 20 extend sidewardly outwardly from the proximal flange of the tubular member 16 adjacent opposite sides thereof. A distal flange 22 extends around the tubular member 14 adjacent the distal end 16 thereof. The tubular member 14 defines an outer surface 24 between the proximal flange 19 and the distal flange 22 which forms a bite area 25 for the teeth of the subject on which the subject may bite. The access device 10 is engaged in the mouth of the subject with the proximal flange 19 and the proximal side flanges 20 externally of the mouth of the subject 5 and abutting the lips thereof, and the distal flange 22 located within the mouth of the subject behind the teeth thereof.

[0159] A communicating means for communicating the access device 10 to a vacuum applying means for applying a vacuum to the access device 10 comprises a manifold 31 located in the access device 10. The vacuum applying means is located in the insufflator 7 and will be described below. The manifold 31 is formed by an annular chamber 32 extending circumferentially around the tubular member 14 towards the proximal end 15 thereof between the outer surface 24 of the tubular member 14 and an inner surface 33 which defines the instrument channel 18. At least one, and in this embodiment of the invention a plurality of first inlet ports 27 of the manifold 31 extend from the annular chamber 32 and terminate in the instrument channel 18 towards the proximal end 15 thereof and communicate the instrument channel with the annular chamber 32 for applying a vacuum to the instrument channel 18 when a vacuum is applied to the annular chamber 32 of the manifold 31, as will be described below. The first inlet ports 27 are spaced apart circumferentially around the instrument channel 18. An outlet port 29 extends from one of the proximal side flanges 20 and communicates with the annular chamber 32 of the manifold 31 through a communicating bore 30 extending through the corresponding one of the proximal side flanges 20. The outlet port 29 is adapted for connecting to the vacuum applying means of the insufflator 7, which as will be described below, applies vacuum to the outlet port 29 which in turn is applied to the instrument channel 18 of the access device 10 through the first inlet ports 27 as will be described below.

[0160] A sealing means comprising an annular sealing disc 34 is located in the instrument channel 18 of the access device 10 adjacent the proximal end 15 thereof for sealably and slideably engaging the endoscope 9 in the instrument channel 18. The annular sealing disc 34 comprises a flexible resilient material extending inwardly into the instrument channel 18 from the access device 10. An endoscope accommodating opening 36 extends through the annular sealing disc 34 for slideably and sealably engaging the endoscope 9 in the annular sealing disc 34. The annular sealing disc 34 is located adjacent the proximal end 15 of the access device 10 proximally of the first inlet ports 27, so that when a vacuum is applied to the first inlet ports 27, the full effect of the vacuum is applied to the instrument channel 18 with minimal leakage from the proximal end 15 of the instrument channel 18.

[0161] At least one, and in this embodiment of the invention a plurality of second inlet ports 35 are located in the outer surface 24 of the tubular member 14 and are spaced apart circumferentially around the tubular member 14 and communicate with the annular chamber 32 of the manifold 31, so that when a vacuum is applied to the outlet port 29, a vacuum is applied to the second inlet ports 35.

[0162] Before describing the access device 10 and its use in further detail, the insufflator 7 will now be described.

[0163] The insufflator 7 comprises a housing 37 illustrated in broken lines in Fig. 1. A flow controller 39 located in the housing 37 is connected between a first inlet port 40 in the housing 37 and a first outlet port 41 also in the housing 37. The first inlet port 40 is adapted for connecting to a pressurised insufflating gas source 43, which in this embodiment of the invention is provided by a hospital insufflating gas source, typically, a pressurised source of carbon dioxide. The insufflating gas from the insufflating gas source 43 is connected to the flow controller 39 through the first inlet port 40 and is delivered under the control of the flow controller 39 through the first outlet port 41 to the endoscope 9 through a first conduit 44. The first conduit 44 connects the flow controller 39 to an inlet port 56 of the endoscope 9, which in turn is connected to the insufflating channel 57 of the endoscope 9 for accommodating insufflating gas from the flow controller 39 through the insufflating channel 57 to the stomach 3 of the subject 5 for insufflating the stomach 3 as will be described below.

[0164] A second outlet port 45 in the housing 37 is adapted for connecting to a vacuum source 46, which in this embodiment of the invention comprises a vacuum source of a hospital. The vacuum applying means, in this embodiment of the invention comprising a three-state vacuum control valve 47 is located in the housing 37, and is connected between the second outlet port 45 and a second inlet port 49. The vacuum control valve 47 is connected through the second inlet port 49 and through a second conduit 48 to the outlet port 29 of the mouth engaging access device 10 for applying vacuum to the first and second inlet ports 27 and 35 of the access device 10.

[0165] The vacuum control valve 47 is selectively operable in a first state for applying a first vacuum at an extraction vacuum level to the outlet port 29 of the access device 10, in a second state for applying a second vacuum at a collecting vacuum level to the outlet port 29 of the access device 10, and in a third state for isolating the outlet port 29 of the access device 10 from the vacuum source 46. The operation of the vacuum control valve 47 will be described in detail below. The extraction vacuum level of the first vacuum is a strong vacuum for drawing gases and smoke from the stomach 3 through the oesophagus 8 and through the first and second inlet ports 27 and 35, respectively, of the access device 10. In this case the extraction vacuum level of the first vacuum is such that insufflating gas and other gases and / or smoke are drawn from the stomach 5 at a flow rate of between 3 Litres per minute and 5 Litres per minute. The second vacuum at the collecting vacuum level is a weak vacuum for drawing and collecting gases escaping from the stomach 3 through the access device 10 through the first and second inlet ports 27 and 35 thereof. In this case, the collecting vacuum level is approximately 300mmHg below atmospheric pressure, and is sufficient for collecting escaping gases escaping from the stomach 3 through the instrument channel 18 of the access device 10 and between the access device 10 and the mouth of the subject, but is insufficient fordrawing gases or smoke from the stomach 3 of the subject 5.

[0166] In this embodiment of the invention the vacuum control valve 47 in the first state thereof is adapted to apply the vacuum from the vacuum source 46 at the extraction vacuum level so that insufflating gas and other gases and / or smoke are drawn from the stomach 5 through the oesophagus 9 and the access device 10 at the flow rate of between 3 Litres per minute and 5 Litres per minute. The vacuum control valve 47 in the second state thereof is adapted to apply the vacuum from the vacuum source 46 to the outlet port 29 of the access device 10 as the second vacuum through a restrictor (not shown) in the vacuum control valve 47 for reducing the vacuum to the collecting vacuum level of approximately 300mmHg below atmospheric pressure.

[0167] A filter 55 located in the housing 37 of the insufflator 7 between the vacuum control valve 47 and the second outlet port 45 filters out gases, smoke and pathogens drawn from the access device 10 by the vacuum control valve 47. Although, in some embodiments of the invention the filter 55 may be located between the vacuum control valve 47 and the second inlet port 49, and in other embodiments of the invention the filter 55 may be located in the second conduit 48. Alternatively, the filter may be located between the insufflator 7 and the vacuum source 46.

[0168] A pressure sensor 50 is located in the housing 37 of the insufflator 7 and is connected to a third inlet port 51 in the housing 37. A third conduit 52 connects the third inlet port 51 to the endoscope 9 for communicating the pressure sensor 50 with the stomach 3 of the subject 5 for monitoring the cavity pressure, in this case the stomach pressure through the endoscope 9. In this embodiment of the invention the third conduit 52 is connected to the instrument channel 60 of the endoscope 9 through an inlet port 61 , so that the pressure sensor 50 may continuously monitor the stomach pressure through the endoscope 9. If the endoscope 9 comprises a vacuum channel, the third conduit 52 would be connected to the vacuum channel instead of to the instrument channel. The pressure sensor 50 is adapted to produce a signal indicative of the stomach pressure. Alternatively, the pressure sensor 50 may be adapted to monitor the cavity pressure through the insufflating channel 57 of the endoscope 9 for monitoring cavity pressure through the insufflating channel 57. However, when the pressure sensor 50 is connected to the insufflating channel 57 of the endoscope 9 and the stomach 3 is being insufflated also through the insufflating channel 57 of the endoscope 9, the flow controller 59 is operated to isolate the insufflating channel 57 from the insufflating gas source 43 intermittently so that the signal produced by the pressure sensor 50 is indicative of the pressure in the stomach 3.

[0169] A signal processor, in this embodiment of the invention a microprocessor 53 located in the housing 37 controls the operation of the insufflator 7. An interface 54, which may be any suitable interface, but in this embodiment of the invention comprises a touchscreen interface, is adapted for entering data into the microprocessor 53 and for displaying data under the control of the microprocessor 53 relating to the insufflating of the stomach 3, and images relating to the carrying out of the procedure. In particular, the interface is adapted for inputting a selectable set pressure value within the range of 2mmHg to 20mmHg to which the stomach 3 is to be insufflated, and which in this embodiment of the invention is approximately 10mmHg.

[0170] The microprocessor 53 is programmed to read the signal produced by the pressure sensor 50 indicative of the stomach pressure and to operate the flow controller 39 for controlling delivery of insufflating gas to the stomach 3 for maintaining the stomach pressure at the set pressure value. For so long as the signal read from the pressure sensor 50 is indicative of the stomach pressure being at or below the set pressure value, the microprocessor 53 operates the vacuum control valve 47 in the second state for applying the second vacuum at the collecting vacuum level of approximately 300mmHg below atmospheric pressure to the outlet port 29 of the access device 10 for collecting gases escaping from the stomach 3 through the instrument channel 18 of the access device 10 and between the access device 10 and the mouth 12 of the subject.

[0171] The microprocessor 53 is responsive to the signal read from the pressure sensor 50 being indicative of the stomach pressure exceeding the set pressure value to operate the vacuum control valve 47 from the second state into the first state for producing the first vacuum at the extraction vacuum level which is applied to the outlet port 29 of the access device 10 fordrawing insufflating gas and other gases including smoke at the flow rate of 3 Litres per minute to 5 Litres per minute from the stomach 3 through the oesophagus 8 and the first and second inlet ports 27 and 35 of the access device 10, in order to reduce the stomach pressure to the set pressure value. The stomach pressure may rise above the set pressure value as a result of any one of a number of procedures, which may be carried out in the stomach, for example, a cryogenic procedure, a cauterising procedure such as an argon plasma coagulation procedure, or other cavity pressure increasing procedures which will be well known to those skilled in the art.

[0172] When the microprocessor 53 is operating the vacuum control valve 47 in the first state thereof in response to the signal produced by the pressure sensor 50 being indicative of the stomach pressure exceeding the set pressure value, the microprocessor also operates the flow controller 39 to reduce or pause the supply of insufflating gas to the stomach 3 until the stomach pressure has been reduced to the set pressure value. Once the stomach pressure has been reduced to or below the set pressure value, the microprocessor 53 operates the vacuum control valve 47 into the second state to apply the second vacuum at the collecting vacuum level to the outlet port 29 of the access device 10 to collect gases and / or smoke escaping from the cavity through the access device 10, and the microprocessor 53 operates the flow controller 39 to again control delivery of the insufflating gas to the stomach 3 for maintaining the stomach pressure at the set pressure value.

[0173] Additionally, when the microprocessor 53 is operating the vacuum control valve 47 in the first state thereof in response to the stomach pressure exceeding the set pressure value, the microprocessor 53 operates the vacuum control valve 47 in the first state thereof for a series of predefined vacuum on time periods of approximately 1.5 seconds, each of which is followed by a predefined vacuum off time period of approximately 0.5 seconds. During each predefined vacuum off time period, the microprocessor 53 operates the vacuum control valve 47 into the isolating state isolating the outlet port 29 of the access device 10 from the vacuum source 46, in order to reduce the cavity pressure in incremental steps. During each predefined vacuum off time period, the microprocessor 53 reads the signal indicative of the cavity pressure from the pressure sensor 50, and if the cavity pressure is still above the set pressure value, the microprocessor 53 operates the vacuum control valve 47 in the first state thereof for the next predefined vacuum on time period, and so on, until the cavity pressure has been reduced to or below the set pressure value. At which stage, the microprocessor 53 returns the vacuum control valve 47 from the first state to the second state thereof, and operates the flow controller 39 to maintain the stomach pressure at the set pressure value.

[0174] While in this embodiment of the invention each predefined vacuum on time period has been described as being approximately 1.5 seconds, in some embodiments of the invention each predefined vacuum on time period may range from 1 second to 3 seconds. While each predefined vacuum off time period has been described as being approximately 0.5 seconds, in some embodiments of the invention each predefined vacuum off time period may range from 0.10 seconds to 0.75 seconds.

[0175] A smoke evacuate signal producing means, which in this case comprises a foot pedal operated electrical mono-stable bi-state switch 62 operable by a foot pedal 63, is located externally of the housing 37, and is provided to enable inputting of a smoke evacuate signal to the microprocessor 53 by a surgeon or clinician to operate the insufflator 7 for drawing smoke from the stomach 3 during, for example, a tissue cauterising procedure in the stomach 3. The foot pedal operated switch 62 comprises a normally open electrical switch, which is stable in the open circuit state and is unstable in the closed circuit state. Operating of the foot pedal switch 62 into the closed circuit state produces the smoke evacuate signal, and for so long as the foot pedal switch 62 is maintained in the closed circuit state, the foot pedal operated switch 62 produces the smoke evacuate signal. The microprocessor 53 reads signals from the foot pedal operated switch 62, and on detecting the smoke evacuate signal, the microprocessor 53 operates the vacuum control valve 47 from the second state to the first state in order to apply the first vacuum at the extraction vacuum level to the access device 10 for drawing insufflating gas and smoke from the stomach 3 through the oesophagus 8 and the access device 10 at the flow rate of 3 Litres per minute to 5 Litres per minute. Simultaneously with operating the vacuum control valve 47 from the second state to the first state in response to the smoke evacuate signal, the microprocessor 53 operates the flow controller 39 to increase delivery of insufflating gas to the stomach 3 in order to maintain the stomach pressure at the set pressure value, to in turn increase the flow of insufflating gas through the stomach 3, in order to rapidly remove smoke from the stomach 3. The microprocessor 53 is programmed to operate the vacuum control valve 47 in the first state continuously and to operate the flow controller 39 for maintaining the stomach pressure at the set pressure value until the smoke evacuate signal is terminated by operating the foot pedal operated switch 62 from the closed circuit state to the open circuit state.

[0176] Alternatively, the microprocessor 53 may be programmed to read each alternate operation of the foot pedal operated switch 62 as a signal indicative of the commencement of the smoke evacuate signal, and each other alternate operation of the foot pedal operated switch 62 as a signal indicative of termination of the smoke evacuate signal. For example, the microprocessor 53 would be programmed to interpret a signal from a first operation of the foot pedal operated switch 62 from the open circuit state to the closed circuit state and back to the open circuit state as the commencement of the smoke evacuate signal, and a signal from a second operation of the foot pedal operated switch 62 from the open circuit state to the closed circuit state and back to the open circuit state as the termination of the smoke evacuate signal. An advantage of programming the microprocessor 53 to read each alternate operation of the foot pedal operated switch 62 as commencement of one of the smoke evacuate signals, and each other alternate operation of the foot pedal operated switch 62 as termination of the smoke evacuate signal, is that it avoids the need for the surgeon or clinician to maintain the foot pedal operated switch 62 depressed in the closed circuit state to indicate to the microprocessor 53 that the smoke evacuate signal is active.

[0177] The microprocessor 53 is programmed to be responsive to a collecting vacuum isolating signal for preventing the second vacuum at the collecting vacuum level being applied to the outlet port 29 of the access device 10. The touchscreen interface 54 is adapted to permit inputting of the collecting vacuum isolating signal to the microprocessor 53. The microprocessor 53 in response to the collecting vacuum isolating signal being inputted through the touchscreen interface 54 operates the vacuum control valve 47 in two states only, namely, in the isolating state to isolate the outlet port 29 of the access device 10 from the vacuum source 46, and in the first state to apply the first vacuum at the extraction vacuum level to the outlet port 29 of the access device 10. Accordingly, when the collecting vacuum isolating signal is inputted to the microprocessor 53, and when the microprocessor 53 is operating the flow controller 39 to maintain the stomach pressure at the set pressure value and the microprocessor 53 is not operating the vacuum control valve 47 in the first state, and the stomach pressure is at or below the set pressure value, the microprocessor 53 maintains the vacuum control valve 47 in the isolating state, thereby the second vacuum at the collecting vacuum level not applied to the outlet port 29 of the access device 10 for collecting gases escaping from the stomach through the access device 10.

[0178] The collecting vacuum isolating signal is terminated by inputting a collecting vacuum isolating termination signal into the microprocessor 53 through the touchscreen interface 54. On receipt of the collecting vacuum isolating termination signal, the microprocessor 53 again operates the vacuum control valve 47 in the second state to apply the second vacuum at the collecting vacuum level to the outlet port 29 of the access device 10 when the microprocessor 53 is operating the flow controller 39 to maintain the stomach pressure at the set pressure value and the stomach pressure is at or below the set pressure value.

[0179] In use, the access device 10 is located in the mouth 12 of the subject 5 so that the subject bites on the bite area 25 thereof with his or her teeth. The proximal flange 19 is located externally of the lips of the subject, and the distal flange 22 is located in the mouth of the subject rearwardly of the teeth of the subject. The endoscope 9 is then inserted through the access device 10 with the annular sealing disc 34 slideably engaging the endoscope 9, and then through the mouth 12 and the oesophagus 8 of the subject 5 into the stomach 3 thereof. The insufflator 7 is connected to the insufflating gas source 43 and to the vacuum source 46 through the first inlet port 40 and the second outlet port 45, respectively. The first outlet port 41 is connected to the inlet port 56 of the insufflating channel 57 of the endoscope 9 through the first conduit 44. The second inlet port 49 is connected to the outlet port 29 of the access device 10 through the second conduit 48. The third inlet port 51 of the insufflator 7 is connected to the inlet port 61 of the instrument channel 60 of the endoscope 9 through the third conduit 52. With the insufflator 7 so connected, the insufflating apparatus 1 is ready for use.

[0180] The set pressure value to which the stomach 3 is to be insufflated is entered through the interface 54 to the microprocessor 53. The microprocessor 53 initially operates the flow controller 39 to deliver the insufflating gas to the stomach 3 of the subject 5, and reads the signal from the pressure sensor 50 indicative of the stomach pressure, and operates the flow controller 39 to maintain the stomach pressure at the set pressure value. Provided the collecting vacuum isolating signal has not been entered into the microprocessor 53 through the touch screen interface 54, for so long as the microprocessor 53 is operating the flow controller 39 to maintain the stomach pressure at the set pressure value, the microprocessor 53 operates the vacuum control valve 47 in the second state to apply the second vacuum at the collecting vacuum level to the outlet port 29 of the access device 10 for collecting gases escaping from the stomach 3 through the access device 10. On the stomach pressure exceeding the set pressure value, the microprocessor 53 operates the vacuum control valve 47 from the second state to the first state to apply the first vacuum at the extraction vacuum level to the outlet port 29 of the access device 10 for drawing insufflating gas and any smoke which may exist from the stomach through the oesophagus 8 and the access device 10 at the flow rate of 3 Litres per minute to 5 Litres per minute in order to reduce the stomach pressure to the set pressure value. Additionally, while operating the vacuum control valve 47 in the first state in response to the stomach pressure exceeding the set pressure value, the microprocessor 53 operates the flow controller 39 to reduce or pause delivery of insufflation gas to the stomach until the stomach pressure has been reduced to the set pressure value. When the microprocessor 53 is operating the vacuum control valve 47 in the first state in response to the stomach pressure exceeding the set pressure value, the microprocessor 53 operates the vacuum control valve 47 for the predefined vacuum on time periods and the predefined vacuum off time periods until the stomach pressure is reduced to the set pressure value. At that stage, the microprocessor 53 operates the vacuum control valve 47 from the first state to the second state to apply the second vacuum at the collecting vacuum level to the outlet port 29 of the access device 10, and operates the flow controller 39 to maintain the stomach pressure at the set pressure value.

[0181] On a smoke evacuate signal being inputted to the microprocessor 53 by operating the foot pedal operated switch 62 from the open circuit state to the closed circuit state, the microprocessor 53 operates the vacuum control valve 47 from the second state to the first state to apply the first vacuum at the extraction vacuum level to the outlet port 29 of the access device 10 to draw insufflating gas and smoke from the stomach 3 at the flow rate of 3 Litres per minute to 5 Litres per minute. Simultaneously, the microprocessor 53 operates the flow controller 39 to increase the rate of delivery of insufflating gas to the stomach 3 in order to maintain the stomach pressure at the set pressure value. Thereby the flow of insufflating gas is significantly increased through the stomach 3 in order to rapidly remove insufflating gas and smoke from the stomach through the access device. On termination of the smoke evacuate signal by returning the foot pedal operated switch 62 from the closed circuit state to the open circuit state, the microprocessor 53 operates the vacuum control valve 47 from the first state to the second state in order to apply the second vacuum at the collecting vacuum level to the outlet port 29 of the access device 10, and operates the flow controller 39 to maintain the stomach pressure at the set pressure value.

[0182] If at the commencement of operation of the insufflating apparatus 1 or during operation of the insufflating apparatus 1 the collecting vacuum isolating signal is inputted to the microprocessor 53 through the touchscreen interface 54, the second vacuum is not applied to the access device. In other words while the microprocessor 53 is operating the flow controller 39 to maintain the stomach pressure at the set pressure value, and the stomach pressure remains at or below the set pressure value, the microprocessor 53 operates the vacuum control valve 47 into the isolating state in order to isolate the outlet port 29 of the access device 10 from the vacuum source 46. The microprocessor 53 continues to operate the vacuum control valve 47 in the isolating state to prevent the second vacuum being applied to the outlet port 29 of the access device 10 until the collecting vacuum isolating signal has been terminated.

[0183] Referring now to Figs. 8 to 12 there is illustrated insufflating apparatus according to the invention indicated generally by the reference numeral 70. The insufflating apparatus 70 in this embodiment of the invention is adapted for insufflating the rectum 72 or the colon 73 through the anus 75 during a minimally invasive colonoscopy investigative or surgical procedure being carried out in the rectum 72 or the colon 73. The insufflating apparatus 70 is substantially similar to the insufflating apparatus 1, and similar components are identified by the same reference numerals. The main difference between the insufflating apparatus 70 and the insufflating apparatus 1 lies in the access device for providing access through the anus 75 for a colonoscope 77.

[0184] In this embodiment of the invention the access device comprises an anal access device also according to the invention indicated generally by the reference numeral 79. The anal access device 79 is adapted for engaging in the anus 75 of the subject, and comprises a tubular member 80 of circular transverse crosssection extending between a proximal end 81 and a distal end 82. An instrument channel 84 extends through the tubular member 80 from the proximal end 81 to the distal end 82 for accommodating the colonoscope 77 therethrough into the rectum 72 and / or colon 73, in which the procedure is to be carried out. A proximal flange 85, in this embodiment of the invention a frustoconical flange, extends around the proximal end 81 of the tubular member 80 and diverges proximally in an axial direction from the tubular member 80. The function of the proximal frustoconical flange 85 is to part the cheeks 86 of the buttocks 88 of the subject 5, to provide an easy access lead-in for the colonoscope 77 into the instrument channel

[0185] 84 of the access device 79.

[0186] Like the access device 10, the access device 79 comprises a manifold 87 formed by an annular chamber 90 similar to the annular chamber 32 of the manifold 31 of the access device 10 which extends circumferentially around the tubular member 80 between an inner surface 91 defining the instrument channel 84 and an outer surface 92 of the tubular member 80 which engages the anus 75. A plurality of first inlet ports 89 extend from and communicate with the annular chamber 90 of the manifold 87, and terminate in the instrument channel 84. The first inlet ports 89 are equi-spaced apart circumferentially around the instrument channel 84 adjacent the proximal end 81 thereof, and communicate the instrument channel 84 with the annular chamber 90 of the manifold 87. An outlet port 94 extends from the proximal flange 85 adjacent the proximal end 81 of the tubular member 80, and is connected to the annular chamber 90 of the manifold 87 through a communicating bore 95 extending through a part of the proximal flange 85 from the outlet port 94 to the annular chamber 90, so that on a vacuum being applied to the outlet port 94, the vacuum is applied to the first inlet ports 89 for drawing gases from the instrument channel 84.

[0187] A sealing means comprising an annular sealing disc 96 is located in the instrument channel 84 for slideably and sealably engaging the colonoscope 77 in the instrument channel 84. The annular sealing disc 96, like the annular sealing disc 34 of the access device 10 comprises a flexible resilient material extending around the instrument channel 84 inwardly from the access device 79. A colonoscope accommodating opening 98 extends through the annular sealing disc 96 for slideably and sealably engaging the colonoscope 77 in the instrument channel 84. The annular sealing disc 96 is located adjacent the proximal end 81 of the instrument channel 84 and is spaced apart proximally from the first inlet ports 89, so that when a vacuum is applied to the first inlet ports 89, the full effect of the vacuum is applied to the instrument channel 84 with minimal leakage from the proximal end 81 of the instrument channel 84.

[0188] A plurality of second inlet ports 97 are located spaced apart circumferentially around the outer surface 92 of the tubular member 80 adjacent the proximal end 81 thereof, which also communicate with the annular chamber 90 of the manifold 87, so that when a vacuum is applied to the outlet port 94 the vacuum is applied to the second inlet ports 97. Although, it is envisaged that when either the first vacuum at the extraction vacuum level or the second vacuum at the collecting vacuum level is applied to the outlet port 94 of the access device 79, tissue of the anus 75 may be drawn into the second inlet ports 97, thereby closing the second inlet ports 97, and in some embodiments of the invention it is envisaged that the second inlet ports 97 may be omitted from the access device 79.

[0189] The outlet port 94 of the access device 79 is connected to the second inlet port 49 of the insufflator 7 by a second conduit 99 similar to the second conduit 48 of the insufflating apparatus 1, for in turn connecting the outlet port 94 of the access device 79 to the vacuum control valve 47, so that depending on the operating state of the vacuum control valve 47, the first vacuum at the extraction vacuum level or the second vacuum at the collecting vacuum level is applied to the outlet port 94, or the outlet port 94 may be isolated from the vacuum source 46. Thus, when the vacuum control valve 47 is operating in the first state, the first vacuum at the extraction vacuum level is applied to the outlet port 94 of the access device 79 to draw insufflating and other gases and smoke from the rectum 72 and / or the colon 73, in which the procedure is being carried out, at the flow rate of 3 Litres per minute to 5 Litres per minute through the first inlet ports 89 and possibly the second inlet ports 97 of the access device 79 and in turn through the outlet port 94. When the vacuum control valve 47 is operating in the second state thereof, the second vacuum at the collecting vacuum level is applied to the outlet port 94 of the access device 79, for in turn drawing gases escaping from the rectum 72 and / or the colon 73 through the instrument channel 84 of the access device 79 and between the access device 79 and the anus 75 through the first and second inlet ports 89 and 97 and in turn through the outlet port 94 of the access device 79.

[0190] The flow controller 39 of the insufflator 7 is connected through the first outlet port 41 of the insufflator 7 by a first conduit 100 through an inlet port 102 to the insufflating channel 104 of the colonoscope 77 for insufflating the rectum 72 or colon 73 or both depending on where the procedure is being carried out.

[0191] The pressure sensor 50 of the insufflator 7 is connected to an instrument channel 105 through an inlet port 107 of the colonoscope 77 by a third conduit 106 extending from the third inlet port 51 to the inlet port 107 to the instrument channel 105. Alternatively, the third conduit 106 may be connected to a vacuum channel of the colonoscope, so that the pressure in the colon or rectum could be monitored through the vacuum channel, if the colonoscope included a vacuum channel.

[0192] Use of the insufflating apparatus 70 for insufflating either the rectum 72 or the colon 73 or both of a subject, is substantially similar to insufflating the stomach 3 of a subject 5 by the insufflating apparatus 1 of Figs. 1 to 7, as already described. The set pressure value to which the rectum or colon or both are to be insufflated is entered into the microprocessor 53 through the interface 54. With the access device 79 entered into the anus 75 and with the proximal flange 85 parting the cheeks of the buttocks 88 of the subject 5, the colonoscope 77 is entered through the instrument channel 84 of the access device 79 with the colonoscope 77 slideably and sealably engaging the annular sealing disc 96, and then into the rectum

[0193] 72 or the colon 73.

[0194] Unless a collecting vacuum isolate signal is entered through the touch screen interface 54 or a smoke evacuate signal is entered into the microprocessor 53 through the foot pedal operated switch 62, the microprocessor 53 operates the flow controller 39 to deliver insufflating gas to the rectum 72 or the colon

[0195] 73 to maintain the pressure in the rectum 72 or the colon 73 at the set pressure value in response to the signal from the pressure sensor 50 indicative of the pressure in the rectum 72 and / or the colon 73. For so long as the pressure in the rectum 72 and / or the colon 73 is at or below the set pressure value, the microprocessor 53 operates the vacuum control valve 47 in the second state for applying the second vacuum at the collecting vacuum level to the outlet port 94 of the access device 79 for drawing gases escaping from the rectum 72 and / or the colon 73 through the access device 79.

[0196] On the signal read from the pressure sensor 50 being indicative of the pressure in the rectum 72 and / or the colon 73 exceeding the set pressure value, the microprocessor 53 operates the vacuum control valve 47 from the second state to the first state to apply the first vacuum at the extraction vacuum level to the outlet port 94 of the access device 79 for drawing insufflating and other gases as well as smoke if present from the rectum 72 and / or the colon 73 in order to reduce the pressure in the rectum 72 and / or the colon 73 to the set pressure value. Simultaneously with operating the vacuum control valve 47 in the first state in response to the pressure in the rectum 72 and / or the colon 73 exceeding the set pressure value, the microprocessor 53 operates the flow controller 39 to reduce or pause delivery of insufflating gas to the rectum 72 or the colon 73 to also reduce the pressure in the rectum 72 or the colon 73 to the set pressure value. The microprocessor 53 continues to retain the vacuum control valve 47 in the first state and continues to operate the flow controller 39 to deliver the insufflating gas at the reduced rate or paused until the pressure in the rectum 72 or the colon 73 has been reduced to the set pressure value. At which stage, the microprocessor 53 operates the vacuum control valve 47 into the second state and operates the flow controller 39 to maintain the pressure in the rectum 72 or the colon 73 at the set pressure value in response to the signal read from the pressure sensor 50.

[0197] In the event of the surgeon or clinician carrying out a cauterising procedure in the rectum 72 and / or the colon 73 or other smoke generating procedure, the surgeon or clinician operates the foot pedal switch 62 from the open circuit state to the closed circuit state to produce the smoke evacuate signal. On detecting the smoke evacuate signal from the foot pedal operated switch 62, the microprocessor 53 operates the vacuum control valve 47 from the second state to the first state to apply the first vacuum at the extraction vacuum level to the outlet port 94 of the access device 79. Simultaneously, the microprocessor 53 operates the flow controller 39 to increase the rate at which insufflating gas is being delivered to the colon 73 or the rectum 72 in order to maintain the cavity pressure at the set pressure value, thereby increasing the flow of insufflating gas through the rectum 72 or the colon 73 in order to rapidly remove the smoke from the rectum 72 or the colon 73. The microprocessor 53 maintains the vacuum control valve 47 in the first state and operates the flow controller 39 to maintain the pressure in the rectum 72 or the colon 73 at the set pressure value until the smoke evacuate signal has been terminated by releasing the foot pedal 63 to operate the foot pedal switch 62 from the closed circuit state to the open circuit state. At which stage, the microprocessor 53 operates the vacuum control valve 47 from the first state to the second state and operates the flow controller 39 to maintain the pressure in the rectum 72 or the colon 73 at the set pressure value in response to the signal read from the pressure indicative of the pressure in the rectum 72 or in the colon 73.

[0198] Like the insufflating apparatus 1 of Figs. 1 to 7, if the collecting vacuum isolating signal had been operated at the commencement of operation of the insufflating apparatus 70, or during operation of the insufflating apparatus 70, as described with reference to the insufflating apparatus 1 of Figs. 1 to 7, the microprocessor 53 would operate the vacuum control valve 47 in the isolating state during periods while the pressure in the rectum 72 or the colon 73 was at or below the set pressure value. Accordingly, the microprocessor 53 would only operate the vacuum control valve 47 between the isolating state during periods while the pressure in the rectum 72 or the colon 73 was at or below the set pressure value and the first state in response to the pressure in the rectum 72 or the colon 73 exceeding the set pressure value or in response to the smoke evacuate signal, until the collecting vacuum isolating signal had been terminated.

[0199] Otherwise, the use and operation of the insufflating apparatus 70 is similar to the use and operation of the insufflating apparatus 1.

[0200] Referring now to Figs. 13 to 15 there is illustrated an anal access device also according to the invention indicated generally by the reference numeral 110 for accommodating a colonoscope similar to the colonoscope 77 into the rectum or colon of a subject through the anus thereof, and may be used with the insufflating apparatus 70 described with reference to Figs. 8 to 12 instead of the access device 79. The anal access device 110 is substantially similar to the anal access device 79, and similar components are identified by the same reference numerals. The only difference between the access device 110 and the access device 79 is that instead of the access device 110 being provided with a proximal frustoconical flange 85, the access device 110 is provided with a proximal circular flange 112 extending outwardly and circumferentially around the tubular member 80 adjacent the proximal end thereof. Otherwise, the anal access device 110 is similar to the anal access device 79 and its use is likewise similar.

[0201] Referring now to Fig. 16 there is illustrated an insufflating apparatus according to another embodiment of the invention indicated generally by the reference numeral 120. The insufflating apparatus 120 is adapted for insufflating a cavity, in this case, the stomach of a subject during an endoscopic procedure similar to that described with reference to the insufflating apparatus 1 of Figs. 1 to 7. In this embodiment of the invention the insufflating apparatus 120 is substantially similar to the insufflating apparatus 1, and similar components are identified by the same reference numerals. The only difference between the insufflating apparatus 120 and the insufflating apparatus 1 is in the connection of the first outlet port 41 from the flow controller 40 to the endoscope 9, and the connection of the third inlet port 51 to the pressure sensor 50 to the endoscope 9. In this embodiment of the invention both the flow controller 39 and the pressure sensor 50 are connected through the first outlet port 41 and the third inlet port 51, respectively, through a single conduit 122 to the inlet port 56 of the insufflating channel 57 of the endoscope 9. The single conduit 122 is connected to the first outlet port 41 and the third inlet port 51 by a Y-connector 124.

[0202] Use of the insufflating apparatus 120 is similar to use of the insufflating apparatus 1 with the exception that in order to monitor the stomach pressure by the pressure sensor 50 through the insufflating channel of the endoscope 9, the microprocessor 53 operates the flow controller 39 to sequentially and alternately deliver insufflating gas to the stomach for predefined insufflating on time periods and to pause insufflating of the stomach for predefined insufflating off time periods. Each predefined insufflating on time period is approximately 1.5 seconds, and during each predefined insufflating on time period, the microprocessor 53 operates the flow controller 39 to deliver insufflating gas to the stomach to maintain the stomach pressure at the set pressure value. Each predefined insufflating off time period is approximately 0.5 seconds, and commences as the previous predefined insufflating on time period ends. During each predefined insufflating off time period, the microprocessor 53 operates the flow controller 39 in an off state to pause delivery of insufflating gas to the stomach in order to permit monitoring of the stomach pressure by the pressure sensor 50 through the insufflating channel of the endoscope 9. During each predefined insufflating off time period, the microprocessor 53 reads the signal from the pressure sensor 50 indicative of the stomach pressure, so that on commencement of the next predefined insufflating on time period, which commences as the current predefined insufflating off time period ends, the microprocessor 53 operates the flow controller 39 to deliver insufflating gas to the cavity in order to maintain the cavity pressure at the set pressure value.

[0203] During periods during which the microprocessor 53 is operating the vacuum control valve 47 in the first state to apply the first vacuum at the extraction vacuum level to the access device 10 in response to the smoke evacuate signal applied to the microprocessor 53 by the foot pedal operated switch 62, and in response to the stomach pressure exceeding the set pressure value, the microprocessor 53 also operates the flow controller 39 for consecutive and alternate predefined insufflating on time periods and predefined insufflating off time periods similar to the just described predefined insufflating on and off time periods during which the flow controller 39 is operated by the microprocessor 53 to deliver insufflating gas to the stomach during each predefined insufflating on time period and to operate the flow controller 39 to pause delivery of insufflating gas to the stomach during each predefined insufflating off time period. During each predefined insufflating off time period the microprocessor 53 reads the signal indicative of the stomach pressure from the pressure sensor 50, and on the predefined insufflating on time period, control the flow of insufflating gas to the cavity as appropriate depending on whether the vacuum control valve 47 is being operated in the first state in response to the smoke evacuate signal or in response to the stomach pressure exceeding the set pressure value.

[0204] In some embodiments of the invention it is envisaged that during each predefined insufflating off time period when the vacuum control valve 47 is being operated in the first state, the vacuum control valve 47 may also be operated in the isolating state for isolating the access device 10 and in turn the stomach from the insufflating source in order to permit more accurate measuring of the stomach pressure.

[0205] While each predefined insufflating on time period has been described as being approximately 1.5 seconds, it is envisaged that each predefined insufflating on time period may lie in the range of 1 second to 3 seconds. While each predefined insufflating off time period has been described as being approximately 0.5 seconds, it is envisaged that each predefined insufflating off time period may lie in the range of 0.10 seconds to 0.75 seconds. Otherwise, the operation of the insufflating apparatus 120 is similar to the operation of the insufflating apparatus 1.

[0206] Referring now to Fig. 17 there is illustrated a mouth engaging access device also according to the invention and indicated generally by the reference numeral 130. The access device 130 may be used with any of the insufflators of the insufflating apparatus described with reference to Figs. 1 to 12 and 16. The access device 130 is substantially similar to the mouth engaging access device 10 described with reference to the insufflating apparatus 1 , and similar components are identified by the same reference numerals. The only difference between the mouth engaging access device 130 and the mouth engaging access device 10 lies in the location of the first inlet ports 27. In this embodiment of the invention instead of the first inlet ports 27 being located towards the proximal end 15 of the instrument channel 18 which extends through the access device 130, and terminating in the instrument channel 18, the first inlet ports 27 are located adjacent the distal end 16 of the tubular member 14 adjacent the distal flange 22 thereof substantially clear of the instrument channel 18. The first inlet ports 27 are spaced apart circumferentially around the tubular member 14 and face in a generally distal direction from the access device 130. Each first inlet port 27 is connected to the annular chamber 32 of the manifold 31 through a corresponding connecting bore 132 extending through the tubular member 14 between the inner surface 33 of the tubular member 14 defining the instrument channel 18, and the outer surface 24.

[0207] The advantage of providing the first inlet ports 27 adjacent the distal end 16 of the tubular member 14 substantially clear of the instrument channel 18 and facing in a generally distal direction is that there is no risk of an endoscope extending through the instrument channel 18 acting as a resistance to a vacuum being applied through the access device 130, and in particular there is no risk of an endoscope extending through the instrument channel 18 acting as a resistance to the first vacuum at the extraction vacuum level applied through the access device 130 to the cavity in which the procedure is being carried out for drawing gases and smoke from the cavity.

[0208] In this embodiment of the invention it is envisaged that the second inlet ports 35 may be omitted, since it is envisaged that due to the positioning of the first inlet ports 27 adjacent the distal end 16 of the access device 130, when the second vacuum at the collecting vacuum level is applied to the first inlet ports 27, any gases escaping from the cavity in which the procedure is being carried out will be drawn from the mouth of the subject through the first inlet ports 27. Referring now to Fig. 18 there is illustrated an anal access device according to another embodiment of the invention indicated generally by the reference numeral 140. The access device 140 may be used with any of the insufflators of the insufflating apparatus described with reference to Figs. 1 to 12 and 16. The access device 140 is substantially similar to the access device 79 described with reference to the insufflating apparatus 70 of Figs 8 to 12, and similar components are identified by the same reference numerals. The access device 140 is also an anal access device. The only difference between the anal access device 140 and the anal access device 79 is in the location of the first inlet ports 89. In this embodiment of the invention the first inlet ports 89 are located adjacent the distal end 82 of the tubular member 80 clear of the instrument channel 84, and face in a generally distal direction from the tubular member 80. The first inlet ports 89 are equi-spaced apart circumferentially around the tubular member 80, and each first inlet port 89 is connected to the annular chamber 90 of the manifold 87 through a corresponding connecting bore 142 extending through the tubular member 80 between the inner and outer surfaces 91 and 92 thereof.

[0209] The advantage of providing the first inlet ports 89 adjacent the distal end 82 of the tubular member 80 facing in a generally distal direction from the tubular member 80 and clear of the instrument channel 84 is similar to the advantage achieved by providing the first inlet ports 27 of the access device 130 adjacent the distal end thereof and facing distally from the access device 130.

[0210] It is envisaged that in this embodiment of the invention the second inlet ports 97 may be omitted, since it is envisaged that the first inlet ports 89 being located adjacent the distal end 82 of the tubular member 80 will be sufficient for collecting gases escaping from the cavity being insufflated when the vacuum control valve 47 is being operated in the second state to apply the second vacuum at the collecting vacuum level to the first inlet ports 89.

[0211] Referring now to Figs. 19 to 23 there is illustrated an access device which in this case comprises a mouth engaging access device according to another embodiment of the invention indicated generally by the reference numeral 150. The access device 150 may be used with any of the insufflators of the insufflating apparatus described with reference to Figs. 1 to 12 and 16. The access device 150 comprises a two-part access device which comprises a distal part 151 and a proximal part 152 secured together. The distal part 151 forms a bite block part 153 defining a distal part 154 of an instrument channel 155 extending therethrough. The proximal part 152 forms a communicating element 156 defining a proximal part 157 of the instrument channel 155 extending therethrough. The distal and proximal parts 154 and 157, respectively, of the instrument channel 155 are of circular transverse cross-section of identical and constant diameter, and are axially aligned with each other to form the instrument channel 155 of constant diameter. The communicating element 156 is adapted to communicate the instrument channel 155 with the vacuum control valve 47 of the insufflator 7 of any of the insufflating apparatus of Figs. 1 to 12 and 16 for applying the first vacuum and the second vacuum to the instrument channel 155.

[0212] The bite block part 153 comprises a tubular member 158 extending between a proximal end 160 and a distal end 161 and defining the distal part 154 of the instrument channel 155 extending therethrough from the proximal end 160 to the distal end 161. The tubular member 158 defines a bite block 162 on which a subject may bite with his or her teeth. A proximal circular flange 164 extends circumferentially around and sidewardly outwardly from the tubular member 158 adjacent the proximal end 160 thereof. A pair of side flanges 165 extend sidewardly outwardly from the proximal flange 164 of the tubular member 158 on respective opposite sides of the tubular member 158. The side flanges 165 are adapted for abutting the lips of a subject, and terminate in engagement members 167 for engaging a head-strap (not shown) for securing the bite block part 153 in the mouth of a subject. In this embodiment of the invention the bite block part 153 does not include any inlet or outlet ports for communicating the instrument channel 155 with a vacuum control valve 47, as in the case of the access device 10 described with reference to Figs. 1 to 7 and Fig. 16.

[0213] Turning now to the communicating element 156, the communicating element 156 comprises a communicating means, as will be described below, for communicating the instrument channel 155 of the access device 150 with a vacuum applying means, namely, the vacuum control valve 47 of, for example, the insufflator 7 of Figs. 1 to 7 or a vacuum pump which may be located in an insufflator to which the endoscope would be connected. The communicating element 156 is of annular shape and comprises spaced apart inner and outer circular side walls 168 and 169, respectively, joined by spaced apart proximal and distal end walls 170 and 171, respectively, which together define an annular chamber 173 extending around and within the communicating element 156. The inner side wall 168 together with endoscope accommodating openings 175 and 176 in the proximal and distal end walls 170 and 171 define the proximal part 157 of the instrument channel 155 for accommodating an endoscope therethrough.

[0214] The communicating means comprises the annular chamber and a plurality of first inlet ports 177 extending through the inner side wall 168 of the communicating element 156 which together with the annular chamber 173 form a manifold 174. The first inlet ports 177 are equi-spaced apart circumferentially around the inner side wall 168 and communicate the manifold 174 with the proximal part 157 of the instrument channel 155. An outlet port 180 of the communicating means extends from the outer side wall 169 and communicates with the manifold 174 through a bore 181 extending through the outer side wall 169. The outlet port 180 is adapted for connecting to the second inlet port 49 of, for example, the insufflator 7 of the insufflating apparatus 1 of Figs. 1 to 7, and accordingly, on a vacuum being applied to the outlet port 180 of the communicating element 156, the vacuum is applied to the proximal part 157 of the instrument channel 155 through the manifold 174 and the first inlet ports 177 thereof, and in turn to the instrument channel 155 of the access device 150.

[0215] A sealing means is located in the proximal part 157 of the instrument channel 155 of the communicating element 156 adjacent the proximal end wall 170 and proximally from the first inlet ports 177 for sealably and slideably engaging an endoscope extending through the instrument channel 155. The sealing means comprises an annular sealing disc 182 of a flexible resilient material extending around the inner side wall 168 and inwardly therefrom into the proximal part 157 of the instrument channel 155. An endoscope accommodating opening 184 extending through the annular sealing disc 182 sealably and slideably engages an endoscope extending therethrough. By virtue of the fact that the annular sealing disc 182 is located in the instrument channel 155 proximally of the first inlet ports 177, the full effect of the first and second vacuums applied to the outlet port 180 is transferred to the instrument channel 155 with minimal leakage through the proximal end of the instrument channel 155.

[0216] The communicating element 156 is secured to the proximal flange 164 of the bite block part 153 with the distal end wall 171 of the communicating element 156 abutting and secured to the proximal flange 164, and with the proximal and distal parts 157 and 154 of the instrument channel 155 aligned with each other. The communicating element 156 may be secured to the proximal flange 164 of the bite block part 153 by any suitable means, and in this embodiment of the invention the distal end wall 171 of the communicating element 156 is secured to the proximal flange 164 of the bite block part 153 by a suitable adhesive.

[0217] In this embodiment of the invention the access device 150 is not provided with second inlet ports.

[0218] In use, with the communicating element 156 secured to the bite block part 153 and with the proximal and distal parts 157 and 154, respectively, of the instrument channel 155 aligned, the access device 150 is inserted in the mouth of a subject with the proximal flange 164 abutting the lips of a subject and the bite block 162 defined by the tubular member 158 of the bite block part 153 located in the mouth of a subject, so that the subject may bite on the bite block 162. The outlet port 180 of the communicating element 156 is connected to the second inlet port 49 of the insufflator 7 by a suitable conduit, for example, a conduit similar to the conduit 48 of the insufflating apparatus 1 of Figs. 1 to 7 for applying vacuum to the manifold 174 and in turn through the first inlet ports 177 for in turn applying vacuum to the instrument channel 155 of the access device 150.

[0219] Accordingly, when the first vacuum at the extraction vacuum level is applied to the outlet port 180 of the communicating element 156, insufflating gas and / or smoke is drawn from the cavity of the subject being insufflated through the instrument channel 155 of the access device 150. The gases and / or smoke drawn from the cavity are filtered by the filter 55 of the insufflator 7 of, for example, the insufflating apparatus 1 of Figs. 1 to 7. When the second vacuum at the collecting vacuum level is applied to the outlet port 180 of the communicating element 156, the second vacuum is applied to the instrument channel 155, and any gases or smoke escaping through the instrument channel 155 from the cavity being insufflated are drawn into the manifold 174 through the first inlet ports 177, and are in turn drawn through the outlet port 180 from the manifold 174, and are filtered through the filter 55 of the insufflator 7 of, for example, the insufflating apparatus 1 of Figs. 1 to 7.

[0220] Otherwise, the access device 150 and its use is similar to the access device 10 described with reference to the insufflating apparatus 1 of Figs. 1 to 7 and the insufflating apparatus of Fig. 16.

[0221] It is envisaged that the access device 150 of Figs. 19 to 23 may be adapted as a anal access device. In which case, it is envisaged that the side flanges 165 extending from the proximal flange 164 would be omitted, and suitable side buttocks engaging side flanges extending from the outer periphery of the proximal or distal end walls 170 or 171 of the communicating element on opposite sides thereof, would be provided. Such side flanges would be adapted to diverge outwardly in a proximal direction from the proximal or distal side wall, and would be adapted to engage the cheeks of the buttocks of a subject for separating the cheeks thereof. Additionally, it is envisaged that the outlet port 180 would extend from one of the buttocks engaging side flanges or from the proximal end wall 170 in a proximal direction, and would communicate with the annular chamber 173 of the manifold 174 through the corresponding buttocks engaging side flange or through the proximal end wall 170 for applying the first and second vacuums to the manifold 174. It is also envisaged that the communicating element 154 of the access device 150 may be used in conjunction with the mouth engaging access devices 10 of Figs. 1 to 7 and 16, the mouth engaging access device 130 of Fig. 17, and also in conjunction with the anal access devices 79, 110 and 140 of Figs. 8 to 12, 13 to 15 and 18, if such access devices were provided without the first and second inlet ports, the manifolds and the outlet ports of the communicating means. In the case of the mouth engaging access devices 10 and 130, the communicating element 156 would be secured to the proximal flange 19 of the access devices 10 and 130 with the proximal part 157 of the instrument channel 155 of the communicating element 156 aligned with the instrument channels 18 of the access devices 10 and 130. Thus, by applying vacuum to the outlet port 180 of the communicating element 156, the vacuum would be applied to the instrument channels 18 of the access devices 10 and 130 through the proximal part 157 of the instrument channel 155 of the communicating element 156.

[0222] In the case of the anal access devices 79 and 140 described with reference to Figs. 8 to 12 and 18, the proximal frustoconical flanges 85 of the anal access devices 79 and 140 would be removed and would be replaced by a suitable proximal circular flange extending around and sidewardly outwardly from the proximal end 81 of the anal access devices 79 and 140. The communicating element 156 would be secured to the proximal circular flange of the access devices 79 and 140 by a suitable adhesive with the distal end wall 171 of the communicating element 156 abutting the proximal flange of the anal access devices 79 and 140. A pair of side flanges would be provided diverging sidewardly outwardly in a proximal direction from the outer periphery of the proximal end wall 170 on respective opposite sides thereof for engaging and separating the cheeks of the buttocks of a subject. The outlet port 180 of the communicating element would typically extend from a corresponding one of the side flanges or from the proximal end wall 170 and would communicate with the annular chamber 173 of the manifold 174 through the corresponding side flange or through the proximal end wall 170.

[0223] In the case of the anal access device 110 of Figs. 13 to 15, the distal end wall 171 of the communicating element 156 would be secured by a suitable adhesive to the circular flange 112 adjacent the proximal end 81 of the access device 110. Thereafter, the communicating element 156 would be modified in a similar manner as the communicating element 156 has been described as being modified for securing to the anal access devices 79 and 140.

[0224] Referring now to Fig. 24 there is illustrated an insufflating apparatus according to another embodiment of the invention indicated generally by the reference numeral 190 for insufflating a cavity of a subject during carrying out of a minimally invasive procedure in the cavity. In this case, the insufflating apparatus 190 is adapted for insufflating the stomach of a subject. The insufflating apparatus 190 comprises an insufflator 191 and an access device 192, both of which are substantially similar to the insufflator 7 and the access device 10, respectively, of the insufflating apparatus 1 described with reference to Figs. 1 to 7, and similar components are identified by the same reference numerals. The access device 192 is adapted for engaging in the mouth of a subject, in a similar manner as the access device 10 is engaged in the mouth of a subject. The only difference between the insufflating apparatus 190 and the insufflating apparatus 1 lies in the insufflator 191.

[0225] The insufflator 191 instead of comprising the three-state vacuum control valve 47, comprises a multi-state vacuum control valve 193. The multi-state vacuum control valve 193 is operable in an isolating state, and in first and second states by the microprocessor 53. In the isolating state, the multi-state vacuum control valve 193 isolates the second inlet port 49 from the vacuum source 46, and in turn isolates the access device 10 from the vacuum source 46. In the first state the multi-state vacuum control valve 193 is operable to produce the first vacuum at a plurality of selectable extraction vacuum levels, in this case, five selectable extraction vacuum levels for drawing insufflating gas, other gases and smoke from the stomach of the subject at five respective flow rates. Although, needless to say, the multi-state vacuum control valve 193 when operating in the first state may be adapted to produce the first vacuum at more or less than five selectable extraction vacuum levels. In the second state, the multi-state vacuum control valve 193 is operable to produce the second vacuum at a plurality of selectable collecting vacuum levels, in this embodiment of the invention two selectable collecting vacuum levels.

[0226] The extraction vacuum levels and the collection vacuum levels at which the multi-state vacuum control valve is operable to produce the first vacuum and the second vacuum are stored in memory of the microprocessor 53 cross-referenced with the corresponding settable states of the multi-state vacuum control valve to produce the respective selectable vacuum levels. The extraction vacuum level at which the first vacuum is to be produced by the multi-state vacuum control valve 193 during operation of the insufflating apparatus 190 is selected from a menu of the five selectable extraction vacuum levels and the corresponding flow rates displayed on the touchscreen interface 54. The collection vacuum level at which the second vacuum is to be produced by the multi-state vacuum control valve 193 during operation of the insufflating apparatus 190 is selected from a menu of the two selectable collection vacuum levels displayed on the touchscreen interface 54. The extraction vacuum level and the collection vacuum level at which the insufflating apparatus 190 is to produce the first and second vacuums is inputted into the microprocessor 53 through the touch screen 54 by selecting the appropriate extraction vacuum level and the appropriate collection vacuum level displayed in the respective menus on the touchscreen when the set pressure value is being entered into the microprocessor 53. Once the set pressure value, the extraction vacuum level and the collection vacuum level have been entered into the microprocessor 53 of the insufflator 191, the insufflating apparatus 190 is ready for use.

[0227] Operation of the insufflating apparatus 190 is similar to operation of the insufflating apparatus 1. Initially, the flow controller 39 is operated to maintain the stomach pressure at the set pressure value, and to apply the second vacuum to the access device 192 at the selected collecting vacuum level. On the stomach pressure exceeding the set pressure value, the microprocessor 53 operates the multi-state vacuum control valve 193 to produce the first vacuum at the selected extraction vacuum level, and operation of the multi-state vacuum control valve 193 and the operation of the flow controller 39 by the microprocessor 53 is similar to that already described with reference to the insufflating apparatus 1, until the stomach pressure is reduced to the set pressure value.

[0228] On a smoke evacuate signal being inputted to the microprocessor 53 from the foot pedal operated switch 62, the microprocessor 53 operates the multi-state vacuum control valve 193 from the second state to the first state to produce the first vacuum at the selected extraction vacuum level, and the microprocessor 53 operates the flow controller 39 to increase the delivery of insufflating gas to the stomach in order to maintain the pressure in the stomach at the set pressure value. The microprocessor 53 maintains the multi-state vacuum control valve 193 operating in the first state and operates the flow controller 39 to maintain the stomach pressure at the set pressure value until the smoke evacuate signal has been terminated, at which stage, the microprocessor 53 operates the multi-state vacuum control valve 193 from the first state to the second state to produce the second vacuum at the selected collecting vacuum level and operates the flow controller 39 to maintain the stomach pressure at the set pressure value.

[0229] In an alternative embodiment of the insufflating apparatus 190, the microprocessor 53 is programmed to select the appropriate extraction vacuum level at which the first vacuum is to be produced by the multistate vacuum control valve 193 when the multi-state vacuum control valve 193 is operated by the microprocessor 53 in response to the stomach pressure exceeding the set pressure value. In this embodiment of the insufflating apparatus 190, the microprocessor 53 is programmed to select the appropriate one of the selectable extraction vacuum levels in response to the amount by which the stomach pressure exceeds the set pressure value. In other words, the greater the amount by which the stomach pressure exceeds the set pressure value, the greater will be the selectable extraction vacuum level at which the microprocessor 53 operates the multi-state vacuum control valve 193 to produce the first vacuum.

[0230] Additionally, when the microprocessor 53 is operating the multi-state vacuum control valve 193 in the first state in response to the stomach pressure exceeding the set pressure value, the microprocessor 53 sequentially and alternatively operates the multi-state vacuum control valve 193 in predefined vacuum on time periods and in predefined vacuum off time periods, as already described with reference to the insufflating apparatus 1 described with reference to Figs. 1 to 7. During each predefined vacuum off time period, the microprocessor 53 reads the signal produced by the pressure sensor 50 indicative of the stomach pressure, and selects the appropriate one of the selectable extraction vacuum levels at which the first vacuum is to be produced during the next predefined vacuum off time period in response to the stomach pressure read from the signal produced by the pressure sensor 50. Thus, as the stomach pressure progressively falls, the microprocessor 53 operates the multi-state vacuum control valve 193 to produce the first vacuum at the extraction vacuum level in progressively decreasing ones of the selectable extraction vacuum levels until the stomach pressure is reduced to the set pressure value.

[0231] In this alternative embodiment of the insufflating apparatus 190, the extraction vacuum level at which the first vacuum is produced in response to the smoke evacuate signal may also be selected by the smoke evacuate signal. In which case the smoke evacuate signal would be indicative of the selectable extraction vacuum level at which the first vacuum is to be produced. For example, the smoke evacuate signal generating switch may be provided by a foot pedal operated analogue switch, which would be adapted to produce an analogue current or voltage signal of increasing value in proportion to the degree the foot pedal of the switch is depressed. In which case, the microprocessor 53 would be programmed to operate the multi-state vacuum control valve 193 to produce the first vacuum at the appropriate one of the selectable extraction vacuum levels corresponding to the degree by which the analogue switch is operated by depressing the pedal thereof. In other words, the greater the degree by which the pedal 63 of the analogue switch is depressed, the greater would be the extraction vacuum level selected from the selectable extraction vacuum levels at which the first vacuum would be produced by the multi-state vacuum control valve 193. Such an analogue switch may be, for example, a rheostat switch.

[0232] Alternatively, instead of providing the smoke evacuate signal generating switch as being an analogue switch, the smoke evacuate signal generating switch may be provided by the foot pedal operated mono- stable bi-state switch 62, and the microprocessor would be programmed to determine the selectable extraction vacuum level at which the first vacuum is to be produced by the multi-state vacuum control valve 193 in response to the number of times the foot pedal operated switch 62 is operated from the open circuit state to the closed circuit state and back to the open circuit state in quick succession, the greater the number of times the foot pedal operated switch is operated from the open circuit state to the closed circuit state and back to the open circuit state in quick succession, the greater the selectable extraction vacuum level at which the first vacuum would be produced. For example, if the foot pedal operated monostable bi-state switch 62 is operated once from the open circuit state to the closed circuit state and back to the open circuit state, the microprocessor 53 would be programmed to select the lowest one of the selectable extraction vacuum levels, and if the foot pedal operated switch 62 were operated twice in quick succession, the microprocessor 53 would be programmed to select the next lowest selectable extraction vacuum level at which the first vacuum would be produced, and so on up to the highest selectable evacuation vacuum levels at which the first vacuum may be produced.

[0233] In the insufflating apparatus 190 of Fig. 24 the five selectable extraction vacuum levels are set so that at the first or lowest selectable extraction vacuum level insufflating gas is drawn from the stomach at a flow rate of approximately 1 Litre per minute, at the second or next lowest selectable extraction vacuum level insufflating gas is drawn from the stomach at a flow rate of approximately 3 Litres per minute, at the third selectable extraction vacuum level insufflating gas is drawn from the stomach at a flow rate of approximately 5 Litres per minute, at the fourth selectable extraction vacuum level insufflating gas is drawn from the stomach at a flow rate of approximately 7 Litres per minute, and at the fifth and highest selectable extraction vacuum level insufflating gas is drawn from the stomach at a flow rate of approximately 10 Litres per minute. However, in some embodiments of the invention it is envisaged that the highest flow rate at which insufflating gas is drawn from the stomach or other cavity corresponding to the highest selectable extraction vacuum level may be as high as 20 Litres per minute and in some cases higher. In such cases, it is envisaged that the flow rates corresponding to the five selectable extraction vacuum levels, from say 1 Litre per minute to 20 Litres per minute would be graduated with substantially equal increments between the respective flow rates.

[0234] The selectable collecting vacuum levels are set so that the vacuum at the first and second inlet ports is just sufficient to draw gas and other gases escaping from the stomach of the subject through the access device 192, but are insufficient to draw insufflating gas and other gases from the stomach. The second collecting vacuum level is less than the first collecting vacuum level. Otherwise, the insufflating apparatus 190 and its operation is similar to the insufflating apparatus 1 described with reference to Figs. 1 to 7.

[0235] While the insufflating gas source described with reference to each of the embodiments of the invention has been described as being provided by a hospital insufflating gas source, which typically comprises pressurised carbon dioxide, it will be readily apparent to those skilled in the art that any other suitable insufflating gas source may be provided, for example, the insufflating gas source may be provided by any pressurised source of any suitable gas or air, and in some embodiments of the invention may be provided by a pressurised cylinder of the relevant insufflating gas. It is also envisaged that in some embodiments of the invention the insufflators may be provided with a suitable cylinder of the compressed or liquified gas located within the housing of the insufflator.

[0236] It will also be appreciated that while each of the insufflators have been described as being connected to a hospital vacuum source, any other suitable vacuum source may be provided. For example, in some embodiments of the invention it is envisaged that instead of connecting the insufflators to an external vacuum source, such as a hospital vacuum source, the insufflators may be provided with a vacuum pump which may be located in or externally of the housing of the insufflators. Such a vacuum pump would be operated under the control of the microprocessor of the insufflators. For example, the vacuum pump may be a variable vacuum vacuum pump, or may be a multi-state vacuum pump or may be a three-state vacuum pump. In cases where the vacuum pump is a three-state vacuum pump, the vacuum pump would be operable in an off state and in a first state which would produce the first vacuum at the extraction vacuum level, and a second state which would produce the second vacuum at the collecting vacuum level. In cases where the vacuum pump is a multi-state vacuum pump, the microprocessor would be programmed to operate the vacuum pump in the first state to provide the first vacuum at a plurality of the selectable extraction vacuum levels, and the microprocessor would be programmed when operating the vacuum pump in the second state to produce the second vacuum, the microprocessor may be programmed to operate the vacuum pump in the second state to produce the second vacuum at one or more selectable collecting vacuum levels. In cases where the vacuum source comprises a multi-state vacuum pump, the microprocessor would operate the vacuum pump in a manner similar to that described in the insufflating apparatus of Fig. 24.

[0237] In embodiments of the invention where the vacuum pump is an infinitely variable vacuum vacuum pump, the microprocessor would be similarly programmed to operate the vacuum pump in the first state to produce the first extraction vacuum at a plurality of selectable extraction vacuum levels, and to operate the vacuum pump in the second state to produce the second vacuum at one or more selectable collecting vacuum levels.

[0238] It is also envisaged that instead of providing a vacuum pump, the vacuum may be generated in the housing of the insufflator by a Venturi vacuum generator. In which case, it is envisaged that the Venturi vacuum generator would be connected to the insufflating gas source, and the flow rate of the insufflating gas from the insufflating gas source through to the Venturi vacuum generator would be controlled through a flow control valve in order to operate the Venturi vacuum generator to produce the first vacuum and second vacuum at the respective extraction and collecting vacuum levels. It is envisaged that the flow control valve which would control the delivery of the insufflating gas to the Venturi generator, typically, would be a three-state valve which would be operated by the microprocessor in two of the states to deliver the insufflating gas to the Venturi vacuum generator at respective two flow rates to generate the first vacuum and the second vacuum and in a third state to isolate the Venturi vacuum generator from the insufflating gas source, when no vacuum is required. Alternatively, the flow control valve for controlling the flow rate of the insufflating gas from the insufflating gas source to the Venturi vacuum generator may be an infinitely variable valve or a multi-state valve, and the microprocessor would be programmed to operate the flow control valve in a similar manner as the microprocessor is described in the insufflating apparatus 190 of Fig. 24 above for operating a multi-state vacuum valve.

[0239] It is also envisaged that in cases where the vacuum is controlled by a vacuum control valve operated under the control of the microprocessor, the vacuum control valve may be a multi-state valve having many more operating states than the three states described with reference to the insufflators described with reference to Figs. 1 to 23. For example, it is envisaged that the multi-state valve may be operable under the control of the microprocessor in an isolating state to isolate the outlet port of the access device from the vacuum source, and in a first state to produce the first vacuum at two or more selectable extraction vacuum levels and in a second state to produce the second vacuum at one or more selectable collecting vacuum levels.

[0240] It is also envisaged that in some embodiments of the invention the vacuum control valve may be an infinitely variable vacuum control valve, and in which case, the first vacuum would be selectable at an infinite number of extraction vacuum levels. In which case, it is envisaged that when the first vacuum is selected in response to the smoke evacuate signal, an analogue foot pedal operated switch, for example, a rheostat type switch would be provided, and the extraction vacuum level at which the first vacuum would be provided would be dependent on the amount by which the foot pedal operated switch is operated from the open circuit state.

[0241] It is also envisaged that in cases where the insufflator is provided with a vacuum pump, the vacuum pump may be an infinitely variable vacuum pump, and likewise, the first vacuum may be infinitely variable. In which case, the microprocessor would be programmed to read signals from an analogue switch to determine the extraction vacuum level at which the first vacuum is to be applied to the access device in response to the smoke evacuate signal.

[0242] It is also envisaged that in cases where the vacuum control valve is provided as an infinitely variable valve or in cases where the insufflator is provided with a vacuum pump capable of producing an infinitely variable vacuum, the microprocessor my be programmed to determine the extraction vacuum level at which the first vacuum is to be produced from signals produced by a foot pedal operated mono-stable bistate switch. The extraction vacuum level at which the first vacuum is to be produced would be determined by the number of times the surgeon or clinician operated the foot pedal operated switch in quick succession. For example, if the surgeon or clinician operated the foot pedal operated switch once, the first vacuum would be produced at the lowest selectable extraction vacuum level, and if the surgeon or clinician operated the foot pedal switch twice, the first vacuum would be produced at the next extraction vacuum level, and so on up to the highest extraction vacuum level at which the first vacuum could be produced by the infinitely variable vacuum control valve or the vacuum pump configured to produce an infinitely variable vacuum.

[0243] It is also envisaged that when an infinitely variable vacuum pump or an infinitely variable vacuum control valve is provided, when the vacuum pump or the vacuum control valve is operated in the first state to produce the first vacuum when the vacuum pump or the vacuum control valve is operated in response to the cavity pressure exceeding the set pressure value, that the microprocessor would be programmed to operate the vacuum pump or the vacuum control valve to produce the first vacuum at an appropriate extraction vacuum level depending on the degree by which the cavity pressure exceeds the set pressure value.

[0244] While the signal processors of the insufflators have been described as comprising microprocessors, any other suitable signal processor, for example, a microcontroller, a programmable logic controller or any other suitable control means, or signal processing means may be provided for controlling the operation of the insufflators.

[0245] It will also be appreciated that while specific designs and shapes of access devices have been described, it will be readily apparent to those skilled in the art that any other suitable access devices may be provided.

[0246] While the access devices have been described as being oral access devices and anal access devices, it will be readily apparent to those skilled in the art that other access devices may be provided, for example, it is envisaged that in some embodiments of the invention the access device may be adapted for accommodating an endoscope or a colonoscope or any other suitable instrument, for example, a trocar, through an incision formed in the body of a human or animal subject. The access device would be adapted for applying a vacuum at two vacuum levels, namely, a first vacuum at an extraction vacuum level for drawing insufflating gas, smoke or other gases from the cavity of a subject in which an investigative or surgical procedure is being carried out endoscopically, colonoscopically or laparoscopically, and a second vacuum at a collecting vacuum level for collecting gases escaping from the cavity in which the investigative or surgical procedure is being carried out. Needless to say, the first vacuum may be provided at one or more selectable extraction vacuum levels, and the second vacuum may be provided at one or more collecting vacuum levels.

[0247] While the insufflating apparatus 1 and 120 have been described for carrying out a procedure in the stomach of a subject, it will be readily apparent to those skilled in the art that the insufflating apparatus 1 and 120 may be used for carrying out any endoscopic procedure whereby the endoscope is entered orally into the subject, and the endoscopic procedure may be carried out in the oesophagus, or the intestine. In some embodiments of the invention it is envisaged that the insufflating apparatus 1 and 120 may be used with the endoscope entered orally into the subject for carrying out a procedure in any lumen, vessel, organ or cavity within the abdominal cavity, and in which case, it is envisaged that the endoscope would be entered into the abdominal cavity through an incision formed in the stomach in order to gain access to the lumen, vessel, organ or cavity in the abdominal cavity of a subject.

[0248] It is also envisaged that the insufflating apparatus 70 may be used for carrying out procedures in other cavities, besides the rectum and colon. For example, it is envisaged that the insufflating apparatus 70 with the colonoscope entered anally into the subject may be used for carrying out a procedure in the intestine, or may be used for carrying out a procedure in the abdominal cavity, and in which case, it is envisaged that the colonoscope would be entered into the abdominal cavity through an incision formed in the colon or the intestine in order to access a lumen, vessel, organ or cavity within the abdominal cavity.

[0249] It is also envisaged that the insufflating apparatus as well as being described for oral and anal entry into a subject, may be adapted for entering a lumen, vessel, organ or cavity in a subject through other orifices of the subject, for example, the vagina for carrying out a procedure in the uterus of a subject, whereby any of the access devices may be adapted to engage in the vagina to accommodate the endoscope therethrough. Needless to say, the insufflating apparatus described with reference to the drawings may also be used for carrying out a procedure in any lumen, vessel, organ or cavity in the body of a human or animal subject, whereby the endoscope or a trocar may be entered through an incision formed in the body of a human or animal subject in order to provide access to the lumen, vessel, organ or cavity, and in which case, any of the access devices would be adapted for inserting in the incision prior to entering the endoscope or trocar therethrough.

[0250] It will of course be appreciated that each and every one of the insufflating apparatus described herein may be used for carrying out a procedure in any lumen, vessel, organ or cavity in the body of a human or animal subject.

[0251] While in the embodiments of the invention in which the insufflating apparatus comprises an anal access device, the anal access device has been described as comprising a parallel portion and a frustoconical portion, it is envisaged that in some embodiments of the invention the parallel portion of the access device may be omitted, and in which case the access device would be entirely of a frustoconical shape.

[0252] While the insufflator has been described as comprising a flow controller for controlling the delivery of insufflating gas to the relevant cavity, it will be readily apparent to those skilled in the art that any other suitable flow control means may be provided.

[0253] It will also be appreciated that any suitable pressure sensor may be provided for monitoring pressure in the relevant cavity, and it is envisaged that in some embodiments of the invention the pressure monitoring means, may be located in the cavity being insufflated, and the pressure monitoring means would produce a signal indicative of the cavity pressure, which may be wirelessly transmitted to the microprocessor of the insufflator, or may be hardwired to the microprocessor of the insufflator. Such a pressure sensing means may be located on a distal end of an endoscope or a colonoscope, or may be located on a distal end of a suitable carrier, which would be inserted into the cavity either through an endoscope or a colonoscope, or through the instrument channel defined by the access device.

[0254] Needless to say, any other suitable interface means besides a touchscreen interface may be provided for inputting data into the microprocessor, and in some embodiments of the invention it is envisaged that data may be inputted to the microprocessor through one interface, and data relevant to the operation of the insufflator may be displayed on a separate interface, for example, a visual display screen.

[0255] While the smoke evacuate signal has been described in the embodiments described with reference to the drawings as comprising a foot pedal operated switch, either a food pedal operated mono-stable bi-state switch, or an analogue switch, it will be appreciated that the switch may be operated by any other suitable means besides the foot pedal. For example, such a swich may be hand operated, for example, by a push or a pull lever, or by a rotary hand operated knob, or by a slider, and in the case of an analogue switch, it is envisaged that the analogue switch may be provided by a suitable rotary rheostat or a rotary potentiometer, which typically, would be operated by a rotary hand operated knob. Alternatively, if the analogue switch were provided by a linear rheostat or a linear potentiometer, the analogue switch, typically, would be operable by a manually slidable element, slidable linearly along the rheostat or the potentiometer.

[0256] It is also envisaged that in some embodiments of the invention the smoke evacuate signal as well as or instead of being provided by a smoke evacuate signal producing switch, may be provided by a signal from an instrument which would either generate smoke, or generate pressure in the cavity in which the procedure is being carried out, for example, it is envisaged that the smoke evacuate signal may be derived from a cauterising instrument, and a signal produced by the cauterising instrument on activation of the instrument to commence cauterising would be applied either wirelessly, or through hardwiring to the microprocessor of the insufflator, and the microprocessor would be responsive to such a signal for operating the vacuum applying means in the first state at the extraction vacuum level to produce the first vacuum. The microprocessor, typically, would be programmed to maintain the vacuum applying means in the first state producing the first vacuum at the extraction vacuum level for so long as the instrument was being operated. The microprocessor would be programmed on termination of the signal from the instrument to operate the vacuum applying means from the first state to the second state to produce the second vacuum at the collection vacuum level. The signal indicative of the operation of the instrument may be derived from a power supply powering the instrument, or may be provided by a monitoring device located on or adjacent the instrument for monitoring the power being drawn by the instrument, which would then provide the smoke evacuate signal.

[0257] It is envisaged that while specific ranges of flow rates at which insufflating gas and other gases as well as smoke are drawn from the cavity when the vacuum applying means is operating in the first state to produce the first vacuum at the extraction vacuum level or the selectable extraction vacuum levels have been described, it will be readily apparent to those skilled in the art that other ranges of flow rates at which insufflating gas, other gases and smoke are drawn from the cavity during operation of the vacuum applying means in the first state to produce the first vacuum at the extraction vacuum level or at the selectable extraction vacuum levels may be used. And the selection of such ranges of flow rates will be dependent on the cavity being insufflated, its size, and also the procedure being carried out in the cavity which is likely to produce smoke or high pressures, as well as the volume of smoke to be produced and the value of the pressure to be produced. It will also be appreciated that while specific values of flow rates at which insufflating gas, other gases and smoke are drawn from the cavity when the vacuum applying means is operated in the first state to produce the first vacuum at the extraction vacuum level or at the respective selectable extraction vacuum levels, other suitable flow rates at which insufflating gas, other gases and smoke are drawn from the cavity during operation of the vacuum applying means in the first state to produce the first vacuum at the extraction vacuum level or at the selectable extraction vacuum levels may be used, and such other flow rates will be dependent on the cavity being insufflated, its size and the likely volume of smoke or the likely increase in pressure resulting from the procedure being carried out in the cavity.

Claims

Claims1. An insufflating apparatus for insufflating a cavity in the body of a human or animal subject, the insufflating apparatus comprising an access device adapted for engaging in a bodily orifice of the subject through which the cavity is accessible, the access device extending between a proximal end and a distal end and having an instrument channel extending therethrough from the proximal end to the distal end thereof for accommodating an instrument therethrough to the cavity, a communicating means adapted to communicate with the cavity through the access device, and an insufflator, the insufflator comprising a flow controller for controlling delivery of insufflating gas to the cavity, a pressure sensor for monitoring pressure in the cavity (cavity pressure) and for producing a signal indicative of the cavity pressure, a vacuum applying means adapted for applying vacuum to the communicating means, and a signal processor programmed to read the signal from the pressure sensor and / or to read a smoke evacuate signal, the signal processor being programmed to be responsive to the signal read from the pressure sensor being indicative of the cavity pressure exceeding a set pressure value, or to the smoke evacuate signal to operate the vacuum applying means in a first state to produce a first vacuum at an extraction vacuum level for applying to the communicating means for drawing gases and / or smoke from the cavity through the access device.

2. An insufflating apparatus as claimed in Claim 1 in which the signal processor is programmed to operate the vacuum applying means in the first state for applying the first vacuum to the communicating means until the signal read from the pressure sensor is indicative of the cavity pressure having fallen to or below the set pressure value, or until termination of the smoke evacuate signal.

3. An insufflating apparatus as claimed in Claim 1 or 2 in which the signal processor is programmed to operate the flow controller to control delivery of insufflating gas to the cavity while the vacuum applying means is being operated in the first state for applying the first vacuum to the communicating means.

4. An insufflating apparatus as claimed in any preceding claim in which the signal processor is programmed to operate the flow controller to control delivery of insufflating gas to the cavity while the signal processor is operating the vacuum applying means in the first state thereof in response to the smoke evacuate signal for maintaining the cavity pressure substantially at the set pressure value.

5. An insufflating apparatus as claimed in any preceding claim in which the vacuum applying means is operable in the first state thereof under the control of the signal processor for producing the firstvacuum at at least two selectable extraction vacuum levels.

6. An insufflating apparatus as claimed in Claim 5 in which the signal processor is responsive to the smoke evacuate signal to operate the vacuum applying means to produce the first vacuum at a selected one of the selectable extraction vacuum levels of the first vacuum.

7. An insufflating apparatus as claimed in any preceding claim in which the smoke evacuate signal is produced by a smoke evacuate signal producing means.

8. An insufflating apparatus as claimed in Claim 7 in which the smoke evacuate signal producing means is adapted to produce the smoke evacuate signal indicative of the selectable extraction vacuum level at which the vacuum applying means is to produce the first vacuum in the first state thereof.

9. An insufflating apparatus as claimed in Claim 7 or 8 in which the smoke evacuate signal producing means comprises at least one smoke evacuate signal generating electrical switch or at least one smoke evacuate signal generating electronic switch.

10. An insufflating apparatus as claimed in any of Claims 7 to 9 in which the at least one smoke evacuate signal generating switch is adapted to produce the smoke evacuate signal when the at least one smoke evacuate signal generating switch is operated in one of a closed circuit state or an open circuit state, and the at least one smoke evacuate signal generating switch is adapted to indicate termination of the smoke evacuate signal when the at least one smoke evacuate signal generating switch is operated in the other one of the closed circuit state or the open circuit state.

11. An insufflating apparatus as claimed in any of Claims 7 to 10 in which the at least one smoke evacuate signal generating switch comprises a foot pedal operated switch.

12. An insufflating apparatus as claimed in any of Claims 7 to 11 in which the at least one smoke evacuate signal generating switch comprises a button operated electrical or a button operated electronic switch.

13. An insufflating apparatus as claimed in any of Claims 7 to 12 in which the at least one smoke evacuate signal generating switch comprises a voice operated electrical or a voice operated electronicswitch.

14. An insufflating apparatus as claimed in any of Claims 7 to 13 in which the smoke evacuate signal generating switch comprises an electrical analogue switch or an electronic analogue switch.

15. An insufflating apparatus as claimed in any preceding claim in which the signal processor is responsive to the signal read from the pressure sensor being indicative of the cavity pressure exceeding the set pressure value for operating the flow controller to reduce the rate at which insufflating gas is being delivered to the cavity, or to pause delivery of insufflating gas to the cavity.

16. An insufflating apparatus as claimed in any preceding claim in which the signal processor when operating the flow controller in response to the signal read from the pressure sensor being indicative of the cavity pressure exceeding the set pressure value is programmed to operate the flow controller to reduce the rate at which insufflating gas is being delivered to the cavity or to pause delivery of insufflating gas to the cavity until the cavity pressure has fallen to the set pressure value.

17. An insufflating apparatus as claimed in any preceding claim in which the signal processor is responsive to the amount by which the cavity pressure exceeds the set pressure value for determining the extraction vacuum level at which the first vacuum is to be produced by the vacuum applying means in the first state thereof, so that the greater the amount by which the cavity pressure exceeds the set pressure value, the greater will be the extraction vacuum level of the first vacuum produced by the vacuum applying means in the first state thereof.

18. An insufflating apparatus as claimed in any preceding claim in which the signal processor is programmed in response to the signal produced by the pressure sensor being indicative of the cavity pressure being at or below the set pressure value or the termination or the absence of the smoke evacuate signal to operate the vacuum applying means in a second state to produce a second vacuum at a collecting vacuum level less than the extraction vacuum level or less than the lowest level of the selectable extraction vacuum levels of the first vacuum for applying to the communicating means for collecting gases and / or smoke escaping from the cavity through or adjacent the access device.

19. An insufflating apparatus as claimed in Claim 18 in which the collecting vacuum level of the second vacuum comprises a vacuum level insufficient to draw gases and / or smoke from the cavity butsufficient to draw gases and / or smoke escaping from the cavity through or adjacent the access device.

20. An insufflating apparatus as claimed in Claim 18 or 19 in which the collecting vacuum level of the second vacuum lies in the range of lOOmmHg to 500mmHg below atmospheric pressure.

21. An insufflating apparatus as claimed in any of Claims 18 to 20 in which the collecting vacuum level of the second vacuum lies in the range of 200mmHg to 400mmHg below atmospheric pressure.

22. An insufflating apparatus as claimed in any of Claims 18 to 21 in which the collecting vacuum level of the second vacuum is approximately 300mmHg below atmospheric pressure.

23. An insufflating apparatus as claimed in any preceding claim in which the extraction vacuum level of the first vacuum lies in a range that when applied to the communicating means insufflating gas is drawn from the cavity through the communicating means at a flow rate in the range of 1 Litre per minute to 20 Litres per minute.

24. An insufflating apparatus as claimed in any preceding claim in which the extraction vacuum level of the first vacuum lies in a range that when applied to the communicating means insufflating gas is drawn from the cavity through the communicating means at a flow rate in the range of 2 Litres per minute to 10 Litres per minute.

25. An insufflating apparatus as claimed in any preceding claim in which the extraction vacuum level of the first vacuum when applied to the communicating means insufflating gas is drawn from the cavity through the communicating means at a flow rate of approximately 3 Litres per minute to 5 Litres per minute.

26. An insufflating apparatus as claimed in any preceding claim in which the vacuum applying means comprises a vacuum control valve, adapted for connecting to a vacuum source and to the communicating means.

27. An insufflating apparatus as claimed in Claim 26 in which the vacuum control valve is operable in at least two states, in one of the at least two states the vacuum control valve is operable in an isolating state isolating the communicating means from the vacuum source, and in the other one of the at least twostates, the vacuum control valve is operable in the first state for applying the first vacuum at the extraction vacuum level to the communicating means.

28. An insufflating apparatus as claimed in Claim 27 in which the vacuum control valve comprises a three-state valve operable in the isolating state and in the first state, and operable in the second state for applying the second vacuum at the collecting vacuum level to the communicating means.

29. An insufflating apparatus as claimed in Claim 28 in which the vacuum control valve comprises a multi-state vacuum control valve operable in a plurality of the first states for producing the first vacuum at the respective selectable extraction vacuum levels for applying to the communicating means.

30. An insufflating apparatus as claimed in any of Claims 1 to 25 in which the vacuum applying means comprises a vacuum pump adapted for connecting to the communicating means31. An insufflating apparatus as claimed in Claim 30 in which the vacuum pump is operable in at least a non-vacuum generating state and the first state to produce the first vacuum at the extraction vacuum level.

32. An insufflating apparatus as claimed in Claim 31 in which the vacuum pump is operable in the second state to produce the second vacuum at the collecting vacuum level.

33. An insufflating apparatus as claimed in any preceding claim in which the communicating means comprises a manifold, an outlet port communicating with the manifold, the outlet port being adapted for connection to the vacuum applying means for applying the first vacuum and the second vacuum to the manifold, and at least one first inlet port communicating with the manifold for applying the first vacuum and the second vacuum adjacent the access device.

34. An insufflating apparatus as claimed in Claim 33 in which the manifold is located in the access device, and the at least one first inlet port for applying the first vacuum and the second vacuum adjacent the access device extends from the manifold and terminates in the instrument channel communicating with the instrument channel, or terminates adjacent a distal end of the access device with the at least one first inlet port facing distally from the access device.

35. An insufflating apparatus as claimed in Claim 33 or 34 in which a plurality of the first inlet ports are provided spaced apart circumferentially around the access device.

36. An insufflating apparatus as claimed in any of Claims 33 to 35 in which the first inlet ports are equi-spaced apart circumferentially around the access device.

37. An insufflating apparatus as claimed in any of Claims 33 to 35 in which at least one second inlet port extends from the manifold and terminates in an outer surface of the access device.

38. An insufflating apparatus as claimed in Claim 37 in which a plurality of the second outlet ports are spaced apart circumferentially around the outer surface of the access device.

39. An insufflating apparatus as claimed in any of Claims 33 to 38 in which the manifold extends circumferentially around and within the access device.

40. An insufflating apparatus as claimed in any of Claims 33 to 39 in which the manifold extends completely around the access device.

41. An insufflating apparatus as claimed in any of Claims 33 to 40 in which a sealing means is located in the instrument channel of the access device, the sealing means being adapted to slideably and sealably engage the instrument extending through the instrument channel.

42. An insufflating apparatus as claimed in Claim 41 in which the sealing means comprises a sealing membrane extending into the instrument channel, and terminating in an instrument accommodating opening for slideably and sealably engaging an instrument extending through the instrument channel.

43. An insufflating apparatus as claimed in Claim 42 in which the sealing membrane comprises a resilient material.

44. An insufflating apparatus as claimed in Claim 42 or 43 in which the sealing membrane comprises a flexible material.

45. An insufflating apparatus as claimed in any of Claims 41 to 44 in which the sealing means islocated in the instrument channel intermediate the proximal and distal ends thereof.

46. An insufflating apparatus as claimed in any of Claims 41 to 45 in which the sealing means is located proximally of the at least one first inlet port.

47. An insufflating apparatus as claimed in any preceding claim in which a proximal flange extends sidewardly outwardly from and circumferentially around the access device adjacent the proximal end thereof.

48. An insufflating apparatus as claimed in any preceding claim in which a pair of radially sidewardly outwardly extending proximal side flanges extend from the access device adjacent the proximal end thereof.

49. An insufflating apparatus as claimed in any preceding claim in which the access device is adapted for locating in the mouth of a subject, and defines a bite portion for enabling a subject to bite thereon.

50. An insufflating apparatus as claimed in Claim 49 in which the outlet port from the manifold extends from one of the proximal side flanges of the access device.

51. An insufflating apparatus as claimed in any of Claims 49 to 50 in which a distal flange extends sidewardly outwardly from and circumferentially around the access device adjacent a distal end thereof.

52. An insufflating apparatus as claimed in any of Claims 1 to 48 in which the access device is adapted for locating in the anus of a subject, and the access device comprises an anus engaging element for engaging the anus of a subject.

53. An insufflating apparatus as claimed in Claim 52 in which the proximal flange is engageable with the buttocks of the subject extends sidewardly outwardly from the access device adjacent the proximal end thereof for parting the buttocks of a subject.

54. An insufflating apparatus as claimed in Claim 52 or 53 in which the proximal flange diverges outwardly proximally from the proximal end of the access device.

55. An insufflating apparatus as claimed in any of Claims 52 to 54 in which the outlet port from the manifold extends from the proximal flange.

56. An insufflating apparatus as claimed in any of Claims 33 to 55 in which the outlet port from the manifold extends from the access device adjacent the proximal end thereof.

57. An insufflating apparatus as claimed in any preceding claim in which the access device comprises a distal part and a proximal part, the proximal part comprising the communicating means located therein.

58. An insufflating apparatus as claimed in Claim 57 in which the proximal part of the access device is secured to the distal part thereof.

59. An insufflating apparatus as claimed in Claim 57 or 58 in which the proximal part is secured to the distal part with the instrument channel extending through the proximal and distal parts aligned with each other.

60. An insufflating apparatus as claimed in any of Claims 57 to 59 in which the proximal flange of the access device extends from a proximal end of the proximal part of the access device.

61. An insufflating apparatus as claimed in any of Claims 57 to 59 in which the proximal flange of the access device extends from a distal end of the proximal part of the access device.

62. An insufflating apparatus as claimed in any preceding claim in which an instrument extends through the instrument channel of the access device into the cavity, or through one or more vessels or lumens into the cavity.

63. An insufflating apparatus as claimed in Claim 62 in which the instrument comprises an endoscope or a colonoscope.

64. An insufflating apparatus as claimed in Claim 63 in which the flow controller is connected to one of the channels extending through the endoscope or the colonoscope for insufflating the cavity.

65. An insufflating apparatus as claimed in Claim 63 or 64 in which the pressure sensor is connected to one of the channels extending through the endoscope or the colonoscope for monitoring the cavity pressure.

66. An insufflating apparatus as claimed in any of Claims 63 to 65 in which the flow controller is connected to an insufflating channel, an instrument channel or a vacuum channel of the insufflator or the colonoscope, and the pressure sensor is connected to the other one of the insufflating channel, the instrument channel or the vacuum channel.

67. An insufflating apparatus as claimed in Claim 66 in which the flow controller is connected to the insufflating channel or the instrument channel of the endoscope or the colonoscope, and the pressure sensor is connected to the other one of the insufflating channel and the instrument channel of the endoscope or the colonoscope.

68. An insufflating apparatus as claimed in any of Claims 63 to 66 in which the flow controller and the pressure sensor are connected to the same channel of the endoscope or the colonoscope.

69. An insufflating apparatus as claimed in any preceding claim in which the signal processor is programmed to control the flow controller in response to the signal produced by the pressure sensor to maintain the cavity pressure at the set pressure value.

70. An insufflating apparatus as claimed in any preceding claim in which the set pressure value lies in the range of 2mmHg to 20mmHg.

71. An insufflating apparatus as claimed in any preceding claim in which the set pressure value lies in the range of 7mmHg to 15mmHg.

72. An insufflating apparatus as claimed in any preceding claim in which the set pressure value is approximately lOmmHg.

73. An insufflating apparatus as claimed in any preceding claim in which the set pressure is selectable in the range of 2mmHg to 20mmHg.

74. An insufflating apparatus as claimed in any preceding claim in which the insufflator comprises a first inlet port and a first outlet port, the flow controller being located in a path between the first inlet port and the first outlet port.

75. An insufflating apparatus as claimed in Claim 74 in which the first inlet port is adapted for connecting to a pressurised source of insufflating gas.

76. An insufflating apparatus as claimed in Claim 74 or 75 in which the first outlet port is adapted for connecting to one of the channels of the endoscope or the colonoscope.

77. An insufflating apparatus as claimed in any preceding claim in which the insufflator comprises a second inlet port, and the vacuum applying means is connected to the second inlet port.

78. An insufflating apparatus as claimed in Claim 77 in which the second inlet port is adapted for connecting to the outlet port of the communicating means.

79. An insufflating apparatus as claimed in Claim 77 or 78 in which the insufflator comprises a second outlet port, the second outlet port being adapted for connecting to an external vacuum source.

80. An insufflating apparatus as claimed in Claim 79 in which the vacuum applying means is located in a path between the second inlet port and the second outlet port.

81. An insufflating apparatus as claimed in any preceding claim in which the insufflator comprises a third inlet port, the pressure sensor being connected to the third inlet port.

82. An insufflating apparatus as claimed in Claim 81 in which the third inlet port is adapted for connecting to one of the channels of the endoscope or the colonoscope.

83. An insufflating apparatus as claimed in any preceding claim in which the vacuum applying means comprises a vacuum pump or a vacuum control valve, the vacuum pump or the vacuum control valve being infinitely variable, to produce a vacuum at infinitely variable vacuum levels.

84. An access device for accommodating an instrument through a bodily orifice into a cavity in the body of a human or animal subject during carrying out of a minimally invasive procedure therein, the access device being engageable in the bodily orifice and extending between a proximal end and a distal end and having an instrument channel extending therethrough from the proximal end to the distal end thereof for accommodating the instrument therethrough to the cavity, and comprising a communicating means adapted to receive a first vacuum at an extraction vacuum level and to apply the first vacuum to the cavity for drawing insufflating gas and smoke from the cavity.

85. An access device as claimed in Claim 84 in which the communicating means comprises a manifold, an outlet port communicating with the manifold, the outlet port being adapted for connection to a vacuum applying means for applying the first vacuum to the manifold, and at least one first inlet port in the access device communicating with the manifold for applying the first vacuum to the cavity.

86. An access device as claimed in Claim 85 in which the manifold is located in the access device, and the at least one first inlet port extends from the manifold and terminates in the instrument channel communicating with the instrument channel, or terminates adjacent the distal end of the access device with the at least one first inlet port facing distally from the access device.

87. An access device as claimed in Claim 85 or 86 in which a plurality of the first inlet ports are provided spaced apart circumferentially around the access device.

88. An access device as claimed in any of Claims 85 to 87 in which the first inlet ports are equispaced apart circumferentially around the access device.

89. An access device as claimed in any of Claims 85 to 88 in which at least one second inlet port extends from the manifold and terminates in an outer surface of the access device.

90. An access device as claimed in Claim 90 in which a plurality of the second outlet ports are spaced apart circumferentially around the outer surface of the access device.

91. An access device as claimed in any of Claims 85 to 90 in which the manifold extends circumferentially around the access device within the access device.

92. An access device as claimed in any of Claims 85 to 91 in which the manifold extends completely around the access device.

93. An access device as claimed in any of Claims 85 to 92 in which the manifold comprises a chamber formed within the access device.

94. An access device as claimed in any of Claims 85 to 93 in which a sealing means is located in the instrument channel of the access device, the sealing means being adapted to slideably and sealably engage an instrument extending through the instrument channel.

95. An access device as claimed in Claim 94 in which the sealing means comprises a sealing membrane extending into the instrument channel, and terminating in an instrument accommodating opening for slideably and sealably engaging an instrument extending through the instrument channel.

96. An access device as claimed in Claim 95 in which the sealing membrane comprises a resilient material.

97. An access device as claimed in Claim 95 or 96 in which the sealing membrane comprises a flexible material.

98. An access device as claimed in any of Claims 94 to 97 in which the sealing means is located in the instrument channel intermediate the proximal and distal ends thereof.

99. An access device as claimed in any of Claims 94 to 98 in which the sealing means is located proximally of the at least one first inlet port.

100. An access device as claimed in any of Claims 84 to 99 in which a proximal flange extends sidewardly outwardly from the access device and circumferentially around the access device.

101. An access device as claimed in any of Claims 84 to 100 in which a pair of radially sidewardly outwardly extending proximal flanges extend from the access device adjacent the proximal end thereof.

102. An access device as claimed in any of Claims 84 to 101 in which the access device is adaptedfor locating in the mouth of a subject, and defines a bite portion for enabling a subject to bite thereon.

103. An access device as claimed in Claim 102 in which the outlet port from the manifold extends from one of the proximal side flanges of the access device.

104. An access device as claimed in Claim 102 or 103 in which a distal flange extends sidewardly outwardly from and circumferentially around the access device adjacent a distal end thereof.

105. An access device as claimed in any of Claims 85 to 101 in which the access device is adapted for locating in the anus of a subject, and the access device comprises an anus engaging element engageable with the anus of a subject.

106. An access device as claimed in Claim 105 in which the proximal flange is engageable with the buttocks of a subject and extends sidewardly outwardly from the access device adjacent the proximal end thereof for parting the buttocks of the subject.

107. An access device as claimed in Claim 105 or 106 in which the proximal flange diverges outwardly proximally from the proximal end of the access device.

108. An access device as claimed in any of Claims 105 to 107 in which the outlet port from the manifold extends from the proximal flange.

109. An access device as claimed in any of Claims 85 to 108 in which the outlet port from the manifold extends from the access device adjacent the proximal end thereof.

110. An access device as claimed in any of Claims 84 to 109 in which the access device comprises a distal part and a proximal part, and the proximal part comprises the communicating means located therein.

111. An access device as claimed in Claim 110 in which the proximal part is secured to the distal part with the instrument channel extending through the proximal and distal parts aligned with each other.

112. An access device as claimed in Claim 110 or 111 in which the proximal flange of the accessdevice extends from a proximal end of the distal part of the access device.

113. An access device as claimed in Claim 110 or 111 in which the proximal flange of the access device extends from a distal part of the proximal part of the access device.

114. A method for insufflating a cavity in the body of a human or animal subject, the method comprising: inserting an access device into a bodily orifice of the subject through which the cavity is accessible, the access device extending between a proximal end and a distal end and having an instrument channel extending therethrough between the proximal and distal ends thereof for accommodating an endoscope or a colonoscope therethrough to the cavity, the access device comprising a communicating means adapted to communicate with the cavity through the access device, inserting the endoscope or the colonoscope through the instrument channel of the access device into the cavity, insufflating the cavity by delivering insufflating gas to the cavity through a channel extending through the endoscope or the colonoscope, and applying a first vacuum at an extraction vacuum level to the cavity through the communicating means in response to the cavity pressure exceeding a set pressure value or in response to a smoke evacuate signal for drawing gases and / or smoke from the cavity through the access device.

115. A method as claimed in Claim 114 in which the first vacuum at the extraction vacuum level is applied to the cavity through the communicating means until the cavity pressure has fallen to the set pressure value, or until termination of the smoke evacuate signal.

116. A method as claimed in Claim 114 or 115 in which the delivery of insufflating gas to the cavity is controlled while the first vacuum at the extraction vacuum level is being applied to the cavity through the communicating means.

117. A method as claimed in any of Claims 114 to 116 in which the delivery of insufflating gas to the cavity is controlled while the first vacuum at the extraction vacuum level is being applied to the cavity through the communicating means in response to the smoke evacuate signal for maintaining the cavity pressure substantially at the set pressure value.

118. A method as claimed in any of Claims 114 to 117 in which delivery of insufflating gas to the cavity is increased in response to the cavity pressure falling below the set pressure value when the first vacuum at the extraction vacuum level is being applied to the cavity through the communicating means in response to the smoke evacuate signal to maintain the cavity pressure at the set pressure value.

119. A method as claimed in any of Claims 114 to 118 in which delivery of insufflating gas to the cavity is reduced or paused in response to the cavity pressure exceeding the set pressure value when the first vacuum at the extraction vacuum level is being applied to the cavity in response to the cavity pressure exceeding the set pressure value.

120. A method as claimed in any of Claims 114 to 119 in which the first vacuum is produced by a vacuum applying means, and the vacuum applying means is operable in a first state thereof to produce the first vacuum at at least two selectable extraction vacuum levels.

121. A method as claimed in Claim 120 in which the vacuum applying means is operable in the first state thereof to produce the first vacuum at a plurality of selectable extraction vacuum levels.

122. A method as claimed in Claim 120 or 121 in which the extraction vacuum level at which the first vacuum is applied to the cavity through the communicating means is selected from the selectable extraction vacuum levels thereof in response to the cavity pressure when the first vacuum is being applied to the cavity in response to the cavity pressure exceeding the set pressure value, so that the greater the amount by which the cavity pressure exceeds the set pressure value, the greater will be the extraction vacuum level of the first vacuum.

123. A method as claimed in any of Claims 120 to 122 in which the smoke evacuate signal is indicative of the selectable extraction vacuum level at which the first vacuum is to be produced.

124. A method as claimed in any of Claims 114 to 123 in which the smoke evacuate signal is produced by a smoke evacuate signal producing means.

125. A method as claimed in Claim 124 in which the smoke evacuate signal producing means is adapted to produce the smoke evacuate signal indicative of the selectable extraction vacuum level at which the vacuum applying means operating in the first state thereof is to produce the first vacuum.

126. A method as claimed in any of Claims 114 to 125 in which a second vacuum at a collecting vacuum level of value less than the extraction vacuum level or the lowest level of the selectable extraction vacuum levels of the first vacuum is applied to the communicating means for collecting gases and / or smoke escaping from the cavity through or adjacent the access device in response to the signal produced by the pressure sensor being indicative of the cavity pressure being at or below the set pressure value or the termination or the absence of the smoke evacuate signal.

127. A method as claimed in Claim 126 in which the collecting vacuum level of the second vacuum comprises a vacuum level insufficient to draw gases and / or smoke from the cavity but sufficient to draw gases and / or smoke escaping from the cavity through or adjacent the access device.

128. A method as claimed in Claim 126 or 127 in which the second vacuum lies in the range of lOOmmHg to 500mmHg below atmospheric pressure.

129. A method as claimed in any of Claims 126 to 128 in which the second vacuum lies in the range of 200mmHg to 400mmHg below atmospheric pressure.

130. A method as claimed in any of Claims 126 to 129 in which the second vacuum is approximately 300mmHg below atmospheric pressure.

131. A method as claimed in any of Claims 114 to 130 in which the extraction vacuum level of the first vacuum lies in a range that when applied to the communicating means insufflating gas is drawn from the cavity through the communicating means at a flow rate in the range of 1 Litre per minute to 20 Litres per minute.

132. A method as claimed in any of Claims 114 to 131 in which the extraction vacuum level of the first vacuum lies in a range that when applied to the communicating means insufflating gas is drawn from the cavity through the communicating means at a flow rate in the range of 2 Litres per minute to 10 Litres per minute.

133. A method as claimed in any of Claims 114 to 132 in which the extraction vacuum level of the first vacuum when applied to the communicating means insufflating gas is drawn from the cavity through the communicating means at a flow rate of approximately 3 Litres per minute to 5 Litres per minute.

134. A method as claimed in any of Claims 114 to 133 in which the communicating means comprises a manifold, an outlet port communicating with the manifold, the first vacuum or the second vacuum being applied to the outlet port, and at least one first inlet port communicating with the manifold for applying the first vacuum or the second vacuum adjacent the access device.

135. A method as claimed in Claim 134 in which the manifold is located in the access device, and the at least one first inlet port for applying the first vacuum or the second vacuum adjacent the access device extends from the manifold and terminates in the access device in the instrument channel communicating with the instrument channel, or terminates adjacent a distal end of the access device with the at least one first inlet port facing distally from the access device.

136. A method as claimed in Claim 134 or 135 in which a plurality of the first inlet ports are provided spaced apart circumferentially around the access device.

137. A method as claimed in any of Claims 134 to 136 in which at least one second inlet port extends from the manifold and terminates in an outer surface of the access device.

138. A method as claimed in any of Claims 134 to 137 in which the manifold extends circumferentially around the access device within the access device.

139. A method as claimed in any of Claims 134 to 138 in which a sealing means is located in the instrument channel of the access device, the sealing means being adapted to slideably and sealably engage the endoscope or the colonoscope extending through the instrument channel.

140. A method as claimed in Claim 139 in which the sealing means comprises a sealing membrane extending into the instrument channel, and terminating in an instrument accommodating opening for slideably and sealably engaging the endoscope or the colonoscope.

141. A method as claimed in Claim 140 in which the sealing means is located proximally of the at least one first inlet port.

142. A method as claimed in any of Claims 134 to 141 in which the access device is adapted forlocating in the mouth of a subject, and defines a bite portion for enabling a subject to bite thereon.

143. A method as claimed in Claim 142 in which the access device is secured to the mouth of the subject by a head-strap.

144. A method as claimed in any of Claims 134 to 141 in which the access device is engageable with the anus of a subject for accommodating an endoscope or a colonoscope through the anus.

145. A method as claimed in any of Claims 134 to 144 in which the access device comprises a distal part and a proximal part, and the proximal part comprises the communicating means located therein.

146. A method as claimed in Claim 145 in which the proximal part is secured to the distal part with the instrument channel extending through the proximal and distal parts aligned with each other.

147. A method as claimed in any of Claims 114 to 146 in which the endoscope or the colonoscope is inserted into the cavity through the instrument channel of the access device, or through the instrument channel in the access device and through one or more vessels or lumens into the cavity.

148. A method as claimed in any of Claims 114 to 147 in which the insufflating gas is delivered to the cavity through an insufflating channel, an instrument channel or a vacuum channel of the endoscope or the colonoscope.

149. A method as claimed in any of Claims 114 to 148 in which the cavity pressure is monitored through the insufflating channel, the instrument channel or the vacuum channel of the endoscope or the colonoscope.

150. A method as claimed in any of Claims 114 to 149 in which the insufflating gas is delivered to the cavity through the insufflating channel or the instrument channel of the endoscope or the colonoscope, and the cavity pressure is monitored through the other one of the insufflating channel or the instrument channel.

151. A method as claimed in any of Claims 114 to 150 in which the vacuum applying means is operated under the control of a signal processor to produce the first and second vacuum at the respectiveextraction vacuum level and the collecting vacuum level in response to the cavity pressure and the smoke evacuate signal.

152. A method as claimed in any of Claims 114 to 151 in which the insufflating gas is delivered to the cavity by a flow controller under the control of the signal processor in response to the cavity pressure or in response to the smoke evacuate signal.

153. A method as claimed in any of Claims 114 to 152 in which the set pressure value lies in the range of 2mmHg to 20mmHg.

154. A method as claimed in any of Claims 114 to 153 in which the set pressure value lies in the range of 7mmHg to 15mmHg.

155. A method as claimed in any of Claims 114 to 154 in which the set pressure value is approximately WmmHg.

156. A method as claimed in any of Claims 114 to 155 in which the set pressure is selectable in the range of 2mmHg to 20mmHg.

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