Tube for minimally invasive surgery and associated surgical kit and method

Abstract

The invention relates to a tube (1) for use with a trocar for minimally invasive surgery, wherein the tube (1) has a guide channel (2) through which a shaft (3) of an endoscope or a surgical instrument can be guided in a lead-in direction (5), characterized in that the tube (1) has two seals (4a, 4b) for sealing the shaft (3), which are arranged one after the other in the lead-in direction (5) and delimit and seal a gate chamber (6) which is closed to the outside, and the gate chamber (6) has an access (7) through which a pressure difference (p1-p0) between the gate chamber (6) and the outside (8) can be adjusted. The invention also relates to a surgical kit, an endoscope system and a method for avoiding a larger leakage of filling gas from a tube.

Description

Technical Field

[0001] The present invention relates to a tube for use with a cannula for minimally invasive surgery, wherein the tube has a guide channel through which the handle of an endoscope or surgical instrument can be guided in an insertion direction.

[0002] The present invention also relates to a surgical kit and an endoscope system.

[0003] Finally, the present invention relates to a method for preventing significant leakage of filling gas from a tube (particularly the tube described above) configured for use with a cannula for minimally invasive surgery. The tube has a guide channel through which the handle of an endoscope or surgical instrument can be guided in the direction of introduction. Background Technology

[0004] A cannula is a medical device used in minimally invasive surgery to provide an access point, either sharp or blunt, to a body cavity (e.g., abdominal or thoracic cavity) and keep it open via a tube. This tube provides a guiding channel for introducing an endoscope or surgical instruments into the corresponding body cavity. The typical inner diameter of the tube is typically in the range of 0.5 to 12 mm. For example, to provide access to the abdominal cavity, the cannula is inserted into the abdominal cavity along with the tube through the abdominal wall. The surgeon can then examine the abdominal cavity using an endoscope introduced through the tube after withdrawing the cannula, or perform minimally invasive surgery within the abdominal cavity using grasping instruments, cutting instruments, electrical instruments, or other surgical instruments that can also be introduced through the tube.

[0005] In such surgeries, especially abdominal surgeries, tubes are typically used to inflate body cavities with an inert gas such as carbon dioxide (CO2) to provide greater freedom of movement for the planned procedure. The main problem here is that the filling gas used for inflation (often referred to as the injection gas) can escape uncontrollably from the tubes. This is particularly problematic in the context of infectious diseases, as the filling gas can become contaminated with microorganisms such as bacteria and pathogens after contact with the body's interior.

[0006] Current tubing typically has at least one elastic diaphragm to seal, for example, the handle of the endoscope introduced into the tubing, so that as little filling gas as possible escapes from the body cavity during surgery. Here, a good seal can be achieved, for example, through a cross-shaped slit and the use of an elastic diaphragm material, even when the handle moves axially with the diaphragm within the guide channel of the tubing. Furthermore, self-sealing diaphragms are known, which close once the handle is pulled out of the through-slot. Additionally, the diaphragm can be loaded with a spring element, for example, to generate a compressive force and thus produce an improved seal.

[0007] However, typically in tubes common in existing technologies, a hissing sound can be noticed or heard when the endoscope or instrument introduced into the tube is pulled out, indicating uncontrolled leakage of the filling gas. This is because overpressure is usually established within the body cavity during such procedures. This overpressure is usually regulated by means of an insufflator that guides the pressurized filling gas into or out of the body cavity.

[0008] Uncontrolled gas escape from the cavity also often results in unsatisfactory maintenance of environmental conditions within the body cavity, despite regulation by the insulator, which can interfere with the surgical procedure. Leaks can also cause changes in humidity and / or temperature within the body cavity, which may lead to undesirable fogging of endoscopic optics, obstructing vision.

[0009] Furthermore, existing technologies have disclosed blowers capable of extracting smoke from body cavities (surgical smoke extraction). For this purpose, vapor generated in the body cavity is expelled via the blower, wherein the extracted gas is guided through a filter (e.g., a HEPA filter, which has a filtration efficiency of 99.95% for particles as small as 0.1 μm) to capture contaminants and smoke particles. Summary of the Invention

[0010] In this context, the objective of the present invention is to improve the performance characteristics of the tube and to develop a corresponding method for this purpose.

[0011] To address this task, according to the present invention, a tube of the type described at the beginning is particularly proposed, the tube having two seals for sealing the handle, the seals being arranged successively along the introduction direction and defining and sealing an outwardly closed gate chamber, the gate chamber having an inlet through which the pressure difference between the gate chamber and the outside can be regulated, the two seals being designed such that, regardless of whether the handle is introduced into the guide channel of the tube, a corresponding pressure difference can be maintained between the gate chamber and the external environment, and between the gate chamber and the section of the guide channel connected to the distal seal of the two seals, thereby minimizing the outflow of filling gas from the cavity accessible by the tube through the two seals.

[0012] The "external environment" here can be understood as either the external environment, such as the external environment inside the gate chamber, or as a body cavity (also located outside the gate chamber) that can be accessed via a pipe. Therefore, by introducing or expelling gate gas into the gate chamber, the pressure difference relative to the external space and / or relative to the body cavity can be set or adjusted.

[0013] The entrance to the gate chamber can be designed as a gate gas conduit through which gate gas can be introduced or discharged. The gate gas is preferably not obtained from the environment, but from a source such as a CO2 compressed gas cylinder.

[0014] In other words, the tube according to the invention provides a gate chamber that is sealed relative to the guide channel by means of two seals, either proximal or distal. The seals are designed such that a corresponding pressure differential can be maintained between the gate chamber and the environment, and between the gate chamber and the guide channel in the sections connected to the distal ends of the two seals (and therefore with the body cavity), regardless of whether the handle is introduced into the guide channel of the tube. "Distal" can be understood here as toward the body cavity accessible by the tube (and therefore away from the proximal end of the endoscope introduced into the tube), and "proximal" is understood as away from the body cavity.

[0015] This means that the two seals can be configured to be self-closing, so that both seals seal the gate chamber even when the handle is not introduced. Here, the pressure differential is preferably at least 50 mbar to effectively prevent leakage, as will be explained in more detail later.

[0016] The two seals can be designed, for example, as lip seals, which are particularly capable of flipping in both directions so that a seal can be maintained when the handle is displaced relative to the seal in the direction of introduction, for example, when required during surgical procedures. Furthermore, the seals can have defining or overlapping areas or flaps that can be modified to allow the handle to be guided through without damaging the seal and thus to be repeatedly passed through, wherein the corresponding seal automatically closes again after the handle is pulled out.

[0017] The advantage of the solution according to the invention is that, especially when the handle is introduced into or withdrawn from the guide channel, the escape of the filling gas from the cavity (typically a body cavity) accessible by the tube is effectively minimized. Therefore, by preventing contamination of ambient air by the escaping contaminated filling gas, the safety of surgical personnel is improved, and the quality of maintaining the filling pressure within the body cavity during medical procedures is enhanced (by reducing filling gas leakage).

[0018] For example, the proximal seal of the two seals can be designed to maintain a pressure differential of preferably at least 50 mbar between the gate chamber and the outside environment, even when the handle is pulled out. Furthermore, the distal seal of the two seals can be designed to maintain a pressure differential of preferably at least 50 mbar between the gate chamber and the distally adjacent section of the guide channel, even when the handle is pulled out.

[0019] By introducing gate gas into the gate chamber, overpressure can be generated between the gate chamber and a section of the guide channel, which is connected at its distal end to the distal seal of one of two seals and (in surgical cases) communicates with a body cavity accessible via a tube.

[0020] Conversely, by venting the gate gas from the gate chamber, negative pressure can be created between the gate chamber and the section of the guide channel, and, if necessary, between the gate chamber and ambient air. Furthermore, this allows the filling gas forced into the gate chamber through the distal seal of the two seals to be expelled from the gate chamber, particularly before the (potentially contaminated) filling gas passes through the proximal seal of the two seals. To prevent contaminated filling gas from reaching the environment through the proximal seal as it is drawn out of the gate chamber, the proximal seal sealing the gate chamber relative to ambient air can be designed such that it opens only when a first pressure differential is present, preferably at least 50 mbar higher than a second pressure differential, from which the distal seal, which seals the gate chamber relative to the body cavity, opens.

[0021] The inlet leading to the gate chamber, that is, in particular the stun gas conduit, may have a valve by means of which the flow of stun gas into or out of the gate chamber can be regulated. This, in particular, allows for the controlled introduction and / or discharge of stun gas into and / or from the gate chamber.

[0022] The inlet or gate gas conduit may therefore have a coupling device for airtightly coupling the gas line. The gas line can, for example, be connected to an inlet or a gas source. The coupling device can be designed as a threaded joint, particularly a LUER joint, or a bayonet joint. The gas line can, for example, be formed by means of a pressure-resistant hose that can be connected to an inlet. The inlet leading into the gate chamber may also include a gas guide line integrated into the conduit, connecting the gate chamber to the coupling device.

[0023] Furthermore, it is advantageous for effectively preventing leakage from the gate chamber that the two seals seal the gate chamber and / or the inspection chamber accessible by pipe to the outside, and preferably regardless of whether the handle is introduced into the guide channel through the two seals.

[0024] A preferred design specifies that the proximal seal of the two seals can persistently maintain a pressure difference between the gate chamber and the outside, which is higher than the pressure difference between the gate chamber and the section of the guide channel that is distally connected to the gate chamber, which the distal seal of the two seals can persistently maintain. This ensures that the filling gas that has passed through the distal seal does not simultaneously pass through the proximal seal and thus reach the outside.

[0025] Furthermore, the two seals are configured to automatically close and seal, respectively. This allows the seal to automatically close and thus seal the gate chamber after the handle is pulled out of the respective seal. For this purpose, various embodiments of automatically closing seals are known in the prior art, such as those based on resilient sealing elements with self-resetting force, or based on spring mechanisms that provide a reset force for automatically closing the seal.

[0026] To ensure good adjustability of the internal pressure p1 within the gate chamber, it is preferable that, apart from the two seals and the inlet, the gate chamber is defined by an outwardly closed inner wall. This inner wall preferably remains immovable under overpressure or negative pressure, thereby maintaining a constant volume of the gate chamber. In other words, the inner wall can therefore be designed to be pressure-resistant and immovable, for example, by means of a fixed cavity wall (e.g., made of metal or plastic).

[0027] In a second aspect of the invention, which may be independent, to address the task described at the beginning, an additional tube for use with a cannula for minimally invasive surgery is also proposed. Here, the tube can be designed in particular as described previously. Therefore, according to the invention, to address the task in the tube of the above type, it is particularly proposed that a sealing element be constructed at the distal segment of the tube placed in the region of the insertion site (into the body cavity) during medical surgery, the sealing element concentrically surrounding and sealing the tube.

[0028] This additional sealing element effectively prevents the filling gas from leaking from the body cavity at the insertion site, for example, due to the unsealed transition between the skin surface and the outer surface of the tube.

[0029] For this purpose, it is preferable that the sealing element has a preferably annular contact surface, which is configured to provide an airtight seal to the insertion site by means of direct or indirect contact with the surface of human skin in the insertion site area.

[0030] The sealing element can be constructed, for example, as a preferably flexible and / or resilient sealing sheet, particularly in the form of an adhesive ring. The sealing sheet may have an adhesive layer on its distal underside for convenient and secure sealing. Using this adhesive layer, the desired airtight seal of the body cavity can then be achieved either directly through contact with the skin surface or indirectly, for example, through contact with an adhesive film that is airtightly adhered to the skin surface.

[0031] In another aspect of feasible independent inventive features, the tube described so far can also be further formed by having a UV light source, preferably a UV-LED, that emits UV light, preferably UVC light, into the gate chamber of the tube, the UV light being suitable for killing pathogens that have entered the gate chamber. Therefore, a UVC illumination unit can be installed in the gate chamber, by means of which pathogens, for example, that enter the gate chamber along with the incoming filling gas, can be killed. This design further improves safety when using the tube, because even when a small amount of contaminated filling gas enters the gate chamber, the filling gas can be rendered harmless.

[0032] To address the task described at the beginning, a surgical kit is further proposed, comprising a tube as previously described, and an endoscope or surgical instrument, each having a handle. The surgical kit is now characterized in that the handles are designed and sized to be inserted into a guide channel of the tube and sealed therein by means of the two seals.

[0033] Another surgical kit according to the invention, which accomplishes the above-described task, includes a tube and an insulator for use with a cannula for minimally invasive surgery. Here, the insulator is connected to the tube, for example, via a coupling device and a corresponding gas line, and is also configured to introduce filling gas through the tube into a body cavity, for example, to adjust a specific filling pressure within the body cavity. Even in this kit, the tube can be designed as described above. According to the invention, to solve this task, the insulator of the surgical kit is connected to the gate chamber of the tube via a gate gas conduit and an inlet, the gate chamber being defined and sealed by two seals. Furthermore, the insulator is configured to introduce and / or expel gate gas from the gate chamber via the gate gas conduit.

[0034] The blower can also be formed by two separate blowers, wherein the first blower regulates the filling pressure, and the second blower of the two blowers regulates the pressure p1 in the gate chamber.

[0035] Advantageously, the pressure difference (p1-p0) between the gate chamber and the outside and / or the pressure difference (p1-p2) between the gate chamber and the inspection chamber accessible by pipe can be set, preferably adjusted, by the blower. For this purpose, the blower can have its own pressure regulator and corresponding control electronics.

[0036] The brake gas can be obtained from the same source as the filler gas, which the injector uses to regulate the filling pressure within the body cavity accessible via a tube, such as the filling pressure in a conventional CO2 compressed gas cylinder. However, unlike the filler gas, the brake gas cannot first reach the body cavity from the injector and therefore cannot be contaminated there. In other words, the brake gas conduit can therefore be designed separately from the additional filler gas line, through which the filler gas can be introduced into the tube and from there into the body cavity by means of the injector.

[0037] Therefore, the insufflator can also be configured to regulate the filling pressure of the filling gas in the body cavity. In particular, the overpressure (p2-p0) between the filling gas inside the body and the external environment can be regulated. For this purpose, the pressure in the body cavity can be detected by means of a pressure sensor on the tube, a pressure sensor of the insufflator, or a pressure sensor of an endoscope or other instrument introduced into the body cavity through the tube.

[0038] According to a preferred design, the blower is configured to regulate the internal pressure of the gate chamber. This allows for adjustment of the pressure difference between the distal section of the guide channel and the external environment.

[0039] Furthermore, the blower is preferably designed as a bidirectional blower, allowing the filling gas to be introduced into the tube and thus into the body cavity via the blower, and to be extracted therefrom. Additionally, preferably, the regulation of the gate gas introduced into or discharged from the gate chamber via the gate gas conduit can be designed as bidirectional regulation.

[0040] Alternatively, two separate blowers may be used, which are particularly capable of drawing filling gas from a common source. Thus, while the first blower is configured to regulate the filling pressure in the body cavity, the second blower may be configured to regulate the internal pressure in the gate chamber by introducing and / or discharging gate gas (which may in particular be the same as the filling gas) through an inlet into / outlet of the gate chamber.

[0041] The insulator of the surgical kit can therefore be configured to introduce filling gas at a specific filling pressure into the tube and thus into the examination chamber, or to discharge it from the tube and the examination chamber, via the filling gas line. Thus, the insulator can adjust the filling pressure p2 within a body cavity accessible through the tube.

[0042] Additionally, or alternatively, the blower can be configured to maintain overpressure (p1-p2) in the gate chamber relative to the inspection chamber by introducing gate air into the gate chamber, particularly through the valve. This is preferably done such that once the distal seal is temporarily opened when the handle is introduced or pulled out of the tube, gate air flows from the gate chamber through the distal seal of the two seals towards the inspection chamber. In this case, the blower can then sequentially supply fresh gate air to maintain the desired internal pressure in the gate chamber.

[0043] Alternatively, the blower can also be configured to maintain a negative pressure (p1-p2) in the gate chamber relative to the inspection chamber by discharging gas from the gate chamber, particularly through the valve. This can preferably be done by having the filling gas from the body cavity, flowing into the gate chamber through the distal seal of the two seals and thus briefly reducing the negative pressure, drawn out of the gate chamber by the blower.

[0044] In other words, the blower can therefore be configured to monitor the internal pressure (p1) in the gate chamber. Here, the blower preferably actively regulates the internal pressure p1 to a specific rated value, particularly by introducing gate gas into the gate chamber or by discharging gas from the gate chamber (in each case, unidirectional regulation) or by introducing and / or discharging gas (bidirectional regulation).

[0045] To ensure particularly robust regulation of the internal pressure within the gate chamber, it is advantageous that the blower is configured to actively and automatically introduce or expel gate air into or from the gate chamber via a gate air conduit as needed (automated and regulated bidirectional operation). For this purpose, the blower may also have a regulator (either mechanical or electronically designed) that actively regulates the flow of gate air into and / or out of the gate chamber.

[0046] Here, by using a (preferably optical) motion sensor (which will be described in more detail later), the pulling of the endoscope handle from the two seals can be detected, wherein the adjustment can have been actively reversed in response to the detected movement of the handle to regulate the pressure in the gate chamber in order to avoid excessively drastic changes in the pressure in the gate chamber. Therefore, the motion sensor can provide a trigger signal that initiates active readjustment of the internal pressure in the gate chamber, wherein the tube or endoscope system including the tube can each have corresponding adjustment electronics.

[0047] It is also possible to operate with only temporary adjustment of the regulated pressure in the gate chamber. In this case, the blower is aware of two operating modes: in the first operating mode, the internal pressure of the gate chamber is actively regulated by the blower, especially when inserting or removing an endoscope / instrument into or from the tube. Conversely, if the endoscope / instrument is introduced through and sealed by both seals, the blower can operate in a second operating mode, in which the internal pressure of the gate chamber is monitored but not actively regulated (because there is no concern about leakage in this case). Additionally, the blower can be configured to restart active regulation (and thus automatically switch back to the first operating mode) upon detecting an unacceptable deviation from the preset pressure rating of the gate chamber.

[0048] Furthermore, the tube may also have a pressure sensor, preferably located in the gate chamber or in the gas delivery line leading to the gate chamber. Measurement data detected by the pressure sensor allows for the deduction of whether the instrument has been introduced into the tube or is approximately just about to be withdrawn. Accordingly, an insulator can then be configured to, based on the pressure sensor's measurement data, introduce gate gas into the gate chamber and / or expel gas from the gate chamber. Thus, for example, when withdrawing the endoscope from the tube, sufficient overpressure or, for example, sufficient negative pressure relative to the distal section of the tube's guide passage can always be maintained in the gate chamber, preventing potentially contaminated filling gas from the body cavity from entering the environment.

[0049] To achieve this regulation, trainable algorithms (machine learning) can be used to process the pressure sensor measurements, thereby ensuring the correct pressure in the gate area. Therefore, the blower can have a computing unit that implements a regulation algorithm, particularly based on machine learning methods, to adjust the pressure inside the gate chamber. Furthermore, the blower or tube can also have an additional pressure sensor for detecting the current ambient air pressure.

[0050] Furthermore, the usability of the tubes and surgical kits described to date can be improved by including at least one pressure sensor in the surgical kit, preferably in the tube. This pressure sensor can be configured to measure the ambient atmospheric pressure p0, the internal pressure p1 of the gate chamber, or the filling pressure p2 of a body cavity accessible through the tube. All these design options improve the prevention of leakage.

[0051] Finally, the surgical kit, that is, the tube described above, may include at least one motion sensor for detecting the movement of a handle introduced into the guide channel of the tube. The motion sensor may be implemented capacitively, optically (e.g., by means of a simple grating), or inductively. Such a motion sensor can be advantageously used to regulate the internal pressure of the gate chamber, as will be explained in more detail later.

[0052] Furthermore, it is recommended that the gas exhaust section of the gate chamber be equipped with a particulate filter, preferably a HEPA filter, for filtering out viruses and bacteria. In this design of the tubing or surgical kit, contaminated filling gas can be discharged from the gate chamber and reliably discharged into the environment after filtration.

[0053] To address the task described at the beginning, an endoscopic system is also proposed, comprising an endoscope and a tube or surgical kit as described above. The endoscope is coordinated with the tube and has a handle for this purpose, which is sealable by means of two seals and can be inserted into the guide channel of the tube.

[0054] As already mentioned, undesirable fumes may be generated during the use of endoscopic systems, for example, when tissue is removed intra-abdominalally using HF instruments under endoscopic visualization. To inform the user of potential hazards, the endoscopic system may therefore include a spectrometer configured to analyze the fumes just exiting through the tube and / or issue a warning signal upon detection of fumes. If the spectrometer detects a hazardous condition based on the measured spectrum, it can, for example, place the endoscopic system into a safe operating state by disabling the HF instruments or by activating or increasing fume extraction. Furthermore, the light source in the tube can also be activated to kill pathogens contained in the fumes.

[0055] In particular, according to the present invention, in order to solve the aforementioned task, a method of the type described at the beginning for avoiding large leaks is proposed, wherein the gate gas is introduced into or discharged from an externally closed gate chamber of the pipe through an inlet (especially as further described above), wherein the gate chamber is defined and sealed by two seals.

[0056] In this method, preferably, the pressure difference (p1-p2) between the gate chamber and the guide channel at the distal end connected to the gate chamber can be regulated and / or maintained by introducing and / or venting gate gas.

[0057] In this method, a filling gas, preferably through a tube, and more preferably through a guide channel of the tube, can be introduced into a body cavity that is accessible via the tube. That is, in a specific surgical procedure, the section of the guide channel can be filled with filling gas and connected to a body cavity accessible via the tube.

[0058] According to the first scheme, by introducing fresh gate gas, particularly through the valve, into the gate chamber, an overpressure (p1-p2) of preferably at least 50 mbar can be maintained in the gate chamber relative to the section of the guide channel. This can be done in particular when the gate gas escapes from the gate chamber through a corresponding seal of one of the two seals, thereby briefly reducing the overpressure in the gate chamber. The advantage of this overpressure scheme is that if one of the two seals is temporarily opened during the introduction or withdrawal of the handle, sterile gate gas always flows through the seal. This effectively prevents contaminated filling gas from reaching the gate chamber and from there to the outside. Furthermore, by preventing the escape of filling gas, pressure loss within the body cavity accessible via the tube is effectively avoided.

[0059] In this overpressure scheme (p1 > p2 and (!) p1 > p0, since it is appropriate that p2 > p0), contaminated filling gas usually cannot enter the gate chamber because the gate chamber is overpressured compared to the body cavity; in order to prevent gate gas from reaching the environment from the gate chamber, the proximal seal should be designed to be correspondingly stronger so that the proximal seal can withstand the necessary overpressure p1-p0, especially when introduced into the handle.

[0060] An alternative negative pressure scheme involves maintaining a negative pressure (p1-p2) preferably at least 50 mbar in the gate chamber relative to the section of the guide channel by drawing gas from the gate chamber, particularly through the valve. This can occur, in particular, when gas enters the gate chamber through one of the two seals and thereby briefly reduces the negative pressure in the gate chamber. The gas forced into the gate chamber can be (potentially contaminated) filler gas used to inflate a tube-accessible body cavity, wherein the filler gas enters the gate chamber through the distal seal of the two seals; or the gas forced in can be ambient air, which enters the gate chamber from the outside through the proximal seal of the two seals.

[0061] The negative pressure design means that if one of the two seals is temporarily opened during handle insertion or withdrawal, fill gas or air enters the gate chamber, temporarily reducing the negative pressure. The incoming gas is immediately drawn out, maintaining the negative pressure. This ensures that once contaminated fill gas enters the gate chamber, it cannot pass through the distal seal of the two seals. Because once the distal seal opens, ambient air flows into the gate chamber due to the negative pressure, but no gas flows from the gate chamber into the environment.

[0062] In the negative pressure configuration, although the pressure p1 in the gate chamber is adjusted to be less than the pressure p2 in the body cavity (i.e., p2 > p1), contaminated filling gas can still reach the gate chamber when the distal seal is opened. However, because the internal pressure p1 in the gate chamber can be adjusted to always be less than the (atmospheric) ambient pressure p0, it is particularly applicable that p0 > p1 (negative pressure in the gate chamber relative to the environment) and p2 > p0 (overpressure in the body cavity relative to the environment), effectively preventing contaminated gas from escaping from the chamber to the outside. The advantage of the negative pressure configuration is that, for example, fumes that may be generated in the abdominal cavity when using HF devices can be discharged through the gate chamber by reducing the pressure p1 in the gate chamber.

[0063] Another preferred design of the method specifies that when the handle is introduced into the distal seal of the two seals (and / or also into the proximal seal of the two seals) and / or when the handle is pulled out from the distal seal (and / or when the handle is pulled out from the proximal seal), the internal pressure p1 in the gate chamber is adapted, in particular increased or decreased. For this purpose, it is preferable to detect the introduction and / or pulling out using a motion sensor, particularly the aforementioned motion sensor, which is preferably integrated into the tube. This means that the internal pressure p1 is adapted in response to the detected movement of the handle.

[0064] The internal pressure p1 can be adjusted, for example, by introducing fresh, sterile gate gas into the gate chamber, thereby creating an overpressure relative to the environment and body cavity. Thus, in this configuration, fresh gate gas flows through the distal seal toward the inspection chamber, which is accessible via a tube. This effectively prevents (potentially contaminated) filling gas from being forced into the gate chamber during the introduction / extraction of the handle.

[0065] Alternatively, the internal pressure p1 can be adjusted by extracting the gate gas from the gate chamber, thereby creating a negative pressure relative to the environment. In this case, ambient air therefore always flows into the gate chamber through the proximal seal when the handle is pulled out / introduced, so that uncontaminated filling gas can overcome this flow from the gate chamber to the environment.

[0066] Furthermore, the method can be further improved by performing a flushing process during handle removal or handle introduction to flush the gate chamber with fresh, uncontaminated gate air. For this purpose, the gate chamber is first adjusted to an overpressure relative to the pressure of the filling gas within the body cavity. If the handle is subsequently guided through the upper or lower seal (i.e., pushed in or pulled out), uncontaminated gate air will flow from the gate chamber into the environment (non-critical) through the proximal seal or into the body cavity (again, non-critical) through the distal seal. Thus, especially when the handle is pulled out, the uncontaminated gate air flows around the handle, is forced through the distal seal into the lower section of the tube, and from there into the body cavity. This pushes the contaminated gas in the lower section of the tube back into the body cavity, preventing it from rising within the tube. When changing the endoscope / instrument in the tube, the pressure in the body cavity temporarily increases as fresh gas flows into the body cavity from the gate chamber. However, this can be captured by the insulator when it subsequently releases excess filling gas from the body cavity through the tube.

[0067] The present invention will now be described in more detail with reference to embodiments, but the invention is not limited to these embodiments. Those skilled in the art can derive other embodiments from the following description in conjunction with the foregoing general description and the accompanying drawings.

[0068] In the following description of different preferred embodiments of the invention, functionally consistent elements are given consistent reference numerals even in cases of different designs or shapes. Attached Figure Description

[0069] It is shown that:

[0070] Figure 1 A schematic longitudinal section of a pipe known in the prior art is shown.

[0071] Figure 2 Show Figure 1 Detailed image of the pipe.

[0072] Figure 3 The tube according to the invention is shown, which is introduced into the body cavity at the insertion site by means of a cannula (not shown).

[0073] Figure 4 Show Figure 3 A tube, in which the handle of the endoscope is inserted.

[0074] Figure 5 A surgical kit including the tube and associated air insulator according to the invention is shown.

[0075] Figure 6 This illustrates another tube according to the invention, having a sealing element for sealing the inlet portion.

[0076] Figure 7Different possible designs for the seal are shown, which can be used in pipes according to the invention.

[0077] Figure 8 This illustrates another possible design for a seal with overlapping sealing plates.

[0078] Figure 9 This invention also shows a tube having a UV light source for killing germs, and

[0079] Figure 10 A first overpressure scheme for preventing leakage from the pipe according to the invention is shown, while

[0080] Figure 11 A second negative pressure scheme is shown for preventing leakage from the pipe according to the invention. Detailed Implementation

[0081] Figure 1 This illustrates a commonly used tube 1 design in the prior art, which can be introduced into a body cavity 15 using a cannula to perform minimally invasive surgery. Tube 1 has a guide channel 2, and an endoscope handle 3 can be inserted along... Figure 1 The direction of introduction 5 shown is guided through the guide channel until it enters the body cavity 15.

[0082] like Figure 2 As shown, tube 1 is known in the prior art, having a proximal seal 4a and a further distal seal 4b, by which the endoscope handle 3 can be sealed. This seal is necessary to allow the filling gas 26 to pass through during medical procedures. Figure 2 The configuration shown introduces a filling gas line 27 on tube 1 into a body cavity 15 accessible via tube 1, so as to load the body cavity with the desired filling gas pressure and thereby provide sufficient free space for optical examinations by means of an endoscope.

[0083] Figure 3 The first tube 1 according to the invention is shown. This first tube is used in conjunction with a cannula for minimally invasive surgery, the cannula also having two seals 4a, 4b for sealing the insertion guide channel 2 (e.g., Figure 4 The handle 3 of the endoscope or surgical instrument (shown). Two seals 4a and 4b are arranged successively about the direction of introduction 5 and define an outwardly closed gate chamber 6.

[0084] As in Figure 3 and Figure 4 As shown, the two seals 4a and 4b are designed to close automatically, so that these seals seal the gate chamber 6 regardless of whether the handle 3 is introduced into the guide channel 2 through the gate chamber 6 (e.g., Figure 4(as in the example) or not introduced into the guide channel (such as...) Figure 3 (as in the middle). Furthermore, within the wall of pipe 1, the inlet 7 is constructed via a perforated air guide line 33 that leads into the gate chamber 6. A coupling device 12 in the form of a LUER connector is constructed on the outer side of the inlet 7, such as... Figure 5 As shown, the gas line 13 for inputting the gate gas 11 can be coupled to the LUER connector. Therefore, the pressure difference (p1-p0) between the internal pressure p1 in the gate chamber 6 and the atmospheric environmental pressure p0 in the outside environment 8 can be adjusted via the inlet 7. Figure 3 The filling gas line 27 in the middle also has the same construction for coupling. Figure 5 The LUER coupling device 12 of the gas pipeline 13b in the diagram.

[0085] The proximal seal 4a here can persistently maintain the pressure difference between the gate chamber 6 and the outside environment 8, which is higher than the pressure difference that the distal seal 4b can persistently maintain in the section 9 of the guide channel 2 that is connected to the gate chamber 6 at the distal end (see Figure 4 The pressure difference between the two ends is thus achieved. This ensures that even after the filling gas 26 has passed through the distal seal 4b and the pressure difference p1-p2 is eliminated (which can be detected by a pressure sensor), the proximal seal 4a remains able to withstand the pressure difference, preventing the filling gas 26 entering the gate chamber 6 from reaching the environment 8. This also applies to... Figure 3 As shown, handle 3 has been pulled out of tube 1.

[0086] Figure 5 A surgical kit comprising a tube 1 according to the invention and an associated blower 25 is shown, the surgical kit being used to... Figure 5 As shown, the gas line 13b, which implements the filling gas line 27, is connected to the tube 1 to introduce the filling gas 26 through the guide passage 2 of the tube 1 into the body cavity 15. The blower 25 is connected to the gate chamber 6 of the tube 1 via the inlet 7 via another gas line 13a, which implements the gate gas conduit 28. The blower 25 is now configured to introduce or withdraw the gate gas 11 into or from the gate chamber 6 via the gate gas conduit 28. For this purpose, the blower 25 has a pressure regulator 30a, which enables bidirectional regulation of the gate gas 11.

[0087] Furthermore, the blower 25 regulates the filling gas pressure p2 present in the body cavity 15 using the second pressure regulator 30b. To this end, the blower 25 guides the filling gas 26 through the filling gas line 27 and the guide passage 2 of the tube 1 into the body cavity 15, or discharges the filling gas 26 from the body cavity 15 via this path. In other words, the regulation of the filling gas pressure p2 is also achieved as a bidirectional regulation.

[0088] exist Figure 5 In the illustrated embodiment, the gate gas 11 is the same as the fill gas 26, wherein the blower 25 obtains both the gate gas 11 and the fill gas 26 from a CO2 compressed gas cylinder. The blower 25 also has a HEPA filter through which excess gate gas 11 or excess fill gas 26 can be reliably released to the outside environment 8.

[0089] Utilizing Figure 5 The surgical kit shown, more precisely by means of the insulator 25, can now not only set or adjust the pressure difference p1-p0 between the pressure p1 in the gate chamber 6 and the pressure p0 in the outside environment 8, but also the pressure difference p1-p2 between the pressure p1 in the gate chamber 6 and the pressure p2 of the filling gas present in the lower distal section of the guide channel 2. This, in particular, prevents greater leakage of the filling gas 26 from the pipe 1 into the environment 8.

[0090] like Figure 10 As shown, for example, the internal pressure p1 in the gate chamber 6 can be adjusted to be higher than the external pressure p0 and the filling gas pressure p2 in the body cavity 15. Here, this overpressure p1-p2 is adjusted by introducing fresh gate air 11 into the gate chamber 6 and the blower 25. If the handle 3, for example, is in Figure 4 As shown, when pulled out of tube 1, the lower distal seal 4b opens first, and then, due to overpressure, the uncontaminated gate gas 11 passes through the distal seal 4b into section 9 of the guide channel 2. Thus, the filling gas 26, potentially contaminated by viruses or bacteria from body cavity 15, is effectively prevented from passing through the two seals 4a, 4b until reaching the environment 8.

[0091] Regarding this alternative location, if in Figure 11 As shown, the internal pressure p1 in the gate chamber 6 can also be adjusted to be lower than the external pressure p0 and the filling gas pressure p2. For this purpose, once, for example, the filling gas 26 enters the gate chamber 6 through the lower distal seal 4b and thus briefly reduces the negative pressure in the gate chamber 6, causing the negative pressure p1-p2 to drop below a preset rated value, the blower 25 maintains the negative pressure p1-p2 in the gate chamber 6 relative to the distal section 9 of the guide channel 2 by drawing gas (gate gas 11 and / or filling gas 26) from the gate chamber 6. Potentially contaminated filling gas 26 that has been forced into the gate chamber 6 is thus... Figure 5 The gate gas conduit 28 shown in the figure discharges from the gate chamber 6, where the filling gas 26 can be filtered to intercept any pathogens that may be contained therein.

[0092] Here, in two options ( Figure 10 / Figure 11This ensures that the pressure of the filling gas p2 in the body cavity is always higher than the atmospheric pressure p0, which is required in typical surgical situations.

[0093] Figure 7 Several possible geometries and designs for the distal / proximal seals 4a / 4b of the sealing gate chamber 6 are shown. The seals 4 are designed using an elastic diaphragm in which one or more slits 34 are introduced. This achieves... Figure 4 The endoscope handle 3 shown can be guided through the slit 34, wherein after the endoscope handle 3 is removed, the seal 4 automatically closes and seals again.

[0094] exist Figure 8 In another possible design of the seal 4 shown, the seal 4 automatically closes and thereby seals the gate chamber 6 after the handle 3 is pulled out of the tube 1. For this purpose, the seal 4 is constructed using overlapping membrane flaps. Therefore, in Figure 8 In the example, instead of using a (through) slit 34, an overlapping region is used, which can move relative to each other and provide an opening for the guide handle 3 to pass through in a deflected state.

[0095] Figure 9 Another aspect is shown, which can be configured to improve safety when using the pipe 1 according to the invention. Therefore, in Figure 9 The tube 1 shown in the embodiment has a UVC light source 24 that emits UVC radiation into the gate chamber 6 to kill contaminants, such as viruses, bacteria, or other pathogens, that enter the gate chamber 6. The light source 24 is integrated into the tube 1 in the form of an LED, wherein the tube 1 is made of a UV-transparent material in the area of ​​the LED to allow light to be conducted into the gate chamber 6.

[0096] exist Figure 5 The tube 1 shown according to the invention further includes a pressure sensor 31, which is connected to the inflator 25 via a signal line 29, and the inflator 25 is able to detect the filling gas pressure p2 present in the body cavity 15 by means of the pressure sensor, so as to adjust the filling gas pressure. Figure 5 The surgical kit shown, especially its tube 1, may also have an additional pressure sensor 31, for example, to detect the internal pressure p1 of the gate chamber 6 or, for example, to detect the atmospheric pressure p0.

[0097] In addition, Figure 5In the tube 1, an optical motion sensor 32 is included. This optical motion sensor is also read by the blower 25 and can detect not only the insertion of the handle into the guide channel 2 but also the withdrawal of the handle 3 from the tube 1. Therefore, by means of the motion sensor 32, the blower 25 detects the insertion of the handle 3 into / from the two seals 4a, 4b and, in this case, adapts the internal pressure p1 in the gate chamber 6 to an overpressure higher than that under normal operation. This causes, in this case, during insertion and / or withdrawal, the gate air 11 flows from the gate chamber 6 through the lower distal seal 4b due to the overpressure p1-p2. Figure 5 The filling gas 26, which is potentially contaminated, is squeezed downwards back into the body cavity 15 in the guide channel 2 section 9 shown. Therefore, by flushing the gate chamber 6 with fresh filling gas 11 during the introduction / removal of the handle 3 into the tube 1, the outward leakage of filling gas 26 that has come into contact with the body cavity 15 through the guide channel 2 of the tube 1 and the two seals 4a, 4b into the environment 8 is effectively prevented.

[0098] Figure 6 This illustrates how further possible leakage of the filling gas 26 from the body cavity 15 at the insertion site 17, where the tube 1 has been introduced into the body cavity 15 by means of a cannula. For this purpose, the tube 1 has a sealing element 18 in the form of a sealing disc 21, which has an annular contact surface 19 that is directly bonded to the skin surface 20 in the region of the insertion site 17 by means of an adhesive layer 22 located on the underside of the sealing disc 21, in order to seal the insertion site 17. Alternatively, the skin surface 20 may also first be provided with an airtight adhesive film in the region of the insertion site 17, the adhesive film having an insertion opening for the tube 1 to pass through. After the tube 1 is introduced into the body cavity 15, the sealing disc 21 can then be secured to the adhesive film bonded to the skin surface 20 by means of the adhesive layer 22, where an annular seal can also be achieved.

[0099] like Figure 3 As shown, apart from the two seals 4a and 4b and the inlet 7, the gate chamber 6 is defined by an inner wall 16, which is constructed of pipe 1 and designed to be pressure resistant. This significantly simplifies the regulation of the internal pressure p1 in the gate chamber 6, because the inner wall 16 remains immovable and thus the volume of the gate chamber 6 (ignoring the movement of the two seals 4a and 4b) remains substantially constant.

[0100] exist Figure 4 It can also be seen that the two seals 4a and 4b are designed to maintain the seal of the handle 3 even when the handle 3 moves axially along the introduction direction 5 and the contact line between the handle and the corresponding seals 4a, 4b is axially displaced relative to the tube 1 which is fixedly positioned.

[0101] In general, to avoid dangerous gas leakage from the tube 1, which can be introduced into or is introduced into the body cavity 15 via a cannula, it is proposed that the tube 1 be constructed with a gate chamber 6 sealed by means of seals 4a and 4b, through which the endoscope handle 3 can be introduced into the body cavity 15. Here, the gate chamber 6 is located upstream of the distal section 9 of the guide channel 2 of the tube 1 with respect to the introduction direction 5, and the tube 1 is configured with an inlet 7 that enters into the gate chamber 6. This allows the internal pressure p1 in the gate chamber 6 to be regulated by introducing gate gas 11 into the gate chamber 6 and / or by venting gases 11 and 26 from the gate chamber 6.

[0102] List of reference numerals

[0103] 1 tube

[0104] 2 (pipe) guide channel

[0105] 3. Handles (of endoscopes / surgical instruments)

[0106] 4. Seals (for sealing the tube / inlet direction)

[0107] 5. Introduction of Direction

[0108] 6. Gate Chamber

[0109] 7. Entering the Department

[0110] 8. External factors

[0111] 9 (Guidance Channel) (Remote) Section

[0112] 10 (pipe) (remote) section

[0113] 11. Locking gas

[0114] 12 Coupling devices

[0115] 13 Gas pipelines

[0116] 14. Inspection Room

[0117] 15. Body cavity

[0118] 16. (Inner wall of the gate chamber)

[0119] 17. Introduction site

[0120] 18 Sealing elements

[0121] 19 Contact surfaces

[0122] 20. Skin surface

[0123] 21 Sealing plate

[0124] 22 Adhesive layer

[0125] 23 (Underside of sealing element / sealing plate)

[0126] 24 UV light source

[0127] 25 Blower

[0128] 26. Filling gas

[0129] 27. Filling gas pipeline

[0130] 28. Gas-locking pipe

[0131] 29 Signal Lines

[0132] 30 Pressure Regulator

[0133] 31 Pressure Sensor

[0134] 32 motion sensors

[0135] 33. Air duct (in the pipe, as part of the inlet section)

[0136] 34 Slits

Claims

1. A tube (1) for use with a cannula for minimally invasive surgery, wherein, The tube (1) has a guide channel (2) through which the handle (3) of an endoscope or surgical instrument can be guided in the insertion direction (5), characterized in that, The tube (1) has two seals (4a, 4b) for sealing the handle (3), the seals being arranged successively along the introduction direction (5) and defining and sealing the outwardly closed gate chamber (6). The gate chamber (6) has an inlet (7) through which the pressure difference (p1-p0) between the gate chamber (6) and the outside (8) can be adjusted. The two seals (4a, 4b) are designed such that, regardless of whether the handle (3) is introduced into the guide channel (2) of the tube, a corresponding pressure difference can be maintained between the gate chamber (6) and the external environment, and between the gate chamber (6) and the section (9) of the guide channel (2) connected to the distal seal (4b) of the two seals, thereby minimizing the outflow of filling gas (26) from the cavity accessible by means of the tube (1) through the two seals (4a, 4b).

2. The pipe (1) according to claim 1. in, The proximal seal (4a) of the two seals is designed such that: even when the handle (3) is pulled out, the proximal seal (4a) can maintain the pressure difference between the gate chamber (6) and the outside (8) for a long time, and / or The distal seal (4b) of the two seals is designed such that, even when the handle (3) is pulled out, the distal seal (4b) can maintain the pressure difference between the gate chamber (6) and the section (9) of the guide channel (2) that is distally connected to the gate chamber (6).

3. The tube (1) according to claim 2. The proximal seal (4a) of the two seals is designed to close automatically, and / or The distal seal (4b) of the two seals is designed to close automatically.

4. The tube (1) according to claim 2 or 3. in, The pressure difference is at least 50 mbar.

5. The tube (1) according to any one of claims 1 to 3. in, The inlet (7) has a valve by means of which the gate gas (11) can be regulated to enter or exit the gate chamber (6), and / or The inlet (7) has a coupling device (12) for airtightly coupling gas pipelines.

6. The tube (1) according to any one of claims 1 to 3. in, The inlet (7) has a valve by means of which the gate gas (11) can be regulated to enter or exit the gate chamber (6), so that the gate gas (11) can be controlled to be introduced into the gate chamber (6) and / or discharged from the gate chamber.

7. The tube (1) according to any one of claims 1 to 3. in, The two seals (4a, 4b) seal outwards the gate chamber (6) and / or the inspection chamber (14) accessible via the pipe (1), regardless of whether the handle (3) passes through the two seals (4a, 4b) into the guide channel (2), and / or Among them, the proximal seal (4a) of the two seals can be permanently maintained between the gate chamber (6) and the outside (8), which is higher than the pressure difference between the distal seal (4b) of the two seals and the section (9) of the guide channel (2) connected to the gate chamber (6) at the distal end.

8. The tube (1) according to any one of claims 1 to 3. in, Apart from the two seals (4a, 4b) and the inlet (7), the gate chamber (6) is defined by an outwardly closed inner wall (16).

9. The tube (1) according to claim 8. in, When subjected to overpressure or negative pressure, the inner wall (16) remains immovable and thereby keeps the volume of the gate chamber (6) constant.

10. The tube (1) according to any one of claims 1 to 3. in, A sealing element (18) is constructed in the region of the inlet (17) on the distal section (10) of the tube (1). The sealing element (18) concentrically surrounds the tube (1) and seals the tube (1).

11. The tube (1) according to claim 10. in, The sealing element (18) has a contact surface (19) configured to hermetically seal the introduction portion (17) in the region of the introduction portion (17) by means of direct or indirect contact with the skin surface (20) of a person.

12. The tube (1) according to claim 11. in, The contact surface (19) is an annular contact surface (19).

13. The tube (1) according to claim 11. in, The sealing element (18) is configured as a sealing sheet (21).

14. The tube (1) according to claim 13. in, The sealing sheet (21) is a flexible and / or elastic sealing sheet (21).

15. The tube (1) according to claim 13 or 14. in, The tube has an adhesive layer (22) on the lower (23) of the distal end of the sealing sheet (21), which enables the airtight seal to be achieved either directly by contact with the skin surface (20) or indirectly by contact with the adhesive film that is airtightly applied to the skin surface (20).

16. The tube (1) according to any one of claims 1 to 3. in, The tube (1) has a UV light source (24) that emits UV light into the gate chamber (6) and the UV light is suitable for killing germs that have entered the gate chamber (6).

17. The tube (1) according to claim 16. in, The UV light source (24) is a UV-LED.

18. The tube (1) according to claim 16. in, The UV light is UVC light.

19. The tube (1) according to any one of claims 1 to 3. in, The tube (1) includes at least one pressure sensor (31), which is configured to measure: Atmospheric environmental pressure (p0), or The internal pressure (p1) of the gate chamber (6), or The filling pressure (p2) of the body cavity (15) accessible by the tube (1) is utilized.

20. The tube (1) according to any one of claims 1 to 3. in, The tube (1) includes at least one motion sensor (32) for detecting the movement of the handle (3) introduced into the guide channel (2) of the tube (1).

21. A surgical kit comprising: The tube (1) according to any one of claims 1 to 20, and Endoscopes or surgical instruments each having a handle (3), characterized in that, The handle (3) is designed and sized to be inserted into the guide channel (2) of the tube (1) and sealed thereby by means of the two seals (4a, 4b).

22. A surgical kit comprising: The tube (1) according to any one of claims 1 to 20, used with a cannula for minimally invasive surgery, and An inflator (25) is provided, which can be connected to the tube (1) to introduce filling gas (26) through the tube (1) into the body cavity (15). Its features are, The blower (25) is connected to the gate chamber (6) of the pipe (1) via a gate pipe (28) and an inlet (7), the gate chamber being defined and sealed by two seals (4a, 4b). The blower (25) is configured to introduce and / or discharge gate air (11) into and / or from the gate chamber (6) via the gate air conduit (28). In order to adjust the pressure difference (p1-p0) between the gate chamber (6) and the outside (8) and / or the pressure difference (p1-p2) between the gate chamber (6) and the inspection chamber (14) accessible by means of the pipe (1).

23. The surgical kit according to claim 22, in, The blower (25) is configured to introduce filling gas (26) at a specific filling pressure into the pipe (1) via the filling gas line (27) and thereby into or out of the inspection chamber (14). In order to adjust the filling pressure (p2) in the body cavity (15), which can be accessed by the tube (1).

24. The surgical kit according to claim 22, in, The blower (25) is configured to maintain an overpressure in the gate chamber (6) relative to the inspection chamber (14) by introducing the gate air (11) into the gate chamber (6). This allows the gate gas (11) to flow from the gate chamber (6) through the distal seal (4b) toward the inspection chamber (14) once the distal seal (4b) of the two seals is temporarily opened when the handle (3) is introduced into or pulled out of the tube (1).

25. The surgical kit according to claim 22, in, The blower (25) is configured to maintain a negative pressure in the gate chamber (6) relative to the inspection chamber (14) by discharging gas from the gate chamber (6). The filling gas (26) that flows into the gate chamber (6) through the distal seal (4a) of the two seals and thereby temporarily reduces the negative pressure is drawn out of the gate chamber (6).

26. The surgical kit according to claim 25, in, Gas is discharged from the gate chamber (6) through the valve.

27. The surgical kit according to claim 22, in, The blower (25) is configured to monitor the internal pressure (p1) in the gate chamber (6).

28. The surgical kit according to claim 27, in, The blower (25) is configured to actively adjust the internal pressure (p1) to a predetermined rated value.

29. The surgical kit according to claim 27, in, The blower (25) is configured to actively regulate the internal pressure (p1) to a predetermined rated value by introducing gate air (11) into the gate chamber (6) and / or by discharging gas from the gate chamber (6).

30. An endoscope system, comprising: Endoscope, and The tube (1) according to any one of claims 1 to 20, or The surgical kit according to any one of claims 21 to 29, The endoscope has a handle (3) which can be sealed by means of the two seals (4a, 4b) and can be introduced into the guide channel (2) of the tube (1).

31. The endoscope system according to claim 30, further comprising: A spectrometer configured to analyze flue gas, which is discharged through the tube (1).

32. A method for preventing significant leakage of filling gas (26) from a tube (1) according to any one of claims 1 to 20, said tube being configured for use with a cannula for minimally invasive surgery, in, The tube (1) has a guide channel (2) through which the handle (3) of the endoscope or surgical instrument can be guided in the insertion direction (5). Its features are, The gate gas (11) is introduced into or discharged from the gate chamber (6) of the pipe (1) through the inlet (7). The gate chamber (6) is defined and sealed by two sealing elements (4a, 4b).

33. The method according to claim 32, in, By introducing and / or venting the gate gas (11), the pressure difference (p1-p2) between the gate chamber (6) and the section (9) of the guide channel (2) connected at the distal end to the gate chamber (6) is regulated and / or maintained.

34. The method according to claim 33, in, Once the brake gas (11) escapes from the gate chamber (6) through one of the two seals (4a, 4b) and thereby briefly reduces the overpressure in the gate chamber (6), the overpressure in the gate chamber (6) relative to the section (9) of the guide channel (2) is maintained by introducing fresh brake gas (11) into the gate chamber (6).

35. The method according to any one of claims 32 to 34, in, Once gas is forced into the gate chamber (6) through one of the two seals (4a, 4b) and thereby briefly reduces the negative pressure in the gate chamber (6), the negative pressure in the section (9) of the gate chamber (6) relative to the guide channel (2) is maintained by drawing gas out of the gate chamber (6).

36. The method according to any one of claims 32 to 34, in, When the handle (3) is introduced into the distal seal of the two seals (4b) and / or when the handle (3) is pulled out from the distal seal (4b), it adapts to the internal pressure (p1) in the gate chamber (6).

37. The method according to any one of claims 32 to 34, in, The internal pressure (p1) in the gate chamber (6) is increased or decreased when the handle (3) is introduced into the distal seal of the two seals (4b) and / or when the handle (3) is pulled out of the distal seal (4b).

38. The method according to claim 36, in, The introduction and / or pull-out are detected by means of a motion sensor (32). This enables the adaptation of the internal pressure (p1) to be performed in response to the detection of movement of the handle (3).

39. The method according to claim 38, in, The motion sensor (32) is integrated in the tube (1).

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