VENTILATION DEVICE WITH LINE FOR FILLING A CUFF IN THE TRACHEAL SECTION

Description

[0001] The present invention relates to a ventilation device, such as a tracheostomy tube, comprising a cannula tube and an inflatable cuff. This cuff extends annularly around the cannula tube in the tracheal section on the outside of the tube wall and has a variable lumen for receiving a fluid supplied via a line and through an opening in the cuff.

[0002] Many tracheostomy tubes or endotracheostomy tubes are equipped with a cuff in the tracheal section. The cuff is typically formed by a plastic film wrapped around the tube, which, when deflated, can have a wall thickness ranging from 5 to 300 µm.

[0003] WO2021 / 059183 A1 discloses a ventilation device with an inflatable cuff in the tracheal section and a variable fluid line.

[0004] The cuff is inflatable with air or another fluid and is located in the distal tracheal segment just before the patient end of the cannula tube. The lumen of the cuff is variable in that it enlarges when fluid is pumped into the lumen of the cuff and shrinks when fluid in the lumen is released. The cross-section of the cuff increases and decreases with the cross-section of its lumen, although the difference between the cross-section of the cuff and the cross-section of its lumen is negligible given the thin wall thickness of the plastic film from which the cuff is made.

[0005] The cuff's function is to seal the trachea around the cannula tube. This is achieved by inflating the cuff to a pressure (overpressure relative to ambient or atmospheric pressure) at which the cuff expands to such an extent that it fills the space between the trachea and the cannula tube. Once the cuff's cross-section is large enough to fill and seal the space between the trachea and the cannula tube, it is referred to as a "blocked" cuff.

[0006] This ensures that, in patients receiving artificial ventilation, the ventilation air provided by a ventilator reaches the bronchi completely and then leaves the patient in a defined manner. If the cuff does not seal sufficiently, significant amounts of ventilation air could escape uncontrollably through the natural airways or the tracheostomy. In this case, the ventilator would sound an alarm.

[0007] On the other hand, a cuff also serves to prevent secretions from the subglottic area from entering the bronchi. This could lead to so-called "ventilation-associated pneumonia (VAP)."

[0008] The specific inflation pressure required to inflate a cuff depends, among other things, on the size and design of the cannula. For so-called "high-volume, low-pressure" cuffs, which are filled with air and fold to conform to the tracheal wall, the specific inflation pressure required to inflate the cannula cuff is typically in the range of 15 to 30 mbar. For so-called "low-volume, high-pressure" cuffs, which expand elastically like a balloon when inflated, the specific inflation pressure is typically in the range of 60 to 200 mbar.

[0009] For a cuff to achieve its sealing properties, it must be filled with a sufficient amount of fluid (typically air). Filling occurs either via a filling tube, one end of which opens into the lumen of the cuff, while the other end extends proximally into the extracorporeal area of the ventilation device. Alternatively, the fluid can be supplied to the cuff, at least in part, via a cuff line running in the tube wall of the cannula tube. The term "cuff line" encompasses both variants.

[0010] For structural reasons, the cuff line is often designed differently in the extracorporeal setting than in the intracorporeal setting. For example, in the intracorporeal setting, the cuff line may be provided as a line running in the wall of the cannula tube, while in the extracorporeal setting, it may be provided as a separate inflation tube routed outside the cannula tube.

[0011] The fluid is supplied via a filling valve located at the extracorporeal end of the cuff line or on the control balloon. A syringe or a dedicated device can be connected to this valve to inflate the cuff.

[0012] The inner diameter of a commercially available inflation tube or a cuff line provided in the tube wall is typically between 0.5 and 1 mm in the intracorporeal region. In principle, however, it would be desirable to have cuff lines with significantly larger inner diameters for various reasons. This would, for example, reduce the risk that any condensation present in the inflation tube cannot be set in motion when setting the cuff pressure due to the capillary forces acting here at the typically very low pressure differences of usually no more than 30 mbar. In these cases, water can block the supply line, preventing the pressure equalization required for pressure measurement between the manometer located proximally for pressure measurement and the cuff lumen.If such a situation occurs, the cuff pressure check will lead to incorrect results, as it is only possible to measure the pressure that exists before the blockage and not the pressure that exists behind the blockage in the cuff.

[0013] Another disadvantage of a narrow diameter cuff inlet is that pressure equalization between the pressure at the inflation valve and the pressure in the cuff lumen is often relatively slow. This is particularly disadvantageous when using actively controlled cuff pressure devices.

[0014] However, the inner diameter of the cuff line cannot be chosen arbitrarily, especially in the intracorporeal region. The steric conditions in the trachea are too tight for this, which is the main reason why commercially available filling tubes have the smallest possible diameter or why the cuff line is even integrated into the tube wall of the cannula tube in order to keep the overall cross-section of the ventilation device in the tracheal section as small as possible. Since the wall thickness of the cannula tube cannot be made arbitrarily large for steric reasons, strict limits are also set regarding the cuff line integrated into the cannula wall. Furthermore, the production of a cannula tube with a cuff line integrated into the tube wall is extremely difficult and expensive for cannula tubes manufactured using the injection molding process, as special injection molding tools must be manufactured for this purpose.

[0015] The motivation for the present invention was therefore to provide a ventilation device, such as a tracheostomy tube or an endotracheal tube, which overcomes the disadvantages associated with corresponding devices having a cuff line with a relatively small internal volume and takes into account the difficult steric conditions in the trachea.

[0016] The invention is defined in the appended claims.

[0017] According to the invention, this is achieved by a ventilation device comprising a cannula tube, the tube wall of which has an extracorporeal section, a stoma section and a tracheal section, and an inflatable cuff which extends annularly around the cannula tube in the tracheal section on the outside of the tube wall, wherein the cuff has a variable lumen for receiving a fluid, wherein the ventilation device also has a fluid line with an opening into the lumen of the cuff, wherein the ventilation device is particularly characterized in that the fluid line in the region of the stoma section and / or the tracheal section is formed at least in sections by a film arranged on the outside of the cannula tube, which film forms a variable lumen for the passage of fluid,wherein the variable lumen of a section n of the fluid line formed by the film has a cross-section Qn 2 at a specific filling pressure for blocking the cuff in the range of 15-200 mbar overpressure relative to the ambient pressure (atmospheric pressure) which is at least 3 times larger than the cross-section Qn 1 which exists when there is a negative pressure of -30 mbar in the cuff relative to the ambient pressure (atmospheric pressure).

[0018] A negative pressure of -30 mbar is easily achieved by deflating the cuff, as is usual, using a syringe. In this state, the cuff is typically referred to as "unblocked." Typically, the cuff is unblocked, especially for inserting the cannula into the trachea or shortly before removing a cannula from the trachea.

[0019] When used as intended, the ventilation device according to the invention rests against the stoma of a patient in the area of the stoma section. Extending from the stoma section are the extracorporeal section in the proximal direction and the tracheal section in the distal direction.

[0020] The terms "distal" and "proximal" are used in the context of the present invention from the perspective of a physician using the ventilator, i.e. the proximal end is the end of the ventilator that remains outside the patient's body after insertion into the trachea, while the distal end is inserted into the patient's trachea.

[0021] The stoma section is a standardized area that is slightly longer (adults) or shorter (children) depending on the patient's size and neck diameter. The length of the tracheal section, which directly adjoins the stoma section in the distal direction, also varies accordingly.

[0022] In the present invention, the cuff is preferably located in the tracheal section in an area in front of the distal end of the cannula tube. Depending on the size and neck diameter of the patient, the area in which the cuff is located extends from the distal end of the cannula tube towards the proximal end of the cannula tube over up to 50%, up to 40%, up to 30%, or only up to 20% of the total length of the central longitudinal axis of the cannula tube. Especially in shorter versions for children, the proportion of the area to the cannula tube length is greater (e.g., 40 to 50%) than in longer versions for adults (e.g., 20 to 40%).

[0023] The term "line" is understood in the context of the present invention in the sense of a fluid-carrying line into which a fluid can flow at the at least one provided fluid inlet and from which the fluid can flow out again at the at least one provided fluid outlet after the fluid has flowed through the otherwise fluid-tight line over a certain distance.

[0024] The ventilation device proposed according to the invention has the advantage that the cross section of the inner lumen of the fluid line required for the most trouble-free passage of fluid is formed primarily when fluid is actually flowing through the fluid line. In particular, the variable lumen in the section of the fluid line which is formed according to the invention by a film in this section n has a cross section Qn 2 at a specific filling pressure present in the cuff with an overpressure of 15-200 mbar relative to the ambient pressure (atmospheric pressure), which is at least a factor of 3 larger than the cross section Qn 1 when there is a negative pressure of -30 mbar in the cuff relative to the ambient pressure (atmospheric pressure).

[0025] During the phases in which the cuff is blocked, it is not a problem if the fluid line takes up a slightly larger space, since the air for breathing or ventilation flows exclusively through the cannula tube. Here, the advantage of a large fluid line outweighs the disadvantage. However, during phases in which the cuff is unblocked, it is important that the fluid line takes up as little space as possible. This is the case, for example, when inserting the cannula. But also in phases in which the patient is supposed to inhale and / or exhale past the cannula through the natural airways with the cannula tube closed. In this case, a fluid line that is too large in cross-section would lead to the breathing resistance becoming too great for the patient to breathe independently past the cannula tube. The consequence would be, for example, that the patient would be unable to speak or would only be able to speak with great difficulty. In addition, certain forms of therapy for weaning the patient from the cannula would be more difficult.If the outer diameter of the cannula is too large, this could result in the patient not being able to wean themselves off the cannula and requiring the cannula permanently.

[0026] The fact that the cross section of the inner lumen of the fluid line required for the most trouble-free passage of fluid is formed primarily when fluid actually flows through the fluid line is achieved according to the invention in that the fluid line in the region of the stoma section and / or the tracheal section is formed at least in sections by a film arranged on the outside of the cannula tube, which film defines a lumen that is variable to the extent defined above under the above-mentioned conditions.

[0027] For the purposes of the present invention, the term "ambient pressure" refers to the pressure acting on the film. For a ventilation device that is not in use, that is not inserted into the trachea, and that does not carry fluid, particularly air, through its fluid line, the ambient pressure corresponds to atmospheric pressure, and this pressure acts equally on both the outward-facing and inward-facing sides of the film.

[0028] If the cuff is filled with an overpressure of 15-200 mbar relative to the ambient pressure (atmospheric pressure), a correspondingly increased pressure acts on the inward-facing side of the film, which results in the film having a cross-section Qn 2 in a section n formed by the film. However, if the cuff is emptied and a negative pressure of -30 mbar is applied, the cross-section Qn 1 in the section n is reduced according to the invention by at least a factor of 3.

[0029] In the context of the present invention, the term "cross-section" refers to the area of a cross section through the inner lumen of the cuff line perpendicular to the main flow direction. The cross section Qn 1 of the lumen of the cuff line according to the invention is equal to the area of the cross section through the inner lumen in a section n formed by the film at a negative pressure of -30 mbar. The cross section Qn 2 of the lumen of the cuff line according to the invention is equal to the area of the cross section through the inner lumen in section n at an overpressure of 15-200 mbar present in the cuff and thus also in the line.

[0030] The cross-section is measured in the free state, i.e., in a state in which the ventilation device according to the invention, such as a tracheostomy tube or an endotracheostomy tube, is located outside the body. Thus, the cross-section of the lumen is determined "in free space," i.e., without the expansion of the lumen being mechanically impaired by other objects in the surrounding area.

[0031] The variability of the lumen of a section of the fluid line formed by the film under different pressure conditions can be measured by filling the section of interest with a fluid at an overpressure of 15–200 mbar relative to the ambient pressure (atmospheric pressure). Then, applying a negative pressure of -30 mbar relative to the ambient pressure (atmospheric pressure) and measuring the cross-section of the lumen under the respective pressure conditions using an optical method. To determine the cross-section of the lumen under specific pressure conditions, one could alternatively fill the line with a slowly hardening resin under the conditions of interest. After the resin has hardened, cross-sections can be taken and their dimensions determined.Another method would be to determine the volume of fluid absorbed under different pressure conditions in the section of the pipe of interest and to calculate the resulting cross-sections.

[0032] In order to have the smallest possible cross-section of the entire ventilation device when inserting the ventilation device according to the invention or when removing the ventilation device, thereby making it easier to move the cannula tube through the stoma and / or trachea, the cross-section of the section n of the fluid line formed by the film has a cross-section Qn 1 of at most 0.3 mm square at a negative pressure of -30 mbar in the cuff relative to the ambient pressure (atmospheric pressure).

[0033] Here, section n refers to a section of the fluid line formed by the film, which has a constant cross-section Qn 1 or Qn 2 at a given pressure. If the cross-section Qn 1 or Qn 2 is constant over the entire length of the fluid line formed by the film, then section n extends over this entire length. If the cross-section varies in sections, n refers to the section in which the cross-section is constant.

[0034] In certain embodiments, the fluid line is formed, at least in sections, by a layer of film arranged on the outside of the tube wall of the cannula tube. This is preferably a single-layer film layer, the longitudinal sides of which are fluid-tightly connected to the outside of the tube wall of the cannula tube, for example, by gluing, clamping, or welding.

[0035] In some embodiments, the film consists of a two- or three-layer layer. In this way, for example, the properties of an inner layer of the layer can be selected to minimize the tendency for water droplets to form cohesion. Preferably, an outer or middle layer can be selected to exhibit particularly high tear resistance and / or particularly high mechanical strength.

[0036] Applying the film in a single layer to the outside of the cannula tube wall has the advantage that relatively little film material is required. Secondly, this typically results in a crescent-shaped cross-section of the fluid line's lumen, allowing for a lumen with relatively low radial bulk.

[0037] In special embodiments, the film layer is provided on the outside of the tube wall, at least in sections, over the entire outer cross-sectional circumference of the cannula tube. The film layer thus essentially forms a tube through which the cannula tube extends, allowing the fluid for filling the cuff to flow between this outer film tube and the inner cannula tube.

[0038] In some embodiments, at least one groove-shaped recess is provided longitudinally on the outer side of the tube wall of the cannula tube in the region spanned by the layer of film. This groove-shaped recess, together with the outer side of the tube wall of the cannula tube and the inner side of the film spanning the region, defines the cross-section through which the fluid flows to fill the cuff. The lumen between the inner side of the film and the outer tube wall is thus expanded longitudinally by the cross-section of the wave-shaped recess.

[0039] In certain embodiments, the fluid line is formed, at least in sections, by a tube made of the film, which is arranged on the outside of the tube wall of the cannula tube. In these embodiments, the tube is not designed to enclose the entire cannula tube, but rather is a tube with a cross-section that is significantly smaller than the cross-section of the cannula tube, and this tube is attached to one side of the cannula tube in the longitudinal direction on the outside of the tube wall, for example by gluing, clamping, and / or welding.

[0040] The attachment of the fluid line in the form of a tube made of the film has the advantage that such a tube in itself provides great reliability in terms of tightness, whereas in the case of attaching a layer of the film on the outside of the cannula wall, the connection must be fluid-tight in order to achieve the required tightness.

[0041] Preferably, the section of the fluid line formed by the film extends in the proximal-distal direction over at least 50%, at least 60%, at least 70%, at least 80%, at least 90% or 100% of the section of the cannula tube that lies between the extracorporeal section and the cuff.

[0042] In some embodiments, Qn 2 is achieved by stretching the film at a cuff overpressure of 15-200 mbar. In these embodiments, the reduction of the cross-section to Qn 1 by a negative pressure of -30 mbar occurs at least partially due to the film's elasticity reducing its stretch.

[0043] In other embodiments, Qn 2 is achieved by stretching the film against gravity or the film's inherent stress at an overpressure of 15-200 mbar relative to the ambient pressure (atmospheric pressure), without stretching the film. In these embodiments, the reduction to Qn 1 by a negative pressure of -30 mbar occurs when the film at least partially collapses.

[0044] In special embodiments, Qn 2 is adjusted partly, for example 20-80%, by stretching the film and partly, for example 80-20%, by stretching the film at an overpressure of 15-200 mbar.

[0045] In certain embodiments, the film or film tube has a preformed geometry with a smaller cross-section, whereby the full cross-section only develops when an overpressure in the range of 15-200 mbar is present in the fluid line. At a correspondingly lower pressure, the film or tube returns to the cross-section of the preformed geometry. The preformed geometry can, for example, define one or more longitudinally extending indentations. This can be achieved, for example, by varying the wall thickness of the film in the respective areas.

[0046] In some embodiments, the film of the fluid line has a particularly high tear strength and is tear-resistant at least up to a fluid pressure of 250 mbar. Preferably, the film of the fluid line has an elongation at break according to DIN ISO 527 in the range of 150-600%.

[0047] The tear resistance and variability of the fluid line's lumen are partly determined by the selected plastic polymer material. Another factor is, in part, the layer thickness (wall thickness) of the film. The thinner the film material, the more susceptible it is to damage, such as cracks. Thicker film material, in turn, adds bulk and is therefore a disadvantage. Therefore, careful consideration is required to determine which criteria should be given what weight.

[0048] Depending on the specific requirements and the specific properties of the film used to form the fluid conduit in the present invention, the wall thickness of the film can vary. Wall thicknesses in the range of 5 to 300 µm are particularly suitable, preferably in the range of 10 to 100 µm, and even more preferably in the range of 10 to 30 µm.

[0049] Typically, the film of the fluid line is made of a plastic polymer. Various materials can be used as plastic polymers for the film of the fluid line, including polyurethane, soft PVC, PE, PP, EVA, PEBAX, and silicone. Preferably, the plastic polymer has a Shore A range of 5-90.

[0050] Typically, the sleeve is also made of a plastic polymer film. In certain embodiments, the film of the fluid conduit and the film of the sleeve are formed from the same plastic polymer material. Particularly preferably, in these embodiments, the film and sleeve are seamlessly integrated or formed as a single piece.

[0051] In certain embodiments, the fluid line in the region of the extracorporeal section is formed from a flexible plastic tube which has a greater hardness and / or wall thickness than the film from which the fluid line consists, at least in sections, in the stoma section and / or tracheal section.

[0052] For the purposes of the original disclosure, it is understood that all features as they become apparent to a person skilled in the art from the present description, the appended drawings and the claims, even if they have been specifically described only in connection with certain other features.

[0053] A comprehensive, explicit presentation of all conceivable combinations of features is omitted here for the sake of brevity and readability of the description.

[0054] The attached figures and the associated description schematically illustrate specific embodiments of the invention. These specific embodiments are merely examples of possible combinations of features. However, the invention is by no means limited to these specific embodiments, but encompasses all embodiments covered by the scope of the patent claims, even if they are not explicitly illustrated or described. Figure 1: Figure 1 shows a perspective view of an embodiment of a ventilation device according to the invention, in which the fluid line for filling the cuff in the stoma section and in the tracheal section is provided in the form of a film layer, while in the extracorporeal section the fluid line is continued in the form of a tube. Figure 2: The illustrations a) and b) of Figure 2represent a schematic cross-section through the cannula tube in the tracheal section of an embodiment of a ventilation device according to the invention, in which the fluid line for filling the cuff is realized in the form of a film layer arranged on the outside of the cannula tube. Figure 3: The illustrations a) and b) of Figure 3 represent a schematic cross-section through the cannula tube in the tracheal section of an embodiment of a ventilation device according to the invention, in which the fluid line for filling the cuff is realized in the form of a film tube arranged on the outside of the cannula tube. Figure 4: The illustrations a) and b) of Figure 4represent a schematic cross-section through the cannula tube in the tracheal section of an embodiment of a ventilation device according to the invention, in which the fluid line for filling the cuff is realized in the form of a film layer, wherein the cross-section of the lumen, which results between the film layer and the outside of the cannula tube, is expanded by a groove-shaped recess provided in the wall of the cannula tube. Figure 5: The illustrations a) and b) of Figure 5 represent a schematic cross-section through the cannula tube in the tracheal section of an embodiment of a ventilation device according to the invention, in which the fluid line for filling the cuff is realized in the form of a pre-tensioned film layer arranged on the outside of the cannula tube. Figure 6: In Figure 6A film layer intended to form a fluid line for filling the cuff is shown, which merges seamlessly into the material of the cuff. Figure 7: The Figure 7 The ventilation device shown shows the Figure 6 The one-piece combination of film layer and cuff shown after assembly on the cannula tube of a specific embodiment of a ventilation device according to the invention. Figure 8: In the Figure 8 In the illustrated embodiment of the ventilation device according to the invention, the fluid line for filling the cuff is formed by a layer of the film on the outside of the tube wall extending over the entire outer cross-sectional circumference of the cannula tube in the section shown here. Figure 9: In Figure 9 is a special form of Figure 8shown embodiment, in which the film layer extending over the entire outer cross-sectional circumference of the cannula tube merges seamlessly into the cuff.

[0055] In Figure 1As an example of a ventilation device according to the invention, a tracheostomy cannula 1 is shown, the cannula tube of which has an extracorporeal section 4, a stoma section 5 and a tracheal section 6. The extracorporeal section 4 is the area that extends from the cannula shield 13 in the proximal direction to the proximal end of the cannula. In the distal direction, the cannula shield 13 is first adjoined by the stoma section 5, directly followed by the tracheal section 6. The stoma section 5 is a standardized area that is designed to be slightly longer (adults) or slightly shorter (children) depending on the size and neck diameter of the patient. The length of the tracheal section 6, which directly adjoins the stoma section 5 in the distal direction, also varies accordingly.

[0056] The cannula tube 2 has a proximal opening 10 and a distal opening 9, and at the distal end of the cannula tube 2 there is an inflatable cuff 7, which is shown here in the inflated state. The cuff 7 is filled via a fluid line, which in the embodiment shown here is provided extracorporeally in the form of a fluid hose 8 and, from the cannula shield 13, in the form of a film layer 11 applied to the cannula tube 2. In the embodiment shown here, the film layer is glued to the cannula tube in a fluid-tight manner. At the distal end, the lumen formed between the film layer 11 and the outside of the cannula tube 2 opens into the lumen of the cuff 7, so that fluid introduced into the fluid line at the proximal end reaches the cuff 7, allowing it to be inflated.A control balloon 14 is located at the proximal end of the extracorporeal fluid tube 8, which can be used to tactilely and / or visually check whether the cuff 7 is inflated or not. A filling valve is then attached to the end of the control balloon.

[0057] Figure 2shows a schematic cross-section through the cannula tube 2 of an embodiment of a ventilation device according to the invention in the tracheal section. The tube wall 3 of the cannula tube 2 defines a circular cannula tube interior in this area, through which the respiratory air can flow. A flexible plastic film layer 11 is arranged on the outside of the cannula tube 2, which, when the internal pressure is increased according to the invention, clearly defines a lumen with a cross-section Qn 2 in the section shown here (Figure a). Figure b) shows the state in which the negative pressure according to the invention is present, whereby the cross-section Qn 1 is correspondingly reduced. Even with the naked eye, it can be seen that the cross-section Qn 2 in the embodiment shown here is at least a factor of 3 larger than the cross-section Qn 1 . Depending on the embodiment, folds could also form when negative pressure is applied.

[0058] In Figure 3 a schematic cross-section through the cannula tube 2 shows an embodiment of a ventilation device according to the invention in the tracheal section, wherein here on the outside of the cannula tube 2 on the tube wall 3 a flexible film tube 12 is arranged, which defines a lumen with a cross-section Qn 2 when the internal pressure is increased according to the invention (Figure a)), whereas when the negative pressure is applied according to the invention the cross-section Qn 1 of the film tube 12 is at least 3 times smaller (Figure b)). In the embodiment shown here the film tube 12 is glued fluid-tight to the cannula tube 2.

[0059] In Figure 4 a particular embodiment of the present invention is shown, in which the lumen formed by the film layer 11 in connection with the outside of the tube wall 3 of the cannula tube 2 is, in comparison to the Figure 2illustrated embodiment is enlarged in that a groove-shaped recess 15 is provided in the tube wall 3, which runs in the longitudinal direction of the cannula tube 2 on the outside of the tube wall 3. In the embodiment illustrated here, the film layer 11 is glued to the cannula tube 2 in a fluid-tight manner.

[0060] In Figure 52 shows a special embodiment of a ventilation device according to the invention, in which the film of the film layer 11, which here forms the fluid line in interaction with the outer side of the tube wall 3 of the cannula tube 2, has a pre-formed geometry that is formed when there is no overpressure in the fluid line or even when there is negative pressure. In the embodiment shown here, the pre-formed geometry is designed such that a continuous indentation is formed centrally in the longitudinal direction of the fluid line (Figure b)). When overpressure is applied in the area according to the invention, this indentation is everted outwards and the cross-section of the lumen of the fluid line is thereby increased accordingly (Figure a)). In the embodiment shown here, the film layer 11 is welded to the cannula tube 2 in a fluid-tight manner.

[0061] The Figures 6 and 7illustrate a special embodiment of the ventilation device according to the invention, in which the film layer 11 provided for the formation of the fluid line merges seamlessly into the cuff 7 and is thus formed integrally with it. Figure 6 the film layer 11 together with the sleeve 7 is shown separately, ie in the unassembled state. In Figure 7 the state is then shown in which the film layer 11 is applied to the cannula tube and thus also the cuff 7. In the embodiment shown here, the film layer and the cuff are welded fluid-tight onto the cannula tube.

[0062] Figure 8is a schematic representation of a particular embodiment of the present invention, in which the fluid line is formed by a film layer 11 which runs on the outside of the tube wall 3 of the cannula tube 2 over the entire outer cross-sectional circumference of the cannula tube, so that in practice a tube is produced through which the cannula tube 2 runs, wherein the fluid for filling the cuff can then flow between this outer film tube and the cannula tube located therein.

[0063] In Figure 9 is a variant of the Figure 8illustrated embodiment of the invention. In this variant, the film tube extending over the entire cross-sectional circumference merges seamlessly into the material of the cuff 7, so that the tube formed by the film layer 11 is formed integrally with the cuff 7. The extracorporeally arranged film tube 8 opens into the area of the fluid line formed between the film layer 11 and the outer side of the tube wall 3 of the cannula tube 2 in the area of the cannula shield 13. Reference symbol

[0064] 1Ventilation device 2Cannula tube 3Tube wall 4Extracorporeal section 5Stoma section 6Tracheal section 7Cuff 8Extracorporeal fluid line 9Distal opening 10Proximal opening 11Foil layer (intracorporeal fluid line) 12Foil tube (intracorporeal fluid line) 13Cannula shield 14Control balloon with inflation valve 15Grooved recess QnCross section in section n

Claims

1. Ventilation device (1), in particular a tracheostomy cannula, having ■ a cannula tube (2), the tube wall (3) of which has an extracorporeal portion (4), a stoma portion (5) and a tracheal portion (6), ■ an inflatable cuff (7) which extends annularly around the cannula tube (2) in the tracheal portion (6), on the outer side of the tube wall (3), the cuff (7) having a variable lumen for receiving a fluid, and ■ a fluid line which has an opening into the lumen of the cuff (7), wherein the fluid line, in the region of the stoma portion (5) and / or of the tracheal portion (6), is formed at least in part by a film (11, 12) which is arranged on the outer side of the cannula tube (2) and which forms a variable lumen for the passage of fluid, characterized in that the variable lumen of a portion n of the fluid line formed by the film (11, 12) has, at a specific filling pressure for blocking the cuff in the range of 15 to 200 mbar overpressure relative to the ambient pressure (atmospheric pressure), a cross section Qn2 which is at least a factor of 3 larger than the cross section Qn1 when an underpressure of -30 mbar relative to the ambient pressure (atmospheric pressure) is present in the cuff (7), the term "cross section" referring to the area of a cross section through the inner lumen of the cuff line perpendicular to the main direction of flow.

2. Device according to Claim 1, characterized in that the cross section of the portion n of the fluid line formed by the film (11, 12) has a cross section Qn1 of not more than 0.3 mm2 when there is an underpressure in the cuff of -30 mbar relative to the ambient pressure (atmospheric pressure).

3. Device according to either of Claims 1 and 2, characterized in that the fluid line is formed at least in part by a layer (11) of the film that is arranged on the outer side of the tube wall of the cannula tube.

4. Device according to Claim 3, characterized in that the layer (11) of the film on the outer side of the tube wall extends, at least in part, over the entire outer cross-sectional circumference of the cannula tube.

5. Device according to either of Claims 3 and 4, characterized in that at least one groove-shaped recess (15) is provided in the longitudinal direction on the outer side of the tube wall of the cannula tube in the region spanned by the layer (11) of the film.

6. Device according to either of Claims 1 and 2, characterized in that the fluid line is formed, at least in part, by a hose (12) which consists of the film and which is arranged on the outer side of the tube wall of the cannula tube.

7. Device according to any one of Claims 1 to 6, characterized in that the film of the fluid line has a wall thickness in the range of 5 to 300 µm, preferably in the range of 10 to 30 µm.

8. Device according to any one of Claims 1 to 7, characterized in that the film of the fluid line is tear-resistant at least up to a fluid pressure of 250 mbar.

9. Device according to any one of Claims 1 to 8, characterized in that the film of the fluid line has an elongation at break (according to DIN EN ISO 527) in the range of 150-600%.

10. Device according to any one of Claims 1 to 9, characterized in that the film of the fluid line consists of a plastic polymer having a Shore A in the range of 5 to 90.

11. Device according to any one of Claims 1 to 10, characterized in that the film of the fluid line consists of a plastic polymer selected from polyurethane, soft PVC, PE, PP, EVA, PEBAX and silicone.

12. Device according to any one of Claims 1 to 11, characterized in that the film of the fluid line and the cuff are made in one piece from the same plastic polymer.

13. Device according to any one of Claims 1 to 12, characterized in that the fluid line, in the region of the extracorporeal portion, consists of a flexible plastic hose which has a greater hardness and / or wall thickness than the film from which the fluid line is made, at least in part, in the stoma portion and / or tracheal portion.