FIRE PROTECTION DEVICE FOR OXYGEN-ENRICHED RESPIRATORY GAS THERAPY

Description

[0001] The present invention relates to a device for supplying a patient with oxygen-enriched breathing gas with a fire protection device.

[0002] Patients with severe lung dysfunction are severely limited in their activity, as they often develop shortness of breath even after mild physical exertion. The lung dysfunction can also be so severe that patients experience shortness of breath at rest. If the lung dysfunction cannot be alleviated with medication, e.g., with drugs that dilate the bronchi, the only option is to provide the patient with an increased oxygen content in the air they breathe, which then leads to higher oxygen saturation in the blood even with impaired lung function. This allows patients to become more active again with the help of portable oxygen devices, or, if they are unable to do so, at least to alleviate their shortness of breath.

[0003] Such oxygen supply is usually provided via a tube system that can deliver oxygen or oxygen-enriched air to a patient. The oxygen can be supplied from pressure cylinders, liquid oxygen containers (Dewars), oxygen concentrators or generators, or central oxygen supply systems. The oxygen can be delivered to the patient via a nasal cannula, a breathing mask (closed or open), or a ventilation tube through the mouth / nose or tracheostomy.

[0004] Many patients requiring oxygen suffer from COPD, a chronic obstructive pulmonary disease (COPD), which is usually triggered by long-term smoking. Approximately 20% of patients are unable to refrain from smoking, even during oxygen treatment, despite warnings (see West GA, Primeau P. Nonmedical hazards of long-term oxygen therapy. Respir Care. 1983; 28:906-12). The oxygen significantly accelerates the fire; the cigarettes can burst into flames, often igniting the plastic nasal cannula or breathing mask, as well as the patient's clothing or bedding. The incoming oxygen significantly accelerates the fire, and within a short time the patient's bed or the patient themselves can be engulfed in bright flames. Deaths from these fires have been reported (see Morbidity and Mortality Weekly Report).Fatal fires associated with smoking during long-term oxygen therapy. Maine, Massachusetts, New Hampshire, and Oklahoma. 2000-2007. MMWR. 2008; 57:852-854).

[0005] Devices are already known in which the gas flow is interrupted in the event of a pressure drop in the system. For example, US 6,269,811 B1 discloses a pressure support system that aims to interrupt the gas flow as soon as a primary, pressure-generating system fails. DE 29 29 163 A1, on the other hand, describes a demand breathing valve attached to a face mask that can close under special conditions, for example, when a pressure drop occurs when the mask is removed from the face, to prevent unnecessary gas losses. However, these devices do not offer a solution to the problem of flow interruption in the event of a fire.

[0006] There are already various systems for stopping the flow of oxygen and thus preventing or at least reducing the spread of fire. For example, WO 2014 / 020334 A1 describes a valve that can be installed in the supply hose and, when reached by flames, automatically stops the flow, preventing any more oxygen from flowing in. However, this system has the disadvantage that it is usually installed at the end of the oxygen hose, where it splits into two tubes that then form the so-called nasal cannula through which the patient receives oxygen. The fire therefore has to spread from the primary fire through these two tubes to the connection to the common supply hose in order to activate the valve. This causes oxygen to flow for an unnecessarily long time.In addition, since the fire also spreads through the patient's bedding and / or clothing, the supply hose in front of the valve can be caught in the flames, melt and thus release the oxygen flow again.

[0007] EP 2 682 149 A2 describes a system in which a thin copper wire is integrated into the tube, to which a voltage is applied or whose resistance is measured. If the tube ignites, this copper wire melts, and the oxygen supply is interrupted via a corresponding monitoring device. This arrangement can certainly stop the flow of oxygen much earlier than the one described in WO 2014 / 020334 A1, but it is very complex to manufacture. Since a closed circuit is required, the supply to the patient's nasal cannula must be via two tubes, between which reliable electrical contacts must exist. The electrical connection of the copper wire to the monitoring device is also complex.

[0008] DE 20 2012 009 706 U1 describes a corresponding system with a light guide instead of the copper wire, which is likely to be even more complex.

[0009] US 5,927,312 describes a system with a self-extinguishing tube in which, in the event of a fire, a closure is triggered, essentially stopping the flow of gas. This is achieved through a combination of different materials, with a heat-sensitive material that expands when applied externally around the tube at the desired closure point, or contracts or melts when applied inside the tube. However, as already mentioned in US 5,927,312, installing this system in the nasal cannula would lead to an undesirable increase in material and weight in the facial area. Furthermore, the described system has the same disadvantages as WO 2014 / 020334 A1.

[0010] DE 20 2015 007 512 U1 describes a breathing air tube coated with a non-flammable material, making it difficult to ignite. However, this breathing air tube does not prevent the afterflow of oxygen and cannot prevent cigarette ignition and the resulting oxygen-accelerated ignition of clothing and bedding.

[0011] It is therefore an object of the present invention to provide a technically simple and inexpensive system that ensures an early and safe stop of the inflowing oxygen.

[0012] This object is achieved by means of a device for supplying a patient with oxygen-enriched breathing gas according to claim 1 and by a method for operating such a device according to claim 14. Preferred embodiments of the device and method according to the invention are described in the dependent claims.

[0013] Accordingly, the present invention is directed to a device for supplying a patient with oxygen-enriched breathing gas. The device comprises a device for providing oxygen-enriched breathing gas, a supply line connected to the device, via which the oxygen-enriched breathing gas can be supplied from the device to the patient, and a detector suitable for detecting an increase in the volume flow of oxygen-enriched breathing gas and / or a pressure drop of the oxygen-enriched breathing gas. The device is suitable and configured to prevent or interrupt the supply of the oxygen-enriched breathing gas in the event of an increase in the volume flow of oxygen-enriched breathing gas and / or a pressure drop of the oxygen-enriched breathing gas.The supply line has a region near the patient with increased flow resistance, which is designed such that the flow resistance is reduced under the influence of heat by melting the tube. The device further comprises a valve that prevents the supply of the oxygen-enriched breathing gas in the event of an increase in the volume flow of oxygen-enriched breathing gas and / or a drop in the pressure of the oxygen-enriched breathing gas. The valve is suitable for mechanically and automatically preventing the supply of the oxygen-enriched breathing gas in the event of an increase in the volume flow of oxygen-enriched breathing gas and / or a drop in the pressure of the oxygen-enriched breathing gas.

[0014] In other words, the invention is based on the principle that a flow restriction occurs directly at the point where the oxygen or oxygen-enriched breathing air is delivered (in the simplest case, for example, by a cross-sectional constriction of the supply line), which leads to a relative increase in pressure in the proximal area of ​​the supply line. In the event of a fire in the patient's facial area, e.g. caused by a flaming cigarette, this flow restriction is lifted again because the area with increased flow resistance is designed in such a way that the flow resistance is reduced under the influence of heat. For example, the cross-sectional constriction can melt under the influence of heat. This causes an increase in the volume flow or a pressure drop in the supply line, which in turn leads to the supply of oxygen-enriched breathing gas being stopped. This occurs when the valve is closed.

[0015] The device according to the invention is technically relatively simple and therefore inexpensive to manufacture and guarantees an early and safe stop of the oxygen supply, since the detection of the fire (via the area with an increased flow resistance) takes place close to the patient.

[0016] The device for providing oxygen-enriched breathing gas can be a pressure cylinder, a liquid oxygen vessel (Dewar), an oxygen concentrator or generator, or a central oxygen supply system. The device is suitable for providing a breathing gas with a higher oxygen content than ambient air. If necessary, the oxygen-enriched breathing gas can also be pure oxygen. Depending on the type and function of the device for providing oxygen-enriched breathing gas, the preferred means of preventing or interrupting the breathing gas supply is to switch it off (e.g., concentrator) or close a valve (e.g., pressure cylinder). The former could also be very easily implemented as a ballast into which the plug of the concentrator, for example, is inserted.This has the advantage that existing concentrators can be used with the device according to the invention without complicated or expensive retrofitting.

[0017] The supply line, via which the oxygen-enriched breathing gas can be supplied to a patient from the device for providing oxygen-enriched breathing gas, is connected directly or indirectly to the device for providing oxygen-enriched breathing gas. In particular, a device for regulating the supply flow and / or the pressure in the supply line can be present. The supply line preferably has a supply hose with a nasal cannula or a connector for connection to a breathing mask or a ventilation tube. The region with an increased flow resistance is preferably provided at the patient-side end of the supply hose, at the nasal cannula and / or at the connector. The region with an increased flow resistance is preferably provided as close as possible to the outlet point of the oxygen-enriched breathing gas, since the fire develops most quickly at this outlet point.Preferably, the distance between the area with an increased flow resistance and the exit point of the oxygen-enriched breathing gas is less than 10 cm, more preferably less than 5 cm and particularly preferably less than 3 cm.

[0018] According to a first preferred variant, which does not fall under the wording of the claims, the increase in the volume flow of oxygen-enriched breathing gas and / or the pressure drop of the oxygen-enriched breathing gas in the supply line is detected or measured, and the device for providing oxygen-enriched breathing gas or the valve is switched off or closed by means of a suitable control. For this purpose, the device preferably has a detector suitable for detecting an increase in the volume flow of oxygen-enriched breathing gas in the supply line and / or a pressure drop of the oxygen-enriched breathing gas in the supply line. The detector can be provided in the supply line or on the device for providing oxygen-enriched breathing gas.The device preferably further comprises a controller suitable for closing the valve and / or deactivating the device for providing oxygen-enriched breathing gas if the detector detects an increase in the volume flow of oxygen-enriched breathing gas and / or a pressure drop of the oxygen-enriched breathing gas. The detector is preferably suitable for detecting a relative increase in the volume flow of oxygen-enriched breathing gas in the supply line by at least 50%, preferably by at least 30%, more preferably by at least 20%, particularly preferably by at least 10%. Alternatively or additionally, the detector is preferably suitable for detecting a relative pressure drop of the oxygen-enriched breathing gas in the supply line of at least 50%, preferably by 30%, more preferably by at least 20%, and particularly preferably by at least 10%.

[0019] The controller is preferably configured to use the detector to measure the volume flow of oxygen-enriched breathing gas and / or the pressure of the oxygen-enriched breathing gas during normal operation, preferably after a predetermined period of time after the start of the provision of oxygen-enriched breathing gas, and to define a threshold value. The controller is further preferably configured to prevent the supply of oxygen-enriched breathing gas if a minimum percentage deviation of the measured volume flow of oxygen-enriched breathing gas and / or the measured pressure of the oxygen-enriched breathing gas from the threshold value is determined. The minimum percentage deviation is preferably 50%, more preferably 30%, even more preferably 20%, and particularly preferably 10%.The predetermined time period is preferably at least 10 s, more preferably at least 20 s, even more preferably at least 30 s and particularly preferably at least 1 min. This ensures that the threshold value is only determined when flow equilibrium has already been established and ideally the nasal cannula is already attached to the patient, so that deviations from this normal or threshold value can subsequently be determined.

[0020] Additionally or alternatively, the device may comprise a device or mechanism that ensures that the breathing gas supply is briefly interrupted when the supply line is connected to the device for providing oxygen-enriched breathing gas. If, for example, the user first starts up the concentrator and only then connects the supply line to the concentrator, the device's control system may set an incorrect threshold. The brief interruption triggers the control system to determine a new threshold after the supply line is connected to the concentrator. For this purpose, for example, the hose connection of the supply line could be slightly axially displaceable so that the breathing gas supply is interrupted or the flow or pressure measurement is triggered again when the hose is connected and disconnected.

[0021] According to a second variant of the invention, the valve itself is suitable for mechanically and automatically stopping the supply of oxygen-enriched breathing gas in the event of an increase in the volume flow of oxygen-enriched breathing gas through the valve and / or a drop in pressure of the oxygen-enriched breathing gas at the valve. Preferably, the valve comprises a spring or a magnet that biases the valve into the open position against the flow direction of the oxygen-enriched breathing gas. Preferably, the spring constant of the spring or the force of the magnet is dimensioned such that the valve is closed at a volume flow of 5 l / min and a sudden pressure drop of at least 50%, preferably of at least 30%, particularly preferably of at least 20%.

[0022] The region with increased flow resistance can in principle be provided by very different structural features in all possible variants, as long as it is designed such that the flow resistance is reduced under the influence of heat. In the context of the present invention, this means that the region with increased flow resistance is exposed to a certain minimum temperature for a certain minimum duration. The minimum duration is preferably 10 seconds, more preferably 5 seconds, even more preferably 3 seconds, and particularly preferably 2 seconds. The minimum temperature is preferably 140°C, more preferably 120°C, and particularly preferably 100°C. Accordingly, it is particularly preferred that the region with increased flow resistance is designed such that the flow resistance is reduced when the region is exposed to a temperature of at least 100°C for at least 2 seconds.

[0023] The aim is to reduce the flow resistance of the area under the influence of heat to such an extent that the resulting increase in volume flow or the resulting pressure drop can be detected by a detector or sensor and / or directly leads to the closure of the valve. Accordingly, the reduction in flow resistance required according to the invention depends on the type of detector used or the sensitivity of the valve, as well as on the conditions (pressure and volume flow) under which the breathing gas is administered.

[0024] The latter depend, among other things, on the patient (some patients are supplied with a volume flow of, for example, 5 l / min, others with a volume flow of, for example, 3 l / min) and on the type of device used to provide the enriched breathing gas.

[0025] However, it is preferred that the region with an increased flow resistance has a flow resistance that corresponds to an orifice with a clear diameter of between 0.1 mm and 4 mm, more preferably between 0.3 mm and 3 mm, and particularly preferably between 0.5 mm and 2 mm. It is further preferred that the region with an increased flow resistance has a flow resistance that is less than or equal to the flow resistance of an orifice with a clear diameter of 2 mm, preferably 1.5 mm, and particularly preferably 1 mm. It is further preferred that, for example in the case of several openings with a reduced cross-sectional area, the largest opening in the region with an increased flow resistance has a cross-sectional area of ​​at most 10 mm 2 , preferably at most 5 mm 2 , more preferably at most 3 mm 2 , even more preferably at most 2 mm 2 and particularly preferably at most 1 mm 2 .It is further preferred that the region with an increased flow resistance has a cross-sectional area that is at most 40%, preferably at most 30%, more preferably at most 20%, even more preferably at most 15%, and particularly preferably at most 10% of the maximum cross-sectional area of ​​the remaining supply line. It is further preferred that the region with an increased flow resistance has a flow resistance that is increased by at least 10%, preferably by at least 20%, more preferably by at least 30%, even more preferably by at least 50%, and particularly preferably by at least 100% compared to the flow resistance of the remaining supply line at a volume flow of 5 l / min. Depending on whether a laminar or turbulent flow is present, the flow resistance can also be increased by a factor of at least 2, preferably at least 3, more preferably at least 5, and particularly preferably at least 8.It is further preferred that the region with an increased flow resistance is such that removal and / or destruction of the region at a volume flow of 5 l / min leads to a pressure drop in the supply line of at least 0.05 bar, more preferably of at least 0.1 bar and particularly preferably of at least 0.2 bar.

[0026] Such areas with increased flow resistance can be implemented in various ways. For example, the area with increased flow resistance can comprise one or a combination of the following elements: a region with a reduced opening cross-section, an orifice plate, a nozzle, multiple openings with a reduced cross-sectional area, a labyrinth-like structure, a sieve, a filter such as a sintered filter, a depth filter made of cellulose or plastic fibers, or a membrane filter.

[0027] The reduction in flow resistance under the influence of heat can be achieved using various mechanisms. For example, the area can be made of a material that loses its stability and / or melts under the influence of heat. For example, the area with increased flow resistance can be made of polyethylene with a melting temperature of approximately 100°C. Under the influence of heat, the area with the increased opening cross-section, the nozzle, etc., then melts, reducing the flow resistance in that area. When completely melted, it corresponds to the flow resistance in the rest of the supply line. Alternatively, the reduction in flow resistance under the influence of heat could also be achieved using a highly flammable material. For example, a cellulose filter in the supply line could burn, thus reducing the flow resistance.

[0028] The valve is preferably provided in or on the device for providing oxygen-enriched breathing gas or in the supply line.

[0029] Preferably, the device is further capable of triggering an alarm when the valve shuts off the supply of oxygen-enriched breathing gas. This alarm can be triggered, for example, by the control system closing the valve. Alternatively, the valve trigger could actuate an electrical contact, for example, which triggers a device alarm or an external alarm.

[0030] The device preferably further comprises a source of non-combustible gas, in particular nitrogen, inert gas, and / or carbon dioxide, wherein the device is adapted to flood the supply line with the non-combustible gas when the valve shuts off the supply of the oxygen-enriched breathing gas. For this purpose, a two-way valve or a bypass can be provided distal to the valve, for example.

[0031] If the valve according to the invention or its control always responds when the volume flow of oxygen-enriched breathing gas increases or a pressure drop occurs, it can happen that, for example, when starting up the concentrator or when connecting the supply line to the device for providing oxygen-enriched breathing gas, a rapid pressure increase occurs, which could lead to the valve being closed unintentionally. Therefore, a device is preferably provided that prevents the valve from closing unintentionally. For example, with an electronically controlled valve, it could be ensured that the valve control is only switched on with a time delay of, for example, a few seconds after starting up the concentrator and / or connecting the supply line to the device for providing oxygen-enriched breathing gas.

[0032] After the control has switched on, it first measures the existing pressure or flow in order to then be able to react to a drop in pressure or an increase in flow (or increase in volume flow).

[0033] In the case of a valve capable of mechanically automatically shutting off the supply of oxygen-enriched breathing gas, the valve can preferably be manually held open. For example, the valve housing could have two elastic areas that the user can press with two fingers. These areas, as the elastomer expands into the interior of the valve housing, hold or fix the valve's closing body and then release it again when released. This allows the user to hold the valve open while starting the concentrator and then release the valve again. If the valve is held open magnetically, the valve's closing body could also be held open without contact using a movable iron ring.

[0034] The valve can, for example, be a mechanical flow-stop valve, integrated as a disposable product into the end of the supply line far from the patient. Alternatively, the flow-stop valve could be a separate, reusable part connected directly to the device for delivering oxygen-enriched breathing gas or integrated into it. The valve can also be adjustable to adapt the trigger threshold to the set flow rate. This adjustment can also occur automatically. If the valve is controlled by a controller, it can be an electromagnetic or electromotive valve, for example.

[0035] The present invention further relates to a method for operating a device as described above. The method comprises the following steps: Activating the provision of oxygen-enriched breathing gas by switching on the device for providing oxygen-enriched breathing gas and / or opening a valve, measuring the volume flow of oxygen-enriched breathing gas and / or the pressure of the oxygen-enriched breathing gas and defining a threshold value based on the measurement, wherein the measurement takes place after a predetermined period of time after activation, continuously or repeatedly measuring the volume flow of oxygen-enriched breathing gas and / or the pressure of the oxygen-enriched breathing gas, and

[0036] Deactivation of the supply of oxygen-enriched breathing gas by mechanically closing the valve when a minimum percentage deviation of the measured volume flow of oxygen-enriched breathing gas and / or the measured pressure of the oxygen-enriched breathing gas from the threshold value is detected.

[0037] In the context of the method according to the invention, all preferred features described above in the context of the device according to the invention can be used. In particular, the minimum percentage deviation is preferably 50%, more preferably 30%, even more preferably 20%, and particularly preferably 10%. The predetermined time period is preferably at least 10 s, more preferably at least 20 s, even more preferably at least 30 s, and particularly preferably at least 1 min.

[0038] Preferred embodiments of the present invention are described in more detail below with reference to the figures. They show: Fig. 1 in perspective view a supply line with nasal cannula; Fig. 2 in perspective view the nasal cannula according to Fig. 1 ; Fig. 3 a longitudinal sectional view through a nasal cannula according to the invention according to a preferred embodiment; Fig. 4a longitudinal sectional view through a nasal cannula according to the invention according to a preferred embodiment; Fig. 5 a longitudinal sectional view through a nasal cannula according to the invention according to a preferred embodiment; Fig. 6 a longitudinal sectional view through a nasal cannula according to a preferred embodiment; Fig. 7 a longitudinal sectional view through a valve according to the invention according to a preferred embodiment; Fig. 8 a longitudinal sectional view through a valve according to the invention according to a preferred embodiment; and Fig. 9 a longitudinal sectional view through a valve according to the invention according to a preferred embodiment.

[0039] Figure 1shows a perspective view of a supply line 1 through which the oxygen-enriched breathing gas can be supplied to a patient from a device for providing oxygen-enriched breathing gas (not shown). The supply line 1 has a supply tube 2 with a nasal cannula 4 and a connector 3, by means of which the supply line can be connected to the device for providing oxygen-enriched breathing gas. Such devices for providing oxygen-enriched breathing gas are known from the prior art and require no further description.

[0040] Figure 2 shows the nasal cannula 4 according to Figure 1again in an enlarged perspective view. The nasal cannula 4 has two connectors 4a, by means of which the nasal cannula 4 can be connected to the supply tube 2. Furthermore, the nasal cannula 4 has two nasal prongs 4b, which can be inserted into the nostrils of a patient.

[0041] In the Figures 3 to 6 Preferred embodiments of a nasal cannula according to the invention are shown schematically in longitudinal section. Figures 3 to 6The nasal cannulas 4 shown also each have two connecting pieces 4a and two nasal prongs 4b. Furthermore, two areas with an increased flow resistance 5a and 5b are shown in the nasal cannulas 4. In each case, one such area 5a is shown in one of the connecting pieces 4a and one of the areas 5b is shown in one of the nasal prongs 4b. The areas identified by the reference numerals 5a and 5b represent alternative design variants. In the actual embodiments of the nasal cannula 4, an area 5a with increased flow resistance is preferably provided in each of the connecting pieces 4a or, alternatively, an area 5b with increased flow resistance is provided in each of the nasal prongs 4b. The area with an increased flow resistance can, for example, be formed by an area with a reduced opening cross-section, such as a diaphragm (cf. Figure 3 ), through a sieve or a membrane filter (see Figure 4), through a porous depth filter made of sintered material or fiber material (cf. Figure 5 ) or through a nozzle (cf. Figure 6 ) are provided.

[0042] A simple aperture, as used in Figure 3 This can, under certain circumstances, lead to the escape of oxygen-enriched breathing gas in the form of a sharp or focused jet, which can cause unpleasant sensations in the patient's nose. It is therefore preferable to design the area with increased flow resistance in such a way that it does not increase the exit velocity of the breathing gas. This can be achieved, for example, by using many small openings (see Figure 4) instead of a large opening. Plastic injection molding can also create a labyrinth-like structure, which leads to a corresponding deceleration of the respiratory gas flow. Filters, such as membrane filters or depth filters made of cellulose or plastic, or of porous materials such as sintered polyethylene or glass frit, have a similar effect. Likewise, an area with increased flow resistance can be created in the form of a nozzle (see Figure 6 ) can lead to an expansion of the breathing gas jet.

[0043] Figure 7shows a longitudinal sectional view of a valve according to the invention according to a preferred embodiment. The valve 6 is a valve that is suitable for mechanically and automatically stopping the supply of oxygen-enriched breathing gas in the event of an increase in the volume flow of oxygen-enriched breathing gas and / or a drop in pressure of the oxygen-enriched breathing gas. The valve 6 has a closure body 7, which in Figure 7 shown state due to the flow of oxygen illustrated by an arrow, if this, for example, suddenly increases, is pressed to the right with its seal 9 against the valve seat 11, so that the valve 6 in the in Figure 7 shown state is open. At a smaller volume flow, however, the spring 8 holds the closure body 7 in the closed position to the left, against the flow direction of the oxygen-enriched breathing gas. Figure 7The open position shown represents, to a certain extent, the normal state of the valve during regular supply of oxygen-enriched breathing gas, whereas the closed position of the valve 6 is realized when, for example, at a volume flow of 5 l / min, there is an increase in the volume flow of at least 30%, preferably by at least 20%, and particularly preferably by at least 10%. Such an increase in the volume flow is caused according to the invention by reducing the flow resistance of the area with an increased flow resistance under the influence of heat. For example, the Figures 3 to 6 The structures shown in the respective regions 5a and 5b melt under the influence of heat or are deformed to such an extent that a measurable increase in the volume flow and / or a measurable pressure drop is caused.

[0044] To prevent the valve from accidentally closing automatically due to a resulting pressure increase, for example when the concentrator is switched on or when the supply line is connected to the concentrator, a device can be provided on the valve 6 that allows the closure body 7 to be fixed in the open position. For example, as shown schematically in Figure 8 As shown, two elastic areas 10 (or an annular structure made of an elastomer) are provided, onto which the user can press with two fingers, which causes the elastomer 10 to swell into the interior of the valve housing, whereby the closing body 7 of the valve 6 is held in its current position.

[0045] Additionally or alternatively, a displaceably arranged ring 16 may be provided which extends around a valve housing section 12 and can slide in the distal and proximal direction over the valve housing section 12, as shown in Figure 9 is shown. At the distal end of the valve housing section 12, a projection 13 or another device for limiting the displacement path of the ring 16 in the distal direction can be provided. If the proximal connecting piece 15 of the valve 6 is now connected to, for example, a concentrator, the user, when gripping the valve 6 at the ring 16, will exert a force acting in the proximal direction (see arrow) on the ring 16, which, due to the wedge-shaped proximal section 16a of the ring 16, leads to the balls 14 being pressed into the elastomer 10, so that pre-swelling of the elastomer 10 into the interior of the valve housing holds the closing body 7 of the valve 6 in its current position.

[0046] Instead of the spring 8, the valve 6 can also have a magnetic mechanism, by means of which the valve is biased into the open position against the flow direction of the oxygen-enriched breathing gas. Furthermore, the valve can also be an electromagnetic or electromotive valve controlled by a combination of sensor and control.

Claims

1. A device for supplying a patient with oxygenated breathable gas having: an apparatus for providing oxygenated breathable gas; a supply line (1) connected to the apparatus, through which the oxygenated breathable gas can be supplied from the apparatus to a patient; and a detector which is suitable to detect an increase in the volume flow of oxygenated breathable gas and / or a drop in pressure of the oxygenated breathable gas; wherein the device is suitable to stop the supply of the oxygenated breathable gas if the volume flow of oxygenated breathable gas increases and / or the pressure of the oxygenated breathable gas drops, and wherein the supply line (1) comprises a patient-proximate section (5a; 5b) having an increased flow resistance vis-à-vis the flow resistance of the remaining part of the supply line, which is configured such that the flow resistance is reduced under the effect of heat; further with a valve (6) which stops the supply of the oxygenated breathable gas if the volume flow of oxygenated breathable gas increases and / or the pressure of the oxygenated breathable gas drops, wherein the valve (6) is suitable to automatically stop the supply of the oxygenated breathable gas if the volume flow of oxygenated breathable gas increases and / or the pressure of the oxygenated breathable gas drops.

2. The device according to claim 1, further with a controller which is suitable to switch off the apparatus for providing oxygenated breathable gas and / or to close a valve in case the detector detects an increase in volume flow of oxygenated breathable gas and / or a drop in pressure of the oxygenated breathable gas, wherein the controller is preferably configured to measure the volume flow of oxygenated breathable gas and / or the pressure of the oxygenated breathable gas and to define a threshold value, in normal operation, preferably after a predetermined time period after the supply of oxygenated breathable gas started, by means of the detector.

3. The device according to claim 2, wherein the controller is configured to stop the supply of oxygenated breathable gas when a percentage minimum deviation of the measured volume flow of oxygenated breathable gas and / or the measured pressure of the oxygenated breathable gas from the threshold value is detected, wherein preferably the percentage minimum deviation is 30%, more preferably 20% and particularly preferably 10%.

4. The device according to any one of the preceding claims, wherein the detector is suitable to detect a relative increase in the volume flow of oxygenated breathable gas by 30%, preferably by 20%, particularly preferably by 10% and / or a relative drop in the pressure of the oxygenated breathable gas by 30%, preferably by 20%, particularly preferably by 10%.

5. The device according to any one of the preceding claims, wherein the valve (6) is provided in or at the apparatus for providing oxygenated breathable gas or in the supply line (1), wherein the valve (6) preferably comprises a spring (8) or a magnet which prestresses the valve (6) opposite to the flow direction of the oxygenated breathable gas into the open position, wherein the spring constant of the spring (8) or the force of the magnet is set such that the valve (6) is closed at a volume flow of 5 l / min and a drop in pressure of at least 30%, preferably of at least 20%, particularly preferably of at least 10%.

6. The device according to any one of the preceding claims, wherein the valve (6) has a closing body (7) and a means which is suitable to manually secure the closing body in the open position of the valve.

7. The device according to any one of the preceding claims, wherein the section (5a; 5b) with an increased flow resistance has a flow resistance which corresponds to an aperture having an inner diameter between 0.1 mm and 4 mm, preferably between 0.3 mm and 3 mm and particularly preferably between 0.5 mm and 2 mm and / or is smaller than or equal to the flow resistance of an aperture having an inner diameter of 2 mm, preferably of 1.5 mm and particularly preferably of 1 mm.

8. The device according to any one of the preceding claims, wherein the largest opening in the section (5a; 5b) having an increased flow resistance comprises a cross-sectional area of 10 mm2 at the most, preferably 5 mm2 at the most, more preferably 3 mm2 at the most, even more preferably 2 mm2 at the most and particularly preferably 1 mm2 at the most and / or wherein the section (5a; 5b) having an increased flow resistance comprises a cross-sectional area of 40% at the most, preferably 30% at the most, more preferably 20% at the most, even more preferably 15% at the most and particularly preferably 10% at the most of the maximum cross-sectional area of the remaining part of the supply line.

9. The device according to any one of the preceding claims, wherein the section (5a; 5b) having an increased flow resistance comprises a flow resistance which is increased by at least 10%, preferably by at least 20%, more preferably by at least 30%, even more preferably by at least 50% and particularly preferably by at least 100% vis-à-vis the flow resistance of the remaining part of the supply line at a volume flow of 5 l / min.

10. The device according to any one of the preceding claims, wherein the section (5a; 5b) having an increased flow resistance is configured such that a removal and / or destruction of the section at a volume flow of 5 l / min leads to a drop in pressure in the supply line of at least 0.05 bar, preferably at least 0.1 bar and particularly preferably of at least 0.2 bar.

11. The device according to any one of the preceding claims, wherein the section (5a; 5b) having an increased flow resistance comprises one or a combination of the following elements: section with reduced opening cross-section, aperture, nozzle, a plurality of openings with reduced cross-sectional area, labyrinth-like structure, sieve, filter such as, for example, sinter filters, depth filters made of cellulose or plastic fibres or membrane filters.

12. The device according to any one of the preceding claims, wherein the supply line (1) comprises a supply tube (2) with a nasal cannula (4) or a connector to connect to a breathing mask or a breathing tube, wherein the section (5a; 5b) with an increased flow resistance is provided at the patient-facing end of the supply tube (1), at the nasal cannula (4) and / or at the connector.

13. The device according to any one of the preceding claims, further with a source for incombustible gas, in particular nitrogen, noble gas and / or carbon dioxide, wherein the apparatus is suitable to flood the supply line with the incombustible gas when the supply of the oxygenated breathable gas is stopped.

14. A method for operating a device according to any one of the preceding claims comprising the following steps: activation of the provision of oxygenated breathable gas by switching on the apparatus for supplying oxygenated breathable gas and / or opening of a valve, measuring the volume flow of oxygenated breathable gas and / or the pressure of the oxygenated breathable gas and defining a threshold value on the basis of the measurement, wherein the measurement is conducted after a predetermined time period after the activation, continuous or repeated measurement of the volume flow of oxygenated breathable gas and / or the pressure of the oxygenated breathable gas, and deactivation of the supply of oxygenated breathable gas by automatic mechanical closing of the valve, when a percentage minimum deviation of the measured volume flow of oxygenated breathable gas and / or the measured pressure of the oxygenated breathable gas from the threshold is detected.

15. The method according to claim 14, wherein the percentage minimum deviation is 30%, preferably 20% and particularly preferably 10%.