Device for quantitatively determining the feed of oxygen into blood in an oxygenator

Abstract

The invention relates to a device (20) for determining the feed (V'02) of oxygen into blood in an oxygenator (10), comprising a gas flow sensor (24a, 24b) which is designed to measure a flow (flowsipm. flowsrpout) of an oxygen-containing gas mixture flowing through the oxygenator (10); and a gas sensor unit (26a, 26b; 26, 28, 30) which is designed to measure the oxygen content (p02 / n) of the oxygen-containing gas mixture flowing into the oxygenator (10) and the oxygen content (jDoaoui) of a gas mixture flowing out of the oxygenator (10). For this purpose, the device is designed to determine a discrepancy, in particular a difference, between the oxygen content (po2 / n) of the oxygen-containing gas mixture flowing into the oxygenator (10) and the oxygen content (Po2oui) of the gas mixture flowing out of the oxygenator (10) and to determine the feed (V'O2) of oxygen into the blood flowing through the oxygenator (10) from the determined difference and the flow (JlowsiPin. flowsrpout) measured by the gas flow sensor (24a, 24b).

Description

[0001] Device for quantitatively determining an entry of oxygen into blood in an oxygenator

[0002] The invention relates to a device for quantitatively determining an introduction of oxygen into blood in an oxygenator, a device for introducing oxygen into blood in an oxygenator, which is equipped with a device according to the invention for quantitatively determining the introduction of oxygen, and a device for extracorporeal blood gas exchange with such a device for introducing oxygen into blood.

[0003] The invention further relates to a system for supporting the blood gas exchange of a patient by means of mechanical ventilation and extracorporeal blood gas exchange, wherein the system comprises a device according to the invention for extracorporeal blood gas exchange and a ventilation device for mechanical ventilation of the patient's lungs.

[0004] Physiological gas exchange involves the transfer of oxygen into venous blood (oxygenation) and the removal of carbon dioxide from the venous blood (ventilation). After gas exchange, the deoxygenated and carbon dioxide-rich venous blood is transformed into oxygen-rich and carbon dioxide-poor arterial blood. Physiological gas exchange normally takes place in the lungs. If necessary, this can be supported by mechanical ventilation.

[0005] If physiological gas exchange in the lungs is insufficient to supply a patient's blood with sufficient oxygen, even with mechanical ventilation support, extracorporeal membrane oxygenation (ECMO) can be used. In extracorporeal membrane oxygenation, oxygen is introduced into the patient's blood using an extracorporeal blood gas exchange device, referred to below as an oxygenator. Extracorporeal gas exchange also includes removing carbon dioxide (CO2) from the patient's blood. This is referred to as extracorporeal ventilation or extracorporeal CO2 removal (ECCO2R). The combination of ECMO and ECCO2R is referred to as extracorporeal life support (ECLS).

[0006] In extracorporeal life support, it is desirable to be able to quantitatively determine the amount of oxygen introduced into the blood by means of extracorporeal gas exchange in order to adjust the extracorporeal life support device so that a sufficient oxygen concentration in the arterial blood is achieved. It is often also desirable to be able to quantitatively determine the amount of carbon dioxide (CO2) removed from the blood in order to monitor that the concentration of CO2 in the arterial blood is sufficiently reduced. It is particularly desirable to be able to coordinate the operation of the extracorporeal life support device with the operation of an additional mechanical ventilation device in order to achieve the best possible oxygen supply, and if necessary also the best possible ventilation, for the patient through a suitable combination of mechanical ventilation and extracorporeal life support.

[0007] It is therefore an object of the present invention to provide a device that makes it possible to quantitatively determine the extent of oxygen input into a patient's blood during extracorporeal membrane oxygenation. Furthermore, it is an object of the invention to provide a device that makes it possible to control the input of oxygen into a patient's blood during extracorporeal membrane oxygenation and / or mechanical ventilation in such a way that a sufficient supply of oxygen to the patient is ensured.

[0008] A device according to the invention for quantitatively determining the introduction of oxygen into blood in an oxygenator (or during the passage of blood through an oxygenator) comprises a gas flow sensor designed to measure a flow of an oxygen-containing gas mixture flowing into the oxygenator; and a gas sensor unit designed to measure the oxygen content of the oxygen-containing gas mixture flowing into the oxygenator and the oxygen content of a gas mixture flowing out of the oxygenator.The device is designed to determine a difference, in particular a difference, between the oxygen content of the oxygen-containing gas mixture flowing into the oxygenator and the oxygen content of the gas mixture flowing out of the oxygenator, and to quantitatively determine the introduction of oxygen into blood flowing through the oxygenator from the difference thus determined and the flow measured by the gas flow sensor.

[0009] The flow of the gas mixture flowing through the oxygenator can be measured by means of a flow sensor, for example by means of a mass flow sensor as mass flow or by means of a volume flow sensor as volume flow.

[0010] The flow of the gas mixture flowing through the oxygenator can be measured, in particular, as the flow of a gas mixture flowing into the oxygenator. The fact that the oxygen content and, if applicable, the carbon dioxide content of the gas mixture generally change as it passes through the oxygenator can influence the measured flow of the gas mixture flowing through the oxygenator. If, in addition to the introduction of oxygen into the blood, carbon dioxide is also removed from the blood to approximately the same extent as the gas passes through the oxygenator, the influence on the measured flow is so small that it can possibly be neglected.

[0011] The invention also includes a method for quantitatively determining the introduction of oxygen into blood in an oxygenator, the method comprising: determining the flow of an oxygen-containing gas mixture flowing through the oxygenator, in particular the flow of a gas mixture flowing into the oxygenator and / or the flow of a gas mixture flowing out of the oxygenator;

[0012] Measuring the oxygen content of the oxygen-containing gas mixture supplied to the oxygenator;

[0013] Measuring the oxygen content of a gas mixture flowing out of the oxygenator;

[0014] Determining a difference, in particular a difference, between the measured oxygen content of the oxygen-containing gas mixture supplied to the oxygenator and the measured oxygen content of the gas mixture flowing out of the oxygenator; and quantitatively determining the introduction of oxygen into the blood flowing through the oxygenator from the previously determined difference between the measured oxygen content of the gas mixture supplied to the oxygenator and the measured oxygen content of the gas mixture flowing out of the oxygenator, as well as from the flow of the oxygen-containing gas mixture flowing through the oxygenator.

[0015] Blood taken from a patient's bloodstream and an oxygen-containing gas mixture flow through the oxygenator simultaneously. The oxygenator is designed to transfer oxygen from the oxygen-containing gas mixture into the blood. A basic idea of ​​the invention is to determine the depletion of oxygen in the gas mixture as it flows through the oxygenator and to obtain quantitative information about the degree of oxygenation from the depletion thus determined, in particular based on a difference between the oxygen content of the gas mixture upstream of the oxygenator and the oxygen content of the gas mixture downstream of the oxygenator, in particular to determine the amount of oxygen that has passed from the gas mixture into the patient's blood in the oxygenator.The blood downstream of the oxygenator is enriched compared to the blood upstream of the oxygenator by the amount of oxygen that has passed from the gas mixture into the blood in the oxygenator.

[0016] In a corresponding manner, if desired, the enrichment of carbon dioxide in the gas mixture as it flows through the oxygenator can also be determined, and from the enrichment thus determined, in particular based on a difference between the carbon dioxide content of the gas mixture downstream of the oxygenator and the carbon dioxide content of the gas mixture upstream of the oxygenator (this will generally be zero), quantitative information about the degree of ventilation can be obtained, in particular the amount of carbon dioxide that has passed from the patient's blood into the gas mixture in the oxygenator. The blood downstream of the oxygenator is depleted compared to the blood upstream of the oxygenator by the amount of carbon dioxide that has passed from the patient's blood into the gas mixture downstream of the oxygenator.

[0017] In the context of the invention, "upstream" of the oxygenator means at, in, or before the inlet of the oxygenator; "downstream" of the oxygenator means at, in, or after the outlet of the oxygenator, in each case relative to the flow of the gas mixture through the oxygenator. The oxygen content or carbon dioxide content in the gas mixture and / or in the blood can be expressed as the partial pressure of oxygen or carbon dioxide in the blood or as the partial pressure of oxygen or carbon dioxide in the gas mixture or as the mixing ratio of oxygen or carbon dioxide in the blood or in the gas mixture or as the oxygen saturation of oxygen in the blood or in the gas mixture or the carbon dioxide saturation of carbon dioxide in the blood or in the gas mixture.

[0018] If the total pressure of the gas mixture is known, e.g. from an additional measurement, the concentration of oxygen or carbon dioxide in the gas mixture or the concentration of oxygen or carbon dioxide in the blood can also be determined.

[0019] The extent of extracorporeal blood gas exchange can be considered to be, in particular, the introduction of oxygen into the blood when flowing through an oxygenator (degree of oxygenation) and / or the removal of carbon dioxide from the blood when flowing through the oxygenator (degree of ventilation).

[0020] A device according to the invention makes it possible to determine the extent of extracorporeal blood gas exchange, in particular the amount of oxygen introduced into the blood of a patient by extracorporeal blood gas exchange (ie the

[0021] The oxygenation level (degree of oxygenation) can be determined "bloodless," i.e., without interfering with the bloodstream. In this sense, the device according to the invention functions "contactlessly." The term "contactless" in this context is intended to express that no physical contact with the blood is required to quantitatively determine the oxygen input into the blood and / or the removal of carbon dioxide from the blood in the oxygenator.

[0022] A device according to the invention makes it possible to replace the gas sensor unit and / or sensors of the gas sensor unit used to measure the oxygen content in the gas mixture without having to open and / or interrupt the bloodstream. The gas sensor unit and the sensors can therefore be replaced particularly easily and hygienically, in particular without interfering with the bloodstream. The gas sensor unit can comprise at least one oxygen sensor designed to measure the oxygen content, in particular the partial pressure of oxygen, in a gas mixture flowing through the gas sensor unit.

[0023] The gas sensor unit can also comprise at least one carbon dioxide sensor (CO2 sensor) designed to measure the CO2 content, in particular the partial pressure of CO2, in a gas mixture flowing through the gas sensor unit. By measuring the CO2 content in the gas mixture upstream and downstream of the oxygenator, the CO2 enrichment in the gas mixture as it flows through the oxygenator and, from this, the CO2 removal from the blood (degree of ventilation) can be quantitatively determined. By quantitatively determining and

[0024] By considering the CO2 removal from the blood in addition to determining and considering the oxygen input into the blood, extracorporeal gas exchange can be further optimized. The CO2 sensor can be designed as a separate sensor in addition to an oxygen sensor. A combined oxygen and CO2 sensor can also be provided, which is capable of measuring both the oxygen content and the CO2 content of the gas mixture flowing through the gas sensor unit. Oxygen sensors, CO2 sensors, and combined oxygen and CO2 sensors are referred to below as "gas sensors."

[0025] The device for quantitatively determining the introduction of oxygen into blood in an oxygenator can be designed with only a single gas sensor in such a way that the one gas sensor can selectively measure the oxygen content and / or the CO2

[0026] The gas sensor unit measures the oxygen content of the gas mixture flowing into the oxygenator and the oxygen content and / or the CO2 content of the gas mixture flowing out of the oxygenator. In this context, a single gas sensor means that only one sensor is provided to measure the oxygen content of the gas mixture and that only one sensor is provided to measure the CO2 content of the gas mixture. The fact that the gas sensor unit comprises only one gas sensor can therefore mean that the gas sensor unit comprises a single oxygen sensor and a single CO2 sensor. Alternatively, the gas sensor unit may comprise only a single gas sensor that detects both the oxygen content of the gas mixture, optionally in the gas mixture flowing into the oxygenator and in the gas mixture flowing out of the oxygenator, or the COa content, optionally in the gas mixture flowing into the oxygenator and in the gas mixture flowing out of the oxygenator.

[0027] By using the same gas sensor to measure the oxygen content and / or CO2 content of both the gas mixture flowing into the oxygenator and the gas mixture flowing out of the oxygenator, deviations between the upstream and downstream measured values, which are attributable to systematic measurement errors of the respective gas sensor, can be effectively avoided. Such measurement errors can arise between different sensors, for example, due to manufacturing tolerances or due to sensitivity changes between different sensors that vary greatly over time. When measuring with one and the same sensor, such deviations are insignificant because they cancel each other out when determining the difference between the oxygen content or CO2 content of the gas mixture flowing into the oxygenator and the gas mixture flowing out of the oxygenator.This greatly increases the accuracy with which such differences between the oxygen or CO2 content of the gas mixture flowing into the oxygenator and the gas mixture flowing out of the oxygenator can be measured, compared to measurement setups that use two sensors, one upstream and one downstream of the oxygenator. Furthermore, costs can be reduced, as the cost of one oxygen sensor and the cost of a second CO2 sensor can be eliminated.

[0028] A device that has only a single gas sensor for measuring the oxygen content and, if applicable, the CO2 content can be equipped with at least one gas switching valve that is designed to selectively supply the gas sensor with a gas mixture, at least a portion of the gas mixture supplied to the oxygenator, or with a gas mixture, at least a portion of the gas mixture flowing out of the oxygenator. By switching the at least one gas switching valve, the oxygen content in the gas mixture upstream of the oxygenator and in the gas mixture downstream of the oxygenator can be determined with a single oxygen sensor. Likewise, if applicable, by switching the at least one gas switching valve, the CO2 content in the gas mixture upstream and downstream of the oxygenator can be determined with a single CO2 sensor. The at least one gas switching valve can be designed to periodically, e.g., to switch between a first switching state, in which it supplies the gas sensor with at least the gas mixture supplied to the oxygenator, and a second switching state, in which it supplies the gas sensor with the gas mixture flowing out of the oxygenator. In this way, the oxygen content and, if applicable, the CO2 content of both the gas mixture flowing into the oxygenator and the oxygen content and, if applicable, the CO2 content of the gas mixture flowing out of the oxygenator can be reliably measured, even over a longer period or for the purpose of continuous monitoring, if desired.

[0029] The at least one gas switching valve can, for example, be designed to switch between the first switching state and the second switching state at intervals of between 30 seconds and 120 seconds, in particular at intervals of between 60 seconds and 90 seconds. However, shorter switching times are also possible.

[0030] When using a gas switching valve as described here, the gas supply to the oxygenator can be modulated. Modulating the gas supply means that the gas supply to the oxygenator is increased by the gas flow passed through the gas sensor when and as long as the gas switching valve is switched to the first switching state, in order to compensate for the amount of gas mixture that is passed past the oxygenator to the gas sensor in the first switching state of the gas switching valve.

[0031] This means that the flow of the oxygen-containing gas mixture through the oxygenator is not significantly changed by switching the gas switching valve, but remains constant to such an extent that the extracorporeal gas exchange in the oxygenator is not influenced by switching the gas switching valve, at least not to a relevant extent.

[0032] Multiple gas switching valves can also be provided, allowing the entire gas flow to be selectively directed through both the gas sensor and the oxygenator. In this case, the previously described modulation of the gas supply, which is carried out to compensate for the amount of gas mixture that is directed past the oxygenator to the gas sensor, is not required. Instead of a single gas sensor and at least one gas switching valve, the gas sensor unit can also comprise a first gas sensor and a second gas sensor, wherein the first gas sensor is arranged upstream of the oxygenator and the second gas sensor is arranged downstream of the oxygenator.

[0033] By using two gas sensors, one located upstream and one downstream of the oxygenator, gas switching valves as described above can be dispensed with. Eliminating gas switching valves improves the operational reliability of the device, as errors resulting from malfunctioning gas switching valves can be eliminated. Each of the two gas sensors, located upstream and downstream of the oxygenator, can be configured to measure the oxygen content and / or the CO2 content in the flowing gas mixture.

[0034] Two gas sensors can also be provided upstream and two gas sensors downstream of the oxygenator, one of which is designed as an oxygen sensor for measuring the oxygen content in the flowing gas mixture, and the other as a CO2 sensor for measuring the CO2 content in the flowing gas mixture. If at least two gas sensors are used, one of which is arranged upstream and one downstream of the oxygenator, deviations in the measured values ​​provided by the two gas sensors at identical gas concentrations, which may arise, for example, from manufacturing tolerances in the manufacture of the gas sensors, must be sufficiently small to minimize the measurement errors resulting from such deviations.

[0035] The two gas sensors can, for example, be designed such that a tolerance-related deviation between the measured values ​​delivered by the two gas sensors at the same oxygen concentration or at the same CO2 concentration in the gas mixture is less than 0.5%, in particular less than 0.2%. Such small deviations make it possible to measure and determine the parameters of extracorporeal gas exchange in the oxygenator with sufficient accuracy.

[0036] The required accuracy can be achieved, for example, with sensors that include paramagnetic cells.

[0037] The device for quantitatively determining the introduction of oxygen into blood in an oxygenator can also have a gas delivery device designed to deliver gas mixture, at least a portion of the gas mixture flowing into the oxygenator and / or at least a portion of the gas mixture flowing out of the oxygenator, through the at least one gas sensor unit. The gas delivery device can be arranged upstream of the gas sensor unit in order to deliver gas mixture at positive pressure through the at least one gas sensor unit. The gas delivery device can also be arranged downstream of the gas sensor unit in order to deliver gas mixture at negative pressure through the at least one gas sensor unit, i.e. to suck it through the at least one gas sensor unit.Such a gas conveying device ensures that a quantity of gas mixture flows through the sensor unit that is large enough to determine the oxygen content and / or the CO2 content of the gas mixture with the required accuracy.

[0038] The device can additionally comprise a gas outflow sensor designed to measure the flow rate of the gas mixture flowing out of the oxygenator. By measuring and taking into account the flow rate of the gas mixture flowing out of the oxygenator, the parameters of the extracorporeal gas exchange, in particular the introduction of oxygen into the blood and / or the removal of CO2 from the blood, can be determined with even greater accuracy. To achieve the desired accuracy, the gas inflow sensor and the gas outflow sensor can in particular be designed such that a tolerance-related deviation between the measured values ​​supplied by the gas inflow sensor and the gas outflow sensor, when the same amount of fluid flows through the two sensors, is less than 2%, in particular less than 1%.The device may additionally comprise at least one temperature sensor which is designed to measure the temperature of the gas mixture upstream of the oxygenator and / or the temperature of the gas mixture downstream of the oxygenator and to take this into account in the quantitative determination of the oxygen content in the blood.

[0039] The measured temperature of the gas mixture can be used, in particular, to determine the humidity contained in the gas mixture. Since water (vapor) from the blood is also transferred into the gas mixture in the oxygenator, the gas mixture flowing out of the oxygenator contains a higher proportion of moisture or water vapor than the gas mixture that flowed into the oxygenator. If the flow sensor and the gas sensor are arranged so close to each other in a gas supply line upstream of the oxygenator or in a gas discharge line downstream of the oxygenator that the flow sensor and the gas sensor measure the same gas mixture with the same humidity and the same temperature, the effects of humidity on the measurement compensate each other, so that the oxygen transfer from the gas mixture into the blood can be determined with good accuracy without additional corrections.

[0040] In this case, an increase in flow due to increased humidity of the gas mixture downstream of the oxygenator is compensated by a corresponding reduction in the oxygen partial pressure in the gas mixture exiting the oxygenator.

[0041] However, if the flow sensor and the gas sensor are so far apart that it cannot be guaranteed that the gas mixture flowing through the two sensors has the same humidity and temperature in both sensors, the values ​​measured by the sensors must be corrected to the same gas conditions (temperature and humidity) so that the measurement results of the two sensors match. If a "dry" gas mixture is supplied to the oxygenator, there is no need to correct the values ​​measured upstream of the oxygenator. In the context of the present invention, a gas mixture is considered "dry" if it has a relative humidity of less than 2%, in particular a relative humidity of less than 1%.

[0042] Details of corrections to the values ​​measured by the sensors and those determined from the measured values, which are required due to the moisture contained in the gas mixture in the oxygenator, are described below in connection with the embodiments shown in Figures 2 and 3.

[0043] High humidity or a high water vapor content of the gas mixture flowing out of the oxygenator can lead to the accumulation of water droplets or the condensation of water vapor in the components downstream of the oxygenator, particularly in the gas effluent sensor. Such humidification through the accumulation of water droplets or the condensation of water vapor is undesirable because it can impair the function of the gas effluent sensor, thereby distorting the measurement results. Therefore, a heating device can be provided downstream of the oxygenator, particularly on or in the gas effluent sensor, which makes it possible to heat the gas mixture flowing out of the oxygenator and / or elements of the gas effluent sensor in order to reduce the humidity below the dew point, thus preventing the condensation of water vapor in the gas mixture and the accumulation of water droplets on components.

[0044] The device for quantitatively determining the introduction of oxygen into blood in an oxygenator can have at least one detachable fluid connection that allows an oxygenator to be connected to the device in such a way that a gas mixture flowing through the oxygenator flows through the device in such a way that the oxygen content and / or the CO2 content of the gas mixture upstream of the oxygenator and the oxygen content and / or the CO2 content of the gas mixture downstream of the oxygenator can be measured by the at least one gas sensor unit of the device. Such a fluid connection makes it possible to quickly and easily replace the oxygenator when necessary or desired, e.g. because the oxygenator has reached the end of its service life or the device is to be used for another patient.The oxygenator is therefore not an integral component of a device according to the invention for quantitatively determining the introduction of oxygen into blood by an oxygenator. Rather, the oxygenator is a separate exchange part that can be fluidically connected to and detached from the device, in particular via at least one detachable fluid connection.

[0045] The components of the device for quantitatively determining the introduction of oxygen into blood by an oxygenator can be housed in a common housing. The common housing can be designed such that the oxygenator is also housed in the common housing if it is fluidically connected to the device, e.g., by at least one detachable fluid connection.

[0046] At least a part or a section of a gas discharge line that fluidically connects a gas outlet of the oxygenator to the gas sensor unit can be configured with at least one moisture-permeable element that allows an exchange of moisture between the gas mixture flowing through the respective moisture-permeable element and the environment. This enables the gas mixture to release moisture to the environment and / or absorb moisture from the environment.

[0047] A moisture-permeable element can be arranged in particular in the flow direction of the gas mixture immediately upstream of the gas discharge sensor or immediately upstream of the gas switching valve in the gas discharge line.

[0048] The at least one moisture-permeable element may comprise at least one polymer membrane. The moisture-permeable element may, in particular, comprise at least one "Nation Tube."

[0049] The device can also be designed to determine the oxygen content of the blood flowing into the oxygenator from the previously quantitatively determined oxygen input into the blood. This can be done, in particular, under the assumption that the blood leaving the oxygenator is completely

[0050] Oxygen is saturated, meaning that the blood leaving the oxygenator contains an oxygen content of practically 100% of the maximum possible oxygen content. The oxygen content of the blood flowing into the oxygenator is then determined from the difference between 100% and the oxygen input into the blood in the oxygenator determined by means of the device according to the invention.

[0051] The device may comprise a display device configured to display at least one of the values ​​measured by the sensors and / or at least one of the values ​​determined from the measured values, in particular a value quantitatively describing the introduction of oxygen into the blood as it flows through the oxygenator, and / or a value quantitatively describing the removal of CO2 from the blood as it flows through the oxygenator. Displaying such values ​​enables an operator to change parameters of the extracorporeal gas exchange, for example, the flow rate of the oxygen-containing gas mixture, the flow rate of the blood, and / or the oxygen content of the oxygen-containing gas mixture, in order to adapt the extracorporeal gas exchange to the patient's current ventilation status.

[0052] The invention also encompasses a device for introducing oxygen into blood, wherein the device comprises an oxygenator which is designed to be flowed through both by a patient's blood and by an oxygen-containing gas mixture in such a way that oxygen from the oxygen-containing gas mixture is transferred into the blood (oxygenation). The device for introducing oxygen into blood further comprises a device according to the invention for quantitatively determining the introduction of oxygen into the blood in the oxygenator. Furthermore, the device can also be provided for removing carbon dioxide from blood (ventilation). The oxygenator can also be designed to transfer carbon dioxide from the blood flowing through the oxygenator into the gas mixture flowing through the oxygenator.The device for removing carbon dioxide from blood then comprises a device according to the invention for quantitatively determining the removal of carbon dioxide from blood in the oxygenator.

[0053] The operating parameters of such a device can be adjusted on the basis of the quantitatively determined input of oxygen into the blood and / or on the basis of the quantitatively determined removal of carbon dioxide from the blood in such a way that the best possible extracorporeal gas exchange (with regard to oxygenation and / or ventilation) is achieved in the oxygenator and blood with a predetermined oxygen content and / or a predetermined CO2 content can be made available to the patient.

[0054] The device may comprise a device designed to provide an oxygen-containing gas mixture, in particular an oxygen-rich gas mixture, which is supplied to the oxygenator.

[0055] Alternatively, the device can be connected to an external device that provides an oxygen-containing gas mixture. The external device for providing the oxygen-containing gas mixture can be a blender. The external device can also be a ventilation device, which is intended for mechanical ventilation by supplying ventilation gas to the lungs of a patient. A portion of the ventilation gas from the ventilation device can be supplied to the device according to the invention as an oxygen-containing gas mixture. If a ventilation device is used to provide the oxygen-containing gas mixture, an additional blender may be unnecessary.

[0056] The ventilation device can also be operated in a "blender mode," in which it is not used to ventilate the patient, but exclusively to provide an oxygen-containing gas mixture to a device for extracorporeal blood gas exchange. The device for extracorporeal blood gas exchange, to which the oxygen-containing gas mixture is provided, can be a device for extracorporeal blood gas exchange according to an embodiment of the invention, but also another device for extracorporeal blood gas exchange.

[0057] If the patient's lungs are to be mechanically ventilated in this case in addition to the extracorporeal blood gas exchange, an additional ventilation device can be used for this ventilation.

[0058] The device for providing the oxygen-containing gas mixture can be designed to enable the oxygenator to be flushed. Flushing the oxygenator comprises allowing a flushing fluid, in particular a flushing gas, to flow through the oxygenator for several seconds at a strong flushing fluid flow, in particular a flushing fluid flow of at least 12 l / min, without exceeding a predetermined maximum pressure of the gas mixture in the oxygenator. By flushing the oxygenator in this way, water that has deposited in a membrane of the oxygenator during operation and impairs the efficiency of gas exchange through the membrane can be released from the membrane and flushed out of the oxygenator together with the flushing fluid. The efficiency of the oxygenator can be (again) improved in this way.A purge gas is particularly suitable as the purge fluid; in particular, the same gas mixture can be used that flows through the oxygenator during normal operation for extracorporeal oxygenation and / or ventilation. The invention also encompasses a device for extracorporeal blood gas exchange, which comprises a device according to the invention for introducing oxygen into a patient's blood (oxygenation). Optionally, the device for extracorporeal blood gas exchange also comprises a device for removing carbon dioxide from a patient's blood (ventilation), as described herein.

[0059] The invention further encompasses a system for supporting a patient's blood gas exchange both by means of mechanical ventilation and extracorporeal blood gas exchange. Such a system according to the invention comprises a device according to the invention for extracorporeal blood gas exchange and a ventilation device intended for mechanical ventilation of a patient's lungs.

[0060] Such a system allows the patient's blood gas exchange to be carried out simultaneously both via the patient's lungs, which are supported by the ventilator, and, if necessary, additionally via extracorporeal blood gas exchange. The ventilator and the extracorporeal blood gas exchange device can work in coordination with each other. Alternatively, an additional ventilator can be used for mechanical ventilation of the patient's lungs.

[0061] Such a system makes it possible, in particular, to coordinate intracorporeal blood gas exchange through the lungs supported by the ventilator and extracorporeal blood gas exchange. This allows the patient's blood gas exchange to be particularly well-adjusted to the individual patient's needs.

[0062] The system can comprise at least one display device and be configured to quantitatively determine both the introduction of oxygen into the patient's blood through the lungs / mechanical ventilation and the introduction of oxygen into the patient's blood through extracorporeal blood gas exchange, determined according to the invention, and to display them together on the display device. The system can, in particular, be configured to determine the ratio between the introduction of oxygen into the patient's blood through the lungs / mechanical ventilation and the introduction of oxygen into the patient's blood through extracorporeal blood gas exchange, determined according to the invention, and to display it on a display device.

[0063] The display device can be designed as part of the ventilator for mechanical ventilation of the patient. This allows all values ​​relevant to the patient's oxygen supply to be read compactly and on a single display device, particularly on a screen of the ventilator.

[0064] Alternatively or additionally, the display device may be formed on the device for introducing oxygen into the blood of a patient.

[0065] In addition to the variables relevant to oxygenation described above, the display device can also be configured to display corresponding variables relevant to ventilation, in particular to quantitatively determine the removal of carbon dioxide from the patient's blood through the lungs / mechanical ventilation and the removal of carbon dioxide from the patient's blood through extracorporeal blood gas exchange determined according to the invention and to display them together on the display device. The system can in particular be configured to determine the ratio between the removal of carbon dioxide from the patient's blood through the lungs / mechanical ventilation and the removal of carbon dioxide from the patient's blood through extracorporeal blood gas exchange determined quantitatively according to the invention and to display it on the display device.The joint display of several values ​​that are representative and / or relevant for the patient's blood gas exchange makes it easier for a system operator to visually assess the current status of the patient's blood gas exchange at any time and, if necessary, to adjust parameters of ventilation and / or extracorporeal blood gas exchange in order to improve blood gas exchange and / or monitor and influence the progress of a therapy.

[0066] In a system according to the invention, the ventilation device used for mechanical ventilation of the patient can be designed and provided to provide the required oxygen-containing gas mixture to the device for introducing oxygen into the blood. In this way, an additional device for providing the oxygen-containing gas mixture, such as a blender, can be dispensed with. This allows the cost of the system to be reduced.Alternatively, a first ventilation device can be used to provide the device for introducing oxygen into blood with the oxygen-containing gas mixture required for operation, and an additional, second ventilation device can be used for mechanical ventilation of the patient, so that the provision of oxygen-containing gas mixture to the device for introducing oxygen into blood and the mechanical ventilation of the patient are realized independently of one another.

[0067] The system may also comprise a controller configured to carry out, in a coordinated and automated manner, mechanical support of the patient's breathing by the ventilator on the one hand and extracorporeal blood gas exchange by the device for extracorporeal blood gas exchange on the other hand, in order to support the gas exchange in the blood of a patient and to adapt it as best as possible to the patient's current ventilation status.

[0068] The control can in particular be designed to carry out and adapt the mechanical support of the patient's breathing by the ventilation device on the one hand and the extracorporeal blood gas exchange by the device for extracorporeal blood gas exchange on the other hand on the basis of the entry of oxygen into the blood quantitatively determined by the device for determining the entry of oxygen into the blood and / or on the basis of the determined oxygen content in the blood.

[0069] In this way, the gas exchange effected by the system, in particular the interaction between the mechanical support of the patient's breathing by the ventilator and the extracorporeal blood gas exchange by the device for extracorporeal blood gas exchange, can be adapted particularly efficiently and reliably to the patient's current condition.

[0070] In the following, embodiments of the invention are described in more detail with reference to the attached figures.

[0071] Figure 1 shows a highly simplified schematic representation of a system according to the invention for supporting the blood gas exchange of a patient.

[0072] Figure 2 shows, in a highly simplified schematic representation, an embodiment of a device according to the invention for quantitatively determining the introduction of oxygen into blood by an oxygenator.

[0073] Figure 3 shows, in a highly simplified schematic representation, an alternative embodiment of a device according to the invention for quantitatively determining the introduction of oxygen into blood by an oxygenator. Figure 4 shows, in a highly simplified schematic representation, a further embodiment of a device according to the invention for quantitatively determining the introduction of oxygen into blood by an oxygenator. Figure 1 shows, in a highly simplified schematic representation, a system 1 according to the invention for supporting the blood gas exchange of a patient 4, with a device 2 for extracorporeal blood gas exchange and with a ventilation device 42 for mechanical ventilation of the lungs of the patient 4 through a ventilation tube 45 inserted into the patient's lungs.

[0074] The device 2 for extracorporeal blood gas exchange comprises a blood sampling line 6, via which deoxygenated blood is taken from a patient 4 and fed by a fluid conveying device 8 to a device 15 for introducing oxygen into the blood.

[0075] The device 15 for introducing oxygen into the blood comprises a so-called oxygenator 10 with a blood region 10a, shown schematically in Figure 1 in the lower region of the oxygenator 10, through which the blood conveyed by the fluid conveying device 8 flows, and with a gas region 10b, shown in Figure 1 in the upper region of the oxygenator 10, through which an oxygen-containing gas mixture flows.

[0076] The oxygen-containing gas mixture is provided by a device 16 for providing the oxygen-containing gas mixture, for example, by a blender 16 or a ventilation device 42, which is only indicated very schematically in Figure 1, via a gas supply line 22a. Details of the provision of the gas mixture by the blender or the ventilation device are not shown in Figure 1 for the sake of clarity. The device 16 for providing the oxygen-containing gas mixture is equipped with pressure sensors 17a, 17b, which are designed to measure the ambient pressure p amb and if necessary also the pressure p aw of the oxygen-containing gas mixture provided by the device 16.

[0077] The blood region 10a and the gas region 10b of the oxygenator 10 are separated from each other by a membrane 12. The membrane 12 prevents blood from passing from the blood region 10a into the gas region 10b. However, the membrane 12 is permeable to gases, particularly oxygen (O2) and carbon dioxide (CO2). Consequently, as the oxygen-containing gas mixture and the blood flow through the oxygenator 10, oxygen is transferred from the oxygen-containing gas mixture into the blood. Simultaneously, carbon dioxide from the blood passes into the gas mixture flowing through the oxygenator 10. After the gas mixture has flowed through the gas region 10a of the oxygenator 10, it is discharged through a gas discharge line 22b.

[0078] At the outlet 14 of the blood area 10a of the oxygenator 10, oxygen-containing and CO2-poor blood is available so that it is supplied to the patient 4 via a blood supply line 18.

[0079] The representation of the oxygenator 10 shown in Figure 1 is a purely schematic, highly simplified representation which illustrates the functioning of the oxygenator 10. The actual structure of the oxygenator 10 may differ from the highly simplified representation shown in Figure 1. For example, the oxygenator 10 may have hollow fibers (not shown in the figures) which extend through the blood region 10a and around which the blood flows, with the oxygen-containing gas mixture flowing through the hollow fibers. The fibers are designed such that their walls act as membranes 12 which enable gas exchange between the blood flowing around the fibers and the gas mixture flowing through the hollow fibers.

[0080] The device 16 for providing the oxygen-containing gas mixture can be designed such that it enables the oxygenator 10 to be flushed. Flushing the oxygenator 10 comprises passing a flushing fluid, in particular a flushing gas with a strong fluid flow or gas flow, in particular a fluid flow or gas flow of at least 12 l / min, through the oxygenator 10 for several seconds without exceeding a predetermined maximum pressure of the gas mixture in the oxygenator 10. By flushing the oxygenator 10 in this way, water that has deposited in the membrane 12 of the oxygenator 10 and impairs the efficiency of gas exchange through the membrane 12 can be released from the membrane 12 and flushed out of the oxygenator 10 together with the gas mixture. The efficiency of the oxygenator 10 can be (again) improved in this way.

[0081] In order to be able to adjust the supply of oxygen to the patient 4 by the device 2 for introducing oxygen into the blood of the patient 4 and, if necessary, additionally by a mechanical ventilation device 42 for mechanical ventilation of the patient 4 as required, it is advantageous to adjust the input V' O2 of oxygen into the blood of the patient 4 and / or the discharge V' CO2 CO2 from the blood of the patient 4 through gas exchange in the oxygenator 10 can be quantitatively determined.

[0082] Figure 2 shows in a highly simplified schematic representation an embodiment of a device 20 according to the invention for quantitatively determining the entry V' O2 of oxygen in blood by an oxygenator 10. Optionally, the device 20 can also be used to quantitatively determine the output V' CO2 of CO2from the blood of patient 4.

[0083] The device 20 for quantitatively determining the entry V' O2 of oxygen into the blood comprises a gas flow sensor 24a arranged in the gas supply line 22a, which is used to measure the gas flow STPin (in particular a mass flow or a volume flow) into the oxygenator 10, and a first gas sensor 26a, which is also arranged in the gas supply line 22a and which in particular comprises an oxygen sensor 26a, in order to measure the oxygen content, in particular the partial pressure p O2in of the oxygen in the oxygen-containing gas mixture flowing into the oxygenator 10.

[0084] A gas outflow sensor 24b and a second gas sensor 26b are provided in the gas outflow line 22b downstream of the oxygenator 10. The gas outflow sensor 24b is used to measure the gas outflow flow STPout (in particular a mass flow or a volume flow) from the oxygenator 10 is provided and designed.

[0085] A temperature sensor can be provided in each of the gas inflow sensor 24a and the gas outflow sensor 24b, which is designed to measure the temperature of the sensor housing or the ambient temperature.

[0086] The second gas sensor 26b comprises in particular an oxygen sensor 26b, which makes it possible to measure the oxygen content, in particular the partial pressure p O2out of the oxygen in the gas mixture flowing out of the oxygenator 10.

[0087] Since the gas mixture always flows through the oxygenator 10 in the same direction (from left to right in the illustration in Figure 2), the gas inflow sensor 24a and the gas outflow sensor 24b are designed in such a way that they are suitable for unidirectional continuous operation.

[0088] The gas inflow and gas outflow sensors 24a, 24b can be initially calibrated by first connecting them directly to the outlet of the device 16 for providing oxygen-containing gas mixture and allowing the oxygen-containing gas mixture to flow through them at a defined flow rate.

[0089] The gas flow sensor 24a can also be integrated into the device 16 for providing the oxygen-containing gas mixture. Electric blenders, in particular, can be equipped with a flow sensor that performs the function of the gas flow sensor 24a.

[0090] In addition to the oxygen sensors 26a, 26b, further (gas) sensors, in particular CO2 sensors, can be provided in the gas supply line 22a and the gas discharge line 22b. Combined gas sensors 26a, 26b can also be provided, which are capable of measuring both the oxygen content p O2in or p O2out as well as the CO2 content p CO2inor p CO2out in the gas mixture flowing into the oxygenator 10 and / or in the gas mixture flowing out of the oxygenator 10. In this way, in addition to the entry V' O2 of oxygen into the blood when passing through the oxygenator also the discharge V' CO2 of CO2 from the blood can be quantitatively determined.

[0091] If the CO2 content in the gas mixture flowing out of the oxygenator 10 is high, it may be necessary to adjust the measured gas outflow flow STPout depending on the CO2 content, for example, with a correction factor k specified by the manufacturer of the gas discharge sensor 24b:

[0092] Alternatively, multidimensional models for the flow correction of specific flow sensors are also conceivable. Such models can, for example, also take into account the oxygen and nitrogen content in addition to the CO2 content. Between the gas supply line 22a and a gas inlet 11a of the oxygenator 10, as well as between a gas outlet 11b of the oxygenator 10 and the gas discharge line 22b, a detachable fluid connection 27a, 27b is formed, which allows the oxygenator 10 to be detachably connected to the gas supply line 22a and the gas discharge line 22b in such a way that the oxygenator 10 can be easily replaced by detaching the fluid connections 27a, 27b. The oxygenator 10 is therefore not an integral component of a device 20 according to the invention for quantitatively determining the input V'. O2of oxygen in blood. Rather, the oxygenator 10 is an exchangeable part that can be detachably connected to such a device 20 through the fluid connections 27a, 27b and is connected during operation, as shown in Figure 1. The device according to the invention is designed for coupling with oxygenators 10 of various designs, regardless of the internal configuration of the respective oxygenator.

[0093] The oxygen-containing gas mixture supplied to the oxygenator 10 is "dry", ie it has a moisture content of less than 2%, in particular a moisture content of less than 1%.

[0094] By determining the flow of the oxygen-containing dry gas mixture flowing to the oxygenator 10 STPin (e.g. as mass flow or volume flow) and the oxygen content p O2in(e.g. as partial pressure or mixing ratio) in this incoming gas mixture and by determining the flow of the gas mixture flowing out of the oxygenator 10 STPout (e.g. as mass flow or volume flow) and the oxygen content p O2out (e.g. as partial pressure or mixing ratio) in this outflowing gas mixture, the amount of oxygen V'O2 that has been transferred from the oxygen-containing gas mixture into the blood in the oxygenator 10 can be quantitatively determined:

[0095] Flow is STPout the previously calculated corrected flow flowSTPout_corrCO. In the embodiment shown in Figure 2, especially when the gas mixture flowing through the oxygenator 10 circulates in a closed system, p AWin significantly larger than p AWout be. p AWin can, for example, be between about 0.5 mbar and 15 mbar, while p AWoutis virtually 0 mbar. The changes in p AWin depend on the properties of the oxygenator 10 and the flow provided by the device 16. In the second embodiment, which is shown in Figure 3 and described further below, the system is "open": The gas mixture flowing out of the oxygenator 10 is discharged into the environment through the gas discharge line 22b. In an open system, p AWout = p AWin = 0, so that p AWout and p AWin do not need to be taken into account when calculating \Z'O2.

[0096] With the amount of flow STPout of the outflowing gas mixture may be the gas outflow flowSTPout_corr corrected due to a high CO2 content, as previously described.

[0097] For the measurements described here and the resulting quantitative determination of the amount of oxygen transferred from the oxygen-containing gas mixture into the blood in the oxygenator 10, it is not necessary to intervene in the extracorporeal blood circulation. Therefore, for example, the gas sensors 24a, 26a, 24b, 26b, which generally have a limited service life, can be replaced as needed without interrupting the extracorporeal blood circulation. Replacing the sensors 24a, 26a, 24b, 26b can therefore be carried out particularly easily and hygienically, without blood being released into the environment. Since all the variables to be measured relate solely to the gas mixture, the measurements do not require any physical contact with the blood.

[0098] This allows the use of simpler sensors (especially gas sensors designed for measurement in gaseous fluids), which also have a longer operating time and durability than sensors that come into contact with blood.

[0099] As the blood and the gas mixture flow through the oxygenator 10, moisture from the blood also typically passes into the gas mixture, so that the humidity of the gas mixture is increased as it passes through the oxygenator.

[0100] Increased humidity in the gas mixture can be taken into account when determining the flow rate and oxygen concentration of the gas mixture flowing out of the oxygenator 10. This can be achieved by positioning the sensors 24b and 26b close to one another and thus measuring under the same gas conditions. In particular, the same conditions with regard to the temperature and humidity content of the gas mixture should prevail for both sensors. High humidity in the gas mixture flowing out of the oxygenator 10 can lead to condensation of water vapor contained in the gas mixture in the gas discharge line 22b and / or in the gas discharge sensor 24b. In particular, condensation of water vapor in the gas discharge sensor 24b would falsify the measurement results.

[0101] The gas discharge sensor 24b can therefore be equipped with a heating device 39, which makes it possible to heat the gas discharge sensor 24b, particularly components of the gas discharge sensor 24b that come into contact with the moist gas mixture, in order to prevent water vapor contained in the gas mixture from condensing in the gas discharge sensor 24b and distorting the measurement results. The same applies to moisture that has already condensed upstream, is transported as water droplets to the gas discharge sensor 24b, and precipitates there. This condensed moisture can also evaporate through appropriate heating.

[0102] Alternatively or additionally, other measures can also be taken to prevent the condensation of moisture from the gas mixture and the accumulation of condensed water in the gas discharge line 22b and in the gas discharge sensor 24b. For example, moisture-permeable elements 29, e.g., moisture-permeable tubes or hoses, can be used for at least parts or sections of the gas discharge line 22b. These elements allow an exchange of moisture between the gas mixture flowing through the respective moisture-permeable element 29 and the environment, and thus make it possible to release moisture from the gas mixture to the environment and / or to absorb moisture from the environment into the gas mixture. The gas discharge line 22b can, in particular, be formed with a moisture-permeable element 29 immediately upstream of the gas discharge sensor 24b, as shown in Figure 2.

[0103] The moisture-permeable elements 29 can, in particular, comprise polymer membranes. Moisture-permeable elements 29 are also known as "nation tubes."

[0104] To enter V' O2 of oxygen into the blood or the discharge V' CO2 To be able to determine the CO2 concentration from the blood with the required accuracy, the deviation between the measured values ​​provided by the gas inflow sensor 24a and the gas outflow sensor 24b for the same amount of flowing fluid, which can result in particular from manufacturing tolerances of the gas inflow and gas outflow sensors 24a, 24b, must be sufficiently small. The gas inflow sensor 24a and the gas outflow sensor 24b are therefore preferably designed such that the

[0105] The deviation between the measured values ​​supplied by the gas inflow sensor 24a and the gas outflow sensor 24b for the same gas flow is less than 2%, in particular less than 1%. The deviations between the measured values ​​supplied by the first gas sensor 26a and the second gas sensor 26b for the same oxygen or CO2 concentration in the gas mixture must also be sufficiently small. Preferably, the deviations between the measured values ​​supplied by the two gas sensors 26a, 26b for the same oxygen or CO2 concentration in the gas mixture are less than 0.5%, in particular less than 0.2%. This places high demands on the accuracy of the gas sensors 26a, 26b used, which in particular must have only very small manufacturing tolerances.

[0106] In order to avoid measurement errors resulting from tolerance-related deviations in the measured values ​​supplied by the two gas sensors 26a, 26b, instead of two gas sensors 26a, 26b arranged upstream and downstream of the oxygenator 10, as shown in Figure 2, a single gas sensor 26 can be used to measure both the oxygen or CO2 content of the gas mixture flowing into the oxygenator 10 and the oxygen or CO2 content of the gas mixture flowing out of the oxygenator 10.

[0107] Figure 3 shows in a simplified schematic representation an embodiment of a device 20 according to the invention for quantitatively determining the entry V' O2of oxygen in blood through an oxygenator 10, which is equipped with only a single gas sensor 26. In Figure 3, those components which correspond to those components which have already been described with reference to the embodiment shown in Figure 2 are provided with the same reference numerals as in Figure 2. For an explanation of these components, reference is made to the description of Figure 2, which for these components is in the same

[0108] This applies to the embodiment shown in Figure 3. As in the embodiment shown in Figure 2, the embodiment shown in Figure 3 also comprises a gas supply line 22a for supplying an oxygen-containing gas mixture to the oxygenator 10, and a gas discharge line 22b, which is provided for discharging the gas mixture after it has passed through the oxygenator 10.

[0109] As in the embodiment shown in Figure 2, a gas inflow sensor 24a is arranged in the gas supply line 22a, and a gas outflow sensor 24b and a temperature sensor 25 are provided in or on the gas discharge line 22b.

[0110] The temperature Tempout measured by the temperature sensor 25 can be used to calculate a corrected oxygen pressure p O2outcorr can be used (see below). A dedicated temperature sensor for measuring the temperature of the gas mixture can provide more accurate measurement results than a temperature sensor integrated into the heated gas outlet sensor 24b.

[0111] A first branch 32a is formed on the gas supply line 22a between the gas inflow sensor 24a and the oxygenator 10. A first gas sensor inflow line 34a leads from the first branch 32a to a first inlet 28a of a gas switching valve 28. A second inlet 28b of the gas switching valve 28 is fluidly connected by a second gas sensor inflow line 34b to a second branch 32b formed downstream of the temperature sensor 25 and the gas outflow sensor 24b on the gas discharge line 22b.

[0112] An outlet 28c of the gas switching valve 28 is fluidically connected to a gas sensor 26. In this way, by switching the gas switching valve 28, the gas sensor 26 can be supplied with either a gas mixture from the gas supply line 22a upstream of the oxygenator 10 or a gas mixture from the gas discharge line 22b downstream of the oxygenator 10.

[0113] In the gas sensor inflow line 34b and / or downstream of the gas switching valve 28, at least one of the moisture-permeable elements 29 already described in connection with the embodiment shown in Figure 2 can be provided, which make it possible to remove moisture from the gas sensor flowing from the

[0114] Oxygenator 10 is used to release the gas mixture emerging from the oxygenator 10 into the environment. In this way, moisture that has been introduced into the gas mixture from the blood in the oxygenator 10 can be prevented from condensing in the gas sensor inlet line 34b, in the gas switching valve 28 and / or in the gas sensor 26. Between the outlet 28c of the gas switching valve 28 and the gas sensor 26, a gas delivery device (pump device) 30 is provided, which is designed to deliver the gas mixture at an overpressure through the gas sensor 26. In an alternative exemplary embodiment, which is not explicitly shown in the figures, the gas delivery device 30 can also be arranged downstream of the gas sensor 26, so that it sucks the gas mixture through the gas sensor 26.

[0115] Just like the gas sensors 26a, 26b of the embodiment shown in Figure 2, the single gas sensor 26 may comprise an oxygen sensor, a CO2 sensor or a combination of an oxygen sensor and a CO2 sensor, so that the gas sensor 26 is able to measure the oxygen content p 02 and / or the CO2 content p CO2 in the gas mixture flowing through the gas sensor 26.

[0116] The gas switching valve 28 can in particular be designed to switch between a first switching state and a second switching state.

[0117] In the first switching state of the gas switching valve 28, a portion of the gas mixture flowing through the gas supply line 22a is supplied to the gas sensor 26, so that the oxygen content and / or the CO2 content of the gas mixture flowing into the oxygenator 10 is measured by the gas sensor 26.

[0118] In the second switching state of the gas switching valve 28, a part of the gas mixture from the gas discharge line 22b, which has flowed out of the oxygenator 10, is supplied to the gas sensor 26, so that the oxygen content and / or the CO2 content of the gas flowing out of the oxygenator 10 is measured by the gas sensor 26.

[0119] gas mixture is measured.

[0120] Because, in the exemplary embodiment shown in Figure 3, the oxygen content and / or the CO2 content of the gas mixture flowing into the oxygenator 10 and the oxygen content and / or the CO2 content of the gas mixture flowing out of the oxygenator 10 are measured with the same gas sensor 26, deviations and measurement errors that can result from the oxygen or CO2 content of the gas mixture flowing into the oxygenator 10 and the gas mixture flowing out of the oxygenator 10 being measured with different gas sensors 26a, 26b can be reliably avoided. In particular, differing measurement results that are attributable to systematic errors between different sensors (such as manufacturing-related tolerances, drift processes, temporal changes in sensitivities or sensitivity of a sensor) cancel each other out when differences are formed between measured values ​​measured by the same sensor.As in the embodiment from Figure 2, the humidity of the gas mixture flowing out of the oxygenator is increased, in particular when the gas mixture that is fed to the oxygenator 10 through the gas supply line 22a, for example from a blender, is dry, ie when the gas mixture fed to the oxygenator 10 has a moisture content of less than 2%, in particular a moisture content of less than 1%. Such a low moisture content can be present, for example, if the gas mixture fed to the blender originates from a high-pressure gas source. With a dry gas mixture, it can be assumed that flow. in and pO2 in be measured under the same conditions, even if the gas inflow sensor 24a and the gas sensor 26 are not arranged directly next to each other.

[0121] It cannot be assumed that the gas mixture flowing out of the oxygenator 10 is a dry gas mixture, since in the oxygenator 10 moisture from the blood is introduced into the gas mixture, which can condense in the flow path between the gas outflow sensor 24b and the gas sensor 26.

[0122] In particular, the gas mixture arriving at the gas sensor 26, which has exited the oxygenator 10, can cool down if the line length is sufficiently long. This allows the moisture contained in the gas mixture to condense, which leads to a reduction of the moisture in the gas mixture itself. As a result, the two sensors 24b, 26 measure the flow. out and the pressure p outnot under the same measurement conditions. Depending on the line length and design of the gas sensor inlet line 34b, it may therefore be necessary to correct the measurement result of the gas sensor 26 when detecting the gas mixture flowing out of the oxygenator 10 in order to bring the output-side sensor signals to the same measurement conditions.

[0123] For the correction, a correction factor rp is determined during a calibration, which is described below. Using the correction factor rp, the oxygen partial pressure pO2 measured by the gas sensor 26 can be out a corrected oxygen partial pressure p O2outcorr be calculated:

[0124] This causes the oxygen partial pressure pO2 out to the conditions at the gas flow sensor 24b. The amount of oxygen V'O2 transferred from the gas mixture into the blood is then calculated using the thus corrected oxygen partial pressure p O2outCoorcalculated:

[0125] Since the embodiment shown in Figure 3 is an open system in which the gas mixture flowing out of the oxygenator 10 is discharged into the environment through the gas discharge line 22b and in the environment the ambient pressure p ambient prevails, in this case p AWout = p AWin = 0. p AWout and p AWin are therefore not included in the formula for V'O2 given here.

[0126] In the case of a closed system in which the gas discharge line 22b is not in direct fluid communication with the environment, p AWout and p AWin be taken into account as previously described.

[0127] For calibration, i.e., to determine the correction factor rp, dry, pure oxygen gas, i.e., oxygen gas with a moisture content of less than 2%, in particular with a moisture content of less than 1%, and with an oxygen content of nearly 100%, is introduced into the oxygenator 10 and humidified in the oxygenator 10 to a humidity of 97%. The oxygenator 10 is operated such that no exchange of oxygen and / or CO2 takes place in the oxygenator 10, whereby the oxygen content of the gas flowing through the oxygenator 10 remains unchanged at nearly 100%.

[0128] The pressure pO2 in( dry) of the oxygen gas flowing into the oxygenator 10 and the pressure pO2 out of the dry oxygen gas flowing out of the oxygenator 10 are measured, and the correction factor rp is determined from the difference between the two pressures: rp = pO2 in( dry) - pO2 out

[0129] With the correction factor rp a corrected oxygen pressure p O2outcorr be calculated: p O2outcorr = pO2out(measured)-pH2Oout(at 97% humidity)+rp.pH2O O ut is determined using the so-called Teton equation, assuming that the gas mixture at the gas outlet sensor 24b has a moisture content of 97%:

[0130] The temperature Tempout in °C and the pressure pH2O ou t is given in mbar. Assuming a gas humidity of 97% at the gas outlet sensor 24b, rh* = 97; ie, the humidity value in percent is substituted for rh* in the Teton equation.

[0131] The correction factor rp and pH2O ou / Certain values ​​are stored and can be used when the device is used on a patient 4 to calculate the transfer V'O2 of oxygen from the gas mixture into the blood, taking into account the changed moisture content of the gas mixture. For the calibration described above, it is necessary to operate the oxygenator 10 such that only moisture, but no gases, in particular no oxygen and no CO2, are exchanged in the oxygenator 10. Such operation of the oxygenator 10 can generally only be realized by the manufacturer, in a so-called bench setup. The calibration described above can therefore generally only be performed by the manufacturer, not by the user.

[0132] Devices 20 which are equipped with at least one moisture-permeable element 29 downstream of the oxygenator 10 can also be calibrated by the user.

[0133] For this purpose, in a device 20, as shown schematically in Figure 3, dry, pure oxygen gas is first supplied to the gas sensor 26 through the first gas sensor inlet line 34a and the correspondingly switched gas switching valve 28, as previously described. The pressure pO2 outdry of the dry oxygen gas is measured with the gas sensor 26 and stored for later use.

[0134] In a second step, the dry pure oxygen gas is fed directly to the gas sensor 26 through the moisture-permeable element 29 and the gas switching valve 28.

[0135] The oxygen gas absorbs so much moisture from the environment that the oxygen gas exiting the moisture-permeable element 29 and flowing into the gas sensor 26 has the same moisture content as the ambient air. The pressure pO2 is measured by the gas sensor 26. outambient of the oxygen gas humidified in this way was measured.

[0136] As previously described, the pressure pO2 measured during operation on patient 4 out of the gas flowing out of the oxygenator 10 using the pressure pH2O at 97% humidity, which is determined using the Tetons equation as described above, to pO2 outcorr be corrected in order to determine the correct value for the amount of oxygen V'O2 introduced into the blood from the oxygen-containing gas.

[0137] Since in this method, in which the humidification of the gas takes place only in the moisture-permeable element 29, no controlled humidification of the gas in the oxygenator 10 has to be carried out, for which a special measuring setup is required, devices 20 which are equipped with at least one moisture-permeable element 29 can also be calibrated by the user.

[0138] The calibration of such devices 20 can be repeated as needed, e.g. after replacing one or more components of the device 20 and / or at predetermined time intervals, in order to ensure the correctness of the measurement results provided by the device 20 over the longest possible period.

[0139] In the embodiment shown in Figure 3, which is equipped with only a single gas sensor 26, the gas supply from the device 16 for providing oxygen-containing gas mixture can be modulated to compensate for the missing flow of oxygen-containing gas mixture that does not flow into the oxygenator 10 because it is diverted into the gas sensor 26 through the first gas sensor inflow line 34a and the gas switching valve 28. This means that the gas supply can be increased by the gas flow guided through the gas sensor when the gas switching valve 28 is switched to the first switching state, so that the flow of oxygen-containing gas mixture through the oxygenator 10 is not changed by the switching of the gas switching valve 28, but remains essentially constant. In this way, it can be avoided that the gas exchange in the oxygenator 10 is influenced by the switching of the gas switching valve 28.

[0140] Figure 4 shows a simplified schematic representation of a further embodiment of a device 20 according to the invention for quantitatively determining the entry V' O2 of oxygen in blood by an oxygenator 10. The device 20 shown in Figure 4, like the device 20 shown in Figure 3, is also equipped with only a single gas sensor 26.

[0141] Unlike the device 20 shown in Figure 3, the device 20 shown in Figure 4 comprises three changeover valves 28, 31, 33. In Figure 4, those components of the device 20 which correspond to components which have already been described with reference to the exemplary embodiments shown in Figures 2 and 3 are provided with the same reference numerals as in Figures 2 and 3. For an explanation of these components, reference is made to the description of the exemplary embodiments shown in Figures 2 and 3, which also applies to the exemplary embodiment shown in Figure 4 with regard to the common components.

[0142] The embodiment shown in Figure 4 comprises a first gas switching valve 28, which allows the oxygen-containing gas mixture flowing through the gas supply line 22a, after it has passed the gas inflow sensor 24a, to be fed either directly to the oxygenator 10 or first to the gas sensor 26. The gas mixture supplied to the gas sensor 26 is fed to the gas inlet 11a of the oxygenator 10 via a second gas switching valve 33 after it has flowed through the gas delivery device 30 and the gas sensor 26.

[0143] In the gas discharge line 22b, downstream of the gas discharge sensor 24b, a third gas switching valve 31 is provided, which makes it possible to selectively supply the gas mixture flowing out of the oxygenator 10 to the gas sensor 26.

[0144] By appropriately switching the switching valves 28, 31, 33, the oxygen-rich gas mixture flowing into the oxygenator 10 from the gas supply line 22a, or the oxygen-poor gas mixture flowing out of the oxygenator 10 from the gas discharge line 22b can be passed through the gas sensor 26 in order to be able to determine the oxygen content of the respective gas mixture with the gas sensor 26.

[0145] In the embodiment shown in Figure 4, the entire gas flow flowing through the gas supply line 22a is completely directed into the oxygenator 10. This can be achieved by appropriately switching the switching valves 28, 31, 33.

[0146] In contrast to the embodiment shown in Figure 3, the flow of the oxygen-containing gas mixture flowing through the oxygenator 10 can thus be kept constant. Modulation of the gas flow in the gas supply line 22a, as previously described for the embodiment shown in Figure 3, is therefore not necessary in the embodiment shown in Figure 4.

[0147] In the embodiments shown in Figures 3 and 4, the gas switching valves 28, 31, 33 can be switched between their respective first switching state and their respective second switching state, for example, at intervals between 30 seconds and 120 seconds, in particular at intervals between 60 seconds and 90 seconds. However, shorter intervals are also possible.

[0148] The frequency with which the gas switching valves 28, 31, 33 are switched between their respective first switching state and their respective second switching state can also be variable. The frequency with which the gas switching valves 28, 31, 33 are switched between their respective switching states can, for example, be reduced, i.e., the switching intervals can be extended if the oxygen concentration at the inlet has proven to be constant over some time. In this case, it may be sufficient to check the oxygen concentration only after a change by the user and / or at longer time intervals, e.g., at time intervals of 10 minutes.

[0149] In the embodiments shown in Figures 2, 3 and 4, the device 20 for quantitatively determining the entry V' O2of oxygen into the blood each have an evaluation device 36 which is designed to determine the entry of oxygen into the blood and optionally also the discharge V' from the measured values ​​provided by the pressure sensors 17a, 17b (see Figure 1), the gas inflow sensor 24a, the gas outflow sensor 24b, the at least one gas sensor 26, 26a, 26b and optionally the temperature sensor 25 CO2 of CO2 from the blood quantitatively.

[0150] Assuming that the blood leaving the oxygenator 10 through the outlet 14 of the blood area 10a is almost completely, ie almost 100%, saturated with oxygen, the thus determined entry V' O2 of oxygen into the blood also the oxygen content of the blood before entering the oxygenator

[0151] 10 can be quantitatively determined. From this information, conclusions can be drawn about the condition, in particular the ventilation condition, of the patient 4. In the exemplary embodiments shown in Figures 3 and 4, in which the device 20 is equipped with at least one gas switching valve 28, 31, 33 and with only a single gas sensor 26, the evaluation device 36 is additionally designed as a control device which controls the at least one gas switching valve 28, 31, 33 such that the gas sensor 26 selectively measures the oxygen and / or CO2 content of the gas mixture flowing into the oxygenator 10 and the oxygen and / or CO2 content of the gas mixture flowing out of the oxygenator 10.

[0152] In the embodiment shown in Figure 3, the evaluation device 36 can also be designed to modulate the gas supply from the device 16 for providing oxygen-containing gas mixture (see Figure 1) in order to compensate for the partial amount of the oxygen-containing gas mixture discharged from the gas supply line 22a to the gas sensor 26 upstream of the oxygenator 10, as previously described.

[0153] The values ​​measured by the sensors 17a, 17b, 24a, 24b, 25, 26, 26a, 26b and / or the values ​​determined by the evaluation device 36 from these measured values, in particular the oxygen input V' O2 into the blood and / or the CO2 output V' CO2 from the blood in the oxygenator 10 can be displayed on a display device 38, for example on an electronic screen 38 of the device 20.

[0154] Alternatively or in addition to the display device 38, a communication device 40 can be provided, which is designed to transmit at least one of the measured and / or determined values ​​to a further device 42. For example, at least one of the measured and / or determined values ​​can be transmitted to a ventilation device 42, which is provided to mechanically ventilate the patient 4. The communication device 40 can also be designed to receive values ​​from a further device 42, in particular from a ventilation device 42, so that the values ​​provided by a further device, in particular the ventilation device 42, can also be displayed on the display device 38.

[0155] The communication device 40 can receive from the ventilation device 42, for example, information about the entry V' O2_Lungeof oxygen into the blood of patient 4 through mechanical ventilation performed by the ventilation device 42. This information can be displayed on the display device 38 together with the information determined by the evaluation device 36.

[0156] Optionally, the ratio R = V' O2_Lunge / V' O2 between the entry V' O2_Lunge of oxygen into the blood of the patient 4 through mechanical ventilation and the entry V' O2of oxygen into the patient's blood through extracorporeal blood gas exchange and displayed on the display device 38. Alternatively or additionally, these values ​​can also be displayed on a display device 44 formed on the ventilation device 42 after the values ​​determined by the evaluation device 36 have been transmitted from the communication device 40 to the ventilation device 42. Because all relevant values, in particular the entry V' O2_Lunge of oxygen into the blood of the patient 4 through mechanical ventilation and the entry V' O2 of oxygen into the patient's blood 4 through extracorporeal blood gas exchange and / or their ratio R = V' O2_Lunge / V' O2are displayed on a common display device 38, 44, the operation of the device 2 for extracorporeal blood gas exchange and the ventilation device 42 can be significantly simplified and improved, since all information relevant to blood gas exchange is summarized in one location, so that it can be read together and directly compared with each other. Such a common display enables an operator to coordinate the interaction between mechanical ventilation and extracorporeal blood gas exchange in order to supply the blood of patient 4 with as much oxygen as possible. In addition to or alternatively to the values ​​via the V' entry O2 , V' O2_Lunge of oxygen into the blood of the patient 4, values ​​about the discharge V' CO2 , V' CO2_Lungeof CO2 from the blood of patient 4 by mechanical ventilation and / or by extracorporeal blood gas exchange and / or their ratio R = V' O2_Lunge / V' O2 to each other and displayed on at least one display device 38, 44. The measured and determined values ​​can be transmitted between the communication device 40 and the further device / ventilation device 42 via a wired data connection 43 or via a wireless data connection 43, in particular via a WLAN or Bluetooth® connection 43.

[0157] The sensors 24a, 24b, 25, 26, 26a, 26b, the evaluation device 36, the display device 38, the communication device 40, any gas switching valves 28, 31, 33, and any gas conveying device 30 can be provided as an integral device in a common housing 48. The fluid connections 27a, 27b can be provided in or on the housing 48, which allow the device 20 to be used for quantitatively determining the input V' O2 of oxygen in blood fluidically to an oxygenator 10 in order to create a device 2 for introducing oxygen into blood, as shown schematically in Figure 1.

[0158] The invention also includes a system 1 for supporting the blood gas exchange of a patient 4 by means of mechanical ventilation and extracorporeal blood gas exchange, wherein the system 1 comprises a device 2 according to the invention for extracorporeal blood gas exchange and a ventilation device 42 for mechanical ventilation of the lungs of the patient 4, as shown in Figure 1.

[0159] The device 2 for extracorporeal blood gas exchange and the ventilation device 42 for mechanical ventilation can be designed to communicate with each other via a data connection 43. The devices 2, 42 can in particular be designed to transmit the data and measured values ​​relevant for the blood gas exchange, in particular values ​​via the entry V' O2 , V' O2_Lunge of oxygen into the blood and / or the discharge V' O2 , V' O2_Lungeof CO2 from the blood of the patient 4 together on at least one display device 38, 44, as previously described.

[0160] In such a system 1, the ventilation device 42 can be designed to provide the device 2 for extracorporeal blood gas exchange with an oxygen-containing gas mixture, which is fed to the oxygenator 10 for introducing oxygen into the blood of the patient 4. Such a system 1 can also comprise a common controller 46 designed to control the mechanical respiratory support by the ventilation device 42, on the one hand, and the extracorporeal blood gas exchange by the device 2 for extracorporeal blood gas exchange, on the other hand, in a coordinated manner such that they jointly support the gas exchange with the bloodstream of the patient 4.

[0161] In this case, the controller 46 can be configured, in particular, to control the mechanical respiratory support by the ventilation device 42, on the one hand, and the extracorporeal blood gas exchange by the device 2 for extracorporeal blood gas exchange, on the other hand, based on the oxygen content in the blood of the patient 4 determined by the device 20 for quantitatively determining the oxygen content of blood. Furthermore, the controller 46 can also be configured to take into account the previously determined CO2 content in the patient's blood during the control process.

[0162] In this way, a coordinated gas exchange in the blood of patient 4, which occurs on the one hand through mechanical ventilation and on the other hand through extracorporeal blood gas exchange, can be simplified and improved.

Claims

Claim 1. Device (20) for determining an entry (V') O2 ) of oxygen in blood in an oxygenator (10), wherein the device (20) comprises: a gas flow sensor (24a, 24b) configured to detect a flow (flow STPin , flow STPout ) of an oxygen-containing gas mixture flowing through the oxygenator (10), in particular a flow STPin ) of a gas mixture flowing into the oxygenator (10) and / or a flow ( flow STPout ) of a gas mixture flowing out of the oxygenator (10); and a gas sensor unit (26a, 26b; 26, 28, 30) designed to measure an oxygen content (p O2in ) of the oxygen-containing gas mixture flowing into the oxygenator (10) and an oxygen content (p O2out ) of a gas mixture flowing out of the oxygenator (10); wherein the device is designed to measure a difference, in particular a differential, between the oxygen content (pO2in ) of the oxygen-containing gas mixture flowing into the oxygenator (10) and the oxygen content ( p O2out) to determine the gas mixture flowing out of the oxygenator (10), and from the difference thus determined and the flow measured by the gas flow sensor (24a, 24b) STPin , flow STPout ) the entry (V' O2 ) of oxygen in blood flowing through the oxygenator (10).

2. Device according to claim 1, wherein the gas sensor unit (26a, 26b; 26, 28, 30) comprises at least one oxygen sensor (26a, 26b; 26, 28, 30).

3. Device according to claim 2, wherein the gas sensor unit (26a, 26b; 26, 28, 30) comprises at least one CO2 sensor which is designed separately from the oxygen sensor (26a, 26b; 26, 28, 30).

4. Device according to claim 1 or 2, wherein the gas sensor unit (26a, 26b; 26, 28, 30) at least one combined oxygen and CO2 sensor (26a, 26b; 26, 28, 30) includes, which is capable of both the oxygen content (p 02 ) as well as the CO2 content ( p CO2 ) of the gas mixture.

5. Device (20) according to one of the preceding claims, wherein the gas sensor unit (26a, 26b; 26, 28, 30) comprises only a single oxygen sensor (26) and is designed such that the single oxygen sensor (26) selectively measures the oxygen content (p O2in ) of the gas mixture flowing into the oxygenator (10), and the oxygen content (pO2) out) of the gas mixture flowing out of the oxygenator (10).

6. Device (20) according to claim 5, wherein the gas sensor unit (26a, 26b; 26, 28, 30) has at least one gas switching valve (28) configured to supply to the single oxygen sensor (26) of the gas sensor unit (26a, 26b; 26, 28, 30) either a gas mixture, in any case at least a part of the gas mixture supplied to the oxygenator (10), or a gas mixture, in any case at least a part of the gas mixture flowing out of the oxygenator (10).

7. Device (20) according to claim 6, wherein the at least one gas switching valve (28) is configured to supply the single oxygen sensor (26) alternately at least a part of the gas mixture supplied to the oxygenator (10) and at least a part of the gas mixture flowing out of the oxygenator (10).

8. Device (20) according to claim 7, wherein the gas switching valve (28) is configured to switch between a first switching state and a second switching state at intervals between 30 seconds and 120 seconds, in particular at intervals between 60 seconds and 90 seconds, wherein the In the first switching state, the gas switching valve (28) supplies at least a portion of the gas mixture supplied to the oxygenator (10) to the single oxygen sensor (26), and in the second switching state, the gas switching valve (28) condition supplies at least a part of the gas mixture flowing out of the oxygenator (10) to the single oxygen sensor (26).

9. Device (20) according to any one of claims 5 to 8, wherein the device (20) has a single gas switching valve (28) having a first inlet (28a), a second inlet (28b) and an outlet (28c), wherein the first inlet (28a) of the gas switching valve (28) is connected to a gas supply line (22a) upstream of the oxygenator (10); wherein the second inlet (28b) of the gas switching valve (28) is connected to a gas discharge line (22b) downstream of the oxygenator (10); and wherein the outlet (28c) of the gas switching valve (28) is connected to the oxygen sensor (26).

10. Device (20) according to any one of claims 5 to 8, wherein the gas sensor unit (26a, 26b; 26, 28, 30) has three gas switching valves (28, 31, 33), wherein a first gas switching valve (28) is arranged in the device (20) such that it makes it possible to selectively supply an oxygen-containing gas mixture flowing through the gas supply line (22a) of the oxygenator (10) either directly to the oxygenator (10) or first to the gas sensor (26); wherein a second gas switching valve (33) is arranged in the device (20) such that it makes it possible to selectively supply a gas mixture supplied to the gas sensor (26), after it has flowed through the gas sensor (26), to the oxygenator (10); and wherein a third gas switching valve (31) is arranged in the device (20) in such a way as to make it possible to selectively supply a gas mixture flowing out of the oxygenator (10) to the gas sensor (26).

11. Device (20) according to claim 10, wherein a first output of the first gas switching valve (28) is connected to an input (11a) of the oxygenator (10), and wherein a second output of the first gas switching valve (28) is connected to an input of the gas sensor (26) or to the input of a conveying device (30) arranged upstream of the gas sensor (26).

12. Device (20) according to claim 10 or 11, wherein an inlet of the second gas switching valve (33) is connected to an outlet of the gas sensor (26); and wherein an outlet of the second gas switching valve (31) is connected to the inlet (11a) of the oxygenator (10).

13. Device (20) according to any one of claims 10 to 12, wherein an inlet of the third gas switching valve (31) is connected to a gas discharge line (22b) downstream of the oxygenator (10); and wherein an outlet of the third gas switching valve (31) is connected to an inlet of the gas sensor (26) or to the inlet of a conveying device (30) arranged upstream of the gas sensor (26).

14. Device (20) according to any one of claims 1 to 4, wherein the gas sensor unit (26a, 26b; 26, 28, 30) comprises a first oxygen sensor (26a) and a second oxygen sensor (26), wherein the first oxygen sensor (26a) is arranged upstream of the oxygenator (10) and wherein the second oxygen sensor (26b) is arranged downstream of the oxygenator (10).

15. Device (20) according to claim 14, wherein the first oxygen sensor (26a) and the second oxygen sensor (26b) are designed such that a tolerance-related deviation between measured values ​​supplied by the first and the second oxygen sensor (26a, 26b) at the same oxygen concentration in the gas mixture is less than 0.5%, in particular less than 0.2%.

16. Device (20) according to one of the preceding claims, wherein the device (20) has a conveying device (30) configured to convey the gas mixture at an overpressure through the at least one gas sensor unit (26a, 26b; 26, 28, 30).

17. Device (20) according to one of the preceding claims, wherein the device (20) includes a gas inflow sensor (24a) configured to measure the flow rate. STPin ) of the gas mixture flowing into the oxygenator (10), and / or has a gas outflow sensor (24b) designed to measure the flow (STPout ) of the gas mixture flowing out of the oxygenator (10).

18. Device (20) according to claim 17, wherein the gas inlet sensor (24a) and the gas outlet sensor (24b) are designed such that a tolerance-related deviation between the measured values ​​supplied by the gas inlet sensor (24a) and the gas outlet sensor (24b) at the same flow rate of flowing fluid is less than 2%, in particular less than 1%.

19. Device (20) according to one of the preceding claims comprising at least one temperature sensor (25) configured to measure the temperature (T) of the gas mixture upstream of the oxygenator (10) and / or the temperature (T) of the gas mixture downstream of the oxygenator (10).

20. Device (20) according to claim 19, wherein the device is configured to measure the humidity (pH2O out) of the gas mixture flowing into the oxygenator (10) and / or of the gas mixture flowing out of the oxygenator (10) and in determining the input (V' O2 ) of oxygen into the blood, the device being designed in particular to control the humidity (pH2O out ) of the gas mixture based on the measured temperature (T) of the gas mixture.

21. Device (20) according to one of the preceding claims with a display device (38) configured to display at least one of the measured values ​​and / or at least one value determined from the measured values, in particular a value that represents the entry (V' O2 ) of oxygen in blood that passes through the Oxygenator (10) flows, describes, displays.

22. Device (20) according to one of the preceding claims with a communication device (40) configured to transmit at least one of the measured values ​​and / or at least one value determined from the measured values, in particular a value that represents the entry (V' O2 ) of oxygen in blood flowing through the oxygenator (10) describes to transfer to another device (42).

23. Device (20) according to claim 22, wherein the communication device (40) is configured to transmit the at least one value to the other device (42) via a wired or wireless connection, in particular via a WLAN or Bluetooth® connection (43).

24. Device (20) according to one of the preceding claims, wherein the device has at least one detachable fluid connection (27a, 27b) which makes it possible to connect an oxygenator (10) to the device (20) in such a way that a gas mixture flowing through the oxygenator (10) flows through the device (20) in such a way that the oxygen content (p O2in ) and / or the CO2 content (p CO2in ) of the gas mixture upstream of the oxygenator (10) and the oxygen content (pO2) out ) and / or the CO2 content ( p CO2out) of the gas mixture downstream of the oxygenator (10) by at least one gas sensor unit (26a, 26b; 26, 28, 30).

25. Device (20) according to one of the preceding claims, wherein the device (20) is configured to extract from the specified entry (V' O2 ) of oxygen into the blood to determine the oxygen content of the blood flowing into the oxygenator (10).

26. Device (20) according to one of the preceding claims, wherein the components of the device (20) are housed in a common housing (48).

27. Device (20) according to one of the preceding claims, wherein at least a part or section of a gas discharge line (22b) which fluidically connects a gas outlet (11b) of the oxygenator (10) to the gas sensor unit (26a, 26b; 26, 28, 30) is connected, is formed with at least one moisture-permeable element (29) which allows an exchange of moisture between the gas mixture flowing through the respective moisture-permeable element (29) and the surroundings.

28. Device (20) according to claim 27, wherein a moisture-permeable element (29) is provided in the flow direction of the gas mixture immediately upstream of the gas outflow sensor (24b) or immediately upstream of the gas switching valve (28) in the gas discharge line (22b).

29. Device (20) according to claim 27 or 28, wherein the at least one moisture-permeable element (29) comprises a polymer membrane, wherein the moisture-permeable element (29) in particular comprises at least one "Nafion Tube".

30. Device (15) for introducing oxygen into blood, the device (15) comprising: an oxygenator (10) configured to be permeated by blood and by an oxygen-containing gas mixture such that oxygen is transferred from the oxygen-containing gas mixture into the blood; and a device (20) for quantitatively determining the entry (V' O2 ) of oxygen into the blood according to one of the preceding patent claims.

31. Device (15) for introducing oxygen into blood according to claim 30, wherein the device (15) comprises a device (16, 42) for providing an oxygen-containing gas mixture, in particular an oxygen-rich gas mixture.

32. Device (15) for introducing oxygen into blood according to claim 31, wherein the device (16, 42) for providing oxygen-containing gas mixture is a ventilator (42) or a blender (16). V3. Use of a ventilation device (42) or a blender (16) to provide an oxygen-containing gas mixture, in particular an oxygen-rich gas mixture, to a device (15) for introducing oxygen into blood according to claim 30.

34. Device (2) for extracorporeal blood gas exchange comprising a device (15) for introducing oxygen into blood according to any one of claims 30 to 32.

35. System (1) for supporting the blood gas exchange of a patient (4) by means of mechanical ventilation and extracorporeal blood gas exchange, comprising: a device (2) for extracorporeal blood gas exchange according to claim 34; and a ventilation device (42) for mechanically supporting respiration by the lungs of the patient (4).

36. System (1) for supporting the blood gas exchange of a patient (4) according to claim 35, wherein the system (1) is configured to both the entry (V' O2_Lunge ) of oxygen into the patient's blood (4) through mechanical ventilation as well as the entry (V' O2 ) of oxygen into the patient's blood (4) by extracorporeal blood gas exchange and to display it on a display device (38, 44).

37. System (1) for supporting the blood gas exchange of a patient (4) according to claim 36, wherein the system (1) is configured to determine the ratio (R = V' O2_Lunge / V' O2 ) between the entry ( V' O2_Lunge ) of oxygen into the patient's blood (4) through mechanical ventilation and the entry (V' O2 ) of oxygen into the patient's blood (4) by extracorporeal blood gas exchange and to display it on a display device (38, 44).

38. System (1) for supporting the blood gas exchange of a patient (4) according to one of claims 35 to 37, wherein the system (1) is designed such that the ventilation device (42) provides the oxygen-containing gas mixture to the device (15) for introducing oxygen into the blood.

39. System (1) for supporting the blood gas exchange of a patient (4) according to one of claims 35 to 38, wherein the system (1) has a control unit (46) configured to carry out mechanical respiratory support by means of the ventilation device (42) on the one hand and extracorporeal blood gas exchange by means of the extracorporeal blood gas exchange device (2) on the other hand in a coordinated and automated manner in order to support the gas exchange with the blood circulation of the patient (4).

40. System (1) for supporting the blood gas exchange of a patient (4) according to claim 39, wherein the control unit (46) is configured to control the mechanical respiratory support provided by the ventilator (42) on the one hand and the extracorporeal blood gas exchange provided by the device (2) for extracorporeal blood gas exchange on the other hand, based on the input (V') quantitatively determined by the device (20) for determining the input of oxygen into the blood. O2 ) of oxygen into the blood of a patient (4).

41. Procedure for determining the entry (V') O2 ) of oxygen in blood by an oxygenator (10), the method comprising: Determining a flow STPin , flow STPout ) of an oxygen-containing gas mixture flowing through the oxygenator (10), in particular a flow (flowsTPin) of a gas mixture flowing into the oxygenator (10) and / or a flow (flow STPout) a gas mixture flowing out of the oxygenator (10); Measuring the oxygen content of the (p O2in ) flowing into the oxygenator (10) - the oxygen-containing gas mixture; Measuring oxygen content (pO2) out ) a gas mixture flowing out of the oxygenator (10); Determining a difference, in particular a differential, between the measured oxygen content (p O2in ) of the oxygen-containing gas mixture flowing into the oxygenator (10) and the measured oxygen content (p O2out ) of the gas mixture flowing out of the oxygenator (10); and determining the entry ( ' O2 ) of oxygen into the blood flowing through the oxygenator (10), from the previously determined difference between the measured oxygen content of the oxygen-containing gas mixture flowing into the oxygenator (10) (p O2in ) and the measured oxygen content (pO2) out) of the gas mixture flowing out of the oxygenator (10) as well as from the flow of the oxygen-containing gas mixture flowing through the oxygenator.

42. The method of claim 41, wherein the method further comprises determining the CO2 content of the oxygen-containing gas mixture (p) flowing into the oxygenator (10). CO2in ) and / or a CO2 content ( p CO2out ) of the gas mixture flowing out of the oxygenator (10).

43. The method of claim 41 or 42, wherein the method comprises a temperature (T) and / or a humidity to determine the oxygen-containing gas mixture flowing into the oxygenator (10) and / or the gas mixture flowing out of the oxygenator (10) and in determining the Entry (V' O2 ) of oxygen into the blood to be taken into account.

44. Method according to any one of claims 41 to 43, wherein the method comprises extracting from the specified entry (V' O2) of oxygen into the blood, to determine the oxygen content of the blood flowing into the oxygenator (10).

45. Method for supporting the blood gas exchange of a patient (4), wherein the method comprises determining the oxygen content of blood at an inlet (11a) of an oxygenator (10) provided for enriching blood with oxygen according to the method of claim 44, and by means of a device (2) for extracorporeal blood gas exchange to automatically perform an extracorporeal blood gas exchange based on the previously determined oxygen content in the blood.

46. Method for assisting the blood gas exchange of a patient (4) according to Claim 45, wherein the method further comprises mechanically assisting the patient's (4) breathing by means of a ventilation device (42), and both the entry (V' O2_Lunge) of oxygen into the patient's blood (4) through mechanical ventilation as well as the input (V' O2 ) of oxygen into the patient's blood (4) by extracorporeal blood gas exchange to determine quantitatively.

47. Method for supporting the blood gas exchange of a patient (4) according to claim 46, wherein the method further comprises the entry ( V' O2_Lunge ) from oxygen into the patient's blood (4) through mechanical ventilation and the entry (V' O2 ) of oxygen into the patient's blood (4) by extracorporeal blood gas exchange on at least one display device (38, 44), the method in particular comprising determining the ratio (R = V' O2_Lunge / V' O2 ) between the entry (V' O2_Lunge ) of oxygen into the patient's blood (4) through mechanical ventilation and the entry (V' O2) of oxygen into the patient's blood (4) by extracorporeal blood gas exchange and to display it on the at least one display device (38, 44).

48. Method for assisting the blood gas exchange of a patient (4) according to Claim 46 or 47, wherein the method further comprises coordinating and automatically performing the mechanical respiratory support by the ventilator (42) on the one hand and the extracorporeal blood gas exchange by the device (2) for extracorporeal blood gas exchange on the other hand, based on the oxygen content in the blood determined by the device (20) for determining the oxygen content of blood.

49. Use of a ventilator (42) to supply an oxygen-containing gas mixture, in particular an oxygen-rich gas mixture, to a device (15) for introducing oxygen into blood.

50. Ventilator (42) for mechanically ventilating a patient (4), wherein the ventilator (42) is operable in a blender mode in which the ventilator (42) is configured to supply an oxygen-containing gas mixture, in particular an oxygen-rich gas mixture, to a device (15) for introducing oxygen into blood.

51. Method of operating a ventilation device (42) for the mechanical ventilation of a patient (4) according to claim 50, wherein the method comprises operating the ventilation device (42) in blender mode to provide an oxygen-containing gas mixture, in particular an oxygen-rich gas mixture, to a device (15) for introducing oxygen into blood.

52. The method of claim 51, wherein the ventilation device (42) is simultaneously used for the mechanical ventilation of a patient (4).

53. The method of claim 51, wherein a further ventilation device (42) is used for the mechanical ventilation of a patient (4).

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