Arrangement for supplying a patient-side coupling unit with a gas mixture

Description

[0001] The invention relates to a supply arrangement for supplying a patient-side coupling unit with a gas mixture.

[0002] The invention can be used, for example, for the artificial ventilation of a patient. A patient-side coupling unit, such as a breathing mask, a catheter, or an endotracheal tube, is arranged in or on the patient's body. To artificially ventilate the patient, a gas mixture is delivered to the patient-side coupling unit. This gas mixture comprises oxygen and, in one embodiment, at least one anesthetic. Preferably, a ventilator performs a sequence of breaths and delivers a quantity of the gas mixture to the patient-side coupling unit in each breath.

[0003] It is possible to use breathing air as the gas mixture. Often, it is desirable for the oxygen content in the gas mixture supplied to the patient-side coupling unit to be higher than the oxygen content in the breathing air and to follow a predetermined time profile, for example, remaining constant over time. To achieve this, a gas mixture comprising breathing air and pure oxygen is generated. The invention can be used to generate such a gas mixture.

[0004] A supply arrangement with the features of the preamble of claim 1 is known from US 3,664,361 A. This patent describes a respiratory system that mixes oxygen from a pressure-regulated source (10) with air from an air intake (11) and delivers the mixture to a patient. The air is pumped from the intake (11) by a pump (13) through a first line (14), a manifold (19), and a second line (15) to a proportioning device (20). The oxygen is delivered to the proportioning device (20) via lines (41, 53, 32). A mechanical regulator (33) adjusts the pressure of the oxygen in line (32) to detected fluctuations in the pressure in line (14).The regulator 33 comprises a variable-volume reservoir 35, the reservoir 35 comprising a fixed wall 43, a movable wall 45, and two foldable walls 47, and wherein the reservoir 35 is pressurized above ambient pressure. A balancing valve 37 opens and closes a balancing port 38 in a wall 43 between the reservoir 35 and the line 32. A diaphragm 39 is exposed on one side to the pressure in the line 32 and on the other side to a pressure transmitted via a line 79 to the atmospheric pressure in the line 14.

[0005] The ventilation arrangement of US 4 549 563 A delivers a gas mixture comprising oxygen from a source 11 and nitrogen from a source 21, and optionally an anesthetic, to a breathing mask on a patient's face. The components of the gas mixture are blended together in a mixing unit (circuit 3). A pressure limiter (pressure limiter 40) comprises two chambers 42 and 43, and a diaphragm (diaphragm 41) between the two chambers 42 and 43. Chamber 42 is connected to source 21 and to a line 20, with line 20 leading to the mixing unit 3. Chamber 43 is connected via a line 46 to a line 10, with line 10 connecting source 11 to the mixing unit 3.

[0006] The ventilator 14 of EP 2 425 869 A1 comprises a mixing device and a ventilation unit. In the mixing device, a medical gas, such as oxygen or an anesthetic, is mixed with air. The medical gas is supplied via a gas inlet B and routed through a gas line 10. The air is supplied via an air inlet A and routed through an air line 11. A reducing valve 6, a safety valve 7, a controllable proportional valve 8, and a flow meter 9 are arranged in the gas line 10. A blower 1 and a check valve 2 are arranged in the air line 11. The ventilation unit delivers the gas mixture to a patient as breathing gas via a breathing gas line 12. A flow sensor 3, a controllable proportional valve 4, and a pressure sensor 5 are arranged in the breathing gas line 12. A control unit 13 receives signals from the sensors 9, 3 and is able to control all controllable valves 8, 4.The control is carried out with the aim of ensuring that the gas mixture in the breathing gas line 12 has a desired composition of air and medical gas.

[0007] The invention is based on the objective of providing a supply arrangement with the features of the preamble of claim 1, which is able to supply a patient-side coupling unit with a gas mixture comprising two gas components, wherein the temporal profile of the volume flow and / or the pressure of the supplied gas mixture in a fluid connection to the patient-side coupling unit can be controlled relatively reliably.

[0008] The problem is solved by a supply arrangement with the features of claim 1. Advantageous embodiments are specified in the dependent claims.

[0009] The supply arrangement according to the invention is capable of supplying a patient-side coupling unit with a gas mixture. This gas mixture comprises a first gas component, in particular air, and a second gas component, in particular pure oxygen. It is also possible that one gas component is an anesthetic. The second gas component differs chemically from the first gas component. It is possible that both gas components comprise the same component, for example, both comprising oxygen.

[0010] The patient-side coupling unit is at least temporarily connected to a patient or can be connected to the patient. In particular, the patient-side coupling unit is at least temporarily located in or on the patient's body or can be located there. An endotracheal tube, a catheter, and a breathing mask are examples of a patient-side coupling unit.

[0011] The term "channel" will be used below. A channel is understood to be a component that is capable of guiding a fluid, in particular a gas or gas mixture, along a predetermined trajectory and ideally prevents the fluid from leaving this trajectory. A hose and a tube are examples of a channel. Generally, the intended use of a channel is that the fluid is always, or at least intermittently, guided through the channel in one and the same direction, but not in the opposite direction.

[0012] Furthermore, it is stated below that a fluid connection exists between two components. This means that a fluid can flow from one component to the other, ideally without escaping into the environment. The two components may be directly connected. Alternatively, a gap may exist between the two components, and a fluid conveying unit, such as a hose and / or a channel as described above, may connect them. It is also possible that a fluid flows temporarily from the first component through the fluid connection to the second component, and conversely, from the second component through the fluid connection to the first component. The fluid connection can be permanent or temporary.

[0013] The term "source" will be used below. In the context of the invention, a source is capable of providing a fluid, in particular a gas component of the gas mixture, either permanently or at least temporarily. A source is, in particular, a stationary supply connection or a mobile source, for example, a container with the fluid, especially a compressed air cylinder. It is also possible that a fluid delivery unit, for example, a pump or a blower of a ventilator, functions as a source for a fluid. It is possible that two different types of sources are used for the same gas component, in particular a stationary source and a mobile source.

[0014] The supply arrangement according to the invention comprises a first channel with a supply connection element, which serves as the inlet to the first channel. A fluid connection is established, or can be established, at least temporarily between the supply connection element and a first source. The first source is capable of supplying the first gas component. The first channel is capable of conveying the first gas component from the supply connection element to a mixing point of the supply arrangement. The pressure in the first channel at any given time can vary along the first channel. Typically, the pressure at a point in the first channel varies over time.

[0015] The supply arrangement further includes a pressure reducer with a pressure inlet and a pressure outlet. A pressure reducer is defined as a component that receives a gas, in this case the second gas component, at its pressure inlet at a certain pressure and supplies this gas at a pressure outlet at a certain pressure. The pressure outlet is less than or equal to the pressure inlet and is always less than or equal to a predetermined pressure limit, regardless of the pressure inlet. This pressure limit can be determined by the design of the pressure reducer. Typically, the pressure outlet is variable over time, and the pressure inlet may also be variable. At least intermittently, the pressure reducer directs the gas from the pressure inlet through its internal structure to the pressure outlet.

[0016] A fluid connection exists, or can be established, at least temporarily between the pressure inlet and a second source. This second source is capable of supplying the second gas component. Thanks to this fluid connection, the second gas component can flow from the second source to the pressure inlet.

[0017] The pressure regulator is capable of supplying the second gas component at its downstream pressure outlet. The pressure regulator is designed to supply the second gas component as follows: The pressure profile at the downstream pressure outlet follows the pressure profile at a reference point in the first channel. This reference point can be located in the supply connection, coincide with the mixing point, or be situated between the supply connection and the mixing point.

[0018] The characteristic that the time course of a physical quantity B follows the time course of a physical quantity A means the following: If A increases or decreases, then B also increases or decreases, usually with a certain time delay. At least if A maintains the same value for a sufficiently long period, i.e., if A remains constant during this period, then B will also assume this value at least at the end of this period.

[0019] The supply arrangement also includes a second channel. The pressure reducer's downstream outlet is pneumatically connected to the second channel and / or is in fluid contact with the second channel. The second channel is capable of conveying the second gas component from the pressure mixer's downstream outlet to the mixing point.

[0020] The gas components, which are directed from the two channels to the mixing point, are mixed at the mixing point to form the gas mixture or mix themselves to form the gas mixture.

[0021] Furthermore, the supply arrangement includes an inspiratory channel that leads from the mixing point to the patient-side coupling unit. The inspiratory channel is capable of conveying a gas mixture, generated or produced at the mixing point, or which arises spontaneously at the mixing point, to the patient-side coupling unit.

[0022] According to the invention, the first and second channels open into the mixing point, and the inspiration channel begins at the mixing point. In the simplest case, the mixing point is a purely mechanical component that connects these three channels in a Y-shaped configuration. Alternatively, the mixing point can be implemented by a gas mixer, which blends the two gas components into an ideally homogeneous gas mixture.

[0023] The invention enables the delivery of a gas mixture comprising at least two gas components to the patient-side coupling unit, thereby providing the gas mixture for the patient's mechanical ventilation at the patient-side coupling unit. Because the supply arrangement is designed to compose the gas mixture from at least two gas components, the invention makes it possible in many cases to provide a gas mixture that is tailored to the patient's current mechanical ventilation requirements. In particular, pure oxygen can function as the second gas component, and the proportion of oxygen in the gas mixture can be adjusted and changed as needed. The second gas component can also be an anesthetic, and the proportion of the anesthetic in the gas mixture can be adjusted and changed as needed.

[0024] Because a pressure reducer is positioned between the second source and the second channel, the second source can supply the second gas component at a higher pressure than the first source supplies the first gas component. Since the pressure at the outlet, and thus in the second channel, follows the pressure at the reference point in the first channel, a large pressure difference at the mixing point is generally prevented, even if the two sources supply the two gas components at very different pressures. Thanks to the pressure reducer, the pressure at which the second source supplies the second gas component can also be higher than the maximum permissible pressure of the gas mixture at the patient-side coupling unit or in either the first or second channel.

[0025] These effects of the pressure reducer are particularly advantageous when the first source is a fluid delivery unit of a medical device and the second source is a stationary supply connection or comprises a pressurized cylinder containing the second gas component. Examples of such a fluid delivery unit are a blower or a pump. The first source often supplies the first gas component at a pressure between 20 mbar and 100 mbar. The second source often supplies the second gas component at a pressure between 2 bar and 8 bar. While it is possible, thanks to the invention, to reduce, control, or regulate the pressure at the second source, this is not necessary.

[0026] The pressure reducer supplies the second gas component at its downstream pressure outlet at a pressure that is lower than or at most exactly equal to the pressure at the upstream pressure inlet. According to the invention, the pressure at which the second gas component is supplied at the downstream pressure outlet follows the pressure of the first gas component at the reference point in the first channel. The pressure in the first channel is therefore the master, and the pressure in the second channel is the slave.

[0027] This feature of the invention facilitates the control of the pressure or volume flow rate through the inspiratory channel, i.e., downstream of the mixing point (closed-loop control). Such control is frequently implemented with the control gain objective of ensuring that the actual pressure or volume flow rate at the patient-side coupling unit follows a predetermined target profile.

[0028] Furthermore, this feature facilitates, in some cases, the control of the pressure or volume flow rate upstream of the mixing point, i.e., in the first channel and / or the second channel. In one embodiment, the control objective is for the actual pressure or volume flow rate in the respective channel to follow a predetermined target profile. In another embodiment, the control objective is for the proportion of at least one gas component in the gas mixture to remain within a predetermined target range. One implementation aims to achieve both control objectives. In some cases, it is sufficient to control the pressure in the first channel. Thanks to the invention, the pressure in the second channel then follows the controlled pressure in the first channel.

[0029] Thanks to the invention, the two gas components ideally reach the mixing point with the same pressure profile over time. In practice, the pressure in the second channel follows the pressure in the first channel with a time lag. Thanks to the invention, the difference between the two pressures in the two channels, and thus the pressure difference at the mixing point, generally remains relatively small at all times. Thanks to the invention, reliable control of the volume flow and / or the pressure and / or the mixing ratio in the gas mixture is possible in many cases, even when the target profile specifies rapid changes in pressure and / or volume flow and / or when the pressure at which a source supplies a gas component fluctuates over time. In many cases, the invention enables control in which any deviation from the control pattern is rapidly reduced.Furthermore, the invention reduces the risk of backflow occurring in one channel due to a strong pressure difference between the two channels at the mixing point, which is often undesirable.

[0030] To control the pressure or flow rate over time in the inspiratory channel, it is often sufficient to control the pressure or flow rate over time in the first channel. Thanks to the invention, the pressure or flow rate over time in the second channel follows the pressure or flow rate at the reference point in the first channel, eliminating the need for separate control of the second channel.

[0031] Thanks to the pressure reducer according to the invention, it is not necessary to control or regulate the pressure at which the second source supplies the second gas component. Rather, it is possible for the second source to supply the second gas component at a constant pressure or at a pressure that changes independently of the pressure in the first channel. Nevertheless, thanks to the invention, the pressure in and / or the volume flow through the inspiration channel and / or the mixing ratio in the gas mixture can, in many cases, be regulated relatively reliably. The pressure reducer decouples the second source from the second channel and thus also from the first channel.

[0032] According to the invention, a controllable first valve is able to change the volume flow through the first channel or the pressure in the first channel, for example by means of a variable cross-sectional area (proportional valve). A signal-processing control unit is able to control this first valve. This control unit performs a first control (closed-loop control). In this first control, the control unit receives and processes a signal from a first sensor and controls the first valve depending on this signal.

[0033] In one alternative configuration of this design, the control objective of the first control is that the actual pressure in the first channel follows a predetermined target pressure profile over time. The first sensor is capable of measuring the pressure in the first channel.

[0034] In a second alternative of this configuration, the control objective of the first control is that the temporal profile of the actual volume flow through the first channel follows a predefined target profile of the volume flow. The first sensor is capable of measuring a measure of the volume flow through the first channel.

[0035] These two alternatives can also be combined. The first sensor can then measure both pressure and volumetric flow.

[0036] In one embodiment, the control unit performs a second control function affecting the second channel. A second valve can change the volume flow through and / or the pressure in the second channel. The control unit activates the second valve based on a signal from a second sensor.

[0037] In one alternative configuration of this design, the control objective of the second control is that the actual pressure in the second channel follows a predefined target pressure profile over time. The second sensor is capable of measuring the pressure in the second channel.

[0038] In a second alternative of this configuration, the control objective of the second control system is that the temporal profile of the actual volume flow through the second channel follows a predefined target profile of the volume flow. The second sensor is capable of measuring a measure of the volume flow through the second channel.

[0039] These two alternatives can also be combined. The second sensor can then measure both pressure and volumetric flow.

[0040] According to the invention, the pressure at the back pressure outlet of the pressure reducer, and thus in the second channel, follows the pressure at the reference point in the first channel. This feature simplifies the implementation of the two control systems just described in many cases. Often, the same control algorithm can be used for both systems.

[0041] It is also possible that the control unit controls the volume flow through the first and / or the second channel.

[0042] An alternative or additional control objective in either of these two embodiments can also be that the proportion of the first gas component and / or the proportion of the second gas component in the gas mixture that is created or generated at the mixing point follows a predetermined temporal profile, in particular that it remains constant over time. This control objective can also be achieved more easily thanks to the invention.

[0043] In a preferred embodiment, the supply arrangement includes a pneumatic control line. At one end, the pneumatic control line is pneumatically connected to the pressure reducer, and at the other end to the first channel, specifically at a branch point within the first channel. In this embodiment, the branch point acts as the reference point within the first channel. The pneumatic control line establishes a fluid connection between the first channel, more precisely between the branch point, and the pressure reducer. This fluid connection results in pressure equalization between the two ends of the pneumatic control line, naturally with a certain time delay. Thanks to this fluid connection established by the pneumatic control line, the pressure profile in the pneumatic control line follows the pressure profile at the branch point.Preferably, the pneumatic control line creates a pressure equalization between the pressure at the branch point and the pressure in a section of the pressure reducer connected to the pneumatic control line. If the pressure at the branch point remains constant for a sufficiently long time, the pressure equalization in this section of the pressure reducer will eventually result in the same pressure as at the branch point.

[0044] According to this design, the pneumatic control line is pneumatically connected to the pressure reducer. The pressure reducer ensures that the pressure at the downstream outlet follows the pressure in the pneumatic control line. Overall, this results in the pressure at the downstream outlet following the pressure at the branch point.

[0045] The design with the pneumatic control line often eliminates the need for an electronic control unit to actuate a component of the pressure reducer. Furthermore, while it is possible, this design often makes it unnecessary for a pressure sensor to measure the pressure at the reference point or another measuring point in the first channel and for the control unit to actuate the pressure reducer based on a signal from the pressure sensor. Instead, the pressure reducer can be designed as a purely mechanical and pneumatic component. This often allows for a particularly robust design of the pressure reducer. In one design, the pressure reducer does not require an electrical power supply.Even when the pressure at which the second source supplies the second gas component is many times greater than the pressure at which the first source supplies the first gas component, in many cases the pneumatically operated pressure reducer is able to supply the second gas component at its back pressure outlet without very large forces occurring in the pressure reducer or a very high pressure occurring in the second channel or at the patient-side coupling unit.

[0046] In a further development of the design with the pneumatic control line, the pressure reducer has an internal inlet pressure chamber, an outlet pressure chamber, and a control pressure chamber. The term "chamber" refers to a space that is completely enclosed in a fluid-tight manner, except for optional openings necessitated by the design and, generally, unavoidable slots and holes. It is possible that the housing of the pressure reducer forms at least one wall of such a chamber. The three chambers inside the pressure reducer are fluid-tightly separated from each other, except for optional openings necessitated by the design and unavoidable slots.

[0047] The inlet pressure chamber is connected to the first pressure source via the inlet pressure inlet, or can at least be temporarily connected to it. The outlet pressure chamber is connected to the second channel via the outlet pressure in a fluid-tight manner. Normally, the inlet pressure is present in the inlet pressure chamber, and the outlet pressure in the outlet pressure chamber. The control pressure chamber is connected to the pneumatic control line, or has a fluid connection to it. This connection results in the following: The pressure in the control pressure chamber follows the pressure in the pneumatic control line. The pressure reducer is designed such that the pressure at the outlet pressure outlet follows the pressure in the control pressure chamber over time.

[0048] A preferred embodiment of the three-chamber design is described below. According to this embodiment, the pressure reducer comprises an internal partition and a movable closure. An opening is provided in the partition. The closure can selectively open or close this opening. The partition separates the upstream pressure chamber from the downstream pressure chamber. When the opening is closed, the partition creates a fluid-tight seal between the two chambers. Therefore, different pressures can exist in the two chambers, ideally without pressure equalization. When the opening is open, a fluid connection is established between the upstream pressure chamber and the downstream pressure chamber, allowing pressure equalization to occur. Typically, the pressure in the upstream pressure chamber is higher than the pressure in the downstream pressure chamber.If a connection is established between the two chambers and different pressures exist in the two chambers, the second gas component flows from the second source through the upstream and downstream chambers into the second channel. With the opening open, a certain degree of pressure equalization occurs between the two chambers. This fluid connection is interrupted when the opening is closed, and the second channel is thus separated from the second source. A high pressure in the second source then does not affect the downstream chamber and therefore not the second channel.

[0049] The pressure reducer is designed as follows: The valve releases the opening when a predefined criterion is met. This criterion depends on the pressure in the pilot pressure chamber and / or the pressure in the secondary pressure chamber. For example, the criterion is met when the difference between the pressure in the pilot pressure chamber and the pressure in the secondary pressure chamber exceeds a design-defined pressure differential threshold. Alternatively, the criterion is met when the pressure in the pilot pressure chamber exceeds a design-defined pressure threshold. As long as the criterion is not met, the valve remains closed. For example, a spring or other return element holds the valve in the closed position until the criterion is met. Therefore, the criterion is preferably determined by the design of the pressure reducer.

[0050] In a further development of the implementation with the partition, the pressure reducer includes, in addition to the partition, a movable and / or flexible wall. The movable wall can, in particular, be a rigid wall that is slidably or pivotably arranged, or a wall made of a flexible material, for example, a diaphragm. This movable or flexible wall separates the back pressure chamber from the control pressure chamber, preferably in a fluid-tight manner. Preferably, no opening is incorporated into the movable or flexible wall, so that no fluid can flow from the first channel through the pressure reducer into the second channel, which is often undesirable.

[0051] Because this wall is movable relative to the pressure reducer housing, or flexible, the volume of the back pressure chamber and the volume of the pilot pressure chamber are variable. A pressure difference between the two chambers causes the movable or flexible wall to move, increasing the volume of one chamber and correspondingly decreasing the volume of the other. This achieves a degree of pressure equalization. This movable or flexible wall is operatively connected to the closure for the opening in the partition, preferably by a purely mechanical connection. This connection transmits the movement of the movable or flexible wall to the closure, causing it to move. This movement opens or closes the opening.

[0052] The configuration just described, with the pneumatic control line, pneumatically ensures that the pressure at the downstream outlet of the pressure reducer follows the pressure at the reference point in the first channel. The alternative configuration described below can be combined with the pneumatic control line or used instead of a pneumatic control line. According to this alternative configuration, the supply arrangement includes a pressure sensor and a signal-processing pressure-reducing control unit. It is possible that the control unit that actuates the first valve and / or the second valve is also used as the pressure-reducing control unit. It is also possible that a separate control unit is used.

[0053] The pressure sensor measures the pressure at a measuring point in the first channel. Preferably, this measuring point serves as the reference point. Alternatively, a distance exists between the measuring point and the reference point when viewed in the flow direction, and the pressure at the reference point is derived from the measured pressure at the measuring point and the distance between the measuring point and the reference point. Depending on the measured values, the pressure sensor generates a signal for the pressure at the reference point. The pressure reduction control unit receives and processes this signal. Depending on the received signal, the pressure reduction control unit ensures that the pressure at the downstream pressure outlet follows the pressure at the reference point in the first channel. The pressure reduction control unit preferably uses a suitable control algorithm for this purpose.

[0054] In a further development of the design with the pressure reducing control unit, the pressure reducer has two internal chambers: a pre-pressure chamber and a post-pressure chamber. The pre-pressure chamber is connected to the first pressure source via the pre-pressure inlet, or can at least be connected to it temporarily. The post-pressure chamber is connected to the second channel via the post-pressure outlet in a fluid-tight manner. According to this further development, the pressure reducer includes a pressure reducing actuator, for example, a pump, a piston-cylinder unit, or a component with a solenoid and a spring or other return element. The pressure reducing control unit is able to actuate the pressure reducing actuator based on a signal from the pressure sensor. The pressure reducing actuator is able to change the pressure in the post-pressure chamber, preferably by changing the volume of the post-pressure chamber.By controlling the pressure reducing actuator, the pressure reducing control unit is able to automatically ensure that the pressure in the back pressure chamber follows the pressure at the reference point in the first channel.

[0055] The implementation using the pressure sensor and the pressure reducing actuator often results in the pressure in the back pressure chamber following the pressure in the first channel particularly quickly.

[0056] The implementation with the pneumatic control line and the implementation with the pressure reducing control unit and the pressure reducing actuator can be combined. Firstly, this achieves redundancy. Secondly, in many cases, it results in the pressure at the downstream pressure outlet following the pressure at the reference point more quickly than if only the pneumatic control line or only the pressure reducing actuator were present.

[0057] In one implementation of this training, the pressure reducer comprises a partition between the upstream and downstream pressure chambers, an opening in this partition, and a closure. Possible implementations and advantages of these elements have already been described above as possible implementations and advantages of the design with the pneumatic control line and the lockable partition. The actuated pressure reducer actuator is mechanically connected to the closure. The actuated pressure reducer actuator can move the closure, thereby selectively opening or closing the opening.

[0058] In one embodiment, a movable wall is arranged inside the pressure reducer. This wall is movable relative to another wall of the back pressure chamber, for example, the housing of the pressure reducer. Preferably, this movable wall forms a wall of the back pressure chamber. Movement of the movable wall causes the volume of the back pressure chamber to change. This also changes the pressure in the back pressure chamber. The pressure reducer actuator is mechanically connected to the movable wall. By moving the movable wall, the pressure reducer actuator changes the pressure in the back pressure chamber and thus the pressure at the back pressure outlet of the pressure reducer. Instead of a movable wall, a flexible wall, for example, a diaphragm, can also be used inside the pressure reducer.

[0059] This design enables the pressure reducing control unit to regulate the pressure at the downstream pressure outlet in a relatively reliable manner. The control objective is for the pressure at the downstream pressure outlet to follow the pressure profile at the reference point over time. By actuating the pressure reducing actuator, the pressure reducing control unit changes the volume, and thus the pressure, in the downstream pressure chamber and consequently at the downstream pressure outlet.

[0060] In one embodiment, a control pressure chamber is additionally formed inside the pressure reducer. The pressure reducer actuator is able to change the pressure in the control pressure chamber. The pressure at which this pressure reducer supplies the second gas component at its downstream pressure outlet depends on the pressure in the control pressure chamber as follows: The higher the pressure in the control pressure chamber, the greater the pressure at the downstream pressure outlet.

[0061] The design with the control pressure chamber often allows the control pressure actuator, or at least every mechanical element of the actuator, to be completely enclosed within the control pressure chamber. This leaves the other chamber of the pressure reducer free of the actuator. To a certain extent, the control pressure chamber protects the actuator from external mechanical influences.

[0062] The invention further relates to a supply system capable of supplying a patient-side coupling unit with a gas mixture. The gas mixture comprises a first gas component and a second gas component. The supply system comprises a first source, a second source, and a supply arrangement according to the invention.

[0063] The first source is capable of supplying the first gas component. The second source is capable of supplying the second gas component. A fluid connection is established, at least temporarily, or can be established, between the supply connection element of the first channel of the supply arrangement and the first source. A fluid connection is also established, at least temporarily, or can be established, between the pressure inlet of the pressure reducer of the supply arrangement and the second source.

[0064] In one embodiment, the second source provides the second gas component at a higher pressure than the first source provides the first gas component. For example, the second source is a stationary source connected to an infrastructure supply network or comprises at least one pressurized cylinder. The first source is, for example, an inlet of a fluid delivery unit, in particular a blower or pump, where the fluid delivery unit is, for example, part of a ventilator. The first source can also be any other type of mobile source.

[0065] The invention further relates to a ventilation system for the artificial respiration of a patient, wherein the patient is ventilated with a gas mixture comprising a first gas component and a second gas component. At least one of the two gas components, optionally both gas components, is or contains oxygen. The gas mixture may include a third gas component, for example, an anesthetic.

[0066] The ventilation system includes a fluid conveying unit, for example a blower or a pump, a patient-side coupling unit, and a supply arrangement or supply system according to the invention.

[0067] The patient-side coupling unit is connected to a patient or can at least be temporarily connected to a patient, in particular by being placed in or on the patient's body.

[0068] During mechanical ventilation, a fluid connection is established between a first source, which supplies the first gas component, and the supply connection element. Furthermore, during mechanical ventilation, a fluid connection is established between a second source, which supplies the second gas component, and the upstream pressure inlet of the pressure reducer. The fluid delivery unit is capable of conveying the first gas component from the first source through the first channel to the mixing point. The second gas component flows from the second source to the mixing point, for example, due to a sufficiently high pressure in the second source or through the same or a further fluid delivery unit. The pressure profile at the downstream pressure outlet of the pressure reducer follows the pressure profile at the reference point in the first channel.

[0069] The two gas components are mixed at the mixing point to form a gas mixture, or they mix spontaneously there. The gas mixture generated or formed at the mixing point flows through the inspiratory channel to the patient-side coupling unit.

[0070] The fluid delivery unit executes a sequence of ventilation breaths. In each breath, a quantity of the gas mixture generated or produced at the mixing point is delivered through the inspiratory channel to the patient-side coupling unit. The fluid delivery unit is, or comprises, for example, a pump, a piston-cylinder unit, a blower operating in conjunction with at least one valve, or even a manual resuscitation bag.

[0071] In one application, the patient performs their own breathing during mechanical ventilation, primarily due to their own spontaneous breathing or because their respiratory muscles are externally stimulated. In this application, the fluid delivery unit is preferably controlled such that each of the patient's breaths triggers a ventilation stroke from the fluid delivery unit, and a ventilation stroke is only performed in response to a breath. At least one sensor generates a respiratory signal, which serves as a measure of the patient's own breathing activity. Thus, mechanical ventilation supports the patient's own breathing. Ideally, the ventilation strokes performed by the fluid delivery unit are perfectly synchronized with the patient's own breathing.

[0072] In one embodiment, the fluid delivery unit is connected to the first channel via a fluid flow path and feeds the first gas component into the first channel. Preferably, this first gas component is ambient air or a gas that is supplied from the patient to the fluid delivery unit in a ventilation circuit. A stationary or mobile supply connection feeds the second gas component into the second channel.

[0073] The invention is described below using an exemplary embodiment. Here, it is shown that... Figure 1 schematically shows how a patient is artificially ventilated with a gas mixture of air and oxygen, with two channels supplying the two components; Figure 2 schematically shows a ventilation circuit in which a patient is supplied and anesthetized with a mixture of air, oxygen, and an anesthetic; Figure 3 shows the time course of the volume flow and pressure of the gas mixture flowing to the patient; Figure 4 schematically shows a purely pneumatic pressure reducer; Figure 5 shows an exemplary dependence of the outlet pressure on the volume flow; Figure 6 schematically shows a controlled pressure reducer with a control pressure chamber; Figure 7 schematically shows a controlled pressure reducer without a control pressure chamber.

[0074] In this embodiment, the invention is used to artificially ventilate a patient Pt. A patient-side coupling unit 9, for example a breathing mask, a tube, or a catheter, is attached to or inside the body of the patient Pt.

[0075] A ventilator 100, shown only schematically, performs a sequence of ventilation breaths, delivering a gas mixture to the patient-side coupling unit 9 and thus to the patient Pt in each breath. This gas mixture contains a certain percentage (by volume) of oxygen, the percentage of which is specified by the user. This oxygen percentage can be higher than the oxygen content of ambient air. To increase the oxygen content compared to ambient air, a gas mixture of ambient air and pure oxygen is generated in the exemplary embodiment. The gas mixture can also contain an anesthetic, so that the patient Pt is sedated or anesthetized.

[0076] Figure 1Figure 1 schematically shows an arrangement for generating this gas mixture with a higher oxygen content. The two components of the gas mixture, namely air and pure oxygen, are supplied in two channels K.1 and K.2, with a first channel K.1 supplying the air and a second channel K.2 supplying the oxygen, and with the two channels K.1 and K.2 being combined at a mixing point 8.

[0077] It is possible that a gas mixer blends the two gas components into a gas mixture. Such a gas mixer is described, for example, in DE 102008057180 B3, in DE 102012008108 A1, and in DE 102016001383 A1. In the simplest case, a Y-piece is arranged at mixing point 8.

[0078] From this mixing point 8, an inspiratory channel K.30, for example a tube for inhalation and optionally a two-lumen tube with one lumen for inhalation and one lumen for exhalation, leads to the patient-side coupling unit 9. This inspiratory channel K.30 directs the mixture of air and pure oxygen to the patient-side coupling unit 9.

[0079] A user specifies a desired oxygen content in the gas mixture. For example, the user manually sets the desired oxygen content using a rotary knob 30, as shown schematically.

[0080] A blower 2 or other conveying unit of the ventilator 100 draws in ambient air through an inlet E of the ventilator 100 and feeds the drawn-in air into the first channel K.1. A filter 23 is arranged between the inlet E and the blower 2. In the application according to Figure 1The conveyor unit 2 acts as the source for the first gas component.

[0081] An inlet of the first channel K.1, in the form of a supply connection element V.1, is connected to a supply outlet of the blower 2. Ideally, the pressure in the first channel K.1 follows a predetermined time profile, for example, remaining constant over time. In this embodiment, the pressure in the first channel K.1 is above the maximum ventilation pressure, i.e., above the maximum pressure at which the gas mixture is delivered to the patient-side coupling unit 9 and further into the patient's lungs Pt, and is preferably between 20 mbar and 100 mbar.

[0082] The volume flow, i.e. the flow of gas per unit of time, through the first channel K.1 downstream of the conveying unit 2 and / or the pressure in the first channel K.1 should each follow a predetermined time profile. Figure 3The top figure shows an example of the required time course of the volume flow (Vol'), and the bottom figure shows an example of the required time course of the pressure (P). Values ​​above the x-axis indicate a flow of the gas mixture towards the patient Pt (inhalation, inspiration), values ​​below indicate a flow away from the patient Pt (exhalation, expiration).

[0083] A signal processing control unit 3 performs a control operation, whereby the actual volume flow is the controlled variable and the specified time profile of the volume flow is the reference variable, cf. Figure 1 and Figure 2 The control unit 3 controls a proportional valve 4.1 and thereby changes the volume flow in the first channel K.1 downstream from the proportional valve 4.1 to the mixing point 8.

[0084] In the first channel K.1, a pneumatic resistance 5.1, for example a constriction, is arranged. A volumetric flow sensor 6.1 measures the difference ΔP between the pressure upstream and the pressure downstream of the pneumatic resistance 5.1 and derives a measure of the actual volumetric flow through the first channel K.1 from the pressure difference. Additionally, a pressure sensor 7.1 measures the actual pressure in the first channel K.1 at a measuring point 28.1 downstream of the pneumatic resistance 5.1. The control unit 3 receives a signal from both sensors 6.1 and 7.1.

[0085] The second channel K.2 receives pure oxygen (O2) from a supply line 21, which is connected to a supply port 20. In the example shown, this supply port 20 is permanently installed in a wall W and belongs to a stationary supply system of a hospital infrastructure. It is also possible for the second channel K.2 to receive pure oxygen from at least one pressurized cylinder. The supply port 20 provides the pure oxygen at a pressure between 2 bar and 8 bar. An optional check valve 26 in the supply line 21 prevents pure oxygen from being forced back into the supply port 20 and then into the hospital infrastructure.

[0086] A pneumatic pressure reducer 1 comprises a pressure inlet V.3 and a pressure outlet V.2. The pressure inlet V.3 is connected to the supply line 21, and the pressure outlet V.2 to the second channel K.2. The pressure reducer 1 reduces the pressure from the supply connection 20 so that the pressure at the pressure outlet V.2 of the pressure reducer 1 follows the time-varying pressure at a reference point 11, 28.1 described below. This ensures that the pressure at the pressure outlet V.2 follows the pressure at the supply connection element V.1 and thus the pressure at the supply outlet of the blower 2. How this is achieved is described in more detail below.

[0087] In the second channel K.2, a pneumatic resistor 5.2, a volume flow sensor 6.2, a pressure sensor 7.2, and a proportional valve 4.2 are arranged. These components function in the same way as the corresponding components in the first channel K.1. The pressure sensor 7.2 measures the pressure in the second channel K.2 at a measuring point 28.2. In the exemplary embodiment, the control unit 3 controls the proportional valve 4.2 with the control objective that the actual volume flow through the second channel K.2 follows a predetermined time profile.

[0088] Figure 2 Figure 1 shows another application of the invention in which the patient Pt is not only artificially ventilated but also sedated or anesthetized. The same reference numerals have the same meaning as in Figure 2. Figure 1 .

[0089] The design according to Figure 2 It has the following additional components: an anesthetic vaporizer 27 that generates gaseous anesthetic, an expiratory fluid compound with a first section 31 and a second section 32 and an absorber 25 for CO2 and anesthetic.

[0090] The gaseous anesthetic agent, produced by the anesthetic vaporizer 27, is fed into the gas mixture, which is routed through the inspiratory channel K.30 to the patient-side coupling unit 9 and inhaled by the patient Pt. In the example shown, the anesthetic agent is fed into the first channel K.1 and flows into it to the mixing point 8. It is also possible for it to be fed into the second channel K.2 or into the inspiratory channel K.30.

[0091] The air exhaled by the patient Pt often still contains anesthetic. This anesthetic should not escape into the environment. Therefore, a ventilation circuit is established. The expiratory fluid connection 31, 32 leads from the patient-side coupling unit 9 back to the blower 2. The blower 2 maintains a flow of gas through this ventilation circuit. The first section 31 leads from the patient-side coupling unit to the CO2 absorber 25. This CO2 absorber 25 absorbs carbon dioxide and optionally also anesthetic from the exhaled air. The second section 32 carries the exhaled air, from which the carbon dioxide and optionally the anesthetic have been absorbed, to the filter 23 and from there to the blower 2.

[0092] In this configuration, the absorber 25 acts as the source for the first gas component (air) that enters the first channel K.1.

[0093] As previously explained, a gas mixture is conveyed from mixing point 8 to the patient-side coupling unit 9. The actual volumetric flow rate of this gas mixture downstream from mixing point 8 is intended to follow a predetermined temporal profile. Furthermore, a required oxygen content is specified, preferably as a volume percent. This oxygen content can be constant or variable over time. From the predetermined temporal profile of the volumetric flow rate to the patient-side coupling unit 9, the required oxygen content in the gas mixture, and the known oxygen content in air, a target flow profile for the volumetric flow rate through the first channel K.1 and a target flow profile for the volumetric flow rate through the second channel K.2 are derived. The control unit 3 or a higher-level control unit calculates these two target profiles for the two channels K.1 and K.2, and the control unit 3 controls the two proportional valves 4.1 and 4.2 based on these two target profiles.The control unit 3 therefore performs two volume flow controls, one in the first channel K.1 and one in the second channel K.2. In many cases, the same control algorithm can be used to actuate the two proportional valves 4.1 and 4.2. This is possible in particular because the same pressure exists at the supply outlet of the blower 2 and at the back pressure outlet V.2 of the pressure reducer 1. This is achieved by the pneumatic or electronic control (open-loop control) or regulation (closed-loop control) described below.

[0094] Figure 1 and Figure 4Figure 1 illustrates a pneumatic control of the pressure reducer 1. A pneumatic control line 10 leads from a branch point 11 in the first channel K.1 to a control pressure input V.4 of the pressure reducer 1. This control pressure input V.4 is required for the pneumatic control, but not for the electronic control or regulation described below. Preferably, the pneumatic control line 10 is designed as a flexible hose; it can also be a rigid tube. The branch point 11 is located downstream of the blower 2 and upstream of the proportional valve 4.1; in the embodiment shown, it also begins upstream of the pneumatic resistor 5.1. In one embodiment, this branch point 11 functions as the reference point.

[0095] Thanks to the pneumatic control line 10, the same pressure is always present at the control pressure inlet V.4 of the pressure reducer 1 – except for unavoidable time delays and leaks – as in the first channel K.1, specifically in the section between the blower 2 and the proportional valve 4.1, and in particular as at the reference point (branch point 11). This time-varying pressure in the first channel K.1 acts as a control pressure and thus as a master, and the pressure at the inlet of the second channel K.2 follows this time-varying control pressure as a slave.

[0096] Figure 4 Figure 1 shows an exemplary configuration of a pneumatically operated pressure reducer 1. The inlet pressure V.3 of the pressure reducer 1 is connected to the supply line 21. The control pressure V.4 is connected to the pneumatic control line 10. The second channel K.2 begins at the outlet pressure V.2 of the pressure reducer 1.

[0097] A rigid housing 19 encloses the interior of the pressure reducer 1. Three chambers are formed within this interior, namely a pre-pressure chamber Ka.1, which is connected to the supply line 21 via the pre-pressure inlet V.3, a back pressure chamber Ka.2, which is connected to the second channel K.2 via the back pressure outlet V.2, and a control pressure chamber Ka.3, which is connected to the pneumatic control line 10 via the control pressure inlet V.4.

[0098] A partition 15 in the pressure reducer 1 separates the back pressure chamber Ka.2 from the front pressure chamber Ka.1. Preferably, the partition 15 is rigid. An opening 29 is provided in the partition 15. A spring-loaded closure 13 is linearly movable relative to the partition 15 in two opposite directions (in Figure 3 vertically upwards and downwards) and can open or close this opening 29.

[0099] A movable wall 12 is attached to the inside of the housing of the pressure reducer 1 and separates the control pressure chamber Ka.2 from the back pressure chamber Ka.3. In the exemplary embodiment, the movable wall 12 has the form of a flexible diaphragm. In one embodiment, the diaphragm 12 comprises a centrally arranged fixed plate. The movable wall 12 can also have the form of a rigid plate that is vertically displaceable in both directions relative to the housing 19. Preferably, the movable wall 12 separates the two chambers Ka.2 and Ka.3 from each other in a fluid-tight manner, except for unavoidable leaks.

[0100] The design of the pressure reducer 1 described above causes the second gas component, in this case oxygen, to be located in the upstream pressure chamber Ka.1 and the downstream pressure chamber Ka.2, while the first gas component, in this case air, is located in the control pressure chamber Ka.3. The movable baffle 12 prevents these two gas components from mixing within the pressure reducer 1. When the valve 13 opens the port 29, the two chambers Ka.1 and Ka.2 are in fluid communication with each other, and pressure equalization can occur. When port 29 is closed, the baffle 15 interrupts this fluid communication and prevents pressure equalization.

[0101] A lever 14 is rotatable about a pivot axis DA and rests on top of the movable wall 12, optionally on top of the fixed plate of the membrane. The closure 13 rests on top of the lever 14. As in Figure 4As can be seen, a short lever arm is formed between the axis of rotation DA and the bearing point of the breech 13, and a long lever arm is formed between the axis of rotation DA and the bearing point of the lever 14 on the movable wall 12. This places the movable wall 12 in operative connection with the breech 13 and allows it to exert a large force on the breech 13.

[0102] The pressure in the pre-pressure chamber Ka.1 is the same as in the supply line 21, i.e., a pre-pressure that is preferably between 2 bar and 8 bar and thus many times higher than the pressure in the two channels K.1 and K.2. The pressure in the control pressure chamber Ka.3 is the same as in the pneumatic control line 10 and thus ideally also the same pressure as in the first channel K.1 and there in the section between the blower 2 and the proportional valve 4.1. The pressure in the discharge chamber Ka.2 is the pressure at which the second channel K.2 supplies pure oxygen.

[0103] Thanks to the movable wall 12, the same pressure is always maintained in both chambers Ka.2 and Ka.3, even with a changing control pressure (pressure in the first channel K.1). After a change in the control pressure, i.e., the pressure in the control pressure chamber Ka.3, a settling phase typically elapses until the pressures are equal again. Depending on the position of the movable wall 12, the valve 13 opens or closes the opening 29 in the partition 15, thus allowing or preventing pure oxygen from the supply line 21 from flowing through the pressure reducer 1 into the second channel K.2. At a sufficiently high pressure in the back pressure chamber Ka.2, the movable wall 12, via the actuating connection (lever 14), causes the valve 13 to close the opening 29.

[0104] Ideally, the blower 2 generates a constant pressure, regardless of the volume flow rate. Ideally, this constant pressure is also present at the outlet of the pressure reducer 1. In practice, the generated pressure decreases with increasing volume flow rate. Figure 5This situation is illustrated by the graph, where the x-axis represents the volume flow rate Vol' in [l / min] and the y-axis represents the generated back pressure P in [mbar]. The term "back pressure" refers to the outlet of blower 2. Curve P.2(50) shows the course of the actual pressure P generated by blower 2 as a function of the volume flow rate Vol' in a situation where blower 2 is intended to generate a pressure of 50 mbar. Curve P.2(30) shows the actual pressure at a target pressure of 30 mbar. Curve P.1 shows the actual pressure at the back pressure outlet V.2 of pressure reducer 1. It can be seen that, despite the dependence on the volume flow rate, the pressure at the outlet of pressure reducer 1 corresponds well with the control pressure (back pressure of blower 2).

[0105] Figure 6 and Figure 7 Two alternative designs of the pressure reducer are shown. 1. The same reference symbols have the same meaning as in Figure 1 and Figure 4The reference point is measuring point 28.1, where pressure sensor 7.1 measures the pressure.

[0106] The two alternative configurations eliminate one pneumatic control line 10 from the first channel K.1 to the pressure reducer 1 and one pneumatic control pressure input V.4. Reference symbols have the same meaning as in Figure 4 In both alternative configurations, the pressure reducer 1 has only one inlet, namely the pre-pressure inlet V.3, which in turn connects the pre-pressure chamber Ka.1 with the supply line 21.

[0107] First, the design will be according to Figure 6As described. The movable wall 12 is acted upon from one side by the pressure in the back pressure chamber Ka.2, and from the other side by the force of a spring 16 in the control pressure chamber Ka.3. The spring 16 is connected on one side to the movable wall 12 and on the other side to a mechanical connecting element 18 and tends to expand. An actuated control pressure actuator 17, for example a pump or a piston-cylinder unit, is supported against the housing 19 of the pressure reducer 1 and acts on the connecting element 18 from one side. The control pressure actuator 17 is able to increase or decrease the distance between the connecting element 18 and the lower wall of the housing 19, and thus also the force of the spring 16. The closer the connecting element 18 is to the movable wall 12, the greater the spring force of the spring 16.

[0108] The control unit 3 receives a signal from each of the two pressure sensors 7.1 and 7.2, see below. Figure 1 , and controls the control pressure actuator 17 so that the pressure in the control pressure chamber Ka.3 and thus the pressure in the second channel K.2 follows the pressure in the first channel K.1 downstream of the blower 2.

[0109] The pressure reducer 1 according to Figure 7 It does not include a back pressure chamber or a movable wall. The control pressure actuator 17 is located in the back pressure chamber Ka.2 and is mechanically connected to the breech 13 via the connecting element 18. The control pressure actuator 17 is able to directly move the breech 13 in two opposite vertical directions, thereby selectively moving the breech 13 into either a releasing or a closing position.

[0110] The two configurations according to Figure 4 and according to Figure 6 or Figure 7The components of pressure reducer 1 can be combined with one another. According to this combination, pressure reducer 1 therefore has both the control pressure inlet V.4 and the spring 16, the control pressure actuator 17, and the connecting element 18. The supply arrangement in this combination is preferably as shown in Figure 1 The controlled pressure actuator 17 and the spring 16 can compensate to a certain extent for differences between the pressure in the back pressure chamber Ka.2 and the pressure in the first channel K.1. Reference symbol list

[0111] 1 pneumatic pressure reducer between supply line 21 and the second channel K.2, includes the back pressure outlet V.2, the front pressure inlet V.3 and the optional control pressure inlet V.4 2 The blower of the ventilator 100 includes the inlet E, is connected to the first channel K.1 via a supply outlet, and in one configuration functions as the first source. 3 signal processing control unit, receives signals from the sensors 6.1, 6.2, 7.1, 7.2 and controls the proportional valves 4.1 and 4.2 and, in one embodiment, the control pressure actuator 17. 4.1 The proportional valve in the first channel K.1 is able to change the volume flow through the first channel K.1 and is controlled by the control unit 3. 4.2 The proportional valve in the second channel K.2 is able to change the volume flow through the second channel K.2 and is controlled by the control unit 3. 5.1 pneumatic resistance in the first channel K.1 5.2 pneumatic resistance in the second channel K.2 6.1 Volume flow sensor, measures the pressure difference ΔP upstream and downstream of the pneumatic resistance 5.1 and derives the volume flow through the first channel K.1. 6.2 Volume flow sensor, measures the pressure difference ΔP upstream and downstream of the pneumatic resistance 5.2 and derives the volume flow through the second channel K.2. 7.1 Pressure sensor, measures the pressure in the first channel K.1 at measuring point 28.1. 7.2 Pressure sensor, measures the pressure in the second channel K.2 at measuring point 28.2. 8 Mixing point, into which the two channels K.1 and K.2 merge and in which the inspiration channel K.30 begins. 9 Patient-side coupling unit, connected to mixing point 8 via the inspiratory channel K.30. 10 Pneumatic control line, leads from branch point 11 to the control pressure chamber Ka.3 in the pressure reducer 1, belongs to the pressure reducing control unit. 11 The branching point in the first channel K.1, where the control line 10 begins, functions in one embodiment as the reference point. 12 A movable wall in the form of a membrane in the pressure reducer 1 separates chambers Ka.2 and Ka.3 from each other in a fluid-tight manner. 13 The closure, which selectively opens or closes the connection in the partition wall 15 between the two chambers Ka.1 and Ka.2, is in operative connection with the movable wall 12 via the lever 14. 14 The lever establishes a mechanical connection between the movable wall 12 and the closure 13 and is rotatable about the axis of rotation DA. 15 The rigid partition in the pressure reducer 1, which separates the two chambers Ka.1 and Ka.2 from each other, has an opening 29 which can be closed by the closure 13. 16 The spring is connected to the movable wall 12 and to the connecting element 18, and belongs to the pressure reducing actuator. 17 The control pressure actuator, which moves the connecting element 18 and thus changes the force of the spring 16, is controlled by the control unit 3 and belongs to the pressure reducing actuator. 18 mechanical connecting element between the control pressure actuator 17 and the spring 16 19 Rigid housing of the pressure reducer 1, enclosing the three chambers Ka.1, Ka.2, Ka.3 20 Supply connection in the wall W for pure oxygen, functions as the second source 21 Supply line, leads from supply connection 20 to the pre-pressure inlet V.3, connects supply connection 20 with the pre-pressure chamber Ka.1 in the pressure reducer 1 23 Filter behind inlet E 25 CO2 absorber, in one configuration functions as the first source 26 Check valve in supply line 21 27 Anesthetic vaporizer, generates gaseous anesthetic and feeds it into the first channel K.1. 28.1 The measuring point in the first channel K.1, at which the pressure sensor 7.1 measures the pressure in the first channel K.1, functions in one embodiment as the reference point. 28.2 Measuring point in the second channel K.2, where the pressure sensor 7.2 measures the pressure in the second channel K.2 29 The opening in the partition wall 15 is selectively opened or closed by the closure 13. 30 Rotary knob that a user can turn to specify the required proportion of oxygen in the gas mixture that is delivered to the patient-side coupling unit 9. 31 The first section of the expiratory fluid connection directs the exhaled air from the patient-side coupling unit 9 to the CO2 absorber 25. 32 The second section of the expiratory fluid connection directs the exhaled air, now free of CO2, from the CO2 absorber 25 to the blower 2. 100 A ventilator that generates a gas mixture of breathing air and pure oxygen, artificially ventilates the patient Pt, and comprises the supply arrangement according to the invention. DA axis of rotation about which the lever 14 can rotate E Ambient air inlet K.1 First channel, provides breathing air, is in fluid communication with blower 2, leads into mixing point 8 K.2 The second channel provides pure oxygen, is in fluid communication with the back pressure chamber Ka.2 in the pressure reducer 1, and leads to the mixing point 8. K.30 Inspiration channel, directs the gas mixture from mixing point 8 to the patient-side coupling unit 9 Ka.1 Pre-charge chamber in pressure reducer 1, connected to supply line 21 via pre-charge inlet V.3 Ka.2 Back pressure chamber in pressure reducer 1, connected via the back pressure outlet V.2 to the second channel K.2 Ka.3 The control pressure chamber in the pressure reducer 1, in one embodiment connected to the control line 10 via the control pressure input V.4, contains in another embodiment the spring 16 and the connecting element 18. P Pressure, especially in the inspiration channel K.30 P.1 Time course of the pressure at the back pressure outlet V.2 P.2 Time course of the pressure at the supply connection element V.1 P.2(30) Time course at a target pressure of 30 mbar P.2(50) Time course at a target pressure of 50 mbar Pt Patient, artificially ventilated by ventilator 100, wears the patient-side coupling unit 9 V.1 Supply connection element of the first channel K.1, connected to a supply output of the blower 2 V.2 Back pressure outlet of pressure reducer 1, connected to the second channel K.2 V.3 Pre-charge inlet of the pressure reducer 1, connected to the supply line 21 V.4 Optional control pressure input of pressure reducer 1, connected to control line 10 W The wall has the supply connection 20 for pure oxygen.

Claims

1. Supply arrangement for supplying a patient-side coupling unit (9) with a gas mixture comprising a first gas component (air) and a second gas component (O2), the patient-side coupling unit (9) being connectable or at least temporarily connected to a patient (Pt), the supply arrangement comprising - a first duct (K.1) having a supply connection element (V.1), - a second duct (K.2), - a mixing point (8), - an inspiratory duct (K.30) and - a pressure regulator (1) having an upstream pressure inlet (V.3) and a downstream pressure outlet (V.2), a fluid connection being established or at least temporarily establishable between the supply connection element (V. 1) and a first source (2, 25), namely a source for the first gas component (air),, a fluid connection (21) being established or at least temporarily establishable between the upstream pressure inlet (V.3) of the pressure regulator (1) and a second source (20), namely a source for the second gas component (O2), the downstream pressure outlet (V.2) of the pressure regulator (1) being connected to the second duct (K.2), the first duct (K.1) being designed to guide the first gas component (air) from the supply connection element (V.1) to the mixing point (8), the second duct (K.2) being designed to guide the second gas component (O2) from the downstream pressure outlet (V.2) of the pressure regulator (1) to the mixing point (8), the pressure regulator (1) being designed to provide the second gas component (O2) in such a way that the time course (P.1) of the pressure at the downstream pressure outlet (V.2) of the pressure regulator (1) follows the time course (P.2) of the pressure at a reference point (11, 28.1) in the first duct (K.1), and the inspiratory duct (K.30) being designed to conduct a gas mixture generated or created in the mixing point (8) to the patient-side coupling unit (9), characterized in that the supply arrangement comprises - a first valve (4.1), - a first sensor (6.1, 7.1) and - a signal processing controller (3), the first valve (4.1) being designed to change the volume flow (Vol') through the first duct (K.1) and / or the pressure (P) in the first duct (K.1), the controller (3) being designed - to carry out a first closed-loop control and - during the first closed-loop control, to control the first valve (4.1) depending on the measured values of the first sensor (6.1, 7.1), - the first sensor (7.1) being designed to measure a measure of the pressure (P) in the first duct (K.1) and - the control objective in the first closed-loop control being that the time course of the actual pressure (P) in the first duct (K.1) follows a predetermined target course of the pressure, or - the first sensor (6.1) being designed to measure a measure of the volume flow (Vol') through the first duct (K.1) and - the control objective in the first closed-loop control being that the time course of the actual volume flow (Vol') through the first duct (K.1) follows a predetermined target course of the volume flow.

2. Supply arrangement according to claim 1, characterized in that the supply arrangement additionally comprises - a second valve (4.2) and - a second sensor (6.2, 7.2), the second valve (4.2) being designed to change the volume flow (Vol') through the second duct (K.2) and / or the pressure (P) in the second duct (K.2), the controller (3) being designed - to carry out a second closed-loop control and - during the second closed-loop control, to control the second valve (4.2) depending on the measured values of the second sensor (6.2, 7.2), - the second sensor (7.2) being designed to measure a measure of the pressure (P) in the second duct (K.2) and - the control objective in the second closed-loop control being that the time course of the actual pressure (P) in the second duct (K.2) follows a predetermined target course of the pressure, or - the second sensor (6.2) being designed to measure a measure of the volume flow (Vol') through the second duct (K.2) and - the control objective of the second closed-loop control being that the time course of the actual volume flow (Vol') through the second duct (K.2) follows a predetermined target course of the volume flow.

3. Supply arrangement according to either of the preceding claims, characterized in that the supply arrangement comprises a pneumatic control line (10), the pneumatic control line (10) being pneumatically connected - to the pressure regulator (1) and - to the first duct (K. 1) at a branch-off point (11), the pneumatic control line (10) establishing a fluid connection between the first duct (K.1) and the pressure regulator (1) in such a way that the time course of the pressure in the pneumatic control line (10) follows the time course (P.2) of the pressure at the branch-off point (11), and the pressure regulator (1) being designed to cause the time course (P.1) of the pressure at the downstream pressure outlet (V.2) of the pressure regulator (1) to follow the time course of the pressure in the pneumatic control line (10).

4. Supply arrangement according to claim 3, characterized in that inside the pressure regulator (1) - an upstream pressure chamber (Ka. 1), which is connectable or at least temporarily connected to the first source (20) via the upstream pressure inlet (V.3) of the pressure regulator (1), - a downstream pressure chamber (Ka.2), which is connected to the second duct (K.2) via the downstream pressure outlet (V.2) of the pressure regulator (1), and - a control pressure chamber (Ka.3) are formed, the pneumatic control line (10) being in fluid connection with the control pressure chamber (Ka.3) in such a way that the pressure in the control pressure chamber (Ka.3) follows the pressure in the pneumatic control line (10), and the pressure regulator (1) being designed such that the time course (P.1) of the pressure at the downstream pressure outlet (V.2) follows the time course (P.2) of the pressure in the control pressure chamber (Ka.3).

5. Supply arrangement according to claim 4, characterized in that the pressure regulator (1) comprises - a partition (15) having an opening (29) and - a closure (13), the partition (15) separating the upstream pressure chamber (Ka.1) from the downstream pressure chamber (Ka.2), the opening (29) in the partition (15) connecting the upstream pressure chamber (Ka.1) to the downstream pressure chamber (Ka.2), the closure (13) being capable of selectively opening or closing the opening (29) in the partition (15) and the pressure regulator (1) being designed such that the closure (13) - opens the opening (29) when a predetermined criterion is met, the criterion depending on the pressure in the control pressure chamber (Ka.3) and / or the pressure in the downstream pressure chamber (Ka.2), and - otherwise closes the opening (29).

6. Supply arrangement according to claim 5, characterized in that the pressure regulator (1) comprises a housing (19) and a wall (12) separates the downstream pressure chamber (Ka.2) from the control pressure chamber (Ka.3), the wall (12) between the downstream pressure chamber (Ka.2) and the control pressure chamber (Ka.3) being movable or flexible relative to the housing (19) of the pressure regulator (1) in such a way that the volume of the downstream pressure chamber (Ka.2) and the volume of the control pressure chamber (Ka.3) are changeable, the movable or flexible wall (12) being in operative connection (14) with the closure (13) for the opening (29) in the partition (15).

7. Supply arrangement according to any of the preceding claims, characterized in that the supply arrangement comprises a pressure sensor (7.1) and a signalprocessing pressure regulation controller (3), the pressure sensor (7.1) being designed to measure a measure of the pressure at a measuring point (28.1) in the first duct (K.1), and the pressure regulation controller (3) being designed, depending on a signal from the pressure sensor (7.1), to cause the time course (P.1) of the pressure at the downstream pressure outlet (V.2) to follow the time course (P.2) of the pressure at the reference point (28.1) in the first duct (K.1), the measuring point (28.1) preferably being equal to the reference point (28.1).

8. Supply arrangement according to claim 7, characterized in that a downstream pressure chamber (Ka.2) that is connected to the second duct (K.2) via the downstream pressure outlet (V.2) of the pressure regulator (1) is formed inside the pressure regulator (1) and the pressure regulator (1) comprises a controllable pressure regulator actuator (16, 17, 18), the pressure regulation controller (3) being designed, depending on a signal from the pressure sensor (7.1), - to control the pressure regulator actuator (16, 17, 18) and - to cause, through the control, the time course (P.1) of the pressure in the downstream pressure chamber (Ka.2) to follow the time course (P.2) of the pressure at the reference point (28.1) in the first duct (K.1).

9. Supply arrangement according to claim 8, characterized in that the pressure regulator (1) comprises - an upstream pressure chamber (Ka.1) which is connectable or is at least temporarily connected to the first source (20) via the upstream pressure inlet (V.3), - a partition (15) having an opening (29) and - a closure (13), the partition (15) separating the upstream pressure chamber (Ka.1) from the downstream pressure chamber (Ka.2), the opening (29) in the partition (15) connecting the upstream pressure chamber (Ka.1) to the downstream pressure chamber (Ka.2), the closure (13) being capable of selectively opening or closing the opening (29) in the partition (15) and the pressure regulator actuator (16, 17, 18) being in operative connection (14) with the closure (13).

10. Supply arrangement according to either claim 8 or claim 9, characterized in that a wall (12) of the downstream pressure chamber (Ka.2) is movable relative to another wall (19) of the downstream pressure chamber (Ka.2) in such a way that the volume of the downstream pressure chamber (Ka.2) is changeable, the pressure regulator actuator (16, 17, 18) being in operative connection (14) with the movable wall (12).

11. Supply system for supplying a patient-side coupling unit (9) with a gas mixture comprising a first gas component (air) and a second gas component (O2), wherein the supply system comprises - a first source (2, 25), - a second source (20) and - a supply arrangement according to any of the preceding claims, wherein the first source (2, 25) is designed to provide the first gas component (air), wherein the second source (20) is designed to provide the second gas component (O2), wherein a fluid connection is establishable or is at least temporarily established between the supply connection element (V.1) of the supply arrangement and the first source (2, 25) and wherein a fluid connection (21) is establishable or is at least temporarily established between the upstream pressure inlet (V.3) of the pressure regulator (1) and the second source (20) (20).

12. Supply system according to claim 11, characterized in that the second source (20) provides the second gas component (O2) at a higher pressure than the first source (2) provides the first gas component (air).

13. Ventilation system (100) for artificial ventilation of a patient (Pt) with a gas mixture comprising a first gas component (air) and a second gas component (O2), wherein at least one of the two gas components (air, O2) is oxygen or contains oxygen, wherein the ventilation system comprises - a fluid delivery unit (2), - a patient-side coupling unit (9) and - a supply arrangement according to any of claims 1 to 10 or a supply system according to either claim 11 or claim 12, the patient-side coupling unit (9) being connectable or at least temporarily connected to a patient (Pt), wherein a fluid connection is establishable or is at least temporarily established between the supply connection element (V.1) of the supply arrangement and a first source (2, 25), namely a source for the first gas component (air), wherein the fluid guide unit (2) is designed to deliver the first gas component (air) from the first source (2, 25) through the first duct (K.1) to the mixing point (8), wherein a fluid connection (21) is established or is at least temporarily establishable between the upstream pressure inlet (V.3) of the pressure regulator (1) and a second source (20), namely a source for the second gas component (O2), and wherein the ventilation system (100) is designed - to carry out ventilation strokes and - to direct in each ventilation stroke a quantity of the gas mixture through the inspiratory duct (K.30) to the patient-side coupling unit (9).

14. Ventilation system (100) according to claim 14, characterized in that the first valve (4.1) is designed to change the volume flow through the first duct (K.1), the controller (3) being designed - to derive a target course of the volume flow of the first gas component (air) depending on a predetermined target time course of the volume flow (Vol') of the gas mixture and - to control the first valve (4.1) using the control objective such that the actual volume flow through the first duct (K.1) equals the derived target course of the volume flow of the first gas component (air).

15. Ventilation system (100) according to either claim 13 or claim 14, characterized in that the ventilation system (100) comprises a second valve (4.2), the second valve (4.2) being designed to change the volume flow through the second duct (K.2), and the controller (3) being designed - to derive a target course of the volume flow of the second gas component (O2) depending on a predetermined target time course of the volume flow (Vol') of the gas mixture and - to control the second valve (4.2) using the control objective such that the actual volume flow through the second duct (K.2) equals the derived target course of the volume flow of the second gas component (O2).