Anesthetic dispenser with feed unit and anesthetic agent tank and method of using an anesthetic dispenser

Abstract

The invention relates to an anaesthetic dispenser (100) having a feed unit (9) and an anaesthetic tank (7). In the feed unit, anaesthetic from the anaesthetic tank (7) is mixed with a carrier gas. Liquid anaesthetic (Nm) can be refilled into the anaesthetic tank (7) through a refill opening (6). A predefined operating pressure is maintained in the operating mode. A closure (16) can be moved from a closed position via an intermediate position into an open position and closes the refill opening (6) in both the closed position and the intermediate position. A transition period elapses when the closure (16) is moved from the closed position into the intermediate position. A position sensor (22) detects the event that the closure (16) has moved out of the closed position. In response to this detection, the pressure in the anaesthetic tank is reduced during the transition period to a refill pressure which is still higher than the ambient pressure. The closure (16) is then opened.

Description

Technical Field

[0001] This invention relates to an anesthetic dispenser having a feed unit and an anesthetic canister. In the feed unit, anesthetic from the anesthetic canister is added to a carrier gas, thereby generating a gas mixture comprising the anesthetic. Furthermore, this invention relates to a method for generating this gas mixture using such an anesthetic dispenser. Background Technology

[0002] This type of anesthetic dispenser is typically used to generate a gaseous anesthetic from a liquid anesthetic and to supply the patient with a gaseous mixture comprising a carrier gas and the gaseous anesthetic. The patient is then temporarily anesthetized using this gaseous mixture.

[0003] Various types of anesthetic dispensers are well-known.

[0004] EP2170447B1 and US10406313B2 describe an anesthetic vaporizer (anesthetic vaporizer 100) having an anesthetic canister (container 107 for receiving liquid anesthetic 106). A sealing opening (a protective member in the form of a cap 90) closes a refill opening (refill port 18) through which anesthetic 106 can be refilled into the anesthetic canister 107, and the refill opening includes a valve (a valve system with a filling valve 101). A level sensor (level sensor 102) measures the current level of anesthetic in the anesthetic canister 107. A pressure sensor (pressure sensor 104) measures the pressure in the anesthetic canister 107. A first sensor (93, 74) determines whether the closure 90 is open or closed. A second sensor 78 determines whether a vial of anesthetic has been inserted into the refill opening 18. A syringe valve (syringe valve 111) injects anesthetic into a mixing chamber (chamber 112), and a carrier gas is introduced into the measuring chamber 112 through an inlet (inlet 113). In order to ensure that the anesthetic can be supplied to the patient even when it is refilled into canister 107, the anesthetic is temporarily stored in a buffer storage unit (secondary storage unit 22).

[0005] Devices for supplying liquid anesthetics to an anesthetic dispenser and refilling anesthetics into an anesthetic canister are also described in US2019 / 0117921A1, WO2020 / 030408A1, WO2020 / 167737A1, WO2008 / 151668A1 and WO2005 / 056093A1. Summary of the Invention

[0006] The objective of this invention is to provide anesthetic dispensers and methods for generating gas mixtures comprising anesthetic agents and carrier gases that are mechanically simpler to construct than known anesthetic dispensers and methods while having similar operational safety.

[0007] This task is accomplished by an anesthetic dispenser having the features of claim 1 and by a method having the features of claim 11. Advantageous designs are described in the dependent claims. An advantageous design of the anesthetic dispenser is also an advantageous design of the method, if it is meaningful, and vice versa.

[0008] The anesthetic dispenser according to the invention includes -Feed-in unit, -Anesthetic canister with refill opening, -A closure used for refilling openings. -Anesthetic tubing from the anesthetic canister to the feed unit -Controllable boosting unit and controllable depressurization unit, - Pressure sensor, - Position sensors for closures, and - Control equipment for processing signals.

[0009] The method according to the invention is performed using this anesthetic dispenser.

[0010] The anesthetic dispenser is designed to provide a gas mixture capable of anesthetizing a patient. The gas mixture includes at least one gaseous anesthetic, optionally multiple anesthetics, and a carrier gas, wherein the carrier gas includes oxygen. The carrier gas may be a mixture of multiple gaseous components.

[0011] Anesthetic agents can flow from the anesthetic agent canister through anesthetic agent tubing to the feed unit. The term "tubing" refers to a rigid or flexible fluid delivery unit, particularly a smooth hose, corrugated hose, or pipe.

[0012] The gas mixture is generated in the feed unit by mixing one or more anesthetic agents (preferably each delivered anesthetic agent) with a carrier gas, wherein the anesthetic agent is preferably fed into the carrier gas flow by, for example, injecting, vaporizing, or evaporating the anesthetic agent into the carrier gas flow.

[0013] The anesthetic dispenser can operate in one operating mode. When operating in this mode, at least one anesthetic agent, preferably a liquid anesthetic agent, is delivered from the anesthetic agent tank to the feed unit, and one or more delivered anesthetic agents are mixed with a carrier gas, preferably in the feed carrier gas.

[0014] According to the invention, one or each anesthetic agent used is mixed with the carrier gas, preferably fed into the carrier gas stream. In one design, the carrier gas is a mixture of at least two carrier gas components, and the anesthetic agent is mixed with a gas mixture consisting of the carrier gas components. In another design, breathing air or a mixture of breathing air and other gases flowing to the patient is used as the carrier gas. Optionally, breathing air, as a carrier gas or belonging to the carrier gas, flows from the medical device, particularly a ventilator, to the patient in the breathing circuit and returns to the medical device. The anesthetic agent or one of the anesthetic agents is fed into the carrier gas comprising the breathing air. Alternatively, a carrier gas, preferably generated from at least two carrier gas components, can be fed into the breathing air stream at a first feed point, and the anesthetic agent can be fed into the breathing air stream at a spatially spaced second feed point.

[0015] The pressure sensor measures the actual pressure inside the anesthetic canister and generates a signal indicating the measured pressure. The control device can... - Receive and process the pressure signal. - The pressure increase in the anesthetic canister is triggered and preferably terminated by operating the pressurization unit via the control device. - The pressure reduction in the anesthetic canister is triggered and preferably terminated by operating the decompression unit via the control device.

[0016] The pressurization unit and the depressurization unit can be implemented by the same component that can operate in different modes, or they can be implemented by different components.

[0017] In this operating mode, the actual pressure in the anesthetic canister is at or above a pre-defined operating pressure. This operating pressure is higher than the ambient pressure and can vary over time. The ambient pressure is the current atmospheric pressure in the environment surrounding the anesthetic canister and is either pre-defined or measured. The control device receives the pre-defined or measured ambient pressure value.

[0018] The control device causes the actual pressure in the anesthetic canister to be equal to or higher than the operating pressure in the operating mode. The operating pressure is higher than the ambient pressure. In one design, a predetermined rated operating pressure is provided, which must be observed in the operating mode. This rated operating pressure may be constant or variable over time. The control device performs automatic adjustment with the goal of making the actual pressure in the anesthetic canister equal to the predetermined rated operating pressure. In one design, the control device performs unilateral adjustment with the goal of making the actual pressure equal to or higher than the operating pressure.

[0019] Overpressure in the anesthetic canister relative to ambient pressure facilitates the delivery of anesthetic to the feed unit. Overpressure eliminates the need for a pump to deliver the anesthetic. Furthermore, overpressure reduces the risk of the generally undesirable event of gaseous anesthetic, carrier gas, or other gases or gas mixtures flowing back from the feed unit to the anesthetic canister. In particular, this results in the formation of air bubbles in the liquid.

[0020] It is possible that at least two different anesthetic agents are delivered to the feed unit and mixed sequentially or simultaneously with the carrier gas, thus producing a gas mixture comprising at least two different anesthetic agents. It is also possible that a gas containing at least one anesthetic agent and additional gaseous components such as breathing air or pure oxygen is delivered to the feed unit, and additional anesthetic agents are added there. Hereinafter, for simplicity, "anesthetic agent" will be used and should be understood as "at least one anesthetic agent".

[0021] The anesthetic in the anesthetic canister is consumed, especially since it is used to anesthetize at least one patient. Therefore, the anesthetic must be refilled periodically. According to the invention, the refill opening allows anesthetic to be added to the anesthetic canister, thereby filling it. This anesthetic may come from a container, particularly a bottle, or from a supply line.

[0022] Typically, refilled anesthetics are liquid at room temperature. However, many anesthetics have boiling points that are typically found in enclosed spaces, particularly below 40°C, meaning the anesthetic may evaporate easily. It is desirable that neither gaseous nor liquid anesthetics escape into the environment surrounding the anesthetic dispenser.

[0023] The closure of the refill opening can be moved from a closed position to an open position. In the closed position, the closure seals the refill opening, preferably in a fluid-tight manner, so that no anesthetic can escape from the anesthetic canister into the environment, and no fluid can flow into the anesthetic canister from the outside. The term "fluid-tight" includes the possibility that an unavoidable gap still exists between the closure and the anesthetic canister, and therefore the refill opening cannot be closed in an absolutely fluid-tight manner.

[0024] When the anesthetic dispenser is in operating mode, the closure is in the closed position. When the closure is in the open position, the anesthetic dispenser is in refill mode. In the open position, the closure allows anesthetic to flow from a reservoir (e.g., from a refill container or a fixed supply connection) into the anesthetic tank and thereby fill the tank. In one design, the closure includes a conduit to guide the anesthetic into the anesthetic tank.

[0025] During the transition of the closure from the closed position to the open position, the closure reaches an intermediate position. In this intermediate position, the closure also seals the refill opening and thus prevents a large amount of anesthetic from escaping from the anesthetic canister into the environment. At least one transition period occurs during the movement of the closure from the closed position to the intermediate position.

[0026] According to the present invention, the position sensor automatically detects an event that the closure has moved out of the closed position. The position sensor is designed such that the event is detected before the closure reaches the intermediate position, i.e., during the transition period, preferably in the first quarter of the transition period. Because of the position sensor, no manual user input is required to determine that the closure has now moved. Instead, the event is automatically detected by the position sensor, and a message containing this information is automatically transmitted to the control device. It is possible, but not necessary, to detect the event that the closure has reached the intermediate position.

[0027] In response to receiving a message that the closure has been moved out of the closed position, the control device automatically triggers a pressure reduction step in the anesthetic canister. To trigger the pressure reduction, the control device manipulates the pressure reduction unit. This reduction is performed during a transition period, causing the pressure to drop and become below the operating pressure. However, at least during the transition period, the pressure in the anesthetic canister remains above ambient pressure, and the closure still seals the refill opening. In other words, during the transition period, there is primarily an overpressure relative to the environment in the anesthetic canister. Because the closure seals the refill opening, a significant amount of anesthetic is still not allowed to escape into the environment.

[0028] Preferably, a rated transition pressure is pre-set, which is lower than the rated operating pressure and higher than the ambient pressure, and can be constant or variable over time.

[0029] In one design, the length of the transition period is fixed and predetermined. Preferably, this transition period is at least 5 seconds, particularly preferably at least 10 seconds, and especially at least 30 or 60 seconds. In another design, the transition period ends when a predetermined event occurs, which depends on the actual pressure in the anesthetic canister. For example, this event occurs when the actual pressure drops to a predetermined rated transition pressure. Combinations are also possible: the transition period ends when the shortest possible time period has elapsed and the predetermined event occurs, depending on what subsequent events occur.

[0030] In one design, the control device performs adjustment during a transition period. The objective of this adjustment is to ensure that the actual pressure in the anesthetic canister equals the rated transition pressure during the transition period.

[0031] According to the invention, at least the transition period occurs between the detection that the closure has been removed from the closed position and the opening of the refill opening. Therefore, during this transition period, the refill opening remains closed. Thus, during this transition period, no anesthetic can escape from the anesthetic container into the environment through the refill opening. Escape of anesthetic into the environment is undesirable, as it could cause suffering to people. Furthermore, anesthetic is wasted when it escapes into the environment.

[0032] The control device reduces the pressure in the anesthetic canister in response to detecting that the closure has been removed from the closed position. After this reduction, the pressure in the anesthetic canister is below the operating pressure but still above the ambient pressure. Therefore, it may be possible, but is not necessary, for the refill container or refill opening containing the anesthetic to withstand the operating pressure. It is sufficient for the refill container or refill opening to withstand the lower pressure reached during the transition period. Even at this lower pressure, the anesthetic will not escape from the anesthetic canister into the environment because the closure remains closed.

[0033] During the transition period, the pressure in the anesthetic tank is also maintained above ambient pressure. In many cases, the operating pressure, along with the reduced pressure above ambient pressure, reduces the risk of anesthetic or carrier gas or other gases flowing back into the anesthetic tubing from the anesthetic tank to the feed unit. This is generally undesirable because the anesthetic tubing is supposed to guide liquid anesthetic into the feed unit, where a gaseous mixture of gaseous anesthetic with a predetermined concentration should be generated. Backflow from the feed unit into the anesthetic tubing can cause air bubbles to form within it. Air bubbles in the anesthetic tubing can lead to an undesirable gaseous mixture in the feed unit with incorrect anesthetic concentrations and / or anesthetic concentrations that vary drastically with time and / or location.

[0034] This invention can be used in conjunction with a buffer reservoir for anesthetics. In one possible implementation, the buffer reservoir contains liquid anesthetic and is located between the anesthetic tank and the feed unit. In another possible implementation, the buffer reservoir contains a gas mixture comprising at least one anesthetic and is arranged downstream of the feed unit. The invention can also be combined with two buffer reservoirs, one upstream of the feed unit and one downstream. However, the invention eliminates the need for such a buffer reservoir. Therefore, the invention saves space and results in a simpler mechanical structure. Furthermore, the absence of a buffer reservoir also eliminates the need to monitor its airtightness.

[0035] After the transition period has passed, the refill opening is opened preferentially, for example by means of an actuator that removes the closure from the closed position. Alternatively, the refill opening can be opened manually, for example by unlocking the closure element so that the closure element can be removed from the refill opening and the user can remove the closure from the refill opening.

[0036] In one design of the invention, a desired or required value for the transition time period is predetermined. For example, the mechanical structure of the closure predetermines the transition time period: after the closure is moved from the closed position, the refill opening remains closed during the transition time period, even after the closure has begun to move.

[0037] In one implementation, the enclosure can be moved by means of an actuation unit, and a reduction gear is arranged between the actuation unit and the enclosure to allow the transition time to pass. Due to this reduction gear, the actuator only needs to apply a relatively small force. Alternatively, the enclosure may be difficult to move due to structural reasons.

[0038] In one implementation, the closure is moved relative to the refill opening by two consecutive movements from a closed position to an open position. During the first movement, the closure rotates relative to the refill opening, for example, along a thread, until it reaches an intermediate position. During the second movement, the closure is removed from the refill opening, preferably by a linear movement parallel to the longitudinal axis of the refill opening. This movement process is known from the process of opening a fuel tank cap for a vehicle with an internal combustion engine. A position sensor detects the start of the first (i.e., rotational) movement.

[0039] In another implementation, the closure comprises an actual closure element and a flap. The closure element is located between the flap and the anesthetic canister. To open the refill opening, the flap is first opened, and then the closure element is removed from the refill opening. The flap protects the closure element from mechanical damage and contamination. Furthermore, the flap reduces the risk of accidentally opening the closure element.

[0040] These two implementations can be combined: the sealing element is located between the flip-top and the anesthetic canister, and can be moved out of the refill opening by rotation and further movement.

[0041] In a preferred design, the position sensor is designed to detect the start of the process where the flip-top has moved out of the closed position. In many cases, this design results in a relatively long transition period: this transition period ends at the earliest when the flip-top is fully open and the actual closure element can now be removed or otherwise opened. During this transition period, even when the flip-top is open, the closure element keeps the anesthetic canister closed, preventing anesthetic leakage. Alternatively, the position sensor may detect the process of the closure element moving out of the closed position.

[0042] In another design, a desired or required refill pressure value is predefined, wherein this predefined refill pressure value is higher than the ambient pressure but lower than the operating pressure. It is not necessary to predefine the length (duration) of the transition period in this alternative design. In one design, the refill pressure value is higher than the maximum respiratory pressure—the maximum pressure applied by the ventilator when performing artificial respiration on a patient and anesthetizing the patient using the generated gas mixture.

[0043] Upon detecting an event that the closure has moved out of the closed position, the control device causes the pressure in the anesthetic canister to decrease from the operating pressure to a predetermined refill pressure via pressure control or pressure regulation. The transition period ends when the pressure in the anesthetic canister reaches the predetermined refill pressure. Therefore, the length of the transition period depends on the rate at which the pressure in the anesthetic canister decreases to the refill pressure. This length does not need to be predetermined.

[0044] In this extended design, the control device is capable of manipulating a blocking unit to close the refill opening. The blocking unit remains closed, thereby keeping the refill opening closed during the transition period, i.e., until the pressure in the anesthetic canister drops to the refill pressure.

[0045] On the one hand, the refill pressure can be set low enough that the refill container and refill opening containing the liquid anesthetic can withstand the refill pressure without being damaged, and without the anesthetic escaping from the anesthetic tank into the environment. On the other hand, the refill pressure can be set high enough that the risk of the gas mixture flowing back from the feed unit through the anesthetic line to the anesthetic tank is minimal. The liquid anesthetic should normally flow through the anesthetic line. Such backflow of the gas mixture can cause air bubbles to form in the anesthetic line, which, as explained above, is undesirable. A sufficiently high refill pressure reduces the risk of such air bubbles forming in the anesthetic line.

[0046] If the refill pressure is too low, these air bubbles may appear, particularly due to the respiratory pressure applied by the ventilator during the patient's artificial respiration and anesthesia. Therefore, the pre-set refill pressure is preferably at least as high as the maximum respiratory pressure, and particularly preferably even higher than the maximum respiratory pressure, especially at least 20% higher.

[0047] According to the invention, the anesthetic tubing guides the anesthetic from the anesthetic canister to the feed unit. Typically, at common ambient temperatures (room temperature) between 10°C and 40°C, the anesthetic in the tubing is liquid. In a preferred embodiment, the control device is capable of operating the anesthetic delivery unit, particularly the injection valve. Depending on the operation, the anesthetic delivery unit selectively delivers the anesthetic from the tubing to the feed unit or shuts off. In one implementation, a shut-off anesthetic delivery unit blocks the anesthetic tubing. When the anesthetic dispenser is operating in operating mode, the anesthetic delivery unit delivers the anesthetic to the feed unit.

[0048] According to the invention, the position sensor detects an event that the closure has moved out of the closed position. Preferably, the control device shuts down the anesthetic delivery unit in response to the detection of this event. This design reduces the risk that the anesthetic delivery unit may attempt to deliver anesthetic even when the pressure is too low.

[0049] According to the invention, the position sensor detects an event that the closure has moved out of the closed position. This detection triggers a control device to reduce the pressure in the anesthetic canister. In one design, the anesthetic dispenser includes a treatment line leading from the anesthetic canister to a gas inlet or to the environment, preferably to a fixed treatment connection. A controllable treatment blocking device can selectively release or block the treatment line. The treatment line and the treatment blocking device are part of a pressure reduction unit. If the anesthetic dispenser is operating in operating mode, the treatment line is blocked. After detecting an event that the closure has moved out of the closed position, the control device manipulates the treatment blocking device, and the manipulated treatment blocking device releases the treatment line. Gaseous anesthetic can then be discharged from the anesthetic canister through the treatment line, thereby reducing the pressure in the anesthetic canister. The treatment line preferably leads to an inlet or to the environment.

[0050] This design further reduces the risk of anesthetic leakage into the environment of the anesthetic dispenser. It is possible, but not necessary, to include a buffer reservoir that holds the anesthetic when pressure drops and dispenses it again later.

[0051] The present invention also relates to a system designed for anesthetizing a patient. The system includes a ventilator designed to deliver a gas mixture comprising at least one anesthetic agent and oxygen to the patient and thereby anesthetize the patient. The ventilator preferably performs a series of breathing strokes and delivers a quantity of the gas mixture to the patient in each of these breathing strokes. The system also includes an anesthetic agent dispenser according to the invention. The anesthetic agent dispenser is in fluid communication with the ventilator. A gas mixture comprising at least one anesthetic agent and a carrier gas containing oxygen is delivered to the ventilator through this fluid communication, wherein the gas mixture has been generated in or by the feed unit of the anesthetic agent dispenser.

[0052] Preferably, the ventilator generates a time-varying, particularly oscillating, respiratory pressure during artificial respiration. Particularly preferably, the ventilator performs a series of respiratory strokes. Preferably, the pressure in the anesthetic canister is maintained both during operation of the anesthetic dispenser in operating mode and during transition periods above the maximum respiratory pressure established by the ventilator. This reduces the risk of the gas mixture returning from the ventilator to the feed unit and further into the anesthetic tubing, where it can generate bubbles. Attached Figure Description

[0053] The present invention will now be described based on embodiments. Figure 1 The first embodiment of the present invention is shown; Figure 2 Detailed views illustrate an embodiment of the closure. Figure 3 It shows that according to Figure 1 Modifications to the first implementation method; Figure 4 A second embodiment of the present invention is shown; Figure 5 A third embodiment of the present invention is shown; Figure 6 An exemplary time-varying process of pressure change in the anesthetic canister during refilling is shown. Detailed Implementation

[0054] In an embodiment, the invention is used in an anesthesia system. This anesthesia system supplies a patient P who is fully or at least partially anesthetized with a gas mixture comprising oxygen and / or breathing air and at least one gaseous anesthetic agent. The anesthesia system includes a ventilator and at least one anesthetic agent dispenser according to the invention. Optionally, a second anesthetic agent dispenser according to the invention is provided as a backup.

[0055] In this embodiment, the anesthetic is mixed with a carrier gas. The carrier gas includes at least one of breathing air, oxygen (O2), and nitrous oxide (N2O), preferably two or all three. The carrier gas is generated from a carrier gas component, and the anesthetic is fed into this carrier gas. The anesthesia system supplies the patient with a gaseous mixture comprising the carrier gas and evaporated anesthetic.

[0056] Figure 1 and Figures 3 to 5 Several alternative embodiments of the anesthetic dispenser 100 according to the present invention are shown. Reference is made first to... Figure 1 The first embodiment is described. The ventilator 40 is connected to a patient-side coupling unit 43 via a tubing device 35. The patient-side coupling unit 43 is connected to the patient P and includes, for example, a breathing mask on the patient P's face or a tube or catheter within the patient P's body. Preferably, the tubing device 35 includes a double-lumen flexible tube, thereby establishing a breathing circuit between the patient P and the ventilator 40. This ensures that exhaled gas from the patient P, which may contain anesthetic, returns to the ventilator 40 and does not escape into the environment. The delivery unit of the ventilator 40 maintains the breathing circuit in operation.

[0057] During artificial respiration, the ventilator 40 performs a series of respiratory strokes. For each ventilation stroke, the ventilator 40 generates a pressure in the breathing circuit that is higher than ambient pressure and varies over time. The maximum pressure generated by the ventilator 40 during artificial respiration is referred to as the "maximum respiratory pressure." This maximum respiratory pressure is typically 20 to 30 hPa higher than ambient pressure.

[0058] Figure 1 An anesthesia system 200, designed to anesthetize patient P and including an anesthetic dispenser 100, is also schematically shown.

[0059] A supply connection 20 is installed in the wall W, which provides the components of the carrier gas, preferably under overpressure. The carrier gas components are delivered to a carrier gas mixer 44, which generates carrier gas from the delivered components. The carrier gas mixer 44 can be constructed as described in DE102008057180B3.

[0060] Carrier gas is delivered to the mixing tank 9 of the anesthetic dispenser 100 via carrier gas line 10. The mixing tank 9 is part of the feed unit in this embodiment. Liquid anesthetic Nm at room temperature is delivered to the mixing tank 9 via anesthetic line 21. Both the mixing tank 9 and the anesthetic line 21 belong to the anesthetic dispenser 100, which generates a gaseous anesthetic from the delivered liquid anesthetic Nm and mixes it with the carrier gas. In the illustrated embodiment, heater 26 comes into thermal contact with the mixing tank 9 and evaporates or vaporizes the delivered liquid anesthetic Nm. The gaseous mixture of carrier gas and gaseous anesthetic is delivered to the ventilator 40 via gas mixture line 11.

[0061] In one design, the anesthetic dispenser 100 includes a controllable injection valve 8, which can be opened and closed and serves as an anesthetic delivery unit. When open, the injection valve 8 injects liquid anesthetic Nm into the mixing tank 9. When closed, the injection valve 8 does not inject anesthetic and preferably blocks the anesthetic line 21, thus preventing gas from flowing to the anesthetic tank 7. Preferably, the volumetric flow rate used by the injection valve 8 to inject the liquid anesthetic can be varied to ensure a desired concentration of anesthetic Nm in the gas mixture generated in the mixing tank 9. The volumetric flow rate of the carrier gas through the carrier gas line 10 can also be additionally or alternatively varied. Both measures can help achieve a predetermined concentration of anesthetic in the gas mixture with tolerances.

[0062] Liquid anesthetic Nm is stored in anesthetic tank 7 and flows from tank 7 to mixing tank 9 via anesthetic line 21. In anesthetic tank 7, the liquid anesthetic Nm is under overpressure relative to ambient pressure. More precisely, the gas above the liquid anesthetic Nm in anesthetic tank 7 is under overpressure. Due to this overpressure, a pump is not required to deliver the liquid anesthetic Nm to mixing tank 9. Instead, the overpressure associated with injection valve 8 causes the liquid anesthetic Nm to flow from anesthetic tank 7 into mixing tank 9 via anesthetic line 21.

[0063] The overpressure in the anesthetic canister 7 should remain constant over time or follow a predetermined time-varying process. For example, the overpressure should be at least 1 bar higher than the ambient pressure, preferably 2 bar. This overpressure is referred to below as the "operating pressure". The following example describes how to adjust or control the overpressure.

[0064] Discharge line 3 connects the anesthetic canister 7 to a disposal connection 24 in the wall W. This disposal connection 24 is in fluid communication with a fixed fluid network. A controllable valve 4 is arranged in the discharge line 3. When valve 4 is open, gaseous anesthetic can flow through the discharge line 3 to the disposal connection 24. This reduces the pressure in the anesthetic canister 7 and prevents the anesthetic from escaping into the environment. Check valve 12 prevents gas from flowing from the disposal connection 24 through the discharge line 3 into the anesthetic canister 7.

[0065] Pressure sensor 5 measures the current pressure in anesthetic canister 7. Preferably, pressure sensor 5 measures the overpressure of the gas in anesthetic canister 7 relative to ambient pressure. Pressure in anesthetic canister 7 is built up and can be increased by introducing compressed air or other overpressurized gas from connection 23 in wall W through pressure line 1 into anesthetic canister 7. Controllable valve 2 in pressure line 1 can selectively fully open or fully close pressure line 1 at two end positions. Valve 2 may optionally be designed as a proportional valve or an on / off valve. To increase the pressure in anesthetic canister 7, valve 2 is opened. When valve 2 is closed, the pressure inside anesthetic canister 7 decreases automatically as liquid anesthetic Nm flows out of anesthetic canister 7 through anesthetic line 21.

[0066] Furthermore, the pressure in the anesthetic canister 7 can be controllably reduced by opening valve 4 and allowing gas to flow through discharge line 3 to disposal connection 24. If the pressure in the anesthetic canister 7 exceeds the pressure barrier that opens check valve 12, check valve 12 opens in the flow direction. In one design, the pressure barrier that causes check valve 12 to open can be changed by external control. In another design, the pressure barrier is pre-set by the design of check valve 12, particularly by the ratio of the opening area of ​​check valve 12 to the spring force, thus eliminating the need for external control.

[0067] Preferably, in the operating mode, the pressure in the anesthetic canister 7 is adjusted to maintain a constant operating pressure. This operating pressure allows the desired concentration of anesthetic Nm to be produced in the gas mixture in the mixing tank 9. In one design, the actual pressure in the anesthetic canister 7 is adjusted such that the actual pressure is always equal to a pre-given rated operating pressure.

[0068] The liquid anesthetic Nm in the anesthetic tank 7 is gradually consumed. A measure is taken of the amount of liquid anesthetic Nm currently present in the anesthetic tank 7. In this embodiment, the level sensor 17 includes a float and measures the current level of the liquid anesthetic Nm in the anesthetic tank 7. As an alternative to or addition to the level sensor 17, an observation window 18 is provided in the wall of the anesthetic tank 7. A person or camera can perceive the current level through the observation window 18.

[0069] The control device 33, which processes signals, receives measurements from sensors 5, 17, and 22 and automatically controls valves 2, 4, 8, and 19.

[0070] Since the anesthetic Nm is consumed, it needs to be refilled periodically. The anesthetic container 7 is equipped with tubular refill openings 6 (n>=3) with circular or n corners, which guide the liquid anesthetic into the container 7. In this embodiment, a bottle 30 containing the liquid anesthetic can be placed above the refill opening 6, and the liquid anesthetic flows from the bottle 30 downwards through the refill opening 6 into the container 7. Therefore, the bottle 30 can be placed on the refill opening 6 such that only a small amount of anesthetic escapes, ideally none at all.

[0071] The closure 16 is movable between a closed position and an open position. In the open position, the closure 16 allows liquid anesthetic Nm to flow from the bottle 30 through the refill opening 6 into the anesthetic container 7. In the closed position, the closure 16 seals the refill opening 6 in a fluid-tight manner and prevents liquid or gaseous anesthetic from escaping from the anesthetic container 7 into the environment.

[0072] Figure 2 A detailed view of a preferred embodiment of the refill opening 6 and the closure 16 is shown. The tubular, circular, or n-cornered refill opening 6 extends along a longitudinal axis LA. According to this embodiment, the closure 16 includes a closing element 27 capable of selectively closing or releasing the refill opening 6. For example, the closing element 27 is held in the refill opening 6 in a fluid-tight manner by means of two corresponding threads arranged on the outer wall of the closing element 27 or the inner wall of the refill opening 6. To release the refill opening 6, the closing element 27 is removed from the refill opening 6 by two consecutive movements in time. During the first movement, the closing element 27 rotates about the longitudinal axis LA of the refill opening 6, for example, rotating within the threads of the refill opening 6. After the first movement, the closing element 27 reaches an intermediate position where it still closes the refill opening 6. During the second movement, the closing element 27 is removed from the refill opening 6, preferably by a linear movement parallel to the longitudinal axis LA, causing the refill opening 6 to open. This two-movement process is known from the process of opening a fuel tank cap for a vehicle with an internal combustion engine.

[0073] In one design, the closure 16 further includes a flap 28. A closing element 27 is located between the flap 28 and the anesthetic canister 7. The closing element 27 closes the refill opening 6 both when the flap 28 is closed and open. To open the closure 16, the flap 28 is first opened, and then the closing element 27 is removed from the refill opening 6. In designs with the flap 28, the closing element 27 is also removed from the refill opening 6 by either two consecutive movements as just described or by a single movement. The state where the flap 28 is open and the closing element 27 is still in the refill opening 6 can be referred to as the intermediate position of the closure 16. The chain 29 preferably holds the flap 28 on the refill opening 6, thus preventing the flap 28 from being lost.

[0074] The position sensor 22, schematically shown, detects an event that the flip cover 28 has moved out of the closed position. In designs with the flip cover 28, more time is available after the event that the flip cover 28 has been moved is detected before the refill opening 6 is opened.

[0075] In the design without the flip cover 28, the position sensor 22 detects an event that the closing element 27 has moved out of the closed position. In the design with the flip cover 28, the position sensor 22 can also detect the movement of the closing element 27.

[0076] also, Figure 2 The diagram shows a blocking unit 32 capable of selectively blocking or releasing the closing element 27. The closing element 27, blocked by the blocking unit 32, remains within the refill opening 6 and, preferably, can move back and forth between a closed position and an intermediate position, cannot be removed from the refill opening 6. Thus, the blocked closing element 27 seals the refill opening 6. When the blocking unit 32 has released the closing element 27, the closing element 27 can be removed from the refill opening 6.

[0077] In one design, a presence sensor (not shown) determines whether a closing element 27 is actually present in the refill opening 6 when the flip cover 28 is closed. The absence of the closing element 27 when the flip cover 28 is closed is an error. If the absence of the closing element 27 in the refill opening 6 when the flip cover 28 is closed is detected, an alarm is preferably generated in a human-perceptible manner. Therefore, if the flip cover 28 is opened without the closing element 27, the pressure in the anesthetic canister 7 will suddenly drop to ambient pressure and the anesthetic will escape, which is undesirable.

[0078] The refill opening 6 can be designed, for example, as described in WO2020 / 030408A1.

[0079] This invention enables the refilling of liquid anesthetic Nm while the patient P is connected to the ventilator 40 via the patient-side coupling unit 43 and is under anesthesia. Due to this invention, the supply of the anesthetic and carrier gas mixture to the patient P is only briefly interrupted, allowing the ventilator 40 to maintain the supply of anesthetic to the patient P during this brief interruption without any gas mixture flowing through the gas mixture tubing 11 to the ventilator 40. For example, the ventilator 40 includes its own buffer reservoir, and / or the gas mixture tubing 11 serves as a buffer reservoir. This prevents the patient P from waking up from anesthesia during refilling. This invention also reduces the risk of one of the following undesirable events occurring during the refilling of liquid anesthetic Nm: - Gaseous anesthetic escapes into the environment from the anesthetic canister 7 through the open refill opening 6.

[0080] - Due to the opening of the injection valve 8 or the gap between it and the mixing tank 9, and the low pressure in the anesthetic tank 7, gaseous anesthetic flows from the mixing tank 9 into the anesthetic line 21 and forms bubbles in the liquid anesthetic Nm in the anesthetic line 21.

[0081] - Due to the low pressure in the anesthetic tank 7, the carrier gas in the mixing tank 9 can no longer be rich in enough gaseous anesthetic.

[0082] - Due to the low pressure, the anesthetic Nm began to boil.

[0083] In this embodiment, the pressure in the anesthetic canister 7 is gradually reduced as the anesthetic Nm is refilled. This is described below.

[0084] The refill opening 6 cannot open abruptly, but only gradually and / or with a time delay. This time delay is due to the fact that the closing element 27 must first move to the intermediate position and / or the flip cover 28 must first be opened. A position sensor 22 on the refill opening 6 detects the event that the process of opening the refill opening 6 has begun. For example, the position sensor 22 detects the event that the first movement of the closing element 27 has begun, i.e., the closing element 27 rotates away from the closed position. Alternatively, the position sensor 22 detects the event that the flip cover 28 moves out of the closed position. The position sensor 22 may include a contact sensor, particularly a sensor that detects whether an electrical connection is closed or open. The position sensor 22 may also include, for example, a light barrier, an RFID sensor, and / or a Hall sensor.

[0085] Various such sensors are described in EP2170447B1. Detecting this event triggers the first step described below.

[0086] In the first step, the pressure inside the anesthetic container 7 is reduced from the operating pressure to a predetermined pressure. This pressure, generated during the refilling of anesthetic Nm, is referred to below as the "refill pressure." The refill pressure is less than the aforementioned operating pressure, but preferably greater than the ambient pressure, and is maintained with the refill opening 6 closed and sufficient anesthetic Nm in the anesthetic container 7. The predetermined refill pressure may depend on the anesthetic used.

[0087] Preferably, the refill pressure is higher than the maximum respiratory pressure generated by the ventilator 40 during artificial respiration of patient P. This reduces the risk of undesirable bubbles caused by respiratory pressure forcing the gas mixture back into the mixing tank 9 or even into the anesthetic tubing 21. In one design, this refill pressure is preferably 50 hPa to 100 hPa higher than ambient pressure. This refill pressure is generally sufficient to reliably prevent gaseous anesthetic from the mixing tank 9 from entering the anesthetic tubing 21. Furthermore, the bottle 30 on the refill opening 6 can withstand this pressure.

[0088] If the anesthetic Nm can boil and become liquid at room temperature, the refill pressure is higher. For example, desflurane has a boiling point of 23°C, therefore a refill pressure of 500 to 1000 hPa higher than ambient pressure is used. The bottle 30 containing this anesthetic can withstand this refill pressure. At this refill pressure, the injection valve 8 can be kept open, thus injecting the anesthetic Nm into the mixing tank 9 during refilling. This design is important, especially because the anesthetic effect of desflurane decreases rapidly when the delivery of the gaseous mixture containing desflurane to the patient P is reduced.

[0089] During the first step, the refill opening 6 preferably remains completely closed. For example, a radially acting seal keeps the refill opening 6 completely sealed during the first step. Even when the refill opening 6 is partially open, the free diameter of the refill opening 6 remains small enough at the end of the first step that only a small amount of anesthetic can escape from the anesthetic container 7 into the environment. During the first step, the closure 16 moves from the closed position to an intermediate position. For example, the flip-top 28 opens.

[0090] In one design, control device 33 can manipulate closure 16 or a blocking unit 32 for closure 16. This manipulation causes closure 16 to remain closed at refill opening 6 until the pressure in the anesthetic canister 7 decreases to the refill pressure and thus completes the first step. Only after this does control device 33 release closure 16, allowing it to move from the intermediate position to the open position. In another design, the mechanical construction of refill opening 6 ensures that it remains closed for a sufficiently long time without external control, particularly without manipulating the blocking unit. For example, closure 16 is made difficult to move so that a sufficiently long period of time passes before closure 16 reaches the intermediate position.

[0091] The first step ends when the pressure in anesthetic tank 7 has decreased or dropped to the pre-defined refill pressure. The first step can end by the passage of time or by the event that the pressure in anesthetic tank 7 drops to the refill pressure.

[0092] In the second step, the refill opening 6 is moved until it is fully open. For example, the sealing element 27 is removed from the refill opening 6. The bottle 30 is then placed airtight over the refill opening 6, and the liquid anesthetic Nm flows from the bottle 30 into the anesthetic container 7.

[0093] Two different designs are possible for the second step. In the first design, the bottle 30 and the connection between the bottle 30 and the refill opening 6 are pressure-resistant, allowing the connection to withstand the refill pressure generated in the anesthetic canister 7 during the first step. In this design, the injection valve 8 is preferably kept closed during the second step. The injection valve 8 can also be pre-closed. During the flow of liquid anesthetic Nm from the bottle 30 into the anesthetic canister 7, anesthetic Nm also flows from the anesthetic canister 7 into the mixing tank 9 via the anesthetic line 21 due to overpressure in the anesthetic canister 7.

[0094] In another design, it is also possible, but not necessary, that bottle 30 and the connection can withstand refill pressure. In this alternative design, bottle 30 is preferably in fluid communication with the environment. Conversely, in this alternative design, injection valve 8 is closed in the second step. When refill opening 6 is opened, the pressure in anesthetic canister 7 drops, i.e., drops below the refill pressure, and in extreme cases, drops to ambient pressure. In one design, overpressure persists in mixing canister 9. The refill pressure and the optionally closed injection valve 8 prevent the anesthetic or gas mixture from flowing back from mixing canister 9 into anesthetic canister 7. The gas mixture present in a buffer reservoir (not shown) of ventilator 40 is sufficient to continue supplying anesthetic to patient P for a certain period of time.

[0095] Once the bottle 30 is empty or the anesthetic canister 7 is full, the bottle 30 is pulled out of the refill opening 6 again, the refill opening 6 is closed, and the pressure in the anesthetic canister 7 is increased again, at least to the refill pressure, preferably to a pressure higher than the refill pressure, and particularly preferably to the operating pressure.

[0096] Figure 3 It shows that according to Figure 1 The first design variant. The same reference numerals have the same... Figure 1 The same meaning applies here. Valve 8 in the anesthetic tubing 21 is designed as a throttle valve. A second valve 19 can also block the anesthetic tubing 21 independently of the throttle valve 8. This design creates redundancy, especially in the event that valve 8 or 19 fails to close the anesthetic tubing 21 due to an error.

[0097] In another variant, not shown, check valve 12 is omitted. Valve 4 is an externally operable proportional valve. To reduce the pressure in anesthetic canister 7, valve 4 is first fully opened by operation. When the pressure measured in anesthetic canister 7 approaches a predetermined pressure from above, valve 4 partially closes. This design makes it easier to adjust the pressure in anesthetic canister 7 to the desired refill pressure in the first step.

[0098] Figure 4 A variation is shown where discharge line 3 is replaced by discharge line 3.1. The same reference numerals have the same... Figure 1 The same meaning applies here. The discharge line 3.1 to the treatment connection 24 branches off from the pressure line 1 at the branch point 25, where the pressure line 1 again guides compressed air from the supply connection 23 to the anesthetic tank 7.

[0099] To increase the pressure in the anesthetic canister 7, valve 13 is opened and valve 14 is closed. Check valve 15 in line 1 allows compressed air to be delivered from supply connection 23 to valve 2 and further to the anesthetic canister 7. To decrease the pressure in the anesthetic canister 7, valve 13 is closed and valve 14 is opened. In this case, spring-loaded check valve 12 maintains the remaining pressure in the anesthetic canister 7, such as refill pressure. Check valve 15 closes pressure line 1.

[0100] Figure 5 Another possible design is shown. The same reference numerals have the same... Figure 1 The same meaning as in [the context]. And according to [the context] Figure 4 The design is identical, with discharge line 3.1 branching off from pressure line 1 at branch point 25. To allow compressed air to flow into anesthetic tank 7, valve 13 is opened and valve 14 is closed. To reduce the pressure in anesthetic tank 7, valve 13 is closed and valve 14 is opened. When valve 2 is open, gas can flow through pressure line 1, and when valve 2 is closed, line 1 is shut off. Optionally, valve 2 is designed as a controllable proportional valve.

[0101] Figure 6 An exemplary time-varying process of pressure in anesthetic canister 7 during refilling is shown. Time t is plotted on the x-axis, and pressure P in anesthetic canister 7 is plotted on the y-axis, as overpressure relative to a reference pressure.

[0102] Control device 33, for example, maintains a constant operating pressure Pop until time point t1 by adjusting the opening 6 and valve 4. Figure 1 , Figure 3 ) and valve 14 ( Figure 4 , Figure 5 When closed, injection valve 8 delivers liquid anesthetic Nm, while valves 2 and 19 ( Figure 3 Valve 13 Figure 4 , Figure 5 Temporarily open to increase pressure P.

[0103] At time t1, the contact sensor (position sensor) 22 detects an event that the closure 16 has moved out of its closed position. In response to this detection, the control device 33 causes the pressure in the anesthetic canister 7 to drop above the ambient pressure P. env Refill pressure P fill Therefore, valves 2 and 13 ( Figure 4 , Figure 5 ) closed, and valve 4 ( Figure 1 , Figure 3 ) and valve 14 ( Figure 4 , Figure 5 Open. Injection valve 8 closes. Closure 16 moves from the closed position to the intermediate position and refills opening 6, keeping it closed.

[0104] At time t2, pressure sensor 5 detected that the pressure P inside the anesthetic canister 7 dropped to the refill pressure P. fill The time period from t1 to t2 is the transition period as defined in the claims. In response to this detection, control device 33 causes closure 16 to move or at least release to the open position, thereby opening or at least being able to open refill opening 6. At time t3, closure 16 is in the open position and refill opening 6 is open. Bottle 30 is placed on and enters refill opening 6. Liquid anesthetic Nm flows from bottle 30 into anesthetic tank 7. Due to the opening of refill opening 6, the pressure in anesthetic tank 7 further decreases. However, in this embodiment, pressure P remains above ambient pressure P. env .

[0105] If sufficient anesthetic Nm has flowed from bottle 30 into anesthetic container 7, bottle 30 is removed from refill opening 6. For example, level sensor 17 detects that anesthetic container 17 now contains sufficient liquid anesthetic Nm and outputs a corresponding message. Alternatively, the user may detect that bottle 30 is empty or anesthetic container 7 is full.

[0106] At time t4, bottle 30 is removed from refill opening 6 again. Closure 16 closes again. At time t5, contact sensor 22 detects that closure 16 is in the closed position again. During the time interval between t3 and t4, anesthesia system 200 is in refill mode.

[0107] In one design, the control device 33 automatically triggers at time t5 that the pressure P inside the anesthetic canister 7 rises again to the operating pressure P. opThe steps are as follows. Alternatively, a corresponding message is displayed to the user, requiring the user to confirm or refuse, and the control device 33 causes the pressure to increase after detecting the corresponding confirmed user input. In order to increase the pressure in the anesthetic canister 7, valves 2 and 19 are opened. Figure 3 ) or valve 13 ( Figure 4 , Figure 5 To increase the pressure P until the operating pressure P is reached. op Until then. Valve 4 ( Figure 1 , Figure 3 ) and valve 14 ( Figure 4 , Figure 5 () Close. In addition, injection valve 8 is reopened.

[0108] At time t6, pressure sensor 5 detected that the operating pressure P had been reached again. op At the latest, reconnect injection valve 8. Anesthesia system 200 is now back in operating mode.

[0109] In summary, the present invention relates to an anesthetic dispenser having a feed unit and an anesthetic canister, and a method for generating a gas mixture using such an anesthetic dispenser. In the feed unit, anesthetic from the anesthetic canister is mixed with a carrier gas, thereby generating a gas mixture. Liquid anesthetic canisters can be refilled through a refill opening. In the operating mode of the anesthetic dispenser, the pressure is at a pre-defined operating pressure. A closure can be moved from a closed position through an intermediate position to an open position, closing the refill opening in both the closed and intermediate positions. A transition period occurs as the closure moves from the closed position to the intermediate position. A position sensor detects that the closure has moved out of the closed position. In response to this detection, the pressure in the anesthetic canister drops to a refill pressure still above ambient pressure during the transition period. The closure then opens.

[0110] List of reference numerals 1 Piping from supply connection 23 to anesthetic canister 7 2 Valve in pressure line 1 3 The discharge pipeline from the anesthetic canister 7 to the disposal connection 24 3.1 The discharge pipeline from branch point 25 to disposal connection 24 4 Valve in pipe 3 5 Pressure sensor used to measure the pressure inside the anesthetic canister 7 6 The refill opening extending along the longitudinal axis LA in the anesthetic canister 7 is selectively released or closed by the closure element 16. 7 The anesthetic container for liquid anesthetic Nm includes a pressure sensor 5, a level sensor 17, and an observation window 18, and is connected to the mixing tank 9 via an anesthetic tubing 21. 8 Valve for sealing anesthetic tubing 21 9 The mixing canister, which generates a gas mixture consisting of carrier gas and anesthetic agent Nm, is connected to the gas mixer 14 and the ventilator 40. It is heated by the heater 26, connected to the anesthetic canister 7 via the anesthetic agent line 21, connected to the carrier gas mixer 44 via the carrier gas line 10, and connected to the ventilator 40 via the gas mixture line 11. 10 The carrier gas pipeline carries the carrier gas from the carrier gas mixer 44 to the mixing tank 9. 11 Gas mixing tubing from mixing tank 9 to ventilator 40 12 Check valve in pipeline 3 13 Valve in pressure line 1 14 Valve in pressure line 3.1 15 Check valve in pressure line 1 16 The closure of refill opening 6 is released after the transition time period [t1, t2]. 17 Anesthetic tank 7 liquid level sensor 18 Observation window in anesthetic canister 7 19 The optional second valve in the anesthetic tubing 21 20 The supply connection for carrier gas in wall W 21 The anesthetic pipeline guides the liquid anesthetic Nm from the anesthetic tank 7 to the mixing tank 9. 22 The position sensor on refilled opening 6 detects an event that the closure 16 has moved out of the closed position. 23 The supply connection for compressed air inside the wall W. 24 Disposal connection end in wall W for containing gas mixture 25 At this branch point, pipe 3.1 branches off from pressure pipe 1. 26 Heater of mixing tank 9 27 In one design, the closing element in the refill opening 6 is held in the refill opening 6 by the blocking unit 32. 28 Flip-top, can be opened or closed to refill opening 6 29 The chain that holds the flap 28 on the refill opening 6 30 Bottles containing liquid anesthetics can be placed on refill opening 6. 32 The blocking unit prevents the closure 16 from opening during the transition time periods t1 and t2. 33 The control device processes data, receives measurement values ​​from sensors 5, 17, 19, and 22, and controls valves 2, 4, 8, 13, and 14, as well as the blocking unit 32. 35 The tubing between the ventilator 40 and the coupling unit 43 on the patient side 40 The ventilator, connected to the mixing tank 9 via gas mixture tubing 11 and to the coupling unit 43 on the patient side via tubing device 35, performs the respiratory stroke. 43 The coupling unit on the patient side is connected to the ventilator 40 via tubing device 35. 44 The carrier gas mixer generates carrier gas and connects to the supply connection 20, which is connected to the mixing tank 9 via the carrier gas pipeline 10. 100 The anesthesia dispenser according to the present invention includes a mixing tank 9, an injection valve 8, a heater 26, an anesthetic tank 7, and a control device 33. 200 The system for anesthetizing patient P includes an anesthetic dispenser 100, a ventilator 40, and a carrier gas mixer 44. LA The longitudinal axis and the center axis of the simultaneously refilled opening 6 Nm Liquid anesthetic can be filled into anesthetic canister 7. P The patient, connected to the coupling unit 43 on the patient side, is supplied with a mixture of carrier gas and anesthetic through tubing device 35 and is thus anesthetized by system 200. P env Air pressure in the environment of the anesthetic dispenser 100 P fill The refill pressure in anesthetic tank 7 is lower than the operating pressure P. op And preferably higher than the maximum respiratory pressure generated by the ventilator 40. P op Operating pressure in anesthetic canister 7 t1 The time point at which position sensor 22 detects that the closure 16 has moved out of the closed position. t2 Pressure sensor 5 detected that the pressure inside the anesthetic canister 7 had dropped to the refill pressure P. fill time point t3 The time point at which bottle 30 was placed on the refill opening 6 t4 The time point from when the bottle was removed from the refilled opening 6 was 30. t5 Position sensor 22 detects the time when the closure 16 reaches the closed position again. t6 Pressure sensor 5 detected that the operating pressure P has been reached in the anesthetic canister 7. op time point W Wall with supply connection 20, supply connection 23 and disposal connection 24

Claims

1. Anesthetic agent dispenser (100) comprising - a feed unit (9), - an anesthetic agent tank (7) having a refill opening (6), - a closure (16) for the refill opening (6), - an anesthetic agent line (21) from the anesthetic agent tank (7) to the feed unit (9), - a controllable pressure build-up unit (1, 2, 23) designed to increase or cause an increase in pressure in the anesthetic agent tank (7), - a controllable pressure reduction unit (3, 4, 24) designed to decrease or cause a decrease in pressure in the anesthetic agent tank (7), - a pressure sensor (5) designed to measure a measure of pressure in the anesthetic agent tank (7), - a position sensor (22), and - a control device (33) for processing signals, wherein the closure (16) - is movable from a closed position through an intermediate position into an open position, and - closes the refill opening (6) in the closed position and in the intermediate position and releases the refill opening (6) in the open position, wherein the feed unit (9) is designed to produce a gas mixture comprising a carrier gas and at least one anesthetic agent (Nm), wherein the anesthetic agent dispenser (100) is designed to pass through a transition period [tl, t2] when the closure (16) is moved from the closed position into the intermediate position, wherein the position sensor (22) is designed to automatically detect an event that the closure (16) has moved out of the closed position, wherein the control device (33) is designed to - receive measurement values from the pressure sensor (5) and the position sensor (22), - automatically trigger an increase in pressure in the anesthetic agent tank (7) by manipulating the controllable pressure build-up unit (1, 2, 23), and - automatically trigger a decrease in pressure in the anesthetic agent tank (7) by manipulating the controllable pressure reduction unit (3, 4, 24), wherein the anesthetic agent dispenser (100) is selectively operable in an operating mode or a refilling mode, wherein in the operating mode - the closure (16) is in the closed position, and - said control device (33) maintains the pressure in said anesthetic agent tank (7) at a predetermined operating pressure (P op ) or higher than said operating pressure (P op ), - wherein in the refilling mode - the closure (16) is in the open position, and - the refill opening (6) enables refilling of an anesthetic agent (Nm) into the anesthetic agent tank (7), and wherein the control device (33) is designed to after detecting the event that the closure (16) has moved out of the closed position, trigger a decrease in pressure in the anesthetic agent tank (7) by manipulating the controllable pressure reduction unit (3, 4, 24), to below the pre-defined operating pressure (P op ) in the anaesthetic agent tank (7) and to be held above the ambient pressure (P env ) at least for a transition period [t1, t2].

2. The anesthetic agent dispenser (100) according to claim 1, characterized in that the closure (16) at least in the closed position seals the refill opening (6) in a fluid-tight manner.

3. The anesthetic agent dispenser (100) according to claim 1, characterized in that the control device (33) is designed to, after detecting the event that the closure (16) has moved out of the closed position, decreasing the pressure in the narcotic agent tank (7) from the pre-defined operating pressure (P op ) to a pre-defined refill pressure (P fill ), the pre-defined refill pressure (P fill ) being smaller than the pre-defined operating pressure (P op ) and greater than the ambient pressure (P env ), wherein said transition period [t1, t2] ends when the predefined refilling pressure (P fill ) is reached.

4. The anesthetic agent dispenser (100) according to any one of the preceding claims, characterized in that The anesthetic dispenser (100) comprises a blocking unit (32) which selectively blocks or enables movement of the closure (16) from an intermediate position to an open position, wherein the anesthetic dispenser (100) is designed such that the blocking unit (32) - blocks during a transition period [t1, t2], and - enables after the transition period [t1, t2] has elapsed the closure (16) to move out of the intermediate position.

5. The anesthetic dispenser (100) according to claim 4, characterized in that the control device (33) is designed to operate the blocking unit (32) such that the blocking unit (32) blocks the closure (16) from moving out of the intermediate position, until the pressure in the anesthetic agent tank (7) reaches a predefined refill pressure (P fill ).

6. The anesthetic dispenser (100) according to one of claims 1 to 3, characterized in that the closure (16) comprises a closure element (27) and a flap (28), wherein the closure element (16) - is located between the flap (28) and the anesthetic tank (7), - can obstruct the refill opening (6), and - can be removed from the refill opening (6), wherein the flap (28) can be moved between - a closed position in which the flap (28) closes the refill opening (6), and - an open position in which the flap (28) releases the refill opening (6) and wherein the position sensor (22) is designed to detect an event in which the flap (28) has moved out of the closed position.

7. The anesthetic dispenser (100) according to one of claims 1 to 3, characterized in that the anesthetic dispenser (100) comprises an anesthetic delivery unit (8) which - is arranged in an anesthetic line (21) from the anesthetic tank (7) to the feed-in unit (9), - releases the anesthetic line (21) when the anesthetic dispenser (100) is operated in the operating mode and during the transition period [t1, t2], and - is designed to deliver anesthetic (Nm) from the released anesthetic line (21) to the feed-in unit (9), wherein the control device (33) is designed to switch off the anesthetic delivery unit (8) in response to detecting the event in which the closure (16) has moved out of the closed position.

8. The anesthetic dispenser (100) according to claim 7, characterized in that the anesthetic delivery unit (8) is designed to inject anesthetic (Nm) from the released anesthetic line (21) to the feed-in unit (9).

9. The anesthetic dispenser (100) according to claim 7, characterized in that the switched-off anesthetic delivery unit (8) blocks the anesthetic line (21).

10. The anesthetic dispenser (100) according to one of claims 1 to 3, characterized in that the anesthetic dispenser (100) comprises a treatment line and a controllable treatment blocking device, wherein the treatment line leads from the anesthetic tank (7) to a fixed treatment connection (24) or to the environment, wherein the treatment blockage device is capable of selectively blocking or releasing the treatment line, wherein the treatment blockage device blocks the treatment line when the anesthetic dispenser (100) is operated in an operating mode, and wherein the control device (33) is designed to - in response to detecting that the closure (16) has moved out of the closed position, actuate the treatment blockage device such that the controllable treatment blockage device releases the treatment line, and - after the passage of a transition period [t1, t2] actuate the treatment blockage device such that the controllable treatment blockage device blocks the treatment line.

11. An arrangement comprising - an anesthetic dispenser (100) according to any one of the preceding claims, and - a carrier gas providing unit (44) for providing a carrier gas, wherein the carrier gas providing unit (44) is in fluid communication (10) with the anesthetic dispenser (100).

12. The arrangement according to claim 11, wherein the carrier gas providing unit (44) is a carrier gas mixer.

13. A system (200) for anesthetizing a patient (P) comprising - a breathing machine (40), and - an anesthetic dispenser (100) according to any one of claims 1 to 10 or an arrangement according to claim 11 or 12, wherein the breathing machine (40) is designed to anesthetize a patient (P) using a gas mixture generated by the anesthetic dispenser (100), and wherein the anesthetic dispenser (100) is in fluid communication (11) with the breathing machine (40).

14. The system (200) according to claim 13, characterized in that the breathing machine (40) is designed to - artificially breathe into the anesthetized patient (P), and - generate a maximum breathing pressure during the artificial breathing, wherein the anesthetic dispenser (100) is designed such that the pressure in the anesthetic tank (7) is kept above the maximum breathing pressure for a transition period [t1, t2].

15. A method for generating a gas mixture comprising a carrier gas and at least one anesthetic (Nm) using an anesthetic dispenser (100), the anesthetic dispenser comprising - a feed-in unit (9), - an anesthetic tank (7) having a refill opening (6), - a closure (16) for the refill opening (6), - an anesthetic line (21) leading from the anesthetic tank (7) to the feed-in unit (9), - a controllable pressure build-up unit (1, 2, 23), - a controllable pressure reduction unit (3, 4, 24), - a pressure sensor (5), and - a position sensor (22), wherein the method comprises the step of the pressure sensor (5) measuring the pressure in the anesthetic tank (7) at least once, wherein the anesthetic dispenser (100) is temporarily operated in an operating mode in which the following steps are performed: - the closure (16) is in a closed position in which the closure (16) closes the refill opening (6), - the controllable pressure build-up unit (1, 2, 23) is actuated such that the pressure in the anesthetic tank (7) is increased to a pressure level (p1) above the maximum breathing pressure, and - the controllable pressure reduction unit (3, 4, 24) is actuated such that the pressure in the anesthetic tank (7) is reduced to a pressure level (p2) below the maximum breathing pressure. - using said controllable pressure increasing unit (1, 2, 23) to bring and / or maintain the pressure in said anesthetic agent tank (7) at a pressure equal to a pre-established operating pressure (P op ) or higher than said operating pressure (P op ), - guiding at least one anaesthetic agent (Nm) from the anaesthetic agent tank (7) through the anaesthetic agent line (21) to the feed-in unit (9), and - generating a gas mixture in the feed-in unit (9) which comprises the anaesthetic agent (Nm) to be guided to the feed-in unit (9) and a carrier gas, wherein the anaesthetic agent (Nm) is refilled at least once into the anaesthetic agent tank (7), wherein the step of refilling the anaesthetic agent (Nm) comprises the steps of: - the closure (16) is moved automatically from the closed position through an intermediate position into the open position, - the closure (16) also closes the refill opening (6) in the intermediate position and releases the refill opening (6) in the open position, wherein the closure (16) in the open position enables the refilling of the anaesthetic agent (Nm) into the anaesthetic agent tank (7), and wherein a transition period [t1, t2] elapses during the movement of the closure (16) from the closed position into the intermediate position, - the position sensor (22) detects automatically the event that the closure (16) has moved out of the closed position, - in response to the detection of the event that the closure (16) has moved out of the closed position, The pressure in the anesthetic agent tank (7) is automatically reduced using the controllable pressure reduction unit (3, 4, 24) such that the pressure is reduced below the pre-specified operating pressure (P op ) and is held above the ambient pressure (P env ) at least in the transition period [t1, t2].

16. The method according to claim 15, characterized in that in the closed position the closure (16) closes the refill opening (6) in a fluid-tight manner.

17. The method according to claim 15, characterized in that in the intermediate position the closure (16) also closes the refill opening (6) in a fluid-tight manner.

18. The method according to one of claims 15 to 17, characterized in that Pre-defined refill pressure (P) fill The refill pressure (P) fill The pressure is less than the operating pressure (P). op And greater than the environmental pressure (P) env ),and the step of reducing the pressure in the anaesthetic agent tank (7) is performed as such that the pressure is reduced to a predefined refill pressure (P fill ) in a transition period [t1, t2] wherein said transition period [t1, t2] ends when the refill pressure (P fill ) is reached.

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