DEVICE FOR PROVIDING A BREATHING GAS FLOW ENRICHED WITH ANESTHETIC

Abstract

A method and device, for enriching a gas flow with an anesthetic, include a gas mixer (1), with gas inlets (2a, 2b) and one or more gas outlets (3a, 3b), and an anesthetic dispenser (4) connected to the one or more gas outlets. The anesthetic dispenser at least partially enriches the gas flow to provide a breathing gas flow enriched with anesthetic at a patient connector (5). A control valve (7a) is arranged fluidically in series with the anesthetic dispenser (4). The gas outlet is connected to the patient connector (5) via a gas channel (8), arranged fluidically parallel to the anesthetic dispenser (4) and in which at least another control valve (7b) is arranged. A control unit (6) actuates at least one control valve as a function of a desired value for an anesthetic concentration in the breathing gas flow to change anesthetic concentration at the patient connector (5).

Claims

1. A device for enriching a gas flow with an anesthetic, the device comprising: a gas mixer comprising at least two gas inlets and at least one gas outlet; an anesthetic dispenser; a gas channel fluidically connecting the anesthetic dispenser to the at least one gas outlet, the anesthetic dispenser being configured to enrich an anesthetic dispenser gas flow with an anesthetic at least periodically to provide an enriched breathing gas flow, which is enriched with anesthetic; a first control valve arranged fluidically in series with the anesthetic dispenser; a patient connector fluidically connected to the gas channel; another gas channel fluidically connecting the at least one gas outlet to the patient connector and arranged fluidically parallel to the anesthetic dispenser; a second control valve operatively connected to the other gas channel; and a control unit configured to actuates the first control valve or the second flow valve or both the first control valve or the second flow valve as a function of a desired value for an anesthetic concentration in the breathing gas flow such that the anesthetic concentration is changed at the patient connector toward a desired value or to the desired value.

2. A device in accordance with claim 1, wherein the gas channel and the other gas channel form at least one mixing point at which gas flows are mixed upstream of the patient connector.

3. A device in accordance with claim 2, wherein: the first control valve is arranged between one of the at least two gas inlets and the anesthetic dispenser for changing a first volume flow flowing through the first control valve; the second control valve is arranged between one of the at least two gas inlets and the mixing point, for changing a second volume flow flowing through the control valves; and the control unit actuates the first control valve and the second control valve such that a global carrier gas flow, fed to the patient connector, corresponds to the sum of the first and second volume flows.

4. A device in accordance with claim 3, wherein the at least two gas inlets are supplied with different gases.

5. A device in accordance with claim 1, wherein: the at least one gas outlet comprises a first gas outlet and at least one second gas outlet; and the gas channel connects the first gas outlet to a breathing system with the patient connector; and the other gas channel connects the second gas outlet to the breathing system with the patient connector.

6. A device in accordance with claim 1, further comprising a further gas channel, with a mechanical throttling device, fluidically connecting at least one of the at least two gas inlets and the patient connector.

7. A device in accordance with claim 1, wherein: the control unit switches over at least one of the control valves in a cycle between an open position and a closed position; and a time period during which the respective control valve is in a closed position is longer than a time period during which the control valve is in an open position.

8. A device in accordance with claim 1, wherein the gas mixer is part of an anesthesia apparatus capable of operating independently.

9. A device in accordance with claim 1, further comprising a flow measuring device for measuring at least one gas flow of the gas mixer, the flow measuring device being located inside the gas mixer or forming a part of the gas mixer or both located inside the gas mixer and forming a part of the gas mixer, wherein the first control valve, arranged fluidically in series with the anesthetic dispenser, is controlled algorithmically based on at least one flow measurement in the gas mixer.

10. A method for generating a gas flow enriched with anesthetic, the method comprising: providing a first volume flow of a first gas; providing a second volume flow of a second gas; forming a carrier gas flow from the first volume flow or from the second volume flow or from both the first volume flow and the second volume flow; adding at least one anesthetic to the carrier gas flow with an anesthetic dispenser as a function of a desired value for an anesthetic concentration; and changing the volume flow of the first gas and the volume flow of the second gas taking into account the desired value.

11. A method in accordance with claim 10, wherein the second volume flow is set independently from the first volume flow to a value that is greater than or equal to zero.

12. A method in accordance with claim 10, wherein the anesthetic is added to a mixture of the first gas and the at least one second gas.

13. A method in accordance with claim 10, wherein the anesthetic is added in a gas channel arranged fluidically parallel to a gas channel.

14. A method in accordance with claim 10, wherein the carrier gas flow is composed of the first volume flow and the second volume flow of the at least one second gas and is set to a value of 0.1 L/min to 20 L/min.

15. A method in accordance with claim 10, wherein the anesthetic concentration is determined in a gas flow leaving the anesthetic dispenser before this gas flow is mixed with at least one additional gas flow.

16. A method in accordance with claim 15, wherein the first volume flow and the second volume flow are changed by taking into account the desired value and the anesthetic concentration in the gas flow leaving the anesthetic dispenser.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In the drawings:

[0032] FIG. 1 is a schematic view showing a flow diagram with a controlled gas mixer, which is connected to a mixing point connected to a patient connector via a gas channel, in which an anesthetic dispenser is provided, and via a bypass channel arranged fluidically parallel thereto;

[0033] FIG. 2 is a schematic view showing a flow diagram with a controlled gas mixer, which is connected via a gas channel, in which an anesthetic dispenser is provided, and via a bypass channel arranged fluidically parallel thereto to a patient connector connected directly to the two channels;

[0034] FIG. 3 is a schematic view showing a flow diagram with a controlled gas mixer, which is connected to a mixing point connected to a patient connector via a gas channel, in which an anesthetic dispenser is provided, via a bypass channel arranged fluidically parallel thereto and via a gas channel likewise connected parallel thereto with a throttle;

[0035] FIG. 4 is a schematic view showing a flow diagram with a gas mixer, which is connected to a mixing point connected to a patient connector via a gas channel, in which an anesthetic dispenser is provided, and via a bypass channel arranged fluidically parallel thereto, wherein a control valve each is arranged in the two channels downstream of the gas outlets of the gas mixer;

[0036] FIG. 5 is a schematic view showing a flow diagram with a gas mixer, which is connected to a mixing point connected to a patient connector via a gas channel, in which an anesthetic dispenser is provided, and via a bypass channel arranged fluidically parallel thereto, wherein a control valve each is provided in both channels downstream of the gas outlets of the gas mixer, on the one hand, and an additional control valve is provided downstream of the anesthetic dispenser;

[0037] FIG. 6 is a schematic view showing a flow diagram with a gas mixer, which is connected to a mixing point connected to a patient connector via a gas channel, in which an anesthetic dispenser is provided, and via a bypass channel arranged fluidically parallel thereto, wherein a control valve each is arranged in both channels downstream of the gas outlets of the gas mixer and a gas-measuring module is arranged in the area of the patient connector;

[0038] FIG. 7 is a schematic view showing a flow diagram with a controlled gas mixer, which is connected via four gas channels arranged fluidically in parallel to a mixing point connected to a patient connector, wherein an anesthetic dispenser each is provided in three of the four gas channels; and

[0039] FIG. 8 is a schematic view showing a flow diagram with a controlled gas mixer, which is connected to a mixing point connected to a patient connector via two gas channels arranged fluidically in parallel, wherein one of the two gas channels branches off, in turn, into three gas channels arranged in parallel to one another, in which an anesthetic dispenser each is provided.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] Referring to the drawings, FIG. 1 shows a flow diagram of a device for providing a gas flow, which is enriched with an anesthetic, for anesthetizing a patient 15. The gas flow enriched with anesthetic is fed to a breathing system 11, to which the patient 15 is connected. A so-called Y-piece, at which a gas channel is provided on the patient side for feeding and removing breathing gas, while an inspiratory gas channel as well as a separate expiratory gas channel are provided on the side facing away from the patient, is usually provided for this as a patient connector in the area of the patient. A gas flow enriched with anesthetic is fed to the Y-piece and hence to the patient via the inspiratory gas channel, while the breathing gas exhaled by the patient is removed via the expiratory gas channel. Valves, which preset the flow direction in the breathing system and enable the patient to exhale the gas being exhaled, are provided in the breathing system.

[0041] To supply the patient 15 with a gas enriched with anesthetic, a device configured according to the present invention has a gas mixer 1 with at least two gas inlets 2a, 2b and with at least one anesthetic dispenser 4, which is arranged downstream of the gas mixer 1 in the direction of flow. The anesthetic dispenser 4 is preferably configured as an anesthetic evaporator and adds a volatile anesthetic to a gas flow utilizing the evaporation principle. Halothane, enflurane, isoflurane or sevoflurane are optionally used as anesthetics. However, the present invention is not limited, in principle, to the use of the above-mentioned four anesthetics, but may also be used, in principle, with an anesthetic dispenser 4 that enriches a gas flow with a desflurane.

[0042] According to the exemplary embodiment shown in FIG. 1, the gas mixer 1 has three gas inlets 2a, 2b, 2c, which are connected to corresponding gas lines of a hospital gas supply system. Oxygen, compressed air as well as laughing gas (N.sub.2O) are fed to the gas mixer 1, via the three gas lines and via the gas inlets 2a, 2b, 2c. The gas mixer 1 shown has an electronic control, so that the three gases or two gases and compressed air are either mixed and/or set to the necessary value in relation to the respective volume flow for a carrier gas flow corresponding to the anesthesiologist's specifications. The volume flows of the partial carrier gas flows are set by means of control valves formed as part of the mixer 1. The control valves 7a and 7b may also be provided as valves in the gas channels 8, 14 and may be connected to a control unit 6 (the control valves 7a and 7b as part of the mixer 1 or in the channels 8, 14 is only indicated and the connection to the control unit 6 is not shown so as to not crowd FIGS. 1 and 2). In the example shown in FIG. 1, the controlled gas mixer 1 has two gas outlets 3a, 3b, via which the two partial carrier gas flows, which may controlled by control unit 6 to have the same composition and rates of flow or different compositions and volume rates of flow different compositions and volume rates of flow, flow out.

[0043] A first partial carrier gas flow is sent from the first gas outlet 3b to the anesthetic dispenser 4, enriched there with anesthetic and subsequently mixed at a mixing point 9 with the second partial carrier gas flow, which flows out of the second gas outlet 3a of the gas mixer 1. The value of the volume flow of the carrier gas flow again corresponds at the mixing point 9 to the sum of the individual partial carrier gas flows of different gases fed to the gas mixer 1 via the gas inlets 2a, 2b, 2c as well as of the two partial flows of gas mixtures flowing out via the two gas outlets 3a, 3b. The value of the volume flow at the mixing point 9 corresponds to the volume flow that the patient needs for the anesthesia.

[0044] FIG. 2 shows a special variant of the embodiment explained in connection with

[0045] FIG. 1. Again, up to three different gases or two gases and air are fed to the gas mixer 1 and two partial carrier gas flows of a gas mixture 1 are removed from the gas mixer via two gas outlets 3a, 3b which may controlled to have the same composition and rates of flow or different compositions and volume rates of flow different compositions and volume rates of flow, flow out. The volume flows of the partial carrier gas flows are set by means of control valves formed as part of the mixer or the control valves 7a and 7b are provided as valves in the gas channels 8, 14. The volume flows are controlled with the valves 7a and 7b via the control unit 6. One of the two partial gas flows leaving the gas mixer 1 is fed, in turn, to an anesthetic dispenser 4 via a gas channel 14 and enriched with anesthetic there according to the evaporation principle. The other partial gas flow flows through a bypass channel 8 arranged fluidically parallel to the anesthetic dispenser 4 to the patient connector 5. However, contrary to the exemplary embodiment according to FIG. 1, the two partial gas flows are not mixed before they reach the breathing system, 11 with the patient connector 5, but the two partial gas flows are fed to the breathing system 11 with the patient connector 5 via separate gas channels 8, 14 or lines.

[0046] FIG. 3 shows a gas mixer, to which up to three different gases are again fed from a hospital gas supply system. The gases being fed are mixed as needed within the gas mixer 1 and/or the volume flow of at least one gas flowing through the gas mixer 1 is set as needed. Then, up to three partial gas flows, which may have the same composition and rates of flow or different compositions and volume rates of flow, flow out of the gas mixer 1 via three separate gas outlets 3a, 3b, and 3c.

[0047] A first of these partial gas flows is then fed to an anesthetic dispenser 4 configured as an anesthetic evaporator and arranged in the gas channel for enrichment with anesthetic, and the partial mixed gas flow enriched with anesthetic is sent to a mixing point 9. A second partial mixed gas flow is sent unchanged to the mixing point 9 via a bypass channel 8 arranged fluidically parallel to the anesthetic dispenser 4. A third partial mixed gas flow is sent to the mixing point 9 via a gas outlet 3c of the gas mixer 1, and via a throttling device 10, especially a mechanically adjustable throttle valve. The throttling device 10 causes a pressure drop (loss). The pressure loss caused by the throttling device 10 can be measured by a sensor to provide a flow measurement value. The flow measurement value of the flow through the gas outlet 3b may be provided to a control unit 6. The control unit 6 may then set the gas mixer 1 to adjust the flow out of the gas mixer 1 via the three separate gas outlets 3a, 3b, and 3c. The volume flows may also be controlled with the valves 7a and 7b via the control unit 6. The three partial mixed gas flows are mixed at the mixing point 9 and fed as a common gas flow to the breathing system 11 of the patient 15. The third partial mixed gas flow is throttled such that the pressure loss that is brought about by the anesthetic dispenser 4 is taken into account. A desired volume flow ratio can be set in this manner in a specific way between the three flow paths, which depends on the particular pressure losses in the three flow paths arranged in parallel. The volume flows of the partial carrier gas flows, which flow through the other two gas channels, one of these channels being a bypass channel 8, through which the flow is in parallel to the flow in the anesthetic dispenser 4, are set by means of control valves 7a, 7b, formed as part of the mixer 1, which are adjusted by means of a control unit 6 as a function of the desired global volume flow and the anesthetic concentration at the mixing point 9.

[0048] The exemplary embodiment shown in FIG. 4 corresponds to the exemplary embodiment according to FIG. 2, and control valves 7a, 7b, which are actuated by means of a control unit 6 as a function of the set desired value for an anesthetic concentration in the gas flow being fed to the patient 15, are additionally provided at the two gas outlets 3a, 3b of the gas mixer 1. The volume flow of the first and second partial gas flows leaving the gas mixer 1 can be set specifically to a needed value by the control valves 7a, 7b provided at the gas outlets 3a, 3b of the gas mixer 1. It is even conceivable, in principle, in this case to reduce at least one of the two partial gas flows to 0 (zero) at least at times if needed. The sum of the two partial gas flows leaving the gas mixer 1 will again correspond to the global volume flow of the gases fed to the gas mixer 1 as well as to the volume flow of the carrier gas flow being fed to the patient. The partial gas flows, which flow out of the gas mixer 1, may contain, as needed, a gas or air or else a mixture of at least two gases or of air and at least one gas.

[0049] An anesthetic dispenser 4, configured as an anesthetic evaporator, which enriches the first partial gas flow with a volatile anesthetic, is again provided in one gas channel 14 of the two gas channels 8, 14 arranged fluidically in parallel. After mixing the two partial gas flows at the mixing point 9, the anesthetic concentration corresponds at least approximately to the desired value set by the anesthesiologist for the anesthetic concentration in the breathing gas to be fed to the patient 15.

[0050] To make it possible to actuate the two control valves 7a, 7b in a specific manner, a concentration of the anesthetic is determined in the gas flow by means of a sensor behind the anesthetic dispenser 4 in the direction of flow, namely, in the area of the mixing point 9 of the breathing system 11 with the patient connector 5 and/or between the anesthetic dispenser 4 and the mixing point 9. If the determination of an anesthetic concentration is carried out in the area of the anesthetic dispenser 4 in the gas channel extending between the anesthetic dispenser 4 and the mixing point 9, the determined value is transmitted to a control and analysis unit 6, in which both the volume flow and the anesthetic concentration in the gas flow fed to the patient 15 are determined on the basis of the determined value and of the volume flows of the gas flows flowing through the anesthetic dispenser 4 and the bypass channel 8. Depending on a comparison between these actual values, especially the actual value for the anesthetic concentration in the gas flow sent to the patient 15, and the desired values preset by the user, the control and analysis unit 6 generates at least one control signal in case of a deviation for specifically actuating at least one of the control valves 7a, 7b in order to change the volume flow of the gas flow flowing through these valves 7a, 7b. If it is determined, for example, that the anesthetic concentration in the gas flow being sent to the patient 15 is too high, this concentration can be reduced by increasing the volume flow of the gas flow flowing through the bypass channel 8. If, in addition, the volume flow of the gas flow sent to the patient 15 is to be kept at a constant value or reduced, the volume flow of the carrier gas flow flowing through the anesthetic dispenser 4 must be reduced at the same time by specifically actuating the control valve 7b arranged in this flow channel 14. The determination of the volume flows needed in the respective gas channels is carried out in the control and analysis unit 6, taking into account the preset desired values for the volume flow and/or the anesthetic concentration in the carrier gas flow being sent to the patient 15.

[0051] The exemplary embodiment shown in FIG. 5 complements the exemplary embodiment according to FIG. 4 by an additional control valve 7c, which is arranged at the gas outlet of the anesthetic dispenser 4 configured as an anesthetic evaporator. The volume flow of the partial gas flow leaving the anesthetic dispenser 4 can once again be influenced by providing this additional control valve 7c, which is likewise actuated as a function of the anesthetic concentration value in the breathing gas. By providing two control valves 7b, 7c in this gas channel, especially the pressure loss prevailing on this flow path between the gas outlet 3b of the gas mixer and the mixing point 9 can be set precisely over an especially wide range. Likewise, more anesthetic can reliably be prevented from entering the mixing point 9 even though the control valve 7b directly behind the gas outlet 3b of the gas mixer 1 is already closed by providing the additional control valve 7c behind the anesthetic dispenser 4.

[0052] It is possible to set a ratio of the partial gas flows fed to the mixing point 9 in a specific manner by means of the three control valves 7a, 7b, 7c, two of which are provided at the two gas outlets 3a, 3b of the gas mixer and one at the gas outlet of the anesthetic dispenser 4, especially by changing the pressure losses in the two flow paths between the gas outlets 3a, 3b and the mixing point 9 in a specific manner.

[0053] The flow diagram according to FIG. 6 is complemented, compared to FIG. 5, by a gas-measuring module 12, which is connected, directly or indirectly via a gas line, to a gas channel, which is located in the direction of flow between the mixing point 9 and the breathing system 11 with the patient connector 5. The composition of the gas flowing through the gas channel in this area, on the one hand, and, on the other hand, the anesthetic concentration or, if more than one anesthetic is contained in the gas, also the anesthetic composition are detected by means of the gas-measuring module 12 shown in FIG. 6. Based on the measured values for the gas composition and/or the anesthetic concentration, the control unit 6 generates control signals for actuating the two control valves 7a, 7b arranged at the gas outlets 3a, 3b of the gas mixer 1, taking into account the desired values preset by the user. The control valves 7a, 7b are actuated such that the partial gas flows, of which only a first partial gas flow is enriched with anesthetic by the anesthetic dispenser 4, are split such that a value of the anesthetic concentration that corresponds to the stored or entered desired value becomes established at the mixing point 9 at least after a transition period.

[0054] FIG. 7 shows a special embodiment of the present invention, in which oxygen, laughing gas as well as compressed air are again fed to the gas mixer 1, mixed in a suitable manner in the gas mixer 1 and/or provided as pure gas in the desired quantity and four partial gas flows, which contain each a gas or a mixture of at least two gases or of air and at least one gas, are removed via the four gas outlets 3a, 3b, 3c, 3d, which may be controlled to have the same composition and rates of flow or different compositions and volume rates of flow, of the gas mixer 1. The four flow paths between the gas mixer 1 and mixing point 9 are again arranged fluidically parallel.

[0055] One of the four partial gas flows generated is delivered unchanged to the mixing point 9 via the bypass channel 8. The other partial gas flows are sent each to an anesthetic dispenser 4a, 4b, 4c, in which they are enriched with anesthetic as needed. It is conceivable in this connection that three different anesthetics, which are sent to the patient 15 corresponding to the state of the patient 15 or the current phase of the anesthesia, are contained in the three anesthetic dispensers 4a, 4b, 4c. The three partial gas flows, which flow through each a respective anesthetic dispenser 4 configured as an anesthetic evaporator, are mixed with the fourth partial gas flow at the mixing point 9. It is, of course, conceivable in this connection that not all of the three partial gas flows, which are fed to an anesthetic dispenser 4, are enriched with anesthetic, for example, because no anesthetic is present, at least at times, in one of the anesthetic dispensers 4 or because not all of the three anesthetic dispensers 4 arranged in parallel carry a gas flow. In this case as well, the gas mixer 1 is an electronically controlled gas mixer 1, especially that of an anesthesia apparatus, which brings about a splitting of the global gas flow fed to the gas mixer 1 into the needed partial flows.

[0056] Finally, the exemplary embodiment according to FIG. 8 shows a device for enriching a gas flow with an anesthetic, whose gas mixer 1 has two gas outlets 3a, 3b, to which gas channels 8, 14 are connected, which are merged downstream at a mixing point 9. Two branching points 13a, 13b are provided in one 14 of the two gas channels 8, 14 leaving the gas mixer 1, so that this gas channel is split into three partial gas channels arranged fluidically parallel. An anesthetic dispenser 4a, 4b, 4c configured as an anesthetic evaporator is, in turn, provided in each of these three partial gas channels. The global gas flow is split into the partial gas flows flowing through the different gas channels by means of control valves 7a, 7b, 7c, 7d with this embodiment as well. The control valves 7a, 7b, 7c, 7d, located in the gas channels, are actuated by a control unit 6 as a function of an anesthetic concentration value of the gas flow to be fed to the patient. The connection of the control unit 6 to the control valves 7a, 7b, 7c, 7d, is omitted to not overcrowd FIG. 7. The magnitude of the respective volume flow depends on the value of the global volume flow, on the division into partial gas flows, which is brought about by the gas mixer 1, on the setting of the control valves 7a, 7b, 7c, 7d, as well as on the flow resistances of the individual flow paths.

[0057] It is again essential that the volume flows, which flow through the individual flow paths, are be such that a global volume flow as well as an anesthetic concentration of the gas flow that corresponds to the desired value set by the user, especially for the anesthetic concentration, are generated in the area of the mixing point 9, so that a gas flow conditioned according to the needs can be fed to the breathing system 11 of the patient.

[0058] A further embodiment according to the invention is provided as a variant of the embodiments discussed above. The further embodiment is particularly discussed with reference to FIG. 8. In the variation, at least one of the control valves (7a, 7b, 7c, 7d), arranged in the gas channel comprising the anesthetic dispenser 4 (or 4a, 4b, 4c), is controlled algorithmically based on at least one flow measurement in the gas mixer 1. The control algorithm of the control unit 6, uses an output from a flow measuring device 20, for measuring a gas flow, to control the setting of at least one of the control valves (7a, 7b, 7c, 7d) arranged in the gas channel. The connection of the control unit 6 to the control valves 7a, 7b, 7c, 7d, is omitted to not overcrowd FIG. 8. The flow measuring device 20 (shown in dashed line in FIG. 8 to indicate it is present in a variant of the embodiment of FIG. 8) is located inside and/or is a part of the gas mixer 1. The flow measuring device 20 may be a located inside and/or a part of the gas mixer 1 of one of the other embodiments of FIGS. 1-7. In the variations with the measuring device 20 in or a part of the gas mixer 1, a signal from the measuring device 20, indicating gas flow, is sent to the control unit 6. The control unit 6 then algorithmically controls, based on the output from a measuring device 20, the setting of at least one of the control valves (7a, 7b, 7c, 7d) arranged in the gas channel with the anesthetic dispenser 4 (4a, and/or 4b, and/or 4c).

[0059] While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.

APPENDIX

[0060] 1 Gas mixer
2 Gas inlet

[0061] 2a first gas inlet

[0062] 2b second gas inlet

[0063] 2c third gas inlet

3 Gas outlet

[0064] 3a first gas outlet

[0065] 3b second gas outlet

[0066] 3c third gas outlet

[0067] 3d fourth gas outlet

4 Anesthetic dispenser

[0068] 4a first anesthetic dispenser

[0069] 4b second anesthetic dispenser

[0070] 4c third anesthetic dispenser

5 Patient connector
6 Control unit
7 Control valve

[0071] 7a first control valve

[0072] 7b second control valve

[0073] 7c third control valve

8 Gas channel (bypass channel) arranged parallel to the anesthetic dispenser
9 Mixing point
10 Throttling device
11 Breathing system
12 Gas-measuring module
13 Branching point

[0074] 13a first branching point

[0075] 13b second branching point

14 Gas channel with anesthetic dispenser

15 Patient