Anaesthesia machine and control method of purging valve of anaesthesia machine

Abstract

The invention relates to the technical field of medical instruments, in particular to an anaesthesia machine and a control method of a purge valve of the anaesthesia machine. The anesthesia machine comprises a ventilation loop (1), a ventilation pipeline (2), an inspiration pipeline (3), a sensor (4) and a plurality of sampling pipelines (5), and the ventilation loop (1) is connected with a respiratory system (7) of a user through the ventilation pipeline (2) and the inspiration pipeline (3); one end of each sampling pipeline (5) is connected with the ventilation loop (1), and the other end of each sampling pipeline (5) is connected with the sensor (4); the device is characterized by further comprising a purging assembly which is used for introducing air into the plurality of sampling pipelines (5) respectively so as to purge condensate water in each sampling pipeline (5). According to the anaesthesia machine and the control method of the purging valve of the anaesthesia machine, generation or attachment of condensate water in the sampling pipeline (5) can be effectively prevented, and therefore the stability of an anaesthesia machine system and the accuracy of sampling data are guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to an anesthesia machine and a control method for a purge valve of the anesthesia machine. Background Art

[0002] Anesthesia machines are widely used in surgery to provide patients with stable anesthetic gas and ventilation support. During surgery, the anesthesia machine ventilates users who need anesthetic gas through a fully closed or semi-closed ventilation circuit. Figure 1 As shown, the ventilation circuit 1 is usually composed of multiple pipelines, sensors and connecting devices, which can realize the delivery and discharge of gas. The ventilation circuit 1 is connected to the user's respiratory system 7 through the ventilation pipeline 2 and the inhalation pipeline 3. The respiratory system 7 can be the user's trachea or lungs, or a device that simulates the trachea or lungs of a real person.

[0003] During this process, the respiratory system 7 usually continues to exhale gas containing a large amount of water vapor. Due to the high humidity of the gas, the water vapor may enter the ventilation circuit 1 and may affect the pipeline system of the anesthesia machine and the sensor 4 on the main control board 6.

[0004] like Figure 1 As shown, the ventilation circuit 1 used in the anesthesia machine is often connected to multiple sampling lines 5, including a pressure collection line, a flow collection line, etc. Each sampling line 5 is connected to a sensor 4 respectively. Water vapor enters these sampling lines 5 along with the gas flow, and gradually condenses into water droplets during the cooling process. The condensation of water vapor is due to the decrease in the air flow temperature in the sampling line 5, which causes the water vapor to condense on the wall of the tube after saturation. These condensed waters will accumulate over time and affect the function of the sampling line. Especially after long-term use, the amount of condensed water accumulated on the inner wall of the sampling line 5 may reach a certain level, further affecting the accuracy of the sampling data, and may even cause deviations in the readings of the sensor 4, which may seriously affect the normal operation of the anesthesia machine.

[0005] In addition, the condensation of water vapor not only affects the sampling results of the sensor 4, but may also cause potential interference to the gas circulation and flow control of the entire anesthesia machine. Water accumulation will affect the fluidity of the gas, which may lead to unstable gas supply and increase the risk during anesthesia. Therefore, solving the problem of condensed water accumulation and ensuring the normal operation of the sensor 4 and the sampling pipeline 5 has become an important issue in the design of anesthesia machines.

[0006] In order to reduce the impact of condensed water, traditional solutions usually involve measures such as improving the heating device of the sampling pipeline 5, adding a pipeline insulation layer, etc. However, these solutions still cannot completely eliminate the problem of condensed water accumulation, so a more effective technical solution is urgently needed to prevent the generation of condensed water, so as to ensure the stability of the anesthesia machine system and the accuracy of the sampling data. Summary of the invention

[0007] The object of the present invention is to overcome the above-mentioned defects of the prior art, thereby providing an anesthesia machine and a control method for a purge valve of the anesthesia machine.

[0008] In order to solve the above technical problems, the technical solution of the present invention provides an anesthesia machine, comprising: a ventilation circuit 1, a ventilation pipeline 2, an inhalation pipeline 3, a sensor 4 and a plurality of sampling pipelines 5, wherein the ventilation circuit 1 is connected to the user's respiratory system 7 through the ventilation pipeline 2 and the inhalation pipeline 3; one end of the plurality of sampling pipelines 5 is respectively connected to the ventilation circuit 1, and the other end is respectively connected to the sensor 4; it is characterized in that it also includes: a purge component, which is used to ventilate the plurality of sampling pipelines 5 respectively to purge the condensed water in each sampling pipeline 5.

[0009] As an improvement of the above-mentioned anesthesia machine, the purge assembly includes: a gas source 10 for providing purge gas, a purge valve 8 connected to the gas source 10, a plurality of purge pipelines 9 and a control module, wherein one end of the plurality of purge pipelines 9 is connected to the purge valve 8, and the other end is connected to different sampling pipelines 5; the control module is used to control the connection or disconnection between the purge valve 8 and the plurality of purge pipelines 9 respectively, so that when the purge valve 8 is connected to the purge pipeline 9, the purge gas provided by the gas source 10 is delivered to the sampling pipeline 5 connected to the purge pipeline 9 to purge the condensed water in the sampling pipeline 5.

[0010] As an improvement of the above anesthesia machine, the process of the control module controlling the connection or disconnection between the purge valve 8 and a purge pipeline 9 is as follows:

[0011] Determine the mass m of condensed water generated in the sampling pipeline 5 connected to the purge pipeline 9 per unit time:

[0012] m=Q / L

[0013] Among them, Q is the heat released during the liquefaction of water vapor, and L is the latent heat of vaporization of water;

[0014] Based on the mass m of the condensed water, the volume v of the condensed water generated in the sampling pipeline 5 per unit time is obtained:

[0015] v=m / ρ

[0016] Where, ρ is the water mass;

[0017] The control module controls the time interval t1 for disconnecting the purge valve 8 from the purge pipeline 9 to be:

[0018] t1=V / v

[0019] Wherein, V is the preset condensed water volume threshold;

[0020] The control module controls the minimum duration t2 of the connection between the purge valve 8 and the purge pipeline 9 to be:

[0021] t2=l*π*r 2 / q

[0022] Wherein, l is the length of the sampling pipeline 5 , r is the inner radius of the sampling pipeline 5 , and q is the flow rate of the purge gas output by the purge valve 8 .

[0023] As an improvement of the above anesthesia machine, the heat Q released during the liquefaction of the water vapor is:

[0024] Q=h*A*(T s -T a )

[0025] Wherein, h is the heat transfer coefficient of the sampling pipeline 5, A is the total area of ​​the inner wall of the sampling pipeline 5, T s is the gas temperature in the sampling pipeline 5, T a is the condensation surface temperature;

[0026] The total area A of the inner wall of the sampling pipeline 5 is:

[0027] A=2*π*r*l

[0028] Wherein, r is the inner radius of the sampling pipeline 5 , and l is the length of the sampling pipeline 5 .

[0029] As an improvement of the above anesthesia machine, the preset condensed water volume threshold V is:

[0030] V=8*π*r 2

[0031] Wherein, r is the inner radius of the sampling pipeline 5 .

[0032] As an improvement of the above anesthesia machine, the plurality of sampling pipelines 5 include: an exhaled sampling pipeline group and an inhaled sampling pipeline group; wherein,

[0033] The exhaled air sampling pipeline group includes: an exhaled air flow sampling pipeline and an exhaled air pressure sampling pipeline;

[0034] The inhalation sampling pipeline group includes: an inhalation flow sampling pipeline and an inhalation pressure sampling pipeline;

[0035] Among them, when the breathing system 7 performs an exhalation action, the control module is used to control the connection or disconnection between the purge line 9 and the purge valve 8 connected to the inhalation sampling line group; when the breathing system 7 performs an inhalation action, the control module is used to control the connection or disconnection between the purge line 9 and the purge valve 8 connected to the inhalation sampling line group.

[0036] To achieve another purpose of the present invention, the present invention also provides a control method for a purge valve of an anesthesia machine, which is implemented based on the above-mentioned anesthesia machine, including: controlling the purge valve 8 to be connected or disconnected with a plurality of purge pipelines 9 respectively through a control module, so that when the purge valve 8 is connected to the purge pipeline 9, the purge gas provided by the gas source 10 is delivered to the sampling pipeline 5 connected to the purge pipeline 9 to purge the condensed water in the sampling pipeline 5.

[0037] As an improvement of the above method, the process of the control module controlling the connection or disconnection between the purge valve 8 and a purge pipeline 9 is as follows:

[0038] Determine the mass m of condensed water generated in the sampling pipeline 5 connected to the purge pipeline 9 per unit time:

[0039] m=Q / L

[0040] Among them, Q is the heat released during the liquefaction of water vapor, and L is the latent heat of vaporization of water;

[0041] Based on the mass m of the condensed water, the volume v of the condensed water generated in the sampling pipeline 5 per unit time is obtained:

[0042] v=m / ρ

[0043] Where, ρ is the water mass;

[0044] The time interval t1 during which the control module controls the purge valve 8 to be disconnected from the purge pipeline 9 is obtained:

[0045] t1=V / v

[0046] Wherein, V is the preset condensed water volume threshold;

[0047] The minimum duration t2 for the control module to control the connection between the purge valve 8 and the purge pipeline 9 is obtained:

[0048] t2=l*π*r 2 / q

[0049] Wherein, l is the length of the sampling pipeline 5 , r is the inner radius of the sampling pipeline 5 , and q is the flow rate of the purge gas output by the purge valve 8 .

[0050] As an improvement of the above method, the preset condensed water volume threshold V is:

[0051] V=8*π*r 2

[0052] Wherein, r is the inner radius of the sampling pipeline 5 .

[0053] As an improvement of the above method, the plurality of sampling pipelines 5 include: an exhaled sampling pipeline group and an inhaled sampling pipeline group; wherein,

[0054] The exhaled air sampling pipeline group includes: an exhaled air flow sampling pipeline and an exhaled air pressure sampling pipeline;

[0055] The inhalation sampling pipeline group includes: an inhalation flow sampling pipeline and an inhalation pressure sampling pipeline;

[0056] Among them, when the breathing system 7 performs an exhalation action, the control module controls the connection or disconnection between the purge line 9 and the purge valve 8 connected to the inhalation sampling line group; when the breathing system 7 performs an inhalation action, the control module controls the connection or disconnection between the purge line 9 and the purge valve 8 connected to the inhalation sampling line group.

[0057] Compared with the prior art, the advantage of the present invention is that the anesthesia machine and the control method of the purge valve of the anesthesia machine of the present invention can effectively prevent the generation or adhesion of condensed water in the sampling pipeline 5, thereby ensuring the stability of the anesthesia machine system and the accuracy of the sampling data. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 A schematic diagram of an anesthesia machine of the prior art;

[0059] Figure 2 It is a schematic diagram of the anesthesia machine of the present invention. DETAILED DESCRIPTION

[0060] The technical solution provided by the present invention is further illustrated below in conjunction with embodiments.

[0061] Example 1

[0062] This embodiment provides an anesthesia machine, such as Figure 2 As shown, based on the existing anesthesia machine, this embodiment adds a purge component to the sampling pipeline 5 for ventilating each sampling pipeline 5 to purge the condensed water in each sampling pipeline 5 .

[0063] The purge assembly includes: a gas source 10 for providing purge gas, a purge valve 8 connected to the gas source 10, a plurality of purge pipelines 9 and a control module, wherein one end of the plurality of purge pipelines 9 is connected to the purge valve 8, and the other end is connected to different sampling pipelines 5; the control module is used to control the connection or disconnection between the purge valve 8 and the purge pipeline 9.

[0064] The control strategy of the control module is as follows:

[0065] Determination of purge timing:

[0066] Gas liquefaction refers to the process of gas conversion into liquid under certain pressure and temperature. The speed of this process is affected by temperature, pressure and the characteristics of the gas itself. When the average kinetic energy of gas molecules decreases to a low enough level, they cannot overcome the attraction between each other and condense together.

[0067] The mass m of condensed water generated per unit time is:

[0068] m=Q / L

[0069] Q is the heat released during the liquefaction of water vapor, and L is the latent heat of vaporization of water, which is 2260Kj / kg at room temperature.

[0070] in

[0071] Q=h*A*(T s -T a )

[0072] Where h is the heat transfer coefficient of the sampling pipeline 5. For example, the thermal conductivity of the silicone pipeline used in the device is about 0.15. A is the condensation area, that is, the total area of ​​the inner wall of the sampling pipeline 5. T s is the gas temperature in the sampling pipeline 5, which can be considered as the gas temperature T s Equivalent to a circuit temperature of 37°, T a is the condensation surface temperature, which can be considered as the operating temperature of the equipment, that is, the standard temperature of the operating room 21°, where the condensation area A is:

[0073] A=2*π*r*l

[0074] Wherein, r is the inner radius of the sampling pipeline 5 , and l is the length of the sampling pipeline 5 .

[0075] The volume v of condensed water generated in the sampling pipeline 5 per unit time is calculated according to the above formula:

[0076] v=m / ρ

[0077] Among them, m is the mass of condensed water, ρ is the mass of water;

[0078] When the condensed water volume threshold V meets the following conditions, the sampling pipeline may be blocked, affecting sampling:

[0079] V=8*π*r 2

[0080] Then the optimal interval time t1 of each operation of the purge valve is:

[0081] t1=V / v

[0082] The minimum duration t2 for blowing out the condensed water in this part is:

[0083] t2=l*π*r 2 / q

[0084] Wherein, r is the inner diameter of the sampling pipeline 5, l is the length of the sampling pipeline 5, and q is the flow rate of the purge gas output by the purge valve 8. q is a known quantity and is constant, because when the pressure is determined, the flow rate through the fixed gas resistance is also constant.

[0085] In summary, the anesthesia machine opens the purge valve after ventilation for t1 time, starts the purge function, and blows continuously for t2 time. The types of sampling pipelines 5 that need to be purged include: inspiratory flow sensor pipeline, inspiratory pressure sensor sampling pipeline, expiratory flow sensor pipeline and / or expiratory pressure sampling pipeline, etc. Because the gas in the purge process eventually flows to the circuit, in order not to affect the ventilation control, further, this embodiment also adopts different strategies in the inhalation action and the exhalation action, respectively, and the strategy includes: purging part of the expiratory pipeline during inspiration, and purging part of the inhalation pipeline during exhalation.

[0086] Example 2

[0087] The present embodiment provides a control method for a purge valve of an anesthesia machine, which is implemented based on the anesthesia machine provided in Example 1, including: controlling the purge valve 8 to be connected or disconnected with a plurality of purge pipelines 9 respectively through a control module, so that when the purge valve 8 is connected with the purge pipeline 9, the purge gas provided by the gas source 10 is delivered to the sampling pipeline 5 connected with the purge pipeline 9 to purge the condensed water in the sampling pipeline 5.

[0088] Specifically, the process of the control module controlling the connection or disconnection between the purge valve 8 and a purge pipeline 9 is as follows:

[0089] Determine the mass m of condensed water generated in the sampling pipeline 5 connected to the purge pipeline 9 per unit time:

[0090] m=Q / L

[0091] Among them, Q is the heat released during the liquefaction of water vapor, and L is the latent heat of vaporization of water;

[0092] Based on the mass m of the condensed water, the volume v of the condensed water generated in the sampling pipeline 5 per unit time is obtained:

[0093] v=m / ρ

[0094] Where, ρ is the water mass;

[0095] The time interval t1 during which the control module controls the purge valve 8 to be disconnected from the purge pipeline 9 is obtained:

[0096] t1=V / v

[0097] Wherein, V is the preset condensed water volume threshold;

[0098] The minimum duration t2 for the control module to control the connection between the purge valve 8 and the purge pipeline 9 is obtained:

[0099] t2=l*π*r 2 / q

[0100] Wherein, l is the length of the sampling pipeline 5 , r is the inner radius of the sampling pipeline 5 , and q is the flow rate of the purge gas output by the purge valve 8 .

[0101] Specifically, the preset condensed water volume threshold V is:

[0102] V=8*π*r 2

[0103] Wherein, r is the inner radius of the sampling pipeline 5 .

[0104] Specifically, the plurality of sampling pipelines 5 include: an exhaled sampling pipeline group and an inhaled sampling pipeline group; wherein,

[0105] The exhaled air sampling pipeline group includes: an exhaled air flow sampling pipeline and an exhaled air pressure sampling pipeline;

[0106] The inhalation sampling pipeline group includes: an inhalation flow sampling pipeline and an inhalation pressure sampling pipeline;

[0107] Among them, when the breathing system 7 performs an exhalation action, the control module controls the connection or disconnection between the purge line 9 and the purge valve 8 connected to the inhalation sampling line group; when the breathing system 7 performs an inhalation action, the control module controls the connection or disconnection between the purge line 9 and the purge valve 8 connected to the inhalation sampling line group.

[0108] From the above specific description of the present invention, it can be seen that by using the speed of gas condensing into water and combining it with the actual size of the sampling pipeline 5, the time when the condensed water will block the sampling pipeline 5 can be calculated in advance, and the condensed water can be blown away in advance to prevent sampling abnormalities.

[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention is described in detail with reference to the embodiments, it should be understood by those skilled in the art that any modification or equivalent replacement of the technical solutions of the present invention does not depart from the spirit and scope of the technical solutions of the present invention and should be included in the scope of the claims of the present invention.

Claims

1. An anesthesia machine, comprising: A ventilation circuit (1), a ventilation pipeline (2), an inhalation pipeline (3), a sensor (4) and a plurality of sampling pipelines (5), wherein the ventilation circuit (1) is connected to a user's respiratory system (7) via the ventilation pipeline (2) and the inhalation pipeline (3); one end of the plurality of sampling pipelines (5) is respectively connected to the ventilation circuit (1), and the other end is respectively connected to the sensor (4); and the device is characterized in that it also includes: a purge component for ventilating the plurality of sampling pipelines (5) respectively to purge condensed water in each sampling pipeline (5).

2. The anesthesia machine according to claim 1, characterized in that: The purge assembly comprises: a gas source (10) for providing purge gas, a purge valve (8) connected to the gas source (10), a plurality of purge pipelines (9), and a control module, wherein one end of the plurality of purge pipelines (9) is connected to the purge valve (8), and the other end is connected to different sampling pipelines (5); the control module is used to control the connection or disconnection between the purge valve (8) and the plurality of purge pipelines (9), so that when the purge valve (8) is connected to the purge pipeline (9), the purge gas provided by the gas source (10) is transported to the sampling pipeline (5) connected to the purge pipeline (9), so as to purge condensed water in the sampling pipeline (5).

3. The anesthesia machine according to claim 2, characterized in that: The process of the control module controlling the connection or disconnection between the purge valve (8) and a purge pipeline (9) is as follows: Determine the mass m of condensed water generated in the sampling pipeline (5) connected to the purge pipeline (9) per unit time: m=Q / L Among them, Q is the heat released during the liquefaction of water vapor, and L is the latent heat of vaporization of water; Based on the mass m of the condensed water, the volume v of the condensed water generated in the sampling pipeline (5) per unit time is obtained: v=m / ρ Where, ρ is the water mass; The control module controls the time interval t1 for disconnecting the purge valve (8) from the purge pipeline (9) to be: t1=V / v Wherein, V is the preset condensed water volume threshold; The control module controls the minimum duration t2 of the communication between the purge valve (8) and the purge pipeline (9) to be: t2=l*π*r 2 / q Wherein, l is the length of the sampling pipeline (5), r is the inner radius of the sampling pipeline (5), and q is the flow rate of the purge gas output by the purge valve (8).

4. The anesthesia machine according to claim 3, characterized in that: The preset condensed water volume threshold V is: V＝8*π*r 2 Wherein, r is the inner radius of the sampling pipeline (5).

5. The anesthesia machine according to claim 3, characterized in that: The plurality of sampling pipelines (5) include: an exhaled sampling pipeline group and an inhaled sampling pipeline group; wherein, The exhaled air sampling pipeline group includes: an exhaled air flow sampling pipeline and an exhaled air pressure sampling pipeline; The inhalation sampling pipeline group includes: an inhalation flow sampling pipeline and an inhalation pressure sampling pipeline; Wherein, when the breathing system (7) performs an exhalation action, the control module is used to control the connection or disconnection between the purge pipeline (9) connected to the inhalation sampling pipeline group and the purge valve (8); when the breathing system (7) performs an inhalation action, the control module is used to control the connection or disconnection between the purge pipeline (9) connected to the inhalation sampling pipeline group and the purge valve (8).

6. A method for controlling a purge valve of an anesthesia machine, implemented based on the anesthesia machine of claim 2, comprising: The control module controls the purge valve (8) to be connected or disconnected with a plurality of purge pipelines (9) respectively, so that when the purge valve (8) is connected with the purge pipeline (9), the purge gas provided by the gas source (10) is delivered to the sampling pipeline (5) connected with the purge pipeline (9) to purge the condensed water in the sampling pipeline (5).

7. The control method of the purge valve of the anesthesia machine according to claim 6, characterized in that: The process of the control module controlling the connection or disconnection between the purge valve (8) and a purge pipeline (9) is as follows: Determine the mass m of condensed water generated in the sampling pipeline (5) connected to the purge pipeline (9) per unit time: m=Q / L Among them, Q is the heat released during the liquefaction of water vapor, and L is the latent heat of vaporization of water; Based on the mass m of the condensed water, the volume v of the condensed water generated in the sampling pipeline (5) per unit time is obtained: v=m / ρ Where, ρ is the water mass; The time interval t1 for disconnecting the purge valve (8) and the purge pipeline (9) controlled by the control module is obtained: t1=V / v Wherein, V is the preset condensed water volume threshold; The minimum duration t2 for the control module to control the communication between the purge valve (8) and the purge pipeline (9) is obtained: t2=l*π*r 2 / q Wherein, l is the length of the sampling pipeline (5), r is the inner radius of the sampling pipeline (5), and q is the flow rate of the purge gas output by the purge valve (8).

8. The control method of the purge valve of the anesthesia machine according to claim 7, characterized in that: The preset condensed water volume threshold V is: V＝8*π*r 2 Wherein, r is the inner radius of the sampling pipeline (5).

9. The method for controlling a purge valve of an anesthesia machine according to claim 7, characterized in that: The plurality of sampling pipelines (5) include: an exhaled sampling pipeline group and an inhaled sampling pipeline group; wherein, The exhaled air sampling pipeline group includes: an exhaled air flow sampling pipeline and an exhaled air pressure sampling pipeline; The inhalation sampling pipeline group includes: an inhalation flow sampling pipeline and an inhalation pressure sampling pipeline; When the breathing system (7) performs an exhalation action, the control module controls the connection or disconnection between the purge line (9) connected to the inhalation sampling line group and the purge valve (8); when the breathing system (7) performs an inhalation action, the control module controls the connection or disconnection between the purge line (9) connected to the inhalation sampling line group and the purge valve (8).

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