An anesthesia machine and a method for controlling the purge valve of the anesthesia machine.

Abstract

This invention relates to the field of medical device technology, and particularly to an anesthesia machine and a control method for its purge valve. The anesthesia machine includes: a ventilation circuit (1), a ventilation line (2), an inhalation line (3), a sensor (4), and several sampling lines (5). The ventilation circuit (1) is connected to the user's respiratory system (7) through the ventilation line (2) and the inhalation line (3). One end of each of the several sampling lines (5) is connected to the ventilation circuit (1), and the other end is connected to the sensor (4). The invention is characterized by further including: a purge assembly for venting air into each of the several sampling lines (5) to purge condensate from each sampling line (5). The anesthesia machine and the control method for its purge valve of this invention can effectively prevent the generation or adhesion of condensate in the sampling lines (5), thereby ensuring the stability of the anesthesia machine system and the accuracy of the sampling data.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to an anesthesia machine and a method for controlling the purge valve of the anesthesia machine. Background Technology

[0002] Anesthesia machines are widely used in surgery to provide patients with a stable supply of anesthetic gas and ventilation support. During surgery, the anesthesia machine ventilates the patient requiring anesthetic gas through a fully or semi-closed ventilation circuit. For example... Figure 1 As shown, the ventilation circuit 1 typically consists of multiple tubing, sensors, and connecting devices, enabling gas delivery and discharge. The ventilation circuit 1 is connected to the user's respiratory system 7 via ventilation tubing 2 and inhalation tubing 3. This respiratory system 7 can be the user's trachea or lungs, or it can be a device simulating a real person's trachea or lungs.

[0003] During this process, the respiratory system 7 continuously exhales gas containing a large amount of water vapor. Due to the high humidity of the gas, the water vapor entering the ventilation circuit 1 may affect the tubing and other systems of the anesthesia machine, as well as the sensors 4 on the main control board 6.

[0004] like Figure 1 As shown, the ventilation circuit 1 used in anesthesia machines is typically connected to multiple sampling lines 5, including pressure sampling lines and flow sampling lines. Each sampling line 5 is then connected to a sensor 4. Water vapor enters these sampling lines 5 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 airflow temperature inside the sampling line 5, causing water vapor to saturate and condense on the tube wall. This condensate accumulates over time, affecting the function of the sampling lines. Especially after prolonged use, the amount of condensate 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, potentially affecting the normal operation of the anesthesia machine in severe cases.

[0005] Furthermore, water vapor condensation not only affects the sampling results of sensor 4, but may also potentially interfere with the gas circulation and flow control of the entire anesthesia machine. Accumulated water can affect gas flow, potentially leading to unstable gas supply and increasing risks during anesthesia. Therefore, resolving the condensation problem and ensuring the normal operation of sensor 4 and sampling tubing 5 has become an important issue in anesthesia machine design.

[0006] To reduce the impact of condensation, traditional solutions typically involve improving the heating device of the sampling pipeline 5 and adding insulation layers to the pipeline. However, these solutions still cannot completely eliminate the problem of condensation accumulation. Therefore, a more effective technical solution is urgently needed to prevent condensation generation, thereby ensuring the stability of the anesthesia machine system and the accuracy of the sampling data. Summary of the Invention

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

[0008] To solve the above-mentioned technical problems, the anesthesia machine provided by the technical solution of the present invention includes: a ventilation circuit 1, a ventilation line 2, an inhalation line 3, a sensor 4, and a plurality of sampling lines 5, wherein the ventilation circuit 1 is connected to the user's respiratory system 7 through the ventilation line 2 and the inhalation line 3; one end of each of the plurality of sampling lines 5 is connected to the ventilation circuit 1, and the other end is connected to the sensor 4; characterized in that it further includes: a purge assembly for venting air into the plurality of sampling lines 5 to purge the condensate in each sampling line 5.

[0009] As an improvement to the aforementioned anesthesia machine, the purge assembly includes: a gas source 10 providing purge gas, a purge valve 8 connected to the gas source 10, a plurality of purge lines 9, and a control module. One end of each of the plurality of purge lines 9 is connected to the purge valve 8, and the other end is connected to different sampling lines 5. The control module controls the connection or disconnection between the purge valve 8 and the plurality of purge lines 9. When the purge valve 8 is connected to a purge line 9, the purge gas provided by the gas source 10 is delivered to the sampling line 5 connected to that purge line 9 to purge the condensate in the sampling line 5.

[0010] As an improvement to the aforementioned anesthesia machine, the process by which the control module controls the connection or disconnection between the purge valve 8 and a purge line 9 is as follows:

[0011] Determine the mass m of condensate generated in the sampling line 5 connected to the purging line 9 per unit time:

[0012] m = Q / L

[0013] Where 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 condensate, the volume v of condensate generated per unit time in the sampling pipeline 5 is obtained:

[0015] v = m / ρ

[0016] Where ρ is the mass of water;

[0017] The time interval t1 between the control module controlling the purge valve 8 and the purge pipeline 9 to disconnect is:

[0018] t1 = V / v

[0019] Where V is the preset condensate volume threshold;

[0020] The minimum duration t2 for which the control module controls the connection between the purge valve 8 and the purge pipeline 9 is:

[0021] t2=l*π*r 2 / q

[0022] Where 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 to the aforementioned anesthesia machine, the heat Q released during the liquefaction of the water vapor is:

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

[0025] Where h is the heat transfer coefficient of the sampling pipe 5, A is the total area of ​​the inner wall of the sampling pipe 5, and T s T represents the gas temperature within sampling pipe 5. a The condensation surface temperature is denoted as .

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

[0027] A = 2πrl

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

[0029] As an improvement to the aforementioned anesthesia machine, the preset condensate volume threshold V is:

[0030] V = 8πr 2

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

[0032] As an improvement to the aforementioned anesthesia machine, the plurality of sampling tubing 5 includes: an expiratory sampling tubing group and an inspiratory sampling tubing group; wherein...

[0033] The expiratory sampling tubing assembly includes: an expiratory flow sampling tubing and an expiratory pressure sampling tubing;

[0034] The inhalation sampling tubing assembly includes: an inhalation flow rate sampling tubing and an inhalation pressure sampling tubing;

[0035] Specifically, when the respiratory 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 inspiratory sampling line group; when the respiratory 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 inspiratory sampling line group.

[0036] To achieve another objective of the present invention, the present invention also provides a control method for a purge valve of an anesthesia machine, based on the above-described anesthesia machine, comprising: controlling the purge valve 8 to connect or disconnect with a plurality of purge lines 9 respectively through a control module, such that when the purge valve 8 is connected to the purge line 9, the purge gas provided by the gas source 10 is delivered to the sampling line 5 connected to the purge line 9 to purge the condensate in the sampling line 5.

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

[0038] Determine the mass m of condensate generated in the sampling line 5 connected to the purging line 9 per unit time:

[0039] m = Q / L

[0040] Where 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 condensate, the volume v of condensate generated per unit time in the sampling pipeline 5 is obtained:

[0042] v = m / ρ

[0043] Where ρ is the mass of water;

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

[0045] t1 = V / v

[0046] Where V is the preset condensate volume threshold;

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

[0048] t2=l*π*r 2 / q

[0049] Where 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 to the above method, the preset condensate volume threshold V is:

[0051] V = 8πr 2

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

[0053] As an improvement to the above method, the plurality of sampling tubing 5 includes: an expiratory sampling tubing group and an inspiratory sampling tubing group; wherein...

[0054] The expiratory sampling tubing assembly includes: an expiratory flow sampling tubing and an expiratory pressure sampling tubing;

[0055] The inhalation sampling tubing assembly includes: an inhalation flow rate sampling tubing and an inhalation pressure sampling tubing;

[0056] Specifically, when the respiratory 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 inspiratory sampling line group; when the respiratory 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 inspiratory 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 condensate in the sampling pipeline 5, thereby ensuring the stability of the anesthesia machine system and the accuracy of the sampling data. Attached Figure Description

[0058] Figure 1 This is a schematic diagram of an existing anesthesia machine;

[0059] Figure 2 This is a schematic diagram of the anesthesia machine of the present invention. Detailed Implementation

[0060] The technical solutions provided by the present invention will be further illustrated below with reference to the 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 purging assembly to the sampling pipeline 5, which is used to ventilate each sampling pipeline 5 to purge the condensate in each sampling pipeline 5.

[0063] The purging assembly includes: a gas source 10 that provides purging gas, a purging valve 8 connected to the gas source 10, several purging pipelines 9, and a control module. One end of each purging pipeline 9 is connected to the purging 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 purging valve 8 and the purging pipelines 9.

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

[0065] Determining the timing of purging:

[0066] Gas liquefaction refers to the process by which a gas transforms into a liquid under certain pressure and temperature. The rate of this process is affected by temperature, pressure, and the properties of the gas itself. When the average kinetic energy of gas molecules decreases low enough, they cannot overcome the attraction between them and condense together.

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

[0068] m = Q / L

[0069] Q represents the heat released during the liquefaction of water vapor, and L represents the latent heat of vaporization of water, which is 2260 KJ / 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 pipe 5, for example, if silicone tubing is used in the equipment, its thermal conductivity is approximately 0.15, A is the condensation area, that is, the total area of ​​the inner wall of the sampling pipe 5, and T is the thermal conductivity of the sampling pipe 5. s The gas temperature within sampling pipe 5 is assumed to be T. s Equivalent to a circuit temperature of 37°C, T a The condensation surface temperature can be considered as the operating temperature of the equipment, which is also the standard operating room temperature of 21°C. The condensation area A is:

[0073] A = 2πrl

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

[0075] The volume v of condensate generated per unit time in sampling pipe 5 is calculated using the above formula:

[0076] v = m / ρ

[0077] Where m is the mass of the condensate and ρ is the mass of the water;

[0078] However, the condensate volume threshold V may block the sampling pipeline and affect sampling if it meets the following conditions:

[0079] V = 8πr 2

[0080] The optimal interval t1 for each operation of the purge valve is:

[0081] t1 = V / v

[0082] The minimum duration t2 for blowing out the condensate from this section is:

[0083] t2=l*π*r 2 / q

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

[0085] In summary, the anesthesia machine opens the purge valve and initiates the purge function after ventilation time t1, continuously blowing air for time t2. The types of sampling lines 5 requiring purge include: inspiratory flow sensor line, inspiratory pressure sensor sampling line, expiratory flow sensor line, and / or expiratory pressure sampling line. Because the air during the purge process ultimately flows back to the loop, to avoid affecting ventilation control, this embodiment further employs different strategies during inspiratory and expiratory actions. These strategies include: purging a portion of the expiratory line during inspiratory action, and purging a portion of the inspiratory line during expiratory action.

[0086] Example 2

[0087] This embodiment provides a control method for the purge valve of an anesthesia machine, based on the anesthesia machine provided in Embodiment 1. The method includes: controlling the purge valve 8 to connect or disconnect with a plurality of purge pipelines 9 through a control module. 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 condensate in the sampling pipeline 5.

[0088] Specifically, the process by which the control module controls the connection or disconnection between the purge valve 8 and the purge pipeline 9 is as follows:

[0089] Determine the mass m of condensate generated in the sampling line 5 connected to the purging line 9 per unit time:

[0090] m = Q / L

[0091] Where 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 condensate, the volume v of condensate generated per unit time in the sampling pipeline 5 is obtained:

[0093] v = m / ρ

[0094] Where ρ is the mass of water;

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

[0096] t1 = V / v

[0097] Where V is the preset condensate volume threshold;

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

[0099] t2=l*π*r 2 / q

[0100] Where 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 condensate volume threshold V is:

[0102] V = 8πr 2

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

[0104] Specifically, the plurality of sampling tubing 5 includes: an expiratory sampling tubing group and an inspiratory sampling tubing group; wherein,

[0105] The expiratory sampling tubing assembly includes: an expiratory flow sampling tubing and an expiratory pressure sampling tubing;

[0106] The inhalation sampling tubing assembly includes: an inhalation flow rate sampling tubing and an inhalation pressure sampling tubing;

[0107] Specifically, when the respiratory 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 inspiratory sampling line group; when the respiratory 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 inspiratory sampling line group.

[0108] As can be seen from the above detailed description of the present invention, by using the speed at which gas condenses into water and combining it with the actual size of the sampling pipe 5, the time when the condensate will block the sampling pipe 5 can be calculated in advance, and the condensate 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 it. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. An anesthesia machine, comprising: The system comprises a ventilation circuit (1), a ventilation line (2), an inhalation line (3), a sensor (4), and several sampling lines (5), wherein the ventilation circuit (1) is connected to the user's respiratory system (7) through the ventilation line (2) and the inhalation line (3); one end of each of the several sampling lines (5) is connected to the ventilation circuit (1), and the other end is connected to the sensor (4); characterized in that it further comprises: a purge assembly for ventilating the several sampling lines (5) to purge the condensate in each sampling line (5); The purging assembly includes: a gas source (10) providing purging gas, a purging valve (8) connected to the gas source (10), a plurality of purging pipelines (9), and a control module. One end of each of the plurality of purging pipelines (9) is connected to the purging valve (8), and the other end is connected to different sampling pipelines (5). The control module is used to control the purging valve (8) to connect or disconnect with the plurality of purging pipelines (9). When the purging valve (8) is connected to the purging pipeline (9), the purging gas provided by the gas source (10) is delivered to the sampling pipeline (5) connected to the purging pipeline (9) to purge the condensate in the sampling pipeline (5). The process by which the control module controls the connection or disconnection between the purge valve (8) and a purge pipeline (9) is as follows: Determine the mass m of condensate generated in the sampling line (5) connected to the purging line (9) per unit time: m = Q / L Where 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 condensate, the volume v of condensate generated per unit time in the sampling pipeline (5) is obtained: v = m / ρ Where ρ is the mass of water; The time interval t1 during which the control module controls the purge valve (8) to disconnect from the purge pipeline (9) is: t1 = V / v Where V is the preset condensate volume threshold; The minimum duration t2 for which the control module controls the connection between the purge valve (8) and the purge pipeline (9) is: t2=l*π*r 2 / q where l is the length of the sampling pipeline (5), r is the inner radius of the sampling pipeline (5), and q is the purge gas flow rate output by the purge valve (8); The preset condensate volume threshold V is: V＝8*π*r 2 Where r is the inner radius of the sampling pipeline (5).

2. The anesthesia machine according to claim 1, characterized in that, The plurality of sampling tubing (5) includes: an expiratory sampling tubing group and an inspiratory sampling tubing group; wherein, The expiratory sampling tubing assembly includes: an expiratory flow sampling tubing and an expiratory pressure sampling tubing; The inhalation sampling tubing assembly includes: an inhalation flow rate sampling tubing and an inhalation pressure sampling tubing; When the respiratory 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 inspiratory sampling line group; when the respiratory 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 inspiratory sampling line group.

3. A method for controlling the purge valve of an anesthesia machine, implemented based on the anesthesia machine of claim 1, comprising: The purge valve (8) is connected or disconnected from several purge pipelines (9) by the control module. 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 condensate in the sampling pipeline (5). The process by which the control module controls the connection or disconnection between the purge valve (8) and a purge pipeline (9) is as follows: Determine the mass m of condensate generated in the sampling line (5) connected to the purging line (9) per unit time: m = Q / L Where 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 condensate, the volume v of condensate generated per unit time in the sampling pipeline (5) is obtained: v = m / ρ Where ρ is the mass of water; The time interval t1 during which the control module disconnects the purge valve (8) from the purge line (9) is obtained: t1 = V / v Where V is the preset condensate volume threshold; The minimum duration t2 for which the control module controls the purge valve (8) to be connected to the purge line (9) is obtained: t2=l*π*r 2 / q where l is the length of the sampling pipeline (5), r is the inner radius of the sampling pipeline (5), and q is the purge gas flow rate output by the purge valve (8); The preset condensate volume threshold V is: V＝8*π*r 2 Where r is the inner radius of the sampling pipeline (5).

4. The control method for the purge valve of the anesthesia machine according to claim 3, characterized in that, The plurality of sampling tubing (5) includes: an expiratory sampling tubing group and an inspiratory sampling tubing group; wherein, The expiratory sampling tubing assembly includes: an expiratory flow sampling tubing and an expiratory pressure sampling tubing; The inhalation sampling tubing assembly includes: an inhalation flow rate sampling tubing and an inhalation pressure sampling tubing; When the respiratory 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 respiratory 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.

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