Ventilator automatic air supplement device and method thereof

Abstract

The application discloses a kind of ventilator automatic air supplement device and method thereof, including oxygen supply unit, air supply unit, gas mixing unit, gas output unit, detection unit and control unit, the gas mixing unit includes inner mixing cavity and piston that is movably arranged in inner mixing cavity, air inlet, oxygen inlet and mixed gas outlet are provided on the inner mixing cavity, first valve is provided on the air inlet, second valve is provided on the mixed gas outlet, flow control valve is provided on the oxygen inlet, the oxygen supply unit is connected with flow control valve, the air supply unit is connected with first valve, the gas output unit is connected with second valve, solve the low efficiency of air-oxygen mixing of ventilator, oxygen configuration concentration is not accurate, and the situation that mixed gas is not mixed uniformly.

Description

Technical Field

[0001] This invention belongs to the field of oxygen concentration regulation technology for ventilators, and particularly relates to an automatic supplemental gas device and method for ventilators. Background Technology

[0002] In modern clinical medicine, ventilators, as an effective means of artificially replacing spontaneous ventilation, are widely used for respiratory failure caused by various reasons, anesthetic respiratory management during major surgery, respiratory support therapy, and emergency resuscitation, occupying a very important position in the field of modern medicine. Treatment ventilators generally have two gas sources: oxygen and air. By adjusting the oxygen supply, the oxygen concentration can be adjusted within a wider range. Current air-oxygen mixing methods are mainly active mixing and passive mixing.

[0003] Chinese patent CN213077101U discloses a ventilator air-oxygen mixing module, which introduces an active air-oxygen mixing mechanism. It automatically mixes oxygen and air by venting them into a mixing chamber. The mixing chamber is equipped with baffles to change the direction of airflow and improve the mixing effect. However, the active mixing effect is difficult to guarantee and the mixing efficiency is low. It can be used in small mixing chambers.

[0004] Chinese patent application CN116492559A discloses a method for mixing air and oxygen by combining passive mixing with active mixing. The passive mixing uses stirring blades, which is a common passive mixing method. During the mixing process, the probability of internal collisions does not increase significantly due to the driving force of stirring. Therefore, a long mixing time is required to ensure the mixing quality.

[0005] Based on this, it can be seen that the current air-oxygen mixing method has low efficiency and the mixing quality is difficult to guarantee. Due to the unevenness of gas mixing, the detection results are incorrect, making the acquisition of compensation amount inaccurate and the output gas difficult to meet the required standards. Summary of the Invention

[0006] The purpose of this invention is to provide an automatic air replenishment device and method for ventilators, so as to solve the problems of low air-oxygen mixing efficiency, inaccurate oxygen concentration, and uneven mixing of air and gas in ventilators.

[0007] To achieve the objectives of this invention, an automatic gas replenishment device for a ventilator is disclosed, comprising an oxygen supply unit, an air supply unit, a gas mixing unit, a gas output unit, a detection unit, and a control unit. The control unit is used for overall coordination and control. The gas mixing unit includes an inner mixing chamber and a piston movably disposed within the inner mixing chamber. The inner mixing chamber is provided with an air inlet, an oxygen inlet, and a mixed gas outlet. A first valve is provided on the air inlet, a second valve is provided on the mixed gas outlet, and a flow control valve is provided on the oxygen inlet. The oxygen supply unit is connected to the flow control valve, the air supply unit is connected to the first valve, and the gas output unit is connected to the second valve.

[0008] As a further improvement to the above technical solution:

[0009] The gas output unit is connected to an external mixing chamber, and the detection unit includes a first detection point and a second detection point. The first detection point is located at the inlet end of the external mixing chamber, and the second detection point is located at the outlet end of the external mixing chamber.

[0010] The air inlet of the external mixing chamber is equipped with a three-way valve. The first end of the three-way valve is connected to the external mixing chamber, the second end is connected to the gas output unit, and the third end is connected to the air supply unit.

[0011] The air supply unit includes a gas storage chamber, a third detection point is provided in the gas storage chamber, and the third end of the three-way valve is connected to the gas storage chamber.

[0012] A connecting rod is rotatably mounted on the rear of the piston, and the connecting rod is movably mounted on the crankshaft.

[0013] The first valve and the second valve are elastic push rod structures. A valve control camshaft is provided on the upper part of the elastic push rod structure. The valve control camshaft is connected to the crankshaft through a transmission belt. The crankshaft is connected to a drive disc.

[0014] An air intake filter is provided at the front end of the gas storage chamber.

[0015] It also includes a generator and a charging power supply. The generator is connected to the crankshaft, and the charging power supply is connected to the control unit for overall power supply.

[0016] This invention also discloses an automatic respiration method for a ventilator, comprising the following steps:

[0017] S1. Obtain the required oxygen concentration data. This oxygen concentration acquisition includes the initial selection of values ​​by professionals based on experience and the correction based on the actual situation.

[0018] S2. Based on the required oxygen concentration data, construct the primary regulation model of flow control valve 316;

[0019] S3, the gas mixing unit 3 processes the gas; first, the piston 32 moves downward, and the air in the gas storage chamber 21 enters the inner mixing chamber 31 from the air inlet 311. The first valve 314 is closed, and the oxygen intake is controlled by the flow control valve 316. The piston 32 moves upward to compress the gas mixture. Then the piston 32 moves downward to depressurize the gas mixture. The second valve 315 is opened, and the piston 32 moves upward, and the gas mixture is discharged from the gas mixture outlet 313.

[0020] S4. The first detection point 51 detects the concentration of the mixed gas at the mixed gas outlet 313. If the concentration detection at the first detection point 51 fails, the gas will not enter the external mixing chamber 6 and will flow back to the gas storage chamber 21 from the third end of the three-way valve 61.

[0021] If the concentration detected at the first detection point 51 is qualified, the gas enters the outer mixing chamber 6 and is mixed in the outer mixing chamber 6.

[0022] S5. The oxygen concentration in the gas storage chamber 21 after reflux is detected through the third detection point 53, and a secondary regulation model of the flow control valve 316 is constructed to adjust the oxygen intake.

[0023] S6. The concentration of the gas mixed in the external mixing chamber is detected through the second detection point 52.

[0024] If the test fails, the final regulation model of the flow control valve 316 is constructed to adjust the oxygen intake.

[0025] If the test is passed, it can be discharged.

[0026] The concentration detection includes the following steps:

[0027] S81. Obtain oxygen concentration data for several sections: x1, x2, x3...x i ;

[0028] S82. Perform data homogenization processing:

[0029] S83. Set a standard concentration value S, and determine the relationship between the standard concentration value S and the standard concentration value S.

[0030] If < S, then for the first detection point 51 and the second detection point 52, the concentration detection is considered unqualified;

[0031] If d > S, then set a standard deviation K and determine the relationship between d and K.

[0032] If d < K, then for the first detection point 51 and the second detection point 52, the concentration detection is considered qualified.

[0033] If d > K, the first detection point 51 is considered qualified, while the second detection point 52 is considered unqualified.

[0034] Compared with the prior art, the beneficial effects of the present invention are:

[0035] The automatic gas replenishment device for ventilators of the present invention uses a flow control valve as the driving mechanism for automatic gas replenishment. It adopts a combination of compression mixing and stirring mixing, which significantly improves the mixing efficiency. Through two mixing and oxygen addition, it ensures that the oxygen distribution in the mixed gas is uniform, thus ensuring both the oxygen concentration and the uniform concentration distribution.

[0036] The automatic oxygen replenishment method for ventilators of the present invention can precisely adjust and provide feedback adjustment of the oxygen intake through multiple concentration detection points, so that the oxygen concentration in the mixed gas meets the standard and is mixed evenly, so that the oxygen concentration is the same in each section, thus ensuring the accuracy of oxygen concentration adjustment. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the device structure in Embodiment 1 of the present invention;

[0038] Figure 2 This is a schematic diagram of the device structure in Embodiment 2 of the present invention;

[0039] Figure 3 This is one of the schematic diagrams of the device structure in Embodiment 3 of the present invention;

[0040] Figure 4 This is a second schematic diagram of the device structure in Embodiment 3 of the present invention;

[0041] Figure 5 This is a schematic diagram of the device structure in Embodiment 6 of the present invention;

[0042] Figure 6 This is a schematic diagram of the method flow in Embodiment 6 of the present invention.

[0043] Reference numerals: 1. Oxygen supply unit; 2. Air supply unit; 21. Gas storage chamber; 3. Gas mixing unit; 31. Internal mixing chamber; 311. Air inlet; 312. Oxygen inlet; 313. Mixed gas outlet; 314. First valve; 315. Second valve; 316. Flow control valve; 317. Valve control camshaft; 32. Piston; 321. Connecting rod; 33. Crankshaft; 34. Drive belt; 4. Gas output unit; 5. Detection unit; 51. First detection point; 52. Second detection point; 53. Third detection point; 6. External mixing chamber; 61. Three-way valve; 35. Drive disc; 22. Intake filter; 60. Oxygen compensation port; 7. Generator. Detailed Implementation

[0044] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0045] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0046] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] Example 1

[0049] like Figure 1As shown, the automatic gas replenishment device for the ventilator in this embodiment includes an oxygen supply unit 1, an air supply unit 2, a gas mixing unit 3, a gas output unit 4, a detection unit 5, and a control unit. The gas mixing unit 3 includes an inner mixing chamber 31 and a piston 32 movably disposed in the inner mixing chamber 31. The inner mixing chamber 31 is provided with an air inlet 311, an oxygen inlet 312, and a mixed gas outlet 313. A first valve 314 is provided on the air inlet 311, a second valve 315 is provided on the mixed gas outlet 313, and a flow control valve 316 is provided on the oxygen inlet 312. The oxygen supply unit 1 is connected to the flow control valve 316, the air supply unit 2 is connected to the first valve 314, and the gas output unit 4 is connected to the second valve 315. This embodiment employs compression mixing. Air and oxygen are input into the inner mixing chamber 31, and then the piston 32 moves upward to compress the mixed gas. Next, the piston 32 moves downward to depressurize the mixed gas. During compression, the probability of collisions between molecules increases, as does the probability of collisions between oxygen and air, which is beneficial for mixing. During depressurization, the compressed gas is dispersed, which also has a positive effect on air-oxygen mixing. Through compression and depressurization, the mixing quality of the gas is effectively guaranteed.

[0050] Example 2

[0051] like Figure 2 As shown, unlike Embodiment 1, the gas output unit 4 in this embodiment is connected to an external mixing chamber 6, and the detection unit 5 includes a first detection point 51 and a second detection point 52. The first detection point 51 is located at the inlet end of the external mixing chamber 6, and the second detection point 52 is located at the outlet end of the external mixing chamber 6. Although compression and depressurization can ensure a certain mixing quality, uneven mixing still exists. Based on this, Embodiment 2 uses an external mixing chamber 6 to re-stir and mix the mixed gas, and a stirring mechanism is provided inside the external mixing chamber 6. The purpose of the detection unit 5 is to detect the oxygen concentration in the mixed gas, and the first detection point 51 is used to detect the oxygen concentration at the outlet of the internal mixing chamber 31.

[0052] A three-way valve 61 is installed at the air inlet of the external mixing chamber 6. The first end of the three-way valve 61 is connected to the external mixing chamber 6, the second end is connected to the gas output unit 4, and the third end is connected to the air supply unit 2. Due to mechanical errors, if the oxygen concentration detected at the first detection point 51 is much lower than the standard value (here, "much lower than" means greater than 5%), the mixed gas will be pumped back to the air supply unit 2 through the third end of the three-way valve 61.

[0053] The air supply unit 2 includes a gas storage chamber 21, a third detection point 53 is provided in the gas storage chamber 21, and the third end of the three-way valve 61 is connected to the gas storage chamber 21.

[0054] During use, an oxygen regulation model can be constructed based on the oxygen concentration at the third detection point 53 to adjust the oxygen supply of oxygen supply unit 1.

[0055] Example 3

[0056] like Figure 3 and Figure 4 As shown, unlike Embodiment 2, a connecting rod 321 is rotatably mounted on the rear of the piston 32, and the connecting rod 321 is movably mounted on the crankshaft 33. To improve gas supply efficiency, this embodiment employs a multi-chamber gas configuration, and for ease of drive, a crank-connecting rod structure is used. The chambers can be two, three, four, or more. The movement of the crankshaft 33 drives the connecting rod 321, which in turn drives the piston 32 to move within the inner mixing chamber 31.

[0057] The first valve 314 and the second valve 315 are elastic pushrod structures. A valve control camshaft 317 is mounted on the upper part of the elastic pushrod structure. The valve control camshaft 317 is connected to the crankshaft 33 via a transmission belt 34. The crankshaft 33 is connected to a drive disc 35. The drive structure design here is similar to the layout of a fuel engine, especially the crankshaft, connecting rod, piston, and valve train. Taking one of the internal mixing chambers as an example, as the crankshaft 33 moves, it drives the valve control camshaft 317 to rotate, which in turn drives the elastic pushrod structure. First, it drives the first valve 314 to move. At this time, the piston moves downward, allowing air to enter the chamber. Oxygen also enters the chamber from the flow control valve 316. Then, the piston moves upward, compressing the gas mixture and promoting gas mixing. Then, the piston moves downward, applying pressure to the gas mixture, dispersing any unevenly agglomerated gas and playing a positive role in gas mixing. As the crankshaft continues to rotate, the elastic pushrod structure finally opens the second valve 315, and the piston 32 moves upward, pushing the gas mixture out. The gas mixture is discharged from the gas mixture outlet 313.

[0058] Example 4

[0059] To enhance comfort and safety, an air intake filter 22 is installed at the front end of the gas storage chamber 21. This filter can be used to filter the gas, as well as to heat and humidify it.

[0060] Example 5

[0061] Since medical equipment cannot be affected by power outages, this embodiment also includes a generator 7 and a charging power supply. The generator 7 is connected to the crankshaft 33, and the charging power supply is connected to the control unit for overall power supply. A crank handle is provided on the rotating disc 35 of the crankshaft 33. Operating the crank handle drives the entire device. The device is powered by the charging power supply. During the rotation of the crankshaft 33, the generator 7 is driven to charge the charging power supply, ensuring continuous operation of the device unaffected by external power sources and effectively guaranteeing safe use. When power is available, a motor can drive the crankshaft 33 to charge the charging power supply.

[0062] Example 6

[0063] like Figure 6 As shown in the figure, this embodiment discloses an automatic respiration method for a ventilator, including the following steps:

[0064] S1. Obtain the required oxygen concentration data. This oxygen concentration acquisition includes the initial selection of values ​​by professionals based on experience and corrections based on actual conditions. The required oxygen concentration data is a specific value set as needed, such as an oxygen concentration of 56%, with an allowable error range typically set to ±1%.

[0065] S2. Based on the required oxygen concentration data, construct the primary regulation model of flow control valve 316; the primary regulation model here is the standard oxygen concentration in constant air, and the corresponding amount of oxygen is supplemented according to the air intake.

[0066] S3, the gas mixing unit 3 mixes the incoming gas; here, a compression mixing method is used. First, the piston 32 moves downward, and the air in the gas storage chamber 21 enters the inner mixing chamber 31 through the air inlet 311. The first valve 314 is closed, and the oxygen intake is controlled by the flow control valve 316. The piston 32 moves upward to compress the mixed gas. Then, the piston 32 moves downward to release the pressure of the mixed gas. The second valve 315 is opened, and the piston 32 moves upward, and the mixed gas is discharged from the mixed gas outlet 313. Compared with the traditional blade mixing, the compression mixing method can compress the gas volume, and the gas molecules are closer together, which is conducive to collisions between molecules and completes the mixing, making it effectively mixed.

[0067] S4. The first detection point 51 detects the concentration of the mixed gas at the mixed gas outlet 313. Although the overall concentration of the mixed gas is fixed under the condition that no leakage occurs, whether its mixing is uniform has a significant impact on subsequent use. Based on this, a concentration detection method is introduced, including the following steps:

[0068] S81. Obtain oxygen concentration data for several sections x1, x2, x3...x iThis section involves installing multiple sensors on the pipeline, or conducting multiple tests at the same location to obtain the aforementioned concentration data.

[0069] S82. Perform data homogenization processing: The purpose of homogenization is to determine the mixing effect.

[0070] S83. Set the standard concentration value S, and determine... The relationship between the standard concentration value S and the magnitude of the standard concentration value.

[0071] like For the first detection point 51 and the second detection point 52, the concentration detection is considered unqualified;

[0072] like Then set a standard deviation K, and determine the relationship between d and K.

[0073] If d < K, then for the first detection point 51 and the second detection point 52, the concentration detection is considered qualified.

[0074] If d > K, the first detection point 51 is considered qualified, while the second detection point 52 is considered unqualified.

[0075] If the concentration at the first detection point 51 fails to meet the standard, the gas will not enter the external mixing chamber 6 and will instead flow back to the gas storage chamber 21 from the third end of the three-way valve 61. The failure here is attributed to insufficient oxygen, so the gas is refluxed. Then, the oxygen concentration in the refluxed gas storage chamber 21 is detected at the third detection point 53, and a secondary regulation model for the flow control valve 316 is constructed. The determination of this oxygen concentration allows for further adjustment of the oxygen intake. The first detection point 51 is not affected by the oxygen quantity.

[0076] If the concentration detected at the first detection point 51 is within acceptable limits, the gas enters the outer mixing chamber 6 and is mixed within it. At this point, the oxygen concentration is considered acceptable and meets the standard. To ensure the mixing quality, further mixing is required within the outer mixing chamber. After mixing, the concentration of the gas mixed in the outer mixing chamber is detected at the second detection point 52.

[0077] like Figure 5As shown, if the test fails, a final adjustment model for the flow control valve 316 is constructed to adjust the oxygen intake. There are two possible causes for this failure: one is insufficient oxygen due to poor sealing of the external mixing chamber or other reasons; the other is uneven mixing. This final adjustment model first involves continued mixing in the external mixing chamber, which is equipped with stirring blades. A magnetic, non-contact driving mechanism is used to reduce the need for rotating seals and prevent leakage caused by stirring rotation. If the test still fails, gas is introduced into 21, and the oxygen intake is further adjusted via the flow control valve 316 to ensure adequate oxygen supply. If this cannot be guaranteed, a leak is considered to have occurred, requiring repair to ensure a proper seal.

[0078] If the test is satisfactory, the gas can be discharged. It should be noted that the apparatus and method of this application are not only applicable to ventilator gas supply, but also suitable for hyperbaric oxygen chambers and other scenarios requiring oxygen preparation. The automatic ventilator gas replenishment method of this embodiment can adjust the oxygen intake in real time to ensure qualified oxygen concentration. It employs a combination of compression premixing and stirring mixing, significantly improving mixing efficiency while ensuring mixing quality, thus solving the problems of low air-oxygen mixing efficiency, inaccurate oxygen concentration, and uneven gas mixing in ventilators.

[0079] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics of the solutions is not described in detail here. It will be apparent to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the present invention is defined by the appended claims rather than the foregoing description. Therefore, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. An automatic refueling device for a ventilator, comprising an oxygen supply unit (1), an air supply unit (2), a gas mixing unit (3), a gas output unit (4), a detection unit (5), and a control unit, characterized in that: The gas mixing unit (3) includes an inner mixing chamber (31) and a piston (32) movably disposed in the inner mixing chamber (31). The inner mixing chamber (31) is provided with an air inlet (311), an oxygen inlet (312), and a mixed gas outlet (313). A first valve (314) is provided on the air inlet (311), a second valve (315) is provided on the mixed gas outlet (313), and a flow control valve (316) is provided on the oxygen inlet (312). The oxygen supply unit (1) is connected to the flow control valve (316), and the air supply unit (2) is connected to the first... The gas output unit (4) is connected to the second valve (315). In use, the gas mixing unit (3) processes the gas. First, the piston (32) moves downward, and the air in the gas storage chamber (21) enters the inner mixing chamber (31) from the air inlet (311). The first valve (314) is closed, and the oxygen intake is controlled by the flow control valve (316). The piston (32) moves upward to compress the mixed gas. Then, the piston (32) moves downward to release the pressure of the mixed gas. The second valve (315) is opened, and the piston (32) moves upward to discharge the mixed gas from the mixed gas outlet (313). The gas output unit (4) is connected to an external mixing chamber (6), and the detection unit (5) includes a first detection point (51) and a second detection point (52). The first detection point (51) is located at the inlet end of the external mixing chamber (6), and the second detection point (52) is located at the outlet end of the external mixing chamber (6). The air inlet of the external mixing chamber (6) is provided with a three-way valve (61). The first end of the three-way valve (61) is connected to the external mixing chamber (6), the second end is connected to the gas output unit (4), and the third end is connected to the air supply unit (2). The air supply unit (2) includes a gas storage chamber (21), and a third detection point (53) is provided in the gas storage chamber (21). The third end of the three-way valve (61) is connected to the gas storage chamber (21). The first detection point (51) detects the concentration of the mixed gas at the mixed gas outlet (313). If the concentration detected by the first detection point (51) is qualified, the gas enters the outer mixing chamber (6) and is mixed in the outer mixing chamber (6). If the oxygen concentration detected at the first detection point (51) is much lower than the standard value, the mixed gas is pumped back to the gas storage chamber (21) through the third end of the three-way valve (61); then the oxygen concentration in the gas storage chamber (21) after the return is detected through the third detection point (53), and the oxygen intake is adjusted through the flow control valve (316). The concentration of the gas mixed in the external mixing chamber is detected by the second detection point (52). If the detection is qualified, it can be discharged. If the test fails, the oxygen supply can be further adjusted by the flow control valve (316).

2. The automatic ventilator supplementation device according to claim 1, characterized in that: The piston (32) is rotatably mounted with a connecting rod (321) at its rear, and the connecting rod (321) is movably mounted on the crankshaft (33).

3. The automatic respiration device for a ventilator according to claim 1, characterized in that: The first valve (314) and the second valve (315) are elastic push rod structures. A valve control camshaft (317) is provided on the upper part of the elastic push rod structure. The valve control camshaft (317) is connected to the crankshaft (33) through a transmission belt (34). The crankshaft (33) is connected to a drive disc (35).

4. The automatic respiration device for a ventilator according to claim 1, characterized in that: An air intake filter (22) is provided at the front end of the gas storage chamber (21).

5. The automatic respiration device for a ventilator according to claim 1, characterized in that: It also includes a generator (7) and a charging power supply, wherein the generator (7) is connected to the crankshaft (33) and the charging power supply is connected to the control unit for overall power supply.

6. The automatic respiration device for a ventilator according to claim 1, characterized in that, The concentration detection includes the following steps: S81. Obtain oxygen concentration data for several sections: x1, x2, x3...x i ; S82. Perform data homogenization processing: ; S83. Set the standard concentration value S, and determine... The relationship between the standard concentration value S and the magnitude of the standard concentration value. like <S, for the first detection point (51) and the second detection point (52), the concentration detection is considered unqualified; like If d > S, then set a standard deviation K and determine the relationship between d and K. If d < K, then for the first detection point (51) and the second detection point (52), the concentration detection is considered qualified. If d > K, the first detection point (51) is considered qualified, while the second detection point (52) is considered unqualified.

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