Stepped multi-dimensional calibration method, detection method and electrochemical sensor

Abstract

The invention discloses a stepped multi-dimensional calibration method, a detection method and an electrochemical sensor, and the method comprises the steps: obtaining a first calibration data set of a first temperature environment according to a first group of standard gas concentration data and a first group of voltage variation data; correcting the second group of standard gas concentration data and the second group of voltage variable data to obtain a first group of corrected standard gas concentration data and a first group of corrected voltage variable data, and obtaining a second calibration data set of a second temperature environment; correcting the third group of standard gas concentration data and the third group of voltage variable data to obtain a second group of corrected standard gas concentration data and a second group of corrected voltage variable data, and obtaining a third calibration data set of the environment of the third temperature; the standard unification of the standard gas calibration data is ensured, the operation error, the process error and the detection error caused by the temperature change are obviously reduced, and the problem of low detection precision of the existing calibration technology is solved.

Description

Technical Field

[0001] This invention relates to the field of nitric oxide detection technology, and in particular to a step-by-step multidimensional calibration method, detection method, and electrochemical sensor. Background Technology

[0002] The nitric oxide content in exhaled breath is closely related to airway inflammation. Nitric oxide detection technology for the upper and lower airways, as well as large and small airways, provides important reference for the diagnosis and treatment of airway diseases such as bronchial asthma, chronic cough, and chronic obstructive pulmonary disease. The accuracy of nitric oxide detection directly affects doctors' assessment of patients' conditions. Because the content of nitric oxide in exhaled breath is extremely low, measured in ppb (parts per billion), the precision requirements for the detection sensors are extremely high.

[0003] As the core component for exhaled NO detection, the performance of electrochemical sensors is easily affected by fluctuations in their own structure and manufacturing process. For example, differences in the uniformity of the sensor's sensitive membrane thickness and the microstructure of the electrode spacing can lead to variations in the contact area and degree of reaction with nitric oxide gas, resulting in individual sensitivity deviations. Furthermore, factors such as equipment stability on the production line and batch variations in materials can also affect product quality. Slight differences in the purity and composition of raw materials from different batches can cause fluctuations in the performance of the electrochemical sensor, leading to inconsistent output results for sensors of the same model under the same detection conditions.

[0004] Therefore, precise calibration of each electrochemical sensor is essential to ensure the reliability of exhaled NO detection results and meet clinical diagnostic needs. In existing technologies, the calibration of electrochemical sensors typically involves selecting a single specific temperature (e.g., room temperature 25°C) as the calibration environment, collecting the sensor output signal corresponding to standard NO gas at that temperature, and establishing a linear "concentration-signal" relationship. In actual detection scenarios, only a simple compensation is made for detection results deviating from the calibration temperature using a linear interpolation formula.

[0005] In practical testing, temperature has a significant impact on the detection accuracy of electrochemical sensors. Temperature changes affect the chemical reaction rate within the nitric oxide sensor. Increased temperature accelerates the reaction rate, potentially improving sensor sensitivity, but may also decrease sensor stability, leading to significant fluctuations in measurement results. Conversely, decreased temperature slows the reaction rate, potentially prolonging the sensor's response time (requiring more time to provide accurate measurements) and possibly reducing sensitivity. Current technologies rely solely on linear compensation based on single temperature calibration data, failing to adapt to the nonlinear temperature response characteristics, resulting in a significant increase in detection error as the temperature deviates from the calibration value. Summary of the Invention

[0006] Existing calibration techniques do not consider operational errors, process errors, and temperature changes. They rely solely on linear compensation based on single temperature calibration data, which fails to adapt to the nonlinear temperature response characteristics, resulting in low detection accuracy.

[0007] To address the aforementioned issues, a tiered, multi-dimensional calibration method, detection method, and electrochemical sensor are proposed. By correcting the concentration data in the second and third sets of standard gas concentration data, the benchmark consistency of the standard gas calibration data is ensured. This significantly reduces detection errors caused by operational errors, process errors, and temperature variations. Each electrochemical sensor can be calibrated individually, establishing a dedicated "temperature-concentration-voltage" calibration model. This effectively offsets individual sensitivity deviations caused by production process fluctuations, improves detection consistency, and solves the problem of low detection accuracy in existing calibration technologies.

[0008] Firstly, a hierarchical multi-dimensional calibration method includes:

[0009] Step 100: Place the electrochemical sensor in an environment at a first temperature, acquire the first set of standard gas concentration data, sequentially introduce nitric oxide gas from the first set of standard gas concentration data into the reaction chamber of the electrochemical sensor, acquire the first set of voltage change data, and acquire the first calibration dataset of the first temperature environment based on the first set of standard gas concentration data and the first set of voltage change data.

[0010] Step 200: Place the electrochemical sensor in an environment at a second temperature, acquire a second set of standard gas concentration data, sequentially introduce nitric oxide gas from the second set of standard gas concentration data into the reaction chamber of the electrochemical sensor, acquire a second set of voltage change data, if there is a deviation between the second set of standard gas concentration data and the first set of standard gas concentration data, correct the second set of standard gas concentration data and the second set of voltage change data to obtain a first set of corrected standard gas concentration data and a first set of corrected voltage change data, and acquire a second calibration dataset for the second temperature environment based on the first set of corrected standard gas concentration data and the first set of corrected voltage change data;

[0011] Step 300: Place the electrochemical sensor in a third temperature environment and acquire a third set of standard gas concentration data. Sequentially introduce nitric oxide gas, which represents the third set of standard gas concentration data, into the reaction chamber of the electrochemical sensor to acquire a third set of voltage change data. If there is a deviation between the third set of standard gas concentration data and the first set of standard gas concentration data, correct the third set of standard gas concentration data and the third set of voltage change data to obtain a second set of corrected standard gas concentration data and a second set of corrected voltage change data. Based on the second set of corrected standard gas concentration data and the second set of corrected voltage change data, acquire a third calibration dataset for the third temperature environment.

[0012] Wherein, the second temperature is less than the first temperature, the first temperature is less than the third temperature, and any set of standard gas concentration data includes at least two standard gas concentrations.

[0013] In conjunction with the hierarchical multidimensional calibration method described in the first aspect of the present invention, in a first possible implementation, step 100 includes:

[0014] Step 110: In the environment of the first temperature, in order of increasing concentration, nitric oxide of the first set of standard gas concentration data is introduced into the reaction chamber of the electrochemical sensor, and the voltage change of each concentration is recorded respectively.

[0015] Step 120: Obtain the first calibration dataset using each voltage change and the corresponding standard nitric oxide concentration data, and store the first calibration dataset and the first temperature data in the first storage area of ​​the electrochemical sensor.

[0016] In conjunction with the first possible embodiment of the first aspect of the present invention, in the second possible embodiment, step 200 includes:

[0017] Step 210: In the environment of the second temperature, the second set of standard gas concentrations are introduced into the reaction chamber of the electrochemical sensor, and the voltage change corresponding to each standard gas concentration is recorded.

[0018] Step 220: Obtain the absolute value of the difference between each of the second set of standard gas concentration data and the corresponding data in the first set of standard gas concentration data. If the absolute value of the difference is not zero, correct the second set of standard gas concentration data and the second set of voltage change data.

[0019] In conjunction with the second possible implementation of the first aspect of the present invention, in the third possible implementation, step 220 includes:

[0020] Step 221: Obtain the first correction formula for the second set of standard gas concentration data and the second set of voltage change data under the second temperature environment:

[0021]

[0022] Step 222: Correct the second set of standard gas concentration data according to the first set of standard gas concentration data, and correct the second set of voltage change data according to the first correction formula;

[0023] Where n is a natural number, n = 1, 2, ..., δ n (t1) represents the standard concentration β corresponding to the second temperature environment. n The change in calibration voltage (t1), δ'n (t1) The second temperature corresponds to the concentration data β'. n The voltage change at (t1).

[0024] In conjunction with the first possible embodiment of the first aspect of the present invention, in the fourth possible embodiment, step 300 includes:

[0025] Step 310: In the environment of the third temperature, the third set of standard gas concentrations are introduced into the reaction chamber of the electrochemical sensor, and the voltage change corresponding to each standard gas concentration is recorded.

[0026] Step 320: Obtain the absolute value of the difference between each of the third set of standard gas concentration data and the corresponding data in the first set of standard gas concentration data. If the absolute value of the difference is not zero, correct the third set of standard gas concentration data and the third set of voltage change data.

[0027] In conjunction with the fourth possible implementation of the first aspect of the present invention, in the fifth possible implementation, step 320 includes:

[0028] Step 321: Obtain the second correction formula for the third set of standard gas concentration data and the third set of voltage change data under the third temperature environment:

[0029]

[0030] Step 322: Correct the third set of standard gas concentration data according to the first set of standard gas concentration data, and correct the third set of voltage change data according to the second correction formula;

[0031] Where n is a natural number, n = 1, 2, ..., and δn(t2) is the standard concentration β corresponding to the third temperature environment. n The calibration voltage change of (t2), β” n (t2) The third temperature corresponds to the concentration data β” n The voltage change at (t2).

[0032] Secondly, a detection method employing the hierarchical multidimensional calibration method described in the first aspect includes:

[0033] Step 400: Collect the current ambient temperature and compare it with a first temperature. If the current ambient temperature is equal to or less than the first temperature, read the first calibration dataset and the second calibration dataset. If the current ambient temperature is greater than the first temperature, read the first calibration dataset and the third calibration dataset.

[0034] Step 500: Obtain the fourth set of standard gas concentration data of the current ambient temperature; calculate the fourth set of voltage change corresponding to the standard gas concentration data using linear interpolation based on the first calibration dataset, the second calibration dataset, or the third calibration dataset; and obtain the first virtual calibration dataset based on the fourth set of standard gas concentration data and the fourth set of voltage change.

[0035] Step 600: Based on the first virtual calibration dataset, perform linear fitting using the least squares method to obtain a linear fitting model;

[0036] Step 700: Obtain the current voltage change and calculate the concentration data of nitric oxide exhaled by the user using the linear fitting model.

[0037] In conjunction with the detection method described in the second aspect of the present invention, in a first possible embodiment, step 500 includes:

[0038] Step 510: Construct linear interpolation models for different temperatures to obtain the first linear interpolation model and the second linear interpolation model;

[0039] Step 520: If the current ambient temperature is equal to or less than the first temperature, then construct the first linear interpolation model based on the first calibration dataset and the second calibration dataset, and obtain the first virtual calibration dataset;

[0040] Step 530: If the current ambient temperature is greater than the first temperature, then the second linear interpolation model will be constructed based on the first calibration dataset and the third calibration dataset to obtain the first virtual calibration dataset.

[0041] In conjunction with the detection method described in the second aspect, in a second possible implementation, step 600 includes:

[0042] Step 610: Calculate the slope and intercept of the linear fitting model based on the first virtual calibration dataset;

[0043] Step 620: Construct the linear fitting model based on the slope and intercept.

[0044] Thirdly, an electrochemical sensor is calibrated using the step-by-step multidimensional calibration method described in the first aspect, and its nitric oxide concentration is detected using the detection method described in the second aspect.

[0045] By implementing the tiered multi-dimensional calibration method, detection method, and electrochemical sensor described in this invention, the concentration data in the second set of standard gas concentration data and the concentration data in the third set of standard gas concentration data are corrected. This ensures the benchmark consistency of the standard gas calibration data, significantly reduces detection errors caused by operational errors, process errors, and temperature changes, and allows for individual calibration of each electrochemical sensor, establishing a dedicated "temperature-concentration-voltage" calibration model. This effectively offsets individual sensitivity deviations caused by fluctuations in the production process, improves detection consistency, and solves the problem of low detection accuracy in existing calibration technologies. Attached Figure Description

[0046] To more clearly illustrate the solutions in this application, the accompanying drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a flowchart of an embodiment of a hierarchical multidimensional calibration method of this application;

[0048] Figure 2 yes Figure 1 A flowchart of a specific implementation of S100;

[0049] Figure 3 yes Figure 1 A flowchart of a specific implementation of S200;

[0050] Figure 4 yes Figure 3 A flowchart of a specific implementation of S220;

[0051] Figure 5 yes Figure 1 A flowchart of a specific implementation of S300;

[0052] Figure 6 yes Figure 5 A flowchart of a specific implementation of S320;

[0053] Figure 7 This is a flowchart of an embodiment of a detection method of this application;

[0054] Figure 8 yes Figure 7 A flowchart of a specific implementation of the S500;

[0055] Figure 9 yes Figure 7 A flowchart of a specific implementation of the S600;

[0056] Figure 10 These are schematic diagrams of the three temperature calibration data curves of this application;

[0057] Figure 11 This is a schematic diagram of the linear fitting model curve of this application. Detailed Implementation

[0058] The technical solutions of this invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are all within the scope of protection of this invention.

[0059] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0060] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings of this application are intended to cover non-exclusive inclusion.

[0061] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0062] Existing technologies rely solely on linear compensation based on single temperature calibration data, which fails to adapt to the nonlinear temperature response characteristics, resulting in a significant increase in detection error as the temperature deviates from the calibration value.

[0063] To address the aforementioned issues, a tiered, multi-dimensional calibration method, a detection method, and an electrochemical sensor are proposed.

[0064] Firstly, a hierarchical, multi-dimensional calibration method, such as... Figure 1 , Figure 1This is a flowchart of an embodiment of a hierarchical multidimensional calibration method according to this application; including:

[0065] S100. Place the electrochemical sensor in an environment at a first temperature, acquire the first set of standard gas concentration data, sequentially introduce nitric oxide gas from the first set of standard gas concentration data into the reaction chamber of the electrochemical sensor, acquire the first set of voltage change data, and acquire the first calibration dataset of the first temperature environment based on the first set of standard gas concentration data and the first set of voltage change data.

[0066] In this embodiment, the core reaction for NO detection by the electrochemical sensor is based on a redox reaction, and the chemical equation for nitric oxide is shown in Formula 3:

[0067] NO + 2H₂O → HNO₃ + 3H₂O + +3e - (3)

[0068] As can be seen from Formula 3:

[0069] (1) NO molecules react with the electrochemical sensor to produce electrons (e). - When the NO concentration increases, the number of NO molecules participating in the reaction per unit time increases proportionally, and the total number of electrons released also increases proportionally, that is: "total number of electrons ∝ NO concentration".

[0070] (2) The directional movement of electrons generates a weak current. The current signal is converted into a measurable voltage signal by the built-in amplification circuit of the electrochemical sensor. When the circuit parameters (amplification factor, resistance value, etc.) are fixed, the current magnitude is proportional to the total number of electrons, and the voltage change is proportional to the current magnitude, that is: "voltage change ∝ current ∝ total number of electrons".

[0071] From the above two points, we can conclude that:

[0072] δ∝β (4)

[0073] Where δ represents the change in output voltage of the electrochemical sensor, and β represents the concentration of the introduced NO standard gas. Note: Under the same reaction conditions, the ratio of voltage change to NO concentration is a constant, i.e., the sensitivity K of the electrochemical sensor.

[0074]

[0075] The above relationship holds true under fixed temperature conditions. However, considering the actual ambient temperature during product use and the effect of heat generated by the electronic product itself, its sensitivity K will change non-linearly with temperature.

[0076] In one possible implementation, such as Figure 2 , Figure 2 yes Figure 1 A flowchart of a specific implementation of S100; S100 includes:

[0077] S110. In the first temperature environment, in order of increasing concentration, nitric oxide of the first set of standard gas concentration data is introduced into the reaction chamber of the electrochemical sensor, and the voltage change of each concentration is recorded respectively; S120. The first calibration dataset of the first temperature environment is obtained by using each voltage change and the corresponding standard gas concentration data of nitric oxide, and the first calibration dataset and the first temperature data are stored in the first storage area of ​​the electrochemical sensor.

[0078] In this embodiment, the first temperature environment is a room temperature environment. The electrochemical sensor is first placed in this environment, approximately 25°C, for one hour. After the output voltage stabilizes, room temperature parameter calibration is performed. More data points result in greater accuracy, but considering feasibility, five standard nitric oxide gases with concentrations of β1ppb, β2ppb, β3ppb, β4ppb, and β5ppb can be selected as the first standard gas concentration data. To ensure the calibration data covers clinical testing needs and key diagnostic thresholds, specifically, five standard gas concentrations can be set to 25ppb, 50ppb, 80ppb, 150ppb, and 200ppb. The standard gases are introduced into the electrochemical sensor reaction chamber in ascending order of concentration. After the output voltage stabilizes, the voltage changes δ1(t0), δ2(t0), δ3(t0), δ4(t0), and δ5(t0) for each gas group are recorded, along with the system temperature t0 during calibration.

[0079] The first calibration dataset is (β1(t0), δ1(t0))(β2(t0), δ2(t0))(β3(t0), δ3(t0))(β4(t0), δ4(t0))(β5(t0), δ5(t0)). This dataset and temperature t0 are saved to the first storage area of ​​the storage unit (EEPROM) of the electrochemical sensor, which is the room temperature data storage area.

[0080] S200. Place the electrochemical sensor in an environment at a second temperature and acquire a second set of standard gas concentration data. Sequentially introduce nitric oxide gas from the second set of standard gas concentration data into the reaction chamber of the electrochemical sensor and acquire a second set of voltage change data. If there is a deviation between the second set of standard gas concentration data and the first set of standard gas concentration data, correct the second set of standard gas concentration data and the second set of voltage change data to obtain a first set of corrected standard gas concentration data and a first set of corrected voltage change data. Based on the first set of corrected standard gas concentration data and the first set of corrected voltage change data, acquire a second calibration dataset for the second temperature environment.

[0081] In one possible implementation, such as Figure 3 , Figure 3 yes Figure 1 A flowchart of a specific implementation of S200; S200 includes:

[0082] S210. In an environment with a second temperature, the second set of standard gas concentrations is introduced into the reaction chamber of the electrochemical sensor, and the voltage change corresponding to each standard gas concentration is recorded. S220. The absolute value of the difference between each of the second set of standard gas concentration data and the corresponding data in the first set of standard gas concentration data is obtained. If the absolute value of the difference is not zero, the second set of standard gas concentration data and the second set of voltage change data are corrected.

[0083] In one possible implementation, such as Figure 4 , Figure 4 yes Figure 3 A flowchart of a specific implementation of S220; S220 includes:

[0084] S221. The first correction formula for obtaining the second set of standard gas concentration data and the second set of voltage change data when acquiring the second temperature environment:

[0085]

[0086] S222. Correct the second set of standard gas concentration data based on the first set of standard gas concentration data, and correct the second set of voltage change data based on the first correction formula.

[0087] Where n is a natural number, n = 1, 2, ..., δ n (t1) represents the standard concentration β corresponding to the second temperature environment. n The change in calibration voltage (t1), δ' n (t1) The second temperature corresponds to the concentration data β'. n The voltage change at (t1).

[0088] In this embodiment, the second temperature environment is a low-temperature environment, which can be selected as a calibration environment with a stable temperature of approximately 5°C. After the electrochemical sensor is placed in this environment for 1 hour, low-temperature parameter calibration is performed, following the same steps as described above. Record the low-temperature data (β'1(t1), δ'1(t1))(β'2(t1), δ'2(t1))(β'3(t1), δ'3(t1))(β'4(t1), δ'4(t1))(β'5(t1), δ'5(t1)) and the temperature t1. n (t1) represents the actual concentration of the standard gas used during low-temperature calibration, and should be as close as possible to the standard gas concentration β used during room-temperature calibration. n (t0) are similar, |β' n (t1)-β nThe ideal difference of (t0)| should be controlled within the specified threshold of 1ppb. However, in actual calibration, due to operational errors, equipment process errors, and the influence of temperature, it may exceed the specified threshold of 1ppb. When there is a deviation, it can be corrected based on the theory of "stable environment and constant sensitivity K of electrochemical sensor under the same reaction conditions" (Formula 1) to achieve the benchmark unification of standard gas calibration data.

[0089] Its correction principle is as follows:

[0090] First, the standard gas concentration β1(t0) in the first set of standard gas concentration data corresponds to the voltage change δ1(t0) after the reaction in the reaction chamber of the electrochemical sensor. Therefore, (β1(t0), δ1(t0)) is known. β1(t0) is the benchmark for the subsequent second and third sets of standard gas concentration data. Each set of standard gas concentration data generally has 5 concentration data and 5 corresponding voltage changes. Here, we will only give an example of one concentration data and its voltage change data for illustration.

[0091] The concentration data β'1(t1) in the second set of standard gas concentration data should be as consistent as possible with β1(t0), but there may be deviations in reality. After the reaction, the corresponding voltage change data is δ'1(t1). At this time, based on the voltage change data δ'1(t1) corresponding to the standard gas concentration data β'1(t1), the voltage change data X corresponding to the standard gas concentration data β'1(t1) is converted proportionally, that is:

[0092] β'1(t1) / δ'1(t1)=β1(t0) / XX=β1(t0)*δ'1(t1) / β'1(t1), which is the first correction formula. After conversion, (β1(t0), β1(t0)*δ'1(t1) / β'1(t1)) is the corrected calibration data for the concentration-voltage pair.

[0093] After correction, based on the first set of corrected standard gas concentration data and the first set of corrected voltage change data, a second calibration dataset is established, namely the low-temperature calibration dataset (β1(t1),δ1(t1))(β2(t1),δ2(t1))(β3(t1),δ3(t1))(β4(t1),δ4(t1))(β5(t1),δ5(t1)). This dataset and the system temperature t1 are saved to the second storage area of ​​the storage unit of the electrochemical sensor, namely the low-temperature data storage area.

[0094] S300. Place the electrochemical sensor in an environment with a third temperature and acquire the third set of standard gas concentration data. Then, sequentially introduce nitric oxide gas, which is the concentration data of the third set of standard gas, into the reaction chamber of the electrochemical sensor and acquire the third set of voltage change data. If there is a deviation between the third set of standard gas concentration data and the first set of standard gas concentration data, correct the third set of standard gas concentration data and the third set of voltage change data to obtain the second set of corrected standard gas concentration data and the second set of corrected voltage change data. Based on the second set of corrected standard gas concentration data and the second set of corrected voltage change data, acquire the third calibration dataset for the third temperature environment.

[0095] In one possible implementation, such as Figure 5 , Figure 5 yes Figure 1 A flowchart of a specific implementation of S300; S300 includes:

[0096] S310. In an environment with a third temperature, the third set of standard gas concentrations is introduced into the reaction chamber of the electrochemical sensor, and the voltage change corresponding to each standard gas concentration is recorded. S320. The absolute value of the difference between each of the third set of standard gas concentration data and the corresponding data in the first set of standard gas concentration data is obtained. If the absolute value of the difference is not zero, the third set of standard gas concentration data and the third set of voltage change data are corrected.

[0097] In one possible implementation, such as Figure 6 , Figure 6 yes Figure 5 A flowchart of a specific implementation of S320; S320 includes:

[0098] S321. The second correction formula for obtaining the third set of standard gas concentration data and the third set of voltage change data when acquiring the third temperature environment:

[0099]

[0100] S322. Correct the third set of standard gas concentration data based on the first set of standard gas concentration data, and correct the third set of voltage change data based on the second correction formula.

[0101] Where n is a natural number, n = 1, 2, ..., δ n (t2) represents the standard concentration β corresponding to the third temperature environment. n The calibration voltage change of (t2), δ” n (t2) The third temperature corresponds to the concentration data β” n The voltage change at (t2).

[0102] In this embodiment, the third temperature environment is a high-temperature environment, which can be selected as an ambient temperature of approximately 45°C. After placing the electrochemical sensor for 1 hour, calibration is performed. High-temperature data (β”1(t2), δ”1(t2))(β”2(t2), δ”2(t2))(β”3(t2), δ”3(t2))(β”4(t2), δ”4(t2))(β”5(t2), δ”5(t2)) and temperature t2 are recorded, and |β” n (t2)-β n The ideal difference (t0)| should be controlled within the specified threshold of 1 ppb. However, in actual calibration, due to operational errors, equipment process errors, and the influence of temperature, it may exceed the specified threshold of 1 ppb. When deviation exists, the concentration data in the third set of standard gas concentration data is corrected based on the first set of standard gas concentration data. Then, the voltage change data in the third set is corrected using the second correction formula, which is based on the same correction principle as the first correction formula. Then, a high-temperature calibration dataset (β1(t2),δ1(t2))(β2(t2),δ2(t2))(β3(t2),δ3(t2))(β4(t2),δ4(t2))(β5(t2),δ5(t2)) is established. The high-temperature dataset and the system temperature t2 are saved to the third storage area of ​​the storage unit of the electrochemical sensor, which is the high-temperature data storage area.

[0103] like Figure 10 , Figure 10 This is a schematic diagram of the calibration data curves for the three temperatures in this application; the calibration data at the three temperatures, with the horizontal axis representing the standard gas concentration in ppb and the vertical axis representing the response voltage value.

[0104] In the embodiments of this application, the second ambient temperature is lower than the first ambient temperature, the first ambient temperature is lower than the third ambient temperature, and any set of standard gas concentration data includes at least two standard gas concentrations.

[0105] In this embodiment, by correcting the concentration data in the second set of standard gas concentration data and the concentration data in the third set of standard gas concentration data, the benchmark uniformity of the standard gas calibration data is ensured, significantly reducing the detection error caused by operational error, process error and temperature change. Each electrochemical sensor can be calibrated individually to establish a dedicated "temperature-concentration-voltage" calibration model, effectively offsetting the individual sensitivity deviation caused by production process fluctuations, improving detection consistency, and solving the problem of low detection accuracy in existing calibration technologies.

[0106] Secondly, a detection method employs a tiered, multi-dimensional calibration method as described in the first aspect, such as... Figure 7 , Figure 7 This is a flowchart of an embodiment of a detection method according to this application; including:

[0107] S400: Collect the current ambient temperature and compare it with the first temperature. If the current ambient temperature is equal to or less than the first temperature, read the first calibration dataset and the second calibration dataset. If the current ambient temperature is greater than the first temperature, read the first calibration dataset and the third calibration dataset.

[0108] S500: Obtain the fourth set of standard gas concentration data at the current ambient temperature; calculate the fourth set of voltage changes corresponding to the standard gas concentration data using linear interpolation based on the first calibration dataset, the second calibration dataset, or the third calibration dataset; and obtain the first virtual calibration dataset based on the fourth set of standard gas concentration data and the fourth set of voltage changes.

[0109] In one possible implementation, such as Figure 8 , Figure 8 yes Figure 7 A flowchart of a specific implementation of S500; S500 includes:

[0110] S510. Construct linear interpolation models for different temperatures and obtain a first linear interpolation model and a second linear interpolation model; S520. If the current ambient temperature is equal to or less than the first temperature, construct the first linear interpolation model based on the first calibration dataset and the second calibration dataset and obtain a first virtual calibration dataset; S530. If the current ambient temperature is greater than the first temperature, construct the second linear interpolation model based on the first calibration dataset and the third calibration dataset and obtain a first virtual calibration dataset.

[0111] In this embodiment, during the actual detection phase, the detection system first collects a sample of the user's exhaled breath, introduces the gas sample into the reaction chamber of the electrochemical sensor, records the actual detection voltage V output by the electrochemical sensor, and simultaneously collects the current ambient temperature t through the temperature sensor in the electrochemical sensor board. c The detection system reads three sets of calibration datasets from the electrochemical sensor's storage unit, based on the system's current temperature t. c The interval assignment was determined, and the calibration voltage change δ corresponding to the five standard concentration gases at the current temperature was calculated using linear interpolation. n (t c ):

[0112] When t c When ≤t0, five calibration points (β) are obtained according to the first linear interpolation model. n (t c ),δ n (t c ))

[0113]

[0114] When t cWhen t > 0, five calibration points (β) are obtained according to the second linear interpolation model. n ,δ n (t c ))

[0115]

[0116] Where: n = 1, 2, 3, 4, 5.

[0117] Establish the current temperature t c The dataset (β1(t) c ),δ1(t c ))(β2(t c ),δ2(t c ))(β3(t c ),δ3(t c ))(β4(t c ),δ4(t c ))(β5(t c ),δ5(t c )).

[0118] S600. Based on the first virtual calibration dataset, perform linear fitting using the least squares method to obtain a linear fitting model.

[0119] In one possible implementation, such as Figure 9 , Figure 9 yes Figure 7 A flowchart of a specific implementation of S600; S600 includes:

[0120] S610. Calculate the slope and intercept of the linear fitting model based on the first virtual calibration dataset; S620. Construct and obtain the linear fitting model based on the slope and intercept.

[0121] In this embodiment, considering systematic errors such as sensor baseline noise and circuit zero drift in practical applications, a linear model with intercept is used for fitting, which can improve measurement accuracy. Therefore, linear fitting is performed based on the least squares method to establish a "concentration-voltage change" fitting curve, and the constructed fitting model is as follows:

[0122] y = k*x + b (8)

[0123] Where: x is the voltage change of the sensor response (mV), y is the nitric oxide concentration (ppb), k is the fitting slope (ppb / mV), and b is the fitting intercept (ppb).

[0124] The logic for calculating the least squares fitting coefficients is as follows:

[0125] If the number of calibration data samples is m=5, then the slope and intercept can be calculated as follows:

[0126]

[0127] Where, x n =δ n (t c ), y n =β n .

[0128] according to Figure 11 , Figure 11 This is a schematic diagram of the linear fitting model curve of this application. Linear fitting is performed on the calibration points, and the goodness of fit R0 is... 2 Since the value is greater than 0.99, the sensor's response curve can be linearly fitted.

[0129] S700: Obtain the current voltage change and calculate the concentration of nitric oxide exhaled by the user using a linear fitting model.

[0130] Thirdly, an electrochemical sensor is calibrated using the step-by-step multidimensional calibration method of the first aspect, and its nitric oxide concentration is detected using the detection method of the second aspect.

[0131] The tiered multi-dimensional calibration method, detection method, and electrochemical sensor of this invention, by correcting the concentration data in the second set of standard gas concentration data and the concentration data in the third set of standard gas concentration data, ensures the benchmark uniformity of the standard gas calibration data, significantly reduces detection errors caused by operational errors, process errors, and temperature changes, and allows for individual calibration of each electrochemical sensor to establish a dedicated "temperature-concentration-voltage" calibration model, effectively offsetting individual sensitivity deviations caused by production process fluctuations, improving detection consistency, and solving the problem of low detection accuracy in existing calibration technologies.

[0132] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A hierarchical multi-dimensional calibration method, characterized in that it includes: Step 100: Place the electrochemical sensor in an environment at a first temperature, acquire the first set of standard gas concentration data, sequentially introduce nitric oxide gas from the first set of standard gas concentration data into the reaction chamber of the electrochemical sensor, acquire the first set of voltage change data, and acquire the first calibration dataset of the first temperature environment based on the first set of standard gas concentration data and the first set of voltage change data. Step 200: Place the electrochemical sensor in an environment at a second temperature, acquire a second set of standard gas concentration data, sequentially introduce nitric oxide gas from the second set of standard gas concentration data into the reaction chamber of the electrochemical sensor, acquire a second set of voltage change data, if there is a deviation between the second set of standard gas concentration data and the first set of standard gas concentration data, correct the second set of standard gas concentration data and the second set of voltage change data to obtain a first set of corrected standard gas concentration data and a first set of corrected voltage change data, and acquire a second calibration dataset for the second temperature environment based on the first set of corrected standard gas concentration data and the first set of corrected voltage change data; Step 300: Place the electrochemical sensor in a third temperature environment and acquire a third set of standard gas concentration data. Sequentially introduce nitric oxide gas, which represents the third set of standard gas concentration data, into the reaction chamber of the electrochemical sensor to acquire a third set of voltage change data. If there is a deviation between the third set of standard gas concentration data and the first set of standard gas concentration data, correct the third set of standard gas concentration data and the third set of voltage change data to obtain a second set of corrected standard gas concentration data and a second set of corrected voltage change data. Based on the second set of corrected standard gas concentration data and the second set of corrected voltage change data, acquire a third calibration dataset for the third temperature environment. Wherein, the second temperature is less than the first temperature, the first temperature is less than the third temperature, and any set of standard gas concentration data includes at least two standard gas concentrations.

2. The hierarchical multi-dimensional calibration method according to claim 1, characterized in that, Step 100 includes: Step 110: In the environment of the first temperature, in order of increasing concentration, nitric oxide of the first set of standard gas concentration data is introduced into the reaction chamber of the electrochemical sensor, and the voltage change of each concentration is recorded respectively. Step 120: Obtain the first calibration dataset using each voltage change and the corresponding standard nitric oxide concentration data, and store the first calibration dataset and the first temperature data in the first storage area of ​​the electrochemical sensor.

3. The hierarchical multi-dimensional calibration method according to claim 1, characterized in that, Step 200 includes: Step 210: In the environment of the second temperature, the second set of standard gas concentrations are introduced into the reaction chamber of the electrochemical sensor, and the voltage change corresponding to each standard gas concentration is recorded. Step 220: Obtain the absolute value of the difference between each of the second set of standard gas concentration data and the corresponding data in the first set of standard gas concentration data. If the absolute value of the difference is not zero, correct the second set of standard gas concentration data and the second set of voltage change data.

4. The hierarchical multi-dimensional calibration method according to claim 3, characterized in that, Step 220 includes: Step 221: Obtain the first correction formula for the second set of standard gas concentration data and the second set of voltage change data under the second temperature environment: Step 222: Correct the second set of standard gas concentration data according to the first set of standard gas concentration data, and correct the second set of voltage change data according to the first correction formula; Where n is a natural number, n = 1, 2, ..., δ n (t1) represents the standard concentration β corresponding to the second temperature environment. n The change in calibration voltage (t1), δ' n (t1) The second temperature corresponds to the concentration data β'. n The voltage change at (t1).

5. The hierarchical multi-dimensional calibration method according to claim 1, characterized in that, Step 300 includes: Step 310: In the environment of the third temperature, the third set of standard gas concentrations are introduced into the reaction chamber of the electrochemical sensor, and the voltage change corresponding to each standard gas concentration is recorded. Step 320: Obtain the absolute value of the difference between each of the third set of standard gas concentration data and the corresponding data in the first set of standard gas concentration data. If the absolute value of the difference is not zero, correct the third set of standard gas concentration data and the third set of voltage change data.

6. The hierarchical multi-dimensional calibration method according to claim 5, characterized in that, Step 320 includes: Step 321: Obtain the second correction formula for the third set of standard gas concentration data and the third set of voltage change data under the third temperature environment: Step 322: Correct the third set of standard gas concentration data according to the first set of standard gas concentration data, and correct the third set of voltage change data according to the second correction formula; Where n is a natural number, n = 1, 2, ..., δ n (t2) represents the standard concentration β corresponding to the third temperature environment. n The calibration voltage change of (t2), δ” n (t2) The third temperature corresponds to the concentration data β” n The voltage change at (t2).

7. A detection method, employing the tiered multi-dimensional calibration method according to any one of claims 1-6, characterized in that, include: Step 400: Collect the current ambient temperature and compare it with a first temperature. If the current ambient temperature is equal to or less than the first temperature, read the first calibration dataset and the second calibration dataset. If the current ambient temperature is greater than the first temperature, read the first calibration dataset and the third calibration dataset. Step 500: Obtain the fourth set of standard gas concentration data of the current ambient temperature; calculate the fourth set of voltage change corresponding to the standard gas concentration data using linear interpolation based on the first calibration dataset, the second calibration dataset, or the third calibration dataset; and obtain the first virtual calibration dataset based on the fourth set of standard gas concentration data and the fourth set of voltage change. Step 600: Based on the first virtual calibration dataset, perform linear fitting using the least squares method to obtain a linear fitting model; Step 700: Obtain the current voltage change and calculate the concentration data of nitric oxide exhaled by the user using the linear fitting model.

8. The detection method according to claim 7, characterized in that, Step 500 includes: Step 510: Construct linear interpolation models for different temperatures to obtain the first linear interpolation model and the second linear interpolation model; Step 520: If the current ambient temperature is equal to or less than the first temperature, then construct the first linear interpolation model based on the first calibration dataset and the second calibration dataset, and obtain the first virtual calibration dataset; Step 530: If the current ambient temperature is greater than the first temperature, then the second linear interpolation model will be constructed based on the first calibration dataset and the third calibration dataset to obtain the first virtual calibration dataset.

9. The detection method according to claim 7, characterized in that, Step 600 includes: Step 610: Calculate the slope and intercept of the linear fitting model based on the first virtual calibration dataset; Step 620: Construct the linear fitting model based on the slope and intercept.

10. An electrochemical sensor, characterized in that, The calibration is performed using the step-by-step multi-dimensional calibration method described in any one of claims 1-6, and the nitric oxide concentration is detected using the detection method described in any one of claims 7-9.

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