A method and system for sensor self-calibration of a respiratory support device

Abstract

The application discloses a kind of respiratory support equipment sensor self-calibration method, comprising the following steps: S1, first sensor obtains first oxygen concentration N1, second sensor obtains second oxygen concentration N2;S2, the difference of first oxygen concentration N1 and second oxygen concentration N2 is calculated, and it is judged: if |N1-N2|<K, then execute step S3, if |N1-N2|>K, then execute step S4, K value is set threshold value;S3, obtain initial average concentration and the initial average concentration N0 as output concentration;S4, obtain several oxygen concentrations N1, N2, N3......Ni corresponding to several sensors, and carry out data fitting to it, obtain concentration optimal solution Ny, and the concentration optimal solution Ny is used as output concentration;S5, select the two sensors of measured oxygen concentration closest to optimal solution Ny as working sensor.The application solves the problem of low parameter accuracy caused by the error of sensor measured data or the error of sensor itself.

Description

Technical Field

[0001] This invention belongs to the field of ventilator sensor self-calibration technology, and particularly relates to a method and system for self-calibrating sensors in respiratory support devices. Background Technology

[0002] The operation of a ventilator includes configuring the output gas to the required oxygen concentration, configuring the output gas temperature, configuring the output gas pressure, and discharging the output gas. Both concentration and pressure detection are achieved through sensors.

[0003] Chinese patent application CN112169098A discloses an automatic sensor calibration method. This method controls a turbine to operate at different speeds, uses a pressure sensor to acquire turbine pressure values ​​and a flow sensor to acquire turbine flow values, and then calculates the differences between these values ​​and the initial pressure and flow values ​​at different turbine speeds to obtain the detected pressure and flow differences, thus completing the calibration. This method primarily focuses on pressure calibration. For pressure, a dedicated pressure controller can be installed at the rear of the ventilator to ensure the output pressure. Generally, pressure adjustment and calibration typically involve acquiring missing values ​​and providing appropriate compensation to ensure the output value. However, detecting oxygen concentration and calibrating oxygen sensors are more challenging than pressure adjustment and calibration.

[0004] Chinese patent CN104784793B discloses an automatic calibration method for a ventilator oxygen sensor, which uses a pressure sensor to control the flow rate for calibration. By installing a pressure sensor in the bypass gas path or between the bifurcation point of the main gas path and the gas outlet of the main gas path, the pressure value generated by the gas flow is collected. A micro-sensor monitors the pressure value generated by the gas flow in real time and determines whether there is gas flow through the bypass gas path based on the pressure value, thus deciding whether to increase the gas flow rate, thereby achieving automatic calibration of the oxygen sensor.

[0005] Chinese patent application CN116492559A discloses a method for automatically adjusting the oxygen concentration in a ventilator. It reveals a novel method for using an oxygen sensor, employing a detection-compensation approach for autonomous adjustment. The oxygen concentration is obtained through analysis of a first detection result and a second detection result. The detection result includes oxygen concentration data in several segments, and the system then determines whether the desired oxygen concentration has been reached based on these segment data. However, oxygen sensors can experience measurement errors or abnormal parameters, possibly due to uneven gas mixing. Using these abnormalities for concentration calculations can lead to significant errors, potentially affecting breathing. Therefore, regular calibration and data processing are necessary to ensure the accuracy of the detection parameters. Summary of the Invention

[0006] The objective of the present invention is to provide a method and system for self-calibration of sensors of a respiratory support device, so as to solve the problem of low parameter accuracy caused by errors in the data measured by sensors or the errors of the sensors themselves during the gas concentration detection in the gas distribution process of existing ventilators.

[0007] To achieve the objective of the present invention, the present invention discloses a method for self-calibration of sensors of a respiratory support device, including the following steps:

[0008] S1. A first sensor obtains a first oxygen concentration N1, and a second sensor obtains a second oxygen concentration N2;

[0009] S2. Calculate the difference between the first oxygen concentration N1 and the second oxygen concentration N2, and make a judgment:

[0010] If |N1 - N2| < K, then execute step S3; if |N1 - N2| > K, then execute step S4, where the value of K is a set threshold;

[0011] S3. Obtain the initial average concentration , = , and use this initial average concentration as the output concentration;

[0012] S4. Obtain several oxygen concentrations N1, N2, N3......Ni corresponding to several sensors, perform data fitting on them, obtain the optimal concentration solution Ny, and use this concentration optimal solution Ny as the output concentration;

[0013] S5. Select two sensors with the oxygen concentration closest to the optimal solution Ny as the working sensors.

[0014] Preferably, the data fitting includes the following steps:

[0015] S41. Solve the average oxygen concentration , ;

[0016] S42. According to the average oxygen concentration , eliminate gross errors;

[0017] S43. Solve the new average oxygen concentration ;

[0018] S44. Perform homogenization processing on the data: ;

[0019] S45. Judge the difference between d and the set threshold C. If d < C, then use the current new average oxygen concentration as the optimal solution output, that is, Ny = ;

[0020] If d > C, continue to eliminate gross errors and recalculate , until d < C, then take the current as the optimal solution and output it, i.e., Ny = .

[0021] Preferably, the elimination of gross errors includes the following steps:

[0022] Calculate the residual , = - ;

[0023] Obtain the reference value (N), ;

[0024] Compare the residual with the reference value (N) and judge the relationship between | | and 3 (N),

[0025] If | | > 3 (N), it is considered a gross error and should be eliminated;

[0026] If | | ≤ 3 (N), there is no need to eliminate it.

[0027] The present invention also discloses a sensor self - calibration system for a respiratory support device, including: a detection pipeline, a plurality of detection cavities arranged on the detection pipeline, and sensors extending into the detection cavities. The sensors are connected to a control system. The sensors are divided into working sensors and calibration sensors. The working sensors are used for real - time concentration detection, and the calibration sensors are used to calibrate the working sensors and timely replace the working sensors with large errors.

[0028] The number of working sensors is 2, which are used to detect the current oxygen concentration value and send the current oxygen concentration value to the control system. Through the working module of the control system, the oxygen concentration is compared. If the difference between the oxygen concentration values measured by the two working sensors is less than the threshold, it is considered that no calibration is required, and the average value of the currently measured oxygen concentration is used as the output value. If the difference between the oxygen concentration values measured by the two working sensors is greater than the threshold, it is considered that calibration is required.

[0029] After the calibration sensor is activated, it measures the current oxygen concentration value and, together with the oxygen concentration value measured by the working sensor, sends the data to the control system. The calibration module of the control system performs data fitting on the oxygen concentration value to obtain the optimal concentration solution Ny, which is then used as the output concentration. Furthermore, the two best sensors are selected as new working sensors, and the sensors whose data is discarded undergo standardization testing. Sensors that do not meet the standards are replaced.

[0030] The detection pipe has a threaded opening, and the detection cavity is threadedly connected to the threaded opening. The detection cavity includes a threaded mounting shell, an airflow channel is provided inside the mounting shell, a large chamber is provided in the middle of the airflow channel, and a threaded mounting port is provided on the mounting shell. The sensor is installed through the threaded mounting port, and the sensor's detection end extends into the large chamber.

[0031] An exhaust fan is installed in the airflow channel. The exhaust fan allows sufficient gas to be tested to enter the large chamber. By setting the start and stop times of the exhaust fan, it is possible to ensure that there is enough gas to be tested in the large chamber and to replenish the gas in a timely manner to ensure the accuracy of gas detection.

[0032] Compared with the prior art, the beneficial effects of the present invention are:

[0033] The self-calibration method for respiratory support device sensors of this invention acquires data using two sensors, determines the reasonableness of concentration data, and provides routine detection results, thereby improving the accuracy of the detection data. By generating unreasonable data and periodically calibrating, the accuracy of the working sensor's results is judged. By eliminating unreasonable measurement results, the optimal concentration solution is used as the output value, and the two sensors with the closest detection data are selected as new working sensors to ensure detection accuracy. This solves the problem of low parameter accuracy caused by errors in sensor-measured data or sensor inherent errors. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the self-calibration method flow structure of the present invention;

[0035] Figure 2 This is a schematic diagram of the self-calibration system structure of the present invention;

[0036] Figure 3 This is a schematic diagram of the detection cavity structure of the present invention.

[0037] Reference numerals: 1. Detection pipe; 2. Detection chamber; 3. Sensor; 4. Exhaust fan. Detailed Implementation

[0038] In order to make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the present invention will be further described below in conjunction with specific embodiments.

[0039] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "front end", "rear end", "both ends", "one end", "the other end", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0040] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" 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 directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0042] Embodiment 1

[0043] This embodiment discloses a method for self-calibrating a sensor of a respiratory support device, including the following steps:

[0044] S1. The first sensor obtains the first oxygen concentration N1, and the second sensor obtains the second oxygen concentration N2; the first sensor and the second sensor here do not specifically refer to fixed sensors, and any two sensors can be arbitrarily selected as working sensors. Using two sensors to obtain data can improve the accuracy of the detected data.

[0045] S2. Calculate the difference between the first oxygen concentration N1 and the second oxygen concentration N2, and make a judgment:

[0046] If |N1 - N2| < K, then execute step S3.

[0047] [[ID=2 , = , take this initial average concentration as the output concentration; Although the concentration output value is given at this time, it cannot be guaranteed that the data detected by the two working sensors are both error data. Therefore, at this time, regular calibration has to be relied on to judge the data.

[0048] If |N1 - N2| > K, then execute step S4. The value of K is a set threshold, which can be obtained according to experience, can be a range interval, or can be a fixed value, and is used to initially judge whether it is error data.

[0049] S4. Obtain several oxygen concentrations N1, N2, N3......Ni corresponding to several sensors. The gas in the pipeline is theoretically of the same concentration. Without considering errors, the data measured should be the same. However, in reality, there are errors, including gross errors, and data fitting needs to be performed on the concentration data. The data fitting includes the following steps:

[0050] S41. Solve the average oxygen concentration , ; The calculation of the average value is a conventional technique and will not be elaborated here.

[0051] S42. According to the average oxygen concentration , eliminate gross errors; The gross errors here can be considered as the data with too large deviation values in the data, and they are eliminated to improve the accuracy.

[0052] After eliminating the gross error data, it is necessary to solve the remaining data again to obtain the new average oxygen concentration ;

[0053] S44. Homogenize the data: ; What can be obtained from the homogenization process can be variance, standard deviation, etc., to obtain the data distribution and deviation situation.

[0054] Judge the difference between d and the set threshold C. If d < C, then take the current new average oxygen concentration as the optimal solution output, that is, Ny = ; The threshold C is a set reasonable deviation range. If it is less than the threshold, the new average oxygen concentration can be considered as the optimal data and output with it.

[0055] If d > C, then continue to eliminate gross errors and solve again until d < C, and then take the current as the optimal solution output, that is, Ny = The optimal concentration Ny is taken as the output concentration. When the distribution deviation is too large, it is reasonable to believe that some data still have errors and needs to be removed again. After multiple removals, the uniformity of the distribution can be guaranteed, and there is reason to believe that the new average concentration can be used as the optimal solution for output.

[0056] In steps S42 and S45 above, eliminating gross errors includes the following steps:

[0057] Find the residual , = - ;

[0058] Calculate the reference value (N), ;

[0059] residual Compared with reference value (N) Perform data comparison and determine | | and 3 The relationship between (N),

[0060] If | |>3 If (N) is found, it is considered a gross error and is discarded.

[0061] If | |≤3 If (N), then no removal is required.

[0062] S5. Select the two sensors whose measured oxygen concentration is closest to the optimal solution Ny as working sensors. Since sensors may have errors during the measurement process, new sensors can be used as working sensors. If the same sensor is repeatedly rejected, it is reasonable to believe that the sensor has its own error and needs to be disassembled and standardized for testing. If it does not meet the standard, it should be replaced with a standard sensor to ensure the accuracy of the test data.

[0063] Example 2

[0064] This embodiment discloses a sensor self-calibration system for a respiratory support device, comprising: a detection pipe 1, several detection chambers 2 disposed on the detection pipe 1, and sensors 3 extending into the detection chambers. The sensors 3 are connected to a control system. The sensors 3 are divided into working sensors and calibration sensors. The working sensors are used for real-time concentration detection, and the calibration sensors are used to calibrate the working sensors and promptly replace those with large errors. The detection pipe 1 has a threaded opening, and the detection chambers 2 are threadedly connected to this opening. Each detection chamber 2 includes a threaded mounting shell, and an airflow channel is disposed within the mounting shell. A large chamber is disposed in the middle of the airflow channel. The mounting shell has a threaded mounting port, through which the sensors are mounted. The detection end of the sensor 3 extends into the large chamber. An exhaust fan 4 is disposed in the airflow channel.

[0065] There are two working sensors used to detect the current oxygen concentration and send it to the control system. The control system's working module compares the oxygen concentrations. If the difference between the oxygen concentrations measured by the two working sensors is less than a threshold, then calibration is not required, and the average of the current measured oxygen concentrations is used as the output value. If the difference between the oxygen concentrations measured by the two working sensors is greater than the threshold, then calibration is required.

[0066] After the calibration sensor is activated, it measures the current oxygen concentration value and, together with the oxygen concentration value measured by the working sensor, sends the data to the control system. The calibration module of the control system performs data fitting on the oxygen concentration value to obtain the optimal concentration solution Ny, which is then used as the output concentration. Furthermore, the two best sensors are selected as new working sensors, and the sensors whose data is discarded undergo standardization testing. Sensors that do not meet the standards are replaced.

[0067] 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, intended to encompass all variations falling within the meaning and scope of equivalents of the claims. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A self-calibration method for sensors in a respiratory support device, characterized in that: It includes the following steps: S1. The first sensor obtains the first oxygen concentration N1, and the second sensor obtains the second oxygen concentration N2; S2. Calculate the difference between the first oxygen concentration N1 and the second oxygen concentration N2, and make a judgment: If |N1 - N2| < K, then execute step S3; if |N1 - N2| > K, then execute step S4, where the value of K is a set threshold; S3. Calculate the initial average concentration. , = The initial average concentration As output concentration; S4. Obtain several oxygen concentrations N1, N2, N3......Ni corresponding to several sensors, and perform data fitting on them to obtain the optimal concentration solution Ny, and use the optimal concentration solution Ny as the output concentration; The data fitting includes the following steps: S41. Solve for the average oxygen concentration. , ; S42. Based on average oxygen concentration Eliminate gross errors; S43. Solve for the new average oxygen concentration. ; S44. Perform data homogenization processing: ; S45. Determine the difference between d and the set threshold C. If d < C, then use the current new average oxygen concentration as the optimal solution for output, i.e., Ny = ; If d > C, continue to eliminate gross errors and calculate again , until d < C, then take the current as the optimal solution and output, that is, Ny = ; Step S5. Select two sensors with the oxygen concentration closest to the optimal solution Ny as the working sensors.

2. The self-calibration method for sensors in respiratory support devices according to claim 1, characterized in that: The rejection of gross errors includes the following steps: Find the residual , = - ; Calculate the reference value (N), ; residual Compared with reference value (N) Perform data comparison and determine | | and 3 The relationship between (N), If | |>3 If (N) is found to be a gross error, it will be discarded. If | |≤3 If (N), then no removal is required.

3. A self-calibration system for sensors in a respiratory support device, based on the self-calibration method for sensors in a respiratory support device according to claim 1 or 2, characterized in that, It includes: A detection pipeline (1), several detection chambers (2) arranged on the detection pipeline (1), and sensors (3) extending into the detection chambers. The sensors (3) are connected to a control system. The sensors (3) are divided into working sensors and calibration sensors. The working sensors are used for real-time concentration detection, and the calibration sensors are used to calibrate the working sensors and timely replace the working sensors with large errors.

4. The self-calibration system for respiratory support device sensors according to claim 3, characterized in that, The number of working sensors is 2, which are used to detect the current oxygen concentration value and send the current oxygen concentration value to the control system. Through the working module of the control system, the oxygen concentration is compared. If the difference between the oxygen concentration values measured by the two working sensors is less than the threshold, it is considered that calibration is not required, and the average value of the currently measured oxygen concentration is used as the output value. If the difference between the oxygen concentration values measured by the two working sensors is greater than the threshold, it is considered that calibration is required.

5. The self-calibration system for respiratory support device sensors according to claim 4, characterized in that, After the calibration sensor is awakened, it measures the current oxygen concentration value, combines the oxygen concentration value measured by the working sensor, and sends its data to the control system. Through the calibration module of the control system, data fitting of the oxygen concentration value is performed to obtain the optimal concentration solution Ny, and the optimal concentration solution Ny is used as the output concentration; and the two optimal ones are selected from the sensors as the new working sensors, and the sensors from which data is excluded are subjected to standard detection, and the sensors that do not meet the standards are replaced.

6. The self-calibration system for sensors in a respiratory support device according to claim 5, characterized in that, The detection pipeline (1) is provided with a threaded opening, the detection chamber (2) is threadedly connected to the threaded opening. The detection chamber (2) includes a threaded mounting shell. An air flow channel is arranged inside the mounting shell. A large chamber is arranged in the middle of the air flow channel. The mounting shell is provided with a threaded mounting port, and the sensor (3) is mounted through the threaded mounting port. The detection end of the sensor (3) extends into the large chamber.

7. The self-calibration system for sensors in a respiratory support device according to claim 6, characterized in that, An air extraction fan (4) is arranged in the air flow channel.

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