Ventilation method and ventilation device

Abstract

The embodiment of the present application discloses a ventilation method and a ventilation device, which can improve the accuracy of gas concentration control. The ventilation device comprises a main passage, a first gas passage and a second gas passage, the main passage is used for mixing the first gas and the second gas, at least two passages of the main passage, the first gas passage and the second gas passage are provided with a gas flow sensor; the main passage is provided with a concentration sensor, the method comprises the following steps: obtaining the first concentration corresponding to the first gas in the main passage through the concentration sensor; determining the second concentration corresponding to the first gas in the main passage and the mixed gas flow rate of the main passage through the gas flow sensor arranged in at least two passages; determining the target flow rate corresponding to the first gas based on the first concentration, the second concentration and the mixed gas flow rate, and inputting the first gas into the main passage through the first gas passage according to the target flow rate, so that the first gas output by the main passage reaches the preset target concentration.

Description

Technical Field

[0001] This invention relates to the field of medical device technology. In particular, it relates to a ventilation method and ventilation device. Background Technology

[0002] During mechanical ventilation, a gas with a higher oxygen volume fraction than that in the air is needed to improve the patient's oxygenation, which means changing the oxygen concentration in the inhaled air. When the oxygen concentration is consistently too low, it will cause hypoxemia; when the oxygen concentration is too high, it will lead to oxygen toxicity. Therefore, the accuracy of oxygen concentration is a crucial indicator for mechanical ventilation. The mixed oxygen function is an important feature that achieves accurate control of oxygen concentration by adjusting the ratio of air and oxygen volume flow rates.

[0003] During ventilation, related technologies use oxygen concentration sensors to monitor oxygen concentration in real time and dynamically adjust the system based on the error between the actual and target oxygen concentrations. For example, when the actual oxygen concentration is higher than the target concentration, the oxygen flow rate is reduced to decrease the actual oxygen concentration; when the actual oxygen concentration is lower than the target concentration, the oxygen flow rate is increased to increase the actual oxygen concentration, thereby achieving oxygen concentration control. However, oxygen concentration sensors have a large response delay, which is detrimental to real-time and rapid adjustment of oxygen concentration, thus reducing the accuracy of oxygen concentration control. Summary of the Invention

[0004] The present invention aims to provide a ventilation method and ventilation device that can improve the accuracy of gas concentration control.

[0005] The technical solution of this invention is implemented as follows:

[0006] This invention provides a ventilation method applied to ventilation equipment, comprising:

[0007] The ventilation device includes: a main passage, a first gas passage for inputting a first gas into the main passage, and a second gas passage for inputting a second gas into the main passage. The main passage is used to output a mixed gas formed by the first gas and the second gas to a ventilation port. At least two of the main passage, the first gas passage, and the second gas passage are equipped with gas flow sensors. The main passage is equipped with a concentration sensor for detecting the concentration of the first gas in the main passage. The method includes:

[0008] The concentration sensor is used to obtain the first concentration of the first gas in the main passage.

[0009] The gas flow sensor, which is set in at least two channels, determines the second concentration of the first gas in the main channel and the mixed gas flow rate in the main channel.

[0010] Based on the first concentration of the first gas, the second concentration of the first gas, and the mixed gas flow rate, the target flow rate of the first gas is determined, and the first gas is input into the main channel through the first gas passage according to the target flow rate of the first gas, so that the first gas output by the main channel reaches the preset target concentration.

[0011] This invention provides a ventilation method applied to a ventilation device. The ventilation device includes: a main passage, a first gas passage for inputting a first gas into the main passage, a second gas passage for inputting a second gas into the main passage, and a mixing chamber connected to the first gas passage, the second gas passage, and the main passage respectively. The main passage is used to output a mixture of the first gas and the second gas to a ventilation port during a positive flow process, and to receive return gas entering from the ventilation port during a negative flow process. The main passage is equipped with a total gas flow sensor. The method includes:

[0012] The total gas flow sensor accumulates the volume of the return gas, and when the flow rate changes from negative to positive, the volume of the first gas retained in the mixing chamber is determined based on the volume of the return gas.

[0013] Based on the retention volume of the first gas and the mixed gas flow rate obtained by the total gas flow sensor, the target flow rate of the first gas is determined, and the first gas is input into the main channel through the first gas passage according to the target flow rate of the first gas, so that the first gas output by the main channel reaches a preset target concentration.

[0014] This invention provides a ventilation method applied to a ventilation device. The ventilation device includes: a main passage, a first gas passage for inputting a first gas into the main passage, and a second gas passage for inputting a second gas into the main passage. The main passage is used to output a mixed gas formed by the first gas and the second gas to a ventilation port during a forward flow process. At least two of the main passage, the first gas passage, and the second gas passage are equipped with gas flow sensors. The method includes:

[0015] The gas flow sensor, which is set in at least two channels, determines the second concentration of the first gas in the main channel and the mixed gas flow rate in the main channel.

[0016] Based on the second concentration corresponding to the first gas and the mixed gas flow rate, the target flow rate corresponding to the first gas is determined, and the first gas is input into the main channel through the first gas passage according to the target flow rate corresponding to the first gas, so that the first gas output by the main channel reaches the preset target concentration.

[0017] This invention provides a ventilation device, comprising: a main passage, a first gas passage for inputting a first gas into the main passage, a second gas passage for inputting a second gas into the main passage, and a control module. The main passage is used to output a mixed gas formed by the first gas and the second gas to a ventilation port during a forward flow process. At least two of the main passage, the first gas passage, and the second gas passage are equipped with gas flow sensors; the main passage is equipped with a concentration sensor.

[0018] The concentration sensor is used to obtain the first concentration of the first gas in the main passage;

[0019] The gas flow sensors provided in the at least two passages are used to determine the second concentration of the first gas in the main passage and to determine the mixed gas flow rate in the main passage.

[0020] The control module is used to determine the target flow rate of the first gas based on the first concentration of the first gas, the second concentration of the first gas, and the mixed gas flow rate, and to input the first gas into the main channel through the first gas passage according to the target flow rate of the first gas, so that the first gas output by the main channel reaches a preset target concentration.

[0021] This invention provides a ventilation device, comprising: a main passage, a first gas passage for inputting a first gas into the main passage, a second gas passage for inputting a second gas into the main passage, a mixing chamber connected to the first gas passage, the second gas passage, and the main passage, and a control module. The main passage is used to output a mixture of the first gas and the second gas to a ventilation port during a positive flow rate process, and to receive return gas entering from the ventilation port during a negative flow rate process. The main passage is equipped with a total gas flow sensor.

[0022] The total gas flow sensor is used to accumulate the volume of the return gas.

[0023] The control module is configured to, when the flow rate changes from negative to positive, determine the retention volume of the first gas in the mixing chamber based on the volume of the return gas; determine the target flow rate of the first gas based on the retention volume of the first gas and the mixed gas flow rate obtained by the total gas flow sensor; and input the first gas into the main passage through the first gas passage according to the target flow rate of the first gas, so that the first gas output from the main passage reaches a preset target concentration.

[0024] This invention provides a ventilation device, comprising: a main passage, a first gas passage for inputting a first gas into the main passage, a second gas passage for inputting a second gas into the main passage, and a control module. The main passage is used to output a mixed gas formed by the first gas and the second gas to a ventilation port. At least two of the main passage, the first gas passage, and the second gas passage are equipped with gas flow sensors.

[0025] The gas flow sensors provided in the at least two passages are used to determine the second concentration of the first gas in the main passage and to determine the mixed gas flow rate in the main passage.

[0026] The control module is used to determine the target flow rate of the first gas based on the second concentration of the first gas and the mixed gas flow rate, and to input the first gas into the main channel through the first gas passage according to the target flow rate of the first gas, so that the first gas output by the main channel reaches a preset target concentration.

[0027] This invention provides a ventilation method and ventilation device. By installing gas flow sensors in at least two of the main passage, first gas passage, and second gas passage of the ventilation device, the gas flow rate in at least two passages is acquired, and a second concentration of the first gas in the main passage is determined. The second concentration is calculated using the data from the gas flow sensors. Combined with the first concentration obtained by a concentration sensor and the mixed gas flow rate in the main passage, a target flow rate for the first gas is determined, so that the first gas output from the main passage reaches a preset target concentration according to the target flow rate. Thus, by combining the first gas concentrations calculated using two methods, the concentration of the first gas output from the ventilation device is adjusted and controlled. This overcomes the problems of large time delays and untimely or inaccurate concentration control caused by relying solely on the first concentration measured by a concentration sensor for gas concentration control, thereby improving the accuracy of ventilation concentration control. Attached Figure Description

[0028] Figure 1A schematic diagram of the existing basic oxygen mixing algorithm on ventilation equipment;

[0029] Figure 2-1 A schematic diagram of the air path of a ventilation device provided in an embodiment of the present invention. Figure 1 ;

[0030] Figure 2-2 A second schematic diagram of the air path of a ventilation device provided in an embodiment of the present invention;

[0031] Figure 2-3 A schematic diagram of the air path of a ventilation device provided in an embodiment of the present invention. Figure 3 ;

[0032] Figure 3 A schematic diagram of an optional process of a ventilation method provided in an embodiment of the present invention;

[0033] Figure 4 A schematic diagram of a ventilation method based on dual-ring gas concentration control provided in an embodiment of the present invention;

[0034] Figure 5 A schematic diagram of a ventilation method based on oxygen concentration sensor concentration control provided in an embodiment of the present invention;

[0035] Figure 6 A schematic diagram of the air path of a ventilation device provided in an embodiment of the present invention. Figure 4 ;

[0036] Figure 7 A schematic diagram of an optional process of a ventilation method provided in an embodiment of the present invention;

[0037] Figure 8 This is a schematic diagram of a retention volume estimation model curve provided in an embodiment of the present invention;

[0038] Figure 9 A schematic diagram of a flow velocity curve during ventilation provided in an embodiment of the present invention;

[0039] Figure 10 A schematic diagram of an optional process of a ventilation method provided in an embodiment of the present invention;

[0040] Figure 11 A schematic diagram of an optional process of a ventilation method provided in an embodiment of the present invention;

[0041] Figure 12 This is a schematic diagram of the ventilation method based on volumetric oxygen concentration control provided in an embodiment of the present invention. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on 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.

[0043] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0044] In the following description, the terms "first, second, third" are used merely to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first, second, third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of the invention described herein can be implemented in an order other than that illustrated or described herein.

[0045] 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 invention pertains. The terminology used herein is for the purpose of describing embodiments of the invention only and is not intended to limit the invention.

[0046] Typically, ventilation devices such as ventilators can be categorized into flow-controlled and pressure-controlled ventilation modes. For both of these modes, methods such as... Figure 1 The basic oxygen mixing method shown uses the following method based on the FiO2 oxygen concentration set on the ventilator: Figure 1 The proportion formula shown in the figure The target oxygen percentage is calculated. The target oxygen flow rate is obtained by multiplying the target oxygen percentage by the gas flow rate of the mixed gas output from the main ventilator circuit (based on pressure or flow control). The oxygen flow rate control component in the ventilator's oxygen branch can then adjust according to the target oxygen flow rate, ensuring that the oxygen branch outputs oxygen at that rate, thus achieving concentration control of the ventilator's output oxygen. However, the actual output oxygen flow rate may deviate from the target oxygen flow rate. Therefore, real-time monitoring of the actual oxygen flow rate error is necessary to dynamically adjust the oxygen flow rate based on the error.

[0047] Currently, existing technologies typically use oxygen concentration sensors to monitor oxygen concentration in real time. When the oxygen concentration data measured by the sensor is higher than the target oxygen concentration, the oxygen flow rate is reduced; when the oxygen concentration data measured by the sensor is lower than the target oxygen concentration, the oxygen flow rate is increased to stabilize the output oxygen concentration at the preset level. However, oxygen concentration sensors have the disadvantage of large response delays, resulting in slow feedback of oxygen concentration data, which is not conducive to rapid adjustment of oxygen concentration. Furthermore, due to the significant time delay in oxygen concentration sensor data, it is difficult to accurately reflect the current actual oxygen concentration. Therefore, the accuracy of oxygen concentration adjustment based on oxygen concentration sensor data is poor.

[0048] On the other hand, when the ventilator delivers air, the airflow goes to the body through the main pathway; when the body exhales, some of the exhaled air is expelled through the exhalation valve, while some air may flow back into the ventilator through the main pathway. If the ventilator delivers an oxygen-enriched mixture, the returned air will also be oxygen-enriched. Thus, when the next delivery is initiated after the return flow, the oxygen remaining in the returned air will cause the oxygen concentration of the next delivery to be higher than normal, potentially even gradually increasing to 100%.

[0049] Therefore, to address the impact of recirculated gas on mixed oxygen control, existing technologies typically halt oxygen delivery to the oxygen branch immediately after the recirculation ends and the ventilator begins inhalation. This delay, after a certain period, avoids the influence of oxygen from the recirculated gas on oxygen concentration during the initial inhalation phase. However, this method has drawbacks: if the oxygen delivery delay is long, the actual oxygen concentration may be lower during that delay and higher at other times, leading to instability. Furthermore, after oxygen delivery resumes, the target oxygen flow rate may experience a step change, preventing the actual oxygen flow rate from quickly tracking the target and further reducing the accuracy of oxygen concentration control.

[0050] This invention provides a ventilation method and ventilation device that can improve the accuracy of gas concentration regulation. The ventilation device provided by this invention includes: a main passage, a first gas passage for inputting a first gas into the main passage, a second gas passage for inputting a second gas into the main passage, and a control module. The main passage is used to output a mixed gas formed by the first gas and the second gas to the ventilation port during the forward flow process of the ventilation device. At least two of the main passage, the first gas passage, and the second gas passage are equipped with gas flow sensors; the main passage is equipped with a concentration sensor. In some embodiments, the gas path diagram of the ventilation device provided by this invention can be as follows: Figure 2-1 , Figure 2-2 and Figure 2-3 As shown in any of the examples.

[0051] in, Figure 2-1 A ventilation device is shown in which a first gas flow sensor 11 is provided in the first gas passage, a second gas flow sensor 12 is provided in the second gas passage, and a concentration sensor 13 is provided in the main passage; Figure 2-2 A ventilation device is shown in which a second gas flow sensor 12 is provided in the second gas passage, a total gas flow sensor 14 is provided in the main passage, and a concentration sensor 13 is provided in the main passage. Figure 2-3 The illustration shows a ventilation device in which a first gas flow sensor 11 is installed in the first gas branch, a total gas flow sensor 14 is installed in the main passage, and a concentration sensor 13 is installed in the main passage.

[0052] The concentration sensor 13 is used to obtain the first concentration of the first gas in the main passage.

[0053] At least two gas flow sensors, such as a first gas flow sensor 11 and a second gas flow sensor 12, or a second gas flow sensor 12 and a total gas flow sensor 14, or a first gas flow sensor 11 and a total gas flow sensor 14, are used to determine the second concentration of the first gas in the main passage and to determine the mixed gas flow rate in the main passage.

[0054] Control module, used to control such as Figure 3 The ventilation method shown achieves concentration control of the first gas output from the main passage based on the first concentration of the first gas, the second concentration of the first gas, and the mixed gas flow rate.

[0055] In this embodiment of the invention, the second gas can be a gas containing components of the first gas. For example, the first gas can be oxygen, and the second gas can be air. Accordingly, the first gas passage can be an oxygen passage, such as the high-pressure oxygen branch of a ventilator; the second gas passage can be an air passage, such as the low-pressure air branch of a ventilator. The first gas and the second gas can also be gases with other components, and this embodiment of the invention is not limited thereto.

[0056] Below, for reference Figure 3 The ventilation method provided in the embodiments of the present invention will be described.

[0057] S101. Obtain the first concentration of the first gas in the main passage through the concentration sensor.

[0058] Figure 3 The ventilation method illustrated is applied to a forward flow process in a ventilation device. Here, the forward flow process refers to the process by which the mixed gas in the main passage flows toward the ventilation port. In some embodiments, during the forward flow process, Figure 2-2 and Figure 2-3The mixed gas flow rate measured by the total gas flow sensor 14 is positive. For example, the positive flow rate process can be the inspiratory phase of the ventilator, in which the gas mixed in the air branch and the oxygen branch flows through the main passage of the ventilator to the ventilation port for the patient to inhale.

[0059] In this embodiment of the invention, the ventilation device reads the first concentration of the first gas in the main passage measured by the concentration sensor through the control module.

[0060] S102. Using gas flow sensors configured in at least two channels, determine the second concentration of the first gas in the main channel and the mixed gas flow rate in the main channel.

[0061] In this embodiment of the invention, the gas flow sensor can be used to obtain the gas flow volume per unit time. Furthermore, since the mixed gas volume in the main passage is the sum of the first gas volume output from the first gas passage and the second gas volume output from the second gas passage, gas flow sensors installed in at least two of the main passage, the first gas passage, and the second gas passage can determine the first gas volume and the mixed gas volume in the main passage per unit time. Then, based on the ratio of the first gas volume to the mixed gas volume, the concentration value corresponding to the first gas can be obtained as the second concentration.

[0062] In this embodiment of the invention, the mixed gas flow rate in the main passage can be directly measured by the gas flow sensor on the main passage, or the first gas flow rate and the second gas flow rate can be determined by the gas flow sensors respectively installed on the first gas passage and the second gas passage, and the mixed gas flow rate can be obtained by the sum of the first gas flow rate and the second gas flow rate.

[0063] S103. Based on the first concentration of the first gas, the second concentration of the first gas, and the mixed gas flow rate, determine the target flow rate of the first gas, and input the first gas into the main channel through the first gas passage according to the target flow rate of the first gas, so that the first gas output from the main channel reaches the preset target concentration.

[0064] In this embodiment of the invention, the control module on the ventilation equipment can accurately calculate the current actual concentration of the first gas based on the first concentration of the first gas measured by the concentration sensor, the second concentration of the first gas calculated by the gas flow sensor, and the mixed gas flow rate. Based on the difference between the current actual concentration of the first gas and the preset target concentration, concentration feedback control is performed with the goal of achieving the preset target concentration, and the flow rate required to output the first gas, i.e. the target flow rate of the first gas, is determined together.

[0065] In some embodiments, the control module of the ventilation device can control the opening of the proportional valve in the flow rate control component set on the first gas passage according to the target flow rate corresponding to the first gas, so that the flow rate of the first gas output from the first gas passage reaches the target flow rate corresponding to the first gas.

[0066] In some embodiments, the process of determining the target flow rate of the first gas in S103 can be implemented through S1031-S1032, as follows:

[0067] S1031. Based on the first concentration corresponding to the first gas and the second concentration corresponding to the first gas, determine the corrected concentration corresponding to the first gas.

[0068] In this embodiment of the invention, the control module of the ventilation device can combine the first concentration corresponding to the first gas and the second concentration corresponding to the first gas to jointly determine the actual first gas concentration, and determine the correction concentration corresponding to the first gas based on the difference between the actual first gas concentration and the preset target concentration.

[0069] In some embodiments, the above-mentioned S1031 can be implemented by S201, as follows:

[0070] S201. If the difference between the first concentration corresponding to the first gas and the preset target concentration is greater than the preset error threshold, determine the correction concentration corresponding to the first gas based on the second concentration corresponding to the first gas and the preset target concentration.

[0071] In this embodiment of the invention, if the difference between the first concentration corresponding to the first gas and the preset target concentration is greater than a preset error threshold, it indicates that the sensor data measured by the concentration sensor deviates significantly from the preset target concentration. The ventilation device then uses the second concentration, calculated from the gas volume, as the actual first gas concentration for concentration feedback control. The ventilation device performs error control based on the difference between the second concentration corresponding to the first gas and the preset target concentration to determine the correction concentration corresponding to the first gas.

[0072] For example, in the embodiment corresponding to step S201, proportional-integral-derivative (PID) control is performed based on the difference between the second concentration of the first gas and the preset target concentration. That is, based on the error between the first concentration of the first gas and the preset target concentration, calculation is performed according to at least one of the proportional, integral, and derivative functions, and the calculation result is used as the correction concentration of the first gas.

[0073] In some embodiments, other control algorithms can be used to determine the corrected concentration of the first gas based on the difference between the second concentration of the first gas and the preset target concentration. The specific choice depends on the actual situation, and this embodiment of the invention does not impose limitations.

[0074] It is understandable that when the difference between the first concentration corresponding to the first gas and the preset target concentration is large, the second concentration can be used for concentration feedback control, thereby improving the accuracy of concentration control.

[0075] In some embodiments, the above-mentioned S1031 can also be implemented by S301-S302, as follows:

[0076] S301. If the difference between the first concentration corresponding to the first gas and the preset target concentration is less than or equal to the preset error threshold, the initial correction concentration corresponding to the first gas is determined based on the first concentration corresponding to the first gas and the preset target concentration.

[0077] In this embodiment of the invention, if the difference between the first concentration corresponding to the first gas and the preset target concentration is less than or equal to a preset error threshold, it indicates that the difference between the first concentration corresponding to the first gas and the preset target concentration is small. Therefore, error control can be performed on the first concentration corresponding to the first gas based on the error between the first concentration corresponding to the first gas and the preset target concentration to determine the initial correction concentration corresponding to the first gas. Here, the error control method is similar to the method of determining the correction concentration based on the second concentration corresponding to the first gas in S201, and will not be described again here.

[0078] S302. Determine the correction concentration corresponding to the first gas based on the second concentration corresponding to the first gas and the initial correction concentration corresponding to the first gas.

[0079] In this embodiment of the invention, the control module of the ventilation equipment uses the initial corrected concentration corresponding to the first gas calculated in S301 as the target, and performs error control on the second concentration corresponding to the first gas based on the difference between the initial corrected concentration and the second concentration corresponding to the first gas, and outputs a corrected concentration corresponding to the first gas. Here, the error control method is similar to the method of determining the corrected concentration based on the second concentration corresponding to the first gas in S201, and will not be described again here.

[0080] In some embodiments, the above-mentioned S1031 can be implemented by S401-S402, as follows:

[0081] S401. Determine the initial correction concentration of the first gas based on the first concentration of the first gas and the preset target concentration.

[0082] S402. Determine the correction concentration corresponding to the first gas based on the second concentration corresponding to the first gas and the initial correction concentration corresponding to the first gas.

[0083] In this embodiment of the invention, the control module of the ventilation equipment may also skip judging the difference between the first concentration of the first gas and the preset target concentration, and directly determine the initial correction concentration of the first gas based on the first concentration and the preset target concentration. Then, based on the second concentration of the first gas and the initial correction concentration, the correction concentration of the first gas is determined. The above process is consistent with the method description of the same process in S301, and will not be repeated here.

[0084] Understandably, by using the first and second concentrations respectively to perform error control twice in two dimensions, the accuracy of the corrected concentration corresponding to the first gas obtained in the final calculation is greatly improved.

[0085] S1032. Determine the target flow rate of the first gas based on the corrected concentration of the first gas and the mixed gas flow rate.

[0086] In this embodiment of the invention, the corrected concentration of the first gas represents the required first gas concentration to achieve the preset target concentration based on actual concentration feedback. The control module of the ventilation equipment can determine the flow rate ratio of the first gas in the mixed gas flow rate based on the corrected concentration of the first gas; and determine the target flow rate of the first gas based on the mixed gas flow rate and the flow rate ratio.

[0087] For example, when the first gas is oxygen and the second gas is air, the velocity ratio of the first gas in the mixed gas flow rate can be determined as shown in formula (1), as follows:

[0088]

[0089] In formula (1), P is the velocity ratio of oxygen in the mixed gas flow rate, and FiO2 is the corrected concentration of oxygen.

[0090] In some embodiments, taking oxygen as the first gas and air as the second gas, and combining the methods in S201 and S301-S302 above, the ventilation method provided by the embodiments of the present invention can be as follows: Figure 4 As shown below:

[0091] Figure 4In this process, the set oxygen concentration is equivalent to the preset target concentration, the oxygen concentration monitored by the oxygen concentration sensor is equivalent to the first concentration, and the volumetric oxygen concentration estimated based on the volume of oxygen and the mixed gas is equivalent to the second concentration. When the deviation between the monitored oxygen concentration and the set oxygen concentration is greater than 5%, that is, when the difference between the first concentration and the preset target concentration is greater than the preset error threshold, the initial corrected oxygen concentration is obtained by error control (such as PID control) through the monitoring oxygen concentration control module based on the difference between the set oxygen concentration and the oxygen concentration monitored by the oxygen concentration sensor; then, the corrected oxygen concentration is obtained by error control through the volumetric oxygen concentration control module based on the difference between the initial corrected concentration and the volumetric oxygen concentration. Using the corrected oxygen concentration, the oxygen ratio is calculated according to formula (1), and the target oxygen flow rate is determined by multiplying the mixed gas flow rate output by the pressure control or flow rate control with the oxygen ratio, that is, the target flow rate corresponding to the first gas. The oxygen flow rate is controlled according to the target oxygen flow rate so that the oxygen output from the main channel reaches the set oxygen concentration.

[0092] When the deviation between the monitored oxygen concentration and the set oxygen concentration is less than or equal to 5%, that is, when the difference between the first concentration and the preset target concentration is less than or equal to the preset error threshold, the volumetric oxygen concentration control module (such as a PID control module) is used to perform error control based on the difference between the set oxygen concentration and the volumetric oxygen concentration to obtain the corrected oxygen concentration. Then, the target oxygen flow rate is determined based on the corrected oxygen concentration and the mixed gas flow rate.

[0093] Understandably, by installing gas flow sensors in at least two of the main, first, and second gas passages of the ventilation equipment, the gas flow rates in at least two passages are acquired, and the second concentration of the first gas in the main passage is determined. The second concentration is calculated using the data from the gas flow sensors. Combined with the first concentration obtained from the concentration sensor and the mixed gas flow rate in the main passage, a target flow rate for the first gas is determined, ensuring that the first gas output from the main passage reaches the preset target concentration based on the target flow rate. This achieves the adjustment and control of the first gas concentration output from the ventilation equipment by combining the first gas concentrations calculated using both methods. This overcomes the problems of large time delays and untimely or inaccurate concentration control caused by relying solely on the first concentration measured by the concentration sensor for gas concentration control, thus improving the accuracy of ventilation concentration control.

[0094] It should be noted that in some embodiments, after obtaining the first concentration of the first gas in the main channel through a concentration sensor in S101, if the difference between the first concentration of the first gas and the preset target concentration is less than or equal to a preset error threshold, a corrected concentration of the first gas can also be determined based on the first concentration of the first gas and the preset target concentration; and a target flow rate of the first gas can be determined based on the corrected concentration of the first gas and the mixed gas flow rate. Figure 3 Compared to the included embodiments, this embodiment does not require calculating a second concentration, simplifying computational complexity. That is, when the difference between the first concentration corresponding to the first gas and the preset target concentration is small, based on the ventilation method provided in this embodiment, the difference between the first concentration corresponding to the first gas and the preset target concentration can also be directly used for gas concentration control to determine the target flow rate. For example... Figure 5 As shown.

[0095] In some embodiments, based on Figure 2-3 The airflow diagram of the ventilation device provided in this embodiment of the invention can be further as follows: Figure 6 As shown, it includes: a proportional valve 15 on the first gas passage; a mixing chamber 17 connected to the first gas passage, the second gas passage, and the main passage respectively; and a turbine 16 on the main passage connected between the mixing chamber and the gas flow sensor 13; optionally, a gas filter F1 on the second gas passage, a gas filter F3 on the first gas passage, and a gas filter F2 on the main passage. Based on the above... Figure 2-2 , Figure 2-3 or Figure 6 The ventilation device's main passage can also be used to receive return gas entering from the patient's ventilation port during a negative flow process. Here, a negative flow process refers to the process where gas enters the main passage from the ventilation port, and the mixed gas in the main passage flows towards the mixing chamber. It can be seen that the airflow direction in the negative flow process is opposite to the airflow direction in the positive flow process. In some embodiments, during the negative flow process, Figure 2-2 and Figure 2-3 The mixed gas flow rate measured by the total gas flow sensor 14 is negative. Therefore, different value ranges of the data measured by the total gas flow sensor can be used to determine whether the ventilation device is currently in a positive or negative flow process. For example, a negative flow process can be the expiratory phase of the ventilator, during which a portion of the gas exhaled by the patient flows back into the main pathway through the ventilation port.

[0096] In some embodiments, taking oxygen as the first gas, the mixing chamber 17 can be an oxygen-mixing chamber. It can be seen that during the exhalation phase of the ventilation device, some oxygen-enriched gas will flow back to the main passage or the low-pressure air inlet. Since there is an air filter F1 between the oxygen-mixing chamber connected to the main passage and the low-pressure air inlet, the amount of backflowing gas overflowing into the low-pressure air inlet will be reduced. Therefore, the backflowing gas mainly remains in the oxygen-mixing chamber. It is understandable that this portion of backflowing gas remaining in the oxygen-mixing chamber will affect the oxygen concentration control of the next gas delivery.

[0097] Therefore, embodiments of the present invention also provide a ventilation method, such as... Figure 7 As shown below:

[0098] S501. Accumulate the volume of the return gas using the total gas flow sensor; and when the flow rate changes from negative to positive, determine the retention volume of the first gas retained in the mixing chamber based on the volume of the return gas.

[0099] refer to Figure 6 During the ventilation process, when the flow rate measured by the total gas flow sensor 14 is negative, it indicates that gas backflow has occurred, and the process enters a negative flow rate phase. At this time, the proportional valve 15 closes, and the total gas flow sensor 14 continuously acquires and accumulates the volume of backflow gas entering the main passage during the negative flow rate phase. When the process transitions from a negative to a positive flow rate phase, such as when the flow rate of the total gas flow sensor 14 changes from a negative to a positive value, it indicates that the negative flow rate phase has ended and the positive flow rate phase has begun. At this time, the accumulation of backflow gas stops, and the retention volume corresponding to the first gas retained in the mixing chamber is determined based on the accumulated backflow gas volume.

[0100] In some embodiments, the process of determining the retention volume of the first gas retained in the mixing chamber based on the return gas volume can be implemented by executing S5011-S5014, as follows:

[0101] S5011. Based on the volume of the reflux gas, determine the total volume of the gas retained in the mixing chamber.

[0102] In this embodiment of the invention, the volume of the reflux gas is obtained by accumulating the reflux gas passing through the total gas flow sensor in the main passage. Since the reflux gas mainly remains in the mixing chamber, the portion exceeding the mixing chamber volume has little impact on gas concentration control. Therefore, the total volume of gas remaining in the mixing chamber is determined from the accumulated reflux gas volume.

[0103] In some embodiments, a preset correspondence between the volume of the reflux gas and the total volume of the retained gas can be used to determine the corresponding total volume of the retained gas based on the current volume of the reflux gas.

[0104] For example, the preset correspondence between the volume of the reflux gas and the total volume of the retained gas can be as follows: Figure 8 As shown, Figure 8 The retention volume estimation model shows a numerical curve corresponding to the volume of reflux gas and the total volume of retained gas, which can be obtained from experimental data. Based on... Figure 8 The total volume of retained gas can be determined based on the volume of backflow gas accumulated by the gas total flow sensor during the negative flow process, according to the curve relationship.

[0105] S5012. Obtain the first historical concentration and / or second historical concentration of the first gas during the previous forward flow rate process.

[0106] In this embodiment of the invention, the ventilation device can switch between operating in a positive flow rate process and a negative flow rate process. For the current positive flow rate process of the ventilation device, the first historical concentration is the concentration of the first gas in the main passage determined by the concentration sensor in the previous positive flow rate process; the second historical concentration is the concentration of the first gas in the main passage determined by the gas flow sensor installed in at least one of the first and second gas passages, and the total gas flow sensor, in the previous positive flow rate process. The calculation methods for the first historical concentration and the second historical concentration are similar to the methods for calculating the first and second concentrations in S101 and S102, and will not be repeated here.

[0107] S5013. Determine the third concentration corresponding to the first gas in the stagnant gas based on at least one of the first historical concentration, the second historical concentration and the preset target concentration.

[0108] In this embodiment of the invention, the control module on the ventilation equipment can estimate and approximate the concentration of the first gas in the stagnant gas using at least one of the first historical concentration, the second historical concentration, and the preset target concentration, to obtain the third concentration corresponding to the first gas.

[0109] For example, any one of the first historical concentration, the second historical concentration, and the preset target concentration can be used as the third concentration corresponding to the first gas; or, at least two of the first historical concentration, the second historical concentration, and the preset target concentration can be weighted and averaged to obtain the third concentration corresponding to the first gas, etc. The specific selection is made according to the actual situation, and the embodiments of the present invention are not limited.

[0110] S5014. Based on the third concentration corresponding to the first gas and the total volume of the retained gas, determine the retention volume corresponding to the first gas.

[0111] In this embodiment of the invention, the retention volume of the first gas in the main passage can be determined by multiplying the third concentration corresponding to the first gas by the total volume of the retained gas.

[0112] S502. Based on the retention volume of the first gas and the mixed gas flow rate obtained by the gas total flow sensor, determine the target flow rate of the first gas, and input the first gas into the main channel through the first gas passage according to the target flow rate of the first gas, so that the first gas output by the main channel reaches the preset target concentration.

[0113] In this embodiment of the invention, the control module of the ventilation equipment can determine the retention volume of the first gas retained during the negative flow process through the process in S501. Furthermore, when entering the positive flow process, the target flow rate of the first gas can be determined based on the retention volume of the first gas and the mixed gas flow rate obtained by the total gas flow sensor, thereby fully considering the influence of the retained gas on concentration control and further improving the accuracy of concentration control.

[0114] In some embodiments, S502 can be implemented by S5021-S5024, as follows:

[0115] S5021. Obtain the mixed airflow velocity in the main passage.

[0116] In this embodiment of the invention, the control module of the ventilation equipment can obtain the mixed gas flow rate in the main passage during the current forward flow process through the total gas flow sensor.

[0117] S5022. Determine the first concentration and / or the second concentration of the first gas by using at least one of the following sensors: at least one gas flow sensor provided in the first gas passage and the second gas passage, a concentration sensor on the main passage, and a total gas flow sensor.

[0118] In this embodiment of the invention, the first concentration of the first gas is determined by a concentration sensor on the main passage. The second concentration of the first gas can be determined by gas flow sensors respectively installed in the first gas passage and the second gas passage; or, the second concentration of the first gas can be determined by a combination of a gas flow sensor installed in the first gas passage or the second gas passage and a total gas flow sensor. The method is similar to the method for determining the second concentration in S102, and will not be described again here.

[0119] S5023. Based on the first concentration and / or the second concentration of the first gas, and in conjunction with the mixed gas flow rate, determine the initial flow rate of the first gas.

[0120] In this embodiment of the invention, the control module of the ventilation device can perform error control based solely on the first concentration of the first gas and the preset target concentration to determine the correction concentration of the first gas, and then determine the flow rate of the first gas based on the correction concentration of the first gas and the mixed gas flow rate, which is the initial flow rate of the first gas.

[0121] Alternatively, error control can be performed solely based on the second concentration of the first gas and the preset target concentration to determine the correction concentration of the first gas, and then the initial flow rate of the first gas can be determined based on the correction concentration of the first gas and the mixed gas flow rate.

[0122] Alternatively, the first concentration of the first gas can be adjusted based on the difference between its first concentration and a preset target concentration to obtain an initial corrected concentration. Then, the second concentration of the first gas can be adjusted based on the difference between its initial corrected concentration and a second concentration to output the corrected concentration. Finally, the initial flow rate of the first gas can be determined based on the corrected concentration and the mixed gas flow rate. This method is similar to the methods described in S301-S302 and will not be repeated here.

[0123] S5024. Based on the initial flow rate and the retention volume of the first gas, determine the target flow rate of the first gas.

[0124] In some embodiments, S5024 can be implemented by executing S601, S602, and S604, or by executing S601, S603, and S604, as follows:

[0125] S601. By acquiring and accumulating at least one historical flow rate compensation value between the end time of the negative flow rate process and the current time, determine the remaining retention volume of the first gas at the current time.

[0126] In this embodiment of the invention, the current time refers to any moment within the current positive flow rate process, and the negative flow rate process is equivalent to the negative flow rate process preceding the current positive flow rate process. During the positive flow rate process, as the gas flows towards the vent port, the amount of the first gas retained in the mixing chamber gradually decreases, and its influence on concentration control also gradually diminishes. Therefore, the influence of the retained first gas on the target flow rate of the first gas can be evaluated by determining the remaining volume of the first gas retained in the mixing chamber at the current time.

[0127] In this embodiment of the invention, during the positive flow process, the control module of the ventilation device acquires at least one historical flow rate compensation value from the end time of the previous negative flow process, which is also the start time of the current positive flow process, to the current time, and calculates its cumulative value. Then, based on the difference between the retention volume corresponding to the first gas and the cumulative value corresponding to the at least one historical flow rate compensation value, the remaining retention volume corresponding to the first gas can be determined.

[0128] In some embodiments, the control module of the ventilation device can acquire the flow rate compensation value corresponding to each of the n times between the end time of the previous negative flow rate process and the current time, as at least one historical flow rate compensation value; n is greater than or equal to 1; sum the at least one historical flow rate compensation value to determine the cumulative compensation value corresponding to the first gas at the current time; and determine the remaining retention volume based on the difference between the retention volume corresponding to the first gas and the cumulative compensation value.

[0129] S602. When the remaining volume is greater than the preset volume threshold, determine the flow rate compensation value of the first gas at the current moment based on the initial flow rate of the first gas; and take the difference between the initial flow rate of the first gas and the flow rate compensation value of the first gas at the current moment as the target flow rate of the first gas at the current moment.

[0130] In this embodiment of the invention, when the remaining volume exceeds a preset volume threshold, flow rate compensation needs to continue to reduce the impact of the retained first gas on concentration control. The control module of the ventilation equipment determines the flow rate compensation value corresponding to the first gas at the current moment based on the initial flow rate corresponding to the first gas. For example, the preset volume threshold can be 0, or it can be a pre-set remaining gas volume value that has a relatively small impact on concentration control. The specific selection is made according to the actual situation, and this embodiment of the invention does not limit it.

[0131] In some embodiments, the flow rate compensation value of the first gas at the current moment can be determined based on the initial flow rate of the first gas corresponding to a preset coefficient. That is, the flow rate compensation value of the first gas at the current moment is obtained by weighting the initial flow rate of the first gas according to a fixed coefficient.

[0132] For example, the velocity compensation value of the first gas at the current moment can be calculated using formula (2), as follows:

[0133] F_com(m)=k*F(m) (2)

[0134] In formula (2), m represents the current time, F(m) represents the initial velocity of the first gas at the current time, and F_com(m) represents the velocity compensation value of the first gas at the current time. k is a preset coefficient, which is greater than 0 and less than or equal to 1.

[0135] In some embodiments, the flow rate compensation value of the first gas at the current moment can also be determined based on the dynamically changing compensation coefficient. For example, the compensation coefficient at the current moment can be determined based on the ratio of the remaining retention volume to the retention volume of the first gas; and the flow rate compensation value of the first gas at the current moment can be determined based on the compensation coefficient at the current moment and the initial flow rate of the first gas. As shown in formula (3), the following is true:

[0136] F_com(m)=[V remain (m) / V hold ]*F(m) (3)

[0137] In formula (3), V remain (m) represents the remaining retention volume of the first gas at the current moment, V hold This represents the retention volume corresponding to the first gas. m is an integer greater than or equal to 1.

[0138] In some embodiments, V in formula (3) hold It can be done Figure 7 The retention volume estimation model is obtained. V remain (m) can be obtained by accumulating at least one historical velocity compensation value from the end time of the previous negative velocity process to the current time in S601, for example, as shown in formula (4), as follows:

[0139]

[0140] In formula (4), the end time of the previous negative flow velocity process is equivalent to the current positive flow velocity process, denoted as time 0. Ts represents the duration of at least one sampling period from the end time of the previous negative flow velocity process to the current time m, that is, from time 0 to time m-1. Each sampling period of at least one sampling period corresponds to a historical flow velocity compensation value f_com(n); n represents any time from time 0 to time m-1.

[0141] In some embodiments, the time n or m mentioned above can be a time in a discrete system, for example, it can be a discrete sampling time.

[0142] In some embodiments, during the forward flow process, as the airflow moves in the forward direction, the content of the first gas remaining in the mixing chamber during the previous negative flow process gradually decreases. Therefore, the compensation coefficient at the current moment can also be determined by a preset correspondence between time and compensation coefficient. This correspondence indicates that time is inversely proportional to the compensation coefficient, meaning that the compensation coefficient gradually decreases as time increases. Therefore, the flow rate compensation value corresponding to the first gas at the current moment can be determined based on the compensation coefficient at the current moment and the initial flow rate corresponding to the first gas. For example, as shown in formula (5), the following is an example:

[0143] F_com(m)=e (-rm) *F(m) (5)

[0144] In formula (5), the preset time and the compensation coefficient correspondence is e. (-rt) r can be a preset constant. (-rt)It can be a preset template curve that starts at 1 and gradually decreases towards zero, with each time t corresponding to the value of a compensation coefficient on the curve. (-rm) This represents the compensation coefficient corresponding to the current time m.

[0145] In this embodiment of the invention, since the return gas entering the main passage during the previous negative flow process is also a mixture of the first gas and the second gas, and the second gas also contains gaseous components of the first gas, for example, the gas exhaled by the patient on the ventilator is also oxygen-enriched gas. Therefore, it is also necessary to consider the influence of the first gas component in the second gas on the flow rate compensation. In some embodiments, the current retention concentration of the first gas in the current gas can be determined according to the ratio of the remaining retention volume of the first gas at the current moment to the total volume of the retained gas; and the flow rate compensation value corresponding to the first gas at the current moment can be determined according to the retention concentration of the first gas and the current mixed gas flow rate. For example, as shown in formulas (6) and (7), the following is true:

[0146]

[0147]

[0148] In formula (6), V back This represents the total volume of the retained gas, which is also the total volume of the return gas retained in the mixing chamber. Using formula (6), the difference between the total volume of the retained gas and the remaining retained volume at the current moment is calculated to determine the volume of the second gas in the remaining mixed gas in the mixing chamber at the current moment. c1 is the first preset concentration of the first gas component in the second gas. For example, when the first gas is oxygen and the second gas is air, c1 can be 0.21.

[0149] By calculating the volume of the second gas in the remaining mixed gas and the preset concentration percentage of the first gas component in the second gas using formula (6), the volume c1*[V] of the first gas component contained in the remaining second gas can be determined. back -V remain (m)]. Therefore, c1*[V back -V remain [(m)] and the remaining stagnant volume V of the first gas at the current moment. remain The ratio between the sum of (m) and the total volume of the retained gas, that is... This refers to the current concentration Fi(m) of the first gas in the mixed gas remaining in the mixing chamber at the current moment.

[0150] In formula (7), F_total(m) is the current gas flow rate of the mixed gas as measured by the gas total flow sensor in the main passage, and F_total(m)-F(m) represents the current flow rate of the second gas in the mixed gas flow rate at the current moment; the difference between the current retention concentration Fi(m) of the first gas and the first preset concentration c1, i.e., Fi(m)-c1, represents the concentration of the first gas component in the second gas retained in the mixing chamber at the current moment. c2 represents the second preset concentration of other gas components in the second gas besides the first gas component. For example, when the first gas is oxygen and the second gas is air, c2 can be 0.79.

[0151] Formula (7) is used to calculate the product of the concentration of the first gas component in the second gas remaining in the mixing chamber at the current moment and the current flow rate of the second gas, and the ratio of the product to the second preset concentration, which is used as the flow rate compensation value F_com(m) of the first gas at the current moment.

[0152] In this embodiment of the invention, based on the flow rate compensation value of the first gas at the current moment determined by any of the above methods; when the remaining stagnation volume is greater than a preset volume threshold, the control module of the ventilation equipment uses the difference between the initial flow rate of the first gas and the flow rate compensation value of the first gas at the current moment as the target flow rate of the first gas at the current moment. For example, as shown in formula (8), it is as follows:

[0153] F_valve(m)=F(m)-F_com(m) (8)

[0154] In formula (8), F_valve(m) is the target flow velocity of the first gas at the current moment.

[0155] S603. When the remaining retention volume is greater than the preset volume threshold, sum at least one historical flow rate compensation value, and determine the target flow rate of the first gas at the current moment based on the ratio between the summation result and the retention volume corresponding to the first gas, combined with the initial flow rate of the first gas.

[0156] In some embodiments, the target flow velocity of the first gas at the current moment can also be determined by formula (9):

[0157]

[0158] In formula (9), when the remaining stagnation volume is greater than the preset volume threshold, at least one historical flow rate compensation value is summed, and the target flow rate of the first gas at the current moment is determined based on the ratio between the summation result and the stagnation volume corresponding to the first gas, combined with the initial flow rate of the first gas.

[0159] It should be noted that since formula (9) determines the target flow rate at the current moment based on at least one historical flow rate compensation value prior to the current moment, if the remaining stagnation volume is greater than the preset volume threshold, it is also necessary to determine the flow rate compensation value of the first gas at the current moment based on the initial flow rate of the first gas, so as to be used for the calculation of the target flow rate at the next moment. The method of determining the flow rate compensation value of the first gas at the current moment based on the initial flow rate of the first gas is similar to the relevant methods of formulas (2) and (3) above, and will not be repeated here.

[0160] S604. When the remaining retention volume is less than or equal to a preset volume threshold, the initial flow rate of the first gas is taken as the target flow rate of the first gas at the current moment.

[0161] In this embodiment of the invention, when the remaining volume is less than or equal to a preset volume threshold, it indicates that the remaining first gas in the main passage has little impact on concentration control. The control module of the ventilation device can directly use the initial flow rate of the first gas calculated through concentration feedback control during the forward flow process as the target flow rate of the first gas at the current moment.

[0162] It is understood that, in this embodiment of the invention, during the current forward flow rate process, the retention volume of the first gas in the mixing chamber during the previous negative flow rate process is calculated. Based on the retention volume of the first gas and the mixing gas flow rate of the current forward flow rate process, and on the initial flow rate determined based on the mixing gas flow rate and oxygen concentration control, the initial flow rate of the first gas is compensated for in reverse flow based on the retention volume of the first gas to determine the target flow rate of the first gas. This reduces the impact of the backflowing gas on concentration control and improves the accuracy of gas concentration control.

[0163] In some embodiments of the ventilation method provided by the present invention, taking oxygen as an example as the first gas, the flow rate curve of the ventilation device can be as follows: Figure 9 As shown in the figure, it can be seen that when there is a deviation between the oxygen proportional valve flow rate and the target oxygen flow rate, flow rate compensation can be performed by compensating for the oxygen flow rate, thereby improving the accuracy of oxygen concentration control.

[0164] In some embodiments, based on Figure 3 The positive flow rate process shown in the figure employs a dual-loop concentration feedback control method based on a first and second concentration, combined with... Figure 7A ventilation method is proposed to compensate for the first gas velocity determined in the positive flow process based on the retention volume of the first gas in the previous negative flow process. The main passage is equipped with a total gas flow sensor, and the first gas passage and / or the second gas passage are equipped with gas flow sensors. The main passage is also used to receive return gas entering from the ventilation port during the negative flow process. The ventilation device also includes a mixing chamber connected to the first gas passage, the second gas passage, and the main passage respectively.

[0165] like Figure 10 As shown, Figure 3 Before S101, the ventilation equipment can also execute S001: using a total gas flow sensor, obtain the volume of the return gas accumulated during the negative flow process; and, when the flow process changes from negative to positive, determine the retention volume of the first gas retained in the mixing chamber based on the return gas volume; thus, Figure 3 S103 can be achieved by executing S1031 and S1033, as follows:

[0166] S1031. Based on the first concentration corresponding to the first gas and the second concentration corresponding to the first gas, determine the corrected concentration corresponding to the first gas.

[0167] S1033. Determine the target flow rate of the first gas based on the corrected concentration of the first gas, the mixed gas flow rate, and the retention volume of the first gas.

[0168] The above steps and the above Figure 7 The relevant processes described in the text are consistent and will not be repeated here.

[0169] In some embodiments, determining the target flow rate of the first gas in S1033 based on the corrected concentration of the first gas, the mixed gas flow rate, and the retention volume of the first gas includes:

[0170] Based on the corrected concentration of the first gas, determine the flow rate ratio of the first gas in the mixed gas flow rate; based on the mixed gas flow rate and the flow rate ratio, determine the initial flow rate of the first gas.

[0171] By acquiring at least one historical velocity compensation value between the end time of the cumulative negative velocity process and the current time, the remaining stagnation volume of the first gas at the current time is determined.

[0172] If the remaining volume is greater than the preset volume threshold, the flow rate compensation value of the first gas at the current moment is determined based on the initial flow rate of the first gas. The difference between the initial flow rate of the first gas and the flow rate compensation value of the first gas at the current moment is taken as the target flow rate of the first gas at the current moment.

[0173] If the remaining retention volume is less than or equal to a preset volume threshold, the initial flow rate of the first gas is taken as the target flow rate of the first gas at the current moment.

[0174] In some embodiments, determining the flow rate compensation value of the first gas at the current moment based on the initial flow rate of the first gas includes: determining the flow rate compensation value of the first gas at the current moment according to a preset coefficient and the initial flow rate of the first gas.

[0175] In some embodiments, determining the flow rate compensation value of the first gas at the current moment based on the initial flow rate of the first gas includes: determining the compensation coefficient at the current moment according to the ratio of the remaining retention volume to the retention volume of the first gas; determining the flow rate compensation value of the first gas at the current moment according to the compensation coefficient at the current moment and the initial flow rate of the first gas; or, determining the compensation coefficient at the current moment according to a preset correspondence between time and the compensation coefficient; the correspondence indicates that time is inversely proportional to the compensation coefficient; determining the flow rate compensation value of the first gas at the current moment according to the compensation coefficient at the current moment and the initial flow rate of the first gas; or, determining the current retention concentration of the first gas according to the remaining retention volume and the total volume of the retained gas; and determining the flow rate compensation value of the first gas at the current moment according to the current retention concentration of the first gas and the mixed gas flow rate.

[0176] In some embodiments, determining the remaining stagnation volume of the first gas at the current moment by acquiring at least one historical flow rate compensation value accumulated between the end time of the negative flow rate process and the current time includes:

[0177] Obtain the velocity compensation value corresponding to each of the n time points from the end time of the negative velocity process to the current time point, and use it as at least one historical velocity compensation value; n is greater than or equal to 1; sum the at least one historical velocity compensation value to determine the cumulative compensation value corresponding to the first gas at the current time point; determine the remaining retention volume based on the difference between the retention volume corresponding to the first gas and the cumulative compensation value.

[0178] In some embodiments, determining the target flow rate of the first gas in S1033 based on the corrected concentration of the first gas, the mixed gas flow rate, and the retention volume of the first gas includes: determining the flow rate ratio of the first gas flow rate in the mixed gas flow rate based on the corrected concentration of the first gas; determining the initial flow rate of the first gas based on the mixed gas flow rate and the flow rate ratio; determining the remaining retention volume of the first gas at the current time by acquiring at least one historical flow rate compensation value between the end time of the negative flow rate process and the current time; if the remaining retention volume is greater than a preset volume threshold, summing the at least one historical flow rate compensation value, and determining the target flow rate of the first gas at the current time based on the ratio between the summation result and the retention volume of the first gas, combined with the initial flow rate of the first gas.

[0179] In some embodiments, determining the retention volume of the first gas retained in the mixing chamber based on the return gas volume includes:

[0180] Based on the volume of the reflux gas, determine the total volume of the gas retained in the mixing chamber; obtain the first historical concentration and / or second historical concentration of the first gas in the previous positive flow process before the negative flow process; determine the third concentration of the first gas retained in the mixing chamber based on at least one of the first historical concentration, the second historical concentration, and the preset target concentration; determine the retention volume of the first gas based on the third concentration and the total volume of the retained gas.

[0181] In some embodiments, determining the total volume of gas retained in the mixing chamber based on the volume of the reflux gas includes: determining the corresponding total volume of gas retained according to the volume of the reflux gas in a preset correspondence between the volume of the reflux gas and the total volume of the gas retained.

[0182] In some embodiments, the first gas passage is provided with a first gas flow sensor, and the second gas passage is provided with a second gas flow sensor; the determination of the second concentration of the first gas in the main passage by the gas flow sensors provided through at least two passages includes: determining the first gas volume corresponding to the first gas input into the main passage from the first gas passage using the first gas flow sensor; determining the second gas volume corresponding to the second gas input into the main passage from the second gas passage using the second gas flow sensor; and determining the second concentration of the first gas based on the first gas volume and the second gas volume.

[0183] In some embodiments, the main passage is equipped with a total gas flow sensor, the first gas passage is equipped with a first gas flow sensor, or the second gas passage is equipped with a second gas flow sensor. Determining the second concentration of the first gas in the main passage using the gas flow sensors in at least two passages includes: determining the volume of the mixed gas formed in the main passage using the total gas flow sensor in the main passage; determining the volume of the first gas using the first gas flow sensor; or determining the volume of the second gas using the second gas flow sensor; and determining the second concentration of the first gas based on the volume of the first gas or the volume of the second gas, combined with the volume of the mixed gas.

[0184] It is understood that in this embodiment of the invention, dual-loop concentration feedback control is performed based on the first and second concentrations during the forward flow process. At the same time, the first gas flow rate determined by the dual-loop concentration feedback control is reverse-compensated based on the first gas volume retained during the negative flow process, thereby further improving the accuracy of gas concentration control.

[0185] This invention provides a ventilation device, including a main passage, a first gas passage for inputting a first gas into the main passage, and a second gas passage for inputting a second gas into the main passage. The main passage is used to output a mixed gas formed by the first gas and the second gas to a ventilation port during a forward flow process. At least two of the main passage, the first gas passage, and the second gas passage are equipped with gas flow sensors. Figure 2-1 , Figure 2-2 , Figure 2-3 As shown.

[0186] Based on the above-mentioned ventilation equipment, embodiments of the present invention provide a ventilation method, such as... Figure 11 As shown below:

[0187] S701. Using gas flow sensors configured in at least two channels, determine the second concentration of the first gas in the main channel and the mixed gas flow rate in the main channel.

[0188] Here, the process descriptions in S701 and S102 are consistent, and will not be repeated here.

[0189] S702. Based on the second concentration of the first gas and the mixed gas flow rate, determine the target flow rate of the first gas, and input the first gas into the main channel through the first gas passage according to the target flow rate of the first gas, so that the first gas output from the main channel reaches the preset target concentration.

[0190] In this embodiment of the invention, the control module on the ventilation equipment can perform error control based on the second concentration corresponding to the first gas and the preset target concentration to determine the corrected concentration corresponding to the first gas; and determine the target flow rate corresponding to the first gas based on the corrected concentration corresponding to the first gas and the mixed gas flow rate.

[0191] For example, such as Figure 12 As shown, the first gas is oxygen, and the second concentration corresponding to the first gas is the volumetric oxygen concentration estimated based on the volume of oxygen and the mixed gas. Based on the difference between the volumetric oxygen concentration and the set oxygen concentration, error control is performed by the volumetric oxygen concentration control module to obtain a corrected oxygen concentration, which is then used to determine the target oxygen flow rate.

[0192] Understandably, by using gas flow sensors in at least two pathways, the second concentration corresponding to the first gas in the main pathway is determined. Based on the second concentration of the first gas calculated from its volume, and combined with the mixed gas flow rate, the target flow rate of the first gas is determined. This avoids the problems of large time delays in controlling the gas supply concentration caused by using the first concentration measured by concentration sensors, leading to untimely concentration control and inaccurate concentration control due to untimely control, thus improving the accuracy of ventilation concentration control.

[0193] In some embodiments, a first gas passage is provided with a first gas flow sensor, and a second gas passage is provided with a second gas flow sensor. In the above-described S701, determining the second concentration of the first gas in the main passage through gas flow sensors provided in at least two passages includes: determining the first gas volume corresponding to the first gas input into the main passage from the first gas passage using the first gas flow sensor; determining the second gas volume corresponding to the second gas input into the main passage from the second gas passage using the second gas flow sensor; and determining the second concentration of the first gas based on the first gas volume and the second gas volume.

[0194] In some embodiments, a total gas flow sensor is provided in the main passage, a first gas flow sensor is provided in the first gas passage, or a second gas flow sensor is provided in the second gas passage. In S701 above, determining the second concentration of the first gas in the main passage through gas flow sensors provided in at least two passages includes: determining the volume of the mixed gas formed in the main passage through the total gas flow sensor; determining the volume of the first gas through the first gas flow sensor; or determining the volume of the second gas through the second gas flow sensor; and determining the second concentration of the first gas based on the volume of the first gas or the volume of the second gas, combined with the volume of the mixed gas.

[0195] In some embodiments, determining the target flow rate of the first gas based on the second concentration of the first gas and the mixed gas flow rate in S702 includes: determining the corrected concentration of the first gas based on the second concentration of the first gas and the preset target concentration; determining the flow rate ratio of the first gas flow rate in the mixed gas flow rate based on the corrected concentration of the first gas; and determining the target flow rate of the first gas based on the mixed gas flow rate and the flow rate ratio.

[0196] It should be noted that in practical applications, it is also possible to... Figure 11 The method provided in the paper utilizes the second concentration of the first gas for feedback control in the forward flow process, combined with... Figure 7 The reverse velocity compensation method in the negative velocity process is used to jointly determine the target velocity corresponding to the first gas output by the ventilation equipment, which will not be elaborated here.

[0197] This invention provides a ventilation device, comprising: a main passage, a first gas passage for inputting a first gas into the main passage, a second gas passage for inputting a second gas into the main passage, and a control module. The main passage is used to output a mixed gas formed by the first gas and the second gas to a ventilation port during a forward flow process. At least two of the main passage, the first gas passage, and the second gas passage are equipped with gas flow sensors; the main passage is equipped with a concentration sensor.

[0198] The concentration sensor is used to obtain the first concentration of the first gas in the main passage;

[0199] The gas flow sensors provided in the at least two passages are used to determine the second concentration of the first gas in the main passage and to determine the mixed gas flow rate in the main passage.

[0200] The control module is used to determine the target flow rate of the first gas based on the first concentration of the first gas, the second concentration of the first gas, and the mixed gas flow rate, and to input the first gas into the main channel through the first gas passage according to the target flow rate of the first gas, so that the first gas output by the main channel reaches a preset target concentration.

[0201] In some embodiments, a valve is configured on the first gas passage, and the control module is further configured to control the opening degree of the valve according to the target flow rate corresponding to the first gas, so that the flow rate of the first gas input into the first gas passage reaches the target flow rate corresponding to the first gas.

[0202] In some embodiments, the control module is further configured to: determine an initial correction concentration corresponding to the first gas based on the first concentration corresponding to the first gas and the preset target concentration when the difference between the first concentration corresponding to the first gas and the preset target concentration is less than or equal to a preset error threshold; determine a correction concentration corresponding to the first gas based on the second concentration corresponding to the first gas and the initial correction concentration corresponding to the first gas; and determine a target flow rate corresponding to the first gas based on the correction concentration corresponding to the first gas and the mixed gas flow rate.

[0203] In some embodiments, the control module is further configured to: determine a correction concentration corresponding to the first gas based on a second concentration corresponding to the first gas and the preset target concentration when the difference between the first concentration corresponding to the first gas and the preset target concentration is greater than a preset error threshold; and determine a target flow rate corresponding to the first gas based on the correction concentration corresponding to the first gas and the mixed gas flow rate.

[0204] In some embodiments, the control module is further configured to, after obtaining the first concentration of the first gas in the main passage through the concentration sensor, determine the corrected concentration of the first gas based on the first concentration of the first gas and the preset target concentration; and determine the target flow rate of the first gas based on the corrected concentration of the first gas and the mixed gas flow rate.

[0205] In some embodiments, the control module is further configured to determine an initial correction concentration corresponding to the first gas based on a first concentration corresponding to the first gas and a preset target concentration; determine a correction concentration corresponding to the first gas based on a second concentration corresponding to the first gas and the initial correction concentration corresponding to the first gas; and determine a target flow rate corresponding to the first gas based on the correction concentration corresponding to the first gas and the mixed gas flow rate.

[0206] In some embodiments, the control module is further configured to determine the flow rate ratio of the first gas in the mixed gas flow rate according to the correction concentration corresponding to the first gas; and to determine the target flow rate of the first gas according to the mixed gas flow rate and the flow rate ratio.

[0207] In some embodiments, the main passage is provided with a total gas flow sensor, the first gas passage and / or the second gas passage are provided with gas flow sensors, and the main passage is also used to receive return gas entering from the ventilation port during a negative flow rate process; the ventilation device further includes a mixing chamber connected to the first gas passage, the second gas passage and the main passage respectively;

[0208] The control module is further configured to, before obtaining the first concentration corresponding to the first gas in the main passage through the concentration sensor, accumulate the return gas volume of the return gas during the negative flow rate process through the total gas flow sensor; and, when the process changes from the negative flow rate process to the positive flow rate process, determine the retention volume corresponding to the first gas retained in the mixing chamber based on the return gas volume.

[0209] The control module is further configured to determine the target flow rate of the first gas based on the corrected concentration of the first gas, the mixed gas flow rate, and the retention volume of the first gas.

[0210] In some embodiments, the control module is further configured to: determine the flow rate ratio of the first gas in the mixed gas flow rate according to the correction concentration corresponding to the first gas; determine the initial flow rate of the first gas according to the mixed gas flow rate and the flow rate ratio; determine the remaining retention volume of the first gas at the current time by acquiring and accumulating at least one historical flow rate compensation value from the end time of the negative flow rate process to the current time; if the remaining retention volume is greater than a preset volume threshold, determine the flow rate compensation value of the first gas at the current time based on the initial flow rate of the first gas, and take the difference between the initial flow rate of the first gas and the flow rate compensation value of the first gas at the current time as the target flow rate of the first gas at the current time; if the remaining retention volume is less than or equal to the preset volume threshold, take the initial flow rate of the first gas as the target flow rate of the first gas at the current time.

[0211] In some embodiments, the control module is further configured to determine the flow rate compensation value corresponding to the first gas at the current moment based on the preset coefficient and the initial flow rate corresponding to the first gas.

[0212] In some embodiments, the control module is further configured to: determine a compensation coefficient at the current moment based on the ratio of the remaining stagnation volume to the stagnation volume corresponding to the first gas; determine a flow rate compensation value for the first gas at the current moment based on the compensation coefficient at the current moment and the initial flow rate corresponding to the first gas; or, determine a compensation coefficient at the current moment based on a preset correspondence between time and compensation coefficient, wherein the correspondence indicates that time is inversely proportional to the compensation coefficient; determine a flow rate compensation value for the first gas at the current moment based on the compensation coefficient at the current moment and the initial flow rate corresponding to the first gas; or, determine the current stagnation concentration of the first gas based on the remaining stagnation volume and the total volume of the stagnation gas; and determine a flow rate compensation value for the first gas at the current moment based on the current stagnation concentration of the first gas, the initial flow rate of the first gas, and the mixed gas flow rate.

[0213] In some embodiments, the control module is further configured to acquire the flow rate compensation value corresponding to each of the n times between the end time of the negative flow rate process and the current time, as the at least one historical flow rate compensation value; n is greater than or equal to 1; sum the at least one historical flow rate compensation value to determine the cumulative compensation value corresponding to the first gas at the current time; and determine the remaining retention volume based on the difference between the retention volume corresponding to the first gas and the cumulative compensation value.

[0214] In some embodiments, the control module is further configured to, after determining the remaining stagnant volume of the first gas at the current time by acquiring and accumulating at least one historical flow rate compensation value from the end time of the negative flow rate process to the current time, sum the at least one historical flow rate compensation value if the remaining stagnant volume is greater than a preset volume threshold, and determine the target flow rate of the first gas at the current time based on the ratio between the summation result and the stagnant volume of the first gas, combined with the initial flow rate of the first gas.

[0215] In some embodiments, the control module is further configured to: determine the total volume of gas retained in the mixing chamber based on the volume of the return gas; obtain the first historical concentration and / or the second historical concentration of the first gas in the previous positive flow process of the negative flow process; determine the third concentration of the first gas retained in the mixing chamber based on at least one of the first historical concentration of the first gas, the second historical concentration of the first gas, and a preset target concentration; and determine the retention volume of the first gas based on the third concentration of the first gas and the total volume of the retained gas.

[0216] In some embodiments, the control module is further configured to determine the corresponding total volume of the retained gas based on the volume of the reflux gas, within a preset correspondence between the volume of the reflux gas and the total volume of the retained gas.

[0217] In some embodiments, the first gas passage is provided with a first gas flow sensor, and the second gas passage is provided with a second gas flow sensor; the control module is further configured to determine, by means of the first gas flow sensor, a first gas volume corresponding to a first gas input into the main passage from the first gas passage; determine, by means of the second gas flow sensor, a second gas volume corresponding to a second gas input into the main passage from the second gas passage; and determine, based on the first gas volume and the second gas volume, a second concentration corresponding to the first gas.

[0218] In some embodiments, the main passage is provided with a total gas flow sensor, the first gas passage is provided with a first gas flow sensor, or the second gas passage is provided with a second gas flow sensor; the control module is further configured to determine the volume of the mixed gas formed in the main passage by using the total gas flow sensor on the main passage; determine the volume of the first gas by using the first gas flow sensor; or determine the volume of the second gas by using the second gas flow sensor; and determine the second concentration of the first gas by combining the volume of the first gas or the second gas with the volume of the mixed gas.

[0219] This invention provides a ventilation device, comprising: a main passage, a first gas passage for inputting a first gas into the main passage, a second gas passage for inputting a second gas into the main passage, a mixing chamber connected to the first gas passage, the second gas passage, and the main passage, and a control module. The main passage is used to output a mixture of the first gas and the second gas to a ventilation port during a positive flow rate process, and to receive return gas entering from the ventilation port during a negative flow rate process. The main passage is equipped with a total gas flow sensor.

[0220] The total gas flow sensor is used to accumulate the volume of the return gas.

[0221] The control module is configured to, when the flow rate changes from negative to positive, determine the retention volume of the first gas in the mixing chamber based on the volume of the return gas; determine the target flow rate of the first gas based on the retention volume of the first gas and the mixed gas flow rate obtained by the total gas flow sensor; and input the first gas into the main passage through the first gas passage according to the target flow rate of the first gas, so that the first gas output from the main passage reaches a preset target concentration.

[0222] In some embodiments, the main passage is further provided with a concentration sensor, and / or, at least one of the first gas passage and the second gas passage is provided with a gas flow sensor; the control module is further configured to determine the total volume of gas retained in the mixing chamber based on the return gas volume; acquire a first historical concentration and / or a second historical concentration of the first gas during the previous forward flow rate process, wherein the first historical concentration is the concentration of the first gas in the main passage determined by the concentration sensor during the previous forward flow rate process; the second historical concentration is the concentration of the first gas in the main passage determined by the gas flow sensor provided in at least one of the first gas passage and the second gas passage, and the total gas flow sensor during the previous forward flow rate process; determine a third concentration of the first gas in the retained gas based on at least one of the first historical concentration, the second historical concentration, and a preset target concentration; and determine the retention volume of the first gas based on the third concentration of the first gas and the total volume of the retained gas.

[0223] In some embodiments, the control module is further configured to acquire the mixed gas flow rate in the main passage; determine a first concentration and / or a second concentration of the first gas by using at least one of the following sensors: at least one gas flow sensor disposed in the first gas passage and the second gas passage, a concentration sensor on the main passage, and a total gas flow sensor; wherein the first concentration of the first gas is determined by the concentration sensor on the main passage; the second concentration of the first gas is determined by the gas flow sensors disposed in the first gas passage and the second gas passage respectively; or, the second concentration of the first gas is determined by the gas flow sensor disposed in the first gas passage or the second gas passage, in combination with the total gas flow sensor; determine an initial flow rate of the first gas based on the first concentration and / or the second concentration of the first gas, combined with the mixed gas flow rate; and determine a target flow rate of the first gas based on the initial flow rate of the first gas and the retention volume of the first gas.

[0224] In some embodiments, the control module is further configured to: determine the remaining stagnation volume of the first gas at the current time by acquiring at least one historical flow rate compensation value accumulated from the end time of the negative flow rate process to the current time; if the remaining stagnation volume is greater than a preset volume threshold, determine the flow rate compensation value of the first gas at the current time based on the initial flow rate of the first gas; and use the difference between the initial flow rate of the first gas and the flow rate compensation value of the first gas at the current time as the target flow rate of the first gas at the current time; and if the remaining stagnation volume is less than or equal to the preset volume threshold, use the initial flow rate of the first gas as the target flow rate of the first gas at the current time.

[0225] In some embodiments, the control module is further configured to determine the flow rate compensation value corresponding to the first gas at the current moment based on the preset coefficient and the initial flow rate corresponding to the first gas.

[0226] In some embodiments, the control module is further configured to: determine a compensation coefficient at the current moment based on the ratio of the remaining stagnation volume to the stagnation volume corresponding to the first gas; determine a flow rate compensation value for the first gas at the current moment based on the compensation coefficient at the current moment and the initial flow rate corresponding to the first gas; or, determine a compensation coefficient at the current moment based on a preset correspondence between time and compensation coefficient, wherein the correspondence indicates that time is inversely proportional to the compensation coefficient; determine a flow rate compensation value for the first gas at the current moment based on the compensation coefficient at the current moment and the initial flow rate corresponding to the first gas; or, determine the current stagnation concentration of the first gas based on the remaining stagnation volume and the total volume of the stagnation gas; and determine a flow rate compensation value for the first gas at the current moment based on the current stagnation concentration of the first gas, the initial flow rate of the first gas, and the mixed gas flow rate.

[0227] In some embodiments, the control module is further configured to acquire the flow rate compensation value corresponding to each of the n times between the end time of the negative flow rate process and the current time, as the at least one historical flow rate compensation value; n is greater than or equal to 1; sum the at least one historical flow rate compensation value to determine the cumulative compensation value corresponding to the first gas at the current time; and determine the remaining retention volume based on the difference between the retention volume corresponding to the first gas and the cumulative compensation value.

[0228] In some embodiments, the control module is further configured to, after determining the remaining stagnant volume of the first gas at the current time by acquiring and accumulating at least one historical flow rate compensation value from the end time of the negative flow rate process to the current time, sum the at least one historical flow rate compensation value if the remaining stagnant volume is greater than a preset volume threshold, and determine the target flow rate of the first gas at the current time based on the ratio between the summation result and the stagnant volume of the first gas, combined with the initial flow rate of the first gas.

[0229] In some embodiments, the control module is further configured to determine the corresponding total volume of the retained gas based on the volume of the reflux gas, within a preset correspondence between the volume of the reflux gas and the total volume of the retained gas.

[0230] This invention provides a ventilation device, comprising: a main passage, a first gas passage for inputting a first gas into the main passage, a second gas passage for inputting a second gas into the main passage, and a control module. The main passage is used to output a mixed gas formed by the first gas and the second gas to a ventilation port during a forward flow process. At least two of the main passage, the first gas passage, and the second gas passage are equipped with gas flow sensors.

[0231] The gas flow sensors provided in the at least two passages are used to determine the second concentration of the first gas in the main passage and to determine the mixed gas flow rate in the main passage.

[0232] The control module is used to determine the target flow rate of the first gas based on the second concentration of the first gas and the mixed gas flow rate, and to input the first gas into the main channel through the first gas passage according to the target flow rate of the first gas, so that the first gas output by the main channel reaches a preset target concentration.

[0233] In some embodiments, the control module is further configured to: determine, via the first gas flow sensor, a first gas volume corresponding to a first gas input into the main passage via the first gas passage; determine, via the second gas flow sensor, a second gas volume corresponding to a second gas input into the main passage via the second gas passage; and determine, based on the first gas volume and the second gas volume, a second concentration corresponding to the first gas.

[0234] In some embodiments, the main passage is provided with a total gas flow sensor, the first gas passage is provided with a first gas flow sensor, or the second gas passage is provided with a second gas flow sensor. The control module is further configured to determine the volume of the mixed gas corresponding to the mixed gas formed in the main passage through the total gas flow sensor; determine the volume of the first gas corresponding to the first gas through the first gas flow sensor; or determine the volume of the second gas corresponding to the second gas through the second gas flow sensor; and determine the second concentration of the first gas based on the first gas volume or the second gas volume, combined with the volume of the mixed gas.

[0235] In some embodiments, the control module is further configured to: determine a corrected concentration corresponding to the first gas based on the second concentration corresponding to the first gas and the preset target concentration; determine the flow rate ratio of the first gas in the mixed gas flow rate based on the corrected concentration corresponding to the first gas; and determine the target flow rate corresponding to the first gas based on the mixed gas flow rate and the flow rate ratio.

[0236] It should be noted that the description of the ventilation device embodiments above is similar to the description of the ventilation method embodiments above, and has similar beneficial effects. For technical details not disclosed in the ventilation device embodiments of the present invention, please refer to the description of the ventilation method embodiments of the present invention for understanding.

[0237] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of hardware embodiments, software embodiments, or embodiments combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage and optical storage) containing computer-usable program code.

[0238] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0239] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0240] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0241] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and scope of the present invention are included within the scope of protection of the present invention.

Claims

1. A ventilation device, characterized in that, include: The system comprises a main passage, a first gas passage for inputting a first gas into the main passage, a second gas passage for inputting a second gas into the main passage, and a control module, wherein the second gas includes the first gas; the main passage is used to output a mixture of the first gas and the second gas to a vent port; at least two of the main passage, the first gas passage, and the second gas passage are equipped with gas flow sensors; the main passage is equipped with a concentration sensor. The concentration sensor is used to obtain the first concentration of the first gas in the main passage; The gas flow sensors provided in the at least two passages are used to determine the second concentration of the first gas in the main passage and to determine the mixed gas flow rate in the main passage. The control module is used to determine the target flow rate of the first gas based on the first concentration of the first gas, the second concentration of the first gas, and the mixed gas flow rate, and to input the first gas into the main channel through the first gas passage according to the target flow rate of the first gas, so that the first gas output by the main channel reaches a preset target concentration.

2. The ventilation device according to claim 1, characterized in that, The control module is also used for: If the difference between the first concentration of the first gas and the preset target concentration is less than or equal to a preset error threshold, the initial correction concentration of the first gas is determined based on the first concentration of the first gas and the preset target concentration. The correction concentration corresponding to the first gas is determined based on the second concentration corresponding to the first gas and the initial correction concentration corresponding to the first gas. The target flow rate of the first gas is determined based on the corrected concentration of the first gas and the mixed gas flow rate.

3. The ventilation device according to claim 1, characterized in that, The control module is also used for: If the difference between the first concentration of the first gas and the preset target concentration is greater than a preset error threshold, the correction concentration of the first gas is determined based on the second concentration of the first gas and the preset target concentration. The target flow rate of the first gas is determined based on the corrected concentration of the first gas and the mixed gas flow rate.

4. The ventilation device according to claim 1, characterized in that, The control module is also used for: After obtaining the first concentration of the first gas in the main channel through the concentration sensor, the corrected concentration of the first gas is determined based on the first concentration of the first gas and the preset target concentration. The target flow rate of the first gas is determined based on the corrected concentration of the first gas and the mixed gas flow rate.

5. The ventilation device according to claim 1, characterized in that, The control module is also used for: Based on the first concentration corresponding to the first gas and the preset target concentration, determine the initial correction concentration corresponding to the first gas; The correction concentration corresponding to the first gas is determined based on the second concentration corresponding to the first gas and the initial correction concentration corresponding to the first gas. The target flow rate of the first gas is determined based on the corrected concentration of the first gas and the mixed gas flow rate.

6. The ventilation device according to any one of claims 2-5, characterized in that, The control module is also used for: Based on the corrected concentration of the first gas, determine the flow rate percentage of the first gas in the mixed gas flow rate. The target flow rate corresponding to the first gas is determined based on the mixed gas flow rate and the flow rate ratio.

7. The ventilation device according to any one of claims 2-5, characterized in that, The main passage is equipped with a total gas flow sensor, and the first gas passage and / or the second gas passage are equipped with gas flow sensors. The main passage is also used to receive return gas entering from the ventilation port during a negative flow rate process. The ventilation device also includes a mixing chamber that is connected to the first gas passage, the second gas passage and the main passage respectively. The control module is further configured to, before obtaining the first concentration corresponding to the first gas in the main passage through the concentration sensor, accumulate the return gas volume of the return gas during the negative flow rate process through the total gas flow sensor; and, when the process changes from the negative flow rate process to the positive flow rate process, determine the retention volume corresponding to the first gas retained in the mixing chamber based on the return gas volume. The control module is further configured to determine the target flow rate of the first gas based on the corrected concentration of the first gas, the mixed gas flow rate, and the retention volume of the first gas.

8. The ventilation device according to claim 7, characterized in that, The control module is also used for: Based on the corrected concentration of the first gas, determine the flow rate percentage of the first gas in the mixed gas flow rate. The initial flow rate of the first gas is determined based on the mixed gas flow rate and the flow rate ratio. By acquiring and accumulating at least one historical flow rate compensation value from the end time of the negative flow rate process to the current time, the remaining retention volume of the first gas at the current time is determined. When the remaining volume is greater than a preset volume threshold, the flow rate compensation value of the first gas at the current moment is determined based on the initial flow rate of the first gas, and the difference between the initial flow rate of the first gas and the flow rate compensation value of the first gas at the current moment is taken as the target flow rate of the first gas at the current moment. If the remaining stagnant volume is less than or equal to the preset volume threshold, the initial flow rate corresponding to the first gas is taken as the target flow rate corresponding to the first gas at the current moment.

9. The ventilation device according to claim 8, characterized in that, The control module is also used to determine the flow rate compensation value of the first gas at the current moment based on the preset coefficient and the initial flow rate corresponding to the first gas.

10. The ventilation device according to claim 8, characterized in that, The control module is also used for: The compensation coefficient at the current moment is determined based on the ratio of the remaining retention volume to the retention volume corresponding to the first gas; the flow rate compensation value corresponding to the first gas at the current moment is determined based on the compensation coefficient at the current moment and the initial flow rate corresponding to the first gas. or, The compensation coefficient at the current moment is determined based on a preset correspondence between time and compensation coefficient; the correspondence indicates that time and compensation coefficient are inversely proportional. Based on the compensation coefficient at the current moment and the initial flow rate of the first gas, determine the flow rate compensation value of the first gas at the current moment; or, Based on the remaining stagnation volume and the total volume of stagnation gas, determine the current stagnation concentration of the first gas; based on the current stagnation concentration of the first gas, the initial flow rate of the first gas, and the mixed gas flow rate, determine the flow rate compensation value of the first gas at the current moment.

11. The ventilation device according to any one of claims 8-10, characterized in that, The control module is also used for: Obtain the flow velocity compensation value corresponding to each of the n times between the end time of the negative flow velocity process and the current time, and use it as the at least one historical flow velocity compensation value; n is greater than or equal to 1; Summing the at least one historical flow rate compensation value, the cumulative compensation value of the first gas at the current moment is determined; The remaining retention volume is determined based on the difference between the retention volume corresponding to the first gas and the cumulative compensation value.

12. The ventilation device according to claim 7, characterized in that, The control module is also used for: Based on the corrected concentration of the first gas, determine the flow rate percentage of the first gas in the mixed gas flow rate. The initial flow rate of the first gas is determined based on the mixed gas flow rate and the flow rate ratio. By acquiring and accumulating at least one historical flow rate compensation value from the end time of the negative flow rate process to the current time, the remaining retention volume of the first gas at the current time is determined. If the remaining stagnant volume is greater than a preset volume threshold, the at least one historical flow rate compensation value is summed, and the target flow rate of the first gas at the current moment is determined based on the ratio between the summation result and the stagnant volume corresponding to the first gas, combined with the initial flow rate of the first gas.

13. The ventilation device according to claim 7, characterized in that, The control module is also used for: Based on the volume of the reflux gas, determine the total volume of the gas retained in the mixing chamber; Obtain the first historical concentration and / or second historical concentration of the first gas in the previous positive flow rate process before the negative flow rate process; Based on at least one of the first historical concentration corresponding to the first gas, the second historical concentration corresponding to the first gas, and the preset target concentration, determine the third concentration corresponding to the first gas retained in the mixing chamber; The retention volume of the first gas is determined based on the third concentration corresponding to the first gas and the total volume of the retained gas.

14. The ventilation device according to claim 13, characterized in that, The control module is also used to determine the corresponding total volume of the retained gas based on the volume of the reflux gas, within a preset correspondence between the volume of the reflux gas and the total volume of the retained gas.

15. The ventilation device according to any one of claims 1-5, characterized in that, The first gas passage is equipped with a first gas flow sensor, and the second gas passage is equipped with a second gas flow sensor; the control module is further configured to: The first gas volume corresponding to the first gas input into the main passage from the first gas passage is determined by the first gas flow sensor. The second gas flow sensor is used to determine the volume of the second gas corresponding to the second gas input into the main passage from the second gas passage. The second concentration corresponding to the first gas is determined based on the first gas volume and the second gas volume.

16. The ventilation device according to any one of claims 1-5, characterized in that, The main passage is equipped with a total gas flow sensor, the first gas passage is equipped with a first gas flow sensor, or the second gas passage is equipped with a second gas flow sensor; the control module is further configured to: The volume of the mixed gas formed in the main passage is determined by the total gas flow sensor on the main passage. The first gas volume corresponding to the first gas is determined by the first gas flow sensor; or, the second gas volume corresponding to the second gas is determined by the second gas flow sensor. The second concentration corresponding to the first gas is determined based on the volume of the first gas or the volume of the second gas, combined with the volume of the mixed gas.

17. The ventilation device according to claim 1, characterized in that, A valve is configured on the first gas passage, and the control module is further configured to control the opening of the valve according to the target flow rate corresponding to the first gas, so that the flow rate of the first gas input into the first gas passage reaches the target flow rate corresponding to the first gas.

18. A ventilation device, characterized in that, include: The system comprises a main passage, a first gas passage for inputting a first gas into the main passage, a second gas passage for inputting a second gas into the main passage, a mixing chamber connected to the first gas passage, the second gas passage, and the main passage, and a control module. The main passage is used to output the mixture formed by the first gas and the second gas to a vent port during a positive flow rate process, and to receive return gas entering from the vent port during a negative flow rate process. The main passage is equipped with a total gas flow sensor. The total gas flow sensor is used to accumulate the volume of the return gas. The control module is configured to, when the flow rate changes from negative to positive, determine the retention volume of the first gas in the mixing chamber based on the volume of the return gas; determine the target flow rate of the first gas based on the retention volume of the first gas and the mixed gas flow rate obtained by the total gas flow sensor; and input the first gas into the main passage through the first gas passage according to the target flow rate of the first gas, so that the first gas output from the main passage reaches a preset target concentration.

19. The ventilation device according to claim 18, characterized in that, The main gas passage is further equipped with a concentration sensor, and / or, at least one of the first gas passage and the second gas passage is equipped with a gas flow sensor; the control module is further configured to: Based on the volume of the reflux gas, determine the total volume of the gas retained in the mixing chamber; The first historical concentration and / or second historical concentration of the first gas during the previous forward flow rate process are obtained, wherein the first historical concentration is the concentration of the first gas in the main passage determined by the concentration sensor during the previous forward flow rate process; the second historical concentration is the concentration of the first gas in the main passage determined by the gas flow sensor installed in at least one of the first gas passage and the second gas passage, and by the total gas flow sensor during the previous forward flow rate process. Based on at least one of the first historical concentration, the second historical concentration, and the preset target concentration, determine the third concentration corresponding to the first gas in the stagnant gas; The retention volume of the first gas is determined based on the third concentration corresponding to the first gas and the total volume of the retained gas.

20. The ventilation device according to claim 18 or 19, characterized in that, The control module is also used for: Obtain the mixed airflow velocity in the main passage; A first concentration and / or a second concentration of the first gas are determined by at least one of the following sensors: at least one gas flow sensor provided in the first gas passage and the second gas passage, a concentration sensor on the main passage, and a total gas flow sensor; wherein the first concentration of the first gas is determined by the concentration sensor on the main passage; the second concentration of the first gas is determined by the gas flow sensors provided in the first gas passage and the second gas passage respectively; or, the second concentration of the first gas is determined by the gas flow sensor provided in the first gas passage or the second gas passage, in combination with the total gas flow sensor. Based on the first concentration and / or the second concentration of the first gas, and in conjunction with the mixed gas flow rate, the initial flow rate of the first gas is determined. The target flow rate of the first gas is determined based on the initial flow rate and the retention volume of the first gas.

21. The ventilation device according to claim 20, characterized in that, The control module is also used for: By acquiring and accumulating at least one historical flow rate compensation value from the end time of the negative flow rate process to the current time, the remaining retention volume of the first gas at the current time is determined. When the remaining volume is greater than a preset volume threshold, the flow rate compensation value of the first gas at the current moment is determined based on the initial flow rate of the first gas; and the difference between the initial flow rate of the first gas and the flow rate compensation value of the first gas at the current moment is taken as the target flow rate of the first gas at the current moment. If the remaining stagnant volume is less than or equal to the preset volume threshold, the initial flow rate of the first gas is taken as the target flow rate of the first gas at the current moment.

22. The ventilation device according to claim 21, characterized in that, The control module is also used to determine the flow rate compensation value of the first gas at the current moment based on the preset coefficient and the initial flow rate corresponding to the first gas.

23. The ventilation device according to claim 21, characterized in that, The control module is also used for: The compensation coefficient at the current moment is determined based on the ratio of the remaining retention volume to the retention volume corresponding to the first gas; the flow rate compensation value corresponding to the first gas at the current moment is determined based on the compensation coefficient at the current moment and the initial flow rate corresponding to the first gas. or, The compensation coefficient at the current moment is determined based on a preset correspondence between time and compensation coefficient; the correspondence indicates that time and compensation coefficient are inversely proportional. Based on the compensation coefficient at the current moment and the initial flow rate of the first gas, determine the flow rate compensation value of the first gas at the current moment; or, Based on the remaining stagnation volume and the total volume of stagnation gas, determine the current stagnation concentration of the first gas; based on the current stagnation concentration of the first gas, the initial flow rate of the first gas, and the mixed gas flow rate, determine the flow rate compensation value of the first gas at the current moment.

24. The ventilation device according to any one of claims 21-23, characterized in that, The control module is also used for: Obtain the flow velocity compensation value corresponding to each of the n times between the end time of the negative flow velocity process and the current time, and use it as the at least one historical flow velocity compensation value; n is greater than or equal to 1; Summing the at least one historical flow rate compensation value, the cumulative compensation value of the first gas at the current moment is determined; The remaining retention volume is determined based on the difference between the retention volume corresponding to the first gas and the cumulative compensation value.

25. The ventilation device according to claim 21, characterized in that, The control module is further configured to, after determining the remaining stagnant volume of the first gas at the current moment by acquiring and accumulating at least one historical flow rate compensation value from the end time of the negative flow rate process to the current moment, sum the at least one historical flow rate compensation value if the remaining stagnant volume is greater than a preset volume threshold, and determine the target flow rate of the first gas at the current moment based on the ratio between the summation result and the stagnant volume of the first gas, combined with the initial flow rate of the first gas.

26. The ventilation device according to claim 19, characterized in that, The control module is also used to determine the corresponding total volume of the retained gas based on the volume of the reflux gas, within a preset correspondence between the volume of the reflux gas and the total volume of the retained gas.

27. A ventilation device, characterized in that, include: The system includes a main passage, a first gas passage for inputting a first gas into the main passage, a second gas passage for inputting a second gas into the main passage, and a control module. The second gas contains the first gas. The main passage is used to output a mixture of the first gas and the second gas to a vent port. Gas flow sensors are installed in both the first gas passage and the second gas passage. The gas flow sensor is used to determine the second concentration of the first gas in the main passage and to determine the mixed gas flow rate in the main passage. The control module is used to determine the target flow rate of the first gas based on the second concentration of the first gas and the mixed gas flow rate, and to input the first gas into the main channel through the first gas passage according to the target flow rate of the first gas, so that the first gas output by the main channel reaches a preset target concentration.

28. The ventilation device according to claim 27, characterized in that, The control module is also used for: The first gas volume corresponding to the first gas input into the main passage from the first gas passage is determined by the first gas flow sensor. The second gas flow sensor is used to determine the volume of the second gas corresponding to the second gas input into the main passage from the second gas passage. The second concentration corresponding to the first gas is determined based on the first gas volume and the second gas volume.

29. The ventilation device according to claim 27, characterized in that, The main gas passage is equipped with a total gas flow sensor, the first gas passage is equipped with a first gas flow sensor, or the second gas passage is equipped with a second gas flow sensor. The control module is further configured to: The volume of the mixed gas formed in the main passage is determined by the total gas flow sensor. The first gas volume corresponding to the first gas is determined by the first gas flow sensor; or, the second gas volume corresponding to the second gas is determined by the second gas flow sensor. The second concentration corresponding to the first gas is determined based on the volume of the first gas or the volume of the second gas, combined with the volume of the mixed gas.

30. The ventilation device according to any one of claims 27-29, characterized in that, The control module is also used for: Based on the second concentration corresponding to the first gas and the preset target concentration, determine the correction concentration corresponding to the first gas; Based on the corrected concentration of the first gas, determine the flow rate percentage of the first gas in the mixed gas flow rate. The target flow rate corresponding to the first gas is determined based on the mixed gas flow rate and the flow rate ratio.

Images