Control system of intelligent auxiliary breathing device of breathing mask

Abstract

The invention relates to the field of breathing masks, in particular to a control system of an intelligent auxiliary breathing device of a breathing mask, which comprises an air pressure sensor arranged in an inner cavity of the breathing mask and used for detecting air pressure data, the airflow sensor is arranged in an air inlet channel of the breathing mask and is used for detecting the air inlet flow; the control module is used for executing a control program according to the air pressure data and the air inlet flow; the control program comprises the following steps: dividing breathing actions in the breathing mask into an inspiration stage, a stagnation stage and an expiration stage according to the air inlet flow and the air pressure data; controlling an air inlet fan and an air outlet fan to work according to the breathing stage. According to the control system, the breathing mask auxiliary breathing device can be matched with the breathing stage of the wearer to provide an effective auxiliary breathing effect, and the problem that the wearer cannot be helped to effectively solve the problems of large breathing resistance, breathing fatigue, breathing difficulty and the like due to the fact that the auxiliary breathing effect does not conform to the breathing logic of the wearer is avoided.

Description

Technical Field

[0001] The present application relates to the field of respiratory masks, and particularly to a control system for an intelligent assisted breathing device of a respiratory mask. Background Art

[0002] In special scenarios such as medical first aid, industrial protection, and military operations, wearers often need to use airtight respiratory masks for a long time to isolate harmful gases or maintain oxygen supply. However, when such masks are worn for a long time, water vapor will be generated inside them, and their airtight structure will significantly increase the breathing resistance. Especially for groups with weak breathing ability such as critically ill patients and the elderly, or high-intensity workers such as firefighters and chemical defense soldiers, it is easy to cause breathing fatigue and even the risk of hypoxia. To alleviate this problem, the prior art usually sets an assisted breathing device in the respiratory mask, for example, configuring an air inlet channel and an air outlet channel, and installing an intake fan and an exhaust fan to reduce the breathing resistance through forced air circulation.

[0003] However, although the prior art can play an auxiliary breathing effect to a certain extent, it has such a significant defect: it cannot accurately identify the real-time breathing state of the wearer, such as inhalation, exhalation, and their transition stages, resulting in the disconnection between the fan control logic and the real breathing needs. Since the breathing process has dynamics and individual differences, due to its defects, the prior art is difficult to meet the requirements of complex scenarios. For example, in industrial or military scenarios, the breathing rhythm of the wearer may fluctuate violently with the operation intensity. If the changes in breathing intensity and breathing state cannot be dynamically adapted, resulting in delayed or over-responsive fan response, it will cause air flow disorder, increase energy consumption, and may also interfere with the natural breathing rhythm of the wearer. Summary of the Invention

[0004] In order to solve the problems existing in the prior art and enhance the auxiliary breathing effect of the assisted breathing device of the respiratory mask, the present application provides a control system for an intelligent assisted breathing device of a respiratory mask, including:

[0005] A pressure sensor, arranged in the inner cavity of the respiratory mask to detect pressure data;

[0006] An air flow sensor, arranged in the air inlet channel of the respiratory mask to detect the intake air flow;

[0007] A control module, which executes a control program according to the pressure data and the intake air flow, and the control program includes:

[0008] Dividing the breathing actions in the respiratory mask into an inhalation stage, a stagnation stage, and an exhalation stage according to the intake air flow and the pressure data;

[0009] When the breathing action is in the inhalation stage, start the intake fan and turn off the exhaust fan;

[0010] When the breathing action is in the stagnant stage, turn off the intake fan and turn off the exhaust fan;

[0011] When the breathing action is in the exhalation stage, turn off the intake fan and turn on the exhaust fan.

[0012] Specifically, the control system further includes:

[0013] An infrared sensor, disposed at a position of the breathing mask in contact with the wearer, to detect the wearing fit degree of the breathing mask;

[0014] A sound player, disposed on the outer wall of the breathing mask, to play a prompt audio;

[0015] The control program further includes:

[0016] Judge whether the wearing fit degree meets the set wearing requirements;

[0017] When the wearing requirements are not met, control the sound player to play the prompt audio, turn off the intake fan, turn off the exhaust fan, and terminate the control program.

[0018] Specifically, the control program further includes:

[0019] When the breathing mask starts to work, execute a threshold calculation subroutine to obtain a stagnant air pressure change rate threshold and an inhalation flow rate threshold;

[0020] Compare the intake air flow with the inhalation flow rate threshold, and compare the air pressure data with the stagnant air pressure change rate threshold, so as to divide the breathing action in the breathing mask into an inhalation stage, a stagnant stage, and an exhalation stage.

[0021] Preferably, the threshold calculation subroutine is:

[0022] Capture the first N cycles of the air pressure data, and calculate the stagnant air pressure change rate threshold according to the air pressure change situation in the first N cycles;

[0023] Capture the first N cycles of the intake air flow, and calculate the inhalation flow rate threshold according to the air flow change situation in the first N cycles;

[0024] Wherein N is an adjustable set value.

[0025] Preferably, the method for dividing the breathing action in the breathing mask into an inhalation stage, a stagnant stage, and an exhalation stage is:

[0026] When the intake air flow is greater than the intake air flow rate threshold, it is determined that the breathing action performed in the breathing mask is in the inhalation stage;

[0027] When the intake air flow is less than or equal to the intake air flow threshold value and the instantaneous change rate of the air pressure data is less than or equal to the stagnant air pressure threshold value, it is determined that the breathing action carried out in the breathing mask is in the stagnant stage;

[0028] When the intake air flow is less than or equal to the intake air flow threshold value and the instantaneous change amount of the air pressure data is greater than the stagnant air pressure threshold value, it is determined that the breathing action carried out in the breathing mask is in the exhalation stage.

[0029] Preferably, the method for calculating the stagnant air pressure change rate threshold value is as follows:

[0030] Calculate the first-order differential of the air pressure data in the previous N cycles to obtain a sequence of the air pressure change rates in the previous N cycles;

[0031] Take the average value of the minimum values of the air pressure change rates in the previous N cycles as the stagnant air pressure change rate threshold value.

[0032] Preferably, the method for calculating the intake air flow threshold value is as follows:

[0033] Calculate the average value of the maximum values of the intake air flow in the previous N cycles, and multiply the average value by the sensitivity coefficient as the intake air flow threshold value.

[0034] Specifically, the control program further includes:

[0035] During the operation of the breathing mask, capture the minimum value of the instantaneous change amount of the air pressure data in a breathing cycle as the stagnant air pressure change rate correction value, and multiply the average value of the stagnant air pressure change rate correction value and the stagnant air pressure threshold value by the stagnant air pressure change rate correction coefficient as the new stagnant air pressure change rate threshold value.

[0036] Specifically, the control program further includes: during the operation of the breathing mask, capture the maximum value of the intake air flow in a breathing cycle as the intake air flow correction value, and multiply the average value of the intake air flow correction value and the intake air flow threshold value by the intake air flow correction coefficient as the new intake air flow threshold value.

[0037] Specifically, the control program further includes: during the operation of the breathing mask, capture the maximum value of the intake air flow in a breathing cycle as the fan reference value, and obtain the working parameters of the intake fan and the exhaust fan according to the fan reference value through a mapping relationship, and the working parameters are the working voltages.

[0038] The present application has the following technical effects:

[0039] The air pressure sensor and the air flow sensor are used to accurately identify the breathing phases of the wearer of the breathing mask. The intake fan and the exhaust fan are controlled according to the breathing phases, so that the breathing mask auxiliary breathing device can provide an effective auxiliary breathing effect in coordination with the wearer's breathing phases, avoiding problems such as ineffective auxiliary breathing effect not conforming to the wearer's breathing logic, which may lead to the inability to effectively solve problems such as high breathing resistance, breathing fatigue, and dyspnea for the wearer. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] By referring to the accompanying drawings and reading the following detailed description, the above and other objects, features, and advantages of the exemplary embodiments of the present application will become readily understood. In the drawings, several embodiments of the present application are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts.

[0041] Figure 1 is the architecture diagram of the control system in the embodiment of the present application;

[0042] Figure 2 is the judgment logic diagram of the control program in the embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application.

[0044] In a hospital environment, some patients need to wear a mask for a long time to isolate from external infections. However, these patients are already physically weak and have poor breathing ability. Wearing a mask for a long time will further increase their breathing resistance. Therefore, the masks worn by these patients often have an auxiliary breathing device. The main body of the auxiliary breathing device of the breathing mask involved in this embodiment is composed of an intake fan, an exhaust fan, an intake channel, and an exhaust channel. During the operation of the auxiliary breathing device, the intake rhythm and the exhaust rhythm should be controlled as much as possible to match the breathing rhythm of the patient, and an appropriate flow rate should be provided according to the breathing intensity of the patient. Otherwise, at least the following problems will occur: chaotic air flow inside the mask, excessive air flow invading the patient's body along with the patient's breathing causing physical discomfort, the inability to provide timely assistance when the patient inhales, and the inability to timely discharge the exhaled air when the patient exhales, resulting in an increase in temperature and humidity inside the mask. In addition, the patient may also have problems such as irregular breathing rhythm, which requires the breathing assistance device to be able to make adaptive adjustments according to the changes in the patient's breathing rhythm and breathing intensity.

[0045] In order to enable the auxiliary breathing device of the breathing mask to cooperate with the breathing rhythm of the patient and make adaptive adjustments when the breathing rhythm and breathing intensity of the patient change, this embodiment proposes an auxiliary breathing device for the breathing mask as Figure 1The shown control system includes: a barometric pressure sensor, an air flow sensor, and a control module. The barometric pressure sensor and the air flow sensor collect barometric pressure data and intake air flow and communicate with the control module, and the control module executes a control program based on the barometric pressure data and the intake air flow to perform corresponding control on the intake fan and the exhaust fan.

[0046] Specifically, the FS6122 series medical barometric pressure sensor used in this embodiment is installed on the inner wall of the spherical cavity of the breathing mask, 20 mm above the bridge of the nose. The inventor of this application conducts a simulation analysis on the exhaled air flow in the spherical cavity of this embodiment and finds that this position is in the transition zone between the laminar core area and the turbulent boundary layer of the exhaled air flow, so it can avoid the error caused by the turbulence of the exhaled air flow to the measurement result of the barometric pressure sensor. The unidirectional air flow sensor used in this embodiment is installed in the straight section pipeline of the intake channel of the breathing mask to avoid the interference of the air flow in the exhaust channel. In such a complex air flow environment, the unidirectional air flow sensor can ensure better detection effect.

[0047] Through the analysis of hundreds of respiratory sample data of patients, the inventor of this application finds that the instantaneous change amount of the barometric pressure data can be used to distinguish whether the patient is in the respiratory state or the transition state between exhalation and inhalation, that is, the stagnant state. In the stagnant state, the instantaneous change amount of the barometric pressure data is close to 0, and once the patient is in the exhalation or inhalation state, a positive pressure or a negative pressure will be generated in the cavity, and the instantaneous change amount of the barometric pressure data at this time will increase rapidly. At the same time, it can be distinguished whether the patient is in the inhalation state through the intake air flow. In the inhalation state, the intake air flow will rapidly increase to the peak value, and when the inhalation state ends, it will rapidly drop and approach 0 until the next inhalation state starts. According to this rule, the control system of this embodiment can accurately divide the entire breathing process into the inhalation stage, the stagnant stage, and the exhalation stage only through a barometric pressure sensor and a unidirectional non-interfering air flow sensor, saving a large amount of control costs and reducing the calculation difficulty and data processing difficulty. After dividing the breathing stage, executing the corresponding intake fan and exhaust fan control programs for each breathing stage can effectively provide an assisted breathing effect according to the patient's breathing rhythm.

[0048] When the control system of this embodiment is started, it will first detect whether the breathing mask is correctly worn through an infrared sensor and continuously monitor the wearing condition at a certain frequency throughout the process. Specifically, the control system of this embodiment further includes an infrared sensor and a sound player. The infrared sensor is set at the position of the breathing mask in contact with the wearer to detect the wearing fit degree of the breathing mask. If the difference in infrared reflectivity on both sides of the nose wing exceeds 15%, the sound player will be triggered to play a sound prompt and lock the system, turn off the intake fan, turn off the exhaust fan, and terminate the control program.

[0049] After passing the wearing detection, the system enters the threshold self-learning stage, continuously recording the air pressure and flow rate data of the patient's first 5 natural breathing cycles. Since the air pressure sensor collects the instantaneous air pressure value in the mask cavity at a frequency of 100 Hz, and the air flow sensor measures the intake air flow at a frequency of 50 Hz, the control module has a built-in timestamp synchronization mechanism to perform time alignment on the original data of the two sensors through cubic spline interpolation, eliminating the phase deviation caused by the sampling frequency difference.

[0050] When calculating the threshold of the stagnant air pressure change rate, the control module calculates the first-order differential of the air pressure change rate within each breathing cycle to obtain the air pressure change rate sequence. The air pressure change rate sequence of each cycle is a time series that changes regularly with time. Specifically, within a breathing cycle, starting from the inhalation stage, the air pressure change rate first gradually increases and then gradually decreases. When the stagnant stage starts, the air pressure change rate drops to the minimum value and remains at the minimum value during the stagnant stage until the inhalation stage starts, and the air pressure change rate gradually increases and then decreases again. When the stagnant stage between the inhalation stage and the inhalation stage of the next cycle starts, the air pressure change rate drops to the minimum value again and remains at the minimum value before the inhalation stage of the next cycle starts. Based on this rule, the air pressure change rate sequences of each breathing stage are sorted according to the numerical size, and the average value of the smallest 5% of the air pressure change rates can be used as the reference value of the air pressure change rate in the stagnant stage of this breathing cycle. The average value of the reference values of the air pressure change rates in the stagnant stages of the first 5 breathing cycles is used as the threshold of the stagnant air pressure change rate. In order to improve the response efficiency of the intake fan and the exhaust fan, at this time, on the basis of taking the average value of the reference values of the air pressure change rates in the stagnant stages of the first 5 breathing cycles, a response coefficient (an adjustable value between 1 and 1.5) can be multiplied to make the intake fan and the exhaust fan respond in advance.

[0051] When calculating the inhalation flow rate threshold, first observe the change rule of the intake air flow within a breathing cycle. Starting from the inhalation stage, the intake air flow will quickly mutate to the peak value and quickly drop to the minimum value at the end of the inhalation stage, and always remains at the minimum value during the stagnant stage, the exhalation stage, and the stagnant stage between the exhalation stage and the inhalation stage of the next cycle until the inhalation stage of the next cycle starts. Based on this rule, the average value of the data of the largest 5% of the intake air flow in each cycle is used as the reference value of the intake air flow in this cycle. The average value of the reference values of the intake air flow in the first 5 breathing cycles is used as the inhalation flow rate threshold. Similarly, in order to improve the response efficiency of the intake fan and the exhaust fan, at this time, on the basis of taking the average value of the reference values of the intake air flow in the first 5 breathing cycles, a sensitivity coefficient (an adjustable value between 0.5 and 1) can be multiplied to make the intake fan and the exhaust fan respond in advance. This adaptive calibration method based on individual benchmarks can effectively adapt to the differences in breathing patterns of different patients.

[0052] During the actual operation phase, the system executes real-time decision-making at a cycle of 20 ms, and executes the judgment logic as Figure 2 shown. When it is detected that the current intake air flow exceeds the intake air flow threshold, it is determined that the breathing action performed in the breathing mask is the inhalation phase, and the intake fan is immediately started and the exhaust fan is closed. At this time, the working voltage of the fan is dynamically adjusted according to the sliding average value of the maximum flow values in the previous three breathing cycles through a preset flow-voltage mapping curve to ensure that the intensity of the auxiliary air flow matches the recent breathing depth of the patient. When the intake air flow is less than or equal to the intake air flow threshold, it marks the end of the inhalation phase. The system immediately shuts down all fans and continuously monitors the status of the stagnation phase: continuously calculates the instantaneous change rate of the air pressure data. When the sliding average value of the instantaneous change rates of three consecutive sampling points is less than or equal to the stagnant air pressure threshold, it is determined that the breathing action is in the stagnation phase. In the case where the intake air flow is less than or equal to the intake air flow threshold, if it is detected that the instantaneous change amount of the air pressure data is greater than the stagnant air pressure threshold, then it can be determined that the stagnation phase has ended. At this time, it is determined that the breathing action performed in the breathing mask is the exhalation phase, the intake fan is closed, and the exhaust fan is started. In addition, the breathing mask of this embodiment is also provided with a gas sensor, which is arranged on the side wall of the inner cavity of the breathing mask to continuously monitor the gas components in the cavity, and can identify the concentrations of harmful gases including but not limited to benzene, carbon monoxide, carbon dioxide, chlorine, etc. Compare the concentrations of these gases with the set thresholds. When the concentration of any one of the gases exceeds the threshold, the system forcibly shuts down the intake fan, starts the exhaust fan with the maximum working parameters, and at the same time plays an alarm signal through the sound player to remind the wearer to replace the filter cartridge filter accessories in time, and displays the alarm information on the screen on the outer wall of the mask. The screen arranged on the outer wall of the mask can also display information such as the temperature in the inner cavity of the breathing mask, the fan speed, the battery power, and the usage duration in real time during the normal operation of the breathing mask.

[0053] For the situation of respiratory rhythm fluctuations, the control system of this embodiment is provided with a dynamic threshold correction mechanism. For the stagnant air pressure change rate threshold, after each breathing cycle ends, capture the minimum value of the instantaneous change amount of the air pressure data within a breathing cycle as the stagnant air pressure change rate correction value, perform weighted averaging with the current threshold, and multiply the average value by the stagnant air pressure change rate correction coefficient as the new stagnant air pressure change rate threshold. For the intake air flow threshold, after each breathing cycle ends, capture the minimum value of the instantaneous change amount of the air pressure data within a breathing cycle as the stagnant air pressure change rate correction value, perform weighted averaging with the current threshold, and multiply the average value by the stagnant air pressure change rate correction coefficient as the new stagnant air pressure change rate threshold. This dual adaptive mechanism enables the system to track and adjust sudden changes in breathing patterns in real time.

[0054] Obviously, the embodiments described above are some, but not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without creative efforts shall fall within the scope of protection of this application.

[0055] It should be understood that when terms such as "first" and "second" are used in the claims, the description, and the drawings of this application, they are only used to distinguish different objects and not to describe a specific order. The terms "including" and "comprising" used in the description and claims of this application indicate the presence of the described features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations.

Claims

1. A control system for a breathing mask intelligent auxiliary breathing device, characterized in that: The control system comprises: An air pressure sensor is disposed in the inner cavity of the breathing mask to detect air pressure data; An air flow sensor is arranged in the air inlet passage of the breathing mask to detect the air inlet flow rate; The control module executes a control program according to the air pressure data and the intake air flow rate, wherein the control program includes: According to the air intake flow rate and the air pressure data, the breathing action in the breathing mask is divided into an inhalation phase, a stagnation phase and an exhalation phase; When the breathing action is in the inhalation stage, the air inlet fan is started and the air outlet fan is turned off; When the breathing action is in a stagnant stage, turning off the air inlet fan and turning off the air outlet fan; When the breathing action is in the exhalation stage, the air inlet fan is turned off and the air outlet fan is started.

2. The control system according to claim 1, characterized in that: The control system further comprises: An infrared sensor is arranged at a position of the breathing mask in contact with the wearer to detect the degree of fit of the breathing mask; A sound player, arranged on the outer wall of the breathing mask, plays a prompt audio; The control program also includes: Determining whether the wearing fit meets the set wearing requirements; When the wearing requirements are not met, the sound player is controlled to play the prompt audio, the air intake fan is turned off, the air outlet fan is turned off, and the control program is terminated.

3. The control system according to claim 1, characterized in that: The control program also includes: When the breathing mask starts to work, a threshold calculation subroutine is executed to obtain a stagnation air pressure change rate threshold and an inspiratory flow threshold; The intake air flow is compared with the inhalation flow threshold, and the air pressure data is compared with the stagnation air pressure change rate threshold, so that the breathing action in the breathing mask is divided into an inhalation phase, a stagnation phase and an exhalation phase.

4. The control system according to claim 3, characterized in that: The threshold calculation subroutine is: Capturing the first N cycles of the air pressure data, and calculating a stagnation air pressure change rate threshold value according to the air pressure change in the first N cycles; Capturing the first N cycles of the intake air flow, and calculating the intake air flow threshold according to the airflow change in the first N cycles; Where N is an adjustable setting value.

5. The control system according to claim 3, characterized in that: The method of dividing the breathing action in the breathing mask into an inhalation phase, a stagnation phase and an exhalation phase is as follows: When the air intake flow rate is greater than the air intake flow rate threshold, determining that the breathing action performed in the breathing mask is an inhalation stage; When the intake flow rate is less than or equal to the intake flow rate threshold, and the instantaneous change rate of the air pressure data is less than or equal to the stagnation air pressure threshold, determining that the breathing action performed in the breathing mask is in a stagnation stage; When the intake flow rate is less than or equal to the intake flow rate threshold, and the instantaneous change in the air pressure data is greater than the stagnation pressure threshold, it is determined that the breathing action performed in the breathing mask is in the exhalation stage.

6. The control system according to claim 4, characterized in that: The method for calculating the stagnation air pressure change rate threshold is: Calculate the first-order differential of the air pressure data of the first N periods to obtain the sequence of the air pressure change rate of the first N periods; The average value of the minimum values ​​of the air pressure change rates in the first N cycles is used as the stagnation air pressure change rate threshold.

7. The control system according to claim 4, characterized in that: The method for calculating the inspiratory flow threshold is: The average value of the maximum values ​​of the intake air flow rates in the previous N cycles is calculated, and the average value is multiplied by a sensitivity coefficient to obtain the intake air flow threshold value.

8. The control system according to claim 3, characterized in that: The control program also includes: During the operation of the breathing mask, the minimum value of the instantaneous change of the air pressure data within a breathing cycle is captured as a stagnation air pressure change rate correction value, and the average value of the stagnation air pressure change rate correction value and the stagnation air pressure threshold is multiplied by the stagnation air pressure change rate correction coefficient as a new stagnation air pressure change rate threshold.

9. The control system according to claim 3, characterized in that: The control program also includes: during the operation of the breathing mask, capturing the maximum value of the intake air flow in a breathing cycle as an inhalation flow correction value, and multiplying the average value of the inhalation flow correction value and the inhalation flow threshold by the inhalation flow correction coefficient as a new inhalation flow threshold.

10. The control system according to claim 1, characterized in that: The control program also includes: during the operation of the breathing mask, capturing the maximum value of the intake air flow within a breathing cycle as a fan reference value, and obtaining the operating parameters of the intake fan and the outlet fan through a mapping relationship based on the fan reference value, wherein the operating parameters are the operating voltage.

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