Respiration monitoring system and method based on local air pressure difference dynamic characteristics

Abstract

The invention discloses a respiration monitoring system and method based on local air pressure difference dynamic characteristics, and relates to the field of respiration monitoring. A compressed air source in the system is used for providing an air source; the mass flow controller is used for controlling the oxygen flow; an oxygen inhalation opening is formed in the tube wall of the oxygen inhalation tube; the position of the oxygen inhalation port is opposite to the connection point of the oxygen inhalation tube and the micro differential pressure sensor; the micro differential pressure sensor is used for measuring an air pressure difference signal between the internal pressure of the oxygen inhalation tube and the external atmosphere; the processing unit is connected with the micro-pressure sensor; the processing unit is used for acquiring a reference air pressure difference signal corresponding to a user in a non-breathing state and generating a baseline pressure curve; the processing unit is further used for determining the pressure difference deviation amount according to the real-time air pressure difference signal and the baseline pressure curve; and the breathing amplitude of the user is graded and evaluated according to the differential pressure deviation. Under the continuous oxygen supply condition, non-intrusive, low-cost and high-sensitivity real-time monitoring can be carried out on the breathing state.

Description

Technical Field

[0001] This application relates to the field of respiratory monitoring, and in particular to a respiratory monitoring system and method based on the dynamic characteristics of local air pressure difference. Background Technology

[0002] During outpatient surgeries (such as painless gastroscopy and colonoscopy, and day surgery) and postoperative recovery, patients often require oxygen therapy, typically via nasal cannula. During treatment, respiratory function may be suppressed due to residual anesthesia, sedative effects, or the disease itself, leading to risks such as slowed respiratory rate, decreased tidal volume, or even apnea. However, current monitoring methods are insufficient for real-time assessment of respiratory function under continuous oxygen supply. Therefore, real-time monitoring of the patient's respiratory status is crucial for preventing hypoxemia and ensuring safety.

[0003] Current clinical practice primarily relies on pulse oximetry (SpO2) to assess oxygenation status. However, SpO2 essentially reflects the outcome of oxygenation, not the ventilation process. Under continuous oxygen therapy, even if a patient experiences a halving of tidal volume or brief apnea, SpO2 can still remain within the normal range due to residual alveolar oxygen reserves, resulting in so-called "occult hypoventilation." This monitoring blind spot often leads to intervention lagging behind pathophysiological deterioration, missing the optimal treatment window. To compensate for this deficiency, some medical institutions have attempted to introduce end-tidal carbon dioxide (EtCO2) monitoring. However, EtCO2 monitoring faces issues such as sample dilution and signal drift in low-flow nasal cannula oxygen therapy scenarios, and requires dedicated sampling tubing, making it difficult to implement in general wards. In recent years, researchers have explored alternative solutions such as impedance respiration, wearable chest and abdominal straps, and flexible strain sensors. However, these technologies generally have limitations such as sensitivity to motion artifacts, skin contact dependence, poor comfort, or high cost, making long-term stable use difficult in patients with frequent activity in the early postoperative period.

[0004] The more fundamental problem lies in the fact that all traditional airflow-based detection methods face signal obfuscation under continuous oxygen supply. When 2 slm–4 slm of oxygen continuously flows into the nasal cavity, the weak airflow signal generated by the patient's spontaneous breathing is submerged in the background flow, causing the sensor to be unable to distinguish between "the patient is breathing" and "only oxygen is flowing out." This technical bottleneck significantly reduces the detection rate of existing devices for mild hypoventilation (such as tidal volume dropping to below 50% of normal) or intermittent apnea. Although recent studies have demonstrated that tidal flow curves can be reconstructed using nasal cannula pressure recording, thereby achieving non-invasive and continuous lung function assessment; and flexible capacitive pressure sensors have also been used to build low-cost, wearable respiratory monitoring systems, most of these solutions are carried out under controlled laboratory conditions without continuous high-flow oxygen supply. A simple and reliable engineering implementation path is still lacking for how to stably extract respiratory signals under 2 slm–4 slm or even higher background oxygen supply.

[0005] Therefore, there is an urgent need to provide a new respiratory monitoring system that can directly capture local pressure disturbances caused by breathing, thereby achieving high-sensitivity and low-cost real-time monitoring of respiratory status (especially changes in respiratory amplitude). Summary of the Invention

[0006] The purpose of this application is to provide a respiratory monitoring system and method based on the dynamic characteristics of local air pressure difference, which can perform non-invasive, low-cost, and highly sensitive real-time monitoring of respiratory status under continuous oxygen supply conditions.

[0007] To achieve the above objectives, this application provides the following solution: In a first aspect, this application provides a respiratory monitoring system based on the dynamic characteristics of local air pressure difference. The respiratory monitoring system based on the dynamic characteristics of local air pressure difference includes: a processing unit, a compressed air source, a mass flow controller, an oxygen inhalation tube, and a micro differential pressure sensor connected to the oxygen inhalation tube; the compressed air source, the mass flow controller, and the oxygen inhalation tube are connected in sequence. The compressed air source is used to provide the air supply; the mass flow controller is used to control the oxygen flow rate. The oxygen inhalation tube has an oxygen inlet on its wall; the oxygen inlet is positioned directly opposite the connection point between the oxygen inhalation tube and the micro differential pressure sensor. The micro differential pressure sensor is used to measure the pressure difference between the internal pressure of the oxygen inhalation tube and the external atmosphere. The processing unit is connected to the micro-pressure sensor; the processing unit is used to acquire the reference air pressure difference signal corresponding to the user in a non-breathing state and generate a baseline pressure curve; the processing unit is also used to determine the pressure difference deviation based on the real-time air pressure difference signal and the baseline pressure curve; and to classify and evaluate the user's breathing amplitude based on the pressure difference deviation.

[0008] Optionally, the micro differential pressure sensor is model XGZP6897A micro differential pressure sensor.

[0009] Optionally, the processing unit includes: a signal acquisition module and a processing module; The signal acquisition module is connected to the micro differential pressure sensor and is used to convert the acquired air pressure difference signal into a voltage signal; The processing module is connected to the signal acquisition module and is used to determine the pressure difference deviation based on the real-time air pressure difference signal and the baseline pressure curve; and to classify and evaluate the user's breathing amplitude based on the pressure difference deviation.

[0010] Optionally, the oxygen inhalation tube is connected to the micro differential pressure sensor via a flexible tube.

[0011] Optionally, the respiratory monitoring system based on the dynamic characteristics of local air pressure difference further includes: a reference flow sensor; The reference flow sensor is located downstream of the oxygen inhalation tube and is used to monitor the total oxygen flow.

[0012] Optionally, the respiratory monitoring system based on the dynamic characteristics of local air pressure difference further includes: a voltage input unit; The voltage input unit is connected to the micro differential pressure sensor and the processing unit respectively, and is used to power the micro differential pressure sensor and the processing unit.

[0013] Optionally, the respiratory monitoring system based on the dynamic characteristics of local air pressure difference further includes: a display / alarm unit; The display / alarm unit is connected to the processing unit and is used to display the pressure difference-time curve in real time, and to provide corresponding levels of visual or auditory alarms based on the respiratory amplitude grading assessment results.

[0014] Secondly, this application provides a respiratory monitoring method based on the dynamic characteristics of local air pressure difference, applied to the aforementioned respiratory monitoring system based on the dynamic characteristics of local air pressure difference, characterized in that the respiratory monitoring method based on the dynamic characteristics of local air pressure difference includes: Continuously acquire baseline pressure difference signals corresponding to the user's non-breathing state; and generate a baseline pressure curve based on N baseline pressure difference signals; Real-time acquisition of the air pressure difference signal with each breath of the user; The real-time pressure difference signal is compared with the baseline pressure curve to obtain the pressure difference deviation. Normalize the pressure difference deviation; The respiratory amplitude was graded and assessed based on the normalized pressure difference deviation.

[0015] Optionally, the step of assessing respiratory amplitude grading based on the normalized pressure difference deviation further includes: Based on the assessment results of respiratory amplitude grading, corresponding levels of visual or auditory alarms will be triggered.

[0016] According to the specific embodiments provided in this application, this application has the following technical effects: This application provides a respiratory monitoring system and method based on the dynamic characteristics of local pressure difference. By inserting a micro-differential pressure sensor into the wall of the oxygen cannula directly opposite the oxygen inlet, the system measures dynamic pressure fluctuations within a standard nasal cannula to achieve local pressure difference monitoring, rather than total flow. It directly captures instantaneous pressure disturbances caused by respiration, is unaffected by continuous oxygen supply flow, and is highly sensitive to changes in respiratory amplitude, detecting even weakened or stopped breathing. By establishing a pressure baseline curve for "no breathing" and calculating the pressure difference deviation, it can robustly correlate the pressure difference value with simulated respiratory intensity (100% to 0%), effectively eliminating interference from oxygen supply flow. This application does not rely on airflow direction or volume measurement; instead, it captures transient pressure disturbances caused by respiratory movements within a standard nasal cannula and compares them with a pre-calibrated "no breathing" baseline, thereby directly quantifying the degree of respiratory effort. This application enables non-invasive, low-cost, and highly sensitive real-time monitoring of changes in patient respiratory amplitude under continuous oxygen supply conditions. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of a respiratory monitoring system based on the dynamic characteristics of local air pressure difference in one embodiment of this application; Figure 2 A schematic diagram of normal respiratory data for a micro differential pressure sensor with a range of 0.5 kPa under 1.5 SLM ventilation. Figure 3 A schematic diagram of normal respiratory data for a micro differential pressure sensor with a range of 0.5 kPa under 3.0 SLM ventilation; Figure 4 A schematic diagram of normal respiratory data for a micro differential pressure sensor with a range of 0.5 kPa under 5.0 SLM ventilation. Figure 5 A schematic diagram showing that a micro differential pressure sensor with a range of 0.5 kPa has no respiratory data under 5.0 SLM ventilation. Figure 6A schematic diagram of data analysis for a micro differential pressure sensor with a range of 0.5 kPa; Figure 7 A schematic diagram of the monitoring structure under an oxygen flow rate setting of 3 liters per minute (3 L / min); Figure 8 A schematic diagram of experimental data for monitoring the degree of respiratory depression; Figure 9 A schematic diagram of respiratory intensity monitoring under 2 slm oxygen inhalation; Figure 10 A schematic diagram of respiratory intensity monitoring under 3slm oxygen inhalation; Figure 11 A schematic diagram of respiratory intensity monitoring under 4 slm oxygen inhalation. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] In one exemplary embodiment, such as Figure 1 As shown, a respiratory monitoring system based on the dynamic characteristics of local air pressure difference is provided. The system includes: a processing unit, a compressed air source, a mass flow controller, an oxygen inhalation tube, and a micro differential pressure sensor connected to the oxygen inhalation tube; the compressed air source, the mass flow controller, and the oxygen inhalation tube are connected in sequence. The compressed air source is used to provide the air supply; the mass flow controller is used to control the oxygen flow rate (2 slm, 3 slm, or 4 slm). The oxygen inhalation tube has an oxygen inlet (i.e., a connection point for use with the nostrils) on its wall; the position of the oxygen inlet is directly opposite the connection point between the oxygen inhalation tube and the micro differential pressure sensor, so as to maximize the capture of local pressure changes caused by breathing; The micro differential pressure sensor is used to measure the pressure difference between the internal pressure of the oxygen inhalation tube and the external atmosphere. The processing unit is connected to the micro-pressure sensor; the processing unit is used to acquire the reference pressure difference signal corresponding to the user in a non-breathing state (0 effort) and generate a baseline pressure curve; the processing unit is also used to determine the pressure difference deviation based on the real-time pressure difference signal and the baseline pressure curve; and to classify and evaluate the user's breathing amplitude based on the pressure difference deviation.

[0022] As a specific embodiment, the processing unit is mounted on a computer; The principle behind respiratory status recognition is as follows: (1) During normal breathing: When the user inhales, a negative pressure is formed near the oxygen inlet, and the micro-pressure differential sensor detects negative pressure fluctuations; when exhaling, the gas backflow forms a positive pressure. The overall performance is a sinusoidal periodic fluctuation with a large fluctuation amplitude (measured 80Pa–200Pa).

[0023] (2) When there is no breathing or the breathing is weak: the airflow in the tube tends to be stable, and the pressure fluctuates irregularly in a small range around the set value, with the fluctuation amplitude significantly reduced (measured <20Pa).

[0024] As a specific example, the process of assessing respiratory amplitude grading is as follows: The baseline pressure difference signal is continuously acquired when the user is not breathing; and a baseline pressure curve is generated based on the baseline pressure difference signal N (N=10) times.

[0025] Real-time monitoring of subsequent respiratory fluctuations; if the respiratory rate drops to 70% or 50% of the baseline value, it is classified as mild respiratory depression, moderate respiratory depression, or severe respiratory depression, respectively, thus achieving graded early warning of weakened breathing.

[0026] As a specific embodiment, the processing unit can also analyze respiratory rate stability through FFT or identify abnormal breathing patterns using machine learning models.

[0027] As a specific embodiment, the compressed air source is an oxygen cylinder or a central oxygen supply system; As a specific embodiment, the mass flow controller can be set to oxygen flow rate of 1.5 SLM, 3.0 SLM, or 5.0 SLM; where SLM represents liters per minute (L / min).

[0028] Mass flow controllers can precisely set and adjust the flow rate of their input gas. The specific process is as follows: the gas source delivers the gas to the MFC, and the closed-loop control system inside the MFC will adjust the valve opening in real time according to the target flow rate value set by the software, thereby accurately controlling the gas flow rate output to the downstream pipeline and ensuring that it is stable at the preset value. As a specific embodiment, the micro differential pressure sensor is model XGZP6897A. To improve monitoring sensitivity, the micro differential pressure sensor has a range of ±250 Pa; the ±250 Pa range is adapted to low differential pressure signals during respiration, and as... Figures 2-6 As shown.

[0029] During normal breathing, the air pressure curve resembles a sine curve and exhibits a certain periodicity. The center of fluctuation changes with ventilation, and the fluctuation amplitude is approximately 80 Pa to 200 Pa. When there is no breathing, the air pressure fluctuates irregularly within a small range around a certain value, with the fluctuation amplitude generally within 20 Pa.

[0030] like Figure 7 As shown, with an oxygen flow rate of 3 liters per minute (3L / min), the user was monitored to have completed 14 breaths in one minute, which is consistent with the actual results.

[0031] like Figure 8 As shown, 136 Pa from 0 to 30 seconds represents strong and deep breathing during the normal pre-anesthesia ventilation phase. 80 Pa from 30 to 60 seconds indicates a decrease in amplitude, a natural fluctuation during mild respiratory depression. 60 Pa from 60 to 90 seconds indicates a further decrease in amplitude, representing respiratory fluctuations when breathing is significantly suppressed. If 136 Pa is taken as 100% of the baseline, then 60 Pa is approximately 44% of the baseline. This is usually interpreted as "severe respiratory atony" or "significant respiratory depression," a signal requiring high vigilance.

[0032] As a specific example, the model of the micro differential pressure sensor can also be the Honeywell ASDX series, Sensirion SDP series, etc., with a suitable range (such as ±500Pa or ±2500Pa). As another specific embodiment, two absolute differential pressure sensors are used instead of a micro differential pressure sensor. One absolute differential pressure sensor measures the pressure inside the tube, and the other absolute differential pressure sensor measures the atmospheric pressure. The pressure difference signal is calculated by the difference.

[0033] To ensure the accuracy of pressure difference signal processing, the processing unit includes: a signal acquisition module and a processing module; The signal acquisition module is connected to the micro differential pressure sensor and is used to convert the acquired air pressure difference signal into a voltage signal; The processing module is connected to the signal acquisition module and is used to determine the pressure difference deviation based on the real-time air pressure difference signal and the baseline pressure curve; and to classify and evaluate the user's breathing amplitude based on the pressure difference deviation.

[0034] To achieve a non-serial installation method, the oxygen inhalation tube is connected to the micro differential pressure sensor via a flexible tube.

[0035] To ensure the accuracy of the monitoring data, the respiratory monitoring system based on the dynamic characteristics of local air pressure difference also includes: a reference flow sensor; The reference flow sensor is located downstream of the oxygen inhalation tube and is used to monitor the total oxygen flow.

[0036] As a specific embodiment, the respiratory monitoring system based on the dynamic characteristics of local air pressure difference further includes: a voltage input unit; The voltage input unit is connected to the micro differential pressure sensor and the processing unit respectively, and is used to power the micro differential pressure sensor and the processing unit.

[0037] To provide real-time display and alerts, the respiratory monitoring system based on the dynamic characteristics of local air pressure differences also includes a display / alarm unit; The display / alarm unit is connected to the processing unit and is used to display the pressure difference-time curve in real time, and to provide corresponding levels of visual or auditory alarms based on the respiratory amplitude grading assessment results.

[0038] In one exemplary embodiment, a respiratory monitoring method based on dynamic characteristics of local pressure differences is provided, comprising: S1, continuously collect the baseline pressure difference signal corresponding to the user's non-breathing state N times (e.g., 10 times); and generate a baseline pressure curve based on the N baseline pressure difference signals; S2, which collects the air pressure difference signal for each breath of the user in real time; S3. Compare the real-time pressure difference signal with the baseline pressure curve to obtain the pressure difference deviation ΔP.

[0039] ΔP = P_original – P_no_respiration; S4 normalizes the differential pressure deviation to achieve cross-patient comparability, and as... Figures 9-11 As shown, the normalized breathing intensity exhibits high consistency under different airflow rates, demonstrating that the monitoring system has good robustness and its measurement results are not significantly affected by changes in gas flow rate. At 70% effort: the normalized value for 2 slm is 68.5%, the normalized value for 3 slm is 70.7%, and the normalized value for 4 slm is 72.5%; At 50% effort: normalized value approximately 48–52%; At 30% effort: the normalized value is approximately 28–30%; Low variance (<12%) indicates excellent repeatability.

[0040] The coefficient of variation for all measurements was less than 12%, indicating that the system has excellent measurement repeatability.

[0041] Specifically, under different traffic volumes: When 70% of the respiratory effort is utilized, the normalized values ​​are concentrated in the range of 68.5% - 72.5%. When 50% of the breathing effort is exerted, the normalized values ​​are concentrated in the 48% - 52% range; When 30% of the respiratory effort is used, the normalized values ​​are concentrated in the 28% - 30% range; ;in, This represents the pressure difference deviation at 100% breathing intensity. Statistical analysis includes mean, variance, and coefficient of variation (CV); the mean, standard deviation, and coefficient of variation are used to perform statistical analysis to assess the repeatability and consistency of the system. S5, assess respiratory amplitude grading based on the normalized pressure difference deviation; S5 also includes: Based on the assessment results of respiratory amplitude grading, corresponding levels of visual or auditory alarms will be triggered.

[0042] The following system validation was conducted using an artificial lung to simulate different breathing intensities (100%, 70%, 50%, 30%, 0%) under three typical oxygen therapy flow rates, and further in vivo testing was carried out in healthy volunteers: An artificial lung was used, and a preset flow rate of air was injected into the nasal cannula via MFC (compressed air was used in the experiment; it's unclear whether the type of airflow needs to be specified): 100% effort: 3 slm (3 slm × 100% corresponds to normal physiological tidal volume); 70% effort: 2.1 slm (3 slm × 70%, simulating a mildly reduced breathing state); 50% effort: 1.5 slm (3 slm × 50%, simulating moderately reduced breathing); 30% effort: 0.9 slm (3 slm × 30%, simulating severe respiratory atresia); 0% effort: 0 slm (3 slm × 0%, simulating apnea); Three independent measurements were performed at each oxygen supply flow rate (2 slm, 3 slm, 4 slm).

[0043] Three independent measurements were performed at each airflow rate level to ensure data reliability. Table 1 shows the absolute pressure difference (ΔP, in arbitrary Pa) under different oxygen supply flow rates and breathing intensities. The system response is consistent: ΔP decreases monotonically as breathing effort decreases.

[0044] Table 1. (ΔP) under different oxygen supply flow rates and breathing intensities

[0045] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0046] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0047] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A respiratory monitoring system based on the dynamic characteristics of local air pressure difference, characterized in that, The respiratory monitoring system based on the dynamic characteristics of local air pressure difference includes: a processing unit, a compressed air source, a mass flow controller, an oxygen inhalation tube, and a micro differential pressure sensor connected to the oxygen inhalation tube; the compressed air source, the mass flow controller, and the oxygen inhalation tube are connected in sequence. The compressed air source is used to provide the air supply; the mass flow controller is used to control the oxygen flow rate. The oxygen inhalation tube has an oxygen inlet on its wall; the oxygen inlet is positioned directly opposite the connection point between the oxygen inhalation tube and the micro differential pressure sensor. The micro differential pressure sensor is used to measure the pressure difference between the internal pressure of the oxygen inhalation tube and the external atmosphere. The processing unit is connected to the micro-pressure sensor; the processing unit is used to acquire the reference air pressure difference signal corresponding to the user in a non-breathing state and generate a baseline pressure curve; the processing unit is also used to determine the pressure difference deviation based on the real-time air pressure difference signal and the baseline pressure curve; and to classify and evaluate the user's breathing amplitude based on the pressure difference deviation.

2. The respiratory monitoring system based on the dynamic characteristics of local air pressure difference according to claim 1, characterized in that, The micro differential pressure sensor is model XGZP6897A.

3. The respiratory monitoring system based on the dynamic characteristics of local air pressure difference according to claim 1, characterized in that, The processing unit includes: a signal acquisition module and a processing module; The signal acquisition module is connected to the micro differential pressure sensor and is used to convert the acquired air pressure difference signal into a voltage signal; The processing module is connected to the signal acquisition module and is used to determine the pressure difference deviation based on the real-time air pressure difference signal and the baseline pressure curve; and to classify and evaluate the user's breathing amplitude based on the pressure difference deviation.

4. The respiratory monitoring system based on the dynamic characteristics of local air pressure difference according to claim 1, characterized in that, The oxygen inhalation tube is connected to the micro differential pressure sensor via a flexible tube.

5. The respiratory monitoring system based on the dynamic characteristics of local air pressure difference according to claim 1, characterized in that, The respiratory monitoring system based on the dynamic characteristics of local air pressure difference also includes: a reference flow sensor; The reference flow sensor is located downstream of the oxygen inhalation tube and is used to monitor the total oxygen flow.

6. The respiratory monitoring system based on the dynamic characteristics of local air pressure difference according to claim 1, characterized in that, The respiratory monitoring system based on the dynamic characteristics of local air pressure difference also includes: a voltage input unit; The voltage input unit is connected to the micro differential pressure sensor and the processing unit respectively, and is used to power the micro differential pressure sensor and the processing unit.

7. The respiratory monitoring system based on the dynamic characteristics of local air pressure difference according to claim 1, characterized in that, The respiratory monitoring system based on the dynamic characteristics of local air pressure difference also includes: a display / alarm unit; The display / alarm unit is connected to the processing unit and is used to display the pressure difference-time curve in real time, and to provide corresponding levels of visual or auditory alarms based on the respiratory amplitude grading assessment results.

8. A respiratory monitoring method based on dynamic characteristics of local air pressure difference, applied to the respiratory monitoring system based on dynamic characteristics of local air pressure difference as described in any one of claims 1-7, characterized in that, The respiratory monitoring method based on the dynamic characteristics of local air pressure difference includes: Continuously acquire baseline pressure difference signals corresponding to the user's non-breathing state; and generate a baseline pressure curve based on N baseline pressure difference signals; Real-time acquisition of the air pressure difference signal with each breath of the user; The real-time pressure difference signal is compared with the baseline pressure curve to obtain the pressure difference deviation. Normalize the pressure difference deviation; The respiratory amplitude was graded and assessed based on the normalized pressure difference deviation.

9. The respiratory monitoring method based on the dynamic characteristics of local air pressure difference according to claim 8, characterized in that, The assessment of respiratory amplitude grading based on the normalized differential pressure deviation further includes: Based on the assessment results of respiratory amplitude grading, corresponding levels of visual or auditory alarms will be triggered.

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