A method and device for monitoring respiratory flow based on chest and abdominal motion

Abstract

The application discloses a thoracico-abdominal motion respiration flow monitoring method and device, and relates to the field of respiration monitoring. The method comprises the following steps: acquiring a pressure value of a patient pressure monitoring point; the pressure monitoring point comprises a thoracic pressure monitoring point and an abdominal pressure monitoring point; performing data analysis according to the pressure value to determine a displacement change amount of the pressure monitoring point relative to an initial spatial coordinate; performing nonlinear fitting according to the displacement change amount to determine a thoracic volume change amount and an abdominal volume change amount; determining a respiration parameter according to the thoracic volume change amount and the abdominal volume change amount; the respiration parameter comprises a total lung ventilation, a thoracic respiration contribution ratio, an abdominal respiration contribution ratio and a thoraco-abdominal phase difference. The application realizes low-cost and high-precision respiration flow monitoring.

Description

Technical Field

[0001] This invention relates to the field of respiratory monitoring, and in particular to a method and device for monitoring respiratory flow based on chest and abdominal movements. Background Technology

[0002] Pulmonary ventilation function testing is the most basic test in respiratory function examination. Many lung diseases are related to ventilation dysfunction, such as chronic obstructive pulmonary disease, asthma, and pulmonary edema. Pulmonary ventilation function testing is of great clinical significance for the early screening and auxiliary diagnosis of lung or airway diseases, as well as for assessing lung function tolerance to surgery and exercise intensity.

[0003] Currently, the main methods specifically used for testing pulmonary ventilation function are spirometry and respiratory plethysmography. Spirometry, a traditional flow-based method, can rule out lung diseases such as asthma and emphysema. However, this method requires the subject to wear a breathing mask, which not only restricts the subject's activity and increases airway resistance but also easily alters the subject's breathing pattern, making it unsuitable for long-term monitoring of respiratory status. Respiratory plethysmography, on the other hand, does not require a breathing mask and is a non-invasive respiratory measurement method. However, because this method measures a cross-sectional area of ​​the chest and abdomen based on electromagnetic induction to detect pulmonary ventilation, it suffers from drawbacks such as high error and power consumption, circuit instability, and high cost. Therefore, there is a need to develop instruments or methods that are low-power, low-cost, easy to operate, and meet accuracy requirements, suitable for long-term lung monitoring. Summary of the Invention

[0004] The purpose of this invention is to provide a method and device for monitoring respiratory flow based on chest and abdominal movements, which can achieve low-cost and high-precision monitoring of respiratory flow.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] A method for monitoring respiratory flow based on chest and abdominal movements includes:

[0007] Acquire pressure values ​​at patient pressure monitoring points; these pressure monitoring points include chest pressure monitoring points and abdominal pressure monitoring points.

[0008] Based on the pressure value, data analysis is performed to determine the displacement change of the pressure monitoring point relative to the initial spatial coordinates;

[0009] The changes in chest volume and abdominal volume are determined by nonlinear fitting based on the displacement changes.

[0010] Respiratory parameters are determined based on the changes in thoracic volume and abdominal volume; the respiratory parameters include total lung ventilation, thoracic respiratory contribution ratio, abdominal respiratory contribution ratio, and thoracic-abdominal phase difference.

[0011] Optionally, data analysis is performed based on the pressure value to determine the displacement change of the pressure monitoring point relative to the initial spatial coordinates, specifically including:

[0012] Based on the pressure values ​​at the chest pressure monitoring points, data analysis is performed to determine the displacement change of the chest pressure monitoring points relative to the initial spatial coordinates.

[0013] Based on the pressure values ​​at the abdominal pressure monitoring points, data analysis is performed to determine the displacement change of the abdominal pressure monitoring points relative to the initial spatial coordinates.

[0014] Optionally, nonlinear fitting is performed based on the displacement change to determine the changes in thoracic volume and abdominal volume, specifically including:

[0015] The volume of each unit layer thickness of the torso is obtained by multiplying the area of ​​each cross-section of the torso by the unit thickness of each cross-section of the torso.

[0016] The volumes of each unit thickness of the torso are accumulated to determine the chest volume and abdominal volume at a set time.

[0017] The change in chest volume is obtained by subtracting the initial chest volume from the chest volume at the set time.

[0018] The change in abdominal volume is obtained by subtracting the initial abdominal volume from the abdominal volume at the set time.

[0019] Optionally, respiratory parameters are determined based on the changes in thoracic volume and abdominal volume, specifically including:

[0020] The total lung ventilation, the contribution ratio of thoracic respiration, and the contribution ratio of abdominal respiration are determined based on the changes in thoracic volume and abdominal volume.

[0021] Plot the chest volume change curve and the abdominal volume change curve respectively based on the chest volume change and the abdominal volume change;

[0022] Obtain the peak value of the chest volume change curve and the peak value offset time of the abdominal volume change curve;

[0023] The chest-abdomen phase difference is calculated based on the proportion of the offset time to the signal within the respiratory cycle.

[0024] Optionally, the total lung ventilation, the contribution ratio of thoracic respiration, and the contribution ratio of abdominal respiration are determined based on the changes in thoracic volume and abdominal volume, specifically including:

[0025] The total pulmonary ventilation is obtained by adding the changes in thoracic volume and abdominal volume.

[0026] The thoracic respiratory contribution ratio is obtained by dividing the change in thoracic volume by the total lung ventilation.

[0027] The abdominal respiratory contribution ratio is obtained by dividing the change in abdominal volume by the total lung ventilation.

[0028] The present invention also provides a respiratory flow monitoring device based on chest and abdominal movement, wherein the respiratory flow monitoring device based on chest and abdominal movement applies the aforementioned respiratory flow monitoring method based on chest and abdominal movement, and the respiratory flow monitoring device based on chest and abdominal movement includes: a pressure detection system and a main control chip;

[0029] The pressure detection system includes an elastic vest and multiple piezoresistive thin-film pressure sensor units; the multiple piezoresistive thin-film pressure sensor units are respectively disposed on the inner side of the elastic vest; the piezoresistive thin-film pressure sensor units are used to detect the pressure value at the patient's pressure monitoring point; the main control chip is connected to the piezoresistive thin-film pressure sensor units, and the main control chip is used to determine the patient's respiratory parameters based on the pressure value; the respiratory parameters include total lung ventilation, thoracic respiratory contribution ratio, abdominal respiratory contribution ratio, and thoracic-abdominal phase difference.

[0030] Optionally, the pressure detection system further includes a 16-to-1 selector chip and a linear voltage conversion module connected to the 16-to-1 selector chip; the 16-to-1 selector chip is also connected to the piezoresistive thin-film pressure sensor unit; and the linear voltage conversion module is also connected to the main control chip.

[0031] Optionally, the chest and abdominal movement-based respiratory flow monitoring device further includes a screen display module connected to the main control chip, the screen display module being used to display the pressure value and the respiratory parameters.

[0032] Optionally, the main control chip is an STM32F407ZGT6.

[0033] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0034] This invention acquires pressure values ​​at patient pressure monitoring points, including chest and abdominal pressure monitoring points. Data analysis is performed based on the pressure values ​​to determine the displacement change of each pressure monitoring point relative to its initial spatial coordinates. Nonlinear fitting is then performed based on these displacement changes to determine the changes in chest and abdominal volume. Respiratory parameters are then determined based on these changes, including total lung ventilation, chest respiratory contribution ratio, abdominal respiratory contribution ratio, and chest-abdomen phase difference. By measuring pressure values ​​and utilizing the mathematical concept of infinitesimal elements, the accuracy of measuring chest and abdominal volume changes is improved, thereby enabling high-precision determination of respiratory parameters. Furthermore, this invention, in implementing lung ventilation detection, avoids the instability issues of resonant circuits because it does not involve electromagnetic induction, and its cost is relatively low, solving the power consumption and circuit stability problems of traditional respiratory induction volume plethysmography. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 The flowchart of the respiratory flow monitoring method based on chest and abdominal movement provided by the present invention;

[0037] Figure 2 This is a normal chest and abdominal breathing curve.

[0038] Figure 3 This is a phase difference analysis diagram of the chest and abdominal breathing curves;

[0039] Figure 4 This is a schematic diagram of a respiratory flow monitoring device based on chest and abdominal movements.

[0040] Figure 5 This is a front view of the pressure sensor distribution;

[0041] Figure 6 This is a rear view of the pressure sensor distribution;

[0042] Figure 7 This is a side view of the pressure sensor distribution.

[0043] Symbol explanation:

[0044] Pressure detection system-1, main control chip-2, screen display module-3. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of 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.

[0046] The purpose of this invention is to provide a method and device for monitoring respiratory flow based on chest and abdominal movements, which can achieve low-cost and high-precision monitoring of respiratory flow.

[0047] Konno and Mead's experiments demonstrated that, in terms of pulmonary ventilation, the movement of the human respiratory cavity can be approximated as having two degrees of freedom: the thoracic cavity and the abdominal cavity. Changes in lung volume can be equated to changes in the volume of gas entering the lungs through the mouth and nose. The clinically used respiratory plethysmography (RPP) is based on this experimental conclusion and developed using a fundamental mathematical model. This method measures the cross-sectional area ΔuV of the thoracic cavity. RC and abdominal cavity cross-sectional area ΔuV AB Changes in lung ventilation ΔV are calibrated to achieve this. AO Measurement.

[0048] ΔV AO =Z·ΔuV RC +L·ΔuV AB

[0049] Where Z and L are the motion-volume correlation coefficients of the thoracic cavity and abdominal cavity, respectively.

[0050] In current practical engineering applications, instruments made using traditional respiratory plethysmography only measure a cross-sectional area of ​​the thoracic and abdominal cavities, then substitute this data into an approximate mathematical model of the thoracic and abdominal cavities to approximately calculate the volume change of the entire thoracic and abdominal cavities. Inspired by this method, and to improve the accuracy of non-invasive measurement of pulmonary ventilation, this invention innovatively proposes another non-invasive method for detecting pulmonary ventilation, namely the respiratory motion pressure-volume measurement method described below. The core idea of ​​this method is that as the lungs inhale or exhale, the human body's thoracic and abdominal cavities undergo expansion or contraction trunk movements. Using the minute displacements generated by trunk movements as a bridge, a mathematical model is established between thoracic and abdominal volume, trunk displacement, and respiratory motion pressure to determine pulmonary ventilation and further analyze respiratory parameters.

[0051] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0052] like Figure 1 As shown, the present invention provides a method for monitoring respiratory flow based on chest and abdominal movements, comprising:

[0053] Step 101: Obtain the pressure values ​​at the patient's pressure monitoring points; the pressure monitoring points include chest pressure monitoring points and abdominal pressure monitoring points.

[0054] Step 102: Analyze the data based on the pressure value to determine the displacement change of the pressure monitoring point relative to the initial spatial coordinates.

[0055] Step 102 specifically includes: performing data analysis based on the pressure value of the chest pressure monitoring point to determine the displacement change of the chest pressure monitoring point relative to the initial spatial coordinates; and performing data analysis based on the pressure value of the abdominal pressure monitoring point to determine the displacement change of the abdominal pressure monitoring point relative to the initial spatial coordinates.

[0056] Step 103: Perform nonlinear fitting based on the displacement change to determine the chest volume change and abdominal volume change.

[0057] Step 103 specifically includes: obtaining the volume of each unit layer thickness of the torso by multiplying the area of ​​each cross-section of the torso by the unit thickness of each cross-section of the torso; accumulating the volumes of each unit layer thickness of the torso to determine the chest volume and the abdomen volume at a set time; subtracting the initial chest volume from the chest volume at the set time to obtain the change in chest volume; and subtracting the initial abdomen volume from the abdomen volume at the set time to obtain the change in abdomen volume.

[0058] Step 104: Determine respiratory parameters based on the changes in thoracic volume and abdominal volume; the respiratory parameters include total lung ventilation, thoracic respiratory contribution ratio, abdominal respiratory contribution ratio, and thoracic-abdominal phase difference.

[0059] Step 104 specifically includes: determining the total lung ventilation, the thoracic respiratory contribution ratio, and the abdominal respiratory contribution ratio based on the changes in thoracic volume and abdominal volume; plotting thoracic volume change curves and abdominal volume change curves based on the changes in thoracic volume and abdominal volume, respectively; obtaining the peak value of the thoracic volume change curve and the peak value offset time of the abdominal volume change curve; and calculating the thoracic-abdominal phase difference based on the proportion of the offset time to the signal within the respiratory cycle.

[0060] Specifically, determining the total lung ventilation, the contribution ratio of thoracic respiration, and the contribution ratio of abdominal respiration based on the changes in thoracic volume and abdominal volume includes:

[0061] The total lung ventilation is obtained by adding the changes in thoracic volume and abdominal volume; the thoracic respiratory contribution ratio is obtained by dividing the changes in thoracic volume by the total lung ventilation; and the abdominal respiratory contribution ratio is obtained by dividing the changes in abdominal volume by the total lung ventilation.

[0062] This invention also provides specific working steps for the practical application of the respiratory flow monitoring method based on chest and abdominal movement.

[0063] like Figures 5 to 7 As shown, multiple pressure sensors are integrated in an array on an elastic vest to construct a three-dimensional pressure monitoring system to monitor the pressure of torso movement in real time. Note the distribution requirements: keep the spatial coordinate height of the pressure monitoring points on each cross section the same.

[0064] Establish the relationship between the pressure value F generated by trunk movement and the pulmonary ventilation ΔV AO The mathematical relationship between them:

[0065] 1. Fit an elastic vest onto the customized dynamic breathing exercise phantom, define the three-dimensional spatial coordinates of each pressure monitoring point as the initial spatial coordinates of each point, and calculate the initial chest volume V formed by each initial spatial coordinate. RC0 and initial abdominal volume V AB0 Record the pressure values ​​at each pressure monitoring point at this time and label them as "zero" (not the actual zero value, because the detected pressure values ​​are only positive).

[0066] 2. Under the computer program control of increasing or decreasing air pressure, the phantom lung will fill or empty air to simulate human lung function, causing displacement at various points in the phantom's chest and abdomen (Note: chest and abdominal movements of more than one centimeter can be programmed). The movement displacement of each monitoring point in the chest and abdomen is recorded, and the pressure values ​​of each point detected in real time by the elastic vest are recorded. Data analysis is performed to establish a mathematical relationship between the chest and abdominal movement displacement and the respiratory movement pressure at each pressure monitoring point.

[0067] ΔF RCij =A·Δx RCij 2 +B·Δx RCij

[0068] ΔF ABij =C·Δx ABij 2 +D·Δx ABij

[0069] A and B, and C and D, are the correlation coefficients between chest and abdominal movement and volume, respectively. These coefficients are related to external factors such as vest elasticity and mold manufacturing process, and are all obtained from actual calibration. ΔF RCij ΔF represents the pressure change at a specific monitoring point (ij) on the chest. ABij Δx represents the pressure change at a certain monitoring point ij in the abdomen. RCij Δx represents the change in displacement of a certain monitoring point ij on the chest. ABij This represents the change in displacement of a certain monitoring point ij on the abdomen. Here, i and j represent the numbers of the pressure monitoring points. If i is the same, it means that they are in the same cross section, that is, they have the same spatial height in the rectangular coordinate system. j has no actual physical meaning and is only used for numbering.

[0070] 3. When simulating respiratory motion using a computer-programmed dynamic respiratory motion phantom, the controlled intake and exhaust volumes of the phantom are simultaneously recorded. Data analysis is performed to establish the relationship between chest and abdominal displacement and pulmonary ventilation: First, based on the two-dimensional discrete spatial coordinates formed by the spatial motion displacement of each monitoring point on the same cross-section (the displacement change is reflected by the pressure change, as described in step 2), nonlinear fitting is performed (specifically, the chest cavity is fitted with an ellipse and the abdominal cavity with a circle) to obtain the area of ​​each cross-section of the torso. The volume of each unit thickness of the torso is obtained by multiplying the area of ​​each cross-section by the unit thickness of the torso. The volume of each unit thickness of the torso is then accumulated to obtain the chest cavity volume and abdominal cavity volume at a certain moment. The initial chest volume V is then subtracted from each of these volumes. RC0 and initial abdominal volume V AB0 .

[0071]

[0072]

[0073] ΔV RC This indicates the change in thoracic cavity volume; a i and b i Let Δh and ΔV represent the semi-major and semi-minor axes of the ellipse fitted to the i-th cross-section of the chest, respectively; Δh represents the floor height; ΔV represents the floor height. AB This indicates the change in abdominal cavity volume; r i Let a represent the radius of the circle fitted to the i-th cross-section of the abdomen; where a i b i r i The value is obtained by fitting discrete coordinate points in a two-dimensional space at a certain i-th layer; where V RC0 V represents the initial chest volume. AB0 The initial abdominal volume is represented by N1 and N2, where N1 and N2 represent the number of pressure monitoring point distribution layers (i.e., the number of cross-sectional slices) in the chest and abdomen, respectively. An elastic vest is worn on the patient. Based on the pressure values ​​of chest and abdominal movement fed back by the elastic vest, these values ​​are substituted into the mathematical relationship expression in step 2 to calculate the displacement change of each pressure monitoring point relative to the initial spatial coordinates. Then, the obtained discrete point coordinates are nonlinearly fitted using the method in step 3 and substituted into the mathematical relationship expression in step 3 to calculate the chest and abdominal volume change ΔV. RC With ΔV AB The pulmonary ventilation ΔV can then be calculated. AO .

[0074]

[0075]

[0076] ΔVAO =ΔV RC +ΔV AB

[0077] Based on the calculated changes in thoracic and abdominal volumes, curves representing these changes can be plotted. Further analysis of these curves can then be used to obtain respiratory parameters.

[0078] Based on the real-time monitored changes in thoracic and abdominal volume, a volume change curve is plotted, such as... Figure 2 and Figure 3 As shown, the contribution ratio of thoracic and abdominal respiration can be further determined based on the changes in thoracic and abdominal volumes.

[0079] 1. Total pulmonary ventilation: The sum of the changes in thoracic cavity volume and abdominal cavity volume.

[0080] 2. Thoracic respiratory contribution ratio: the percentage of the change in thoracic cavity volume to the total lung ventilation.

[0081] 3. Abdominal breathing contribution ratio: the percentage of changes in abdominal cavity volume to total lung ventilation.

[0082] The coordination of breathing is judged by the phase difference of the chest and abdominal volume change curves.

[0083] Thoracic-abdominal phase difference: an important parameter for assessing respiratory coordination. This invention calculates the phase difference by measuring the proportion of the time between the peak of the thoracic volume change curve and the peak of the abdominal volume change curve within the signal during the respiratory cycle.

[0084] like Figure 4 As shown, the present invention also provides a respiratory flow monitoring device based on chest and abdominal movement, which applies the above-described respiratory flow monitoring method based on chest and abdominal movement, and includes: a pressure detection system 1 and a main control chip 2.

[0085] The pressure detection system 1 includes an elastic vest and multiple piezoresistive thin-film pressure sensor units. These piezoresistive thin-film pressure sensor units are respectively disposed on the inner side of the elastic vest. Each piezoresistive thin-film pressure sensor unit is used to detect the pressure value at the patient's pressure monitoring point. The main control chip 2 is connected to the piezoresistive thin-film pressure sensor units and is used to determine the patient's respiratory parameters based on the pressure values. The respiratory parameters include total lung ventilation, thoracic respiratory contribution ratio, abdominal respiratory contribution ratio, and thoracic-abdominal phase difference. The main control chip 2 is an STM32F407ZGT6.

[0086] In practical applications, the pressure detection system 1 further includes a 16-to-1 selector chip and a linear voltage conversion module connected to the 16-to-1 selector chip; the 16-to-1 selector chip is also connected to the piezoresistive thin-film pressure sensor unit; and the linear voltage conversion module is also connected to the main control chip 2.

[0087] In practical applications, the respiratory flow monitoring device based on chest and abdominal movement also includes a screen display module 3 connected to the main control chip 2. The screen display module 3 is used to display the pressure value and the respiratory parameters.

[0088] Multiple piezoresistive thin-film pressure sensor units are arranged in an array and fixed inside an elastic vest. The output terminals of the pressure sensors are connected to the selection signal input terminals of multiple 16-to-1 selection chips. The common signal output terminal of the selection chips is then connected to the input terminal of a linear voltage conversion module. The piezoresistive thin-film pressure sensors convert pressure signals into resistance signals. The 16-to-1 selection chips sequentially select and activate the input signal lines of the pressure sensors, acting as selection switches between the pressure sensors and the linear voltage conversion module. The linear voltage conversion module converts the resistance signal received after the selection chips are activated into an analog voltage signal and amplifies it appropriately.

[0089] The output of the linear voltage conversion module is connected to the ADC input pin of the main control chip 2 board. The main control chip 2 is an STM32F407ZGT6. The external ADC (analog-to-digital converter) on the main control chip 2 board converts the analog voltage signal from the linear voltage conversion module into a digital voltage signal; the main control chip 2 then uses mathematical operations to convert the digital voltage signal back into corresponding pressure data. Based on the respiratory motion pressure-volume measurement method described above, this method establishes a mathematical model relating chest and abdominal volume, trunk displacement, and respiratory motion pressure. It is known that the pressure values ​​at each monitoring point on the trunk can reflect the displacement of each point in the chest and abdomen. After the displacement changes, new discrete points are formed in the rectangular space coordinate system. Nonlinear fitting is performed on the discrete points (specifically, elliptical fitting is performed on the chest cavity and circular fitting is performed on the abdomen cavity) to obtain the area of ​​each cross-section of the trunk. Then, the area is approximated by the layer thickness of each cross-section of the trunk. The layer chest volume and the layer abdomen volume are then added together to obtain the total chest volume and abdomen volume. The initial chest volume and abdomen volume are then subtracted from the total chest volume and abdomen volume to obtain the change in chest volume and the change in abdomen volume. The lung ventilation is then calculated.

[0090]

[0091]

[0092] The main control chip performs nonlinear fitting calculations to solve for a certain layer i.i b i r i The value.

[0093]

[0094]

[0095] ΔV AO =ΔV RC +ΔV AB

[0096] A and B, and C and D, are the correlation coefficients between chest and abdominal movement and volume, respectively. These coefficients are related to external factors such as vest elasticity and mold manufacturing process, and are all obtained from actual calibration. ΔF RCij ΔF represents the pressure change at a specific monitoring point (ij) on the chest. ABij Δx represents the pressure change at a certain monitoring point ij in the abdomen. RCij Δx represents the change in displacement of a certain monitoring point ij on the chest. ABij ΔV represents the change in displacement at a monitoring point ij on the abdomen. RC This indicates the change in thoracic cavity volume; a i and b i Let Δh and ΔV represent the semi-major and semi-minor axes of the ellipse fitted to the i-th cross-section of the chest, respectively; Δh represents the floor height; ΔV represents the floor height. AB This indicates the change in abdominal cavity volume; r i Let a represent the radius of the circle fitted to the i-th cross-section of the abdomen; where a i b i r i The value is obtained by fitting discrete coordinate points in a two-dimensional space at a certain i-th layer; where V RC0 V represents the initial chest volume. AB0 This represents the initial abdominal volume; where N1 and N2 represent the number of pressure monitoring point distribution layers (i.e., the number of cross-sectional slices) in the chest and abdomen, respectively. ΔV AO It indicates lung ventilation.

[0097] Screen display module 3: The adapted TFTLCD screen is directly plugged into the interface of the main control chip board 2. This module is responsible for real-time dynamic display of the three-dimensional pressure values ​​of each monitoring point generated by trunk respiratory movements, and displays the chest and abdominal volume change curves and real-time values ​​of lung ventilation at the bottom of the screen.

[0098] Operation process:

[0099] 1. Turn on the device and have the subject put on the vest.

[0100] 2. The subject adjusts their posture and can start real-time monitoring by pressing the touch screen button.

[0101] 3. You can observe the pressure changes caused by real-time respiratory movements of the torso on the screen; you can observe the chest and abdominal volume change curves on the screen; you can read respiratory characteristic parameters such as lung ventilation on the screen.

[0102] 4. End via touchscreen button and return to the menu interface.

[0103] Unlike existing lung ventilation measurement products on the market, this invention utilizes an innovative respiratory motion pressure-volume measurement method. Devices based on this method support the quantitative detection of pressure values ​​generated in various parts of the chest and abdomen during respiratory motion. By employing the mathematical concept of infinitesimal elements, it accurately measures changes in respiratory volume in the chest and abdomen, thereby calculating lung ventilation.

[0104] In particular, to make the theoretically calculated lung ventilation more accurate, unlike the traditional respiratory plethysmography method which only calculates the area of ​​one cross-section and uses an approximate three-dimensional mathematical model to represent the chest and abdomen contours to calculate volume changes, this invention calculates the planar area of ​​each cross-section formed by the pressure monitoring points in a rectangular coordinate system, multiplies it by the unit thickness of each cross-section of the torso to obtain the volume of each unit thickness of the torso, and then accumulates the volumes of each unit thickness of the torso to obtain the chest and abdominal volumes at a certain moment. Subtracting the initial chest and abdominal volumes respectively approximates the volume changes of chest and abdominal respiratory movements. Compared with the traditional respiratory plethysmography method, this significantly improves the accuracy of measuring chest and abdominal volume changes. Furthermore, when implementing the lung ventilation detection function, this invention does not involve principles such as electromagnetic induction, thus avoiding the problem of resonant circuit instability, and has a relatively low cost, solving the power consumption and circuit stability problems of the traditional respiratory plethysmography method. In addition, this invention enables real-time three-dimensional monitoring of respiratory movement pressure in the human torso, supports real-time three-dimensional display of the pressure generated by the patient's chest and abdomen respiratory movements, and enhances the visualization of the pulmonary ventilation function examination process.

[0105] This invention utilizes multiple distributed pressure sensor units integrated on an elastic vest to construct a three-dimensional real-time monitoring system for trunk respiratory motion pressure. Furthermore, it innovatively proposes a respiratory motion pressure-volume measurement method to transform it into an indirect real-time monitoring of chest and abdominal volume, thereby achieving the purpose of monitoring lung ventilation.

[0106] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0107] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, 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 the present invention.

Claims

1. A thoraco-abdominal motion-based respiratory flow monitoring method, characterized by, The method comprises the following steps: acquiring pressure values of patient pressure monitoring points; the pressure monitoring points comprise a chest pressure monitoring point and an abdominal pressure monitoring point; the pressure values are collected by using a plurality of pressure sensors arranged in an array; performing data analysis according to the pressure values to determine displacement change amounts of the pressure monitoring points relative to initial spatial coordinates; performing nonlinear fitting according to the displacement change amounts to determine chest volume change amounts and abdominal volume change amounts, specifically comprising: performing nonlinear fitting according to the displacement change amounts to obtain areas of each cross section of a torso; obtaining volumes of each unit layer thickness of the torso by multiplying the areas of each cross section of the torso by unit thicknesses of each cross section of the torso; adding the volumes of each unit layer thickness of the torso to determine a chest volume at a set time and an abdominal volume at the set time; subtracting an initial chest volume from the chest volume at the set time to obtain a chest volume change amount; subtracting an initial abdominal volume from the abdominal volume at the set time to obtain an abdominal volume change amount; performing elliptical fitting on a chest cavity and circular fitting on an abdominal cavity; determining respiratory parameters according to the chest volume change amounts and the abdominal volume change amounts, specifically comprising: determining total lung ventilation, chest respiratory contribution ratio and abdominal respiratory contribution ratio according to the chest volume change amounts and the abdominal volume change amounts; drawing a chest volume change curve and an abdominal volume change curve according to the chest volume change amounts and the abdominal volume change amounts, respectively; acquiring a peak value of the chest volume change curve and a peak value offset time of the abdominal volume change curve; calculating a chest-abdominal phase difference according to a proportion of the offset time in a signal within a respiratory cycle; the respiratory parameters comprise total lung ventilation, chest respiratory contribution ratio, abdominal respiratory contribution ratio and chest-abdominal phase difference.

2. The method of claim 1, wherein, The method comprises the following steps: performing data analysis according to the pressure values to determine displacement change amounts of the pressure monitoring points relative to initial spatial coordinates, specifically comprising: performing data analysis according to the pressure values of the chest pressure monitoring point to determine a displacement change amount of the chest pressure monitoring point relative to an initial spatial coordinate; 3. The method of claim 1, wherein the thoraco-abdominal motion is determined by a chest and abdomen motion sensor. performing data analysis according to the pressure values of the abdominal pressure monitoring point to determine a displacement change amount of the abdominal pressure monitoring point relative to an initial spatial coordinate. The method comprises the following steps: determining total lung ventilation, chest respiratory contribution ratio and abdominal respiratory contribution ratio according to the chest volume change amounts and the abdominal volume change amounts, specifically comprising: adding the chest volume change amounts and the abdominal volume change amounts to obtain total lung ventilation; 4. A thoraco-abdominal motion based respiratory flow monitoring device, characterized by dividing the chest volume change amounts by the total lung ventilation to obtain chest respiratory contribution ratio; dividing the abdominal volume change amounts by the total lung ventilation to obtain abdominal respiratory contribution ratio. The chest-abdominal motion respiratory flow monitoring device applies the chest-abdominal motion respiratory flow monitoring method according to any one of claims 1-3, and the chest-abdominal motion respiratory flow monitoring device comprises a pressure detection system and a main control chip. The pressure detection system comprises an elastic vest and a plurality of piezoresistive thin film pressure sensor units; the plurality of piezoresistive thin film pressure sensor units are respectively arranged on the inner side of the elastic vest; the piezoresistive thin film pressure sensor units are used for detecting the pressure value of a patient pressure monitoring point; the main control chip is connected with the piezoresistive thin film pressure sensor units, and the main control chip is used for determining the respiratory parameter of the patient according to the pressure value; the respiratory parameter comprises total lung ventilation, chest breathing contribution ratio, abdominal breathing contribution ratio and chest-abdominal phase difference.

5. The thoraco-abdominal motion-based respiratory flow monitoring device according to claim 4, characterized in that The pressure detection system further comprises a sixteen-to-one gating chip and a linear voltage conversion module connected with the sixteen-to-one gating chip; the sixteen-to-one gating chip is further connected with the piezoresistive thin film pressure sensor units; and the linear voltage conversion module is further connected with the main control chip.

6. The thoraco-abdominal motion based respiration flow monitoring device according to claim 4, characterized by The pressure detection system further comprises a screen display module connected with the main control chip, and the screen display module is used for displaying the pressure value and the respiratory parameter.

7. The thoraco-abdominal motion based respiration flow monitoring device according to claim 4, characterized by The model of the main control chip is STM32F407ZGT6.

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