Respiratory function test device and metabolic rate calculation method

Abstract

The invention provides a respiratory function testing device and a metabolic rate calculation method, and relates to the technical field of metabolic rate calculation. Comprising an inspiration branch, an expiration branch and a breathing mask, and the breathing mask is connected with the inspiration branch and the expiration branch through a tee joint. The ends, away from the breathing mask, of the inspiration branch and the expiration branch are connected with a first box body and a second box body respectively, the first box body and the second box body are communicated with the outside, and a first oxygen and carbon dioxide composite detector and a second oxygen and carbon dioxide composite detector are arranged in the first box body and the second box body respectively. The inspiration branch is provided with a first one-way valve and a flow sensor, and the expiration branch is provided with a second one-way valve. According to the device, the breathing process is divided into an inspiration path and an expiration path, related physiological parameters of an individual in the breathing process are measured, accurate and convenient measurement of data is achieved, a metabolic rate calculation model based on the heart rate and the breathing frequency is established, the model is directly applied to calculation of the metabolic rate, and calculation convenience and accuracy are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of metabolic rate calculation, and in particular relates to a respiratory function testing device and a metabolic rate calculation method. Background Art

[0002] Metabolic rate plays an important role in human health and daily life. It not only affects energy consumption and weight management, but is also closely related to various physiological functions and disease risks. However, accurate measurement of metabolic rate faces many challenges in practice. Currently, the main methods for measuring metabolic rate include indirect calorimetry and doubly labeled water method.

[0003] Indirect calorimetry measures oxygen consumption and carbon dioxide production to estimate energy consumption. Depending on the way gas is collected, indirect calorimetry can be divided into mask / face shield type, ventilation hood, energy metabolism chamber, such as VO2000, Cosmed portable gas analyzer, etc. However, most of these gas analyzers are expensive and have restrictions on working hours and conditions.

[0004] The doubly labeled water method measures energy consumption by the dissipation rate of labeled water isotopes and is suitable for long-term measurements, but it is costly and complex to operate.

[0005] In addition, the standard metabolic rate calculation methods in the prior art are usually based on the resting metabolic rate formula, mainly relying on fixed formulas and reference tables, which have limitations in terms of individual differences and dynamics. Due to the failure to fully consider individual physiological differences, the estimation of metabolic rate is often not accurate enough. In addition, these methods are usually unable to reflect the metabolic changes of the human body in different activity states in real time, lack adaptability, especially in predicting energy consumption in activities of different intensities or types, which affects their application effect in accurate metabolic rate prediction and real-time monitoring.

[0006] Therefore, all of the above traditional methods have their own shortcomings. Summary of the invention

[0007] In order to overcome the shortcomings of the above-mentioned prior art, the present invention provides a respiratory function testing device and a metabolic rate calculation method, designs a device that divides the breathing process into two paths, namely, inhalation and exhalation, measures the relevant physiological parameters of the individual during the breathing process, and realizes accurate and convenient measurement of data. Finally, a metabolic rate calculation model based on heart rate and respiratory frequency is established, and the model is directly applied to calculate the metabolic rate, thereby realizing calculation convenience and accuracy.

[0008] To achieve the above objectives, one or more embodiments of the present invention provide the following technical solutions:

[0009] A first aspect of the present invention provides a respiratory function testing device.

[0010] A respiratory function testing device comprises an inhalation branch, an exhalation branch and a breathing mask, wherein the breathing mask is connected to the inhalation branch and the exhalation branch respectively through a three-way connection; the ends of the inhalation branch and the exhalation branch away from the breathing mask are respectively connected to a first box and a second box, wherein the first box and the second box are both connected to the outside and are respectively provided with a first oxygen and carbon dioxide composite detector and a second oxygen and carbon dioxide composite detector; the inhalation branch is provided with a first check valve and a flow sensor, and the exhalation branch is provided with a second check valve; wherein:

[0011] The No. 1 oxygen and carbon dioxide composite detector is used to detect the concentration of oxygen and carbon dioxide in the No. 1 box;

[0012] The No. 2 oxygen and carbon dioxide composite detector is used to detect the concentration of oxygen and carbon dioxide in the No. 2 box;

[0013] The opening direction of the No. 1 one-way valve is from the No. 1 box side to the breathing mask side;

[0014] The opening direction of the second one-way valve is from the breathing mask side to the second box side;

[0015] The flow sensor is used to monitor the personnel's inhalation flow data from the side of the first box to the side of the breathing mask.

[0016] As an optional technical solution, the inhalation branch includes a No. 1 universal breathing hose and a No. 1 connecting pipe, the No. 1 connecting pipe is connected to the No. 1 box, a flow sensor is arranged between one end of the No. 1 universal breathing hose and the No. 1 connecting pipe, the other end of the No. 1 universal breathing hose is connected to a tee, and the No. 1 one-way valve is arranged inside the No. 1 universal breathing hose.

[0017] As an optional technical solution, the exhalation branch includes a No. 2 universal breathing hose and a No. 2 connecting pipe that are connected to each other, the No. 2 connecting pipe is connected to the No. 2 box, one end of the No. 2 universal breathing hose is connected to a tee, and the No. 2 one-way valve is arranged inside the No. 2 universal breathing hose.

[0018] As an optional technical solution, fans are provided in both the first box and the second box.

[0019] As an optional technical solution, the breathing mask is connected to the three-way connection through a pipeline, and the breathing mask is an integrated mouth and nose mask.

[0020] As an optional technical solution, a No. 1 hole and a No. 2 hole are respectively provided on the opposite side walls of the No. 1 box body, the No. 1 hole is used to connect with the inhalation branch, and the No. 2 hole is used to connect with the outside world; a No. 3 hole and a No. 4 hole are respectively provided on the opposite side walls of the No. 2 box body, the No. 3 hole is used to connect with the exhalation branch, and the No. 4 hole is used to connect with the outside world.

[0021] As an optional technical solution, the inhalation branch, the exhalation branch, the connection between the inhalation branch and the breathing mask, the connection between the exhalation branch and the breathing mask, the connection between the inhalation branch and the first box, and the connection between the exhalation branch and the second box are all sealed.

[0022] A second aspect of the present invention provides a method for calculating metabolic rate.

[0023] The metabolic rate calculation method based on the respiratory function test device of the first aspect comprises the following steps:

[0024] Obtain the height and weight of the person to be tested and determine the body surface area;

[0025] In the standard metabolic rate calculation formula, the lung ventilation is replaced by the respiratory rate and tidal volume, and the respiratory rate parameter is introduced;

[0026] The actual measurement data of the respiratory function test device is obtained, the product of tidal volume and oxygen concentration difference is fitted with the heart rate, the heart rate parameter is introduced, and a metabolic rate calculation model based on heart rate and respiratory frequency is constructed;

[0027] Based on the metabolic rate calculation model, combined with the heart rate and respiratory rate of the person to be tested, the metabolic rate of the person to be tested is obtained.

[0028] As an optional technical solution, it also includes calculating the tidal volume and oxygen concentration difference of the person to be tested based on the actual measurement data. The specific formula is:

[0029] Δ02=(0 2始 -0 2末 );

[0030]

[0031] Among them, ΔO2 is the percentage of oxygen concentration change per unit time; O 2始 is the oxygen concentration ratio in the initial air of box 1; O 2末 V is the oxygen concentration in the air at the end of box 1; T is the tidal volume; RR is the respiratory rate; Q is the instantaneous flow rate; t1 is the test start time, and t2 is the test end time;

[0032] or,

[0033] The product of tidal volume and oxygen concentration difference is fitted with heart rate, and the fitting result is:

[0034] For men, the relationship between heart rate and oxygen consumption per breath is as follows:

[0035] y=0.6895×HR-23.332(R 2 =0.7305);

[0036] For women, the relationship between heart rate and oxygen consumption per breath is as follows:

[0037] y=0.4541×HR-21.105(R 2 =0.7604);

[0038] Where y is the oxygen consumption in a single breath, which is the product of tidal volume and the percentage of oxygen concentration change per unit time; HR is heart rate; R 2 is the fitting coefficient.

[0039] As an optional technical solution, a metabolic rate calculation model based on heart rate and respiratory rate is constructed as follows:

[0040] male:

[0041]

[0042] female:

[0043]

[0044] Where M is metabolic rate; RR is respiratory rate; HR is heart rate; A du is the human body surface area.

[0045] One or more of the above technical solutions have the following beneficial effects:

[0046] The present invention provides a respiratory function testing device and a metabolic rate calculation method. By setting a No. 1 box, a No. 2 box, an inhalation branch, an exhalation branch and a breathing mask, a device is designed to divide the breathing process into two paths of inhalation and exhalation. The device can be used to collect gases in the inhalation and exhalation paths respectively, and use devices such as oxygen and carbon dioxide composite detectors to measure relevant physiological parameters of an individual during the breathing process, thereby achieving accurate and convenient measurement of data.

[0047] On this basis, the metabolic rate calculation method of the present invention is based on the metabolic rate calculation method in the ISO8996 standard, and the product of the tidal volume and the oxygen concentration difference in the measured data is used to establish a linear regression equation model with the heart rate, and the respiratory rate and heart rate are further introduced to establish a metabolic rate calculation model based on the heart rate and respiratory rate. Compared with the traditional metabolic rate measurement method, this method greatly reduces the equipment cost and can be widely used in daily life.

[0048] The respiratory function testing device of the present invention is portable, low-cost, and can achieve accurate measurement, and can be used to measure the gas flow (i.e., lung ventilation volume) during breathing and the change in oxygen concentration before and after breathing.

[0049] The present invention ultimately combines breathing-related physiological parameters (respiratory frequency, tidal volume, etc.) with heart rate, establishes a metabolic rate calculation model based on heart rate and respiratory frequency, and directly applies the model to calculate the metabolic rate, thereby achieving calculation convenience and accuracy.

[0050] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0052] Figure 1 FIG. 4 is a diagram showing the structure of the device of the first embodiment.

[0053] Figure 2 This is a method flow chart of the second embodiment.

[0054] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0055] 1. Box No. 1; 2. Box No. 2; 3. Oxygen and carbon dioxide compound detector No. 1; 4. Fan; 5. Hole No. 2; 6. Hole No. 4; 7. Metal ring for fixing the bearing; 8. Connecting pipe No. 1; 9. Flow sensor; 10. Universal breathing hose No. 1; 11. Breathing mask; 12. Rubber pipe joint; 13. Tee; 14. One-way valve No. 1; 15. One-way valve No. 2; 16. Universal breathing hose No. 2; 17. Connecting pipe No. 2; 18. Oxygen and carbon dioxide compound detector No. 2; 19. Small rectangular door. DETAILED DESCRIPTION

[0056] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0057] It should be noted that the terms used herein are for describing specific embodiments only and are not intended to be limiting of exemplary embodiments according to the present invention.

[0058] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0059] The overall concept of the present invention:

[0060] As introduced in the background technology, metabolic rate is a key indicator for measuring human energy expenditure and is essential for understanding energy balance, weight management, athletic performance and overall health. However, traditional metabolic rate measurement methods such as indirect calorimetry and double-labeled water method have problems such as high cost, complex operation and strict requirements for laboratory environment, and usually cannot provide real-time data. Indirect calorimetry requires expensive equipment and a specific environment, and the double-labeled water method has high requirements for sample processing and analysis.

[0061] In contrast, heart rate and respiratory rate are important physiological indicators that reflect the metabolic state of the human body. The metabolic rate estimation method based on heart rate and respiratory rate provides a simpler and real-time solution. Heart rate reflects changes in the heart's energy needs, while respiratory rate is directly related to the oxygen uptake rate. Using these two physiological parameters can effectively estimate metabolic rate, reduce dependence on complex equipment, and monitor individual energy expenditure in real time. This method not only improves the convenience of measurement, but also has important significance for dynamic adjustments in sports training and health management.

[0062] Therefore, how to estimate the metabolic rate based on heart rate and respiratory rate, and design a respiratory function test device for measuring physiological parameters during a person's breathing process, so as to accurately and conveniently estimate the human metabolic rate based on the obtained data, has become a technical problem that needs to be solved urgently.

[0063] Based on this, the present invention relates to a respiratory function test device and a metabolic rate calculation method based on the respiratory function test device. The device includes two acrylic boxes, equipped with oxygen and carbon dioxide composite detectors and micro fans, monitors the inhalation flow through a gas flow sensor, and separates the inhalation and exhalation paths through an integrated mouth and nose mask, a Y-shaped three-way and a one-way valve. The device can accurately collect and analyze respiratory data, and in combination with measured data, using respiratory rate and tidal volume parameters, and introducing heart rate as a correction, establishes linear regression models for men and women respectively, and proposes a new metabolic rate calculation model based on heart rate and respiratory rate, which is suitable for metabolic rate estimation under different activity levels, and provides a simple and practical calculation method for metabolic rate measurement.

[0064] Embodiment 1

[0065] like Figure 1 As shown, the present embodiment discloses a respiratory function test device, including an inhalation branch, an exhalation branch and a breathing mask 11, wherein the breathing mask 11 is connected to the inhalation branch and the exhalation branch respectively through a three-way 13; the ends of the inhalation branch and the exhalation branch away from the breathing mask 11 are respectively connected to a first box 1 and a second box 2, wherein the first box 1 and the second box 2 are both connected to the outside and are respectively provided with a first oxygen and carbon dioxide composite detector 3 and a second oxygen and carbon dioxide composite detector 18; a first check valve 14 and a flow sensor 9 are provided on the inhalation branch, and a second check valve 15 is provided on the exhalation branch; wherein:

[0066] The No. 1 oxygen and carbon dioxide composite detector 3 is used to detect the concentration of oxygen and carbon dioxide in the No. 1 box 1;

[0067] The second oxygen and carbon dioxide composite detector 18 is used to detect the concentration of oxygen and carbon dioxide in the second box 2;

[0068] The opening direction of the first check valve 14 is from the first box 1 side to the breathing mask 11 side;

[0069] The opening direction of the second check valve 15 is from the side of the breathing mask 11 to the side of the second box 2;

[0070] The flow sensor 9 is used to monitor the inhalation flow data of personnel from the side of the first box 1 to the side of the breathing mask 11.

[0071] like Figure 1 As shown, both the first box 1 and the second box 2 are acrylic boxes, which can be closed inside, and a small rectangular door 19 is opened on the top. A hinge is installed above the small door, and a sealing strip is installed around it to ensure good sealing. By controlling the opening and closing of the small rectangular door 19, the corresponding oxygen and carbon dioxide composite detectors and the vertical micro fan 4 can be placed in the first box 1 and the second box respectively, and the two boxes are fixed on a plane. The space for collecting gas should be minimized as much as possible while ensuring airtightness.

[0072] The branch connected to box No. 1 is the inhalation branch, and the gas flow direction is from the side of box No. 1 to the side of the mouth-nose integrated breathing mask 11. The branch connected to box No. 2 is the exhalation branch, and the gas flow direction is from the side of the mouth-nose integrated breathing mask 11 to the side of box No. 2.

[0073] Small circular holes are respectively provided on the front and rear sides of the two boxes, wherein the front and rear side walls of the first box 1 are respectively provided with a No. 1 hole and a No. 2 hole 5, the No. 1 hole is used to be connected with the inhalation branch, and the No. 2 hole 5 is used to be connected with the outside world; the front and rear side walls of the second box 2 are respectively provided with a No. 3 hole and a No. 4 hole 6, the No. 3 hole is used to be connected with the exhalation branch, and the No. 4 hole 6 is used to be connected with the outside world.

[0074] The circular small hole No. 2 hole 5 opened on the rear side of the No. 1 box 1 can ensure that the air outside the No. 1 box 1 can flow in under pressure. The circular small hole No. 4 hole 6, which is the same as the No. 1 box 1, is opened on the rear side of the No. 2 box 2 to ensure that the air in the box can flow out under pressure.

[0075] Further, the inhalation branch includes a No. 1 breathing universal hose 10 and a No. 1 connecting pipe 8, the No. 1 connecting pipe 8 is connected to the No. 1 box 1, a flow sensor 9 is arranged between one end of the No. 1 breathing universal hose 10 and the No. 1 connecting pipe 8, the other end of the No. 1 breathing universal hose 10 is connected to a three-way valve 13, and the No. 1 one-way valve 14 is arranged inside the No. 1 breathing universal hose 10;

[0076] The exhalation branch includes a No. 2 universal breathing hose 16 and a No. 2 connecting pipe 17 which are connected to each other. The No. 2 connecting pipe 17 is connected to the No. 2 box 2. One end of the No. 2 universal breathing hose 16 is connected to the three-way valve 13. The No. 2 one-way valve 15 is arranged inside the No. 2 universal breathing hose 16.

[0077] Among them, the No. 1 connecting pipe 8 and the No. 2 connecting pipe 17 are both PVC pipes.

[0078] More specifically, the small holes on the front sides of the No. 1 box 1 and the No. 2 box 2, namely the No. 1 hole and the No. 3 hole, are connected and extended with the PVC material pipe through the fixed bearing metal ring 7 to ensure that the inner diameter of the pipe is consistent with the small hole.

[0079] On the intake branch, the gas flow sensor 9 is arranged at the end of the No. 1 connecting pipe 8. In order to achieve a better connection, a transparent silicone tube is used to wrap the outside of the No. 1 connecting pipe 8 to ensure that the inner diameter of the transparent silicone tube is the same as the outer diameter of the gas flow sensor 9, thereby better ensuring the airtightness.

[0080] The gas flow sensor 9 is connected to the No. 1 connecting pipe 8 near the port on the side of the No. 1 box 1, and is connected to the No. 1 breathing universal hose 10 near the side of the mouth and nose integrated breathing mask 11. The direction of the gas flow sensor 9 is controlled to ensure that the gas flow sensor 9 can monitor the inhalation flow data of the person from the side of the No. 1 box 1 to the side of the mouth and nose integrated breathing mask 11.

[0081] Furthermore, the gas flow sensor 9 has different designs for the inlet and outlet, which is error-proof and reduces the dead zone to a minimum. The mass flow and relative pressure can be directly measured, the response time is fast, and linear digital and analog signals can be provided at the same time, and the measurement accuracy is guaranteed.

[0082] It can be understood that the breathing mask 11 mentioned in this embodiment is an integrated mouth and nose breathing mask 11, and the integrated mouth and nose breathing mask 11 includes a strap and a rubber tube joint 12 connected to each other. The integrated mouth and nose breathing mask 11 is connected to the Y-shaped tee 13 through the rubber tube joint 12, ensuring that the interface is consistent with the inner diameter of the main pipe of the Y-shaped tee 13, so that the exhaled gas can be discharged from the main pipe as much as possible under the action of pressure, avoiding the reuse of exhaled gas, reducing the dead space volume, and preventing gas infiltration;

[0083] The branch pipes of the Y-type three-way 13 are respectively connected to the No. 1 one-way valve 14 and the No. 2 one-way valve 15 in opposite directions, dividing the two sides into an inhalation side and an exhalation side. The inhalation side one-way valve is the No. 1 one-way valve 14, and the gas allows the airflow direction to pass through to be set from the No. 1 box 1 side to the mouth and nose integrated breathing mask 11 side. The inhalation side one-way valve is connected to the gas flow sensor 9 through the No. 1 breathing universal hose 10; the exhalation side one-way valve is the No. 2 one-way valve 15, and the gas allows the airflow direction to pass through to be from the mouth and nose integrated breathing mask 11 side to the No. 2 box 2 side. The exhalation side one-way valve is connected to the PVC material pipe on the front side of the No. 2 box 2 through the No. 2 breathing universal hose 16.

[0084] The mouth-nose integrated breathing mask 11 is connected to the Y-type tee 13 through a rubber tube joint 12. The tee 13 is provided with two one-way valves in opposite directions for separating the inhalation and exhalation paths; the one-way valves are used to ensure the one-way flow of gas to prevent the gas from flowing back during the breathing process; the two branches of the Y-type tee 13 are respectively connected to the one-way valves in opposite directions to ensure that the gas in the breathing process flows to the corresponding box during the inhalation and exhalation processes.

[0085] When the No. 1 one-way valve 14 and the No. 2 one-way valve 15 are in normal working condition, when the gas pressure in the normal working direction is greater than the reverse pressure, the valve seat is pressed against the valve body and the gas one-way valve is closed; when the reverse pressure is greater than the pressure in the normal working direction, the valve disc is pushed open, the gas flows through the valve body channel, and the gas one-way valve opens.

[0086] Therefore, when a person inhales, due to the effect of the No. 1 one-way valve 14, only the air in the No. 1 box 1 is inhaled, and the changes in the concentrations of oxygen and carbon dioxide in the No. 1 box 1 and the inhalation flow rate can be monitored by the No. 1 oxygen and carbon dioxide composite detector 3 and the gas flow sensor 9;

[0087] When a person exhales, the gas is released into the second box 2, and the oxygen and carbon dioxide concentrations in the second box 2 can be monitored by the second oxygen and carbon dioxide composite detector 18.

[0088] Therefore, the changes in gas concentration in the two boxes are changes in various objective physiological parameters of inhalation and exhalation during the breathing process of a person.

[0089] In this embodiment, the inhalation branch, the exhalation branch, the connection between the inhalation branch and the breathing mask 11, the connection between the exhalation branch and the breathing mask 11, the connection between the inhalation branch and the first box 1, and the connection between the exhalation branch and the second box 2 are all sealed. Specifically, all the connections of the system can be sealed twice with sealing tape to prevent gas infiltration or leakage, thereby ensuring the accuracy of the measurement.

[0090] Working principle:

[0091] The respiratory function test device in this embodiment includes two closable acrylic boxes, and an oxygen and carbon dioxide composite detector and a micro fan 4 are placed through a rectangular small door 19, and the air inflow and outflow are ensured through the circular holes on the front and rear sides of the first box 1 and the second box 2. The gas flow sensor 9 is connected to the transparent silicone tube and the universal breathing hose on the front side of the first box 1 to monitor the inhalation flow data; the first oxygen and carbon dioxide composite detector 3 is used to detect the oxygen and carbon dioxide concentrations in the first box 1; the second oxygen and carbon dioxide composite detector 18 is used to detect the oxygen and carbon dioxide concentrations in the second box 2.

[0092] The integrated mouth-nose breathing mask 11 is connected to the Y-type tee 13 through a rubber tube joint 12. The branches of the Y-type tee 13 are respectively connected to one-way valves in opposite directions, dividing the two sides into the inhalation side and the exhalation side. When inhaling, only the air in the No. 1 box 1 connected to the inhalation branch is inhaled, and the changes in oxygen and carbon dioxide concentrations in the No. 1 box 1 are monitored by the composite detector; when exhaling, the gas is released to the No. 2 box 2 connected to the exhalation branch, and the changes in gas concentration in the No. 2 box 2 are also monitored based on the composite detector.

[0093] All connections in the system are sealed with sealing tape to prevent gas leakage, thereby obtaining accurate measured data and accurately measuring the concentration changes of various physiological parameters during the breathing process of personnel.

[0094] More specifically, the above measured data is expressed as:

[0095] CO 2始 , is the percentage of carbon dioxide concentration in the initial air of box 2;

[0096] CO 2末 , is the percentage of carbon dioxide concentration in the air at the end of box 2;

[0097] O 2始 , is the oxygen concentration ratio in the initial air of box 1;

[0098] O 2末 , is the oxygen concentration ratio in the air at the end of box 1;

[0099] Q, is the instantaneous inhalation flow rate detected by the gas flow sensor 9;

[0100] RR, respiratory rate;

[0101] HR stands for heart rate.

[0102] The measured data obtained by the above measurement can be applied to the calculation in the second embodiment of the present invention.

[0103] Embodiment 2

[0104] This embodiment discloses a method for calculating metabolic rate.

[0105] like Figure 2 As shown, based on the metabolic rate calculation method of the respiratory function test device described in Example 1, the metabolic rate calculation formula is adjusted according to the relationship between the respiratory frequency and the heart rate in the measured data to adapt to the metabolic rate estimation under different activity levels. The following steps are included:

[0106] Obtain the wearer's height and weight to determine the body surface area;

[0107] According to the metabolic rate calculation formula and oxygen consumption calculation formula provided by ISO8996 standard, the pulmonary ventilation volume is replaced by respiratory rate and tidal volume, and the respiratory rate parameter is introduced;

[0108] According to the measured data, the product of tidal volume and oxygen concentration difference (i.e. oxygen consumption concentration in a single breath) was fitted with heart rate, and the heart rate parameter was introduced. Finally, the metabolic rate calculation formula based on heart rate and respiratory frequency for men and women with different activity levels was obtained.

[0109] Since heart rate and respiratory rate are important physiological indicators that reflect the metabolic state of the human body, by monitoring these indicators and combining them with individual characteristics such as age, gender, and weight, a mathematical model can be established to estimate the metabolic rate more accurately. Compared with traditional methods, this measurement method based on heart rate and respiratory rate is not only convenient and low-cost, but also suitable for a wide range of daily applications, and has great potential and application prospects.

[0110] Specific:

[0111] Get the height and weight of the person to be tested and determine the body surface area, as shown in the following formula:

[0112]

[0113] In the formula, A du is the human body surface area, W b is body weight; H b For height.

[0114] The standard metabolic rate calculation formula mentioned is the metabolic rate calculation formula provided by ISO8996 standard. According to the metabolic rate calculation formula and oxygen consumption calculation formula provided by ISO8996 standard, the pulmonary ventilation is replaced by respiratory rate and tidal volume, and the respiratory rate parameter is introduced, as shown in the following formula:

[0115]

[0116] V E =RR×V T

[0117] Where, M is metabolic rate; RQ is respiratory quotient, the international standard value is 0.85; V O2 is oxygen uptake; P is standard atmospheric pressure, the international value is 101325pa; P a V is the partial pressure of water vapor in the exhaled gas. When the exhaled gas temperature is 34°C, the saturated water vapor partial pressure is 5320 Pa. E is lung flux; t 呼 is the exhaled gas temperature, generally 34°C; ΔO2 is the oxygen concentration change per unit time, i.e., the oxygen concentration difference; V T RR is the respiratory rate.

[0118] The respiratory quotient is the ratio of the volume or molar number of carbon dioxide released to the oxygen absorbed in the same time; the tidal volume is the flow rate of gas during breathing measured by a gas flowmeter. On the basis of a known respiratory rate, the instantaneous flow-time curve is integrated to obtain the flow rate when inhaled air, and then divided by the respiratory rate to obtain the tidal volume.

[0119] The measured data in the above embodiment 1 is applied as follows:

[0120] ΔO2=(O 2始 -O 2末 )

[0121]

[0122]

[0123] In the formula, O 2始 is the oxygen concentration ratio in the initial air of box 1; O 2末 is the oxygen concentration ratio in the air at the end of the No. 1 chamber; ΔO2 is the oxygen concentration change ratio per unit time, i.e., oxygen concentration difference; VCO2 is the rate of production of carbon dioxide; V O2 is oxygen uptake; RQ is respiratory quotient, the international standard value is 0.85; P is standard atmospheric pressure, the international standard value is 101325pa; P a is the partial pressure of water vapor in the exhaled gas. When the exhaled gas temperature is 34°C, the saturated water vapor partial pressure is 5320 Pa. CO 2始 is the percentage of carbon dioxide concentration in the initial air of box 2; CO 2末 is the percentage of carbon dioxide concentration in the air at the end of the second chamber; t 呼 is the exhaled gas temperature, generally 34°C; T is the unit time; Q is the instantaneous flow rate; t1 is the test start time, t2 is the test end time; RR is the respiratory rate.

[0124] According to the measured data in Example 1, a linear regression fitting is performed between the product of tidal volume and oxygen concentration difference (i.e., oxygen consumption concentration during a single breath) and the heart rate. The following are the data types and representative values ​​used in the fitting process:

[0125] Data Types Sample Data (Male) Sample Data (Female) Heart rate (HR, beats / min) 60、70、80 65、75、85 <![CDATA[Tidal volume (V T , ml / breath)]]> 500、520、540 480、500、520 <![CDATA[Oxygen concentration difference (ΔO2, %)]]> 5.0、5.5、6.0 5.2、5.7、6.1

[0126] Finally, the relationship between heart rate and oxygen consumption in a single breath is obtained, and ΔO2 is replaced by heart rate, as shown in the following formula:

[0127] For men, the relationship between heart rate and oxygen consumption per breath is as follows:

[0128] y=0.6895×HR-23.332(R 2 =0.7305)

[0129] For women, the relationship between heart rate and oxygen consumption per breath is as follows:

[0130] y=0.4541×HR-21.105(R 2 =0.7604)

[0131] Where y is the oxygen consumption in a single breath, which is the product of tidal volume and the percentage change of oxygen concentration per unit time; HR is the heart rate.

[0132] Combining the above formulas, we finally get the calculation model based on heart rate and breathing rate for men and women, as shown below:

[0133] male:

[0134]

[0135] female:

[0136]

[0137] Where M is metabolic rate; RR is respiratory rate; HR is heart rate; A du is the human body surface area.

[0138] Finally, based on the metabolic rate calculation model determined above, combined with the heart rate and respiratory rate of the person to be tested, the metabolic rate of the person to be tested is estimated, and the metabolic state of the person to be tested is evaluated.

[0139] The above technical scheme, a respiratory function test system that can be used to measure the physiological parameters of a person's breathing process, includes two closable acrylic boxes through a rectangular small door 19 on the upper side, and an oxygen and carbon dioxide composite detector is placed inside to monitor the changes in the oxygen and carbon dioxide concentrations in the box. The front and rear sides of the two boxes are provided with small holes of the same aperture. In the inhalation branch, the front small hole is connected to the gas flow sensor 9 through a PVC pipe wrapped with a transparent silicone tube, while in the exhalation branch, the front small hole is directly connected to the one-way valve of the exhalation branch through a PVC pipe. The rear small holes of the two boxes are used for the inflow and outflow of air respectively, and the gas flow sensor 9 is used to monitor the gas flow during the person's inhalation process. The mouth and nose integrated breathing mask 11 is connected to the Y-type three-way 13 through a rubber joint, and the three-way 13 branch is provided with two one-way valves in different directions to ensure the separation of the inhalation and exhalation paths. Sealing tape is used for secondary sealing at each connection of the system to ensure that the gas does not leak.

[0140] The system divides the breathing of personnel into inhalation and exhalation branches through a one-way valve, and collects the gas during breathing through a closed box. The oxygen and carbon dioxide composite detector is used to monitor the oxygen and carbon dioxide concentrations in the box, thereby reflecting the changes in the metabolic rate and respiratory function of personnel during the breathing process.

[0141] Applying the theory of metabolic rate in ISO 8996 standard, the calculation of metabolic rate involves oxygen intake and carbon dioxide emission, which are usually calculated based on lung ventilation. On this basis, the embodiment of the present invention introduces respiratory rate and tidal volume, and determines the relationship between oxygen consumption and heart rate through measured data analysis. For men and women, respective linear regression models are established. Finally, combined with these theoretical models, a new metabolic rate calculation method based on heart rate and respiratory rate is proposed. This method can accurately estimate metabolic rate at different activity levels, providing a more direct and practical calculation method.

[0142] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A respiratory function testing device, characterized in that: It comprises an inhalation branch, an exhalation branch and a breathing mask, wherein the breathing mask is connected to the inhalation branch and the exhalation branch respectively through a three-way connection; the ends of the inhalation branch and the exhalation branch away from the breathing mask are respectively connected to a first box and a second box, wherein the first box and the second box are both connected to the outside and are respectively provided with a first oxygen and carbon dioxide composite detector and a second oxygen and carbon dioxide composite detector; the inhalation branch is provided with a first check valve and a flow sensor, and the exhalation branch is provided with a second check valve; wherein: The No. 1 oxygen and carbon dioxide composite detector is used to detect the concentration of oxygen and carbon dioxide in the No. 1 box; The No. 2 oxygen and carbon dioxide composite detector is used to detect the concentration of oxygen and carbon dioxide in the No. 2 box; The opening direction of the No. 1 one-way valve is from the No. 1 box side to the breathing mask side; The opening direction of the second one-way valve is from the breathing mask side to the second box side; The flow sensor is used to monitor the personnel's inhalation flow data from the side of the first box to the side of the breathing mask.

2. The respiratory function testing device according to claim 1, characterized in that: The inhalation branch includes a No. 1 universal breathing hose and a No. 1 connecting pipe, the No. 1 connecting pipe is connected to the No. 1 box, a flow sensor is arranged between one end of the No. 1 universal breathing hose and the No. 1 connecting pipe, the other end of the No. 1 universal breathing hose is connected to a tee, and the No. 1 one-way valve is arranged inside the No. 1 universal breathing hose.

3. The respiratory function testing device according to claim 1, characterized in that: The exhalation branch includes a No. 2 universal breathing hose and a No. 2 connecting pipe that are connected to each other. The No. 2 connecting pipe is connected to the No. 2 box body. One end of the No. 2 universal breathing hose is connected to a three-way connection. The No. 2 one-way valve is arranged inside the No. 2 universal breathing hose.

4. The respiratory function testing device according to claim 1, characterized in that: The first box and the second box are both provided with fans.

5. The respiratory function testing device according to claim 1, characterized in that: The breathing mask is connected to the three-way connection through a pipeline, and the breathing mask is an integrated mouth-nose mask.

6. The respiratory function testing device according to claim 1, characterized in that: A No. 1 hole and a No. 2 hole are respectively arranged on the opposite side walls of the No. 1 box body, the No. 1 hole is used to be connected with the inhalation branch, and the No. 2 hole is used to be connected with the outside world; a No. 3 hole and a No. 4 hole are respectively arranged on the opposite side walls of the No. 2 box body, the No. 3 hole is used to be connected with the exhalation branch, and the No. 4 hole is used to be connected with the outside world.

7. The respiratory function testing device according to claim 1, characterized in that: The inhalation branch, the exhalation branch, the connection between the inhalation branch and the breathing mask, the connection between the exhalation branch and the breathing mask, the connection between the inhalation branch and the first box, and the connection between the exhalation branch and the second box are all sealed.

8. A metabolic rate calculation method based on the respiratory function test device according to any one of claims 1 to 7, characterized in that: The following steps are involved: Obtain the height and weight of the person to be tested and determine the body surface area; In the standard metabolic rate calculation formula, the lung ventilation is replaced by the respiratory rate and tidal volume, and the respiratory rate parameter is introduced; The actual measurement data of the respiratory function test device is obtained, the product of tidal volume and oxygen concentration difference is fitted with the heart rate, the heart rate parameter is introduced, and a metabolic rate calculation model based on heart rate and respiratory frequency is constructed; Based on the metabolic rate calculation model, combined with the heart rate and respiratory rate of the person to be tested, the metabolic rate of the person to be tested is obtained.

9. The metabolic rate calculation method according to claim 8, characterized in that: It also includes calculating the tidal volume and oxygen concentration difference of the person to be tested based on the actual measurement data. The specific formula is: ΔO2=(O 2始 -O 2末 ); Among them, ΔO2 is the percentage of oxygen concentration change per unit time; O 2始 is the oxygen concentration ratio in the initial air of box 1; O 2末 V is the oxygen concentration in the air at the end of box 1; T is the tidal volume; RR is the respiratory rate; Q is the instantaneous flow rate; t1 is the test start time, and t2 is the test end time; or, The product of tidal volume and oxygen concentration difference is fitted with heart rate, and the fitting result is: For men, the relationship between heart rate and oxygen consumption per breath is as follows: y=0.6895×HR-23.332(R 2 =0.7305); For women, the relationship between heart rate and oxygen consumption per breath is as follows: y=0.4541×HR-21.105(R 2 =0.7604); Where y is the oxygen consumption in a single breath, which is the product of tidal volume and the percentage of oxygen concentration change per unit time; HR is heart rate; R 2 is the fitting coefficient.

10. The metabolic rate calculation method according to claim 8, characterized in that: The metabolic rate calculation model based on heart rate and respiratory rate is constructed as follows: male: female: Where M is metabolic rate; RR is respiratory rate; HR is heart rate; A du is the human body surface area.

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