CN209932744U

CN209932744U - Portable expiration detection device

Info

Publication number: CN209932744U
Application number: CN201920233834.5U
Authority: CN
Inventors: 刘博引; 陈裕殷; 徐洪涛
Original assignee: Beijing Zhiji Future Medical Technology Co Ltd
Current assignee: Beijing Zhiji Future Medical Technology Co Ltd
Priority date: 2019-02-22
Filing date: 2019-02-22
Publication date: 2020-01-14
Anticipated expiration: 2029-02-22

Abstract

The embodiment of the utility model discloses portable expiration detection device, expiration detection device includes gas drying device, gas detection device and gas exhaust apparatus, wherein, gas drying device include the intake pipe and with intake-tube connection's drying tube, the cross sectional area of intake pipe is greater than the cross sectional area of drying tube, the drying tube intussuseption is filled with porous material. The embodiment of the utility model provides a still provide expiration detection method. The embodiment of the utility model provides a porous material adopts silica gel and/or 3A molecular sieve, can change in real time, and drying effect is good moreover, has improved detection device testing result's accuracy simultaneously. Meanwhile, automatic gas collection and discharge are realized by integrating a pressure sensor and a fan; the gas one-way valve is utilized to construct a sealable gas detection environment, the accuracy of a detection result is improved, and the service life of the expiration detection device is prolonged by using a simple and replaceable sensor module.

Description

Portable expiration detection device

Technical Field

The embodiment of the utility model provides a relate to medical instrument technical field, concretely relates to portable expiration detection device.

Background

In order to effectively prevent and control obesity and related diseases which may be caused by obesity, real-time monitoring of the body weight of the ordinary population is important. For the understanding of obesity control, a well-accepted theoretical model is CICO (Calories-In-Calories-Out). The theoretical model indicates that the increase or decrease of the body weight of an individual depends on the balance between caloric intake and consumption. If the caloric intake is greater or less than the consumption over a period of time, the individual involved is faced with an increase or decrease in body weight. In practical application, the theoretical model is mainly used for calculating the weight increase and decrease trend of an individual by calculating the levels of food calorie intake and static Energy consumption (REE)^2–4. However, in the practice of the CICO theory, people tend to focus on only limiting caloric intake of food, such as selective diet, and neglect the importance of static energy expenditure involved in another part of the theory. Studies have shown that when the body ingests food at a level that is not normal, the level of metabolism is also reduced. This is considered a human biological system, a self-protective means for maintaining weight^2–4. For the calculation of the calorie of a food, one can quantify it more accurately according to the kind of food ingested and its mass (unit: gram). In contrast, the consumption of static energy is not as straightforward computationally. This is mainly because the differences in gene composition, metabolic mechanisms, height, weight, etc. from person to person all affect the level of static energy expenditure of an individual. Therefore, to solve the problem of weight (caloric intake/expenditure) monitoring, a method/apparatus is needed that can achieve static caloric expenditure detection and quantification.

Among the numerous methods, indirect calorimetry (Ind)irect Calorimetry) is a widely recognized method of caloric monitoring (gold standard recommended by the world health organization)^5，6. The method is based on measuring the amount of carbon dioxide (V) produced by a person during one or more breaths_CO2Generation) and consumption of oxygen (V)_O2Consumption) in units of volume. These two values can be used to calculate the amount of heat generated (kcal) to be 3.9 × V_O2Consumption +1, 11 XV_CO2Generation)⁷Or calculating Respiratory Quotient (RQ ═ V)_CO2Generation/V_O2Consumption)⁸And judging whether the main consumption substrate of metabolism is carbohydrate, fat or protein according to the value. Table 1 lists the respiratory quotient for different nutrient metabolism. The characteristic respiratory quotient corresponding to the three nutrient substances of carbohydrate, fat and protein is 1, 0.7 and 0.8 respectively⁸. Since a meal is inevitably contaminated with various nutrients, the respiratory quotient during the intake of food and metabolism of healthy people should be between 0.67 and 1.3⁹. In the non-exercise state, the respiratory quotient is more than 1, which indicates that fat is formed in the human body at the moment, no fat is consumed or the consumption is very low, and the detected person can be prompted to have the tendency of increasing the weight. In the process of losing weight, for example, after finishing one hour of exercise or in a diet state, whether the value of the respiratory quotient is close to 0.7 can be used for judging the condition of fat burning of a human body or whether the human body is in a hungry state. Accordingly, in a non-exercise, non-hungry state, if a person's respiratory quotient value is around 0.7, it indicates that the person is not able to metabolize glucose well, risking diabetes.

TABLE 1 respiratory quotient corresponding to metabolism of different nutrient substrates

Metabolic substrates	English name	Type of nutrition	Chemical formula (II)	Respiratory quotient calculation formula	Respiratory quotient
						Glucose	Glucose	Carbohydrate compound	C6H12O6	C6H12O6+6O2→6CO2+6H2O	6/6＝1
Palmitic acid	Palmitic Acid	Fat	C16H32O2	C16H32O2+23O2→16CO2+16H2O	16/23＝0.70
						Albumin	Albumin	Protein	C72H112N18O22S	C72H112N18O22S+77O2→63CO2+38H2O+SO3+9CO(NH2)2	63/77＝0.82

From a healthy person's perspective, calorie intake and consumption depend on meal type and exercise intensity, respectively, and resting states do not consume calories effectively. Exercise may be one of the preferred ways to achieve a relatively rapid heat dissipation effect. As mentioned earlier, most people tend to exercise solely the control of caloric intake of food, by dieting to achieve weight loss. However, this practice is not ideal in practice, because starvation leads to a simultaneous decrease in metabolic efficiency. At present, the mode of controlling calorie intake from diet is mainly to eat low-sugar and low-fat food, but the method can only reduce relative calorie intake and can not play a role in calorie consumption. Blindly dieting and picky eating can not only ensure good weight-reducing effect, but also induce other damages to the body if the degree is not controlled properly. Therefore, the prediction of the weight-losing effect can be indirectly judged through the exercise efficiency, namely the breathing quotient.

Because of differences in gene constitution, metabolic mechanism, and the like between individuals, caloric intake/caloric expenditure accompanying the same exercise amount for the same food varies among individuals. Therefore, the individual respiratory quotient detector can effectively provide heat intake and consumption condition feedback for the detector according to individual physique difference, and can meet the requirements of monitoring and controlling the weight of common people.

Currently, the Indirect calorimetry instrument widely used is mainly a large exercise cardio-pulmonary/energy metabolism tester (index calorimetric metabolic cart). Instruments of this type are frequently found in public places such as hospitals and health care centers. Although the instrument can effectively complete the detection of corresponding indexes with high standards, the instrument has the defects of high cost, great weight and the like which limit the practicability and convenience of the detection, for example, a person to be detected needs to carry a mask in the whole testing process and can only move in a limited space, and the use process is very inconvenient.

In addition to the above-described large-scale breath test instrument, a relatively practical and convenient breath test instrument generally has several or more of the following features. In one or some breath test instruments, the measurement of oxygen concentration is achieved by fluorescence quenching. The method utilizes a fluorophore that binds oxygen to detect the concentration of oxygen. Under different oxygen concentrations, the different wavelengths of light emitted by the fluorophores will have corresponding changes in intensity. Because the method has high dependence on the humidity and the temperature of the detection environment and also relates to the problem that the fluorescent material is subjected to photobleaching, the detection accuracy can be uncontrollably changed along with the increase of the use time, so that the detection result is meaningless. For the measurement of the carbon dioxide concentration, the expiration detection instrument or the expiration detection instruments indirectly measure the carbon dioxide concentration by acquiring the concentration information of common gases in the air, such as water vapor, oxygen, nitrogen and the like. In the indirect detection process, interference and errors occurring in each link are accumulated to a final detection result.

In the existing breath detectors, an indirect heat measuring method for measuring the contents of oxygen and carbon dioxide in the exhaled air of a human body by using dry chemistry and a colorimetric method is also adopted. The method is realized by the following steps: the user aims at the related instrument to breathe normally and regularly through the mouthpiece, and the breathing habit of the user can be recorded by the instrument during the breathing habit for later-stage auxiliary calculation and value taking. Meanwhile, oxygen and carbon dioxide in the exhaled air of the user respectively react with dry chemical materials which have gas selectivity and are distinguished by colors, so that partial materials are volatilized and discolored. This color change is detected by the corresponding led light source and light sensor and is correlated to the gas volume/concentration. In combination with the above data, the apparatus will feed back the current energy expenditure and caloric intake to the user. Although the instrument can feed back the generation and consumption of heat in a short time, the main defect of the instrument is that the corresponding gas detection dry chemical material belongs to a consumption type material. From the point of consumable material, the long-term use of the instrument requires a large investment cost, which is inconvenient for the popularization of the product. In a conventional gas concentration detection device, gas concentration detection generally calculates the volume of oxygen and carbon dioxide by a method of correlating gas flow rate and concentration.

In summary, the breath detector in the prior art has the defects of large volume and weight, inconvenient use, high use cost, inaccurate detection result caused by insufficient breath detection processing and the like, and further improvement is needed.

SUMMERY OF THE UTILITY MODEL

Therefore, the embodiment of the utility model provides a portable expiration detection device and detection method to solve among the prior art inaccurate, the detection device bulky, with high costs, the inconvenient scheduling problem of operation of detection device testing result.

In order to achieve the above object, the embodiment of the present invention provides the following technical solutions:

a portable breath detection device comprises a gas drying device, a gas detection device and a gas discharge device, wherein the gas drying device comprises a gas inlet pipe and a drying pipe connected with the gas inlet pipe, the cross section area of the gas inlet pipe is larger than that of the drying pipe, and a porous material is filled in the drying pipe;

the gas detection device comprises a gas chamber, a pressure sensor, an oxygen sensor, a carbon dioxide sensor and a single chip microcomputer, wherein the pressure sensor, the oxygen sensor, the carbon dioxide sensor and the pressure sensor are communicated with the gas chamber;

the drying tube is communicated with the air chamber, and a temperature control device is arranged between the drying tube and the air chamber.

Preferably, a first check valve is arranged in the drying pipe, and a second check valve is arranged in an exhaust pipe of the gas exhaust device.

Preferably, the breath detection device further comprises a calibration gas device, and an oxygen storage chamber, a nitrogen storage chamber and a carbon dioxide storage chamber are respectively arranged in the calibration gas device;

and the air chamber is also provided with an interface for connecting a calibration gas device.

Preferably, a humidity sensor is further arranged in the air chamber and connected with the single chip microcomputer.

Preferably, the porous material adopts silica gel and/or 3A molecular sieve.

Preferably, the breath detection device further comprises a communication device, and the single chip microcomputer is connected with the terminal through the communication device.

Preferably, the gas exhaust device comprises an exhaust pipe and a fan mounted at an outlet end of the exhaust pipe, and an inlet end of the exhaust pipe is connected to the air chamber.

Preferably, the outlet end of the exhaust pipe is provided with a bending part.

The embodiment of the utility model provides a still provide a respiratory commodity detection method, including following step:

calibrating the carbon dioxide sensor and the oxygen sensor by using calibration gas;

the exhaled air is dried by the air drying device, so that the exhaled air of different test detection batches keeps relatively consistent humidity after reaching the air chamber;

measuring relatively static, dry exhaled gas entering the air chamber by the oxygen sensor and the carbon dioxide sensor;

processing signals measured by the oxygen sensor and the carbon dioxide sensor through the singlechip to obtain the concentrations of oxygen and carbon dioxide in the exhaled air;

and the singlechip calculates the respiratory quotient according to the concentrations of the oxygen and the carbon dioxide in the exhaled air and the concentration of corresponding air in the atmosphere.

Preferably, the calibration process includes determining a coefficient of the formula y ═ kx + b using an oxygen or carbon dioxide calibration gas, where y is the concentration of oxygen or carbon dioxide in the measured gas, x is the signal strength measured by the oxygen or carbon dioxide sensor, and k, b are coefficients, and the calibration gas uses 10% and 20.9% by volume of oxygen (balance gas is nitrogen); and carbon dioxide in volume fractions of 0.04% and 6% (balance gas nitrogen).

The embodiment of the utility model provides a have following advantage:

the embodiment of the utility model provides a to the influence factor that human exhalation gas probably involves of detection, integrated simple and easy, efficient steam processing method, adopt static gas detection method, choice gas sensitive element, when having ensured the detection accuracy degree, improved the life of product, reduced user's economic cost. The embodiment of the utility model provides an in, porous material adopts silica gel and/or 3A molecular sieve, and above-mentioned porous material can change in real time, and drying effect is good moreover, has improved detection device testing environment's uniformity and the accuracy of result. Automatic gas collection and discharge are realized by integrating a pressure sensor and a fan; a gas check valve is utilized to construct a sealable gas detection environment; a simple, replaceable sensor module is used to extend the useful life of the breath detection apparatus. The utility model discloses a detection, through the consumption that detects oxygen and the formation of carbon dioxide calculate user's breathing quotient to with this correlation user's metabolism and the condition of fat burning.

Drawings

In order to more clearly illustrate the implementation of the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It should be apparent that the drawings in the following description are merely exemplary, and that other embodiments can be derived from the drawings provided by those of ordinary skill in the art without inventive effort.

The structure, ratio, size and the like shown in the present specification are only used for matching with the content disclosed in the specification, so as to be known and read by people familiar with the technology, and are not used for limiting the limit conditions that the embodiments of the present invention can be implemented, so that the present invention has no technical essential significance, and any structure modification, ratio relationship change or size adjustment should fall within the scope that the technical content disclosed in the embodiments of the present invention can cover without affecting the efficacy that the embodiments of the present invention can produce and the purpose that can be achieved.

Fig. 1 is a schematic diagram of a portable breath detection device provided in embodiment 1 of the present invention;

fig. 2 is a schematic structural view of a portable breath detection device provided in embodiment 2 of the present invention;

fig. 3 is an exploded view of the structure of a portable breath detection device provided in embodiment 2 of the present invention;

fig. 4 is a schematic structural view of a drying device provided in embodiment 2 of the present invention;

fig. 5 is a schematic structural view of a portable breath detection device provided in embodiment 3 of the present invention;

fig. 6 is a schematic structural view of a portable breath detection device provided in embodiment 4 of the present invention;

in the figure: 100-a drying device; 110-an air inlet pipe; 120-a drying tube; 121-a first one-way valve; 200-a gas detection device; 210-an oxygen sensor; 220, 230-pressure sensor interface; 240-carbon dioxide sensor; 250-an interface; 300-gas exhaust means; 310-a fan; 320-an exhaust pipe; 321-a second one-way valve; 330-a bending part; 400-a temperature control device; 500-display screen.

Detailed Description

Embodiments of the present invention will be described in detail with reference to the specific embodiments, and other advantages and effects of the embodiments of the present invention will be apparent to those skilled in the art from the disclosure herein. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts belong to the scope protected by the embodiments of the present invention.

As shown in fig. 1 to 3, an embodiment of the present invention provides a portable breath detection device, which includes a gas drying device 100, a gas detection device 200, and a gas exhaust device 300, wherein the gas drying device 100 includes an air inlet pipe 110 and a drying pipe 120 connected to the air inlet pipe 110, the cross-sectional area of the air inlet pipe 110 is greater than the cross-sectional area of the drying pipe 120, and the drying pipe 120 is filled with a porous material; the gas detection device 200 comprises a gas chamber, a pressure sensor 220 connected with the gas chamber, an oxygen sensor 210, a carbon dioxide sensor 240 and a single chip microcomputer, wherein the oxygen sensor 210 and the carbon dioxide sensor 240 are respectively connected with the single chip microcomputer; the drying tube 120 is communicated with the air chamber, the temperature control device 400 is arranged between the drying tube 120 and the air chamber, the air inlet tube 110 and the pipeline part of the drying tube 120 are designed, so that different batches of detection gas is ensured, the temperature in the air chamber reaches 37 ℃ uniformly, detection errors of various sensors possibly caused by the change of the detection environment temperature are avoided, and the influence of numerical value deviation on the final result in respiratory quotient calculation is reduced.

Specifically, as shown in fig. 4, the utility model discloses the cross sectional area of intake pipe 110 among drying device 100 of embodiment is greater than the cross sectional area of drying pipe 120, drying pipe 120 says length to be less than 5cm, and its cross sectional diameter is not more than 1cm, examine the in-process that gaseous entering air chamber by intake pipe 110, the temperature control device 400 of air chamber entry end can be with gaseous temperature control at 37 ℃, intake pipe 110 has certain length, cross sectional area is less simultaneously, can ensure that the air current slowly passes through temperature control device 400, make the gas that passes through can fully contact with temperature control device 400. Since the cross-sectional area of the gas inlet pipe 110 is relatively small, that is, the conveying capacity per unit time is small, the temperature control device 400 can be beneficial to fully heating the gas entering the gas chamber. The cross sectional area of the air inlet pipe 110 is larger than that of the drying pipe 120, and meanwhile, the temperature control device 400 is arranged between the drying pipe 120 and the air chamber, so that the same temperature environment is provided for the sensor to detect the gas to be detected, and errors among different batches of gas to be detected are reduced.

When the user blows air through the air inlet tube 110, saliva entrained in the exhaled air and condensed water formed after hitting the wall of the air inlet tube 110 are first blocked on the tube wall at the intersection of the air inlet tube 110 and the drying tube 120. The exhaled gas enters the drying duct 120 of smaller cross section. The drying pipe 120 is filled with silica gel and 3A molecular sieve, preferably, the mass ratio of the silica gel to the 3A molecular sieve is 1: 1, further absorbing the water vapor in the gas passing through the pipeline, and finally achieving the effect of gas drying, wherein the used silica gel and the 3A molecular sieve can be recycled and subjected to high-temperature heating treatment for cyclic utilization. The embodiment of the utility model provides a through setting up drying tube 120 to set up steam adsorption material in drying tube 120, through reducing steam to the influence that detects gas, reducible testing result's error.

As shown in fig. 3, the embodiment of the present invention provides a first check valve 121 in the drying tube 120, and a second check valve 321 in the exhaust pipe 320 of the gas exhaust device 300, so that after the inspector stops blowing the mouthpiece, the inspection gas and the air chamber form an isolated and stable system without being affected by the external air flow. The first check valve 121 and the second check valve 321 only allow the gas to be opened along the flow direction of the exhaled gas, and meanwhile, when the exhaled gas is filled in the gas chamber, the exhaled gas is static in the gas chamber, so that the gas chamber forms a relatively closed space, and the gas to be detected reaches a relatively static state, therefore, the existence of the check valves enables a relatively closed gas detection environment to be formed in the gas chamber; after the collection of the exhaled gas is finished, the external air pressure is not enough to trigger the opening of the one-way valve, so that the gas in the air chamber is relatively static, interference factors possibly brought to the gas detected by the sensor due to the uneven flow of the gas are eliminated, the numerical value output by the sensor is kept in a floating range with the deviation of less than 0.5%, and the requirement on the detection accuracy of the respiratory quotient is met.

The volume of the air chamber of the embodiment of the utility model is set to 100-200ml, which mainly considers the necessity of collecting the terminal gas and conveniently carries the expiration detection device. The normal population can exhale 500ml of gas at one time, wherein about 150ml of gas comes from nasal cavity, trachea and bronchus, and the part of gas is not in direct contact with alveolar gas, cannot correctly reflect the use and generation of gas related to metabolism, and is defined as ineffective gas. The selection of the volume of the air chamber is helpful for collecting the tail gas as a detection target to obtain an accurate detection result. During use, the user first slowly inhales and holds his breath for 3 seconds, and then blows the instrument uniformly at the normal exhalation speed for 5 seconds, and the exhaled air in the air chamber is the exhaled air other than the ineffective air. For some people who can not breathe out gas in an amount of 500ml, the gas finally reserved in the gas chamber can be guaranteed not to be interfered by invalid gas.

As shown in fig. 2, the breath detection device according to the embodiment of the present invention further includes a calibration gas device, and an oxygen storage chamber, a nitrogen storage chamber, and a carbon dioxide storage chamber are respectively disposed in the calibration gas device; the chamber also has an interface 250 for a calibration gas device.

As convertible implementation mode, the utility model discloses still be equipped with humidity transducer in the air chamber, humidity transducer is connected with the singlechip, and through the data of humidity transducer feedback, can detect the air humidity of the gas in the air chamber, according to the result of the air humidity that detects, can change the porous material in drying tube 120, improve drying tube 120's drying effect.

As shown in fig. 3 and 6, the gas exhaust apparatus 300 includes an exhaust pipe 320, and a fan 310 installed at an outlet end of the exhaust pipe 320, and an inlet end of the exhaust pipe 320 is connected to the plenum. The outlet end of the exhaust pipe 320 is provided with a bending part 330, which can maintain the stability of the gas in the gas chamber to a certain extent, and is helpful for the sensor to detect the gas to obtain a more accurate result. The utility model discloses the implementation is connected with the air chamber through setting up pressure sensor 220, pressure sensor respectively through setting up

pressure sensor interface

220, 230 on the air chamber in the air chamber, sets up fan 310 and is connected sensor, fan 310 and singlechip at the exhaust port end. The fan 310 is kept on after the expiration detection means is turned on, and when the pressure sensor 220 detects that the gas pressure in the air chamber is greater than the atmospheric pressure to some extent, the fan 310 is turned off immediately and kept off for a certain period of time thereafter. The time when the fan 310 is turned off is less than or equal to 2min, that is, the time when the fan is turned off, the sensor can effectively detect and output an accurate gas concentration value. In order to effectively achieve the gas discharge, a fan 310 is installed at an outlet end of the exhaust pipe 320, and when the fan 310 is turned on, the first check valve 121 and the second check valve 321 are opened. The method ensures that a user can finish multiple measurements in a short time, can effectively avoid data deviation and even errors caused by improper operation, such as uneven blowing, and enhances the repeatability of the use of the instrument and the accuracy of a detection result.

The utility model discloses expiration detection device still includes communication device, and the singlechip passes through communication device and is connected with the terminal, and terminal equipment includes cell-phone, notebook computer etc.. The mobile phone end can exchange data with the cloud background through the mobile phone end by using a mobile phone end program, and on one hand, a result can be displayed on a display screen of the mobile phone end or the result calculated by terminal equipment such as a mobile phone is fed back to the display screen of the expiration detection device. The mobile phone end can obtain additional service items, such as diet management, sports advice and the like. The mobile phone and the cloud platform are built, so that the collection, calculation and statistics of detection data are facilitated, and the optimization of the instrument, the upgrade of the algorithm, the expansion of additional functions and even the update of products are realized.

The embodiment of the utility model provides a still provide a respiratory commodity detection method, it includes following step: calibrating the carbon dioxide sensor 240 and the oxygen sensor 210 by using the calibration gas; before the measurement, the oxygen sensor 210 was calibrated by introducing 10% and 20.9% by volume of oxygen gas, respectively, into the calibration gas unit in communication with the gas chamber, and by introducing 0.04% and 6% by volume of carbon dioxide gas, with nitrogen as the balance gas. The process of calibrating the gas includes a process of determining a coefficient in the formula y ═ kx + b using the calibration gas, where y is the concentration of oxygen or carbon dioxide gas in the measured gas, x is the signal intensity of the corresponding oxygen or carbon dioxide gas measured by the sensor, and k, b are coefficients. For example, the oxygen concentration value is calculated by obtaining y after calibration_{Oxygen concentration}＝k₁x_{Oxygen sensor signal}+b₁After the values of k1 and b1 are obtained, the signals of the sensors in the detection process are combined. The concentration value of carbon dioxide gas is firstly calibrated by_{Concentration of carbon dioxide}＝k₂x_{Carbon dioxide sensor signal}+b₂Middle k₂And b₂Is obtained in combination with the signal of the sensor during the detection.

Drying the exhaled gas by a gas drying device 100 to obtain dry gas to be detected; measuring the dry breath detection into the gas cell by the oxygen sensor 210, the carbon dioxide sensor 240; processing the signals measured by the oxygen sensor 210 and the carbon dioxide sensor 240 through the single chip microcomputer to obtain the concentrations of oxygen and carbon dioxide in the exhaled air; the singlechip calculates the respiratory quotient according to the oxygen and the carbon dioxide or sends the concentration results of the oxygen and the carbon dioxide to the terminal or the cloud server, and the mobile phone terminal and the cloud server further process the data to obtain the numerical value of the respiratory quotient.

The embodiment of the utility model provides an in, the calculation of breathing quotient is realized through following formula:

in Eq.1, [ O2_Into]For the concentration of oxygen in the inspired gas (i.e., atmospheric air) [ O2_{Go out}]Concentration of oxygen in exhaled breath, [ CO2 ]_Into]For the concentration of carbon dioxide in the inspired gas (i.e. atmospheric air) [ CO2_{Go out}]V is the volume of the chamber, which is the concentration of carbon dioxide in the exhaled air. Since the V air chamber exists in the numerator and the denominator of the operation formula at the same time, the V air chamber and the denominator are mutually offset, namely theoretically, the size of the air chamber does not influence the calculation result of the respiratory quotient. In practice, however, the relatively large space in the detection environment is more conducive to gas diffusion and steady state in a confined environment. This also directly affects the efficiency and accuracy of the detection. In practice, therefore, the necessity of limiting the volume of the gas chamber for collecting the end gas is considered, as is the necessity of providing a sufficiently large passive diffusion space for the gas.

The embodiment of the utility model provides an in, the sensor that detects oxygen is electrochemical sensor, as long as there is oxygen in waiting to examine the gas, will consume the reactant among the electrochemical sensor always, when reactant consumed a certain amount, the signal of telecommunication of the output of sensor need do the relevance with the concentration of actual gas again, carries out recalibration. The electrochemical sensor and the air chamber are of a pluggable structure, so that a user is allowed to replace the electrical sensor, and the service life of the expiration detection device is effectively prolonged.

As shown in fig. 5, when the user blows air into the air inlet tube 110 of the drying device 100, the exhaled air is dried by the drying device 100, and the dried air is heated to 37 ℃ by the temperature control device 400 after passing through the drying tube 120. Due to the existence of the one-way valve, the air chamber can form an isolated system isolated from the outside under the condition of not being subjected to the outside pressure, and a stable detection environment is provided for the sensor to detect the gas concentration. The pressure sensors 220 in the air chambers are communicated with each other through the air guide hose, and when an increase in air pressure in the air chambers is detected, the release of the fan 310 may be controlled to be turned off or on according to the magnitude of the increase in pressure. If the pressure detected by the pressure sensor exceeds a certain value, the fan 310 is turned off, and after the gas sensor detects the concentration of the gas in the gas chamber, the fan 310 is controlled to be turned on until the user blows the next time. The oxygen sensor 210 and the carbon dioxide sensor 240 send the measured oxygen gas and carbon dioxide gas concentration signals to the single chip for processing, the single chip sends the processed oxygen concentration values and carbon dioxide concentration values to the cloud or terminal equipment through the communication device, and the cloud server or terminal calculates the breathing quotient by using a formula Eq.1 and feeds the relevant result back to a user of the instrument; or the processed result is displayed through the display screen 500 by the single chip microcomputer to obtain the calculation result of the final respiratory quotient. The calculation result information of the breathing trader can be fed back to a mobile phone end program of the user through the communication device, and the user can be used for guiding and planning diet control and exercise suggestion according to the calculation result of the breathing trader.

The embodiment of the utility model provides an in, porous material adopts silica gel and/or 3A molecular sieve, and above-mentioned porous material can change in real time, and drying effect is good moreover, has improved detection device testing result's accuracy simultaneously. Meanwhile, automatic gas collection and discharge are realized by integrating a pressure sensor and a fan; the gas one-way valve is utilized to construct a sealable gas detection environment, and a simple and replaceable detection sensor module is used to prolong the service life of the expiration detection device.

Although the embodiments of the present invention have been described in detail with reference to the general description and the specific embodiments, it is apparent that modifications or improvements may be made to the embodiments of the present invention, which are apparent to those skilled in the art. Therefore, such modifications and improvements are intended to be included within the scope of the embodiments of the present invention as claimed and not departing from the spirit of the embodiments of the present invention.

Claims

1. A portable expired air detection device is characterized by comprising a gas drying device, a gas detection device and a gas discharge device, wherein the gas drying device comprises a gas inlet pipe and a drying pipe connected with the gas inlet pipe, the cross section area of the gas inlet pipe is larger than that of the drying pipe, and a porous material is filled in the drying pipe;

2. The portable breath detection device of claim 1,

a first one-way valve is arranged in the drying pipe, and a second one-way valve is arranged in an exhaust pipe of the gas exhaust device.

3. The portable breath detection device of claim 1,

the expiration detection device also comprises a calibration gas device, and an oxygen storage chamber, a nitrogen storage chamber and a carbon dioxide storage chamber are respectively arranged in the calibration gas device;

4. The portable breath detection device of claim 1,

and a humidity sensor is also arranged in the air chamber and connected with the singlechip.

5. The portable breath detection device of claim 1,

the porous material adopts silica gel and/or 3A molecular sieve.

6. The portable breath detection device of claim 1,

the breath detection device further comprises a communication device, and the single chip microcomputer is connected with the terminal through the communication device.

7. The portable breath detection device of claim 1,

the gas exhaust device comprises an exhaust pipe and a fan arranged at the outlet end of the exhaust pipe, and the inlet end of the exhaust pipe is connected with the air chamber.

8. The portable breath detection device of claim 7,

the outlet end of the exhaust pipe is provided with a bending part.