A breath sampling method and device

Abstract

The present invention discloses an exhaled breath sampling method and device. The exhaled breath sampling method comprises the following steps: collecting the CO2 concentration value v[n] of the patient's breath in real time and storing it in a first array; calculating the slope ratio k according to the slope ratio calculation formula and storing it in a fourth array; comparing and analyzing the slope ratio k and the current CO2 concentration value v[i], if k∈(0, K out ) and v[i]>T out When the sampling valve is opened, sampling is performed; K out is the preset exhalation slope ratio threshold, T out is the preset exhaled concentration threshold; compare and analyze the current CO2 concentration value v[i], if v i <T in , close the sampling valve and stop sampling; where T in The exhaled air sampling method and device can automatically collect alveolar air, reduce the difficulty of exhaled air sampling, and improve sampling accuracy and efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of breath sampling, and in particular to a breath sampling method and device. Background Art

[0002] The breath diagnosis method for disease detection is non-invasive, fast, and convenient, and is gaining more and more attention. For the breath diagnosis instruments currently used in clinical practice, it is more meaningful to analyze the gas at the end of exhalation, because the gas at the front end of exhalation is generally mixed with a lot of air, and the measurement is greatly affected by the environment; and the gas at the end of exhalation is basically alveolar gas, which is directly discharged from the body after the blood circulation and alveolar gas exchange, and can carry a lot of health status information, which can best reflect the current health status of the human body.

[0003] The current exhaled air sampling method mainly relies on the manual judgment and control of medical staff to collect the gas at the end of exhalation by operating the solenoid valve during the patient's exhalation. However, this sampling method has high requirements on the patient's breathing stability. For some infants with low cognitive ability and adults with no active consciousness or cognitive impairment, it is difficult to collect alveolar gas at the end of exhalation. Summary of the invention

[0004] The purpose of the present invention is to provide a breath sampling method and device, which can automatically collect alveolar gas, reduce the difficulty of breath sampling, and improve the sampling accuracy and efficiency.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] A breath sampling method comprises the following steps:

[0007] Collect the CO2 concentration value v[n] of the patient's breathing in real time and store it in a first array; wherein n is an integer and n≥3;

[0008] The slope ratio k is calculated according to the slope ratio calculation formula and stored in the fourth array; the slope ratio calculation formula is: k=(v[i]-v[i-1]) / (v[i-1]-v[i-2]), where i is an integer and 3≤i≤n; if v[i]-v[i-1]=0, k=0; if v[i-1]-v[i-2]=0, k=0xFFFF;

[0009] Compare and analyze the slope ratio k and the current CO2 concentration value v[i]. If k∈(0, K out ) and v[i]>T out When the sampling valve is opened, sampling is performed; among them, K out is the preset exhalation slope ratio threshold, T out is the preset exhaled concentration threshold;

[0010] Compare and analyze the current CO2 concentration value v[i], if vi<T in , close the sampling valve and stop sampling; where T in is the preset inhalation concentration threshold.

[0011] Among them, the exhaled concentration threshold T is obtained out and T in The following steps are involved:

[0012] Obtain the maximum CO2 concentration value and the minimum CO2 concentration value of each respiratory cycle from the first array, and store them in the second array and the third array respectively;

[0013] Calculates the average of all values ​​in the second array , the average value of all data in the third array , and the difference Δv, ;

[0014] Calculate the exhaled concentration threshold T according to the formula out and T in ,

[0015] ;

[0016] ; where η, γ∈(0, 1).

[0017] Among them, obtain the exhalation slope ratio threshold K out The following steps are involved:

[0018] Obtain the first value less than 1 in each respiratory cycle from the fourth array and store it in the fifth value;

[0019] Obtain the maximum value and the minimum value from the fifth array, and calculate the difference Δk between the two; calculate the average value of all values ​​in the fifth array;

[0020] Calculate the exhalation slope ratio threshold K out , K out = +δΔk; where 0<δ<1.

[0021] The following steps are also included:

[0022] Get the sampling flow and sampling time;

[0023] Cumulative calculation of sampling volume;

[0024] When the sampling volume is greater than or equal to the preset value, close the sampling valve and stop sampling.

[0025] A breath sampling device, comprising:

[0026] Collection front end;

[0027] A gas pipeline having an air inlet, a gas collecting port and an air exhaust port; the air inlet is connected to the collection front end; the air exhaust port is connected to the outside;

[0028] a gas collecting container communicated with the gas collecting port;

[0029] A CO2 concentration sensor, a flow sensor, an air pump and a three-way valve connected to the gas pipeline; the CO2 concentration sensor is used to collect the CO2 concentration in the gas pipeline in real time; the flow sensor is used to collect the gas flow in the gas pipeline during the gas collection process; the three-way valve is used to control the outlet end of the air pump to be connected to the air inlet or the exhaust port;

[0030] A control unit is electrically connected to the CO2 concentration sensor, the flow sensor, the air pump and the three-way valve, and can set the exhalation slope ratio threshold K according to the exhalation rule. out , exhaled concentration threshold T out And the inhalation concentration threshold T in , and when the collected CO2 concentration data meets the exhalation slope ratio threshold K out and exhaled concentration threshold T out When the inhalation concentration threshold T is met, the three-way valve is controlled so that the outlet of the air pump is only connected to the air inlet; and in When the condition is met, the three-way valve is controlled so that the outlet end of the air pump is only connected to the exhaust port.

[0031] Wherein, a filter is arranged between the collection front end and the air inlet.

[0032] It also includes a human-machine interface, which is connected to the control unit and is used for users to input parameters and instructions and display sampling data.

[0033] The beneficial effects of the present invention are as follows: the present invention provides a breath sampling method and device, when the CO2 concentration data collected in the breath meets the exhalation slope ratio threshold K out and exhaled concentration threshold T out When the inhalation concentration threshold T is met, gas collection begins. in When the conditions are met, stop collecting gas; thus, the alveolar gas can be automatically collected, the difficulty of exhaled air sampling is reduced, and the sampling accuracy and efficiency are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a structural schematic diagram of a breath sampling device provided by the present invention. DETAILED DESCRIPTION

[0035] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0036] A breath sampling method comprises the following steps:

[0037] Collect the CO2 concentration value v[n] of the patient's breathing in real time and store it in a first array; wherein n is an integer and n≥3;

[0038] The slope ratio k is calculated according to the slope ratio calculation formula and stored in the fourth array; the slope ratio calculation formula is: k=(v[i]-v[i-1]) / (v[i-1]-v[i-2]), where i is an integer and 3≤i≤n; if v[i]-v[i-1]=0, k=0; if v[i-1]-v[i-2]=0, k=0xFFFF;

[0039] Compare and analyze the slope ratio k and the current CO2 concentration value v[i]. If k∈(0, K out ) and v[i]>T out When the sampling valve is opened, sampling is performed; among them, K out is the preset exhalation slope ratio threshold, T out is the preset exhaled concentration threshold;

[0040] Compare and analyze the current CO2 concentration value v[i], if vi<T in , close the sampling valve and stop sampling; where T in is the preset inhalation concentration threshold.

[0041] Among them, the exhaled concentration threshold T is obtained out and T in The following steps are involved:

[0042] Obtain the maximum CO2 concentration value and the minimum CO2 concentration value of each respiratory cycle from the first array, and store them in the second array and the third array respectively;

[0043] Calculates the average of all values ​​in the second array , the average value of all data in the third array , and the difference Δv, ;

[0044] Calculate the exhaled concentration threshold T according to the formula out and T in ,

[0045] ;

[0046] ; where η, γ∈(0, 1).

[0047] Among them, obtain the exhalation slope ratio threshold K out The following steps are involved:

[0048] Obtain the first value less than 1 in each respiratory cycle from the fourth array and store it in the fifth value;

[0049] Obtain the maximum value and the minimum value from the fifth array, and calculate the difference Δk between the two; calculate the average value of all values ​​in the fifth array;

[0050] Calculate the exhalation slope ratio threshold K out , K out = +δΔk; where 0<δ<1.

[0051] The following steps are also included:

[0052] Get the sampling flow and sampling time;

[0053] Cumulative calculation of sampling volume;

[0054] When the sampling volume is greater than or equal to the preset value, close the sampling valve and stop sampling.

[0055] The present invention also provides an exhaled breath sampling device, including a collection front end 1, a gas pipeline 3, a gas collecting container 9, a CO2 concentration sensor 4 connected to the gas pipeline, a flow sensor 5, an air pump 6 and a three-way valve 7, and a control unit 8. Among them, the collection front end 1 is a nasal tube or a mask. The gas pipeline has an air inlet 31, a gas collecting port 32 and an exhaust port 33. The air inlet 31 is connected to the collection front end 1, the exhaust port 33 is connected to the outside, and the gas collecting port 32 is connected to the gas collecting container 9. The CO2 concentration sensor 4 is used to collect the CO2 concentration in the gas pipeline in real time; the flow sensor 5 is used to collect the gas flow in the gas pipeline during the gas collection process; the three-way valve 7 is used to control the outlet end of the air pump 6 to be connected to the gas collecting port 32 or the exhaust port 33; the control unit 8 is electrically connected to the CO2 concentration sensor 4, the flow sensor 5, the air pump 6 and the three-way valve 7, and can set the exhalation slope ratio threshold value K according to the exhalation law. out , exhaled concentration threshold T out And the inhalation concentration threshold T in， And when the collected CO2 concentration data meets the exhalation slope ratio threshold K out and exhaled concentration threshold T out When the suction concentration threshold T is met, the three-way valve 7 is controlled so that the outlet of the air pump 6 is only connected to the air collecting port 32; and in When the condition is met, the three-way valve 7 is controlled so that the outlet end of the air pump 6 is only connected to the exhaust port 33.

[0056] The gas collecting container 9 may be a gas collecting bag, or the buffer chamber or analysis chamber of the detection equipment may be directly used to collect the gas.

[0057] Furthermore, a filter 2 is provided between the collection front end 1 and the air inlet 3 for water-gas separation.

[0058] The breath sampling device also includes a human-machine interface, which is connected to the control unit 8 and is used for the user to input parameters and instructions and display sampling data.

[0059] The exhaled air sampling method and exhaled air sampling device of the present invention use CO2 concentration and CO2 concentration slope ratio k to determine whether the exhaled gas is alveolar gas. Gas collection is performed only when the two parameters meet the conditions at the same time; when the CO2 concentration drops below the inhaled concentration threshold Tin, gas collection is stopped. Therefore, the exhaled air sampling method and exhaled air sampling device can realize automatic alveolar gas collection, reduce the difficulty of exhaled air sampling, and improve sampling accuracy and efficiency.

[0060] The technical principle of the present invention is described above in conjunction with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations herein, those skilled in the art can associate other specific implementations of the present invention without paying creative labor, and these methods will fall within the scope of protection of the present invention.

Claims

1. A breath sampling method, characterized in that: The following steps are involved: Collect the CO2 concentration value v[n] of the patient's breathing in real time and store it in a first array; wherein n is an integer and n≥3; The slope ratio k is calculated according to the slope ratio calculation formula and stored in the fourth array; the slope ratio calculation formula is: k = (v[i] - v[i-1]) / (v[i-1] - v[i-2]), where i is an integer and 3≤i≤n; Compare and analyze the slope ratio k and the current CO2 concentration value v[i]. If k∈(0, K out ) and v[i]>T out When the sampling valve is opened, sampling is performed; among them, K out is the preset exhalation slope ratio threshold, T out is the preset exhaled concentration threshold; Compare and analyze the current CO2 concentration value v[i], if v i <T in , close the sampling valve and stop sampling; where T in is the preset inhalation concentration threshold; Get the exhalation slope ratio threshold K out The following steps are involved: Obtain the first value less than 1 in each respiratory cycle from the fourth array and store it in the fifth value; Get the maximum and minimum values ​​from the fifth array and calculate the difference Δk between them; calculate the average value of all values ​​in the fifth array Calculate the exhalation slope ratio threshold K out , Among them, 0<δ<1; Among them, the exhaled concentration threshold T is obtained out and T in The following steps are involved: Obtain the maximum CO2 concentration value and the minimum CO2 concentration value of each respiratory cycle from the first array, and store them in the second array and the third array respectively; Calculates the average of all values ​​in the second array The average value of all data in the third array and the difference Δv, Calculate the exhaled concentration threshold T according to the formula out and T in , Among them, η, γ∈(0,1).

2. A breath sampling method according to claim 1, characterized in that: The following steps are also included: Get the sampling flow and sampling time; Cumulative calculation of sampling volume; When the sampling volume is greater than or equal to the preset value, close the sampling valve and stop sampling.

3. A breath sampling device based on the breath sampling method according to any one of claims 1 to 2, characterized in that: include: Collection front end; A gas pipeline having a gas inlet, a gas collecting port and a gas exhaust port; The air inlet is connected to the collection front end; the air outlet is connected to the outside; a gas collecting container communicated with the gas collecting port; A CO2 concentration sensor, a flow sensor, an air pump and a three-way valve connected to the gas pipeline; the CO2 concentration sensor is used to collect the CO2 concentration in the gas pipeline in real time; the flow sensor is used to collect the gas flow in the gas pipeline during the gas collection process; the three-way valve is used to control the outlet end of the air pump to be connected to the gas collection port or the exhaust port; A control unit is electrically connected to the CO2 concentration sensor, the flow sensor, the air pump and the three-way valve, and can set the exhalation slope ratio threshold K according to the exhalation rule. out , exhaled concentration threshold T out And the inhalation concentration threshold T in , and when the collected CO2 concentration data meets the exhalation slope ratio threshold K out and exhaled concentration threshold T out When the suction concentration threshold T is met, the three-way valve is controlled so that the outlet of the air pump is only connected to the air collecting port; and in When the condition is met, the three-way valve is controlled so that the outlet end of the air pump is only connected to the exhaust port.

4. A breath sampling device according to claim 3, characterized in that: A filter is arranged between the collection front end and the air inlet.

5. A breath sampling device according to claim 3, characterized in that: It also includes a human-machine interface, which is connected to the control unit and is used for users to input parameters and instructions and display sampling data.

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