Calibration device and method for metabolic rate of human metabolic chamber

Abstract

The present invention discloses a device and method for calibrating the metabolic rate of a human body metabolic chamber, comprising an air pump, the air inlet of the air pump being connected to the human body metabolic chamber, the air outlet of the air pump being connected in sequence to a three-way valve, a first solenoid valve, and an oxygen separator; the oxygen outlet of the oxygen separator being connected to an O2 flowmeter; the other port of the three-way valve being connected to the human body metabolic chamber via a second solenoid valve; the residual gas outlet of the oxygen separator being connected to the human body metabolic chamber via a third solenoid valve; a CO2 cylinder gas, the air outlet of the CO2 cylinder gas being connected in sequence to the human body metabolic chamber via a fourth solenoid valve and a CO2 flow controller; and a PLC controller being connected to the first to fourth solenoid valves, the O2 flowmeter, the CO2 flow controller, and the air pump, respectively. The PLC controller simulates the inhalation oxygen consumption function and the exhalation carbon dioxide production function by controlling the four solenoid valves, and can trace the value of the metabolic rate test results of the human body metabolic chamber.

Description

Technical Field

[0001] The present invention relates to measurement and detection technology, and more particularly to a device and method for calibrating the metabolic rate of a human body metabolic chamber. Background Art

[0002] The human metabolic chamber uses indirect calorimetry to measure human energy metabolism. It is the latest tool in energy metabolism research and one of the "gold standards" for human energy measurement. Based on the human metabolic rate formula, the Wier formula: EE (kcal / min) = 3.941 VO2 (L / min) + 1.106 VCO2 (L / min) or EE (kJ) = 16.3 VO2 (L) + 4.6 VCO2 (L), it calculates the subject's metabolic rate. The measurement error generally does not exceed ±10%. Currently, metabolic chambers are widely used to assess energy metabolism and investigate mechanisms in physiological activities such as diet, sleep, and exercise, as well as in conditions such as obesity and type 2 diabetes. Over the past few decades, the prevalence of metabolic diseases has steadily increased, raising concerns about the role of energy balance in metabolic diseases. This has led to broad applications of precise human metabolic chambers in medical research.

[0003] As a vital medical research facility widely used for measuring human metabolic rate, its test results are directly linked to patient treatment methods and outcomes, ultimately impacting patient outcomes. However, currently, there is a lack of unified technical standards and specifications for determining the accuracy of metabolic rate test results in metabolic chambers, both domestically and internationally. Manufacturers also have varying factory calibration procedures, leading to significant discrepancies in measurement results between devices produced by different manufacturers, and even between devices of the same model from the same manufacturer. This directly impacts the final assessment of a patient's metabolic status. Therefore, research into traceability technology for metabolic rate test results in precision human metabolic chambers is urgently needed to ensure the accuracy and consistency of these test results.

[0004] In summary, the existing traceability of metabolic rate test results in human metabolic chambers has the following defects:

[0005] 1. At present, the calibration procedures of metabolic chamber manufacturers for metabolic chambers are still based on the calibration of the numerical accuracy of each sensor, such as the numerical accuracy of instruments such as mass flow meters, carbon dioxide sensors, and oxygen content sensors installed in the metabolic chamber, or the accuracy of mass spectrometers used to test the concentration of the above gases. 3The subject's individual breath volume is extremely small compared to the volume of the metabolic chamber. The carbon dioxide produced and oxygen consumed by each breath are transferred through the chamber's piping to the test instrument, often exceeding the instrument's sensitivity and measurement accuracy. This can lead to significant measurement errors in the metabolic rate test results.

[0006] 2. The non-standard human metabolic simulation device can simulate the human respiratory process according to the principle of indirect calorimetry, thereby completing the traceability of the measurement value of the human metabolic chamber. Summary of the Invention

[0007] In view of the problems existing in the prior art, the purpose of the present invention is to provide a device and method for calibrating the metabolic rate of a human metabolic chamber.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] In one aspect of the present invention, a device for calibrating the metabolic rate of a human metabolic chamber is provided. The device is disposed outside the human metabolic chamber and includes an air pump, wherein the air inlet of the air pump is connected to the human metabolic chamber, and the air outlet of the air pump is sequentially connected to a three-way valve, a first solenoid valve, and an oxygen separator; the oxygen outlet of the oxygen separator is connected to an O2 flowmeter; the other port of the three-way valve is connected to the human metabolic chamber via a second solenoid valve; and the residual gas outlet of the oxygen separator is connected to the human metabolic chamber via a third solenoid valve.

[0010] It also includes a CO2 cylinder gas, the gas outlet of which is connected to the human body metabolism chamber through a fourth solenoid valve and a CO2 flow controller in sequence;

[0011] It also includes a PLC controller, which is respectively connected to the first solenoid valve, the second solenoid valve, the third solenoid valve, the fourth solenoid valve, the O2 flow meter, the CO2 flow controller and the air pump.

[0012] Another aspect of the present invention provides a method for calibrating the metabolic rate of a human body metabolic chamber, the specific steps of the method are:

[0013] A. The PLC controller controls the first, third, and fourth solenoid valves to be in the closed state, and the second solenoid valve to be in the open state. The PLC controller also controls the vacuum pump to operate and extract the gas in the human metabolic chamber according to a predetermined vacuum flow rate and then return it to the human metabolic chamber.

[0014] B. The PLC controller controls the second and fourth solenoid valves to be closed, and the first and third solenoid valves to be open. The PLC controller controls the air extraction pump to extract air at a preset oxygen consumption rate for a preset oxygen inhalation time. The O2 flowmeter transmits real-time oxygen flow data to the PLC controller. At this time, the gas in the human metabolic chamber flows through the first solenoid valve to the oxygen separator, where the oxygen in the gas is separated and discharged. The remaining gas flows back into the human metabolic chamber through the third solenoid valve.

[0015] C. The PLC controller controls the first and third solenoid valves to be closed, and the second and fourth solenoid valves to be open. The PLC controller controls the CO2 flow controller to pump air at a preset CO2 production rate until the preset exhalation time. The CO2 flow controller transmits real-time carbon dioxide flow data to the PLC controller.

[0016] D. Repeat steps B and C until the preset breathing rate is reached;

[0017] E. The PLC controller calculates the simulated human metabolic rate using the human metabolic rate formula based on the received oxygen flow rate data and carbon dioxide flow rate data;

[0018] The oxygen consumption flow data and carbon dioxide flow data are obtained from the test in the human metabolic chamber, and the human metabolic rate to be calibrated is obtained through the human metabolic rate formula;

[0019] The indication error between the simulated human metabolic rate and the human metabolic rate to be calibrated can be used to trace the value of the metabolic rate test results in the human metabolic chamber.

[0020] Compared with the prior art, the device and method for calibrating the metabolic rate of a human metabolic chamber of the present invention can complete the traceability of the value of the test results of the metabolic rate of the human metabolic chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the principle of an embodiment of the present invention. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0023] See also Figure 1The device for calibrating the metabolic rate of a human metabolic chamber is shown. It is located outside the human metabolic chamber and includes an air pump 11. The air inlet of the air pump is connected to the human metabolic chamber 10, and the air outlet of the air pump is connected in sequence to a three-way valve 12, a first solenoid valve 13, and an oxygen separator 14. The oxygen outlet of the oxygen separator is connected to an O2 flowmeter 15. The other end of the three-way valve is connected to the human metabolic chamber via a second solenoid valve 16. The residual gas outlet of the oxygen separator is connected to the human metabolic chamber via a third solenoid valve 17.

[0024] It also includes a CO2 cylinder gas 18, the gas outlet of the CO2 cylinder gas is connected to the human body metabolism chamber through a fourth solenoid valve 19 and a CO2 flow controller 20 in sequence;

[0025] It also includes a PLC controller (not shown in the figure), which is respectively connected to the first solenoid valve, the second solenoid valve, the third solenoid valve, the fourth solenoid valve, the O2 flow meter, the CO2 flow controller and the air pump.

[0026] The calibration device for the metabolic rate of a human body metabolic chamber of the present invention comprises the following specific steps:

[0027] 1. The PLC controller controls the first, third, and fourth solenoid valves to be closed, and the second solenoid valve to be open. The PLC controller also controls the vacuum pump to pump gas out of the human metabolic chamber at a predetermined flow rate and then return it to the chamber. This creates a closed-loop system with the calibration device of the present invention. This allows the vacuum pump to reach the predetermined flow rate in advance, providing a stable gas flow for subsequent processes, primarily ensuring the subsequent oxygen consumption flow rate.

[0028] 2. When simulating human inhalation, the PLC controller controls the second and fourth solenoid valves to be in the closed state, and the first and third solenoid valves to be in the open state; the PLC controller controls the vacuum pump to pump air at a preset oxygen consumption rate until the preset oxygen inhalation time; the O2 flowmeter transmits real-time oxygen flow data to the PLC controller; at this time, the gas in the human metabolic chamber flows to the oxygen separator through the first solenoid valve, and the oxygen in the gas is separated and discharged under the action of the oxygen separator, and the remaining gas flows back to the human metabolic chamber through the third solenoid valve. At this time, the simulation device completes the simulation of the inhalation oxygen consumption function.

[0029] 3. When simulating human exhalation, the PLC controller controls the first and third solenoid valves to be in the closed state, and the second and fourth solenoid valves to be in the open state; the PLC controller controls the CO2 flow controller to pump air at a preset CO2 production rate to the preset exhalation time; the CO2 flow controller also transmits real-time carbon dioxide flow data to the PLC controller, completing the simulation of the exhalation carbon dioxide production function.

[0030] The numerical settings of oxygen consumption rate and CO2 production rate are shown in Table 1

[0031] Table 1

[0032] model Oxygen consumption rate L / h <![CDATA[CO2 production rate L / h]]> sleep 18.1±1.0 14.1±1.5 Rest 19.0±1.2 17.2±1.1 light activity 28.2±1.9 23.5±1.2 Moderate activity 51.8±4.6 45.8±6.5

[0033] 4. Repeat steps B and C until the preset respiratory rate is reached. See Table 2 for respiratory rate settings.

[0034] Table 2

[0035] model Respiratory rate (times / min) aldult 16-20 child 20-30 Newborns 30-45 Adult Sports 20-24

[0036] It can be seen that the above-mentioned settings enable the calibration device of the present invention to simulate different metabolic activities of humans, providing a standard metabolic level for the subsequent calibration of the human metabolic chamber.

[0037] 5. The PLC controller uses the received oxygen flow data and carbon dioxide flow data to derive the simulated human metabolic rate using the human metabolic rate formula;

[0038] The oxygen consumption flow data and carbon dioxide flow data are obtained from the test in the human metabolic chamber, and the human metabolic rate to be calibrated is obtained through the human metabolic rate formula;

[0039] The indication error between the simulated human metabolic rate and the human metabolic rate to be calibrated can be used to trace the value of the metabolic rate test results in the human metabolic chamber.

[0040] Those skilled in the art should recognize that the above embodiments are only used to illustrate the purpose of the present invention and are not intended to limit the present invention. As long as they are within the spirit and scope of the present invention, any changes and modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. A calibration device for metabolic rate of a human body metabolic chamber, located outside the human body metabolic chamber, characterized in that: It includes an air pump, the air inlet of the air pump is connected to the human body metabolism chamber, the air outlet of the air pump is connected to a three-way valve, a first solenoid valve and an oxygen separator in sequence; the oxygen outlet of the oxygen separator is connected to an O2 flowmeter; the other port of the three-way valve is connected to the human body metabolism chamber through a second solenoid valve; the residual gas outlet of the oxygen separator is connected to the human body metabolism chamber through a third solenoid valve; It also includes a CO2 cylinder gas, the gas outlet of which is connected to the human body metabolism chamber through a fourth solenoid valve and a CO2 flow controller in sequence; It also includes a PLC controller, which is respectively connected to the first solenoid valve, the second solenoid valve, the third solenoid valve, the fourth solenoid valve, the O2 flow meter, the CO2 flow controller and the air pump.

2. A calibration method for implementing the calibration device according to claim 1, characterized in that: The specific steps of this method are: A. The PLC controller controls the first, third, and fourth solenoid valves to be in the closed state, and the second solenoid valve to be in the open state. The PLC controller also controls the vacuum pump to operate and extract the gas in the human metabolic chamber according to a predetermined vacuum flow rate and then return it to the human metabolic chamber. B. The PLC controller controls the second and fourth solenoid valves to be closed, and the first and third solenoid valves to be open. The PLC controller controls the air extraction pump to extract air at a preset oxygen consumption rate for a preset oxygen inhalation time. The O2 flowmeter transmits real-time oxygen flow data to the PLC controller. At this time, the gas in the human metabolic chamber flows through the first solenoid valve to the oxygen separator, where the oxygen in the gas is separated and discharged. The remaining gas flows back into the human metabolic chamber through the third solenoid valve. C. The PLC controller controls the first and third solenoid valves to be closed, and the second and fourth solenoid valves to be open. The PLC controller controls the CO2 flow controller to pump air at a preset CO2 production rate until the preset exhalation time. The CO2 flow controller transmits real-time carbon dioxide flow data to the PLC controller. D. Repeat steps B and C until the preset breathing rate is reached; E. The PLC controller calculates the simulated human metabolic rate using the human metabolic rate formula based on the received oxygen flow rate data and carbon dioxide flow rate data; The oxygen consumption flow data and carbon dioxide flow data are obtained from the test in the human metabolic chamber, and the human metabolic rate to be calibrated is obtained through the human metabolic rate formula; The indication error between the simulated human metabolic rate and the human metabolic rate to be calibrated can be used to trace the value of the metabolic rate test results in the human metabolic chamber.

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