Metabolic rate testing method for working personnel in deep ground environment

Abstract

The invention discloses a method for testing the metabolic rate of a worker in a deep ground environment, which comprises the following steps of: recording the environment temperature and the ground gradient of a high-temperature and high-humidity mine, the heart rate of a miner, the adaptive days of the miner, the labor intensity of the miner, the weight of the miner, the height of the miner and the weight of the miner, collecting gas exhaled by the miner, and measuring the concentration of oxygen and the concentration of carbon dioxide in the exhaled gas; on the basis, respiratory entropy is calculated, and a measured value of the metabolic rate is obtained; according to the miner labor intensity, the miner body weight, the miner load weight and the ground slope, calculating a metabolic rate standard value, and comparing the measured metabolic rate value with the metabolic rate standard value; according to the environment temperature of the high-temperature and high-humidity mine, the labor intensity of miners and the weight of the miners, predicting the metabolic rate by adopting a multivariate stepwise linear regression method; and according to the adaptive days of the miner and the heart rate of the miner, dynamically predicting the operation time appreciation rate of the miner by using a multiple regression model. The metabolic rate of the miner can be conveniently and accurately calculated, and occupational health and safety of the miner are effectively guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of mine safety technology, specifically relating to a method for testing the metabolic rate of workers in deep underground environments. Background Technology

[0002] With increasing mining depth, the heat hazards caused by the high temperature and humidity environment underground are becoming increasingly prominent, seriously affecting miners' physiological workload and operational safety. Metabolic rate is a key parameter in human thermal comfort models, significantly influencing human thermal comfort perception and response. Furthermore, the dynamic changes in metabolic rate are a crucial factor directly affecting human thermoregulation; that is, metabolic rate is closely related to thermal comfort. Accurate measurement of metabolic rate is fundamental to studying human thermal comfort during exercise and is a prerequisite for calculating human thermal balance, thermophysiological, and thermopsychological responses. Summary of the Invention

[0003] The purpose of this invention is to provide a method for testing the metabolic rate of workers in deep underground environments, which can conveniently and accurately calculate the metabolic rate of miners and effectively ensure their occupational health and safety.

[0004] To achieve the above objectives, the present invention provides a method for testing the metabolic rate of workers in deep-earth environments, comprising the following steps: S1. Record the ambient temperature, ground slope, miner's heart rate, number of days miners adapt, miner's labor intensity, miner's weight, miner's height, and miner's load in the high temperature and humidity mine. Also, collect the miners' exhaled gas and measure the concentrations of oxygen and carbon dioxide in the exhaled gas. S2. Calculate the respiratory entropy based on the oxygen and carbon dioxide concentrations of exhaled gas measured in S1, and obtain the measured value of metabolic rate. S3. Based on the miner's labor intensity, weight, load, and ground slope in S1, calculate the standard value of metabolic rate, and compare the measured value of metabolic rate calculated in S2 with the standard value of metabolic rate. S4. Based on the ambient temperature of the high-temperature and high-humidity mine, the labor intensity of miners, and the weight of miners' loads in S1, the metabolic rate is predicted using a multiple stepwise linear regression method. S5. Based on the number of days of adaptation and the miner's heart rate in S1, use a multiple regression model to dynamically predict their metabolic rate during operation.

[0005] As a further aspect of the present invention, the expression for the measured metabolic rate in S2 is as follows: ; Where M1 is the measured metabolic rate, W / m 2 ; EE is the energy equivalent, expressed by the formula: RQ is the respiratory entropy, expressed by the formula: ; and For oxygen consumption rate and carbon dioxide production rate, in L / h; The formula for the human body surface area is: m 2 W b For miners' weight, kg; H b The miner's height is in centimeters.

[0006] As a further aspect of the present invention: the expression for the standard value of metabolic rate in S3 is as follows: ; ; Among them, M W W is the standard value for metabolic rate. G is walking speed, km / h; G is ground slope, %; W b is the miner's weight, kg; L is the miner's load weight, kg.

[0007] As a further aspect of the present invention: the expression for predicting metabolic rate in S4 is as follows: ; Where M2 is the predicted metabolic rate, W / m 2 ;t a The ambient temperature is in °C. is walking speed, km / h; L is the weight carried by the miner, kg.

[0008] As a further aspect of the present invention: the expression for the metabolic rate during the predicted operation in S5 is as follows: ; Where M3 is the metabolic rate during operation, W / m 2 ;d ac To accommodate the number of days; HR re This represents the percentage of heart rate reserve.

[0009] Compared with the prior art, the beneficial effects of the present invention are as follows: 1) High precision and accuracy. Unlike screening, observation, and analytical metabolic rate measurement methods, the oxygen consumption measurement method is a professional-grade metabolic rate measurement method. Within the range of measurement precision or time and exercise research precision, its uncertainty is ±5%, with low error risk and high measurement precision and accuracy.

[0010] 2) High convenience. The respiratory entropy is calculated by measuring the human body's oxygen consumption and carbon dioxide production, and then the metabolic rate is calculated.

[0011] 3) It has good temporal resolution. It can measure metabolism from resting metabolic rate to exercise metabolic rate and can capture rapid dynamic changes in metabolic rate.

[0012] 4) Simple and convenient operation. Staff only need to wear a mask to collect exhaled air, and the whole process is painless and non-invasive. At the same time, staff are allowed to engage in low to moderate intensity activities, and the ecological validity is far higher than that of the direct calorimetry method.

[0013] 5) Wide range of applications. It can be applied to deep earth engineering, clinical medicine, and other fields. Attached Figure Description

[0014] Figure 1 This is a flowchart of the method of the present invention.

[0015] Figure 2 This is a flowchart illustrating the calculation of the measured metabolic rate of this invention.

[0016] Figure 3 This is a comparison chart of the variance between the measured and standard values ​​of the metabolic rate of this invention.

[0017] Figure 4 This is a Bland-Altman scatter plot of the measured and predicted values ​​of environmental temperature, labor intensity, and metabolic rate under load in this invention.

[0018] Figure 5 This is a Bland-Altman scatter plot of the measured and predicted reserve heart rate values ​​of this invention. Detailed Implementation

[0019] The invention will now be further described with reference to the accompanying drawings.

[0020] like Figure 1 As shown, a method for testing the metabolic rate of workers in deep-earth environments includes the following steps: S1. During the experiment, record parameters such as ambient temperature, ground slope, miner's heart rate, number of days miners adapt, miner's labor intensity, miner's weight, miner's height, and miner's load weight.

[0021] Oxygen consumption reaches a steady state after 3 to 5 minutes. Exhaled gas collection begins approximately 5 minutes later without interruption. The main working period lasts 5 to 10 minutes. Exhaled gas collection stops when the workload changes.

[0022] In the process of determining metabolic rate, detecting the oxygen and carbon dioxide content in the miners' exhaled gas is crucial. After collecting the miners' exhaled gas, the concentrations of oxygen and carbon dioxide in the exhaled gas are measured using a pump-type composite gas detector.

[0023] S2. Based on the oxygen and carbon dioxide concentrations of exhaled gas measured in S1, calculate the oxygen consumption rate and carbon dioxide production rate, and then obtain the respiratory entropy. Calculate the measured metabolic rate using the formula.

[0024] ; Where M1 is the measured metabolic rate, W / m 2 EE stands for Energy Equivalent, used to convert oxygen consumption rate into metabolic rate, expressed by the formula: RQ is the respiratory entropy, expressed by the formula: ; and For oxygen consumption rate and carbon dioxide production rate, in L / h; The formula for the human body surface area is: m 2 W b For miners' weight, kg; H b The miner's height is in centimeters.

[0025] The energy equivalent depends on the metabolic type represented by respiratory entropy (RQ). When determining the metabolic rate, a mean respiratory entropy of 0.85 and an energy equivalent (EE) of 5.68 are typically used. In this case, it is not necessary to measure the carbon dioxide production rate, but the error is relatively large. This invention measures the accurate carbon dioxide production rate, and the specific calculation process is as follows: Figure 2 As shown.

[0026] Figure 2 middle, and This represents the concentration of oxygen and carbon dioxide in exhaled gas. For dry gas, the gas volume should be related to a temperature of 0 °C and a pressure of 103.1 kPa (normal atmospheric pressure) (i.e., STPD conditions: standard temperature and pressure). Since the saturated pressure of water vapor in the collected air is a function of temperature, which is determined by the ambient temperature (ATPS conditions: atmospheric temperature and pressure), the reduction factor f can be calculated using the partial pressure of water vapor, the corrected volumetric flow rate of expired gas can be calculated, the concentrations of oxygen and carbon dioxide in exhaled gas can be detected, the oxygen consumption rate and carbon dioxide generation rate can be calculated, and thus the respiratory entropy can be obtained.

[0027] ; ; ; ; In the formula, Indicates the reduction factor; and Here, atmospheric pressure and saturated water vapor partial pressure are given in kPa. For exhaled air; This represents the corrected exhaled gas volumetric flow rate, in L / h; Expresses the volumetric flow rate of exhaled gases, in L / h; This indicates the oxygen consumption rate, expressed in L / h. Indicates the concentration of oxygen in exhaled breath, %VOL; The rate of carbon dioxide formation is expressed in L / h. This indicates the concentration of carbon dioxide in exhaled breath, expressed as %VOL.

[0028] S3. Based on parameters such as the miner's labor intensity, weight, load, and ground slope in S1, calculate the standard value of metabolic rate, and compare the measured value of metabolic rate calculated based on S2 with the standard value.

[0029] The following analysis examines the differences between the metabolic rate of personnel in a mining environment and standard values, comparing the measured values ​​with those of ISO 7730, ISO 8996, and ASHRAE Standards. Figure 3 As shown. The metabolic rate of men during walking, as defined in ISO 8996, is calculated using the following formula given in the standard: ; ; In the formula, The standard value for metabolic rate is W / m³. 2 ; Walking speed, km / h; The slope is % of the ground slope. Weight, in kg; The weight is the load-bearing weight, expressed in kg.

[0030] S4. Using SPSS software, with the measured metabolic rate as the dependent variable and the ambient temperature of the high-temperature and high-humidity mine, the miners' labor intensity and load intensity as independent variables, a multiple stepwise linear regression method was used to establish a predictive equation for the metabolic rate.

[0031] Based on experimental data and real downhole data, the expression for predicting metabolic rate is determined as follows: ; In the formula, M2 is the predicted metabolic rate, W / m 2 ;t a Ambient temperature (°C); L represents the weight carried (kg); and walking speed (km / h) represents the walking speed.

[0032] S5. Based on the miners' adaptation days and real-time heart rate in S1, a multivariate regression model is used to dynamically predict their metabolic rate during operation.

[0033] Based on experimental data and actual downhole data, the expression for the predicted metabolic rate during operation is determined as follows: ; In the formula, M3 is the metabolic rate during operation, W / m 2 ;d ac To accommodate the number of days; HR re This represents the percentage of heart rate reserve.

[0034] like Figure 3 The chart shows a comparison of the variance between measured and standard values ​​of metabolic rate. The measured metabolic rate values ​​during walking were significantly higher than those given by various current standards. Compared to the four standards, the experimental values ​​are closer to the ISO 7730 standard, but this standard still underestimates the walking metabolic rate. This difference may stem from the fact that the recommended values ​​of ISO 7730 and ASHRAE standards are based on the higher muscle density of European and American populations, who have relatively higher resting metabolic rates. The lower standing metabolic rate in East Asians can be attributed to their higher body fat levels, lower muscle density, and lower basal metabolic rate.

[0035] like Figure 4 The figure shows a Bland-Altman scatter plot of the measured and predicted values ​​of metabolic rate based on ambient temperature, labor intensity, and load weight. The predicted metabolic rate values ​​of this invention are in high agreement with the measured values ​​of other researchers. When M < 200 W / m², most of the residuals of the prediction equation fall within the 95% confidence interval, indicating a high agreement between the predicted and measured values. However, the predicted values ​​are generally slightly higher than the measured values; while when M > 200 W / m², the predicted values ​​are lower than the measured values. This may be because the equation does not consider other key environmental factors, such as ambient humidity.

[0036] like Figure 5 The image shows a Bland-Altman scatter plot comparing the measured and predicted values ​​of heart rate reserve. The results indicate that 94.32% of the residuals fall within the confidence interval, while 95.45% of the residuals in the heart rate reserve model fall within the confidence interval, showing an improvement over the former. This suggests that predicting metabolic rate using heart rate reserve is more accurate.

Claims

1. A method of testing metabolic rate of a deep-earth worker, characterized by, The method comprises the following steps: S1, recording the environmental temperature of high-temperature and high-humidity mine, ground slope, miner's heart rate, miner's adaptation days, miner's labor intensity, miner's body weight, miner's height, miner's weight-carrying weight, collecting the exhaled gas of the miner, and measuring the respective concentrations of oxygen and carbon dioxide in the exhaled gas; S2, calculating the respiratory entropy according to the measured oxygen concentration and carbon dioxide concentration of the exhaled gas in S1 to obtain a measured metabolic rate value; S3, calculating a standard metabolic rate value according to the miner's labor intensity, miner's body weight, miner's weight-carrying weight, and ground slope in S1, and comparing the measured metabolic rate value calculated in S2 with the standard metabolic rate value; S4, predicting the metabolic rate according to the environmental temperature of high-temperature and high-humidity mine, miner's labor intensity, and miner's weight-carrying weight in S1 by using a multiple stepwise linear regression method; S5, dynamically predicting the working metabolic rate of the miner according to the miner's adaptation days and miner's heart rate in S1 by using a multiple regression model.

2. A method for testing metabolic rate of workers in deep earth environments according to claim 1, characterized by, The expression of the measured metabolic rate value in S2 is as follows: ； Where M1 is the measured metabolic rate, W / m 2 ; EE is the energy equivalent, expressed by the formula: ; RQ is the respiratory quotient, expressed by the formula: ; and are the oxygen consumption rate and carbon dioxide production rate, L / h; is the body surface area, expressed by the formula: , m 2 ; W b is the weight of the miner, kg; H b is the height of the miner, cm.

3. A method for testing metabolic rate of workers in deep earth environments according to claim 1, characterized by, The expression of the standard metabolic rate value in S3 is as follows: ； ； where M W is the metabolic rate standard value, W; is the walking speed, km / h; G is the ground slope, %; W b is the miner's body weight, kg; L is the miner's load weight, kg.

4. A method for testing metabolic rate of workers in deep earth environments according to claim 1, characterized by, The expression of the predicted metabolic rate in S4 is as follows: ； where M2 is the predicted metabolic rate, W / m 2 ; t a is the ambient temperature, °C; is the walking speed, km / h; and L is the weight of the miner, kg.

5. A method for testing metabolic rate of workers in deep earth environments according to claim 1, characterized by, The expression of the predicted working metabolic rate in S5 is as follows: ； where M3 is the metabolic rate of the work, W / m 2 ; d ac is the number of days to adapt; HR re is the percentage of the reserve heart rate.

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