CZ289192B6 - Method of measurement and evaluation of lung function parameters - Google Patents

Abstract

The proposed measuring and evaluating method of lung functioning parameters in children of pre-school age and of a defined gender and height is carried out by measuring a maximum expiration curve in dependence on outflow-volume and subsequent comparison of the obtained values with values calculated from equations to thereby evaluating lung state.

Description

The invention relates to medicine, in particular to a method of measuring and for evaluating parameters of respiratory organ function.

BACKGROUND OF THE INVENTION

Determining lung function parameters is an essential part of functional examination of vital organs. Measurements of lung vital capacity and maximum expiratory rates are essential for determining change in habits, lifestyle changes, or to determine further examination.

Comprehensive lung examination consists of several procedures that are not very “friendly” to the person under investigation. X-rays are damaging to human tissue and repeated administration in young children is particularly inappropriate. Clinical examination may be uncomfortable for someone (palpation, tapping, listening) and its correct evaluation depends on the individual 20 abilities and experience of the examiner. Measurements of the lung ventilation properties should be repeated several times, as the scattering of the measured values is large and the measurements are not reproducible.

For functional examination of the lungs, devices are provided which enable, on the basis of record 25, a maximum flow-volume exhalation curve and from its peak exhalation rate to assess lung function. Functional examination depends on the ability of the examined person to cooperate, ie to achieve the actual peak exhalation rate.

So far, the examination may not accurately determine the lung function and health of the examined person, their evaluation usually depends on the optimal assessment influenced by long-term practice of the doctor. As a whole, they are difficult to apply to less collaborating observers, especially small children.

SUMMARY OF THE INVENTION

These deficiencies are eliminated by the method of measuring and evaluating lung function parameters in preschool children using a spirometer by measuring the vital capacity of FVC [ml] in millimeters, the one-second vital capacity of FEVi [ml] in milliliters, the peak exhalation rate of 40 PEF [1 / s ] in liters per second, exhalation rates for 25% of MEF25 vital capacity [1 / s] in liters per second, exhalation rates for 50% of MEF50 vital capacity [1 / s] in liters per second, exhalation rates for 75% of MEF75 vital capacity [1 / s] in liters per second, areas defined by the maximum exhalation curve Aex [l ² / s] in quadrate liters per second as a function of flow-volume and comparing these values with values calculated from ln FVC equations [ml], (boys) = -6.04522 + 2.77587 ln height [cm]; cv = 10%, r = 0.86, ln FVC [ml], (girls) = -3.89521 + 2.31474 ln height [cm]; cv = 9.8%, r = 0.84, ln FEVi [ml], (boys + girls) = -4.28412 + 2.38775 ln height [cm]; cv = 9.8%, r = 0.84, ln PEF [1 / s], (boys + girls) = -8.54538 + 1.99379 ln height [cm]; cv = 15%, r = 0.62, ln MEF75 [1 / s], (boys + girls) = -9.62916 + 2.21106 ln height [cm]; cv = 16.1%, r = 0.62, ln MEF50 [1 / s], (boys + girls) = -10.0976 + 2.25767 ln height [cm]; cv = 21.9%, r = 0.46, ln Aex [ ¹² / s], (boys) = -21.9613 + 4.76734 ln height [cm]; cv = 18.2%, r = 0.82, ln Aex [ ¹² / s], (girls) = -19.4105 + 4.21151 ln height [cm]; cv = 18.2%, r = 0.81, ln Aex [ ¹² / s], (boys + girls) = -20.7602 + 4.50593 ln height [cm]; cv = 18.3%, r = 0.81

The lung condition is evaluated.

Height [cm] indicates body height in centimeters, c.v. is the coefficient of regression tolerance, r is the correlation coefficient and the quantities are

FVC - Forced Vítal Capacity - exhaled vital capacity,

PEF - Peak Expiratory Flow

MEF - Maximum Expiratory Flow at 25% vital capacity

FEV - Forced Expiratory Volume in One Second

Aex- Area under the maximum expiratory flow-volume curve.

From experimental measurements and many years of experience and observations it was found that in children of 20 preschool age the closest dependence of monitored lung functional parameters on body height is found.

Thus, it is possible to more accurately determine the condition and disorders of lung function, i.e., airway patency or lung size change, and thus to determine in a timely manner a procedure for improving this condition or a method for further examination. To assess functional abnormalities in the examined children, the types and parameters of correlation functions were obtained from examination of a large group of children with absolutely perfect lung function.

The method of measuring and evaluating lung parameters is therefore best suited for preschool children, with the lower age limit not only depending on the child's ability to cooperate in the examination, but also on the examiner's experience with the examination.

On the flow-volume exhalation curve, the main peak exhalation rate is influenced by the momentary state of observation or its degree of cooperation in functional examination. Therefore, the most important values determined from the maximum flow-volume exhalation curve are the maximum exhalation rates for 75%, 50% and 25% of vital capacity, which are reproducible. It is therefore essential that the measurement and evaluation of the most important parameters depend not on the will or ability of the subject to cooperate with the investigator, ie exerting maximum effort on expiration into the device, but on the physiological and physical characteristics of the subject.

The measured values that deviate from the tolerance band of the individual dependence are a signal for further determination of the procedure to improve this condition or further examination.

The use of the invention is revolutionary for the preventive examination of preschool children, in whom it is more sensitive and more plausible than clinical examination. It enables very early determination of steps leading to the optimization of the state of the monitored organ.

BRIEF DESCRIPTION OF THE DRAWINGS

The evaluation of the lung function parameters of the invention is illustrated in more detail in the accompanying graphs.

Fig. 1 shows the dependence of exhaled vital capacity of FVC on boys height.

Fig. 2 shows the dependence of the exhaled vital capacity of the FVC on the height of the girls.

Figure 3 shows the dependence of one second vital capacity (FEV) on the height of the child.

Fig. 4 shows the dependence of peak exhalation rate PEF on the height of the child.

Figure 5 shows the exhalation rate for 25% of the MEF25 vital capacity versus infant height.

-2GB 289192 B6

Fig. 6 shows the exhalation rate for 50% of the MEF50 vital capacity to the height of the child.

Fig. 7 shows the exhalation rate for 75% of the MEF75 vital capacity to the height of the child.

Fig. 8 is a plot of the area defined by the maximum exhalation curve Aex from the flow-volume to height of boys.

Fig. 9 shows the dependence of the area defined by the maximum exhalation curve Aex from the flow-volume to height of the girls.

Fig. 10 shows the area bounded by the maximum exhalation curve Aex from the flow-volume to height of the infant.

DETAILED DESCRIPTION OF THE INVENTION

Example 1

During a preventive examination, a child, usually of pre-school age, is subjected to examination of functional parameters of the lungs so that the values of vital lung capacity, expiratory rates and their course over time are measured by exhalation into the measuring device. The measured values are compared with the graphs and their tolerances according to Figures 1 - 10, which represent dependence according to regression equations with correlation of measured functional parameters with body height. The position of the points representing the measured values relative to the curves determines the functional state of the organ to be monitored, and the evaluation reveals a possible abnormality of the lung function. On this basis it is then possible to determine changes in habits, lifestyle changes or, if necessary, to determine another method of examination.

Example 2

The child, usually of pre-school age, is subjected to a preventive examination of the lung functional parameters by means of a special device so that the values of vital capacity of the lungs and their course in time are measured by exhalation into the tube. The software under which the instrument operates includes regression equations with correlation of measured function parameters with body height. Through this, the measurement is evaluated and the investigator is immediately informed of any abnormal lung function. On this basis it is then possible to determine changes in habits, lifestyle changes or, if necessary, to determine another method of examination.

Industrial applicability

The method of measuring and evaluating lung function parameters performed on an apparatus operating on the principle according to the invention is advantageously applied both in the basic preventive examination of a child's organ and in the detection of its functional disorders.

Claims (1)

Method for measuring and evaluating lung function parameters in preschool children for a particular sex and height using a spirometer, characterized in that by measuring the exhaled vital capacity FVC, one second vital capacity FEV _b peak exhalation rate PEF, exhalation rate for 25% vital capacity MEF25, exhalation rates for 50% vital 10 capacities MEF50, exhalation rates for 75% vital capacity MEF75, areas defined by the maximum flow-volume exhalation curve Aex and comparing these values with the values calculated from ln FVC equations [ml], (boys) = -6.04522 + 2.77587 ln height [cm]; cv = 10%, r = 0.86 15 ln FVC [ml], (girls) = -3.89521 + 2.31474 ln height [cm]; c.v. = 9.8%, r = 0.84, ln FEVi [ml], (boys + girls) = -4.28412 + 2.38775 ln height [cm]; c.v. = 9.8%, r = 0.84, ln PEF [1 / s], (boys + girls) = -8.54538 + 1.99379 ln height [cm]; c.v. = 15%, r = 0.62, ln MEF75 [1 / s], (boys + girls) = -9.62916 + 2.21106 ln height [cm]; c.v. = 16.1%, r = 0.62, ln MEF50 [1 / s], (boys + girls) = -10.0976 + 2.25767 ln height [cm]; c.v. = 21.9%, r = 0.46, 20 ln Aex [ ¹² / s], (boys) = -21.9613 + 4.76734 ln height [cm]; cv = 18.2%, r = 0.82, ln Aex [ ¹² / s], (girls) = -19.4105 + 4.21151 ln height [cm]; cv = 18.2%, r = 0.81, ln Aex [ ¹² / s], (boys + girls) = -20.7602 + 4.50593 ln height [cm]; cv = 18.3%, r = 0.81 the lung condition is evaluated, where cv is the coefficient of regression tolerance, r is the correlation coefficient and the quantities are FVC - Forced Vítal Capacity - exhaled vital capacity, 30 PEF - Peak Expiratory Flow MEF - Maximum Expiratory Flow at 25% welcomed capacity - maximum expiratory rate at 25% vital capacity, 35 FEV - Forced Expiratory Volume in One Second Aex- Area under the maximum expiratory flow-volume curve.