RU2550127C1 - Hardware-software complex for estimating condition of respiration regulating system and method of application thereof - Google Patents

Abstract

FIELD: medicine.SUBSTANCE: elaborated hardware-software complex is intended for application in conditions of a polyclinic, in limited closed volumes, with a person staying in which can be connected with the change of the respiratory centre sensitivity to breathing gases (Oand CO) in a changed gas medium, as well as in specialised research institutions for carrying out experiments aimed at the study of the human cardiorespiratory system. The elaborated complex consists of three units: a unit of gas distribution (A1), a unit of gas supply (A2), a unit of collection and processing data and system control (A3). Unit A1 represents a closable and openable breathing circuit. The unit includes the following main elements, connected to each other by means of tubes: a metal reservoir with a bag, a ventilator, a chemical absorber of carbon dioxide (CA), a regulator of flow through CA, a system of valves and three-way taps, hoses, a valve box, as well as a device, made with a possibility of realisation of biological feedback (BFB) by the patient's noting their state and transmission of data about the state into a terminal device of unit A3. The unit of gas supply is made with a possibility of regulated supply of gases into unit A1 by means of an electrically controlled choke, with atmospheric air or atmospheric air with an increased or reduced oxygen content being used as the supplied gases. The unit of collection and processing of data and system control includes a terminal device with software, realising control over movement of the gases and their parameters in unit A1. The said control is possible in a manual, automatic mode; as well as with an account of signals, obtained from BFB device; sensors of concentrations of gases, sensors of flows, sensors of measurement of physiological parameters, information from which is transmitted into the terminal device by means of a converter. The method of estimating the condition of the respiration regulating system by means of the elaborated hardware-software complex includes carrying out a number of stages. First, a preparatory stage is realised at which the dosed supply of gases from the unit of gas supply (A2) into the unit of gas distribution (A1) is performed. Continuous mixing of the gases in the respiratory circuit is realised during the time of supply of the gases into unit A1 in course of entire rebreathing by operation of an air pump. After that, a stage of estimating the condition of the respiration regulating system is performed, for which purpose the tested person is connected to a respirator, connected to the valve box via a filter, and performs breathing through the mouth with the closed nasal way, with inhalation being made through an inhalation hose and exhalation - through an exhalation hose. At the beginning of the stage of estimating the condition of the respiration regulating system HSC is set in a free respiration mode, in which the respiratory circuit is closed, and the tested person performs breathing with atmospheric air through the inhalation and exhalation hoses, the system of three-way taps, with the determination of a value of partial oxygen, carbon dioxide in alveolar air and ventilation of the tested person's lungs. After that, a manoeuvre of arbitrary hyperventilation is performed in the free respiration mode until a specified safe gas composition of exhaled air is achieved. After that, by switching the three-way taps the tested person passes into the mode of rebreathing, before which the tested person performs deep exhalation into atmosphere, then realises inhalation-exhalation from the circuit. The tested person breathes from the box space outside the bag, atmospheric air enters and leaves the bag simultaneously through the sensor of the air flow, with measuring in this way parameters of lung ventilation. Finally, transfer into the free respiration mode is performed by switching the three-way taps. The said results are achieved due to the possibility of applying only own metabolic carbon dioxide for performing a hypercapnic impact; application of the principle of complex control by means of feedback; application of an oxygen generator for filling the system with a hyperoxic mixture and dosed supply of oxygen into the system, applied in the test of respiration with the hyperoxic gas mixture and with the support of constant oxygen concentration (isooxic gas mixture) in the system; automation of measurements.EFFECT: provision of safe, objective and comprehensive estimation of operation of the person's respiration regulating system.31 cl, 4 dwg

Description

The invention relates to medicine and can be used to assess the state of the respiratory regulation system. The developed hardware-software complex is intended for use in outpatient conditions, in limited confined volumes, the presence of a person in which may be associated with changes in the sensitivity of the respiratory center to respiratory gases (O ₂ and CO ₂ ) in an altered gas environment, as well as in specialized scientific and research institutions to conduct experiments to study the cardiorespiratory system of a person.

Disturbances of external respiration arising from chronic obstructive pulmonary diseases, asthma and other diseases constitute a significant part of socially significant diseases. With these and other diseases, respiratory regulation disorders often occur. Compensation of respiratory failure is largely determined by the characteristics of the respiratory regulation system. Although currently developed methods for determining the sensitivity of human respiration to carbon dioxide and oxygen, they are practically not used, since they require a large number of manipulations. In addition, the poor comparability of the results obtained using different techniques remains an important problem.

The following devices are known for assessing the state of the respiratory regulation system:

- to assess the response of the respiratory center in hyperbaric conditions (Yakhontov B.O., Shulagin Yu.A. Ventilatory response to CO ₂ in divers under the influence of various hyperbaric factors. In the book: "Hyperbaric medicine", proceedings of the VII International Congress on Hyperbaric Medicine , September 2-6, 1981, vol. 2, Publishing House, "Science", M., 1983, pp. 195-198; Suvorov A.V. External respiration and gas exchange of a person during a prolonged stay in hyperbaric conditions. on the postgraduate student of medical sciences, Moscow, IBMP, 1986, 137 p.);

- a hardware-software complex (AIC) for determining the effect of hypercapnia on human ventilation (Shulagin Yu.A., Dyachenko A.I., Ermolaev E.S., Goncharov A.O. Development of a method for assessing the sensitivity of human respiration to carbon dioxide in gravitational physiology // Technologies of living systems, 2012. Volume 9, No. 10, pp. 14-22; Eugene S. Ermolaev, Alexander I. Dyachenkol, Yury A. Shulagin, Alexander O. Goncharov, Artem V. Demin. Effect of head-down human body position on chemoreflex control of breathing // M. Long (Ed.): World Congress on Medical Physics and Biomedical Engineering, IFMBE Proceedings, vol. 39, pp.2068-2071, 2012. www.springerlink.com ISSN: 1680-0737.)

- hardware-software experimental setup for determining the effect of hypoxia and hypercapnia on human ventilation in zero gravity (Prisk, G. Kim, Ann R. Elliott, and John B. West. Sustained microgravity reduces the human ventilatory response to hypoxia but not to hypercapnia. J Appl Physiol 88: 1421-1430, 2000).

- a hardware-software complex (APC) for determining the effect of oxygen and carbon dioxide on human ventilation (Duffin, J., 2007. Measuring the ventilatory response to hypoxia. J. Physiol. 584, p. 285-293.), developing a classical method Read DJC A clinical method for assessing the ventilatory response to carbon dioxide. // Aust. Ann. Med. 1967, V.16, N 1, P.20-32.

However, experimental studies of breathing with the participation of divers in modeling deep-sea diving and microgravity in space flight revealed new facts indicating the need for additional studies of breathing regulation, including among divers and astronauts during space flight. In particular, in space flight an increase in the duration of the breath-holding was revealed, the reasons for which remain hypothetical.

Known analog devices have the following disadvantages:

1) additional equipment is necessary, in particular cylinders with compressed carbon dioxide and oxygen, which does not allow the device to be used in conditions that do not allow the use of cylinders;

2) the rate of increase in the concentration of CO ₂ and decrease in the concentration of O ₂ is determined by the volume of the bag, tubes and lungs of a person, as well as the rate of oxygen consumption and carbon dioxide evolution, therefore, they cannot vary arbitrarily. Differences in these characteristics of the subjects lead to differences in the rates of CO ₂ rise, which can lead to an erroneous interpretation of the results.

3) poor comparability of the results obtained using different methods.

The disadvantages of analogues are eliminated in the developed complex.

The problem to be solved in the invention was the development of a hardware-software complex designed to study the system of regulation of human respiration, eliminating the disadvantages of analogues.

The achieved result is to provide a safe, objective and comprehensive assessment of the functioning of the human respiratory regulation system.

The technical result is achieved due to:

- the possibility of using only its own metabolic carbon dioxide to exert a hypercapnic effect;

- the use of the principle of controlling the complex through feedback, which means controlling the flow of the gas mixture through the chemical absorber CP (15) or bypass due to the fan (12) (fan). At the same time, the values of flows through CP (15) and bypass depend on the contents of carbon dioxide and oxygen in the circuit, as well as human ventilation. The performance (flow) of the fan (12) is adjusted to the person’s own ventilation so that the person does not feel the resistance of the ventilation circuit;

- use of an oxygen generator to fill the system with a hyperoxic mixture and dosed oxygen supply to the system used in the breath test with a hyperoxic gas mixture and while maintaining a constant oxygen concentration in the system (isoxic gas mixture);

- automation of measurements.

The developed complex consists of three blocks:

A1 - gas distribution unit.

A2 - Gas supply unit.

A3 - Data Acquisition and Control Unit

Brief Description of the Drawings

Figure 1 presents the scheme of the agro-industrial complex.

Figure 2. The functional scheme of the agricultural industry is presented.

In figure 1 and figure 2 is indicated:

1) - air flow sensor,

2) - filter,

3) - mouthpiece,

4) - valve box,

5) - gas intake gas analyzer,

6) - rod

7) - hose

8) - tablet,

9) - three-way valve,

10) - four-way valve (closes / opens the circuit),

11) - boxing with a bag,

12) - electric supercharger,

13) - a medical table,

14) - three-way valve with electric drive,

15) - chemical absorber CO ₂ (CP),

16) - electric drive control unit,

17) - power supply,

18) - block forming a gas mixture,

19) - electrically controlled throttle,

20) - stand for the terminal device,

21) - terminal device,

22) - block wireless data transmission,

23) - gas analyzers,

24) - analog-to-digital Converter (ADC),

25) - pipe.

Figure 3. Determination of ventilation response to CO ₂ during hypoxic-hypercapnic breathing:

A is the partial pressure of O ₂ ,

B is the partial pressure of CO ₂ ,

C is the respiratory flow rate,

D is an example of analysis of a tester's ventilation reaction.

Figure 4. Determination of the ventilation reaction to CO ₂ in hyperoxic-hypercapnic respiration:

A is the partial pressure of O ₂ ,

B is the partial pressure of CO ₂ ,

C is the respiratory flow rate,

D is an example of an analysis of a subject’s ventilation response.

Valve timing unit (A1)

The gas distribution unit is a lockable and unlockable breathing circuit. The block consists of the following main elements interconnected by means of tubes:

1) a metal container with a bag (11),

2) fan (12),

3) chemical absorber of carbon dioxide (CP) (15),

4) flow regulator (14) through HP (15),

5) a system of valves and three-way valves, hoses, valve box (4),

6) a device (8) made with the possibility of implementing biological feedback (BFB) by marking the subject with his condition and transmitting status data to the terminal device (21) of block A3.

Elements (A1) are interconnected by tubes of large cross section, which provides low resistance to breathing. The block is filled with a respiratory gas mixture of a certain composition. The gas distribution is regulated by the choice of flow directions by switching the three-way valve system (9), the flow rate and the initial parameters of the filled gas mixture in the circuit. The small working volume of the breathing circuit (35 liters) with the CP turned off (15) provides a high rate of filling the system with carbon dioxide, the adjustable flow cross section through the CP (15) and bypass by means of an electrically operated valve (14) and the flow rate by means of a fan (12) allow you to vary the speed filling systems in a wide range.

System data acquisition and processing unit (A3)

The block includes the following main elements:

1) terminal device (21) with software that implements control of the movement of gases and their parameters in block A1,

2) gas analyzers (23),

3) air flow sensors (1),

4) sensors for measuring physiological parameters, information from which is transmitted through an analog-to-digital converter to the ADC (24) to a terminal device (21).

This unit is made with the possibility of hardware-software control of the gas composition of the respiratory mixture and assessment of the state of the respiratory regulation system.

Work on the agricultural sector is carried out in two stages: the preparatory stage and the stage of assessing the state of the respiratory regulation system.

The stage of assessing the state of the respiratory regulation system is carried out sequentially in two operating modes of the AIC.

The modes set with the help of hardware-software control are:

1) The breathing mode of atmospheric air, in which the following maneuvers are implemented and investigated: calm breathing, holding the breath, hyperventilation and recovery after return breathing.

2) The mode of return breathing, in which the following maneuvers are implemented and investigated: a) hypoxic-hypercapnic, hypoxic-isocapnic, hyperoxic-hypercapnic, isoxic-hypercapnic, hypoxic-poikilokapnic return breathing;

b) breath holding, hyperventilation.

AIC allows you to conduct tests that consistently include different breathing patterns:

1) Test "Determining the ventilation reaction to CO ₂ during hypoxic-hypercapnic return breathing", including calm breathing in atmospheric air, hyperventilation of atmospheric air, hypoxic-hypercapnic return breathing, calm breathing in atmospheric air. Figure 3 shows an example of a test.

2) Test "Determining the ventilation reaction to CO ₂ during hyperoxic-hypercapnic return breathing", including calm breathing in atmospheric air, hyperventilation of atmospheric air, hyperoxic-hypercapnic return breathing, calm breathing in atmospheric air. Figure 4 shows an example of a test.

3) Other necessary tests.

The advantages of the proposed complex and the tests carried out with its help are as follows: without the use of cylinders with compressed gas, it is possible to quickly obtain the characteristics of the state (chemosensitivity) of the respiratory regulation system under various influences. For example, the parameters A and B found in Fig. 3D of a linear approximation of the dependence of lung ventilation Vi on PCO ₂ characterize the state (chemosensitivity) of the respiratory regulation system to CO ₂ under hypoxic-hypercapnic exposure. Analysis of the dependence of ventilation on PCO ₂ is justified, since the level of PO ₂ does not fall below 60 mm Hg. Therefore, hypoxia changes only the sensitivity to CO ₂ , but is not a significant active factor that could make an independent contribution to lung ventilation.

When breathing a hyperoxic mixture, the peripheral receptors of the synocarotid reflexogenic zone are turned off. All that remains is the contribution of the central (medullary) chemoreceptors. On fig.4D gives an assessment of the parameters A and B, characterizing this contribution.

Other additional tests with different levels of partial pressures of oxygen and carbon dioxide will allow us to identify the dependence of ventilation on alveolar / arterial partial pressures of gases, taking into account the non-additivity of the effect of hypoxia and hyperoxia (i.e. the presence of a ventilation component associated with both the partial pressure of oxygen and partial carbon dioxide pressure).

Gas supply unit (A2)

This unit provides an adjustable supply of gas mixture to unit A1 by means of an electrically controlled throttle (19). The unit includes a gas mixture forming unit (18), which can be used as an oxygen generator, and any oxygen generator is used to generate oxygen, including an adsorption oxygen generator, and filling block A1 with carbon dioxide can only occur due to gas released from the examined person as a result of their own metabolism.

In addition, the following design features are implemented in the agricultural sector.

The respiratory circuit is mounted in a mobile medical table (13) on wheels with a brake, which excludes the movement of the table during the experiments.

The design of the installation includes platforms for installing gas analyzers (23) and a container for special adapters, spare parts and other details.

The unit is equipped with a stand (20) for the terminal device (21), which is easy to fold and fasten with straps to the side of the unit for convenient transportation.

The unit is equipped with a rod-holder (6) for the valve box (4) connected to the subject. The holder bar (6) allows you to move and fix the valve box in space relative to the subject, which allows you to conduct research in various poses and conditions, without causing inconvenience to the subject.

The design provides for a special bracket directly in front of the test subject under the tablet (8) or a panel with a scale for subjectively assessing the test load on their breathing during tests using the Borg index.

The design is quickly collapsible, which allows to disinfect its individual parts after lengthy experiments.

The design provides a bag-cover that completely covers the installation, which provides protection against pollution during transportation or long-term storage.

The work of the AIC to assess the state of the respiratory regulation system is implemented as follows.

Before the study, a preparatory stage is carried out in which a metered supply of gases from the gas supply unit (A2) to the gas distribution unit (A1) is carried out. The characteristics of the gas mixture are controlled from the interface of the AIC. After filling the system with gas mixture, the breathing circuit closes, the fan (12) continuously mixes the mixture in the breathing circuit, and the flow through the CP (15) is blocked by an electric valve (14). The non-return valve eliminates spontaneous absorption of carbon dioxide from the circuit when the CP is blocked (15).

Next, the stage of assessing the state of the respiratory regulation system is performed, while the subject is connected to a respirator (3) connected to the valve box (4) through the filter (2). Breathing is done through the mouth, the nasal passage is blocked. Inhalation is through the inhalation hose, exhalation is through the exhalation hose (7). In the free breathing mode, the respiratory circuit is closed, and the test subject is connected through the inspiratory and expiratory hoses (7), a system of taps (9) to the atmosphere. The gas analyzer sensors (23) and the air flow sensor (1) record the composition of the gas mixture and respiratory flow during free breathing.

The AIC instantly enters the breathing mode by switching the taps (9), while the subject is connected to the respiratory circuit. An inextensible bag in a metal box (11) changes the volume in accordance with the respiratory cycles of a person. The air flow sensor (1) connected to the bag allows you to register the test person’s respiratory flow.

The test subject begins breathing after a deep exhalation into the atmosphere. Then he takes a breath from the circuit. Since the circuit is a closed system of a certain volume, during inhalation, a previously collapsed inextensible bag is inflated by the volume of the inspiration. Then the person exhales into the circuit. In this case, the bag falls on the exhalation volume into the circuit. Thus, respiratory cycles occur during the return breath, up to switching to breathing with atmospheric air.

The bag is connected to the atmosphere through an air flow sensor (1). Since the total volume of gas in the bag and gas that is in the box outside the bag is always equal to the volume of the box, the volume of inhalation and exhalation into the space of the box outside the bag causes a change in the volume of the bag equal to the volume of inspiration and exhalation. At the same time, atmospheric air of constant composition passes from the bag through the air flow sensor, which ensures accurate registration of tidal volumes and ventilation of the subject. Direct registration of the respiratory flow in the circuit does not provide an accurate registration of the flow, since during the return breathing the composition of the air in the circuit changes, and the characteristics of the air flow sensor depend on the composition of the air. The values of tidal volumes and ventilation are further used to assess the state of the human respiratory regulation system. The mode of return breathing continues until failure or until the specified composition of air in the respiratory circuit is reached.

The fan (12) provides a continuous flow in the circuit, uniform mixing of the gas mixture and reduces the respiratory resistance of the test person when inhaling and exhaling, adjusting the performance of the fan (12) to the person’s own ventilation.

After the return breathing mode is completed, the AIC goes into breathing mode with atmospheric air, and the subject again switches to the atmosphere using taps (9).

To purge the breathing circuit, the four-way valve (10) opens the circuit, and the fan (12) blows it for several minutes.

A pipe (25) is provided in the circuit for taking gas samples from the circuit during the experiment, mounted in series with the fan (12). The pipe (25) can be used to connect to it the gas intake of gas analyzers (5), a pressure sensor and, if necessary, connect a gas supply unit (A2) to it.

To control the AIC, the corresponding software is installed on the terminal device (21), in addition, the system provides for a manual control mode. The software allows you to set the automatic control mode of the gas mixture parameters in the circuit, while changing the flow through CP (15) and the flow rate in the system, as well as switching to free breathing, are performed automatically depending on the partial pressures of oxygen and carbon dioxide, slew rate and ventilation test subject. This allows the system to adapt to the subject and set the same effect on the subjects.

The system provides a manual control mode that allows you to make adjustments to the operating mode of the AIC, to control the flow rate and regulate the flow through CP (15), as well as to prematurely stop the experiment.

The software allows you to:

- register signals from sensors (23) and (1);

- process the received signal;

- regulate the flow through CP (15);

- regulate the flow from the oxygen generator (18);

- regulate the flow in the circuit and through the CP (15) by means of the air flow sensor (1) located at the CP (15).

Assessment of a person’s emotional state and his sensations caused by a ventilation reaction before the experiment and after the end of the return breathing period, as well as during the return breathing, is provided by software installed on the tablet device (8) located on the bracket in front of the subject. Data from the tablet (8) is transmitted wirelessly (22) to the terminal device (21).

On the tablet (8), software is installed to register subjective data on the well-being of the subject. To assess the emotional state of a person and his sensations caused by a ventilation reaction before the experiment and after the end of the period of return breathing, the subject is asked to answer the test questions on a subjective assessment of the state of the body. During the test, the subject assesses the respiratory load using the Borg load index (shortness of breath test).

Claims (30)

1. Automated hardware-software complex for assessing the state of the respiratory regulation system, including
a gas distribution unit (A1) mounted in a mobile medical table on casters with a brake and connected to a respirator,
gas supply unit (A2),
system data acquisition and processing unit (A3),
wherein
the gas distribution unit (A1), made in the form of a lockable and unlockable breathing circuit, consisting of interconnected by means of tubes: a metal container with a bag, a fan (12), a chemical absorber (CP) (15), a flow regulator (14) through CP ( 15), a system of valves and three-way valves, hoses (7), valve box (4), moreover, the gas distribution in the circuit is provided by switching the system of three-way valves (9), as well as a device (8) configured to realize biological feedback communication (BOS), by marking the subject with his condition, and transmitting data to the terminal device of block A3,
the gas supply unit (A2) is arranged to provide controlled supply of gases to the A1 unit by means of an electrically controlled throttle (19), wherein the supplied gases are atmospheric air, atmospheric air with an increased or decreased oxygen content,
the data acquisition and processing unit and system control (A3) includes a terminal device (21) with software that implements control of the movement of gases and their parameters in block A1, and this control is possible in a manual, automatic mode; and also taking into account the signals received from the biofeedback device (8); gas concentration sensors, flow sensors, sensors for measuring physiological parameters, information from which is transmitted via a converter to a terminal device (21). 2. The device according to claim 1, in which a calcareous chemical absorber (KhPI) is used as a chemical absorbent of CP (15). 3. The device according to claim 1, in which an oxygen generator is further included in the composition of block A2. 4. The device according to claim 3, in which an oxygen adsorption generator is used as an oxygen generator. 5. The device according to claim 1, in which the software for the terminal device (21) of block A3 is configured to control the absorption of carbon dioxide, gas supply to the circuit before or during the study. 6. The device according to claim 1, in which the software of the terminal device (21) is implemented with the ability to set the breathing mode for testing respiratory function. 7. The device according to claim 6, in which the preset breathing modes are: return breathing modes: hypoxic-hypercapnic, hypoxic-normocapnic, normoxic-hypercapnic, hyperoxic-hypercapnic; or a combination of breathing and breath holdings; or breathing mode. 9. The device according to claim 1, in which the control of gas parameters, such as changing the flow through CP (15), the flow rate of gases in the system, flow through the throttle (19) of block A2, switching to free breathing mode, is automatically performed taking into account pressure of oxygen and carbon dioxide, flow rate and ventilation of the test. 10. The device according to claim 1, in which the composition of block A2 further includes a cylinder with compressed gas or gases or cylinders with compressed gases connected through a gearbox. 11. The device according to claim 1, in which the air blower (12) is made in the form of a propeller on a magnetic coupling. 12. The device according to claim 1, in which a nozzle (25) is mounted in the respiratory circuit. 13. The device according to item 12, in which the pipe (25) is made with the possibility of additional connection during the study of block A2 for a controlled supply of gases to the circuit. 14. The device according to item 12, in which the pipe (25) is configured to take samples from the circuit during the study. 15. The device according to item 12, in which the pipe (25) is configured to connect to it a gas inlet (5), gas analyzers (23), a pressure sensor. 16. The device according to claim 1, in which the manual control mode implies the possibility of setting the flow rate and regulating the flow through CP, as well as prematurely stopping the study. 17. The device according to claim 1, in which the block A3 is configured to register and process signals from sensors for controlling the flow rate through CP (15) and in the circuit. 18. The device according to claim 1, in which the portable medical table (13) further comprises a bracket for the device (8) for the biofeedback. 19. The device according to claim 1, in which the device (8) for the biofeedback is made in the form of a scale for the subjective assessment of the test worker's breathing load during the study. 20. The device according to claim 1, in which the device (8) for the biofeedback is made with the possibility of demonstration in the on-line mode to the subject of the prescribed breathing maneuvers. 21. The device according to claim 1, in which there is additionally a stand (20) for placing the terminal device (21) on a mobile medical table (18) on wheels with a brake as part of the table. 22. The device according to item 21, according to which the stand (20) is folding, with the possibility of mounting to the side surface of the table. 23. The device according to claim 1, in which to place the valve box (4) as part of a mobile medical table (13) on wheels with a brake, there is additionally a movable rod-holder (6). 24. The device according to claim 1, in which the design of a mobile medical table (13) on wheels with a brake has platforms for installing gas analyzers (23) and a container for adapters, spare parts and other details. 25. The device according to claim 1, in which an additional bag is included in the complex for closing the mobile medical table (13) on wheels with a brake. 26. The method for assessing the state of the respiratory regulation system using the hardware-software complex according to claim 1, including
the preparatory stage, in which the metered supply of gases from the gas supply unit (A2) to the gas distribution unit (A1) is carried out, moreover, during the supply of gases to the A1 unit and during the entire return breathing, they are continuously mixed in the breathing circuit through the operation of the air blower ( 12);
the next step is the assessment of the state of the respiratory regulation system, for which the subject is connected to a respirator (3) connected to the valve box (4) through the filter (2), and performs breathing through the mouth with the nasal passage blocked, and inhalation is made through the inhalation hose, exhale - through the exhalation hose (7);
At the beginning of the stage of assessing the state of the respiratory regulation system, the AIC is brought into free breathing mode, in which the respiratory circuit is closed, and the subject breathes atmospheric air through the inhalation and exhalation hoses (7), a system of three-way valves (9); in this case, the values of partial oxygen, carbon dioxide in the alveolar air and lung ventilation of the test person are determined,
then, in free breathing mode, a maneuver of arbitrary hyperventilation is performed until the specified safe gas composition of the exhaled air is reached,
after which, by switching the three-way valves, it enters the breathing return mode, before which the subject performs a deep exhalation into the atmosphere, then exhales and exhales from the circuit, while the subject breathes out of the box space (11) outside the bag, while atmospheric air enters and leaves the bag through the air flow sensor (1), thereby measuring the parameters of ventilation of the lungs,
in conclusion, the transition to the free breathing mode is performed by switching the three-way valves. 27. The method according to p. 26, in which, in the process of performing breathing, the partial pressure of carbon dioxide in the circuit is set by increasing or decreasing the flow rate through the CP (15), using an electrically operated valve (14), a fan (12) and a flow sensor in HP. 28. The method according to p. 26, in which the flow rate of gases supplied to the circuit is additionally regulated during the process of return breathing using an electrically controlled throttle (19) connected to the pipe (25). 29. The method according to p. 26, in which additionally, during the process of performing return breathing, breath tests are performed aimed at determining the chemosensitivity of the breathing regulation system, the tests being implemented by setting the composition of the gases in the circuit at the beginning of the return breathing and regulating the composition of the gases during the return breathing . 30. The method according to clause 29, in which the following tests are performed: a test to evaluate a person’s ventilation reaction to hypercapnia combined with hypoxia; test for assessing the poikilocapnic ventilation reaction of a person to hypoxia; test for evaluating a person’s ventilation reaction to hypercapnia with a hyperoxic gas mixture. 31. The method according to p. 26, in which in addition to the process of performing the preparatory phase when filling the circuit with gases from A2, the gas is purified from carbon dioxide by passing gases in the circuit through open CP (15).

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