RU2221597C2 - Device for producing hypoxic hypercapnia - Google Patents

Abstract

FIELD: medical engineering. SUBSTANCE: device has labyrinth canals produced as partitions movable relative to each other to vary additional dead space volume and the resulting gas concentration in alveolar air. Deflectors are mounted in the labyrinth canals to reduce turbulence of exhaled air and improve its stratification into portions to enable one to increase carbon dioxide concentration and oxygen deficiency in alveolar air. EFFECT: controllable carbon dioxide concentration. 4 dwg, 1 tbl

Description

 The invention relates to medicine, namely to cardiology, neurology and pulmonology, and can be used to study the body's response to dosed hypoxic hypercapnia, in particular to assess the reactivity of cerebral vessels and perfusion reserve of cerebral circulation, as well as to carry out hypercapnic training aimed at increasing resistance (resistance) of the body to adverse stress factors, training of adaptive systems, preparation for surgical interventions with temporary cessation of blood flow through the arteries that feed the brain, and the treatment of diseases, in particular cerebrovascular disorders, coronary circulation disorders, hypertension, respiratory failure, etc.

 A device is known (A.S. USSR 1123692), which contains a series-connected housing with a dead space tank, a mixer with a diaphragm for supplying atmospheric air, a spool assembly, a nozzle with an additional dead space capacity and a mouthpiece that provides carbon dioxide dosing in the range 1 -5% due to the regulation of air supply from the surrounding space.

 The disadvantages of the known device are the following.

 1. The inability to create a concentration of carbon dioxide in the inhaled air of more than 5%, which is necessary for assessing the perfusion reserve of cerebral circulation and conducting effective hypercapnic training.

 2. The device has a complex structure and does not allow to achieve maximum stratification of exhaled air in portions, which leads to a decrease in the effective concentration of carbon dioxide.

 The closest in technical essence and the achieved positive result is a device (a. USSR 747474), consisting of a rectangular casing with a dead space capacity in the form of parallel labyrinth channels formed by partitions installed inside the casing. In this case, the housing walls have holes with plugs. The mouthpiece is removable.

 The disadvantages of the known device are the following.

 1. The inability to smoothly adjust the volume of the "dead" space and, accordingly, dosing the concentration of carbon dioxide.

 2. Inconvenience when working with traffic jams.

 A positive result of the claimed device is the creation of an effective concentration of carbon dioxide in the alveolar air with the possibility of dosing. A positive result of the claimed device is achieved by the fact that the labyrinth channels are made in the form of partitions with the ability to move relative to each other, which allows you to change the additional volume of the "dead" space and, accordingly, the concentration of gases in the alveolar air; fairings are installed in the labyrinth channels to reduce the turbulence of exhaled air and improve its separation into portions, which allows increasing the concentration of carbon dioxide and oxygen deficiency in the alveolar air.

 The inventive device (Fig. 1) for dosing hypoxic hypercapnia is made of medical plastic and is represented by a housing 1 with a dead space capacity in the form of parallel labyrinth channels 2 with a cross-sectional area close to the cross-sectional area of the trachea. Due to the displacement of the movable partitions "a" and "b", mounted on the transverse plates 3 mounted inside the housing, relative to the fixed partitions "c", the volume of the "dead" space in the range from 500 to 1500 ml gradually changes with the help of the handles 4. To better exfoliate and reduce the turbulence of the exhaled gas flow in the labyrinth channels, fairings 5 are installed, fixed to the movable partitions "a" and "b". The device is equipped with a removable mouthpiece 6 and tube 7.

 The device operates as follows.

 Breathing is carried out through the mouthpiece 6, and nasal breathing is turned off. In FIG. 2 shows the principle of regulating the additional volume of "dead" space. An additional volume of "dead" space (DOMP) is set at the desired level from 500 to 1500 ml (Fig. 1 - 500 ml, Fig. 2 - 1500 ml). Within 1 minute of breathing through the device in the alveolar air, the concentration of carbon dioxide is set in the range of 5-6%, depending on the selected value of the additional volume of "dead" space.

 The value of fairings for creating an effective concentration of carbon dioxide in the inhaled air has been experimentally proven. For this, two devices were used that increase the amount of "dead" space. One of them is the claimed design with fairings, the other without them. Breathing through the devices was carried out for one minute. The Priestley tube was used to take alveolar air. Gas analysis was performed on a Spirolyt-2 apparatus (Germany). The results of the experiment are presented in the table (figure 3). The table shows that the device with fairings creates a significantly higher concentration of carbon dioxide in the alveolar air compared with the device without fairings. This is due to the fact that the fairings provide a decrease in turbulence and mixing of the flow of the exhaled gas mixture, which leads to a better separation of the gas mixture into portions and an increase in the alveolar concentration of carbon dioxide.

 An example of using the inventive device.

Patient S., 55 years old, after briefing and 5 minutes rest breathed through a device for creating hypoxic hypercapnia for one minute, sequentially with an additional volume of “dead” space of 500 ml, 1000 ml, 1500 ml. The initial concentration of CO ₂ in the alveolar air was 3.9%. When using DOMP 500 ml - 4.5%; 1000 ml - 5.1%; 1500 ml - 5.6%.

Next, we studied the dynamics of increasing the concentration of CO ₂ in the alveolar air using DOMP - 1500 ml for two minutes of figure 4. The concentration of CO ₂ significantly increased in the first minute of breathing through the device and then did not significantly change.

 Thus, the advantages of the device are as follows.

1. The presence of a mechanism for changing the volume of the labyrinth channels allows you to achieve a smooth adjustment of the concentration of CO ₂ in the alveolar air.

 2. The presence of fairings in the labyrinth channels allows for maximum stratification of the exhaled gas mixture flow, to reduce turbulence and thereby increase the concentration of carbon dioxide in the alveolar air.

 3. The device has a simple design, is easily processed with disinfectants.

Claims (1)

A device for creating hypoxic hypercapnia, comprising a housing with a dead space capacity in the form of parallel labyrinth channels, a mouthpiece and a tube, characterized in that transverse plates are mounted inside the housing, on which movable partitions are mounted, which can be moved relative to the fixed partitions using handles and in the labyrinth channels fairings are fixed to the movable partitions.

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