Breathing gas circulation system for respiratory assist device

Abstract

The present invention relates to a breathing gas circulation system to be connected to a water chamber of a respiratory assist device to guide a heated / humidified breathing gas to a patient, wherein a circuit unit comprises: an intake tube, one lengthwise end of which connects to a water chamber so as to communicate therewith, and which delivers a heated / humidified breathing gas to the patient; a branch unit which connects to the other lengthwise end of the intake tube so as to communicate therewith, and which connects to a breathing mask worn on the patient, so as to communicate therewith; and a discharge tube, one lengthwise end of which connects to the branch unit so as to communicate therewith, and the other lengthwise end of which connects to an artificial respirator to guide thereto the gas generated subsequent to the breathing of the patient.

Description

Respiratory gas circulation system of respiratory assist device

[0001] The present invention relates to a respiratory gas circulation system of a respiratory assistance device, and more particularly, to a respiratory gas circulation system of a respiratory assistance device configured to deliver respiratory gas to a patient via a chamber portion of the respiratory assistance device, and further to measure the temperature and humidity of the respiratory gas.

[0002] In general, surgical patients requiring anesthesia, critically ill patients, or elderly patients who have difficulty breathing on their own are forced to breathe through a ventilator. However, the respiratory gas (anesthetic, oxygen, etc.) supplied to the patient through the ventilator has the problem of causing other side effects because the temperature and humidity are low.

[0003] To elaborate, the respiratory gas inhaled by a patient through a ventilator is not only cold enough to chill the patient, but also dehydrates the patient's airways and lungs due to its dryness. Furthermore, as the respiratory gas supplied from the ventilator condenses within the tube as it passes through it, the water droplets formed within the tube can be directly inhaled into the patient's lungs, potentially causing other health problems, such as dryness, ulcers, mucus plug formation, and mucociliary dysfunction in the patient's bronchial mucosa.

[0004] Currently, respiratory assistance devices are being used to appropriately control the temperature of the respiratory gas supplied from the ventilator to solve the above problems.

[0005] A respiratory assistance device may be configured to provide a patient with respiratory gas having an appropriate temperature and humidity by heating and humidifying respiratory gas generated from a respirator, and may largely include: a chamber in which distilled water is stored; a heating unit that heats the distilled water stored in the chamber; and a respiratory gas circulation system that delivers respiratory gas passing through the chamber to the patient and simultaneously delivers gas generated after the patient's breathing to the respirator.

[0006] Among them, the respiratory gas circulation system is configured to include an inhalation tube that guides respiratory gas by connecting the chamber and a respiratory mask worn on the patient's mouth.

[0007] Additionally, a heating wire for heating the respiratory gas and a sensor for detecting the temperature / humidity of the respiratory gas are provided inside the suction tube.

[0008] However, since the conventional respiratory gas circulation system is configured to include a power cable for supplying power to the heating wire and another power cable for supplying power to the sensor unit as separate components, there is a problem in that it requires a user, such as a nurse, to take care of each power cable and then connect them to each of the suction tubes.

[0009] In addition, the power cables not only detract from the aesthetic appeal of the patient's room, but also restrict the range of motion of the patient's family or the user, and more seriously, there is a problem of them being separated from the suction tube due to interference with unintended movements of the patient's family or the user.

[0010] In addition, since the above power cables are very expensive and are consumables, there is a problem of increasing the financial burden on users and patients.

[0011] Accordingly, the applicant of the present invention proposed the present invention to solve the above-mentioned problems, and a related prior art document is 'Medical automatic temperature and humidity controller with anti-condensation function' of Korean Patent No. 10-1479545.

[0012] The present invention is intended to solve the above problems, and the purpose of the present invention is to provide a respiratory gas circulation system of a respiratory assistance device that provides a circuit that is easy to install and simplified, thereby providing convenience in storage and installation to the user.

[0013] The present invention provides a respiratory gas circulation system that is connected to a water chamber of a respiratory assistance device and guides a heated / humidified respiratory gas to a patient, the system comprising: an inhalation tube, one longitudinal end of which is communicatively connected to the water chamber and which delivers the heated / humidified respiratory gas to the patient; a branch portion, which is communicatively connected to the other longitudinal end of the inhalation tube and which is communicatively connected to a respiratory mask worn by the patient; and an exhaust tube, one longitudinal end of which is communicatively connected to the branch portion and the other longitudinal end of which is connected to a ventilator and which guides a gas generated after the patient's breathing to the ventilator.

[0014] In addition, it may further include a heating wire for heating the respiratory gas and a sensor unit for detecting the temperature and humidity of the respiratory gas.

[0015] Additionally, the heating wire may be provided inside the suction tube or the discharge tube in a spiral shape.

[0016] Additionally, the heating wire can sequentially pass through the suction tube, the branch section, and the discharge tube.

[0017] In addition, the branch section may include a main pipe that is communicatively connected to the breathing mask; a first guide pipe that branches off from the main pipe and is communicatively connected to the other longitudinal end of the suction tube; and a second guide pipe that branches off from the main pipe and is communicatively connected to one longitudinal end of the discharge tube.

[0018] In addition, it further includes a connecting portion that connects the longitudinal other end of the suction tube and the first guide tube so that they can be communicated with each other; and the sensor portion and a fixing portion that supports the sensor portion can be arranged inside the connecting portion.

[0019] In addition, the connecting portion includes an insertion tube inserted into the longitudinal other end of the suction tube; and a receiving tube that is communicatively connected to the insertion tube and has an outer diameter and an inner diameter larger than the outer diameter and inner diameter of the insertion tube; and the first guide tube can be inserted into the receiving tube.

[0020] Additionally, the length of the first guide tube inserted into the receiving tube may be shorter than the length of the receiving tube.

[0021] In addition, the fixed part can be placed in a space between one longitudinal end of the first guide tube inserted into the receiving tube and a step surface formed at a connection point between the insertion tube and the receiving tube.

[0022] In addition, the fixing member includes a pair of curvature members that are arranged at a predetermined interval from each other inside the receiving tube and form a curvature corresponding to the inner curvature of the receiving tube; a connecting member that connects longitudinal ends of the pair of curvature members to each other; and a fastening member that is arranged at a distance from the connecting member and connects longitudinal ends of the pair of curvature members to each other; and the sensor unit can be detachably coupled to the fastening member.

[0023] Additionally, the above-mentioned curvature member can be in contact with the inner surface of the receiving tube.

[0024] In addition, the fastening member may include a pair of vertical members formed to extend in the direction in which the connecting member is arranged from the longitudinal other end of the curved member; a horizontal member that connects the pair of vertical members to each other and defines a 'ㄷ' shaped groove in which the sensor part can be seated in cooperation with the pair of vertical members; and a hook that protrudes from the vertical member and prevents the sensor part seated in the groove from being detached.

[0025] In addition, it may include a connecting portion that connects one longitudinal end of the suction tube and the discharge port of the water chamber so as to be communicatively connected to each other, and is connected to a power cable to supply power to the heating wire and the sensor portion.

[0026] The respiratory gas circulation system of a respiratory assistance device according to one embodiment of the present invention provides a configuration in which a heating wire is arranged in a spiral shape inside an inhalation tube through which respiratory gas passes, thereby providing respiratory gas having a temperature that is easy for a patient to breathe.

[0027] In addition, the respiratory assistance device according to one embodiment of the present invention provides a fixing part that is detachably provided inside the connecting part while supporting a sensor part that measures the temperature and humidity of respiratory gas, thereby providing convenience in replacing and repairing the sensor part and preventing the sensor part from moving due to external force.

[0028] Figure 1 is a drawing showing the configuration of a respiratory assistance device according to one embodiment of the present invention.

[0029] Figure 2 is a perspective view of a circuit unit according to one embodiment of the present invention.

[0030] Figure 3 is an exploded perspective view of a circuit portion according to one embodiment of the present invention.

[0031] Fig. 4 is a cross-sectional view of the circuit section shown in Fig. 2 viewed from the front.

[0032] Figure 5 is a perspective view of a fixing part according to one embodiment of the present invention.

[0033] Figure 6 is a cross-sectional view showing a state in which a fixing part and a sensor part are arranged inside a receiving tube according to one embodiment of the present invention.

[0034] Fig. 7 is a drawing of the inside of the suction tube and the discharge tube viewed in the direction of arrow A shown in Fig. 6 with the branch part shown in Fig. 6 removed.

[0035] Figure 8 is a perspective view of the main body and chamber portion of a respiratory assistance device according to one embodiment of the present invention.

[0036] The advantages and features of the present invention and the methods for achieving them will become clear with reference to the embodiments described in detail below together with the accompanying drawings.

[0037] However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and these embodiments are provided only to ensure that the disclosure of the present invention is complete and to fully inform a person having ordinary skill in the art to which the present invention pertains of the scope of the invention, and the present invention is defined only by the scope of the claims.

[0038] Hereinafter, with reference to FIGS. 1 to 8, a respiratory gas circulation system of a respiratory assistance device according to one embodiment of the present invention will be described in detail. In describing the present invention, specific descriptions of related known functions or configurations are omitted to avoid obscuring the gist of the invention.

[0039] FIG. 1 is a drawing showing the configuration of a respiratory assistance device according to an embodiment of the present invention, FIG. 2 is a perspective view of a circuit unit according to an embodiment of the present invention, FIG. 3 is an exploded perspective view of a circuit unit according to an embodiment of the present invention, FIG. 4 is a cross-sectional view of the circuit unit shown in FIG. 2 as viewed from the front, FIG. 5 is a perspective view of a fixing unit according to an embodiment of the present invention, FIG. 6 is a cross-sectional view showing a state in which a fixing unit and a sensor unit are arranged inside a receiving tube according to an embodiment of the present invention, FIG. 7 is a view looking inside a suction tube and an exhaust tube in the direction of arrow A shown in FIG. 6 with the branch unit shown in FIG. 6 removed, and FIG. 8 is a perspective view of a main body and a chamber unit of a respiratory assistance device according to an embodiment of the present invention.

[0040] For reference, this project is the result of a local government-university collaboration-based regional innovation project (2021RIS-001), funded by the Ministry of Education and supported by the National Research Foundation of Korea in 2024.

[0041] This research was supported by "Regional Innovation Strategy (RIS)" through the National Research Foundation of Korea(NRF) funded by the Ministry of Education(MOE)(2021RIS-001)

[0042] As illustrated in FIG. 1, a respiratory gas circulation system (100) according to one embodiment of the present invention can be connected to a chamber portion (300) constituting a respiratory assistance device (10) to guide heated / humidified respiratory gas.

[0043] First, the chamber part (300) may include, as shown in FIG. 8, a water chamber (310) provided on the upper part of the main body (200) and in which distilled water is stored; a heat-conducting plate (not shown) provided on the lower part of the water chamber (310) and in contact with the heating plate (210); and a cover (330) provided along the circumferential direction of the heat-conducting plate (not shown) and detachably coupled to a guide frame (220) provided on the upper part of the main body (200).

[0044] On one side of the upper surface of the water chamber (310) constituting the chamber section (300), a respiratory gas discharge port (312) is formed that is communicatively connected to the suction tube (110) of the respiratory gas circulation system (100) according to one embodiment of the present invention, and on the other side of the upper surface of the water chamber (310), as illustrated in FIG. 1, an air inlet port (313) that is communicatively connected to the air tube (1a) connected to the artificial respirator (1) may be formed.

[0045] A respiratory gas circulation system (100) according to one embodiment of the present invention is connected to a water chamber (310) configured as described above, and can deliver respiratory gas passing through the water chamber (310) to a patient.

[0046] The above respiratory gas circulation system (100) may include, as illustrated in FIGS. 1 to 7, a suction tube (110) having one longitudinal end communicatively connected to the water chamber (310) and delivering heated / humidified respiratory gas to a patient; a branch portion (120) having the other longitudinal end communicatively connected to the suction tube (110) and being communicatively connected to a respiratory mask worn by a patient; and an exhaust tube (130) having one longitudinal end communicatively connected to the branch portion (120) and the other longitudinal end connected to a respirator (1) to guide gas generated after the patient's breathing to the respirator (1).

[0047] For reference, as illustrated in FIG. 1, respiratory gas generated from the artificial respirator (1) can flow in the direction of arrow A through the air tube (1a) and then flow into the internal space of the water chamber (310) constituting the chamber portion (300).

[0048] The respiratory gas introduced into the internal space of the water chamber (310) can flow in the direction of arrow B through the suction tube (110). In addition, the respiratory gas flowing along the suction tube (110) can be delivered to the patient through the branch section (120) described later.

[0049] Then, the patient can breathe easily using the respiratory gas delivered through the suction tube (110).

[0050] Additionally, the gas generated after the patient breathes can flow in the direction of arrow C through the discharge tube (130). And, the discharged gas flowing along the discharge tube (130) can be delivered to the artificial respirator (1).

[0051] Here, the suction tube (110) not only delivers respiratory gas to the patient via the water chamber (310), but also heats the respiratory gas so that the patient can receive respiratory gas at a temperature suitable for breathing.

[0052] That is, a heating wire (h) for heating the respiratory gas and a sensor unit (140) for detecting the temperature and humidity of the respiratory gas heated by the heating wire may be provided inside the suction tube (110).

[0053] The above heating wire (h) may pass through the interior of the suction tube (110), the interior of the branch section (120), and the interior of the discharge tube (130), as illustrated in Fig. 4. At this time, the heating wire (h) may be configured as a pair and may be provided in a spirally wound state inside the suction tube (110) or the discharge tube (130).

[0054] One longitudinal end of the heating wire (h) may be connected to a connection terminal (163) provided inside a connection portion (160) to be described later, as illustrated in FIG. 4. In addition, the other longitudinal end of the heating wire (h) may be arranged at the other longitudinal end of the discharge tube (130) sequentially via the suction tube (110), the branch portion (120), and the discharge tube (130). At this time, the other longitudinal end of the heating wire (h) may be connected to a fixture (131) built into the other longitudinal end of the discharge tube (130).

[0055] The heating wire (h) can be wound in a spiral shape so as to be biased toward the inner surface of the suction tube (110) or the inner surface of the discharge tube (130) so as not to interfere with the flow of respiratory gas.

[0056] The respiratory gas sequentially delivered to the patient through the water chamber (310), the suction tube (110), and the branch section (120) can be heated by the heating wire (h) provided inside the suction tube (110) to form a temperature at which the patient can easily breathe. For example, the respiratory gas can be delivered to the patient while being heated by the heating wire (h) to form a temperature of 37°C or higher and 40°C or lower.

[0057] In addition, the gas discharged from the patient after the patient's breathing can be delivered to the artificial respirator (1) while being heated by the heating wire (h) provided inside the branch section (120) and inside the discharge tube (130).

[0058] The heating wire (h) provided inside the branch part (120) and inside the discharge tube (130) not only prevents the gas discharged from the patient from condensing inside the discharge tube (130), but also prevents the temperature of the respiratory gas passing through the internal space of the branch part (120) from dropping. That is, the heating wire (h) provided inside the branch part (120) can prevent the temperature of the respiratory gas, which is primarily heated inside the suction tube (110), from dropping due to the internal temperature of the branch part (120) when it reaches the branch part (120). In addition, the heating wire (h) provided inside the discharge tube (130) serves to keep the internal temperature of the branch part (120) constant.

[0059] The branch section (120) may include, as shown in FIGS. 2 to 4 and 6, a main tube (121) that is communicatively connected to a respiratory mask worn by a patient; a first guide tube (122) that branches off from the main tube (121) and is communicatively connected to the other longitudinal end of the suction tube (110); and a second guide tube (123) that branches off from the main tube (121) and is communicatively connected to one longitudinal end of the discharge tube (130).

[0060] The main tube (121) forms a space through which respiratory gas delivered to the patient or gas discharged from the patient passes.

[0061] The first guide tube (122) serves to deliver respiratory gas through the suction tube (110) to the main tube (121).

[0062] The second guide tube (123) serves to deliver the patient's exhaust gas through the main tube (121) to the exhaust tube (130).

[0063] Meanwhile, as shown in FIGS. 4 to 7, the first guide tube (122) and the second guide tube (123) of the branch section (120) can be connected to the suction tube (110) or the discharge tube (130) via a hollow connecting portion (124, 124').

[0064] The above connecting portion (124, 124') may include an insertion tube (124a, 124a') that is inserted into the longitudinal other end of the suction tube (110) or the longitudinal one end of the discharge tube (130); and a receiving tube (124b, 124b') that is connected so as to be communicatively connected to the insertion tube (124a, 124a') and has an outer diameter and an inner diameter that are larger than the outer diameter and inner diameter of the insertion tube (124a, 124a').

[0065] The outer diameter of the insertion tube (124a, 124a') can be said to be smaller than the inner diameter of the other longitudinal end of the suction tube (110) or the inner diameter of one longitudinal end of the discharge tube (130).

[0066] When the inner diameter of the other longitudinal end of the suction tube (110) or one longitudinal end of the discharge tube (130) is inserted into the insertion tube (124a, 124a'), the other longitudinal end of the suction tube (110) or one longitudinal end of the discharge tube (130) can come into contact with the step surface (d1) formed at the connection point between the insertion tube (124a, 124a') and the receiving tube (124b, 124b').

[0067] The inner diameter of the above-mentioned receiving tube (124b, 124b') can be said to be naturally larger than the outer diameter of the first guide tube (122) or the outer diameter of the second guide tube (123).

[0068] Accordingly, the first guide tube (122) or the second guide tube (123) can be inserted into the interior of the receiving tube (124b, 124b).

[0069] Here, the length of the first guide tube (122) or the second guide tube (123) inserted into the interior of the receiving tube (124b, 124b') can be said to be shorter than the length of the receiving tube (124b, 124b').

[0070] Meanwhile, inside the receiving tube (124b) connected to the first guide tube (122), the sensor unit (140) and the fixing unit (150) supporting the sensor unit (140) may be arranged.

[0071] The above sensor unit (140) can be said to be a component that measures the temperature and humidity of the respiratory gas passing through the longitudinal other end of the suction tube (110).

[0072] The sensor unit (140) is preferably positioned in a section before the respiratory gas passing through the suction tube (110) is delivered to the patient, so as to accurately measure the temperature and humidity of the respiratory gas. Accordingly, it is preferably positioned inside the receiving tube (124b), which is a section before the respiratory gas is delivered to the patient's mouth through the entire length of the suction tube (110), so as to measure the temperature and humidity of the respiratory gas.

[0073] If the sensor unit (140) is placed inside the suction tube (110), there is a risk that the sensor unit (140) may be damaged during the process of expanding and contracting the suction tube (110), and there is also a problem of not being able to accurately measure temperature / humidity changes that occur during the process of respiratory gas flowing along the length of the suction tube (110).

[0074] The temperature and humidity of the respiratory gas measured by the sensor unit (140), or the internal temperature and humidity of the suction tube (110), can be displayed on the display of the main body (200) and transmitted to the user.

[0075] For reference, the sensor unit (140) for measuring the temperature and humidity of the fluid is a configuration that can be easily selected by a person skilled in the art, so in the specification of the present invention, a detailed description of the configuration of the sensor unit (140) is omitted so as not to obscure the gist of the invention.

[0076] The above-mentioned fixed part (150), as shown in FIGS. 5 to 7, can be placed in a space (S3) between one longitudinal end of the first guide tube (122) inserted into the receiving tube (124b) and a step surface (d2) formed at the connection point between the insertion tube (124a) and the receiving tube (124b).

[0077] The above fixed part (150) supports the sensor part (140) that measures the temperature and humidity of the respiratory gas so that it does not come into contact with the inner surface of the receiving tube (124b), and further guides the power line connected to the sensor part (140) so that it does not interfere with the flow of the respiratory gas.

[0078] The above-mentioned fixed member (150) may include a pair of curvature members (151) that are arranged at a predetermined interval from each other inside the receiving tube (124b) and form a curvature corresponding to the inner curvature of the receiving tube (124b); a connecting member (152) that connects one longitudinal end of the pair of curvature members (151) to each other; and a fastening member (123) that is arranged at a distance from the connecting member (152) and connects the other longitudinal end of the pair of curvature members (151) to each other.

[0079] A pair of curvature members (151) are arranged in the space between one longitudinal end of the first guide tube (122) and the step surface (d2) formed in the receiving tube (124b), and can be in contact with the inner surface of the receiving tube (124b).

[0080] Accordingly, one end of the width direction of the curvature member (151) can be fixedly placed inside the receiving tube (124b) by being pressed against one end of the length direction of the first guide tube (122).

[0081] For reference, the curvature member (151) is first inserted into the interior of the receiving tube (124b) before the first guide tube (122) is inserted into the interior of the receiving tube (124b), so that the other end in the width direction can come into contact with the step surface (d2).

[0082] The above connecting member (152) can be said to be a component that does not come into contact with the inner surface of the receiving tube (124b) when the curvature member (151) comes into contact with the inner surface of the receiving tube (124b).

[0083] The connecting member (152) can be said to be a part that is gripped by the user when there is a need to separate the fixed part (150) from the inside of the receiving tube (124b).

[0084]

[0085] Therefore, it is preferable that the connecting member (152) be formed in a form that does not contact the inner surface of the receiving tube (124b) so that it can be easily gripped by the user's hand or a separate gripping tool, as shown in FIG. 7, and that a pair of curved members (151) are connected to each other.

[0086] The fastening member (153) can be said to be a component that defines a space in which the sensor unit (140) can be installed.

[0087] The fastening member (153) may include a pair of vertical members (153a) that extend from the longitudinal end of the curved member (151) in the direction in which the connecting member (152) is arranged; a horizontal member (153b) that connects the pair of vertical members (153a) to each other and defines a 'ㄷ' shaped groove in which the sensor unit (140) can be seated by cooperating with the pair of vertical members (153a); and a hook (153c) that protrudes from the vertical member (153a) and prevents the sensor unit (140) seated in the groove from being detached.

[0088] The fastening member (153) configured as described above can form a 'ㄷ' shaped groove in which the sensor unit (140) can be installed, as described above.

[0089] Accordingly, the sensor part (140) can be placed inside the receiving tube (124b) while being supported by the fixing part (140) by being seated in the groove formed by the fastening member (153).

[0090] The fixed part (150) configured as described above allows the sensor part (140) to be stably positioned inside the receiving tube (124b) without movement due to external force, and when necessary, allows the sensor part (140) to be easily taken out inside the receiving tube (124b), thereby providing convenience for replacement or repair.

[0091] Meanwhile, as shown in FIGS. 1 and 2 to 4, a connecting portion (160) may be provided at one longitudinal end of the suction tube (110).

[0092] The above connection part (160) can be said to be a configuration that guides the respiratory gas discharged from the respiratory gas discharge port (312) of the water chamber (310) to the suction tube (110) and, in addition, transmits power to the heating wire (h) and the sensor part (140).

[0093] Accordingly, the connecting portion (160) may include a connecting tube (161) that is communicatively connected to the respiratory gas discharge port (312) of the water chamber (310); a terminal receiving tube (162) that is communicatively connected to the connecting tube (161) and the suction tube (110); and a connecting terminal (163) that is provided inside the terminal receiving tube (162) and is electrically connected to the heating wire (h) and the sensor unit (140).

[0094] The connecting tube (161) serves to guide the respiratory gas passing through the water chamber (310) to the suction tube (110) while being connected to one end of the longitudinal direction of the suction tube (110).

[0095] The terminal receiving tube (162) provides a space in which a connection terminal (163) that is electrically connected to a power plug (20, see Fig. 1) can be received while being integrally connected to the connection tube (161). Accordingly, when the power plug (20, see Fig. 1) is connected to the connection terminal (163), power can be transmitted to the heating wire (h) and the sensor unit (140).

[0096] The connecting portion (160) configured as described above has a configuration in which it is directly connected to the power line of the heating wire (h) and the sensor unit (140) passing through the interior of the suction tube (110) while being communicatively connected to the interior of the suction tube (110), thereby enabling the omission of a separate power line for transmitting power to the heating wire (h) and the sensor unit (140), and further simplifying the configuration of the respiratory gas circulation system (100), thereby increasing the user's convenience of use.

[0097] Although specific embodiments of the present invention have been described so far, it is obvious that various modifications are possible within the scope of the present invention.

[0098] Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the claims described below, but also by equivalents of the claims.

[0099] The present invention can be sold and used in the medical device industry.

Claims

1. A respiratory gas circulation system that is connected to the water chamber of a respiratory assistance device and provides heated / humidified respiratory gas to the patient. A suction tube having one end longitudinally connected to the water chamber and delivering heated / humidified respiratory gas to the patient; A branch portion that is communicatively connected to the longitudinal end of the above suction tube and is communicatively connected to a breathing mask worn by a patient; and A respiratory gas circulation system of a respiratory assistance device, characterized in that it includes an exhaust tube, one longitudinal end of which is connected to the branch section in a communicable manner, and the other longitudinal end of which is connected to a respirator to guide gas generated after a patient's breathing to the respirator.

2. In paragraph 1, A respiratory gas circulation system of a respiratory assistance device, characterized in that it further includes a heating wire for heating the respiratory gas and a sensor unit for detecting the temperature and humidity of the respiratory gas.

3. In paragraph 2, A respiratory gas circulation system of a respiratory assistance device, characterized in that the heating wire is wound in a spiral shape and provided inside the suction tube or the discharge tube.

4. In paragraph 3, A respiratory gas circulation system of a respiratory assistance device, characterized in that the above heating wire sequentially passes through the suction tube, the branch section, and the discharge tube.

5. In paragraph 4, The above branch is, A main pipe that is connected to the above breathing mask; A first guide pipe branching from the main pipe and being connected to the longitudinal end of the suction tube in a communicable manner; and A respiratory gas circulation system of a respiratory assistance device, characterized in that it includes a second guide tube branched from the main tube and connected in a manner that it can communicate with one end of the longitudinal direction of the discharge tube.

6. In paragraph 5, It further includes a connecting portion that connects the longitudinal end of the suction tube and the first guide tube so that they can be communicated with each other; A respiratory gas circulation system of a respiratory assistance device, characterized in that the sensor part and the fixing part supporting the sensor part are arranged inside the above connecting part.

7. In paragraph 6, The above connection part is, An insertion tube inserted into the longitudinal end of the above suction tube; and A receiving tube that is connected to the insertion tube in a communicable manner and has an outer diameter and an inner diameter larger than the outer diameter and inner diameter of the insertion tube; A respiratory gas circulation system of a respiratory assistance device, characterized in that the first guide tube is inserted into the above-mentioned receiving tube.

8. In paragraph 7, A respiratory gas circulation system of a respiratory assistance device, characterized in that the length of the first guide tube inserted into the receiving tube is shorter than the length of the receiving tube.

9. In paragraph 8, The above fixed part, A respiratory gas circulation system of a respiratory assistance device characterized in that it is seated in the space between the longitudinal end of the first guide tube inserted into the above-mentioned receiving tube and the step surface formed at the connection point of the insertion tube and the receiving tube.

10. In paragraph 9, The above fixed part, A pair of curvature members arranged at a predetermined interval from each other inside the above-mentioned receiving tube and forming a curvature corresponding to the inner curvature of the above-mentioned receiving tube; A connecting member connecting one longitudinal end of the above pair of curved members; and A fastening member is disposed spaced apart from the above connecting member and connects the longitudinal ends of the pair of curved members to each other; A respiratory gas circulation system of a respiratory assistance device, characterized in that the sensor part is detachably connected to the fastening member.

11. In paragraph 10, A respiratory gas circulation system of a respiratory assistance device, characterized in that the above-mentioned curvature member is in contact with the inner surface of the above-mentioned receiving tube.

12. In paragraph 11, The above fastening member is, A pair of vertical members formed to extend in the direction in which the connecting member is arranged from the longitudinal end of the above-mentioned curved member; A horizontal member that connects the pair of vertical members to each other and defines a 'ㄷ' shaped groove in which the sensor unit can be installed in cooperation with the pair of vertical members; and A respiratory gas circulation system of a respiratory assistance device, characterized in that it includes a hook that protrudes from the vertical member and prevents the sensor part from being dislodged from the groove.

13. In paragraph 2, A respiratory gas circulation system of a respiratory assistance device, characterized in that it includes a connecting portion that connects one longitudinal end of the suction tube and the outlet of the water chamber so as to be communicatively connected to each other and is connected to a power cable to supply power to the heating wire and the sensor portion.

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