Control system for mixing of carbon dioxide, nitrogen and oxygen

Abstract

The invention relates to the technical field of breathing machines, in particular to a carbon dioxide, nitrogen and oxygen mixing control system which comprises a nitrogen gas path, an oxygen gas path, a carbon dioxide gas path, a mixing cavity, a breathing valve and a controller. The nitrogen gas path, the oxygen gas path and the carbon dioxide gas path are arranged in parallel and communicate with the mixing cavity, and the mixing cavity communicates with the breathing valve; a flow sensor is arranged between the mixing cavity and the breather valve, a fourth pressure sensor is connected between the flow sensor and the mixing cavity in parallel, and a gas concentration sensor is connected between the flow sensor and the breather valve in parallel. The controller is in control connection with the nitrogen gas path, the oxygen gas path, the carbon dioxide gas path, the fourth pressure sensor, the flow sensor and the gas concentration sensor. According to the invention, accurate control of the gas proportion is realized, and accurate regulation and control of the gas proportion can be carried out according to the requirements of a patient.

Description

Technical Field

[0001] The present invention relates to the technical field of ventilators, and in particular to a control system for mixing three gases of carbon dioxide, nitrogen and oxygen. Background Art

[0002] Cerebrovascular reactivity (CVR) refers to the ability of cerebral blood vessels to contract and relax when encountering stimulation (such as changes in cerebral perfusion pressure and arterial CO2 partial pressure levels), which can reflect the reserve capacity of cerebral blood vessels. The property of cerebral blood vessels changing with the level of arterial CO2 partial pressure (PaCO2) is called cerebral vascular carbon dioxide reactivity (CVR-CO2). By detecting CVR-CO2, the regulatory ability of cerebral blood vessels and the state of collateral circulation can be evaluated, which is of great significance for the early diagnosis, treatment and prognosis evaluation of many diseases (stroke, cognitive dysfunction, etc.).

[0003] Nitrogen and oxygen are the main gases when the human body breathes. If the concentration of carbon dioxide is to be controlled, a mixing device for these three gases is required. Currently, there is no device on the market that mixes carbon dioxide, nitrogen, and oxygen and controls the concentration of the three gases. Currently, the most similar gas mixing equipment, such as ventilators, mixes air and oxygen, and also does not have the ability to control the mixing of the three gases. Therefore, it is very valuable to invent a control and breathing device for the mixing of the three gases to achieve the control of different concentrations of the three gases, thereby achieving different cerebrovascular carbon dioxide reactivity (CVR-CO2). Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the related art. To this end, the present invention provides a control system for mixing carbon dioxide, nitrogen and oxygen, which solves the technical problem that traditional ventilators do not have the mixing control of carbon dioxide, nitrogen and oxygen, and realizes the precise control of carbon dioxide, nitrogen and oxygen, and can accurately adjust the gas ratio according to the patient's needs.

[0005] The present invention provides a control system for mixing three gases of carbon dioxide, nitrogen and oxygen, comprising a nitrogen gas circuit, an oxygen gas circuit, a carbon dioxide gas circuit, a mixing chamber, a breathing valve and a controller, wherein the nitrogen gas circuit, the oxygen gas circuit and the carbon dioxide gas circuit are arranged in parallel and are connected to the mixing chamber, the mixing chamber is connected to the breathing valve, a flow sensor is arranged between the mixing chamber and the breathing valve, a fourth pressure sensor is connected in parallel between the flow sensor and the mixing chamber, a gas concentration sensor is connected in parallel between the flow sensor and the breathing valve, the breathing valve is used to access a patient end, and the controller is controlled to be connected to the nitrogen gas circuit, the oxygen gas circuit, the carbon dioxide gas circuit, the fourth pressure sensor, the flow sensor and the gas concentration sensor; The controller stores control logic , in, Indicates the total flow rate of the mixed gas, represents the gas flow rate of carbon dioxide, Indicates the proportion of carbon dioxide in the mixed gas. represents the gas flow rate of oxygen, Indicates the proportion of oxygen in the mixed gas. represents the gas flow rate of nitrogen, Indicates the proportion of nitrogen in the mixed gas; By setting the total flow rate of the mixed gas, the proportion of carbon dioxide in the mixed gas, and the proportion of oxygen in the mixed gas in the controller according to the patient's needs, the controller can then obtain the proportion of nitrogen in the mixed gas. The controller can then obtain the gas flow rates of nitrogen, oxygen, and carbon dioxide and correspondingly adjust the nitrogen gas circuit, oxygen gas circuit, and carbon dioxide gas circuit to supply gas to the patient.

[0006] A further improvement of the control system for the mixture of carbon dioxide, nitrogen and oxygen of the present invention is that the nitrogen gas circuit includes a nitrogen inlet, a nitrogen filter, a nitrogen pressure reducing valve, a nitrogen proportional valve, a nitrogen flow normalizer and a nitrogen differential pressure flow sensor connected in sequence, the second end of the nitrogen differential pressure flow sensor is connected to the mixing chamber, the nitrogen gas circuit also includes a nitrogen safety valve, the first end of the nitrogen safety valve is formed with a nitrogen exhaust port and the second end is connected between the nitrogen filter and the nitrogen pressure reducing valve.

[0007] A further improvement of the control system for the mixture of carbon dioxide, nitrogen and oxygen of the present invention is that the nitrogen gas circuit also includes a nitrogen pressure sensor connected between the nitrogen filter and the nitrogen pressure reducing valve, and the nitrogen pressure sensor is connected to the controller.

[0008] A further improvement of the control system for the mixture of carbon dioxide, nitrogen and oxygen of the present invention is that the oxygen gas circuit includes an oxygen inlet, an oxygen filter, an oxygen pressure reducing valve, an oxygen proportional valve, an oxygen flow normalizer and an oxygen pressure differential flow sensor connected in sequence, the second end of the oxygen pressure differential flow sensor is connected to the mixing chamber, the oxygen gas circuit also includes an oxygen safety valve, the first end of the oxygen safety valve is formed with an oxygen exhaust port and the second end is connected between the oxygen filter and the oxygen pressure reducing valve.

[0009] A further improvement of the control system for the mixture of carbon dioxide, nitrogen and oxygen of the present invention is that the oxygen gas circuit also includes an oxygen pressure sensor connected between the oxygen filter and the oxygen pressure reducing valve, and the oxygen pressure sensor is connected to the controller.

[0010] A further improvement of the control system for the mixture of carbon dioxide, nitrogen and oxygen of the present invention is that the carbon dioxide gas circuit includes a carbon dioxide inlet, a carbon dioxide filter, a carbon dioxide pressure reducing valve, a carbon dioxide proportional valve, a carbon dioxide flow normalizer and a carbon dioxide differential pressure flow sensor connected in sequence, the second end of the carbon dioxide differential pressure flow sensor is connected to the mixing chamber, and the carbon dioxide gas circuit also includes a carbon dioxide safety valve, a first end of the carbon dioxide safety valve is formed with a carbon dioxide exhaust port and the second end is connected between the carbon dioxide filter and the carbon dioxide pressure reducing valve.

[0011] A further improvement of the control system of the mixture of carbon dioxide, nitrogen and oxygen of the present invention is that the carbon dioxide gas circuit also includes a carbon dioxide pressure sensor connected between the carbon dioxide filter and the carbon dioxide pressure reducing valve, and the carbon dioxide pressure sensor is connected to the controller.

[0012] A further improvement of the control system for mixing carbon dioxide, nitrogen and oxygen in the present invention is that the mixing chamber is a serpentine airway or has an airflow baffle structure inside to disperse and mix the airflow.

[0013] A further improvement of the control system for the mixture of carbon dioxide, nitrogen and oxygen of the present invention is that it also includes a gas storage structure arranged on the breathing valve.

[0014] A further improvement of the control system for the mixture of carbon dioxide, nitrogen and oxygen of the present invention is that the gas storage structure is a gas storage bag; The breathing valve includes an H-shaped tube connected to the air storage bag and a U-shaped tube connected to the H-shaped tube, the H-shaped tube includes a first tube portion corresponding to the air storage bag, a second tube portion parallel to the first tube portion, and a third tube portion located between the first tube portion and the second tube portion, and the U-shaped tube is connected to the first tube portion and the second tube portion; The U-shaped tube is provided with an air port for the patient to inhale and exhale, and a first one-way valve is provided between the U-shaped tube and the second tube portion; The first tube portion is provided with an air inlet, and the air inlet is connected to the flow sensor; The first pipe portion is also connected to a pressure relief valve; A second one-way valve is provided between the first pipe portion and the U-shaped pipe; The third pipe portion is provided with a third one-way valve.

[0015] The control system for the mixture of carbon dioxide, nitrogen and oxygen of the present invention can configure gases in corresponding proportions according to patient needs by setting up nitrogen gas circuits, oxygen gas circuits and carbon dioxide gas circuits, and obtains data detected by pressure sensors, differential pressure flow sensors and flow sensors through controllers, thereby accurately adjusting the valve opening of the proportional valve, thereby regulating the ratio of gases and improving the accuracy of gas supply to patients by the ventilator.

[0016] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a structural schematic diagram of a control system for mixing three gases of carbon dioxide, nitrogen and oxygen provided by the present invention.

[0019] Figure 2 It is a schematic diagram of the gas storage structure in the control system for the mixture of carbon dioxide, nitrogen and oxygen provided by the present invention.

[0020] Figure 3 It is a structural schematic diagram of a breathing valve and a patient end in a control system for a mixture of carbon dioxide, nitrogen and oxygen provided by the present invention.

[0021] Figure 4 It is a structural schematic diagram of the breathing valve in the control system for mixing carbon dioxide, nitrogen and oxygen provided by the present invention.

[0022] Reference numerals: 11. Nitrogen filter; 12. Nitrogen safety valve; 13. Nitrogen pressure reducing valve; 14. Nitrogen proportional valve; 15. Nitrogen flow normalizer; 16. Nitrogen differential pressure flow sensor; 101. First solenoid valve; 102. Second solenoid valve; 21. Oxygen filter; 22. Oxygen safety valve; 23. Oxygen pressure reducing valve; 24. Oxygen proportional valve; 25. Oxygen flow normalizer; 26. Oxygen differential pressure flow sensor; 31. Carbon dioxide filter; 32. Carbon dioxide safety valve; 33. Carbon dioxide pressure reducing valve; 34. Carbon dioxide proportional valve; 35. Carbon dioxide flow normalizer; 36. Carbon dioxide differential pressure flow sensor; 41. Mixing chamber; 42. Exhaust safety valve; 43. Flow sensor; 51. breathing valve; 52. patient end; 61. Nitrogen pressure sensor; 62. Oxygen pressure sensor; 63. Carbon dioxide pressure sensor; 64. Fourth pressure sensor; 7. Controller; 8. Gas concentration sensor; 91. Air storage bag; 92. Pressure relief valve; 93. Air inlet; 94. Second one-way valve; 95. Third one-way valve; 96. First one-way valve; 97. Air port. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. The following embodiments are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0024] Combine the following Figure 1 A control system for mixing three gases of carbon dioxide, nitrogen and oxygen is described in the present invention, comprising a nitrogen gas circuit, an oxygen gas circuit, a carbon dioxide gas circuit, a mixing chamber 41, a breathing valve 51 and a controller, wherein the nitrogen gas circuit, the oxygen gas circuit and the carbon dioxide gas circuit are arranged in parallel and are connected to the mixing chamber 41, the mixing chamber 41 is connected to the breathing valve 51, a flow sensor 43 is arranged between the mixing chamber 41 and the breathing valve 51, a fourth pressure sensor 64 is connected in parallel between the flow sensor 43 and the mixing chamber 41, a gas concentration sensor 8 is connected in parallel between the flow sensor 43 and the breathing valve 51, the breathing valve 51 is used to access the patient end, and a controller 7 is connected to the nitrogen gas circuit, the oxygen gas circuit, the carbon dioxide gas circuit, the fourth pressure sensor 64, the flow sensor 43 and the gas concentration sensor 8; The controller stores control logic , in, Indicates the total flow rate of the mixed gas (in L / min), Indicates the gas flow rate of carbon dioxide (in L / min), Indicates the proportion of carbon dioxide in the mixed gas. Indicates the gas flow rate of oxygen (in L / min), Indicates the proportion of oxygen in the mixed gas. Indicates the gas flow rate of nitrogen (in L / min), Indicates the proportion of nitrogen in the mixed gas; By setting the total flow rate of the mixed gas, the proportion of carbon dioxide in the mixed gas, and the proportion of oxygen in the mixed gas in the controller according to the patient's needs, the controller can then obtain the proportion of nitrogen in the mixed gas. The controller can then obtain the gas flow rates of nitrogen, oxygen, and carbon dioxide and correspondingly adjust the nitrogen gas circuit, oxygen gas circuit, and carbon dioxide gas circuit to supply gas to the patient.

[0025] In a preferred implementation case of the control system for the mixture of carbon dioxide, nitrogen and oxygen of the present invention, the nitrogen gas circuit includes a nitrogen inlet, a nitrogen filter 11, a nitrogen pressure reducing valve 13, a nitrogen proportional valve 14, a nitrogen flow normalizer 15 and a nitrogen pressure differential flow sensor 16 connected in sequence, the second end of the nitrogen pressure differential flow sensor 16 is connected to the mixing chamber 41, and the nitrogen gas circuit also includes a nitrogen safety valve 12, the first end of the nitrogen safety valve 12 is formed with a nitrogen exhaust port and the second end is connected between the nitrogen filter 11 and the nitrogen pressure reducing valve 13.

[0026] Specifically, the nitrogen gas circuit also includes a nitrogen pressure sensor 61 connected between the nitrogen filter 11 and the nitrogen pressure reducing valve 13. The nitrogen pressure sensor 61 is connected to the controller 7. The controller 7 identifies the data of the nitrogen pressure sensor 61 to adjust the valve opening of the nitrogen proportional valve 14 to avoid a malfunction caused by excessive nitrogen gas circuit pressure.

[0027] Furthermore, the oxygen gas circuit includes an oxygen inlet, an oxygen filter 21, an oxygen pressure reducing valve 23, an oxygen proportional valve 24, an oxygen flow normalizer 25 and an oxygen differential pressure flow sensor 26 which are connected in sequence. The second end of the oxygen differential pressure flow sensor 26 is connected to the mixing chamber 41. The oxygen gas circuit also includes an oxygen safety valve 22. The first end of the oxygen safety valve 22 is formed with an oxygen exhaust port and the second end is connected between the oxygen filter 21 and the oxygen pressure reducing valve 23.

[0028] Specifically, the oxygen gas circuit also includes an oxygen pressure sensor 62 connected between the oxygen filter 21 and the oxygen pressure reducing valve 23. The oxygen pressure sensor 62 is connected to the controller 7. The controller 7 identifies the data of the oxygen pressure sensor 62 to adjust the valve opening of the oxygen proportional valve 24 to avoid malfunction caused by excessive pressure in the oxygen gas circuit.

[0029] Furthermore, the carbon dioxide gas circuit includes a carbon dioxide inlet, a carbon dioxide filter 31, a carbon dioxide pressure reducing valve 33, a carbon dioxide proportional valve 34, a carbon dioxide flow normalizer 35 and a carbon dioxide differential pressure flow sensor 36 connected in sequence, the second end of the carbon dioxide differential pressure flow sensor 36 is connected to the mixing chamber 41, and the carbon dioxide gas circuit also includes a carbon dioxide safety valve 32, the first end of the carbon dioxide safety valve 32 is formed with a carbon dioxide exhaust port and the second end is connected between the carbon dioxide filter 31 and the carbon dioxide pressure reducing valve 33.

[0030] Specifically, the carbon dioxide gas circuit also includes a carbon dioxide pressure sensor 63 connected between the carbon dioxide filter 31 and the carbon dioxide pressure reducing valve 33. The carbon dioxide pressure sensor 63 is connected to the controller 7. The controller 7 identifies the data of the carbon dioxide pressure sensor 63 to adjust the valve opening of the carbon dioxide proportional valve 34 to avoid malfunction caused by excessive pressure in the carbon dioxide gas circuit.

[0031] Furthermore, the interior of the mixing chamber 41 is a serpentine airway or an air flow baffle structure to disperse and mix the airflow. The mixing chamber 41 is also connected to an exhaust safety valve 42. When the gas pressure in the mixing chamber 41 is too high, the exhaust safety valve 42 can be opened to reduce the pressure in the mixing chamber 41.

[0032] Furthermore, it also includes an air storage structure arranged on the breathing valve 51.

[0033] Specifically, Figure 2 As shown, the gas storage structure is an air storage bag 91; The breathing valve 51 includes an H-shaped tube connected to the air storage bag 91 and a U-shaped tube connected to the H-shaped tube. The H-shaped tube includes a first tube portion corresponding to the air storage bag 91, a second tube portion parallel to the first tube portion, and a third tube portion located between the first tube portion and the second tube portion. The U-shaped tube is connected to the first tube portion and the second tube portion. The U-shaped tube is provided with an air port 97 for the patient to inhale and exhale, and a first one-way valve 96 is arranged between the U-shaped tube and the second tube portion; the first tube portion is provided with an air inlet 93, and the air inlet 93 is connected to the flow sensor 43; the first tube portion is also connected to a pressure relief valve 92; a second one-way valve 94 is arranged between the first tube portion and the U-shaped tube; and a third one-way valve 95 is arranged on the third tube portion.

[0034] Specifically, when the patient needs to inhale, he inhales from the air inlet 93, and when he exhales, he exhausts air into the atmosphere normally. When the patient inhales, the second one-way valve 94 opens, while the first one-way valve 96 closes, and the patient inhales; when the patient exhales, the first one-way valve 96 opens, while the second one-way valve 94 closes, and the patient exhales. The on-off of the first one-way valve 96 and the second one-way valve 94 serves as a switch for the patient's inhalation and exhalation airways, which responds quickly and reduces the patient's breathing resistance, thereby improving the patient's comfort.

[0035] Specifically, the gas storage structure has a protective function, mainly providing emergency inhalation. During the patient's normal inhalation process, part of the gas is stored in the gas storage bag 91. The gas storage bag 91 can be a flexible elastic deformation structure, such as a balloon, a sac, etc., or it can be non-deformable, such as a gas tank. When the gas in the gas storage bag 91 reaches a certain pressure, the gas is discharged from the pressure relief valve 92 to maintain the constant pressure in the gas storage bag 91. At the same time, the concentration of the gas in the gas storage bag 91 also changes with the change of the gas supply concentration. When the normal gas supply is cut off, the patient generates negative pressure by inhaling, thereby opening the second one-way valve 94 to inhale from the gas storage bag 91, and when the gas in the gas storage bag 91 is consumed, the negative pressure will then open the third one-way valve 95, and after the patient exhales to generate positive pressure, the first one-way valve 96 will be opened to exhaust, thereby ensuring the patient's normal breathing.

[0036] In another specific implementation case, Figure 3 As shown, the breathing valve 51 is configured as an open air path structure, which includes a T-shaped tube, a U-shaped tube and a tail tube. The first end of the T-shaped tube forms an air inlet, the second end forms an exhaust port, and the third end is connected to the first end of the U-shaped tube. The tail tube is connected to the second end of the U-shaped tube. The U-shaped tube has an air port 97 for the patient to inhale and exhale. The patient end 52 is connected to the air port 97. The first one-way valve 96 is arranged between the U-shaped tube and the tail tube, and the second one-way valve 94 is arranged between the third end of the T-shaped tube and the U-shaped tube.

[0037] In another specific implementation case, Figure 4 As shown, a first solenoid valve 101 and a second solenoid valve 102 are arranged in the breathing valve, a first end of the first solenoid valve is connected to the air path between the air inlet and the mixing chamber, a second end is connected to the patient end and a third end is connected to the controller 7, a first end of the second solenoid valve 102 is connected to the connecting pipeline between the first solenoid valve and the patient end, a second end forms an exhalation end and a third end is connected to the controller 7, a fourth pressure sensor 64, a flow sensor 43 and a gas concentration sensor 8 are arranged in parallel, one end of the fourth pressure sensor 64 is connected between the first solenoid valve and the patient end and the other end is connected to the controller 7. One end is connected to the controller 7, and the gas in the mixing chamber enters the first solenoid valve 101 or the gas storage structure through the inhalation end. The left side of the gas storage structure is connected to the pressure relief valve, and the left end of the pressure relief valve is connected to the atmosphere. A fourth one-way valve is arranged on the line between the gas storage structure and the patient end, and a fifth one-way valve is connected in parallel to the line connecting the gas storage structure and the patient end. A sixth one-way valve is arranged between the gas storage structure and the first solenoid valve. The valve opening of the first solenoid valve and the second solenoid valve can be adjusted by the controller 7, and the patient end 52 can realize inhalation from two positions of the first solenoid valve and the gas storage structure.

[0038] Specifically, taking the oxygen gas circuit as an example, the oxygen entering the gas circuit is filtered through the oxygen filter 21 to remove impurities in the oxygen, and then the oxygen safety valve 22 detects whether the gas pressure is too high, too low or moderate, so as to determine whether to alarm through the controller 7. When the pressure is too high, the oxygen safety valve 22 releases the pressure so that the oxygen gas circuit reaches a suitable pressure without causing harm to the human body, thereby playing a role in safety protection; the pressure is reduced to a constant value and suitable for the pressure required by the subsequent components through the oxygen pressure reducing valve 23. The oxygen proportional valve 24 adjusts the valve opening to regulate the gas flow of the oxygen gas circuit. The oxygen flow regularizer stabilizes the flow before the gas enters the oxygen pressure differential flow sensor 26, so that the flow measured data is accurate. When the oxygen pressure differential flow sensor 26 detects that the actual flow rate deviates from the set flow rate, it is fed back to the oxygen proportional valve 24 in real time for correction and adjustment, thereby ensuring the accuracy of the output. The control principle of each component in the nitrogen gas circuit and the carbon dioxide gas circuit is the same as the control principle of each component in the oxygen gas circuit, which will not be repeated here.

[0039] Specifically, since the carbon dioxide flow rate required for the carbon dioxide gas circuit is very small, the carbon dioxide proportional valve 34 is a micro-flow throttle valve. For example, when testing a tidal volume of 300 mL, calculated based on the maximum carbon dioxide concentration of 4%, the gas volume required for a single inhalation is only 12 mL, and the inhalation time is 1 s, then the carbon dioxide flow rate is 12 mL / s. This flow rate is very small, and precise regulation can be achieved using a micro-flow throttle valve with an accuracy of up to ±0.3%.

[0040] Specifically, in order to control the accuracy of feedback and the economy of cost, the gas flow in the carbon dioxide gas circuit is relatively small. Therefore, the air resistance at the air inlet position of the carbon dioxide differential pressure flow sensor 36 is set to an adjustable structure. The adjustable structure can be a filter with different mesh sizes, or a structural part with adjustable air resistance size. In this way, the measuring range of the carbon dioxide differential pressure flow sensor 36 can be controlled within a smaller range, thereby ensuring the accuracy of the measurement.

[0041] Preferably, the air resistance setting of the air intake position of the nitrogen differential pressure flow sensor 16 and the oxygen differential pressure flow sensor 26 can also be set as an adjustable structure.

[0042] In a specific implementation case, the user sets the total flow rate of the mixed gas, the proportion of nitrogen in the mixed gas, and the proportion of oxygen in the mixed gas in the controller 7 according to the patient's needs, and then the controller 7 obtains the proportion of carbon dioxide in the mixed gas, and then the controller 7 obtains the gas flow rates of nitrogen, oxygen and carbon dioxide and correspondingly regulates the nitrogen gas circuit, oxygen gas circuit, and carbon dioxide gas circuit to supply gas to the patient, and the patient inhales and exhales through the gas port 97.

[0043] The control system for the mixture of carbon dioxide, nitrogen and oxygen of the present invention can configure gases in corresponding proportions according to patient needs by setting up nitrogen gas circuits, oxygen gas circuits and carbon dioxide gas circuits, and obtains data detected by the pressure sensor, the differential pressure flow sensor 43 and the flow sensor 43 through the controller 7, so as to accurately adjust the valve opening of the proportional valve, thereby regulating the ratio of the gases and improving the accuracy of the ventilator's gas supply to the patient.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control system for a mixture of carbon dioxide, nitrogen and oxygen, characterized in that: It comprises a nitrogen gas circuit, an oxygen gas circuit, a carbon dioxide gas circuit, a mixing chamber, a breathing valve and a controller, wherein the nitrogen gas circuit, the oxygen gas circuit and the carbon dioxide gas circuit are arranged in parallel and are connected to the mixing chamber, the mixing chamber is connected to the breathing valve, a flow sensor is arranged between the mixing chamber and the breathing valve, a fourth pressure sensor is connected in parallel between the flow sensor and the mixing chamber, a gas concentration sensor is connected in parallel between the flow sensor and the breathing valve, the breathing valve is used to access the patient end, and the controller is controlled to be connected to the nitrogen gas circuit, the oxygen gas circuit, the carbon dioxide gas circuit, the fourth pressure sensor, the flow sensor and the gas concentration sensor; The controller stores control logic , in, Indicates the total flow rate of the mixed gas, represents the gas flow rate of carbon dioxide, Indicates the proportion of carbon dioxide in the mixed gas. represents the gas flow rate of oxygen, Indicates the proportion of oxygen in the mixed gas. represents the gas flow rate of nitrogen, Indicates the proportion of nitrogen in the mixed gas; By setting the total flow rate of the mixed gas, the proportion of carbon dioxide in the mixed gas, and the proportion of oxygen in the mixed gas in the controller according to the patient's needs, the controller can then obtain the proportion of nitrogen in the mixed gas. The controller can then obtain the gas flow rates of nitrogen, oxygen, and carbon dioxide and correspondingly adjust the nitrogen gas circuit, oxygen gas circuit, and carbon dioxide gas circuit to supply gas to the patient.

2. The carbon dioxide, nitrogen and oxygen three-gas mixing control system according to claim 1 is characterized in that: The nitrogen gas circuit includes a nitrogen inlet, a nitrogen filter, a nitrogen pressure reducing valve, a nitrogen proportional valve, a nitrogen flow normalizer and a nitrogen differential pressure flow sensor which are connected in sequence. The second end of the nitrogen differential pressure flow sensor is connected to the mixing chamber. The nitrogen gas circuit also includes a nitrogen safety valve. A nitrogen exhaust port is formed at the first end of the nitrogen safety valve and the second end is connected between the nitrogen filter and the nitrogen pressure reducing valve.

3. The control system for the mixture of carbon dioxide, nitrogen and oxygen according to claim 2, characterized in that: The nitrogen gas circuit also includes a nitrogen pressure sensor connected between the nitrogen filter and the nitrogen pressure reducing valve, and the nitrogen pressure sensor is connected to the controller.

4. The carbon dioxide, nitrogen and oxygen three-gas mixing control system according to claim 1, characterized in that: The oxygen gas circuit includes an oxygen inlet, an oxygen filter, an oxygen pressure reducing valve, an oxygen proportional valve, an oxygen flow normalizer and an oxygen differential pressure flow sensor which are connected in sequence. The second end of the oxygen differential pressure flow sensor is connected to the mixing chamber. The oxygen gas circuit also includes an oxygen safety valve. The first end of the oxygen safety valve is formed with an oxygen exhaust port and the second end is connected between the oxygen filter and the oxygen pressure reducing valve.

5. The control system for the mixture of carbon dioxide, nitrogen and oxygen according to claim 4, characterized in that: The oxygen gas circuit further includes an oxygen pressure sensor connected between the oxygen filter and the oxygen pressure reducing valve, and the oxygen pressure sensor is connected to the controller.

6. The carbon dioxide, nitrogen and oxygen three-gas mixing control system according to claim 1, characterized in that: The carbon dioxide gas circuit includes a carbon dioxide inlet, a carbon dioxide filter, a carbon dioxide pressure reducing valve, a carbon dioxide proportional valve, a carbon dioxide flow normalizer and a carbon dioxide differential pressure flow sensor connected in sequence, the second end of the carbon dioxide differential pressure flow sensor is connected to the mixing chamber, and the carbon dioxide gas circuit also includes a carbon dioxide safety valve, the first end of the carbon dioxide safety valve is formed with a carbon dioxide exhaust port and the second end is connected between the carbon dioxide filter and the carbon dioxide pressure reducing valve.

7. The carbon dioxide, nitrogen and oxygen three-gas mixing control system according to claim 6, characterized in that: The carbon dioxide gas circuit further includes a carbon dioxide pressure sensor connected between the carbon dioxide filter and the carbon dioxide pressure reducing valve, and the carbon dioxide pressure sensor is connected to the controller.

8. The carbon dioxide, nitrogen and oxygen three-gas mixing control system according to claim 1, characterized in that: The interior of the mixing chamber is a serpentine airway or an airflow baffle structure to disperse and mix the airflow.

9. The carbon dioxide, nitrogen and oxygen three-gas mixing control system according to claim 1, characterized in that: It also includes a gas storage structure arranged on the breathing valve.

10. The control system for the mixture of carbon dioxide, nitrogen and oxygen according to claim 9, characterized in that: The gas storage structure is an air storage bag; The breathing valve includes an H-shaped tube connected to the air storage bag and a U-shaped tube connected to the H-shaped tube, the H-shaped tube includes a first tube portion corresponding to the air storage bag, a second tube portion parallel to the first tube portion, and a third tube portion located between the first tube portion and the second tube portion, and the U-shaped tube is connected to the first tube portion and the second tube portion; The U-shaped tube is provided with an air port for the patient to inhale and exhale, and a first one-way valve is provided between the U-shaped tube and the second tube portion; The first tube portion is provided with an air inlet, and the air inlet is connected to the flow sensor; The first pipe portion is also connected to a pressure relief valve; A second one-way valve and a pipe flow sensor are provided between the first pipe portion and the U-shaped pipe; The third pipe portion is provided with a third one-way valve.

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