Respiratory system loop gain measurement device

Abstract

The application discloses a kind of respiratory system loop gain measuring equipment, the respiratory system loop gain measuring equipment includes first gas supply unit, second gas supply unit, inhalation pipeline, breathing device and first measuring device.The respiratory system loop gain measuring equipment according to the present application causes the oxygen and carbon dioxide concentration change in the blood of subject by supplying first gas and second gas to the subject respectively, and then adjusts the ventilation volume through the human body chemoreceptor of subject, while measuring the characteristic parameter of exhaled gas of subject by first measuring device, and the respiratory stability of subject can be evaluated according to the change of characteristic parameter of exhaled gas.

Description

Technical Field

[0001] This invention relates to the field of measurement, and in particular to a device for measuring the loop gain of a respiratory system. Background Technology

[0002] In the human respiratory system, changes in the concentration of inhaled oxygen and carbon dioxide lead to changes in the partial pressures of oxygen and carbon dioxide in the blood. Chemoreceptors detect these changes and adjust ventilation accordingly. Changes in ventilation, in turn, affect the concentration of exhaled carbon dioxide. Therefore, the respiratory system can be modeled as a feedback closed-loop control system using control theory principles. The loop gain parameter of this system characterizes the magnitude of the ventilatory response to changes in the partial pressures of oxygen and carbon dioxide in the blood. Studies have shown that loop gain can serve as an indicator for assessing sleep-disordered breathing at high altitudes: individuals with high loop gain often struggle to maintain stable and effective control of their ventilation. Consequently, compared to individuals with low loop gain, changes in the partial pressures of oxygen and carbon dioxide in their blood typically trigger more severe ventilatory responses, resulting in a disordered breathing pattern alternating between hypoventilation, apnea, and hyperventilation. Therefore, individuals with high loop gain may disrupt their normal breathing patterns during sleep, thus affecting sleep quality and increasing the risk of chain reactions.

[0003] Currently, there is a lack of loop gain measurement equipment for evaluating the respiratory stability of subjects in related technologies. Summary of the Invention

[0004] This invention aims to at least solve one of the technical problems existing in the prior art. Therefore, one object of this invention is to provide a respiratory system loop gain measurement device. According to this invention, the respiratory system loop gain measurement device supplies a first gas and a second gas to a subject, causing changes in the partial pressures of oxygen and carbon dioxide in the subject's blood. This, in turn, regulates ventilation through the subject's chemoreceptors. Simultaneously, a first measuring device collects characteristic parameters of the subject's exhaled gas, and the respiratory stability of the subject can be evaluated based on changes in these characteristic parameters.

[0005] The respiratory system loop gain measurement device according to the present invention includes: a first gas supply unit, the first gas supply unit being provided with a first gas supply end and adapted to provide a first gas; a second gas supply unit, the second gas supply unit being provided with a second gas supply end and adapted to provide a second gas; an inhalation tubing, one end of which is selectively connected to the first gas supply end and the second gas supply end respectively; a breathing device, the breathing device being connected to one end of the inhalation tubing; and a first measuring device, the first measuring device being connected to the breathing device and adapted to detect the concentration and / or pressure of the gas discharged by the breathing device.

[0006] According to the respiratory system loop gain measurement device of the present invention, a first gas supply unit and a second gas supply unit are provided. The first gas supply unit is adapted to provide a first gas, and the second gas supply unit is adapted to provide a second gas. One end of the inhalation tubing is selectively connected to the first gas supply unit and the second gas supply unit, respectively, allowing the first gas or the second gas to be selectively introduced. Since the breathing device is connected to one end of the inhalation tubing, the subject inhales the first gas and the second gas respectively through the breathing device, causing changes in the partial pressures of oxygen and carbon dioxide in the subject's blood, which in turn regulates the ventilation rate through the subject's chemoreceptors. Simultaneously, the respiratory system loop gain measurement device includes a first measuring device that measures the concentration and / or pressure of the subject's exhaled gas to collect characteristic parameters of the subject's exhaled gas. Changes in these characteristic parameters can be used to evaluate the subject's respiratory stability.

[0007] According to some embodiments of the present invention, the first gas supply unit includes: a gas supply device, wherein the gas supply device is configured to provide a plurality of gases, each gas supply device being adapted to provide a different gas; a gas mixing device, wherein a gas mixing chamber is formed within the gas mixing device, the gas mixing chamber being selectively connected to the gas supply device; and a flow valve, wherein the flow valve is configured to correspond one-to-one with the gas supply device and is disposed between the corresponding gas supply device and the gas mixing chamber.

[0008] According to some embodiments of the present invention, a first gas detection device is provided in the mixing chamber, the first gas detection device being adapted to detect the gas concentration in the mixing chamber, and at least one of the flow valves is connected to the first gas detection device and the opening degree of the flow valve is adjusted according to the gas concentration in the mixing chamber.

[0009] According to some embodiments of the present invention, a first pressure detection device is provided in the mixing chamber, the first pressure detection device being adapted to detect the pressure in the mixing chamber, and at least one of the flow valves is connected to the first pressure detection device and the opening degree of the flow valve is adjusted according to the pressure in the mixing chamber.

[0010] According to some embodiments of the present invention, the respiratory system loop gain measuring device further includes: a buffer device, wherein the buffer device is provided with a buffer chamber communicating with the mixing chamber.

[0011] According to some embodiments of the present invention, the respiratory system loop gain measuring device further includes: a second measuring device disposed between one end of the inhalation tubing and the respiratory device, the second measuring device being adapted to detect the concentration and / or pressure of the gas inhaled by the respiratory device.

[0012] According to some embodiments of the present invention, both the first measuring device and the second measuring device include: a main pipeline having a first flow chamber in communication with the breathing device; a pressure sensor disposed in the first flow chamber and adapted to detect the gas pressure in the first flow chamber; and an oxygen concentration sensor disposed in the first flow chamber and adapted to detect the oxygen concentration in the first flow chamber.

[0013] According to some embodiments of the present invention, both the first measuring device and the second measuring device further include: a secondary pipeline disposed on the main pipeline and having a second flow cavity formed therein; a carbon dioxide concentration sensor disposed in the second flow cavity; and a pump body, the inlet of the pump body being connected to the first flow cavity and the outlet of the pump body being connected to the carbon dioxide concentration sensor.

[0014] According to some embodiments of the present invention, a drying element located upstream of the oxygen concentration sensor is disposed in the first flow cavity.

[0015] According to some embodiments of the present invention, the respiratory system loop gain measuring device further includes: a first flow meter disposed between the first air supply end and the inhalation tubing; a second flow meter disposed between the second air supply end and the inhalation tubing; and a third flow meter disposed downstream of the respiratory device and adapted to detect the flow rate of the gas discharged from the respiratory device.

[0016] According to some embodiments of the present invention, a first control valve is provided between the first air supply end and the suction line to control the connection or disconnection between the first air supply end and the suction line; a second control valve is provided between the second air supply end and the suction line to control the connection or disconnection between the second air supply end and the suction line.

[0017] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0019] Figure 1 This is a schematic diagram of the structure of a respiratory system loop gain measurement device according to an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of the first measuring device according to an embodiment of the present invention;

[0021] Figure 3 The curves showing the change of carbon dioxide partial pressure and flow rate over time are plotted using the respiratory system loop gain measurement device according to an embodiment of the present invention.

[0022] Figure 4 These are curves showing the changes in carbon dioxide partial pressure and flow rate with the number of breaths, plotted using the respiratory system loop gain measurement device according to an embodiment of the present invention.

[0023] Figure label:

[0024] Respiratory system loop gain measurement device 1;

[0025] First gas supply unit 11, gas supply device 111, gas mixing device 112, flow valve 113, first gas detection device 114, first pressure detection device 115, buffer device 116.

[0026] Second air supply unit 12, inhalation tubing 13, breathing device 14;

[0027] First measuring device 15, pressure sensor 151, oxygen concentration sensor 152, carbon dioxide concentration sensor 153, pump body 154;

[0028] Second measuring device 16, first flow meter 17, second flow meter 18, third flow meter 19, first control valve 20, second control valve 21. Detailed Implementation

[0029] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0030] The following is for reference. Figures 1-4 A respiratory system loop gain measurement device 1 according to an embodiment of the present invention is described.

[0031] like Figure 1 As shown, the respiratory system loop gain measuring device 1 according to the present invention includes a first gas supply unit 11, a second gas supply unit 12, an inhalation tubing 13, a breathing device 14, and a first measuring device 15. The first gas supply unit 11 is provided with a first gas supply end and is adapted to provide a first gas. The second gas supply unit 12 is provided with a second gas supply end and is adapted to provide a second gas. One end of the inhalation tubing 13 is selectively connected to the first gas supply end and the second gas supply end, respectively. The breathing device 14 is connected to one end of the inhalation tubing 13. The first measuring device 15 is connected to the breathing device 14 and is adapted to detect the concentration and / or pressure of the gas discharged by the breathing device 14.

[0032] In related technologies, changes in the partial pressure of oxygen and carbon dioxide in human blood can trigger a ventilation response, the magnitude of which varies from person to person. However, there is currently a lack of a respiratory system loop gain measurement device to evaluate the respiratory stability of subjects.

[0033] According to the respiratory system loop gain measurement device 1 of the present invention, a first gas supply unit 11 and a second gas supply unit 12 are provided. The first gas supply unit 11 is adapted to provide a first gas, and the second gas supply unit 12 is adapted to provide a second gas. One end of the inhalation tubing 13 is selectively connected to the first gas supply end and the second gas supply end, respectively, allowing the first gas or the second gas to be selectively introduced. Since the breathing device 14 is connected to one end of the inhalation tubing 13, the subject inhales the first gas and the second gas through the breathing device 14, causing changes in the partial pressures of oxygen and carbon dioxide in the subject's blood, which in turn regulates the ventilation rate through the subject's human chemoreceptors. At the same time, the respiratory system loop gain measurement device 1 is equipped with a first measuring device 15, which measures the concentration and / or pressure of the subject's exhaled gas, which is beneficial for collecting characteristic parameters of the subject's exhaled gas. The respiratory stability of the subject can be evaluated based on the changes in the characteristic parameters of the exhaled gas.

[0034] Therefore, the respiratory system loop gain measurement device 1 of this application, by supplying the first gas and the second gas to the subject respectively, causes changes in the partial pressure of oxygen and carbon dioxide in the subject's blood, and then regulates the ventilation through the subject's human chemoreceptors. At the same time, the first measuring device 15 collects the characteristic parameters of the subject's exhaled gas, and the respiratory stability of the subject can be evaluated based on the changes in the characteristic parameters of the exhaled gas.

[0035] According to some embodiments of the present invention, such as Figure 1As shown, the first gas supply unit 11 includes a gas supply device 111, a gas mixing device 112, and a flow valve 113. Multiple gas supply devices 111 are configured, each adapted to supply different gases. A mixing chamber is formed within the gas mixing device 112, and each mixing chamber is selectively connected to a gas supply device 111. Multiple flow valves 113 are configured to correspond one-to-one with each gas supply device 111 and are disposed between the corresponding gas supply device 111 and the mixing chamber. In this embodiment, the first gas supply unit 11 prepares a first gas by mixing different gases. The gas supply device 111 serves as a gas source, and multiple gas supply devices 111 are adapted to supply multiple gases. The gas supply device 111 inputs gas into the mixing device 112, where different types of gases are mixed within the mixing chamber, thereby preparing a mixed gas that serves as the first gas. The flow valve 113 controls the flow rate of a gas by controlling the gas flow rate input from the gas supply device 111 to the gas mixing device 112. By constructing multiple flow valves 113 corresponding one-to-one with the gas supply device 111, multiple flow valves 113 control the flow rate of multiple gases, thereby controlling the concentration of multiple gases in the first gas, thus preparing a first gas of a specific concentration.

[0036] In some embodiments, the gas supply device 111 includes a nitrogen supply device 111, an oxygen supply device 111, and a carbon dioxide supply device 111; the second gas supply unit 12 is connected to the atmosphere, and the second gas is air. The nitrogen supply device 111 is adapted to supply nitrogen to the gas mixing device 112, the oxygen supply device 111 is adapted to supply oxygen to the gas mixing device 112, and the carbon dioxide supply device 111 is adapted to supply carbon dioxide to the gas mixing device 112. The gas supply device 111 can prepare a gas of a specific concentration under the control of the flow valve 113. Since the second gas is air, the variable can be controlled by preparing a first gas with the same nitrogen concentration as air, i.e., a first gas with a nitrogen concentration of 78%. At the same time, the oxygen and carbon dioxide concentrations of the first gas are different from those of air, so as to ensure that the subject can change the oxygen and carbon dioxide concentrations in the blood by inhaling the first gas and the second gas respectively. By configuring the second gas supply unit 12 to be connected to the atmosphere and the second gas to be air, on the one hand, artificial gas sources can be reduced, saving costs, and on the other hand, since the air concentration is fixed, it is easier to control variables for measurement experiments. Furthermore, the physiological needs of the subjects during the measurement process can be met.

[0037] In some embodiments, the first gas supply unit 11 further includes a solenoid valve. The solenoid valve is configured as a plurality of valves corresponding one-to-one with the gas supply device 111 and disposed between the corresponding gas supply device 111 and the mixing chamber. The solenoid valve precisely controls the input amount of a gas by controlling the opening and closing of the gas pipeline between the gas supply device 111 and the mixing chamber. By configuring multiple solenoid valves corresponding one-to-one with the gas supply device 111, the multiple solenoid valves control the input amounts of multiple gases, thereby controlling the amount of the first gas.

[0038] In some embodiments, the first gas supply unit 11 further includes a multi-port connector, through which multiple gas supply devices 111 can be selectively connected to the mixing chamber. The multi-port connector includes multiple inlets and one outlet. The gas pipelines containing the multiple gas supply devices 111 are connected in parallel and connected to the inlets of the multi-port connector. The mixing chamber is connected to the outlet of the multi-port connector. By providing the multi-port connector, multiple gas supply devices 111 can simultaneously supply gas into the mixing chamber, which is beneficial for the first gas supply unit 11 to prepare a mixture containing multiple gases.

[0039] According to some embodiments of the present invention, such as Figure 1 As shown, a first gas detection device 114 is installed inside the mixing chamber. The first gas detection device 114 is suitable for detecting the gas concentration inside the mixing chamber. At least one flow valve 113 is connected to the first gas detection device 114 and adjusts the opening of the flow valve 113 according to the gas concentration inside the mixing chamber. The first gas detection device 114 determines the difference between the actual concentration and the predetermined concentration of the mixed gas inside the mixing chamber by detecting the gas concentration in real time. At the same time, by connecting to the flow valve 113, the flow valve 113 adjusts its opening according to the difference between the actual concentration and the predetermined concentration of the gas transmitted through the controlled gas pipeline inside the mixing chamber, thereby enabling the actual concentration of the mixed gas inside the mixing chamber to quickly reach the predetermined concentration. The smaller the actual concentration of the gas transmitted through the controlled gas pipeline inside the mixing chamber is compared to the predetermined concentration, the larger the opening of the flow valve 113; the larger the actual concentration of the gas transmitted through the controlled gas pipeline inside the mixing chamber is compared to the predetermined concentration, the smaller the opening of the flow valve 113.

[0040] In some embodiments, a fan is provided inside the mixing chamber. The fan can agitate the airflow. By providing a fan inside the mixing chamber, the fan accelerates the gas flow within the mixing chamber, thereby increasing the mixing efficiency of multiple gases while ensuring the accuracy of the gas concentration detected by the first gas detection device 114.

[0041] According to some embodiments of the present invention, such as Figure 1As shown, a first pressure detection device 115 is installed inside the mixing chamber. The first pressure detection device 115 is adapted to detect the pressure inside the mixing chamber. At least one flow valve 113 is connected to the first pressure detection device 115 and its opening is adjusted according to the pressure inside the mixing chamber. By detecting the pressure inside the mixing chamber, the first pressure detection device 115 determines the difference between the actual amount of the first gas and the predetermined amount. When the actual pressure inside the mixing chamber detected by the first pressure detection device 115 reaches the predetermined pressure, it indicates that the actual amount of the first gas prepared is equal to the predetermined amount. The first pressure detection device 115 controls the flow valve 113 and the solenoid valve to close. The first gas supply unit 11 controls the amount of the first gas produced by setting a first pressure detection device 115 and at least one flow valve 113 connected to the first pressure detection device 115 and adjusting the opening of the flow valve 113 according to the pressure in the mixing chamber. Based on the difference between the actual amount of the first gas and the predetermined amount, the first pressure detection device 115 controls the opening of the flow valve 113, thereby controlling the flow rate of the gas pipeline where the flow valve 113 is located, so that the actual amount of the first gas quickly reaches the predetermined amount.

[0042] According to some embodiments of the present invention, such as Figure 1 As shown, the respiratory system loop gain measurement device 1 also includes a buffer device 116, which has a buffer chamber communicating with the mixing chamber. The buffer device 116 serves as a storage device for the first gas and includes the buffer chamber. The buffer chamber provides buffer space for the first gas, and simultaneously, through its communication with the mixing chamber, allows various gases in the mixing chamber to mix and flow into the buffer chamber. By incorporating the buffer device 116, which provides buffer space for the first gas, the respiratory system loop gain measurement device 1 increases the permissible preparation amount of the first gas, thus facilitating the respiratory stability test of the subject.

[0043] According to some embodiments of the present invention, such as Figure 1 As shown, the respiratory system loop gain measurement device 1 also includes a second measuring device 16, which is disposed between one end of the inhalation tubing 13 and the breathing device 14. The second measuring device 16 is adapted to detect the concentration and / or pressure of the gas inhaled by the breathing device 14. By setting up the second measuring device 16, the respiratory system loop gain measurement device 1 measures the concentration and / or pressure of the gas inhaled by the subject, facilitating the acquisition of characteristic parameters of the inhaled gas. Acquiring these characteristic parameters ensures the accuracy of the gas concentration inhaled during a single breath, improving the accuracy of the measurement results. Simultaneously, by acquiring the characteristic parameters of the inhaled gas during multiple breaths, a correspondence can be established between the inhaled and exhaled gas characteristics, which is beneficial for evaluating the subject's respiratory stability.

[0044] According to some embodiments of the present invention, such as Figure 2 As shown, both the first measuring device 15 and the second measuring device 16 include a main pipeline, a pressure sensor 151, and an oxygen concentration sensor 152. A first flow chamber communicating with the breathing device 14 is formed within the main pipeline. The pressure sensor 151 is disposed within the first flow chamber and is adapted to detect the gas pressure within the first flow chamber. The oxygen concentration sensor 152 is disposed within the first flow chamber and is adapted to detect the oxygen concentration within the first flow chamber. The main pipeline serves as a transmission pipeline for inhaled or exhaled gas and is provided with the first flow chamber for gas flow. Since the first flow chamber is connected to the breathing device 14, the subject's inhaled gas flows into the breathing device 14 through the first flow chamber, and the subject's exhaled gas flows out of the breathing device 14 through the first flow chamber. The respiratory system loop gain measuring device 1 uses the pressure sensor 151 and the oxygen concentration sensor 152 disposed within the first flow chamber. The pressure sensor 151 detects the gas pressure within the first flow chamber, and the oxygen concentration sensor 152 detects the oxygen concentration within the first flow chamber, to facilitate the acquisition of the pressure and oxygen concentration of inhaled and exhaled gas.

[0045] According to some embodiments of the present invention, such as Figure 2 As shown, both the first measuring device 15 and the second measuring device 16 further include a secondary pipeline, a carbon dioxide concentration sensor 153, and a pump body 154. The secondary pipeline is located on the main pipeline and forms a second flow chamber inside. The carbon dioxide concentration sensor 153 is located in the second flow chamber. The inlet of the pump body 154 is connected to the first flow chamber, and the outlet of the pump body 154 is connected to the carbon dioxide concentration sensor 153. The pump body 154 serves as a power device for transporting gas. Its inlet is connected to the first flow chamber, and its outlet is connected to the carbon dioxide concentration sensor 153. The pump body 154 draws gas from the first flow chamber and delivers it to the carbon dioxide concentration sensor 153, which is suitable for detecting the carbon dioxide concentration of the gas. Since the detection value of carbon dioxide concentration sensor 153 is sensitive to gas flow rate, a secondary pipeline is set up. The second flow chamber of the secondary pipeline provides a space for pump body 154 and carbon dioxide concentration sensor 153. Pump body 154 extracts gas from the first flow chamber, and carbon dioxide concentration sensor 153 detects the carbon dioxide concentration of the extracted gas, which can improve the detection accuracy of carbon dioxide concentration.

[0046] According to some embodiments of the present invention, a drying element is disposed in the first flow cavity upstream of the oxygen concentration sensor 152. The drying element can absorb moisture. By disposing of the drying element upstream of the oxygen concentration sensor 152, the oxygen concentration sensor 152 detects the gas dried by the drying element, thereby reducing the impact of airflow humidity on the detection accuracy of the oxygen concentration sensor 152.

[0047] In some embodiments, the inlet of the pump body 154 is connected to the downstream of the oxygen concentration sensor 152, and the outlet of the carbon dioxide concentration sensor 153 is connected to the downstream of the oxygen concentration sensor 152. A drying element located upstream of the oxygen concentration sensor 152 is disposed in the first flow chamber. The pump body 154 draws gas from the downstream of the oxygen concentration sensor 152, and the gas flows into the downstream of the oxygen concentration sensor 152 after passing through the carbon dioxide concentration sensor 153. Since the drying element is located upstream of the oxygen concentration sensor 152, the influence of airflow humidity on the detection accuracy of the carbon dioxide concentration sensor 153 is reduced.

[0048] According to some embodiments of the present invention, the respiratory system loop gain measurement device 1 further includes a first flow meter 17, a second flow meter 18, and a third flow meter 19. The first flow meter 17 is disposed between the first gas supply end and the inhalation tubing 13; the second flow meter 18 is disposed between the second gas supply end and the inhalation tubing 13; and the third flow meter 19 is disposed downstream of the breathing device 14 and is adapted to detect the flow rate of the gas discharged from the breathing device 14. The first flow meter 17, disposed between the first gas supply end and the inhalation tubing 13, is adapted to detect the gas flow rate of the first gas inhaled by the subject; the second flow meter 18, disposed between the second gas supply end and the inhalation tubing 13, is adapted to detect the gas flow rate of the second gas inhaled by the subject. The respiratory system loop gain measurement device 1, by setting the first flow meter 17 and the second flow meter 18, detects the gas flow rate of the gas inhaled by the subject, thereby facilitating the acquisition of the gas flow rate of the gas inhaled by the subject. The third flow meter 19 is located downstream of the breathing device 14 and is suitable for detecting the gas flow rate of the subject's exhaled gas, so as to facilitate the collection of the gas flow rate of the subject's exhaled gas.

[0049] According to some embodiments of the present invention, a first control valve 20 is provided between the first gas supply end and the inhalation tubing 13 to control the connection or disconnection between the first gas supply end and the inhalation tubing 13; a second control valve 21 is provided between the second gas supply end and the inhalation tubing 13 to control the connection or disconnection between the second gas supply end and the inhalation tubing 13. When the subject inhales the first gas, the first control valve 20 connects the inhalation tubing 13 to the first gas supply end, and the second control valve 21 disconnects the inhalation tubing 13 from the second gas supply end; when the subject inhales the second gas, the second control valve 21 connects the inhalation tubing 13 to the second gas supply end, and the first control valve 20 disconnects the inhalation tubing 13 from the first gas supply end. The respiratory system loop gain measurement device 1, by providing the first control valve 20 and the second control valve 21, enables one end of the inhalation tubing 13 to be selectively connected to the first gas supply end and the second gas supply end, respectively.

[0050] In some embodiments, the respiratory system loop gain measuring device 1 further includes a three-way connector. The three-way connector includes two inlets and one outlet. The gas pipeline containing the first gas supply end is connected in parallel with the gas pipeline containing the second gas supply end. Simultaneously, the first gas supply end is connected to one inlet of the three-way connector, the second gas supply end is connected to the other inlet of the three-way connector, and the inhalation pipeline 13 is connected to the outlet of the three-way connector. By providing the three-way connector, the respiratory system loop gain measuring device 1 allows gas to be input into the inhalation pipeline 13 from either the first or second gas supply end, thereby enabling one end of the inhalation pipeline 13 to be selectively connected to both the first and second gas supply ends.

[0051] In some embodiments, one-way valves are provided on the gas pipeline where the first gas supply end is located and the gas pipeline where the second gas supply end is located. The one-way valves are both located at the end of the gas pipeline connected to the tee connector. The one-way valves ensure that the first gas and the second gas flow into the suction pipeline 13 in one direction, avoiding gas backflow that would cause the first gas and the second gas to mix, and ensuring accurate measurement results.

[0052] In some embodiments, the respiratory system loop gain measurement device 1 further includes an exhalation tubing, and a first measuring device 15 is disposed in the exhalation tubing. The exhalation tubing allows the subject's exhaled gas to flow through it. By disposing of the first measuring device 15 in the exhalation tubing, the subject's exhaled gas passes through the first measuring device 15, thereby detecting characteristic parameters of the subject's exhaled gas. Simultaneously, the inhalation tubing 13, the exhalation tubing, and the breathing device 14 are connected via a three-way connector. The three-way connector includes an inlet, an outlet, and an inlet-outlet port. The inhalation tubing 13 is connected to the inlet of the three-way connector, the exhalation tubing is connected to the outlet of the three-way connector, and the breathing device 14 is connected to the inlet-outlet port of the three-way connector. The inhalation tubing 13 is connected to the three-way connector via a one-way valve, allowing the gas from the inhalation tubing 13 to flow unidirectionally into the breathing device 14; the exhalation tubing is connected to the three-way connector via a one-way valve, allowing the breathing device 14 to flow unidirectionally into the exhalation tubing. The inhalation tubing 13 outputs gas and inputs the gas into the breathing device 14 through a three-way connector. The subject inhales the gas through the breathing device 14 and then exhales the gas, which flows into the exhalation tubing.

[0053] In some embodiments, the exhalation tubing is connected to the atmosphere, and a one-way valve is provided between the first measuring device 15 and the outside world. The gas exhaled by the subject flows into the atmosphere after passing through the first measuring device 15. By providing a one-way valve between the first measuring device 15 and the outside world, the one-way valve prevents outside air from flowing into the first measuring device 15, ensuring the accuracy of the detection results of the first measuring device 15.

[0054] In some embodiments, the respiratory system loop gain measurement device 1 further includes a computer, which is adapted to acquire the sensing signals of the first gas detection device 114, the first pressure detection device 115, the first measuring device 15, the second measuring device 16, the first flow meter 17, the second flow meter 18 and the third flow meter 19, and simultaneously control the flow valve 113, the first control valve 20 and the second control valve 21 according to the sensing signals, and store and calculate data according to the sensing signals.

[0055] The following is a brief description of the measurement process using a respiratory system loop gain measuring device 1 according to an embodiment of the present invention.

[0056] The computer inputs the concentration of the first gas mixture to be prepared, such as 4% carbon dioxide, 21% oxygen, and 75% nitrogen. The computer controls the opening of the flow valve 113 to enable the first gas supply unit 11 to automatically prepare the first gas. At the same time, the computer adjusts the opening of the flow valve 113 according to the difference between the mixed gas concentration and the predetermined concentration to quickly prepare the first gas. When the gas pressure in the mixing chamber is greater than the atmospheric pressure by a predetermined difference, such as 5 kPa, the computer controls the flow valve 113 and the solenoid valve to close, and the preparation of the first gas is completed. After the first gas is prepared, the computer begins measuring and collecting data. The subject breathes through the breathing device 14. The first measuring device 15 and the second measuring device 16 measure the oxygen concentration, carbon dioxide concentration, and gas pressure of the inhaled and exhaled gases. The first flow meter 17 and the second flow meter 18 measure the gas flow rate of the inhaled gas, and the third flow meter 19 measures the gas flow rate of the exhaled gas. Simultaneously, the computer collects and saves the sensor signals from the first measuring device 15, the second measuring device 16, the first flow meter 17, the second flow meter 18, and the third flow meter 19 in real time. The computer also determines the subject's end-expiration time based on the zero gas flow rate measured by the third flow meter 19, and controls the first control valve 20 and the second control valve 21 to alternately open and close at the end-expiration time. This causes the inhaled gas to switch back and forth between the first and second gases, resulting in changes in the oxygen concentration and partial pressure of carbon dioxide in the subject's blood. This, in turn, frequently adjusts the ventilation rate through the body's chemoreceptors. The computer collects and saves the test data during the test. The computer calculates based on the measurement data and plots curves showing the changes in carbon dioxide partial pressure of the first measuring device 15, the carbon dioxide partial pressure of the second measuring device 16, and the flow rate over time, such as... Figure 3 As shown; simultaneously calculate the partial pressure of inhaled carbon dioxide, the partial pressure of exhaled carbon dioxide, and the average flow rate of each exhalation, and plot the curves of the partial pressure of inhaled carbon dioxide, the partial pressure of exhaled carbon dioxide, and the flow rate as a function of the number of breaths, as shown. Figure 4As shown. By substituting the calculated parameters into the human respiratory system model, the loop gain value of the subject can be calculated. The loop gain value can be used to evaluate the respiratory stability of the subject.

[0057] In the description of this invention, "first feature" and "second feature" may include one or more of the features.

[0058] In the description of this invention, "a plurality of" means two or more.

[0059] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0060] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A respiratory system loop gain measurement device, characterized in that, include: The first gas supply unit (11) is provided with a first gas supply end and is adapted to provide a first gas; The first gas supply unit (11) includes: a gas supply device (111), which is configured as a plurality of gas supply devices and is respectively a nitrogen gas supply device, an oxygen gas supply device and a carbon dioxide gas supply device, each of which is adapted to provide different gases; a gas mixing device (112), which has a gas mixing chamber formed therein, and the gas mixing chamber is selectively connected to the gas supply device (111); and a flow valve (113), which is configured as a plurality of flow valves corresponding one-to-one with the gas supply device (111) and is disposed between the corresponding gas supply device (111) and the gas mixing chamber; The second gas supply unit (12) is provided with a second gas supply end. The second gas supply unit (12) is adapted to provide a second gas. The second gas supply unit (12) is connected to the atmosphere. The second gas is air. An inhalation tubing (13) is provided, one end of which can be selectively connected to the first air supply end and the second air supply end respectively; a first control valve (20) is provided between the first air supply end and the inhalation tubing (13) to control the connection or disconnection between the first air supply end and the inhalation tubing (13); a second control valve (21) is provided between the second air supply end and the inhalation tubing (13) to control the connection or disconnection between the second air supply end and the inhalation tubing (13); Breathing device (14), wherein one end of the breathing device (14) is connected to the inhalation tubing (13); A first measuring device (15) is connected to the breathing device (14) and is adapted to detect the concentration and / or pressure of the gas discharged by the breathing device (14); A second measuring device (16) is disposed between one end of the inhalation tubing (13) and the breathing device (14), and the second measuring device (16) is adapted to detect the concentration and / or pressure of the gas inhaled by the breathing device (14); The first flow meter (17) is disposed between the first air supply end and the suction pipe (13); The second flow meter (18) is disposed between the second air supply end and the suction pipe (13); A third flow meter (19) is located downstream of the breathing device (14) and is adapted to detect the flow rate of the gas discharged from the breathing device (14). The computer is used to: determine the end of expiration based on the zero flow rate detected by the third flow meter (19), and control the first control valve (20) and the second control valve (21) to alternately open and close at the end of expiration so that the gas inhaled by the subject alternately switches between the first gas and the second gas; collect test data, generate curve data of the change of carbon dioxide partial pressure and flow rate with time and number of breaths, calculate the inhaled carbon dioxide partial pressure, exhaled carbon dioxide partial pressure and average expiratory flow rate for each breath, and calculate the loop gain value for evaluating respiratory stability based on the human respiratory system model.

2. The respiratory system loop gain measurement device of claim 1, wherein, A first gas detection device (114) is provided in the mixing chamber. The first gas detection device (114) is adapted to detect the gas concentration in the mixing chamber. At least one flow valve (113) is connected to the first gas detection device (114) and the opening degree of the flow valve (113) is adjusted according to the gas concentration in the mixing chamber.

3. The respiratory system loop gain measurement device of claim 1, wherein, A first pressure detection device (115) is provided in the mixing chamber. The first pressure detection device (115) is adapted to detect the pressure in the mixing chamber. At least one flow valve (113) is connected to the first pressure detection device (115) and adjusts the opening of the flow valve (113) according to the pressure in the mixing chamber.

4. The respiratory system loop gain measurement device according to claim 1, characterized in that, Also includes: The buffer device (116) is provided with a buffer cavity that communicates with the mixing chamber.

5. The respiratory system loop gain measurement device of claim 1, wherein, Both the first measuring device (15) and the second measuring device (16) include: The main pipeline has a first flow chamber that communicates with the breathing device (14); A pressure sensor (151) is disposed in the first flow cavity and is adapted to detect the gas pressure in the first flow cavity; An oxygen concentration sensor (152) is disposed in the first flow cavity and is adapted to detect the oxygen concentration in the first flow cavity.

6. The breathing system loop gain measuring device of claim 5, wherein, Both the first measuring device (15) and the second measuring device (16) further include: A secondary pipeline is provided on the main pipeline and has a second flow cavity formed inside it; A carbon dioxide concentration sensor (153) is disposed in the second flow chamber; The pump body (154) has an air inlet connected to the first flow chamber and an air outlet connected to the carbon dioxide concentration sensor (153).

7. The respiratory system loop gain measuring device of claim 5, wherein, A drying element is provided in the first flow cavity upstream of the oxygen concentration sensor (152).

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