Sleep Apnea-Hypopnea Disease Modeling System

Abstract

This invention relates to the field of medical experimental equipment technology and proposes a sleep apnea-hypopnea disease modeling system, comprising an experimental animal, a sealed enclosure, a main control unit, a communication unit, an EEG / EMG monitoring circuit, and a valve control circuit. The experimental animal is placed in the sealed enclosure, which has an exhaust port. The input terminal of the EEG / EMG monitoring circuit is connected to the head of the experimental animal, and the output terminal of the EEG / EMG monitoring circuit is connected to the main control unit. The main control unit communicates with a host computer via the communication unit. The input terminal of the valve control circuit is connected to the main control unit, and the output terminal of the valve control circuit is connected to a first solenoid valve controlling a first gas cylinder and a second solenoid valve controlling a second gas cylinder. This technical solution solves the problem in related technologies where OSAHS experimental animal models cannot accurately simulate the clinical OSAHS disease process.

Description

Technical Field

[0001] This invention relates to the field of medical experimental equipment technology, specifically to a sleep apnea-hypopnea disease modeling system. Background Technology

[0002] Sleep apnea-hypopnea syndrome (OSAHS) is a sleep-disordered breathing condition of unknown etiology, clinically characterized by difficulty breathing or apnea during sleep, while breathing is normal when awake. Due to recurrent episodes of hypoxemia and hypercapnia during sleep, it leads to repeated awakenings, fragmented sleep, and daytime sleepiness. OSAHS is a high-risk factor for hypertension, coronary heart disease, diabetes, and cerebrovascular disease, and is also a common cause of traffic accidents and even sudden death during the night. Therefore, OSAHS is a potentially fatal sleep-disordered breathing condition.

[0003] Due to ethical and other constraints, it is necessary to construct experimental animal models of OSAHS to further study the pathogenesis of OSAHS and its complications. Currently, the construction of experimental animal models of OSAHS mainly simulates clinical OSAHS patients by intermittently administering hypoxia to experimental animals. A key drawback is that intermittent hypoxia cannot perfectly match the sleep state; it cannot achieve the scenario where experimental animals only inhale hypoxia during sleep and normal oxygen during wakefulness, thus failing to accurately simulate the course of clinical OSAHS. Furthermore, existing EEG / EMG monitoring has low accuracy, thus failing to provide more realistic experimental data. Summary of the Invention

[0004] This invention proposes a modeling system for sleep apnea-hypopnea disease, which solves the problem that experimental animal models of OSAHS in related technologies cannot well simulate the clinical OSAHS disease process.

[0005] The technical solution of the present invention is as follows:

[0006] The sleep apnea-hypopnea disease modeling system includes experimental animals, a closed enclosure, a main control unit, a communication unit, an EEG / EMG monitoring circuit, and a valve control circuit.

[0007] The experimental animal is placed in the sealed enclosure, which is equipped with an exhaust vent. The input terminal of the EEG / EMG monitoring circuit is connected to the head of the experimental animal, and the output terminal of the EEG / EMG monitoring circuit is connected to the main control unit. The main control unit communicates with a host computer via the communication unit.

[0008] The input terminal of the valve control circuit is connected to the main control unit, the output terminal of the valve control circuit is connected to the first solenoid valve controlling the first gas cylinder, and the output terminal of the valve control circuit is connected to the second solenoid valve controlling the second gas cylinder.

[0009] Furthermore, the present invention also includes a carbon dioxide monitoring circuit, the input terminal of which is connected to the inside of the enclosed enclosure, and the output terminal of which is connected to the main control unit.

[0010] Furthermore, the EEG / EMG monitoring circuit described in this invention includes a first electrode J1, a second electrode J2, operational amplifiers U2 and U3, resistors R2, R3, R4, R6, and R7, a transistor Q1, operational amplifier U4, and resistor R8.

[0011] The first electrode J1 is connected to the non-inverting input terminal of operational amplifier U2 via a shielded cable. The second electrode J2 is connected to the non-inverting input terminal of operational amplifier U3 via a shielded cable. The inverting input terminal of operational amplifier U2 is connected to the inverting input terminal of operational amplifier U3 via resistor R3. The output terminal of operational amplifier U2 is connected to the inverting input terminal of operational amplifier U2 via resistor R2. The output terminal of operational amplifier U3 is connected to the inverting input terminal of operational amplifier U3 via resistor R4. The output terminals of operational amplifier U2 and operational amplifier U3 are connected to the first input terminal of the main control unit via an amplifier circuit.

[0012] The output terminal of operational amplifier U2 is connected to the collector of transistor Q1 through resistor R6. The output terminal of operational amplifier U3 is connected to the collector of transistor Q1 through resistor R7. The emitter of transistor Q1 is connected to the inverting input terminal of operational amplifier U4. The non-inverting input terminal of operational amplifier U4 is connected to the collector of transistor Q1. The output terminal of operational amplifier U4 is connected to the base of transistor Q1. The inverting input terminal of operational amplifier U4 is connected to the shielding layer of the shielded cable through resistor R8.

[0013] Furthermore, the present invention also includes a feedback circuit, which includes operational amplifier U7, resistor R12, operational amplifier U8, resistor R13, resistor R14, and a third electrode J3. The non-inverting input terminal of operational amplifier U7 is connected to the emitter of transistor Q1, the output terminal of operational amplifier U7 is connected to the inverting input terminal of operational amplifier U7, the output terminal of operational amplifier U7 is connected to the inverting input terminal of operational amplifier U8 through resistor R12, the non-inverting input terminal of operational amplifier U8 is connected to the Vref reference voltage, the output terminal of operational amplifier U8 is connected to the inverting input terminal of operational amplifier U8 through resistor R13, and the output terminal of operational amplifier U8 is connected to the third electrode J3 through resistor R14.

[0014] Furthermore, the amplification circuit described in this invention includes a resistor R9, an operational amplifier U1, a resistor R10, and a resistor R11. The first end of the resistor R9 is connected to the output terminal of the operational amplifier U2, and the second end of the resistor R9 is connected to the non-inverting input terminal of the operational amplifier U1. The first end of the resistor R10 is connected to the output terminal of the operational amplifier U3, and the second end of the resistor R10 is connected to the inverting input terminal of the operational amplifier U1. The output terminal of the operational amplifier U1 is connected to the inverting input terminal of the operational amplifier U1 through the resistor R11, and the output terminal of the operational amplifier U1 is connected to the first input terminal of the main control unit.

[0015] Furthermore, a filter circuit is further included between the output terminal of the operational amplifier U1 and the first input terminal of the main control unit in this invention. The filter circuit includes resistors R15 and R16, capacitors C8, C9, C7, R17, operational amplifier U9, variable resistor RP1, and operational amplifier U10. The first end of resistor R15 is connected to the output terminal of operational amplifier U1, and the second end of resistor R15 is connected to the non-inverting input terminal of operational amplifier U9 through resistor R16. The first end of capacitor C8 is connected to the first end of resistor R15, and the second end of capacitor C8 is connected to the non-inverting input terminal of operational amplifier U9 through capacitor C9. The output terminal of operational amplifier U9 is connected to the inverting input terminal of operational amplifier U9. The output terminal of operational amplifier U9 is connected to the first terminal of rheostat RP1. The second terminal of rheostat RP1 is grounded. The sliding terminal of rheostat RP1 is connected to the non-inverting input terminal of operational amplifier U10. The output terminal of operational amplifier U10 is connected to the inverting input terminal of operational amplifier U10. The output terminal of operational amplifier U9 is connected to the second terminal of capacitor C8 through resistor R17. The output terminal of operational amplifier U10 is connected to the second terminal of resistor R15 through capacitor C7. The output terminal of operational amplifier U10 is connected to the first input terminal of the main control unit.

[0016] Furthermore, the valve control circuit of this invention includes two branches with identical circuit structures. Each branch includes an optocoupler U13, resistors R27 and R26, a transistor Q5, and a relay K1. The first input terminal of the optocoupler U13 is connected to a 5V power supply, and the second input terminal of the optocoupler U13 is connected to the second output terminal of the main control unit. The first output terminal of the optocoupler U13 is connected to a 5V power supply through resistor R27, and the second output terminal of the optocoupler U13 is connected to the base of the transistor Q5 through resistor R26. The collector of the transistor Q5 is connected to the first input terminal of the relay K1, and the second input terminal of the relay K1 is connected to a 5V power supply. The emitter of the transistor Q5 is grounded, the normally open terminal of the relay K1 is connected to the power supply, and the common terminal of the relay K1 is connected to the first solenoid valve.

[0017] Furthermore, the carbon dioxide monitoring circuit of the present invention includes an infrared sensor P1, an operational amplifier U11, resistors R21 and R22. The power supply terminal of the infrared sensor P1 is connected to a 5V power supply. The output terminal of the infrared sensor P1 is connected to the non-inverting input terminal of the operational amplifier U11. The ground terminal of the infrared sensor P1 is grounded. The inverting input terminal of the operational amplifier U11 is grounded through the resistor R21. The output terminal of the operational amplifier U11 is connected to the inverting input terminal of the operational amplifier U11 through the resistor R22. The output terminal of the operational amplifier U11 is connected to the second input terminal of the main control unit.

[0018] Furthermore, the carbon dioxide monitoring circuit of the present invention also includes a resistor R19, a capacitor C11, a resistor R20, and a capacitor C12. The first end of the resistor R19 is connected to the output terminal of the infrared sensor P1, the second end of the resistor R19 is grounded through the capacitor C11, the second end of the resistor R19 is connected to the first end of the resistor R20, the second end of the resistor R20 is grounded through the capacitor C12, and the second end of the resistor R20 is connected to the non-inverting input terminal of the operational amplifier U11.

[0019] The working principle and beneficial effects of this invention are as follows:

[0020] In this invention, experimental animals are placed in a sealed enclosure, and their sleep state can be identified by their electroencephalogram (EEG) and electromyogram (EMG) waves. An EEG / EMG monitoring circuit monitors the EEG / EMG signals of the experimental animals, processes the monitored signals, and sends them to the main control unit. The main control unit then transmits the EEG signals to a host computer via a communication circuit. The host computer can observe the waveforms of the EEG / EMG signals of the experimental animals, thereby determining their sleep state.

[0021] When laboratory animals are awake, a normal oxygen supply needs to be maintained. In this invention, when the laboratory animal is awake, the main control unit sends a command to the valve control circuit. Upon receiving the command, the valve control circuit closes the second solenoid valve and opens the first solenoid valve. When the laboratory animal is asleep, the normal oxygen supply is stopped, and low-oxygen gas is supplied to the sealed chamber. When the mouse enters sleep, the main control unit receives a sudden change in the electroencephalogram (EEG) / electromyogram (EMG) signal and sends a command to the valve control circuit to open the second solenoid valve, close the first solenoid valve, and begin supplying low-oxygen gas. When the laboratory animal becomes awake again, the change in the EEG / EMG signal changes the state of the first and second solenoid valves, and normal oxygen is supplied.

[0022] In this way, the opening and closing states of the first and second solenoid valves can be automatically, in real time, and repeatedly controlled based on the differences in EEG / EMG signals of experimental animals during sleep and wakefulness. This achieves the goal of supplying low oxygen during sleep and normal oxygen during wakefulness, simulating the breathing difficulties and apnea experienced by patients with OSAHS during sleep, and providing methods and strong data for research on overcoming sleep apnea-hypopnea disease. Attached Figure Description

[0023] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0024] Figure 1 This is a block diagram illustrating the principle of the OSAHS experimental animal model in this invention.

[0025] Figure 2 This is a circuit diagram of the electroencephalogram (EEG) / electromyogram (EMG) monitoring circuit in this invention;

[0026] Figure 3 This is a circuit diagram of the feedback circuit in this invention;

[0027] Figure 4 This is a circuit diagram of the amplifier circuit in this invention;

[0028] Figure 5 This is a circuit diagram of the filter circuit in this invention;

[0029] Figure 6 This is a circuit diagram of the valve control circuit in this invention;

[0030] Figure 7 This is a circuit diagram of the carbon dioxide monitoring circuit in this invention. Detailed Implementation

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0032] Example 1

[0033] like Figure 1As shown in the figure, this embodiment proposes a sleep apnea-hypopnea disease modeling system, including an experimental animal, a closed box, a main control unit, a communication unit, an EEG / EMG monitoring circuit, and a valve control circuit. The experimental animal is placed in the closed box, which is equipped with an exhaust port. The input terminal of the EEG / EMG monitoring circuit is connected to the head of the experimental animal, and the output terminal of the EEG / EMG monitoring circuit is connected to the main control unit. The main control unit communicates with a host computer via the communication unit. The input terminal of the valve control circuit is connected to the main control unit, and the output terminal of the valve control circuit is connected to a first solenoid valve controlling a first gas cylinder and a second solenoid valve controlling a second gas cylinder.

[0034] In this embodiment, mice are used as experimental animals. The mice are placed in a closed chamber, and their sleep state can be determined by observing their electroencephalogram (EEG) and electromyographic (EMG) waveforms. An EEG / EMG monitoring circuit monitors the mice's EEG / EMG signals, processes the signals, and sends them to the main control unit. The main control unit then transmits the EEG / EMG signals to a host computer via a communication circuit. The host computer can observe the waveforms of the mice's EEG / EMG signals, thereby determining their sleep state.

[0035] When the mice are awake, they need to maintain a normal oxygen supply. In this embodiment, the first gas cylinder is an oxygen cylinder, and the second gas cylinder is a carbon dioxide mixed gas cylinder (low-oxygen gas). When the mice are awake, the main control unit sends a command to the valve control circuit. After receiving the command, the valve control circuit closes the second solenoid valve and opens the first solenoid valve. When the mice are asleep, the normal oxygen supply stops, and carbon dioxide mixed gas is supplied to the closed chamber. When the mice fall asleep, the main control unit receives a sudden change in the EEG / EMG signal and sends a command to the valve control circuit to open the second solenoid valve, close the first solenoid valve, and start supplying carbon dioxide mixed gas.

[0036] When the mice regain consciousness, changes in their electroencephalogram (EEG) / electromyogram (EMG) signals alter the states of the first and second solenoid valves, supplying normal oxygen. Thus, the opening and closing states of the first and second solenoid valves can be automatically, in real-time, and repeatedly controlled based on the differences in EEG / EMG signals between sleep and wakefulness. This achieves the goal of supplying low oxygen during sleep and normal oxygen during wakefulness, simulating the breathing difficulties / apnea experienced by OSAHS patients during sleep, providing methods and data for research into overcoming sleep apnea-hypopnea disease. Simultaneously, connecting the exhaust port on the sealed chamber to an air pump ensures that the gas inside the sealed chamber remains unobstructed.

[0037] like Figure 1As shown, this embodiment also includes a carbon dioxide monitoring circuit. The input terminal of the carbon dioxide monitoring circuit is connected to the inside of the enclosed box, and the output terminal of the carbon dioxide monitoring circuit is connected to the main control unit.

[0038] To more accurately simulate the apnea-hypopnea syndrome in patients, this embodiment can monitor the carbon dioxide content inside the sealed chamber in real time. The carbon dioxide monitoring circuit is used to monitor the carbon dioxide content and convert the monitored carbon dioxide concentration into a corresponding electrical signal and send it to the main control unit. The carbon dioxide concentration inside the chamber can be displayed in real time on the host computer.

[0039] like Figure 2 As shown, the EEG / EMG monitoring circuit in this embodiment includes a first electrode J1, a second electrode J2, operational amplifiers U2 and U3, resistors R2, R3, R4, R6, and R7, a transistor Q1, operational amplifier U4, and resistor R8. The first electrode J1 is connected to the non-inverting input of operational amplifier U2 via a shielded cable. The second electrode J2 is connected to the non-inverting input of operational amplifier U3 via a shielded cable. The inverting input of operational amplifier U2 is connected to the inverting input of operational amplifier U3 via resistor R3. The output of operational amplifier U2 is connected to the inverting input of operational amplifier U2 via resistor R2. The output of operational amplifier U3 is connected to the inverting input of operational amplifier U3 via resistor R4. The inverting input terminal of operational amplifier U3 is connected. The output terminals of operational amplifier U2 and operational amplifier U3 are connected to the first input terminal of the main control unit through an amplifier circuit. The output terminal of operational amplifier U2 is connected to the collector of transistor Q1 through resistor R6. The output terminal of operational amplifier U3 is connected to the collector of transistor Q1 through resistor R7. The emitter of transistor Q1 is connected to the inverting input terminal of operational amplifier U4. The non-inverting input terminal of operational amplifier U4 is connected to the collector of transistor Q1. The output terminal of operational amplifier U4 is connected to the base of transistor Q1. The inverting input terminal of operational amplifier U4 is connected to the shielding layer of the shielded cable through resistor R8.

[0040] In this embodiment, the first electrode J1 and the second electrode J2 are placed on the head of the mouse to monitor the mouse's electroencephalogram (EEG) signal. Since the mouse's EEG signal is very weak, it needs to be amplified by an amplification circuit and then sent to the main control unit. The main control unit sends the amplified EEG signal to the host computer through a communication circuit. The host computer can observe the mouse's sleep state. When it is determined that the mouse is sleeping, the oxygen supply is reduced to simulate the breathing apnea-hypopnea syndrome in patients with sleep apnea-hypopnea disease. The mouse's physical condition is also observed, thereby providing data for overcoming sleep apnea-hypopnea disease.

[0041] Specifically, the working principle of the EEG / EMG monitoring circuit is as follows: The first electrode J1 and the second electrode J2 are used to monitor the EEG signals of the mice. These EEG signals are sent to the non-inverting inputs of operational amplifiers U2 and U3 respectively via shielded cables. Operational amplifiers U2 and U3 constitute a differential amplifier circuit, which improves the anti-interference capability of the EEG signals and reduces zero drift. Because the differential amplifier circuit has high input resistance and low output resistance, it can improve the effectiveness of EEG signal transmission. Resistors R1 and C1, and resistors R5 and C2 respectively constitute low-pass filter circuits to filter out high-frequency noise signals and reduce circuit interference. Since the EEG signals of the mice are very weak, the gain of the differential amplifier circuit cannot meet the monitoring requirements. Therefore, the EEG signals output by operational amplifiers U2 and U3 are further amplified by the amplifier circuit before being sent to the first input of the main control unit.

[0042] In this circuit, transistor Q1 and operational amplifier U4 form a constant current follower circuit. By acquiring the common-mode voltage signal output from operational amplifiers U2 and U3, the signal is sent to the shielding layer of the shielded cable after passing through the constant current follower circuit. This suppresses the common-mode voltage, reduces the impact of distributed capacitance on the circuit, and improves the common-mode rejection ratio of the differential amplifier circuit. Specifically, operational amplifier U4 forms a comparator amplifier. During monitoring, the voltage at the non-inverting input of operational amplifier U4 is greater than the voltage at the inverting input, resulting in a high-level output from operational amplifier U4. Transistor Q1 is turned on, and the sampled voltage is sent to the shielding layer of the shielded cable after passing through transistor Q1 and resistor R8. Simultaneously, the sampled voltage is sent to the inverting input of operational amplifier U4. During monitoring, if the sampling current is too large or too small, it will affect the accuracy of the mouse EEG signal. Therefore, when the sampling signal current increases, the voltage at the inverting input of operational amplifier U4 increases, the voltage at the output of operational amplifier U4 decreases, and the base current of transistor Q1 decreases, thus leading to a decrease in the collector current of transistor Q1. Conversely, when the sampling signal current decreases, the voltage at the inverting input of operational amplifier U4 decreases, the voltage at the output of operational amplifier U4 increases, and the base current of transistor Q1 increases, thus leading to an increase in the collector current of transistor Q1. This stabilizes the sampling signal current and improves the monitoring accuracy of the mouse EEG signal.

[0043] like Figure 3 As shown, this embodiment also includes a feedback circuit, which includes operational amplifier U7, resistor R12, operational amplifier U8, resistor R13, resistor R14 and third electrode J3. The non-inverting input of operational amplifier U7 is connected to the emitter of transistor Q1, the output of operational amplifier U7 is connected to the inverting input of operational amplifier U7, the output of operational amplifier U7 is connected to the inverting input of operational amplifier U8 through resistor R12, the non-inverting input of operational amplifier U8 is connected to the Vref reference voltage, the output of operational amplifier U8 is connected to the inverting input of operational amplifier U8 through resistor R13, and the output of operational amplifier U8 is connected to the third electrode J3 through resistor R14.

[0044] In this embodiment, the feedback circuit is used to further suppress common-mode signals and further improve the common-mode rejection capability. The common-mode voltage output by transistor Q1 is applied to the non-inverting input of operational amplifier U7. Operational amplifier U7 forms a follower, and operational amplifier U8 forms an inverting amplifier circuit. The amplified signal is sent to the third electrode J3. The third electrode J3 is placed on the body of the mouse to form common-mode voltage negative feedback, which can reduce the input value of common-mode voltage, thereby improving the circuit's ability to resist power frequency interference.

[0045] like Figure 4 As shown, the amplifier circuit in this embodiment includes resistor R9, operational amplifier U1, resistor R10, and resistor R11. The first end of resistor R9 is connected to the output terminal of operational amplifier U2, and the second end of resistor R9 is connected to the non-inverting input terminal of operational amplifier U1. The first end of resistor R10 is connected to the output terminal of operational amplifier U3, and the second end of resistor R10 is connected to the inverting input terminal of operational amplifier U1. The output terminal of operational amplifier U1 is connected to the inverting input terminal of operational amplifier U1 through resistor R11. The output terminal of operational amplifier U1 is connected to the first input terminal of the main control unit.

[0046] In this embodiment, the amplifier circuit is used to further amplify the output signal of the differential amplifier circuit. The operational amplifier U1 constitutes a differential amplifier circuit, which converts the two output signals of the differential amplifier circuit into one signal and outputs it to the first input terminal of the main control unit. The main control unit sends the EEG signal to the host computer through the communication unit, and the EEG / EMG waveform signal is formed on the host computer.

[0047] like Figure 5 As shown, in this embodiment, a filter circuit is also included between the output terminal of operational amplifier U1 and the first input terminal of the main control unit. The filter circuit includes resistors R15 and R16, capacitors C8, C9, C7, resistor R17, operational amplifier U9, rheostat RP1, and operational amplifier U10. The first end of resistor R15 is connected to the output terminal of operational amplifier U1, and the second end of resistor R15 is connected to the non-inverting input terminal of operational amplifier U9 through resistor R16. The first end of capacitor C8 is connected to the first end of resistor R15, and the second end of capacitor C8 is connected to operational amplifier U9 through capacitor C9. The non-inverting input terminal of op-amp U10 is connected to the inverting input terminal of op-amp U9. The output terminal of op-amp U9 is connected to the first terminal of rheostat RP1, and the second terminal of rheostat RP1 is grounded. The sliding terminal of rheostat RP1 is connected to the non-inverting input terminal of op-amp U10. The output terminal of op-amp U10 is connected to the inverting input terminal of op-amp U10. The output terminal of op-amp U9 is connected to the second terminal of capacitor C8 through resistor R17. The output terminal of op-amp U10 is connected to the second terminal of resistor R15 through capacitor C7. The output terminal of op-amp U10 is connected to the first input terminal of the main control unit.

[0048] In this embodiment, power frequency interference is the main interference to the EEG signal. Power frequency interference is caused by power lines, surrounding instruments and equipment, and distributed capacitance. Although the aforementioned EEG / EMG monitoring circuit has good suppression capabilities for common-mode interference, some power frequency interference enters the circuit as differential-mode signals. If these signals are not filtered out, it will seriously affect the monitoring accuracy of the mouse's EEG signal. In this embodiment, a band-stop filter is constructed using a dual-T-type RC network to filter out power frequency interference in the signal.

[0049] like Figure 6 As shown, the valve control circuit in this embodiment includes two branches with identical circuit structures. Each branch includes an optocoupler U13, resistors R27 and R26, a transistor Q5, and a relay K1. The first input terminal of the optocoupler U13 is connected to a 5V power supply, and the second input terminal of the optocoupler U13 is connected to the second output terminal of the main control unit. The first output terminal of the optocoupler U13 is connected to a 5V power supply through resistor R27, and the second output terminal of the optocoupler U13 is connected to the base of the transistor Q5 through resistor R26. The collector of the transistor Q5 is connected to the first input terminal of the relay K1, and the second input terminal of the relay K1 is connected to a 5V power supply. The emitter of the transistor Q5 is grounded, the normally open terminal of the relay K1 is connected to the power supply, and the common terminal of the relay K1 is connected to the first solenoid valve.

[0050] When the mice in the sealed chamber are awake, the solenoid valve connected to the oxygen cylinder is opened to provide an appropriate amount of oxygen to the chamber, ensuring the mice's oxygen supply. When the mice are asleep, the solenoid valve of the oxygen cylinder is closed to stop the supply of oxygen to the chamber. At the same time, the solenoid valve connected to the carbon dioxide mixture cylinder is opened to supply a certain amount of carbon dioxide mixture to the chamber, thereby simulating the breathing apnea that occurs during sleep in patients with sleep apnea-hypopnea disease.

[0051] In this embodiment, taking the control of the solenoid valve connected to the oxygen cylinder as an example, when the mouse is awake, the main control unit sends a low-level signal to the second input terminal of the optocoupler U13, the optocoupler U13 is turned on, the optocoupler U13 outputs a high-level signal to the base of the transistor Q5, the transistor Q5 is turned on, the relay K1 is energized and energized, the common terminal of the relay K1 is connected to the normally open terminal of the relay K1, the solenoid valve is powered on and opened, and the oxygen cylinder supplies oxygen to the chamber through the solenoid valve. When the mouse enters a sleep state, the main control unit outputs a high-level signal to the second input terminal of the optocoupler U13, the optocoupler U13 is turned off, the transistor Q5 is also turned off, the relay K1 is de-energized, and the solenoid valve connected to the oxygen cylinder is closed.

[0052] like Figure 7As shown, the carbon dioxide monitoring circuit in this embodiment includes an infrared sensor P1, an operational amplifier U11, resistors R21 and R22. The power supply terminal of the infrared sensor P1 is connected to a 5V power supply. The output terminal of the infrared sensor P1 is connected to the non-inverting input terminal of the operational amplifier U11. The ground terminal of the infrared sensor P1 is grounded. The inverting input terminal of the operational amplifier U11 is grounded through resistor R21. The output terminal of the operational amplifier U11 is connected to the inverting input terminal of the operational amplifier U11 through resistor R22. The output terminal of the operational amplifier U11 is connected to the second input terminal of the main control unit.

[0053] In this embodiment, the carbon dioxide monitoring circuit is used to monitor the carbon dioxide content inside the sealed chamber.

[0054] Infrared sensor P1 is used to monitor the carbon dioxide concentration inside the sealed chamber and convert the monitored carbon dioxide gas concentration into a corresponding electrical signal. The electrical signal output by infrared sensor P1 is relatively weak, so it needs to be amplified. Operational amplifier U11 forms an amplification circuit, and finally the amplified electrical signal is sent to the main control unit.

[0055] like Figure 7 As shown, the carbon dioxide monitoring circuit in this embodiment also includes resistor R19, capacitor C11, resistor R20 and capacitor C12. The first end of resistor R19 is connected to the output terminal of infrared sensor P1, the second end of resistor R19 is grounded through capacitor C11, the second end of resistor R19 is connected to the first end of resistor R20, the second end of resistor R20 is grounded through capacitor C12, and the second end of resistor R20 is connected to the non-inverting input terminal of operational amplifier U11.

[0056] When the carbon dioxide monitoring circuit monitors the carbon dioxide concentration inside the closed box, the circuit will also contain a large number of interference signals. These interference signals will affect the monitoring accuracy of carbon dioxide. Therefore, in this embodiment, a second-order low-pass filter circuit is added between the output terminal of the infrared sensor P1 and the non-inverting input terminal of the operational amplifier U11. The second-order low-pass filter circuit is composed of resistor R19, capacitor C11, resistor R20 and capacitor C12, which is used to filter out high-frequency noise and spurious signals in the signal.

[0057] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A sleep apnea-hypopnea disease modeling system, characterized in that, It includes laboratory animals, a sealed enclosure, a main control unit, a communication unit, an EEG / EMG monitoring circuit, and a valve control circuit. The experimental animal is placed in the sealed enclosure, which is equipped with an exhaust vent. The input terminal of the EEG / EMG monitoring circuit is connected to the head of the experimental animal, and the output terminal of the EEG / EMG monitoring circuit is connected to the main control unit. The main control unit communicates with a host computer via the communication unit. The input terminal of the valve control circuit is connected to the main control unit, the output terminal of the valve control circuit is connected to the first solenoid valve controlling the first gas cylinder, and the output terminal of the valve control circuit is connected to the second solenoid valve controlling the second gas cylinder. When the mouse is awake, the main control unit sends a command to the valve control circuit. Upon receiving the command, the valve control circuit closes the second solenoid valve and opens the first solenoid valve. When the mouse is asleep, the normal oxygen supply is stopped, and carbon dioxide mixture is supplied to the closed chamber. When the mouse enters sleep, the main control unit receives a sudden change in the EEG / EMG signal and sends a command to the valve control circuit to open the second solenoid valve, close the first solenoid valve, and start supplying carbon dioxide mixture. The EEG / EMG monitoring circuit includes a first electrode J1, a second electrode J2, operational amplifiers U2 and U3, resistors R2, R3, R4, R6, and R7, a transistor Q1, operational amplifier U4, and resistor R8. The first electrode J1 is connected to the non-inverting input terminal of operational amplifier U2 via a shielded cable. The second electrode J2 is connected to the non-inverting input terminal of operational amplifier U3 via a shielded cable. The inverting input terminal of operational amplifier U2 is connected to the inverting input terminal of operational amplifier U3 via resistor R3. The output terminal of operational amplifier U2 is connected to the inverting input terminal of operational amplifier U2 via resistor R2. The output terminal of operational amplifier U3 is connected to the inverting input terminal of operational amplifier U3 via resistor R4. The output terminals of operational amplifier U2 and operational amplifier U3 are connected to the first input terminal of the main control unit via an amplifier circuit. The output terminal of operational amplifier U2 is connected to the collector of transistor Q1 through resistor R6. The output terminal of operational amplifier U3 is connected to the collector of transistor Q1 through resistor R7. The emitter of transistor Q1 is connected to the inverting input terminal of operational amplifier U4. The non-inverting input terminal of operational amplifier U4 is connected to the collector of transistor Q1. The output terminal of operational amplifier U4 is connected to the base of transistor Q1. The inverting input terminal of operational amplifier U4 is connected to the shielding layer of the shielded cable through resistor R8.

2. The sleep apnea-hypopnea disease modeling system according to claim 1, characterized in that, It also includes a carbon dioxide monitoring circuit, the input of which is connected to the inside of the enclosed enclosure, and the output of which is connected to the main control unit.

3. The sleep apnea-hypopnea disease modeling system according to claim 1, characterized in that, It also includes a feedback circuit, which comprises operational amplifier U7, resistors R12 and U8, resistors R13 and R14, and a third electrode J3. The non-inverting input of operational amplifier U7 is connected to the emitter of transistor Q1, and the output of operational amplifier U7 is connected to the inverting input of operational amplifier U7. The output of operational amplifier U7 is connected to the inverting input of operational amplifier U8 through resistor R12. The non-inverting input of operational amplifier U8 is connected to the Vref reference voltage, and the output of operational amplifier U8 is connected to the inverting input of operational amplifier U8 through resistor R13. The output of operational amplifier U8 is connected to the third electrode J3 through resistor R14.

4. The sleep apnea-hypopnea disease modeling system according to claim 1, characterized in that, The amplifier circuit includes resistor R9, operational amplifier U1, resistor R10, and resistor R11. The first end of resistor R9 is connected to the output terminal of operational amplifier U2, and the second end of resistor R9 is connected to the non-inverting input terminal of operational amplifier U1. The first end of resistor R10 is connected to the output terminal of operational amplifier U3, and the second end of resistor R10 is connected to the inverting input terminal of operational amplifier U1. The output terminal of operational amplifier U1 is connected to the inverting input terminal of operational amplifier U1 through resistor R11, and the output terminal of operational amplifier U1 is connected to the first input terminal of the main control unit.

5. The sleep apnea-hypopnea disease modeling system according to claim 4, characterized in that, A filter circuit is further included between the output terminal of the operational amplifier U1 and the first input terminal of the main control unit. The filter circuit includes resistors R15 and R16, capacitors C8, C9, C7, R17, operational amplifier U9, a variable resistor RP1, and operational amplifier U10. The first end of resistor R15 is connected to the output terminal of operational amplifier U1, and the second end of resistor R15 is connected to the non-inverting input terminal of operational amplifier U9 through resistor R16. The first end of capacitor C8 is connected to the first end of resistor R15, and the second end of capacitor C8 is connected to the non-inverting input terminal of operational amplifier U9 through capacitor C9. The output terminal of operational amplifier U9 is connected to the inverting input terminal of operational amplifier U9. The output terminal of operational amplifier U9 is connected to the first terminal of rheostat RP1. The second terminal of rheostat RP1 is grounded. The sliding terminal of rheostat RP1 is connected to the non-inverting input terminal of operational amplifier U10. The output terminal of operational amplifier U10 is connected to the inverting input terminal of operational amplifier U10. The output terminal of operational amplifier U9 is connected to the second terminal of capacitor C8 through resistor R17. The output terminal of operational amplifier U10 is connected to the second terminal of resistor R15 through capacitor C7. The output terminal of operational amplifier U10 is connected to the first input terminal of the main control unit.

6. The sleep apnea-hypopnea disease modeling system according to claim 1, characterized in that, The valve control circuit includes two branches with identical circuit structures. Each branch includes an optocoupler U13, resistors R27 and R26, a transistor Q5, and a relay K1. The first input terminal of the optocoupler U13 is connected to a 5V power supply, and the second input terminal of the optocoupler U13 is connected to the second output terminal of the main control unit. The first output terminal of the optocoupler U13 is connected to a 5V power supply through resistor R27, and the second output terminal of the optocoupler U13 is connected to the base of the transistor Q5 through resistor R26. The collector of the transistor Q5 is connected to the first input terminal of the relay K1, and the second input terminal of the relay K1 is connected to a 5V power supply. The emitter of the transistor Q5 is grounded, the normally open terminal of the relay K1 is connected to the power supply, and the common terminal of the relay K1 is connected to the first solenoid valve.

7. The sleep apnea-hypopnea disease modeling system according to claim 2, characterized in that, The carbon dioxide monitoring circuit includes an infrared sensor P1, an operational amplifier U11, resistors R21 and R22. The power supply terminal of the infrared sensor P1 is connected to a 5V power supply. The output terminal of the infrared sensor P1 is connected to the non-inverting input terminal of the operational amplifier U11. The ground terminal of the infrared sensor P1 is grounded. The inverting input terminal of the operational amplifier U11 is grounded through the resistor R21. The output terminal of the operational amplifier U11 is connected to the inverting input terminal of the operational amplifier U11 through the resistor R22. The output terminal of the operational amplifier U11 is connected to the second input terminal of the main control unit.

8. The sleep apnea-hypopnea disease modeling system according to claim 7, characterized in that, The carbon dioxide monitoring circuit also includes resistor R19, capacitor C11, resistor R20, and capacitor C12. The first end of resistor R19 is connected to the output terminal of infrared sensor P1, the second end of resistor R19 is grounded through capacitor C11, the second end of resistor R19 is connected to the first end of resistor R20, the second end of resistor R20 is grounded through capacitor C12, and the second end of resistor R20 is connected to the non-inverting input terminal of operational amplifier U11.

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