Organ-like chip-oriented in-vitro multi-gas-liquid-channel life maintenance culture system

Abstract

The invention discloses an in-vitro multi-gas-liquid-channel life maintenance culture system for organoid chips, and belongs to the technical field of in-vitro culture for organoid chips. The problem that an existing cell and tissue culture box is not suitable for culturing organoid samples needing a high-oxygen-concentration environment due to the lack of an oxygen concentration control channel is solved. The device comprises a control room, a culture room and a connecting device for the control room and the culture room, the control chamber comprises a material supply device for supplying liquid and gas, an interface for supplying materials such as oxygen, an interface for supplying signals and electric power, and an interface for receiving data signals from a temperature and humidity sensor, a carbon dioxide concentration sensor, an oxygen concentration sensor and a gas flow meter of the culture chamber; the single-chip microcomputer control chip is used for receiving signals, processing the signals and realizing control; the culture room is used for providing an environment for culturing the schematic organs. And the connecting device provided with the oxygen measuring cavity is used for connecting the control chamber and the culture chamber to realize material transportation and data interaction between the control chamber and the culture chamber.

Description

Technical Field

[0001] The present invention belongs to the technical field of in vitro culture for organoid chips, and particularly relates to an in vitro culture system for organoid chips. Background Art

[0002] The pharmaceutical field continues to explore drug discovery and R & D architectures aimed at achieving high yields and high efficiency. Nevertheless, the current in vitro 2D or 3D cell culture technologies and in vivo animal experimental models still have significant deficiencies in efficiently and accurately evaluating the effectiveness and toxicity of drugs at the preclinical stage, which limits their application in testing human subjects before clinical trial approval. Organoids, as a three-dimensional cell model, provide a powerful in vitro experimental platform for tissue and disease biology research.

[0003] On this basis, the organoid chip culture system further constructs a life culture system that promotes the growth of organoids by precisely regulating the internal microenvironment and simulating human physiological conditions. Organoid chips show broad application prospects in the fields of precision medicine and biodefense strategies. However, most of the currently widely used incubators are cabinet-type incubators, which are large in volume and heavy in weight, cannot be installed on a microscopic imaging platform for microscopic monitoring of the entire life cycle of organoid samples, and are not convenient to move, unable to meet potential needs such as home sampling for patients with limited mobility in clinical practice and sample transfer between different experimental platforms, and are not suitable for organoid culture. A small number of existing small-volume incubators can solve the above problems to a certain extent, but their structures are simple and the control channels are limited. Most of them can only control the temperature, humidity and carbon dioxide concentration of the culture environment, and are not suitable for certain organoids that require a specific growth environment, especially samples that need to be cultured in a high oxygen concentration environment. Therefore, it is necessary to design an organoid culture system that can be installed on a microscopic imaging platform, is lightweight and flat, and is convenient to move, and has more control channels. At the same time, it is necessary to solve the problems of re-design of the structure and control method derived from adding control channels. Summary of the Invention

[0004] The present invention solves the problem that existing cell and tissue incubators lack oxygen concentration control channels and are not suitable for culturing organoid samples that require a high oxygen concentration environment.

[0005] An in vitro multi-gas-liquid channel life maintenance culture system for organoid chips, comprising: a control room, a culture room, and a connecting device connecting the two;

[0006] The control room includes a single-chip microcomputer control chip, a material supply device and an interface;

[0007] The interface includes a material supply interface; the material supply interface includes a culture medium interface for supplying culture medium to the organoids in the culture chamber, an oxygen interface for introducing oxygen into the culture chamber, a mixed air interface for introducing mixed air into the culture chamber; a water tank interface for replenishing water into the water tank and an exhaust gas interface for receiving the exhaust gas discharged from the culture chamber;

[0008] The material supply device includes a liquid supply part and a gas supply part; the liquid supply part is driven by multiple liquid pumps. The input ends of the multiple liquid pumps are respectively connected to the culture medium storage tank and the water storage tank, and the output ends are respectively connected to the culture medium interface and the water tank interface; the multiple liquid pumps are controlled by a single-chip microcomputer control chip to adjust the flow rates of the culture medium and purified water input into the culture chamber; the gas supply part is driven by a gas mixer and regulated by an electromagnetic flow rate valve. The input ends of the gas mixer are respectively connected to the mixed air storage tank and the carbon dioxide storage tank. The two input gases will be mixed in different proportions in the gas mixer, and this proportion is controlled by the single-chip microcomputer control chip to adjust the carbon dioxide concentration in the mixed gas output by the gas mixer, and further adjust the carbon dioxide concentration in the culture chamber; the output end of the gas mixer is connected to the mixed air interface through the electromagnetic flow rate valve; the oxygen storage tank is connected to the oxygen interface through the electromagnetic flow rate valve, and the opening degree of the electromagnetic flow rate valve is controlled by the single-chip microcomputer control chip to adjust the flow rates of the two gases introduced into the culture chamber and then adjust the gas concentration in the culture chamber;

[0009] The single-chip microcomputer control chip is responsible for receiving the data signals from the temperature and humidity sensor, carbon dioxide concentration sensor, oxygen concentration sensor, and gas flow meter, and performing signal processing. The signal processing includes multi-channel PID controller calculation, oxygen concentration calculation, and signal visualization processing; the multi-channel PID controllers are respectively: input the oxygen concentration in the culture chamber and output the opening degree of the electromagnetic flow rate valve of the oxygen channel; input the carbon dioxide concentration in the culture chamber and output the mixing ratio of the gas mixer; input the water level of the water tank and output the flow rate of the purified water channel of the multiple liquid pumps; input the temperature and humidity in the culture chamber and output the power of the two heaters in the culture chamber; the single-chip microcomputer control chip outputs control signals to control the electromagnetic flow rate valve, top heater, bottom heater, liquid pump, and gas mixer;

[0010] The culture chamber includes an organoid chip slot, a temperature and humidity sensor, a carbon dioxide concentration sensor, a bottom heater, a water tank and a water level gauge, and a gas flow meter;

[0011] The water level gauge is used to measure the water level of the water tank;

[0012] The organoid slot is equipped with a microfluidic interface for fixing the organoid chip and is connected to the liquid interface of the culture chamber to receive the culture medium input from the control room;

[0013] A temperature and humidity sensor and a carbon dioxide concentration sensor are used to measure the temperature, humidity and carbon dioxide concentration in the effective area inside the culture chamber;

[0014] A gas flowmeter is located at the exhaust gas interface of the culture chamber and is used to measure the flow rate of the exhaust gas discharged from the culture chamber;

[0015] The bottom heater is used to heat the culture chamber and the water tank;

[0016] The connection device is used to connect the control room and the culture chamber to realize the material transportation and data interaction between the two, and includes a fluid conduit, a pre-heater, and an oxygen measurement chamber;

[0017] The fluid conduit includes an oxygen conduit, a mixed air conduit, an exhaust gas conduit, a culture solution conduit, and a water tank conduit;

[0018] The pre-heater is used to pre-heat the gas and liquid output from the control room;

[0019] The oxygen measurement chamber is externally placed outside the culture chamber. The oxygen measurement chamber is connected in parallel to the exhaust gas conduit of the connection device. An oxygen concentration sensor is installed inside the cavity of the oxygen measurement chamber to measure the oxygen concentration in the exhaust gas, which is used to assist the single-chip microcomputer controller to calculate the oxygen concentration in the central area of the culture chamber.

[0020] Furthermore, the interface of the control room also includes a power interface. The power interface uses a USB interface, which is used to provide power and transmit data; the USB interface integrates an IIC communication bus, a 5V positive electrode, a 24V positive electrode, and a ground wire. The 5V and 24V are connected in parallel to the power subsystem, and the IIC communication bus is connected in parallel to the IIC communication interface of the single-chip microcomputer control chip;

[0021] The connection device also includes a power cable, which integrates a 5V positive line, a 24V positive line, a ground wire, and an IIC communication bus. Both ends of the cable are connected to USB connectors to realize the energy and data interaction between the culture chamber and the control room;

[0022] The culture chamber is also provided with a power interface. The power interface uses a USB interface, which is used to connect the power cable in the connection device. The USB interface integrates an IIC communication bus, a 24V positive electrode, a 5V positive electrode, and a ground wire. The power lines and electronic components in the culture chamber are respectively connected to the corresponding above-mentioned sub-interfaces, that is, the temperature and humidity sensor, the gas flowmeter, and the carbon dioxide concentration sensor in the culture chamber are respectively connected in parallel to 5V-GND, that is, connected in parallel to the IIC bus, and the heater is connected in parallel to 24V-GND;

[0023] The oxygen concentration sensor inside the oxygen measurement chamber is connected in parallel to the power cable of the connection device to receive 5V-GND power supply and serves as an IIC communication slave device.

[0024] Furthermore, the power subsystem is also used to provide a 3.3V power supply, and the 3.3V power supply is used to power the single-chip microcomputer control chip.

[0025] Furthermore, the control room also includes a key array, which is connected to the single-chip microcomputer control chip. The single-chip microcomputer control chip receives signals from the key array and executes corresponding commands according to the instructions expressed by the key array signals. The 3.3V power supply provided by the power subsystem is also used to power the key array.

[0026] Furthermore, the control room also includes a display screen for displaying status information of the culture chamber and / or visual information corresponding to the instructions expressed by the key array signals.

[0027] Furthermore, the culture chamber also includes a box cover, and a top heater is embedded in the box cover; the top heater is connected in parallel to the 24V-GND power supply line of the culture chamber to obtain power.

[0028] Furthermore, the preheater is flat in shape, and a plurality of fluid conduits and power cables are wrapped side by side inside the preheater, and the plurality of fluid conduits include at least an oxygen conduit, a mixed air conduit, an exhaust gas conduit, a culture medium conduit, and a water tank conduit; the preheater is installed with a tee, and the exhaust gas conduit is connected to the tee pipe inside the heater, and the tee pipe structure has two outlets, one outlet is connected to the oxygen measuring chamber, and the other outlet is connected to the control chamber, and the exhaust gas is divided into two parts and respectively introduced into the control chamber and the oxygen measuring chamber; the preheater is also provided with a "T-shaped" cable connection structure, and the power cable is divided into three sections and connected by the "T-shaped" cable connection structure, two of which are connected to the control room and the culture chamber respectively through a USB interface, and the 24V-GND line in the third section provides 24V power to the preheater, and the 5V-GND line in the third section is connected to the oxygen concentration sensor in the oxygen measurement chamber to provide 5V power to the oxygen concentration sensor.

[0029] Furthermore, the oxygen interface and the mixed air interface of the culture chamber are located at the center height of the culture chamber, and the exhaust gas interface is arranged on the opposite side of the oxygen interface and the mixed air interface.

[0030] The present invention proposes a culture system that can maintain a stable biological state for a long time in vitro. The system provides an in vitro culture scheme for organoid chips by accurately simulating the in vivo environment to ensure its consistency with the in vivo environment. This scheme is particularly suitable for maintaining the state of organoids that require a high oxygen concentration environment in vivo, thereby keeping them synchronized with the state of the organism in vivo for a period of time. In particular, the present invention provides an oxygen concentration control channel to achieve the cultivation of organoid samples that require a high oxygen concentration environment. The gas channel design method of the present invention can not only achieve accurate oxygen concentration measurement, but also greatly avoid engineering problems such as mutual interference between multiple gas channels.

[0031] Meanwhile, the present invention provides a portable organoid culture system. This device adopts a highly integrated design, providing users with a compact and precise organoid preservation system. By integrating a complex organoid culture platform into a lightweight and flattened culture system and combining it with a sliding lid design, the dissipation of internal gas is effectively reduced, the airtightness of the culture chamber is improved, and thus interference from the external environment is avoided. In addition, the present invention provides a life culture system that is economical, efficient, and meets the needs of personalized treatment. For the in vitro culture of organoid chips, this life culture system provides users with a tool for in vitro organoid culture at a relatively low cost (about one thousand yuan), significantly reducing the economic burden of cultivating, preserving, and transporting organoids during personalized treatment.

[0032] Furthermore, in the in vitro multi-gas-liquid channel life support culture system for organoid chips, the multi-channel PID controller makes control based on the data of the prediction module. The design process of the multi-channel PID controller and the prediction module is as follows:

[0033] S100. Conduct finite element simulation analysis to obtain prior data:

[0034] Perform three-dimensional modeling according to the optimized and redesigned culture chamber structure, fill the fluid domain, and mesh the fluid domain. Study the oxygen concentration, carbon dioxide concentration, temperature, and humidity in the central area of the culture chamber, conduct transient analysis, and save the simulation results. Adjust and input the gas flow rates of two different gas interfaces, the power of the heater in the culture chamber, and the carbon dioxide concentration in the mixed air. Repeat the process multiple times respectively and save the simulation results separately;

[0035] S200. Conduct system identification to obtain the culture chamber environment regulation model:

[0036] According to the simulation result data set obtained from the finite element analysis, take the oxygen concentration, carbon dioxide concentration, temperature, and humidity in the central area of the culture chamber as the outputs, and take the gas flow rate of the oxygen interface, the gas flow rate of the mixed air interface, the carbon dioxide concentration in the mixed air, and the power of the heater in the culture chamber as the controllable quantities for system identification, obtaining the state space equation representation of the oxygen, carbon dioxide concentration, temperature, and humidity in the central area of the culture chamber with respect to the controllable quantities, as the culture chamber environment regulation model;

[0037] S300. Design a multi-channel PID controller:

[0038] The multi-channel PID controllers are respectively: input the oxygen concentration in the culture chamber and output the opening degree of the electromagnetic flow valve in the oxygen channel; input the carbon dioxide concentration in the culture chamber and output the mixing ratio of the gas mixer; input the water level in the water tank and output the flow rate of the purified water channel of the multi-channel liquid pump; input the temperature and humidity in the culture chamber and output the power of the heater in the culture chamber;

[0039] S400, Design Prediction Module:

[0040] Based on the culture chamber environment regulation model, input the opening degree of the electromagnetic flow velocity valve of the oxygen channel designed by the multi-channel PID controller, the mixing ratio of carbon dioxide and mixed air in the gas mixer, and the heater power of the culture chamber into the model, and output the situation of the culture chamber environment indicators within the next n control cycles of the model, that is, the oxygen and carbon dioxide concentrations and temperature and humidity in the central area of the culture chamber. And obtain the correction amount in the current control cycle based on the change of the culture chamber environment within the n control cycles:

[0041] For the oxygen concentration control channel, record the output result of the PID controller in the i-th control cycle as u0(i), and this value will be used as the input of the prediction module. The prediction module makes a prediction: According to the culture chamber environment regulation model obtained in S200, iteratively predict the oxygen concentration in the central area of the culture chamber within the next n control cycles when the actuator directly executes this control signal, and obtain a series of discrete concentration data. The oxygen concentration in the k-th control cycle relative to the i-th control cycle is denoted as c p (i, k), and denote the set desired oxygen steady-state concentration as c0, and calculate c p (i, k) for all points that satisfy c ph (i, k) > c0, the ||c ph (i, k) - c0||2 2 And sum them up as Calculate c p (i, k) for all points that satisfy c pl (i, k) ≤ c0, the ||c pl (i, k) - c0||2 2 And sum them up as Calculate K(l h (i) - l l (i)) as the output of the prediction module on the oxygen concentration control channel, that is, the correction amount u p (i), where K is a negative gain coefficient;

[0042] Finally, the corrected control signal input to the actuator in the i-th control cycle is denoted as u(i) = u0(i) + u p (i), that is, the actual control signal;

[0043] The control calculation logic of other control channels is the same as that of the oxygen channel.

[0044] Furthermore, the oxygen concentration in the culture chamber of the PID controller in the oxygen channel of the multi-channel input PID controller is determined through calculation. The calculation process of the oxygen concentration in the culture chamber includes the following steps:

[0045] A1. Obtain the gas flow model and state observer inside the connection device. The gas flow model and state observer inside the connection device are obtained through the following steps:

[0046] 1) Obtain the prior data obtained in advance. The process of obtaining the prior data is as follows:

[0047] In the finite element simulation analysis software, perform three-dimensional modeling according to the structures of the exhaust gas duct w and the oxygen measurement chamber in the designed connection device structure, fill the fluid domain and perform mesh division on the fluid domain, study the oxygen concentration in the oxygen measurement chamber and perform transient analysis and save the simulation results, adjust the oxygen concentration in the central area of the culture chamber and the gas flow rate at the exhaust gas interface w of the culture chamber, and save the simulation results separately multiple times;

[0048] 2) The gas flow model inside the connection device obtained through system identification based on the prior data:

[0049] According to the data set obtained from the finite element analysis, take the gas flow rate at the exhaust gas interface w of the culture chamber at the k-th simulation step as the input u s (k), take the oxygen concentration in the oxygen measurement chamber at the k-th simulation step as the output y s (k), and take the oxygen concentration in the central area of the culture chamber at the k-th simulation step as the state variable x s (k), perform system identification calculation to obtain the state space equation representation of the oxygen concentration in the oxygen measurement chamber with respect to the gas flow rate at the exhaust gas interface w of the culture chamber, that is, the gas flow model inside the connection device:

[0050] x s (k + 1) = A s x s (k) + B s u s (k)

[0051] y s (k) = C s x s (k)

[0052] Among them, A s represents the discrete state coefficient of the flow model, B s represents the discrete input coefficient of the flow model, and C s represents the discrete output coefficient of the flow model;

[0053] 3) Design a state observer according to the gas flow model:

[0054]

[0055] Among them, represents the observed value obtained by the state observer, i.e., the observed oxygen concentration; L is the coefficient of the observer; represents the gas flow rate at the waste gas interface w of the culture chamber measured by the gas flow meter at the k-th moment, represents the oxygen concentration in the oxygen measurement chamber measured by the oxygen concentration sensor at the k-th moment;

[0056] A2. Calculate the oxygen concentration in the central area of the culture chamber based on the oxygen concentration in the oxygen measurement chamber:

[0057] Use the input and output of the gas flow model measured by the gas flow meter and the oxygen concentration sensor, and the observed value of the state observer corresponding to the gas flow model inside the connection device, i.e., the calculated oxygen concentration.

[0058] The present invention proposes a control method based on prior finite element simulation analysis data for the control design of a complex fluid domain with multiple gas channels, including a PID control system, a prediction module, and a gas concentration delay calculation; it can control the environment of the culture chamber in a timely and accurate manner, providing an organoid with a survival condition similar to the human body's internal environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 is a schematic diagram of the front (display side) structure of the control room;

[0060] Figure 2 is a schematic diagram of the back structure of the control room;

[0061] Figure 3 is a schematic diagram of one side structure of the culture chamber;

[0062] Figure 4 is a schematic diagram of the other side structure of the culture chamber;

[0063] Figure 5 is a schematic diagram of the connection device structure;

[0064] Figure 6 is a schematic diagram of the oxygen measurement chamber and pre-heater dimensions;

[0065] Figure 7 is a schematic diagram of the control strategy;

[0066] Figure 8 is a schematic diagram of the oxygen channel control effect;

[0067] Figure 9 is a schematic diagram of the culture chamber interface distribution and device installation;

[0068] Figure 10 is a schematic diagram of the control room button distribution and OLED interface. DETAILED DESCRIPTION OF THE INVENTION

[0069] The present invention proposes a novel life - maintaining culture system for in vitro - cultured organoids, specifically relating to the design of a portable culture system based on organoid chip technology. This culture system integrates a comprehensive environmental variable adjustment module, including a temperature and humidity adjustment unit and a gas concentration (involving carbon dioxide and oxygen) adjustment unit, to achieve precise control of the basic environmental conditions inside the culture system. Through the designed control algorithm, the present invention aims to provide a survival condition similar to the human internal environment for organoids, ensuring the stability and consistency of the organoid state.

[0070] The design of this culture system aims to provide a long - term stable and controllable in vitro culture environment for experimental scenarios such as observing the process of organoids from induced growth to the entire life cycle under a microscope and the changes in diseased organ samples under the action of drugs. This environment can meet the requirements of controlling experimental variables, thus providing an experimental organoid chip platform for drug screening, treatment plan formulation, and prognosis evaluation in tumor treatment. Through this platform, researchers can conduct more precise and systematic experimental studies to promote the development of personalized medicine and precision treatment. Specific Embodiment 1:

[0072] An in vitro multi - gas - liquid channel life - maintaining culture system for an organoid chip described in this embodiment mainly includes: a control room, a culture room, and a connecting device connecting the two. The present invention aims to design a lightweight and flattened organoid sample culture system. Therefore, the volume of the culture room is very small. To save space as much as possible and reserve enough space for installing the organoid chip, the present invention only integrates necessary and extremely small - volume partial sensors inside the culture room, and other actuators such as mass exchange devices and other larger - volume components are integrated in the control room independent of the culture room, and a connecting device for connecting the two parts to achieve mass, energy, and data interaction is designed.

[0073] As Figure 1 and Figure 2 shown, the control room includes a single - chip microcomputer control chip, a power supply subsystem, a substance supply device, an OLED display screen, a key array, and interfaces, etc.;

[0074] The interfaces include two major parts: a substance supply interface and a power interface:

[0075] The substance supply interface includes a culture medium interface Aq for providing culture medium to the samples in the culture room; an oxygen interface ga for introducing oxygen into the culture room; a mixed air interface gb for introducing mixed air into the culture room; a water tank interface l for replenishing water into the water tank; and an exhaust gas interface w for receiving the exhaust gas discharged from the culture room. The above interfaces all adopt common fluid interfaces;

[0076] The power interface uses a USB interface and is connected to the culture chamber through a connecting device for providing power and transmitting data. The USB interface integrates an IIC communication bus, a 5V positive pole, a 24V positive pole, and a ground wire. Among them, the two power supplies are connected in parallel to the power supply subsystem of the control room, and the IIC communication bus is connected in parallel to the IIC communication interface of the single-chip microcomputer control chip.

[0077] The substance supply device includes two parts: a liquid supply part and a gas supply part.

[0078] The liquid supply part is driven by multiple liquid pumps. The input ends of the multiple liquid pumps are respectively connected to the culture medium storage tank and the water storage tank, and the output ends are respectively connected to the culture medium interface Aq and the water tank interface l. The multiple liquid pumps are controlled by the single-chip microcomputer control chip to adjust the flow rates of the culture medium and purified water input into the culture chamber.

[0079] The gas supply part is driven by a gas mixer and regulated by an electromagnetic flow valve. The input ends of the gas mixer are respectively connected to the mixed air storage tank and the carbon dioxide storage tank. The two input gases will be mixed in different proportions in the gas mixer. This proportion is controlled by the single-chip microcomputer control chip, and then the adjustment of the carbon dioxide concentration in the mixed gas output by the gas mixer is realized, and further the adjustment of the carbon dioxide concentration in the culture chamber is realized. The output end of the gas mixer is connected to the mixed air interface gb through the electromagnetic flow valve. The oxygen storage tank is connected to the oxygen interface ga through the electromagnetic flow valve. The opening degree of the electromagnetic flow valve is controlled by the single-chip microcomputer control chip to realize the adjustment of the flow rates of the two gases introduced into the culture chamber, and then the adjustment of the gas concentration in the culture chamber is realized.

[0080] Due to the limited internal space of the control room, the various storage tanks may not be installed inside the control room. Therefore, corresponding interfaces are reserved on the back of the control room, and a substance source such as an oxygen cylinder can be connected to the control room through these interfaces, and the required substances can be input into the actuators inside the control room.

[0081] The substance supply device provides the nutrients and test drugs required for the growth of organoids through the microfluidic interface of the organoid chip, and uses a supporting liquid conduit to connect the culture medium interface Aq inside the culture chamber and the microchannel liquid supply tank of the organoid chip to realize the input of the culture medium into the organoid chip. It should be noted that the present invention does not involve the specific design of the organoid chip, only considers interacting with the interface of the organoid chip. The organoid chip mentioned above is prior art and will not be elaborated in the present invention.

[0082] The single-chip microcontroller control chip is responsible for receiving data and signals from the temperature and humidity sensor, carbon dioxide concentration sensor, oxygen concentration sensor, gas flow meter, and key array, and performing signal processing. The signal processing includes multi-channel PID controller calculation, oxygen concentration calculation, and signal visualization processing. The multi-channel PID controllers are as follows: input the oxygen concentration in the culture chamber and output the opening degree of the electromagnetic flow valve in the oxygen channel; input the carbon dioxide concentration in the culture chamber and output the mixing ratio of the gas mixer; input the water level in the water tank and output the flow rate of the multi-channel liquid pump's purified water channel; input the temperature and humidity in the culture chamber and output the power of the two heaters in the culture chamber. The single-chip microcontroller control chip outputs control signals to control the electromagnetic flow valve, top heater, bottom heater, liquid pump, and gas mixer, and displays relevant information on the OLED display screen.

[0083] The oxygen concentration in the culture chamber is obtained through calculation. The oxygen concentration calculation process is that the single-chip microcontroller control chip collects the measured values of the gas flow meter and oxygen concentration sensor; according to the gas discharge flow rate at the waste gas interface in the culture chamber and the oxygen concentration in the oxygen measurement chamber, the oxygen concentration in the central area of the culture chamber is solved.

[0084] The single-chip microcontroller control chip receives the signals from the key array, executes corresponding commands according to the instructions input by the key array, and displays the corresponding visualization information on the OLED display screen.

[0085] In the power supply subsystem, the 3.3V power supply supplies power to the single-chip microcontroller control chip separately inside the control room. The 5V low-voltage power supply is used to supply power to the electromagnetic speed control valve, carbon dioxide concentration sensor, oxygen concentration sensor, gas flow meter, temperature and humidity sensor, and OLED display screen. The 24V high-power power supply is connected to the material supply device to supply power to the multi-channel liquid pump, heater, and gas mixer. The voltage conversion is achieved through boost or buck components and power amplifiers. At the same time, the output power of the power amplifier is controlled by the signal of the single-chip microcontroller control chip.

[0086] The key array is located on the front outer panel of the control room and includes numeric keys from 0 to 9, four direction keys, an Auto key, an Enter key, a switch key, and an encoding knob for adjusting input data and the display information on the OLED display. To facilitate the user to call various functions, the present invention provides a key array on the front panel of the control room. The numeric keys are used to input data to be set, such as the desired oxygen concentration in the culture chamber, etc.; the direction keys are used to adjust the cursor position, and the text at the cursor position will be highlighted; the Auto key is used to set the specific values of the oxygen, carbon dioxide concentrations, temperature, and humidity in the culture chamber and the tracking curve to facilitate judging the control effect of the environment in the culture chamber; the Enter key is used to confirm key input. After pressing, the text at the cursor position will flash periodically, and at this time, the parameter value at this position can be adjusted through the keys and the knob; the switch key is used to control the power subsystem; the encoding knob integrates the functions of the direction keys and the numeric keys, can adjust the cursor position, and after confirming key input, the value can be adjusted by turning the knob. The knob and the keys are located on both sides of the front panel of the control room to support two-handed operation to improve efficiency, and it is more intuitive to adjust data through the knob. The key array is connected to the microcontroller control chip, and various parameters set through the key array will be stored in the memory of the microcontroller and used as expected values to guide the calculation of the PID controller. Key operations will drive the microcontroller to execute different instructions.

[0087] The OLED display is used to display the status information of the culture chamber, including the expected temperature, humidity, oxygen concentration, and carbon dioxide concentration indicators set during the culture preparation period, whether the changes of various indicators inside the culture chamber are stable during the culture process, and error messages such as problems existing during the culture process, such as some necessary interfaces not being connected, the water level in the water tank being too low, and the actual indicators deviating too much from the expectations, affecting the survival of organoids, etc.

[0088] As Figure 3 and Figure 4 shown, the culture chamber includes an organoid chip slot, a temperature and humidity sensor, a carbon dioxide concentration sensor, a bottom heater, a lid and a top heater, a water tank and a water level gauge, a gas flow meter, and a USB interface;

[0089] Purified water is injected into the water tank to maintain a high humidity environment. At the same time, the high specific heat capacity of water can enhance the anti-interference ability of the temperature in the culture chamber. The water level in the water tank is 15 mm high, and the water injection volume is about 28 cc.

[0090] The water level gauge is used to measure the water level to ensure that there is sufficient water in the water tank. When the water level in the water tank is lower than the preset water level, the water level gauge will output a switch signal to the control room through the connection device. After receiving the switch signal, the microcontroller controls the liquid pump to supplement purified water into the water tank until the preset water level is reached.

[0091] The organoid slot is equipped with a microfluidic interface for fixing the organoid chip and is connected to the liquid interface of the culture chamber to receive the culture medium input from the control chamber.

[0092] The temperature and humidity sensor and the carbon dioxide concentration sensor are attached to the partition of the water tank and are used to measure the temperature, humidity and carbon dioxide concentration in the central area inside the culture chamber. The two sensors are connected in parallel on the IIC communication bus of the culture chamber as slaves and are connected in parallel on the 5V-GND power supply line of the culture chamber to obtain power. The temperature and humidity sensor and the carbon dioxide concentration sensor monitor and transmit environmental data to the control chamber in real time, which is used as the basis for the single-chip microcomputer control chip to calculate the control quantity and output the control signal.

[0093] The gas flowmeter is located at the exhaust gas interface w of the culture chamber and is used to measure the flow rate of the exhaust gas discharged from the culture chamber. This sensor is connected in parallel on the IIC communication bus of the culture chamber as a slave and is connected in parallel on the 5V-GND power supply line of the culture chamber to obtain power.

[0094] The bottom heater is used to heat the culture chamber to ensure that the organoids are at an appropriate growth temperature (37±0.5°C); at the same time, the bottom heater is used to heat the water tank to evaporate the water in it to create a high humidity environment of more than 90% and then reduce the evaporation of the culture medium. The two heaters are connected in parallel on the 24V-GND power supply line of the culture chamber to obtain power.

[0095] In the present invention, all the circuits inside the culture chamber are embedded inside the mechanical frame of the culture chamber, that is, the box wall. The IIC communication bus, the 5V positive electrode, the 24V positive electrode and the ground wire are integrally connected to the USB interface of the culture chamber. The culture chamber realizes data and energy interaction with the USB interface on the control chamber through this interface and is connected through the power cable of the connecting device.

[0096] The box cover adopts a sliding cover design. The outer frame of the box cover is made of opaque material and is embedded with the top heater circuit. The width of the outer frame is about the same as the width of the water tank. Most of the central area is the top heater and is directly opposite to the area inside the culture chamber for installing the organoid chip. The top heater uses resistive glass to improve the heating efficiency and avoid fogging inside the glass box cover, which affects the observation.

[0097] At the same time, a bracket for fixing the fluid conduit is provided on the side of the box wall.

[0098] All the power devices inside the culture chamber are connected in parallel to the overall circuit of the control chamber through the connecting device. Among them, the two heaters are powered by a 24V power supply, and the three sensors are powered by a 5V logic power supply and establish data interaction with the single-chip microcomputer control chip.

[0099] The culture chamber is provided with a USB interface for connecting the power cable in the connection device. The USB interface integrates an IIC communication bus, a 24V positive pole, a 5V positive pole, and a ground wire. The power lines and electronic components embedded in the inner wall of the culture chamber are respectively connected to the corresponding sub-interfaces above. That is, the temperature and humidity sensor, gas flow meter, and carbon dioxide concentration sensor in the culture chamber are respectively connected in parallel to 5V-GND, that is, connected in parallel to the IIC bus, and the heater is connected in parallel to 24V-GND.

[0100] As Figure 5 shown, the connection device is used to connect the control room and the culture chamber to achieve material transportation and data interaction between the two, including a power cable, fluid conduits, a pre-heater, and an oxygen measurement chamber. Among them, the fluid conduits include three gas conduits for transporting oxygen, transporting mixed air, and transporting the exhaust gas discharged from the culture chamber, namely conduit ga, conduit gb, and conduit w, and two liquid conduits for transporting the drug-containing culture solution and purified water, namely conduit Aq and conduit l. The five conduits respectively correspond to the oxygen interface ga, mixed air interface gb, exhaust gas interface w, culture solution interface Aq, and water tank interface l on the control room and the culture chamber.

[0101] The power cable integrates a 5V positive line, a 24V positive line, a ground wire, and an IIC communication bus to achieve energy and data interaction between the culture chamber and the control room. Both ends of the cable are connected to USB connectors.

[0102] During use, one end of the five fluid conduits of the connection device is respectively connected to the corresponding control room interface, and the other end is connected to the corresponding culture chamber interface. One end of the power cable is connected to the control room USB interface, and the other end is connected to the culture chamber USB interface. Oxygen and mixed air are respectively input into the culture chamber from the control room through conduit ga and conduit gb. The exhaust gas in the culture chamber is input into the control room from the culture chamber through conduit w. Purified water is input into the culture chamber water tank from the control room through conduit l. The culture solution is input into the culture chamber from the control room through conduit Aq.

[0103] Multiple general fluid interfaces are reserved on the back of the control room, which support connecting other experimental platforms to further analyze the exhaust gas components, or these interfaces can not be connected, and the exhaust gas will be directly discharged into the atmosphere in the control room.

[0104] In order to ensure the stability of the environmental control in the culture chamber, a pre-heater is specially designed in the present invention. It is internally provided with heating wires for preheating the gas and liquid output from the control room to avoid interfering with the environment in the culture chamber.

[0105] The oxygen measurement chamber is intended to measure the oxygen concentration in the culture chamber. The present invention adds oxygen as a culture environment element, and it is necessary to control the oxygen concentration inside the culture chamber to be stably maintained at the desired concentration during the culture process, which inevitably requires an oxygen concentration sensor to measure the oxygen concentration inside the culture chamber. However, most of the existing oxygen concentration sensors are relatively large in size. Common oxygen concentration sensors are generally cylindrical structures with a diameter of about 2 cm and a height of about 1.6 cm. The effective area relative to the culture chamber is about 14 cm*10 cm, which cannot be directly ignored. If placed directly in the culture chamber, the culture space of the sample will be significantly reduced. The sensor needs to measure the gas concentration in the central area of ​​the culture chamber, so the oxygen concentration sensor needs to be installed close to the center, which makes the area lost in the culture chamber larger than the area occupied by the sensor itself. To this end, the present invention innovatively designs an external oxygen measurement chamber, which receives the exhaust gas discharged from the culture chamber. The single-chip microcomputer control chip can calculate the oxygen concentration in the central area of ​​the culture chamber by measuring the oxygen concentration in the exhaust gas discharged from the culture chamber. The cavity itself is relatively small in size and is mainly used to install an oxygen concentration sensor and reserve a small amount of space for accommodating the exhaust gas discharged from the culture chamber for sensor sampling, so as to avoid excessive gas being retained in the oxygen measurement chamber and causing large measurement errors. The cavity is attached to the pre-heater to save space. The oxygen measurement chamber needs to be connected in parallel to the exhaust gas duct w of the connecting device, so as to realize the input of a part of the exhaust gas discharged from the culture chamber into the oxygen measurement chamber. At the same time, the oxygen concentration sensor inside the oxygen measurement chamber needs to be connected in parallel to the power cable of the connecting device to receive 5V-GND power supply and serve as an IIC communication slave. The present invention adopts a three-way connection method to provide a parallel interface for the oxygen measurement chamber.

[0106] The preheater is flat in shape, and five fluid conduits (three gas conduits and two liquid conduits) are wrapped inside the preheater side by side with the power cable. A through hole is required on the center line of the upper surface of the preheater and directly opposite the exhaust gas conduit w, and a tee is installed. The exhaust gas conduit w is connected to the three-way pipe inside the heater. The three-way pipe structure has two outlets, one outlet is connected to the oxygen measurement chamber, and the other outlet is connected to the control chamber. The exhaust gas is divided into two parts, which are respectively introduced into the control chamber and the oxygen measurement chamber. The hard structure of the three-way has a supporting and limiting effect on the oxygen measurement chamber. The exhaust gas flowing through the oxygen measurement chamber will eventually flow into the control chamber, and a very small part of the exhaust gas will stay briefly inside the oxygen measurement chamber for sampling by the oxygen sensor. The control room has limited components and cannot perform complex gas composition analysis. Therefore, it is necessary to reserve interfaces for interaction with the analysis platform. Then, for the sake of structural regularity, the exhaust gas is discharged through these interfaces. If other platforms are connected, the exhaust gas will be introduced into these platforms.

[0107] A "T-shaped" cable connection structure is set at the midline of the upper surface of the preheater and directly opposite the power cable. The power cable is divided into three segments and is also connected inside the preheater through the "T-shaped" cable connection structure. Two of the segments are respectively connected to the control room and the culture room through USB interfaces. The third segment of the cable provides 24V power to the preheater and is also connected to the oxygen concentration sensor in the oxygen measurement chamber to provide 5V power. The oxygen concentration sensor is built in the center position at the top of the oxygen measurement chamber. In fact, the preheater is connected in parallel to the 24V-GND line in the third segment of the cable. The oxygen sensor is built in the center position at the top of the oxygen measurement chamber, connected in parallel to the 5V-GND line in the third segment of the cable and also connected in parallel to the IIC bus as a data communication slave device, thus realizing the power supply to the preheater and the power supply and data communication of the oxygen concentration sensor. For the specific dimensions of the oxygen measurement chamber and the preheater, please refer to Figure 6 。

[0108] Since the present invention adds a gas channel and an oxygen channel, it is necessary to redesign the mechanical structure of the culture room. At the same time, compared with the case where only a single gas is introduced and the gas can diffuse into the culture room relatively quickly and evenly, when multiple channels introduce gases, due to the different flow rates and molar concentrations of the introduced gases, the airflows will affect each other due to the Bernoulli effect, resulting in difficulty for the gases to diffuse evenly into the interior of the culture room. To solve the above problems, the present invention uses finite element simulation analysis as a support to design and optimize the mechanical structure of the culture room, especially the distribution of the gas channels.

[0109] To facilitate the uniform diffusion of gases, the oxygen interface ga and the mixed air interface gb of the culture room are located at the central height position of the culture room. The following problems are encountered during the design process:

[0110] (A) If the two gas channels proposed in this example introduce gases at the same flow rate, the two airflows will attract each other under the Bernoulli effect, and finally the steady-state distribution of the two gases will show a polarized state, and the gases in the culture room are extremely uneven; if the two gas channels are adjusted separately in terms of speed, the low-flow air will still be affected by the high-flow air, and the magnitude relationship between the airflows of the two gas channels will show an alternating change under the control of the controller. Although this can weaken the polarization phenomenon of the gas distribution, it takes a long time for the gas distribution inside the culture room to reach uniformity.

[0111] (B) Due to the existence of two gas channels, if the gas input and output interfaces of the culture room are both located on the same side of the culture room, the gases will diffuse towards the outlet direction after being introduced into the culture room, and the gas inlet closer to the exhaust gas outlet will be more affected. The introduced gases will be discharged under the action of air pressure before they are fully diffused into the culture room, which will seriously affect the control performance of the gas concentration.

[0112] Based on the above two points, in the present invention, the gas outlet, i.e., the waste gas interface w, is arranged on the side opposite to the gas inlets, i.e., interfaces ga and gb. The relatively large distance and the symmetrical structure effectively reduce the interference between the gas outlet and the inlets. At the same time, the gas inside the culture chamber will move from the side where the gas is introduced to the outlet side relatively quickly under the action of air pressure, improving the gas diffusion efficiency and alleviating the situation of gas retention and accumulation in the culture chamber.

[0113] In addition, the present invention provides a solution using the Bernoulli effect for problem (A). When designing the channels, one of the two gas interfaces, i.e., the mixed air interface gb, introduces mixed air at a fixed high flow rate. Carbon dioxide, the gas whose concentration needs to be controlled at a lower level, is allowed to be added to the mixed air. At the same time, the gas mixer in the control chamber supports adjusting the concentration of this gas in the mixed air, replacing the traditional method of adjusting the flow rate to achieve concentration control. The other interface, i.e., the oxygen interface ga, introduces oxygen at a low flow rate, and the concentration of this gas is adjusted by adjusting the flow rate of the introduced gas. Furthermore, the Bernoulli effect still exists among multiple airflows, but a situation is formed where a high-flow main airflow attracts and drives other low-flow airflows, effectively improving the gas diffusion efficiency.

[0114] The present invention conducts corresponding finite element simulation analysis based on the above principles, uses the data obtained from the finite element analysis as an experimental data set, and obtains the state space equation representation of the finite element model using the system identification theory. On this basis, the appropriate layout of the two gas interfaces and the flow rate ratio of the gases introduced into the two gas interfaces are obtained through the particle swarm optimization algorithm. The optimization process is as follows:

[0115] (1) Finite element simulation analysis: Establish a three-dimensional model of the culture chamber in the finite element analysis software, fill the fluid domain, and perform mesh division on the fluid domain. Study the oxygen and carbon dioxide concentrations in the central region of the culture chamber and conduct a 30s transient analysis to save data. Select different gas interface layouts and different flow rates of the two gases introduced, and repeat the above process ten to fifteen times respectively and save the data to form a prior data set for system identification.

[0116] (2) System identification: According to the data set obtained from the finite element analysis, take the oxygen concentration, carbon dioxide concentration, and the uniformity of the two gases in the central region of the culture chamber as outputs, and take the distribution of the two gas interfaces and the flow rates of the two gases as inputs, and conduct system identification calculations to obtain the state space equation representation of the gas flow model in the culture chamber. The uniformity of the gas is represented by the standard deviation of the gas concentrations at 10 different positions on the two diagonals of the culture chamber. The model obtained from the above system identification process is called the excitation model.

[0117] The above system identification process uses the MOESP algorithm of the MIMO system (multi-input multi-output system) and adopts a linear state space model where x m (k) ∈ R n represents the state variable of the excitation model at time k, u m (k) ∈ R m represents the input of the excitation model at time k, y m (k) ∈ R p represents the output of the excitation model at time k, A m ∈ R n×n represents the discrete state matrix of the excitation model, B m ∈ R n×m represents the discrete input matrix of the excitation model, C m ∈ R p×n represents the discrete output matrix of the excitation model, D m ∈ R p×m represents the discrete direct transfer matrix of the excitation model. According to step (1), u m (k) is a four-dimensional vector composed of the distribution of two gas interfaces and the flow rates of two gases. y m (k) is a four-dimensional vector composed of the oxygen concentration, carbon dioxide concentration, and the uniformity of two gases in the central area of the culture chamber. In the present invention, a third-order model is selected for system identification. Therefore, the dimensions of the above vector matrices are determined as x m (k) ∈ R 3 , u m (k) ∈ R 4 , y m (k) ∈ R 4 , A m ∈ R 3×3 , B m ∈ R 3×4 , C m ∈ R 4×3 , D m ∈ R 4×4 .

[0118] (3) Particle Swarm Optimization Algorithm: After obtaining the state - space equation representation of the finite - element model of gas flow in the culture chamber, it is used as the mechanism of the model. The quantity v to be optimized, which describes the distribution of two gas interfaces and the flow rates of two gases, is randomly initialized. That is, the vector to be optimized includes the horizontal positions of the two interfaces at the front panel of the culture chamber and the flow rates of the two gases. Next, an optimization iteration is carried out to search for the optimal situation of the oxygen concentration, carbon - dioxide concentration, and the uniformity of the two gases in the central area of the culture chamber, that is, when v takes what value, the uniformity of oxygen and carbon dioxide in the central area of the culture chamber can reach the optimal. This value is the result of the optimized redesign. In the present invention, the interfaces adopt a symmetric design, and all interfaces are located at the median height of the culture chamber. Only the horizontal positions of the interfaces on the surface of the culture chamber need to be considered. At the same time, considering that the culture chamber needs to be placed on a microscopic imaging platform and its structure needs to be relatively regular, the interfaces of the culture chamber are all located on the box walls of the narrow sides of the culture chamber.

[0119] (4) Result Verification: According to the optimized result, re - model and conduct finite - element simulation analysis to verify the effectiveness of the optimized result.

[0120] In summary, the present invention has carried out an optimized redesign of the mechanical structure of the culture chamber, enabling the multiple gases introduced to quickly and evenly diffuse into the interior of the culture chamber. At the same time, the design similar to the air - displacement method enables the waste gas to be effectively discharged from the culture chamber to avoid gas accumulation affecting the stability of the culture environment.

[0121] In addition, the design method proposed in the present invention is not only applicable to adding an oxygen channel, but also applicable to introducing other gases. It is still applicable to optimize and redesign the mechanical structure when more gas channels need to be added.

[0122] The multi - path PID controller of this embodiment makes control based on the data of the prediction module. The design processes of the multi - path PID controller and the prediction module are as follows:

[0123] The control algorithm of the control room takes the PID algorithm as the core, and on the basis of PID control, a prediction module is added to optimize and adjust the control quantity designed by the PID controller to form the final control signal.

[0124] Considering that the adjustment ability of the lightweight and low-power material delivery actuator is limited, there is a certain lag in gas concentration adjustment. At the same time, long-term operation may cause the continuously introduced gas to accumulate excessively in the culture chamber. Using a single PID controller will generate a large steady-state error; in scenarios where such regulation has time delay and is prone to overshoot oscillation, and the transient optimal control signal cannot ensure that the environmental indicators in the culture chamber reach the desired optimal state during the adjustment process, a predictive control method is adopted to solve this problem. However, considering the limited computing power and storage capacity of the single-chip microcomputer control chip used in the present invention, when dealing with predictive control based on a complex fluid model with multiple control variables, it may occur that the time for the single-chip microcomputer control chip to calculate the optimal control variable is longer than the control period of the culture system. This situation is intolerable in control design. To address the above problems, the present invention adds a prediction module as a feedforward control channel to the traditional PID control method to optimize the designed control variable, inheriting the long-term planning ability of predictive control to a certain extent, reducing overshoot oscillation and improving the dynamic performance of the control system, while overcoming the difficulties of its high computational complexity and long time required, which are difficult to implement on a lightweight and low-power computing platform. The specific implementation process of the algorithm is as follows:

[0125] S100. Conduct finite element simulation analysis to obtain prior data:

[0126] In the finite element simulation analysis software, perform three-dimensional modeling according to the optimized redesigned culture chamber structure, fill the fluid domain and perform mesh division on the fluid domain. Study the oxygen concentration, carbon dioxide concentration, temperature, and humidity in the central area of the culture chamber and conduct transient analysis, and save the simulation results within 30 s. Adjust the gas flow rates of the two gas inlets, the power of the heater in the culture chamber (i.e., the evaporation power of the purified water in the water tank, and this adjustment is mainly for the temperature and humidity in the culture chamber), and the carbon dioxide concentration in the mixed air. Repeat the above process ten to fifteen times (as long as the accuracy requirements of system identification can be met) respectively and save the simulation results. The finite element simulation will save the calculation results in the form of images or tables, and read and analyze these saved data in system identification.

[0127] S200. Conduct system identification based on the prior data to obtain the culture chamber environment adjustment model:

[0128] Based on the simulation result dataset obtained from finite element analysis, the oxygen concentration, carbon dioxide concentration, and temperature and humidity in the central area of the culture chamber (the indicators in the central area of the culture chamber are the data to be obtained) are used as outputs, and the gas flow rate at the oxygen interface, the gas flow rate at the mixed air interface, the carbon dioxide concentration in the mixed air (i.e., the carbon dioxide concentration in the mixed air input into the culture chamber), and the power of the heater in the culture chamber are used as controllable quantities (inputs) for system identification to obtain the state space equation representation of the oxygen, carbon dioxide concentrations, and temperature and humidity in the central area of the culture chamber with respect to the controllable quantities, which is used as the culture chamber environment adjustment model (hereinafter referred to as the adjustment model), that is, the model for subsequent prediction analysis, which is also the pre - process of subsequent prediction. The obtained state space model will be used as the iteration basis for prediction analysis. Finite element analysis is non - analytical and cannot be encapsulated in a single - chip microcomputer to guide the prediction algorithm, so it is necessary to perform system identification on the finite element analysis results to obtain an available prediction basis model.

[0129] The process of system identification: Obtain the output under the action of the input and save these data; Determine the model based on these data. In this embodiment, it is in the form of a state space equation and the model order, and use numerical analysis software to fit the parameters of the model according to the data in the previous step.

[0130] In this embodiment, the central area is defined as follows: The area enclosed by the inner wall of the water tank partition is taken as the central area, the 20 - mm - wide border is taken as the peripheral area, and the other areas are the central area. When detecting, 20 points are evenly taken in the central area, and the average gas concentration at these points is solved as the gas concentration in the central area of the culture chamber. In other embodiments, it can be determined according to actual needs, and even the space in the culture chamber can be directly used according to the control accuracy.

[0131] Actually, S100 is to obtain the output of the system under the action of the input by using finite element analysis, and S200 is the process of system identification and parameter fitting based on these data.

[0132] The above - mentioned system identification process also uses the MOESP algorithm of the MIMO system and adopts a linear state space model where x c (k) ∈ R n represents the state variable of the adjustment model at time k, u c (k) ∈ R m represents the input of the adjustment model at time k, y c (k) ∈ R p represents the output of the adjustment model at time k, A c ∈ R n×n represents the discrete state matrix of the adjustment model, B c ∈ R n×mDenote the discrete input matrix of the adjustment model, C c ∈R p×n Denote the discrete output matrix of the adjustment model, D c ∈R p×m Denote the discrete direct transfer matrix of the adjustment model. According to u in S100 c (k) is a four-dimensional vector composed of four indicators: the gas flow rate at the oxygen interface, the gas flow rate at the mixed air interface, the carbon dioxide concentration in the mixed air (i.e., the carbon dioxide concentration in the mixed air input into the culture chamber), and the power of the heater in the culture chamber. y c (k) is a four-dimensional vector composed of four indicators: the oxygen concentration, carbon dioxide concentration, temperature, and humidity in the central area of the culture chamber. In the present invention, a third-order model is selected for system identification. Therefore, the dimension of the above vector matrix is determined as x c (k)∈R 3 , u c (k)∈R 4 , y c (k)∈R 4 , A c ∈R 3×3 , B c ∈R 3 ×4 , C c ∈R 4×3 , D c ∈R 4×4 .

[0133] S300. Design a multi-channel PID controller:

[0134] The multi-channel PID controllers are respectively: input the calculated oxygen concentration in the culture chamber (actually the oxygen concentration in the central area of the culture chamber), and output the opening of the electromagnetic flow valve in the oxygen channel; input the carbon dioxide concentration in the culture chamber, and output the mixing ratio of the gas mixer; input the water level in the water tank, and output the flow rate of the purified water channel of the multi-channel liquid pump; input the temperature and humidity in the culture chamber, and output the power of the heater in the culture chamber.

[0135] Among them, the PID gain coefficients of different control channels need to be tuned through the experimental effects of the physical experimental platform.

[0136] S400. Design a prediction module:

[0137] According to the culture chamber environment regulation model obtained by system identification, input the opening degree of the electromagnetic flow valve of the oxygen channel designed by the multi-channel PID controller (i.e., the gas flow rate at the ga interface of the culture chamber), the mixing ratio of carbon dioxide and mixed air in the gas mixer (i.e., the carbon dioxide concentration in the mixed air introduced into the culture chamber), and the heater power of the culture chamber into the model, and output the situation of the culture chamber environment indicators (i.e., the oxygen, carbon dioxide concentrations, and temperature and humidity in the central area of the culture chamber) within the next 30 control cycles of the model. Based on the changes in the culture chamber environment within 30 control cycles, obtain the correction amount within the current control cycle, realize the prediction of the changes in the culture chamber environment indicators within the next 30 control cycles under the influence of the output result of the PID controller in this control cycle, and save the data; compare and analyze these data with the expected steady state. Taking the oxygen concentration control channel as an example, record the output result of the PID controller in the i-th control cycle as u0(i), and this value will be used as the input of the prediction module. The prediction module makes a prediction: according to the culture chamber environment regulation model obtained in S200, iteratively predict the oxygen concentration in the central area of the culture chamber within the next 30 control cycles when the actuator directly executes this control signal, and obtain a series of discrete concentration data. The oxygen concentration in the k-th control cycle relative to the i-th global control cycle is denoted as c p (i,k), record the set expected oxygen steady-state concentration as c0, and calculate c p (i,k) for all points where c ph (i,k) > c0 (assume there are n1 such points) of ||c ph (i,k) - c0||2 2 and sum them up to be Calculate c p (i,k) for all points where c pl (i,k) ≤ c0, and the ||c pl (i,k) - c0||2 2 and sum them up to be where n = 30 represents the number of control cycles to be predicted, calculate K(l h (i) - l l (i)) as the output of the prediction module on the oxygen concentration control channel, denoted as u p (i), where K is a negative gain coefficient. Then the corrected control signal input to the actuator in the i-th control cycle is denoted as u(i) = u0(i) + u p (i).

[0138] The calculation logics for other control channels such as carbon dioxide and temperature and humidity are the same as above. The negative gain coefficients K for different control channels need to be tuned based on the experimental effects of physical experiment vouchers.

[0139] The output of the PID controller is input into the prediction module, which calculates the change of the environment in the culture chamber within 30 control cycles. For example, if the control cycle is 0.1 s, the prediction module will deduce the impact on the culture chamber in the next 3 s by executing the control quantity designed by the controller, and then obtain the correction quantity u in the current control cycle based on the change of the environment in the culture chamber within 30 control cycles. p (i), and correct the control quantity output by the PID controller according to the prediction result to finally obtain the actual control signal input to the actuator.

[0140] Considering the accuracy and reliability of the prediction analysis, theoretically, the entire control cycle should be predicted, and then it is necessary to predict and calculate the changes within a sufficiently large number of future control cycles. However, on the one hand, it is actually impossible to achieve a sufficiently large number, and on the other hand, considering that the chip computing power of the lightweight structure proposed in the present invention is limited and difficult to support overly complex calculations, and after exceeding a certain limit, the system's response to a step signal tends to be stable, so it is not necessary to predict the future for too long. Therefore, in the present invention, 30 future control cycles are selected to minimize the calculation volume while ensuring the prediction performance to adapt to the hardware. The prediction module has a higher priority. After the prediction module predicts and calculates the changes in the next 30 control cycles and gives a correction signal for one control cycle, it is added to the control quantity output by the PID controller to adjust the situation where the environmental indicators in the culture chamber exceed or fall short of the expectation in the future. If it exceeds the expectation, the prediction module outputs a negative signal to reduce the output signal of the PID, and the corrected signal is applied to the actuator to reduce overshoot. Conversely, the prediction module outputs a positive signal to strengthen the PID output signal to accelerate convergence.

[0141] The purpose of the previous steps of finite element and system identification is to provide a theoretical model for prediction. At the same time, compared with the complex finite element model, the much simpler state space model can greatly reduce the complexity of the algorithm.

[0142] The scheme effectively solves the problem of large steady-state error caused by excessive gas accumulation. Through repeated adjustment of the experimental and simulation results, appropriate parameters with better effects are obtained, the influence brought by step signals, etc. is reduced, and a robust, stable, and fast-response algorithm system is realized. Thus, precise control of the environmental parameters in the culture chamber is achieved, ensuring the consistency of cultured organoids. The specific control strategy is as Figure 7 .

[0143] PID oxygen channel signal calculation: Since an external oxygen measurement device is designed, considering that the oxygen measurement process has hysteresis due to the time required for gas flow, an algorithm for calculating the oxygen concentration in the central area of the culture chamber according to the oxygen concentration in the oxygen measurement chamber measured by the oxygen concentration sensor needs to be designed. The specific process is as follows:

[0144] 1) Obtain prior data through finite element simulation analysis: In the finite element simulation analysis software, perform 3D modeling according to the structures of the exhaust gas duct w and the oxygen measurement chamber in the designed connection device, fill the fluid domain and perform mesh division on the fluid domain, study the oxygen concentration in the oxygen measurement chamber and conduct transient analysis, and save the simulation results within 30 s. Adjust the oxygen concentration in the central area of the culture chamber and the gas flow rate at the exhaust gas interface w of the culture chamber, repeat the above process ten to fifteen times respectively and save the simulation results respectively.

[0145] 2) Obtain the gas flow model inside the connection device through system identification based on the prior data:

[0146] According to the data set obtained from the finite element analysis, take the gas flow rate at the exhaust gas interface w of the culture chamber at the k-th simulation step as the input u s (k), take the oxygen concentration in the oxygen measurement chamber at the k-th simulation step as the output y s (k), and take the oxygen concentration in the central area of the culture chamber at the k-th simulation step as the state variable x s (k). Conduct system identification calculation to obtain the state space equation representation of the oxygen concentration in the oxygen measurement chamber with respect to the gas flow rate at the exhaust gas interface w of the culture chamber. In the present invention, it is discretely represented by a linear model as That is, the gas flow model inside the connection device (hereinafter referred to as the flow model), where A s represents the discrete state coefficient of the flow model, B s represents the discrete input coefficient of the flow model, and C s represents the discrete output coefficient of the flow model.

[0147] The input u s and the output y s are represented in the form of time series as where u s The sequence is saved as the value set when adjusting the gas flow rate at the exhaust gas interface w of the culture chamber during the finite element simulation process. The length of the sequence is the total number of samples in the finite element simulation, that is, the result of dividing the simulation time by the simulation step. For example, when setting the simulation time to 15 s and the simulation step to 0.1 s during the finite element simulation, and setting the gas flow rate at the exhaust gas interface w of the culture chamber to remain at 5 cm / s in the first 5 s at the start of the simulation and then remain at 10 cm / s in the next 10 s, then The unit is cm / s, and the y s The sequence is saved as the time series of the oxygen concentration in the oxygen measurement chamber calculated after setting the gas flow rate at the exhaust gas interface w of the culture chamber during the finite element simulation process. The saving logic is the same as that of u s .

[0148] The above model is a single-input single-output system. The least squares method can be used to fit the three coefficients A s , B s , C s . It should be noted that the observability of the model needs to be tested when performing the above system identification.

[0149] 3) Calculate the oxygen concentration in the central area of the culture chamber according to the oxygen concentration in the oxygen measurement chamber:

[0150] Design a state observer according to the obtained state space equation. The input and output of the gas flow model can be measured by sensors (gas flow meter and oxygen concentration sensor). Then, the state variables of the model, that is, the oxygen concentration in the central area of the culture chamber, can be solved. This data will be used as the feedback of the oxygen concentration control channel to guide the PID controller to perform calculations. The initial state of the state variable is known that the oxygen concentration in the central area of the culture chamber is the same as the oxygen concentration in the atmosphere. Then, the state variable at any time, that is, the oxygen concentration in the center of the culture chamber, can be calculated by integral iteration.

[0151] The state observer is designed based on the state space model obtained in the previous steps 1) and 2). The Luenberger observer can be expressed as In the equation, A s , B s , C s have been obtained by system identification. The coefficient L of the observer is designed according to the state space calculation obtained by system identification. By solving the characteristic equation det[λ - (A s - LC s )] = 0, where λ is the expected pole of the observer set. This value is generally taken as negative, and its absolute value will affect the convergence speed of the observer. Then, all the coefficients in the observer equation are known. Then, a difference equation about the state variable can be obtained. The observer can run on a physical platform or a simulation platform and perform state quantity estimation and observation. In the equation represents the gas flow rate at the waste gas interface w of the culture chamber measured by the gas flow meter at the k-th moment, represents the oxygen concentration in the oxygen measurement chamber measured by the oxygen concentration sensor at the k-th moment. Then, the initial state quantity x s (0) is known (under the initial condition, the gas environment in the oxygen measurement chamber is the same as that inside the culture chamber, and the measurement value of the oxygen concentration sensor at this time can be taken as the initial state quantity). Take this value as to start the observer. Then, the state variable estimated by the observer at any time can be iteratively calculated Then, the calculated state observation quantity will be used as the measured value of the oxygen channel, that is, the oxygen concentration in the central area of the culture chamber, and fed back to the PID controller for error calculation.

[0152] System performance: During the process of culturing organoid chips in vitro, to ensure the success of culturing, this product has the ability to precisely regulate environmental parameters. Specifically, the system can maintain the temperature of the organoids between 36°C and 37°C, with a temperature control accuracy of ±0.4°C; the relative humidity is controlled at 90% RH, with a control accuracy of ±0.3% RH; the carbon dioxide concentration is stabilized at 5%, with a control accuracy of ±0.2%; the oxygen concentration control accuracy is ±0.5% to promote the normal growth of the organoid chips. In addition, when designing this product, the light transmittance and airtightness of the culture system box are fully considered to prevent contamination of the organoid chips, thus meeting the requirements for the consistency of organoid culture.

[0153] The present invention adopts an efficient thermal management system. By injecting warm water at 37°C into the water tank and operating at the rated power, the internal gas environment can be heated from 25°C to 37°C within 6.6 seconds. When gas is introduced at a flow rate of 160 ml / min at the gas interface, the culture system can respond to a step change in gas concentration within 22 seconds, that is, the oxygen concentration at the center position of the culture chamber can rapidly increase from 21% to 70%, thereby realizing a rapid adjustment of the culture environment. A schematic diagram of the control effect is given taking the oxygen control channel as an example as Figure 8 .

[0154] Example:

[0155] This example is a lightweight organoid culture system. Its main structure is an incubator, which is used to maintain the stability of the external environment of the organoids, provide a good culture environment for the organoids, and ensure the consistency of the organoids; it can be used in hospitals and pharmaceutical companies for tissue culture and drug screening of human organoids. The lightweight equipment is easy to carry and is suitable for taking samples from bedridden patients at home.

[0156] I. System installation and commissioning:

[0157] 1) Installation of the control room: Place the box on a horizontal tabletop, connect the 220V to 12V power plug or use an independent 12V DC power supply, connect the gas source such as an oxygen cylinder to obtain the mixed air raw material, and connect the devices including the data communication bus, power interface, and gas and liquid interfaces required. The unconnected interfaces are placed in a closed state.

[0158] 2) Installation of the culture chamber: Place the incubator on a horizontal tabletop to avoid shaking the incubator too violently. Connect the devices including the data communication bus, power interface, and gas and liquid interfaces required. The unconnected interfaces are placed in a closed state. Select a suitable organoid chip slot, connect the microfluidic interface, and cover the box lid.

[0159] 3) Channel connection: The water supply channel of the culture chamber water tank (interface l), the microfluidic substance supply channel (interface Aq), and the exhaust gas output channel (interface W) are connected using a universal quick-insert self-locking fluid interface. Interfaces ga and gb are used to introduce oxygen and mixed air respectively. When connecting, slide the slider to expose the fine holes on the box wall and insert the gas guide hose. Then adjust the insertion length of the catheter and slide the slider at the same time so that the limit piece on the catheter is embedded in the slider groove for fixation. If a certain gas channel is not used, slide the slider to block the corresponding gas channel interface. The contact surface between the slider and the box wall is a frosted surface, which can avoid gas leakage to a certain extent and improve airtightness. The distribution of the culture chamber interfaces and the installation of the slider and sensor are as Figure 9 .

[0160] 4) Debugging: Power on the control room power supply, check whether the electronic components can work normally, and check whether the material flow channel is blocked.

[0161] II. Description of the operation process:

[0162] 1) Description of the control room buttons: The on / off key is used to manage the total power supply of the system. Long press it for 3 s to turn on or off the culture system to prevent accidental touch. The power supply should be turned on before putting the sample for culture and turned off after removing the sample to end the culture; Use the direction keys to adjust the cursor to select the indicators or parameters to be configured on the OLED display screen. Press the enter key to enter the adjustment and press it again to end the adjustment. Configure the specific environmental values such as temperature (in degrees Celsius °C), relative humidity (%), oxygen concentration, and carbon dioxide concentration (the gas concentration is uniformly in volume concentration %). By default, the temperature is 37 °C, the relative humidity is 90%, the carbon dioxide concentration is 5%, and the oxygen concentration is 21%; Press the Auto key to display the temperature, humidity, and gas concentration in the box in real time and display the tracking curve on the OLED display screen for 1 min. When the water level in the box is too low, and the humidity and temperature deviate from the preset parameters, the buzzer starts to emit a prompt sound, and the cursor moves to the warning displayed on the OLED display screen. At this time, the system should be turned off to check the problem and press the enter key to view the specific error message to avoid damaging the components and killing the organoids. The distribution of the control room buttons and the OLED interface are as Figure 10 shown.

[0163] 2) Preparation for culture:

[0164] Power on the control room, start the gas source output, and ventilate for a period of time to clean all gas channels and remove impurities. Transfer the incubator to the experimental platform as needed. Open the box lid. Before use, add an appropriate amount of pure water (marked with a water line) to the water tank to prevent liquid overflow caused by too high a water level, resulting in pollution inside the box or damage to the electronic components. Insert the organoid chip and start culturing after closing the box lid.

[0165] III. Repair and maintenance:

[0166] After one organoid culture is completed, the remaining purified water in the water tank should be drained and dried, and a cleaning and sterilization should be carried out to prevent contamination of the organoids cultured next time. If the incubator is not used, disconnect the power supply and store the equipment in a dry place to avoid moisture on the heating element, which may cause short circuits and other faults, reducing the service life of the components.

[0167] IV. Safety Warnings:

[0168] During the organoid culture process, biological protection should be done to avoid harming physical health. After the culture is completed, thorough sterilization should be carried out to avoid causing biological hazards. The power of the heating element is increased, and after power-off, it should be allowed to cool down for a period of time to avoid scalding.

[0169] The above examples of the present invention are only for illustrating in detail the calculation model and calculation process of the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or variations can be made on the basis of the above description. It is impossible to enumerate all the implementation manners here. Any obvious changes or variations derived from the technical solutions of the present invention still fall within the protection scope of the present invention.

Claims

1. An in vitro multi-gas-liquid channel life-sustaining culture system for organoid chips, characterized in that: include: A control room, a culture room, and a connecting device connecting the two; The control room includes a single-chip control chip, a material supply device and an interface; The interface includes a material supply interface; the material supply interface includes a culture liquid interface for providing culture liquid to the organoids in the culture chamber, an oxygen interface for introducing oxygen into the culture chamber, a mixed air interface for introducing mixed air into the culture chamber; a water tank interface for replenishing water in the water tank and an exhaust gas interface for receiving exhaust gas discharged from the culture chamber; The material supply device includes a liquid supply part and a gas supply part; the liquid supply part is driven by a multi-channel liquid pump, the input end of the multi-channel liquid pump is respectively connected to the culture liquid storage tank and the water storage tank, and the output end is respectively connected to the culture liquid interface and the water tank interface; the multi-channel liquid pump is controlled by a single-chip microcomputer control chip to adjust the flow rate of the culture liquid and the purified water input into the culture chamber; the gas supply part is driven by a gas mixer and regulated by an electromagnetic flow rate valve, the input end of the gas mixer is respectively connected to the mixed air storage tank and the carbon dioxide storage tank, and the two input gases will be mixed in different proportions in the gas mixer, and the proportion is controlled by the single-chip microcomputer control chip to achieve the adjustment of the carbon dioxide concentration in the mixed gas output by the gas mixer, and further achieve the adjustment of the carbon dioxide concentration in the culture chamber; the output end of the gas mixer is connected to the mixed air interface through the electromagnetic flow rate valve; the oxygen storage tank is connected to the oxygen interface through the electromagnetic flow rate valve, and the opening of the electromagnetic flow rate valve is controlled by the single-chip microcomputer control chip to achieve the adjustment of the flow rate of the two gases entering the culture chamber and then achieve the adjustment of the gas concentration in the culture chamber; The single-chip microcomputer control chip is responsible for receiving data signals from the temperature and humidity sensor, carbon dioxide concentration sensor, oxygen concentration sensor, and gas flow meter, and performing signal processing, which includes multi-channel PID controller calculation, oxygen concentration solution, and signal visualization processing; the multi-channel PID controllers are: input oxygen concentration in the culture chamber, output the opening of the electromagnetic flow valve of the oxygen channel; input carbon dioxide concentration in the culture chamber, output the mixing ratio of the gas mixer; input water level in the water tank, output the flow of the water purification channel of the multi-channel liquid pump; input temperature and humidity in the culture chamber, and output the power of the two heaters in the culture chamber; the single-chip microcomputer control chip outputs control signals to control the electromagnetic flow valve, top heater, bottom heater, liquid pump, and gas mixer; The culture chamber includes an organoid chip slot, a temperature and humidity sensor, a carbon dioxide concentration sensor, a bottom heater, a water tank and a water level meter, and a gas flow meter; The water level gauge is used to measure the water level in the tank; The organoid slot is equipped with a microfluidic interface for fixing the organoid chip, and is connected to the liquid interface of the culture chamber to receive the culture fluid input from the control chamber; Temperature and humidity sensors and carbon dioxide concentration sensors are used to measure the temperature, humidity and carbon dioxide concentration in the effective area inside the culture room; The gas flow meter is located at the exhaust gas interface of the culture chamber and is used to measure the flow rate of the exhaust gas discharged from the culture chamber; The bottom heater is used to heat the culture chamber and the water tank; The connecting device is used to connect the control room and the culture room to realize material transportation and data interaction between the two, and includes a fluid conduit, a preheater, and an oxygen measurement chamber; The fluid conduits include an oxygen conduit, a mixed air conduit, an exhaust gas conduit, a culture medium conduit, and a water tank conduit; The preheater is used to preheat the gas and liquid output from the control room; The oxygen measuring chamber is placed outside the culture chamber, and the oxygen measuring chamber is connected in parallel to the exhaust gas duct of the connecting device. An oxygen concentration sensor is installed inside the oxygen measuring chamber to measure the oxygen concentration in the exhaust gas, which is used to assist the single-chip microcomputer controller to calculate the oxygen concentration in the central area of ​​the culture chamber.

2. The in vitro multi-gas-liquid channel life-sustaining culture system for organoid chips according to claim 1, characterized in that: The interface of the control room also includes a power interface, which uses a USB interface for providing power and transmitting data; the USB interface integrates an IIC communication bus, a 5V positive electrode, a 24V positive electrode, and a ground wire, 5V and 24V are connected in parallel to the power subsystem, and the IIC communication bus is connected in parallel to the IIC communication interface of the single-chip control chip; The connection device also includes a power cable, which integrates a 5V positive line, a 24V positive line, a ground line, and an IIC communication bus. Both ends of the cable are connected to USB connectors to achieve energy and data interaction between the culture room and the control room. The culture chamber is also provided with a power interface, which adopts a USB interface for connecting a power cable in a connection device. The USB interface integrates an IIC communication bus, a 24V positive electrode, a 5V positive electrode, and a ground wire. The power circuit and electronic components in the culture chamber are respectively connected to the corresponding sub-interfaces, that is, the temperature and humidity sensor, the gas flow meter, and the carbon dioxide concentration sensor in the culture chamber are respectively connected in parallel to 5V-GND, that is, connected in parallel to the IIC bus, and the heater is connected in parallel to 24V-GND; The oxygen concentration sensor inside the oxygen measurement chamber is connected in parallel to the power cable of the connection device to receive 5V-GND power supply and serve as an IIC communication slave.

3. The in vitro multi-gas-liquid channel life-sustaining culture system for organoid chips according to claim 2, characterized in that: The power subsystem is also used to provide 3.3V power, and the 3.3V power is used to power the microcontroller control chip.

4. The in vitro multi-gas-liquid channel life-sustaining culture system for organoid chips according to claim 3, characterized in that: The control room also includes a key array, which is connected to the single-chip microcomputer control chip. The single-chip microcomputer control chip receives signals from the key array and executes corresponding commands according to the instructions expressed by the key array signals. The 3.3V power supply provided by the power subsystem is also used to power the key array.

5. The in vitro multi-gas-liquid channel life-sustaining culture system for organoid chips according to claim 4, characterized in that: The control room also includes a display screen for displaying status information of the culture chamber and / or visual information corresponding to the instructions expressed by the key array signals.

6. The in vitro multi-gas-liquid channel life-sustaining culture system for organoid chips according to claim 1, characterized in that: The culture chamber also includes a box cover, and a top heater is embedded in the box cover; the top heater is connected in parallel to the 24V-GND power supply line of the culture chamber to obtain power.

7. The in vitro multi-gas-liquid channel life-sustaining culture system for organoid chips according to claim 2, characterized in that: The preheater is flat in shape, and a plurality of fluid conduits and power cables are wrapped side by side inside the preheater, and the plurality of fluid conduits at least include an oxygen conduit, a mixed air conduit, an exhaust gas conduit, a culture fluid conduit, and a water tank conduit; the preheater is installed with a tee, and the exhaust gas conduit is connected to the tee pipe inside the heater, and the tee pipe structure has two outlets, one outlet is connected to the oxygen measuring chamber, and the other outlet is connected to the control chamber, and the exhaust gas is divided into two parts and respectively introduced into the control chamber and the oxygen measuring chamber; the preheater is also provided with a "T-shaped" cable connection structure, and the power cable is divided into three sections and connected by the "T-shaped" cable connection structure, wherein two sections are connected to the control chamber and the culture chamber respectively through a USB interface, and the 24V-GND line in the third section provides a 24V power supply to the preheater, and the 5V-GND line in the third section is connected to the oxygen concentration sensor in the oxygen measurement chamber to provide a 5V power supply to the oxygen concentration sensor.

8. An in vitro multi-gas-liquid channel life-sustaining culture system for organoid chips according to any one of claims 1 to 7, characterized in that: The oxygen interface and the mixed air interface of the culture chamber are located at the center height of the culture chamber, and the exhaust gas interface is arranged on the opposite side of the oxygen interface and the mixed air interface.

9. The in vitro multi-gas-liquid channel life-sustaining culture system for organoid chips according to claim 8, characterized in that: The multi-channel PID controller performs control based on the data of the prediction module. The design process of the multi-channel PID controller and the prediction module is as follows: S100, perform finite element simulation analysis to obtain prior data: According to the optimization and redesign of the culture chamber structure, a three-dimensional model is performed, the fluid domain is filled and meshed, the oxygen concentration, carbon dioxide concentration, temperature, and humidity in the center area of ​​the culture chamber are studied, transient analysis is performed, and the simulation results are saved, the gas flow rate of the two different gas interfaces, the heater power in the culture chamber, and the carbon dioxide concentration in the mixed air are adjusted, and the process is repeated multiple times and the simulation results are saved respectively; S200, perform system identification to obtain a culture room environment adjustment model: According to the simulation result data set obtained by finite element analysis, the oxygen concentration, carbon dioxide concentration, temperature and humidity in the central area of ​​the culture room are taken as outputs, and the gas flow rate of the oxygen interface, the gas flow rate of the mixed air interface, the carbon dioxide concentration in the mixed air, and the heater power in the culture room are taken as controllable quantities for system identification. The state space equation representation of the oxygen and carbon dioxide concentrations and the temperature and humidity in the central area of ​​the culture room with respect to the controllable quantities is obtained as the culture room environment regulation model. S300, design of multi-channel PID controller: The multi-channel PID controllers are: input the oxygen concentration in the culture chamber, output the opening of the electromagnetic flow rate valve of the oxygen channel; input the carbon dioxide concentration in the culture chamber, output the mixing ratio of the gas mixer; input the water level in the water tank, output the flow rate of the water purification channel of the multi-channel liquid pump; input the temperature and humidity in the culture chamber, output the heater power in the culture chamber; S400, design prediction module: Based on the culture room environment adjustment model, the electromagnetic flow rate valve opening of the oxygen channel designed by the multi-channel PID controller, the mixing ratio of carbon dioxide and mixed air in the gas mixer, and the heater power of the culture room are input into the model. The model outputs the environmental indicators of the culture room in the next n control cycles, that is, the oxygen and carbon dioxide concentrations and temperature and humidity in the central area of ​​the culture room. Based on the changes in the environment in the culture room within n control cycles, the correction amount in the current control cycle is obtained: For the oxygen concentration control channel, the output result of the PID controller in the i-th control cycle is recorded as u0(i). This value will be used as the input of the prediction module. The prediction module predicts: according to the iterative prediction model of the culture room environment adjustment model obtained in S200, the oxygen concentration in the central area of ​​the culture room is predicted in the next n control cycles when the actuator directly executes the control signal, and a series of discrete concentration data is obtained. The oxygen concentration in the k-th control cycle in the future relative to the i-th control cycle is recorded as c p (i, k), let the expected steady-state oxygen concentration be c0, calculate c p All the (i,k) that satisfy c ph ||c of the point where (i,k)>c0 ph (i,k)-c0||2 2 And sum to Calculate c p All the (i,k) that satisfy c pl ||c of the point (i,k)≤c0 pl (i,k)-c0||2 2 And sum to Calculate K(l h (i)-l l (i)) is used as the output of the prediction module on the oxygen concentration control channel, i.e., the correction value u p (i), where K is a negative gain coefficient; Finally, the corrected control signal input to the actuator in the i-th control cycle is recorded as u(i)=u0(i)+u p (i), i.e., the actual control signal; The control calculation logic of other control channels is the same as that of the oxygen channel.

10. The in vitro multi-gas-liquid channel life-sustaining culture system for organoid chips according to claim 9, characterized in that: The oxygen concentration in the culture chamber input to the PID controller of the oxygen channel in the multi-channel PID controller is determined by solving. The solving process of the oxygen concentration in the culture chamber includes the following steps: A1. Obtaining a gas flow model and a state observer inside the connecting device. The gas flow model and the state observer inside the connecting device are obtained by the following steps: 1) Obtain the prior data obtained in advance. The process of obtaining the prior data in advance is as follows: In the finite element simulation analysis software, three-dimensional modeling is performed according to the structure of the exhaust gas conduit w and the oxygen measurement chamber in the designed connection device structure, the fluid domain is filled and meshed, the oxygen concentration in the oxygen measurement chamber is studied and transient analysis is performed and the simulation results are saved, the oxygen concentration in the central area of ​​the culture chamber and the gas flow rate at the exhaust gas interface w of the culture chamber are adjusted, and the simulation results are saved for multiple times respectively; 2) Gas flow model inside the connection device obtained by system identification based on prior data: According to the data set obtained by finite element analysis, the gas flow rate at the exhaust gas interface w of the culture chamber at the kth simulation step is used as the input u s (k), the oxygen concentration in the oxygen measurement chamber at the kth simulation step is taken as the output y s (k), the oxygen concentration in the center of the culture chamber at the kth simulation step is taken as the state variable x s (k) Perform system identification calculation to obtain the state space equation representation of the oxygen concentration in the oxygen measurement chamber with respect to the gas flow rate at the waste gas interface w of the culture chamber, that is, the gas flow model inside the connection device: x s (k+1)=A s x s (k)+B s u s (k) y s (k)=C s x s (k) Among them, A s represents the discrete state coefficient of the flow model, B s represents the discrete input coefficients of the flow model, C s represents the discrete output coefficients of the flow model; 3) Design a state observer based on the gas flow model: in, represents the observed value observed by the state observer, that is, the observed oxygen concentration; L is the coefficient of the observer; represents the gas flow rate at the waste gas interface w of the culture chamber measured by the gas flow meter at the kth moment, represents the oxygen concentration in the oxygen measurement chamber measured by the oxygen concentration sensor at the kth moment; A2. Calculate the oxygen concentration in the center of the culture chamber based on the oxygen concentration in the oxygen measurement chamber: The gas flow meter and the oxygen concentration sensor are used to measure the input and output of the gas flow model, and the oxygen concentration is calculated based on the observation value of the state observer corresponding to the gas flow model inside the connecting device.

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