A cryogenic tube aspiration control system and method

Abstract

The application belongs to the technical field of automation control and biological sample storage, and discloses a cryopreservation tube suction control system and method, aiming at solving the problems of slow vacuum breaking response, easy sample pollution by external environment and high energy consumption in the adsorption and holding stage of the existing vacuum suction system. The system comprises a power unit, a vacuum energy storage unit, a gas path execution unit, a pressure detection unit and a control unit, adopts a micro-positive pressure cabin as a vacuum breaking clean gas source, realizes fast vacuum breaking through the structure of double vacuum breaking valves in series with a vacuum pump, and utilizes the pre-stored negative pressure energy of a gas storage tank to eliminate the need for continuous operation of the vacuum pump. The control method comprises the processes of pre-vacuumizing, vacuum suction and adsorption, adsorption and holding, vacuum breaking and releasing, and fault grading response. The application effectively improves the release response speed of the cryopreservation tube, eliminates the invasion of external pollutants, significantly reduces the energy consumption of the system, prolongs the service life of the equipment, and is suitable for sample automated access operation in scenes such as biological sample libraries and low-temperature automated storage equipment.

Description

Technical Field

[0001] This invention relates to the fields of automated control and biological sample storage technology, specifically to a cryopreservation tube aspiration control system and method. Background Technology

[0002] The aspiration control system for biological sample cryopreservation tubes is mainly used in scenarios such as biobanks and low-temperature automated storage equipment. It is a core component for realizing automated storage, retrieval, and transportation of biological samples, and its performance directly affects the safety of biological sample storage and the efficiency of automated storage and retrieval.

[0003] Existing technologies include various cryovial aspiration control systems based on the principle of vacuum adsorption. These systems typically employ a structure where a vacuum pump is directly connected to the gas path of the suction head. The vacuum pump creates negative pressure to adsorb the cryovials, and the release is achieved by opening a vacuum-breaking valve to introduce outside air. However, the vacuum-breaking process in existing systems directly introduces outside air, which is subject to significant pressure fluctuations and difficult-to-control flow rate. This results in a slow vacuum-breaking response and a delay in cryovial release. Furthermore, dust, moisture, and microorganisms in the outside air can easily enter the gas path and sample storage area with the airflow, posing a risk of contamination to biological samples. In addition, existing systems require the vacuum pump to operate continuously during the adsorption and holding phase to maintain negative pressure. This not only results in unnecessary energy consumption but also generates continuous heat, interfering with the temperature stability of the cryogenic storage environment. The prolonged continuous operation of the vacuum pump also accelerates component wear and shortens the equipment's lifespan. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned defects in the existing cryopreservation tube vacuum aspiration control system, and to provide a cryopreservation tube aspiration control system and method to solve the problems of slow release response speed and easy contamination of biological samples caused by directly introducing outside air in the vacuum breaking stage of the existing system. At the same time, it solves the problems of excessive energy consumption, heat generation interference with the low temperature storage environment, and shortened equipment life caused by the continuous operation of the vacuum pump in the adsorption and holding stage of the existing system, so as to realize the efficient, safe, and low-energy automated aspiration and release operation of biological sample cryopreservation tubes.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a cryopreservation tube suction control system, comprising a power unit, a vacuum energy storage unit, a gas path execution unit, a pressure detection unit, and a control unit. The power unit includes a motor and a vacuum pump. The output end of the motor is connected to the vacuum pump for providing suction power to the system. The vacuum energy storage unit includes a gas storage tank. The inlet of the gas storage tank is connected to the suction port of the vacuum pump via a one-way valve. The exhaust ports of the gas storage tank and the vacuum pump are both connected to a micro-positive pressure chamber. The micro-positive pressure chamber is a closed chamber of the sample storage device, maintaining a constant micro-positive pressure state internally, which can isolate external contaminants from entering, while providing a stable and clean gas source for vacuum breaking operations. The gas path execution unit includes a suction head, a filter, a vacuum suction valve, a first vacuum breaking valve, and a second vacuum breaking valve. The air port of the suction head is connected to the inlet of the filter via a first gas path. The air outlet of the filter is connected to the inlet of the vacuum suction valve via a second gas path. The air outlet of the vacuum suction valve is connected to the negative pressure interface of the gas storage tank. The inlet of the first vacuum-breaking valve is connected to the pressure-stabilizing outlet of the micro-positive pressure chamber. A pressure-stabilizing structure is installed at the pressure-stabilizing outlet to output a constant-pressure airflow, preventing pressure fluctuations during vacuum breaking. The outlet of the first vacuum-breaking valve is connected to the inlet of the vacuum pump, and the inlet of the second vacuum-breaking valve is connected to the exhaust port of the vacuum pump. The outlet of the second vacuum-breaking valve is connected to the first air path via a third air path. The pressure detection unit includes a vacuum pressure gauge, which is installed on the air path between the negative pressure interface of the gas storage tank and the outlet of the vacuum suction valve, for real-time detection of the vacuum level within the system. The control unit is electrically connected to the motor, the vacuum suction valve, the first vacuum-breaking valve, the second vacuum-breaking valve, and the vacuum pressure gauge. The control unit is configured to control the on / off state of each valve and the operating state of the motor based on the detection signal from the vacuum pressure gauge. This solution connects the vacuum breaking air path to the micro-positive pressure chamber and uses a vacuum pump as a pressurization element connected in series in the vacuum breaking air path. It can utilize the stable air source of the micro-positive pressure chamber and the pressurization effect of the vacuum pump to quickly restore the internal pressure of the suction head to positive pressure, while completely preventing outside air from entering the system. This fundamentally solves the problems of slow vacuum breaking response and sample contamination in existing technologies. By setting up a gas storage tank as a vacuum energy storage unit, negative pressure energy can be stored in advance. During the adsorption and holding stages, there is no need for the vacuum pump to run continuously, which effectively reduces system energy consumption and heat generation.

[0006] Furthermore, the vacuum energy storage unit also includes a graded vacuum preset module, which is electrically connected to the control unit and is used to input at least two different target vacuum thresholds for the gas storage tank to the control unit. The graded vacuum preset module has a built-in vacuum parameter table corresponding to cryopreservation tubes with different sample information, and can match the corresponding target vacuum level according to the capacity, weight, and sealing performance of the cryopreservation tube. The control unit is configured to control the motor to drive the vacuum pump according to the input target vacuum threshold until the vacuum pressure gauge detects that the vacuum level in the gas storage tank has reached the corresponding target threshold, at which point the motor enters standby mode. This structure can prevent excessively high vacuum levels from causing deformation of the cryopreservation tube cap or sample leakage, while also preventing excessively low vacuum levels from causing weak adsorption, further improving the system's versatility and safety.

[0007] Furthermore, the filter employs a two-stage cascaded filtration structure, including a first-stage coarse filter and a second-stage precision filter. The inlet of the first-stage coarse filter is connected to a first gas path, and the outlet of the first-stage coarse filter is connected to the inlet of the second-stage precision filter. The outlet of the second-stage precision filter is connected to a second gas path. The first-stage coarse filter filters large particles of dust and debris in the airflow, while the second-stage precision filter filters fine particles, water vapor, and microorganisms. This two-stage filtration significantly improves filtration efficiency, protects downstream gas path components from contamination, and prevents cross-contamination of samples. The one-way valve is configured to allow gas to flow only from the inlet of the gas storage tank to the outlet of the vacuum pump, preventing gas backflow after the vacuum pump stops operating, which could lead to a decrease in the vacuum level of the gas storage tank.

[0008] Furthermore, a gas path damping adjustment component is provided in the third gas path. This component includes an adjustable throttle valve and a one-way check valve. The inlet of the adjustable throttle valve is connected to the outlet of the second vacuum breaking valve, and the outlet of the adjustable throttle valve is connected to the inlet of the one-way check valve. The outlet of the one-way check valve is connected to the first gas path. The adjustable throttle valve can adjust the airflow rate and speed during vacuum breaking according to actual needs, preventing excessive airflow from blowing away or causing the cryovial to shift position, ensuring the cryovial can be accurately placed in the target location. The one-way check valve is configured to only allow gas to flow from the second vacuum breaking valve to the suction head, preventing gas from flowing back into the vacuum breaking gas path during the vacuum suction stage, thus ensuring stable system vacuum.

[0009] Furthermore, the control unit includes an adsorption stability monitoring subunit. This subunit is configured to collect pressure data from a vacuum gauge in real time during the adsorption holding phase, when the vacuum valve remains open, and calculate the pressure fluctuation value per unit time. The pressure fluctuation value reflects the sealing status between the suction head and the cryovial. When the seal is poor, the pressure will continuously drop or the fluctuation will increase. When the pressure fluctuation value exceeds a preset fluctuation threshold, the control unit controls the motor to start to replenish the vacuum in the gas storage tank until the pressure fluctuation value falls back below the preset fluctuation threshold. This subunit can monitor the adsorption status in real time, promptly detect problems such as poor sealing and compensate for them, effectively preventing the cryovial from falling off during transportation.

[0010] A control method for a cryopreservation tube aspiration control system based on any one of the above-mentioned methods includes the following steps: S1 Pre-vacuum Standby Process: The control unit controls the motor to drive the vacuum pump, pumping the gas from the storage tank to the micro-positive pressure chamber until the vacuum pressure gauge detects that the vacuum level in the storage tank has reached the preset initial threshold, at which point the motor enters standby mode. This pre-vacuum standby process allows for the pre-storage of sufficient negative pressure energy when the system is idle, enabling immediate adsorption operation upon receiving an adsorption command, significantly improving the system's response speed. S2 vacuum adsorption process: When the command to aspirate the cryopreservation tube is received, the control unit controls the vacuum valve to open. The gas in the cavity between the suction head and the top cover of the cryopreservation tube enters the gas storage tank in sequence through the first gas path, the filter, the second gas path, and the vacuum valve, so that a negative pressure adsorption is formed between the suction head and the cryopreservation tube. S3 Adsorption and Holding Process: The control unit keeps the vacuum valve open and monitors the vacuum level in the gas path in real time through the vacuum pressure gauge to maintain stable adsorption of the cryopreservation tube by the suction head; S4 Vacuum Breaking Release Process: When a command to release the cryopreservation tube is received, the control unit closes the vacuum valve and simultaneously opens the first and second vacuum breaking valves. The gas in the micro-positive pressure chamber enters the first air path rapidly through the first vacuum breaking valve, the vacuum pump, the second vacuum breaking valve, and the third air path, restoring the pressure inside the suction head to positive pressure. The cryopreservation tube separates from the suction head under the action of gravity.

[0011] Further, step S1 specifically includes: The S11 control unit acquires sample information from the cryovials to be aspirated, and calls the corresponding vacuum matching logic based on the parameters to determine the target vacuum threshold. The vacuum matching logic can automatically adjust the target vacuum level according to different parameters of the cryovials, eliminating the need for manual setting and improving the system's automation and versatility. The S12 control unit controls the motor to drive the vacuum pump at the rated speed, and the vacuum pressure gauge collects the vacuum level data in the gas storage tank in real time and feeds it back to the control unit. When the vacuum level reaches the target vacuum threshold (S13), the control unit stops the motor and enters standby mode. If the standby time exceeds a preset threshold, the control unit automatically starts the motor to replenish the vacuum until the vacuum level returns to the target threshold. This automatic vacuum replenishment function ensures the gas tank maintains sufficient negative pressure reserve, ready to respond to suction commands at any time.

[0012] Furthermore, in step S4, the control unit employs a time-sequential valve control strategy to perform the vacuum breaking operation, specifically including: The S41 control unit first closes the vacuum valve, and after a first preset time delay, opens the first vacuum breaking valve. S42 opens the first vacuum breaking valve and, after a second preset time delay, opens the second vacuum breaking valve; When the vacuum pressure gauge detects that the pressure in the first gas path reaches the preset positive pressure threshold, the control unit simultaneously closes the first and second vacuum breaking valves, completing the vacuum breaking and release operation. This time-sequential valve control strategy avoids gas path impact caused by simultaneous valve opening and closing, protecting gas path components and ensuring a smooth pressure rise inside the suction head, thus guaranteeing a stable release of the cryopreservation tube.

[0013] Furthermore, step S3 specifically includes: The S31 control unit keeps the vacuum valve open and collects real-time vacuum data in the gas path through the vacuum pressure gauge at a preset sampling frequency. The S32 control unit compares the real-time vacuum level data with the preset vacuum level threshold. If the real-time vacuum level is lower than the preset vacuum level threshold, the dynamic vacuum level compensation mechanism is activated. Under the S33 dynamic vacuum compensation mechanism, the control unit controls the motor to run at low speed to drive the vacuum pump for pumping compensation until the real-time vacuum level recovers to above the preset vacuum level threshold, at which point the control unit stops the motor. This dynamic vacuum compensation mechanism uses low-speed pumping to avoid excessive vacuum fluctuations and further reduce energy consumption.

[0014] Furthermore, it also includes an exception handling process, which adopts a fault-level response mechanism, specifically including: When the vacuum pressure gauge detects that the vacuum level in the gas storage tank cannot reach the target threshold within a preset time, it is determined to be a level one fault, the control unit issues a level one alarm signal and stops the current operation; When the vacuum level continues to decrease during the adsorption and holding phase and the dynamic vacuum compensation mechanism cannot restore it, it is determined to be a level two fault. The control unit issues a level two alarm signal and performs an emergency vacuum release operation. When the valve action feedback signal is inconsistent with the control command, it is determined to be a level three fault. The control unit issues a level three alarm signal and cuts off the system power supply. The fault classification response mechanism can take different handling measures according to the severity of the fault, ensuring system safety while protecting biological samples from loss to the greatest extent possible.

[0015] Compared with the prior art, the present invention provides a cryopreservation tube aspiration control system, which has the following beneficial effects: This invention connects the exhaust port of the gas storage tank and the exhaust port of the vacuum pump to a micro-positive pressure chamber, and adopts a vacuum breaking air path structure with a first vacuum breaking valve, a vacuum pump and a second vacuum breaking valve connected in series. By utilizing the stable gas source provided by the micro-positive pressure chamber and the pressurization effect of the vacuum pump, the internal pressure of the suction head can be restored to positive pressure in a very short time, which effectively improves the response speed of vacuum breaking and release, while preventing external contaminants from entering the gas path and sample storage environment, thus ensuring the storage safety of biological samples.

[0016] This invention uses a gas storage tank as a vacuum energy storage unit. After the gas storage tank is evacuated to a set vacuum level by a vacuum pump, the motor can enter standby mode. During the adsorption and holding stage of the cryopreservation tube, the negative pressure reserve in the gas storage tank provides a stable adsorption force, eliminating the need for continuous operation of the vacuum pump. This significantly reduces the overall energy consumption of the system, reduces the interference of heat generated by the system operation on the low-temperature storage environment, and also reduces the operating time of the vacuum pump, effectively extending the service life of the vacuum pump. Attached Figure Description

[0017] Figure 1 This is a system architecture diagram of a cryopreservation tube aspiration control system and method according to the present invention; Figure 2 This is a schematic diagram of the steps of a cryopreservation tube aspiration control system and method according to the present invention. Detailed Implementation

[0018] Please see Figure 1-2 This invention provides a technical solution: a cryopreservation tube aspiration control system, integrated into the automated storage and retrieval unit of a biological sample cryogenic storage device. All electrical components are sealed to prevent condensation in the low-temperature environment from affecting electrical performance. The system's power unit consists of a motor and a vacuum pump. The motor is a high-precision servo motor, and its output is connected to the input shaft of the vacuum pump via a flexible coupling. The flexible coupling compensates for coaxiality errors between the motor and the vacuum pump, while absorbing vibrations generated during operation and reducing system noise. The motor operates at a fixed frequency and speed of 3000 rpm.

[0019] The vacuum pump is a piston-type vacuum pump, which has the advantages of simple maintenance, reliable operation, and stable pumping speed. Its rated pumping speed is matched according to the volume of the gas storage tank to ensure that the gas storage tank can be evacuated to the set vacuum level within a reasonable time. The vacuum pump's suction port is connected to the outlet of the one-way valve through a flexible gas pipeline, and the vacuum pump's exhaust port is connected to the return port of the micro-positive pressure chamber through a flexible gas pipeline. All gas pipelines are connected using flared compression fittings. Flared compression fittings have the advantages of good sealing performance, high pressure resistance, low temperature resistance, and convenient installation, which can effectively prevent gas leakage.

[0020] The vacuum energy storage unit includes a gas storage tank and a staged vacuum preset module. The gas storage tank is a horizontal, sealed pressure vessel welded from 304 stainless steel. Its volume is designed according to the system's maximum adsorption requirements, capable of storing sufficient negative pressure energy to meet the needs of continuous multiple adsorptions of cryopreservation tubes without frequent vacuum pump starts. The top of the gas storage tank has three ports: an inlet, a negative pressure port, and an outlet. The inlet is connected to the inlet of a one-way valve via a flexible gas pipe. The one-way valve is a spring-loaded type, its flow direction strictly limited to allow gas to flow only from the gas storage tank's inlet to the vacuum pump's extraction port. When the vacuum pump stops running, the one-way valve automatically closes to prevent gas backflow into the gas storage tank, thus preventing a drop in vacuum. The outlet of the gas storage tank is connected to the return port of the micro-positive pressure chamber via a flexible gas pipe, allowing the gas extracted from the gas storage tank to be directly discharged into the micro-positive pressure chamber, avoiding direct discharge into the external environment and preventing pollution. The negative pressure interface of the gas storage tank is connected to the detection end of the vacuum pressure gauge through a flexible gas pipeline, and is also connected to the outlet of the vacuum valve through the same flexible gas pipeline. The vacuum pressure gauge uses a diaphragm pressure sensor, which can accurately detect pressure changes in the gas pipeline in real time. The signal output end of the vacuum pressure gauge is electrically connected to the analog input module of the control unit, which can convert the detected pressure signal into a standard 4-20mA analog signal and transmit it to the control unit. The analog-to-digital converter inside the control unit converts the analog signal into a digital signal for processing.

[0021] The top of the gas storage tank is equipped with a safety valve interface, which features a spring-loaded safety valve. The opening pressure of the safety valve is set slightly higher than the internal pressure of the micro-positive pressure chamber. When the pressure inside the gas storage tank abnormally rises above the safety threshold, the safety valve automatically opens to release the pressure, preventing overpressure explosion and ensuring system safety. The graded vacuum preset module is integrated into the human-machine interface of the control unit. This interface uses a color LCD touchscreen and displays the system's operating status, vacuum data, valve status, and fault information. It also allows operators to input and modify system parameters via the touchscreen. The graded vacuum preset module contains non-volatile memory capable of storing at least 10 sets of target vacuum threshold parameters for different cryovials. Each set includes the minimum adsorption vacuum, maximum safe vacuum, and holding vacuum threshold. Operators can select the corresponding parameter set via the touchscreen based on the type of cryovial used, or manually input custom parameters. Parameter settings are automatically saved to the non-volatile memory and are not lost after a power outage.

[0022] The gas path execution unit includes a pipette tip, filter, vacuum valve, first vacuum breaking valve, second vacuum breaking valve, and gas path damping adjustment assembly. The pipette tip is made of metal, offering advantages such as low-temperature resistance, chemical corrosion resistance, and high mechanical strength. The pipette tip assembly can draw biological samples at temperatures around -140℃. A gas path interface is located at the top of the pipette tip, connecting to the filter's inlet via a flexible gas path pipe. The filter employs a two-stage cascade filtration structure, including a first-stage coarse filter and a second-stage precision filter. Both filters utilize a quick-release design for rapid disassembly and replacement without tools. The first-stage coarse filter has a filtration accuracy of 5 microns, using a polypropylene melt-blown filter element, effectively filtering large particles, debris, and fibers from the gas flow, protecting the downstream precision filter and valves from damage. The second-stage precision filter has a filtration accuracy of 0.22 microns, using a polytetrafluoroethylene pleated filter element, effectively filtering bacteria, viruses, small particles, and moisture from the gas flow, preventing sample cross-contamination and corrosion of gas path components. The air outlet of the filter is connected to the air inlet of the vacuum valve through a flexible air passage. The vacuum valve, the first vacuum breaking valve and the second vacuum breaking valve are all normally closed two-position two-way solenoid control valves. The valve body is made of 304 stainless steel and the seal is made of fluororubber. It has the advantages of low temperature resistance, chemical corrosion resistance, good sealing performance and fast response speed. Its response time is no more than 10 milliseconds, which can quickly execute the switching command of the control unit.

[0023] The control terminals of the three solenoid valves are all electrically connected to the digital output module of the control unit. The control unit can control the on / off state of the solenoid valves by outputting high and low level signals. Each solenoid valve is equipped with a position feedback sensor, which can detect the valve's on / off state in real time and transmit the feedback signal to the digital input module of the control unit. The control unit determines whether the valve is operating normally by comparing the control command and the feedback signal. The air inlet of the first vacuum breaking valve is connected to the pressure stabilizing outlet of the micro-positive pressure chamber through a flexible air passage. A pressure stabilizing valve is installed at the pressure stabilizing outlet of the micro-positive pressure chamber, which can stabilize the pressure inside the micro-positive pressure chamber at a set value and output a clean airflow with a constant pressure to avoid excessive airflow pressure fluctuations during vacuum breaking. The air outlet of the first vacuum breaking valve is connected to the air inlet of the vacuum pump through a flexible air passage. The air inlet of the second vacuum breaking valve is connected to the exhaust port of the vacuum pump through a flexible air passage. The air outlet of the second vacuum breaking valve is connected to the air inlet of the air path damping adjustment component through a flexible air passage. The air outlet of the air path damping adjustment component is connected to the first air path between the suction head and the filter through a flexible air passage. The gas path damping adjustment assembly includes an adjustable throttle valve and a one-way check valve. The adjustable throttle valve is a needle-type throttle valve, which allows precise adjustment of the gas path flow area by rotating the adjusting needle, thereby regulating the gas flow rate and velocity during vacuum breaking. Operators can pre-adjust the opening of the adjustable throttle valve according to the weight and type of the cryovial to ensure smooth release. The one-way check valve is a spring-loaded one-way valve, whose conduction direction is limited to allowing gas to flow only from the second vacuum breaking valve to the suction head. This effectively prevents gas from flowing back into the first gas path from the vacuum breaking gas path during the vacuum suction stage, ensuring stable system vacuum.

[0024] In addition to the aforementioned vacuum pressure gauge, the pressure detection unit also includes a chamber pressure sensor installed inside the micro-positive pressure chamber. This capacitive pressure sensor can detect pressure changes within the chamber in real time and transmit the signal to the control unit. The control unit can adjust relevant parameters for the vacuum breaking operation based on the sensor's data to ensure consistent vacuum breaking performance. The control unit uses a programmable logic controller (PLC) as its core controller, integrating a central processing unit (CPU), memory, input / output modules, communication modules, and a power supply module. The CPU is a 32-bit high-performance processor capable of rapidly processing various input signals and executing control algorithms. The memory includes random access memory (RAM) and read-only memory (ROM) for storing system programs, control parameters, and operational data.

[0025] The control unit's input / output modules include digital input modules, digital output modules, and analog input modules. The digital input modules receive valve position feedback signals, sensor signals, and operation button signals. The digital output modules control the operation of motors, solenoid valves, and alarm devices. The analog input modules receive analog signals from vacuum gauges and chamber pressure sensors. The communication module supports multiple communication interfaces such as RS485, Ethernet, and USB, enabling data communication with external devices such as host computers, robotic arm controllers, and barcode scanners, achieving remote system control and data interaction. The control unit's power supply module uses a switching power supply, converting AC 220V to DC 24V and DC 5V to power the various electrical components of the system. The power supply module has overvoltage, overcurrent, and short-circuit protection functions, effectively protecting electrical components from damage. The control unit has a pre-programmed system control program. The program adopts a modular design, including an initialization module, self-test module, pre-vacuum control module, adsorption control module, holding control module, release control module, anomaly handling module, and human-machine interface module. These modules are independent yet cooperative, working together to complete the various functions of the system.

[0026] After the system is powered on, it first executes the initialization process. The control unit initializes and sets up each hardware module, configures the functions of the input / output ports, and initializes the memory and communication interface. Then, it executes the self-test process, sequentially checking the status of the motor, solenoid valve, vacuum gauge, chamber pressure sensor, and communication module. If any component is detected to be faulty, the control unit immediately issues an audible and visual alarm signal and displays the fault code and fault information on the human-machine interface. The system stops running and waits for the operator to troubleshoot the fault. If the self-test passes, the system enters standby mode, waiting to receive operation commands. When the system receives the automatic operation command, it first executes the S1 pre-vacuum standby process, which specifically includes three steps: S11, S12, and S13. In step S11, the control unit first obtains the sample information of the cryopreservation tube to be aspirated from the barcode scanner or host computer through the communication interface. The parameters include the capacity, weight, top cap diameter and sealing performance level of the cryopreservation tube. The control unit calls the vacuum degree matching logic stored internally and searches for the corresponding target vacuum degree threshold, maintaining vacuum degree threshold and adsorption completion threshold in the parameter table of the graded vacuum degree preset module according to the obtained and stored sample information. If the corresponding parameter group is not found, the default parameters are used.

[0027] The vacuum matching logic is established based on a large amount of experimental data. It can automatically match the most suitable vacuum parameters according to the physical characteristics of the cryovials, ensuring firm adsorption while avoiding excessive vacuum that could cause cryovial cap deformation or sample leakage. In step S12, the control unit sends a start command to the motor, controlling it to drive the vacuum pump at its rated speed. The vacuum pump begins to extract gas from the gas storage tank, which then passes through a one-way valve and the vacuum pump before being discharged into the micro-positive pressure chamber, gradually increasing the vacuum level within the tank. During this process, a vacuum pressure gauge collects vacuum level data from the gas storage tank in real time at a sampling frequency of 10 times per second and transmits the data to the control unit. The control unit performs a moving average filtering process on the collected raw data to remove high-frequency interference signals, obtaining a stable vacuum level value. In step S13, the control unit compares the filtered vacuum level value with the target vacuum level threshold. When the vacuum level value reaches the target threshold, the control unit sends a stop command to the motor, which smoothly stops running according to a preset deceleration curve, and the system enters standby mode. Simultaneously, the control unit starts an internal timer to record standby time. When the standby time exceeds a preset threshold, the control unit automatically starts the motor to replenish the vacuum until the vacuum level returns to the target threshold. Then, it enters standby mode again, repeating this cycle to ensure the gas tank always maintains sufficient negative pressure reserve, ready to respond to suction commands at any time. The preset threshold is determined based on the natural leakage rate of the gas tank; the lower the natural leakage rate, the larger the threshold, typically set to 30 to 60 minutes.

[0028] When the control unit receives the command to pick up the cryovial, it executes the S2 vacuum adsorption process. First, the control unit sends a motion command to the robotic arm controller via the communication interface, controlling the robotic arm to move the suction head along a preset trajectory to a preset position above the target cryovial. Then, the control unit controls the robotic arm to move downwards at a low speed until the silicone sealing ring at the lower end of the suction head is tightly fitted against the cryovial cap. The downward stroke of the robotic arm is precisely controlled by preset parameters to ensure that the silicone sealing ring generates appropriate compression, forming a good seal. Subsequently, the control unit sends an opening command to the vacuum valve, which opens rapidly. The negative pressure in the gas tank is quickly transmitted through the gas path to the sealed cavity between the suction head and the cryovial cap. Under the action of the pressure difference, the gas in the cavity passes sequentially through the suction head, the first-stage coarse filter, the second-stage precision filter, and the vacuum valve into the gas tank. The pressure in the cavity drops rapidly, forming a negative pressure adsorption force that firmly adsorbs the cryovial onto the suction head. During this process, the vacuum pressure gauge monitors the change in vacuum level in the gas path in real time. When the vacuum level reaches the preset adsorption completion threshold, the control unit determines that the adsorption is successful and sends a motion command to the robotic arm controller, which controls the robotic arm to move the cryopreservation tube along the preset trajectory to the target position.

[0029] After the robotic arm moves the cryopreservation tube to above the target position, the system executes the S3 adsorption and holding process, which includes three steps: S31, S32, and S33. In step S31, the control unit keeps the vacuum valve continuously open, and the vacuum gauge collects real-time vacuum data in the gas path at a sampling frequency of 20 times per second, transmitting the data to the control unit. The control unit filters the data and stores it in its internal memory. Simultaneously, the adsorption stability monitoring subunit within the control unit begins operation, calculating the pressure fluctuation value per unit time in real time. The pressure fluctuation value is obtained by calculating the standard deviation of the pressure values ​​at 10 consecutive sampling points, accurately reflecting the pressure stability and sealing status within the gas path. In step S32, the control unit compares the real-time vacuum value with a preset holding vacuum threshold. The holding vacuum threshold is slightly lower than the target vacuum threshold, allowing a certain degree of natural leakage within the gas path. If the real-time vacuum level is higher than the maintaining vacuum threshold, it indicates that the vacuum level in the gas path is sufficient to maintain a stable adsorption force. The control unit does not perform any operation and continues to monitor the vacuum level change. If the real-time vacuum level is lower than the maintaining vacuum threshold, it indicates that the vacuum level in the gas path is insufficient and needs to be supplemented. The control unit immediately activates the dynamic vacuum compensation mechanism. In step S33, the dynamic vacuum compensation mechanism first calculates the difference between the current real-time vacuum level and the maintaining vacuum threshold. Based on the magnitude of the difference, it determines the motor's compensation speed and compensation time. The larger the difference, the higher the compensation speed and the longer the compensation time.

[0030] The control unit then sends a start command to the motor, controlling it to run at a predetermined compensation speed at low speed, driving the vacuum pump for gas compensation. During this process, the vacuum pressure gauge continuously monitors changes in the vacuum level within the gas path. When the vacuum level recovers to above the maintaining vacuum threshold, the control unit sends a stop command to the motor, stopping its operation and completing one vacuum compensation cycle. If, during the compensation process, the pressure fluctuation value calculated by the adsorption stability monitoring subunit exceeds the preset fluctuation threshold, it indicates a poor seal between the suction head and the cryovial, suggesting a significant leak. The control unit issues a warning signal while performing vacuum compensation, reminding the operator to check the seal. If the pressure fluctuation value continues to exceed the fluctuation threshold for more than 5 seconds, and the dynamic vacuum compensation mechanism cannot restore the vacuum level to above the maintaining vacuum threshold, the control unit determines it as a level two fault and immediately executes an emergency vacuum release operation.

[0031] When the control unit receives the command to release the cryovial, it executes the S4 vacuum-breaking release procedure. The control unit first controls the robotic arm to move the cryovial to a preset height above the target position. This preset height is set based on the length of the cryovial and the depth of the target container, ensuring the cryovial falls smoothly into the target container after release without collision or tipping. Then, the control unit employs a time-sequential valve control strategy to perform the vacuum-breaking operation, which includes three steps: S41, S42, and S43. In step S41, the control unit first sends a closing command to the vacuum suction valve, which closes rapidly, cutting off the airflow connection between the gas tank and the suction head. After a first preset time delay, it sends an opening command to the first vacuum-breaking valve, which opens rapidly. The first preset time is set based on the closing response time of the vacuum suction valve, typically 20 milliseconds, ensuring the vacuum suction valve is completely closed before opening the first vacuum-breaking valve, preventing short circuits that could cause a decrease in vacuum within the gas tank. In step S42, after the first vacuum breaking valve opens, the clean gas in the micro-positive pressure chamber, under the influence of the pressure difference, enters the vacuum pump's inlet through the first vacuum breaking valve. After a second preset time delay, the control unit sends an opening command to the second vacuum breaking valve, which opens rapidly. The second preset time is set based on the vacuum pump's response time, typically 10 milliseconds, to ensure the vacuum pump first establishes a certain inlet pressure, preventing excessive airflow impact after the second vacuum breaking valve opens. After the second vacuum breaking valve opens, the gas, pressurized by the vacuum pump, passes sequentially through the second vacuum breaking valve, the adjustable throttle valve, and the one-way check valve, quickly entering the first gas path, causing the pressure inside the suction head to rise rapidly. During this process, the adjustable throttle valve regulates the airflow rate and speed, preventing excessive airflow from blowing away the cryovial or causing it to shift position, while the one-way check valve prevents gas from flowing back into the vacuum pump. In step S43, the vacuum pressure gauge monitors the pressure changes in the first gas path in real time. When the pressure reaches the preset positive pressure threshold, the control unit determines that vacuum breaking is complete and simultaneously sends a closing command to the first and second vacuum breaking valves. Both valves close rapidly, completing the vacuum breaking and release operation. The preset positive pressure threshold is slightly higher than the internal pressure of the micro-positive pressure chamber, ensuring that the suction head's internal pressure is completely restored and the suction force is completely eliminated. At this point, the cryopreservation tube falls smoothly under gravity into the target container. The control unit sends a motion command to the robotic arm controller, controlling the robotic arm to return to the standby position, awaiting the next suction command.

[0032] Throughout the system's operation, the anomaly handling process remains active. The control unit monitors the operational status and parameter changes of all components in real time, employing a fault-level response mechanism to handle different types of faults. When the vacuum gauge detects that the vacuum level in the gas storage tank cannot reach the target vacuum threshold within the preset evacuation time, it is classified as a Level 1 fault. The preset evacuation time is determined based on the volume of the gas storage tank and the evacuation rate of the vacuum pump, typically set to 30 seconds. At this time, the control unit issues a Level 1 audible and visual alarm signal, displays the fault message "Vacuum establishment failed" on the human-machine interface, and stops all current operations, awaiting the operator's inspection to check whether the vacuum pump is operating normally, whether there are leaks in the gas path, and whether the vacuum gauge is functioning correctly. When the vacuum level continues to decrease during the adsorption and maintenance phase, and the dynamic vacuum compensation mechanism fails to restore the vacuum level to above the maintenance vacuum threshold after three consecutive runs, it is classified as a Level 2 fault. In this case, the control unit issues a Level 2 emergency audible and visual alarm signal, immediately executes an emergency vacuum release operation, places the cryovials in the nearest safe location to prevent them from falling off and causing loss of biological samples, and simultaneously displays the fault message "Adsorption failed" on the human-machine interface. When the control unit sends a switching command to the solenoid valve and does not receive a corresponding position feedback signal within a preset feedback time, it is determined to be a level three fault. The preset feedback time is usually set to 50 milliseconds. At this time, the control unit issues the highest level three audible and visual alarm signal, immediately cuts off the main power supply to the system, stops the operation of all components to prevent the fault from escalating further, and displays the fault information "valve fault" on the human-machine interface, recording the time of the fault occurrence and related parameters to facilitate troubleshooting and maintenance by operators.

[0033] After system installation, airtightness testing and parameter calibration are required. The airtightness test involves closing all valves, evacuating the gas tank to a vacuum of -0.08 MPa, then turning off the vacuum pump and allowing it to stand for 24 hours. The vacuum level is then observed; if the decrease is less than 0.005 MPa, the gas path is considered well-sealed and meets usage requirements. Parameter calibration includes vacuum gauge calibration and adjustable throttle valve calibration. The vacuum gauge is calibrated using a standard pressure source to ensure its measurement accuracy meets requirements. The adjustable throttle valve is adjusted by observing the release status of the cryovials until they fall smoothly and accurately into the target position. During daily use, the system requires regular maintenance, including replacing the filter cartridge every 3 months, checking the valve sealing performance and the operating status of the motor and vacuum pump every 6 months, and calibrating the vacuum gauge and safety valve annually to ensure the system is always in good operating condition.

Claims

1. A cryopreservation tube suction control system, characterized in that, The system includes a power unit, a vacuum energy storage unit, a gas path execution unit, a pressure detection unit, and a control unit. The power unit includes a motor and a vacuum pump, with the motor's output connected to the vacuum pump. The vacuum energy storage unit includes a gas storage tank; the gas inlet of the tank is connected to the vacuum pump's suction port via a one-way valve, and the gas outlet of the tank and the vacuum pump are both connected to a micro-positive pressure chamber. The gas path execution unit includes a suction head, a filter, a vacuum suction valve, a first vacuum breaking valve, and a second vacuum breaking valve. The suction head's air inlet is connected to the filter's air inlet via a first gas path, and the filter's air outlet is connected to the vacuum suction valve's air inlet via a second gas path. The vacuum suction valve's air outlet is connected to the negative pressure chamber of the gas storage tank. The pressure interface is connected; the air inlet of the first vacuum breaking valve is connected to the pressure stabilizing air outlet of the micro-positive pressure chamber, the air outlet of the first vacuum breaking valve is connected to the air inlet of the vacuum pump, the air inlet of the second vacuum breaking valve is connected to the exhaust port of the vacuum pump, and the air outlet of the second vacuum breaking valve is connected to the first air path through the third air path; the pressure detection unit includes a vacuum pressure gauge, which is installed on the air path between the negative pressure interface of the gas storage tank and the air outlet of the vacuum suction valve; the control unit is electrically connected to the motor, the vacuum suction valve, the first vacuum breaking valve, the second vacuum breaking valve and the vacuum pressure gauge respectively, and the control unit is configured to control the on / off state of each valve and the running state of the motor according to the detection signal of the vacuum pressure gauge.

2. The cryopreservation tube suction control system according to claim 1, characterized in that, The vacuum energy storage unit also includes a graded vacuum degree preset module, which is electrically connected to the control unit and is used to input at least two different target vacuum degree thresholds for the gas storage tank to the control unit. The control unit is configured to control the motor to drive the vacuum pump to run according to the input target vacuum degree threshold until the vacuum pressure gauge detects that the vacuum degree in the gas storage tank has reached the corresponding target threshold, and then control the motor to enter the standby state.

3. The cryopreservation tube suction control system according to claim 1, characterized in that, The filter adopts a two-stage series filtration structure, including a first-stage coarse filter and a second-stage precision filter. The air inlet of the first-stage coarse filter is connected to a first air path, the air outlet of the first-stage coarse filter is connected to the air inlet of the second-stage precision filter, and the air outlet of the second-stage precision filter is connected to a second air path. The one-way valve is configured to allow gas to flow only from the air inlet of the gas storage tank to the air outlet of the vacuum pump.

4. The cryopreservation tube suction control system according to claim 1, characterized in that, The third gas path is equipped with a gas path damping adjustment component, which includes an adjustable throttle valve and a one-way check valve. The inlet of the adjustable throttle valve is connected to the outlet of the second vacuum breaking valve, and the outlet of the adjustable throttle valve is connected to the inlet of the one-way check valve. The outlet of the one-way check valve is connected to the first gas path, and the conduction direction of the one-way check valve is configured to allow gas to flow from the second vacuum breaking valve to the suction head only.

5. The cryopreservation tube suction control system according to claim 1, characterized in that, The control unit includes an adsorption stability monitoring subunit, which is configured to collect pressure data from a vacuum pressure gauge in real time and calculate the pressure fluctuation value per unit time during the adsorption holding phase when the vacuum valve is kept open; when the pressure fluctuation value exceeds a preset fluctuation threshold, the control unit controls the motor to start to replenish the vacuum in the gas storage tank until the pressure fluctuation value falls back below the preset fluctuation threshold.

6. A control method for a cryopreservation tube suction control system according to any one of claims 1 to 5, characterized in that, Includes the following steps: S1 pre-vacuum standby process: The control unit controls the motor to drive the vacuum pump to pump the gas in the gas storage tank to the micro-positive pressure chamber until the vacuum pressure gauge detects that the vacuum degree in the gas storage tank has reached the preset initial threshold, and then controls the motor to enter the standby state. S2 vacuum adsorption process: When the command to aspirate the cryopreservation tube is received, the control unit controls the vacuum valve to open. The gas in the cavity between the suction head and the top cover of the cryopreservation tube enters the gas storage tank in sequence through the first gas path, the filter, the second gas path, and the vacuum valve, so that a negative pressure adsorption is formed between the suction head and the cryopreservation tube. S3 Adsorption and Holding Process: The control unit keeps the vacuum valve open and monitors the vacuum level in the gas path in real time through the vacuum pressure gauge to maintain stable adsorption of the cryopreservation tube by the suction head; S4 Vacuum Breaking Release Process: When a command to release the cryopreservation tube is received, the control unit closes the vacuum valve and simultaneously opens the first and second vacuum breaking valves. The gas in the micro-positive pressure chamber enters the first air path rapidly through the first vacuum breaking valve, the vacuum pump, the second vacuum breaking valve, and the third air path, restoring the pressure inside the suction head to positive pressure. The cryopreservation tube separates from the suction head under the action of gravity.

7. The control method according to claim 6, characterized in that, Step S1 specifically includes: The S11 control unit acquires the sample information stored in the cryopreservation tube to be aspirated, and calls the corresponding vacuum matching logic based on the sample information to determine the target vacuum threshold. The S12 control unit controls the motor to drive the vacuum pump at the rated speed, and the vacuum pressure gauge collects the vacuum level data in the gas storage tank in real time and feeds it back to the control unit. When the vacuum level data reaches the target vacuum level threshold, the control unit controls the motor to stop running and enters standby mode. If the standby time exceeds the preset time threshold, the control unit automatically starts the motor to replenish the vacuum level until the vacuum level is restored to the target vacuum level threshold.

8. The control method according to claim 6, characterized in that, In step S4, the control unit employs a time-sequential valve control strategy to perform the vacuum breaking operation, specifically including: The S41 control unit first closes the vacuum valve, and after a first preset time delay, opens the first vacuum breaking valve. S42 opens the first vacuum breaking valve and, after a second preset time delay, opens the second vacuum breaking valve; When the vacuum pressure gauge detects that the pressure in the first gas path has reached the preset positive pressure threshold, the control unit simultaneously closes the first vacuum breaking valve and the second vacuum breaking valve to complete the vacuum breaking and release operation.

9. The control method according to claim 6, characterized in that, Step S3 specifically includes: The S31 control unit keeps the vacuum valve open and collects real-time vacuum data in the gas path through the vacuum pressure gauge at a preset sampling frequency. The S32 control unit compares the real-time vacuum level data with the preset vacuum level threshold. If the real-time vacuum level is lower than the preset vacuum level threshold, the dynamic vacuum level compensation mechanism is activated. Under the S33 dynamic vacuum compensation mechanism, the control unit controls the motor to run at low speed to drive the vacuum pump for pumping compensation until the real-time vacuum degree is restored to above the preset vacuum degree threshold, and then controls the motor to stop running.

10. The control method according to claim 6, characterized in that, It also includes an exception handling process, which adopts a fault classification response mechanism, specifically including: When the vacuum pressure gauge detects that the vacuum level in the gas storage tank cannot reach the target threshold within a preset time, it is determined to be a level one fault, the control unit issues a level one alarm signal and stops the current operation; When the vacuum level continues to decrease during the adsorption and holding phase and the dynamic vacuum compensation mechanism cannot restore it, it is determined to be a level two fault. The control unit issues a level two alarm signal and performs an emergency vacuum release operation. When the valve action feedback signal is inconsistent with the control command, it is determined to be a level three fault. The control unit issues a level three alarm signal and cuts off the system power supply.

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