Quaternary pump liquid mixing system

Abstract

The application discloses a quaternary pump liquid phase mixing system, which comprises a controller, a proportional valve, a driving check valve, a liquid infusion pump and a pressure sensor. The controller is used for controlling the proportional valve to be turned on and the liquid infusion pump to suck liquid. The pressure sensor is used for detecting pressure information in the liquid infusion pump. The controller is further used for determining a liquid suction starting point of the liquid infusion pump based on the pressure information and controlling the driving check valve to be opened after the liquid suction starting point. The controller is further used for determining a current mixing ratio of mixed liquid according to the absorbance of the mixed liquid, and when the current ratio of the mixed liquid meets an extreme value, calculating an absorbance error of the mixed solution according to linear variation of the absorbance of the current mixed liquid, so as to correct the opening and closing degree of the driving check valve. Through the above setting, the liquid flow phase mixing accuracy in the quaternary pump liquid phase mixing system can be improved, and the service life of the quaternary pump liquid phase mixing system is prolonged.

Description

Technical Field

[0001] This application relates to the field of liquid mixing technology, and more particularly to a quaternary pump liquid phase mixing system. Background Technology

[0002] A quaternary pump is a type of pump used in liquid chromatography systems. It can mix multiple different liquids to create the desired mobile phase. It can process multiple different liquids simultaneously and mix them in proportion to generate the desired mobile phase according to actual needs.

[0003] Currently, passive check valves are generally used as the opening and closing channels for pumps, but passive check valves have a short service life, which reduces the service life of quaternary pumps.

[0004] Meanwhile, the accuracy of liquid phase mixing in a quaternary pump is one of its important indicators, as it affects the accuracy and stability of liquid mixing. Summary of the Invention

[0005] The purpose of this application is to provide a quaternary pump liquid phase mixing system that can improve the mixing accuracy of the liquid mobile phase in the quaternary pump liquid phase mixing system and extend the service life of the quaternary pump liquid phase mixing system.

[0006] To achieve the above objectives, this application adopts the following technical solution: A quaternary pump liquid-phase mixing system includes a controller, a proportional valve, an active check valve, an infusion pump, and a pressure sensor. The controller controls the proportional valve to open, allowing the infusion pump to draw liquid. The pressure sensor detects the internal pressure of the infusion pump and transmits this information to the controller. The controller also determines the infusion pump's liquid-drawing start point based on the pressure information and controls the active check valve to open after the start point. Furthermore, the controller controls the proportion of different liquids in the mobile phase of the proportional valve, ensuring that the multiple liquids drawn into the infusion pump are mixed according to a preset mixing ratio. The system also includes a liquid component detection component to acquire the absorbance of the mixed liquid in the infusion pump. The controller further determines the current mixing ratio of the mixed liquid based on its absorbance. When the current mixing ratio meets an extreme value, the controller calculates the absorbance error of the mixed solution based on the linear change in the current absorbance of the mixed liquid to correct the opening / closing degree of the active check valve.

[0007] Furthermore, the controller is also used to gradually increase the opening degree of the active check valve by a preset step size before the infusion pump starts to draw liquid for the first time, and to take the moment when the liquid emerges from the active check valve as the start point of the infusion pump's suction. The system also includes a motor encoder, which is used to acquire the motor position signal of the infusion pump and transmit the motor position signal of the infusion pump to the controller. The controller is used to record the infusion pump's suction stroke based on the motor position signal.

[0008] Furthermore, the controller is also used to: adjust the duty cycle of the control current of the active check valve, and control the opening and closing degree of the active check valve by the control current with different duty cycles; during the closing end time period of the active check valve, adjust the opening current and closing current of the active check valve in an iterative manner using a binary method until the absorbance error of the mixed solution is reduced to within a preset range, so as to correct the opening and closing degree of the active check valve, wherein the control current includes the opening current and the closing current.

[0009] Furthermore, when the controller corrects the opening and closing degree of the active check valve, it uses an H-bridge motor driver chip to control the control current input to the active check valve and adjusts the duty cycle of the pulse width modulation (PWM) wave of the control current according to the parabolic function curve.

[0010] Furthermore, the controller is also used to: determine the total suction stroke of the infusion pump based on the screw coefficient of the infusion pump and the total volume of various solutions; determine the position information of the end point of the suction stroke of the infusion pump based on the position information of the starting point of the suction stroke and the total suction stroke of the infusion pump; and determine the valve cutting point of the proportional valve based on the proportion of each liquid in the current mobile phase and the position information of the starting and ending points.

[0011] Furthermore, the controller is also used to: split the liquid with the largest proportion in the mobile phase of the proportional valve into two parts, which are input at the beginning and end of the mobile phase of the proportional valve, respectively; the number of liquid types contained in the mobile phase of the proportional valve is equal to the number of valve cut-off points of the proportional valve.

[0012] Furthermore, the active check valve includes: a voice coil motor, a diaphragm, a push rod on the diaphragm, a ball above the push rod, and a spring that cooperates with the ball. The voice coil motor is used to lift the push rod on the diaphragm to open the active check valve, and to close the active check valve by the gravity of the ball falling back and the elastic force of the spring.

[0013] Furthermore, the controller is also used to: adjust the duty cycle of the control current of the active check valve; and control the height of the voice coil motor lifting the push rod by controlling the control current with different duty cycles, thereby controlling the opening and closing degree of the active check valve.

[0014] Furthermore, when controlling the opening and closing degree of the active one-way valve, the controller uses an H-bridge motor driver chip to control the control current of the input voice coil motor, and adjusts the duty cycle of the pulse width modulation (PWM) wave of the control current according to the parabolic function curve.

[0015] Furthermore, the controller is also used to determine, based on the current pressure information of the infusion pump detected by the pressure sensor, that when the internal pressure of the infusion pump and the external pressure of the infusion pump are in balance, to use the current moment as the starting point for opening the active check valve.

[0016] Furthermore, the controller is also used to store the pressure value in the internal pressure information of the infusion pump as the external pressure value of the infusion pump at the end of the infusion pump's suction stroke.

[0017] Furthermore, the controller is located inside and / or outside the quaternary pump liquid phase mixing system; when the controller is located outside the quaternary pump liquid phase mixing system, the controller is a cloud platform.

[0018] The quaternary pump liquid phase mixing system of this application can determine the balance point of internal and external pressure through a pressure sensor and use this as the starting point for opening the active check valve, thereby avoiding backflow of the mobile phase and correcting the opening degree of the active check valve to improve the mixing accuracy of the liquid mobile phase in the quaternary pump liquid phase mixing system; at the same time, the active check valve solves the problem of the short service life of the passive check valve, thereby improving the service life of the quaternary pump liquid phase mixing system. Attached Figure Description

[0019] Figure 1 This is a structural block diagram of a quaternary pump liquid phase mixing system provided in an embodiment of this application.

[0020] Figure 2 This is a partial structural block diagram of a quaternary pump liquid-phase mixing system provided in an embodiment of this application.

[0021] Figure 3 A schematic diagram of the active check valve of the quaternary pump liquid phase mixing system provided in the embodiments of this application.

[0022] Figure 4 This is a schematic diagram of the voice coil motor of the active one-way valve provided in the embodiments of this application under different states.

[0023] Figure 5 This is a schematic diagram showing the current changes of a voice coil motor under different states in related technologies.

[0024] Figure 6 This is a schematic diagram illustrating the current changes of a voice coil motor under different states, as provided in an embodiment of this application.

[0025] Figure 7 A flowchart illustrating the control method for a quaternary pump liquid-phase mixing system provided in this application embodiment.

[0026] Figure 8 This is a block diagram of the communication structure of a quaternary pump liquid phase mixing system provided in an embodiment of this application. Detailed Implementation

[0027] The present application will be described in detail below with reference to the specific embodiments shown in the accompanying drawings. However, these embodiments do not limit the present application. Any structural, methodological, or functional modifications made by those skilled in the art based on these embodiments are included within the protection scope of the present application.

[0028] like Figure 1 As shown in the figure, this application provides a quaternary pump liquid phase mixing system 100, which includes a controller 11, a proportional valve 12, an active check valve 13, an infusion pump 14, and a pressure sensor 15.

[0029] It should be noted that a quaternary pump is a type of pump used in liquid chromatography systems. It can mix multiple different liquids to create the desired mobile phase. It can process multiple different liquids simultaneously and mix them in proportion according to actual needs to generate the required mobile phase.

[0030] In this application, the quaternary pump liquid phase mixing system 100 is capable of mixing two, three, or four liquids to generate the desired mobile phase.

[0031] It should be noted that different liquids can be placed in different solvent bottles 200, and each solvent bottle 200 corresponds to a channel of the proportional valve 12. Thus, by opening different channels of the proportional valve 12, the quaternary pump liquid phase mixing system 100 can mix a variety of different liquids to create the desired mobile phase.

[0032] The controller 11 can be a central processing unit (CPU), a general-purpose processor, a network processor (NP), a digital signal processor (DSP), a microprocessor, a microcontroller, a programmable logic device (PLD), or any combination thereof. The controller 11 can also be any other device with processing capabilities, such as a circuit, device, or software module, without limitation. In one example, the controller 11 may include one or more CPUs.

[0033] The proportional valve 12 is a control valve that can continuously and precisely regulate flow or pressure according to an input signal (electric, pneumatic or hydraulic).

[0034] The active check valve 13 is a check valve that is actively opened or closed by an external control signal, unlike traditional passive check valves that rely on pressure differential (such as spring-loaded or gravity-operated types). The active check valve 13 combines the backflow prevention characteristics of a check valve with active control capabilities, making it suitable for systems requiring precise flow management.

[0035] Pressure sensor 15 is a measuring device that converts pressure signals into electrical signals and is used to monitor pressure changes in gases or liquids.

[0036] Furthermore, current quaternary pump liquid mixing systems 100 generally employ passive check valves. Passive check valves (such as spring-loaded, gravity-driven, and diaphragm-driven valves) rely on fluid pressure differentials for automatic opening and closing, making them prone to damage in complex operating conditions like those in quaternary pump liquid mixing systems 100. In this application, however, the active check valve 13 precisely controls the opening and closing speed and stroke through electromagnetic / piezoelectric drive, avoiding hard impacts and thus resisting mechanical fatigue. Moreover, the active check valve 13 adjusts the closing speed via electrical signals or buffer circuits, thereby enhancing its anti-liquid hammer capability and achieving gradual closure. This solves the problem of the short service life of passive check valves, thereby improving the overall service life of the quaternary pump liquid mixing system 100.

[0037] In this application, the controller 11 is electrically connected to the proportional valve 12, the active check valve 13, the infusion pump 14, and the pressure sensor 15. Specifically, the controller 11 is used to control the proportional valve 12 to open, so that liquid corresponding to a different channel of the proportional valve 12 can be delivered to the infusion pump 14 through the proportional valve 12.

[0038] More specifically, when the proportional valve 12 is open, the controller 11 can control the infusion pump 14 to draw liquid, so that the liquid corresponding to the open proportional valve 12 channel can be delivered to the infusion pump 14 through the proportional valve 12.

[0039] Pressure sensor 15 is located inside infusion pump 14 so that it can detect pressure information inside infusion pump 14. Pressure sensor 15 can transmit pressure information to controller 11, so that controller 11 can determine the infusion pump 14 suction start point based on pressure information, and controller 11 can control active check valve 13 to open after the suction start point.

[0040] Because the active check valve exhibits a diaphragm pumping effect—that is, in a fluid system, the diaphragm inside the active check valve deforms during rapid opening and closing or periodic operation, leading to changes in system volume and resulting in fluid pressure fluctuations and pulsating flow phenomena similar to those of a diaphragm pump—the active check valve 13 in this embodiment of the application employs the following measures to address the aforementioned diaphragm pumping effect: When the infusion pump 14 enters the suction state, there is a certain coordinated delay between the suction start time of the proportional valve 12 and the opening time of the active check valve 13. Backflow will occur when the pressure inside the infusion pump 14 is greater than the external mobile phase pressure. Therefore, the pressure sensor 15 is used to determine the balance point of the internal and external pressures and uses this as the starting point for opening the active check valve 13, thereby avoiding backflow of the mobile phase and improving the mixing accuracy of the liquid mobile phase in the quaternary pump liquid phase mixing system 100.

[0041] In summary, the quaternary pump liquid phase mixing system 100 of this application has high accuracy in mixing the liquid mobile phase and a long service life.

[0042] In this embodiment, the controller 11 can also use the current moment as the starting point for opening the active check valve 13 when it is determined that the internal pressure of the infusion pump 14 and the external pressure of the infusion pump 14 are in balance, based on the current pressure information of the infusion pump 14 detected by the pressure sensor 15.

[0043] Optionally, in two adjacent suction cycles, the internal pressure of the infusion pump 14 at the end of the previous suction cycle is equal to the external pressure of the infusion pump 14. Therefore, the external pressure of the infusion pump 14 at the beginning of the next suction cycle is the same as the internal pressure of the infusion pump 14 at the end of the previous suction cycle. In this application, the controller 11 is also used to store the pressure value in the internal pressure information of the infusion pump 14 as the pressure value of the external pressure of the infusion pump 14 at the end of the suction stroke of the infusion pump. This helps the controller 11 to determine that the internal pressure of the infusion pump 14 and the external pressure of the infusion pump 14 are balanced based on the pressure information, thereby determining the suction start point of the infusion pump 14, and controlling the active check valve 13 to open after the suction start point.

[0044] It should be noted that, since there is no previous suction cycle during the first suction cycle of the infusion pump 14, i.e., the first suction cycle of the quaternary pump liquid phase mixing system 100, the controller 11 is also used to gradually increase the opening degree of the active check valve 13 by a preset step size before the first suction of the infusion pump 14 begins. The moment when liquid emerges from the active check valve 13 is taken as the suction start point of the infusion pump 14.

[0045] like Figure 2As shown, in one implementation, the quaternary pump liquid-phase mixing system 100 includes a motor encoder 16. The motor encoder 16 is a sensor that converts the position, speed, or direction of a motor shaft into an electrical signal, and can be applied in precision motion control fields such as servo control, robotics, and CNC machine tools. In this application, the infusion pump 14 is driven by a motor to achieve liquid suction. The motor encoder 16 can acquire the motor position signal of the infusion pump 14 and transmit this signal to the controller 11. The controller 11 is used to record the infusion pump suction stroke of the infusion pump 14 based on the motor position signal, thereby obtaining the infusion pump suction stroke at different times.

[0046] In one implementation, the controller 11 is also used to control the proportion of different liquids in the mobile phase of the proportional valve 12, so that the multiple liquids drawn into the infusion pump 14 are mixed according to a preset mixing ratio. Specifically, the controller 11 can control the opening and closing of the proportional valve 12 channel corresponding to each liquid according to the required proportion of each liquid in the mobile phase, that is, the controller 11 can control the preset mixing ratio, so that the infusion pump 14 can draw each liquid in the required proportion, thereby making the mobile phase in the infusion pump 14 meet the requirements.

[0047] For example, the preset mixing ratio can be a predetermined mixing ratio of various liquids to be input into the quaternary pump liquid phase mixing system 100 before the liquid aspiration begins, which is the target mixing ratio of the mixed liquid to be output. The preset mixing ratio includes the proportion of each liquid in the desired mobile phase, and the preset mixing ratio can be adjusted according to actual needs to obtain different mobile phases.

[0048] In this embodiment, the quaternary pump liquid phase mixing system 100 further includes a liquid component detection component 17, which is used to obtain the absorbance of the mixed liquid (i.e., the mobile phase) in the infusion pump 14, so that the controller 11 can determine the current mixing ratio of the mixed liquid based on the absorbance of the mixed liquid.

[0049] Among them, the liquid component detection component 17 can be a PDA detector (Photodiode Array Detector). The PDA detector can detect light signals of multiple wavelengths at the same time, providing high-sensitivity and high-resolution analytical data, thereby enabling the acquisition of the proportion of various liquids in the mixed liquid.

[0050] In an optional embodiment of this application, the controller 11 can calculate the absorbance error of the mixed solution based on the linear change in absorbance of the mixed liquid when the current proportion of the mixed liquid meets an extreme value, so as to correct the opening degree of the active one-way valve 13. Here, the current proportion of the mixed liquid meeting an extreme value means that the mixed liquid contains a first liquid with a proportion less than a preset minimum proportion value and / or a second liquid with a proportion greater than a preset maximum proportion value, wherein the preset minimum proportion value is less than the preset maximum proportion value.

[0051] It should be noted that the calculation error of the absorbance of the mixed solution based on the linear change of absorbance of the current mixed liquid will be described below, and will not be repeated here.

[0052] Because of the diaphragm pump effect of the check valve, the ratio of the first liquid and / or the second liquid in the mobile phase may deviate from the preset mixing ratio, which will lead to a decrease in the mixing accuracy of the liquid mobile phase. Therefore, in this embodiment, by correcting the opening and closing degree of the active check valve 13 by the controller 11, the ratio of the first liquid and / or the second liquid in the mobile phase can be changed, thereby making the ratio of the first liquid and / or the second liquid consistent with the preset mixing ratio, and thus improving the mixing accuracy of the liquid mobile phase in the quaternary pump liquid phase mixing system 100.

[0053] As an optional implementation, the preset minimum ratio can be set to any value between 5% and 10%, and the preset maximum ratio can be set to any value between 85% and 95%. It should be noted that the preset minimum and maximum ratios in this application can be adjusted according to the implementation situation to improve the mixing accuracy of the mobile phase under different operating conditions.

[0054] In one implementation, the controller 11 in this application embodiment can adjust the duty cycle of the control current of the active check valve 13, and correct the opening and closing degree of the active check valve 13 by using control currents with different duty cycles.

[0055] like Figure 3As shown in this embodiment, the active one-way valve 13 includes a housing 131, a voice coil motor 132, a diaphragm 133, a push rod 134 located on the diaphragm 133, a ball 135 located above the push rod 134, and a spring 136 cooperating with the ball 135. The housing 131 has an outlet 1311 and an inlet 1312. When the active one-way valve 13 is closed, the ball 135 blocks the channel between the outlet 1311 and the inlet 1312 to maintain the closure of the active one-way valve 13. The voice coil motor 132, as the driving element for opening the active one-way valve 13, lifts the push rod 134 on the diaphragm 133, allowing the push rod 134 to lift the ball 135. At this time, the ball 135 opens the channel between the outlet 1311 and the inlet 1312, thereby opening the active one-way valve 13. When the active check valve 13 needs to be closed, the ball 135 is closed by gravity and the spring force of the spring 136. It should be noted that the gravity of the ball 135 allows it to return to a state that blocks the passage between the outlet 1311 and the inlet 1312; this state is defined as the blocked state. The spring force of the spring 136 acts on the ball 135, giving it a tendency to return to the blocked state.

[0056] In this embodiment, the controller 11 can adjust the duty cycle of the control current of the active one-way valve 13. By controlling the height of the voice coil motor 132 lifting the push rod 134 through different duty cycle control currents, the opening and closing degree of the active one-way valve 13 can be controlled. That is, the opening and closing degree of the active one-way valve 13 is achieved by cooperating with the voice coil motor 132 through different duty cycle control currents.

[0057] Optionally, when the controller 11 controls the opening and closing degree of the active one-way valve 13, it uses an H-bridge motor driver chip to control the control current of the input voice coil motor 132.

[0058] For example, the H-bridge motor drive chip can be integrated on the controller 11, or the H-bridge motor drive chip can be connected to the controller 11 so that the controller 11 and the H-bridge motor drive chip can communicate with each other.

[0059] For example, by keeping one input pin of the H-bridge motor driver chip at a high level and using a PWM (Pulse Width Modulation) wave with a different duty cycle on the other input pin, different lifting forces can be applied to the voice coil motor 132, thereby controlling the active one-way valve 13 to complete different opening degrees.

[0060] like Figure 4As shown, in order to ensure that the initial state of the voice coil motor 132 is in a basically consistent position, the state of the voice coil motor 132 is divided into a close state (i.e., closed state), an arm state (i.e., near-open state), and an open state (i.e., open state). That is, the active one-way valve 13 can switch between the above three states.

[0061] It should be noted that the control current in the three states of the voice coil motor 132 includes a closing current, a near-opening current, and an opening current. When the voice coil motor 132 is in the closed state, a closing current is input to output a first upward force on the push rod 134; when the voice coil motor 132 is in the open state, a near-opening current is input to output a second upward force on the push rod 134 to nearly open the active one-way valve 13, thereby reducing the impact on pipeline pressure when the active one-way valve 13 opens; when the voice coil motor 132 is in the open state, an opening current is input to output a third upward force on the push rod 134, thereby fully opening the active one-way valve 13 for liquid aspiration. Specifically, the closing current is less than the near-opening current, and the near-opening current is less than the opening current; the first upward force is less than the second upward force, and the second upward force is less than the third upward force.

[0062] The currents (i.e., closing current, near-open current, and opening current) in the close, arm, and open states are determined as follows: Connect solvent bottle 200 to active check valve 13 via a pipeline and place it at a height approximately one meter above the active check valve 13. Then, gradually increase the duty cycle of the control current of the active check valve 13 in 1% increments from 0 until just a droplet emerges from the outlet of the active check valve 13. Record the current at this point. Then, based on the system usage conditions, if the ARM state is close to being turned on, its value is fine-tuned to determine the current magnitude in the ARM state. That is, the magnitude of the current close to the opening value is The current in the closed state (i.e., the shut-off current) can be [0, ...]. For any given value, the initial closing current can be set to 0, and the closing current can be corrected subsequently while ensuring that the active one-way valve 13 remains closed. The current in the open state can be calculated by the downward pressure of the spring 136 under the maximum stroke of the voice coil motor 132, thereby calculating the corresponding control PWM duty cycle.

[0063] It should be noted that, through the above settings, before the infusion pump 14 begins its first suction, the controller 11 gradually increases the opening degree of the active check valve 13 by a preset step size, and the moment when liquid emerges from the active check valve 13 is taken as the suction start point of the infusion pump 14. The preset step size can be 1% as described above, or it can be adjusted according to actual needs.

[0064] However, due to such Figure 5 The direct step transition shown leads to significant pipeline impact on the check valve, causing it to exhibit a diaphragm pump effect. This, in turn, affects the mixing accuracy of the liquid mobile phase in the quaternary pump liquid phase mixing system 100 under high concentration conditions. Therefore, in this application, according to... Figure 6 The change in the parabolic function curve shown adjusts the duty cycle of the pulse width modulation (PWM) wave of the control current, so that the opening and closing process of the active one-way valve 13 is smooth and adjustable.

[0065] For example, the transition curve between the shut-off current and the near-open current is a parabolic function curve, that is, the current change curve of the voice coil motor 132 from the close state to the arm state is a parabolic function curve; the transition curve between the near-open current and the open current is a parabolic function curve, that is, the current change curve of the voice coil motor 132 from the arm state to the open state is a parabolic function curve; the transition curve between the open current and the shut-off current is a parabolic function curve, that is, the current change curve of the voice coil motor 132 from the open state to the close state is a parabolic function curve.

[0066] The following explanation uses the transition of the voice coil motor 132 from the close state to the arm state as an example. The time required to switch from the close state to the arm state is defined as follows: The formula for the parabolic function curve is as follows: (Formula 1); in, This is the current when the voice coil motor 132 is in arm mode (i.e., close to the turn-on current). This is the current when the voice coil motor 132 is in the closed state (i.e., the shut-off current). .

[0067] Optionally, the formulas for the current change curves of the voice coil motor 132 transitioning from the arm state to the open state, the current change curves of the voice coil motor 132 transitioning from the open state to the closed state, and the current change curves of the voice coil motor 132 transitioning from the closed state to the arm state are the same, and will not be repeated here.

[0068] To achieve better mixing accuracy, it is necessary to combine the mixing performance of the liquid component detection component 17 under the response test method to fine-tune the current of the active one-way valve 13 in the closed and open states. This allows the controller 11 to calculate the absorbance error of the mixed solution based on the linear change of the absorbance of the mixed liquid when the current ratio of the mixed liquid meets the extreme value, so as to correct the opening and closing degree of the active one-way valve 13.

[0069] The response test method involves using two solutions with significantly different absorbance, such as 100% solution A and 100% solution B, where the absorbance difference between the two solutions at a specific wavelength is greater than 300 mAU. The formula for the absorbance of solution B is as follows: (Formula 2); in, t represents the absorbance of solution B, and t represents time, in minutes.

[0070] It should be noted that Formula 2 is the linear function of the absorbance of the mixed liquid.

[0071] The above response test method allows for a transition from a mixed solution of 100% A solution and 0% B solution to a mixed solution of 0% A solution and 100% B solution within a time period of 0 to 30 minutes. The flow rate during the transition of the mixed solution can be set according to the actual usage.

[0072] Specifically, the initial time t0, the time approaching the end t1, and the time at the end t2 are recorded respectively. The absorbance error Err of the mixed solution is calculated. The formula for calculating the absorbance error Err of the mixed solution is as follows: Err = (Formula 3); in, Let be the absorbance of solution B at time t0. Let be the absorbance of solution B at time t1. Let be the absorbance of solution B at time t2.

[0073] For example, the absorbance at t0=0, t1=28.5 and t2=30 is recorded respectively. , and Substituting the above values ​​into Formula 3, we can see that... Err=

[0074] While satisfying the functions of the active one-way valve 13 in both closed and open states, the current in the closed state should be increased or decreased in the open state. A binary search method can be used to quickly determine the current in the closed state (i.e., the closing current) or the current in the open state (i.e., the opening current). Specifically, during the closing time interval, the opening and closing currents of the active one-way valve 13 are adjusted iteratively using the binary search method until the absorbance error of the mixed solution is reduced to within a preset range, thereby correcting the opening / closing degree of the active one-way valve 13.

[0075] For example, the upper and lower bounds of the binary adjustment for the current in the closed state (i.e., the shut-off current) are [ , The upper and lower bounds of the current in the open state (i.e., the turn-on current) are adjusted using the binary method. , ].in, That is, the above [0, Any value in, That is, the above. , This is the opening current calculated from the downward pressure of spring 136. The first and second closing intervals of the closing current can be obtained using the bisection method (taking the first iteration as an example, the first closing interval is [...]). , The second closed interval is [ ]. , ]), and the first and second opening intervals of the opening current can be obtained (taking the first iteration as an example, the first opening interval is [ , The second open interval is [ ], , After correcting the current in either the closed or open state (e.g., selecting the closing current within the first closed range, or selecting the opening current within the first open range), first determine whether the adjusted current in either the closed or open state meets the basic functional requirements of the system (i.e., the closing current ensures the active check valve 13 is closed, and the opening current ensures the active check valve 13 is open). If not, it indicates that the closing current is too large or the opening current is too small. If the closing current is too large, the correction value for the closing current can be directly found within the second closed range; if the opening current is too small, the correction value for the opening current can be directly found within the second open range. If the basic functional requirements of the system are met, continue to correct the closing current within the first closed range, or continue to correct the opening current within the first open range. On the basis of ensuring normal system function, repeat the above test method to confirm the absorbance error Err of the mixed solution until the absorbance error Err of the mixed solution drops to less than 1%, at which point the correction of the opening degree of the active check valve 13 can be stopped. The current in the closed state (i.e., the current at the end of the experiment) and the current in the open state (i.e., the current at the beginning of the experiment) can be corrected simultaneously after the results of one experiment are obtained. It should be noted that the preset range in this application can be 1% as mentioned above, or it can be other values, and this application does not impose any restrictions.

[0076] It should be noted that after correcting the opening and closing currents, the precise values ​​of the opening and closing currents are obtained. Then, the H-bridge motor driver chip is used to control the control current of the input active check valve 13, according to... Figure 6 The change in the parabolic function curve shown adjusts the duty cycle of the pulse width modulation (PWM) wave of the control current, so that the opening and closing process of the active one-way valve 13 is smooth and adjustable.

[0077] In one implementation, the infusion pump 14 includes a lead screw that can be driven by a motor to achieve liquid suction by the infusion pump 14. The controller 11 can also determine the total suction stroke of the infusion pump 14 based on the lead screw coefficient and the total volume of various solutions.

[0078] Furthermore, the controller 11 can also determine the position information of the end point of the infusion pump's suction stroke based on the position information of the starting point of the infusion pump's suction stroke and the total suction stroke of the infusion pump 14. The position information of the starting point of the infusion pump's suction stroke is the position information acquired by the motor encoder 16 at the starting point of the opening of the active check valve 13. For example, the position information of the end point of the infusion pump's suction stroke can be calculated using the following formula: (Formula 4); in, This provides the location information of the end point of the suction stroke of the infusion pump. This provides the position information for the starting point of the infusion pump's suction stroke, where r is the resolution of the motor encoder 16, and L is the total suction stroke of the infusion pump 14. This is the lead screw coefficient of infusion pump 14.

[0079] At this time, the controller 11 can determine the valve cut-off point of the proportional valve 12 based on the proportion of each liquid in the current mobile phase and the position information of the starting point and the position information of the ending point. That is, it can determine the valve cut-off point of each channel of the proportional valve 12. Through the above settings, multiple liquids can be mixed according to a preset mixing ratio, thereby improving the mixing accuracy of the liquid mobile phase in the quaternary pump liquid phase mixing system 100.

[0080] However, during the initial and final stages of liquid suction by the infusion pump 14, the acceleration and deceleration processes cause instability in the suction state. Therefore, the proportional valve 12 can be modified as follows to improve the accuracy of the output mixed liquid: The liquid with the largest proportion in the mobile phase of the proportional valve 12 is split into two parts, which are input at the beginning and end of the mobile phase time of the proportional valve 12, respectively.

[0081] Specifically, the liquid with the largest proportion in the mobile phase is divided into two parts, the first part and the second part, with the same volume. The infusion pump 14 draws in the first part at the beginning of the aspiration phase and the second part at the end of the aspiration phase. This improves the stability of the aspiration process by placing the liquid with the smallest proportion in the mobile phase in the middle region of the aspiration section of the infusion pump 14. The middle region of the aspiration section of the infusion pump 14 is the aspiration phase located between the beginning and end of the aspiration phase.

[0082] Since the liquid with the largest proportion in the mobile phase of the proportional valve 12 is split into two parts, the number of liquid types contained in the mobile phase of the proportional valve 12 is equal to the number of valve cutting points of the proportional valve 12.

[0083] Therefore, taking the case where there are four types of liquids, named Liquid 1, Liquid 2, Liquid 3, and Liquid 4 respectively, and Liquid 1 has the largest proportion in the mobile phase, the calculation formula for the cutting point of the proportional valve 12 is as follows: (Formula 5) Where A represents the proportion of liquid 1 in the mobile phase, B represents the proportion of liquid 2 in the mobile phase, C represents the proportion of liquid 3 in the mobile phase, and D represents the proportion of liquid 4 in the mobile phase. This is the position of the first valve cutting point. This is the location of the second valve cutting point. This is the location of the third valve cutting point. This is the fourth valve-cutting point. This is the fifth valve-cutting point.

[0084] As one implementation method, due to the diaphragm pump effect of the one-way valve, when the current ratio of the mixed liquid meets the extreme value condition, the ratio of the first liquid and / or the second liquid in the mobile phase will deviate from the preset mixing ratio. Here, the current ratio of the mixed liquid meeting the extreme value condition means that the mixed liquid contains a first liquid with a ratio less than a preset minimum ratio and / or a second liquid with a ratio greater than a preset maximum ratio, wherein the preset minimum ratio is less than the preset maximum ratio.

[0085] Therefore, in order to ensure the mixing effect when the current ratio of the mixed liquids meets the extreme conditions, the mixing ratio values ​​of the first liquid and / or the second liquid under extreme conditions can be linearly calibrated.

[0086] Specifically, based on a preset mixing ratio, the ideal absorbance values ​​for the first liquid and / or the second liquid are determined by the liquid component detection unit 17. After one liquid absorption cycle, the liquid component detection unit 17 acquires the actual absorbance values ​​for the first liquid and / or the second liquid. Based on the ideal and actual absorbance values, calibration coefficients for the first liquid and / or the second liquid are obtained. Based on the calibration coefficients, the cut-off point of the proportional valve 12 is corrected.

[0087] More specifically, the calibration factor is equal to the ideal absorbance value divided by the actual absorbance value.

[0088] In this embodiment, the calibration of Formula 5 can be achieved using the following formula: (Formula 6) in, greater than 1 and less than integers, 1 or +1, This represents the proportion of liquid 1 in the mobile phase. This refers to the proportion of liquid 2, liquid 3, or liquid 4 in the mobile phase. This is the calibration coefficient.

[0089] It should be noted that the calibration coefficient Calculated using the following formula: (Formula 7) in, The calibration coefficient for the first liquid. The calibration coefficient for the second liquid. To preset the minimum ratio value, This is the preset maximum ratio value.

[0090] With the above settings, when the current ratio of the mixed liquid meets the extreme value condition, the mixing ratio value of the first liquid and / or the second liquid under the extreme value condition can be linearly calibrated, thereby improving the mixing accuracy of the liquid mobile phase in the quaternary pump liquid phase mixing system 100.

[0091] like Figure 7 As shown, as one implementation, this application embodiment also provides a control method for a quaternary pump liquid-phase mixing system 100, which includes the following steps: S1: Based on the pressure information inside the infusion pump 14, determine the suction start point of the infusion pump 14, and control the active check valve 13 to open after the suction start point; S2: Based on the screw coefficient of the infusion pump 14 and the total volume of various solutions, determine the total suction stroke of the infusion pump 14; and based on the position information of the starting point of the suction stroke of the infusion pump 14 and the total suction stroke of the infusion pump 14, determine the position information of the ending point of the suction stroke of the infusion pump 14. S3: Determine the valve-cutting point of proportional valve 12 based on the proportion of each liquid in the current mobile phase and the position information of the starting point and the ending point. S4: Determine the current mixing ratio of the mixed liquid (i.e., the mobile phase) based on the absorbance of the mixed liquid. When the current mixing ratio of the mixed liquid meets the extreme value condition, correct the cutting point of the proportional valve 12.

[0092] In step S1, the duty cycle of the control current of the active check valve 13 is adjusted. Different duty cycles of the control current correct the opening and closing degree of the active check valve 13, ensuring that the active check valve 13 can open and close at the start and end of liquid suction while minimizing the diaphragm pump effect. This control method can be implemented by the controller 11. The controller 11 can be a central processing unit (CPU), a general-purpose processor, a network processor (NP), a digital signal processor (DSP), a microprocessor, a microcontroller, a programmable logic device (PLD), or any combination thereof. The controller 11 can also be any other device with processing capabilities, such as a circuit, device, or software module, without limitation. In one example, the controller 11 may include one or more CPUs.

[0093] The controller 11 may include one or more, and may be located inside and / or outside the quaternary pump liquid phase mixing system 100, without limitation herein.

[0094] like Figure 8 As shown, as one implementation, the quaternary pump liquid phase mixing system 100 also includes a communication interface 18, a memory 19, and a communication bus 10, wherein the controller 11, the communication interface 18, and the memory 19 communicate with each other through the communication bus 10.

[0095] The communication interface 18 is used to communicate with other devices or other communication networks. These other communication networks can be Ethernet, Radio Access Network (RAN), Wireless Local Area Networks (WLAN), etc. The communication interface 18 can be a module, circuit, transceiver, or any device capable of enabling communication.

[0096] For example, when the controller 11 is located outside the quaternary pump liquid mixing system 100, the controller 11 can control the active check valve 13, proportional valve 12, infusion pump 14, etc. through the communication interface 18, thereby realizing cloud-based control of the quaternary pump liquid mixing system 100. That is, at this time, the controller 11 is a cloud platform.

[0097] Memory 19 is used to store instructions. These instructions can be computer programs.

[0098] The memory 19 can be a read-only memory (ROM) or other type of static storage device that can store static information and / or instructions; it can also be a random access memory (RAM) or other type of dynamic storage device that can store information and / or instructions; it can also be an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), disk storage media, or other magnetic storage devices, etc., without limitation.

[0099] It should be noted that the memory 19 can exist independently of the controller 11 or be integrated with the controller 11. The memory 19 can be used to store instructions, program code, or some data. The memory 19 can be located inside or outside the quaternary pump liquid phase mixing system 100, without limitation.

[0100] In the description of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. The "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. Furthermore, "at least one" means one or more, and "multiple" means two or more. The terms "first," "second," etc., do not limit the quantity or order of execution, and "first," "second," etc., do not necessarily imply differences.

[0101] It should be noted that, in this application, the terms "exemplary" or "for example" are used to indicate that something is being described as an example, illustration, or illustration. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or design solutions. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0102] Although preferred embodiments of the present application have been disclosed for illustrative purposes, those skilled in the art will recognize that various modifications, additions, and substitutions are possible without departing from the scope and spirit of the present application as disclosed in the appended claims.

Claims

1. A quaternary pump liquid-phase mixing system, characterized in that, Includes controller, proportional valve, active check valve, infusion pump, and pressure sensor. The controller is used to control the proportional valve to open, and the infusion pump to draw in liquid; The pressure sensor is used to detect the pressure information inside the infusion pump and transmit the pressure information to the controller; The controller is also used to determine the infusion pump's suction start point based on the pressure information, and control the active check valve to open after the suction start point; The controller is also used to control the proportion of different liquids in the flowing phase of the proportional valve, so that the multiple liquids drawn in by the infusion pump are mixed according to a preset mixing ratio. The system also includes a liquid composition detection component, which is used to obtain the absorbance of the mixed liquid in the infusion pump; The controller is also configured to determine the current mixing ratio of the mixed liquid based on the absorbance of the mixed liquid, and when the current mixing ratio of the mixed liquid meets the extreme value condition, calculate the absorbance error of the mixed solution based on the linear change of the absorbance of the current mixed liquid, so as to correct the opening and closing degree of the active one-way valve.

2. The system according to claim 1, characterized in that, The controller is also used to gradually increase the opening degree of the active check valve by a preset step size before the infusion pump starts to draw liquid for the first time, and to take the moment when the liquid emerges from the active check valve as the start point of the infusion pump's suction. The system also includes a motor encoder. The motor encoder is used to acquire the motor position signal of the infusion pump and transmit the motor position signal of the infusion pump to the controller; The controller is used to record the infusion pump suction stroke of the infusion pump based on the motor position signal.

3. The system according to claim 1, characterized in that, The controller is also used for: The duty cycle of the control current of the active check valve is adjusted, and the opening and closing degree of the active check valve is controlled by the control current with different duty cycles. During the closing end time period of the active one-way valve, the opening current and closing current of the active one-way valve are adjusted iteratively using a binary method until the absorbance error of the mixed solution is reduced to within a preset range, so as to correct the opening and closing degree of the active one-way valve. The control current includes the opening current and the closing current.

4. The system according to claim 1, characterized in that, When the controller corrects the opening degree of the active one-way valve, it uses an H-bridge motor driver chip to control the control current input to the active one-way valve and adjusts the duty cycle of the pulse width modulation (PWM) wave of the control current according to the parabolic function curve change method.

5. The system according to claim 1, characterized in that, The controller is also used for: The total suction stroke of the infusion pump is determined based on the lead screw coefficient of the infusion pump and the total volume of the various solutions. Based on the location information of the starting point of the infusion pump's suction stroke and the total suction stroke of the infusion pump, the location information of the ending point of the infusion pump's suction stroke is determined. The valve cut-off point of the proportional valve is determined based on the proportion of each liquid in the current flowing phase of the proportional valve, the position information of the starting point, and the position information of the ending point.

6. The system according to claim 5, characterized in that, The controller is also used for: The liquid with the highest proportion in the mobile phase of the proportional valve is divided into two parts, which are input at the beginning and end of the mobile phase of the proportional valve, respectively. The number of liquid types contained in the flowing phase of the proportional valve is equal to the number of valve cut-off points of the proportional valve.

7. The system according to claim 1, characterized in that, The active check valve includes: A voice coil motor, a diaphragm, a push rod located on the diaphragm, a ball located above the push rod, and a spring cooperating with the ball. The voice coil motor is used to lift the push rod on the diaphragm to open the active one-way valve, and to close the active one-way valve by the gravity of the ball falling back and the elastic force of the spring.

8. The system according to claim 7, characterized in that, The controller is also used for: Adjust the duty cycle of the control current of the active check valve; The opening and closing degree of the active one-way valve is controlled by controlling the height of the voice coil motor lifting the push rod by controlling the current with different duty cycles.

9. The system according to claim 8, characterized in that, When the controller corrects the opening degree of the active one-way valve, it uses an H-bridge motor driver chip to control the control current input to the voice coil motor and adjusts the duty cycle of the pulse width modulation (PWM) wave of the control current according to the parabolic function curve.

10. The system according to claim 2, characterized in that, The controller is further configured to, based on the current pressure information of the infusion pump detected by the pressure sensor, determine when the internal pressure of the infusion pump and the external pressure of the infusion pump are in equilibrium, use the current moment as the starting point for opening the active check valve.

11. The system according to claim 2, characterized in that, The controller is also used for, At the end of the infusion pump's suction stroke, the pressure value in the internal pressure information of the infusion pump is stored as the external pressure value of the infusion pump.

12. The system according to claim 1, characterized in that, The controller is located inside and / or outside the quaternary pump liquid phase mixing system; when the controller is located outside the quaternary pump liquid phase mixing system, the controller is a cloud platform.

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