A sample double-needle sampling device and control method

Abstract

The present invention discloses a sample double-needle sampling device and a control method. Driven by the sampling needle driving assembly, the first sample needle and the second sample needle can respectively perform independent vertical movements, and can simultaneously contact the liquid surface or independently contact the liquid surface according to control requirements. Through the liquid surface sensing assembly, the vertical movement position detection and feedback of the sample needle can be realized; through the anti-collision module, damage to the sample needle caused by vertical impact can be avoided. The sample double-needle sampling device of the present invention adopts the method of double-needle independent sampling in a high-speed biochemical analyzer, which can solve the problems of high requirements for the liquid path system and unstable sampling in double-needle aerial drainage sampling. At the same time, since the sample needle can perform independent vertical movement, it is avoided that the two needles simultaneously reach the reaction liquid surface, resulting in carry-over contamination, thereby improving the accuracy of the instrument detection results.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to a sample double-needle pipetting device and a control method therefor. Background Art

[0002] Currently, the sample pipetting device in a fully automatic biochemical analyzer is mainly used for pipetting samples and is an important and indispensable device in the fully automatic biochemical analyzer system. In the sample pipetting methods of a fully automatic biochemical analyzer, there are usually the following two pipetting methods:

[0003] Method 1: First, add the sample to the reaction cup, that is, lower the sample needle to the bottom of the reaction cup and then eject the sample to adhere the sample to the bottom of the reaction cup.

[0004] Method 2: First, add the reagent and then add the sample. This method is divided into two types. The first type is to lower the sample needle below the liquid level where the reagent has been previously added and then eject the sample; the second type is to lower the sample needle to a certain height above the liquid level where the reagent has been previously added and eject the sample in the air. Currently, Method 2 has a relatively high pipetting accuracy, and satisfactory pipetting accuracy and repeatability can also be obtained in the case of 1 μL. However, in the double-needle structure on a high-speed biochemical analyzer, if pipetting is to be performed below the liquid level, the sample needle will be contaminated and cannot continue to be pipetted into the reaction cups in the second circle. Because different reagent items may be involved, reagent cross-contamination will occur.

[0005] In a high-speed fully automatic biochemical analyzer, especially in a biochemical analyzer with a speed above 1200, most of the instruments on the market adopt a reaction disk with a double-layer structure, and the sample pipetting needles are all of a double-needle structure, and both needles are of a fixed structure. In order to achieve the sample pipetting function, only air-drainage pipetting can be used. Because if the double needles are lowered to the liquid level for pipetting, serious carry-over cross-contamination will occur, and it is difficult to obtain satisfactory pipetting accuracy and repeatability in the case of a small sample volume, which has a great impact on the accuracy of the instrument's detection results. This is a difficult problem. The sample pipetting device of the present invention can effectively solve this technical problem. Summary of the Invention

[0006] The purpose of the present invention is to provide a sample double-needle pipetting device and a control method therefor, aiming to solve the problem that the sample needles with a double-needle structure cannot be lowered to the liquid level for pipetting in a high-speed fully automatic biochemical analyzer.

[0007] To achieve the above-mentioned object, the present invention adopts a sample double-needle sampling device, comprising a sampling needle mounting frame, a sampling needle drive assembly and a double-needle assembly, wherein the sampling needle drive assembly is fixed adjacent to the double-needle assembly on the sampling needle mounting frame, and the sampling needle drive assembly comprises a motor fixing sheet metal, a drive motor, a toggle wheel and a limit optical coupler, wherein the drive motor is fixedly connected to the sampling needle mounting frame via the motor fixing sheet metal, the toggle wheel is fixedly connected to the output end of the drive motor, and the limit optical coupler is fixedly connected to the motor fixing sheet metal and is located below the toggle wheel;

[0008] The double-needle assembly includes a guide module, a first sample needle, a second sample needle, a motion return spring and an adjustment block. The adjustment block is fixedly connected to the sample needle mounting bracket and is located below the two guide modules. There are two guide modules, and the two guide modules are arranged above the adjustment block. The motion return spring is arranged between each guide module and the adjustment block. The first sample needle and the second sample needle are respectively arranged on the two guide modules, and the first sample needle and the second sample needle pass through the adjustment block. The driving motor controls the forward and reverse rotation of the toggle wheel to drive the first sample needle and the second sample needle to move downward to achieve sample addition.

[0009] In which, the guide module includes a guide block, a guide base and an anti-collision guide column, the guide block is fixedly connected to the first sample needle and the second sample needle respectively, the guide block is fixedly connected to the motion return spring and is located below the guide block, and the anti-collision guide column is fixedly connected to the guide base.

[0010] Wherein, the double-needle assembly further includes an anti-collision module, which includes an anti-collision optical coupler and an anti-collision reset spring, and the anti-collision optical coupler and the anti-collision reset spring are both arranged on the anti-collision guide column.

[0011] The toggle wheel is provided with a boss that moves in cooperation with the guide block, and a plurality of limiting grooves that cooperate with the limiting optical coupler.

[0012] In which, the double-needle assembly also includes a guide column, a positioning sleeve and a double-needle cannula, one end of the guide column is fixedly connected to the adjustment block, the other end of the guide column passes through the guide base and the guide block, and the motion return spring is sleeved on the outside of the guide column, the double-needle cannula is fixedly connected to the adjustment block and is located below the adjustment block, and the ends of the first sample needle and the second sample needle away from the guide block are fixed in the double-needle cannula through the positioning sleeve.

[0013] Among them, the sample double-needle loading device also includes a liquid level sensing component, which includes a PCBA board and a mounting sheet metal. The mounting sheet metal is fixedly connected to the loading needle mounting bracket and is located at one end of the loading needle mounting bracket away from the double-needle component. The PCBA board is fixedly connected to the mounting sheet metal and is connected to the double-needle component through a wire.

[0014] The present invention also provides a control method for a double-needle sample loading device, comprising the following steps: receiving a loading signal, controlling the drive motor to drive the first sample needle or the second sample needle of the double-needle assembly to move downward into a reaction cup;

[0015] When the sample needle touches the liquid surface, a liquid surface sensing signal is triggered. The liquid surface sensing system feeds the signal back to the instrument control system, causing it to stop the drive motor and stop the movement. The sample needle stays at the liquid surface for sample addition.

[0016] After the sample is added, the driving motor is driven to reverse, the initial position limit groove of the toggle wheel enters the limit optical coupler, the boss on the toggle wheel returns to the initial position, and the motion reset spring returns the sample needle to the initial position.

[0017] The beneficial effects of the present invention are as follows: the driving motor controls the forward and reverse rotation of the toggle wheel to respectively drive the first sample needle and the second sample needle of the double-needle assembly to move downward, so that the double-needle sample adding device can be used in a high-speed biochemical analyzer in a double-needle independent sample adding manner, thereby solving the high requirements of the liquid circuit system and the unstable sample adding for the double-needle mid-air liquid discharge sample adding. At the same time, since the sample needle can move vertically independently, it is avoided that the two needles are simultaneously lowered to the reaction liquid surface to avoid carrying contamination, thereby improving the accuracy of the instrument detection results. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 It is a schematic structural diagram of the double-needle sample adding device of the present invention;

[0020] Figure 2 It is a partial enlarged structural schematic diagram of the double-needle sample adding device of the present invention;

[0021] Figure 3 It is a schematic structural diagram of the double needle assembly of the present invention;

[0022] Figure 4 It is a structural schematic diagram of the sample injection needle drive assembly of the present invention;

[0023] Figure 5 This is a schematic diagram of the state of the driving component when adding sample in the present invention;

[0024] Figure 6 This is a schematic diagram of the state of the double needle assembly when adding sample according to the present invention;

[0025] Figure 7 This is a schematic diagram of the state in which the sample needle vertically impacts during sample addition in the present invention;

[0026] Figure 8 1 is a flow chart of the double-needle sample addition control method of the present invention;

[0027] In the figure: 1-sample needle mounting bracket, 2-double needle assembly, 3-sample needle drive assembly, 4-liquid level sensing assembly, 5-anti-collision module, 6-limiting optical coupler, 7-reaction cup, 21-first sample needle, 22-second sample needle, 23-guide module, 231-guide block, 232-guide base, 233-anti-collision guide column, 24-guide column, 25-motion reset spring, 26-adjustment block, 27-positioning sleeve, 28-double needle cannula, 31-drive motor, 32-motor fixing sheet metal, 33-toggle wheel, 331-boss, 332-limiting groove, 41-PCBA board, 42-mounting sheet metal, 51-anti-collision optical coupler, 52-anti-collision reset spring. DETAILED DESCRIPTION

[0028] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0029] In the description of the present invention, it should be understood that the terms "length," "width," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," "outside," and the like, indicating positions or location relationships, are based on the positions or location relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, in the description of the present invention, "plurality" means two or more, unless otherwise expressly and specifically defined.

[0030] See also Figures 1 to 7, the present invention provides a sample double-needle pipetting device, including a pipetting needle mounting bracket 1, a pipetting needle driving assembly 3 and a double-needle assembly 2. The pipetting needle driving assembly 3 and the double-needle assembly 2 are fixedly adjacent to each other on the pipetting needle mounting bracket 1. The pipetting needle driving assembly 3 includes a motor fixing sheet metal 32, a driving motor 31, a dial wheel 33 and a limit optocoupler 6. The driving motor 31 is fixedly connected to the pipetting needle mounting bracket 1 through the motor fixing sheet metal 32. The dial wheel 33 is fixedly connected to the output end of the driving motor 31. The limit optocoupler 6 is fixedly connected to the motor fixing sheet metal 32 and is located below the dial wheel 33;

[0031] The double-needle assembly 2 includes a guiding module 23, a first sample needle 21, a second sample needle 22, a movement return spring 25 and an adjustment block 26. The adjustment block 26 is fixedly connected to the pipetting needle mounting bracket 1 and is located below the two guiding modules 23. The number of the guiding modules 23 is two, and the two guiding modules 23 are arranged above the adjustment block 26. A movement return spring 25 is arranged between each guiding module 23 and the adjustment block 26. The first sample needle 21 and the second sample needle 22 are respectively arranged on the two guiding modules 23, and the first sample needle 21 and the second sample needle 22 penetrate through the adjustment block 26. The driving motor 31 controls the forward and reverse rotation of the dial wheel 33 to respectively drive the first sample needle 21 and the second sample needle 22 to move downward to achieve pipetting.

[0032] Further, the guiding module 23 includes a guiding block 231, a guiding base 232 and an anti-collision guiding column 233. The guiding block 231 is fixedly connected to the first sample needle 21 and the second sample needle 22 respectively. The guiding block 231 is fixedly connected to the movement return spring 25 and is located below the guiding block 231. The anti-collision guiding column 233 is fixedly connected to the guiding base 232.

[0033] Further, the double-needle assembly 2 further includes an anti-collision module 5. The anti-collision module 5 includes an anti-collision optocoupler 51 and an anti-collision return spring 52. The anti-collision optocoupler 51 and the anti-collision return spring 52 are both arranged on the anti-collision guiding column 233.

[0034] Further, the dial wheel 33 has a boss 331 that cooperates with the guiding block 231 in movement, and a plurality of limit grooves 332 that cooperate with the limit optocoupler 6.

[0035] Furthermore, the double-needle assembly 2 also includes a guide column 24, a positioning sleeve 27 and a double-needle cannula 28. One end of the guide column 24 is fixedly connected to the adjusting block 26, and the other end of the guide column 24 passes through the guide base 232 and the guide block 231, and the motion return spring 25 is sleeved on the outside of the guide column 24. The double-needle cannula 28 is fixedly connected to the adjusting block 26 and is located below the adjusting block 26. The ends of the first sample needle 21 and the second sample needle 22 away from the guide block 231 are fixed in the double-needle cannula 28 by the positioning sleeve 27.

[0036] Furthermore, the sample double-needle loading device also includes a liquid level sensing component 4, which includes a PCBA board 41 and a mounting sheet metal 42. The mounting sheet metal 42 is fixedly connected to the loading needle mounting bracket 1 and is located at one end of the loading needle mounting bracket 1 away from the double-needle component 2. The PCBA board 41 is fixedly connected to the mounting sheet metal 42 and is connected to the double-needle component 2 via a wire.

[0037] In this embodiment, the sample double-needle sampling device includes the sample needle mounting frame, the sample needle driving assembly 3, the double-needle assembly 2 and the liquid level sensing assembly 4. The sample needle driving assembly 3 is installed adjacent to the double-needle assembly 2 on the sample needle mounting frame 1. The sample needle driving assembly 3 is provided with a toggle wheel 33, which is installed on the motor shaft of the drive motor 31. The drive motor 31 controls the forward and reverse rotation of the toggle wheel 33 to respectively drive the first sample needle 21 and the second sample needle 22 of the double-needle assembly 2 to move downward. The guide blocks 231 are respectively connected to the first sample needle 21 and the second sample needle 22 is fixedly connected, the toggle wheel 33 toggles the guide base 232 to realize the downward movement of the double needles, and the motion reset spring 25 enables the guide module 23 to complete the reset action after the sample addition is completed and the toggle wheel 33 returns to the initial position. The anti-collision module 5 includes the anti-collision optical coupler 51 and the anti-collision reset spring 52. The anti-collision optical coupler 51 cooperates with the guide block 231 to realize the anti-collision function. The anti-collision reset spring 52 returns to a normal state after the anti-collision function is triggered; the liquid level sensing component 4 is installed on the end of the sample needle mounting frame 1 away from the double needle component 2 through the fixed sheet metal, and the double needle is connected by a wire to realize the liquid level sensing function;

[0038] The toggle wheel 33 is designed with a code disk structure similar to that of a code disk, and the code disk of the toggle wheel 33 rotates in the groove of the position-limiting optical coupler 6. The code disk of the toggle wheel 33 is provided with a boss 331 and a plurality of position-limiting slots 332. The boss 331 cooperates with the guide block 231 of the double needle assembly 2 for movement; the position-limiting slots 332 cooperate with the position-limiting optical coupler 6 to achieve motion positioning or position limiting.

[0039] The forward and reverse rotation of the driving motor 31 causes the dial wheel 33 to rotate clockwise or counterclockwise. There are limiting grooves 332 on both sides of the boss 331 of the dial wheel 33. No matter whether the dial wheel 33 rotates clockwise or counterclockwise, it will not rotate excessively and damage the limiting optocoupler 6. After the dial wheel 33 rotates a certain angle, the boss 331 will contact the guiding base 232 of the double-needle assembly 2, and continuous rotation will cause the double-needle assembly 2 to move downward into the reaction cup 7 for sample addition.

[0040] The guiding module 23 and the movement reset spring 25 are respectively installed in the guiding column 24 and can slide freely. The other end of the guiding block 231 of the guiding module 23 is connected to the sample needle and can drive the sample needle to perform the same action along with the guiding block 231. The first sample needle 21 and the second sample needle 22 are fixed in the double-needle sleeve 28 through the positioning sleeve 27. The double-needle sleeve 28 and the guiding column 24 are respectively fixed on the adjusting block 26, and the double-needle assembly 2 is installed on the sample addition needle mounting bracket 1 through the adjusting block 26.

[0041] The first sample needle 21 and the second sample needle 22 are in clearance fit with the positioning sleeve 27 and the guiding base 232. The sample needle can slide freely therein, is fixedly connected to the guiding block 231, and moves along with the guiding block 231. The positioning sleeve 27 is in interference fit with the double-needle sleeve 28. The double-needle sleeve 28 is relatively fixed in the adjusting block 26. The guiding column 24 is installed on the adjusting block 26. The movement reset spring 25 is sleeved in the guiding column 24, and its top abuts against the bottom of the guiding base 232 with a certain compression amount.

[0042] The anti-collision guiding column 233 is installed on the guiding base 232. The anti-collision optocoupler 51 and the anti-collision reset spring 52 of the anti-collision device are both installed on the anti-collision guiding column 233. The guiding block 231 has a structure similar to a retaining piece, which cooperates with the anti-collision optocoupler 51 and the anti-collision reset spring 52 to achieve the anti-collision function. The anti-collision optocoupler 51 is installed at the top of the anti-collision guiding column 233, and the anti-collision reset spring 52 is installed inside the anti-collision guiding column 233 to reset the guiding block 231 after the anti-collision function is achieved.

[0043] The guiding bottom block and the guiding base 232 of the guiding module 23 are separable to achieve an anti-collision action. The anti-collision guiding column 233 is installed on the guiding base 232 and passes through the guiding block 231. The anti-collision return spring 52 is sleeved in the middle and has a certain compression amount. The anti-collision optocoupler 51 is installed at the top of the anti-collision guiding column 233. Under normal conditions, the top of the guiding base 232 abuts against the bottom of the guiding block 231 and is relatively pressed by the movement return spring 25 and the anti-collision return spring 52. When the sample needle is vertically impacted, the guiding base 232 and the guiding block 231 are separated. The guiding base 232 continues to move downward until the baffle structure of the guiding block 231 enters the anti-collision optocoupler 51, triggering an optocoupler signal. The instrument control system issues an order to stop the driving motor 31 from operating, avoiding damage to the sampling needle due to impact and reducing the instrument usage cost. After returning to normal, the movement return spring 25 and the anti-collision return spring 52 act together to make the guiding base 232 and the guiding block 231 fit together again.

[0044] When the first sample needle 21 or the second sample needle 22 of the double-needle assembly 2 moves downward to the liquid level in the reaction cup 7, it triggers liquid level sensing. The PCBA board 41 receives the signal and feeds it back to the instrument control system. The instrument control system controls the driving motor 31 of the sampling needle driving assembly 3 to stop operating, realizing the liquid level sensing function.

[0045] Please refer to Figure 8 , the present invention also provides a control method for a sample double-needle sampling device, including the following steps:

[0046] S101: Receive a sampling signal, and control the driving motor 31 to drive the first sample needle 21 or the second sample needle 22 of the double-needle assembly 2 to move downward into the reaction cup 7;

[0047] S102: When the sample needle touches the liquid level, it triggers a liquid level sensing signal. The liquid level sensing system feeds the signal back to the instrument control system, causing it to stop the driving motor 31 from operating. The sample needle stays at the liquid level for sampling;

[0048] S103: After the sampling is completed, drive the driving motor 31 to reverse. The initial position limiting groove 332 of the toggle wheel 33 enters the limiting optocoupler 6, and the boss 331 on the toggle wheel 33 returns to the initial position. The movement return spring 25 makes the sample needle return to the initial position.

[0049] In this embodiment, the drive motor 31 of the sample double-needle sampling device is driven upon receiving a sampling signal, and the dial wheel 33 rotates clockwise or counterclockwise. Its boss 331 contacts the guiding module 23 of the double-needle assembly 2 and continues to rotate, causing the guiding module 23 to drive the first sample needle 21 or the second sample needle 22 to move downward into the reaction cup 7. The tip of the needle touches the liquid surface, triggering a liquid surface induction signal. After the liquid surface reaction system receives the signal, it feeds back the information to the instrument control system. The instrument control system issues a signal to stop the operation of the drive motor 31. The sample needle stays at the liquid surface position and performs a sampling operation. After the sampling is completed, the drive motor 31 rotates in reverse, and the guiding module 23 moves upward under the action of the movement return spring 25. At this time, the limit groove 332 at the initial position of the dial wheel 33 enters the limit optocoupler 6, triggering an optocoupler signal. The instrument control system issues a signal to stop the operation of the drive motor 31. At this time, the boss 331 on the dial wheel 33 and the guiding module 23 both return to the initial position, completing one round of sampling operation.

[0050] If the sample needle does not touch the liquid surface or does not trigger the anti-collision function during the downward movement, the drive motor 31 will continue to rotate. At this time, the limit grooves 332 on both sides of the boss 331 of the dial wheel 33 enter the limit optocoupler 6, triggering an optocoupler signal. The instrument control system will also issue a signal to stop the operation of the drive motor 31 to prevent the dial wheel 33 from colliding with the limit optocoupler 6 and damaging the optocoupler, reducing the use cost.

[0051] In summary, for a sample double-needle sampling device and control method of the present invention, the sampling needle mounting bracket 1 is connected to the rotating shaft of the sampling mechanism as a carrier, and each component and device is mounted thereon; the double-needle assembly 2 includes the first sample needle 21, the second sample needle 22 and corresponding movement reset structures, and is driven by the sampling needle driving assembly 3, so that the first sample needle 21 and the second sample needle 22 can perform separate vertical movements respectively. Through the liquid level sensing assembly 4, the vertical movement position detection and feedback of the sample needle can be realized; through the anti-collision module 5, the sample needle can be prevented from being damaged by vertical impact. In the high-speed biochemical analyzer, the sample double-needle sampling device of the present invention uses the method of double-needle separate sampling, which can solve the problems of high requirements for the liquid path system and unstable sampling in double-needle air-drainage sampling. At the same time, since the sample needles can perform vertical movements separately, it is avoided that the two needles reach the reaction liquid level at the same time, resulting in carry-over contamination, thereby improving the accuracy of the instrument detection results. This invention effectively solves several technical bottlenecks of high-speed biochemical instruments: the minimum sampling volume can reach 1 μL, and the accuracy and CV value of the minimum sample sampling volume are effectively improved; the risk of cross-contamination is effectively reduced; the adverse effects of the sampling action on the sample are effectively reduced. For example, the dilution and contamination of the sample can be reduced by 50% compared with the original; it does not affect the subsequent testing and use of the sample.

[0052] The above-disclosed is only a preferred embodiment of the present invention. Of course, it cannot be used to limit the scope of the rights of the present invention. Those of ordinary skill in the art can understand all or part of the processes of implementing the above embodiments, and the equivalent changes made according to the claims of the present invention still fall within the scope covered by the present invention.

Claims

1. A double-needle sample adding device, characterized in that: It includes a sample needle mounting frame, a sample needle drive assembly and a double needle assembly, wherein the sample needle drive assembly is fixed adjacent to the double needle assembly on the sample needle mounting frame, and the sample needle drive assembly includes a motor fixing sheet metal, a drive motor, a toggle wheel and a limit optical coupler, wherein the drive motor is fixedly connected to the sample needle mounting frame via the motor fixing sheet metal, the toggle wheel is fixedly connected to the output end of the drive motor, and the limit optical coupler is fixedly connected to the motor fixing sheet metal and is located below the toggle wheel; The double-needle assembly includes a guide module, a first sample needle, a second sample needle, a motion return spring and an adjustment block. The adjustment block is fixedly connected to the sample needle mounting frame and is located below the two guide modules. There are two guide modules, and the two guide modules are arranged above the adjustment block. The motion return spring is arranged between each guide module and the adjustment block. The first sample needle and the second sample needle are respectively arranged on the two guide modules, and the first sample needle and the second sample needle pass through the adjustment block. The driving motor controls the forward and reverse rotation of the toggle wheel to respectively drive the first sample needle and the second sample needle to move downward to achieve sample loading. The guide module includes a guide block, a guide base, and an anti-collision guide column. The guide blocks are fixedly connected to the first sample needle and the second sample needle respectively. The guide block is fixedly connected to the motion return spring and is located below the guide block. The anti-collision guide column is fixedly connected to the guide base. The toggle wheel is provided with a boss that cooperates with the guide block for movement, and a plurality of limiting grooves that cooperate with the limiting optical coupler; the limiting grooves are provided on both sides of the boss of the toggle wheel.

2. The double-needle sample loading device according to claim 1, wherein: The double-needle assembly further includes an anti-collision module, which includes an anti-collision optical coupler and an anti-collision reset spring. Both the anti-collision optical coupler and the anti-collision reset spring are arranged on the anti-collision guide column.

3. The double-needle sample loading device according to claim 1, wherein: The double-needle assembly also includes a guide post, a positioning sleeve and a double-needle cannula. One end of the guide post is fixedly connected to the adjustment block, and the other end of the guide post passes through the guide base and the guide block. The motion return spring is sleeved on the outside of the guide post. The double-needle cannula is fixedly connected to the adjustment block and is located below the adjustment block. The ends of the first sample needle and the second sample needle away from the guide block are fixed in the double-needle cannula by the positioning sleeve.

4. The double-needle sample loading device according to any one of claims 1 to 3, characterized in that: The sample double-needle sampling device further includes a liquid level sensing component, which includes a PCBA board and a mounting sheet metal. The mounting sheet metal is fixedly connected to the sampling needle mounting frame and is located at one end of the sampling needle mounting frame away from the double-needle component. The PCBA board is fixedly connected to the mounting sheet metal and is connected to the double-needle component through a wire.

5. A control method for a sample double-needle sampling device, applied to the sample double-needle sampling device according to any one of claims 1 to 4, characterized in that, It includes the following steps: Receiving a sampling signal, controlling the drive motor to drive the first sample needle or the second sample needle of the double-needle component to move downward into the reaction cup; When the sample needle touches the liquid level, a liquid level induction signal is triggered, and the liquid level induction system feeds back the signal to the instrument control system to stop the drive motor from operating, and the sample needle stays at the liquid level for sampling; After the sampling is completed, drive the drive motor to reverse. The initial position limiting groove of the toggle wheel enters the limit optocoupler, the boss on the toggle wheel returns to the initial position, and the movement reset spring returns the sample needle to the initial position.

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