Blood sample automatic mixing method and device based on machine vision analysis

Abstract

The present application relates to the technical field of automatic mixing of blood samples, and particularly relates to a blood sample automatic mixing method and device based on machine vision analysis, which comprises a frame body, a sliding block connected to the frame body, a rotating part rotatably connected to the sliding block, a fixed sleeve fixedly connected to the rotating part, a first rotating shaft rotatably connected in the fixed sleeve, the first rotating shaft being rotatably connected to the rotating part, a second rotating shaft spline-connected to the first rotating shaft, and a fixed rod slidably connected to the fixed sleeve, the fixed rod being provided with a machine vision module at one end close to the clamping module. The present application adopts a compound mixing structure of revolution oscillation and rotation, cooperates with a machine vision closed-loop regulation and control and a variable-position mechanism for two-dimensional synchronous force reduction, can gradually reduce the mixing strength with the improvement of the blood mixing uniformity, and avoids hemolysis of fragile red blood cells of newborns due to continuous high mechanical stress.

Description

Technical Field

[0001] This invention relates to the field of automated blood sample mixing technology, and in particular to an automated blood sample mixing method and apparatus based on machine vision analysis. Background Technology

[0002] Blood sample homogenization is a critical pretreatment step before clinical in vitro diagnostic testing. The homogenization uniformity directly determines the accuracy and repeatability of test results such as routine blood tests and biochemical analyses. For micro-volume peripheral blood samples from newborns and infants, which are characterized by small blood volume, high red blood cell membrane fragility, and large hematocrit, dense red blood cell precipitation can form at the bottom of the tube within a short time after standing. This places much stricter requirements on the flow field disturbance capability, force control precision, and sample protection performance of the homogenizing equipment than on adult samples.

[0003] Chinese Patent Publication No. CN121830221A discloses a blood sample mixing device and a blood analyzer, comprising: a base and a base plate fixed on the base; the base plate is provided with a power mechanism, an eccentric rotation mechanism, and a mixing chamber with a hollow cavity structure; the eccentric rotation mechanism includes an eccentric shaft and a mixing component, the lower end of the eccentric shaft is fixed to the base plate by a bearing, the upper end is rotatably connected to a connector by a bearing, and the other end of the connector is fixed to a transfer shaft; the base plate is also provided with a U-shaped groove, and the end of the transfer shaft is fixed with a bearing to form a sliding connection with the U-shaped groove; the power mechanism drives the eccentric shaft to rotate, and in conjunction with the sliding of the transfer shaft in the U-shaped groove, drives the mixing component to perform elliptical reciprocating motion; the mixing component is fixed to the connector, and the upper part of the mixing component is provided with an insertion rod for insertion into the hollow structure at the bottom of a test tube; when the test tube is placed in the mixing chamber, the insertion rod is located in the hollow structure at the bottom of the test tube, and the elliptical reciprocating motion of the insertion rod collidees with the inner wall of the test tube.

[0004] Therefore, the existing technologies mentioned above have the following problems: they rely solely on axial oscillations generated by eccentric collisions to achieve mixing, without the coordination of circumferential rotational shear flow field, resulting in limited efficiency in breaking up dense red blood cell deposits at the bottom of the tube; the impact force is constant throughout the mixing process and cannot be dynamically reduced as the mixing progresses; and the mixing process is controlled solely by a preset running time, making it impossible to adjust the mixing intensity and termination time in real time according to samples with different blood volumes and hematocrits, which easily leads to problems of insufficient or excessive mixing, and poor consistency in mixing quality between different samples. Summary of the Invention

[0005] To address these issues, the present invention provides an automatic blood sample mixing method and apparatus based on machine vision analysis, which overcomes the problems in the prior art where there is no circumferential rotational shear flow field, the efficiency of breaking up dense red blood cell sediment at the bottom of the tube is limited, and the impact force is constant throughout the mixing process and cannot be dynamically reduced with the progress.

[0006] To achieve the above objectives, the present invention provides an automatic blood sample mixing device based on machine vision analysis, comprising a frame; The slider is slidably connected to the frame. A rotating component is rotatably connected to the slider, and a fixed sleeve is fixedly connected to the rotating component. A first rotating shaft is rotatably connected inside the fixed sleeve, and the first rotating shaft is rotatably connected to the rotating component. A second rotating shaft is splinedly connected to the first rotating shaft. A rolling element is installed at the end of the second rotating shaft away from the fixed sleeve. A clamping module is installed at the end of the second rotating shaft away from the fixed sleeve. The clamping module is used to clamp and fix the blood sample tube. A fixed rod is slidably connected to the fixed sleeve. The fixed rod is in a limited rotational engagement with the second rotating shaft. A machine vision module is installed at one end of the fixed rod near the clamping module. The machine vision module is used to monitor and analyze the state of the blood sample in the blood sample tube. A limiting plate is fixedly connected to the frame, and the limiting plate is in a limiting engagement with the rolling element on the second rotating shaft; A power mechanism, disposed on the slider, is used to cause the rotating component to rotate relative to the slider; A displacement mechanism is provided on the frame to allow the slider to slide relative to the frame.

[0007] Furthermore, the machine vision module includes: A high-definition visual acquisition unit is used to acquire the status of the blood sample in the blood sample tube in real time. The vision processing control unit is used to analyze and process the state of the blood sample in the collected blood sample tube.

[0008] Furthermore, the power mechanism includes: A drive motor is mounted on the slider, and a gear set is provided between the output shaft of the drive motor and the rotating component; A drive shaft is rotatably connected to the rotating component, and a bevel gear is fixedly connected to one end of the drive shaft; A connecting rod is fixedly connected to the slider, and a rack is fixedly connected to the connecting rod, the rack meshing with the bevel gear; The first transmission wheel is fixedly connected to the other end of the drive shaft; A drive shaft is rotatably connected to the rotating component. A universal joint is provided between the drive shaft and the first rotating shaft. A second drive wheel is splined to the drive shaft, and the second drive wheel is drively connected to the first drive wheel.

[0009] Furthermore, the first transmission wheel is a conical wheel, used to change the transmission ratio between it and the second transmission wheel.

[0010] Furthermore, the displacement mechanism includes: An electric push rod is installed on the frame, and the telescopic end of the electric push rod is fixedly connected to the slider; The first limiting member is rotatably connected to the frame, and the first limiting member is provided with a limiting groove, which is inclined. The second limiting member is rotatably connected to the transmission shaft and slides within the limiting groove. An elastic element is fixedly connected between the first rotating shaft and the second rotating shaft.

[0011] Furthermore, the inclination direction of the limiting groove is consistent with the direction in which the diameter of the first transmission wheel decreases from top to bottom.

[0012] Furthermore, the limiting plate is part of a spherical shell, and the rack is arc-shaped, used to change the relative position and relative motion state between the fixed sleeve and the second rotating shaft.

[0013] Furthermore, the center of the sphere of the limiting plate, the axis of the rack, and the rotation center of the rotating member around the slider coincide.

[0014] Furthermore, the maximum rotation angle of the rotating component around the slider is an obtuse angle, and each time it rotates to the limit position, the opening of the blood sample tube faces upward.

[0015] An automated blood sample mixing method based on machine vision analysis, applied to an automated blood sample mixing device based on machine vision analysis, includes the following steps: The blood sample tube is clamped and fixed in the clamping module. The power mechanism is started to drive the blood sample tube to reciprocate obtuse angle oscillation and revolution. At the same time, the mechanical linkage drives the blood sample tube to rotate around the second rotation axis to perform compound strong mixing. During the mixing process, the machine vision module swings synchronously with the fixed sleeve, continuously and dynamically acquiring images of the blood inside the blood sample tube, and identifying the uniformity of mixing in real time. When the uniformity reaches the preset threshold, the displacement mechanism drives the slider to move down, and the pure mechanical synchronous reduction of the revolution radius and the speed of rotation slows down, thus smoothly attenuating the mixing force. Each time the rotating component swings to its limit position, it pauses briefly. The machine vision module acquires a static image to complete the homogenization verification. Based on the verification result, the slider position is corrected to adjust the mixing intensity. After the mixture reaches the required consistency, the displacement mechanism drives the slider to reset in short segments, using inertia to collect the blood from the tube wall to the bottom of the tube, thus completing the sample mixing pretreatment.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention uses a composite mixing architecture of revolution and rotation, combined with machine vision closed-loop control and displacement mechanism for dual-dimensional synchronous force reduction, which can gradually reduce the mixing intensity as the blood mixing uniformity increases; in the initial stage, high-intensity mixing is used to quickly disperse the dense red blood cell deposits at the bottom of the tube, and in the later stage of mixing, the centrifugal force and shear force are steadily reduced, avoiding hemolysis of fragile neonatal red blood cells due to continuous high mechanical stress. This solves the technical contradiction of existing fixed-parameter mixing equipment that "cannot simultaneously address insufficient mixing and sample hemolysis", and is specifically designed for homogenization pretreatment before micro-volume blood testing.

[0017] Furthermore, this invention utilizes the mechanical power-taking structure of rack and pinion and bevel gear to directly extract rotational power from the revolution and oscillation motion. Only a single drive motor is needed to synchronously realize the dual compound motion of revolution and rotation, without the need for an independent rotation drive source and electronic control synchronization system. The overall structure is compact, the transmission consistency is high, the manufacturing cost is low, and there is no electronic control synchronization error during operation.

[0018] Furthermore, this invention drives the slider to move via an electric push rod, and relies on the mechanical linkage between the inclined limiting groove and the conical friction wheel to simultaneously achieve stepless reduction of the rotation speed and linear reduction of the revolution radius. The two-dimensional mixing force is synchronously and smoothly attenuated, and there is no gear impact during the force adjustment process, avoiding sudden changes in the blood flow field that could cause eddies and cell damage. Moreover, only one drive signal is needed to complete the adjustment, and the control logic is simple and the adjustment accuracy is high.

[0019] Furthermore, this invention utilizes a dual-mode visual detection mechanism that combines dynamic real-time acquisition with static re-inspection at extreme positions. Dynamic acquisition ensures real-time closed-loop control of the mixing intensity, while static high-precision images serve as a verification benchmark to correct dynamic imaging errors. This balances the continuity of the mixing process with the accuracy of state determination, enabling precise adaptive parameter tuning without frequent machine stoppages for testing.

[0020] Furthermore, the present invention performs segmented short upward movements by resetting the slider. During the resetting process, the residual blood on the tube wall is collected synchronously using inertia. There is no need to configure an additional independent collection mechanism, which not only ensures sufficient effective blood volume at the bottom of the tube, but also avoids the risk of test result deviation and transport leakage caused by sample adhering to the tube wall. Attached Figure Description

[0021] Figure 1 This is an overall structural diagram of an embodiment of the present invention; Figure 2 This is a schematic diagram of the rotating component and its parts according to an embodiment of the present invention; Figure 3 This is a cross-sectional view of the slider and its components according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the fixed sleeve and its components according to an embodiment of the present invention; Figure 5 This is a cross-sectional view of the structure of the fixed sleeve and its components according to an embodiment of the present invention; Figure 6 This is a structural cross-sectional view of the fixed sleeve, the first rotating shaft, and the second rotating shaft according to an embodiment of the present invention; Figure 7 This is an exploded view of the parts on the fixing sleeve according to an embodiment of the present invention; Figure 8 This is a flowchart illustrating the process of an embodiment of the present invention.

[0022] Reference numerals: Frame 1, Slider 2, Rotating component 3, Fixed sleeve 4, First rotating shaft 5, Second rotating shaft 6, Clamping module 7, Fixed rod 8, Machine vision module 9, Limiting plate 10, Drive motor 11, Gear set 12, Drive shaft 13, Bevel gear 14, Connecting rod 15, Rack 16, First transmission wheel 17, Transmission shaft 18, Second transmission wheel 19, Electric push rod 20, First limiting component 21, Limiting groove 22, Second limiting component 23, Elastic element 24, Blood sample tube 101. Detailed Implementation

[0023] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0024] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0025] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0026] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0027] Please see Figures 1-7As shown, this invention proposes an automatic blood sample mixing device based on machine vision analysis, comprising: a frame 1; a slider 2 slidably connected to the frame 1; a rotating component 3 rotatably connected to the slider 2, the rotating component 3 being fixedly connected to a fixing sleeve 4, the maximum rotation angle of the rotating component 3 around the slider 2 being an obtuse angle, and each time it rotates to the limit position, the opening of the blood sample tube 101 is always facing upwards; a first rotating shaft 5 rotatably connected inside the fixing sleeve 4, the first rotating shaft 5 being rotatably connected to the rotating component 3; a second rotating shaft 6 splinedly connected to the first rotating shaft 5, a rolling element being installed at one end of the second rotating shaft 6 away from the fixing sleeve 4, and a clamping module 7 being installed at the other end of the second rotating shaft 6 away from the fixing sleeve 4, the clamping module 7 being used to clamp and fix the blood sample tube 101.

[0028] Please see Figure 1 , Figure 4 and Figure 7 As shown, a fixed rod 8 is slidably connected to the fixed sleeve 4, and the fixed rod 8 is in a limited rotational engagement with the second rotating shaft 6. A machine vision module 9 is installed at one end of the fixed rod 8 near the clamping module 7. The machine vision module 9 is used to monitor and analyze the state of the blood sample in the blood sample tube 101. A limiting plate 10 is fixedly connected to the frame 1, and the limiting plate 10 is in a limited rotational engagement with the rolling element on the second rotating shaft 6. A power mechanism is set on the slider 2, which is used to make the rotating part 3 rotate relative to the slider 2. A displacement mechanism is set on the frame 1, which is used to make the slider 2 slide relative to the frame 1. The machine vision module 9 includes: a high-definition vision acquisition unit, which is used to acquire the state of the blood sample in the blood sample tube 101 in real time; and a vision processing control unit, which is used to analyze and process the acquired state of the blood sample in the blood sample tube 101.

[0029] In this embodiment, the frame 1 is made of aluminum alloy profile splicing, the slider 2 has a sliding stroke of 80mm, the rotating part 3 is a hollow swing arm structure, the fixed sleeve 4 is a stainless steel cylinder, the clamping module 7 is an elastic claw structure, and the inner wall is provided with a silicone anti-slip pad, which can clamp a micro blood sample tube 101 with a diameter of 4-6mm, and the clamping coaxiality error is ≤0.1mm.

[0030] In this embodiment, the maximum swing angle of the rotating component 3 around the slider 2 is 120°, that is, it deflects 60° forward and backward, and the whole swing range is obtuse. Mechanical limit blocks and photoelectric position sensors (not shown in the figure) are set at the front and rear limit positions of the rotating component to ensure the swing accuracy of ±0.5°. When the rotating component swings to any front or rear limit position, the opening of the blood sample tube 101 remains vertically upward, the tube body makes an angle of 0° with the vertical direction, and the end face of the tube opening is horizontal. At the limit position, the drive motor pauses briefly for 0.3s, and the tube rotation is synchronously locked during the pause.

[0031] In this embodiment, a boss is provided at the right end of the fixing rod 8 for being limited by the fixing sleeve 4. The fixing rod 8 does not rotate with the second rotating shaft 6, but only moves and swings synchronously with it. The limiting plate 10 is fastened to the left side of the frame 1 by the column. The limiting plate 10 is an arc-shaped plate, and the concave plate surface faces the right side of the slider 2.

[0032] In this embodiment, the high-definition vision acquisition unit uses a global shutter industrial camera with its lens facing the upper middle part of the blood sample tube 101. It is equipped with a coaxial ring LED fill light, with the fill light angle at 45° to the wall of the blood sample tube to avoid the tube wall reflection interfering with the imaging. The vision processing control unit is an embedded ARM processor, integrated inside the housing of the machine vision module 9. It has a built-in blood layer recognition algorithm and a mixing uniformity calculation model, and can directly output the mixing state judgment signal and the displacement mechanism control signal without the need for an external host computer. The high-definition vision acquisition unit and the vision processing control unit are electrically connected via a flexible ribbon cable.

[0033] Specifically, this invention achieves a combined mixing action of reciprocating oscillation and rotation of the blood sample tube through a power mechanism. At the same time, relying on a displacement mechanism, it can simultaneously complete the dual-dimensional force adjustment of reducing the radius of rotation and decreasing the rotation speed. This achieves rapid dispersal of dense red blood cell deposits at the bottom of the tube through high-intensity mixing in the initial stage, and stable attenuation of centrifugal force and shear force in the later stage of mixing. This avoids hemolysis of fragile neonatal red blood cells due to continuous high mechanical stress. The device does not require multiple independent drive motors and independent control systems. The overall structure is compact, the operation is highly reliable, and the manufacturing cost is low, making it suitable for the batch sample preprocessing needs of clinical laboratory departments.

[0034] The machine vision module integrates acquisition and processing, eliminating the need for additional industrial control computers and image acquisition cards. It features high integration and low deployment costs. The global shutter industrial camera can clearly capture blood images during dynamic swinging processes, and together with the embedded control unit, it can achieve millisecond-level status feedback, ensuring the real-time performance of the mixing closed-loop control.

[0035] The obtuse-angle swing angle provides sufficient axial centrifugal convection stroke to efficiently break up the red blood cell deposits at the bottom of the blood sample tube 101; the tube opening is always facing upward at the extreme position, which can completely avoid the risk of blood sample overflowing from the tube opening, contaminating the equipment and cross-infection with the sample; at the same time, the fixed stop at the extreme position provides a stable imaging station for machine vision static re-examination, without the need for additional positioning mechanisms.

[0036] The power mechanism drives the rotating part 3 to swing backward from the middle position. When it reaches the 60° rear limit position, it triggers the limit sensor and the motor brakes briefly for 0.3 seconds. At this time, the opening of the blood sample tube 101 is vertically upward, and there is no risk of blood sample spillage from the blood sample tube 101. During the pause, the machine vision module acquires static high-definition images to complete a high-precision re-inspection of the mixing uniformity. After the re-inspection is completed, the power mechanism drives the rotating part 3 to swing forward to the front limit position and pauses again for re-inspection. This cycle is repeated to complete the entire mixing process.

[0037] In this embodiment, the displacement mechanism drives the slider 2 to slide vertically along the frame 1, adjusting the revolution radius of the blood sample tube 101; the power mechanism drives the rotating component 3 to reciprocate at an obtuse angle around the rotation center of the slider 2, and the rotating component 3 drives the fixed sleeve 4, the first rotating shaft 5, the second rotating shaft 6, the clamping module 7, and the blood sample tube 101 to revolve and swing; at the same time, the power mechanism mechanically extracts force from the swinging motion and outputs it to the first rotating shaft 5, the second rotating shaft 6, and the clamping module 7 through the transmission chain, causing the blood sample tube 101 to continuously rotate around its own axis, forming a composite mixing flow field of revolution + rotation; during the mixing process, the machine vision module 9 swings synchronously with the fixed rod 8, facing the blood sample tube 101 throughout the process, and collects images of the blood layering state in the tube in real time and outputs analysis signals, thereby controlling the operating state of the displacement mechanism and realizing adaptive adjustment of the mixing force.

[0038] The high-definition visual acquisition unit continuously acquires images of the blood inside the blood sample tube 101 throughout its revolution and oscillation, and transmits them synchronously to the visual processing control unit. The visual processing control unit performs grayscale correction, edge extraction, and layer recognition on the images, and calculates the current layer thickness, grayscale uniformity, and clot feature value of the blood. When the uniformity reaches a preset threshold, a control signal is output to the displacement mechanism to drive the slider 2 to move and reduce the mixing force. When the rotating part 3 oscillates to its limit position and stops, the high-definition visual acquisition unit acquires a frame of static high-precision image, which is then used by the visual processing control unit for final homogenization verification, forming a dual-mode detection closed loop of dynamic real-time control and static precise re-examination.

[0039] Please see Figures 1-3As shown, the power mechanism includes: a drive motor 11, mounted on the slider 2, with a gear set 12 provided between the output shaft of the drive motor 11 and the rotating member 3; a drive shaft 13, rotatably connected to the rotating member 3, with a bevel gear 14 fixedly connected to one end of the drive shaft 13; a connecting rod 15, fixedly connected to the slider 2, with a rack 16 fixedly connected to the connecting rod 15, the rack 16 meshing with the bevel gear 14; a first transmission wheel 17, fixedly connected to the other end of the drive shaft 13; and a transmission shaft 18, rotatably connected to the rotating member 3, with a universal joint provided between the transmission shaft 18 and the first rotating shaft 5, and a second transmission wheel 19 splinedly connected to the transmission shaft 18, the second transmission wheel 19 being drively connected to the first transmission wheel 17.

[0040] Please see Figures 1-3 As shown, the first transmission wheel 17 is a conical wheel, used to change the transmission ratio between it and the second transmission wheel 19; the limiting plate 10 is part of a spherical shell, and the rack 16 is arc-shaped, used to change the relative position and relative motion state between the fixed sleeve 4 and the second rotating shaft 6, and the center of the sphere of the limiting plate 10, the axis of the rack 16 and the rotating component coincide around the rotation center of the slider 2.

[0041] In this embodiment, the gear set 12 is a cylindrical spur gear reduction set. The driving gear is fixedly connected to the output shaft of the drive motor 11, and the driven gear is fixedly connected to the rotating part 3. The rack 16 is an arc-shaped involute rack with the same module as the bevel gear 14. The tooth surface faces the bevel gear 14 and the two are in a meshing state. The transmission shaft 18 and the first rotating shaft 5 transmit torque through the universal joint between them. The second transmission wheel 19 is pressed against the working surface of the first transmission wheel 17 and transmits torque by friction.

[0042] In this embodiment, the first transmission wheel 17 has a cone angle of 15°, the wheel body base material is aluminum alloy, and the working surface is sprayed with a 1mm thick rubber coating with a friction coefficient ≥0.8 to ensure that the friction transmission is slip-free. The second transmission wheel 19 is a cylindrical friction wheel with a smooth polyurethane material on the working surface, which is in close contact with the working surface of the first transmission wheel 17.

[0043] Specifically, this invention utilizes a mechanical power-taking structure of arc-shaped rack 16 + bevel gear 14 to directly extract rotational power from the revolution and oscillation motion of the rotating component 3. There is no need to configure an independent drive source for the rotation of the blood sample tube. The entire transmission chain is a purely mechanical structure with no electronic control synchronization error. The rotation speed and oscillation angle are strictly matched, resulting in strong motion consistency. At the same time, the gear set 12 reduces speed to ensure smooth oscillation operation, and the universal joint structure can adapt to the axial displacement and angular deviation of the transmission shaft 18, ensuring smooth transmission without jamming.

[0044] By utilizing the conical wheel friction transmission structure, the transmission ratio can be continuously and steplessly changed by moving the second transmission wheel 19 axially. The rotation speed adjustment process is smooth and without gear impact, avoiding the shearing impact on blood caused by sudden speed changes, which is suitable for the mixing and protection needs of fragile red blood cells in newborns. At the same time, the friction transmission structure is simple, easy to assemble, requires no gear meshing, and has low operating noise.

[0045] In this embodiment, the drive motor 11 outputs torque, which is reduced by the gear set 12 and drives the rotating part 3 to oscillate back and forth around the rotation center of the slider 2. During the oscillation of the rotating part 3, the bevel gear 14 moves synchronously with the drive shaft 13 in an arc trajectory. Since the rack 16 is fixed to the slider 2 through the connecting rod 15 and remains stationary in the horizontal direction, the bevel gear 14 rolls along the arc rack 16 and generates its own rotational motion, which in turn drives the drive shaft 13 and the first transmission wheel 17 to rotate synchronously. The first transmission wheel 17 drives the second transmission wheel 19 to rotate through friction transmission. The torque is transmitted to the first rotating shaft 5 through the transmission shaft 18 and the universal joint, and then drives the second rotating shaft 6 and the clamping module 7 to rotate through the spline engagement, finally realizing the full rotation of the blood sample tube 101. That is, every time the rotating part completes one reciprocating oscillation, the blood sample tube synchronously completes the corresponding number of rotations, and the two movements are strictly mechanically linked.

[0046] When mixing begins, the second drive wheel 19 is initially located at the large end of the first drive wheel 17. At this time, the first drive wheel 17 rotates at its maximum speed, aiming to mix the blood sample intensely, accelerate the mixing process, and improve mixing efficiency. As the mixing time increases, the mixing state of the blood sample gradually stabilizes. During this process, the high-definition vision acquisition unit continuously acquires images of the blood inside the blood sample tube 101. When the uniformity reaches a preset threshold, a control signal is output to the displacement mechanism, driving the slider 2 to move downward. When the drive shaft 18 drives the second drive wheel 19 to move towards the small end of the first drive wheel 17, the contact circumference diameter decreases, the output speed of the second drive wheel 19 decreases, and the rotation speed of the blood sample tube 101 decreases synchronously. The rotation speed can be continuously adjusted by changing the contact diameter without changing the output speed of the drive motor 11, achieving the attenuation of mixing force purely mechanically.

[0047] When the rotating part 3 swings to its limit position and stops, the high-definition vision acquisition unit acquires a static high-precision image. The vision processing control unit performs the final homogenization verification. If the verification result is consistent with the result of the blood sample tube 101 during the movement, no interference is needed. The slider 2 and its parts continue to move downward to maintain the mixing intensity decreasing. If the uniformity of the verification result is less than that of the blood sample tube 101 during the movement, the vision processing control unit controls the displacement mechanism to move the slider 2 and its parts upward to appropriately increase the mixing intensity, thereby improving the mixing efficiency while ensuring that the blood sample can withstand the mixing intensity.

[0048] Please see Figures 1-3As shown, the displacement mechanism includes: an electric push rod 20, installed on the frame 1, with the telescopic end of the electric push rod 20 fixedly connected to the slider 2; a first limiting member 21, rotatably connected to the frame 1, with the rotation centers of both coinciding with the axis of the rack 16; the first limiting member 21 is provided with a limiting groove 22, which is inclined; the inclination direction of the limiting groove 22 is consistent with the direction of decreasing diameter of the first transmission wheel 17 from top to bottom.

[0049] Please see Figure 2 , Figure 6 and Figure 7 As shown, the second limiting member 23 is rotatably connected to the transmission shaft 18. The second limiting member 23 is axially limited in contact with the second transmission wheel 19, so that when the second limiting member 23 moves, it will push the second transmission wheel 19 to move synchronously. The second limiting member 23 slides in the limiting groove 22. An elastic element 24 is fixedly connected between the first rotating shaft 5 and the second rotating shaft 6.

[0050] In this embodiment, the electric push rod 20 is a miniature DC linear push rod, with its telescopic end fastened downward to the top surface of the slider 2 by bolts, used to drive the slider 2 to slide vertically up and down along the guide rail; the limiting groove 22 is located on the left side of the first limiting member 21, and the elastic element 24 is a spring that is always in a compressed state, used to provide axial pressure to the second rotating shaft 6, so that the rolling element at the end of the second rotating shaft 6 is pressed against the surface of the limiting plate 10.

[0051] In this embodiment, the limiting groove 22 gradually tilts to the right from top to bottom. The tilting slope of the limiting groove 22 is designed to match the cone angle of the first transmission wheel 17, ensuring that the vertical displacement of the slider 2 is linearly related to the attenuation of the rotation speed of the blood sample tube 101.

[0052] Specifically, this invention uses a single electric push rod 20 to drive the slider 2 to move. Relying on the mechanical constraint of the limiting groove 22, the axial displacement of the transmission shaft 18 and the telescopic displacement of the second rotating shaft 6 are realized simultaneously. The rotation speed adjustment and the revolution radius adjustment are completed in one action. The mixing force of the two dimensions is synchronously attenuated. The control logic is extremely simple. Only one drive signal is needed to complete the force adjustment, which greatly reduces the equipment control cost. The pre-tightening structure of the elastic element 24 can eliminate the transmission gap throughout the process, ensuring transmission accuracy and operation stability.

[0053] The inclination direction of the limiting groove 22 is consistent with the direction of the diameter reduction of the first transmission wheel 17, so as to ensure that the reduction of the radius of rotation and the reduction of the rotation speed are synchronous and linear during the downward movement of the slider 2, the mixing force decays evenly and gently, and there will be no sudden change in force in a single dimension, avoiding the risk of eddy currents and hemolysis of blood samples due to sudden changes in force; at the same time, the linear correspondence facilitates the calibration of the control program and the adjustment accuracy is higher.

[0054] In this embodiment, when the machine vision module 9 detects an increase in the uniformity of blood mixing and the need to reduce the mixing force, the telescopic end of the electric push rod 20 moves downward, causing the slider 2 to move downward as well. The slider 2 slides relative to the frame 1. During the downward movement of the slider 2, the second limiting member 23 slides along the inclined limiting groove 22. The second limiting member 23 is constrained by the groove wall and begins to move to the right. The second limiting member 23 drives the second transmission wheel 19 to move to the right as well. The second transmission wheel 19 slides relative to the transmission shaft 18. The second transmission wheel 19 moves axially toward the small diameter end of the first transmission wheel 17, reducing the contact diameter between the second transmission wheel 19 and the first transmission wheel 17, lowering the rotational transmission ratio, and causing the rotational speed of the blood sample tube 101 to decrease synchronously.

[0055] Specifically, when the slider 2 slides down a unit distance, the second limiting member 23 moves synchronously along the inclined limiting groove 22 by a unit axial distance, driving the second transmission wheel 19 to move a corresponding distance towards the small end of the first transmission wheel 17, and the rotation speed decreases linearly according to a fixed ratio; at the same time, the second rotating shaft 6 synchronously contracts the corresponding length, and the revolution radius decreases linearly according to a fixed ratio; the attenuation rates of the two are strictly matched, and the centrifugal force and shear force decrease synchronously and steadily during the mixing process, the blood flow field is stable and there is no violent disturbance, which ensures the mixing efficiency and avoids mechanical damage to red blood cells.

[0056] At the same time, the slider 2 moves down, causing the rotating part 3 and the fixed sleeve 4 to move down as a whole. Under the thrust of the elastic element 24, the rolling element at the end of the second rotating shaft 6 rolls along the surface of the limiting plate 10. The second rotating shaft 6 contracts inward along the spline, and the revolution radius of the blood sample tube 101 shrinks synchronously. That is, the slider 2 moves down once, and the rotation speed and the revolution radius are reduced synchronously by pure mechanical synchronization. The mixing force is reduced synchronously in two dimensions until the blood sample is mixed.

[0057] After the blood sample is mixed, the telescopic end of the electric push rod 20 is moved upward in short segments to reset. The telescopic end of the electric push rod 20 drives the slider 2 and its parts to move upward together. By using this upward reset action, the blood sample in the blood sample tube 101 moves towards the bottom of the tube under the action of inertia until all parts are completely reset.

[0058] Please see Figures 1-8 As shown, an automatic blood sample mixing method based on machine vision analysis, applied to the aforementioned automatic blood sample mixing device based on machine vision analysis, includes the following steps: Step S1: Clamp and fix the blood sample tube 101 to the clamping module 7, start the power mechanism, drive the blood sample tube 101 to reciprocate obtuse angle oscillation revolution, and at the same time mechanical linkage drive the blood sample tube 101 to rotate around the second rotation axis 6 to perform compound strong mixing. Step S2: During the mixing process, the machine vision module 9 swings synchronously with the fixed sleeve 4, continuously and dynamically acquiring blood images inside the blood sample tube 101, and identifying the mixing uniformity in real time. Step S3: When the uniformity reaches the preset threshold, the displacement mechanism drives the slider 2 to move down, and the pure mechanical synchronous reduction of the revolution radius and the rotation speed reduces the mixing force smoothly. Step S4: The rotating part 3 pauses briefly each time it swings to its limit position. The machine vision module 9 acquires a static image to complete the homogenization verification. Based on the verification result, the position of the slider 2 is corrected to adjust the mixing intensity. Step S5: After the mixing reaches the standard, the displacement mechanism drives the slider 2 to reset in short segments, using inertia to collect the blood sample from the tube wall to the bottom of the tube, thus completing the sample mixing pretreatment.

[0059] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. An automatic blood sample mixing device based on machine vision analysis, characterized in that, Includes the frame; The slider is slidably connected to the frame. A rotating component is rotatably connected to the slider, and a fixed sleeve is fixedly connected to the rotating component. A first rotating shaft is rotatably connected inside the fixed sleeve, and the first rotating shaft is rotatably connected to the rotating component. A second rotating shaft is splinedly connected to the first rotating shaft. A rolling element is installed at the end of the second rotating shaft away from the fixed sleeve. A clamping module is installed at the end of the second rotating shaft away from the fixed sleeve. The clamping module is used to clamp and fix the blood sample tube. A fixed rod is slidably connected to the fixed sleeve. The fixed rod is in a limited rotational engagement with the second rotating shaft. A machine vision module is installed at one end of the fixed rod near the clamping module. The machine vision module is used to monitor and analyze the state of the blood sample in the blood sample tube. A limiting plate is fixedly connected to the frame, and the limiting plate is in a limiting engagement with the rolling element on the second rotating shaft; A power mechanism, disposed on the slider, is used to cause the rotating component to rotate relative to the slider; A displacement mechanism is provided on the frame to allow the slider to slide relative to the frame.

2. The automatic blood sample mixing device based on machine vision analysis according to claim 1, characterized in that, The machine vision module includes: A high-definition visual acquisition unit is used to acquire the status of the blood sample in the blood sample tube in real time. The vision processing control unit is used to analyze and process the state of the blood sample in the collected blood sample tube.

3. The automatic blood sample mixing device based on machine vision analysis according to claim 2, characterized in that, The power mechanism includes: A drive motor is mounted on the slider, and a gear set is provided between the output shaft of the drive motor and the rotating component; A drive shaft is rotatably connected to the rotating component, and a bevel gear is fixedly connected to one end of the drive shaft; A connecting rod is fixedly connected to the slider, and a rack is fixedly connected to the connecting rod, the rack meshing with the bevel gear; The first transmission wheel is fixedly connected to the other end of the drive shaft; A drive shaft is rotatably connected to the rotating component. A universal joint is provided between the drive shaft and the first rotating shaft. A second drive wheel is splined to the drive shaft, and the second drive wheel is drively connected to the first drive wheel.

4. The automatic blood sample mixing device based on machine vision analysis according to claim 3, characterized in that, The first transmission wheel is a conical wheel, used to change the transmission ratio between it and the second transmission wheel.

5. The automatic blood sample mixing device based on machine vision analysis according to claim 4, characterized in that, The displacement mechanism includes: An electric push rod is installed on the frame, and the telescopic end of the electric push rod is fixedly connected to the slider; The first limiting member is rotatably connected to the frame, and the first limiting member is provided with a limiting groove, which is inclined. The second limiting member is rotatably connected to the transmission shaft and slides within the limiting groove. An elastic element is fixedly connected between the first rotating shaft and the second rotating shaft.

6. The automatic blood sample mixing device based on machine vision analysis according to claim 5, characterized in that, The inclination direction of the limiting groove is consistent with the direction in which the diameter of the first transmission wheel decreases from top to bottom.

7. The automatic blood sample mixing device based on machine vision analysis according to claim 6, characterized in that, The limiting plate is part of a spherical shell, and the rack is arc-shaped, used to change the relative position and relative motion state between the fixed sleeve and the second rotating shaft.

8. The automatic blood sample mixing device based on machine vision analysis according to claim 7, characterized in that, Furthermore, the center of the sphere of the limiting plate, the axis of the rack, and the rotation center of the rotating component around the slider coincide.

9. The automatic blood sample mixing device based on machine vision analysis according to claim 8, characterized in that, The maximum rotation angle of the rotating component around the slider is an obtuse angle, and the opening of the blood sample tube faces upwards each time it reaches its limit position.

10. A method for automatically mixing blood samples based on machine vision analysis, applied to the automatic blood sample mixing device based on machine vision analysis as described in any one of claims 1-9, comprising the following steps: The blood sample tube is clamped and fixed in the clamping module. The power mechanism is started to drive the blood sample tube to reciprocate obtuse angle oscillation and revolution. At the same time, the mechanical linkage drives the blood sample tube to rotate around the second rotation axis to perform compound strong mixing. During the mixing process, the machine vision module swings synchronously with the fixed sleeve, continuously and dynamically acquiring images of the blood inside the blood sample tube, and identifying the uniformity of mixing in real time. When the uniformity reaches the preset threshold, the displacement mechanism drives the slider to move down, and the pure mechanical synchronous reduction of the revolution radius and the speed of rotation slows down, thus smoothly attenuating the mixing force. Each time the rotating component swings to its limit position, it pauses briefly. The machine vision module acquires a static image to complete the homogenization verification. Based on the verification result, the slider position is corrected to adjust the mixing intensity. After the mixture reaches the required consistency, the displacement mechanism drives the slider to reset in short segments, using inertia to collect the blood from the tube wall to the bottom of the tube, thus completing the sample mixing pretreatment.

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