Micro-fluidic chip imaging positioning device and imaging positioning method

Abstract

The invention discloses a micro-fluidic chip imaging positioning device and an imaging positioning method, and belongs to the technical field of micro-fluidic chip positioning. According to the technical scheme, the method comprises the following steps: taking a photo of a micro-fluidic chip by using a macroscopic camera, and carrying out distortion correction; carrying out mark point or channel identification on the micro-fluidic chip according to the micro-fluidic chip mark point or channel identification model; performing coordinate transformation according to the calibration matrix to obtain a pixel coordinate set in microscopic camera coordinates, namely a positioning coordinate set of the micro-fluidic chip; coordinates of any position of the micro-fluidic chip can be obtained according to the positioning coordinate set, and imaging positioning of the micro-fluidic chip is completed. The micro-fluidic chip clamp is applied to the aspect of micro-fluidic chip imaging positioning, overcomes the defects caused by an existing micro-fluidic chip clamp, solves the technical problems of universality, automation and high precision of micro-fluidic chip positioning, and has the characteristics of rapidness, automation, high precision and universality.

Description

Technical Field

[0001] The invention belongs to the technical field of microfluidic chip positioning, and in particular relates to a microfluidic chip imaging positioning device and an imaging positioning method. Background Art

[0002] Microfluidic chip technology plays an important role in the fields of chemistry, medicine and biology due to its small size, low sample volume, low pollution and high efficiency. In the field of biology, it is generally necessary to observe or detect biological samples in microfluidic chips under microscopy, so the fixation and positioning of the chip play a very important role. The current common method is to design a microfluidic chip fixture or ferrule for a specific chip structure, rely on the hole positioning or edge positioning of the fixture, rely on the flexible material on the fixture (generally elastic sealing ring, flexible gasket, etc.) to provide clamping force for compression and sealing, and then fix the fixture or ferrule as a whole on the observation platform.

[0003] Chinese patent CN201320465462.1 discloses a microfluidic chip rapid positioning device, the main components of which are composed of a three-dimensional platform and a positioning sleeve. The microfluidic chip is inserted into the positioning sleeve and clamped. The sleeve is fixed on the three-dimensional translation stage. The position of the microfluidic chip can be adjusted by controlling the movement of the three-dimensional platform. The advantages of this method are easy to use and fast positioning.

[0004] However, the method disclosed in the above patent has certain limitations. Specifically: First, the design accuracy and debugging accuracy of the fixture are required to be high. For soft material chips such as PDMS, excessive clamping force will cause serious deformation of the chip, resulting in blockage of the microfluidic channel. Too small clamping force will cause leakage of the chip. For hard material chips such as glass, repeated contact with the fixture will cause small glass slag to accumulate in the fixture, thereby affecting the positioning accuracy. At the same time, in order to adapt to the fixture, high requirements are also placed on the processing accuracy of chips of the same model but different batches; secondly, different structures of microfluidic chips are required to process different biological samples, but the fixture needs to be designed for each fixed model of microfluidic chip, which is not universal, thus resulting in low efficiency and high cost; thirdly, the replacement of the chip requires manual operation due to positioning and clamping, and automation cannot be achieved; finally, the above positioning method also involves the coupling of the chip fixture and the observation platform. Affected by the structural accuracy, there will be a small position difference each time it is placed, and the uncertainty is very large. Summary of the invention

[0005] The details of one or more embodiments of the present invention are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent.

[0006] The present invention proposes a microfluidic chip imaging positioning device and an imaging positioning method, which solve the drawbacks of the existing microfluidic chip fixture and the technical problems of universality, automation and high precision of microfluidic chip positioning, and has the characteristics of rapidity, automation, high precision and universality.

[0007] The present invention discloses a microfluidic chip imaging positioning method, comprising the following steps:

[0008] Use a macro camera to take pictures of the microfluidic chip and perform distortion correction;

[0009] Identifying the landmarks or channels of the microfluidic chip according to the landmark or channel identification model of the microfluidic chip;

[0010] The coordinate transformation is performed according to the calibration matrix to obtain the pixel coordinate set in the microscopic camera coordinate, which is the positioning coordinate set of the microfluidic chip;

[0011] The coordinates of any position of the microfluidic chip can be obtained according to the positioning coordinate set, and the imaging positioning of the microfluidic chip can be completed;

[0012] The calibration matrix and microfluidic chip landmark or channel recognition model are established by the following method:

[0013] Place the distortion correction plate, take a photo of the distortion correction plate with a macro camera, and calculate the distortion correction matrix M0 of the macro camera based on the photo;

[0014] After verifying that the distortion correction residual meets the requirements, place the macro calibration plate, take a photo of the macro calibration plate with the macro camera, correct the photo distortion according to M0, and then perform N-point calibration to obtain the transformation matrix M1 of the macro camera coordinates and the 3D platform coordinates;

[0015] After verifying that the error between the measured value and the predicted value meets the requirements, place the microscopic calibration plate, take a photo of the calibration plate with the microscopic camera, perform N-point calibration based on the photo, and obtain the transformation matrix M2 of the three-dimensional platform coordinates and the microscopic camera coordinates;

[0016] After verifying that the error between the measured value and the predicted value meets the requirements, place the microfluidic chip and use a macro camera to take photos of the microfluidic chip. This batch of photos is used as a training set for chip recognition. The training set for chip recognition is corrected for distortion according to M0, and a microfluidic chip landmark or channel recognition model is established based on a deep learning algorithm.

[0017] On the other hand, the present invention discloses a microfluidic chip imaging positioning device for the above-mentioned microfluidic chip imaging positioning method, including a microscopic illumination module, a microscopic imaging module, a chip movement and macroscopic illumination module, a macroscopic imaging module, and an optical path multiplexing module; the microscopic illumination module includes a compound eye lens assembly, the compound eye lens assembly includes two compound eye lenses, the optical axes of the two compound eye lenses are parallel to each other, and the focus of each lens array element in one compound eye lens coincides with the center of the lens array element at the corresponding position of the other compound eye lens; the microscopic imaging module is used to perform infinite microscopic imaging of the sample and provide visualized sample morphology and spatial position; the chip movement and macroscopic illumination module scans and moves the microfluidic chip and provides bright field illumination for macroscopic imaging; the macroscopic imaging module performs macroscopic visual imaging of the entire chip for positioning; the optical path multiplexing module combines the microscopic illumination module with the macroscopic imaging module.

[0018] In some embodiments, the chip movement and macro-illumination module further includes: a three-dimensional electric scanning platform, a macro-light source, and a microfluidic chip holder; the three-dimensional electric scanning platform moves in the XY direction to move the microfluidic chip forward, backward, left and right for scanning, and moves in the Z direction to perform microscopic focusing on the microfluidic chip; the macro-light source performs side illumination of the microfluidic chip; the microfluidic chip holder is fixed on the three-dimensional electric scanning platform, and a placement area for placing the microfluidic chip is provided on the microfluidic chip holder, and the macro-light source is fixed on the microfluidic chip holder and distributed circumferentially along the microfluidic chip.

[0019] In some of the embodiments, the microfluidic chip bracket further includes: a bracket body, a placement area, and a light board; the bracket body is fixedly connected to the three-dimensional electric scanning platform; the placement area is opened on the bracket body, and the microfluidic chip is fixed in the placement area; the light board is fixedly connected to the bracket body and distributed circumferentially along the placement area; the macro light source is a plurality of white light LEDs, and the plurality of white light LEDs are evenly fixed on the light board along the circumference of the placement area.

[0020] In some of the embodiments, the microfluidic chip support further comprises a light board cover that is disposed above the plurality of white light LEDs and is detachably fixedly connected to the light board.

[0021] In some embodiments, the light board is a split structure, including a first light board arranged on one side of the placement area, and a second light board arranged on the other side of the placement area; the light board cover includes a first light board cover fixedly connected to the first light board, and a second light board cover fixedly connected to the second light board.

[0022] In some of the embodiments, the microscopic illumination module further comprises: a microscopic light source, a collimator for collimating the divergent light of the microscopic light source into parallel light, a reflector for making a 90° turn on the light path to compress the volume of the light path, and a condenser.

[0023] In some of the embodiments, the microscopic imaging module includes: a microscope objective lens, a microscopic imaging lens assembly that focuses the sample image onto a microscopic camera, and a microscopic camera that receives imaging signals; the macroscopic imaging module includes: a visual imaging lens assembly that focuses the microfluidic chip image onto the macroscopic camera, and a macroscopic camera that receives imaging signals from the microfluidic chip.

[0024] In some of the embodiments, the optical path multiplexing module further includes: a condenser, a condenser switching assembly, and a beam splitter prism; the condenser switching assembly fixes the condenser and controls the condenser to be located at a first position entering the optical path or a second position cutting out the optical path; when the condenser is located at the first position, the condenser is located above the microfluidic chip, the main light rays of the condenser and the microscopic illumination module are coaxial, and the macroscopic imaging module does not work; when the condenser is located at the second position, the macroscopic imaging module performs macroscopic imaging of the microfluidic chip, and the microscopic illumination module does not work; the beam splitter prism is located above the first position, the light of the microscopic illumination module is transmitted through the beam splitter prism, and the light reflected back from the microfluidic chip illuminated by the macroscopic light source is reflected through the beam splitter prism into the visual imaging lens assembly.

[0025] In some of the embodiments, the microfluidic chip imaging and positioning device further comprises a computer control system, which is electrically connected to the microscopic illumination module, the microscopic imaging module, the chip movement and macroscopic illumination module, the macroscopic imaging module, and the optical path multiplexing module.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present invention provides a microfluidic chip imaging positioning method and a microfluidic chip imaging positioning device, which can completely replace the traditional positioning solution based on chip fixtures, and its advantages are specifically embodied in:

[0028] 1. Strong versatility. It does not require separate design for microfluidic chips with different structures. First, it can be applied to microfluidic chips with different internal structures such as liquid circuits and gas circuits. Secondly, as long as the appearance size of the microfluidic chip within the detection field of view of the macro imaging module is met, it can be directly detected. It has strong versatility, which not only avoids the shortcomings of high design accuracy and debugging accuracy of the fixture, but also reduces the requirements for chip accuracy, thereby reducing costs and improving detection efficiency.

[0029] 2. Improved automation. This device solves the problem that the chip fixture cannot be automated due to positioning and clamping. Through the chip bracket structure design, common optical path coupling and other designs, it reserves space for automated equipment operation, and can achieve completely unattended automated positioning and detection;

[0030] 3. Fast and high-precision. This device is based on visual imaging positioning, which avoids the chip fixture loading process. Chip positioning can be completed in seconds, and the efficiency is increased by more than ten times. This device is based on a high-resolution macro camera, combined with deep learning algorithm modeling and identification positioning, and the positioning accuracy can reach 1μm. Compared with the mechanical positioning error of 10-100μm, the accuracy is significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0032] Figure 1 A schematic diagram of the structure of a microfluidic chip imaging and positioning device provided in an embodiment of the present invention;

[0033] Figure 2 A schematic diagram of the structure of a microfluidic chip support provided by an embodiment of the present invention;

[0034] Figure 3 A schematic diagram of the structure of a fly-eye lens assembly provided in an embodiment of the present invention;

[0035] Figure 4 A schematic diagram of the visual imaging positioning process of a microfluidic chip provided in an embodiment of the present invention;

[0036] Figure 5 A schematic diagram of a process for establishing a microfluidic chip landmark or channel recognition model provided by an embodiment of the present invention;

[0037] Figure 6 A schematic diagram of the arrangement of a macro light source provided by an embodiment of the present invention on a light board;

[0038] Figure 7 A simulated diagram of the illumination spot at the sample provided by an embodiment of the present invention;

[0039] Figure 8 This is an imaging effect diagram of a microfluidic chip provided by an embodiment of the present invention;

[0040] Description of the drawings: 101, compound eye lens assembly; 102, microscopic light source; 103, collimator; 104, reflector; 105, condenser; 201, three-dimensional electric scanning platform; 202, macroscopic light source;

[0041] 2031, bracket body; 2032, light board; 2033, light board cover;

[0042] 301. Microscope objective lens; 302. Microscope imaging lens assembly; 303. Microscopic camera; 401. Visual imaging lens assembly; 402. Macroscopic camera; 501. Condenser switching assembly; 502. Beam splitter prism; 60. Computer control system; 70. Microfluidic chip. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is described and illustrated below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Based on the embodiments provided by the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0044] Obviously, the drawings described below are only some examples or embodiments of the present invention. For ordinary technicians in this field, the present invention can also be applied to other similar scenarios based on these drawings without creative work. In addition, it can also be understood that although the efforts made in this development process may be complicated and lengthy, for ordinary technicians in this field related to the content disclosed by the present invention, some changes in design, manufacturing or production based on the technical content disclosed by the present invention are just conventional technical means, and should not be understood as insufficient content disclosed by the present invention.

[0045] Reference to "embodiments" in the present invention means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those of ordinary skill in the art that the embodiments described in the present invention may be combined with other embodiments without conflict.

[0046] Unless otherwise defined, the technical terms or scientific terms involved in the present invention shall have the usual meanings understood by persons with ordinary skills in the technical field to which the present invention belongs. The words "one", "a", "a", "the" and the like involved in the present invention do not indicate a quantity limitation and may indicate the singular or plural. The terms "include", "comprise", "have" and any of their variations involved in the present invention are intended to cover non-exclusive inclusions; for example, a process, method, system, product or device including a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units that are not listed, or may also include other steps or units inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in the present invention are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "multiple" involved in the present invention refers to two or more. "And / or" describes the association relationship of associated objects, indicating that there may be three relationships, for example, "A and / or B" may indicate: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects in the front and back relation are in an "or" relationship. The terms "first", "second", "third" and the like involved in the present invention are only used to distinguish similar objects and do not represent a specific ordering of the objects.

[0047] On the one hand, the present invention discloses a microfluidic chip 70 imaging positioning method, such as Figure 4 As shown, the following steps are included:

[0048] Using the macro camera 402 to take a picture of the microfluidic chip 70 and perform distortion correction;

[0049] Identify the landmarks or channels of the microfluidic chip 70 according to the landmark or channel identification model of the microfluidic chip 70;

[0050] The coordinate transformation is performed according to the calibration matrix to obtain a pixel coordinate set in the coordinates of the microscopic camera 303, which is the positioning coordinate set of the microfluidic chip 70;

[0051] The coordinates of any position of the microfluidic chip 70 can be obtained according to the positioning coordinate set, and the imaging positioning of the microfluidic chip 70 is completed;

[0052] like Figure 5 As shown, the calibration matrix and the landmark or channel recognition model of the microfluidic chip 70 are established by the following method:

[0053] Place the distortion correction plate, and the macro camera 402 takes a photo of the distortion correction plate, and calculates the distortion correction matrix M0 of the macro camera 402 based on the photo;

[0054] After verifying that the distortion correction residual meets the requirements, place the macro calibration plate, and the macro camera 402 takes a photo of the macro calibration plate. The photo distortion is corrected according to M0, and then N-point calibration is performed to obtain the transformation matrix M1 of the macro camera 402 coordinates and the three-dimensional platform coordinates;

[0055] After verifying that the measured value and the predicted value error meet the requirements, place the microscopic calibration plate, take a photo of the calibration plate with the microscopic camera 303, perform N-point calibration based on the photo, and obtain the transformation matrix M2 of the three-dimensional platform coordinates and the microscopic camera 303 coordinates;

[0056] After verifying that the error between the measured value and the predicted value meets the requirements, place the microfluidic chip 70 and use the macro camera 402 to take photos of the microfluidic chip 70. This batch of photos is used as a training set for chip identification. The training set for chip identification is distorted according to M0, and a landmark point or channel identification model for the microfluidic chip 70 is established based on a deep learning algorithm.

[0057] The above imaging positioning method first needs to be calibrated and modeled. Specifically, it includes: 1. Calibration of the coordinate position transformation relationship between the macro camera 402 and the micro camera 303 relative to the three-dimensional electric scanning platform 201; 2. Due to the large field of view of the macro camera 402, it is necessary to calibrate the distortion correction of the macro camera 402; 3. In order to identify the chip for easy positioning, it is necessary to establish a recognition model of chip landmarks or channels based on a deep learning algorithm. The specific process is as follows: Figure 5 The calibration and modeling work is performed after the device is installed and adjusted, and only needs to be performed once, and is directly built into the upper computer software on the computer control system 60, and does not need to be updated with the difference of the microfluidic chip 70.

[0058] After calibration and model building, the above device can be used to perform visual imaging positioning on the microfluidic chip 70. Including: 1. The macro camera 402 takes a photo of the chip and performs distortion correction; 2. The chip is marked with points or channels according to the model; 3. The coordinate transformation is performed according to the calibration matrix to obtain a pixel coordinate set in the coordinates of the micro camera 303, which is the positioning coordinate set of the chip; 4. The coordinates of any position of the chip can be obtained based on the positioning coordinate set, so as to facilitate the imaging, identification, detection, scanning and other tasks of the sample in the chip. The specific process is as follows Figure 4 shown.

[0059] Another aspect of the present invention discloses a microfluidic chip 70 imaging positioning device used in the above-mentioned microfluidic chip 70 imaging positioning method, such as Figure 1 As shown, it includes a microscopic illumination module, a microscopic imaging module, a chip moving and macroscopic illumination module, a macroscopic imaging module, and an optical path multiplexing module; the microscopic illumination module includes a compound eye lens assembly 101, such as Figure 3As shown, the compound eye lens assembly 101 includes two compound eye lenses, the optical axes of the two compound eye lenses are parallel to each other, and the focus of each lens array element in one compound eye lens coincides with the center of the lens array element at the corresponding position of the other compound eye lens; the microscopic imaging module is used to perform infinite microscopic imaging of the sample, providing visualized sample morphology and spatial position; the chip movement and macroscopic illumination module scans and moves the microfluidic chip 70, and provides bright field illumination for macroscopic imaging; the macroscopic imaging module performs macroscopic visual imaging of the entire chip for positioning. In some embodiments, the microscopic illumination module further includes: a microscopic light source 102, a collimator 103 that collimates the divergent light of the microscopic light source 102 into parallel light, a reflector 104 that makes a 90° turn on the light path to compress the light path volume, and a condenser 105; the light path multiplexing module is used to organically combine the microscopic illumination module with the macroscopic imaging module.

[0060] Regarding the microscopic illumination module, it should be noted that the microscopic illumination module provides suitable bright field illumination for microscopic imaging, and includes a microscopic light source 102, which provides a light source for microscopic bright field imaging. The microscopic light source 102 can be a white light LED or a halogen lamp, etc.; a collimator 103, which collimates the divergent light of the light source into parallel light; a compound eye lens assembly 101, which contains two compound eye lenses with completely identical parameters, and whose function is to improve the uniformity and brightness of the illumination; a reflector 104, which functions to make a 90° turn on the light path to compress the volume of the light path; and a condenser 105, which functions to converge the light from the compound eye lens assembly 101 into a uniform square light spot to illuminate the sample area. The microscopic illumination module is one of the core modules of the present device, and its main function is to provide high light energy utilization and high uniformity illumination for microscopic imaging. The compound eye lens assembly 101 is the key to achieving the above-mentioned effects. The optical axes of the two compound eye lenses it contains are parallel to each other, and the focal point of each lens array element in the first compound eye lens coincides with the center of the lens array element at the corresponding position of the second lens. The appearance structure of the compound eye lens is as follows: Figure 3As shown. When the microscopic illumination module is working normally, the light emitted by the microscopic light source 102 forms parallel light through the collimator 103. The parallel light passes through each lens array element of the first fly-eye lens and is focused to the center of the lens array element at the corresponding position of the second lens array element. The first fly-eye lens divides the wide light beam of illumination into multiple fine light beams for illumination. The uniformity within the range of each fine light beam must be extremely large. Due to the uniformity of the wide light beam's individual illumination range, and because the entire system is a rotationally symmetrical system, the tiny unevenness of the edge of each fine light beam is mutually compensated due to the superposition of symmetrical positions, which further improves the uniformity of illumination and enables the light energy within the entire aperture to be effectively and evenly utilized. The second fly-eye lens acts as a field lens, and the light spot emitted by it is then focused on the sample through the condenser 105. Each small focused light spot at the sample is illuminated by the light emitted from all points of the light source. At the same time, the light beams emitted from each point on the light source overlap and intersect within the same field of view on the illumination light spot. Therefore, all the small light spots converge together to obtain a uniform square light spot to illuminate the sample area, as shown in FIG. Figure 7 shown.

[0061] In some embodiments, the chip movement and macroscopic illumination module further comprises: a three-dimensional electric scanning platform 201, a macroscopic light source 202, and a microfluidic chip 70 support; the three-dimensional electric scanning platform 201 moves in the XY direction to make the microfluidic chip 70 move forward, backward, left and right for scanning, and moves in the Z direction to make the microfluidic chip 70 perform microscopic focusing; the macroscopic light source 202 performs lateral illumination on the microfluidic chip 70; the microfluidic chip 70 support is fixed on the three-dimensional electric scanning platform 201, and a placement area for placing the microfluidic chip 70 is provided on the microfluidic chip 70 support, and the macroscopic light source 202 is fixed on the microfluidic chip 70 support and distributed along the circumference of the microfluidic chip 70. Figure 2 As shown, the microfluidic chip 70 support further includes: a support body 2031, a placement area, and a light board 2032; the support body 2031 is fixedly connected to the three-dimensional electric scanning platform 201; the placement area is opened on the support body 2031, and the microfluidic chip 70 is fixed in the placement area; the light board 2032 is fixedly connected to the support body 2031 and distributed along the circumference of the placement area; the macro light source 202 is a plurality of white light LEDs, such as Figure 6 As shown, a plurality of white light LEDs are evenly fixed on the light board 2032 along the circumference of the placement area.

[0062] The chip movement and macroscopic illumination module is used to scan and move the chip and provide suitable bright field illumination for macroscopic imaging. It includes a three-dimensional electric scanning platform 201, which is controlled by a DC motor to move the microfluidic chip 70 with high precision. The XY direction movement makes the chip move forward, backward, left and right for scanning, and the Z direction movement makes the chip perform microscopic focusing. The platform accuracy and resolution can be configured according to the needs. In this embodiment, the minimum step value of the platform is 20nm, and the repeat positioning accuracy during the movement is 0.5μm; the macroscopic light source 202 provides the light source for macroscopic bright field imaging. The macroscopic light source 202 is composed of a series of LED lights evenly distributed around the microfluidic chip 70, which illuminates the microfluidic chip 70 from the side; the microfluidic chip 70 bracket is used to fix the macroscopic light source 202 and provide a placement area for the chip. The biggest difficulty in macroscopic visual imaging positioning of the microfluidic chip 70 is that the microfluidic chip 70 is generally made of fully transparent material, and in order to ensure the microscopic imaging effect, the light transmittance of the material is relatively high. When the chip is imaged by ordinary coaxial illumination or transmitted illumination, most of the light is transmitted or scattered, and the background will cause great interference, making it impossible to see the fine structure of the internal channel of the chip, and even the appearance contour cannot be clearly distinguished from the background. Therefore, the present invention proposes an integrated microfluidic chip 70 bracket design based on side illumination, and its structure is as follows: Figure 2 As shown, it includes a bracket body 2031, a first light board 2032, a second light board 2032, a first light board cover 2033, and a second light board cover 2033. The bracket body 2031 is fastened to the three-dimensional electric scanning platform 201 by screws on one hand, and on the other hand, it serves as a carrier of the chip and the macroscopic lateral illumination light source, and reserves space at the upper and lower structures to facilitate the mechanical gripper to clamp and place the chip, so as to achieve full automation; the first light board 2032 and the second light board 2032 are structured as shown in FIG. Figure 6 As shown, a plurality of white light LEDs are symmetrically distributed on the microfluidic chip 70 to evenly illuminate the microfluidic chip 70 from the side. The first light board cover 2033 and the second light board cover 2033 respectively isolate and protect the light board 2032 and decorate the light board 2032. The integrated microfluidic chip 70 has a simple structure, a small size, and is easy to use. It can meet the needs of automated operation and has strong versatility. Taking a certain microfluidic chip 70 sample as an example, the imaging effect is as follows Figure 8 As shown, it can be seen that for the channels in the microfluidic chip 70, the images of the marking points and the like are clear and have a high contrast with the background.

[0063] In some of the embodiments, the microfluidic chip 70 support further includes a light board cover 2033 which is disposed above the plurality of white light LEDs and is detachably fixedly connected to the light board 2032 .

[0064] In some embodiments, the light board 2032 is a split structure, including a first light board 2032 arranged on one side of the placement area, and a second light board 2032 arranged on the other side of the placement area; the light board cover 2033 includes a first light board cover 2033 fixedly connected to the first light board 2032, and a second light board cover 2033 fixedly connected to the second light board 2032.

[0065] In some embodiments, the microscopic imaging module includes: a microscope objective 301, a microscopic imaging lens assembly 302 for focusing the sample image onto a microscopic camera 303, and a microscopic camera 303 for receiving imaging signals. The microscopic imaging module is used to perform infinite microscopic imaging of the sample and provide visualized sample morphology and spatial position. It includes a microscope objective 301, which is used for microscopic magnification imaging, and is characterized by high magnification (≥50X), high NA (≥0.8), ultra-flat field, and apochromatic aberration; a microscopic imaging lens assembly 302, which is used to focus the sample image onto the microscopic camera 303, and is characterized by wide-field imaging, apochromatic aberration, and achieving diffraction limit over the entire field of view; a microscopic camera 303, which receives imaging signals and can configure its resolution and field of view parameters as needed.

[0066] In some embodiments, the macro imaging module includes: a visual imaging lens assembly 401 that focuses the image of the microfluidic chip 70 onto the macro camera 402, and a macro camera 402 that receives the imaging signal of the microfluidic chip 70. The macro imaging module is used to perform macroscopic visual imaging of the entire chip for positioning, and includes a visual imaging lens assembly 401, which is used to focus the chip image onto the macro camera 402, and is characterized by a large field of view: it can cover the size of the entire chip, and a long working distance: it is convenient to couple with the microscopic illumination module in the same optical path; the macro camera 402 receives the chip imaging signal, and is characterized by high resolution (20 million pixels and above): to clearly image the microscopic channels of the microfluidic chip 70, and a large field of view: to clearly image the entire chip field of view.

[0067] In some of the embodiments, the optical path multiplexing module organically combines the microscopic illumination module with the macroscopic imaging module, and further includes: a condenser 105, a condenser switching component 501, and a beam splitter prism 502; the condenser switching component 501 fixes the condenser 105 and controls the condenser 105 to be located at a first position entering the optical path or a second position cutting out the optical path; when the condenser 105 is located at the first position, the condenser 105 is located above the microfluidic chip 70, the condenser 105 and the main light of the microscopic illumination module are coaxial, and the macroscopic imaging module does not work; when the condenser 105 is located at the second position, the macroscopic imaging module performs macroscopic imaging of the microfluidic chip 70, and the microscopic illumination module does not work; the beam splitter prism 502 is located above the first position, the light of the microscopic illumination module is transmitted through the beam splitter prism 502, and the light reflected back from the microfluidic chip 70 illuminated by the macroscopic light source 202 is reflected through the beam splitter prism 502 and enters the visual imaging lens assembly 401.

[0068] The function of the optical path multiplexing module is to organically combine the microscopic illumination module and the macroscopic imaging module for optical path multiplexing. This common optical path design greatly reduces the volume and complexity of the overall device, and can realize the functions of the two modules without moving the chip, thereby improving efficiency. The module includes a beam splitter prism 502, which is used to transmit the light of the microscopic illumination module so that it can be converged into a uniform square light spot by the condenser 105 at the back to illuminate the sample area, and at the same time, the light reflected back from the chip illuminated by the macroscopic light source 202 is reflected into the visual imaging lens assembly 401, which can also be replaced by other beam splitters such as a flat-plate beam splitter and a thin-film beam splitter; a condenser switching assembly 501, on which the condenser 105 is fixed by a flange. The assembly controls the condenser 105 to enter and cut out of the light path. When entering the light path, the condenser 105 and the main light of the microscopic illumination module are coaxial to form a microscopic illumination spot, and the macroscopic imaging module does not work. When cutting out of the light path, the macroscopic imaging module performs macroscopic imaging of the chip, and the microscopic illumination module does not work. When the condenser 105 cuts out of the light path, the area above the microfluidic chip 70 becomes larger, which is convenient for the mechanical gripper to clamp and place the chip to achieve full automation. The condenser switching assembly 501 can be implemented by a linear motor module, an angle deflection module or a magnetic grating encoder servo.

[0069] In some of the embodiments, the imaging and positioning device of the microfluidic chip 70 further includes a computer control system 60, which is electrically connected to the microscopic illumination module, the microscopic imaging module, the chip movement and macroscopic illumination module, the macroscopic imaging module, and the optical path multiplexing module.

[0070] The computer control system 60 is the control and display center of the entire device. It can issue control instructions and control processes through the host computer software, including controlling the switch and brightness of the microscopic light source 102 and the macroscopic light source 202; controlling the speed, direction, step value, distance and other parameters of the three-dimensional electric scanning platform 201; controlling the condenser switching component 501, thereby controlling the condenser 105 to enter and cut out of the light path; controlling the exposure time, white balance and other parameters of the microscopic camera 303 and the macroscopic camera 402. In addition, the system is also responsible for the display of the sample and the chip image plane, and the method of positioning the microfluidic chip 70 and measuring the sample in the chip is built in the host computer software.

[0071] The above-mentioned imaging positioning method and imaging positioning device of the microfluidic chip 70 can completely replace the traditional positioning solution based on the chip fixture, and its advantages are specifically embodied in:

[0072] 1. Strong versatility. It does not need to design microfluidic chips 70 with different structures separately. First, it can be applied to microfluidic chips 70 with different internal structures such as liquid circuits and gas circuits. Secondly, as long as the appearance size of the microfluidic chip 70 within the detection field of view of the macro imaging module is met, it can be directly detected. It has strong versatility, which not only avoids the shortcomings of high design accuracy and debugging accuracy of the fixture, but also reduces the requirements for chip accuracy, thereby reducing costs and improving detection efficiency.

[0073] 2. Improved automation. This device solves the problem that the chip fixture cannot be automated due to positioning and clamping. Through the chip bracket structure design, common optical path coupling and other designs, it reserves space for automated equipment operation, and can achieve completely unattended automated positioning and detection;

[0074] 3. Fast and high-precision. This device is based on visual imaging positioning, which avoids the chip fixture loading process. The chip positioning can be completed in seconds, and the efficiency is increased by more than ten times. This device is based on a high-resolution macro camera 402, combined with deep learning algorithm modeling and identification positioning, and the positioning accuracy can reach 1μm. Compared with the mechanical positioning error of 10-100μm, the accuracy is significantly improved.

[0075] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0076] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A microfluidic chip imaging positioning method, characterized in that: The following steps are involved: Use a macro camera to take pictures of the microfluidic chip and perform distortion correction; Identifying the landmarks or channels of the microfluidic chip according to the landmark or channel identification model of the microfluidic chip; The coordinate transformation is performed according to the calibration matrix to obtain the pixel coordinate set in the microscopic camera coordinate, which is the positioning coordinate set of the microfluidic chip; The coordinates of any position of the microfluidic chip can be obtained according to the positioning coordinate set, and the imaging positioning of the microfluidic chip can be completed; The calibration matrix and microfluidic chip landmark or channel recognition model are established by the following method: Place the distortion correction plate, take a photo of the distortion correction plate with a macro camera, and calculate the distortion correction matrix M0 of the macro camera based on the photo; After verifying that the distortion correction residual meets the requirements, place the macro calibration plate, take a photo of the macro calibration plate with the macro camera, correct the photo distortion according to M0, and then perform N-point calibration to obtain the transformation matrix M1 of the macro camera coordinates and the 3D platform coordinates; After verifying that the error between the measured value and the predicted value meets the requirements, place the microscopic calibration plate, take a photo of the calibration plate with the microscopic camera, perform N-point calibration based on the photo, and obtain the transformation matrix M2 of the three-dimensional platform coordinates and the microscopic camera coordinates; After verifying that the error between the measured value and the predicted value meets the requirements, place the microfluidic chip and use a macro camera to take photos of the microfluidic chip. This batch of photos is used as a training set for chip recognition. The training set for chip recognition is corrected for distortion according to M0, and a microfluidic chip landmark or channel recognition model is established based on a deep learning algorithm.

2. A microfluidic chip imaging positioning device for use in the microfluidic chip imaging positioning method according to claim 1, characterized in that: include A microscopic lighting module, the microscopic lighting module includes a fly-eye lens assembly, the fly-eye lens assembly includes two fly-eye lenses, the optical axes of the two fly-eye lenses are parallel to each other, and the focus of each lens array element in one fly-eye lens coincides with the center of the lens array element at the corresponding position of the other fly-eye lens; Microscopic imaging module, used to perform infinite microscopic imaging of samples, providing visualization of sample morphology and spatial position; The chip movement and macro-illumination module scans and moves the microfluidic chip and provides bright field illumination for macro-imaging; Macro imaging module, which performs macro visual imaging of the entire chip for positioning; And an optical path multiplexing module, which combines the microscopic illumination module with the macroscopic imaging module.

3. The microfluidic chip imaging positioning device according to claim 2, characterized in that: The chip movement and macro illumination module further comprises: The three-dimensional electric scanning platform moves in the XY direction to move the microfluidic chip forward, backward, left and right for scanning, and moves in the Z direction to perform microscopic focusing of the microfluidic chip; A macro light source provides side illumination of the microfluidic chip; The microfluidic chip holder is fixed on the three-dimensional electric scanning platform. A placement area for placing the microfluidic chip is provided on the microfluidic chip holder. The macro light source is fixed on the microfluidic chip holder and distributed along the circumference of the microfluidic chip.

4. The microfluidic chip imaging positioning device according to claim 3, characterized in that: The microfluidic chip support further comprises: The bracket body is fixedly connected to the three-dimensional electric scanning platform; A placement area is provided on the support body, and the microfluidic chip is fixed in the placement area; The light panel is fixedly connected to the bracket body and distributed along the circumference of the placement area; The macro light source is a plurality of white light LEDs, and the plurality of white light LEDs are evenly fixed on the lamp board along the circumference of the placement area.

5. The microfluidic chip imaging positioning device according to claim 4, characterized in that: The microfluidic chip support also includes a light board cover plate which is arranged above the plurality of white light LEDs and is detachably fixedly connected to the light board.

6. The microfluidic chip imaging positioning device according to claim 5, characterized in that: The light board is a split structure, including a first light board arranged on one side of the placement area, and a second light board arranged on the other side of the placement area; the light board cover includes a first light board cover fixedly connected to the first light board, and a second light board cover fixedly connected to the second light board.

7. The microfluidic chip imaging positioning device according to claim 2, characterized in that: The microscopic lighting module further includes: a microscopic light source, a collimator for collimating the divergent light of the microscopic light source into parallel light, a reflector for making a 90° turn on the light path to compress the volume of the light path, and a condenser.

8. The microfluidic chip imaging positioning device according to claim 2, characterized in that: The microscopic imaging module includes: a microscope objective lens, a microscopic imaging lens assembly that focuses the sample image onto the microscopic camera, and a microscopic camera that receives imaging signals; the macroscopic imaging module includes: a visual imaging lens assembly that focuses the microfluidic chip image onto the macroscopic camera, and a macroscopic camera that receives imaging signals from the microfluidic chip.

9. The microfluidic chip imaging positioning device according to claim 7, characterized in that: The optical path multiplexing module further comprises: A condenser switching assembly fixes the condenser and controls the condenser to be located at a first position entering the light path or a second position cutting out the light path; when the condenser is located at the first position, the condenser is located above the microfluidic chip, the main light beams of the condenser and the microscopic illumination module are coaxial, and the macroscopic imaging module does not work; when the condenser is located at the second position, the macroscopic imaging module performs macroscopic imaging of the microfluidic chip, and the microscopic illumination module does not work; The beam splitter prism is located above the first position. The light from the microscopic illumination module is transmitted through the beam splitter prism, and the light reflected back from the microfluidic chip illuminated by the macroscopic light source is reflected through the beam splitter prism and enters the visual imaging lens assembly.

10. The microfluidic chip imaging positioning device according to claim 9, characterized in that: The microfluidic chip imaging positioning device also includes a computer control system, which is electrically connected to the microscopic illumination module, the microscopic imaging module, the chip movement and macroscopic illumination module, the macroscopic imaging module, and the optical path multiplexing module.

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