Device for screening and separating circulating tumor cells and method for detecting circulating tumor cells

Abstract

Provided is a device for screening and separating circulating tumor cells (CTCs), comprising: a chamber module, the chamber module being provided with a mixing chamber, a screening chamber and a waste liquid chamber, and the mixing chamber, the screening chamber and the waste liquid chamber being sequentially communicated; a control module, the control module being mounted on the chamber module, and the control module being configured to control, according to the motion state thereof, whether to discharge a liquid from the mixing chamber to the screening chamber; a temperature control module, the temperature control module being mounted on the chamber module, and the temperature control module being configured to control the temperature in the mixing chamber; and a magnetic enrichment module, the magnetic enrichment module being configured to form a magnetic field in the mixing chamber. Provided is the device for screening and separating CTCs on the basis of immunomagnetic bead separation technology. The device has a compact structure and a small size, is convenient to operate, and has the function of simulating the constant-temperature environment in human bodies to assist in reaction incubation, thereby ensuring the reliability and precision of detection.

Description

Circulating tumor cell screening and isolation device and circulating tumor cell detection method Technical Field

[0001] This invention belongs to the field of medical testing technology and relates to a circulating tumor cell screening and separation device and a circulating tumor cell detection method. Background Technology

[0002] Circulating tumor cells (CTCs) are tumor cells that detach from primary or metastatic tumors and enter the bloodstream. CTC detection is crucial for early cancer diagnosis, disease monitoring, treatment evaluation, and prognosis. CTCs are extremely rare in blood (only 0-100 CTCs per mL), making the enrichment and detection of CTCs from the blood a key challenge. Among various enrichment methods, immunomagnetic bead assays are widely used due to their rapid and non-destructive separation. This method is based on the binding of CTC surface-specific antigens to antibodies on magnetic beads, achieving enrichment through an external magnetic field, followed by detection using surface-enhanced Raman scattering (SERS) technology.

[0003] Previously, the screening and separation of CTCs in blood usually relied on manual operation, which was cumbersome and inefficient. Although some devices based on immunomagnetic bead separation technology for screening and separating CTCs exist, these devices are usually large, cumbersome to operate, and their structure and functions are not perfect. They lack isothermal incubation capabilities, which may lead to a decrease in the accuracy of the test. Technical issues

[0004] The purpose of this invention is to address the aforementioned problems in the existing technology by proposing a circulating tumor cell screening and separation device and a circulating tumor cell detection method. Technical solutions

[0005] The objective of this invention can be achieved through the following technical solution: a circulating tumor cell screening and separation device, comprising:

[0006] The chamber module includes a mixing chamber, a screening chamber, and a waste liquid chamber, which are connected in sequence.

[0007] A control module is installed in the chamber module and is configured to control whether liquid is discharged from the mixing chamber to the screening chamber based on its own movement state.

[0008] A temperature control module is installed in the chamber module and is configured to control the temperature inside the mixing chamber.

[0009] A magnetic enrichment module is configured to generate a magnetic field within the mixing cavity.

[0010] Preferably, the chamber module includes a mixing chamber, a screening chamber, and a waste liquid chamber. The mixing chamber is disposed within the mixing chamber, the screening chamber is disposed within the screening chamber, and the waste liquid chamber is disposed within the waste liquid chamber. The screening chamber and the waste liquid chamber are detachably connected, and the mixing chamber and the screening chamber are detachably connected.

[0011] Preferably, the mixing chamber, the screening chamber, and the waste liquid chamber are arranged sequentially from top to bottom, with the bottom of the mixing chamber communicating with the top of the screening chamber, and the bottom of the screening chamber communicating with the top of the waste liquid chamber.

[0012] Preferably, the screening chamber is provided with at least one fixing component, the fixing component including a filter membrane fixing ring, the filter membrane fixing ring being detachably connected to the screening chamber, and a detachable filter membrane being installed between the filter membrane fixing ring and the screening chamber, the filter membrane being located inside the screening chamber.

[0013] Preferably, a detachable baffle is installed between the filter membrane fixing ring and the screening chamber. The baffle is located inside the screening chamber and has several small holes. The filter membrane is in close contact with the baffle.

[0014] Preferably, the fixing assembly further includes a window fixing ring, which is detachably connected to the filter membrane fixing ring, and a detachable glass window is installed between the window fixing ring and the filter membrane fixing ring.

[0015] Preferably, the control module includes a piston block movably disposed within the mixing chamber. The outer peripheral surface of the piston block is sealed against the chamber wall of the mixing chamber, thereby dividing the mixing chamber into an upper chamber and a lower chamber. The upper chamber is the portion extending from the top of the mixing chamber to the upper surface of the piston block, and the lower chamber is the portion extending from the lower surface of the piston block to the bottom of the mixing chamber. The top of the upper chamber is closed, and the bottom of the lower chamber communicates with the screening chamber.

[0016] When the piston block is stationary, the flow path between the upper cavity and the lower cavity is closed; when the piston block moves in a direction that reduces the volume of the upper cavity and increases the volume of the lower cavity, the flow path between the upper cavity and the lower cavity is open.

[0017] Preferably, the outer wall of the mixing chamber is provided with a first connector and a second connector, which are respectively connected to two different areas of the mixing chamber and are connected by a liquid guide pipe; the moving stroke range of the piston block includes the liquid discharge stroke range, when the piston block is located in the liquid discharge stroke range, the first connector is connected to the upper cavity and the second connector is connected to the lower cavity, when the piston block moves in a direction that reduces the volume of the upper cavity and increases the volume of the lower cavity, the upper cavity and the lower cavity are connected by the liquid guide pipe.

[0018] Preferably, the piston block has a valve hole, the upper cavity and the lower cavity are connected through the valve hole, and a first one-way valve is installed in the valve hole; when the piston block is stationary or moves in a direction that increases the volume of the upper cavity and decreases the volume of the lower cavity, the first one-way valve is in a closed state; when the piston block moves in a direction that decreases the volume of the upper cavity and increases the volume of the lower cavity, the first one-way valve is in an open state.

[0019] Preferably, the mixing chamber is provided with a top cover, which seals the top of the upper cavity. The top cover has an air hole, and a second one-way valve is installed in the air hole. When the piston block moves in a direction that increases the volume of the upper cavity and decreases the volume of the lower cavity, the second one-way valve is in an open state. When the piston block moves in a direction that decreases the volume of the upper cavity and increases the volume of the lower cavity, the second one-way valve is in a closed state.

[0020] Preferably, the control module further includes a drive rod that passes through the upper cavity and connects to the piston block.

[0021] Preferably, the control module further includes a drive element connected to the drive rod, the drive element being configured to drive the piston block to move via the drive rod.

[0022] Preferably, the temperature control module includes a heating element, a temperature sensing element, and a controller. The heating element and the temperature sensing element are both electrically connected to the controller. The heating element and the temperature sensing element are both installed in the mixing chamber. The temperature sensing element is configured to measure the temperature inside the mixing chamber and feed it back to the controller. The controller is configured to control the heating element to operate based on the temperature signal fed back by the temperature sensing element so that the mixing chamber maintains a set temperature.

[0023] Preferably, the mixing chamber is provided with a sandwich cavity, the sandwich cavity surrounds the outer periphery of the mixing chamber, and the heating element is fixedly disposed within the sandwich cavity.

[0024] Preferably, the magnetic enrichment module includes an electromagnet, which is configured to generate a magnetic field when energized and remove the magnetic field when de-energized, and the electromagnet is installed in the portion of the drive rod located in the upper cavity.

[0025] Preferably, the drive rod has a mounting hole inside, and the electromagnet is fixedly installed in the mounting hole.

[0026] Preferably, it also includes an ultrasonic module inserted into the mixing chamber, the ultrasonic module being configured to generate high-frequency vibrations within the mixing chamber.

[0027] A method for detecting circulating tumor cells includes the following steps:

[0028] S1: Adjust the circulating tumor cell screening and separation device to its initial state, ensure that the mixing chamber is clean and dry, and drive the piston block to move to the bottom of the mixing chamber through the driving element;

[0029] S2: Inject the blood sample and the nanomagnetic probe into the upper cavity of the mixing chamber for reaction culture, and then start the temperature control module to simulate the constant temperature environment of the human body in the mixing chamber. During the reaction culture process, the CTCs in the blood sample and the nanomagnetic probe combine to form CTCs-magnetic bead complex.

[0030] S3: After the reaction cultivation process reaches the set time, the electromagnet is activated, and the magnetic field generated by the electromagnet captures the CTCs-magnetic bead complex.

[0031] S4: The driving element drives the piston block to move upward, the waste liquid in the upper cavity is discharged into the lower cavity, and then the waste liquid enters the waste liquid chamber through the screening chamber;

[0032] S5: Remove the screening chamber, then install the filter membrane onto the screening chamber to seal the screening chamber, install the screening chamber between the mixing chamber and the waste liquid chamber, and then drive the piston block to move down to the bottom of the mixing chamber;

[0033] S6: Inject cleaning fluid into the upper cavity, then turn off the electromagnet to remove the magnetic field, start the ultrasonic module to clean the upper cavity, and then drive the piston block to move upward so that the cleaning fluid in the upper cavity is discharged into the lower cavity. The cleaning fluid enters the waste liquid chamber through the screening chamber, and the CTCs-magnetic bead complex in the cleaning fluid is blocked by the filter membrane.

[0034] S7: Remove the screening chamber again, then install the glass window onto the screening chamber, and then place the screening chamber under a Raman spectrometer for detection. Beneficial effects

[0035] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0036] 1. A device for screening and separating CTCs based on immunomagnetic bead separation technology is provided. This device has a compact structure, small size, and convenient operation. It also has the function of simulating the constant temperature environment of the human body to assist in the reaction and culture, ensuring the reliability and accuracy of detection.

[0037] 2. During the cleaning phase, the screening chamber can be individually detached from the filter membrane, and then the screening chamber with the filter membrane can be reassembled between the mixing chamber and the waste liquid chamber to ensure that the filter membrane can intercept CTCs-magnetic bead complexes during the cleaning process.

[0038] 3. The detachable screening chamber design enables in-situ Raman detection. After the cleaning stage, there is no need to remove the filter membrane or CTCs-magnetic bead complex from the screening chamber. Instead, the screening chamber is cleverly detached from the device and fitted with a glass window. The screening chamber can then be placed directly on the detection platform of the Raman spectrometer, avoiding potential contamination during the transfer process and improving the accuracy and reliability of the detection results.

[0039] 4. The presence of the piston block enables liquid transfer within a limited space in the mixing chamber, eliminating the need for additional waste liquid removal operations. The liquid discharge function is achieved by controlling the movement of the piston block, greatly improving the automation and convenience of the device. This design can automatically control liquid discharge after reaction cultivation and automatically perform cleaning during the cleaning stage, simplifying the operation process.

[0040] 5. During the enrichment stage, the electromagnet can be energized to generate a magnetic field, which can attract and fix the CTCs-magnetic bead complex. During the cleaning stage, the electromagnet can be de-energized to remove the magnetic field, allowing the cleaning fluid to rinse and collect the CTCs-magnetic bead complex. This design makes the device more flexible and convenient to use and greatly improves the degree of automation. Attached Figure Description

[0041] Figure 1 is a schematic diagram of the circulating tumor cell screening and separation device of the present invention.

[0042] Figure 2 is an exploded view of the circulating tumor cell screening and separation device of the present invention.

[0043] Figure 3 is a structural schematic diagram of Embodiment 1 of the present invention.

[0044] Figure 4 is a schematic diagram of the mixing chamber and piston block in Embodiment 1 of the present invention.

[0045] Figure 5 is a structural schematic diagram of Embodiment 2 of the present invention.

[0046] Figure 6 is a schematic diagram of the mixing chamber and piston block in Embodiment 2 of the present invention.

[0047] Figure 7 is a schematic diagram of the connection between the electromagnet and the drive rod of the present invention.

[0048] Figure 8 is an axonometric view of the screening chamber of the present invention.

[0049] Figure 9 is an exploded view of the screening chamber of the present invention.

[0050] In the diagram, 100 is the mixing chamber; 110 is the mixing cavity; 111 is the upper cavity; 112 is the lower cavity; 120 is the first connector; 130 is the second connector; 140 is the liquid guide tube; 150 is the top cover; 151 is the vent; 152 is the second one-way valve; 160 is the interlayer cavity; 200 is the screening chamber; 210 is the screening cavity; 220 is the fixing assembly; 221 is the filter membrane fixing ring; 222 is the window fixing ring; 230 is the filter membrane; 240 is the baffle; 250 is the glass window; 300 is the waste liquid chamber; 310 is the waste liquid cavity; 410 is the piston block; 411 is the valve hole; 412 is the first one-way valve; 420 is the drive rod; 421 is the mounting hole; 430 is the drive element; 510 is the heating element; 520 is the temperature measuring element; 600 is the electromagnet; and 700 is the ultrasonic module. Embodiments of the present invention

[0051] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0052] As shown in Figures 1 to 9, a circulating tumor cell screening and separation device includes: a chamber module, which is provided with a mixing chamber 110, a screening chamber 210, and a waste liquid chamber 310, which are sequentially connected; a control module, which is installed in the chamber module and is configured to control whether liquid is discharged from the mixing chamber 110 to the screening chamber 210 according to its own movement state; a temperature control module, which is installed in the chamber module and is configured to control the temperature inside the mixing chamber 110; and a magnetic enrichment module, which is configured to generate a magnetic field inside the mixing chamber 110.

[0053] This screening and separation device is based on immunomagnetic bead separation (IMS) technology for screening and separating circulating tumor cells (CTCs). The target cells (circulating tumor cells) separated and screened using this device can be detected by surface-enhanced Raman scattering (SERS) technology. This device provides a reaction culture space for the binding of nanomagnetic probes (magnetic SERS probes) with circulating tumor cells. An external magnetic field attracts and immobilizes these nanomagnetic probes bound to the target cells, while unbound components are eluted from the solution, thus achieving effective separation of target cells from other components.

[0054] The chamber module is the core of the entire device, comprising a mixing chamber 110, a screening chamber 210, and a waste liquid chamber 310 connected in sequence. The mixing chamber 110 plays multiple roles in different operational stages: it functions as a reaction chamber during the reaction incubation stage and as a cleaning chamber during the cleaning stage. The screening chamber 210 is located on the path from the mixing chamber 110 to the waste liquid chamber 310. The screening chamber 210 houses a filter membrane 230, which intercepts and collects target cells (CTCs) while allowing liquid or other components to pass through. The waste liquid chamber 310 collects the waste liquid generated during the screening and separation process, and the waste liquid within 310 can be discharged through a drain port. This highly integrated design significantly reduces the size of the device, making the overall design more compact and convenient to use.

[0055] The main function of the control module is to manage the liquid flow within the mixing chamber 110 and control the connection between the mixing chamber 110 and the screening chamber 210. During the reaction incubation stage, the control module isolates the mixing chamber 110 from the screening chamber 210; during the enrichment stage, it discharges waste liquid into the screening chamber 210; and during the cleaning stage, it discharges cleaning solution into the screening chamber 210. The temperature control module heats the mixing chamber 110 and maintains the temperature within it at a set value. The temperature control module is typically set to 37°C to simulate the constant temperature environment of the human body, ensuring that cells react under optimal conditions. The magnetic enrichment module generates a magnetic field within the mixing chamber 110 to adsorb target cells (CTCs) carrying nano-magnetic probes. By adjusting the magnetic field strength, the enrichment effect can be optimized. These modules enable a complete process of constant temperature incubation, automatic enrichment, waste liquid discharge, and cleaning, providing more comprehensive and complete functionality and significantly improving the reliability and accuracy of detection.

[0056] It should be noted that without a temperature control module, a suitable reaction environment cannot be provided in the mixing chamber 110, which may lead to unsatisfactory reaction incubation results. In addition, the lack of a temperature control module means that the temperature in the mixing chamber 110 may fluctuate with changes in the external environment, resulting in inconsistent reaction incubation conditions and thus affecting the reliability of the test results.

[0057] As shown in Figures 1 to 6, 8 and 9, based on the above embodiment, the chamber module includes a mixing chamber 100, a screening chamber 200 and a waste liquid chamber 300. The mixing chamber 110 is disposed in the mixing chamber 100, the screening chamber 210 is disposed in the screening chamber 200, and the waste liquid chamber 310 is disposed in the waste liquid chamber 300. The screening chamber 200 and the waste liquid chamber 300 are detachably connected, and the mixing chamber 100 and the screening chamber 200 are detachably connected.

[0058] The mixing chamber 100 has a top cover 150, which can seal the top of the mixing chamber 110. The outer wall of the mixing chamber 100 or the top cover 150 is provided with an inlet hole, which communicates with the mixing chamber 110. Blood samples, nanomagnetic probes, and washing solution (PBS buffer) can enter the mixing chamber 110 through the inlet hole. The screening chamber 200 has a flange structure and is detachably installed between the mixing chamber 100 and the waste liquid chamber 300. Sealing rings are installed between the screening chamber 200 and the mixing chamber 100, as well as between the screening chamber 200 and the waste liquid chamber 300.

[0059] Before the cleaning stage, the screening chamber 200 is without the filter membrane 230 and glass window 250 to ensure that the waste liquid passes smoothly through the screening chamber 210. If the filter membrane 230 is installed before the cleaning stage, other components in the waste liquid may clog or damage the filter membrane 230, or unreacted and bound nanomagnetic probes in the waste liquid may adhere to the surface of the filter membrane 230, causing false positives. During the cleaning stage, the screening chamber 200 can be disassembled separately, the filter membrane 230 can be installed, and then the screening chamber 200 with the filter membrane 230 can be reassembled between the mixing chamber 100 and the waste liquid chamber 300 to ensure that the filter membrane 230 can intercept the CTCs-magnetic bead complex during the cleaning process.

[0060] After cleaning, the screening chamber 200 is disassembled again, and a glass window 250 is installed on it. The screening chamber 200 can then be directly placed under a Raman spectrometer for detection. This detachable design achieves in-situ Raman detection. After the cleaning stage, there is no need to remove the filter membrane 230 or the CTCs-magnetic bead composite from the screening chamber 200. Instead, the screening chamber 200 is cleverly detached from the device and, after the glass window 250 is installed, it can be directly placed on the detection platform of the Raman spectrometer. This avoids potential contamination during transfer and improves the accuracy and reliability of the detection results.

[0061] Based on the above embodiments, the mixing chamber 100, the screening chamber 200 and the waste liquid chamber 300 are arranged sequentially from top to bottom. The bottom of the mixing chamber 110 is connected to the top of the screening chamber 210, and the bottom of the screening chamber 210 is connected to the top of the waste liquid chamber 310.

[0062] In this embodiment, the liquid can flow directly from the mixing chamber 110 into the screening chamber 210, and then into the waste liquid chamber 310, forming a simple straight flow path. Utilizing gravity, the liquid can flow naturally from top to bottom, reducing reliance on pumps and other power equipment. Furthermore, this vertically arranged design makes the entire device more compact, contributing to its miniaturization.

[0063] As shown in Figures 1 to 6, 8 and 9, based on the above embodiment, the screening chamber 200 is provided with at least one fixing component 220. The fixing component 220 includes a filter membrane fixing ring 221, which is detachably connected to the screening chamber 200. A detachable filter membrane 230 is installed between the filter membrane fixing ring 221 and the screening chamber 200, and the filter membrane 230 is located inside the screening cavity 210.

[0064] The filter membrane retaining ring 221 is used to fix the filter membrane 230 at the port of the screening chamber 200. In this example, the filter membrane retaining ring 221 is threaded to the port of the screening chamber 200. The user can easily unscrew the filter membrane retaining ring 221, then install the filter membrane 230 at the port of the screening chamber 200, and then screw the filter membrane retaining ring 221 in to fix the filter membrane 230 in place, ensuring that the filter membrane 230 will not shift or deform during the screening process.

[0065] Based on the above embodiments, a detachable baffle 240 is also installed between the filter membrane fixing ring 221 and the screening chamber 200. The baffle 240 is located inside the screening chamber 210 and has several small holes. The filter membrane 230 is tightly attached to the baffle 240.

[0066] Baffle 240 supports filter membrane 230 and has relatively large openings to allow liquid and other components to pass through. In this example, filter membrane 230 is attached to baffle 240 to form a single integrated structure. During installation, first remove filter membrane retaining ring 221, then install the integrated structure consisting of filter membrane 230 and baffle 240 onto screening chamber 200, and finally install filter membrane retaining ring 221 for fixation.

[0067] Based on the above embodiments, the fixing component 220 further includes a window fixing ring 222, which is detachably connected to the filter membrane fixing ring 221, and a detachable glass window 250 is installed between the window fixing ring 222 and the filter membrane fixing ring 221.

[0068] Since the screening chamber 200 needs to be transferred to the detection platform of the Raman spectrometer for in-situ Raman detection, a glass window 250 needs to be installed before detection. The glass window 250 is located above the filter membrane 230 and is usually made of high-transmittance quartz. As an additional physical barrier, the glass window 250 can reduce the influence of the external environment on the interior of the screening chamber 210 and protect the sample and internal components from damage.

[0069] In this example, both the upper and lower ports of the screening chamber 200 are equipped with fixing components 220, which allows for the installation of two sets of filter membranes 230. The two sets of filter membranes 230 can form a double barrier, improving the collection effect of CTCs-magnetic bead complexes and further enhancing the accuracy of detection.

[0070] As shown in Figures 1 to 6, based on the above embodiment, the control module includes a piston block 410, which is movably disposed within the mixing chamber 110. The outer peripheral surface of the piston block 410 is sealed against the cavity wall of the mixing chamber 110, thereby dividing the mixing chamber 110 into an upper cavity 111 and a lower cavity 112. The upper cavity 111 is the portion between the top of the mixing chamber 110 and the upper surface of the piston block 410, and the lower cavity 112 is the portion between the lower surface of the piston block 410 and the bottom of the mixing chamber 110. The top of the upper cavity 111 is closed, and the bottom of the lower cavity 112 is connected to the screening chamber 210. When the piston block 410 is stationary, the flow path between the upper cavity 111 and the lower cavity 112 is closed. When the piston block 410 moves in a direction that reduces the volume of the upper cavity 111 and increases the volume of the lower cavity 112, the flow path between the upper cavity 111 and the lower cavity 112 is open.

[0071] The mixing chamber 110 is divided into an upper chamber 111 and a lower chamber 112 by a piston block 410. Since the top of the upper chamber 111 is closed, the liquid inside can only flow into the lower chamber 112. The bottom of the lower chamber 112 is connected to the screening chamber 210, meaning that the liquid inside the lower chamber 112 can directly flow into the screening chamber 210, thereby discharging the liquid from the mixing chamber 110. The stroke position of the piston block 410 determines the volume of the upper chamber 111 and the lower chamber 112; when the volume of the upper chamber 111 increases, the volume of the lower chamber 112 decreases; when the volume of the upper chamber 111 decreases, the volume of the lower chamber 112 increases. That is, when the piston block 410 moves, the volume of the upper chamber 111 is inversely proportional to the volume of the lower chamber 112.

[0072] It should be noted that the direction in which the volume of the upper cavity 111 decreases and the volume of the lower cavity 112 increases refers to the direction in which the piston block 410 moves upward (i.e., the direction in which the piston block 410 moves toward the top of the mixing chamber 110), while the direction in which the volume of the upper cavity 111 increases and the volume of the lower cavity 112 decreases refers to the direction in which the piston block 410 moves downward (i.e., the direction in which the piston block 410 moves toward the screening chamber 210).

[0073] The main function of piston block 410 is to control the flow path from upper cavity 111 to lower cavity 112 and to force liquid transfer through its own movement. When piston block 410 is stationary, the flow path between upper cavity 111 and lower cavity 112 is closed. At this time, liquid can remain in upper cavity 111, but the liquid cannot flow to lower cavity 112. Therefore, during the reaction incubation stage, piston block 410 remains stationary, and the nanomagnetic probe and blood sample can undergo reaction incubation within upper cavity 111. During the enrichment and cleaning stages, piston block 410 moves in a direction that reduces the volume of upper cavity 111 and increases the volume of lower cavity 112 (piston block 410 moves upward), unblocking the flow path from upper cavity 111 to lower cavity 112, and compressing the liquid in upper cavity 111, thereby transferring the liquid in upper cavity 111 to lower cavity 112; then piston block 410 moves in a direction that increases the volume of upper cavity 111 and decreases the volume of lower cavity 112 (piston block 410 moves downward), thereby transferring the liquid in lower cavity 112 to screening chamber 210.

[0074] In practical use, the piston block 410 generally reciprocates, that is, it moves up and down. When the piston block 410 moves upward, the liquid in the upper cavity 111 can flow to the lower cavity 112; when the piston block 410 moves downward, it can cause the liquid in the lower cavity 112 to flow to the screening chamber 210. Therefore, the reciprocating motion of the piston block 410 can better achieve the liquid transfer function, that is, to transfer the liquid from the upper cavity 111 to the lower cavity 112, and then from the lower cavity 112 to the screening chamber 210.

[0075] The presence of piston block 410 enables liquid transfer within a limited space in mixing chamber 110, eliminating the need for additional waste liquid removal. Controlling the movement of piston block 410 to achieve the drainage function significantly improves the automation and convenience of the device. This design allows for automatic drainage control after reaction cultivation and automatic cleaning during the cleaning stage, simplifying the operation process. Example 1

[0076] As shown in Figures 1, 3, 4, 8, and 9, the outer wall of the mixing chamber 100 is provided with a first connector 120 and a second connector 130. The first connector 120 and the second connector 130 are respectively connected to two different areas of the mixing chamber 110. The first connector 120 and the second connector 130 are connected through a liquid guide pipe 140. The movement stroke range of the piston block 410 includes the liquid discharge stroke range. When the piston block 410 is located in the liquid discharge stroke range, the first connector 120 is connected to the upper cavity 111 and the second connector 130 is connected to the lower cavity 112. When the piston block 410 moves in a direction that reduces the volume of the upper cavity 111 and increases the volume of the lower cavity 112, the upper cavity 111 and the lower cavity 112 are connected through the liquid guide pipe 140.

[0077] In this embodiment, a liquid guide pipe 140 is designed as a flow path between the upper cavity 111 and the lower cavity 112. The piston block 410 can control whether the liquid is transferred through this flow path by its own movement. When the piston block 410 moves upward, the pressure in the upper cavity 111 increases, so the liquid in the upper cavity 111 enters the lower cavity 112 through the liquid guide pipe 140; when the piston block 410 moves downward, the pressure in the lower cavity 112 increases, so the liquid in the lower cavity 112 enters the screening chamber 210. During the downward movement of the piston block 410, the interface between the second connector 130 and the lower cavity 112 is gradually sealed by the piston block 410 to prevent liquid backflow.

[0078] The specific working process of Example 1 is as follows: In the initial state, the piston block 410 is at the bottom of the mixing chamber 110, thereby sealing the junction of the mixing chamber 110 and the screening chamber 210, as well as the interface between the second connector 130 and the lower chamber 112. At this time, blood samples and nanomagnetic probes can be put into the upper chamber 111 for reaction and incubation. When the device needs to perform a drainage operation, the piston block 410 is pulled upward. When the piston block 410 enters the drainage stroke range, the upper chamber 111 and the lower chamber 112 are connected through the liquid guide tube 140. As the piston block 410 continues to move upward, the liquid in the upper chamber 111 enters the lower chamber 112 through the liquid guide tube 140. After the piston block 410 moves upward to the predetermined position, it can move downward. When the piston block 410 moves downward, it can cause the liquid in the lower chamber 112 to flow to the screening chamber 210. The piston block 410 can be pulled repeatedly to achieve the purpose of drainage or cleaning. Example 2

[0079] As shown in Figures 1, 2, 5 to 9, the piston block 410 has a valve hole 411. The upper cavity 111 and the lower cavity 112 are connected through the valve hole 411. A first one-way valve 412 is installed in the valve hole 411. When the piston block 410 is stationary or moves in a direction that increases the volume of the upper cavity 111 and decreases the volume of the lower cavity 112, the first one-way valve 412 is in a closed state. When the piston block 410 moves in a direction that decreases the volume of the upper cavity 111 and increases the volume of the lower cavity 112, the first one-way valve 412 is in an open state.

[0080] In this embodiment, a valve hole 411 is designed within the piston block 410 as a flow path between the upper cavity 111 and the lower cavity 112. A first one-way valve 412 is designed to control the opening and closing of the valve hole 411. The opening and closing state of the first one-way valve 412 can be controlled by the movement state of the piston block 410. The first one-way valve 412 ensures that liquid can only flow from the upper cavity 111 to the lower cavity 112. When the piston block 410 is stationary or moves downward, the valve core of the first one-way valve 412 is closed under the action of the spring, thereby sealing the valve hole 411 and ensuring isolation between the upper cavity 111 and the lower cavity 112. When the piston block 410 moves upward, the pressure in the upper cavity 111 increases, and the liquid in the upper cavity 111 can push open the valve core of the first one-way valve 412 and enter the lower cavity 112 through the valve hole 411.

[0081] The specific working process of Example 2 is as follows: In the initial state, the piston block 410 is at the bottom of the mixing chamber 110, thereby sealing the junction of the mixing chamber 110 and the screening chamber 210. The first one-way valve 412 is in the closed state, thereby sealing the valve hole 411. At this time, blood samples and nanomagnetic probes can be put into the upper chamber 111 for reaction and incubation. When the device needs to perform a drainage operation, the piston block 410 is pulled upward, and the first one-way valve 412 is in the open state. The liquid in the upper chamber 111 enters the lower chamber 112 through the valve hole 411. When the piston block 410 moves downward, the first one-way valve 412 is in the closed state. The piston block 410 can apply pressure to the liquid in the lower chamber 112, and the liquid in the lower chamber 112 cannot flow back into the upper chamber 111. In actual operation, the piston block 410 can be pulled repeatedly to achieve the purpose of drainage or cleaning.

[0082] As shown in Figures 1 to 6, compared to Example 1, Example 2 does not require the installation of a liquid guide tube 140 on the outer wall of the mixing chamber 100, reducing the complexity of the device, making the overall structure simpler, and also reducing the risk of leakage. Moreover, Example 2 has a simpler liquid transfer control logic, faster liquid transfer speed, shorter response time, and the liquid does not need to pass through the external liquid guide tube 140, which can reduce the possibility of CTCs-magnetic bead composite adhering to the liquid guide tube 140.

[0083] As shown in Figures 1, 2, 5 to 9, based on Embodiment 2, the mixing chamber 100 is provided with a top cover 150, which seals the top of the upper cavity 111. The top cover 150 has an air hole 151, and a second one-way valve 152 is installed in the air hole 151. When the piston block 410 moves in a direction that increases the volume of the upper cavity 111 and decreases the volume of the lower cavity 112, the second one-way valve 152 is in the open state. When the piston block 410 moves in a direction that decreases the volume of the upper cavity 111 and increases the volume of the lower cavity 112, the second one-way valve 152 is in the closed state.

[0084] The top cover 150 seals the top of the upper cavity 111, ensuring that liquid and gas inside the upper cavity 111 do not leak from the top. The vent 151 of the top cover 150 allows external gas to enter the upper cavity 111, thus balancing the pressure difference between the inside and outside. Because a second one-way valve 152 is installed inside the vent 151, the second one-way valve 152 ensures that gas can only enter the upper cavity 111 from the outside, and the liquid inside the upper cavity 111 cannot push open the valve core of the second one-way valve 152 to flow out. Only when the pressure inside the upper cavity 111 decreases to a certain level can external gas push open the valve core of the second one-way valve 152 and enter the upper cavity 111.

[0085] In Embodiment 2, when the piston block 410 moves downward, the volume of the upper cavity 111 increases. At this time, the upper cavity 111 is in a vacuum state, making it difficult for the piston block 410 to move downward. Therefore, it is necessary to set up an air hole 151 and a second one-way valve 152 to balance the pressure difference. In specific operation, when the piston block 410 moves downward, the first one-way valve 412 is in the closed state, and the second one-way valve 152 is opened by the external gas and enters the upper cavity 111, so that the piston block 410 can move downward smoothly. When the piston block 410 moves upward, the first one-way valve 412 is in the open state, and the second one-way valve 152 is in the closed state. The liquid in the upper cavity 111 cannot flow out from the air hole 151, but can only flow into the lower cavity 112 through the valve hole 411.

[0086] As shown in Figures 1 to 9, based on the above-described embodiments, the control module further includes a drive rod 420, which is inserted into the upper cavity 111 and connected to the piston block 410.

[0087] The drive rod 420 can precisely control the movement of the piston block 410. The drive rod 420 can drive the piston block 410 to move up or down, thereby realizing the reciprocating motion of the piston block 410.

[0088] Based on the above embodiments, the control module further includes a drive element 430, which is connected to the drive rod 420. The drive element 430 is configured to drive the piston block 410 to move via the drive rod 420.

[0089] The drive element 430 is the power source for the control module, preferably an electric actuator. A support frame is provided at the top of the mixing chamber 100, and the drive element 430 is fixedly mounted on the support frame. The drive element 430 is connected to the piston block 410 via a drive rod 420, transmitting power to the piston block 410 so that it can move up and down according to a preset program or operating command. The drive element 430 enables the device to automatically transfer liquid from the upper chamber 111 to the lower chamber 112 and then to the screening chamber 210 without additional manual operation, significantly improving the automation level of the device.

[0090] As shown in Figures 1 to 6, based on the above-described embodiment, the temperature control module includes a heating element 510, a temperature sensing element 520, and a controller. Both the heating element 510 and the temperature sensing element 520 are electrically connected to the controller. Both the heating element 510 and the temperature sensing element 520 are installed in the mixing chamber 100. The temperature sensing element 520 is configured to measure the temperature inside the mixing chamber 110 and feed it back to the controller. The controller is configured to control the heating element 510 to operate according to the temperature signal fed back by the temperature sensing element 520 so that the mixing chamber 110 maintains a set temperature.

[0091] Heating element 510 is installed in mixing chamber 100 to heat mixing cavity 110. Heating element 510 is preferably a heating jacket with a resistance wire inside. Temperature sensing element 520 is used to measure the actual temperature inside mixing cavity 110. Temperature sensing element 520 is preferably a thermocouple or a thermistor. Temperature sensing element 520 can monitor temperature changes in real time and feed the temperature signal back to the controller. The controller is responsible for receiving the temperature signal fed back by temperature sensing element 520 and controlling the heating element 510 to work according to the temperature signal, thereby ensuring that the temperature inside mixing cavity 110 is stable at the set value.

[0092] The temperature control module, through the coordinated operation of the heating element 510, the temperature sensing element 520, and the controller, can simulate a constant temperature cultivation environment and achieve fully automated temperature management. Users only need to set the temperature value, and the subsequent temperature control is automatically completed by the system, making this device very convenient to use.

[0093] Based on the above embodiments, the mixing chamber 100 is provided with a sandwich cavity 160, which surrounds the outer periphery of the mixing chamber 110, and the heating element 510 is fixedly disposed in the sandwich cavity 160.

[0094] The mixing chamber 100 is actually composed of an outer shell and an inner liner, with the inner liner located inside the outer shell, forming a sandwich cavity 160 between them. The mixing chamber 110 is located within the inner liner. This design ensures that the heating element 510 can heat the mixing chamber 110 through the wall of the inner liner, ensuring efficient heat transfer into the mixing chamber 110. Furthermore, the user cannot directly touch the heating element 510, preventing accidental burns. In addition, placing the heating element 510 within the sandwich cavity 160 also has an insulation effect, reducing heat loss to the outside and improving heating efficiency and energy utilization.

[0095] As shown in Figures 1 to 7, based on the above-described embodiments, the magnetic enrichment module includes an electromagnet 600. The electromagnet 600 is configured to generate a magnetic field when energized and remove the magnetic field when de-energized. The electromagnet 600 is installed in the part of the drive rod 420 located inside the upper cavity 111.

[0096] During the enrichment stage, the electromagnet 600 can be energized to generate a magnetic field, which attracts and fixes the CTCs-magnetic bead complex. During the cleaning stage, the electromagnet 600 can be de-energized to remove the magnetic field, allowing the cleaning fluid to rinse and collect the CTCs-magnetic bead complex. This design makes the device more flexible and convenient to use, and greatly improves its automation level. Furthermore, the magnetic field strength of the electromagnet 600 can be controlled by adjusting the current, thereby optimizing the enrichment effect. Therefore, in actual operation, this device can select an appropriate magnetic field strength according to the detection requirements and conditions to ensure the best enrichment effect.

[0097] Based on the above implementation method, the drive rod 420 has a mounting hole 421 inside, and the electromagnet 600 is fixedly installed in the mounting hole 421.

[0098] The installation position of the electromagnet 600 has a significant impact on the enrichment effect. If the electromagnet 600 is installed outside the mixing chamber 110, the magnetic field strength decreases rapidly with distance, so the CTCs-magnetic bead complex near the electromagnet 600 can be effectively attracted together, while the CTCs-magnetic bead complex further away cannot be effectively enriched due to the weak magnetic field strength. If the electromagnet 600 is directly inserted into the mixing chamber 110, because the drive rod 420 is located at the center of the mixing chamber 110, the electromagnet 600 cannot be located at the center of the mixing chamber 110 due to interference, resulting in an uneven distribution of magnetic field strength. More importantly, if the electromagnet 600 is directly placed inside the mixing chamber 110, it will directly contact the liquid or sample inside the mixing chamber 110, increasing the risk of contamination; moreover, because the piston block 410 needs to move up and down, the piston block 410 may collide or interfere with the electromagnet 600.

[0099] For the reasons mentioned above, in this embodiment, the electromagnet 600 is specifically placed inside the drive rod 420. Since the drive rod 420 is located at the center of the mixing chamber 110, the electromagnet 600 is also located at the center of the mixing chamber 110, resulting in a uniform distribution of the magnetic field strength within the mixing chamber 110. Furthermore, placing the electromagnet 600 inside the drive rod 420 completely solves the problem of collision or interference between the piston block 410 and the electromagnet 600 during movement, while ensuring that the electromagnet 600 does not come into contact with the liquid within the mixing chamber 110.

[0100] As shown in Figures 1 to 7, based on the above embodiments, an ultrasonic module 700 is also included. The ultrasonic module 700 is inserted into the mixing chamber 110 and is configured to generate high-frequency vibrations within the mixing chamber 110.

[0101] The main function of the ultrasonic module 700 is to improve the cleaning effect during the cleaning stage. Because the magnetic field generated by the electromagnet 600 inside the drive rod 420 attracts and fixes the CTCs-magnetic bead complex to the surface of the drive rod 420, even after the magnetic field is removed, some CTCs-magnetic bead complex will still adhere to the surface of the drive rod 420. The ultrasonic module 700 can generate high-frequency vibrations in the cleaning fluid, loosening these CTCs-magnetic bead complexes adsorbed on the drive rod 420, thus allowing the cleaning fluid to more effectively rinse and collect these CTCs-magnetic bead complexes.

[0102] It should also be noted that the ultrasound module 700 not only improves the cleaning effect during the cleaning stage but also plays a crucial role in the reaction culture stage. During the reaction culture stage, the nanomagnetic probes placed in the mixing chamber 110 may fall onto other components in the blood, causing them to adhere to these components and potentially leading to false positives in subsequent testing. The ultrasound module 700 can separate the nanomagnetic probes from these components through high-frequency vibration, effectively shaking them off from non-target cells and preventing false positives.

[0103] As shown in Figures 1 to 9, it is important to note that this device, due to its comprehensive functions, has the capability to execute the entire operation process with a single button. Simply insert a blood sample and a nanomagnetic probe, then start the device. The heating element 510, temperature sensing element 520, and controller work together to simulate a constant-temperature incubation environment within the mixing chamber 110. The ultrasonic module 700 is activated to disperse the nanomagnetic probe. After incubation, the heating element 510 automatically de-energizes, and the electromagnet 600 automatically energizes, adsorbing the CTCs-magnetic bead composite onto the surface of the drive rod 420. Then, the drive element 430, via the drive rod 420, moves the piston block 410 up and down, thereby discharging the waste liquid from the mixing chamber 110. Next, the filter membrane 230 and baffle 240 are installed on the screening chamber 200. Then, the system controls the electromagnet 600 to be de-energized, thereby removing the magnetic field. Cleaning fluid is injected into the upper cavity 111, and the ultrasonic module 700 is activated to assist in cleaning. Simultaneously, the drive element 430 drives the piston block 410 up and down via the drive rod 420, thus achieving an automatic cleaning effect. After cleaning is completed, the system shuts down the ultrasonic module 700 and the drive element 430, and prompts the user to remove the screening chamber 200 for in-situ Raman detection. The entire operation involves very few manual steps; most steps can be automated.

[0104] As shown in Figures 1 to 9, a method for detecting circulating tumor cells includes the following steps:

[0105] S1: Adjust the circulating tumor cell screening and separation device to the initial state, ensure that the mixing chamber 110 is clean and dry, and drive the piston block 410 to move to the bottom of the mixing chamber 110 through the drive element 430;

[0106] S2: Inject the blood sample and the nanomagnetic probe into the upper cavity 111 of the mixing chamber 110 for reaction culture, and then start the temperature control module to simulate the human body constant temperature environment in the mixing chamber 110. During the reaction culture process, the CTCs in the blood sample and the nanomagnetic probe combine to form CTCs-magnetic bead complex.

[0107] S3: After the reaction cultivation process reaches the set time, the electromagnet 600 is activated. The magnetic field generated by the electromagnet 600 captures the CTCs-magnetic bead complex.

[0108] S4: The driving element 430 drives the piston block 410 to move upward, and the waste liquid in the upper cavity 111 is discharged to the lower cavity 112. Then the waste liquid enters the waste liquid cavity 310 through the screening cavity 210.

[0109] S5: Remove the screening chamber 200, then install the filter membrane 230 onto the screening chamber 200 so that the filter membrane 230 seals the screening chamber 210. Install the screening chamber 200 between the mixing chamber 100 and the waste liquid chamber 300, and then drive the piston block 410 to move down to the bottom of the mixing chamber 110.

[0110] S6: Inject cleaning fluid into the upper cavity 111, then turn off the electromagnet 600 to remove the magnetic field, start the ultrasonic module 700 to clean the upper cavity 111, and then drive the piston block 410 to move upward, so that the cleaning fluid in the upper cavity 111 is discharged into the lower cavity 112. The cleaning fluid enters the waste liquid chamber 310 through the screening chamber 210. The CTCs-magnetic bead complex in the cleaning fluid is blocked by the filter membrane 230.

[0111] S7: Remove the screening chamber 200 again, then install the glass window 250 onto the screening chamber 200, and then place the screening chamber 200 under the Raman spectrometer for detection.

[0112] This method utilizes a circulating tumor cell screening and separation device to automatically perform cultivation, enrichment, separation, washing, and screening operations, followed by in-situ detection in the screening chamber 200 under Raman spectroscopy. This method improves the accuracy and reliability of detection, reduces manual operation steps, and significantly increases detection efficiency.

[0113] In step S1, the piston block 410 is positioned at the bottom of the mixing chamber 110, making room for the subsequent injection of blood samples and nanomagnetic probes. The electromagnet 600 is de-energized to ensure that the nanomagnetic probes are not attracted in the initial stage. The screening chamber 200 is not equipped with a filter membrane 230 and a baffle 240, ensuring that waste liquid can pass through the screening chamber 210. In step S2, the mixing chamber 110 simulates a constant temperature environment similar to that of the human body (typically 37°C) to promote the effective binding of CTCs and nanomagnetic probes, thereby forming a CTCs-magnetic bead complex. Step S3 utilizes the magnetic field generated by the electromagnet 600 to capture the CTCs-magnetic bead complex. In step S4, the driving element 430 drives the piston block 410 to move up and down repeatedly, thereby discharging the waste liquid. The waste liquid in chamber 111 is used to reduce the influence of non-target components; step S5 is to install a filter membrane 230 on the screening chamber 200 to facilitate the screening of CTCs-magnetic bead complexes; step S6 is the cleaning step, which requires injecting cleaning fluid into the upper chamber 111 and turning off the electromagnet 600. With the assistance of ultrasonic vibration, the cleaning fluid washes and collects the CTCs-magnetic bead complexes. The driving element 430 drives the piston block 410 to move up and down repeatedly, so that the cleaning fluid enters the screening chamber 210. The cleaning fluid can pass through the filter membrane 230 into the waste liquid chamber 310, while the CTCs-magnetic bead complexes are blocked by the filter membrane 230; step S7 is actually the detection step, in which the screening chamber 200 is disassembled and placed under a Raman spectrometer for detection.

[0114] This method boasts a high degree of automation, allowing the entire operation to be run with a single click, reducing manual intervention and improving operational efficiency. Furthermore, by using heating element 510, temperature sensing element 520, and controller within the mixing chamber 110 to simulate a constant-temperature incubation environment (typically 37°C), this method promotes the effective binding of the nanomagnetic probe to CTCs, enhancing detection accuracy. The multifunctional mixing chamber 110 integrates multiple functions such as reaction incubation, enrichment, and cleaning, ensuring all operations are completed in a closed environment, avoiding cross-contamination and improving operational efficiency. The detachable design allows the screening chamber 200 to be directly placed under a Raman spectrometer for detection without additional sample transfer, achieving true in-situ detection and avoiding sample transfer between different containers, thus reducing the possibility of contamination.

[0115] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0116] Furthermore, in this invention, descriptions involving "first," "second," "a," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature.

[0117] In this invention, unless otherwise explicitly specified and limited, the terms "connection" and "fixed" should be interpreted broadly. For example, "fixed" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction between two elements, unless otherwise explicitly limited.

[0118] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

Claims

1. A circulating tumor cell screening and separation device, characterized in that, include: The chamber module includes a mixing chamber, a screening chamber, and a waste liquid chamber, which are connected in sequence. A control module is installed in the chamber module and is configured to control whether liquid is discharged from the mixing chamber to the screening chamber based on its own movement state. A temperature control module is installed in the chamber module and is configured to control the temperature inside the mixing chamber. A magnetic enrichment module is configured to generate a magnetic field within the mixing cavity.

2. The circulating tumor cell screening and separation device as described in claim 1, characterized in that: The chamber module includes a mixing chamber, a screening chamber, and a waste liquid chamber. The mixing chamber is located inside the mixing chamber, the screening chamber is located inside the screening chamber, and the waste liquid chamber is located inside the waste liquid chamber. The screening chamber and the waste liquid chamber are detachably connected, and the mixing chamber and the screening chamber are detachably connected.

3. The circulating tumor cell screening and separation device as described in claim 2, characterized in that: The mixing chamber, the screening chamber, and the waste liquid chamber are arranged sequentially from top to bottom. The bottom of the mixing chamber is connected to the top of the screening chamber, and the bottom of the screening chamber is connected to the top of the waste liquid chamber.

4. The circulating tumor cell screening and separation device as described in claim 3, characterized in that: The screening chamber is provided with at least one fixing component, the fixing component including a filter membrane fixing ring, the filter membrane fixing ring being detachably connected to the screening chamber, and a detachable filter membrane being installed between the filter membrane fixing ring and the screening chamber, the filter membrane being located inside the screening chamber.

5. The circulating tumor cell screening and separation device as described in claim 4, characterized in that: A detachable baffle is also installed between the filter membrane fixing ring and the screening chamber. The baffle is located inside the screening chamber and has several small holes. The filter membrane is in close contact with the baffle.

6. The circulating tumor cell screening and separation device as described in claim 4, characterized in that: The fixing assembly also includes a window fixing ring, which is detachably connected to the filter membrane fixing ring, and a detachable glass window is installed between the window fixing ring and the filter membrane fixing ring.

7. The circulating tumor cell screening and separation device as described in claim 3, characterized in that: The control module includes a piston block movably disposed within the mixing chamber. The outer peripheral surface of the piston block is sealed against the wall of the mixing chamber, thereby dividing the mixing chamber into an upper chamber and a lower chamber. The upper chamber is the portion extending from the top of the mixing chamber to the upper surface of the piston block, and the lower chamber is the portion extending from the lower surface of the piston block to the bottom of the mixing chamber. The top of the upper chamber is closed, and the bottom of the lower chamber communicates with the screening chamber. When the piston block is stationary, the flow path between the upper cavity and the lower cavity is closed; when the piston block moves in a direction that reduces the volume of the upper cavity and increases the volume of the lower cavity, the flow path between the upper cavity and the lower cavity is open.

8. The circulating tumor cell screening and separation device as described in claim 7, characterized in that: The outer wall of the mixing chamber is provided with a first connector and a second connector, which are respectively connected to two different areas of the mixing chamber. The first connector and the second connector are connected through a liquid guide pipe. The movement range of the piston block includes the liquid discharge range. When the piston block is located in the liquid discharge range, the first connector is connected to the upper cavity and the second connector is connected to the lower cavity. When the piston block moves in a direction that reduces the volume of the upper cavity and increases the volume of the lower cavity, the upper cavity and the lower cavity are connected through the liquid guide pipe.

9. The circulating tumor cell screening and separation device as described in claim 7, characterized in that: The piston block has a valve hole, through which the upper cavity and the lower cavity are connected. A first one-way valve is installed in the valve hole. When the piston block is stationary or moves in a direction that increases the volume of the upper cavity and decreases the volume of the lower cavity, the first one-way valve is closed. When the piston block moves in a direction that decreases the volume of the upper cavity and increases the volume of the lower cavity, the first one-way valve is open.

10. The circulating tumor cell screening and separation device as described in claim 9, characterized in that: The mixing chamber is provided with a top cover, which seals the top of the upper cavity. The top cover has an air hole, and a second one-way valve is installed in the air hole. When the piston block moves in a direction that increases the volume of the upper cavity and decreases the volume of the lower cavity, the second one-way valve is in the open state. When the piston block moves in a direction that decreases the volume of the upper cavity and increases the volume of the lower cavity, the second one-way valve is in the closed state.

11. The circulating tumor cell screening and separation device as described in claim 7, characterized in that: The control module also includes a drive rod that passes through the upper cavity and connects to the piston block.

12. The circulating tumor cell screening and separation device as described in claim 11, characterized in that: The control module further includes a drive element connected to the drive rod, and the drive element is configured to drive the piston block to move via the drive rod.

13. The circulating tumor cell screening and separation device as described in claim 2, characterized in that: The temperature control module includes a heating element, a temperature measuring element, and a controller. The heating element and the temperature measuring element are both electrically connected to the controller. The heating element and the temperature measuring element are both installed in the mixing chamber. The temperature measuring element is configured to measure the temperature inside the mixing chamber and feed it back to the controller. The controller is configured to control the heating element to operate based on the temperature signal fed back by the temperature measuring element so that the mixing chamber maintains a set temperature.

14. The circulating tumor cell screening and separation device as described in claim 13, characterized in that: The mixing chamber is provided with a sandwich cavity, which surrounds the outer periphery of the mixing chamber, and the heating element is fixedly disposed within the sandwich cavity.

15. The circulating tumor cell screening and separation device as described in claim 11, characterized in that: The magnetic enrichment module includes an electromagnet, which is configured to generate a magnetic field when energized and remove the magnetic field when de-energized. The electromagnet is installed in the portion of the drive rod located within the upper cavity.

16. The circulating tumor cell screening and separation device as described in claim 15, characterized in that: The drive rod has an internal mounting hole, and the electromagnet is fixedly installed in the mounting hole.

17. The circulating tumor cell screening and separation device as described in claim 1, characterized in that: It also includes an ultrasonic module, which is inserted into the mixing chamber and is configured to generate high-frequency vibrations within the mixing chamber.

18. A method for detecting circulating tumor cells, characterized in that, The steps include the following: S1: Adjust the circulating tumor cell screening and separation device as described in claim 1 to the initial state, ensure that the mixing chamber is clean and dry, and drive the piston block to move to the bottom of the mixing chamber by the driving element; S2: Inject the blood sample and the nanomagnetic probe into the upper cavity of the mixing chamber for reaction culture, and then start the temperature control module to simulate the constant temperature environment of the human body in the mixing chamber. During the reaction culture process, the CTCs in the blood sample and the nanomagnetic probe combine to form CTCs-magnetic bead complex. S3: After the reaction cultivation process reaches the set time, the electromagnet is activated, and the magnetic field generated by the electromagnet captures the CTCs-magnetic bead complex. S4: The driving element drives the piston block to move upward, and the waste liquid in the upper cavity is discharged into the lower cavity. Then the waste liquid enters the waste liquid chamber through the screening chamber. S5: Remove the screening chamber, then install the filter membrane onto the screening chamber to seal the screening chamber, install the screening chamber between the mixing chamber and the waste liquid chamber, and then drive the piston block to move down to the bottom of the mixing chamber; S6: Inject cleaning fluid into the upper cavity, then turn off the electromagnet to remove the magnetic field, start the ultrasonic module to clean the upper cavity, and then drive the piston block to move upward so that the cleaning fluid in the upper cavity is discharged into the lower cavity. The cleaning fluid enters the waste liquid chamber through the screening chamber, and the CTCs-magnetic bead complex in the cleaning fluid is blocked by the filter membrane. S7: Remove the screening chamber again, then install the glass window onto the screening chamber, and then place the screening chamber under a Raman spectrometer for detection.

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