A centrifugal force driven screw-on type lipemic sample separation centrifuge tube and method

Abstract

This invention discloses a centrifugal force-driven threaded spiral centrifuge tube and method for separating lipid and blood samples, belonging to the field of medical testing consumables technology. It includes an outer centrifuge tube, an inner centrifuge tube, and a cap. The open end of the outer centrifuge tube has a first internal thread region on its inner wall. The inner centrifuge tube is coaxially nested within the outer centrifuge tube, with a separation medium at its lower part and a driving slider at its top outer periphery. A collection cavity is formed between the bottom of the inner centrifuge tube and the bottom of the outer centrifuge tube. The cap and the open end of the outer centrifuge tube are sealed and detachably connected by an interference fit or a snap-fit ​​structure. The inner wall of the cap has a third internal thread region connected to the first internal thread region. Centrifugal force drives the driving slider to spirally slide along the first and third internal thread regions, causing the inner centrifuge tube to rotate and axially lift, connecting the inner centrifuge tube and the cap as a single unit. After centrifugation, the cap and the inner centrifuge tube are removed together from the outer centrifuge tube, leaving a clear test solution (with lipids and cell residue removed) at the bottom of the outer centrifuge tube.

Description

Technical Field

[0001] This invention belongs to the field of medical testing consumables technology, specifically relating to a centrifugal force-driven screw-on centrifuge tube and method for separating lipemia samples, which is particularly suitable for pretreatment of lipemia serum before clinical biochemical and immunological tests. Background Technology

[0002] In clinical testing, a large number of chylomicrons in lipemia samples can scatter the detection light path, interfere with the absorbance of biochemical indicators and immune response signals, and cause the test results to be distorted. The existing solution is to delipase blood samples by high-speed centrifugation (10,000-30,000×g). However, conventional processing methods have multiple drawbacks: (1) Ordinary single-chamber centrifuge tubes: After high-speed centrifugation, the upper lipid layer is easily remixed during pipetting and transport. Operators need to accurately aspirate the lower clear liquid, which has a high operational threshold and is prone to aerosol contamination during pipetting; (2) Commercial ultrafiltration centrifuge tubes: The upper limit of centrifugal force they can withstand is only 2,000-2,500×g, which cannot meet the high-speed centrifugation conditions of more than 10,000×g required for lipoprotein delipidemization, resulting in insufficient delipidemization efficiency; (3) Traditional two-stage layered centrifuge tubes: The inner and outer tubes are assembled only by threads or interference fits. The inner and outer tubes need to be manually twisted before and after centrifugation, which is cumbersome and the twisting process is prone to touching the sample and causing contamination. In addition, the inner tube is prone to shifting under different centrifugal forces, and the liquid flow channel is prone to blockage, resulting in a significant decrease in the recovery rate of the clear liquid. Therefore, there is an urgent need for a centrifugation force driven threaded screw-fit lipoprotein sample separation centrifuge tube with a simplified structure, convenient operation, and anti-contamination properties. Summary of the Invention

[0003] Technical problem solved: To address the shortcomings of the prior art, this invention provides a centrifugal force-driven threaded connection centrifuge tube and method for separating lipid blood samples. This centrifuge tube can withstand high-speed centrifugation of 10,000-30,000×g. During centrifugation, fat and clear liquid are automatically separated. After centrifugation, the inner tube (including the fat layer) can be removed by pulling off the cap, and the clear liquid in the outer tube can be directly obtained. This centrifuge tube automatically completes the threaded connection between the inner tube and the cap using centrifugal force, eliminating the need for manual alignment or tightening. Furthermore, various optional gap retention structures are provided between the inner and outer tubes to adapt to stable separation under different centrifugal force conditions.

[0004] Technical solution: The present invention provides a centrifugal force-driven screw-on type lipemia sample separation centrifuge tube, comprising: The centrifuge outer tube has a closed conical bottom at one end and an open structure at the other end; the centrifuge outer tube includes a tube body, and a first internal thread area is formed on the upper end of the inner wall of the open end of the tube body. The centrifuge inner tube is coaxially nested inside the centrifuge outer tube; the lower part of the centrifuge inner tube is provided with a separation medium that allows liquid to pass through but retains lipids and cell debris, and the outer periphery of its top is provided with a drive slider that is threadedly connected to the first internal thread area; a partition structure is provided between the centrifuge inner tube and the centrifuge outer tube to maintain the flow of liquid, and the partition structure maintains the formation of a collection cavity between the bottom of the centrifuge inner tube and the bottom of the centrifuge outer tube; The cap is sealed and detachably connected to the open end of the centrifuge outer tube by an interference fit or a snap-fit ​​structure; the inner wall of the cap is provided with a third internal thread area that connects to the first internal thread area; During the centrifugation acceleration phase, the centrifugal force drives the drive slider to slide spirally along the first internal thread area, thereby driving the centrifuge inner tube to rotate and lift axially. Under the continuous action of the centrifugal force, the drive slider disengages from the first internal thread area and screws into the third internal thread area, connecting the centrifuge inner tube and the cap into one unit. After centrifugation, the cap and the centrifuge inner tube are removed from the centrifuge outer tube. The bottom of the centrifuge outer tube retains the clear test solution after removing lipids and cell residues.

[0005] Preferably, the spacing structure consists of 2-6 support protrusions located on the lower part of the outer wall of the centrifuge inner tube.

[0006] Preferably, the spacing structure is a support rib or a boss located at the bottom of the inner wall of the centrifuge outer tube.

[0007] Preferably, a limiting ring is provided on the inner wall of the tube at the bottom of the first internal thread area. Rotating the centrifugal inner tube drives the driving slider to spiral down along the first internal thread area and support it at the limiting ring, so that the centrifugal inner tube extends into the bottom of the centrifugal outer tube to form a length difference suspended structure.

[0008] Preferably, both the first internal thread area and the third internal thread area are composed of 2-4 spiral grooves; the end of the spiral groove in the first internal thread area and the beginning of the spiral groove in the third internal thread area are respectively provided with open notches for driving the slider to disengage and enter.

[0009] Preferably, the spiral groove has a helix angle of 10°-30°, a groove depth of 1-1.5mm, and a lead of 8-15mm; the number of driving sliders is 2-4 and they are symmetrically arranged circumferentially along the outer wall of the inner tube, and the helix angle along the circumferential direction of the centrifugal inner tube is consistent with that of the spiral groove; the total axial stroke of the driving sliders sliding along the spiral groove is 4-8mm.

[0010] Preferably, the conical bottom cone angle of the centrifuge outer tube is 30°-60°, and its wall thickness is 1.0-1.5mm.

[0011] Preferably, the separation medium is a microporous plate, a sintered porous material, or a composite filter membrane, with a pore size of 0.8-1.2 μm, a porosity of 50%-60%, a thickness of ≤100 μm, and is hydrophilically treated.

[0012] Preferably, the outer wall of the open end of the pipe body is provided with a first external thread area; the inner wall of the lower end of the cap is provided with an installation step, and the inner wall of the installation step is provided with a second internal thread area that is threadedly connected to the first external thread area; a support ring is fixedly fitted on the outer wall of the open end of the pipe body at the lower edge of the first external thread area.

[0013] This invention also discloses a high-speed centrifugation method for separating lipemia samples from the above-mentioned centrifuge tubes, comprising the following steps: Step 1: Insert the centrifuge inner tube into the centrifuge outer tube, and drive the drive slider to slide spirally along the first internal thread area to the starting end by rotating the centrifuge inner tube to complete the pre-installation semi-limit connection; Step 2: Add the lipemia sample into the inner lumen of the centrifuge tube, seal the cap to the open end of the outer centrifuge tube, and align the first internal thread area with the third internal thread area. Step 3: Place the assembled centrifuge tube in a high-speed centrifuge and centrifuge for 20-40 minutes at a centrifugal force of 10,000-30,000 × g. During centrifugation, the drive slider slides spirally along the thread grooves of the first and third internal thread areas, causing the centrifuge inner tube to rotate and rise, so that the centrifuge inner tube is fixedly connected to the cap. Low-density fat, blood cells, and chylomicrons in the lipemia sample are trapped in the centrifuge inner tube by the separation medium, while the clear liquid phase penetrates the separation medium and enters the collection chamber of the centrifuge outer tube. Step 4: After the centrifuge stops, hold the outer tube and separate the cap from the outer tube. Remove the inner tube along with the cap as a whole. Discard the inner tube along with the fat and residue. Collect the clear liquid from the outer tube and perform biochemical and immunological tests.

[0014] Compared with the prior art, the present invention has at least the following beneficial technical effects: 1. The centrifuge tubes of this invention can withstand high-speed centrifuges with a wide range of 10,000 to 30,000 × g, covering the needs of most medical laboratory equipment; they use a special hydrophilic microporous separation medium to efficiently retain chylomicrons, with a lipid removal rate of ≥90% and a clarified liquid recovery rate of ≥85%, meeting the accuracy requirements of clinical testing. 2. The centrifuge tube's inner tube only needs to be driven by high-speed centrifugal force to move the slider along the first and third internal thread areas to complete the rotation and lifting of the inner tube, and automatically screw and lock with the cap. There is no need for manual alignment, manual screwing of the inner and outer tube threads, or liquid transfer and separation steps. Only three steps are required: sample loading, centrifugation, and cap removal. After centrifugation, the cap only needs to be separated from the outer tube to automatically remove the inner tube. All lipids and residues are trapped in the closed cavity formed by the inner tube and the cap. There is no finger contact with the sample area throughout the process, eliminating cross-contamination. 3. The centrifuge tube can adopt a structure without reinforcing ribs, and is integrally molded with a conical bottom. It relies on the conical bottom itself to bear pressure, and the center of the conical bottom collects trace amounts of residual liquid samples, avoiding waste of precious samples; it simplifies the injection mold, reduces the production raw material cost, and is suitable for mass production of disposable consumables; 4. The spacing structure between the inner and outer centrifuge tubes can be flexibly selected according to the target centrifugal force. Three types of replaceable spacing structures can be selected to adapt to low, medium and high centrifugal force conditions, maintain a stable liquid flow gap, prevent blockage of the separation medium, and take into account both reliability and stability. Attached Figure Description

[0015] Figure 1 This is an axial structural cross-sectional view of the centrifuge tube of the present invention (showing the outer centrifuge tube, the inner centrifuge tube, and the cap assembly structure); Figure 2 for Figure 1 A schematic diagram of the assembly structure of the centrifuge outer tube and the centrifuge inner tube (showing the connection state of the centrifuge inner tube and the centrifuge outer tube before liquid injection); Figure 3 for Figure 1 A schematic diagram of the assembly structure of the centrifuge outer tube, centrifuge inner tube, and cap (showing the state of the centrifuge tube after liquid injection and before centrifugation); Figure 4 for Figure 3 A schematic diagram of the assembly structure of the centrifuge outer tube, centrifuge inner tube, and cap (showing the state of the centrifuge tube before sampling after centrifugation); Figure 5 for Figure 4 A schematic diagram of the separation structure of the outer and inner tubes of the centrifuge and the cap (showing the state of the centrifuge tube during sampling); Figure 6 for Figure 1 Enlarged structural diagram of point A in the centrifuge tube.

[0016] Figure descriptions: 100. Centrifuge tube; 1. Outer centrifuge tube; 11. Tube body; 12. Support ring; 13. First external thread area; 14. First internal thread area; 15. Limiting ring; 2. Inner centrifuge tube; 21. Separation medium; 22. Drive slider; 3. Cap; 31. Mounting step; 32. Second internal thread area; 33. Third internal thread area. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following description is provided in conjunction with the appendix. Figures 1-6 The technical solutions of the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0018] like Figures 1-6 As shown, this invention discloses a centrifugal force-driven threaded centrifuge tube for separating lipid blood samples. The centrifuge tube 100 mainly includes an outer centrifuge tube 1, an inner centrifuge tube 2, and a cap 3. One end of the outer centrifuge tube 1 has a closed conical bottom, and the other end has an open structure. The outer centrifuge tube 1 includes a tube body 11, and a first internal thread area 14 is formed on the upper end of the inner wall of the open end of the tube body 11. The inner centrifuge tube 2 is coaxially nested inside the outer centrifuge tube 1. The lower part of the inner centrifuge tube 2 is provided with a separation medium 21 that allows liquid to pass through but retains lipids and cell debris. The outer periphery of its top is provided with a driving slider 22 that is threadedly connected to the first internal thread area 14. A spacer structure is provided between the inner centrifuge tube 2 and the outer centrifuge tube 1 to maintain liquid flow, and the spacer structure maintains a collection cavity of 2-10 mm between the bottom of the inner centrifuge tube 2 and the bottom of the outer centrifuge tube 1. The cap 3 and the open end of the centrifuge tube 1 are sealed and detachably connected by an interference fit or snap-fit ​​structure. The inner wall of the cap 3 is provided with a third internal thread area 33 that connects to the first internal thread area 14. Under the centrifugal force, the driving slider 22 can smoothly enter and rotate and slide along the third internal thread area 33 after spiraling away from the first internal thread area 14. During the centrifugation acceleration stage, the centrifugal force drives the driving slider 22 to spirally slide along the first internal thread area 14, thereby driving the centrifuge tube 2 to rotate and lift axially. Under the continuous action of the centrifugal force, the driving slider 22 is disengaged from the first internal thread area 14 and screwed into the third internal thread area 33, connecting the centrifuge tube 2 and the cap 3 into one unit. After centrifugation, it is only necessary to separate the cap 3 from the centrifuge tube 1 to remove the cap 3 together with the centrifuge tube 2 from the centrifuge tube 1. The bottom of the centrifuge tube 1 retains the clear test solution after removing lipids and cell residues. The separation of the centrifuge tube and the centrifuge tube is carried out without any finger contact with the sample area, thus preventing cross-contamination.

[0019] The spacer structure between the inner and outer centrifuge tubes is designed to improve the structural stability of the inner centrifuge tube during centrifugation. In a preferred embodiment, the spacer structure consists of 2-6 support protrusions (not shown in the figure) located on the lower part of the outer wall of the inner centrifuge tube 2. These support protrusions provide stable support to the inner wall of the outer centrifuge tube 1 during centrifugation. In another preferred embodiment, the spacer structure consists of support ribs or protrusions located at the bottom of the inner wall of the outer centrifuge tube 1. The lower end of the inner centrifuge tube 2 can be supported on these support ribs or protrusions to provide stable support. This spacer structure between the inner and outer centrifuge tubes allows for flexible selection of three replaceable spacer structures based on the target centrifugal force, adapting to low, medium, and high centrifugal force conditions. It maintains a stable liquid flow gap between the inner and outer centrifuge tubes, preventing blockage of the separation medium and balancing reliability and stability.

[0020] In a preferred embodiment, a limiting ring 15 is also provided on the inner wall of the tube body 11 at the bottom of the first internal thread area 14. When the centrifugal inner tube 2 and the centrifugal outer tube 1 are pre-assembled, the centrifugal inner tube 2 is rotated to drive the driving slider 22 to spiral down along the first internal thread area 14 until it is supported at the limiting ring 15. The limiting ring 15 restricts the length of the centrifugal inner tube 2 extending into the centrifugal outer tube 1, thereby forming a length difference suspension structure between the bottom of the centrifugal inner tube 2 and the bottom of the centrifugal outer tube 1, that is, a collection cavity for collecting the clarified liquid is formed at the bottom of the centrifugal outer tube 1.

[0021] In a preferred embodiment, both the first internal thread area 14 and the third internal thread area 33 are composed of 2-4 spiral grooves. The ends of the spiral grooves of the first internal thread area 14 and the beginnings of the spiral grooves of the third internal thread area 33 are respectively provided with open notches for the drive slider to disengage and enter. The open notches are fitted with the cap 3 and the centrifugal outer tube 1 by an interference fit or a snap-fit ​​structure, so that the first internal thread area 14 and the third internal thread area 33 can be accurately connected. The open notches allow for a certain assembly error between the cap 3 and the centrifugal outer tube 1 without affecting the connection between the first internal thread area 14 and the third internal thread area 33.

[0022] In a preferred embodiment, the helix angle of the spiral groove is 10°-30°, the groove depth is 1-1.5mm, and the lead is 8-15mm. The number of drive sliders is 2-4, symmetrically arranged circumferentially along the outer wall of the inner tube, and the helix angle along the circumference of the centrifugal inner tube is consistent with the spiral groove. The total axial stroke of the drive slider 22 sliding along the spiral groove is 4-8mm. It should be noted that the 2-4 drive sliders 22 essentially form a spiral toothed ring adapted to the spiral groove. Increasing the number of drive sliders 22 can form a multi-stage spiral toothed ring adapted to the spiral groove. However, to reduce the frictional resistance between the drive slider 22 and the spiral groove of the first internal thread area 14 and the third internal thread area 33, a single spiral toothed ring is sufficient to achieve the function of rotating and lifting the centrifugal inner tube. In addition, to further reduce rotational friction resistance, both the first internal thread area 14 and the third internal thread area 33 can be made of metal bushings with internal thread teeth. The metal bushings can be fixedly connected to the centrifuge outer tube and the cap in a nested manner. Correspondingly, the drive slider 22 also adopts a metal structure, thereby reducing the centrifugal force required to lift the centrifuge inner tube.

[0023] In a preferred embodiment, the conical bottom of the centrifuge outer tube 1 has a cone angle of 30°-60° and a wall thickness of 1.0-1.5 mm; the bottom shape of the centrifuge inner tube 2 can be the same as the bottom shape of the centrifuge outer tube 1, and its thickness can be the same as that of the centrifuge outer tube 1. The centrifuge tube body can adopt a structure without reinforcing ribs, and the conical bottom is integrally molded, relying on the conical bottom itself to bear pressure. The center of the conical bottom collects trace amounts of residual liquid samples, avoiding waste of precious samples; it simplifies the injection mold, reduces the cost of raw materials, and is suitable for mass production of disposable consumables.

[0024] In a preferred embodiment, the separation medium 21 can be a microporous plate, sintered porous material, or composite filter membrane, with a pore size of 0.8-1.2 μm, a porosity of 50%-60%, a thickness ≤100 μm, and undergo hydrophilic treatment. This application uses a dedicated hydrophilic microporous separation medium to efficiently retain chylomicrons, achieving a lipid removal rate ≥90% and a clarified liquid recovery rate ≥85%, meeting the accuracy requirements of clinical testing.

[0025] In a preferred embodiment, such as Figures 1-6 As shown, the cap 3 and the open end of the centrifuge tube 1 are sealed and detachably connected by an interference fit. Specifically, the outer wall of the open end of the tube body 11 is provided with a first external thread area 13, and a support ring 12 is fixedly fitted on the lower edge of the first external thread area 13 on the outer wall of the open end of the tube body 11. The lower inner wall of the cap 3 is provided with an installation step 31, and the inner wall of the installation step 31 is provided with a second internal thread area 32 that is threadedly connected to the first external thread area 13. When the cap 3 and the centrifuge tube 1 are assembled, the first external thread area 13 and the second internal thread area 32 are fully engaged, and the top end of the centrifuge tube 1 is supported on the inner end face of the installation step 31, and the lower end face of the cap 3 is supported on the support ring 12. The installation position of the support ring 12 and the engagement length of the first external thread area 13 and the second internal thread area 32 are set according to the requirements. After the assembly is completed, the requirement that the end of the spiral groove of the first internal thread area 14 and the beginning end of the spiral groove of the third internal thread area 33 be connected through an open notch is met. It should be noted that when the cap 3 and the open end of the centrifugal outer tube 1 are connected by a snap-fit ​​structure to achieve a sealed and detachable connection, the snap-fit ​​structure also satisfies the requirement that the end of the spiral groove of the first internal thread area 14 and the beginning of the spiral groove of the third internal thread area 33 be connected through an open notch.

[0026] This invention also discloses a high-speed centrifugation method for separating lipemia samples from the above-mentioned centrifuge tubes, the separation method comprising the following specific steps: (a) Insert the inner centrifuge tube 2 into the outer centrifuge tube 1, and rotate the inner centrifuge tube 2 to drive the drive slider 22 to slide spirally along the first internal thread area 14 to the starting end, completing the pre-installed semi-limited connection (e.g., ...). Figure 2 (As shown). A lipemia sample is added to the inner cavity of the centrifuge inner tube 2. The cap 3 is then sealed to the open end of the centrifuge outer tube 1, ensuring that the first internal thread area 14 aligns with the third internal thread area 33. At this time, the drive slider 22 is connected to the first internal thread area 14, and the centrifuge inner tube 2 and cap 3 are separated (as shown). Figure 3 (As shown).

[0027] (II) Place the assembled centrifuge tube in a high-speed centrifuge and centrifuge for 20-40 minutes under a centrifugal force of 10000-30000×g. During centrifugation, the drive slider 22 engages with the thread grooves of the first internal thread area 14 and the third internal thread area 33. As the centrifugal force drives the drive slider 22 to rotate and slide along the first internal thread area 14 and the third internal thread area 33, the inclined surface of the spiral groove converts the radial force into an axial component force, pushing the drive slider to slide upward along the spiral groove. At the same time, the inclined surface of the spiral groove converts the axial force into a rotational torque, causing the centrifuge inner tube to continue to rotate, thereby driving the centrifuge inner tube 2 to rotate and rise until the drive slider 22 rotates and engages with the third internal thread area 33. After several turns of engagement, the centrifuge inner tube 2 is fixedly connected to the cap 3. Meanwhile, the lipid layer (low density) in the lipemia sample accumulates at the top of the centrifuge inner tube; the clarified liquid passes through the separation medium 21 at the bottom of the centrifuge inner tube and enters the collection chamber of the centrifuge outer tube (the gap between the inner and outer tubes and the conical bottom of the outer tube); blood cells and debris are trapped at the bottom of the centrifuge inner tube; the spacer structure between the inner and outer tubes ensures that there is always a sufficient gap between the bottom of the inner and outer tubes to maintain smooth liquid flow.

[0028] (III) After the centrifuge is stopped, the operator holds the outer centrifuge tube 1 and separates the cap 3 from the outer centrifuge tube 1 (by unscrewing or pulling it out). Since the inner centrifuge tube 2 is threadedly connected to the cap 3, the inner centrifuge tube 2 will be removed along with the cap 3 as a whole. The inner centrifuge tube 2, along with the fat and residue, and the cap, will be discarded or further processed as a whole. The clear liquid collected and stored in the conical bottom of the outer centrifuge tube 1 can be poured directly or aspirated through the conical bottom for subsequent biochemical and immunological testing.

[0029] The centrifuge tubes and high-speed centrifugation separation method of the present invention will be further described below with reference to specific embodiments.

[0030] Example 1: In this example, the spacer structure adopts a support protrusion spacer structure, which is suitable for ultra-high centrifugal (15000-30000×g) working conditions.

[0031] (1) Specific structural parameters of centrifuge tube: The outer centrifuge tube 1 is made of PC material, with an outer diameter of 16mm, a total height of 60mm, a wall thickness of 1.2mm, and a cone bottom cone angle of 45°; the inner wall of the open end of the outer centrifuge tube is inlaid with a spiral bushing made of 316L stainless steel as the first internal thread area. The inner wall of the spiral bushing has 2-4 spiral grooves with a spiral groove helix angle of 15°, a groove depth of 1.2mm, and a lead of 10.1mm. The first internal thread area and the third internal thread area have the same spiral bushing, and the width of the open notch corresponding to the spiral bushing is 2mm. The centrifuge inner tube 2 is made of PC material, with an upper outer diameter of 12mm, a lower outer diameter of 11.5mm, and a height of 50mm. The bottom of the inner tube 2 is embedded with laser-drilled PI microporous separation medium 21, with a pore size of 1.0μm, a porosity of 55%, and a thickness of 80μm, modified by plasma hydrophilic treatment. Two drive sliders 22, each 3mm × 3mm in size, are symmetrically arranged on the upper part of the outer wall of the inner tube 2, with a 0.4mm radius at the root. Four support protrusions, each 1mm in diameter and 1.5mm high, are evenly spaced circumferentially on the lower part of the outer wall of the inner tube 2. The cap 3 is made of PC material, with an M10 × 1.5 internal thread in the second internal thread area 32, 6mm in length. The cap has an inner diameter of 15.8mm, forming a 0.2mm interference seal with the 16mm outer diameter of the centrifuge outer tube via a threaded connection structure. The outer wall of the cap 3 can be textured with anti-slip patterns.

[0032] (2) Experimental conditions: Lipid sample: 5 mL human lipid serum, triglycerides > 5 mmol / L; centrifugation parameters: 15000 × g, centrifugation at room temperature for 25 min.

[0033] (3) Experimental results: During the centrifugation acceleration stage, the inner tube of the centrifuge rotated and rose automatically, and did not loosen after being fully screwed into the cap thread; after the cap separated from the outer tube of the centrifuge, the inner tube of the centrifuge completely carried out the fat layer and cell residue; 4.3 mL of clear liquid was collected from the outer tube of the centrifuge, the triglyceride removal rate was 91%, and the clear liquid recovery rate was 86%; the inner tube of the centrifuge did not tilt during the centrifugation process, and the separation medium did not stick to the bottom and cause blockage.

[0034] Example 2: In this example, the inner and outer tubes of the centrifuge tube adopt a length difference suspension structure, which is suitable for ultra-high centrifugation (10000-15000×g) conditions.

[0035] (1) Specific structural parameters of the centrifuge tube: The parameters of the outer centrifuge tube 1 are the same as in Example 1. The total height of the inner centrifuge tube 2 is 55m. There is no supporting protrusion structure on the lower outer periphery of the inner centrifuge tube 2. The outer wall of the inner centrifuge tube 2 is provided with 2-3 rings of driving teeth along the tube body axis. Each ring of driving teeth is surrounded by 3 driving sliders 22 symmetrically arranged from the circumference of the tube body towards the center to increase the contact area between the inner centrifuge tube and the outer centrifuge tube, thereby improving the stability of the inner centrifuge tube in the centrifugation separation process. In this example, the bottom of the inner centrifuge tube is initially in a suspended state. As the inner centrifuge tube rotates and rises during the centrifugation process, the capacity of the collection chamber at the bottom of the outer centrifuge tube is further increased. Other parameters are the same as in Example 1. The parameters of the cap are the same as in Example 1.

[0036] (2) Experimental conditions: Lipid sample: 5 mL human lipemia serum, triglycerides > 5 mmol / L; centrifugation parameters: 10000 × g, centrifugation at room temperature for 35 min.

[0037] (3) Experimental results: During the centrifugation acceleration stage, the inner tube of the centrifuge slid smoothly without jamming and was fully screwed into the cap thread for reliable locking; the bottom of the inner tube of the centrifuge was naturally suspended and formed a flow gap with the inner wall of the outer tube of the centrifuge, and the liquid flowed smoothly; 4.1 mL of clear liquid was collected in the outer tube of the centrifuge, the triglyceride removal rate was 88%, and the clear liquid recovery rate was 82%, which is suitable for batch processing of mild lipemia samples.

[0038] Example 3: In this example, the spacer structure adopts a support rib spacer structure set at the bottom of the centrifuge outer tube, which is suitable for ultra-high centrifugation (30000×g) conditions.

[0039] (1) Specific structural parameters of the centrifuge tube: Three radial support ribs are arranged on the inner wall of the conical bottom of the outer centrifuge tube 1. The ribs are 2mm high and 1.5mm wide. The other parameters of the outer tube are the same as in Example 1. The total height of the inner centrifuge tube 2 is 50mm. The bottom of the inner centrifuge tube 2 is flat, and no support protrusion structure is provided on the outer periphery of the bottom of the inner centrifuge tube 2. Other parameters are the same as in Example 1. The parameters of the cap are the same as in Example 1.

[0040] (2) Experimental conditions: Lipid sample: 5 mL human lipid serum, triglycerides > 5 mmol / L; centrifugation parameters: 30000 × g, centrifugation at room temperature for 20 min.

[0041] (3) Experimental results: The bottom of the centrifuge inner tube is stably supported on the support ribs at the bottom of the centrifuge outer tube. The coaxiality between the centrifuge inner tube and the centrifuge outer tube is excellent. The centrifuge inner tube will not be radially offset under ultra-high centrifugation. The separation medium does not stick to the bottom throughout the process, and the separation effect is stable. The recovery rate of the clarified liquid is 89%, and the lipid retention effect is optimal, which is suitable for the emergency scenario of rapid lipid removal in severe lipemia.

[0042] The core inventive aspect of this invention lies in achieving automatic lifting of the inner and outer centrifuge tubes during high-speed centrifugation and integral connection with the cap. This application employs a threaded connection structure, based on centrifugal force, to convert radial action into axial driving force for the inner centrifuge tube, which is further converted into a helical driving force for driving the slider along the first and third internal thread areas, thereby achieving axial lifting of the inner centrifuge tube along the outer centrifuge tube. The helical driving mechanical principle and strength verification process are as follows: 1. The structure of the centrifuge tube: The spiral groove is set on the inner wall of the open end of the outer centrifuge tube 1 and has a constant spiral angle (α); the driving slider is set on the upper part of the outer wall of the inner centrifuge tube and embedded in the spiral groove, and can rotate and slide along the groove; the driving slider and the spiral groove form a sliding spiral pair, which converts linear motion and rotational motion into each other.

[0043] 2. Screw pair force drive conversion logic: (1) Centrifugal force (F) r When the centrifuge rotates at high speed, the inner tube and the blood lipid sample are subjected to centrifugal force in a radial outward direction. Since there is only a small radial gap between the inner tube and the outer tube, the upper part of the inner tube engages with the spiral groove of the first internal thread area through the drive slider, so that the drive slider generates positive pressure on the inclined surface of the spiral groove.

[0044] (2) Inclined centrifugal force component: The inclined surface of the spiral groove decomposes the radial centrifugal force into an axial component (F). axial This, in turn, pushes the drive slider to slide upward along the spiral groove.

[0045] (3) Rotational motion: When the drive slider moves along the spiral groove, it is forced to rotate around the axis due to the geometric constraints of the spiral groove, thereby driving the entire centrifuge inner tube to rotate and rise.

[0046] 3. Motion transformation relationship and force analysis: (1) Let the helix angle α of the spiral groove (the angle between the tangent of the spiral groove and the horizontal plane), the sliding distance L of the driving slider (the length along the spiral groove), the axial rising height H of the centrifugal inner tube, and the rotation angle θ (radians) of the centrifugal inner tube. Geometric relationship: H=L×sinα; θ=L×cosα / R; where R is the radius of the cylindrical surface where the spiral groove is located (approximately equal to the radius of the centrifugal inner tube and half the groove depth). A smaller α can obtain a larger axial thrust, but a smaller rotation angle; a larger α has the opposite effect; the helix angle α of the spiral groove in this application is 15°-20°, which takes into account both thrust and rotation requirements.

[0047] (2) Centrifugal force formula: Fr = m × ω² × r; Taking 15,000 × g as an example: the mass of the centrifuge inner tube and the sample mass ≈ 8 g = 0.008 kg, the radius of rotation is taken as 0.1 m, ω = rad / s, F r=0.008×(1212)²×0.1≈1175N (approximately 120kg). Under the conditions of α=20° and friction coefficient μ=0.35, the net axial force is approximately 14.5N (approximately 1.5kg), which is sufficient to overcome the self-weight of the centrifuge inner tube (approximately 0.03kg) and frictional resistance, driving the centrifuge inner tube to rise.

[0048] 4. Key parameter selection for centrifuge tubes: The helix angle α of the spiral grooves corresponding to the first and third inner spiral zones of the centrifuge outer tube and cap should be 15°-20°. Too low a helix angle will make it difficult to drive, while too high an angle will shorten the rotation stroke (the range of helix angle can be appropriately widened to 10°-30°). The coefficient of friction μ should be ≤0.35. Self-lubricating materials, surface coatings, or metal materials should be selected. For example, the coefficient of friction μ of polytetrafluoroethylene (PTFE) is 0.04-0.1, that of ultra-high molecular weight polyethylene (UHMWPE) is 0.07-0.3, and that of polyoxymethylene (POM, acetal) is 0.1-0.3. Similarly, the coefficient of friction between cast iron and steel under lubrication conditions can be as low as 0.05-0.15, and that between steel and bronze / brass under lubrication conditions can be as low as 0.03-0.19. The spiral groove depth should be 1.0-1.5mm. A spiral groove depth that is too shallow will easily cause the tube to come off, while a depth that is too deep will increase friction. The number of drive sliders is 2-4 (one toothed ring), symmetrically distributed to achieve uniform axial circumferential force distribution. The thread lead is 1.5-2.0mm, matching the stroke of the spiral groove to ensure complete screwing in; the radial clearance between the inner and outer centrifuge tubes is 0.2-0.4mm, the smaller the clearance, the more direct the centrifugal force transmission between the drive sliders and the spiral grooves. In summary, the outer centrifuge tube, inner centrifuge tube, and cap are preferably made of PC (polycarbonate); the separation medium is preferably polyimide (PI) or PEEK; the inner wall of the outer centrifuge tube containing the spiral groove and the cap can be made of 316L stainless steel inserts or titanium alloy inserts, which are injection molded through inserts. The coefficient of friction between the drive slider (PC / PEEK) and the stainless steel spiral groove can be reduced by polishing the spiral groove surface to Ra≤0.35μm, adding lubricants (such as PTFE coating), or using self-lubricating plastics (such as POM). Because the stainless steel spiral groove has high contact stress when subjected to the maximum positive pressure N≈1100N, multiple drive sliders (such as 2-4) are used to share the load, and the drive slider material is selected from high-strength plastics such as PEEK; since the centrifuge tube is a disposable consumable, there is no need for a long life design, and the sliding friction scheme is sufficient to meet the requirements.

[0049] The above are preferred embodiments of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A centrifugal force-driven threaded screw-on centrifuge tube for separating lipid and blood samples, characterized in that, include: Centrifuge outer tube (1), one end of the centrifuge outer tube (1) is a closed conical bottom and the other end is an open structure; the centrifuge outer tube (1) includes a tube body (11), and the upper end of the inner wall of the open end of the tube body (11) is provided with a first internal thread area (14). Centrifuge inner tube (2), which is coaxially nested inside centrifuge outer tube (1); the lower part of the centrifuge inner tube (2) is provided with a separation medium (21) that allows liquid to pass through but traps lipids and cell debris, and the top outer periphery is provided with a drive slider (22) that is threadedly connected to the first internal thread area (14); a spacer structure is provided between the centrifuge inner tube (2) and the centrifuge outer tube (1) to maintain liquid flow, and the spacer structure maintains the formation of a collection cavity between the bottom of the centrifuge inner tube (2) and the bottom of the centrifuge outer tube (1); The cap (3) is sealed and detachable by means of an interference fit or a snap-fit ​​structure with the open end of the centrifugal outer tube (1); the inner wall of the cap (3) is provided with a third internal thread area (33) that is connected to the first internal thread area (14). During the centrifugation acceleration phase, the centrifugal force drives the drive slider (8) to slide spirally along the first internal thread area (14), thereby driving the centrifugal inner tube (2) to rotate and lift axially. Under the continuous action of the centrifugal force, the drive slider (8) is disengaged from the first internal thread area (14) and screwed into the third internal thread area (33), connecting the centrifugal inner tube (2) and the cap (3) into one unit. After centrifugation, the cap (3) and the centrifugal inner tube (2) are removed from the centrifugal outer tube (1), and the bottom of the centrifugal outer tube (1) retains the clear test solution after removing lipids and cell residues.

2. The centrifugal force-driven threaded screw-on lipoprotein sample separation centrifuge tube according to claim 1, characterized in that, The spacer structure consists of 2-6 support protrusions located on the lower part of the outer wall of the centrifugal inner tube (2).

3. The centrifugal force-driven threaded screw-on lipoprotein sample separation centrifuge tube according to claim 1, characterized in that, The spacer structure is a support rib or protrusion set at the bottom of the inner wall of the centrifugal outer tube (1).

4. The centrifugal force-driven threaded screw-on lipoprotein sample separation centrifuge tube according to claim 1, characterized in that, The inner wall of the tube (11) is provided with a limit ring (15) at the bottom of the first internal thread area (14). Rotating the centrifugal inner tube (2) drives the driving slider (22) to spiral down along the first internal thread area (14) and support it at the limit ring (15), so that the centrifugal inner tube (2) extends into the bottom of the centrifugal outer tube (1) to form a length difference suspended structure.

5. The centrifugal force-driven threaded screw-on lipoprotein sample separation centrifuge tube according to claim 1, characterized in that, The first internal thread area (14) and the third internal thread area (33) are both composed of 2-4 spiral grooves; the end of the spiral groove of the first internal thread area (14) and the beginning of the spiral groove of the third internal thread area (33) are respectively provided with open notches for driving the slider to disengage and enter.

6. The centrifugal force-driven threaded screw-on lipoprotein sample separation centrifuge tube according to claim 5, characterized in that, The spiral groove has a helix angle of 10°-30°, a groove depth of 1-1.5mm, and a lead of 8-15mm; the number of driving sliders is 2-4 and they are symmetrically arranged along the outer wall of the inner tube, and the helix angle along the circumference of the centrifugal inner tube is consistent with the spiral groove. The total axial stroke of the driving slider (22) sliding along the spiral groove is 4-8mm.

7. The centrifugal force-driven threaded screw-on lipoprotein sample separation centrifuge tube according to claim 1, characterized in that, The conical bottom cone angle of the centrifuge outer tube (1) is 30°-60°, and its wall thickness is 1.0-1.5mm.

8. The centrifugal force-driven threaded screw-on lipoprotein sample separation centrifuge tube according to claim 1, characterized in that, The separation medium (21) is a microporous plate, sintered porous material or composite filter membrane with a pore size of 0.8-1.2μm, a porosity of 50%-60% and a thickness of ≤100μm, and is hydrophilically treated.

9. The centrifugal force-driven threaded screw-on lipoprotein sample separation centrifuge tube according to claim 1, characterized in that, The outer wall of the open end of the tube body (11) is provided with a first external thread area (13); the inner wall of the lower end of the cap (3) is provided with an installation step (31), and the inner wall of the installation step (31) is provided with a second internal thread area (32) that is threadedly connected to the first external thread area (13); a support ring (12) is fixedly fitted on the outer wall of the open end of the tube body (11) at the lower edge of the first external thread area (13).

10. A method for high-speed centrifugation separation of lipemia samples based on any one of the centrifuge tubes described in claims 1-9, characterized in that, Includes the following steps: Step 1: Insert the centrifuge inner tube (2) into the centrifuge outer tube (1), and drive the drive slider (8) to slide spirally along the first internal thread area (14) to the starting end by rotating the centrifuge inner tube (2), thus completing the pre-installation semi-limited connection; Step 2: Add the lipemia sample into the inner cavity of the centrifuge inner tube (2), seal the cap (3) to the open end of the centrifuge outer tube (1), and make the first internal thread area (14) and the third internal thread area (33) align. Step 3: Place the assembled centrifuge tube in a high-speed centrifuge and centrifuge for 20-40 minutes at a centrifugal force of 10000-30000×g. During centrifugation, the drive slider (22) slides spirally along the thread grooves of the first internal thread area (14) and the third internal thread area (33), causing the centrifuge inner tube (2) to rotate and rise, so that the centrifuge inner tube (2) is fixedly connected to the cap (3). Low-density fat, blood cells, and chylomicrons in the lipemia sample are retained in the centrifuge inner tube (2) by the separation medium, and the clear liquid phase penetrates the separation medium (21) and enters the collection chamber of the centrifuge outer tube (1). Step 4: After the centrifuge stops, hold the outer tube (1) and separate the cap (3) from the outer tube (1). The inner tube (2) is removed along with the cap (3). The inner tube (2) along with the fat and residue is discarded. The clear liquid in the outer tube (1) is collected and subjected to biochemical and immunological tests.

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