Plasma sampling device

Abstract

The utility model provides a plasma sampling device, which belongs to the technical field of medical instruments and comprises a sampling barrel and a connecting sleeve. A plurality of liquid inlets which are transversely distributed are circumferentially formed in the bottom of the sampling barrel, a push-pull rod is longitudinally arranged in an inner cavity of the sampling barrel, a piston plate is arranged at the lower end of the push-pull rod, the piston plate is axially and slidably sealed along the inner cavity of the sampling barrel, and an operation part is arranged at the upper end of the push-pull rod; the sampling barrel is sleeved with the connecting sleeve, a plurality of elastic pull rods are arranged in the circumferential direction of the connecting sleeve, and a clamping plate is arranged at the tail end of each elastic pull rod and clamped to the outer edge of the upper end opening of the separating barrel. According to the plasma sampling device provided by the utility model, the sampling barrel can be stably fixed in the middle of the upper part of the separating barrel, so that the sampling barrel can be prevented from shaking in the sampling process. The plasma is horizontally sucked into the sampling barrel through the plurality of liquid inlets which are transversely arranged, so that rising liquid flow can be prevented from carrying blood components on the lower layer, and the real characteristics of the plasma can be accurately reflected.

Description

Technical Field

[0001] This utility model belongs to the field of medical device technology, and more specifically, relates to a plasma sampling device. Background Technology

[0002] In modern medicine and many fields of biological science research, the separation and precise sampling of plasma are crucial fundamental steps. As an important component of blood, plasma contains a wealth of biomarkers, proteins, hormones, and other components with key research and diagnostic value.

[0003] Typically, a separation cylinder is used to separate plasma from other blood components such as blood cells. The separation principle is based on the density differences between the components. When a blood sample is placed in the separation cylinder and undergoes a specific centrifugation process, plasma, due to its relatively low density, gradually rises to the upper layer of the cylinder, while heavier components such as blood cells sink to the lower layer, thus achieving a preliminary stratification effect and facilitating subsequent plasma collection.

[0004] In actual plasma sampling, the sampling tube draws plasma from the upper layer of the separation cylinder. Due to the insertion of the sampling tube and the pressure changes within the tube during extraction, an upward surge of plasma is formed at the lower end of the tube. The velocity and force of this surge can, in some cases, disrupt the previously stable stratification interface, allowing lower blood components to be entrained into the rising flow and subsequently drawn into the tube. Furthermore, when the sampling tube is manually held, hand tremors and shaking are unavoidable, causing momentary changes in the vertical depth of the sampling tube. If the depth is not accurately controlled, the lower end of the sampling tube may accidentally penetrate into the lower blood layer, resulting in the unintended aspiration of the lower fluid into the tube. All these factors combined inevitably lead to the collection of plasma samples containing unwanted impurities such as blood cells, resulting in biased sampling results that fail to accurately reflect the true characteristics of the plasma. This significantly impacts the accuracy of subsequent medical diagnoses based on plasma samples and the reliability of research data. Utility Model Content

[0005] The purpose of this invention is to provide a plasma sampling device that addresses the problem that plasma samples are easily contaminated with unwanted blood cells and other impurities during sampling, leading to deviations in sampling results and an inability to accurately reflect the true characteristics of the plasma.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is: to provide a plasma sampling device, comprising:

[0007] A sampling cylinder has multiple horizontally arranged liquid inlets on its bottom circumferentially. A push-pull rod is longitudinally arranged in the inner cavity of the sampling cylinder. A piston plate is provided at the lower end of the push-pull rod. The piston plate slides and seals along the inner cavity of the sampling cylinder. The upper end of the push-pull rod extends out of the inner cavity of the sampling cylinder and is provided with an operating part.

[0008] A connecting sleeve is fitted over the outside of the sampling cylinder. The connecting sleeve is provided with multiple elastic pull rods in the circumferential direction. The ends of the elastic pull rods are provided with clamping plates. The multiple elastic pull rods are stretched outward along the axial direction and clamped onto the outer edge of the upper port of the separation cylinder by means of the clamping plates.

[0009] In one possible implementation, the elastic rod includes:

[0010] An outer sleeve, one end of which is connected to the outer wall of the connecting sleeve;

[0011] A telescopic rod, one inner end of which passes through the outer end of the outer sleeve, and a retaining plate is disposed at the outer end of the telescopic rod;

[0012] A compression spring is disposed in the inner cavity of the outer sleeve and fitted onto the telescopic rod. The compression spring is used to provide a restoring force for the telescopic rod to move inward.

[0013] In one possible implementation, the outer periphery of the connecting sleeve is provided with a plurality of threaded holes, and one end of the inner side of the outer sleeve is threaded into the threaded holes.

[0014] In one possible implementation, an end cap is detachably installed on one outer end of the outer sleeve, and a retaining ring is provided on one inner end of the telescopic rod through the end cap. The two ends of the compression spring abut against the end cap and the retaining ring, respectively.

[0015] In one possible implementation, a first threaded rod is provided at one outer end of the telescopic rod, the outer diameter of the first threaded rod being smaller than the outer diameter of the telescopic rod, the clamping plate is fitted onto the first threaded rod, and a first nut for pressing the clamping plate is threaded to one outer end of the first threaded rod.

[0016] In one possible implementation, a baffle is threaded onto the upper end of the sampling cylinder, a through hole is provided in the middle of the baffle, the push-pull rod extends longitudinally through the through hole, and the operating part is located above the baffle.

[0017] In one possible implementation, the upper end face of the baffle is provided with a plurality of radial ribs in the circumferential direction.

[0018] In one possible implementation, a reinforcing plate is provided circumferentially on the upper end of the outer wall of the sampling tube.

[0019] In one possible implementation, the lower end of the push-pull rod is provided with a second threaded rod, the outer diameter of the second threaded rod being smaller than the outer diameter of the push-pull rod, the piston plate being fitted onto the second threaded rod, and the lower end of the second threaded rod being threadedly connected with a second nut for pressing the piston plate.

[0020] In one possible implementation, the bottom of the sampling tube is provided with a conical end, and the plurality of liquid inlets are arranged in at least two sets from top to bottom in an alternating manner, with the plurality of liquid inlets in the same set being circumferentially opened on the outer periphery of the conical end.

[0021] The beneficial effects of the plasma sampling device provided by this utility model are as follows: Compared with the prior art, the sampling tube is placed in the upper middle part of the separation tube, and multiple elastic levers are pulled outwards to extend the locking plates at the ends of the levers to the outer side of the separation tube sidewall. Releasing the levers causes them to retract and engage the locking plates with the outer circumferential side of the upper port of the separation tube, thus stably fixing the sampling tube in the upper middle part of the separation tube. At this time, the bottom of the sampling tube is inserted into the upper layer of plasma liquid inside the separation tube. Holding the upper part of the sampling tube with one hand and the operating part with the other hand, pulling upwards causes the piston plate to move upwards within the inner cavity of the sampling tube, creating a negative pressure in the lower chamber of the piston plate. Plasma liquid enters the lower part of the sampling tube chamber through multiple inlets. The plasma sampling device provided by this utility model can stably fix the sampling tube in the upper middle part of the separation tube, preventing shaking during sampling. Plasma is horizontally drawn into the sampling tube through multiple horizontally arranged inlets. This avoids the rising liquid flow carrying away lower blood components, which would otherwise contaminate the sampling tube with unwanted blood cells and other impurities, thus accurately reflecting the true characteristics of the plasma. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 Top view of the plasma sampling device provided by this utility model;

[0024] Figure 2 for Figure 1 Sectional view along the middle AA;

[0025] Figure 3 for Figure 2 A magnified view of a section at point B in the middle;

[0026] Figure 4 for Figure 2 A magnified view of a section at point C;

[0027] Figure 5 for Figure 2 A magnified view of a section at point D;

[0028] Figure 6 A top view of the baffle provided by this utility model;

[0029] Figure 7 A top view of the plasma sampling device provided by this utility model in its working state;

[0030] Figure 8 This is a front view of the plasma sampling device provided by this utility model in its working state.

[0031] In the diagram: 1. Sampling cylinder; 2. Push-pull rod; 3. Piston plate; 4. Operating part; 5. Baffle; 6. Radial rib; 7. Reinforcing plate; 8. Conical end; 9. Liquid inlet; 10. Connecting sleeve; 11. Outer sleeve; 12. Telescopic rod; 13. Compression spring; 14. End cap; 15. Retaining ring; 16. First threaded rod; 17. First nut; 18. Second threaded rod; 19. Second nut; 20. Clamping plate; 21. Buffer pad. Detailed Implementation

[0032] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0033] Unless otherwise explicitly specified, the use of terms such as "first," "second," or "third" is intended to distinguish different objects, not to describe a specific order.

[0034] Unless otherwise expressly defined, the use of directional terms such as “center,” “lateral,” “longitudinal,” “horizontal,” “vertical,” “top,” “bottom,” “inner,” “outer,” “upper,” “lower,” “front,” “back,” “left,” “right,” “clockwise,” “counterclockwise,” “high,” and “low” to indicate orientation or positional relationships is based on the orientation and positional relationships shown in the accompanying drawings and is only for the convenience of describing the present invention and simplifying the description. It is not intended to indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the specific protection scope of the present invention.

[0035] Please see Figure 1 , Figure 2 , Figure 7 and Figure 8 The plasma sampling device provided by this utility model will now be described. The plasma sampling device includes a sampling cylinder 1 and a connecting sleeve 10. The bottom of the sampling cylinder 1 has multiple horizontally arranged liquid inlets 9. The inner cavity of the sampling cylinder 1 is longitudinally provided with a push-pull rod 2. The lower end of the push-pull rod 2 is provided with a piston plate 3. The piston plate 3 slides and seals along the inner cavity of the sampling cylinder 1. The upper end of the push-pull rod 2 extends out of the inner cavity of the sampling cylinder 1 and is provided with an operating part 4. The connecting sleeve 10 is sleeved on the outside of the sampling cylinder 1. The connecting sleeve 10 is circumferentially provided with multiple elastic pull rods. The end of the elastic pull rod is provided with a clamping plate 20. The multiple elastic pull rods are stretched outward along the axial direction and are clamped to the outer edge of the upper port of the separation cylinder by means of the clamping plate 20.

[0036] Compared with the prior art, the plasma sampling device provided by this utility model places the sampling cylinder 1 in the upper middle part of the separation cylinder. Multiple elastic levers are pulled outwards, causing the retaining plates 20 at the ends of the levers to extend to the outer sidewall of the separation cylinder. Releasing the levers causes them to retract, engaging the retaining plates 20 around the outer edge of the upper port of the separation cylinder, thus stably fixing the sampling cylinder 1 in the upper middle part of the separation cylinder. At this time, the bottom of the sampling cylinder 1 is inserted into the upper layer of plasma liquid inside the separation cylinder. Holding the upper part of the sampling cylinder 1 with one hand and the operating part 4 with the other, pulling upwards causes the push-pull rod 2 to move the piston plate 3 upwards within the inner cavity of the sampling cylinder 1, creating a negative pressure in the lower chamber of the piston plate 3. Plasma liquid then enters the lower part of the sampling cylinder 1 chamber through multiple inlets 9. This plasma sampling device provides a stable fixation of the sampling cylinder 1 in the upper middle part of the separation cylinder, preventing shaking during sampling. Plasma is horizontally drawn into the sampling cylinder 1 through multiple horizontally arranged inlets 9. This avoids the rising liquid flow carrying away lower blood components, which would cause the sampling cylinder 1 to be contaminated with unwanted blood cells and other impurities, thus accurately reflecting the true characteristics of the plasma.

[0037] The connecting sleeve 10 is threaded onto the threads of the outer wall of the sampling tube. Rotating the threaded sleeve allows for height adjustment, thereby regulating the insertion depth of the sampling tube 1 into the separation tube. This ensures accurate insertion of the sampling tube 1 into the plasma layer, regardless of the separation tube depth or the blood level. Alternatively, the connecting sleeve 10 can employ a split clamp structure for height adjustment and fixation, or use locating pins on the outer periphery to fix the entire connecting sleeve 10 at any height.

[0038] Please see Figure 2 and Figure 3The elastic pull rod includes an outer sleeve 11, a telescopic rod 12, and a compression spring 13. One inner end of the outer sleeve 11 is connected to the outer wall of the connecting sleeve 10; one inner end of the telescopic rod 12 passes through the outer end of the outer sleeve 11, and a retaining plate 20 is disposed on the outer end of the telescopic rod 12; the compression spring 13 is disposed within the inner cavity of the outer sleeve 11 and fitted onto the telescopic rod 12, providing a rebound force for the telescopic rod 12 to move inward. This elastic pull rod design greatly improves the ease of use and stability of the plasma sampling device. In actual operation, when the elastic pull rod is stretched outward, the telescopic rod 12 overcomes the elastic force of the compression spring 13 and moves outward, allowing the retaining plate 20 to extend smoothly to the outer side wall of the separation cylinder. When the elastic pull rod is released, the compression spring 13 quickly rebounds, pushing the telescopic rod 12 inward, thereby tightly engaging the retaining plate 20 against the outer edge of the upper port of the separation cylinder. The entire fixing process is simple and quick. Furthermore, the rebound force provided by the compression spring 13 can adapt to the size difference of the separation cylinder. Even if there is a certain tolerance in the diameter of the separation cylinders from different batches, the elastic tie rod can ensure a tight fit and ensure that the sampling cylinder 1 is firmly fixed.

[0039] Preferably, a rubber buffer layer 21 is provided on the side of the clamping plate 20 that contacts the separating cylinder. This increases friction and protects the separating cylinder, preventing the clamping plate 20 from scratching the surface of the separating cylinder during the fixing process. Furthermore, the clamping plate 20 is designed with a certain curvature to better fit the circular outer wall of the separating cylinder, further improving the stability of the fixing.

[0040] Please see Figure 2 The connecting sleeve 10 has multiple threaded holes on its outer periphery, and one end of the outer sleeve 11 is threaded into these holes. During installation, the outer sleeve 11 is simply screwed into the threaded holes for easy fixation, ensuring the elastic pull rod functions correctly. This connection method also facilitates disassembly, making it easy to replace damaged or worn elastic pull rods and reducing maintenance costs. If the outer sleeve 11 or connecting sleeve 10 is damaged, they can be replaced separately, eliminating the need for a complete replacement and saving resources. Furthermore, the threaded connection allows for adjustment of the elastic pull rod's position and angle according to actual needs. When dealing with different sized separation cylinders, the elastic pull rod can be fine-tuned to better engage the clamping plate 20 at the outer edge of the upper port of the separation cylinder, improving the device's adaptability and ensuring sampling accuracy.

[0041] Please see Figure 2 and Figure 3An end cap 14 is detachably installed on one outer end of the outer sleeve 11. A retaining ring 15 is provided on the inner end of the telescopic rod 12, passing through the end cap 14. The two ends of the compression spring 13 abut against the end cap 14 and the retaining ring 15, respectively. The detachable design of the end cap 14 greatly facilitates the installation and maintenance of the entire elastic rod assembly. If the compression spring 13 is damaged or fatigued, and needs replacement, the end cap 14 can be directly removed, and the damaged spring can be easily removed for replacement without complicated operations or professional tools, effectively reducing maintenance and time costs. The retaining ring 15 prevents the telescopic rod 12 from being pulled out excessively, ensuring that the compression spring 13 is always within the appropriate compression and rebound stroke range, avoiding failure of the elastic rod due to excessive displacement of the telescopic rod 12. The end cap 14 provides a stable support surface for the compression spring 13, ensuring that the compression spring 13 does not shift or tilt during extension and retraction, thus allowing the telescopic rod 12 to extend and retract smoothly, and enabling the clamping plate 20 to be more stably clamped onto the outer edge of the upper port of the separation cylinder, ensuring the reliability of the sampling cylinder 1's fixation. The end cap 14 is installed on one end of the outer sleeve 11, effectively preventing dust, impurities, and other foreign objects from entering the inner part of the outer sleeve 11 and preventing them from contacting the compression spring 13 and the telescopic rod 12. These foreign objects may affect the elastic performance of the compression spring 13 or increase the frictional resistance between the telescopic rod 12 and the outer sleeve 11, causing the elastic rod to extend or retract unevenly. The protective function of the end cap 14 helps extend the service life of the various components of the elastic rod and ensures the long-term stable operation of the plasma sampling device.

[0042] Please see Figure 2 and Figure 4A first threaded rod 16 is provided at one outer end of the telescopic rod 12. The outer diameter of the first threaded rod 16 is smaller than that of the telescopic rod 12. The clamping plate 20 is fitted onto the first threaded rod 16, and a first nut 17 for pressing the clamping plate 20 is threaded onto one outer end of the first threaded rod 16. During installation, simply fit the clamping plate 20 onto the first threaded rod 16, and then rotate the first nut 17. When dealing with different sizes of separation cylinders, the operator can precisely adjust the position of the clamping plate 20 to ensure that it can fit tightly against the outer edge of the upper port of the separation cylinder, thereby achieving a more stable fixation of the sampling cylinder 1. The pressing action of the first nut 17 on the clamping plate 20 provides a solid connection between the clamping plate 20 and the telescopic rod 12. During plasma sampling, the device may be affected by various external forces, such as slight vibration and shaking. This tight connection ensures that the clamping plate 20 will not loosen or shift under these external forces, and always maintains a reliable clamping state on the separation cylinder. This not only ensures the stability of the sampling cylinder 1 during the sampling process, avoiding sampling errors caused by the shaking of the sampling cylinder 1, but also extends the service life of the entire device and reduces the need for frequent maintenance or replacement due to loose parts. The advantages of this structure become even more apparent when the clamping plate 20 wears out or is damaged due to long-term use, or when different types of clamping plates 20 need to be replaced according to different usage requirements. Operators can easily remove and replace the clamping plate 20 simply by unscrewing the first nut 17. Similarly, if the first threaded rod 16 or the telescopic rod 12 malfunctions, the relevant parts can be easily disassembled for repair or replacement, greatly reducing the maintenance difficulty and cost of the device and improving work efficiency.

[0043] Please see Figure 2 , Figure 5 and Figure 6 A baffle 5 is threaded onto the upper end of the sampling cylinder 1. A through hole is provided in the center of the baffle 5, through which a push-pull rod 2 longitudinally passes. The operating part 4 is located above the baffle 5. The through hole of the baffle 5 provides precise guidance for the push-pull rod 2, ensuring its stability during longitudinal movement without deviation or wobbling. When the operator pulls the operating part 4, the push-pull rod 2 smoothly rises or falls along the central axis of the through hole, causing the piston plate 3 to slide smoothly within the sampling cylinder 1. This ensures a good seal between the piston plate 3 and the inner wall of the sampling cylinder 1, maintaining the stability of pressure changes during sampling and preventing the impact of push-pull rod 2 wobbling on plasma aspiration, thus ensuring sampling accuracy. The baffle 5 also effectively prevents external dust, impurities, and other contaminants from entering the sampling cylinder 1, avoiding contamination of the collected plasma sample.

[0044] Preferably, the upper end face of the baffle 5 is provided with multiple radial ribs 6. In actual operation, the operator needs to frequently contact the baffle 5 for sampling operations, and the presence of the radial ribs 6 greatly increases the friction of the baffle 5 surface. When the operator's hand contacts the baffle 5, these radial ribs 6 can effectively prevent hand slippage, making the operation more stable and reliable. Similarly, when disassembling and assembling the baffle 5, the baffle 5 can be quickly disassembled and assembled by hand-tightening the radial ribs 6.

[0045] Please see Figure 2 A reinforcing plate 7 is circumferentially provided on the upper outer wall of the sampling tube 1. During sampling, holding the reinforcing plate 7 with one hand effectively fixes the sampling tube 1, counteracting the reaction force generated when the other hand pulls the operating part 4, preventing the sampling tube 1 from shaking or shifting. In the laboratory, if the sample volume is small and the sampling accuracy requirement is extremely high, the reinforcing plate 7 can help the operator control the sampling tube 1 more steadily, ensuring that the depth and angle of each sampling are consistent, thus improving the sampling success rate. Structurally, the reinforcing plate 7 also enhances the overall strength of the sampling tube 1. For example, when the sampling device is stored in the medical case, if it is squeezed by other instruments, the reinforcing plate 7 can protect the sampling tube 1, extend its service life, and reduce the cost of use.

[0046] Please see Figure 2 The lower end of the push-pull rod 2 is provided with a second threaded rod 18, the outer diameter of which is smaller than that of the push-pull rod 2. The piston plate 3 is fitted onto the second threaded rod 18, and the lower end of the second threaded rod 18 is threaded with a second nut 19 for pressing the piston plate 3. The design of the second threaded rod 18 and the second nut 19 makes the installation of the piston plate 3 very convenient. During installation, simply fit the piston plate 3 onto the second threaded rod 18 and then tighten the second nut 19 to firmly fix the piston plate 3 onto the push-pull rod 2. The pressing action of the second nut 19 on the piston plate 3 ensures the stability of the piston plate 3 on the push-pull rod 2. During plasma sampling, the push-pull rod 2 drives the piston plate 3 to move up and down inside the sampling cylinder 1. The piston plate 3 needs to maintain a good seal with the inner wall of the sampling cylinder 1 to achieve effective fluid extraction and drainage operations.

[0047] Please see Figure 2The sampling cylinder 1 has a conical end 8 at its bottom, with at least two sets of multiple inlets 9 arranged alternately from top to bottom. Multiple inlets 9 within the same set are circumferentially located around the outer periphery of the conical end 8. This staggered arrangement of multiple sets of inlets 9 increases the number of channels through which plasma enters the sampling cylinder 1. During sampling, plasma can flow into the sampling cylinder 1 simultaneously from multiple directions. Compared to designs with a single inlet 9 or fewer inlets 9, this significantly shortens sampling time and improves sampling efficiency. The circumferential location of the inlets 9 within the same set ensures that plasma enters evenly from all sides of the bottom of the sampling cylinder 1. This avoids situations where the plasma flow rate is too fast or too slow in certain areas due to uneven distribution of the inlets 9, ensuring that the collected plasma sample is more homogeneous in composition and properties, thus improving sample representativeness. The conical end 8 helps guide the plasma smoothly into the inlets 9. After plasma stratification, impurities such as blood cells concentrate in the lower layer. The slope of the conical end 8 allows the plasma to flow more smoothly into the sampling cylinder 1 using its own gravity and flow inertia when it flows into the inlet 9, reducing the possibility of lower-layer impurities being carried away due to turbulent flow. At the same time, the staggered distribution of the inlets 9 creates a complex flow pattern when the plasma enters, further reducing the risk of lower-layer impurities being drawn in, ensuring that the collected plasma sample is purer and more accurately reflects the true characteristics of the plasma.

[0048] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A plasma sampling device, characterized in that, include: A sampling cylinder (1) has multiple horizontally arranged liquid inlets (9) on its bottom circumferentially. A push-pull rod (2) is arranged longitudinally in the inner cavity of the sampling cylinder (1). A piston plate (3) is provided at the lower end of the push-pull rod (2). The piston plate (3) slides and seals along the inner cavity of the sampling cylinder (1). The upper end of the push-pull rod (2) passes through the inner cavity of the sampling cylinder (1) and is provided with an operating part (4). A connecting sleeve (10) is fitted over the outside of the sampling cylinder (1). The connecting sleeve (10) is provided with a plurality of elastic pull rods in the circumferential direction. The end of the elastic pull rod is provided with a clamping plate (20). The plurality of elastic pull rods are stretched outward along the axial direction and clamped onto the outer edge of the upper port of the separation cylinder by means of the clamping plate (20).

2. The plasma sampling device as described in claim 1, characterized in that, The elastic tie rod includes: Outer tube (11), one end of which is connected to the outer wall of the connecting sleeve (10); Telescopic rod (12), one end of which is inserted into the outer end of the outer sleeve (11), and the clamping plate (20) is disposed at the outer end of the telescopic rod (12); A compression spring (13) is disposed in the inner cavity of the outer sleeve (11) and fitted onto the telescopic rod (12). The compression spring (13) is used to provide a restoring force for the telescopic rod (12) to move inward.

3. The plasma sampling device as described in claim 2, characterized in that, The outer periphery of the connecting sleeve (10) is provided with multiple threaded holes, and one end of the inner side of the outer sleeve (11) is threaded into the threaded holes.

4. The plasma sampling device as described in claim 2, characterized in that, An end cap (14) is detachably installed on one side of the outer sleeve (11), and a retaining ring (15) is provided on the inner side of the telescopic rod (12) through the end cap (14). The two ends of the compression spring (13) abut against the end cap (14) and the retaining ring (15) respectively.

5. The plasma sampling device as described in claim 2, characterized in that, The telescopic rod (12) has a first threaded rod (16) at one outer end. The outer diameter of the first threaded rod (16) is smaller than the outer diameter of the telescopic rod (12). The clamping plate (20) is fitted onto the first threaded rod (16). The outer end of the first threaded rod (16) is threaded with a first nut (17) for pressing the clamping plate (20).

6. The plasma sampling device as described in claim 1, characterized in that, The upper end of the sampling cylinder (1) is threaded with a baffle (5), and a through hole is provided in the middle of the baffle (5). The push-pull rod (2) passes through the through hole longitudinally, and the operating part (4) is located above the baffle (5).

7. The plasma sampling device as described in claim 6, characterized in that, The upper end face of the baffle (5) is provided with multiple radial ribs (6).

8. The plasma sampling device as described in claim 1, characterized in that, A reinforcing plate (7) is provided circumferentially on the upper part of the outer wall of the sampling tube (1).

9. The plasma sampling device as described in claim 1, characterized in that, The lower end of the push-pull rod (2) is provided with a second threaded rod (18), the outer diameter of the second threaded rod (18) is smaller than the outer diameter of the push-pull rod (2), the piston plate (3) is fitted on the second threaded rod (18), and the lower end of the second threaded rod (18) is threadedly connected with a second nut (19) for pressing the piston plate (3).

10. The plasma sampling device as described in claim 1, characterized in that, The bottom of the sampling tube (1) is provided with a conical end (8), and at least two sets of multiple liquid inlets (9) are arranged alternately from top to bottom. Multiple liquid inlets (9) in the same set are circumferentially opened on the outer periphery of the conical end (8).

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