CN220399461U

CN220399461U - Sample analyzer

Info

Publication number: CN220399461U
Application number: CN202321057740.XU
Authority: CN
Inventors: 袁雄; 杨桂才; 张勇; 程蛟
Original assignee: Shenzhen Mindray Bio Medical Electronics Co Ltd
Current assignee: Shenzhen Mindray Bio Medical Electronics Co Ltd
Priority date: 2023-05-05
Filing date: 2023-05-05
Publication date: 2024-01-26
Anticipated expiration: 2033-05-05

Abstract

The embodiment of the application provides a sample analyzer, including a dispensing mechanism and an injection device, wherein the injection device comprises an injector, a mounting seat and a driving mechanism, the injector comprises an injection cylinder, a piston rod and a piston head, a first end of the piston rod is positioned in the injection cylinder and connected with the piston head, a second end of the piston rod is positioned outside the injection cylinder and connected with the driving mechanism, and the piston rod is not radially restrained between one end of the injection cylinder far away from a suction port and a connecting part of the piston rod and the driving mechanism; the piston head has a length in the axial direction of not less than 5mm and/or has at least two seal ring structures, each of which is arranged at intervals in the axial direction. According to the embodiment of the application, the piston head and the driving mechanism can realize radial constraint on the piston rod, and the motion stability of the piston rod is ensured; in addition, the piston rod is not worn at one end of the injection tube far away from the suction port and between the piston rod and the connecting part of the driving mechanism, so that the service life of the injection device is prolonged.

Description

Sample analyzer

Technical Field

The application relates to the technical field of medical instruments, in particular to a sample analyzer.

Background

The sample analyzer needs to quantitatively fill reagents and samples into a reaction container by using an injection device to perform a reaction and test the reaction result. The accuracy and reliability of the injection device directly affects the performance and reliability of the sample analyzer.

In the related art, a push rod of an injection device is fixed on a driving slide block, and the push rod moves up and down along with the driving slide block. However, in the related art, the push rod is easy to wear and blacken, and fine scraps generated by wear can slowly move to the piston head along with the up-and-down movement of the push rod, so that the sealing surface is easy to fail, and further, the leakage and the failure of the injection device are caused.

Disclosure of Invention

In view of this, the embodiment of the application is expected to provide a sample analyzer, the guiding effect of the piston rod of the injection device is better, and the service life of the injection device can be prolonged.

An embodiment of the present application provides a sample analyzer, including:

a dispensing mechanism for dispensing a target liquid, the target liquid comprising at least one of a sample, a reagent, or a cleaning fluid;

a detection device for detecting a reaction liquid formed by at least sample and reagent preparation to obtain a detection result;

the injection device comprises an injector, a mounting seat and a driving mechanism, wherein the injector comprises an injection cylinder, a piston rod and a piston head, a first end of the piston rod is positioned in the injection cylinder and connected with the piston head, a second end of the piston rod is positioned outside the injection cylinder and connected with the driving mechanism, the injection cylinder is provided with a suction port, the suction port is connected with the dispensing mechanism through a pipeline and is used for providing power for dispensing liquid to the dispensing mechanism, the driving mechanism is used for driving the piston rod to axially reciprocate,

the piston rod is free from radial constraint between one end of the injection cylinder, which is far away from the suction port, and a connecting part of the piston rod and the driving mechanism;

the piston head has a length in the axial direction of not less than 5mm and/or has at least two sealing ring structures, each of which is arranged at intervals in the axial direction.

In some embodiments, the dispensing mechanism comprises a moving mechanism and a pipetting needle arranged on the moving mechanism, the moving component is used for driving the pipetting needle to move between different operation positions, and the suction opening is communicated with the pipetting needle and is used for providing positive pressure or negative pressure for the pipetting needle so that the pipetting needle sucks or discharges samples and/or reagents to prepare a reaction liquid.

In some embodiments, the piston head and the drive mechanism achieve a two-point radial constraint on the piston rod.

In some embodiments, the entirety of the piston head is a rigid structural member.

In some embodiments, the piston head is a unitary structure.

In some embodiments, the piston head has at least two seal ring structures, and the gap between adjacent seal ring structures is filled with a lubricating material.

In some embodiments, the piston head has 3 to 6 seal ring structures.

In some embodiments, the piston head has at least two sealing ring structures, and the area of contact of the sealing ring structure nearest to the suction port with the inner wall of the syringe barrel is greater than the area of contact of the remaining sealing ring structures with the inner wall of the syringe barrel.

In some embodiments, the piston head is provided with a threaded bore and the end of the piston rod is provided with a threaded rod section which screws into the threaded bore to effect connection of the piston head and the piston rod.

In some embodiments, the end of the syringe adjacent the drive mechanism is free of an end cap.

In some embodiments, the outer surface of the piston rod is provided with a wear layer.

In some embodiments, the wear layer comprises a heat shrink sleeve that is sleeved over the piston rod; and/or the wear layer comprises a coating attached to an outer surface of the piston rod.

In some embodiments, the mounting base comprises a base, a positioning block and a locking piece, the driving mechanism is mounted on the base, the positioning block is connected to one side of the base, the positioning block is provided with a V-shaped groove, the injection cylinder penetrates through the V-shaped groove, and the locking piece is at least partially arranged at the opening of the V-shaped groove and supports the injection cylinder on the side walls of two sides of the V-shaped groove.

In some embodiments, the number of V-shaped grooves is two, the two V-shaped grooves are arranged along the axial direction of the injection cylinder, the injection cylinder passes through the two V-shaped grooves, and the cooperation of the two V-shaped grooves and the locking piece fixes the injection cylinder on the positioning block.

According to the sample analyzer disclosed by the embodiment of the application, the contact part of the piston head and the injection cylinder has a longer axial length, so that the guiding and radial constraint action of the piston head on the piston rod can be enhanced, the piston head and the driving mechanism can realize radial constraint on the piston rod, and the motion stability of the piston rod is ensured; in addition, since the piston rod is not radially restrained between the end of the injection tube away from the suction port and the connection part of the piston rod and the driving mechanism, the piston rod cannot be worn in the area, the problem of abrasion of the piston rod caused by friction between the piston rod and the guide nut in the related art can be solved, and the service life of the injection device is prolonged.

Drawings

FIG. 1 is a simplified schematic diagram of a sample analyzer according to an embodiment of the present application;

FIG. 2 is a schematic view of an injection device according to an embodiment of the present application;

FIG. 3 is a schematic view of a syringe according to an embodiment of the present application;

FIG. 4 is a cross-sectional view of the device shown in FIG. 3;

fig. 5 is an enlarged partial schematic view at the piston head of fig. 4.

Description of the reference numerals

A sample cell 11; a sample dispensing mechanism 12; a reagent unit 13; a reagent dispensing mechanism 14; a mixing mechanism 15; a reaction member 16; a photodetection unit 17;

an injection device 20; a syringe 21; a syringe 211; a suction port 211a; a piston rod 212; threaded rod segment 2121; a piston head 213; a screw hole 213a; cyclic structures 2131, 2132, 2133, 2134, 2135;

a slider 221; a base 231; a positioning block 232; a V-shaped groove 232a; a locking piece 233; a screw 234;

Detailed Description

Embodiments of the present application are described in further detail below with reference to the accompanying drawings and examples. The following examples are illustrative of the present application but are not intended to limit the scope of the present application.

The embodiment of the application provides a sample analyzer.

The specific type of the sample analyzer is not limited, and may be, for example, an immunoassay analyzer, a biochemical analyzer, a coagulation analyzer, a blood rheology analyzer, or the like.

Before explaining the present utility model in detail, a structure of a sample analyzer will be exemplified.

Referring to fig. 1, the sample analyzer may include a sample cell 11, a sample dispensing mechanism 12, a reagent cell 13, a reagent dispensing mechanism 14, a mixing mechanism 15, a reaction part 16, a photometric part 17, and the like.

The sample cell 11 is used to carry a sample. The sample cell 11 may be a sample tray comprising a plurality of sample sites where sample sites such as sample tubes may be placed, the sample tray being capable of dispatching samples to corresponding locations by rotating its tray structure, e.g. for the sample dispensing mechanism 12 to aspirate samples.

The sample dispensing mechanism 12 is used to aspirate and discharge a sample into a reaction cup to be loaded. The sample dispensing mechanism 12 is provided with a sample needle, sucks the sample carried by the sample cell 11 by movement of the sample needle, moves to a cuvette to be loaded with a sample, and discharges the sample to the cuvette.

The reagent unit 13 is for carrying a reagent. In one embodiment, the reagent unit 13 may be a reagent disk, where the reagent disk is configured in a disk-shaped structure and has a plurality of positions for carrying reagent containers, and the reagent unit 13 can rotate and drive the reagent containers carried by the reagent unit to rotate to a specific position, for example, a position where the reagent is sucked by the reagent dispensing mechanism 14. The number of reagent units 13 may be one or more.

The reagent dispensing mechanism 14 is used to aspirate and discharge the reagent into the cuvette to be filled with the reagent. The reagent dispensing mechanism 14 is provided with a reagent needle, sucks the reagent carried by the reagent unit 13 by movement of the reagent needle, moves to a cuvette to be filled with a reagent, and discharges the reagent to the cuvette.

The mixing mechanism 15 is used for mixing the reaction liquid to be mixed in the reaction cup. Illustratively, the mixing mechanism 15 is provided with a stirring rod for uniformly mixing and stirring the reaction liquid to be uniformly mixed in the reaction cup.

The number of mixing mechanisms 15 may be one or more.

The reaction part 16 has at least one place for placing a reaction cup and incubating the reaction liquid in the reaction cup. For example, the reaction component 16 may be a reaction disk, which is arranged in a disk-like structure, and has one or more placement sites for placing reaction cups, and the reaction disk can rotate and drive the reaction cups in the placement sites to rotate, so as to schedule the reaction cups in the reaction disk and incubate the reaction liquid in the reaction cups.

The photodetection unit 17 is configured to photodetect the reaction solution after incubation, and obtain reaction data of the sample. For example, the photodetection means 17 detects the luminescence intensity of the reaction solution to be measured, and calculates the concentration of the component to be measured in the sample from the calibration curve. In one embodiment, the photodetection part 17 is separately provided outside the reaction part 16.

In order to avoid cross contamination of samples and reagents, the sample needle/reagent needle is cleaned after sampling and sample adding are finished, and the next sampling and sample adding action can be performed after the cleaning is finished.

The sample analyzer of the embodiment of the application comprises a dispensing mechanism and a detection device injection device 20.

The dispensing mechanism is used to dispense a target liquid, wherein the target liquid comprises at least one of a sample, a reagent, or a wash liquid.

Of course, the target liquid may also include other types, e.g., substrates, magnetic separation liquids, etc.

And the detection device is used for detecting the reaction liquid formed by preparing at least the sample and the reagent so as to obtain a detection result. The detection means may be, for example, the photodetection means 17 described above.

Referring to fig. 2 to 5, the injection device 20 includes a syringe 21, a mount, and a driving mechanism, and the syringe 21 includes a syringe barrel 211, a piston rod 212, and a piston head 213. The syringe 211 has a suction port 211a, and the suction port 211a is connected to the dispensing mechanism through a pipe for powering the dispensing mechanism to dispense the liquid, so that the dispensing mechanism dispenses the target liquid under the power.

The dispensing mechanism may be the sample dispensing mechanism and/or the reagent dispensing mechanism described above.

For example, in some embodiments, the sample dispensing mechanism and the reagent dispensing mechanism share the same injection device 20, and a switching valve is provided in the fluid path between the sample dispensing mechanism, the reagent dispensing mechanism, and the injection device 20, and the switching valve is used to distribute the power of the injection device 20 between the sample dispensing mechanism and the reagent dispensing mechanism. In other embodiments, the number of injection devices 20 is multiple, with one injection device 20 powering the sample dispensing mechanism and another injection device 20 powering the reagent dispensing mechanism.

The drive mechanism is used to drive the piston rod 212 to axially reciprocate.

A first end of piston rod 212 is positioned within syringe 211 and is coupled to piston head 213.

The second end of the piston rod 212 is located outside the syringe 211 and is connected to a drive mechanism.

The circumferential surface of the piston head 213 is in sliding contact with the inner wall of the syringe 211, and the piston head 213 radially restrains the piston rod 212. The drive mechanism also causes radial binding to the piston rod 212, i.e. the piston rod 212 has at least two radial binding.

The piston rod 212 has no radial restriction between the end of the syringe 211 remote from the suction port 211a and the connection point of the piston rod 212 to the drive mechanism. Therefore, the piston rod 212 does not come into contact with other components when the syringe barrel 211 of the syringe barrel 211 reciprocates axially away from the space between the end of the suction port 211a and the drive mechanism.

In the related art, an end cover is disposed at one end of the syringe barrel far away from the suction port, for example, the end cover is a guide nut, the piston rod passes through the guide nut, and the guide nut guides the axial reciprocating motion of the piston rod. However, friction between the guide nut and the piston rod causes particles to be generated on the surface of the piston rod due to abrasion, and the particles enter the injection cylinder along with the piston rod and move to the piston head, so that the sealing performance of the piston head is affected, and the accuracy of the injector is further affected, and even the injector is not effective.

In this embodiment, since the piston rod 212 has no radial constraint between the end of the injection tube 211 away from the suction port 211a and the connection portion between the piston rod 212 and the driving mechanism, the piston rod 212 will not wear in this area, so that the problem of piston rod wear caused by friction between the piston rod and the guide nut in the related art can be improved, and the service life of the injection device 20 can be prolonged.

Illustratively, the length of the piston head 213 in the axial direction is not less than 5mm, and/or, referring to fig. 5, the piston head 213 has at least two seal ring structures 2131, 2132, 2133, 2134, 2135, each seal ring structure 2131, 2132, 2133, 2134, 2135 being axially spaced apart.

In embodiments where the axial length of piston head 213 is not less than 5mm, the contact of piston head 213 with syringe 211 has a longer axial length, which can enhance the guiding and radial constraining action of piston head 213 on piston rod 212.

In embodiments where the piston head 213 has at least two sealing ring structures 2131, 2132, 2133, 2134, 2135, all sealing ring structures 2131, 2132, 2133, 2134, 2135 can also enable the piston head 213 to have a longer axial length, which can enhance the guiding and radial constraining action of the piston head 213 on the piston rod 212; in addition, since the seal ring structures 2131, 2132, 2133, 2134 and 2135 are arranged at intervals, in the case that the piston heads 213 have the same axial length, the contact area between the piston heads 213 and the inner wall of the injection tube 211 in the embodiment of the present application is small, so that the friction force between the piston heads 213 and the injection tube 211 can be reduced, the output power of the driving mechanism is reduced, and the energy-saving effect is achieved.

Illustratively, the dispensing mechanism includes a moving mechanism and a pipetting needle disposed on the moving mechanism, the moving member for driving the pipetting needle to move between different operating positions, and the suction port 211a communicates with the pipetting needle for providing positive or negative pressure to the pipetting needle to suck or discharge the target liquid. For example, when the moving mechanism drives the pipetting needle to move to the first operation position, the injection device provides negative pressure for the pipetting needle, and the pipetting needle sucks target liquid under the action of the negative pressure; when the moving mechanism drives the liquid transferring needle to move to the second operation position, the injection device provides positive pressure for the liquid transferring needle, and the liquid transferring needle discharges target liquid under the positive pressure effect.

Illustratively, the piston head 213 and the drive mechanism achieve a two-point radial constraint on the piston rod 212. That is, the piston rod 212 is free of radial constraints in the remainder, except for the piston head 213 and the drive mechanism. The piston head 213 and the driving mechanism are located at opposite ends of the piston rod 212, and two-point radial constraint can ensure the motion stability of the piston rod 212, simplify the structure, further reduce the abrasion of the piston rod 212, and prolong the service life of the piston rod 212. In addition, the two radial constraints also prevent the piston rod 212 from mechanically overconstraining.

Illustratively, the entirety of the piston head 213 is a rigid structural member. Such as a rigid plastic part, or a structural part made of other polymer materials.

The hard structural member can keep its shape under the action of external force, and is not easy to deform. In this embodiment, the piston head 213 does not undergo significant elastic deformation, so that the piston head 213 and the inner wall of the syringe 211 can maintain good sealing contact, a gap is not easy to generate, sealing performance is ensured, and in addition, a good guiding effect can be performed on the piston rod 212, so that the possibility of deflection of the end portion of the piston rod 212 is reduced.

Illustratively, the piston head 213 is of unitary construction. For example, a one-piece injection molded part. In this embodiment, the piston head 213 has a better structural strength, and the piston head 213 can be ensured to have a dimensional accuracy and a lot consistency by a tool such as a die without splicing a plurality of parts.

The material of the syringe 211 is not limited, and includes, for example, but is not limited to, organic glass, inorganic glass, and the like.

Illustratively, the gaps 213b between adjacent seal ring structures 2131, 2132, 2133, 2134, 2135 are filled with a lubricating material. The lubricating material may be a lubricating oil, grease, or the like, and is not limited herein.

The lubricating material can act to lubricate and reduce friction between the piston head 213 and the inner wall of the syringe 211, and in addition, the lubricating material permeates into the contact surface between the piston head 213 and the inner wall of the syringe 211 to form a film layer, so that the sealing effect of the piston head 213 is enhanced.

The number of piston heads 213 is not limited, for example, 2, 3, 4, or more than 4.

Illustratively, the piston head 213 has 3-6 seal ring structures 2131, 2132, 2133, 2134, 2135. For example 3, 4, 5 or 6. In this embodiment, the number of sealing ring structures 2131, 2132, 2133, 2134, 2135 provides for both better radial restraint and guidance of piston head 213 against piston rod 212 and relatively proper friction between piston head 213 and the inner wall of barrel 211.

Illustratively, in some embodiments, the contact area of the seal ring structure 2131 closest to the suction port 211a with the inner wall of the syringe 211 is greater than the contact area of the remaining seal ring structures 2132, 2133, 2134, 2135 with the inner wall of the syringe 211, i.e., the contact area of any one of the seal ring structures 2132, 2133, 2134, 2135 with the inner wall of the syringe 211 is less than the contact area of the seal ring structure 2131 with the inner wall of the syringe 211. The sealing ring structure 2131 closest to the suction port 211a plays a major role in the sealing performance of the piston head 213, and thus, it is necessary to secure a large contact area between the sealing ring structure 2131 and the inner wall of the syringe 211 to secure the sealing reliability therebetween. While the contact area of the remaining seal ring structures 2132, 2133, 2134, 2135 is relatively small to minimize the total contact area between the piston head 213 and the inner wall of the syringe 211, reducing friction.

The contact areas of the remaining seal ring structures 2132, 2133, 2134, 2135 and the inner wall of the syringe 211 may be the same or may be different, or may be partially the same or partially different.

In other embodiments, the contact area of each seal ring structure 2131, 2132, 2133, 2134, 2135 with the inner wall of the syringe 211 is the same.

The specific manner of connection of piston head 213 and piston rod 212 is not limited, as long as the two can be connected together.

For example, referring to fig. 5, piston head 213 is provided with a threaded bore 213a and the end of piston rod 212 is provided with a threaded rod section 2121, with threaded rod section 2121 threaded into threaded bore 213a to effect connection of piston head 213 and piston rod 212. Therefore, the connection between the two can be realized without fastening pieces such as screws, and the connection is convenient, the structure is simple and reliable.

Illustratively, the end of the piston rod 212 remote from the piston head 213 is provided with a connector 212a, the connector 212a being connected to a drive mechanism.

Illustratively, the end of the syringe 211 adjacent the drive mechanism has no end cap. I.e., the end cap of the related art is eliminated.

Of course, in other embodiments, an end cap may be provided at the end of the syringe 211, with the exception that the end cap does not contact the piston rod 212 and does not affect the movement of the piston rod 212.

The material of the piston rod 212 is required to ensure that the piston rod 212 has good structural strength and bending rigidity. For example, the piston rod 212 is made of stainless steel.

Illustratively, the outer surface of the piston rod 212 is provided with a wear layer. The wear-resistant layer can promote the wearability of piston rod 212, promotes piston rod 212's life. In addition, the wear-resistant layer wraps the outer surface of the piston rod 212, so that the rust prevention and corrosion prevention effects of the piston rod 212 can be improved.

The specific construction of the wear layer is not limited.

For example, in some embodiments, the wear layer comprises a heat shrink sleeve that is sleeved over the piston rod 212; and/or the wear layer comprises a coating attached to an outer surface of the piston rod.

Heat shrinkable sleeves are products which shrink when heated, and which are produced by stretching a plastic such as a polyolefin during the production process, and which shrink back to their original dimensions by heating the stretched product.

The piston rod 212 is sleeved with the heat-shrinkable tube, so that the assembly is simple and the cost is low.

The coating may be a nano ceramic coating, an alloy coating, a high molecular ceramic polymer coating, etc., without limitation.

For example, referring to fig. 2, the mounting base includes a base 231, a positioning block 232 and a locking member 233, and the driving mechanism is mounted on the base 231. The mount is directly or indirectly connected to the frame through the base 231.

The specific structure of the driving mechanism is not limited.

For example, in some embodiments, the drive mechanism includes a slider 221, a motor, and a transmission mechanism. The piston rod 212 is connected to the slider 221, and the transmission mechanism is used for converting the rotation of the motor shaft of the motor into the linear movement of the slider, and the slider 221 drives the piston rod 212 to linearly reciprocate through the forward and reverse rotation of the motor shaft.

In some embodiments, the transmission mechanism comprises one or more gears, and the sliding block 221 is provided with a rack, and the gears are meshed with the rack for transmission.

In other embodiments, the drive mechanism comprises a screw, the slider being provided with an internal thread, the screw being connected to the slider, the screw converting its rotation into a linear movement of the slider 221 when rotated.

In some embodiments, the base 231 has a mounting cavity therein, and the electrode and the driving mechanism are disposed in the mounting cavity, and the slider 221 is located outside the base 231 and is convenient to connect with the piston rod 212.

For example, referring to fig. 2, the positioning block 232 is connected to one side of the base 231, the positioning block 232 is provided with a V-shaped groove 232a, the syringe 211 passes through the V-shaped groove 232a, the locking piece 233 is at least partially disposed at the opening of the V-shaped groove 232a, and the syringe 211 is abutted against the side walls on two sides of the V-shaped groove 232 a.

In this embodiment, whether or not the syringe 211 and the V-shaped groove 232a have a machining error, the locking piece 233 can reliably abut the syringe 211 against the side walls on both sides of the V-shaped groove 232a, so as to radially constrain the syringe 211, prevent the syringe 211 from moving axially, and have reliable positioning and simple positioning modes.

Illustratively, the locking member 233 is in a sheet shape and covers the opening of the V-shaped groove 232a, and the screw 234 passes through the locking member 233 and is screwed into the positioning block 232, so that the locking member 233 is fixed to the positioning block 232.

The number of V-grooves 232a is not limited, and may be one, two, or more than two.

Illustratively, the number of V-shaped grooves 232a is two, the two V-shaped grooves 232a are arranged along the axial direction of the syringe 211, the syringe 211 passes through the two V-shaped grooves 232a, and the cooperation of the two V-shaped grooves 232a and the locking piece 233 fixes the syringe 211 on the positioning block 232. The two V-shaped grooves 232a can better position the syringe 211, prevent the syringe 211 from deflecting, and can not form over-constraint on the syringe 211.

In the description of the present application, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the embodiments of the present application. In this application, the schematic representations of the above terms are not necessarily for the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the various embodiments or examples described herein, as well as the features of the various embodiments or examples, may be combined by those skilled in the art without contradiction.

The foregoing description is only of the preferred embodiments of the present application and is not intended to limit the same, but rather, various modifications and variations can be made by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A sample analyzer, comprising:

2. The sample analyzer of claim 1, wherein the dispensing mechanism comprises a movement mechanism and a pipetting needle disposed on the movement mechanism, the movement member for driving the pipetting needle to move between different operating positions, the aspiration port in communication with the pipetting needle for providing positive or negative pressure to the pipetting needle for allowing the pipetting needle to aspirate or discharge samples and/or reagents for preparing a reaction solution.

3. The sample analyzer of claim 1, wherein the piston head and the drive mechanism achieve a two-point radial constraint on the piston rod.

4. The sample analyzer of claim 1, wherein the entirety of the piston head is a rigid structural member.

5. The sample analyzer of claim 1, wherein the piston head is of unitary construction.

6. The sample analyzer of claim 1, wherein the piston head has at least two seal ring structures, and a gap between adjacent seal ring structures is filled with a lubricating material.

7. The sample analyzer of claim 1, wherein the piston head has 3-6 seal ring structures.

8. The sample analyzer of claim 1, wherein the piston head has at least two sealing ring structures, and wherein the area of contact of the sealing ring structure closest to the suction port with the inner wall of the syringe is greater than the area of contact of the remaining sealing ring structures with the inner wall of the syringe.

9. The sample analyzer of claim 1, wherein the piston head is provided with a threaded bore and the end of the piston rod is provided with a threaded rod section that threads into the threaded bore to effect connection of the piston head and the piston rod.

10. The sample analyzer of claim 1, wherein an end of the syringe proximate the drive mechanism is free of an end cap.

11. The sample analyzer of claim 1, wherein an outer surface of the piston rod is provided with a wear layer.

12. The sample analyzer of claim 11, wherein the wear layer comprises a heat shrink sleeve, the heat shrink sleeve being sleeved over the piston rod; and/or the wear layer comprises a coating attached to an outer surface of the piston rod.

13. The sample analyzer of claim 1, wherein the mounting base comprises a base, a positioning block and a locking piece, the driving mechanism is mounted on the base, the positioning block is connected to one side of the base, the positioning block is provided with a V-shaped groove, the syringe penetrates through the V-shaped groove, the locking piece is at least partially arranged at the opening of the V-shaped groove, and the syringe is propped against the side walls of two sides of the V-shaped groove.

14. The sample analyzer of claim 13, wherein the number of V-shaped grooves is two, the two V-shaped grooves being arranged in an axial direction of the syringe, the syringe passing through the two V-shaped grooves, cooperation of the two V-shaped grooves and the locking member securing the syringe to the positioning block.