Sample adding needle, liquid level detection device, liquid level detection method and sample analyzer

Abstract

The embodiment of the invention discloses a sample adding needle, a liquid level detection device, a liquid level detection method and a sample analyser, the sample adding needle comprises a conductive needle core, a first insulating layer, a conductive sleeve, a heating piece, a second insulating layer and a shell, and the conductive sleeve is arranged outside the conductive needle core in a sleeving mode; the first insulating layer is arranged between the inner wall of the conductive sleeve and the outer wall of the conductive needle core, the heating piece is arranged on the outer wall of the conductive sleeve in a sleeving mode and used for heating liquid in the sample adding channel, the shell is arranged outside the heating piece in a sleeving mode, the second insulating layer is arranged between the heating piece and the shell, and a detection capacitor is formed between the conductive needle core and the conductive sleeve. The liquid level detection function can be achieved according to the change of the detection capacitor between the conductive needle core and the conductive sleeve, the heating piece is arranged on the outer wall of the conductive sleeve in a sleeving mode, namely, the heating piece is arranged outside the detection capacitor, dielectric constant change caused by the heating piece can be eliminated as much as possible, and then sudden change of the detection capacitor is avoided; and the accuracy of liquid level detection is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a sample adding needle, a liquid level detection device and a liquid level detection method, and a sample analyzer. Background Art

[0002] Existing in vitro diagnostic equipment such as immunology, biochemistry, and coagulation have increasingly higher requirements for the test speed of the entire equipment. In the sample detection reaction system, since the reagents are stored in an environment of 2-15 degrees, in order to effectively improve the sample reaction efficiency, a heating function and a liquid level detection function are introduced into the existing sample needle. The sample needle can preheat the reagents during the sample transportation process, thereby reducing the test time and increasing the test speed.

[0003] The outer wall and inner wall of the existing sampling needle form a capacitor, and glue, heating wire and insulating material are filled between the outer wall and the inner wall of the needle. The heating work of the heating wire will cause a large change in the dielectric constant and insulation gap of the sampling needle, thereby causing a sudden change in capacitance, which can easily lead to false touch of the liquid level detection. Summary of the invention

[0004] The purpose of the present invention is to propose a sample adding needle, a liquid level detection device and a liquid level detection method, and a sample analyzer, aiming to solve the problem that the heating work of the heating wire in the existing sample adding needle will cause a large change in the dielectric constant and the insulation gap of the sample adding needle, thereby causing a sudden change in capacitance, which is easy to cause false touch of the liquid level detection.

[0005] In a first aspect, the present invention provides a sample loading needle, the sample loading needle comprising a conductive needle core, a first insulating layer, a conductive sleeve, a heating element, a second insulating layer and an outer shell, the conductive needle core is provided with a sample loading channel and a sample loading hole connected to the sample loading channel, the conductive sleeve is sleeved on the outside of the conductive needle core, the first insulating layer is arranged between the inner wall of the conductive sleeve and the outer wall of the conductive needle core, the heating element is sleeved on the outer wall of the conductive sleeve and is used to heat the liquid in the sample loading channel, the outer shell is sleeved on the outside of the heating element, and the second insulating layer is arranged between the heating element and the outer shell;

[0006] Wherein, a detection capacitor is formed between the conductive needle core and the conductive sleeve, and the conductive needle core and the conductive sleeve are respectively used to be electrically connected to a control circuit.

[0007] In one embodiment, the conductive sleeve is grounded, the heating element is a heating wire, and the heating wire is completely wound around the outer wall of the conductive sleeve.

[0008] In one embodiment, the density of winding of the heating wire around the outer wall of the conductive sleeve gradually decreases from the needle tip of the conductive needle core to the tail of the conductive needle core.

[0009] In one embodiment, the conductive sleeve is grounded, the housing is a metal sleeve or a non-metal sleeve, the housing is cylindrical and is used for coaxial assembly with the driving mechanism; and / or

[0010] The sample adding needle also includes a heat shrink tube, which is sleeved on the outer wall of the heating element, and at least a part of the second insulating layer is filled between the inner wall of the heat shrink tube and the outer wall of the conductive sleeve.

[0011] In one embodiment, the thickness of the first insulating layer is not greater than 0.5 mm, or the gap size between the conductive sleeve and the conductive needle core is not greater than 0.5 mm.

[0012] In one embodiment, the conductive sleeve is a structural member made of metal; and / or

[0013] The second insulating layer is an insulating structure formed by solidifying glue.

[0014] In one embodiment, the sample injection needle further includes a temperature sensor, which is disposed on the outer wall of the conductive sleeve and close to the needle tip of the conductive needle core, and the temperature sensor is used to sense the temperature of the liquid in the sample injection channel; and / or

[0015] The sample addition needle also includes a temperature switch, which is arranged outside the conductive needle core and is used to cut off the power supply to the heating element when it is sensed that the temperature of the liquid in the sample addition channel exceeds a preset value.

[0016] In a second aspect, the present invention further provides a liquid level detection device, the liquid level detection device comprising a control circuit, a drive mechanism and a sample adding needle of any one of the above embodiments, the conductive needle core, the conductive sleeve and the heating element are electrically connected to the control circuit respectively, and the conductive sleeve is grounded;

[0017] The driving mechanism is connected to the sample adding needle and is used to drive the sample adding needle to move.

[0018] In a third aspect, the present invention further provides a liquid level detection method, which is applied to the liquid level detection device of the above embodiment, and the liquid level detection method comprises the following steps:

[0019] After the preset conditions are met, the liquid level detection device performs a liquid level detection action;

[0020] The preset conditions include one or more of the heating element stopping heating for a preset time, the sample adding needle being moved to a preset area by the driving mechanism, and the sample adding needle being cleaned.

[0021] In a fourth aspect, the present invention further provides a sample analyzer, which comprises an analysis device and the liquid level detection device of the above embodiment.

[0022] The embodiments of the present invention have the following beneficial effects:

[0023] With the sample adding needle of the present invention, the conductive sleeve is sleeved on the outside of the conductive needle core, the first insulating layer is arranged between the inner wall of the conductive sleeve and the outer wall of the conductive needle core, a detection capacitor is formed between the conductive needle core and the conductive sleeve, and the conductive needle core and the conductive sleeve are respectively used to be electrically connected to the control circuit, so that the liquid level detection function can be realized according to the change of the detection capacitance between the conductive needle core and the conductive sleeve. Since the heating element is sleeved on the outer wall of the conductive sleeve, that is, the heating element is arranged outside the detection capacitor, the change of the dielectric constant caused by the heating element can be eliminated as much as possible, thereby avoiding the sudden change of the detection capacitance and ensuring the accuracy of the liquid level detection.

[0024] The above-mentioned sample adding needle is applied to a liquid level detection device and a sample analyzer. Since the heating element is sleeved on the outer wall of the conductive sleeve, the change in the dielectric constant caused by the heating element can be eliminated as much as possible, thereby providing a heating function for the sample adding needle while ensuring the accuracy of the liquid level detection function.

[0025] By adopting the liquid level detection method of the present invention and applying the sample adding needle of the present invention, the change in dielectric constant caused by the heating element can be eliminated as much as possible, thereby providing a heating function for the sample adding needle while ensuring the accuracy of the liquid level detection function. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] in:

[0028] Figure 1 FIG. 1 is a schematic diagram of the cross-sectional structure of a sample adding needle in an embodiment.

[0029] Figure 2 for Figure 1 An enlarged schematic diagram of part A of the sample injection needle is shown.

[0030] Figure 3 for Figure 1 The schematic diagram of capacitance detection of the sample injection needle is shown.

[0031] Figure numbers: 10, sample injection needle; 100, conductive needle core; 200, first insulating layer; 300, conductive sleeve; 400, heating element; 500, second insulating layer; 510, first part; 520, second part; 600, housing; 700, heat shrink tube; 810, temperature sensor; 820, temperature switch; 910, first fixing member; 920, second fixing member; 930, third fixing member. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0034] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0035] The embodiment of the present invention provides a sample analyzer, which can detect and analyze samples (such as blood, urine, etc.) and provide reliable digital evidence for clinical diagnosis of various diseases of patients.

[0036] See also Figures 1 to 3 A sample analyzer of one embodiment includes an analyzing device and a liquid level detecting device, wherein the liquid level detecting device includes a control circuit, a driving mechanism and a sample adding needle 10. The control circuit is electrically connected to the sample adding needle 10 and is used to detect the detection capacitance of the sample adding needle 10, thereby realizing the liquid level detecting function of the liquid level detecting device. The driving mechanism is connected to the sample adding needle 10 and is used to drive the sample adding needle 10 to move, thereby being able to transfer the liquid in the sample adding needle 10.

[0037] In this embodiment, the sample loading needle 10 includes a conductive needle core 100, a first insulating layer 200, a conductive sleeve 300, a heating element 400, a second insulating layer 500 and a shell 600. A sample loading channel and a sample loading hole connected to the sample loading channel are opened in the conductive needle core 100, so that liquid can be sucked into the sample loading channel through the sample loading hole.

[0038] The conductive sleeve 300 is sleeved on the outside of the conductive needle core 100, the first insulating layer 200 is arranged between the inner wall of the conductive sleeve 300 and the outer wall of the conductive needle core 100, the heating element 400 is sleeved on the outer wall of the conductive sleeve 300 and is used to heat the liquid in the sample addition channel, the outer shell 600 is sleeved on the outside of the heating element 400, the second insulating layer 500 is arranged between the heating element 400 and the outer shell 600, and the conductive needle core 100 and the conductive sleeve 300 form a detection capacitor, so that the conductive needle core 100 can be detected according to the conductive needle core 100. The liquid level detection function is realized by detecting the change of the capacitance between the conductive sleeve 300 and the conductive sleeve 300. Since the heating element 400 is sleeved on the outer wall of the conductive sleeve 300, that is, the heating element 400 is arranged outside the detection capacitor, the insulating layer medium of the detection capacitor becomes single and will not be affected by stray capacitance such as the heating element 400. Therefore, the change of the dielectric constant caused by the heating element 400 can be eliminated as much as possible, thereby avoiding the sudden change of the detection capacitance, and thus providing the heating function for the sample injection needle 10 while ensuring the accuracy of the liquid level detection function.

[0039] In this embodiment, the conductive needle core 100, the conductive sleeve 300 and the heating element 400 are electrically connected to the control circuit respectively. The control circuit can detect the change of the detection capacitance between the conductive needle core 100 and the conductive sleeve 300, thereby realizing the liquid level detection function. At the same time, the control circuit can also control the heating operation of the heating element 400, thereby realizing the heating function.

[0040] It is understandable that the sample analyzer also includes an aspiration and discharge device, which is connected to the sample loading channel of the sample loading needle 10. The aspiration and discharge device can aspirate liquid from the sample loading hole into the sample loading channel, and can also discharge the liquid in the sample loading channel from the sample loading hole, thereby realizing the throughput of the sample loading needle 10 for the liquid, and the liquid can be selected as a reagent or a sample.

[0041] During specific operation, when the needle tip of the needle core contacts the liquid in the container, the detection capacitance between the conductive needle core 100 and the conductive sleeve 300 will change, and the control circuit can detect the change in the detection capacitance, thereby determining that the sample needle 10 has entered the liquid surface of the liquid in the container. At this time, the suction and discharge device can suck the liquid from the sample hole into the sample channel. At the same time, the driving mechanism can control the sample needle 10 to stop at a preset depth in the liquid surface, thereby preventing the sample needle 10 from touching the bottom wall of the container and hitting the needle.

[0042] In one embodiment, the sample loading hole is opened at the needle tip of the conductive needle core 100, that is, the sample loading hole is opened at the end or side of the needle tip, so as to facilitate the sample loading needle 10 to fully absorb the liquid in the container. When the sample loading needle 10 is a puncture needle, the sample loading hole is usually opened on the side of the needle tip.

[0043] In one embodiment, please continue to refer to Figures 1 to 3 The conductive sleeve 300 is grounded, so that a shielding layer can be formed at the conductive sleeve 300 to prevent the conductive needle core 100 and the conductive sleeve 300 from forming stray capacitance outside the conductive sleeve 300, thereby ensuring the accuracy and reliability of the liquid level detection device.

[0044] Furthermore, in the present embodiment, the outer shell 600 is a metal sleeve or a non-metal sleeve, and the outer shell 600 is cylindrical and is used for coaxial assembly with the driving mechanism. Through the setting of the outer shell 600, the sample adding needle 10 is conveniently installed coaxially on the driving mechanism, thereby ensuring the assembly accuracy and convenience of the sample adding needle 10, thereby ensuring the position accuracy and reliability of the movement of the sample adding needle 10.

[0045] When the outer shell 600 is a non-metal sleeve, the outer shell 600 may be a sleeve structure made of plastic.

[0046] When the outer shell 600 is a metal sleeve, the outer shell 600 is grounded, so that external interference can be shielded by the outer shell 600. The axial length of the outer shell 600 is not greater than the axial length of the conductive sleeve 300, and the outer shell 600 is completely covered on the outside of the conductive sleeve 300, so that the coupling capacitance and stray capacitance caused by the outer shell 600 can be better shielded by the conductive sleeve 300, thereby ensuring the accuracy and reliability of the liquid level detection device.

[0047] Furthermore, in the present embodiment, the heating element 400 is a heating wire, and the heating wire is completely wound around the outer wall of the conductive sleeve 300. That is to say, the axial dimension of the heating wire wound around the outer wall of the conductive sleeve 300 is less than or equal to the axial dimension of the conductive sleeve 300, so that the coupling capacitance and stray capacitance caused by the heating wire can be better shielded by the conductive sleeve 300, thereby ensuring the accuracy and reliability of the liquid level detection device.

[0048] Through the above arrangement, the conductive needle core 100 can be completely shielded by the conductive sleeve 300 to prevent the surrounding metal and conductive materials from forming stray capacitance on the conductive needle core 100 .

[0049] Specifically, the winding density of the heating wire on the outer wall of the conductive sleeve 300 gradually decreases from the needle tip of the conductive needle core 100 to the tail of the conductive needle core 100, so that the heating power of the heating wire to the liquid in the heating channel can be configured to gradually decrease from the needle tip of the conductive needle core 100 to the tail of the conductive needle core 100, and a larger heating power is used to quickly heat the liquid sucked by the sample needle 10 to a preset temperature. Of course, in other embodiments, the heating wire can also be evenly distributed on the outer wall of the conductive sleeve 300, and the heating power of the heating element 400 at different positions in the heating channel can be configured by adjusting the winding density of the heating wire on the outer wall of the conductive sleeve 300, so as to configure the heating wire according to the heating demand of the liquid in the heating channel. Of course, the winding density of the heating wire on the outer wall of the conductive sleeve 300 is also limited by the size of the conductive sleeve 300 and the size and length of the heating wire.

[0050] In one embodiment, please continue to refer to Figures 1 to 3 The sample needle 10 also includes a heat shrink tube 700, which is sleeved on the outer wall of the heating element 400, and at least part of the second insulating layer 500 is filled between the inner wall of the heat shrink tube 700 and the outer wall of the conductive sleeve 300. When the heating element 400 is heated, the heat shrink tube 700 can absorb heat and shrink and deform to shrink the needle core, the first insulating layer 200, the conductive sleeve 300 and at least part of the second insulating layer 500 into one body, thereby eliminating the gap between the needle core, the first insulating layer 200 and the conductive sleeve 300, avoiding the generation of the insulation gap and causing a sudden change in capacitance, and ensuring the accuracy and reliability of the liquid level detection device. The setting of the heat shrink tube 700 can eliminate the influence of heating on the internal structure of the sample needle 10, avoid deformation of the physical structure in the sample needle 10, and thus eliminate the influence of the dielectric constant of the insulating medium.

[0051] In this embodiment, the second insulating layer 500 is an insulating structure formed by solidified glue, so that the conductive sleeve 300 and the heating wire are insulated from the outer shell 600. Specifically, the second insulating layer 500 includes a first part 510 arranged between the inner wall of the heat shrink tube 700 and the outer wall of the conductive sleeve 300, and a second part 520 arranged between the outer wall of the heat shrink tube 700 and the inner wall of the outer shell 600, so as to bond the heat shrink tube 700 and the outer shell 600 to the outside of the conductive sleeve 300 through the second glue layer.

[0052] In one embodiment, please continue to refer to Figures 1 to 3, the conductive sleeve 300 is a structural part made of metal, so that the conductive sleeve 300 can conduct electricity. Furthermore, the conductive sleeve 300 can be selected as a structural part made of copper foil. The conductive sleeve 300 can absorb the heat generated by the heating element 400 and transfer the heat to the liquid in the heating channel. Through the setting of the conductive sleeve 300, the uniformity of heat transfer can be ensured, thereby ensuring the uniformity of liquid heating in the heating channel. Specifically, the conductive needle core 100 is a structural part made of metal. Of course, the conductive sleeve 300 can also be a structural part made of other metals such as silver foil and aluminum foil, or the conductive sleeve 300 can also be a structural part stamped by a metal CNC machine tool.

[0053] In this embodiment, the gap size between the conductive sleeve 300 and the conductive needle core 100 is no greater than 0.5 mm, so as to ensure the heat transfer efficiency of the first insulating layer 200 and avoid affecting the preheating efficiency of the heating element 400 .

[0054] The purpose of setting a small gap between the conductive sleeve 300 and the conductive needle core 100 is to control the heat conduction from the conductive sleeve 300 to the conductive needle core 100. The size of the gap between the conductive sleeve 300 and the conductive needle core 100 needs to be able to preheat the liquid in the sample injection channel to the target temperature within a fixed time.

[0055] Specifically, the first insulating layer 200 may be a thermally conductive insulating adhesive paper coated on the outer wall of the conductive needle core 100. Of course, the first insulating layer 200 may also be an insulating layer formed by solidifying insulating adhesive.

[0056] It can be understood that the closer the distance between the two electrodes of the detection capacitor is, the larger the detection capacitance is. The two electrodes of the detection capacitor are the conductive sleeve 300 and the conductive needle core 100 respectively. Therefore, the gap size between the conductive sleeve 300 and the conductive needle core 100 is configured to be as small as possible, then the larger the detection capacitance of the sample needle 10 is. Moreover, there is no need to set components such as a heating element 400 between the conductive sleeve 300 and the conductive needle core 100, thereby avoiding the coupling capacitance and stray capacitance caused, thereby ensuring the accuracy and reliability of the liquid level detection device.

[0057] Specifically, the thickness of the first insulating layer 200 is not greater than 0.5 mm, so that the gap size between the conductive sleeve 300 and the conductive needle core 100 is not greater than 0.5 mm. The gap size between the conductive sleeve 300 and the conductive needle core 100 can be selected to be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm or 0.5 mm, that is, the thickness of the first insulating layer 200 can be selected to be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm or 0.5 mm.

[0058] Preferably, the thickness of the first insulating layer 200 is not greater than 0.1 mm, so that the gap size between the conductive sleeve 300 and the conductive needle core 100 is not greater than 0.1 mm. The gap size between the conductive sleeve 300 and the conductive needle core 100 can be selected as 0.07 mm, 0.08 mm or 0.09 mm, that is, the thickness of the first insulating layer 200 can be selected as 0.07 mm, 0.08 mm or 0.09 mm. Of course, in other embodiments, the thickness of the first insulating layer 200 can also be greater than 0.5 mm, for example, the thickness of the first insulating layer 200 can also be selected as 0.6 mm, 0.7 mm, etc., but as the thickness of the first insulating layer 200 increases, it will affect the preheating efficiency of the heating element 400. In this embodiment, the smaller the gap size between the conductive sleeve 300 and the conductive needle core 100, the higher the preheating efficiency of the heating element 400, but it is also necessary to ensure the insulation performance of the first insulating layer 200.

[0059] In one embodiment, please continue to refer to Figures 1 to 3 The sample injection needle 10 also includes a temperature sensor 810, which is arranged on the outer wall of the conductive sleeve 300 and is arranged near the needle tip of the conductive needle core 100. The temperature sensor 810 is used to sense the temperature of the liquid in the sample injection channel, thereby controlling the working condition of the heating element 400 according to the temperature data sensed by the temperature sensor 810.

[0060] Furthermore, the sample loading needle 10 also includes a temperature switch 820, which is arranged outside the conductive needle core 100 and is used to disconnect the power supply to the heating element 400 when the temperature of the liquid in the sample loading channel exceeds a preset value, thereby preventing the liquid in the heating channel from overheating and losing active ingredients. Specifically, the temperature switch 820 is connected in series between the heating element 400 and the control circuit. When the temperature switch 820 senses that the temperature of the liquid in the sample loading channel is too high, the temperature switch 820 disconnects the power supply to the heating element 400. At this time, the heating element 400 is disconnected from the control circuit. When the temperature of the liquid in the sample loading channel drops to a preset value, the temperature switch 820 restores the power supply to the heating element 400. At this time, the heating element 400 can work normally under the control of the control circuit. The temperature sensor 810 and the temperature switch 820 cooperate to control the temperature of the liquid in the sample loading channel.

[0061] In this embodiment, the sample needle 10 is placed vertically, and the needle tip of the conductive needle core 100 is located at the bottom. The sample needle 10 also includes an upper fixing structure and a lower fixing structure. The lower ends of the conductive needle core 100, the conductive sleeve 300, the shell 600 and the heat shrink tube 700 in the sample needle 10 are installed through the lower fixing structure, and the upper ends of the conductive needle core 100, the conductive sleeve 300, the shell 600 and the heat shrink tube 700 in the sample needle 10 are installed through the upper fixing structure, wherein the lower fixing structure is provided with a , and is a first fixing member 910, the first fixing member 910 is a fixed end cover, the upper end fixing structure is provided with two, and are respectively a second fixing member 920 and a third fixing member 930, the second fixing member 920 is a fixed sleeve, and is sleeved on the outer wall of the conductive needle core 100, the second fixing member 920 is provided with a accommodating cavity for accommodating the temperature switch 820, the third fixing member 930 is a fixed end cover, and is fixed to the side of the second fixing member 920 away from the needle tip of the conductive needle core 100, thereby realizing the assembly of various components in the sampling needle 10.

[0062] See also Figures 1 to 3 The liquid level detection method of one embodiment is used for the liquid level detection device of the above embodiment, and the liquid level detection method comprises the following steps:

[0063] After the preset conditions are met, the liquid level detection device performs a liquid level detection action.

[0064] It can be understood that a detection capacitor is formed between the conductive needle core 100 and the conductive sleeve 300, and the conductive needle core 100 and the conductive sleeve 300 are electrically connected to the control circuit respectively, so that the liquid level detection function can be realized according to the change of the detection capacitance between the conductive needle core 100 and the conductive sleeve 300. Since the heating element 400 is sleeved on the outer wall of the conductive sleeve 300, that is, the heating element 400 is arranged outside the detection capacitor, the change of the dielectric constant caused by the heating element 400 can be eliminated as much as possible, thereby avoiding the sudden change of the detection capacitance, and thus providing the heating function for the sample adding needle 10 while ensuring the accuracy of the liquid level detection function.

[0065] In this embodiment, the preset conditions include one or more of the heating element 400 turning off heating for a preset time, the sample adding needle 10 being moved to a preset area by the driving mechanism, and the sample adding needle 10 being cleaned.

[0066] It should be noted that since the sampling needle 10 not only needs to perform the liquid aspiration step, the heating step and the liquid level detection step, it also needs to perform the outer wall cleaning step of the sampling needle 10 and the step of transferring the liquid through the sampling needle 10, etc., the liquid level detection step will not be started until the sampling needle 10 completes other execution steps and moves to a preset height above the liquid surface under the drive of the driving mechanism.

[0067] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A sample adding needle, characterized in that: The sample loading needle comprises a conductive needle core, a first insulating layer, a conductive sleeve, a heating element, a second insulating layer and an outer shell. The conductive needle core is provided with a sample loading channel and a sample loading hole connected to the sample loading channel. The conductive sleeve is sleeved on the outside of the conductive needle core. The first insulating layer is arranged between the inner wall of the conductive sleeve and the outer wall of the conductive needle core. The heating element is sleeved on the outer wall of the conductive sleeve and is used to heat the liquid in the sample loading channel. The outer shell is sleeved on the outside of the heating element. The second insulating layer is arranged between the heating element and the outer shell. Wherein, a detection capacitor is formed between the conductive needle core and the conductive sleeve, and the conductive needle core and the conductive sleeve are respectively used to be electrically connected to a control circuit.

2. The sample injection needle according to claim 1, characterized in that: The conductive sleeve is grounded, the heating element is a heating wire, and the heating wire is completely wound around the outer wall of the conductive sleeve.

3. The sample injection needle according to claim 2, characterized in that: The winding density of the heating wire on the outer wall of the conductive sleeve gradually decreases from the needle tip of the conductive needle core to the tail of the conductive needle core.

4. The sample injection needle according to claim 1, characterized in that: The conductive sleeve is grounded, the housing is a metal sleeve or a non-metal sleeve, the housing is cylindrical and is used for coaxial assembly with the driving mechanism; and / or The sample adding needle also includes a heat shrink tube, which is sleeved on the outer wall of the heating element, and at least a part of the second insulating layer is filled between the inner wall of the heat shrink tube and the outer wall of the conductive sleeve.

5. The sample injection needle according to claim 1, characterized in that: The thickness of the first insulating layer is not greater than 0.5 mm, or the gap size between the conductive sleeve and the conductive needle core is not greater than 0.5 mm.

6. The sample injection needle according to claim 1, characterized in that: The conductive sleeve is a structural member made of metal; and / or The second insulating layer is an insulating structure formed by solidifying glue.

7. The sample injection needle according to claim 1, characterized in that: The sample injection needle further comprises a temperature sensor, which is arranged on the outer wall of the conductive sleeve and close to the needle tip of the conductive needle core, and is used to sense the temperature of the liquid in the sample injection channel; and / or The sample addition needle also includes a temperature switch, which is arranged outside the conductive needle core and is used to cut off the power supply to the heating element when it is sensed that the temperature of the liquid in the sample addition channel exceeds a preset value.

8. A liquid level detection device, characterized in that: The liquid level detection device comprises a control circuit, a driving mechanism and the sample addition needle according to any one of claims 1 to 7, the conductive needle core, the conductive sleeve and the heating element are electrically connected to the control circuit respectively, and the conductive sleeve is grounded; The driving mechanism is connected to the sample adding needle and is used to drive the sample adding needle to move.

9. A liquid level detection method, characterized in that: The liquid level detection method is applied to the liquid level detection device according to claim 8, and the liquid level detection method comprises the following steps: After the preset conditions are met, the liquid level detection device performs a liquid level detection action; The preset conditions include one or more of the heating element stopping heating for a preset time, the sample adding needle being moved to a preset area by the driving mechanism, and the sample adding needle being cleaned.

10. A sample analyzer, characterized in that: The sample analyzer comprises an analyzing device and the liquid level detection device according to claim 8.

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