Sample collection device for urine sample RNA analysis

Abstract

The utility model discloses a sample collection device for urine sample RNA analysis, it includes liquid taking device, RNA collection pipe and urine collection pipe, liquid taking device can be inserted to urine collection pipe inside and be used for sucking the urine to be examined, RNA collection pipe includes the lysis cavity and adsorption cavity, and adsorption cavity is connected in lysis cavity, liquid taking device can be inserted to lysis cavity inside and will be examined urine injects in lysis cavity, and the diaphragm that can be punctured is equipped between lysis cavity and adsorption cavity, and the liquid in lysis cavity flows into adsorption cavity by puncturing diaphragm. The whole process operation of urine sample's collection, lysis and RNA collection can be realized, and the urine to be examined need not be transferred for many times, reduces the risk of RNA degradation and pollution, improves the stability of RNA extraction, and the collection and pretreatment of urine RNA are rapidly completed without professional laboratory equipment, the sampling efficiency is greatly improved, and the demand of on -the -spot collection, transportation and long -term preservation can be satisfied.

Description

Technical Field

[0001] This utility model relates to the field of medical devices, and in particular to a sample collection device for RNA analysis of urine samples. Background Technology

[0002] Urine, as a non-invasive and easily collected biological sample, is increasingly becoming an important material for liquid biopsies due to its content of various RNA molecules originating from the urinary system and systemic circulation. Urine RNA analysis is of great significance for clinical and scientific research, including early disease detection, etiological studies, and monitoring of treatment efficacy. However, RNA molecules are highly susceptible to degradation by RNases in the environment. Traditional urine RNA collection typically requires on-site cryogenic equipment or immediate addition of stabilizers, which is cumbersome and time-delayed. Therefore, there is an urgent need for a device that can immediately collect and stabilize RNA after urine collection, simplifying sample processing and suitable for on-site collection, transportation, and long-term preservation. Utility Model Content

[0003] The technical problem to be solved by this invention is to overcome the shortcomings of existing technologies, such as the need for on-site low-temperature equipment or immediate addition of stabilizers for RNA collection, which are cumbersome and time-delayed, and the fact that RNA molecules are highly susceptible to degradation by RNase in the environment. This invention provides a sample collection device for RNA analysis of urine samples.

[0004] The present invention solves the above-mentioned technical problems through the following technical solution:

[0005] A sample collection device for RNA analysis of urine samples is characterized in that it includes a liquid extractor, an RNA collection tube, and a urine collection tube for containing urine to be tested. The liquid extractor can be inserted into the urine collection tube to aspirate the urine to be tested. The RNA collection tube includes a lysis chamber containing reagents and an adsorption chamber containing adsorbed RNA. The adsorption chamber is connected to the lysis chamber. The liquid extractor can be inserted into the lysis chamber and inject the urine to be tested into the lysis chamber. A puncturable septum is provided between the lysis chamber and the adsorption chamber, and the liquid in the lysis chamber can be allowed to flow into the adsorption chamber by puncturing the septum.

[0006] In this solution, the aforementioned structure allows the sampler to directly draw urine from the urine collection tube and inject it into the lysis chamber without the need for additional transfer containers. This avoids contact between the urine sample and the external environment, reducing the risk of RNA degradation. The puncturable septum between the lysis chamber and the adsorption chamber ensures that the reagents in the lysis chamber remain separated from those in the adsorption chamber before use, guaranteeing that the lysis and adsorption processes proceed in a predetermined order and improving the stability of RNA extraction. Ultimately, the entire process of urine sample collection, lysis, and RNA collection is achieved without the need for multiple transfers of the urine sample, reducing the risk of RNA degradation and contamination, and improving the stability of RNA extraction. This allows for rapid collection and pretreatment of urine RNA without the need for specialized laboratory equipment, significantly improving sampling efficiency and meeting the needs of on-site collection, transportation, and long-term preservation.

[0007] Preferably, the top of the lysis chamber is covered with a first membrane structure so that a sealed space is formed inside the lysis chamber between the first membrane structure and the diaphragm, and the liquid extractor punctures the first membrane structure and injects the urine to be tested into the lysis chamber.

[0008] In this scheme, the above-mentioned structural form is adopted. The first membrane structure completely isolates the inside of the lysis chamber from the outside world, preventing the reagents inside the lysis chamber from coming into contact with the outside world and ensuring the stability of the lysis reagents. The diaphragm prevents the lysis solution from flowing into the adsorption chamber in advance, so that the lysis chamber is in a completely sealed state, ensuring that the urine sample to be tested can complete the lysis reaction in a sealed environment after injection, avoiding RNA from coming into contact with the outside world during the lysis process and causing degradation, further improving sample stability and simplifying the operation.

[0009] Preferably, the RNA collection tube further includes a first cap, which is detachably connected to the top of the lysis chamber, and the first membrane structure is disposed on the first cap.

[0010] In this solution, the above-mentioned structural form is adopted, which makes production more convenient, the sealing performance more reliable, and facilitates the subsequent encapsulation of lysis reagents. At the same time, the first membrane structure is set on the first tube cap. When the first membrane structure is damaged, the lysis chamber can be replaced by removing the first tube cap, which is convenient, quick, and reduces the user's operating costs.

[0011] Preferably, the bottom of the adsorption chamber is provided with a through hole for the discharge of waste liquid, and the RNA collection tube further includes a waste liquid chamber located directly below the through hole and used to collect the waste liquid.

[0012] In this scheme, the above-mentioned structural form is adopted, so that the lysed urine to be tested flows through the solid adsorption column in the adsorption chamber under the action of gravity. After the solid adsorption column adsorbs RNA, the remaining waste liquid flows into the waste liquid chamber through the through hole under the action of gravity. The whole process does not require additional operation, is simple to operate, has high RNA extraction efficiency, and the waste liquid is collected in the waste liquid chamber for convenient centralized treatment, avoiding pollution.

[0013] Preferably, the waste liquid chamber is detachably connected to the pyrolysis chamber and / or the adsorption chamber.

[0014] In this scheme, the above-mentioned structure is adopted. When the waste liquid chamber is full, the waste liquid can be collected and treated by simply unscrewing the waste liquid chamber. The waste liquid treatment process is simple, convenient and efficient. After the RNA separation is completed, the adsorption chamber and the waste liquid chamber can be separated to obtain the separated RNA. It is convenient, fast and efficient.

[0015] Preferably, the adsorption chamber and the pyrolysis chamber are detachably connected.

[0016] In this solution, the above-mentioned structural form makes it easier and faster to assemble and disassemble the adsorption chamber and the pyrolysis chamber, and the sealing performance between the adsorption chamber and the pyrolysis chamber is more reliable.

[0017] Preferably, the liquid collection device includes a syringe with a piston rod, a sampling needle, and a filter membrane needle. Both the sampling needle and the filter membrane needle are detachably connected to the syringe and have an extraction state and an injection state. In the extraction state, the syringe is connected to the sampling needle, and the sampling needle is inserted into the urine collection tube to draw the urine sample into the syringe. In the injection state, the syringe is connected to the filter membrane needle, and the filter membrane needle is inserted into the lysis chamber to inject the urine sample from the syringe into the lysis chamber.

[0018] In this scheme, the above-mentioned structural form is adopted. During the extraction process, the second membrane structure isolates the urine sample from the outside world, protecting the RNA in the urine from external interference and improving the stability of the RNA in the urine sample. During the injection process, the urine sample is completely isolated from the outside world, preventing RNA degradation and ensuring the integrity and stability of the RNA in the urine sample. After filtration by the filter membrane, large particulate impurities and cell debris can be effectively removed, improving the reliability of subsequent molecular detection.

[0019] Preferably, the urine collection tube includes a second cap and a tube body, the second cap being detachably connected to the tube body, and the tube body and the second cap sealingly accommodating the urine to be tested.

[0020] In this scheme, the above-mentioned structure makes it more convenient and faster to collect the urine to be tested through the urine collection tube, and the urine to be tested is sealed and stored in the urine collection tube to prevent the RNA in the urine to be tested from being degraded.

[0021] Preferably, the second tube cap is covered with a second membrane structure, and the liquid extractor punctures the second membrane structure to extract the urine to be tested.

[0022] In this scheme, the above-mentioned structural form is adopted. The second membrane structure isolates the urine sample from the outside world, protects the RNA in the urine from external interference, and improves the stability of the RNA in the urine sample.

[0023] Preferably, the pyrolysis chamber includes a cylindrical section and a constricted section, the cross-sectional area of ​​the constricted section gradually decreases from top to bottom, the large port of the constricted section is connected to the bottom of the cylindrical section, and the constricted section is in communication with the cylindrical section, and the diaphragm is connected to the small port of the constricted section.

[0024] In this scheme, the above-mentioned structural form is adopted so that the contraction section acts as a buffer chamber of the lysis chamber, absorbing the impact force generated by the urine sample injected by the sampler, avoiding direct impact of urine on the diaphragm, protecting the diaphragm and preventing premature rupture; the contraction section allows the lysed urine sample to flow quickly along the inclined surface of the contraction section to the small port where the diaphragm is located, reducing the residue of urine sample in the lysis chamber and improving the RNA recovery rate.

[0025] The positive and progressive effects of this utility model are as follows:

[0026] This invention relates to a sample collection device for RNA analysis of urine samples. The sampler directly draws urine from the collection tube and injects it into the lysis chamber, eliminating the need for additional transfer containers and preventing contact between the urine sample and the external environment, thus reducing the risk of RNA degradation. A puncturable diaphragm between the lysis chamber and the adsorption chamber ensures that the reagents in the lysis chamber remain separated from those in the adsorption chamber before use, guaranteeing that the lysis and adsorption processes proceed in a predetermined order and improving the stability of RNA extraction. Ultimately, the entire process of urine sample collection, lysis, and RNA collection is achieved without the need for multiple transfers of the urine sample, reducing the risk of RNA degradation and contamination, and improving the stability of RNA extraction. This device allows for rapid collection and pretreatment of urine RNA without the need for specialized laboratory equipment, significantly improving detection efficiency and meeting the needs of on-site collection, transportation, and long-term preservation. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the sample collection device for RNA analysis of urine samples according to an embodiment of the present invention.

[0028] Explanation of reference numerals in the attached figures:

[0029] Sample collection device 1 for RNA analysis of urine samples

[0030] Urine collection tube 2

[0031] Second pipe cover 21

[0032] Tube body 22

[0033] Second membrane structure 23

[0034] Liquid dispenser 3

[0035] Syringe 31

[0036] 32 needles with filter membrane

[0037] Filter membrane 321

[0038] Sampling needle 33

[0039] RNA collection tube 4

[0040] rupture chamber 41

[0041] First membrane structure 411

[0042] Diaphragm 412

[0043] Cylindrical part 413

[0044] Shrinkage section 414

[0045] First tube cap 42

[0046] Adsorption cavity 43

[0047] Through hole 431

[0048] Waste liquid chamber 44 Detailed Implementation

[0049] The present invention will be described more clearly and completely below with reference to the accompanying drawings, using a preferred embodiment.

[0050] like Figure 1As shown, this embodiment discloses a sample collection device 1 for RNA analysis of urine samples. The sample collection device 1 for RNA analysis of urine samples includes a liquid extractor 3, an RNA collection tube 4, and a urine collection tube 2 for containing urine to be tested. The liquid extractor 3 can be inserted into the urine collection tube 2 and used to draw urine to be tested. The RNA collection tube 4 includes a lysis chamber 41 with reagents inside and an adsorption chamber 43 with RNA adsorption inside. The adsorption chamber 43 is connected to the lysis chamber 41. The liquid extractor 3 can be inserted into the lysis chamber 41 and inject the urine to be tested into the lysis chamber 41. A puncturable diaphragm 412 is provided between the lysis chamber 41 and the adsorption chamber 43. By puncturing the diaphragm 412, the liquid in the lysis chamber 41 flows into the adsorption chamber 43.

[0051] The liquid collector 3 can directly draw urine from the urine collection tube 2 and inject it into the lysis chamber 41 without the need for an additional transfer container, thus avoiding contact between the urine sample and the external environment and reducing the risk of RNA degradation. The puncturable septum 412 between the lysis chamber 41 and the adsorption chamber 43 keeps the reagents in the lysis chamber 41 separate from the adsorption chamber 43 before use, ensuring that the lysis and adsorption processes proceed in a predetermined order and improving the stability of RNA extraction. Finally, the entire process of urine sample collection, lysis, and RNA collection is realized without the need for multiple transfers of the urine sample, reducing the risk of RNA degradation and contamination, improving the stability of RNA extraction, and quickly completing the collection and pretreatment of urine RNA without the need for professional laboratory equipment, greatly improving sampling efficiency and meeting the needs of on-site collection, transportation, and long-term preservation.

[0052] In this embodiment, the reagents in the lysis chamber 41 are RNase inhibitors and lysis buffers, and the adsorption chamber 43 is filled with a solid adsorption column with the diameter of the solid adsorption column being equal to the inner diameter of the lysis chamber 41. In other embodiments, the RNase inhibitors and lysis buffers in the lysis chamber 41 can be selected as needed to adapt to different urine sample types and RNA stability requirements.

[0053] The top of the lysis chamber 41 is covered with a first membrane structure 411 so that the interior of the lysis chamber 41 is formed between the first membrane structure 411 and the diaphragm 412. The liquid extractor 3 punctures the first membrane structure 411 and injects the urine to be tested into the lysis chamber 41.

[0054] In this embodiment, the first membrane structure 411 is a membrane structure that does not allow liquid to pass through but allows the sampling needle 33 to pass through. The first membrane structure 411 and the diaphragm 412 form a sealed space inside the lysis chamber 41. The first membrane structure 411 completely isolates the inside of the lysis chamber 41 from the outside world, preventing the reagents inside the lysis chamber 41 from contacting the outside world and ensuring the stability of the lysis reagents. The diaphragm 412 prevents the lysis solution from flowing into the adsorption chamber 43 in advance, so that the lysis chamber 41 is in a completely sealed state, ensuring that the urine sample to be tested can complete the lysis reaction in a sealed environment after injection, avoiding RNA degradation due to contact with the outside world during the lysis process, further improving sample stability and simplifying operation.

[0055] The RNA collection tube 4 also includes a first cap 42, which is detachably connected to the top of the lysis chamber 41. A first membrane structure 411 is disposed on the first cap 42. The first membrane structure 411 being disposed on the first cap 42 allows for separate production and assembly of the first cap 42 and the first membrane structure 411. Compared to integrating the first membrane structure 411 with the lysis chamber 41, this method is more convenient to produce, provides more reliable sealing, and facilitates subsequent encapsulation of lysis reagents. Furthermore, the first membrane structure 411 being disposed on the first cap 42 allows for easy replacement of the first membrane structure 411 if it is damaged, thus reducing user costs.

[0056] The bottom of the adsorption chamber 43 is provided with a through hole 431 for the outflow of waste liquid. The RNA collection tube 4 also includes a waste liquid chamber 44, which is located directly below the through hole 431 and is used to collect waste liquid. The through hole 431 at the bottom of the adsorption chamber 43 allows the lysed urine sample to flow through the solid adsorption column in the adsorption chamber 43 under gravity. After the solid adsorption column adsorbs RNA, the remaining waste liquid flows into the waste liquid chamber 44 through the through hole 431 under gravity. The entire process requires no additional operation, is simple to operate, has high RNA extraction efficiency, and the waste liquid collected in the waste liquid chamber 44 is convenient for centralized treatment, avoiding contamination.

[0057] The waste liquid chamber 44 is detachably connected to the pyrolysis chamber 41. This allows the waste liquid to be collected and processed simply by unscrewing the waste liquid chamber 44 when it is full, making the waste liquid treatment process simple, convenient, and efficient.

[0058] The waste liquid chamber 44 is detachably connected to the adsorption chamber 43. This allows the separated RNA to be obtained simply by separating the adsorption chamber 43 from the waste liquid chamber 44 after RNA separation, which is convenient, quick, and efficient.

[0059] The adsorption chamber 43 and the pyrolysis chamber 41 are detachably connected. This makes it easier and faster to assemble and disassemble the adsorption chamber 43 and the pyrolysis chamber 41, and makes the sealing performance between the adsorption chamber 43 and the pyrolysis chamber 41 more reliable.

[0060] In this embodiment, the detachable connection is a threaded connection; in other embodiments, the detachable connection can be a snap-fit ​​connection.

[0061] The liquid collection device 3 includes a syringe 31 with a piston rod, a sampling needle 33, and a filter-membrane needle 32. The sampling needle 33 and the filter-membrane needle 32 are detachably connected to the syringe 31 and have an extraction state and an injection state. In the extraction state, the syringe 31 is connected to the sampling needle 33, and the sampling needle 33 is inserted into the urine collection tube 2 to draw the urine to be tested into the syringe 31. In the injection state, the syringe 31 is connected to the filter-membrane needle 32, and the filter-membrane needle 32 is inserted into the lysis chamber 41 to inject the urine to be tested from the syringe 31 into the lysis chamber 41.

[0062] In the extraction phase, the syringe 31 is connected to the sampling needle 33. The needle is inserted into the urine collection tube 2 through the second membrane structure 23. The plunger with a piston is pulled to extract the urine to be tested into the syringe 31, which has volume markings. During extraction, the second membrane structure 23 isolates the urine from the outside environment, protecting the RNA in the urine from external interference and improving the stability of the RNA in the urine. In the injection phase, the syringe 31 is connected to the filter-membrane needle 32. The filter-membrane needle 32 is inserted into the lysis chamber 41 through the first membrane structure 411. The plunger with a piston is pushed, and the urine to be tested is filtered through the filter membrane 321 on the filter-membrane needle 32 and injected into the lysis chamber 41. During injection, the urine to be tested is completely isolated from the outside environment, preventing RNA degradation and ensuring the integrity and stability of the RNA in the urine. After filtration through the filter membrane 321, large particulate impurities and cell debris can be effectively removed, improving the reliability of subsequent molecular detection.

[0063] The urine collection tube 2 includes a second cap 21 and a tube body 22. The second cap 21 is detachably connected to the tube body 22, and the tube body 22 and the second cap 21 are sealed together to contain the urine to be tested. The detachable connection between the second cap 21 and the tube body 22 allows the urine collection tube 2 to collect urine simply by unscrewing the second cap 21, collecting the urine into the urine collection tube 2, and then screwing the second cap 21 back on. This makes collecting urine more convenient and faster, and the sealed storage of the urine in the urine collection tube 2 prevents RNA degradation in the urine.

[0064] In this embodiment, the tube body 22 of the urine collection tube 2 has volume graduations to facilitate the collection of quantitative urine samples.

[0065] The second cap 21 is covered with a second membrane structure 23. The liquid collector 3 punctures the second membrane structure 23 and is used to collect the urine sample. The second membrane structure 23 isolates the urine sample from the outside environment, protecting the RNA in the urine from external interference and improving the stability of the RNA in the urine sample.

[0066] The lysis chamber 41 includes a cylindrical portion 413 and a constricting portion 414. The cross-sectional area of ​​the constricting portion 414 gradually decreases from top to bottom. The large port of the constricting portion 414 is connected to the bottom of the cylindrical portion 413 and is in communication with the cylindrical portion 413. The diaphragm 412 is connected to the small port of the constricting portion 414. The connection between the constricting portion 414 and the cylindrical portion 413, and the connection between the diaphragm 412 and the small port of the constricting portion 414, allows the constricting portion 414 to act as a buffer chamber for the lysis chamber 41, absorbing the impact force generated by the urine sample injected by the liquid collector 3, preventing the urine from directly impacting the diaphragm 412, protecting the diaphragm 412, and preventing premature rupture. The constricting portion 414 also allows the lysed urine sample to flow quickly along the inclined surface of the constricting portion 414 to the small port where the diaphragm 412 is located, reducing the residual urine sample in the lysis chamber 41 and improving the RNA recovery rate.

[0067] In this embodiment, the urine collection tube 2, the liquid collector 3, and the RNA collection tube 4 are all designed for single use to reduce the risk of cross-contamination.

[0068] The operating steps of this utility model during use are as follows:

[0069] 1. Open the second cap 21 of the urine collection tube 2, collect the urine to be tested into the tube body 22, and then tighten the second cap 21 again to achieve airtight preservation of the urine to be tested.

[0070] 2. Assemble the syringe of the liquid collector 3 with the sampling needle 33, and push and pull the piston to draw the required volume of urine to be tested.

[0071] 3. Connect the syringe 31 to the filter-membrane needle 32, insert the filter-membrane needle 32 into the first membrane structure 411 above the lysis chamber 41 of the RNA collection tube 4, and inject the urine sample to be tested into the lysis chamber 41 through the filter-membrane needle 32. At the same time, the filter membrane 321 of the filter-membrane needle 32 can block large particulate impurities and cell debris, ensuring that the liquid entering the lysis chamber 41 is a homogeneous sample.

[0072] 4. Within the lysis chamber 41, the urine sample to be tested is thoroughly mixed with the RNase inhibitor and lysis buffer to promote RNA stabilization and complete cell lysis.

[0073] 5. Use a needle to puncture the membrane 412 between the disintegration chamber 41 and the adsorption chamber 43, allowing the mixed liquid to flow into the adsorption chamber 43; the mixed liquid passes through the solid adsorption column, and the RNA is efficiently captured, while the waste liquid smoothly enters the waste liquid chamber 44 through the through hole 431 of the adsorption chamber 43.

[0074] 6. After RNA adsorption is complete, the adsorption chamber 43 can be removed from the RNA collection tube 4 for subsequent nucleic acid extraction or analysis experiments, ensuring that the operation is simple, safe and free from cross-contamination.

[0075] While specific embodiments of this utility model have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of this utility model is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this utility model, but all such changes and modifications fall within the scope of protection of this utility model.

Claims

1. A sample collection device for RNA analysis of urine samples, characterized in that, It includes a liquid sampler, an RNA collection tube, and a urine collection tube for containing urine to be tested. The liquid sampler can be inserted into the urine collection tube to draw up the urine to be tested. The RNA collection tube includes a lysis chamber containing reagents and an adsorption chamber containing RNA. The adsorption chamber is connected to the lysis chamber. The liquid sampler can be inserted into the lysis chamber and inject the urine to be tested into the lysis chamber. A puncturable septum is provided between the lysis chamber and the adsorption chamber. By puncturing the septum, the liquid in the lysis chamber can flow into the adsorption chamber.

2. The sample collection device for RNA analysis of urine samples as described in claim 1, characterized in that, The top of the lysis chamber is covered with a first membrane structure so that a sealed space is formed inside the lysis chamber between the first membrane structure and the diaphragm. The liquid extractor punctures the first membrane structure and injects the urine to be tested into the lysis chamber.

3. The sample collection device for RNA analysis of urine samples as described in claim 2, characterized in that, The RNA collection tube also includes a first cap, which is detachably connected to the top of the lysis chamber, and the first membrane structure is disposed on the first cap.

4. The sample collection device for RNA analysis of urine samples as described in claim 1, characterized in that, The bottom of the adsorption chamber is provided with a through hole for the outflow of waste liquid. The RNA collection tube also includes a waste liquid chamber, which is located directly below the through hole and is used to collect the waste liquid.

5. The sample collection device for RNA analysis of urine samples as described in claim 4, characterized in that, The waste liquid chamber is detachably connected to the pyrolysis chamber and / or the adsorption chamber.

6. The sample collection device for RNA analysis of urine samples as described in claim 1, characterized in that, The adsorption chamber and the pyrolysis chamber are detachably connected.

7. The sample collection device for RNA analysis of urine samples as described in claim 1, characterized in that, The liquid sampler includes a syringe with a piston push rod, a sampling needle, and a needle with a filter membrane. The sampling needle and the needle with the filter membrane are detachably connected to the syringe and have a drawing state and an injection state. In the extraction state, the syringe is connected to the sampling needle, and the sampling needle is inserted into the urine collection tube to draw the urine to be tested into the syringe; In the injection state, the syringe is connected to the filter-membrane needle, and the filter-membrane needle is inserted into the lysis chamber to inject the urine sample to be tested from the syringe into the lysis chamber.

8. The sample collection device for RNA analysis of urine samples as described in claim 1, characterized in that, The urine collection tube includes a second cap and a tube body, the second cap being detachably connected to the tube body, and the tube body and the second cap sealingly accommodating the urine to be tested.

9. The sample collection device for RNA analysis of urine samples as described in claim 8, characterized in that, The second tube cap is covered with a second membrane structure, and the liquid extractor punctures the second membrane structure to extract the urine to be tested.

10. The sample collection device for RNA analysis of urine samples as described in claim 1, characterized in that, The pyrolysis chamber includes a cylindrical part and a constriction part. The cross-sectional area of ​​the constriction part gradually decreases from top to bottom. The large port of the constriction part is connected to the bottom of the cylindrical part, and the constriction part is in communication with the cylindrical part. The diaphragm is connected to the small port of the constriction part.

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