Closed carrying rod convenient to operate and capable of preventing liquid nitrogen from leaking

Abstract

The utility model discloses a closed carrying rod which is convenient to operate and capable of preventing liquid nitrogen from leaking, and comprises a sleeve, a carrying rod inserted into the sleeve, a pipe cap covered on the sleeve and a spring, a loading area is arranged at the insertion end of the loading rod, and a first circular truncated cone slope is arranged at the handheld end of the loading rod; a second circular-truncated-cone slope matched with the first circular-truncated-cone slope is arranged in the sleeve, and the lower end of the first circular-truncated-cone slope is inserted into the second circular-truncated-cone slope to form tight fit; the spring is sleeved on the carrying rod, the top end of the spring abuts against the pipe cap, and the bottom end of the spring abuts against the top face of the first circular truncated cone inclined face. The loading rod is continuously pushed to be tightly plugged through the tension of the spring, so that the integrating degree between the sleeve and the loading rod is increased, an embryo needs to be in a closed state during freezing, storage and resuscitation, and liquid nitrogen is prevented from permeating into the sleeve and polluting the embryo. Therefore, tedious operation of ultrasonic welding in the prior art is avoided, and damage of harmful substances such as VOC to embryos is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of assisted reproduction, in particular to a closed carrier rod which is easy to operate and prevents liquid nitrogen from leaking in. Background Art

[0002] Vitrification technology has been widely used in the cryopreservation of human oocytes and embryos at different developmental stages due to its advantages such as high survival rate of embryos after thawing, less manpower and time required, and no need for large equipment. Currently, there are many types of vitrified carriers, which are divided into open carriers and closed carriers according to whether the embryos are in direct contact with liquid nitrogen during the freezing process.

[0003] In the 1990s, Kato Corporation of Japan developed a completely open cryotop, which is made of polymer injection molding. The oocytes are placed on the carrier, and a metal head counterweight is added to the front edge of the carrier to prevent the carrier from floating on the liquid nitrogen during freezing. The completely open cryotop has an ultra-fast freezing rate (23,000-100,000℃ / min), but along with the ultra-fast freezing rate brought by "complete opening", it also inevitably causes the risk of liquid nitrogen contamination. At the same time, long-term open storage of oocytes in liquid nitrogen may cause the loss of biological samples.

[0004] Subsequently, Denmark's Aureligen developed and launched a "first open freezing, then closed storage" cryobar McGill Cryoleaf TM The carrier rod comprises a protective cover, a carrier rod and a lock for locking the protective cover and the carrier rod. During use, (1) first "unlock" the protective cover and the carrier rod, and immerse the protective cover in liquid nitrogen in advance; (2) load the oocyte on the frozen carrier rod; (3) immerse the carrier rod loaded with the oocyte in liquid nitrogen, and quickly "lock" the protective cover pre-immersed in liquid nitrogen with the carrier rod body under liquid nitrogen environment; (4) place the "locked" carrier rod body and protective cover in a liquid nitrogen tank for long-term storage. "Open freezing" makes McGill Cryoleaf TM With ultra-high freezing rate, “closed storage” greatly reduces the possibility of biological sample loss, but McGill Cryoleaf TM The risk of germ cells being contaminated by liquid nitrogen during the open freezing process cannot be avoided.

[0005] In 2010, the French Cryo Blo System developed the HSV (high security vitrification) closed freezing system, which consists of three parts: an oocyte loading rod with a curved groove at the front end, an HSV sleeve with one end open and the other end sealed and a metal rod installed at the sealed end, and auxiliary transfer accessories. The oocyte loading rod and HSV sleeve are heat-sealed and immersed in liquid nitrogen for freezing, shielding the possible contamination caused by liquid nitrogen, but the cooling rate is reduced to 2900℃ / min.

[0006] In 2012, Kato's Cryotop CL[510(k)K112695] used heat-sealing technology to seal the oocyte-loaded carrier with a protective sleeve before immersing it in liquid nitrogen to isolate the oocyte from liquid nitrogen. At the same time, a metal head was installed at the front end of the protective sleeve to accelerate cooling, and a metal ring was installed in the middle of the carrier to prevent breakage during thawing. The "closed" freezing and storage not only isolates liquid nitrogen contamination, but also significantly reduces the freezing rate (3,000°C / min).

[0007] From the above content and the existing closed-type carrier rod designs, such as CN109362705A-A closed-type vitrification cryocarrier and CN113412832A-Freezing carrier rod and its manufacturing method, the "closed" vitrification cryocarrier rod is mostly a "tube" sleeve "rod" structure. Before immersing in liquid nitrogen for freezing, the user first uses a heat sealer to seal the "tube" and "rod" to achieve a completely closed state, or simply presses them with threads. There are obvious disadvantages: (1) Since the closed-type freezing carrier rods are all made of polymer materials by injection molding, when they are in extreme temperature changes (liquid nitrogen freezing temperature -196°C, recovery temperature 37°C), there is rapid thermal expansion and contraction. It is impossible to avoid the slow leakage of liquid nitrogen into the gap between the "tube" and the "rod" by simply plugging or threading the "tube" and the "rod", thereby contaminating the embryo. Therefore, only ultrasonic welding heat sealing can be used. (2) However, on the one hand, the outer tube may not be fully melted or the seal may not be tight during heat sealing, which may lead to chronic liquid nitrogen infiltration that is difficult to detect and thus contaminate the embryo. On the other hand, when thawing, the seal needs to be cut with scissors to separate the "tube" and "rod" before thawing the embryo, which results in cumbersome operation steps. (3) When using heat seals, harmful substances such as VOCs can damage the embryo. Therefore, we designed a closed carrier rod that is easy to operate and prevents liquid nitrogen from leaking. Utility Model Content

[0008] In order to solve the above technical problems, the utility model provides a closed carrier rod which has a simple structure and can effectively prevent liquid nitrogen from leaking in.

[0009] The utility model solves the above-mentioned technical problems as follows:

[0010] A closed carrier rod which is easy to operate and prevents liquid nitrogen from leaking in comprises a sleeve, a carrier rod inserted into the sleeve, a cap covering the sleeve, and a spring;

[0011] The insertion end of the carrying rod is provided with a loading area, and the hand-held end of the carrying rod is provided with a first truncated cone inclined surface;

[0012] The sleeve is a hollow sleeve with one end closed and the other end open, the interior of the sleeve is provided with a second truncated cone slope matched with the first truncated cone slope, and the lower end of the first truncated cone slope is inserted into the second truncated cone slope to form a tight fit;

[0013] The spring is sleeved on the carrier rod, the top end of the spring supports the tube cap, and the bottom end of the spring abuts against the top surface of the first truncated cone slope. In a free state, the length of the spring is greater than the distance from the contact position between the top end of the spring and the tube cap to the top surface of the first truncated cone slope.

[0014] During the use of the closed carrier rod of the utility model, which is easy to operate and prevents liquid nitrogen from leaking in, the closed carrier rod is finally placed in liquid nitrogen for storage. The freezing temperature of liquid nitrogen is -196°C. Therefore, when the closed carrier rod is lowered from room temperature to -196°C, due to the rapid thermal expansion and contraction, when the sleeve and the tube cap are only fixed by threads, it is impossible to prevent liquid nitrogen from slowly seeping into the interior of the sleeve from the gap between the sleeve and the tube cap. Similarly, due to the rapid thermal expansion and contraction, when the sleeve and the carrier rod are only connected by the lower end of the first truncated cone inclined surface inserted into the second truncated cone inclined surface to form a tight fit, it is also impossible to prevent liquid nitrogen from leaking into the interior of the sleeve from the gap between the sleeve and the carrier rod to contaminate the embryo. Therefore, the prior art usually adopts a thermal sealing method of ultrasonic welding, but the shortcomings of ultrasonic welding have been described in detail in the background technology. The present design solves the problem of liquid nitrogen leakage between the sleeve and the carrier rod through a simple spring design. Specifically, when the threads between the sleeve and the tube cap are tightened, the top of the spring presses against the tube cap, and the spring is compressed. When a gap exists between the sleeve and the carrier rod due to rapid thermal expansion and contraction, the spring tension pushes the lower end of the first truncated cone slope of the carrier rod and the second truncated cone slope of the sleeve to further plug it. That is to say, as long as there is a gap, the spring tension will continuously form a tight fit with the sleeve to prevent the infiltration of liquid nitrogen and embryo contamination. Similarly, when the embryo is in the process of resuscitation, the temperature of the liquid nitrogen is -196°C and the resuscitation temperature is 37°C. Due to rapid thermal expansion and contraction, a gap will also form between the sleeve and the carrier rod. Under the action of the spring tension, the lower end of the first truncated cone slope of the carrier rod and the second truncated cone slope of the sleeve will still be pushed to further plug it, preventing the infiltration of liquid nitrogen and embryo contamination.

[0015] Furthermore, the open end of the sleeve is provided with an external thread, and the interior of the pipe cap is provided with an internal thread matching the external thread. When the pipe cap is screwed downward relative to the sleeve, the spring is forced to compress, and under the action of the spring tension, the lower end of the first truncated cone slope of the carrier rod is pushed to further tighten with the second truncated cone slope of the sleeve.

[0016] Furthermore, the tube cap is provided with a stepped through hole, the top of the spring bears against the shoulder of the stepped through hole, the handheld end of the carrier rod is higher than the top surface of the tube cap, and a clamping ring is sandwiched between the handheld end and the top surface of the tube cap to prevent the spring from falling out and to seal. During the installation process of this closed carrier rod that is easy to operate and prevents liquid nitrogen from leaking in, the spring is first sleeved on the carrier rod, and then the tube cap is sleeved from the handheld end of the carrier rod, the handheld end of the carrier rod passes through the stepped through hole, and the top of the spring bears against the shoulder of the stepped through hole. At this time, a clamping ring is installed between the handheld end of the carrier rod and the top surface of the tube cap, which, on the one hand, prevents the carrier rod from falling off the tube cap and the spring from being lost, and on the other hand, can seal the stepped through hole to prevent liquid nitrogen from entering.

[0017] Furthermore, the material of the carrier rod, the sleeve and the cap is the same. When the materials are the same, the coefficients of thermal expansion and contraction are the same, and the increase of the gap between the carrier rod and the sleeve, or the increase of the gap between the sleeve and the cap due to thermal expansion and contraction is minimized.

[0018] Furthermore, the material of the carrier rod, sleeve and cap is at least one of PE, PP, PET, PS, SB, SBC and PVA.

[0019] Furthermore, the closed type carrier rod which is easy to operate and prevents liquid nitrogen from leaking in further comprises a counterweight, and the counterweight is fixed at the closed end of the sleeve.

[0020] Furthermore, the loading area is an arc-shaped thin sheet, and the thickness of the arc-shaped thin sheet is 0.02 mm to 0.10 mm.

[0021] Furthermore, a section of cylinder extends upward from the top surface of the first truncated cone inclined surface, and the bottom end of the spring abuts against the top surface of the cylinder.

[0022] Furthermore, the length of the sleeve is 65-80 mm, and the diameter of the sleeve is 4-7 mm.

[0023] Furthermore, the length of the carrier rod is 70-90mm, and the diameter of the carrier rod is 2-5mm. In actual operation, for a closed carrier rod with a sleeve sleeve carrier rod, if the diameter of the outer sleeve is large, the distance between the sleeve and the loading area of ​​the carrier rod is large, and if the material of the outer sleeve is thicker; after being packaged and immersed in liquid nitrogen, the liquid nitrogen does not directly contact the oocyte loading area, but slowly passes the temperature through the gap between the sleeve and the loading area in a manner similar to a barrier "water bath", thereby freezing the oocyte. This process reduces the freezing rate. Based on the above process, the distance between the loading area and the sleeve needs to be reduced, and the sleeve needs to be as thin as possible. It is understandable that the inventor can design the curvature or shape of the loading area so that the loading area is close to the inner wall of the sleeve, and the low temperature is quickly transmitted to the oocyte, so that the reproductive sample can quickly reach a vitrified state.

[0024] The utility model has the following advantages over the prior art:

[0025] 1. The utility model is easy to operate and prevents liquid nitrogen from leaking into the closed carrier rod. The lower end of the first truncated cone slope of the carrier rod is continuously pushed by the spring tension to plug the second truncated cone slope of the sleeve tightly, thereby increasing the fit between the sleeve and the carrier rod, so that the embryo needs to be in a closed state during freezing, storage, and recovery, preventing liquid nitrogen from penetrating into the sleeve and contaminating the embryo. Therefore, the cumbersome operation of ultrasonic welding in the prior art is avoided, and harmful substances such as VOC are prevented from causing damage to the embryo.

[0026] 2. By using the same material for the carrier rod, sleeve and cap, the increase in the gap between the carrier rod and the sleeve, or the increase in the gap between the sleeve and the cap due to thermal expansion and contraction can be minimized.

[0027] 3. Through the design of the diameter and thickness of the sleeve, and the design of the curvature and shape of the loading area, the loading area is closely attached to the inner wall of the sleeve, and the low temperature is quickly transmitted to the oocyte, so that the reproductive sample can quickly reach the vitrified state.

[0028] The terms used herein, such as "lower", "upper", etc., indicating spatial relative positions, are used for the purpose of convenience to describe the relationship of one feature relative to another feature as shown in the drawings. It is understood that, depending on the different positions of the products, the terms of spatial relative positions may be intended to include different orientations in addition to the orientations shown in the drawings, and should not be construed as limitations on the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of Example 1.

[0030] Figure 2 yes Figure 1 Exploded diagram.

[0031] Figure 3 It is a schematic diagram of the structure of the casing.

[0032] Figure 4 It is a schematic diagram of the pipe cap structure. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0034] Embodiment 1:

[0035] like Figure 1 , Figure 2 As shown, the closed type carrier rod which is easy to operate and prevents liquid nitrogen from leaking in comprises a sleeve 1, a carrier rod 2 inserted into the sleeve 1, a cap 3 covering the sleeve 1, and a spring 4;

[0036] like Figure 2 As shown, the insertion end of the carrying rod 2 is provided with a loading area 21, and the hand-held end 22 of the carrying rod 2 is provided with a first truncated cone inclined surface 23;

[0037] like Figure 2 , Figure 3 As shown, the sleeve 1 is a hollow sleeve with one end closed and the other end open. The sleeve 1 is provided with a second truncated cone slope 11 that matches the first truncated cone slope 23. The lower end of the first truncated cone slope 23 is inserted into the second truncated cone slope 11 to form a tight fit.

[0038] The spring 4 is sleeved on the carrier rod 2, the top end of the spring 4 presses against the tube cap 3, and the bottom end of the spring 4 abuts against the top surface of the first truncated cone slope 23. In a free state, the length of the spring 4 is greater than the distance from the contact position between the top end of the spring and the tube cap 3 to the top surface of the first truncated cone slope 23.

[0039] During the use of the closed carrier rod of the utility model, which is easy to operate and prevents liquid nitrogen from leaking in, the closed carrier rod is finally placed in liquid nitrogen for storage. The freezing temperature of liquid nitrogen is -196°C. Therefore, when the closed carrier rod is lowered from room temperature to -196°C, due to the rapid thermal expansion and contraction, when the sleeve 1 and the cap 3 are only fixed by threads, it is impossible to prevent liquid nitrogen from slowly seeping into the interior of the sleeve 1 from the gap between the sleeve 1 and the cap 3. Similarly, due to the rapid thermal expansion and contraction, the sleeve 1 and the carrier rod 2 only rely on the lower end of the first truncated cone slope 23 to insert the second truncated cone slope 11 to form a tight fit, and it is also impossible to prevent liquid nitrogen from leaking into the interior of the sleeve 1 from the gap between the sleeve 1 and the carrier rod 2 to contaminate the embryo. Therefore, the prior art usually adopts the thermal sealing method of ultrasonic welding, but the shortcomings of ultrasonic welding have been described in detail in the background technology. This design solves the problem of liquid nitrogen leakage between the sleeve 1 and the carrier rod 2 through a simple spring 4 design. Specifically, when the threads between the sleeve 1 and the cap 3 are tightened, the top of the spring 4 is against the cap 3, and the spring 4 is compressed. When there is a gap between the sleeve 1 and the carrier rod 2 due to rapid thermal expansion and contraction, under the action of the tension of the spring 4, the lower end of the first truncated cone slope 23 of the carrier rod 2 is pushed to be further plugged with the second truncated cone slope 11 of the sleeve 1. That is to say, as long as there is a gap, under the tension of the spring 4, the carrier rod 2 and the sleeve 1 will continuously form a tight fit to prevent the infiltration of liquid nitrogen and prevent embryo contamination. Similarly, when the embryo is in the process of resuscitation, the temperature of the liquid nitrogen is -196°C and the resuscitation temperature is 37°C. Due to the rapid thermal expansion and contraction, a gap will also be formed between the sleeve 1 and the carrier rod 2. Under the action of the tension of the spring 4, the lower end of the first truncated cone slope 23 of the carrier rod 2 will still be pushed to be further plugged with the second truncated cone slope 11 of the sleeve 1 to prevent the infiltration of liquid nitrogen and prevent embryo contamination.

[0040] In this embodiment, Figure 2 , Figure 3 , Figure 4 As shown, the open end of the sleeve 1 is provided with an external thread 12, and the interior of the pipe cap 3 is provided with an internal thread 31 that matches the external thread 12. When the pipe cap 3 is screwed downward relative to the sleeve 1, the spring 4 is forced to compress, and under the action of the tension of the spring 4, the lower end of the first truncated cone slope 23 of the carrier rod 2 is pushed to further tighten with the second truncated cone slope 11 of the sleeve.

[0041] In this embodiment, Figure 1 , Figure 2 , Figure 4As shown, the tube cap is provided with a stepped through hole 32, the top of the spring 4 is against the shoulder of the stepped through hole 32, the hand-held end 22 of the carrier rod 1 is higher than the top surface of the tube cap 3, and a clamping ring 5 is sandwiched between the hand-held end 22 and the top surface of the tube cap 3 to prevent the spring 4 from falling out and to play a sealing role. During the installation process of the closed carrier rod which is easy to operate and prevents liquid nitrogen from leaking in, the spring 4 is first sleeved on the carrier rod 2, and then the tube cap 3 is inserted from the hand-held end 22 of the carrier rod 2, the hand-held end 22 of the carrier rod 2 passes through the stepped through hole 32, and the top of the spring 4 is against the shoulder of the stepped through hole 32. At this time, the clamping ring 5 is installed between the hand-held end 22 of the carrier rod 2 and the top surface of the tube cap 3, which can prevent the carrier rod 2 from falling off the tube cap 3 and the spring 4 from being lost, and can seal the stepped through hole 32 to prevent liquid nitrogen from entering.

[0042] In this embodiment, Figure 1 , Figure 2 As shown, the material of the carrier rod 2, the sleeve 1 and the cap 3 is the same. When the materials are the same, the coefficients of thermal expansion and contraction are the same, and the increase of the gap between the carrier rod 2 and the sleeve 1, or the increase of the gap between the sleeve 1 and the cap 3 due to thermal expansion and contraction is minimized.

[0043] In this embodiment, the material of the carrier rod 2, the sleeve 1 and the cap 3 is PE.

[0044] In this embodiment, Figure 2 As shown, the closed type carrier rod which is easy to operate and prevents liquid nitrogen from leaking in further comprises a counterweight 6 , and the counterweight 6 is fixed at the closed end of the sleeve 1 .

[0045] In this embodiment, the loading area 21 is an arc-shaped thin sheet, and the thickness of the arc-shaped thin sheet is 0.02 mm to 0.10 mm.

[0046] In this embodiment, Figure 2 As shown, a section of cylinder 24 extends upward from the top surface of the first truncated cone inclined surface 23 , and the bottom end of the spring 4 abuts against the top surface of the cylinder 24 .

[0047] In this embodiment, the length of the sleeve is 73 mm and the diameter of the sleeve is 5 mm.

[0048] In this embodiment, the length of the carrier rod is 82 mm, and the diameter of the carrier rod is 2.5 mm.

[0049] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the protection scope of the present invention.

Claims

1. A closed carrier straw that is easy to operate and prevents liquid nitrogen from leaking in, comprising a sleeve, a carrier straw inserted into the sleeve, and a cap covering the sleeve, characterized in that: Also includes springs; The insertion end of the carrying rod is provided with a loading area, and the hand-held end of the carrying rod is provided with a first truncated cone inclined surface; The sleeve is a hollow sleeve with one end closed and the other end open, the interior of the sleeve is provided with a second truncated cone slope matched with the first truncated cone slope, and the lower end of the first truncated cone slope is inserted into the second truncated cone slope to form a tight fit; The spring is sleeved on the carrier rod, the top end of the spring supports the tube cap, and the bottom end of the spring abuts against the top surface of the first truncated cone slope. In a free state, the length of the spring is greater than the distance from the contact position between the top end of the spring and the tube cap to the top surface of the first truncated cone slope.

2. The closed type carrier rod which is easy to operate and prevents liquid nitrogen from leaking in according to claim 1, characterized in that: The open end of the sleeve is provided with an external thread, and the interior of the pipe cap is provided with an internal thread matching the external thread.

3. The closed type carrier rod which is easy to operate and prevents liquid nitrogen from leaking in according to claim 1, characterized in that: The tube cap is provided with a stepped through hole, the top end of the spring bears against the shoulder of the stepped through hole, the hand-held end of the carrier rod is higher than the top surface of the tube cap, and a clamping ring is sandwiched between the hand-held end and the top surface of the tube cap to prevent the spring from falling out and to perform a sealing function.

4. The closed carrier rod that is easy to operate and prevents liquid nitrogen from leaking in according to claim 1, characterized in that: The materials of the carrier rod, sleeve and tube cap are the same.

5. The closed type carrier rod which is easy to operate and prevents liquid nitrogen from leaking in according to claim 4, characterized in that: The material of the carrier rod, sleeve and tube cap is at least one of PE, PP, PET, PS, SB, SBC and PVA.

6. The closed type carrier rod which is easy to operate and prevents liquid nitrogen from leaking in according to claim 1, characterized in that: Also included is a counterweight, which is fixedly located at the closed end of the sleeve.

7. The closed type carrier rod which is easy to operate and prevents liquid nitrogen from leaking in according to claim 1, characterized in that: The loading area is an arc-shaped thin sheet, and the thickness of the arc-shaped thin sheet is 0.02mm-0.10mm.

8. The closed type carrier rod which is easy to operate and prevents liquid nitrogen from leaking in according to claim 1, characterized in that: A section of cylinder extends upward from the top surface of the first truncated cone inclined surface, and the bottom end of the spring abuts against the top surface of the cylinder.

9. The closed type carrier rod which is easy to operate and prevents liquid nitrogen from leaking in according to claim 1, characterized in that: The length of the sleeve is 65-80 mm, and the diameter of the sleeve is 4-7 mm.

10. The closed type carrier rod which is easy to operate and prevents liquid nitrogen from leaking in according to claim 1, characterized in that: The length of the carrier rod is 70-90 mm, and the diameter of the carrier rod is 2-5 mm.

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