Quantitative vacuum blood collection tube

Abstract

The utility model aims to provide a quantitative vacuum blood collection tube, and relates to the field of vacuum blood collection tubes. Comprising a sealing plug, a blood collection tube body, a guide tube, a floating block and a sealing ring, the guide tube is used for ensuring that the floating block moves along the guide tube in the blood collection process, the sealing ring is used for ensuring the sealing effect, and the floating block is matched with a check block on the inner side of the guide tube to cut off a blood collection channel. The sealing plug is used for sealing the middle opening of the upper portion of the guide tube and facilitating insertion of the blood taking needle. In the blood sampling process, the floating block can be gradually lifted along with increase of the blood sampling amount until the floating block and the check block on the inner side of the guide pipe achieve sealing and cut off of the blood sampling channel through the sealing ring, a small-size guide pipe closed space is formed, the blood sampling process is stopped along with rapid increase of air pressure in the closed space, and quantitative blood sampling is achieved. According to the utility model, blood collection can be automatically stopped according to the blood collection amount in the vacuum blood collection tube, and the requirement on a blood collector in the blood collection process is reduced.

Description

Technical Field

[0001] This utility model patent relates to the field of vacuum blood collection tubes, specifically a vacuum blood collection tube for achieving quantitative blood collection. Background Technology

[0002] Vacuum blood collection tubes have a lower pressure inside their cavity than atmospheric pressure, creating a vacuum. During blood collection, a needle connects the vein to the collection tube, and blood flows from the vein to the tube under the pressure difference, thus achieving the blood collection function. In practice, some laboratory tests have strict requirements on the amount of blood collected; too much or too little blood can affect the accuracy of the test results, necessitating precise control of the blood volume during the collection process. Existing vacuum blood collection tubes cannot automatically stop the blood collection process based on whether the current blood volume in the tube meets the requirements. This often requires manual monitoring of the blood volume markings and manual pauses of the blood collection process, making the process complex and resulting in poor accuracy in controlling the blood volume.

[0003] As existing technology, Chinese patent CN220236884U utilizes the principle that changes in blood volume within the blood collection tube cause an increase in internal pressure. The elastic diaphragm deforms differently under different pressure conditions. When the pressure corresponding to a specified blood volume is reached, the deformation of the elastic diaphragm triggers a sealing plate to cut off the blood flow, achieving quantitative blood collection. However, this method still has the following problems: for negative pressure blood collection tubes, slow leakage often occurs, leading to changes in internal pressure. In such cases, determining the blood volume by sensing the pressure through the elastic diaphragm will no longer be accurate. Chinese patent CN221617021U uses an adjusting screw to drive a magnetic ring, which in turn drives the blood collection piston, increasing the space and achieving quantitative blood collection by changing the tube volume. However, manual reading of the blood volume is still required during operation, making the process complex. Utility Model Content

[0004] The purpose of this invention is to provide a quantitative vacuum blood collection tube. During the blood collection process, when the blood volume in the blood collection tube meets the requirements, the blood collection channel is immediately closed, thereby achieving precise control of the blood collection volume and solving the problems mentioned in the background art.

[0005] To solve the above technical problems, this utility model adopts the following technical solution: a quantitative vacuum blood collection tube, comprising a sealing plug, a guide tube, a blood collection tube body, a float, and a sealing ring. Its characteristic is that: an inner baffle is machined inside the guide tube, and when the inner baffle is positioned at different heights in the guide tube, it can form quantitative blood collection tubes with different blood collection volumes; a float is installed inside the guide tube, the float being a closed shell, and an annular sealing ring is installed in a groove on the upper side of the float. During blood collection, the blood in the guide tube will exert buoyancy on the float, causing the float to rise along the inner wall of the guide tube until the sealing ring on the float contacts the lower inclined surface of the inner baffle, thus cutting off the blood collection channel and achieving the purpose of quantitative blood collection.

[0006] To further improve the design, the upper part of the inner baffle of the guide tube is a sloped surface that tilts downward toward the center of the blood collection tube, so as to allow blood to flow downward through the inner baffle of the guide tube better. The lower part of the inner baffle of the guide tube is a sloped surface that tilts upward toward the center of the blood collection tube. The slope of the lower part of the baffle and the slope of the upper part of the float are tilted at the same angle relative to the horizontal direction, so as to achieve a tight seal under the action of the sealing ring.

[0007] Further improvements include a cylindrical blood collection tube body with an open top and external threads machined along its upper outer edge; the external threads of the blood collection tube body cooperate with the internal threads of the guide tube to achieve fixation and sealing between the blood collection tube body and the guide tube.

[0008] To further improve the system, an opening is provided on the side of the guide tube below the inner side block, ensuring communication between the gas chamber inside the guide tube and the blood collection tube body during blood collection, thereby achieving the same air pressure in the two chambers.

[0009] Further improvements include an opening at the bottom of the guide tube to ensure communication between the inside of the guide tube and the liquid chamber inside the blood collection tube body, thereby enabling blood to flow from the inside of the guide tube to the bottom of the blood collection tube body.

[0010] To further improve the design, the float is further provided with a side channel and a bottom channel on its side and bottom, respectively, to ensure the unobstructed flow of blood collection from the blood collection needle to the bottom opening of the guide tube during the blood collection process.

[0011] Further improvements were made, such that the maximum outer diameter of the float is smaller than the inner diameter of the tube body below the inner side stop of the guide tube, ensuring that the float can move freely up and down along the tube body below the inner side stop of the guide tube.

[0012] Further improvements include installing the sealing plug on the upper part of the guide tube to seal the opening at the upper part of the guide tube, while facilitating the insertion of the blood collection needle, thereby establishing a blood collection channel from the vein to the upper part of the guide tube.

[0013] When the vacuum blood collection tube using the above technical solution is not being used for blood collection, and is placed vertically, the float will be at the bottom of the guide tube due to gravity. During blood collection, the insertion of the blood collection needle establishes a blood collection channel from the vein to the upper part of the guide tube. Simultaneously, because the maximum inner diameter of the float is smaller than the inner diameter of the tube body below the inner baffle of the guide tube, and because the float has side and lower channels, the blood collection channel from the upper part of the guide tube to the opening at the bottom of the guide tube is also unobstructed, allowing blood to be collected into the blood collection tube body. The lower edge of the inner baffle of the guide tube has an opening, ensuring that the air pressure and blood level are consistent in both the blood collection tube body and the sealed space of the guide tube. As the blood collection process progresses and the blood volume increases, the float gradually rises under buoyancy until the sealing ring on the float contacts the lower part of the inner baffle of the guide tube, cutting off the blood collection channel and forming a closed space in the guide tube. At this point, the blood collection process immediately stops.

[0014] When this technical solution is adopted, the blood collection process stops quickly as the blood collection channel is closed, thereby achieving the purpose of automatic quantitative blood collection.

[0015] This utility model has the following beneficial effects:

[0016] 1. Unlike vacuum blood collection tubes with graduated markings, this technology does not require manual monitoring of the blood graduation line during the blood collection process. When the set blood collection volume is reached, the blood collection channel can be automatically closed, achieving automatic quantitative blood collection.

[0017] 2. Unlike existing technologies that determine whether to close the blood collection channel based on the air pressure inside the vacuum blood collection tube, this invention directly determines whether to close the blood collection channel based on the blood level inside the vacuum blood collection tube, eliminating interference caused by air pressure deviation. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of the present invention before blood collection.

[0019] Figure 2 This is a cross-sectional view of the present invention during the blood collection process.

[0020] Figure 3 This is a cross-sectional view of the present invention when a certain amount of blood has been collected.

[0021] Figure 4 for Figure 2 Enlarged view of part A

[0022] Figure 5 for Figure 2 BB section view

[0023] Figure 6 for Figure 2 Enlarged view of part C

[0024] Figure 7 for Figure 3 Enlarged view of part D

[0025] In the diagram: 1-Sealing plug; 2-Guide tube; 3-Blood collection tube body; 4-Float; 5-Sealing ring; 6-Blood collection needle; 7-Liquid level line; 8-Sealed space of guide tube; 201-Internal thread of guide tube; 202-Bottom opening of guide tube; 203-Side opening of guide tube; 204-Inner stop block of guide tube; 205-Upper slope of stop block; 206-Lower slope of stop block; 301-External thread of blood collection tube body; 401-Lower channel of float block; 402-Side channel of float block; 403-Upper slope of float block; 404-Upper groove of float block. Detailed Implementation

[0026] To more clearly demonstrate the technical means and innovative features of this utility model, a more detailed and complete description is provided below with reference to the accompanying drawings of the embodiments of this utility model. Obviously, the described embodiments are only one embodiment of this utility model, and not all embodiments.

[0027] like Figure 1 As shown, a quantitative vacuum blood collection tube includes a sealing plug 1, a guide tube 2, a blood collection tube body 3, a float 4, and a sealing ring 5. Specifically, the cylindrical sealing plug 1 is installed at the upper middle opening of the hollow guide tube 2 to achieve a seal at the middle opening of the guide tube 2, while simultaneously... Figure 2 As shown, the sealing plug 1 is made of rubber to facilitate the insertion of the blood collection needle 6, thereby establishing a blood collection channel from the vein to the upper part of the guide tube 2. Figure 4 As shown, the upper part of the guide tube 2 is machined with an internal thread 201, which mates with the external thread 301 machined on the upper outer side of the circular hollow blood collection tube body 3. This allows the guide tube 2 to be installed on the blood collection tube body 3, while simultaneously achieving a seal between the guide tube 2 and the blood collection tube body 3. Figure 5 and Figure 7 As shown, the inner diameter of the guide tube 2 below the inner stop block 204 of the guide tube with an annular structure is larger than the maximum outer diameter of the float 4. The float 4 can move freely up and down below the inner stop block 204 of the guide tube. At this time, the guide tube 2 guides the float 4. Figure 6 As shown, the bottom of the guide tube 2 is machined with a guide tube bottom opening 202. Blood flowing into the guide tube 2 can flow into the bottom of the blood collection tube body 3 through this opening. At the same time, the maximum diameter of the guide tube bottom opening 202 is smaller than the maximum outer diameter of the float 4, which ensures that the float 4 is always inside the guide tube. Figure 7As shown, an inner guide tube block 204 is machined on the inner side of the middle section of the guide tube 2. The upper inclined surface 205 of the block has a certain angle of inclination relative to the horizontal plane, which facilitates the passage of blood from the upper part of the guide tube 2 through the inner guide tube block 204. When the blood collection volume meets the requirements, the lower inclined surface 206 of the block approaches the upper inclined surface 403 of the float block until it compresses the sealing ring 5, thereby cutting off the blood collection channel and forming a sealed space 8 in the guide tube. The lower inclined surface 206 of the block and the upper inclined surface 403 of the float block have the same angle of inclination relative to the horizontal plane to achieve a better sealing effect. A guide tube side opening 203 is provided below the inner guide tube block 204 to ensure the communication between the gas chamber inside the guide tube 2 and the gas collection tube body 3 during the blood collection process, thereby achieving a balance of gas pressure in the two chambers.

[0028] like Figure 1-3 , Figure 5 and Figure 7 As shown, float 4 is a thin-walled, sealed shell structure. Its overall mass is lighter than that of water of the same volume, so it floats on the surface of the liquid. Furthermore, due to the guiding effect of guide tube 2, float 4 will float at different positions when there are different blood volumes at different levels in the vacuum blood collection tube. Figure 7 As shown, the float 4 has a side channel 402 and a bottom channel 401 respectively processed on its side and bottom, which are used to ensure the unobstructed blood collection channel from the blood collection needle 6 to the bottom opening 202 of the guide tube during blood collection. A groove 404 is processed on the upper inclined surface 403 of the float to accommodate the sealing ring 5. The sealing ring 5 fits tightly against the inner surface of the groove 404 on one hand, and protrudes from the inclined surface on the other. When the required blood collection volume is reached, it closely cooperates with the lower inclined surface 206 of the guide tube 2 to cut off the blood collection channel, forming a closed space 8 in the guide tube.

[0029] The entire blood collection process is as follows: Figure 1 As shown, the vacuum blood collection tube is placed vertically. When no blood is being collected, the float 4 will naturally fall to the bottom of the guide tube 2 due to gravity; as Figure 2 As shown, during blood collection, when the buoyancy of the blood on the float 4 is greater than the weight of the float 4, the float 4 will always float above the liquid level line 7 as the amount of blood collected increases. Due to the guiding effect of the guide tube 2, the float 4 always moves upward along the guide tube 3 in a definite direction; as shown... Figure 3 As shown, when the set blood collection volume is reached, the sealing ring 5 on the float 4 rises to contact the inner stop block 204 of the guide tube, causing the blood collection channel to be cut off at the contact point between the inner stop block 204 of the guide tube and the sealing ring 5, forming a closed space 8 in the guide tube. At this time, the blood collection speed drops rapidly until it stops.

[0030] The working principle of the quantitative vacuum blood collection tube disclosed in this utility model is as follows: During production, the inside of the vacuum blood collection tube is evacuated to a certain degree of vacuum. At this time, the pressure inside the blood collection tube body 3 is lower than the atmospheric pressure, and the space inside the blood collection tube body 3 and the space inside the guide tube 2 are connected. When the blood collection needle 6 is connected to the vein on one side and the sealing plug 1 is inserted on the other side, under the action of negative pressure inside the vacuum blood collection tube, blood will flow from the vein into the vacuum blood collection tube. As the amount of blood in the vacuum blood collection tube increases, the blood level line 7 will gradually rise. When it exceeds the bottom of the float 4, according to Archimedes' principle, the blood will generate buoyancy on the float 4, and the magnitude of the buoyancy F is... 浮 =G 液排 =m 液排 g = gV 排 ρ 液 Since the float 4 is a hollow shell structure and its weight is lighter than the same volume of water, when the buoyancy is greater than the weight of the float 4, the float 4 will rise along the inner wall of the guide tube 2. When the blood collection volume reaches the predetermined blood collection volume, since the inner diameter of the guide tube inner side block 204 is smaller than the outer diameter of the float 4, the float 4 will be limited by the guide tube block 204. At the same time, the sealing ring 5 on the float 4 contacts the guide tube block 204 to form a seal. At this time, the guide tube 2 forms a guide tube closed space 8 above this position.

[0031] The closed space 8 of the guide tube is smaller than the remaining gas space inside the vacuum blood collection tube. Let the amount of gas in the vacuum blood collection tube when the closed space 8 of the guide tube is first formed be n1, the volume of the remaining gas space be V1, the amount of gas in the closed space 8 of the guide tube be n2, and the volume of the space be V2, where V1 / V2=a (a>1). According to the ideal gas law, n1 / n2=a.

[0032] Assuming that when the closed space 8 of the guide tube cannot be formed, the continued suction volume is V. 变 When blood volume is high, the gas space volume decreases by V. 变 At this time, the pressure P1 inside the vacuum blood collection tube that affects blood collection satisfies formula (1) according to the ideal gas law.

[0033] P1(V1-V 变 )=n1RT (1)

[0034] Where T is temperature (K), n is amount of substance of the gas (mol), and R is molar gas constant (also called universal gas constant) (J / (mol·K)).

[0035] When the technical solution of this utility model is adopted, due to the formation of the closed space 8 of the guide tube, the pressure that plays a role in blood collection is the pressure in the closed space 8 of the guide tube. When the volume collected in the closed space 8 of the guide tube continues to be V, 变After the blood volume is collected, the pressure P2 in the closed space 8 of the guide tube that plays a role in blood collection satisfies formula (2) according to the ideal gas law.

[0036] P2(V2-V 变 )=n2RT (2)

[0037] By combining formulas (1) and (2), and the equations V1 / V2=a and n1 / n2=a, we can simplify to obtain formula (3).

[0038] P1 / P2=(V1-aV 变 ) / (V1-V 变 (3)

[0039] Since a>1, then P1 / P2<1, indicating that after adopting this practical technical solution, the pressure of P2 is higher, which corresponds to the vacuum degree that plays a role in blood collection decreasing rapidly, causing the blood collection process to stop quickly, thereby achieving the purpose of quantitative blood collection. Moreover, the larger the value of a, the faster the vacuum degree that plays a role in blood collection decreases.

[0040] The above-described embodiments are merely a preferred embodiment of this utility model. It should be noted that those skilled in the art can make various improvements and modifications without departing from the technical principles of this utility model, and these improvements or modifications should also be considered within the scope of protection of this utility model.

Claims

1. A quantitative vacuum blood collection tube comprising a guide tube (2) and a float (4), characterized in that: The guide pipe (2) is internally provided with a guide pipe inner side stopper (204); the float (4) is installed in the guide pipe (2) and can move up and down along the guide pipe (2), the lower limit position of the float (4) is the bottom of the guide pipe (2), and the upper limit position of the float (4) is the lower part of the guide pipe inner side stopper (204).

2. The evacuated tube of claim 1, wherein: The guide pipe (2) is internally provided with a guide pipe inner side stopper (204); the float (4) is installed in the guide pipe (2) and can move up and down along the guide pipe (2), the lower limit position of the float (4) is the bottom of the guide pipe (2), and the upper limit position of the float (4) is the lower part of the guide pipe inner side stopper (204).

3. The quantitative vacuum blood collection tube as described in claim 1, characterized in that: The float (4) is a closed shell, when blood sampling, the blood in the guide pipe (2) will generate a buoyancy effect on the float (4), and the float (4) will rise along the inner wall of the guide pipe (2).

4. The evacuated tube of claim 3, wherein: The maximum outer diameter of the float (4) is smaller than the inner diameter of the pipe body below the guide pipe inner side stopper (204); the inclination angle of the upper side inclined surface (403) of the float (4) and the lower part inclined surface of the guide pipe inner side stopper (204) relative to the horizontal plane is the same.

5. A quantitative vacuum blood collection tube as described in claim 3, characterized in that: The side surface and the lower part of the float (4) are respectively provided with a float side surface channel (402) and a float lower part channel (401).

6. The evacuated tube of claim 3, wherein: The upper side inclined surface (403) of the float (4) is provided with a float upper side slot (404), and the ring-shaped sealing ring (5) is installed in the float upper side slot (404).

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