A quantitative blood sampling device for blood culture

Abstract

The application discloses a blood sampling device for blood culture, which comprises a flexible catheter, a blood sampling needle assembly and a bottle body puncture assembly arranged at two ends of the flexible catheter, and a volume-adjustable quantitative assembly arranged in the middle section of the flexible catheter; the quantitative assembly comprises a flexible inner capsule in communication with the inner cavity of the catheter, a rigid outer cavity body wrapped outside the inner capsule, and a volume adjusting mechanism for adjusting and limiting the effective expansion volume of the inner capsule; the catheter is provided with a first switch valve and a second switch valve, and the inner wall of the catheter and / or the inner wall of the inner capsule is provided with an anticoagulant coating. The application realizes flexible adjustment and accurate control of the blood sampling volume by a mechanical limiting mode, can meet the blood sampling requirements of different patient groups by one set of device, and unifies the production standard without producing multiple specifications. The blood sampling process of the device is completed in a closed pipeline, and the device is matched with an integrated multi-bottle puncture adapter, so that the quantitative blood sample can be continuously and aseptically distributed to multiple blood culture bottles under one-time venous puncture, and the device is convenient to operate and accurate in quantification.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and more specifically, to a quantitative blood collection device for blood culture. Background Technology

[0002] Blood culture is the gold standard for diagnosing bloodstream infections and bacteremia, and its accuracy directly depends on the quality of blood sample collection. Currently, there are two main methods of blood collection commonly used in clinical practice:

[0003] The first method is the direct injection method, which involves using a syringe to puncture a blood vessel to draw blood, and then injecting the blood from the syringe into multiple blood culture bottles. This process is cumbersome, and the risk of blood contamination increases due to repeated needle exposure and multiple punctures of the blood culture bottle openings during transfer. Furthermore, this method makes it difficult to precisely control the amount of blood injected into each blood culture bottle (the routine blood collection volume for adults is usually 8-10 ml per bottle, and even less for children or special tests). Insufficient blood volume will reduce the positive detection rate, while excessive blood volume may affect the accuracy of the test results due to an imbalance in the blood-to-culture medium ratio.

[0004] The second method is the butterfly needle blood collection method, which involves directly introducing blood into the blood culture bottle through a butterfly needle and connecting tubing. However, when collecting multiple blood samples (such as a pair of aerobic and anaerobic bottles, or more bottles), the operator must remove the current blood culture bottle and replace it with a new one after the negative pressure has been exhausted. During the replacement process, blood flow is forcibly interrupted, and the stagnant blood in the tubing is very prone to coagulation, causing blockage and leading to blood collection failure.

[0005] In addition, some existing technologies attempt to use a balloon to temporarily store blood for quantitative collection. For example, patent publication number CN216907976U discloses a quantitative blood collection device, which sets a balloon at one end of the blood collection tube. By squeezing the balloon, negative pressure is generated to draw blood, and quantitative blood collection is achieved by restricting the movement of the balloon between the front and rear contraction openings. However, this solution is mainly suitable for micro-volume fingertip blood collection scenarios. Its balloon volume is fixed and cannot flexibly adapt to the different blood collection volume requirements of different groups such as adults and children. At the same time, the balloon in this solution relies solely on its own elastic recoil when deflated, resulting in incomplete and slow deflation, which can easily lead to blood residue and affect the quantitative accuracy of multiple consecutive blood collections.

[0006] In summary, although existing technologies have made improvements in specific aspects of blood culture collection (such as quantitative measurement, contamination control, and micro-volume blood collection), the following technical problems still exist: First, the volume of the blood collection device is usually fixed, which cannot flexibly adapt to the different requirements of blood collection volume for different patient groups and different testing items; second, during the process of collecting blood from multiple bottles, the operator needs to repeatedly change the blood culture bottle, and the puncture needle is exposed to the air multiple times, which poses a high risk of contamination; third, the blood storage chamber used for temporary blood storage often relies on its own elastic recoil or the negative pressure inside the blood culture bottle when emptying, resulting in incomplete emptying and affecting the quantitative accuracy of subsequent blood collection.

[0007] Therefore, there is an urgent need in the existing technology for a blood collection device that can adapt to different blood collection volume requirements and continuously, quantitatively, and aseptically dispense blood samples to one or more blood culture bottles, in order to solve the technical problems of low operating efficiency, inaccurate blood volume control, poor versatility, and high risk of contamination in the existing technology. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the prior art and provide a volume-adjustable quantitative blood collection device for blood culture, so as to solve the problems of existing blood collection devices being unable to flexibly adapt to different blood collection volume requirements, cumbersome operation of multiple blood collection bottles, inaccurate blood volume control, and easy contamination.

[0009] To achieve the above objectives, the present invention provides a volume-adjustable quantitative blood collection device for blood culture, comprising a flexible catheter and blood collection needle assemblies and a bottle puncture assembly disposed at both ends of the flexible catheter.

[0010] The flexible catheter has a volume-adjustable metering component in its middle section; the volume-adjustable metering component includes: a flexible inner bladder communicating with the inner lumen of the flexible catheter; a rigid outer cavity surrounding the flexible inner bladder; and a volume adjustment mechanism for adjusting and limiting the effective expansion volume of the flexible inner bladder within the rigid outer cavity.

[0011] A first switching valve is provided on the flexible catheter, located between the blood collection needle assembly and the volume-adjustable metering assembly; a second switching valve is provided on the flexible catheter, located between the volume-adjustable metering assembly and the bottle puncture assembly; an anticoagulant coating is provided on the inner wall of the flexible catheter and / or the inner wall of the flexible inner capsule.

[0012] With the above structure, before blood collection, the operator can pre-set the effective expansion volume of the flexible inner bladder according to the target blood volume required for this collection through the volume adjustment mechanism. During blood collection, the first switch valve is opened and the second switch valve is closed. The patient's blood flows into the flexible inner bladder through the flexible catheter under the action of blood pressure or negative pressure of the blood culture bottle, causing it to expand. Due to the physical limitations of the rigid outer cavity and the volume adjustment mechanism, the flexible inner bladder cannot expand further after expanding to the preset volume, thus achieving precise quantification in one go. Subsequently, the first switch valve is closed and the second switch valve is opened, releasing the quantified blood in the flexible inner bladder into the blood culture bottle. By repeating this cycle, precise and consistent quantitative blood samples can be continuously injected into one or more blood culture bottles with a single venipuncture.

[0013] As a preferred technical solution, the volume adjustment mechanism includes an adjustment push plate and a positioning component. The adjustment push plate is slidably disposed within the rigid outer cavity and matches the shape of the inner wall of the rigid outer cavity. The positioning component is used to fix the adjustment push plate at different axial positions within the rigid outer cavity to change the spatial volume between the adjustment push plate and the proximal end of the flexible inner bladder, thereby limiting the effective expansion volume of the flexible inner bladder. This structure is simple and reliable, achieving stepless or stepped volume adjustment through mechanical limiting.

[0014] As a preferred technical solution, the positioning component is a sliding locking mechanism, including: two sliding grooves symmetrically opened along the outer wall of the rigid outer cavity, and multiple locking slots spaced apart along the length direction on the groove wall of each sliding groove;

[0015] A slip ring fitted outside the rigid outer cavity, the slip ring being able to slide along the axial direction of the rigid outer cavity and rotate about its axis;

[0016] Two connecting pins are symmetrically arranged on opposite sides of the slip ring. One end of each connecting pin is fixedly connected to the slip ring, and the other end passes through the corresponding slide groove and is fixedly connected to the edge of the adjusting push plate.

[0017] The radial dimension of the connecting pin matches the width of the groove; the radial dimension of the connecting pin is smaller than the width of the groove.

[0018] As another preferred technical solution, the two grooves extend along the axial direction of the rigid outer cavity to the bottom end of the rigid outer cavity;

[0019] An operating handle is connected to the adjusting push plate. The operating handle extends axially toward the proximal end and passes through the rear end face of the rigid outer cavity.

[0020] As a preferred technical solution, the rigid outer cavity is made of transparent material, its outer wall is provided with volume scale, and the adjustment push plate is provided with indicator marks for indicating the volume scale.

[0021] As a preferred technical solution, the flexible inner capsule is made of a medical-grade elastomer material with ultra-high compliance and elastic recovery capabilities, including medical-grade liquid silicone or medical-grade thermoplastic polyurethane; its wall thickness is 0.3-0.5 mm. This material selection and wall thickness design ensure that the flexible inner capsule has good elastic recovery capabilities and structural strength.

[0022] As a preferred technical solution, the inner or outer wall of the flexible inner bladder is provided with a pre-formed axial or circumferential corrugated structure so that the flexible inner bladder unfolds in an orderly manner along a preset direction during the expansion process, preventing irregular wrinkles, ensuring consistent expansion shape each time, and improving volume accuracy.

[0023] As a preferred technical solution, the outer wall of the flexible inner capsule and / or the inner wall of the rigid outer cavity are provided with mutually cooperating guide structures to guide the flexible inner capsule to expand uniformly along the axial direction during the expansion process, thereby further improving the quantitative repeatability accuracy.

[0024] As a preferred technical solution, the bottle puncture assembly is an integrated multi-bottle puncture adapter. The integrated multi-bottle puncture adapter includes an adapter body, a fluid inlet port disposed on the adapter body, and at least two branch puncture needles extending from the adapter body; the fluid inlet port is connected to the flexible catheter; each branch puncture needle is used to independently puncture and connect to a blood culture bottle; and an independent branch switch valve is provided on the fluid channel between each branch puncture needle and the fluid inlet port.

[0025] As a preferred technical solution, the first switching valve is a one-way valve, and its conduction direction is from the blood collection needle assembly to the volume adjustable metering assembly to prevent blood backflow; the second switching valve and the branch switching valve are clamp-on switching valves or plug-in switching valves.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] This invention, through the cooperation of a volume adjustment mechanism and a rigid outer cavity, allows for flexible and precise setting of the blood collection volume within a certain range. The operator simply rotates and pulls the operating handle located at the rear end of the rigid outer cavity to smoothly move the adjustment push plate along the double-sided sliding grooves. The adjustment push plate is then securely locked at the target volume position through the rotational locking mechanism of the connecting pin and the slot. One device can meet the diverse blood collection volume needs of adults, children, newborns, and different testing items, significantly improving the device's versatility and clinical applicability. More importantly, since a single device can cover the blood collection volume needs of the entire population and all scenarios, manufacturers do not need to design, produce, and stock multiple models of products for different blood collection volume specifications; this greatly simplifies the product line, unifies production standards, and reduces the complexity and cost of mold development, production line switching, inventory management, and logistics distribution.

[0028] This invention employs a mechanical limiting method to physically constrain the effective expansion space of the flexible inner capsule. After the adjusting push plate is locked, the expansion endpoint of the flexible inner capsule is completely consistent each time it is inflated, fundamentally ensuring high volumetric repeatability accuracy between multiple blood collection operations. In a preferred embodiment, the flexible inner capsule is made of medical-grade liquid silicone or thermoplastic polyurethane with high compliance and elastic recovery capabilities. Its wall thickness and mechanical properties are optimized to fully adhere to the inner wall of the rigid outer cavity and the end face of the adjusting push plate. Simultaneously, the pre-fabricated corrugated and guiding structures on the flexible inner capsule guide its orderly expansion along a preset direction during expansion, effectively avoiding the formation of irregular wrinkles. During emptying, the operator can directly push the adjusting push plate to the bottom of the cavity to actively squeeze out all the blood from the flexible inner capsule, ensuring thorough emptying without residue and further guaranteeing quantitative accuracy during consecutive blood collection operations.

[0029] Furthermore, the device's integrated multi-bottle puncture adapter allows all target blood culture bottles to be aseptically connected in one go before blood collection begins. During blood collection, the operator only needs to control the branch valves in sequence, without needing to remove or replace the puncture needle, completely eliminating the risks of contamination and needlestick injuries during multi-bottle switching, while maintaining the continuity of blood flow and avoiding the problem of blood clotting and blockage in the tubing.

[0030] The entire blood collection process is completed within a closed tubing system. The core structure of the device employs a purely mechanical design, eliminating electronic components and fundamentally avoiding the sterilization challenges, reliability risks, and increased costs associated with electronic components. The components are structurally simple, with clear assembly relationships, and the manufacturing processes are mature (such as injection molding and dip molding), facilitating automated production and keeping costs under control. Its high reliability and low cost make it particularly suitable for large-scale, disposable use as a consumable in busy clinical environments such as emergency rooms, intensive care units, and laboratories. Attached Figure Description

[0031] Figure 1This is a schematic diagram of the structure of a volume-adjustable quantitative blood collection device provided in Embodiment 1 of the present invention.

[0032] Figure 2 This is a partial structural enlarged view of the volume-adjustable quantitative component using a sliding locking mechanism in Embodiment 2 of the present invention.

[0033] Figure 3 This is a schematic diagram of the structure of the adjusting push plate that also has a venting function in Embodiment 3 of the present invention.

[0034] Figure 4 This is a schematic diagram of the integrated multi-bottle puncture adapter in Embodiment 4 of the present invention.

[0035] Figure 5 This is a schematic diagram of the flexible inner capsule anti-wrinkle structure in Embodiment 5 of the present invention. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0037] Example 1

[0038] See Figure 1 This embodiment provides a volume-adjustable quantitative blood collection device for blood culture. The device includes a flexible catheter 1 and blood collection needle assemblies 2 and a bottle puncture assembly 3 disposed at both ends of the flexible catheter 1. The blood collection needle assembly 2 is a conventional butterfly needle or a straight blood collection needle, used for puncturing a patient's blood vessel. The bottle puncture assembly 3 is a hollow puncture needle, which can be covered with a retractable protective sleeve to maintain sterility when inserted into a blood culture bottle 9 and automatically cover the needle tip after withdrawal. The flexible catheter 1 is a medical-grade PVC or polyurethane flexible tube.

[0039] The core improvement of this invention lies in the provision of a volume-adjustable metering component 100 in the middle section of the flexible catheter 1. The volume-adjustable metering component 100 includes a flexible inner capsule 110, a rigid outer cavity 120, and a volume adjustment mechanism. The flexible inner capsule 110 communicates with the inner lumen of the flexible catheter 1. The flexible inner capsule 110 is made of a medical-grade elastomer material with ultra-high compliance and elastic recovery capabilities. In a specific example, the flexible inner capsule 110 is made of medical-grade liquid silicone with a thickness of 0.3-0.5 mm (specifically, a wall thickness of 0.4 mm is optional), and the wall thickness tolerance is controlled within ±0.05 mm, exhibiting good biocompatibility and elastic recovery capabilities. The rigid outer cavity 120 is made of transparent medical-grade polycarbonate and wraps around the flexible inner capsule 110, providing support and protection. Its outer wall is provided with volume markings 124.

[0040] The volume-adjustable metering assembly of this invention requires the flexible inner capsule to undergo a significant deformation from complete emptying to complete adhesion within the confined space formed by the rigid outer cavity and the adjusting push plate, and to maintain consistent deformation behavior throughout multiple blood collection cycles. Therefore, the choice of material for the flexible inner capsule is crucial.

[0041] Extensive experimental verification has shown that the flexible inner capsule is preferably made of medical-grade liquid silicone or medical-grade thermoplastic polyurethane. Medical-grade liquid silicone typically has an elongation at break of 200%-800%, with some high-elongation models exceeding 1000%, a resilience of over 40%, and a compression set of 5%-30%. Medical-grade TPU has an elongation at break of 400%-700%, a resilience close to 100%, and an instantaneous recovery rate ≥90%. The high compliance and excellent elastic recovery of these materials ensure that the flexible inner capsule can fully and uniformly expand within the volume adjustment range to completely adhere to the rigid outer cavity wall and the end face of the adjustment push plate, avoiding incomplete expansion or localized stress concentration caused by excessive material rigidity. This ensures the volume accuracy of each blood collection and consistency across multiple uses.

[0042] The volume adjustment mechanism is used to adjust and limit the effective expansion volume of the flexible inner bladder 110 within the rigid outer cavity 120. In this embodiment, the volume adjustment mechanism includes an adjustment push plate 130 and a sliding locking mechanism as a positioning component. The adjustment push plate 130 is a circular plate that is slidably disposed inside the rigid outer cavity 120, and its outer edge matches the shape of the inner wall of the rigid outer cavity 120. The specific structure of the sliding locking mechanism will be described in detail in Embodiment 2.

[0043] On the flexible catheter 1, a first switching valve 5 is provided between the blood collection needle assembly 2 and the volume adjustable metering assembly 100. It is a one-way valve, and the conduction direction is towards the volume adjustable metering assembly 100. A second switching valve 6 is provided between the volume adjustable metering assembly 100 and the bottle puncture assembly 3. It is a clamp-on switching valve.

[0044] In addition, the inner walls of the flexible catheter 1 and the flexible inner balloon 110 are coated with a heparin anticoagulant coating to prevent blood from clotting inside the tubing and balloon.

[0045] Blood collection procedure:

[0046] Before blood collection, the operator, according to the blood collection volume determined by the doctor's order (e.g., 10ml), pushes the slip ring 140 to move the adjusting push plate 130 axially along the rigid outer cavity 120, so that the indicator mark on the adjusting push plate 130 is aligned with the 10ml volume scale 124 on the outer wall, and the position is locked by the sliding locking mechanism. At this time, the space volume between the adjusting push plate 130 and the proximal end of the flexible inner capsule 110 is limited to 10ml.

[0047] Insert the blood collection needle assembly 2 into the patient's blood vessel and insert the bottle puncture assembly 3 into the first blood culture bottle 9. Keep the second switch valve 6 closed and open the first switch valve 5. Under the influence of the patient's blood pressure, blood flows into the flexible inner capsule 110 through the flexible catheter 1. The flexible inner capsule 110 gradually expands. When it expands to contact the adjusting push plate 130, the inner capsule cannot expand further due to the physical limitation of the rigid outer cavity 120 and the adjusting push plate 130, indicating that an accurate 10ml of blood has been collected.

[0048] At this point, close the first valve 5 and open the second valve 6. The 10ml of blood inside the flexible inner capsule 110 is rapidly drawn into the blood culture bottle 9 under the combined action of its own elastic recoil and the negative pressure inside the bottle. After observing that the flexible inner capsule 110 is completely emptied, close the second valve 6.

[0049] If a second blood culture bottle needs to be collected, the operator pulls the bottle puncture component 3 out of the first bottle, inserts it into the second blood culture bottle 9, and repeats the above cycle of "opening the first switch valve 5 → filling → closing the first switch valve 5 → opening the second switch valve 6 → emptying → closing the second switch valve 6".

[0050] Example 2

[0051] See Figure 2 This embodiment details the specific structure of the sliding locking mechanism described in Embodiment 1. To ensure that the adjusting push plate 130 remains perpendicular to the axis of the rigid outer cavity 120 during sliding and locking, this embodiment employs a sliding locking mechanism with symmetrical drive on both sides.

[0052] This organization includes:

[0053] On the outer wall of the rigid outer cavity 120, two sliding grooves 122 are symmetrically opened along its axial direction. On at least one side of the groove wall of each sliding groove 122, a plurality of slots 123 are spaced apart along the length direction, and the opening direction of the slots 123 is at a certain angle (e.g., vertical or inclined) to the extending direction of the sliding groove 122.

[0054] A slip ring 140 is fitted onto the outside of the rigid outer cavity 120. The inner diameter of the slip ring 140 is slightly larger than the outer diameter of the rigid outer cavity 120, allowing it to slide freely along the axial direction and rotate around the axis.

[0055] The slip ring 140 is fixedly connected to the adjusting push plate 130 located inside the rigid outer cavity 120 by two connecting pins 142 that pass through the corresponding sliding grooves 122. The two connecting pins 142 are symmetrically arranged on opposite sides of the slip ring 140. One end of each connecting pin 142 is fixed to the inner wall of the slip ring 140, and the other end passes through the corresponding sliding groove 122 and is fixedly connected (or snapped) to the edge of the adjusting push plate 130. The radial dimension of the connecting pin 142 matches the width of the sliding groove 122, so that it plays a guiding role when sliding in the sliding groove 122; at the same time, the radial dimension of the connecting pin 142 is smaller than the width of the slot 123, so that when the slip ring 140 rotates, the connecting pin 142 can be screwed into or out of the slot 123.

[0056] Volume markings 124 are respectively marked on the outer wall of the cavity next to the two slides 122. The position of each slot 123 corresponds to a commonly used preset blood collection volume (such as 2ml, 5ml, 8ml, 10ml, 20ml).

[0057] When volume adjustment is required, the operator holds the slip ring 140 and rotates it at a certain angle, causing the connecting pin 142 to disengage from the current slot 123 and enter the main channel of the slide groove 122. At this time, the slip ring 140 can slide freely along the axial direction of the slide groove 122, driving the internal adjusting push plate 130 to move synchronously through the connecting pin 142. Due to the use of dual-sided symmetrical drive, the adjusting push plate 130 always remains perpendicular to the axis during movement, without tilting or jamming.

[0058] When the slip ring 140 moves to the slot 123 corresponding to the target volume scale, the operator rotates the slip ring 140 in the opposite direction, causing the connecting pins 142 on both sides to simultaneously screw into the corresponding slots 123. The axial limiting effect of the slots 123 on the connecting pins 142 securely locks the slip ring 140 and the adjusting push plate 130 in this axial position, completing the volume setting.

[0059] This embodiment uses a sliding groove, slot, slip ring and connecting pin arranged symmetrically on both sides, and adopts a rotary locking method. The structure is simple, the number of parts is small, the operation is intuitive and the locking is reliable. It effectively solves the technical problems that single-sided drive is prone to push plate deflection and elastic buckle is prone to fatigue failure, and significantly improves the accuracy of volume setting and the reliability of long-term use.

[0060] Example 3

[0061] See Figure 3 This embodiment provides a preferred solution for adjusting the push plate to have both volume setting and emptying functions. This embodiment further optimizes the double-sided sliding locking mechanism described in Embodiment 2.

[0062] In this embodiment, two grooves 122 extend along the axial direction of the rigid outer cavity 120 from the rear end of the cavity to the bottom end of the cavity (i.e., near the proximal end of the flexible inner bladder 110).

[0063] An operating handle 132 is fixedly connected to the top center of the adjusting push plate 130. The operating handle 132 is rod-shaped, extending axially towards the proximal end (rearward) of the rigid outer cavity 120, and passing through the central hole of the rear end face of the rigid outer cavity 120 to the outside. The tail end of the operating handle 132 may be provided with a push-pull plate or a horizontal handle to facilitate the operator to apply force with one thumb or palm. A sealing ring or sliding bearing structure is provided between the operating handle 132 and the central hole of the rear end face of the rigid outer cavity 120 to ensure the smoothness of the operating handle 132 during rotation and axial sliding and the cleanliness of the cavity interior.

[0064] When emptying is required, open the second switch valve 6. The operator rotates the operating handle 132, causing the connecting pin 142 to disengage from the slot 123. Then, push the operating handle 132 directly forward (towards the proximal end of the flexible inner capsule 110), causing the adjusting push plate 130 to move forward along the slide groove 122. The end face of the adjusting push plate 130 presses against the outer wall of the flexible inner capsule 110, actively draining the blood inside into the blood culture bottle 9 via the second switch valve 6. Since the slide groove 122 extends to the bottom of the cavity, the adjusting push plate 130 can be pushed all the way to the proximal end of the flexible inner capsule 110, ensuring complete emptying.

[0065] In this embodiment, by placing the operating handle at the top center of the adjusting push plate and extending it axially, the operator can complete all actions of rotation unlocking / locking and push-pull volume adjustment / emptying with one hand, resulting in a natural operating posture and balanced force application. Simultaneously, the adjusting push plate can be directly used as an emptying plate, making the structure simpler and more compact, significantly improving the convenience and reliability of clinical use.

[0066] Example 4

[0067] See Figure 4The difference between this embodiment and the previous embodiment is that the bottle puncture component 3 is replaced by an integrated multi-bottle puncture adapter 300.

[0068] The integrated multi-bottle puncture adapter 300 includes an adapter body 310, a fluid inlet 312 disposed on the adapter body 310, and three branch puncture needles 313 extending from the adapter body 310. The fluid inlet 312 is sealed to the flexible catheter 1. Each branch puncture needle 313 is used to independently puncture and connect to a blood culture bottle 9. An independent branch switch valve 314 is provided on the fluid channel between each branch puncture needle 313 and the fluid inlet 312. In this embodiment, the branch switch valve 314 is a plug valve.

[0069] Before blood collection, the operator aseptically connects three blood culture bottles 9 (e.g., one aerobic bottle, one anaerobic bottle, and one spare bottle) to three branch puncture needles 313 respectively, and all branch switch valves 314 are initially in the closed state.

[0070] After the blood collection needle assembly 2 punctures the blood vessel, a single quantification (e.g., collecting 10 ml of blood) is performed using the volume-adjustable quantification assembly 100 in the same manner as in Example 1. Then, the operator opens the branch switch valve 314 corresponding to the first branch to inject 10 ml of blood from the flexible inner capsule 110 into the first blood culture bottle; after closing the branch switch valve 314, the first switch valve 5 is opened again to inflate the flexible inner capsule 110, completing the second quantification, and then the branch switch valve 314 corresponding to the second branch is opened to inject blood into the second blood culture bottle; and so on.

[0071] This embodiment ensures that all blood culture bottles are aseptically connected before blood collection begins, eliminating the need to remove and reinsert the puncture needle during subsequent blood collection, thus completely eliminating the risks of contamination and needlestick injuries when switching between multiple bottles. Simultaneously, the branch switch valve 314 allows for precise control of the blood injection sequence; for example, blood can be injected first into the aerobic bottle before the anaerobic bottle, preventing the accidental introduction of air into the anaerobic bottle and meeting the standardized requirements for clinical blood culture collection.

[0072] Example 5

[0073] See Figure 5 This embodiment focuses on demonstrating the anti-wrinkle structure design of the flexible inner capsule 110.

[0074] like Figure 5As shown in section (a), the inner wall of the flexible inner capsule 110 is provided with multiple pre-formed axial corrugated structures 111. When the flexible inner capsule 110 is not filled with fluid, these corrugated structures are in an orderly folded state. When blood enters, the corrugated structures guide the inner capsule to unfold in an orderly manner along the axis, like the bellows of an accordion, effectively avoiding random wrinkles caused by uneven local stress and ensuring a high degree of consistency in the expansion shape each time.

[0075] like Figure 5 As shown in section (b), the outer wall of the flexible inner bladder 110 is provided with a guide protrusion 112 extending axially, while a guide groove 121 is provided at a corresponding position on the inner wall of the rigid outer cavity 120. The guide protrusion 112 and the guide groove 121 cooperate with each other to guide the flexible inner bladder 110 to move strictly along the axial direction during expansion and contraction, preventing it from shifting or twisting in the radial direction, and further improving the repeatability accuracy of volume measurement.

[0076] The two anti-wrinkle and guiding structures in this embodiment can be used individually or in combination. These structural designs ensure high accuracy and reliability of the volume-adjustable metering component 100 during repeated use.

[0077] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A quantitative blood collection device for blood culture, comprising a flexible catheter (1) and blood collection needle assemblies (2) and a vial puncture assembly (3) disposed at both ends of the flexible catheter (1), characterized in that, It also includes a volume-adjustable metering assembly (100) disposed in the middle section of the flexible catheter (1); The volume-adjustable metering component (100) includes: A flexible inner capsule (110) is connected to the lumen of the flexible catheter (1); A rigid outer cavity (120) is wrapped around the outside of the flexible inner capsule (110); A volume adjustment mechanism for adjusting and limiting the effective expansion volume of the flexible inner bladder (110) within the rigid outer cavity (120); A first switching valve (5) is disposed on the flexible catheter (1) between the blood collection needle assembly (2) and the volume adjustable quantitative assembly (100); The second switching valve (6) is disposed on the flexible conduit (1) between the volume adjustable metering component (100) and the bottle puncture component (3); Furthermore, the inner wall of the flexible catheter (1) and / or the inner wall of the flexible inner capsule (110) are provided with an anticoagulant coating.

2. The quantitative blood collection device for blood culture as described in claim 1, characterized in that, The volume adjustment mechanism includes an adjustment push plate (130) and a positioning component; The adjusting push plate (130) is slidably disposed within the rigid outer cavity (120) and matches the inner wall shape of the rigid outer cavity (120); The positioning component is used to fix the adjusting push plate (130) at different axial positions within the rigid outer cavity (120) to change the spatial volume between the adjusting push plate (130) and the proximal end of the flexible inner capsule (110).

3. The quantitative blood collection device for blood culture as described in claim 2, characterized in that, The positioning component is a sliding locking mechanism, including: Two sliding grooves (122) are symmetrically opened along the outer wall of the rigid outer cavity (120), and multiple slots (123) are spaced apart along the length direction on the groove wall of each sliding groove (122). A slip ring (140) is sleeved on the outside of the rigid outer cavity (120). The slip ring (140) can slide along the axial direction of the rigid outer cavity (120) and rotate about its axis. Two connecting pins (142) are symmetrically arranged on opposite sides of the slip ring (140). One end of each connecting pin (142) is fixedly connected to the slip ring (140), and the other end passes through the corresponding slide groove (122) and is fixedly connected to the edge of the adjusting push plate (130). The radial dimension of the connecting pin (142) matches the width of the slide (122); the radial dimension of the connecting pin (142) is smaller than the width of the slot (123).

4. The quantitative blood collection device for blood culture as described in claim 3, characterized in that, The two grooves (122) extend along the axial direction of the rigid outer cavity (120) to the bottom end of the rigid outer cavity (120); An operating handle (132) is connected to the adjusting push plate (130), and the operating handle (132) extends axially toward the proximal end and passes through the rear end face of the rigid outer cavity (120).

5. The quantitative blood collection device for blood culture as described in claim 1, characterized in that, The rigid outer cavity (120) is made of transparent material, and its outer wall is provided with volume scale (124). The adjustment push plate (130) is provided with indicator marks for indicating the volume scale (124).

6. The quantitative blood collection device for blood culture as described in claim 1, characterized in that, The anticoagulant coating is at least one of heparin coating, hirudin coating, or polyethylene glycol anti-protein adsorption coating; The flexible inner capsule (110) is made of a medical-grade elastomer material with ultra-high compliance and elastic recovery capability, including medical-grade liquid silicone or medical-grade thermoplastic polyurethane; the wall thickness of the flexible inner capsule (110) is 0.3-0.5 mm.

7. The quantitative blood collection device for blood culture as described in claim 1, characterized in that, The inner or outer wall of the flexible inner bladder (110) is provided with a pre-formed axial or circumferential corrugated structure (111).

8. The quantitative blood collection device for blood culture as described in claim 1, characterized in that, The outer wall of the flexible inner capsule (110) and / or the inner wall of the rigid outer cavity (120) are provided with mutually cooperating guide structures, which are used to guide the flexible inner capsule (110) to expand uniformly along the axial direction during the expansion process.

9. The quantitative blood collection device for blood culture as described in claim 1, characterized in that, The bottle puncture assembly (3) is an integrated multi-bottle puncture adapter (300), which includes: Adapter body (310); A liquid inlet (320) is provided on the adapter body (310) for connection with the flexible conduit (1); At least two branch puncture needles (330) extend from the adapter body (310), each of the branch puncture needles (330) being used to independently puncture and connect to a blood culture bottle (9); Each branch puncture needle (330) is provided with an independent branch switch valve (340) in the fluid channel between the branch puncture needle (330) and the inlet port (320).

10. The quantitative blood collection device for blood culture as described in claim 1, characterized in that, The branch switch valve (340) is a clamp-on switch valve or a plug switch valve; the first switch valve (5) is a one-way valve, and its conduction direction is from the blood collection needle assembly (2) to the volume adjustable quantitative assembly (100). The second switching valve (6) is a clamp-on switching valve or a plug-in switching valve.

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