An arterial blood gas needle and piston

Abstract

The utility model discloses an artery blood gas needle and piston relates to medical instrument technical field. The piston includes silica gel cover, and its top surface is designed as the conical frustum structure and is circular array and is opened multiple inclined through -hole, and the inside sets up the gas permeable membrane and forms the gas passage, and the bottom is through the connecting hole and is inserted the hollow push -pull link. The conical frustum structure guides the gas directional discharge along the through -hole when blood sampling, and the gas permeable membrane realizes gas -liquid separation, and effectively reduces bubble residue and blood leakage from the piston gap. The push -pull link adopts the hollow structure cooperation screw part, guide hole and support hole and forms multistage positioning system, through the taper hole direction correction assembly angle, and the support rod rigid cooperation promotes the push -pull stability, and the counterbore and the limiting ring prevent displacement overrun. The sealing ring of silica gel cover side integral molding enhances the needle cylinder inner wall adhesion, and the boss sunken through -hole structure optimizes the airflow path. The design significantly improves blood gas separation efficiency and anti -leakage performance, and guarantees the detection result reliability.

Description

TECHNICAL FIELD

[0001] The utility model relates to medical instrument technical field, concretely relates to an arterial blood gas needle and piston. BACKGROUND

[0002] Arterial blood sampling is a technique for observing arterial blood oxygen and acid-base balance, and is often used for diagnosing lung diseases and heart diseases, and evaluating patient's respiratory function, acid-base balance and metabolic state. The medical instrument for collecting arterial blood samples includes an arterial blood sample collector as shown in the announcement number CN205268175U, which has a needle cylinder, a push-pull rod and a piston core assembly including a piston. After collecting an arterial blood sample, water vapor or tiny bubbles mixed in the blood need to be separated from the blood itself to prevent them from interfering with the test results.

[0003] However, the conventional arterial blood gas needle piston collects blood with the needle head tilted upward, and uses gravity to reduce the bubbles generated by blood impact. After blood collection, the needle cylinder is flicked to make the bubbles gather at the top, and then the piston is pressed to expel air. This treatment method does not completely expel water vapor or tiny bubbles, and blood can easily leak from the piston gap when the needle head is tilted upward, resulting in sample loss. Such problems can reduce the reliability of test results, and even require repeated blood collection. UTILITY MODEL CONTENT

[0004] The utility model aims at overcoming the deficiencies of the prior art, and provides an arterial blood gas needle piston, which solves the technical problems of incomplete blood gas separation and easy blood leakage of the conventional blood gas needle.

[0005] To achieve the above-mentioned purpose, the utility model provides the technical scheme as follows: An arterial blood gas needle piston includes a silica gel sleeve, the top surface of the silica gel sleeve is a conical frustum structure and is arranged in a circular array, a plurality of inclined through holes are uniformly arranged, a gas permeable membrane is arranged on the inner side of the silica gel sleeve, the through holes are connected to one side of the gas permeable membrane, a connecting hole for connecting the push-pull rod is arranged on the bottom surface of the silica gel sleeve, the end of the push-pull rod is embedded into the connecting hole, and the push-pull rod is a hollow structure.

[0006] Further, a threaded part connected by threads is coaxially arranged inside the silica gel sleeve. After the push-pull rod is embedded into the silica gel sleeve by relying on the elastic force of the silica gel sleeve, the silica gel sleeve is fixed by a clamp or hand, and then the push-pull rod is tightened, thereby improving the fixed connection effect of the two.

[0007] Further, a guide hole is arranged between the threaded part and the connecting hole in the silica gel sleeve, the guide hole is a tapered hole structure, the first end surface of the tapered hole is connected to the threaded part, the second end surface of the tapered hole is connected to the connecting hole, the diameter of the first end surface is smaller than that of the second end surface, and the push-pull rod is guided when it is inserted into the silica gel sleeve.

[0008] Furthermore, a support hole is provided between the connecting hole and the guide hole. The push-pull rod is provided with a support rod adapted to the support hole. The support hole is a cylindrical structure, and the diameter of the second end face of the conical hole is less than or equal to the bottom diameter of the cylinder. The silicone sleeve on the outside of the support rod acts as a thin wall. Supported by the support rod, it allows the piston to retain radial deformation for sealing while reducing the deformation of the piston in the middle, forming a support within the silicone sleeve. Furthermore, the end face of the connecting hole away from the cavity silicone sleeve is also provided with a countersunk hole, and the push rod is provided with a limiting ring adapted to the countersunk hole.

[0009] Furthermore, the silicone sleeve has multiple sealing rings arranged radially on its side, and the sealing rings are integrally connected to the silicone sleeve.

[0010] Furthermore, the top surface of the silicone sleeve is provided with a boss, and multiple through holes form a recessed structure on the boss.

[0011] Furthermore, the diameter of the connecting hole is 2.8-3.2 mm, the depth of the guide hole is 1-2 mm, and the depth of the support hole is 5-10 mm.

[0012] Furthermore, the arterial blood gas needle piston is a disposable item.

[0013] This utility model also relates to an arterial blood gas needle having any of the above-mentioned technical features, including a syringe, wherein the blood gas needle piston is disposed inside the syringe and slides along the syringe.

[0014] The advantages and beneficial effects of this utility model are as follows: The frustum-shaped structure and circular array of through holes on the top surface of the silicone sleeve, combined with the breathable membrane, form an exhaust channel. The inclined through holes of the frustum-shaped structure can guide gas to be discharged efficiently, reducing air bubble residue. The breathable membrane allows gas to pass through while preventing blood or liquid backflow, avoiding sample contamination. The threaded push-pull rod is coaxially positioned with the silicone sleeve, and the tapered structure of the guide hole can adaptively correct the insertion angle of the push-pull rod, ensuring assembly accuracy. The support hole and the support rod of the push-pull rod form a rigid fit, reducing offset during the push-pull process and improving operational stability. The sealing ring is integrally molded with the silicone sleeve, reducing assembly gaps and enhancing the fit with the inner wall of the syringe. The countersunk hole and the limiting ring can prevent excessive displacement of the push-pull rod. Attached Figure Description

[0015] Fig. 1 This is a cross-sectional structural diagram of the silicone sleeve of this utility model; Fig. 2 This is a schematic diagram of the top surface structure of the silicone sleeve of this utility model; Fig. 3 This is a cross-sectional structural schematic diagram of the push-pull rod of this utility model; Reference numerals: 1-Silicone sleeve, 2-Through hole, 3-Ventilating membrane, 4-Connecting hole, 5-Push-pull rod, 6-Threaded part, 7-Guide hole, 8-Support hole, 9-Support rod, 10-Counterhole, 11-Limiting ring, 12-Sealing ring, 13-Boss. Detailed Implementation

[0016] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solution of this utility model and should not be construed as limiting the scope of protection of this utility model.

[0017] Example 1 For an arterial blood flow needle piston, please refer to [link / reference]. Figs. 1-3 The device includes a silicone sleeve 1, which is integrally molded from medical-grade silicone. The top surface is designed as a truncated cone with a 15° cone angle, and five inclined through holes 2 arranged in a circular array on its surface. A 10mm diameter polytetrafluoroethylene (PTFE) breathable membrane is attached to the inner side of the silicone sleeve 1 to form a gas-liquid separation channel. The push-pull rod 5 is a hollow rod structure with an inner diameter of 2mm, and its end is interference-fitted into a 3mm diameter connecting hole 4 at the bottom of the silicone sleeve 1. Three annular sealing rings 12 are provided on the outer side of the silicone sleeve 1, which can form a dynamic seal with the inner wall of the syringe.

[0018] Example 2 An arterial blood flow needle piston differs from Embodiment 1 in that, from top to bottom, the silicone sleeve has a threaded portion 6, a guide hole 7, and a support hole 8 sequentially arranged on the connecting hole 4. A countersunk hole 10 is also provided outside the connecting hole 4. The push-pull rod 5 has an external thread corresponding to the threaded portion 6 for rotatable connection. A support rod 9 and a limiting ring 11 are also present. The push-pull rod 5 is also threadedly connected to the silicone sleeve via the threaded portion 6. The guide hole 7 has a first end face diameter of 2.8 mm, a second end face diameter of 3.2 mm, and a depth of 1.5 mm. The support hole 8 has a height of 5 mm.

[0019] Example 3 An arterial blood flow needle piston differs from Embodiment 2 only in that a boss 13 is provided on the top of the cone, and the inlet of the through hole 2 is located on the side wall of the boss to form a sunken structure.

[0020] The pistons of Examples 1-3 are inserted into a 10mm inner diameter polycarbonate syringe and used with a 22G puncture needle for arterial blood sampling tests. The hollow channel of the push-pull rod 5 is directly connected to the atmosphere. When the syringe needle tip is tilted downward at 45°, the gas can be discharged from the push-pull rod 5 through the breathable membrane 3 at a speed of up to 3mL / s. The sealing ring 12 keeps the piston sliding resistance stable at 1.5-2N. With the support rod 9 and the support hole 8 in cooperation, the push-pull offset angle is ≤0.5°. The limiting ring 11 limits the piston displacement error to <±0.3mm.

[0021] The working principle of this invention is as follows: after blood enters the syringe, gas automatically gathers towards the push-pull rod due to density differences. The inclined through-holes on the surface of the cone form an airflow channel; high-pressure gas preferentially enters the breathable membrane through the through-holes, achieving initial gas-liquid separation. The breathable membrane allows gas molecules to pass through but blocks liquid. After passing through the breathable membrane via the through-holes, the gas enters the hollow cavity of the push-pull rod and is finally discharged into the atmosphere. When the operator gently pushes the piston, the pressure difference drives the gas to exit directionally along this path, eliminating the need to tilt the syringe. The recessed through-holes on the side wall of the boss form an L-shaped channel. When the piston retracts, blood is difficult to enter the through-holes due to surface tension, while gas can pass freely, enhancing unidirectional exhaust. The annular sealing ring on the side of the silicone sleeve is interference-fitted with the inner wall of the syringe. When the piston moves, the sealing ring is deformed under pressure, compensating for manufacturing tolerances in real time and preventing blood leakage from the piston edge. The conical structure of the guide hole automatically guides the rod and silicone sleeve when the push-pull rod is inserted. The support rod and support hole provide rigid support for the piston. The limiting ring and the countersunk hole work together to limit the push and pull, preventing excessive pushing that could cause the vent membrane to rupture or the piston to come out during pullback.

[0022] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. An arterial blood gas needle piston, characterized in that: The device includes a silicone sleeve (1), the top surface of which is a frustum structure and has multiple inclined through holes (2) evenly distributed in a circular array. A breathable membrane (3) is provided on the inner side of the silicone sleeve (1), and the through holes (2) are connected to one side of the breathable membrane (3). A connecting hole (4) is provided on the bottom surface of the silicone sleeve (1), and the end of the push-pull rod (5) is embedded in the connecting hole (4). The push-pull rod (5) is a hollow structure.

2. The arterial blood gas needle piston according to claim 1, characterized in that: The silicone sleeve (1) has a threaded part (6) inside which is coaxially connected to the push-pull rod (5) via a thread.

3. The arterial blood gas needle piston according to claim 2, characterized in that: A guide hole (7) is provided between the threaded part (6) and the connecting hole (4). The guide hole (7) is a tapered hole structure, and the diameter of its first end face is smaller than the diameter of its second end face.

4. The arterial blood gas needle piston according to claim 3, characterized in that: A support hole (8) is provided between the connecting hole (4) and the guide hole (7). The push-pull rod (5) is provided with a support rod (9) adapted to the support hole (8). The support hole (8) is a cylindrical structure and the diameter of the second end face of the conical hole is less than or equal to the diameter of the bottom surface of the cylinder.

5. The arterial blood gas needle piston according to claim 4, characterized in that: The end face of the connecting hole (4) is provided with a countersunk hole (10), and the push-pull rod (5) is provided with a limiting ring (11) adapted to the countersunk hole (10).

6. The arterial blood gas needle piston according to claim 1, characterized in that: The silicone sleeve (1) has an integrally formed sealing ring (12) arranged radially on its side.

7. The arterial blood gas needle piston according to claim 1, characterized in that: The top surface of the silicone sleeve (1) is provided with a boss (13), and the through hole (2) forms a sunken structure on the boss (13).

8. The arterial blood gas needle piston according to claim 4, characterized in that: The diameter of the connecting hole (4) is 2.8-3.2 mm, the depth of the guide hole (7) is 1-2 mm, and the depth of the support hole (8) is 5-10 mm.

9. The arterial blood gas needle piston according to claim 1, characterized in that: The arterial blood gas needle piston is a single-use product.

10. An arterial blood gas needle, characterized in that: The device includes a syringe and an arterial blood gas needle piston as described in any one of claims 1-9, wherein the piston is slidably disposed within the inner cavity of the syringe.

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