Bubble removal cap

Abstract

To achieve an air bubble removal cap which can reduce a risk of contamination by blood.SOLUTION: An air bubble removal cap comprises: a main body cylinder part 101 which has a connector part 112 having a ventilation filter 104 fixed to a tip end side, and a nozzle of a syringe to be inserted at a base end side; and an outside cylinder part 102 surrounding the main body cylinder part 101. A base end of the outside cylinder part 102 is closer to a base end side than a base end of the main body cylinder part 101.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a defoaming cap. [Background Art]

[0002] When analyzing dissolved gas in blood, air bubbles contained in a collected blood sample cause an increase in measurement error. For this reason, when collecting a sample for analyzing dissolved gas or the like, it is common to use a dedicated syringe or the like that makes air less likely to enter. However, even if a dedicated syringe is used, it is difficult to completely prevent air bubbles from entering.

[0003] Air bubbles mixed in during blood collection can be collected at the upper part by pointing the syringe upward after blood collection, and pushed out from the needle tip by pressing the plunger. However, when pushing out the air bubbles, a small amount of blood is also pushed out. Blood pushed out from the needle tip can cause medical accidents such as infections.

[0004] The use of a ventilation filter that blocks the passage of blood has been studied to enable pushing out air bubbles while avoiding contamination with blood. For example, by preparing a defoaming cap having a ventilation filter, attaching the defoaming cap to a syringe after blood collection, and then performing an operation to push out air bubbles, blood can be prevented from being pushed out to the outside (see, for example, Patent Document 1). [Prior Art Documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Laid-Open No. 4-231967. [Summary of the Invention] [Problem to be Solved by the Invention]

[0006] However, conventional bubble removal caps can cause blood contamination during attachment and removal from syringes. For example, when attaching a bubble removal cap to a nozzle, if the tip of the nozzle touches the base end of the connector part of the bubble removal cap, blood may adhere to the outside of the bubble removal cap. If the bubble removal cap is then grasped without noticing the blood on the outside, the risk of blood contamination increases. While it is possible to prevent blood from adhering to the outside by carefully operating the cap so that the tip of the nozzle does not touch the base end of the connector part, it is impossible to consistently perform such an operation successfully every time.

[0007] The objective of this disclosure is to develop a bubble-removing cap that reduces the risk of blood contamination. [Means for solving the problem]

[0008] One embodiment of the bubble removal cap of the present disclosure comprises a main body cylindrical portion having a vent filter fixed to the tip end and a connector portion into which a syringe nozzle is inserted at the base end, and an outer cylindrical portion surrounding the main body cylindrical portion, wherein the base end of the outer cylindrical portion is located closer to the base end than the base end of the main body cylindrical portion.

[0009] In one embodiment of the bubble removal cap, the base end of the outer cylindrical portion surrounding the main cylindrical portion is located closer to the base end than the base end of the main cylindrical portion. Therefore, when inserting the syringe nozzle into the connector portion provided on the base end side of the main cylindrical portion, even if the end of the nozzle unintentionally touches the end of the connector portion and blood adheres to the outside of the connector portion, the operator can avoid unintentionally touching the blood-covered connector portion. In addition, a ventilation filter provided on the tip side of the main cylindrical portion allows for the removal of bubbles without pushing blood out.

[0010] In one embodiment of the bubble removal cap, the outer diameter of the main body cylinder is smaller than the inner diameter of the syringe coupler, and the inner diameter of the outer cylinder is larger than the outer diameter of the syringe coupler. With this configuration, the coupler can be used as a guide when inserting the nozzle into the connector, making attachment to and detachment from the syringe smoother.

[0011] In one embodiment of the bubble removal cap, the base end surface of the outer cylinder and the base end surface of the main cylinder can be inclined inward. This configuration makes it easier to insert the syringe coupler and nozzle into the outer cylinder and connector, and reduces the possibility of blood contamination during installation.

[0012] In one embodiment of the bubble removal cap, the main body cylinder can have a bubble separation chamber formed on the proximal end side of the ventilation filter, and an orifice formed between the bubble separation chamber and the connector. This configuration makes it less likely for the ventilation filter to become wet with blood and lose its breathability before the bubbles at the nozzle tip are pushed out, and even if bubbles remain, they are less likely to flow back towards the nozzle.

[0013] In one embodiment of the air bubble removal cap, the tip of the outer cylinder may coincide with the tip of the main cylinder, or it may extend further toward the tip than the tip of the main cylinder. With this configuration, the air bubble removal cap can be placed on a table with the tip facing downwards for insertion, further reducing blood contamination during installation. [Effects of the Invention]

[0014] The bubble removal cap of this disclosure can reduce the risk of blood contamination. [Brief explanation of the drawing]

[0015] [Figure 1] This is a perspective view showing a bubble removal cap according to one embodiment. [Figure 2] This is a perspective view showing a bubble removal cap according to one embodiment. [Figure 3] This is a cross-sectional view taken along line III-III in Figure 1. [Modes for carrying out the invention]

[0016] As shown in Figures 1 to 3, the bubble removal cap 100 according to one embodiment comprises a main cylindrical portion 101 and an outer cylindrical portion 102 that is connected to the main cylindrical portion 101 by a flange portion 103 and surrounds the main cylindrical portion 101.

[0017] The main cylindrical portion 101 has a filter holding portion 111 at the tip end for holding the ventilation filter 104, and a connector portion 112 at the base end. The ventilation filter 104 is a filter that allows gas to pass through but prevents liquid from passing through, and can be a hydrophobic resin filter or a sintered body filter.

[0018] An orifice nozzle 115 is formed between the filter holding portion 111 and the connector portion 112 of the main cylindrical portion 101, and a hollow bubble separation chamber 114 is formed surrounding the orifice nozzle 115. A gap is provided between the tip of the orifice nozzle 115 and the vent filter 104. The connector portion 112 of the main cylindrical portion 101 is fitted into a liquid-tight seal when a syringe nozzle is inserted into it. A typical syringe nozzle is a male Luer connector, and the connector portion 112 is a female Luer connector. However, other configurations are possible as long as the two can be fitted together in a liquid-tight seal.

[0019] When inserting the nozzle of a syringe into the connector portion 112, if perfect alignment cannot be achieved, the tip of the nozzle will abut against the proximal end wall 116 of the connector portion 112, which may cause blood to adhere to the outside of the connector portion 112. However, since the outer diameter of the nozzle is substantially equal to the inner diameter of the connector portion 112, it is extremely difficult to prevent the tip of the nozzle from coming into contact with the proximal end wall 116. In the present embodiment, the main body cylinder portion 101 is surrounded by a large-diameter outer cylinder portion 102, and the proximal end of the outer cylinder portion 102 is located closer to the proximal side than the proximal end of the main body cylinder portion 101. The inner diameter of the outer cylinder portion 102 is larger than the outer diameter of the nozzle, and is designed to have a clearance with the outer diameter of the nozzle. Therefore, it is easy to insert the tip of the nozzle into the outer cylinder portion 102 without touching the proximal end wall 126 of the outer cylinder portion 102. It should be noted that if the clearance is excessively large, when blood drips between the outer cylinder portion 102 and the connector portion 112, blood will easily flow around to the outside. For this reason, the clearance is preferably 0.1 mm or more and 1 mm or less. Even if the tip of the nozzle abuts against the proximal end wall 116 of the connector portion 112 and blood adheres to the outside of the connector portion 112, since the connector portion 112 is surrounded by the outer cylinder portion 102, it is possible to avoid a situation where an operator unintentionally touches the connector portion 112 to which blood has adhered.

[0020] From the viewpoint of avoiding contamination by blood, the distance d1 between the proximal end of the connector portion 112 and the proximal end of the outer cylinder portion 102 is preferably increased to a certain extent, and more preferably 3 mm or more. From the viewpoints of ease of nozzle insertion and ease of molding, it is preferably 5 mm or less.

[0021] When using a syringe having a coupler that can be screwed with a female connector, it is preferable that the outer diameter of the main body cylinder portion 101 is made slightly smaller than the inner diameter of the coupler, and the inner diameter of the outer cylinder portion 102 is made slightly larger than the outer diameter of the coupler. With this configuration, the gap between the main body cylinder portion 101 and the outer cylinder portion 102 can serve as a guide for inserting and aligning the coupler, so it becomes even easier to insert the nozzle of the syringe into the connector portion 112.

[0022] In the present embodiment, the proximal end wall 126 of the outer cylindrical portion 102 is an inclined surface that slopes inward. This allows the coupler to be guided more smoothly into the outer cylindrical portion 102, and automatically positions the nozzle of the syringe, so that the nozzle can be smoothly inserted into the connector portion 112. In the present embodiment, the proximal end wall 116 of the connector portion 112 is also an inclined surface that slopes inward. Accordingly, even if the coupler hits the proximal end wall 116 of the connector portion 112, it is guided inward, allowing the nozzle to be inserted into the connector portion 112 even more smoothly.

[0023] In the present embodiment, the distal end of the outer cylindrical portion 102 is located closer to the distal side than the distal end of the main body cylindrical portion 101. With such a configuration, it is easy to place the defoaming cap on a stand with the distal side facing downward and insert the nozzle of the syringe from above. When the nozzle is inserted into the connector portion 112 placed on the stand, the insertion operation can be performed without holding the defoaming cap 100, thereby making medical accidents less likely to occur. Since the distal end of the outer cylindrical portion 102 is located closer to the distal side than the distal end of the main body cylindrical portion 101, not only can the distal end of the main body cylindrical portion 101 be prevented from touching the surface of the stand when the defoaming cap is placed on the stand, but also situations where the distal end of the main body cylindrical portion 101 is unintentionally touched by a finger or the like can be made less likely to occur. However, configurations are also possible in which the position of the distal end of the outer cylindrical portion 102 matches the position of the distal end of the main body cylindrical portion 101, or the distal end of the main body cylindrical portion 101 is located closer to the distal side than the distal end of the outer cylindrical portion 102.

[0024] In the present embodiment, the outer cylindrical portion 102 has a thickened rim portion 121 on the distal side. Therefore, the defoaming cap 100 can be stably placed on a stand or the like with the distal side facing downward. In addition, the defoaming cap 100 can be prevented from being easily damaged even when force is applied during insertion of the syringe nozzle into the connector portion 112. Furthermore, compared to the case where the entire outer cylindrical portion 102 is thickened, molding accuracy can be improved, and situations such as rattling occurring when placed on a stand due to defective molding can be reduced.

[0025] In this embodiment, the outer cylindrical portion 102 has an outer shape with a substantially square cross-section on the base end side of the rim portion 121, having four gripping surfaces 122. By making the outer shape of the outer cylindrical portion 102 have gripping surfaces 122, the bubble removal cap can be easily gripped. The outer shape of the outer cylindrical portion 102 is not limited to a substantially square shape, but can also be substantially triangular or substantially polygonal with five or more sides. The gripping surfaces 122 are not perfectly flat, but can be slightly curved surfaces that fit the fingers. The outer shape of the outer cylindrical portion 102 can also be a circular or elliptical shape formed entirely by curved surfaces.

[0026] In this embodiment, thick pillars 123 are formed between the four gripping surfaces 122. By forming the pillars 123, the strength of the outer cylindrical portion 102 can be increased while making the gripping surfaces 122 thinner. Alternatively, instead of forming the pillars 123, the entire outer cylindrical portion 102, including the gripping surfaces 122, can be made thicker.

[0027] In this embodiment, the outer cylindrical portion 102 is formed by two walls: an outer wall 127 and an inner wall 128. The outer wall 127 and the inner wall 128 are connected at the base end, and the other parts are separated by a gap 129. With this configuration, an outer cylindrical portion 102 having a predetermined inner diameter and outer diameter can be easily formed without increasing the wall thickness. However, the outer cylindrical portion 102 can also be formed with a single wall instead of a double-wall structure.

[0028] When using the bubble removal cap 100 of this embodiment, first, the nozzle of the syringe used to collect blood is inserted into the connector portion 112 of the main body cylinder portion 101 and fitted together. Then, with the nozzle facing upwards, the syringe is flicked or otherwise used to collect air bubbles in the nozzle portion, and the plunger is pressed. The blood containing air bubbles is pushed through the orifice nozzle 115 into the bubble separation chamber 114. At this time, the air in the bubble separation chamber 114 is discharged to the outside through the ventilation filter 104. Until the bubble separation chamber 114 is filled with blood, the blood pushed out from the orifice nozzle 115 descends and accumulates in the bubble separation chamber 114 from the base end, and the air bubbles pushed out with the blood rise and are discharged through the ventilation filter 104 along with the air in the bubble separation chamber 114. Since the blood cannot pass through the ventilation filter, only the air bubbles can be removed without pushing the blood out of the bubble removal cap 100.

[0029] If the ventilation filter 104 becomes wet with blood, air will also be unable to pass through, so a small amount of air may remain in the bubble separation chamber 114. However, the blood in the bubble separation chamber 114 is not used for analysis, and the backflow of any remaining air from the bubble separation chamber 114 to the syringe side is suppressed by the orifice nozzle 115, so even if air remains in the bubble separation chamber 114, it will not affect the measurement.

[0030] The volume of the bubble separation chamber 114 is not particularly limited, but from the viewpoint of sufficiently removing air bubbles in the syringe, it is preferably 30% or more, more preferably 50% or more, of the volume of the nozzle portion of the syringe. From the viewpoint of reducing dead volume, it is preferable that it be smaller than the volume of the nozzle portion, but it can also be larger than the volume of the nozzle portion. In this case, it is preferably 120% or less, more preferably 110% or less.

[0031] In this embodiment, the inner diameter of the filter holding portion 111 is made smaller than the inner diameter of the connector portion 112. This makes it easy to reduce the dead volume of the bubble separation chamber 114 and thus reduce the amount of blood that is discarded. However, the size of the filter holding portion 111 can be optimized according to the size of the vent filter 104 used.

[0032] In this embodiment, the flange portion 103 connecting the main cylindrical portion 101 and the outer cylindrical portion 102 is formed at a position substantially aligned with the base end of the orifice nozzle 115. However, the flange portion 103 may also be formed at other positions.

[0033] A male threaded portion that engages with the syringe coupler can also be formed on the outer surface of the connector portion 112. This makes it less likely for the bubble removal cap 100 to detach from the syringe nozzle during operation.

[0034] In this embodiment, the main body cylinder 101 and the outer cylinder 102 are not particularly limited, but can be formed from transparent materials such as polypropylene and acrylic. By forming the main body cylinder 101 and the outer cylinder 102 from transparent materials, it is possible to visually confirm that the syringe nozzle has been inserted into the connector 112 and that blood has flowed into the bubble separation chamber 114 and that the bubbles have been removed. Note that the main body cylinder 101 and the outer cylinder 102 do not have to be completely transparent, but can be semi-transparent to the extent that the flow of blood can be observed.

[0035] The bubble removal cap 100 of this embodiment can be combined with a syringe having a filter gasket used for arterial blood collection, but it can also be combined with a regular syringe. [Industrial applicability]

[0036] The bubble-removing cap of this disclosure can reduce the risk of blood contamination and is useful in the medical field and other applications. [Explanation of symbols]

[0037] 100 Bubble Removal Caps 101 Main body cylindrical part 102 Outer cylinder part 103 Flange section 104 Ventilation filter 111 Filter holding section 112 Connector section 114 Bubble Separation Chamber 115 Orifice Nozzle 116 Base wall 121 Rim section 122 Gripping surface 123 Pillar 126 Base wall 127 Outside wall 128 Inner wall 129 gap

Claims

1. A bubble removal cap, The main body has a cylindrical section with a ventilation filter fixed to the tip and a connector section into which the syringe nozzle is inserted at the base end, It comprises an outer cylindrical portion surrounding the main cylindrical portion, The outer diameter of the main body cylinder is smaller than the inner diameter of the syringe coupler. The inner diameter of the outer cylindrical portion is larger than the outer diameter of the syringe coupler. The gap between the main body cylinder and the outer cylinder functions as a guide for the insertion and alignment of the syringe coupler. The outer cylindrical portion has a portion facing the main cylindrical portion that forms the gap, and a portion that extends from the facing portion beyond the base end of the main cylindrical portion toward the base end, and the base end of the outer cylindrical portion is located at the very base end of the bubble removal cap, a bubble removal cap for a syringe.

2. The bubble removal cap according to claim 1, wherein the base end surface of the outer cylindrical portion and the base end surface of the main cylindrical portion are inclined surfaces that are inclined inward.

3. The bubble removal cap according to claim 1, wherein the main body cylindrical portion has a bubble separation chamber formed on the base end side of the ventilation filter and an orifice nozzle formed between the bubble separation chamber and the connector portion.

4. The bubble removal cap according to claim 1, wherein the tip of the outer cylindrical portion coincides with the tip of the main cylindrical portion, or extends further toward the tip than the tip of the main cylindrical portion.

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