Method for manufacturing a gas metering adapter and window unit

Abstract

To provide an adapter for gas measurement having a simple configuration, and capable of enhancing measurement accuracy.SOLUTION: An adapter for gas measurement comprises a flow pipe part 21 through which gas passes, and a window unit 13 that has a window part 31 that transmits measurement light for measuring components of the gas passing through the flow pipe part, and a mounting part 32 that is mounted to the flow pipe part. In the window unit, the window part and the mounting part are integrally molded as one part, and formed of a material containing cyclo olefin copolymer or cyclo olefin polymer. An inner surface 50 and an outer surface 60 of the window part are flat.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a gas measurement adapter and also to a method for manufacturing a window unit provided in the gas measurement adapter. [Background technology]

[0002] An airway adapter having a transparent window is attached to the flow path of a ventilator that artificially breathes a living body in order to measure a specific component of gas such as respiratory gas (see Patent Documents 1 and 2). It is known that the respiratory gas flowing through this airway adapter contains moisture, and water droplets generated from this moisture flow along the inner wall of the airway adapter. If these water droplets pass through the transparent window, they may block infrared rays used for measurement, resulting in measurement errors. For this reason, for example, the airway adapter disclosed in Patent Document 1 is equipped with a frame that protrudes from the inner peripheral surface of the flow tube and surrounds the transparent window, and is configured so that water droplets pass outside the frame. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-74822 A [Patent Document 2] U.S. Patent No. 7,629,039 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the window of the airway adapter of Patent Document 1 is made up of multiple components and is complicated. The airway adapter of Patent Document 2 has a gate mark formed in the center of the window, which may scatter the measurement light and reduce the measurement accuracy. The airway adapters of Patent Documents 1 and 2 have room for improvement in these respects.

[0005] An object of the present invention is to provide a gas measurement adapter that is simple in configuration and yet capable of improving measurement accuracy, and a method for manufacturing a window unit provided in the gas measurement adapter. [Means for solving the problem]

[0006] In order to achieve the above object, a gas measurement adapter according to one aspect of the present invention comprises: A flow tube portion through which gas passes; a window unit including a window portion that transmits a measurement light for measuring a component of the gas passing through the flow tube portion, and an attachment portion for attachment to the flow tube portion; Equipped with The window unit is formed by integrally molding the window portion and the mounting portion as one part, and is made of a material containing a cycloolefin copolymer or a cycloolefin polymer, The inner and outer surfaces of the window are flat.

[0007] The gas measurement adapter according to the above configuration includes a window unit having a window portion that transmits measurement light and an attachment portion for attachment to a flow tube portion. The window unit is formed by integrally molding the window portion and the attachment portion as one part, and is made of a material containing a cycloolefin copolymer or a cycloolefin polymer. These materials are capable of transmitting infrared rays and can be molded using a side gate type mold. Therefore, since the window portion can be molded using a side gate type mold, the inner and outer surfaces of the window portion can be molded flat. In this manner, the above-described configuration makes it possible to improve the measurement accuracy while maintaining a simple configuration.

[0008] In addition, a method for manufacturing a window unit according to one aspect of the present invention for achieving the above object includes the steps of: A method for manufacturing a window unit having a window portion that transmits measurement light for measuring a component of a gas passing through a flow tube portion, and an attachment portion for attachment to the flow tube portion, comprising the steps of: The window unit is molded as a single unit by injecting a resin material containing cyclo olefin copolymer or cyclo olefin polymer toward the cavity from a gate provided on the side of the parting surface of the mold corresponding to the integral molding of the window portion and the mounting portion. In this manner, according to the above-described configuration, the window unit can be integrally molded by injecting the cycloolefin copolymer or the resin material containing the cycloolefin polymer toward the cavity by the side gate method. Therefore, according to such a method for manufacturing a window unit, the window unit can be easily molded. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a left side view of a gas measurement adapter according to one embodiment. [Diagram 2] FIG. 2 is a partial enlarged view of the sensor mounting portion of FIG. [Diagram 3] FIG. 3 is a cross-sectional view taken along line AA in FIG. [Figure 4] FIG. 4 is an enlarged view of the sensor mounting portion of FIG. [Diagram 5] FIG. 5 is an enlarged view of the portion surrounded by the dashed line C in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, examples of embodiments will be described in detail with reference to the accompanying drawings. Note that the terms "upper", "lower", "left", "right", "front" and "rear" used in this specification and the drawings are directions indicated for the convenience of explanation, and are not intended to be limited to the directions shown in the drawings.

[0011] 1 is a left side view of a gas measurement adapter 1 according to one embodiment. The gas measurement adapter 1 is an adapter used when optically measuring the concentration of a specific component (e.g., carbon dioxide) contained in the respiratory gas of a patient who requires respiratory management (hereinafter, referred to as a subject).

[0012] 1, the gas measurement adapter 1 includes a first connection adapter 11 provided at the front end, a second connection adapter 12 provided at the rear end, and a sensor attachment portion 20 provided between the first connection adapter 11 and the second connection adapter 12. The left side surface of the gas measurement adapter 1 and the right side surface of the gas measurement adapter 1 are symmetrical.

[0013] The first connection adaptor 11 is formed in a cylindrical shape. The first connection adaptor 11 can be connected to an air supply source and an exhalation outlet of the artificial respirator via a connecting member such as a Y-shaped tube. The second connection adaptor 12 is formed in a cylindrical shape with a larger diameter than the first connection adaptor 11. The second connection adaptor 12 can be connected to a subject-side device such as a tracheal tube or a mask.

[0014] Fig. 2 is a partially enlarged view showing the sensor attachment part 20 of the gas measurement adapter 1. As shown in Fig. 2, a respiratory gas concentration sensor (not shown) for optically measuring the concentration of a specific gas contained in the respiratory gas of the subject can be attached to the sensor attachment part 20. The sensor attachment part 20 includes a flow tube part 21 through which the respiratory gas of the subject passes, and a window unit 13 that can be attached to the flow tube part 21.

[0015] Fig. 3 is a cross-sectional view taken along line AA in Fig. 1. As shown in Fig. 3, the sensor attachment portion 20 has recesses 23a and 23b formed on the left and right sides, respectively. These recesses 23a and 23b are recesses into which the respiratory gas concentration sensor is fitted. The recesses 23a and 23b are defined by the outer surface of the flow tube portion 21.

[0016] 3, an air passage 41 (41a, 41b, 41c) for ventilating the respiratory gas of the subject is formed inside the gas measurement adapter 1. The air passage 41 is formed, for example, as a single air passage in which the air passage 41a inside the first connection adapter 11, the air passage 41b inside the sensor attachment part 20, and the air passage 41c inside the second connection adapter 12 are connected to each other.

[0017] The air passage 41a of the first connection adaptor 11 and the air passage 41c of the second connection adaptor 12 are formed in a cylindrical shape. The air passage 41b of the sensor attachment portion 20 is formed in a rectangular shape with a width W2 in the left-right direction narrower than a width W5 in the up-down direction (see FIG. 1). The width W2 in the left-right direction of the air passage 41b is formed narrower than the width W1 in the left-right direction of the air passage 41a (diameter of the air passage 41a) and the width W3 in the left-right direction of the air passage 41c (diameter of the air passage 41c). On the other hand, as illustrated in FIG. 1, the width W5 in the up-down direction of the air passage 41b is formed to be the same length as the width W4 in the up-down direction of the air passage 41a and the width W6 in the up-down direction of the air passage 41c.

[0018] Next, the flow tube section 21 will be described with reference to Fig. 3 and Fig. 4. Fig. 4 is a partially enlarged view showing the inside of the sensor attachment section 20. As illustrated in Fig. 3, the flow tube section 21 is a tube section that passes the respiratory air of the subject flowing from the second connection adaptor 12 to an exhalation outlet (not shown) connected to the first connection adaptor 11. The thickness of the flow tube section 21 is formed to be different for each part according to the shapes of the recesses 23a and 23b.

[0019] As illustrated in Fig. 4, the flow tube section 21 has an opening 210 and a mounting section 211. The opening 210 is circular (see Fig. 2) and is provided at approximately the center of the flow tube section 21 in a cross-sectional view. The opening 210 is configured so that the window unit 13 can be attached. The mounting section 211 is annular and is disposed so as to surround the opening 210.

[0020] Next, the window unit 13 will be described with reference to Figures 4 and 5. Figure 5 is an enlarged view of the portion surrounded by the dashed line C in Figure 4. As illustrated in Figures 4 and 5, the window unit 13 is a thin circular member. The window unit 13 includes a window section 31 that transmits measurement light for measuring components of the subject's respiratory gas passing through the flow tube section 21, and an attachment section 32 for attaching the window unit 13 to the flow tube section 21.

[0021] The window 31 is configured to transmit light (measurement light) for measuring components of respiratory gas. The window 31 is substantially circular (see FIG. 2). The diameter of the window 31 is 6 mm or less, and preferably about 5.5 mm. The mounting part 32 is annular and disposed so as to surround the window 31. The window 31 and the mounting part 32 are integrally formed so as to be continuous with each other.

[0022] 5, the window portion 31 is formed to have a constant thickness. The window portion 31 is formed to have a thickness smaller than the thickness of the flow tube portion 21.

[0023] The thickness of the window portion 31 and the mounting portion 32 are relatively thin, and are approximately equal to each other. The mounting portion 32 is disposed outside the window portion 31 in the window unit 13. The thickness dimension of the window portion 31 is approximately equal to the thickness dimension of the mounting portion 211. Furthermore, the radial length of the mounting portion 32 (the front-rear direction in the cross-sectional view of FIG. 5) is approximately equal to the radial length of the mounting portion 211.

[0024] The window unit 13 is integrally molded so that, in a cross-sectional view, the two mounting parts 32 extend to form end parts 320 in the front-rear direction, and the window part 31 has an embossed shape that protrudes in the left-right direction (left direction in the example of FIG. 5) from the mounting part 32. In this case, it is preferable that the window part 31 also extends in the front-rear direction. The shape of the connection part 33 between the window part 31 and the mounting part 32 is tapered (a shape that is oblique from the right front direction to the left rear direction, or from the right rear direction to the left front direction in FIG. 5).

[0025] The placement portion 211 and the mounting portion 32 preferably have corresponding shapes when the window unit 13 is fitted into the opening 210. That is, it is preferable that the upper surface of the placement portion 211 (the plane in contact with the mounting portion 32) and the lower surface of the mounting portion 32 are approximately parallel. In this case, when the window unit 13 is fitted into the opening 210, there is no gap between the placement portion 211 and the mounting portion 32. In addition, the taper angle of the tapered surface at the end of the placement portion 211 on the opening 210 side is approximately the same as the taper angle of the tapered surface formed by the mounting portion 32 and the window portion 31 of the window unit 13. Therefore, when the window unit 13 is fitted into the opening 210, there is no gap between the two tapered surfaces.

[0026] Furthermore, the outer surface 212 of the flow tube portion 21 and the outer surface 321 of the mounting portion 32 form a flat surface without any steps when the window unit 13 is fitted into the flow tube portion 21. Similarly, the inner surface 213 of the flow tube portion 21 and the inner surface 50 of the window portion 31 form a flat surface without any steps when the window unit 13 is fitted into the flow tube portion 21. In this way, when the window unit 13 is fitted into the flow tube portion 21, no steps or the like are generated between the flow tube portion 21 and the window unit 13. In other words, when the window unit 13 is fitted into the flow tube portion 21, the surface formed by the flow tube portion 21 and the window unit 13 is a flat surface.

[0027] The inner surface 50 of the window portion 31 and the outer surface 60 of the window portion 31 are flat. In a state where the window unit 13 is removed from the flow tube portion 21, the distance D1 between the first end 21a and the second end 21b, which are the left and right ends of the opening 210 of the flow tube portion 21, is approximately equal to the length L1 in the front-rear direction of the window portion 31. Therefore, when the window unit 13 is attached to the flow tube portion 21, the mounting portion 32 is placed on the placement portion 211, and the window portion 31 is fitted into the opening 210. In this manner, in a state where the window portion 31 is fitted into the opening 210, the mounting portion 32 constitutes the end 320 in the extension direction of the window portion 31, and is fixed so as to be fitted into the placement portion 211. By fitting the extended mounting portion 32 into the placement portion 211, even if an external force is applied, the extended mounting portion 32 receives the external force, thereby reducing the risk of the window unit 13 coming off.

[0028] 4, when the window unit 13 is attached to the flow tube portion 21, the window unit 13 is disposed so as to face the left and right side surfaces of the sensor attachment portion 20. Furthermore, when the window unit 13 is attached to the flow tube portion 21, the window unit 13 is located in the center of the recesses 23a and 23b.

[0029] When the window unit 13 is attached to the flow tube portion 21, there is no step or unevenness between the inner surface 50 of the window portion 31 and the inner surface 51 of the flow tube portion 21. In other words, when the window unit 13 is attached to the flow tube portion 21, the inner surface 50 of the window portion 31 and the inner surface 51 of the flow tube portion 21 are continuous and flush with each other, and this continuous surface is flat. The inner surface 50 of the window portion 31 and the inner surface 51 of the flow tube portion 21 are surfaces that form the air passage 41b of the sensor attachment portion 20, i.e., the surfaces that come into contact with the respiratory gas of the subject.

[0030] An anti-fogging layer is formed on the inner surface 50 of the window portion 31. The anti-fogging layer has a function of absorbing water molecules and has hydrophilic anti-fogging performance. The anti-fogging layer can also be a layer for imparting physical strength such as scratch resistance and surface hardness. The anti-fogging layer can be formed, for example, by drying or curing a resin composition for the anti-fogging layer. The resin composition for the anti-fogging layer can be produced, for example, by adding various additives such as an anti-fogging agent to polyethylene or polyvinyl chloride.

[0031] Next, a method for measuring components of the subject's respiratory gas using the respiratory gas concentration sensor will be described. When the respiratory gas concentration sensor is attached to the sensor attachment section 20, a light emitting section and a light receiving section provided in the respiratory gas concentration sensor are arranged facing each other in the pair of windows 31. The respiratory gas concentration sensor attached to the sensor attachment section 20 is positioned at a predetermined position by being locked by a pair of locking members 22a, 22b provided facing each other on the upper part of the sensor attachment section 20.

[0032] Light (e.g., infrared light) emitted from the light-emitting section of the respiratory gas concentration sensor passes through the window section 31 arranged opposite to it. The light emitted from the light-emitting section is attenuated according to the concentration of carbon dioxide gas contained in the subject's breath and received by the light-receiving section. The light-receiving section transmits a light-receiving signal according to the intensity of the received light to a carbon dioxide gas measuring device (not shown). The carbon dioxide gas measuring device (not shown) measures the concentration of carbon dioxide gas contained in the subject's breath based on the light-receiving signal transmitted from the light-receiving section.

[0033] Next, a method for molding the window unit 13 will be described. The window unit 13 is formed by integrally molding the window portion 31 and the mounting portion 32 as one component. The window portion 31 and the mounting portion 32 are molded as an integrated component (window unit 13) by, for example, a resin molding method including injection molding. Such a resin molding method is, for example, a resin molding method using a side gate type mold.

[0034] The side gate method is a molding method in which a gate is provided on the side of the parting surface of a mold, and a resin material is injected from the gate toward a cavity to mold a resin. When molding the window unit 13 using a mold using the side gate method, for example, a gate is provided at a position corresponding to the outer periphery of the mounting portion 32, and a resin material is injected from the gate. In this manner, the window unit 13 can be molded.

[0035] The window unit 13 is preferably molded from a material that has high fluidity in a mold and an appropriate absorptivity of the measurement light. Examples of such materials include cycloolefin copolymers and cycloolefin polymers. Note that the window unit 13 may contain a material other than cycloolefin copolymers and cycloolefin polymers. Also, the window unit 13 may contain, for example, an additive.

[0036] However, the gas measurement adapter disclosed in Patent Document 1 has many parts and is complicated. In addition, the inner part of the frame provided on the side wall of the flow tube protrudes inward from the inner peripheral surface of the flow tube, so the surface of the anti-fogging layer is located inside the inner peripheral surface of the flow tube. Furthermore, since the transparent sheet on which the anti-fogging layer is formed is attached to the window, there is a risk that water will accumulate on the inner peripheral surface of the window.

[0037] The window of the gas measurement adapter disclosed in Patent Document 2 is molded by a mold in which a gate is provided at a position corresponding to the center of the window, and therefore a gate mark is formed at the center of the window. A large amount of measurement light can pass through the center of the window. When the measurement light hits the gate mark, the measurement light is scattered by the gate mark. Therefore, if there is a gate mark at the center of the window, the light collection accuracy may decrease, and the measurement accuracy may decrease.

[0038] According to the manufacturing method of the gas measurement adapter 1 and the window unit 13 of this embodiment, the window unit 13 of the gas measurement adapter 1 is integrally molded with the window portion 31 and the mounting portion 32 as one part. Furthermore, the window unit 13 is formed from a material containing a cycloolefin copolymer or a cycloolefin polymer. These materials can transmit infrared rays and can be molded using a side gate type mold. Therefore, the window unit 13 can be molded using a side gate type mold. When the window unit 13 is molded using a side gate type mold, the inner surface 50 and the outer surface 60 of the window portion 31 become flat. In this way, the gas measurement adapter 1 has a simple configuration, while being able to accurately measure specific components (e.g., carbon dioxide) contained in the breath of the subject.

[0039] Furthermore, in the gas measurement adapter 1 according to this embodiment, the diameter of the window portion 31 is 6 mm or less, which is relatively small. Therefore, even if the window portion 31 is integrally molded with the mounting portion 32, the inner surface 50 and the outer surface 60 of the window portion 31 can be made flat with high precision.

[0040] Furthermore, according to the gas measurement adapter 1 of this embodiment, the thickness of the window portion 31 and the thickness of the mounting portion 32 are approximately equal, so that a large step is unlikely to be formed between the window portion 31 and the mounting portion 32.

[0041] Moreover, according to the gas measurement adapter 1 of this embodiment, the mounting portions 32 are provided at the ends 320 in the extension direction of the window portion 31, and extend in approximately the same direction as the extension direction of the window portion 31. Moreover, the window portion 31 is molded in an embossed shape so as to be convex from the mounting portion 32. This makes it easy to fit the window unit 13 into the opening 210.

[0042] Furthermore, according to the gas measurement adapter 1 of this embodiment, a taper is formed between the mounting portion 32 and the window portion 31, so that the window unit 13 can be easily fitted into the opening portion 210.

[0043] Furthermore, according to the gas measurement adapter 1 of this embodiment, the outer surface 212 of the flow tube portion 21 and the outer surface 321 of the mounting portion 32 form a flat surface without any steps, making it easy to determine whether the window unit 13 is correctly mounted on the flow tube portion 21.

[0044] Furthermore, according to the gas measurement adapter 1 of this embodiment, the inner surface 51 of the flow tube portion 21 and the inner surface 50 of the window portion 31 form flat surfaces without any steps, which does not easily impede the movement of gas such as respiratory gas within the flow tube portion 21. As a result, it is possible to accurately measure specific components (e.g., carbon dioxide) contained in the respiratory gas of the subject.

[0045] Furthermore, according to the manufacturing method for the window unit 13 of this embodiment, the mounting parts 32 are provided at the ends 320 in the extension direction of the window part 31, and the gates provided on the sides of the parting surface of the mold are provided at positions corresponding to the outer periphery of the mounting parts 32 of the mold. Therefore, according to the manufacturing method for the window unit 13 of this embodiment, the side gate method makes it possible to more easily mold the window unit 13 in which the window part 31 and the mounting part 32 are integrally molded as a single component.

[0046] The above-described embodiment is for the purpose of facilitating understanding of the present invention, and is not intended to limit the present invention. The present invention can be modified and improved without departing from the spirit and scope of the present invention.

[0047] In the above embodiment, the inner surface 50 of the window portion 31 and the inner surface 51 of the flow tube portion 21 are formed in a flat shape, but the inner surface 50 of the window portion 31 and the inner surface 51 of the flow tube portion 21 may be formed in a curved shape without a step. Note that, although the ability to respond to external forces is reduced, a configuration in which tapered surfaces corresponding to the ends of the window portion 31 and the flow tube portion 21 are provided and fitted together without providing the mounting portion 32 may also be used. [Explanation of symbols]

[0048] 1: gas measurement adapter, 11: first connection adapter, 12: second connection adapter, 13: window unit, 20: sensor mounting portion, 21: flow tube portion, 21a: first end portion, 21b: second end portion, 22a: locking member, 22b: locking member, 23a, 23b: recess, 31: window portion, 32: mounting portion, 33: connection portion, 41: ventilation path, 50, 51, 213: inner surface, 60, 212, 321: outer surface, 210: opening, 211: mounting portion, 320: end portion

Claims

1. A flow tube portion through which gas passes; a window unit including a window portion that transmits a measurement light for measuring a component of the gas passing through the flow tube portion, and an attachment portion for attachment to the flow tube portion; Equipped with The window unit is formed by integrally molding the window portion and the mounting portion as one part, and is made of a material containing a cycloolefin copolymer or a cycloolefin polymer, the inner and outer surfaces of the window are flat; A gas measurement adapter, wherein the window portion and the mounting portion have the same thickness.

2. 2. The gas measurement adaptor according to claim 1, wherein the diameter of said window portion is 6 mm or less.

3. the mounting portions are provided at both ends in an extension direction of the window portion, and extend in substantially the same direction as the extension direction of the window portion, 3. The gas measurement adaptor according to claim 1, wherein the window portion is molded in an embossed shape so as to protrude from the mounting portion.

4. The gas measurement adaptor according to claim 1 , wherein a taper is formed between the mounting portion and the window portion.

5. 5. The gas measurement adaptor according to claim 1, wherein an outer surface of said flow tube portion and an outer surface of said mounting portion form a flat surface without any steps.

6. 6. The gas measurement adaptor according to claim 1, wherein an inner surface of said flow tube portion and an inner surface of said window portion form a flat surface without any step.

7. A method for manufacturing a window unit having a window portion that transmits a measurement light for measuring a component of a gas passing through a flow tube portion, and a mounting portion for mounting to the flow tube portion, the window portion having a thickness equal to that of the mounting portion, the method comprising the steps of: a gate provided on a side of a parting surface of a mold corresponding to integral molding of the window portion and the mounting portion, and a resin material containing a cycloolefin copolymer or a cycloolefin polymer is injected toward a cavity, thereby integrally molding the window unit.

8. The mounting portion is provided on both ends in an extension direction of the window portion, The manufacturing method according to claim 7 , wherein the gate is provided at a position corresponding to an outer periphery of the mounting portion in the mold.

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