JP4998895B2 - Carbon dioxide gas sensor - Google Patents

Description

  The present invention relates to a sensor for measuring carbon dioxide in breathing air, which measures the concentration or partial pressure of carbon dioxide in breathing air discharged from the nostril or mouth of a living body or the presence or absence of carbon dioxide.

  In general, when optically measuring the concentration of carbon dioxide in the respiratory gas of a living body, the respiratory gas is passed through a cylindrical airway adapter, and the respiratory gas is irradiated with infrared light from the light emitting element. The light quantity reduced according to the amount of light absorbed by carbon dioxide in the air is detected by the light receiving element, and the carbon dioxide concentration is measured.

  FIG. 16 shows a schematic configuration of an example of such a conventional carbon dioxide gas measurement sensor. In FIG. 16, one end 101a of an airway adapter 101 that is formed in a substantially cylindrical shape and through which respiratory gas passes is connected to a tube that is intubated into a patient's trachea, and the other end 101b is connected to a Y piece of a breathing circuit such as an artificial respirator. Connected. The intermediate portion of the airway adapter 101 has a rectangular cross section, and concentric circular windows 101c and 101d are formed on two opposing surfaces of the intermediate portion.

  The sensor body 102 is formed in a substantially rectangular tube shape, and a U-shaped cutout portion into which the intermediate portion of the airway adapter 101 is fitted and mounted is formed in the intermediate portion. The two opposing surfaces of the notch are in contact with the windows 101c and 101d of the airway adapter 101, respectively. A light emitting element 103 that emits infrared light is disposed on one side of the notch in the sensor body 102.

  An optical filter 104 and a light receiving element 105 that absorb only light having a wavelength absorbed by carbon dioxide gas are arranged on the opposite side of the light emitting element 103 with respect to the notch in the sensor main body 102. The light emitting element 103 and the light receiving element 105 are connected to the monitor main body 107 via the lead wire 106. The intermediate portion of the airway adapter 101 is configured to be detachable from the sensor main body 102.

  In the conventional carbon dioxide concentration measurement sensor configured as described above, light emitted from the light emitting element 103 is received through the window 101c, the breathing gas in the airway adapter 101, the window 101d, and the optical filter 104. Incident on the element 105. Then, the light amount reduced in accordance with the carbon dioxide concentration is detected by the light receiving element 105, and the output signal of the light receiving element 105 is input to the monitor body 107 and displayed as the carbon dioxide concentration.

  In the above conventional example, the airway adapter 101 through which breathing gas passes is attached to the sensor main body 102. However, as another conventional example, the sampling tube is connected to the sensor main body installed in the monitor main body. Is also known.

  In the other conventional example, one end of the sampling tube for sucking a part of the breathing gas is connected to the airway adapter through which the breathing gas passes, and the other end is connected to the monitor body. A pump is provided in the monitor body, and the sucked respiratory gas is guided to the sensor body in the monitor body.

  Furthermore, as shown in FIG. 17, an apparatus that can measure the concentration of carbon dioxide in mouth respiratory air in addition to nasal respiratory air has also been proposed (see, for example, Patent Document 1).

  The proposed device comprises a respiratory gas collection device 110, which comprises a nasal cannula 111 for collecting nasal respiratory gas and an outwardly convex mouse guide 113 for collecting mouth respiratory gas. A mouth gas collecting member 114 disposed inside the mouse guide 113 for collecting mouth respiratory gas, and a flexible one end joined to the upper outside of the mouse guide 113 and the other end attached to the nasal cannula 111. The connecting stem 112 is adjustable.

US Pat. No. 5,046,491

  However, the conventional respiratory gas collection device 110 (see FIG. 17) has a large number of parts because the connection stem 112 is configured as a separate member, and the connection stem 112 is placed in two places, the mouse guide 113 and the nasal cannula 111. Since it needs to be attached, it takes a lot of man-hours and, consequently, costs are considerable.

  In addition, when oxygen supply is also performed, an oxygen supply tube is attached. However, in the conventional oxygen supply tube, even if the prong is inserted into the nostril, or the prong is not inserted into the nostril. Since the oxygen supplied from the nasal cavity was directed directly to the nostrils, there was a problem that the rapid drying of the nostrils made the patient uncomfortable.

  The present invention has been made in view of the above-mentioned problems, and its purpose is to prevent oxygen supplied from the prongs from being directly injected into the nostrils in order to prevent rapid drying of the nostrils. An object of the present invention is to provide a carbon dioxide measuring sensor that can be manufactured at low cost while minimizing the number of steps.

One aspect of the present invention is a carbon dioxide gas measurement sensor that measures the concentration or partial pressure of carbon dioxide in the breathing air of a living body or the presence or absence of carbon dioxide gas. A lower part of the nostril of the living body and provided on the upper part of the mouth of the living body so as to be attachable, and a support member that supports the light emitting means and the light receiving means, and a support member that is provided in the support member. said breathing air can pass across the optical axis respiratory passages when a lower mounted on top of the mouth of the oxygen supply tube for supplying oxygen, the support the oxygen supply tube comprising a locking member for freely engaging removably on the back of the member, in a state in which the oxygen supply tube is engaged with the locking member, the prongs of the oxygen supply tube inserted into the nostrils of the living body A length not, characterized in that the oxygen supplied from the prongs wherein the prongs so as not emitted directly into the nostrils of the living body is placed.

According to another aspect of the present invention, there is provided a carbon dioxide gas measuring sensor that measures the concentration or partial pressure of carbon dioxide in the breathing air of a living body or the presence or absence of carbon dioxide gas. A support member provided in the lower part of the nostril of the living body and in an upper part of the mouth of the living body to support the light emitting means and the light receiving means, and provided in the support member, said breathing air can pass across the optical axis respiratory passages when a lower mounted on an upper portion of the opening of the nostril, and the oxygen supply tube for supplying oxygen, the oxygen supply tube A locking member for detachably locking the back surface of the support member , and the locking member includes a prong of the oxygen supply tube when the oxygen supply tube is locked to the locking member. From Oxygen being is characterized by being configured so as not emitted directly into the nostrils of the living body.

  According to one aspect of the present invention, the concentration or partial pressure of carbon dioxide in the breathing air of a living body or the presence or absence of carbon dioxide can be measured, and oxygen is supplied from a prong of an oxygen supply tube. Oxygen is not injected directly into the nostril of the living body, and a rapid drying of the nostril can be prevented.

  According to another aspect of the present invention, it is possible to measure the concentration or partial pressure of carbon dioxide in the respiratory air of a living body or the presence or absence of carbon dioxide, and for oxygen supply, an oxygen supply tube is used. The oxygen supplied from the prong of the oxygen supply tube is not directly injected into the nostril of the living body and can be prevented from being rapidly dried.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view showing a state in which a carbon dioxide gas measuring sensor 1 according to this embodiment is attached to a person 3. The carbon dioxide measuring sensor 1 emits light as a light emitting means disposed on the optical axis so as to measure the concentration or partial pressure of carbon dioxide in the breathing air of a person 3 as an example of a living body or the presence or absence of carbon dioxide. When the element 10 and the light receiving element 11 as the light receiving means, the airway case 12 as a support member for supporting the light emitting element 10 and the light receiving element 11, and the airway case 12 are mounted below the nostrils 31 of the person 3, A breathing air passage 13 (see FIG. 2) through which the breathing air of the person 3 can pass across the optical axis is provided.

  Further, the carbon dioxide measuring sensor 1 is disposed on a protruding wall 19 extending to the lower side of the airway case 12 and extends in a parallel direction along the face of the person 3, and an appropriate amount around the horizontal axis 14. A mouse guide 15 that can be rotated in the front-rear direction so as to approach or move away from the mouth 32 of the person 3 with an appropriate rotation resistance, and a lead wire 16 a that transmits a light emission signal from a carbon dioxide measuring device (not shown) to the light emitting element 10. And a lead wire 16b for sending a light receiving signal from the light receiving element 11 to the carbon dioxide measuring device (not shown).

  Next, each component described above will be described. The airway case 12 is formed of a resin that is not flexible. As shown in FIG. 2, the light emitting element 10 and the light receiving element 11 are hermetically sealed by antifogging films 17 and 17 that transmit light on the opposite surface side and do not cause fogging due to breathing air, as shown in FIG. Has been.

  The respiratory passage 13 is defined by the inner walls 12a and 12b of the airway case and the antifogging films 17 and 17.

  Further, an optical filter (not shown) that transmits only light having a wavelength absorbed by carbon dioxide gas is provided on the light receiving element 11 side. Note that reference numeral 18 in FIG. 2 denotes an antifogging film case.

  The lead wires 16 a and 16 b are attached to the light emitting element 10 and the light receiving element 11.

  A flexible tube (nasal tube) 21 is connected to the respiratory passage 13 as shown in FIG. The flexible tube 21 is formed of silicone rubber or the like, but can be formed of vinyl chloride, polypropylene, polyethylene, elastomer, or the like.

  The flexible tube 21 has a pair of insertion portions 21a and 21b formed in a Y shape. By inserting these insertion portions 21 a and 21 b into the nostrils 31 of the person 3 (see FIG. 1), nasal respiratory air is guided to the respiratory air passage 13 via the flexible tube 21.

  Further, the mouse guide 15 is attached to the airway case 12 on the opposite side of the flexible tube 21 connected to the breathing air passage 13 so that the breathing air flows through the breathing air passage 13. The mouse guide 15 is formed in a tongue-like shape with a flexible material, and the width b is formed within an appropriate size, in this example, within 20 mm.

  This width b is narrow enough to allow the person 3 to wear the carbon dioxide sensor 1 and insert the suction tube 23 (see FIG. 1) into the oral cavity, and can sufficiently receive respiratory air from the oral cavity. It is preferable to make it wide. For this purpose, the width b of the mouse guide 15 is preferably about 5 mm to 20 mm.

  Side walls 22 (see FIG. 4) are provided on both sides of the mouse guide 15 so that the side of the mouth 32 is concave so as not to let the breathing air escape as much as possible.

  Further, as shown in FIG. 4, the mouse guide 15 is formed in the mouth 32 of the person 3 (see FIG. 1) around the horizontal shaft 14 that is locked to the protruding wall 19 that extends below the airway case 12. It is configured to be rotatable in the direction X that approaches or separates from the front, that is, in the front-rear direction. The sensor 1 is mounted so that the direction of the arrow F is on the face side.

  The material of the mouse guide 15 can be appropriately selected from flexible materials such as vinyl chloride, polypropylene, polyethylene, silicone rubber, and elastomer.

  As shown in FIGS. 3 and 4, the protruding wall 19 includes walls 19 a, 19 b, and 19 c that extend in three directions except for the face side of the person 3 below the airway case 12. It is continuous without a gap. The walls 19a and 19b are provided with coaxial holes 20 and 20 that are parallel to the face of the person 3 and formed in the horizontal direction.

  As shown in FIG. 3, the horizontal shaft 14 is formed integrally with the mouse guide 15 and is composed of the same size and coaxial mushroom-shaped shafts 14a and 14b. The outer diameters of the small diameter portions of the shafts 14a and 14b are slightly larger than the inner diameters of the holes 20 and 20 of the walls 19a and 19b before the shafts 14a and 14b are inserted into the holes 20 and 20 for assembly. The shafts 14a and 14b are fitted into the holes 20 and 20 of the walls 19a and 19b, respectively. Accordingly, the mouse guide 15 can be rotated with an appropriate resistance around the holes 20 and 20 (the shafts 14a and 14b).

  A slit may be inserted into the mushroom-shaped heads of the shafts 14a and 14b. Thus, the shafts 14a and 14b can be more easily inserted into the holes 20 and 20, respectively.

  As shown in FIG. 4, the wall 19 c of the protruding wall 19 is an end of the mouse guide 15 that is close to the horizontal axis 14 even when the mouse guide 15 is in a position close to the face of the person 3 (position indicated by a broken line). It is comprised so that the part 15a may be covered, and the distribution | circulation resistance of the respiratory air which flows into the respiratory air passage 13 from the oral cavity is decreased.

  By arranging the mouse guide 15 at the mouth of the person 3 as shown in FIG. 1, mouth breathing air is reliably guided along the mouse guide 15 to the breathing air passage 13.

  Since the mouse guide 15 is rotatable with an appropriate resistance in the front-rear direction around the horizontal axis 14, even when the shape or size of the face of the person 3 changes, the mouse guide 15 is moved along the shape of the face. The position can be adjusted and the person's 3 mouth 32 can be approached.

  Accordingly, most of the mouth breathing air of the person 3 can be reliably guided to the breathing air passage 13 of the airway case 12 without escaping from the mouse guide 15. Thereby, the carbon dioxide gas concentration of mouth breathing air can be measured reliably and accurately.

  Further, since the horizontal shaft 14 is integrally formed with the mouse guide 15, the number of parts and man-hours can be minimized and the manufacturing can be made inexpensively.

  In the above embodiment, the shafts 14a and 14b and the holes 20 and 20 are fitted as interference fits in order to give resistance to the rotation of the mouse guide 15, but before the shafts 14a and 14b are assembled to the holes 20 and 20, respectively. In this state, the dimension c of the mouse guide 15 shown in FIG. 3 (the distance between the roots of the shafts 14a and 14b) may be larger than the distance inside the walls 19a and 19b. By doing so, a repulsive force is generated at the contact portion in the horizontal direction between the mouse guide 15 and the walls 19a, 19b in the assembled state, and an appropriate resistance can be given to the rotation of the mouse guide 15.

  In this case, the small diameters of the shafts 14a and 14b may be made smaller than the inner diameters of the holes 20 and 20 so as to fit the gaps, respectively. This simplifies assembly.

  Furthermore, the dimension c of the mouse guide 15 may be made larger than the distance inside the walls 19a and 19b, and the shafts 14a and 14b may be formed in a column shape to fit the holes 20 and 20, respectively. This further simplifies assembly.

  When the small diameters of the shafts 14a and 14b are made smaller than the inner diameters of the holes 20 and 20, respectively, and the gap is fitted, the material of the mouse guide 15 is flexible considering the case where the mouse guide 15 touches the living body. A material is desirable, but when the outer peripheral edge of the mouse guide 15 is shaped so as not to be painful even if it touches a living body, a non-flexible resin or the like may be used.

  In any of the above embodiments, the horizontal shaft 14 is formed integrally with the mouse guide 15 and the hole 20 is provided in the protruding wall 19 of the airway case 12, but the horizontal shaft 14 is formed integrally with the protruding wall 19 and the hole 20 is formed. May be provided in the mouse guide 15.

  In this case, if the mouse guide 15 is formed of a flexible material, the horizontal shaft 14 formed of a non-flexible resin can be more easily inserted into the hole 20.

  Furthermore, in any of the above-described embodiments, the protruding wall 19 is configured by the three walls 19a, 19b, and 19c. However, the protruding wall 19 may have a wall except for the face side of the person 3, for example, the horizontal cross section of the protruding wall 19 is half. A circular shape, a semi-elliptical shape, etc. may be sufficient.

  Further, as shown in FIG. 5, the carbon dioxide gas measurement sensor 1 of the present embodiment is provided with an attachment hook 33 on the back side (side opposite to the side facing the face when attached) of the airway case 12 to provide oxygen. Oxygen can be supplied by attaching a supply tube 34 (which may be a general-purpose tube).

  For example, as shown in FIG. 6, the attachment hook 33 has a tubular hook portion 33 a having an opening 33 c so that the oxygen supply tube 34 can be attached. The tube portion between the two prongs 35 of the oxygen supply tube 34 is attached from the opening 33c. In order to prevent deformation due to external force applied to the prongs 35, the width of the tubular hook portion 33 a is preferably the same as the distance between the two prongs 35. By using an elastic material, the tubular hook portion 33a can be adapted even when the diameter of the oxygen supply tube 34 is different. Such an attachment hook 33 is adhered to the back surface of the airway case 12. Alternatively, as shown in FIG. 7B, the airway case 12 and the attachment hook 33 may be integrally formed.

FIG. 7A is a view showing a state in which the oxygen supply tube 34 is attached to the attachment hook 33 for use. Reference numeral 34 a denotes an oxygen supply port of the oxygen supply tube 34. Reference numeral 16c denotes a connector for electrically connecting a current for driving the light emitting element 10 and a signal detected by the light receiving element 11 to the measuring apparatus.
At this time, the prongs 35 are not inserted into the nostrils, and are further arranged so that oxygen supplied from the prongs is not directly injected into the nostrils. By doing in this way, the rapid drying of a nostril can be prevented.
In order to achieve such an arrangement, in the example shown in FIG. 7A, the attachment hook 33 is provided so that the prongs 35 are arranged on the upper surface of the airway case 12. In this case, the oxygen supplied from the prong 35 is not directly injected into the nostrils, but the oxygen once hits the skin under the nose and is sucked into the nostrils.

FIG. 8A is another example in which the arrangement of the attachment hooks 33 is different. As shown in FIG. 8A, the attachment hook 33 is provided so that the prongs 35 are along the back surface of the airway case 12. In this case, the oxygen supplied from the prongs 35 is parallel to the back surface of the airway case 12 and directed toward the flexible tube 21 and is sucked into the drifting nostril.
As shown in FIG. 8B, the mounting hook 33 may be formed by integrally forming the airway case 12 and the mounting hook 33.

FIG. 9A shows still another example in which the arrangement of the attachment hooks 33 is different. As shown in FIG. 9A, the attachment hook 33 is provided so that the prongs 35 are along the bottom surface of the airway case 12. In this case as well, as in FIG. 7A, oxygen supplied from the prongs 35 is sucked without being directly injected into the nostrils.
As shown in FIG. 9B, the attachment hook 33 may be formed by integrally forming the airway case 12 and the attachment hook 33.

FIG. 10A shows still another example in which the arrangement of the attachment hooks 33 is different. As shown in FIG. 10A, the attachment hook 33 is installed on the back surface of the airway case 12 with the handle 33 b of the attachment hook sufficiently long so that the tip of the prong 35 is directed to the back surface of the airway case 12. With this configuration, the oxygen supply tube 34 can be attached to the tubular hook portion 33a and oxygen can be supplied toward the face. The oxygen supplied from the prongs 35 once hits the airway case 12 and is sucked into the nostril and oral cavity. The direction in which the tip of the prong 35 faces the face can be adjusted by the angle at which the oxygen supply tube 34 is attached to the tubular hook 33 a of the attachment hook 33.
As shown in FIG. 10B, the mounting hook 33 may be formed by integrally forming the airway case 12 and the mounting hook 33.

Further, the attachment hook 33 may be provided on another side surface of the airway case 12, and the attachment hook 33 may be configured to lock the prongs 35.
Furthermore, in the present invention, in order to accurately measure the concentration or partial pressure of carbon dioxide gas or the presence or absence of carbon dioxide gas even when the respiration rate is low, it is retained in the respiratory air passage during mouth breathing. It is possible to provide a vent for quickly discharging the gas being discharged to the outside.

  Subsequently, a carbon dioxide gas measurement sensor 51 according to another example of the present embodiment will be described with reference to FIGS. 11 to 14. The carbon dioxide gas measuring sensor 51 is different from the carbon dioxide gas measuring sensor 1 described with reference to FIGS. 1 to 4 in that a vent hole is provided, but the other configurations are the same. Therefore, in the carbon dioxide gas measuring sensor 51, the same reference numerals are given to the components corresponding to those of the carbon dioxide gas measuring sensor 1, and the description thereof is omitted.

  FIG. 11 is a plan view of a carbon dioxide gas measurement sensor 51 according to another example of the present embodiment. 12 is a cross-sectional view taken along the line CC in FIG. 11, and FIG. 13 is a diagram illustrating the flow of mouth breath when the carbon dioxide gas measurement sensor 51 is worn on a person 3.

  On the upper side of the airway case 12 as a support member, the pair of insertion portions 21a and 21b into the nostril 31 of the flexible tube 21 having a small passage cross-sectional area is extended on the opposite side, and merges in the vicinity of the respiratory passage 13 A junction 40 having a large cross-sectional area is defined. The merging portion 40 communicates adjacent to the respiratory passage 13 having a larger passage cross-sectional area. The flexible tube 21 and the merging portion 40 constitute a nasal respiratory introduction member 42. The outer wall of the merging portion 40 is connected to the outside of the merging portion 40 so that the gas staying in the respiratory passage 13 can be quickly discharged to the outside when breathing out from the mouth. A pore 41 is formed.

As described above, the vent hole 41 quickly discharges the gas staying in the respiratory air passage 13 to the outside when exhaling from the mouth. Further, in order to prevent the exhaled air from the nose from flowing out through the vent hole 41 to the outside, the gas passing through the vent hole 41 is further prevented from facing the nasal exhalation flow direction. The installation location and shape are determined so that the distribution is not hindered by the face.
Therefore, as shown in FIGS. 11 to 13, the vent hole 41 is circular (for example, 2 mm in diameter) and is formed on the outer wall of the junction 40 so as to be positioned at the center of the opposite side opposite to the face. Has been. In FIG. 11, the carbon dioxide measuring sensor 51 is mounted so that the direction of the arrow F is on the face side.

Next, the operation of such a configuration will be described.
As shown by an arrow in FIG. 13, when exhaling from the mouth 32, mouth breath is introduced into the breathing air passage 13 through the mouse guide 15, and the gas staying in the breathing air passage 13 joins the confluence. Extruded to the part 40. The pushed-out gas flows out through the vent hole 41 and simultaneously enters the nostril 31 through the flexible tube 21 and then flows out. Since the flexible tube 21 is long and has a small passage cross-sectional area, the flow resistance to the gas is large, and the vent hole 41 is provided in the junction 40 adjacent to the breathing passage 13. Therefore, the gas tends to flow out from the vent hole 41 to the outside.

  Further, even if the flexible tube 21 is clogged with nasal discharge or the like, the gas can flow out from the vent hole 41 when mouth breath flows into the respiratory passage 13.

  Thus, since the vent hole 41 is provided, the escape of gas in the respiratory passage 13 is good. Therefore, when exhaling from the mouth, the gas staying in the breathing passage 13 is discharged to the outside, and the mouth breath quickly flows. As a result, it is possible to accurately measure the concentration or partial pressure of carbon dioxide in the mouth breath or the presence or absence of carbon dioxide even when the respiration rate is low.

  Next, an example is shown in which the carbon dioxide concentration in the breath is measured and evaluated using a carbon dioxide measuring sensor having a vent and a carbon dioxide measuring sensor having no vent.

This measurement evaluation was made by measuring and comparing the carbon dioxide concentration with the carbon dioxide measurement sensor 51 described with reference to FIGS. 11 to 13 and the carbon dioxide measurement sensor 1 without the vent hole 41, and will be described below. And measured.
Using a model of a human face and nasal cavity, each sensor is attached as shown in FIG. 13, and a predetermined time corresponding to the time when a person normally exhales an amount of gas to be measured corresponding to weak exhalation Sent by a delivery pump, discharged from the mouth, and then sucked in an amount equivalent to weak suction by a vacuum pump instead of the delivery pump for a predetermined time corresponding to the time that a normal person inhales, and performed them alternately and continuously. It was. As the gas to be measured, a gas in which carbon dioxide gas was mixed with air to have a concentration close to the concentration of carbon dioxide gas in human breath was used.

  FIG. 14 shows the measurement results of this measurement evaluation. In FIG. 14, the solid line indicates the measurement result by the carbon dioxide measuring sensor 51 having the vent 41, and the broken line indicates the measurement result by the carbon dioxide measuring sensor 1 without the vent 41.

  As can be seen from FIG. 14, when there is a vent hole 41, the carbon dioxide gas concentration rises immediately after the start of discharge of the gas to be measured and is saturated. This indicates that the gas to be measured is quickly flowing into the breathing passage 13, and the effect of the vent hole 41 is well exhibited.

  On the other hand, when there is no vent hole, the carbon dioxide concentration does not rise immediately even if the gas to be measured is discharged, but rises with a delay and gradually increases. The increase continues until the start of suction, and then the carbon dioxide concentration does not saturate and begins to decrease. This indicates that the gas to be measured flows into the respiratory passage 13 only gradually.

  As described above, the vent hole 41 can accurately measure the concentration of carbon dioxide in the exhaled breath even when the respiration rate is small.

  In addition, when the vent hole 41 is present after the start of suction, the carbon dioxide gas concentration quickly falls. This is because external gas flows into the respiratory passage 13 through the vent hole 41 and the gas to be measured is It indicates that it has been promptly discharged to the outside.

  In the carbon dioxide measuring sensor 51, the nasal respiratory introduction member 42 is joined to a pair of tubes (a pair of insertion portions 21a and 21b into the nostril 31 of the flexible tube 21) and one end of each of the tubes. However, the configuration of the nasal respiratory introduction member 42 is not limited to this. For example, the nasal breathing introduction member may be constituted by a single tube, and in that case, a ventilation hole is formed in the tube in the vicinity of the connection portion between the tube and the respiratory passage 13.

  The shape of the vent hole 41 is, for example, a circle having a diameter of 2 mm, and is provided on the outer wall of the merging portion 40 so as to be located at the center on the side not facing the living body. The shape and installation location of the vent hole 41 are not limited to this, and can be set so as to satisfy the above-described conditions depending on the structure of the flexible tube 21, the merging portion 40, the respiratory passage 13, and the like. FIG. 15 shows a modification of the place where the air holes are formed. FIG. 15 is an enlarged view of the vicinity of the junction 40 shown in FIG. 13, and the vent holes are formed by the imaginary lines 41a, 41b, 41c, and 41d shown in FIG. It can be formed at a position or the like. Since the vent hole 41c and the like are formed at a position where there is a possibility of being blocked by the living body, the opening shape may be an oval shape whose longitudinal direction is parallel to the face.

It is a perspective view which shows the state which mounted | wore the person 3 with the carbon dioxide measuring sensor 1 which concerns on this embodiment. 2 is a cross-sectional view showing an airway case 12. FIG. It is AA sectional drawing of FIG. It is the figure seen from the direction of B arrow of FIG. It is a figure which shows a mode that the oxygen supply tube 34 is attached to the carbon dioxide gas measurement sensor 1 which concerns on the modification of this embodiment. 4 is a perspective view of an attachment hook 33. FIG. (A) is a perspective view which shows the state which attaches and uses the oxygen supply tube 34 to the attachment hook 33, (b) is a perspective view of the attachment hook 33 of this example. (A) is a perspective view which shows the state which mounted | wore the person 3 with the carbon dioxide measuring sensor 1 which concerns on the other modification of this embodiment, (b) is a perspective view of the attachment hook 33 of this example. (A) is a perspective view which shows the state which mounted | wore the person 3 with the carbon dioxide measuring sensor 1 which concerns on the further another modification of this embodiment, (b) is a perspective view of the attachment hook 33 of this example. (A) is a perspective view which shows the state which mounted | wore the person 3 with the carbon dioxide measuring sensor 1 which concerns on the further another modification of this embodiment, (b) is a perspective view of the attachment hook 33 of this example. It is a top view which shows the carbon dioxide measuring sensor 51 which concerns on the further another modification of this embodiment. It is CC sectional drawing of FIG. It is a figure which shows the flow of the mouth breath when the carbon dioxide gas measurement sensor 51 is mounted | worn with the person 3. FIG. The result of having measured and evaluated the carbon dioxide gas concentration of the mouth breath using the carbon dioxide measuring sensor 51 provided with the vent and the carbon dioxide measuring sensor 1 without the vent is shown. It is a figure which shows the modification of the place which forms a vent hole. It is a figure which shows a prior art example. It is a figure which shows another prior art example.

Explanation of symbols

1,51 Carbon dioxide sensor 3 people (living body)
10 Light emitting element (light emitting means)
11 Light receiving element (light receiving means)
12 Airway case (supporting member)
12a, 12b Inner wall 13 Respiratory passage 14 Horizontal axis 14a, 14b Mushroom shaft 15 Mouse guide 16a, 16b Lead wire 17 Antifogging film 18 Antifogging film case 19 Protruding part 19a, 19b, 19c Wall 20 Hole 21 Flexible tube 21a, 21b Insertion portion 22 Side wall 23 Suction tube 31 Nostril 32 Port 33 Mounting hook (locking member)
34 Oxygen supply tube 35 Prong 40 Junction part 41 Vent hole 42 Nasal breathing introduction member 101 Airway adapter 101a One end 101b Other end 101c Window part 101d Window part 102 Sensor body 103 Light emitting element 104 Optical filter 105 Light receiving element 106 Lead wire 107 Monitor body DESCRIPTION OF SYMBOLS 110 Respiratory gas collection device 111 Nasal cannula 112 Connection stem 113 Mouse guide 114 Oral gas collection member

Claims (2)

In a carbon dioxide gas measurement sensor that measures the concentration or partial pressure of carbon dioxide in the breathing air of a living body or the presence or absence of carbon dioxide,
A light emitting means and a light receiving means arranged opposite to each other on the optical axis;
A support member that is provided at the lower part of the nostril of the living body and can be mounted on the upper part of the mouth of the living body, and supports the light emitting means and the light receiving means;
A respiratory passage that is provided in the support member and through which the respiratory air can pass across the optical axis when the support member is attached to the lower part of the nostril of the living body and the upper part of the mouth ;
An oxygen supply tube for supplying oxygen;
A locking member for detachably locking the oxygen supply tube to the back surface of the support member;
In the state in which the oxygen supply tube is locked to the locking member, the prongs of the oxygen supply tube have a length that is not inserted into the nostril of the living body, and oxygen supplied from the prongs enters the nostrils of the living body. A carbon dioxide gas measuring sensor, wherein the prongs are arranged so as not to be directly injected. In a carbon dioxide gas measurement sensor that measures the concentration or partial pressure of carbon dioxide in the breathing air of a living body or the presence or absence of carbon dioxide,
A light emitting means and a light receiving means arranged opposite to each other on the optical axis;
A support member that is provided at the lower part of the nostril of the living body and can be mounted on the upper part of the mouth of the living body, and supports the light emitting means and the light receiving means;
A respiratory passage that is provided in the support member and through which the respiratory air can pass across the optical axis when the support member is attached to the lower part of the nostril of the living body and the upper part of the mouth ;
An oxygen supply tube for supplying oxygen;
Comprising a locking member for freely engaging removably said oxygen supply tube on the back of the support member,
The locking member is configured such that oxygen supplied from a prong of the oxygen supply tube is not directly injected into the nostril of the living body when the oxygen supply tube is locked to the locking member. Carbon dioxide gas measurement sensor.

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