JP7471657B2 - Breath capture device - Google Patents

Description

The present invention relates to a device for capturing the breath of an animal or human.

Conventionally, breath analysis has been known as one of the methods for diagnosing cancer. Breath analysis diagnoses cancer by analyzing the amount of volatile substances called biomarkers contained in breath. Since the biomarkers in breath are in low concentration, a technique is known for increasing the adsorption area by using an adsorption plate in which an adsorbent for volatile organic gas molecules is applied to a three-dimensional microstructure produced by MEMS technology in order to concentrate them (e.g., Patent Document 1, etc.). This adsorption plate is known to be one in which one side of a silicon substrate is dry-etched, one in which a large number of carbon nanotube bundles are provided upright on a silicon substrate, or one in which one side is formed into a plate-like shape with fine projections and recesses by using a resin structure (e.g., Non-Patent Document 1, etc.). By using such an adsorption plate, low concentration gases on the order of ppb can be concentrated and analyzed by an analytical device such as a gas chromatograph that can only detect ppm order.

JP 2016-11929 A Lee Sang-seok, "Investigation of an inexpensive micro-preconcentrator using a resin structure for early cancer diagnosis," [online], June 12, 2019, Grant-in-Aid for Scientific Research Research Results Report, [Retrieved August 31, 2021], Internet <URL: https://kaken.nii.ac.jp/ja/file/KAKENHI-PROJECT-16K04919/16K04919seika.pdf>

The above conventional suction plates can be made small and have excellent suction performance, but their small size makes them difficult to handle and there is no way to properly capture exhaled breath.

Therefore, the main objective of the present invention is to provide a breath capture device that has a compact suction plate that is easy to handle and can capture breath appropriately.

To achieve the above object, one aspect of the present invention provides a breath capture device comprising a main body having a flow path for passing breath, and a holder that is detachable from the main body, detachably holds an adsorption plate having a gas adsorption surface, and positions the adsorption plate within the flow path, and the main body has an insertion port through which the holder can be inserted and removed in a direction intersecting the flow path.

According to another aspect of the present invention, the holder includes a plurality of replaceable holders, each of which has a different intersection angle between the axis of the flow path and the suction plate it holds.

According to another aspect of the present invention, the holder may be configured so that the angle of intersection between the axis of the flow path and the suction plate it holds can be changed.

According to another aspect of the present invention, the device further includes a positioning mechanism for fixing the orientation of the gas adsorption surface, the positioning mechanism having a key provided on one of the holder and the main body, and a number of key grooves provided on the other of the holder and the main body with which the key engages, and the intersecting angle of the adsorption plate with respect to the axis of the flow path can be changed by engaging the key with one of the number of key grooves.

According to another aspect of the present invention, the holder is attached to the main body so as to be rotatable about a rotation axis that intersects with the axis of the flow path, and is configured to be able to hold any rotation angle position by frictionally engaging with the main body via a rubber O-ring, and the intersection angle of the suction plate with respect to the axis of the flow path can be changed.

According to another aspect of the invention, the holder and the main body are provided with markings that indicate the rotational angle position of the holder.

According to another aspect of the present invention, the holder holds the suction plate so that the suction plate crosses the axis of the flow path obliquely.

According to another aspect of the present invention, the main body has an insertion opening through which the holder can be inserted and removed in a direction intersecting the flow path, and the holder has a gripping portion for gripping the holder, a support portion connected to the gripping portion for supporting the suction plate within the flow path, and a movable stopper for removably holding the suction plate supported by the support portion.

According to another aspect of the present invention, the movable stopper is slidably inserted into a guide hole provided in the gripping portion and has a tip that engages with the suction plate.

According to another aspect of the present invention, the movable stopper has a locking portion that locks into a locking portion provided in the guide hole, and the locking portion is provided at an engagement position where the movable stopper engages with the suction plate and a non-engagement position where the movable stopper does not engage with the suction plate.

According to the present invention, the suction plate is removably held by the holder, and the holder that holds the suction plate is removably inserted into the insertion port of the main body, so that the suction plate can be placed in the flow path. Therefore, if the suction plate is held by the holder, the holder can be attached to the main body, and the suction plate can be placed in the flow path where the exhaled air flows, and the exhaled air can be appropriately captured.

FIG. 1 is a front view of one embodiment of a breath capture device according to the present invention. FIG. 2 is a plan view of the breath capture device of FIG. 1; FIG. 4 is an enlarged cross-sectional view taken along line III-III of FIG. 3. FIG. 4 is a partially enlarged view of FIG. 3 . FIG. 2 is a front view showing a main body which is a component of the breath capture device of FIG. 1; FIG. 6 is a plan view of the main body of FIG. 5 . FIG. 7 is a cross-sectional view taken along line VII-VII of FIG. 6. FIG. 6 is a right side view of the main body of FIG. 5 . FIG. 6 is a left side view of the main body of FIG. 5 . FIG. 2 is a plan view showing a holder, which is a component of the breath capture device of FIG. 1. FIG. 11 is a front view of the holder of FIG. 10 . FIG. 11 is a left side view of the holder of FIG. 10 . FIG. 13 is a partially enlarged view of FIG. 12 . 2 is a plan view showing a movable stopper, which is a component of the breath capture device of FIG. 1; FIG. FIG. 15 is a side view of the movable stopper of FIG. 14 . FIG. 15 is a bottom view of the movable stopper of FIG. 14 . FIG. 11 is a plan view showing a modification of the holder of FIG. 10; 11 is a plan view showing another modified embodiment of the holder of FIG. 10. FIG. 4 is a graph showing an analysis of gas captured by a breath capture device according to one embodiment of the present invention. 4 is a graph showing the results of an analysis of gas captured by a breath capture device according to another embodiment of the present invention. 11 is a graph showing the results of an analysis of gas captured by a breath capture device according to yet another embodiment of the present invention. FIG. 13 is a front view of another embodiment of a breath capture device according to the present invention. FIG. 7 is a plan view showing a modification of the body of FIG. 6; FIG. 7 is a plan view showing yet another modified embodiment of the main body of FIG. 6. FIG. 25 is a front view showing a holder to be attached to the main body of FIG. 24. 26 is a front view showing an exhaled breath capture device in which the holder of FIG. 25 is attached to the main body of FIG. 24. FIG. 27 is a plan view of the breath capture device of FIG. 26.

Embodiments of the breath capture device according to the present invention will be described below with reference to Figures 1 to 14. Note that the same or similar components are designated by the same reference numerals throughout all figures and all embodiments.

As shown in FIG. 1, the breath capture device 1 includes a main body 3 having a flow path 2 for passing breath, and a holder 4 that removably holds an adsorption plate P (see FIGS. 4 and 13) having a gas adsorption surface Ps and is removably attached to the main body 3.

The adsorption plate P has a gas adsorption surface Ps, and can be any known one, such as one that is a three-dimensional microstructure formed by dry etching one side of a silicon substrate using MEMS technology, one that is a three-dimensional microstructure formed by providing a large number of carbon nanotubes in a vertical position on a silicon substrate, or one that is a plate-like structure with a fine uneven surface on one side using a resin structure. An adsorbent for volatile organic gas molecules (such as the porous polymer adsorbent TENAX-TA) is applied to the gas adsorption surface. As another adsorption plate P, a thin plate coated with an adsorbent may also be used. In this embodiment, a silicon substrate is etched using MEMS manufacturing technology, and TENAX-TA, an adsorbent for volatile organic gases from exhaled breath that serves as a biomarker, is applied to the etched surface, and a thin disk-shaped adsorption plate with a diameter of about 1 cm is used, with the surface coated with the adsorbent exposed (see FIG. 4).

As shown in Figures 6 and 7, the main body 3 has an insertion port 3a into which the holder 4 can be inserted and removed in a direction (Z-axis direction) intersecting the axial line X direction of the flow path 2. The inner peripheral surface of the insertion port 3a is provided with a key groove 3b1 into which a positioning key 4a (Figures 3 and 11) abutting against the outer peripheral surface of the holder 4 fits. By fitting the positioning key 4a into the key groove 3b1, the gas adsorption surface Ps of the adsorption plate P is positioned so as to face the direction in which it receives the flow of exhaled air passing through the flow path 2.

Referring to Figures 10 to 16, the holder 4 includes a gripping portion 4b for gripping the holder 4, a support portion 4c connected to the gripping portion 4b and supporting the suction plate P, and a movable stopper 4d for removably fixing the suction plate P to the support portion 4c.

The grip portion 4b is formed with dimensions and a shape that allows it to be held by pinching it with the fingers. In the illustrated example, the grip portion 4b is cylindrical, but it may be prismatic or have other shapes.

The support portion 4c is a groove into which a portion of the periphery of the suction plate P fits. As shown in Figures 12 and 13, the support portion 4c is provided in two locations in this example, but it can also be provided in only one location or in three or more locations. The support portion 4c is not limited to being groove-shaped, and can also be hook-shaped or have other support shapes.

The movable stopper 4d is slidably inserted into a guide hole 4b1 provided in the gripping portion 4b. The movable stopper 4d has an engaging portion 4d1 that engages with the interlocking portions 4b2, 4b3 provided on the inner surface of the guide hole 4b1. Referring to Figures 14 to 16, the engaging portion 4d1 is formed by a protrusion provided on the flexible portion 4d2. The flexible portion 4d2 is flexible due to the provision of a slit 4d2 in the movable stopper 4d to make it thin-walled. The protrusion that constitutes the engaging portion 4d1 is semispherical. The interlocking portions 4b2, 4b3 are formed by recesses into which the engaging portion 4d1 fits. When the movable stopper 4d is inserted into the guide hole 4b1, the flexible portion 4d2 elastically deforms and bends inwardly into the slit 4d2, and when the protrusion that constitutes the locking portion 4d1 reaches the position of the recess that constitutes the locked portion 4b2 or 4b3, the bent flexible portion 4d2 elastically returns to its original position, and the protrusion of the locking portion 4d1 fits into the recess of the locked portion 4b2 or 4b3, and the locking portion 4d1 locks into the locked portion 4b2 or 4b3.

The tip of the movable stopper 4d has an engagement portion 4e that engages with a portion of the periphery of the suction plate P. The engagement portion 4e can be configured as a step as shown in the example. The rear end portion 4f of the movable stopper 4d protrudes from the grip portion 4b of the holder 4 and can be held by fingers, and is used to slide the movable stopper 4d.

The engaged portion 4b2 is provided at an engagement position where the movable stopper 4d engages with the suction plate P, and the engaged portion 4b3 is provided at a non-engagement position where the movable stopper 4d does not engage with the suction plate P. Since the suction plate P is thin and easily damaged, by engaging the engaging portion 4d1 with the engaged portion 4b1 at an appropriate engagement position, it is possible to prevent excessive load from being applied to the suction plate and damage to the suction plate P.

The suction plate P is held in the holder 4 by being sandwiched between the support portion 4c and the movable stopper 4d. The suction plate P can be easily attached and detached by simply sliding the movable stopper 4d. The suction plate P can be held with tweezers or the like and set in the holder.

In Figures 12 and 13, reference numeral 4j denotes a guide groove into which the movable stopper 4d fits, and reference numeral 4k denotes a recess that provides space for the tips of the tweezers that grip the suction plate P.

As described above, the suction plate P is detachably held by the holder 4, and the holder 4 holding the suction plate P is detachably inserted into the insertion port 3a of the main body 3, so that the suction plate P can be placed in the flow path 2. If the suction plate P is held by the holder 4, the holder 4 can be attached to the main body 3, and the suction plate P can be placed in the flow path 2 through which the exhaled air flows. The exhaled air can be properly captured, and the small and difficult to handle suction plate P can be easily attached and replaced.

The holder 4 has a flange 4g between the grip 4b and the positioning key 4a. The flange 4g abuts against the periphery of the insertion port 3a of the main body 3. When the holder 4 is inserted into the insertion port 3a, the flange 4g positions the grip 4b outside the main body 2 and functions as a positioning device so that the suction plate P is positioned at a predetermined position within the flow path 2. The holder 4 has a rubber O-ring 4i (Figure 3) attached to the circumferential groove 4h, and is airtightly fitted into the insertion port 3a.

When the holder 4 is inserted into the main body 3, the flow path 2 is partially blocked by the holder 4, but a gap is left through which the exhaled air can pass through the flow path 2. Therefore, the exhaled air that flows in from one opening of the flow path 2 can flow out from the other opening of the flow path 2. The exhaled air comes into contact with the adsorption plate P held by the holder 4 midway through the flow path 2, and the volatile organic gases in the exhaled air are adsorbed onto the gas adsorption surface Ps.

As shown in Figures 3 and 7, the cross-sectional area of the flow path 2 is wide at the position where the suction plate P is placed and narrowed on the outlet side of the exhaled air. By narrowing the outlet side of the flow path 2, the exhaled air that has flowed into the flow path 2 can be retained around the suction plate P.

One side (the breath inlet side) of the flow path 2 is a first tube connection part 2a into which a tube such as an intubation tube (not shown) can be inserted and connected. The other side of the flow path 2 is provided with a second tube connection part 2b consisting of a hose joint 3c, which can be used for connecting an anesthesia tube, etc. Breath from a subject (animal or human) is sent to the flow path 2 of the breath capture device 1 through an intubation tube, and volatile organic gases in the breath are adsorbed by the adsorption plate P held by the holder 4. The breath flowing in from one side of the flow path 2 is discharged to the other side of the flow path 2. The holder 4 is then removed from the main body 3, the movable stopper 4d is slid, and the adsorption plate P is removed from the support part 4c of the holder 4. The removed adsorption plate P is heated to a high temperature (e.g., 300°C) by a heating device not shown, and the adsorbed volatile organic gases are evaporated and analyzed for components by gas chromatography.

The holder 4 shown in Figures 3 and 4 has an intersection angle θ of 90° between the axis X of the flow path 2 and the suction plate P. The intersection angle θ means the minimum angle between the axis X and the suction plate P. On the other hand, the holder 4A shown in Figure 17 holds the suction plate P so that it intersects the axis X of the flow path 2 at an angle of 75°. The holder 4B shown in Figure 18 holds the suction plate P so that it intersects the axis X of the flow path 2 at an angle of 15°. The movable stopper 4d engages with the periphery of the suction plate P so that the suction plate P fitted into the groove-shaped support portion 4c does not fall out. The holder 4 and the holder 4A can be attached to the main body 3 interchangeably.

Figures 19 to 21 show the results of gas chromatography analysis of the volatile organic gas molecules in the captured breath when the holder 4, holder 4A, and holder 4B are interchangeable. The graph in Figure 19 shows the case when the crossing angle θ is 90°, the graph in Figure 20 shows the case when the crossing angle is 75°, and Figure 21 shows the case when the crossing angle is 15°. When the crossing angle is 90° (Figure 19), the amount of volatile organic gas molecules captured is large, when the crossing angle θ is 75° (Figure 20), many species of volatile organic gas molecules are captured, and when the crossing angle is 15° (Figure 21), both the amount and species of volatile organic gas molecules captured are small. This means that the amount and species of volatile organic gas molecules captured differ depending on the direction in which the breath hits the adsorption plate P.

The intersection angle θ can be set appropriately within the range of 5° to 90° depending on the amount and type of molecules to be analyzed.

As shown in Figure 22, the main body 3 has multiple insertion openings 3a (Figure 6), and multiple holders 4, 4A with different intersection angles θ can be attached simultaneously. Figure 22 shows an example with two holders, but it can also be configured so that three or more holders can be attached.

Figure 23 shows the main body 3 of another embodiment of the breath capture device according to the present invention. As shown in Figure 23, the insertion port 3a of the main body 3 is provided with multiple key grooves 3b1 and 3b2. The other configurations are the same as those of the breath capture device shown in Figures 1 to 16. The key grooves 3b1 and 3b2 are formed at a predetermined angular interval. By engaging the key 4a (see Figures 3 and 11) of the holder 4 with any of the multiple key grooves 3b1 and 3b2, it is possible to change the intersection angle θ of the held suction plate P with respect to the axis X of the flow path 2, as shown by the imaginary line in Figure 23. With this configuration, it is not necessary to separately prepare a holder 4A with a different intersection angle θ as described above. It is also possible to provide a key groove in the holder 4 and a key in the main body 3.

24 to 27 show still another embodiment of the breath capture device according to the present invention. The breath capture device 1 shown in Figs. 24 to 27 does not have the key groove of the above embodiment in the insertion port 3a of the main body 3 as shown in Fig. 24, and does not have the key of the above embodiment in the holder 4 as shown in Fig. 25. The holder 4 and the main body 3 are provided with indicators 5m and 5n indicating the rotation angle position of the holder 4. The other configurations are the same as those of the breath capture device 1 shown in Figs. 1 to 16. In the illustrated example, the indicator 5m is a mark of the reference position, and the indicator 5n is an angle scale. According to this configuration, the holder 4 is attached to the main body 3 so as to be rotatable around the rotation axis Y that intersects with the axis X of the flow path 2. This makes it possible to change the intersection angle θ of the held suction plate P with respect to the axis X of the flow path 2. In addition, the holder 4 can be held at any rotation angle position by frictionally engaging with the main body 3 via a rubber O-ring 4i.

The present invention should not be interpreted as being limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention.

1 Breath capture device 2 Flow path 3 Main body 3a Insertion port 3b1, 3b2 Key groove 4, 4A Holder 4a Key 4b Grip portion 4b1 Guide hole 4b2 Locked portion 4b3 Locked portion 4c Support portion 4d Movable stopper 4d1 Locking portion 4i Rubber O-ring 5m, 5n Marking P Adsorption plate Ps Gas adsorption surface X Axis θ Intersection angle

Claims (10)

A main body having a flow path for passing exhaled air;
a holder that is detachably attached to the main body, detachably holds an adsorption plate having a gas adsorption surface and to be subjected to analysis , and disposes the adsorption plate in the flow path;
The body of the breath capture device has an insertion port through which the holder can be inserted and removed in a direction intersecting the flow path. The breath capture device of claim 1, wherein the holder includes a plurality of replaceable holders each having a different intersection angle between the axis of the flow path and the suction plate held by the holder, and the plurality of types of replaceable holders are configured to be mutually interchangeable and attachable to the insertion port . The breath capture device according to claim 1, wherein the holder is configured so that the intersection angle between the axis of the flow path and the suction plate it holds can be changed. The breath capture device according to claim 3 further comprises a positioning mechanism for fixing the orientation of the gas adsorption surface, the positioning mechanism having a key provided on one of the holder and the main body, and a number of key grooves provided on the other of the holder and the main body with which the key engages, and the crossing angle of the adsorption plate with respect to the axis of the flow path can be changed by engaging the key with one of the number of key grooves. The breath capture device according to claim 3, wherein the holder is attached to the main body so as to be rotatable about a rotation axis that intersects with the axis of the flow path, and is configured to be able to hold any rotation angle position by frictionally engaging with the main body via a rubber O-ring, and the intersection angle of the suction plate with respect to the axis of the flow path can be changed. The breath capture device according to claim 5, wherein the holder and the main body are provided with markings indicating the rotational angle position of the holder. The breath capture device according to claim 1, wherein the holder holds the suction plate so that the suction plate crosses the axis of the flow path obliquely. The breath capture device according to claim 1, wherein the holder comprises a gripping portion for gripping the holder, a support portion connected to the gripping portion for supporting the suction plate in the flow path, and a movable stopper for removably holding the suction plate supported by the support portion. The breath capture device according to claim 8, wherein the movable stopper is slidably inserted into a guide hole provided in the gripping portion and has a tip that engages with the suction plate. the movable stopper includes a locking portion that is engaged with a locked portion provided in the guide hole,
The breath capture device according to claim 9 , wherein the engaging portion is provided at an engagement position where the movable stopper engages with the suction plate and at a non-engagement position where the movable stopper does not engage with the suction plate.