JP2017083175A - Breath diagnosis device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-accuracy breath diagnosis device.SOLUTION: According to an embodiment of the present invention, a breath diagnosis device is provided that includes a cell unit, a light source unit, a detection unit, and a control unit. The cell unit includes a space. A sample gas including breath that includes a first substance and a second substance differing from the first substance is introduced into the space. The light source unit causes first light of a first wavelength between a plurality of peaks of light absorption of the first substance and second light of a second wavelength differing from the first wavelength to enter the space. The detection unit detects the intensity of the first light having passed through the space in which the sample gas is introduced, and the intensity of the second light having passed through the space in which the sample gas is introduced. The control unit calculates the concentration of the second substance in the sample gas on the basis of the intensity of the first light and the intensity of the second light.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a breath diagnosis apparatus.

  In the expiration diagnosis apparatus, the expiration gas is measured. From this measurement result, disease prevention and early detection become easier. In the breath diagnosis apparatus, it is desired to obtain a highly accurate measurement result.

JP 2003-232732 A

  Embodiments of the present invention provide a highly accurate breath diagnosis apparatus.

  According to the embodiment of the present invention, there is provided a breath diagnosis apparatus including a cell unit, a light source unit, a detection unit, and a control unit. The cell part includes a space. A sample gas containing exhaled air containing a first substance and a second substance different from the first substance is introduced into the space. The light source unit causes first light having a first wavelength between a plurality of peaks of light absorption of the first substance and second light having a second wavelength different from the first wavelength to be incident on the space. . The detection unit detects the intensity of the first light passing through the space where the sample gas is introduced and the intensity of the second light passing through the space where the sample gas is introduced. . The control unit calculates the concentration of the second substance in the sample gas based on the intensity of the first light and the intensity of the second light.

It is a mimetic diagram illustrating the breath diagnostic device concerning a 1st embodiment. It is a graph which illustrates the characteristic of the substance contained in sample gas. FIG. 3A and FIG. 3B are graphs illustrating characteristics of substances contained in the sample gas. It is a schematic diagram which illustrates another breath diagnostic apparatus which concerns on 1st Embodiment. It is a mimetic diagram which illustrates a part of exhalation diagnostic device concerning a 1st embodiment. It is a mimetic diagram which illustrates a part of exhalation diagnostic device concerning a 1st embodiment. FIG. 7A and FIG. 7B are schematic views illustrating a part of the breath diagnosis apparatus according to the first embodiment. FIG. 8A to FIG. 8C are schematic views illustrating a part of the breath diagnosis apparatus according to the embodiment. It is a schematic diagram which illustrates the breath diagnostic apparatus which concerns on 2nd Embodiment. It is a schematic diagram which illustrates another breath diagnostic apparatus which concerns on 2nd Embodiment.

Embodiments of the present invention will be described below with reference to the drawings.
The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between the parts, and the like are not necessarily the same as actual ones. Further, even when the same part is represented, the dimensions and ratios may be represented differently depending on the drawings.
Note that, in the present specification and each drawing, the same elements as those described above with reference to the previous drawings are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.

(First embodiment)
FIG. 1 is a schematic view illustrating the breath diagnosis apparatus according to the first embodiment.
As shown in FIG. 1, the breath diagnosis apparatus 110 according to the present embodiment includes a cell unit 20, a light source unit 30, a detection unit 40, and a control unit 45.

  A sample gas 50 including exhaled air 50 a is introduced into the cell unit 20. For example, the cell unit 20 includes a space 23s. The sample gas 50 including the exhaled air 50a is introduced into the space 23s.

  The exhalation 50a is, for example, exhalation of animals including humans. The exhalation 50a includes a first substance 51 and a second substance 52. The first substance 51 is, for example, water. The second substance 52 is, for example, acetone. The second substance 52 is a substance related to the purpose of diagnosis in the breath diagnosis apparatus 110. For example, when suffering from diabetes, the concentration of acetone in the exhaled breath 50a increases as compared to when healthy. In the breath diagnosis apparatus 110, the health condition is diagnosed by measuring the concentration of a substance (for example, acetone). An example of the second substance 52 will be described later. The first substance 51 is a substance different from the second substance 52 included in the exhaled breath 50a.

  The light source unit 30 causes the first light L1 having the first wavelength and the second light L2 having the second wavelength to enter the space 23s. The second wavelength is different from the first wavelength. These lights correspond to the measurement light 30L.

  As will be described later, the first wavelength is a wavelength between a plurality of peaks of light absorption of the first substance 51 (for example, water). The first substance 51 has high light absorption at a plurality of wavelengths. That is, there are a plurality of wavelengths (peak wavelengths) corresponding to light absorption peaks (maximum values). The first wavelength is not a peak wavelength but a wavelength between a plurality of peak wavelengths. The first wavelength may be a wavelength corresponding to the bottom of absorption, for example.

  In this example, the light source unit 30 includes a light emitting unit 30a and a driving unit 30b. The drive unit 30b is electrically connected to the light emitting unit 30a. The drive unit 30b supplies power for light emission to the light emitting unit 30a. As will be described later, for example, an external resonator (EC) type quantum cascade laser (QCL) is used as the light emitting unit 30a. An example of the light emitting unit 30a will be described later.

  The detection unit 40 detects the intensity (first intensity) of the first light L1 that has passed through the space 23s into which the sample gas 50 is introduced. The detection unit 40 detects the intensity (second intensity) of the second light L2 that has passed through the space 23s into which the sample gas 50 is introduced.

  Based on the first intensity (the intensity of the first light L1) and the second intensity (the intensity of the second light L2) detected by the detection unit 40, the control unit 45 determines the second substance 52 in the sample gas 50. Calculate the concentration. An example of the operation of the control unit 45 will be described later.

  As shown in FIG. 1, the breath diagnosis apparatus 110 further includes a supply unit 10 i and a discharge unit 10 o.

  The sample gas 50 is supplied to the supply unit 10i. The sample gas 50 introduced from the supply unit 10i is introduced into the cell unit 20 through the first pipe 15a. The first pipe 15 a is provided between the supply unit 10 i and the cell unit 20. On the other hand, the sample gas 50 introduced into the cell unit 20 reaches the discharge unit 10o through the second pipe 15b. The sample gas 50 is discharged to the outside through the discharge unit 10o. For example, a fan may be provided in the discharge unit 10o. Exhaust efficiency is improved.

  In this example, the cell unit 20 includes a first reflection unit 21 and a second reflection unit 22. The first reflection unit 21 and the second reflection unit 22 are reflective to the measurement light 30L.

  The sample gas 50 introduced from the supply unit 10 i is introduced into the space 23 s between the first reflection unit 21 and the second reflection unit 22.

  For example, the cell unit 20 further includes a cell 23, for example. For example, a space 23 s is formed by the cell 23. At least a part of the space 23 s is disposed between the first reflecting part 21 and the second reflecting part 22.

  The measurement light 30L (the first light L1 and the second light L2) is reflected by the first reflecting part 21 and the second reflecting part 22, and is between the first reflecting part 21 and the second reflecting part 22 (space 23s). ) Multiple round trips. A part of the measurement light 30 </ b> L is absorbed by the substances (first substance 51 and second substance 52) contained in the sample gas 50. Of the measurement light 30L, a component having a wavelength peculiar to the substance is absorbed. The degree of absorption depends on the concentration of the substance.

  For example, the detection unit 40 detects the measurement light 30L that has passed through the space 23s in a state where the sample gas 50 is introduced into the space 23s.

  For the detection unit 40, an element having sensitivity in the infrared region is used. For the detection unit 40, for example, a thermopile or a semiconductor element (for example, MCT (HgCdTe)) is used. In the embodiment, the detection unit 40 is optional.

  In this example, a housing 10w is further provided. For example, the cell unit 20, the light source unit 30, the detection unit 40, the first pipe 15a, and the second pipe 15b are stored in the housing 10w.

  In this example, the first optical component 36a is provided between the light source unit 30 and the cell unit 20 on the optical path of the measurement light 30L. A second optical component 36b is provided between the cell unit 20 and the detection unit 40 on the optical path. These optical components include, for example, a condensing optical element. A filter may be used for these optical components. Optical switches may be used for these optical components. The optical components are provided as necessary and may be omitted.

  Thus, the breath diagnosis apparatus 110 is provided with the cell unit 20 including the space 23s into which the sample gas 50 is introduced, and the light source unit 30 that emits the measurement light 30L. The detection unit 40 detects the measurement light 30L that has passed through the space 23s into which the sample gas 50 has been introduced, and detects the light intensity (first intensity and second intensity). The absorption of the measurement light 30L by the substances (the first substance 51 and the second substance 52) contained in the exhaled breath 50a is measured. Thereby, the density | concentration of the substance contained in the expiration 50a is measured.

FIG. 2 is a graph illustrating characteristics of a substance contained in the sample gas.
FIG. 2 illustrates an absorption spectrum of water (first absorption spectrum 51 s) and an absorption spectrum of acetone (second absorption spectrum 52 s). Water is an example of the first substance 51. Acetone is an example of the second substance 52. The horizontal axis is the wavelength λ (μm: micrometer). The vertical axis represents the absorption rate Ab.

  As shown in FIG. 2, in the second absorption spectrum 52 s of acetone, in the region where the wavelength λ is about 7.6 μm or more and less than 8.06 μm, the absorptance Ab is substantially 0%. In the second absorption spectrum 52s, in the region where the wavelength λ is about 7.15 μm or more and about 7.5 μm or less, and in the region where the wavelength λ is 8.06 μm or more and 8.45 μm or less, the absorption Ab is 1% or more. .

  For example, when light having a wavelength in the range of about 7.6 μm or more and less than 8.06 μm is used, it is difficult to detect the concentration of acetone. For example, when light having a wavelength of 8.06 μm or more and 8.45 μm or less is used, the absorptance Ab changes according to the concentration of acetone. By detecting the intensity of light having a wavelength of 8.06 μm or more and 8.45 μm or less, an amount related to the concentration of acetone in the sample gas 50 can be obtained. A wavelength between 8.06 μm and 8.45 μm is a candidate for the second wavelength λ2.

  On the other hand, in the range where the wavelength λ is about 7.15 μm or more and about 7.5 μm, the second absorption spectrum 52 s is relatively high, but the first absorption spectrum 51 s is very high. For this reason, if light having a wavelength of about 7.15 μm or more and about 7.5 μm or less is used, it is difficult to separate the first absorption spectrum 51s and the second absorption spectrum 52s. For this reason, in the case of a combination of water and acetone, it is preferable to use light of any wavelength in the wavelength range of 8.06 μm to 8.45 μm for detection of acetone.

  In the embodiment, in the wavelength range of 8.06 μm or more and 8.45 μm or less, a wavelength having a low absorption rate Ab of the first absorption spectrum 51s of water is used. Thereby, the influence of water can be suppressed. Therefore, as the second wavelength λ2, a wavelength having a low water absorption rate Ab in the wavelength range of 8.06 μm to 8.45 μm is used as the second wavelength λ2.

  When the second substance 52 is acetone, for example, at least one of 8.12 μm and 8.32 μm can be used as the second wavelength λ2. In FIG. 2, the second wavelength λ2 is displayed as a case where 8.32 μm light is used.

  When the light absorption in the sample gas 50 (exhalation 50a) containing acetone and water is detected using the second wavelength λ2, the absorption of water is included in addition to the absorption of acetone. For this reason, correction is performed in consideration of the influence of water.

  That is, the concentration of water (first substance 51) in the sample gas 50 is detected. In detection of water (first substance 51), a wavelength at which the influence of acetone (second substance 52) does not substantially occur is used.

  For example, since the absorbance Ab of acetone is substantially 0% at a wavelength of about 7.6 μm or more and less than 8.06 μm, the light in this range has a wavelength when measuring the concentration of water (first Candidate for wavelength λ1).

  As illustrated in FIG. 2, the first absorption spectrum 51 s has a plurality of peaks 51 p. There is a peak-to-peak region 51b between the plurality of peaks 51p. In the embodiment, the wavelength of the peak-to-peak region 51b is employed as the first wavelength λ1.

  For example, when the first substance 51 is water, as the first wavelength λ1, for example, at least one of 7.63 μm, 7.8 μm, 7.83 μm, and 7.92 μm can be used.

  In the wavelength region including the first wavelength λ1, the light absorption change rate with respect to the change in the wavelength of the first substance 51 is lower than the change rate with respect to the wavelength change in the wavelength region including the peak wavelength. At the first wavelength λ1, the degree of change in light absorption with respect to the wavelength variation of the first substance 51 is relatively small. As the first wavelength λ1, for example, the wavelength of the stable minimum point of the absorption spectrum can be used.

  Thus, in the embodiment, the first wavelength λ1 is not a wavelength corresponding to the peak 51p, but a wavelength between the plurality of peaks 51p. As a result, even when the first wavelength λ1 fluctuates, a light absorption value can be stably obtained.

  If detection is performed using a wavelength corresponding to the light absorption peak 51p of the first substance 51, the value of light absorption changes when there is a change in wavelength. On the other hand, in the embodiment, the first wavelength λ1 is a wavelength having a small light absorption variation with respect to the wavelength variation. The concentration of the first substance 51 is obtained using the first light L1 having this wavelength. Based on the value, the detection result of the second light L2 having the second wavelength λ2 is corrected to obtain the concentration of the second substance 52 (for example, acetone). The value obtained by this is highly accurate. According to the embodiment, a highly accurate breath diagnosis apparatus can be provided.

  When using light of a plurality of wavelengths as the measurement light 30L, a reference example using a plurality of lasers can be considered. For example, a plurality of lasers each emitting a single wavelength of light are used. At this time, the wavelength of the light is substantially constant, and the fluctuation of the wavelength is small. However, in a configuration using a plurality of lasers, the apparatus becomes large and difficult to use. There are limitations on the application of the breath diagnosis apparatus. For example, the same problem occurs in a method using a light source that emits light of a wide range of wavelengths and a wavelength filter.

  On the other hand, by using a light source capable of emitting light of a plurality of wavelengths, the apparatus can be reduced in size and the application range is expanded. For example, light having a plurality of wavelengths can be obtained by using a laser system having a variable wavelength. For example, in the embodiment, light having a plurality of wavelengths is obtained by using an external resonator (EC) type quantum cascade laser (QCL) described later. In EC-QCL, light having a relatively narrow spectral width can be obtained. And the change range of a wavelength is wide. For example, the width of the changeable wavelength range is about 1 μm.

  At this time, in EC-QCL, the wavelength of emitted light (for example, the first light L1 and the second light L2) may fluctuate.

  At this time, by using the above-described wavelength (the wavelength between the plurality of peaks 51p) as the first wavelength λ1, fluctuations in the obtained light absorption can be suppressed even when the wavelengths fluctuate. As a result, fluctuations in the detection result of the concentration of the first substance 51 (for example, water) can be suppressed. By correcting using the concentration of the first substance 51 whose fluctuation is suppressed, the concentration of the second substance 52 (for example, acetone) can be obtained with high accuracy.

  If the absorption rate Ab of the first substance 51 (for example, water) at the first wavelength λ1 is excessively low, the detection of the first substance 51 is difficult. For this reason, the first wavelength λ1 is determined so that the absorption rate Ab of the first substance 51 becomes a certain level or more. For example, the absorption rate Ab of the first substance (for example, water) at the first wavelength λ1 is higher than the absorption rate Ab of the second substance 52 (for example, acetone) at the second wavelength λ2. . For example, the absorption rate Ab of the first substance at the first wavelength λ1 is preferably 5 times or more than the absorption rate Ab of the second substance 52 at the second wavelength λ2. More preferably, it is 10 times or more.

  However, when the absorption rate Ab is excessively high at the first wavelength λ1, the change rate of the light absorption with respect to the change in the wavelength becomes high, and thus the detection result varies greatly. For this reason, the first wavelength λ1 is set so that the absorption rate Ab does not become excessively high.

  In the embodiment, the light absorptance at the first wavelength λ1 is, for example, 20 of the maximum value of the plurality of peaks 51p of the light absorptance of the first substance 51 in the range where the wavelength λ is 7.5 μm or more and 7.95 μm or less. % Or less. In the example shown in FIG. 2, the peak of the absorption rate Ab of the first substance 51 (water) in the range where the wavelength λ is 7.5 μm or more and 7.95 μm or less is 98%. For example, when the wavelength λ is 7.63 μm, 7.8 μm, 7.83 μm, and 7.92 μm, the absorptance Ab is about 3% or more and about 6%. Thus, the first wavelength λ1 is not less than 7.6 μm and not more than 7.95 μm. As described above, by using a wavelength at which the absorption rate Ab lower than that of the peak 51p is used, the wavelength dependency of the absorption rate Ab can be reduced, and the detection result can be easily obtained stably.

  Thus, by reducing the light absorption at the first wavelength λ1, the wavelength dependence of the light absorption is reduced. For this reason, the fluctuation | variation of a detection result can be suppressed and a highly accurate result is obtained.

  The first wavelength λ1 may be determined based on the absorption coefficient.

FIG. 3A and FIG. 3B are graphs illustrating characteristics of substances contained in the sample gas.
These figures illustrate the absorption spectrum (first absorption spectrum 51 s) of water (first substance 51). The horizontal axis in these figures is the wavelength λ. The vertical axis | shaft of Fig.3 (a) is absorption coefficient Ac (cm <^-1> ). The vertical axis | shaft of FIG.3 (b) displays the absorption coefficient Ac logarithmically.

  As shown in FIGS. 3A and 3B, a plurality of peaks 51p are also obtained in the characteristics of the absorption coefficient Ac. There is a peak-to-peak region 51b between the plurality of peaks 51p. The wavelength of the peak-to-peak region 51b is used as the first wavelength λ1.

  For example, in breath diagnosis, it is practical to use light of 7.0 μm or more and 7.95 μm or less. For this reason, for example, the wavelength at which the light absorption coefficient Ac of 0.1% or less of the maximum value of the light absorption coefficient Ac of the first substance 51 obtained in the range of 7.0 μm to 7.95 μm is obtained. It is preferable to use it as the first wavelength λ1.

In the example shown in FIGS. 3A and 3B, the absorption coefficient Ac is the highest when the wavelength λ is about 7.04 μm. Its highest value is about 2 cm ⁻¹ . 0.1% of this value is about 0.002 cm ⁻¹ . The wavelength at which the absorption coefficient Ac below this value is obtained is used as the first wavelength λ1. There are several wavelengths that satisfy such conditions as follows.

  For example, when the first substance 51 is water and the second substance 52 is acetone, the first wavelength λ1 is 7.6 μm to 7.95 μm, and the second wavelength λ2 is 8.1 μm to 8. 4 μm or less. The center wavelength of the first wavelength λ1 is, for example, at least one of 7.63 μm, 7.8 μm, 7.83 μm, and 7.92 μm. For example, when the second substance 52 is ethanol, the center wavelength of the second wavelength λ2 is, for example, at least one of 8.0 μm and 8.12 μm.

  For example, when the first substance 51 is water and the second substance 52 is ethanol, the first wavelength λ1 is 7.6 μm to 7.95 μm and the second wavelength λ2 is 7.98 μm to 8 .2 μm or less. The center wavelength of the first wavelength λ1 is, for example, at least one of 7.63 μm, 7.8 μm, 7.83 μm, and 7.92 μm. For example, when the second substance 52 is ethanol, the center wavelength of the second wavelength λ2 is, for example, at least one of 8.0 μm and 8.12 μm.

  For example, in the embodiment, in the initial state, the space 23s of the cell 23 is substantially filled with air. In this state, detection using the second light L2 (initial second light detection) is performed. The result obtained at this time is the light absorption of the second light L2 in the air.

  At the first time, exhaled air 50a is blown into the supply unit 10i. Exhaled air 50 a (sample gas 50) is introduced into the space 23 s of the cell 23. In this state, detection using the second light L2 (sample gas second light detection) is performed. The result obtained at this time is the result of the total light absorption of the first substance 51 and the second substance 52.

  A concentration corresponding to the sum of the first substance 51 and the second substance 52 is obtained by obtaining a ratio of the result of the sample gas second light detection to the result of the initial second light detection. This value is taken as the second light detection result.

  At a second time after the first time, the state where the sample gas 50 is introduced into the space 23s is maintained. At the second time, detection using the first light L1 (sample gas first light detection) is performed. Since the second substance 52 is not absorbed at the first wavelength λ1 of the first light L1, the result of the first light detection of the sample gas is substantially the light absorption corresponding to the concentration of the first substance 51 (water). It becomes the value of.

  After the second time, the sample gas 50 in the space 23s is exhausted. For example, the sample gas 50 is exhausted to the outside through the discharge unit 10o. A fan may be used. Air is introduced from the supply unit 10i. The space 23s is filled with air. In this state, detection using the first light L1 (initial first light detection) is performed. The result obtained at this time is the light absorption of the first light L1 in the air.

  The concentration of the first substance 51 is obtained by obtaining the ratio of the result of the sample gas first light detection to the result of the initial first light detection. This value is taken as the first light detection result.

  The second light detection result is corrected using the first light detection result. The influence of the first substance 51 is substantially eliminated. Thereby, the concentration of the second substance 52 is obtained. The determined value is accurate.

  Thus, in the embodiment, for example, the detection using the first light L1 is performed after the detection using the second light L2.

  As illustrated in FIG. 2, the light absorption of the second substance 52 (for example, acetone) is lower than the light absorption of the first substance 51 (for example, water). That is, the SN ratio of detection of the second substance 52 using the second light L2 is low.

  On the other hand, the state of the sample gas 50 in the space 23s may change after the exhalation 50a is blown. For example, the concentration of exhaled breath 50a in the space 23s may decrease with time.

  In the embodiment, the detection using the second light L2 for detecting the second substance 52 is performed at a relatively close time from the start of the exhalation of the exhalation 50a (first time). Thereby, the detection using the second light L2 can be performed before the state in the space 23s changes. Thereby, the light absorption of the 2nd substance 52 with a low degree of light absorption is detectable with high precision.

  On the other hand, the light absorption of the first substance 51 (for example, water) is high. For this reason, in the detection of the first light L1 of the first substance 51, the SN ratio is high. For this reason, the influence of the elapsed time after the breath 50a is blown on the detection result is relatively small.

  For example, the operation may be controlled by the control unit 45. The control unit 45 performs a first operation and a second operation. The second operation is performed after the first operation. In the first operation, the control unit 45 causes the light source unit 30 to emit the second light L2 and causes the detection unit 40 to detect the intensity of the second light L2. In the second operation, the control unit 45 causes the light source unit 30 to emit the first light L1 and causes the detection unit 40 to detect the intensity of the first light L1. That is, the detection using the first light L1 is performed after the detection using the second light L2. Detection with higher accuracy becomes possible.

FIG. 4 is a schematic view illustrating another breath diagnosis apparatus according to the first embodiment.
As shown in FIG. 4, in another breath diagnosis apparatus 111 according to the present embodiment, a first substance sensor 61 is further provided. The first substance sensor 61 is disposed, for example, in the housing 10w. For example, the first substance sensor 61 detects the concentration of the first substance 51 in the outer space outside the cell unit 20.

  For example, an electric hygrometer is used as the first substance sensor 61.

  The controller 45 further calculates the concentration of the second substance 52 in the sample gas 50 based on the concentration of the first substance 51 detected by the first substance sensor 61. That is, the controller 45 determines the second substance in the sample gas 50 based on the intensity of the first light, the intensity of the second light, and the concentration of the first substance 51 detected by the first substance sensor 61. The density of 52 is calculated. The concentration of the second substance 52 can be obtained with higher accuracy.

Hereinafter, an example of the light emitting unit 30a of the light source unit 30 will be described.
FIG. 5 is a schematic view illustrating a part of the breath diagnosis apparatus according to the first embodiment.
As illustrated in FIG. 5, the light source unit 30 (the light emitting unit 30a) includes a semiconductor light emitting element 30aL and a wavelength control unit 30aC. As will be described later, the semiconductor light emitting element 30aL emits emitted light by energy relaxation of electrons in subbands of a plurality of quantum wells, for example. For example, the wavelength control unit 30aC adjusts the wavelength of the emitted light to generate the first light L1 and the second light L2.

  For example, the wavelength control unit 30aC includes a first adjustment mechanism. The first adjustment mechanism shifts the wavelength of the infrared laser light emitted from the semiconductor light emitting element 30aL into the absorption spectrum of one kind of gas among the plurality of gases included in the exhaled breath 50a. The wavelength control unit 30aC may further include a second adjustment mechanism. For example, the second adjustment mechanism adjusts the wavelength by shifting the wavelength in the absorption spectrum of one kind of gas.

  For example, the first adjustment mechanism includes a diffraction grating 71. The diffraction grating 71 is provided so as to intersect with the optical axis 31Lx of the semiconductor light emitting element 30aL. The diffraction grating 71 forms an external resonator. The incident angle of the infrared laser light to the diffraction grating 71 is changed according to the absorption spectra of the plurality of substances contained in the sample gas 50. The incident angle is changed to, for example, angles β1 to β4. Thereby, the wavelength of infrared laser light is changed.

  For example, a stepping motor 99 and a drive control unit 98 are provided. The drive control unit 98 controls (drives) the stepping motor 99. The diffraction grating 71 is rotationally controlled by the stepping motor 99 and the drive control unit 98 around an axis that intersects the optical axis 31Lx.

  It is preferable to provide an antireflection coating film AR on the end face of the semiconductor light emitting element 30aL on the diffraction grating 71 side. A partially reflective coating film PR (Perfect Reflection) may be provided. The semiconductor light emitting element 30aL is disposed between the partial reflection coating film PR and the antireflection coating film AR. An external resonator is formed between the partially reflective coating film PR and the diffraction grating 71.

  In the embodiment, the wavelength may be further accurately adjusted by the second adjustment mechanism. For example, the drive part 30b (refer FIG. 1) can be used as a 2nd adjustment mechanism. The drive unit 30b changes at least one of the operating current value and the duty of the semiconductor light emitting element 30aL. The temperature control unit 90 may be used as the second adjustment mechanism. The temperature control unit 90 changes the temperature of the semiconductor light emitting element 30aL. For example, a Peltier element or the like is used as the temperature control unit 90. For example, a stress generating element may be used as the second adjustment mechanism. The stress generating element changes the external resonator length. As the stress generating element, for example, a piezo element or the like can be used.

FIG. 6 is a schematic view illustrating a part of the breath diagnosis apparatus according to the first embodiment.
FIG. 6 shows another example of the light emitting unit 30a.
In this example, a diffraction grating 71a is used as the first adjustment mechanism. The diffraction grating 71a moves in an XY plane that intersects the optical axis 31Lx of the semiconductor light emitting element 30aL at a predetermined incident angle γ. The diffraction grating 71 a is moved by, for example, the stepping motor 99 and the drive control unit 98. An external resonator (EC) is formed by the diffraction grating 71a and the partially reflective coating film PR of the semiconductor light emitting element 30aL. The measurement light 30 </ b> L emitted from the partial reflection coating film PR enters the cell unit 20.

FIG. 7A and FIG. 7B are schematic views illustrating a part of the breath diagnosis apparatus according to the first embodiment.
These drawings are schematic plan views showing examples of the diffraction grating 71a.
As illustrated in FIGS. 7A and 7B, the diffraction grating 71 has a plurality of regions. In a plurality of regions, the pitch of the grating is different.

  In the example shown in FIG. 7A, the pitch of the grating differs along the X direction. A plurality of regions having different pitches are provided. The resonance wavelength is region rg2> region rg1> region rg3. For example, the wavelength can be adjusted by moving in the X direction.

  In the example shown in FIG. 7B, the resonance wavelength is region rg5> region rg6> region rg7> region rg4. For example, the diffraction grating 71a is moved along the arrow direction SD illustrated in FIG. Thereby, a wavelength can be adjusted. The cross-sectional shape of the diffraction grating 71a may be asymmetric.

FIG. 8A to FIG. 8C are schematic views illustrating a part of the breath diagnosis apparatus according to the embodiment.
FIG. 8A is a schematic perspective view. FIG. 8B is a cross-sectional view taken along line A1-A2 of FIG. FIG. 8C is a schematic view illustrating the operation of the light source unit 30.
In this example, a semiconductor light emitting element 30 aL is used as the light source unit 30. A laser is used as the semiconductor light emitting element 30aL. In this example, a quantum cascade laser is used.

  As shown in FIG. 8A, the semiconductor light emitting element 30aL includes the substrate 35, the stacked body 31, the first electrode 34a, the second electrode 34b, the dielectric layer 32 (first dielectric layer), and the like. And an insulating layer 33 (second dielectric layer).

  A substrate 35 is provided between the first electrode 34a and the second electrode 34b. The substrate 35 includes a first portion 35a, a second portion 35b, and a third portion 35c. These parts are arranged in one plane. This plane intersects (for example, parallel) with respect to the direction from the first electrode 34a to the second electrode 34b. A third portion 35c is disposed between the first portion 35a and the second portion 35b.

  The stacked body 31 is provided between the third portion 35c and the first electrode 34a. The dielectric layer 32 is provided between the first portion 35a and the first electrode 34a and between the second portion 35b and the first electrode 34a. An insulating layer 33 is provided between the dielectric layer 32 and the first electrode 34a.

  The stacked body 31 has a stripe shape. The stacked body 31 functions as a ridge waveguide RG. The two end surfaces of the ridge waveguide RG become mirror surfaces. The light 31L emitted from the stacked body 31 is emitted from the end face (light emission surface). The light 31L is an infrared laser beam. The optical axis 31Lx of the light 31L is along the extending direction of the ridge waveguide RG.

  As shown in FIG. 8B, the stacked body 31 includes, for example, a first cladding layer 31a, a first guide layer 31b, an active layer 31c, a second guide layer 31d, and a second cladding layer 31e. ,including. These layers are arranged in this order along the direction from the substrate 35 toward the first electrode 34a. Each of the refractive index of the first cladding layer 31a and the refractive index of the second cladding layer 31e is based on the refractive index of the first guide layer 31b, the refractive index of the active layer 31c, and the refractive index of the second guide layer 31d. Is also low. The light 31L generated in the active layer 31c is confined in the stacked body 31. The first guide layer 31b and the first cladding layer 31a may be collectively referred to as a cladding layer. The second guide layer 31d and the second cladding layer 31e may be collectively referred to as a cladding layer.

  The stacked body 31 has a first side surface 31sa and a second side surface 31sb that are perpendicular to the optical axis 31Lx. A distance 31w (width) between the first side surface 31sa and the second side surface 31sb is, for example, not less than 5 μm and not more than 20 μm. Thereby, for example, the control in the horizontal / horizontal mode is facilitated, and the output is easily improved. If the distance 31w is excessively long, a high-order mode is likely to occur in the horizontal and transverse mode, and the output is difficult to increase.

  The refractive index of the dielectric layer 32 is lower than the refractive index of the active layer 31c. Thereby, the ridge waveguide RG is formed by the dielectric layer 32 along the optical axis 31Lx.

  As shown in FIG. 8C, the active layer 31c has, for example, a cascade structure. In the cascade structure, for example, the first regions r1 and the second regions r2 are alternately stacked. The unit structure r3 includes a first region r1 and a second region r2. A plurality of unit structures r3 are provided.

  For example, a first barrier layer BL1 and a first quantum well layer WL1 are provided in the first region r1. A second barrier layer BL2 is provided in the second region r2. For example, the third barrier layer BL3 and the second quantum well layer WL2 are provided in another first region r1a. The fourth barrier layer BL4 is provided in another second region r2a.

  In the first region r1, an intersubband optical transition of the first quantum well layer WL1 occurs. Thereby, for example, light 31La having a wavelength of 3 μm or more and 18 μm or less is emitted.

  In the second region r2, the energy of carriers c1 (for example, electrons) injected from the first region r1 can be relaxed.

  In the quantum well layer (for example, the first quantum well layer WL1), the well width WLt is, for example, 5 nm or less. When the well width WLt is so narrow, the energy levels are discrete, and for example, the first subband WLa (high level Lu) and the second subband WLb (low level Ll) are generated. Carriers c1 injected from the first barrier layer BL1 are effectively confined in the first quantum well layer WL1.

  When the carrier c1 transitions from the high level Lu to the low level Ll, light 31La corresponding to the energy difference (difference between the high level Lu and the low level Ll) is emitted. That is, an optical transition occurs.

  Similarly, light 31Lb is emitted from the second quantum well layer WL2 in another first region r1a.

  In the embodiment, the quantum well layer may include a plurality of wells with overlapping wave functions. The high levels Lu of the plurality of quantum well layers may be the same. The low levels Ll of the plurality of quantum well layers may be the same as each other.

  For example, the intersubband optical transition occurs in either the conduction band or the valence band. For example, recombination of holes and electrons by a pn junction is not necessary. For example, an optical transition is caused by either the hole or electron carrier c1, and light is emitted.

  In the active layer 31c, for example, the voltage applied between the first electrode 34a and the second electrode 34b causes the carrier c1 (for example, electrons) to be quantum via the barrier layer (for example, the first barrier layer BL1). Implanted into the well layer (for example, the first quantum well layer WL1). This causes an intersubband optical transition.

  The second region r2 has, for example, a plurality of subbands. The subband is, for example, a miniband. The energy difference in the subband is small. The subband is preferably close to a continuous energy band. As a result, the energy of the carrier c1 (electrons) is relaxed.

  In the second region r2, for example, light (for example, infrared rays having a wavelength of 3 μm to 18 μm) is not substantially emitted. The carriers c1 (electrons) of the low level L1 in the first region r1 pass through the second barrier layer BL2 and are injected into the second region r2 and relaxed. The carrier c1 is injected into another first region r1a that is cascade-connected. An optical transition occurs in this first region r1a.

  In the cascade structure, an optical transition occurs in each of the plurality of unit structures r3. This makes it easy to obtain a high light output in the entire active layer 31c.

  As described above, the light source unit 30 includes the semiconductor light emitting element 30aL. The semiconductor light emitting device 30aL emits the measurement light 30L by energy relaxation of electrons in subbands of a plurality of quantum wells (for example, the first quantum well layer WL1 and the second quantum well layer WL2).

For example, GaAs is used for the quantum well layers (for example, the first quantum well layer WL1 and the second quantum well layer WL2). For example, Al _x Ga _1-x As (0 <x <1) is used for the barrier layer (for example, the first to fourth barrier layers BL1 to BL4, etc.), for example. At this time, for example, when GaAs is used as the substrate 35, good lattice matching is obtained in the quantum well layer and the barrier layer.

The first cladding layer 31a and the second cladding layer 31e include, for example, Si as an n-type impurity. The impurity concentration in these layers is, for example, 1 × 10 ¹⁸ cm ⁻³ or more and 1 × 10 ²⁰ cm ⁻³ or less (for example, about 6 × 10 ¹⁸ cm ⁻³ ). The thickness of each of these layers is, for example, not less than 0.5 μm and not more than 2 μm (for example, about 1 μm).

The first guide layer 31b and the second guide layer 31d include, for example, Si as an n-type impurity. The impurity concentration in these layers is, for example, 1 × 10 ¹⁶ cm ⁻³ or more and 1 × 10 ¹⁷ cm ⁻³ or less (for example, about 4 × 10 ¹⁶ cm ⁻³ ). The thickness of each of these layers is, for example, 2 μm or more and 5 μm or less (for example, 3.5 μm).

  The distance 31w (the width of the stacked body 31, that is, the width of the active layer 31c) is, for example, 5 μm or more and 20 μm or less (for example, about 14 μm).

  The length of the ridge waveguide RG is, for example, 1 mm or more and 5 mm or less (for example, about 3 mm). The semiconductor light emitting element 30aL operates at an operating voltage of 10 V or less, for example. The current consumption is lower than that of a carbon dioxide laser device or the like. Thereby, operation with low power consumption is possible.

(Second Embodiment)
FIG. 9 is a schematic view illustrating the breath diagnosis apparatus according to the second embodiment.
As shown in FIG. 9, in the breath diagnosis apparatus 120 according to the present embodiment, a first detector 65 is provided. Other than this, since it is the same as the breath diagnosis apparatus 110, the description is omitted.

  The first detector 65 detects the first substance 51 in the sample gas 50. A semiconductor type sensor is used as the first detector 65. In this example, the first detector 65 is attached to the inner wall of the cell 23.

  The amount (concentration) of the first substance 51 (water) in the sample gas 50 in the space 23s is measured by the first detector 65. The control unit 45 calculates the concentration of the second substance 52 in the sample gas 50 based on the concentration of the first substance 51 obtained by the first detector 65 and the intensity of the second light L2.

  Also in the breath diagnosis apparatus 120, the influence of the first substance 51 (for example, water) can be substantially removed. A highly accurate breath diagnosis apparatus can be provided.

FIG. 10 is a schematic view illustrating another breath diagnosis apparatus according to the second embodiment.
As shown in FIG. 10, in the breath diagnosis apparatus 121 according to the present embodiment, a light emitting unit 66 a and a light detecting unit 66 b are used as the first detector 65. Other than this, since it is the same as the breath diagnosis apparatus 120, its description is omitted.

  The light emitting portion 66a causes near infrared light 66c to enter the space 23s into which the sample gas 50 is introduced. The light detection unit 66b detects the intensity of the near-infrared light 66c that has passed through the space 23s into which the sample gas 50 has been introduced.

  For example, a laser diode is used as the light detection unit 66b. A photodiode is used as the light detection unit 66b.

  For example, the near-infrared light 66 c is absorbed by the first substance 51 when passing through the space 23 s. A signal corresponding to the concentration of the first substance 51 in the space 23s is obtained from the detection result of the light detection unit 66b.

  The controller 45 calculates the concentration of the second substance 52 in the sample gas 50 based on the concentration of the first substance 51 detected by the first detector 65 and the intensity of the second light L2. Thereby, the density | concentration of the 2nd substance 52 is obtained correctly.

  According to the embodiment, a highly accurate breath diagnosis apparatus can be provided.

  The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. For example, a specific configuration of each element such as a supply unit, a cell unit, a reflection unit, a light source unit, a detection unit, and a control unit included in the breath diagnosis apparatus can be appropriately selected from a known range by those skilled in the art. The present invention is included in the scope of the present invention as long as the invention can be carried out in the same manner and the same effect can be obtained.

  Moreover, what combined any two or more elements of each specific example in the technically possible range is also included in the scope of the present invention as long as the gist of the present invention is included.

  In addition, based on the breath diagnostic apparatus described above as an embodiment of the present invention, all breath diagnostic apparatuses that can be implemented by a person skilled in the art with appropriate design changes also include the scope of the present invention as long as they include the gist of the present invention. Belonging to.

  In addition, in the category of the idea of the present invention, those skilled in the art can conceive of various changes and modifications, and it is understood that these changes and modifications also belong to the scope of the present invention. .

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  10i ... Supply unit, 10o ... Discharge unit, 10w ... Case, 15a ... First piping, 15b ... Second piping, 20 ... Cell unit, 21, 22 ... First, second reflection unit, 23 ... Cell, 23s ... 30, light source unit, 30L, measuring light, 30a, light emitting unit, 30aC, wavelength control unit, 30aL, semiconductor light emitting element, 30b, drive unit, 31 ... laminate, 31L, 31La, 31Lb, light, 31Lx, light Axis, 31a ... first cladding layer, 31b ... first guide layer, 31c ... active layer, 31d ... second guide layer, 31e ... second cladding layer, 31sa ... first side surface, 31sb ... second side surface, 31w ... distance 32 ... Dielectric layer, 33 ... Insulating layer, 34a ... First electrode, 34b ... Second electrode, 35 ... Substrate, 35a-35c ... First to third parts, 36a, 36b ... First, second light Scientific part 40 ... detection part 45 ... control part 50 ... sample gas 50a ... exhalation 51 ... first substance 51b ... inter-peak region 51p ... peak 51s first absorption spectrum 52 ... second substance 52 s... First absorption spectrum 61. First substance sensor 65. First detector 66 a. Light emitting part 66 b. Light detecting part 66 c. Near infrared light 71, 71 a. Temperature control unit, 98 ... drive control unit, 99 ... stepping motor, β1 to β4 ... angle, γ ... incident angle, λ ... wavelength, λ1, λ2 ... first and second wavelengths, 110, 111, 120, 121 ... exhalation Diagnostic device, AR ... Anti-reflection coating film, Ab ... Absorption rate, BL1-BL4 ... First to fourth barrier layers, L1, L2 ... First, second light, Ll ... Low level, Lu ... High level, PR ... Partial reflection RG ... ridge waveguide, SD ... arrow direction, WL1, WL2 ... first and second quantum well layers, WLa ... first subband, WLb ... second subband, WLt ... well width, c1 ... carrier, r1, r1a ... first region, r2, r2a ... second region, r3 ... unit structure, rg1-rg7 ... region

Claims (12)

A cell part including a space into which a sample gas containing exhaled gas including a first substance and a second substance different from the first substance is introduced;
A light source unit that makes the first light of the first wavelength between the plurality of peaks of light absorption of the first substance and the second light of the second wavelength different from the first wavelength enter the space;
A detector that detects the intensity of the first light that has passed through the space into which the sample gas has been introduced and the intensity of the second light that has passed through the space into which the sample gas has been introduced;
A control unit that calculates the concentration of the second substance in the sample gas based on the intensity of the first light and the intensity of the second light;
A breath diagnosis apparatus comprising: The light source unit is
A semiconductor light emitting device that emits emitted light by energy relaxation of electrons in subbands of a plurality of quantum wells;
A wavelength controller that adjusts the wavelength of the emitted light to generate the first light and the second light;
The breath diagnosis apparatus according to claim 1, comprising: The first wavelength is not less than 7.6 micrometers and not more than 7.95 micrometers,
The breath diagnosis apparatus according to claim 1 or 2, wherein the second wavelength is not less than 8.1 micrometers and not more than 8.4 micrometers. The first substance includes water;
The breath diagnosis apparatus according to claim 3, wherein the second substance includes acetone. The first wavelength is not less than 7.6 micrometers and not more than 7.95 micrometers,
The breath diagnosis apparatus according to claim 1 or 2, wherein the second wavelength is 7.98 micrometers or more and 8.2 micrometers or less. The first substance includes water;
The breath diagnosis apparatus according to claim 5, wherein the second substance includes ethanol. The control unit performs a first operation and a second operation performed after the first operation,
The first operation includes causing the light source unit to emit the second light and causing the detection unit to detect the intensity of the second light,
The breath diagnosis according to any one of claims 1 to 6, wherein the second operation includes causing the light source unit to emit the first light and causing the detection unit to detect the intensity of the first light. apparatus. A first substance sensor for detecting a concentration of the first substance in an outer space outside the cell unit;
The control unit calculates the concentration of the second substance in the sample gas based on the concentration of the first substance detected by the first substance sensor. The breath diagnosis apparatus according to claim 1.   The breath diagnosis apparatus according to claim 1, further comprising a first detector that detects the first substance in the sample gas.   The breath diagnosis apparatus according to claim 9, wherein the detection unit includes a semiconductor sensor. The first detector is
A light emitting part for allowing near infrared light to enter the space into which the sample gas is introduced;
A light detection unit that detects the intensity of the near-infrared light that has passed through the space into which the sample gas has been introduced;
The breath diagnosis apparatus according to claim 9. The cell part is
A first reflecting portion that is reflective to the measurement light;
A second reflecting portion that is reflective to the measurement light;
Including
The space is disposed between the first reflecting portion and the second reflecting portion,
The breath diagnosis apparatus according to any one of claims 1 to 11, wherein the measurement light is reflected by the first reflection unit and the second reflection unit and passes through the space.

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