JP2007151641A - Radiation spectral densitometer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiation spectral densitometer capable of detecting the spectrums of a plurality of infrared rays of different wavelengths by a single sensor and suppressing unwanted infrared ray incidence on the sensor. <P>SOLUTION: The radiation spectral densitometer is provided with an infrared ray waveguide, an infrared ray chopper, a spectral filter, an infrared ray detector for detecting the infrared rays from an infrared ray emitter through the infrared ray waveguide, a means for calculating the density of an object component inside the infrared ray emitter from the output of the infrared ray detector, and a display and preservation means for displaying and preserving the density, wherein a plurality of openings for optically connecting the infrared ray waveguide and the infrared ray detector to the infrared ray chopper are provided and the spectral filter is arranged in at least one of the plurality of openings. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a radiation spectral densitometer for noninvasively and noninvasively measuring the concentration of a target component such as a blood component or a tissue component contained in an infrared radiator such as a human body.

  As a device for noninvasive detection of the concentration of an analyte (for example, glucose) in human tissue such as blood, there is one proposed in Patent Document 1, for example. FIG. 10 is a diagram schematically showing a configuration of a radiation spectral densitometer proposed in Patent Document 1. As shown in FIG. 10, the conventional emission spectral densitometer includes a plastic cover 62, a reflecting mirror 63, an infrared waveguide 64, an optical valve 65, an infrared filter set 66, a detector 67, an electronic circuit 68, a microcomputer 69 and A display device 60 is included.

  For example, infrared light from a target object 61 such as a human body passes through an infrared waveguide 64 inserted into a reflecting mirror 63 having a plastic cover 62 and passes through the infrared light according to time in order to start infrared measurement. Through an optical valve 5 that can be turned on or off. Thereafter, the infrared ray is detected by a detection device 67 having sensitivity to the infrared ray.

The detection device 67 includes an infrared filter set 66, and an infrared spectrum is selected by the infrared filter set 66. The detection device 67 generates an electrical signal indicating the intensity of the received infrared rays, and the electronic circuit 68 and the microcomputer 69 determine the correlation between the spectral intensity of the infrared rays radiated from the human body and the concentration of the analyte. Calculate the concentration of. The obtained concentration of the analyte is displayed on the display device 60.
JP-T-2001-503999

  However, the conventional radiation spectral densitometer as described above has the following problems. First, in order to detect a plurality of infrared spectra having different wavelengths, an infrared detector includes a multi-sensor having a plurality of sensors mounted in one package, or a plurality of sensors corresponding to each spectrum. It was used. For this reason, the difference in sensitivity between individual sensors and changes over time may cause an error in the spectrum intensity of the detected infrared, and the finite amount of infrared light may be divided by multiple sensors. There has been a problem that the light intensity of the sensor decreases, the S / N ratio decreases, and the detection sensitivity also decreases.

  Secondly, a thermopile sensor or pyroelectric sensor generally used as an infrared detection device has a characteristic of having a viewing angle, and the sensor detects incident infrared rays within such a viewing angle. Therefore, the infrared rays to be detected propagate through the infrared waveguide and pass through the optical valve. In this case, there is a certain distance between the infrared waveguide and the infrared detection device. Become. In general, since the viewing angle of a thermopile or pyroelectric sensor is very large, infrared rays from other than the infrared waveguide are incident on the infrared detection device, causing an error in the spectral intensity of the detected infrared rays.

  Therefore, the present invention has been made to solve the above-described conventional problems, and a plurality of infrared spectra having different wavelengths can be detected by a single sensor, and unnecessary infrared rays to the sensor can be detected. An object of the present invention is to provide a radiation spectral densitometer that can suppress incidence, detect an infrared spectrum with high accuracy, and measure the concentration of a target component.

In order to solve the above problems, the present invention provides:
An infrared waveguide, an infrared chopper, a spectral filter, an infrared detector for detecting infrared rays from the infrared emitter through the infrared waveguide, and an object in the infrared emitter from the output of the infrared detector Means for calculating the concentration of the component, and display storage means for displaying and storing the concentration,
The infrared chopper has a plurality of openings for optically connecting the infrared waveguide and the infrared detector,
Provided is a radiation spectral densitometer, wherein the spectral filter is placed in at least one of the plurality of openings.
With such a configuration, a plurality of infrared spectra having different wavelengths can be detected by a single infrared detector.

In the radiation spectral densitometer of the present invention, it is preferable that the opening has a diameter defined by a straight line connecting the infrared detector and an end of the infrared waveguide.
With such a configuration, it is possible to prevent unnecessary infrared rays from entering the infrared detector, detect the infrared spectrum with high accuracy, and measure the concentration of the target component.

According to the present invention, a plurality of infrared spectra having different wavelengths can be detected by a single sensor, unnecessary infrared incidence to the sensor is suppressed, the infrared spectrum is detected with high accuracy, and the target component is detected. A radiation spectrodensitometer capable of measuring the concentration can be provided.
In addition, according to the present invention, since only a single sensor is used, the sensitivity between infrared sensors when using a plurality of sensors and the correction due to changes in sensitivity over time can be increased. It is possible to provide a radiation spectral densitometer capable of accurate detection and miniaturized.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or an equivalent part, and the overlapping description may be abbreviate | omitted.

Embodiment 1
FIG. 1 is a schematic diagram showing a configuration of a preferred embodiment of a radiation spectral densitometer of the present invention. In the present embodiment, a case will be described in which a tympanic membrane that is a part of a living body is used as an infrared radiator, and a blood glucose level is measured as the concentration of a target component to be analyzed.

  As shown in FIG. 1, a radiation spectral densitometer 10 of the present embodiment includes an insertion guide 2 for insertion into the ear canal of the ear, an infrared waveguide 3 for transmitting infrared radiation due to the body temperature of the eardrum 1, and An infrared chopper 4 including a rotating plate 4a that can be rotated by a motor 4b is provided. The normal direction of the main surface of the rotating plate 4a (that is, the direction of the arrow X in FIG. 1) is substantially equal to the length direction of the infrared waveguide 3 and the direction of the light beam from the infrared sensor 6. The positional relationship among the waveguide 3, the infrared chopper 4, and the infrared sensor 6 is set.

  Here, FIG. 2 is a front view of the infrared chopper 4 as viewed from the direction of the arrow X in FIG. 1, and FIG. 3 is a view showing a cross section taken along line AA in FIG. As shown in FIGS. 1 and 2, four openings 5 are provided in the rotating plate 4 a of the infrared chopper 4, and spectral filters 5 a, 5 b and 5 c and a filter 5 d are installed in these openings 5. ing.

  The radiation spectral densitometer 10 includes a single infrared sensor 6 sensitive to infrared rays, an electronic circuit 7 for driving and controlling the infrared chopper 4 and infrared sensor 6, amplification of output signals of the infrared sensor 6, and the like. A signal processing device 8 for converting the output signal of the infrared sensor 6 from the electronic circuit 7 into the concentration of the target component, and a display for displaying the result of the signal processing device 8 to the user and storing it together with the measurement date and time. Storage means 9 is included.

  As the display storage means, for example, a monitor (display display), a storage device, an external input device, and a device including a processor for controlling them can be used. More specifically, for example, a small computer with a monitor, a small terminal, a PDA, a mobile phone, and the like can be given.

The operation method of the radiation spectral densitometer of the present embodiment having the above configuration will be described below.
First, the eardrum 1 is an infrared emitter and emits infrared rays at that temperature. There is a physical fact that an object other than an absolute temperature of 0 Kelvin emits electromagnetic waves, and the relationship between the amount of radiation, absolute temperature, and wavelength is known as Planck's law. In this Frank's law, the radiation amount of an actual object changes based on the emissivity ε (0 <ε ≦ 1), which is a coefficient based on an ideal black body, but the emissivity ε of a human skin is It is about 0.98 and has a high emissivity.

  Further, the change of the radiation spectrum having the dependency on the wavelength with respect to the ideal black body can be expressed by using the monochromatic emissivity εi indicating the emissivity ε for each wavelength. The radiation spectrum in the eardrum 1 varies depending on the components contained in the blood in the eardrum 1 and the tissue components of the eardrum 1 and directly correlates with the component concentration.

  Here, since the temperature of the eardrum 1 reflects the temperature of the hypothalamus that controls the body temperature of the brain, it can be said that the deep body temperature, which is the highest temperature in the human body, is exposed outside the body. In addition, the infrared radiation intensity of the eardrum 1 increases as the temperature rises, and is also a part that exhibits the strongest infrared radiation intensity in the human body. Furthermore, since the eardrum 1 is very thin with a thickness of about 0.1 mm, and includes a skin layer, a proper layer and a mucous membrane layer in this thickness direction, and also has blood vessels, it is the most compact compared to other places. This is a place where blood vessels and tissues including blood are formed.

  At least a radiation spectrum having information on the concentration of the target component (glucose) in the blood, that is, information on the blood glucose level, is emitted as infrared rays from the eardrum 1 due to body temperature. The radiation of an ideal black body in the normal body temperature range has an intensity distribution that becomes maximum at a wavelength of 8 μm to 11 μm. The blood sugar level is the glucose concentration in the blood, and the wavelengths that can identify glucose include 8.00 μm, 9.29 μm, 9.55 μm, 9.75 μm, 9.89 μm, and 10.98 μm. Is available.

  The infrared rays from the eardrum 1 are incident on the eardrum 1 side end portion 3a of the infrared waveguide 3 inserted into the ear canal (not shown) by the insertion guide 2 and are directly or internally reflected repeatedly. It propagates through the waveguide 3 and reaches the other end 3b. As a material constituting the insertion guide 2, for example, a thermoplastic resin such as polyacrylic acid, polystyrene, polyester, polyvinyl chloride, polycarbonate, and polypropylene can be used.

  Moreover, as a material which comprises the infrared waveguide 3, the metal with low emissivity (epsilon), such as aluminum, copper, and stainless steel, can be used, for example. In this case, a coating made of gold, silver, copper, or the like having a lower emissivity ε may be provided on at least the inner surface of the infrared waveguide 3 by, for example, vapor deposition, sputtering, or plating. In addition, as a material which comprises an infrared fiber, chalcogenite glass etc. are mentioned, for example.

  The infrared waveguide 3 can be made of a material other than these metals, for example, a thermoplastic resin such as polyacrylic acid, polystyrene, polyester, polyvinyl chloride, polycarbonate, and polypropylene. In this case, it is preferable to provide a coating made of, for example, gold, silver, or copper having a lower emissivity ε, for example, by vapor deposition, sputtering, plating, or the like on at least the inner surface of the infrared waveguide 3.

  Infrared radiation emitted from the eardrum 1 and passing through the infrared waveguide 3 is transmitted through the spectral filter 5a, 5b or 5c or the filter 5d installed in the opening 5 of the infrared chopper 4, and has a specific wavelength of the infrared radiation. Only the spectrum enters the infrared sensor 6, and the infrared sensor 6 converts the spectrum into an electric signal proportional to the intensity of the incident radiation spectrum.

  Here, the infrared chopper 4, the spectral filters 5 a, 5 b and 5 c and the filter 5 d will be described in more detail with reference to FIGS. 2 and 3. As shown in FIGS. 2 and 3, the infrared chopper 4 has a rotating plate 4a and rotating means 4b such as a motor, and the rotating plate 4a can be rotated in the direction of arrow Y by the rotating means 4b. .

  In the rotating plate 4a, four openings 5 are provided on the AA line and the BB line orthogonal to each other through the center C and at the same distance from the center C, and these openings 5 are provided. Spectral filters 5a, 5b and 5c and a filter 5d are arranged inside. That is, the rotary plate 4a is provided with spectral filters 5a, 5b and 5c and a filter 5d at equal angles and distances as viewed from the center C. In addition, what is necessary is just to provide so that the said same angle and distance may be satisfy | filled when changing the number of the openings 5. FIG.

  And the infrared chopper 4 has the opening 5 of the rotating plate 4a by the positional relationship which can connect the infrared waveguide 3 and the infrared sensor 6 optically. That is, when the opening 5 comes to the position shown in FIG. 1 due to the rotation of the rotating plate 4a, it is indicated by the line P from the infrared sensor 6 through the infrared waveguide 3 to the eardrum 1 through the opening 5. Light can pass through.

  Here, as a material constituting the rotating plate 4a, a metal having a low emissivity ε, such as aluminum, copper, and stainless steel, can be used. In this case, a coating film made of, for example, gold, silver, or copper having a lower emissivity ε may be provided on at least the surface of the rotating plate 4a by, for example, vapor deposition, sputtering, or plating.

  The rotating plate 4a can be made of a material other than these metals, for example, a thermoplastic resin such as polyacrylic acid, polystyrene, polyester, polyvinyl chloride, polycarbonate, and polypropylene. In this case, it is preferable to provide a coating made of, for example, gold, silver or copper having a lower emissivity ε, for example, by vapor deposition, sputtering, plating, or the like on at least the surface of the rotating plate 4a.

  Further, as the rotating means 4b, for example, a motor such as a DC motor, an AC motor, a stepping motor, and a servo motor can be used. In the present embodiment, the rotating plate 4a is circular and rotates, but the rotating plate 4a may be semicircular or fan-shaped, and may be repeatedly moved.

  The number of rotations of the rotating plate 4a depends on the specifications of the infrared sensor 6, but the rotating plate 4a is preferably rotated at, for example, several Hz to several tens Hz. This is because the sensitivity of a thermopile or pyroelectric sensor suitably used as the infrared sensor 6 has frequency dependency, and particularly has high sensitivity at several Hz to several tens Hz, and can be detected with high accuracy. .

  As the spectral filters 5a, 5b and 5c and the filter 5d, various spectral filters can be used. For example, a narrow band filter manufactured by US JDS Uniphase or Spectrogen in Sweden can be preferably used. is there. This preferable narrow-band filter is obtained by laminating a plurality of layers having different refractive indexes by vapor deposition, sputtering, or the like on a substrate transparent to a spectral wavelength composed of, for example, Si, Ge, ZnSe, or the like. Is a thing

  However, in the present embodiment, the spectral filters 5a, 5b and 5c and the filter 5d are selected so as to be able to separate wavelengths capable of identifying glucose, and the filter 5d recognizes glucose. A substrate made of a single material that transmits all of the above infrared rays and does not have the impossible characteristics is used. Therefore, the filter 5d is not provided, and the opening 5 in which the filter 5d is disposed may be used as it is.

  Various infrared sensors 6 can be used. For example, a thermopile and a pyroelectric sensor having sensitivity to infrared rays can be used. As a commercially available product, for example, a product of Nippon Ceramic Co., Ltd. or PerkinElmer, USA can be suitably used. In the present embodiment, a thermopile is used.

  Here, FIG. 4 shows an example of an output pattern obtained from the infrared sensor 6 when the radiation spectral densitometer 10 of the present embodiment having the configuration shown in FIG. 1 is operated. In FIG. 4, the horizontal axis indicates time (unit is arbitrary), and the vertical axis is the intensity (unit is arbitrary) of the output electric signal of the infrared sensor 6. The rotational movement of the infrared chopper 4 is controlled by an electronic circuit 7, and the infrared rays from the infrared waveguide 3 are transmitted from the infrared sensor 6 and the infrared waveguide by the spectral filters 5 a, 5 b and 5 c and the filter 5 d at a certain time interval. 3 is incident on the infrared sensor 6 only at the moment when it is optically connected to 3 and outputs an electrical signal proportional to the incident intensity.

  Moreover, since an electrical signal is periodically output by the rotational movement of the rotating plate 4a of the infrared chopper 4, it is preferable to obtain a waveform indicating an average value of a plurality of electrical signals using the electronic circuit 7. A peak A in FIG. 4 corresponds to a multiple-time average waveform of the infrared sensor 6 corresponding to the infrared light transmitted through the filter 5d. Similarly, the peak B corresponds to the spectral filter 5a, the peak C corresponds to the spectral filter 5b, and the peak D corresponds to the spectral filter 5c.

From the peak value of the electrical output signal of the infrared sensor corresponding to each of the spectral filters 5a, 5b and 5c and the filter 5d obtained as described above, the signal processing device 9 calculates the glucose concentration as a blood glucose level as follows. calculate.
First, the peak A indicating the infrared intensity transmitted through the filter 5d has a direct correlation with the temperature of the eardrum 1. Similar to the ear thermometer and the non-contact radiation thermometer, the relationship between the integral value of the ideal black body radiation spectrum and the integral value of the radiation spectrum of the eardrum 1 at a certain temperature is expressed by the Stefan-Boltzmann law. Are in a relationship. Therefore, the temperature of the eardrum 1 can be calculated from the peak A.

  Also, the radiation spectrum intensity of the ideal black body is given by Planck's law. From Kirchhoff's law showing the relationship between the absorptance and the emissivity, the absorptance increases as the glucose concentration increases, and at the same time, the monochromatic emissivity εi Also gets higher. That is, the peaks B and C, which are infrared intensities transmitted through the spectral filters 5a, 5b and 5c, which are narrowband filters in a wavelength band capable of recognizing glucose, and the radiation of an ideal black body at the temperature of the eardrum 1 By calculating the monochromatic emissivity εi, which is the ratio of the spectral intensity, the glucose concentration that is the blood glucose level can be obtained.

  Here, the monochromatic emissivity εi is calculated from each of the three spectral filters. The average value of the emissivity εi is the glucose concentration, or the ideal black body at the total intensity of the three peak values and the wavelengths of the three spectral filters. It is also possible to calculate the glucose concentration from the combined monochromatic emissivity with the total emission spectrum intensity.

  In general, the bandwidth of a narrow band filter, which is a spectral filter, is about ± 1% of the center wavelength with a half-value width of transmittance. For example, when the center wavelength is 10 μm, the full width at half maximum is ± 0.1 μm. That is, in the case of a spectral filter, an infrared radiation spectrum other than the wavelength capable of recognizing glucose is transmitted, thereby lowering the recognition accuracy. Therefore, it is beneficial to install a plurality of spectral filters as in this embodiment to increase the recognition accuracy.

  Alternatively, in order to correct the degree of influence of components other than glucose, such as albumin, which is also a blood component, entering the bandwidth of a narrow-band filter that is a spectral filter capable of recognizing glucose, at least one of the three spectral filters It is also possible to use a spectral filter capable of recognizing the component concentration of more than one sheet so that this component can be obtained.

  Here, four openings 5 are provided in the infrared chopper 4, one is used for measuring the temperature of the eardrum 1, and the remaining three are provided with spectral filters capable of recognizing glucose. In addition, one or more spectral filters capable of recognizing the target component are sufficient.

  The sensitivity of the thermopile used for the infrared sensor 6 varies depending on the temperature of the thermopile, and the output electrical signal with respect to the incident infrared intensity varies. Therefore, when using a thermopile, although not shown, it is also useful to detect the temperature of the thermopile by installing a thermistor, a resistance temperature detector, a thermocouple, or the like and thereby perform thermopile sensitivity correction. The same applies to the case where a pyroelectric sensor is used. However, in the case of a pyroelectric sensor, the output of an electric signal is only at the moment when there is a change in incident infrared intensity.

  That is, when the thermopile is used as the infrared sensor 6, the infrared ray from the rotary plate 4a is detected when the rotary plate 4a portion of the infrared chopper 4 faces the thermopile. As described above, since at least the surface of the rotating plate 4a is made of a low emissivity material, it hardly emits infrared rays, but outputs an electrical signal corresponding to the rotating plate 4a.

  On the other hand, when the pyroelectric sensor is used as the infrared sensor 6, the infrared ray from the rotating plate 4a is not detected even if the rotating plate 4a portion of the infrared chopper 4 faces the pyroelectric sensor. However, when the pyroelectric sensor changes from the time point facing the rotating plate 4a to the time point facing the spectral filter (that is, when the pyroelectric sensor faces the boundary between the rotating plate 4a and the spectral filter) , When the pyroelectric sensor changes from the time when it faces the spectral filter to the time when it faces the rotating plate 4a (that is, when the pyroelectric sensor faces the boundary between the spectral filter and the rotating plate 4a), An electrical signal is output to

  In the radiation spectral densitometer 1 of the present embodiment, at least the insertion guide 2, the infrared waveguide 3, the infrared chopper 4, the spectral filter 5, the infrared sensor 6, and the electronic circuit 7 are integrated. Is desirable. The electronic circuit 7 and the signal processing means 8 or the signal processing means 8 and the display storage means 9 are physically separated, but if they are connected by wire or wirelessly, they are inserted into the ear. Therefore, it is possible to reduce the size and ease of insertion of the device, and to make it possible for the user to recognize the display contents with certainty.

  According to the radiation spectral densitometer 10 of Embodiment 1 of the present invention as described above, a plurality of openings are provided on the infrared chopper, and a plurality of spectral filters having different spectral wavelengths are provided on at least one of the openings. The infrared radiation spectrum that has passed through the aperture and the spectral filter can be detected by a single infrared sensor. Sensitivity correction between infrared sensors when multiple infrared sensors are used, and changes in sensitivity over time In addition to being able to perform highly accurate detection without the need for correction, it is possible to reduce the size of the apparatus.

<< Embodiment 2 >>
Next, a second embodiment of the radiation spectral densitometer of the present invention will be described. The radiation spectral densitometer of the second embodiment is obtained by replacing the infrared chopper 4 in the radiation spectral densitometer 10 of the first embodiment shown in FIG. 1 with a different configuration, and the configuration other than the infrared chopper 4 is implemented. This is the same as the radiation spectral densitometer 10 of the first embodiment.
Hereinafter, the infrared chopper 14 provided in the radiation spectral densitometer of the second embodiment will be described. FIG. 5 is a front view of the rotating plate 14a of the infrared chopper 14 provided in the radiation spectral densitometer of the present embodiment, and FIG. 6 is a cross-sectional view taken along line AA in FIG.

  In FIG. 6, the infrared chopper 14 includes a rotating plate 14a and rotating means 14b such as a motor as in the first embodiment, and four openings 15 are provided in the rotating plate 14a at equal distances and angles. However, in the present embodiment, as can be seen from FIGS. 5 and 6, the three spectral filters 5 a above the openings 15 (positions covering the openings 15 on the left surface of the rotating plate 14 a in FIG. 6). It is characterized in that 5b and 5c are provided.

Here, the viewing angle of the infrared sensor 6 in the radiation spectral densitometer of the present embodiment will be described. 7 and 8 are schematic diagrams for explaining the viewing angle of the infrared sensor 16.
In FIG. 7, as indicated by alternate long and short dash lines l ₁ and l ₂ , an infrared incident range (a range surrounded by alternate long and short dash lines l ₁ and l ₂ ) that can be detected by the infrared sensor 6 and the spectral filter 5a is an infrared waveguide. 3 and a space between the infrared sensor 6 and the spectral filter 5a. For this reason, infrared rays other than the infrared waveguide 3 having useful information may be taken into the infrared sensor 6, which causes a decrease in accuracy.

  In general, the infrared sensor 6 has a viewing angle of about 100 ° in all angles when a special and expensive lens is not attached, and the viewing range is about 10 mm away and a diameter of about 24 mm. If the diameter of the infrared waveguide 3 to be inserted into the ear is 3 mm, most of the infrared light incident on the infrared sensor 6 comes from other than the infrared waveguide 3 as it is.

Therefore, in the present embodiment, as shown in FIG. 8, the diameter of the opening 15 on the rotating plate 14a is a straight line (solid line) connecting the infrared sensor 6 and the end portions 3b ₁ and 3b _{2 of the} infrared waveguide 3. The radiation spectral densitometer is designed so that m ₁ and m ₂ ) are equal to or less than the maximum width of the portion intersecting the rotating plate 14a. With such a configuration, it is possible to more reliably detect only infrared light from the infrared waveguide 3 that provides useful information.

Here, for easy understanding, FIG. 9 shows an enlarged view of the vicinity of the opening 15 of the rotating plate 14a in FIG. As shown in FIG. 9, in the present embodiment, the diameter n ₁ of the opening 15 on the rotating plate 14a is a straight line (solid line) connecting the infrared sensor 6 and the end portions 3b ₁ and 3b _{2 of the} infrared waveguide 3. The radiation spectral densitometer is designed so that m ₁ and m ₂ ) substantially coincide with the maximum width n _{2 of the} portion intersecting the rotating plate 14a, that is, satisfy the relational expression: n ₁ ≈n ₂ .

Furthermore, the design as described above, the thickness of the rotational plate 14a, distance Z ₁ and the rotation plate 14a and the infrared sensor of the diameter of the opening 15, the diameter of the infrared waveguide 3, an infrared waveguide 3 and the rotary plate 14a 6 by adjusting at least one of the distance Z _{2 to} 6 and the viewing angle of the infrared sensor 6.

As described above, in this embodiment, the principle described with reference to FIGS. 8 and 9 is applied, and the infrared chopper 14 and the spectral filters 5a, 5b, and 5c having the structures shown in FIGS. 5 and 6 are used. 8 and 9, four openings 15 are provided on the rotating plate 14a, but a straight line (solid line) connecting the infrared sensor 6 (see FIG. 1) to the ends 3b ₁ and 3b ₂ of the infrared waveguide 3 is shown. m ₁ and m ₂ ) define the diameters of the four openings 15 such that the maximum width n _{2 of the} portion intersecting the rotating plate 14 a is the diameter of the opening 15.

  Although the spectral filters 5a, 5c and 5c in FIGS. 5 and 6 are configured not to be inserted into the opening 15 but placed on the opening 15, the operation method of the radiation spectral densitometer of the present embodiment is as follows. The operation method of the radiation spectral densitometer of the first embodiment using the infrared chopper 4 described with reference to FIGS. 2 and 3 is not changed at all.

  As described above, according to the radiation spectral densitometer of the second embodiment of the present invention, by defining the opening diameter on the infrared chopper so that only infrared rays from the infrared waveguide are incident on the infrared sensor, Even if an infrared sensor having a wide viewing angle is used, incidence of information other than infrared with information can be prevented and high detection accuracy can be obtained.

  In the above embodiment, the case of the human eardrum has been described as the infrared radiator, but the radiation spectral densitometer of the present invention can also be used to analyze infrared radiators such as other biological parts. Is possible. Further, in the above embodiment, the case where the blood glucose level (glucose concentration) is obtained using glucose as the target component has been described. However, if the radiation spectral densitometer of the present invention is used, other blood components and tissue components are similarly used. It is possible to measure.

  In the second embodiment, the relationship between the opening provided in the rotating plate of the infrared chopper and the maximum width of the portion where the straight line connecting the end of the infrared waveguide from the infrared sensor intersects the rotating plate. Although described, it is preferable that the same relationship is satisfied also in the first embodiment.

  In Embodiments 1 and 2, four openings are provided, and one of them is not provided with a spectral filter. However, the number of these openings is within a range that does not impair the effect of the present invention. If necessary, it can be adjusted appropriately. For example, a window material that does not have spectral characteristics (for example, silicon, germanium, barium fluoride, thallium bromoiodide, thallium bromochloride, sodium chloride, potassium bromide, potassium chloride, iodine) A window material made of cesium iodide, zinc selenide, or zinc sulfide) may be disposed.

  As described above, the radiation spectral densitometer according to the present invention includes a plurality of apertures on the infrared chopper, and a plurality of apertures and spectral filters by providing spectral filters having different spectral wavelengths on at least one or more apertures. It is possible to detect the emission spectrum of the emitted infrared radiation that has passed through a single infrared sensor, and it is necessary to correct the sensitivity between infrared sensors when multiple infrared sensors are used, and to correct the change in sensitivity over time. It is useful as a method for noninvasively and noninvasively measuring the blood component and tissue component concentration of the human body, with the effect of enabling highly accurate detection and miniaturization of the device. It is.

It is a schematic diagram which shows the structure of suitable one Embodiment of the radiation spectral densitometer of this invention. It is a front view of the infrared chopper 4 seen from the direction of the arrow X in FIG. It is a figure which shows the AA line cross section in FIG. It is a figure which shows an example of the output pattern obtained from the infrared sensor 6 when the radiation spectral densitometer 10 of Embodiment 1 of this invention which has the structure shown in FIG. 1 is operated. It is a front view of the rotation board 14a among the infrared choppers 14 with which the radiation spectral densitometer of Embodiment 2 of this invention is equipped. It is a figure which shows the AA line cross section in FIG. It is the schematic for demonstrating the viewing angle of the infrared sensor 16 in Embodiment 2 of this invention. It is another schematic diagram for demonstrating the viewing angle of the infrared sensor 16 in Embodiment 2 of this invention. It is the figure which expanded the opening 15 vicinity of the rotating plate 14a in FIG. It is a figure which shows typically the structure of the conventional radiation spectral densitometer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tympanic membrane 2 Insertion guide 3 Infrared waveguide 4, 14 Infrared chopper 5, 15 Opening 5a, 5b, 5c, 15a, 15b, 15c Spectral filter 5d Filter 6 Infrared sensor 7 Electronic circuit 8 Signal processing means 9 Display storage means 60 Display Device 61 Target object 62 Plastic cover 63 Reflector 64 Infrared waveguide 65 Optical valve 66 Infrared filter set 67 Detector 68 Electronic circuit 69 Microcomputer

Claims (6)

An infrared waveguide, an infrared chopper, a spectral filter, an infrared detector for detecting infrared rays from the infrared emitter through the infrared waveguide, and an object in the infrared emitter from the output of the infrared detector Means for calculating the concentration of the component, and display storage means for displaying and storing the concentration,
The infrared chopper has a plurality of openings for optically connecting the infrared waveguide and the infrared detector,
An emission spectral densitometer, wherein the spectral filter is disposed in at least one of the plurality of openings.   The radiation spectral densitometer according to claim 1, wherein the opening has a diameter defined by a straight line connecting the infrared detector and an end of the infrared waveguide. The infrared radiator is at least a part of a living body, and the target component is a blood component of the living body;
The radiation spectral densitometer according to claim 1 or 2. The infrared waveguide is a hollow infrared waveguide or an infrared fiber;
The radiation spectral densitometer according to claim 3. A window material having no spectral characteristics is disposed in at least one of the plurality of openings, or a spectral filter is not disposed;
The radiation spectral densitometer according to claim 3. The part is the eardrum and the blood component is glucose;
The radiation spectral densitometer according to claim 3, wherein:

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