JP4901432B2 - Component concentration measuring device - Google Patents

Description

  The present invention relates to a non-invasive component concentration measuring apparatus for an object to be measured such as a human being, an animal, or a fruit, and a control method for the component concentration measuring apparatus.

  With the aging of society, dealing with adult diseases is becoming a major issue. In blood glucose level and other tests, blood collection is necessary, which places a heavy burden on the patient. Therefore, a non-invasive component concentration measurement apparatus that does not collect blood has attracted attention. As a non-invasive component concentration measuring device that has been developed so far, the skin is irradiated with electromagnetic waves and absorbed by blood molecules to be measured, for example, glucose molecules in the case of blood glucose levels, and heated locally. A photoacoustic method that observes a sound wave generated from a living body due to thermal expansion has attracted attention.

  However, the interaction between glucose and electromagnetic waves is small, and there is a limit to the intensity of electromagnetic waves that can be safely irradiated to a living body, so that a sufficient effect has not been achieved in measuring blood glucose levels in the living body.

  7 and 8 are diagrams showing a configuration example of a conventional blood component concentration measuring apparatus using a photoacoustic method as a conventional example. FIG. 7 shows a first conventional example using a light pulse as an electromagnetic wave (see, for example, Non-Patent Document 1). In this example, blood glucose, that is, glucose is the measurement target as the blood component. In FIG. 7, a driving circuit 604 supplies a pulsed excitation current to a pulse light source 616, the pulse light source 616 generates a light pulse having a sub-microsecond duration, and the generated light pulse irradiates the object 610 to be measured. Is done. The light pulse generates a sound wave called a pulsed photoacoustic signal inside the object to be measured 610, and the generated sound wave is detected by the ultrasonic detector 613 and further converted into an electric signal proportional to the sound pressure.

  The waveform of the converted electric signal is observed by the waveform observer 620. This waveform observer 620 is triggered by a signal synchronized with the excitation current, the converted electric signal is displayed at a fixed position on the tube surface of the waveform observer 620, and the converted electric signal is measured by integrating and averaging. can do. By analyzing the amplitude of the electrical signal thus obtained, the blood sugar level inside the device under test 610, that is, the amount of glucose is measured. In the case of the example shown in FIG. 7, an optical pulse having a sub-microsecond pulse width is repeatedly generated at a maximum of 1 kHz, and 1024 optical pulses are averaged to measure the electrical signal. However, sufficient accuracy is obtained. It is not done.

  Therefore, a second conventional example using a light source that is continuously intensity-modulated has been disclosed for the purpose of improving accuracy. FIG. 8 shows the configuration of a second conventional apparatus (see, for example, Patent Document 1). In this example as well, blood sugar is the main measurement target, and high accuracy is attempted using a plurality of light sources having different wavelengths. In order to avoid complicated explanation, the operation when the number of light sources is 2 will be described with reference to FIG. In FIG. 8, light sources having different wavelengths, that is, a first light source 601 and a second light source 605 are driven by a drive circuit 604 and a drive circuit 608, respectively, and output continuous light.

  Light output from the first light source 601 and the second light source 605 is intermittently driven by a chopper plate 617 that is driven by a motor 618 and rotates at a constant rotational speed. Here, the chopper plate 617 is formed of an opaque material, and a relatively small number of openings are formed on the circumference around which the light of the first light source 601 and the second light source 605 passes with the axis of the motor 618 as the center. Is formed.

With the above-described configuration, the light output from each of the first light source 601 and the second light source 605 is intensity-modulated with the disjoint modulation frequency f ₁ and modulation frequency f ₂ and then combined by the combining unit 609. The object to be measured 610 is irradiated as one light beam.

Inside the object to be measured 610 photoacoustic signal having the frequency f ₁ is generated by the light of the first light source 601, the photoacoustic signal having the frequency f ₂ is generated by the light of the second light source 605, these photoacoustic The signal is detected by the acoustic sensor 619 and converted into an electric signal proportional to the sound pressure, and the frequency spectrum is observed by the frequency analyzer 621. In this example, the wavelengths of the plurality of light sources are all set to the absorption wavelength of glucose, and the intensity of the photoacoustic signal corresponding to each wavelength is measured as an electrical signal corresponding to the amount of glucose contained in the blood. The

Here, the relationship between the intensity of the measured value of the photoacoustic signal and the value obtained by measuring the glucose content by separately collected blood is stored in advance, and the amount of glucose is measured from the measured value of the photoacoustic signal. ing.
JP-A-10-189 University of Oulu (University of Oulu, Finland) thesis “Pulsed photoacoustic techniques and glouces determination in human blood and tissue” (IBS 951-42-6690-0, ftk / 95.

  The conventional example described above has the following problems. In the measurement of the component concentration by the photoacoustic method, a local temperature change occurs in the portion to be measured of the object to be measured due to intermittent emission of light. Since the component to be measured included in the measurement object has temperature dependency, the photoacoustic signal generated by the measurement object also has temperature dependency. Due to the temperature dependence of the photoacoustic signal, there is a problem that the measurement accuracy of the component concentration measuring apparatus is significantly lowered.

  It is an object of the present invention to provide a component concentration measuring apparatus capable of measuring a component concentration of an object to be measured with high accuracy, and a control method for the component concentration measuring apparatus, which prevent a decrease in measurement accuracy due to temperature dependence. .

(Means for solving the problem)
In order to solve the above problems, a component concentration measuring apparatus according to the present invention is characterized in that a temperature change of an object to be measured is obtained and correction is performed based on the temperature change.

Specifically, the component concentration measuring apparatus according to the present invention includes an optical modulation unit that electrically modulates intensity of two light beams having different wavelengths with signals of the same frequency and opposite phase, and the optical modulation unit modulates the light. Optical combining means for combining the two light beams, light emitting means for emitting the light combined by the optical combining means to the object to be measured, and temperature measuring means for measuring the temperature of the object to be measured And detecting a photoacoustic signal generated from the measured object by light from the light emitting means, obtaining a temperature change of the measured object from the temperature of the measured object measured by the temperature measuring means, Sound wave detecting means for performing correction based on the change , wherein the temperature measuring means transmits the light from the light emitting means, contacts the object to be measured, and has thermal conductivity, thereby measuring the object to be measured. Window that transfers the heat of the object, the window at the opening A window frame that holds the temperature measuring device and the light emitting means inside and has heat conductivity and transmits heat of the object to be measured transmitted to the window; and a temperature of the window frame. A temperature measuring device for measuring the temperature of the object to be measured by measuring, so that the light from the light emitting means reflected or scattered by the object to be measured does not cross the optical path of the light passing through the window Formed on the surface of the window to reflect light reflected or scattered by the object to be measured, or light from the light emitting means reflected or scattered by the object to be measured passes through the window. A linear polarizing plate or optical isolator that is mounted on the window so as to cross the optical path of the light passing therethrough and transmits light from the light emitting means, or mounted on the inner surface of the window frame and reflected by the object to be measured Or out of the scattered light passing through the window Characterized in that it comprises a light absorbing material that absorbs light.

The component concentration measuring apparatus obtains the local temperature change of the object to be measured, and performs arithmetic correction based on the temperature change to prevent a decrease in measurement accuracy due to temperature dependence, The component concentration of the object to be measured can be measured with high accuracy.
The component concentration measuring apparatus can bring the window into contact with the object to be measured without preventing the window from emitting light to the object to be measured. The temperature can be measured more accurately.

  In the component concentration measuring apparatus according to the present invention, the window and the window frame are preferably formed of a material having a thermal conductivity of 230 W / m · K or more.

  In the component concentration measuring apparatus, the window and the window frame can easily transmit heat of the object to be measured, and the temperature measuring device can measure the temperature of the object to be measured more accurately.

Since the component concentration measuring apparatus includes a light reflecting film, it is possible to reduce the situation where light reflected or scattered by the object to be measured is transmitted through the window and absorbed by the window frame to generate heat, and the temperature measurement is performed. The instrument can measure the temperature of the object to be measured more accurately.

Since the component concentration measuring apparatus includes a linearly polarizing plate or an optical isolator, it is possible to reduce the situation where light reflected or scattered by the object to be measured passes through the window and is absorbed by the window frame to generate heat, The temperature measuring device can measure the temperature of the object to be measured more accurately.

Additional constituent concentration measuring apparatus, comprising a light absorbing material, wherein it is possible to reduce the situation in which light reflected or scattered by the object to be measured generates heat is absorbed by the window frame, wherein the temperature measuring device of the object to be measured The temperature can be measured more accurately.

  In the component concentration measuring apparatus according to the present invention, it is preferable to include a heat insulating material that covers the surface of the window and / or covers the surface of the window frame so as not to cross the optical path of the light from the light emitting means.

  In the component concentration measuring device, the heat insulating material reduces the influence of heat transmitted through the window and / or the window frame, and the temperature measuring device can measure the temperature of the object to be measured more accurately.

  The present invention can provide a component concentration measuring apparatus and a method for controlling the component concentration measuring apparatus that can prevent the measurement accuracy from being lowered due to temperature dependency and can measure the component concentration of the measurement object with high accuracy.

(Best Mode for Carrying Out the Invention)
Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiment described below is an example of the configuration of the present invention, and the present invention is not limited to the following embodiment. In addition, in the component concentration measuring apparatus according to each embodiment, a part that can be realized by a normal technique such as a power source or a control unit that controls the entire operation is not shown, and the same members and the same parts are denoted by the same reference numerals. .

  FIG. 1 shows a schematic diagram of a component concentration measuring apparatus according to this embodiment. The component concentration measuring apparatus 100 according to the present embodiment is modulated by the light modulating unit 110 that electrically modulates the intensity of two waves of different wavelengths with signals of the same frequency and opposite phase, and the light modulating unit 110. Optical combining means 120 for combining two light beams, light emitting means 140 for emitting the light combined by the optical combining means 120 to the measurement object 199, and temperature measurement means for measuring the temperature of the measurement object 199 200 and a photoacoustic signal generated from the measured object 199 by the light from the light emitting means 140, the temperature change of the measured object 199 is obtained from the temperature of the measured object 199 measured by the temperature measuring means 200, and the temperature And a sound wave detection unit 150 that performs correction based on the change. Furthermore, the light modulation means 110 in FIG. 1 includes two drive circuits 111a and 111b, two light sources 112a and 112b, a delay adjuster 113, and a transmitter 114. 1 includes a sound wave detector 151, a preamplifier 152, a phase detection amplifier 153, a photoacoustic signal output terminal 154, and a component concentration calculation unit 155. 1 includes a window 210, a temperature measuring device 220, and a temperature signal output terminal 230.

  An example of the light source 112 is a distributed feedback semiconductor laser (DFB-LD). Here, it is preferable that the light sources 112a and 112b have different wavelengths and output light having an absorption wavelength of the measurement object 199. In the component concentration measuring apparatus 100 of FIG. 1, the oscillation wavelength of the light source 112a is 1.38 μm, and the oscillation wavelength of the light source 112b is 1.61 μm. Moreover, it is preferable that the light source 112 can change the wavelength of the light output by heating or cooling with a heater or a Peltier element. For example, the light source 112 has a wavelength stability of 0.1 nm and can stabilize the temperature of the light source 112 in units of 0.1 ° C.

  For example, a drive circuit 111a that supplies power to the light source 112a is connected to the light source 112a, and a drive circuit 111b that supplies power to the light source 112b is connected to the light source 112b. For example, the drive circuit 111 directly modulates the light output from the light source 112 at a frequency of 500 kHz. The transmitter 114 generates a pulse train having an arbitrary frequency, for example, a frequency of 1 kHz to 1 MHz, and outputs this to the drive circuits 111a and 111b. The delay adjuster 113 can give a delay with an accuracy of, for example, 0.1 ns, and gives a delay of half the cycle to the pulse train generated by the transmitter 114 in order to drive the light sources 112a and 112b in opposite phases. Adjust to

  The light propagation unit 130a connects, for example, between the light source 112a and an optical input terminal (not shown) of the optical multiplexing unit 120. Moreover, the light propagation means 130b connects between the light source 112b and the optical input terminal of the optical multiplexing means 120, for example. An example of the optical multiplexing means 120 is an optical coupler. The light propagation means 130 includes, for example, an optical fiber or an optical waveguide.

  The light emitting means 140 is connected to, for example, a light output terminal (not shown) of the optical multiplexing means 120. Here, the light emitting means 140 is preferably provided with an emission port 141 at the tip. Examples of the exit 141 include an optical fiber collimator, a material made of BK7 (registered trademark), SFL-11 (registered trademark), a quartz or sapphire total reflection prism, or a ferrule.

  In the device under test 199, light is photothermally converted from the light emitting means 140, and heat is generated. The measurement object 199 includes a human body or a part of the human body, for example, a finger. If the measured object 199 is a finger, the component concentration measuring apparatus 100 can measure the concentration of glucose in blood. Examples of the measurement object 199 include, for example, experimental rats, fruits such as mandarin oranges, or a sample collected from a human body or an experimental rat. If the DUT 199 is a fruit, the component concentration measuring apparatus 100 can measure the sugar content of the fruit, that is, the sweetness of the fruit.

  The heat generated in the device under test 199 is measured by the temperature measuring device 220 through the window 210, for example. For example, the temperature measuring device 220 outputs the measured temperature of the measured object 199 to the temperature signal output terminal 230. In addition, for example, a component concentration calculation unit 155 is connected to the temperature signal output terminal 230. For example, the component concentration calculation unit 155 obtains a temperature change of the measurement object 199 based on the temperature signal output from the temperature signal output terminal 230 and corrects based on the temperature change. This correction value S ′ is expressed by Equation 1.

ここで、ｓは光音響信号の強度、χは２波長の光の吸光度差温度係数、及び、ΔＴは被測定物１９９の温度変化である。

Here, s is the intensity of the photoacoustic signal, χ is an absorbance difference temperature coefficient of light of two wavelengths, and ΔT is a temperature change of the object 199 to be measured.

  The device under test 199 from which light is emitted from the light emitting means 140 generates a photoacoustic signal by the photoacoustic effect. The sound wave detector 151 detects, for example, a photoacoustic signal generated by the measurement object 199 and converts it into an electrical signal. Here, it is preferable that the sound wave detector 151 adjusts the resonance frequency at which the detection sensitivity is highest to a frequency that matches the modulation frequency of the light modulator 110, for example, 500 kHz. An example of the sound wave detector 151 is an ultrasonic sensor. For example, the preamplifier 152 amplifies and outputs an electrical signal from the sound wave detector 151. For example, the phase detection amplifier 153 extracts an electrical signal having the same frequency component as the modulation frequency of the optical modulation unit 110 and outputs the electrical signal to the photoacoustic signal output terminal 154. For example, a component concentration calculation unit 155 is connected to the photoacoustic signal output terminal 154. The component concentration calculation unit 155 calculates the component concentration of the device under test 199 based on, for example, an electrical signal output from the photoacoustic signal output terminal 154. The component concentration M of the object 199 to be measured is expressed by Equation 2.

ここで、α^（Ｗ）は背景（主に水）の吸光度、α^（ｇ）は測定対象となる成分（例えば、血液）の吸光度、ｓ_１は１波長の光音響信号の強度、及び、ｓ’は数１の補正値である。

Here, α ^(W) is the absorbance of the background (mainly water), α ^(g) is the absorbance of the component to be measured (for example, blood), s ₁ is the intensity of the photoacoustic signal of one wavelength, and s 'Is the correction value of Equation 1.

  The component concentration measuring apparatus 100 can be controlled as follows. In the control method of the component concentration measuring apparatus according to the present embodiment, the light modulation means 110 electrically modulates the intensity of two waves of different wavelengths with signals of the same frequency and opposite phase, and the light multiplexing means 120 The two light beams modulated by the modulating unit 110 are combined, the light emitting unit 140 emits the light combined by the optical combining unit 120 to the object to be measured 199, and the temperature measuring unit 200 detects the object to be measured 199. The temperature is measured, and the sound wave detection means 150 detects the photoacoustic signal generated from the measurement object 199 by the light from the light emitting means 140, and the measurement object from the temperature of the measurement object 199 measured by the temperature measurement means 200. A temperature change of 199 is obtained, and correction is performed based on the temperature change. As described above, the component concentration measurement device and the control method of the component concentration measurement device according to the present embodiment obtain the local temperature change of the object 199 to be measured, and perform arithmetic correction based on the temperature change. Therefore, it is possible to prevent a decrease in measurement accuracy due to temperature dependency and to measure the component concentration of the measurement object 199 with high accuracy.

  Here, in the control method of the component concentration measurement apparatus according to the present embodiment, the temperature measurement unit 200 is in contact with the measurement object 199 while the temperature measurement unit 200 measures the temperature of the measurement object 199. Is preferred. In FIG. 1, the window 210 of the temperature measuring means 200 is in contact with the object to be measured 199. The component concentration measurement apparatus 100 makes the temperature measurement unit 200 contact the measurement object 199, whereby the temperature of the measurement object 199 is easily transmitted to the temperature measurement unit 200, and the temperature measurement unit 200 determines the temperature of the measurement object 199. It can be measured more accurately.

  Hereinafter, the component concentration measuring apparatus according to the present embodiment will be described in more detail. FIG. 2 shows a longitudinal sectional view of a component concentration measuring apparatus having a casing. As shown in FIG. 2, in the component concentration measuring apparatus according to the present embodiment, the temperature measuring means measures the temperature of the window 210 that transmits the light from the light emitting means 140 and the object to be measured (not shown). And a window frame 240 that holds the window 210 and mounts the temperature measuring device 220. The window frame 240 is fixed inside and further includes a housing 300 that houses the window 210 and the temperature measuring device 220. It is preferable. The housing 300 is, for example, a plastic clip-type housing including a pinching mechanism 300c having screws 310 and a spring 320 and housing bodies 300a and 300b. The housing 300 houses, for example, the sound wave detector 151 on the housing body 300a side, and houses the light emitting means 140, the window 210, and the temperature measuring device 220 on the housing body 300b side. By tightening the screw 310, the object to be measured can be sandwiched between the casing main bodies 300a and 300b.

  The temperature measuring device 220 is preferably disposed near the window 210 and the object to be measured. Examples of the temperature measuring device 220 include temperature sensors such as platinum resistors and thermistors. The cord 220a is connected to the temperature measuring device 220, for example, and transmits a temperature signal measured by the temperature measuring device 220. For example, the light emitting means 140 is mounted with a right-angle prism as the emission port 141 at the tip. The code 151a is connected to, for example, the sound wave detector 151 and transmits a photoacoustic signal detected by the sound wave detector 151.

  In the component concentration measuring apparatus 100, the window 210 can be brought into contact with the object to be measured without preventing the window 210 from emitting light to the object to be measured, and the temperature measuring device 220 can more accurately set the temperature of the object to be measured. Can be measured. At this time, it is preferable that the temperature measuring device 220 is slightly raised from the housing 300. Heat conduction from the object to be measured can be improved, the object to be measured can be easily sandwiched, and the object to be measured can be strongly pressed against the window 210.

In the component concentration measuring apparatus according to this embodiment, the window 210 and the window frame 240 are preferably formed of a material having a thermal conductivity of 230 W / m · K or more. An example of the material of the window 210 is sapphire. The material of the window frame 240 includes aluminum, copper, gold, or silver. Among the materials used for the window 210 and the window frame 240, silver has the highest thermal conductivity, and the thermal conductivity of silver is 420 W / m · K. Moreover, in order to shorten the time until the temperature of the window 210 becomes constant after the object to be measured contacts, it is preferable that the window frame 240 has a small volume, for example, 3 cm ³ or less. In the component concentration measuring apparatus 100, the window 210 and the window frame 240 can easily transmit the heat of the object to be measured, and the temperature measuring device 220 can measure the temperature of the object to be measured more accurately.

  When light reflected or scattered by the object to be measured passes through the window 210, the light may be absorbed by the window frame 240 and generate heat. Due to this heat, the temperature measuring device 220 may not be able to accurately measure the temperature of the object to be measured. In the component concentration measuring apparatus according to the present embodiment, the window 210 is mounted so that the linearly polarizing plate 250 that transmits the light from the light emitting means 140 intersects the optical path of the light from the light emitting means 140. preferable. In FIG. 2, the linear polarizing plate 250 is mounted so as to be positioned between the emission port 141 and the window 210. In addition, an optical isolator (not shown) may be mounted instead of the linear polarizing plate 250, and it is preferable to mount an optical isolator using a Faraday rotator having the best extinction ratio. The linearly polarizing plate 250 does not transmit the light reflected or scattered by the object to be measured, and the component concentration measuring apparatus 100 allows the light reflected or scattered by the object to be measured to pass through the window 210 and be absorbed by the window frame 240. Therefore, the temperature measuring device 220 can measure the temperature of the object to be measured more accurately.

In the component concentration measuring apparatus according to the present embodiment, it is preferable to include a heat insulating material 270 that covers the surface of the window frame 240. As the heat insulating material 270, for example, there are rubber, fiber, or polystyrene foam having a characteristic of insulating heat from the casing 300 and the outside air. The component concentration measuring apparatus 100 can reduce the influence of heat transmitted to the window frame 240 by the heat insulating material 270, for example, can insulate the heat generated by the light reflected or scattered by the outside air or the measurement object being absorbed by the housing 300 , The temperature measuring device 220 can measure the temperature of the object to be measured more accurately. FIG. 2 shows a case where the surface of the window frame 240 is covered with a heat insulating material, but the surface of the window 210 may be covered with a heat insulating material 270 so as not to cross the optical path of light from the light emitting means 140. Further, the surface of the window frame 240 may be covered with the heat insulating material 270, and the surface of the window 210 may be covered with the heat insulating material 270 so as not to cross the optical path of light from the light emitting means 140 (not shown).

  FIG. 3 shows a longitudinal sectional view of the window frame. In the component concentration measuring apparatus according to the present embodiment, the window 210 prevents the light reflecting film 280 that reflects the light reflected or scattered by the object to be measured from intersecting the optical path of the light from the light emitting means 140 on the surface. It is preferable to be formed. In FIG. 3, the light reflecting film 280 is formed on the lower surface of the window 210, but the light reflecting film 280 may be formed on the upper surface of the window 210. The light reflecting film 280 can be formed by evaporating a metal such as aluminum, copper, silver, or gold. Since the light reflection film 280 further reflects the light reflected or scattered by the object to be measured, the component concentration measurement apparatus 100 transmits the light reflected or scattered by the object to be measured through the window 210 and is absorbed by the window frame 240. Therefore, the temperature measuring device 220 can measure the temperature of the object to be measured more accurately.

  FIG. 4 shows a top view of the window frame. For example, the groove 241 is provided in the window frame 240, and the temperature measuring device 220 is bonded to the groove 241 with an adhesive having high thermal conductivity. In FIG. 4, the shape of the window 210 is a disk shape, but is not particularly limited.

  FIG. 5 shows a vertical cross-sectional view of a window frame with a light absorber attached. FIG. 6 shows a top view of a window frame in which a light absorber is mounted. In the component concentration measuring apparatus 100 according to the present embodiment, it is preferable that the window frame 240 has a light absorber 290 that absorbs light reflected or scattered by the measurement object on the surface thereof. For example, the light absorber 290 is mounted on the surface of the window frame 240 so as to be positioned below the light emitting unit 141. Examples of the light absorber 290 include black rubber or black fiber. Further, when the light absorber 290 is black rubber, it is preferable to use foamed rubber having low thermal conductivity in order to make it difficult to transfer heat due to light absorption to the window frame 240. Further, a heat insulating material may be sandwiched between the surface of the window frame 240 and the light absorber 290 (not shown). Since the light absorber 290 absorbs the light reflected or scattered by the measurement object, the component concentration measurement apparatus 100 can reduce the situation where the light reflected or scattered by the measurement object is absorbed by the window frame 240 and generates heat. The temperature measuring device 220 can measure the temperature of the object to be measured more accurately.

  The component concentration measuring apparatus according to the present invention can be used for daily health management and cosmetic check. Moreover, not only humans but also animals can be used for health management. Moreover, the component concentration measuring apparatus according to the present invention can be applied not only to humans and animals but also to the field of measuring component concentrations in liquids, for example, sugar content measurement of fruits.

It is the schematic of a component density | concentration measuring apparatus. It is a longitudinal cross-sectional view of the component concentration measuring apparatus of a form provided with a housing | casing. It is a longitudinal cross-sectional view of a window frame. It is a top view of a window frame. It is a longitudinal cross-sectional view of the window frame of the form which mounted | wore the absorber. It is a top view of the window frame of the form which mounted | wore the absorber. It is a figure which shows the structural example of the conventional blood component concentration measuring apparatus by the conventional photoacoustic method. It is a figure which shows the structural example of the conventional blood component concentration measuring apparatus by the conventional photoacoustic method.

Explanation of symbols

100: Component concentration measuring device 110: Light modulation means 111, 111a, 111b: Drive circuits 112, 112a, 112b: Light source 113: Delay adjuster 114: Oscillator 120: Optical multiplexing means 130, 130a, 130b: Light propagation means 140: Light emitting means 141: Emission port 150: Sound wave detecting means 151: Sound wave detectors 151a, 220a: Code 152: Preamplifier 153: Phase detection amplifier 154: Photoacoustic signal output terminal 155: Component concentration calculation unit 199: Object to be measured 200: temperature measuring means 210: window 220: temperature measuring device 230: temperature signal output terminal 240: window frame 241: groove 250: linearly polarizing plate 270: heat insulating material 280: light reflecting film 290: absorber 300: housing 300a, 300b: Housing body 300c: Pinching mechanism 310: Screw 320: Spring 601: First light source 604: Dynamic circuit 605: second light source 608: drive circuit 609: multiplexer 610: device under test 613: ultrasonic detector 616: pulse light source 617: chopper plate 618: motor 619: acoustic sensor 620: waveform observer 621: Frequency analyzer

Claims (3)

Light modulation means for electrically intensity-modulating two waves of light of different wavelengths with signals of the same frequency and opposite phase;
Optical multiplexing means for combining the two light beams modulated by the optical modulation means;
Light emitting means for emitting the light combined by the optical combining means to the object to be measured;
Temperature measuring means for measuring the temperature of the object to be measured;
A photoacoustic signal generated from the object to be measured is detected by light from the light emitting means, and a temperature change of the object to be measured is obtained from the temperature of the object to be measured which is measured by the temperature measuring means. A sound wave detecting means for performing correction based on;
Equipped with a,
The temperature measuring means transmits the light from the light emitting means, contacts the object to be measured, and has thermal conductivity so that the heat of the object to be measured is transmitted, and the window is held by an opening. In addition, a window frame that holds the temperature measuring device and the light emitting means inside and has heat conductivity to transmit the heat of the object to be measured transmitted to the window, and measures the temperature of the window frame Having a temperature measuring device for measuring the temperature of the object to be measured,
Light that is formed on the surface of the window so that the light from the light emitting means reflected or scattered by the object to be measured does not cross the optical path of the light passing through the window, and is reflected or scattered by the object to be measured A light reflecting film that reflects
A linearly polarizing plate that is attached to the window so that light from the light emitting means reflected or scattered by the object to be measured crosses an optical path of light passing through the window and transmits light from the light emitting means, or Optical isolator or
A component concentration measuring device comprising a light absorber that is attached to an inner surface of the window frame and absorbs light transmitted through the window among light reflected or scattered by the object to be measured . 2. The component concentration measuring apparatus according to claim 1 , wherein the window and the window frame are made of a material having a thermal conductivity of 230 W / m · K or more. 3. The component concentration measurement according to claim 1, further comprising a heat insulating material that covers the surface of the window and / or covers the surface of the window frame so as not to cross the optical path of the light from the light emitting means. apparatus.

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