JP2008125543A - Constituent concentration measuring apparatus - Google Patents

Constituent concentration measuring apparatus Download PDF

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JP2008125543A
JP2008125543A JP2006310243A JP2006310243A JP2008125543A JP 2008125543 A JP2008125543 A JP 2008125543A JP 2006310243 A JP2006310243 A JP 2006310243A JP 2006310243 A JP2006310243 A JP 2006310243A JP 2008125543 A JP2008125543 A JP 2008125543A
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light
polarization maintaining
polarization
maintaining
component concentration
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Takuro Tajima
卓郎 田島
Kazunori Naganuma
和則 長沼
Yuichi Okabe
勇一 岡部
Junichi Shimada
純一 嶋田
Tsuneyuki Haga
恒之 芳賀
Katsuyoshi Hayashi
勝義 林
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Nippon Telegraph and Telephone Corp
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a constituent concentration measuring apparatus which reduces measurement errors due to a polarization dependence and measures the constituent concentration of an object to be measured with high precision. <P>SOLUTION: The constituent concentration measuring apparatus 100 comprises a light modifier 110 which modifies beams of light of two wavelengths, a polarization maintaining and light multiplexing means 120 which multiplexes the beams of light of two wavelengths modified by a light modifier while maintaining the polarization states of the beams of light of two wavelengths, a polarization maintaining and light transmitting means 130 which connects the light modifier 110 and the polarization maintaining and light multiplexing means 120 and transmits each of the beams of light of two wavelengths while maintaining the polarization states of the beams of light of two wavelengths, and a polarization maintaining and light radiating means 140 which radiates light multiplexed by the polarization maintaining and light multiplexing means 120 onto an object to be measured 199 while maintaining the polarization states of the light multiplexed by the polarization maintaining and light multiplexing means 120. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

本発明は、人間、動物又は果実等の被測定物の非侵襲な成分濃度測定装置に関する。   The present invention relates to a non-invasive component concentration measurement apparatus for an object to be measured such as a human being, an animal, or a fruit.

高齢化が進み、成人病に対する対応が大きな課題になりつつある。血糖値などの検査においては血液の採取が必要なために患者にとって大きな負担となるので、血液を採取しない非侵襲な成分濃度測定装置が注目されている。現在までに開発された非侵襲な成分濃度測定装置としては、皮膚内に電磁波を照射し、測定対象とする血液成分、例えば、血糖値の場合はグルコース分子に吸収され、局所的に加熱して熱膨張を起こして生体内から発生する音波を観測する、光音響法が注目されている。   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.

しかし、グルコースと電磁波との相互作用は小さく、また生体に安全に照射し得る電磁波の強度には制限があり、生体の血糖値測定においては、十分な効果をあげるに至っていない。   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.

図４および図５は、従来例として、光音響法による従来の血液成分濃度測定装置の構成例を示す図である。図４は光パルスを電磁波として用いた第１の従来例である（例えば、非特許文献１参照。）。本例では血液成分として血糖、すなわちグルコースを測定対象としている。図４において、駆動回路６０４はパルス状の励起電流をパルス光源６１６に供給し、パルス光源６１６はサブマイクロ秒の持続時間を有する光パルスを発生し、発生した光パルスは被測定物６１０に照射される。光パルスは被測定物６１０の内部にパルス状の光音響信号と呼ばれる音波を発生させ、発生した音波は超音波検出器６１３により検出され、さらに音圧に比例した電気信号に変換される。   4 and 5 are diagrams showing a configuration example of a conventional blood component concentration measuring apparatus using a photoacoustic method as a conventional example. FIG. 4 shows a first conventional example using an optical 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. 4, a drive 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.

変換された電気信号の波形は波形観測器６２０により観測される。この波形観測器６２０は上記励起電流に同期した信号によりトリガされ、変換された電気信号は波形観測器６２０の管面上の一定位置に表示され、変換された電気信号は積算及び平均して測定することができる。このようにして得られた電気信号の振幅を解析して、被測定物６１０の内部の血糖値、すなわちグルコースの量が測定される。図４に示す例の場合はサブマイクロ秒のパルス幅の光パルスを最大１ｋＨｚの繰り返しで発生し、１０２４個の光パルスを平均して、前記電気信号を測定しているが十分な精度が得られていない。   The waveform of the converted electric signal is observed by the waveform observer 620. The waveform observer 620 is triggered by a signal synchronized with the excitation current, the converted electrical signal is displayed at a fixed position on the tube surface of the waveform observer 620, and the converted electrical signal is measured by integrating and averaging. can do. By analyzing the amplitude of the electric 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. 4, 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.

そこで、より精度を高める目的で、連続的に強度変調した光源を用いる第２の従来例が開示されている。図５に第２の従来例の装置の構成を示す（例えば、特許文献１参照。）。本例も血糖を主な測定対象として、異なる波長の複数の光源を用いて、高精度化を試みている。説明の煩雑さを避けるために、図５により光源の数が２の場合の動作を説明する。図５において、異なる波長の光源、即ち、第１の光源６０１及び第２の光源６０５は、それぞれ駆動回路６０４及び駆動回路６０８により駆動され、連続光を出力する。   Therefore, a second conventional example using a light source that is continuously intensity-modulated has been disclosed for the purpose of improving accuracy. FIG. 5 shows a 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. 5, 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.

第１の光源６０１及び第２の光源６０５が出力する光は、モータ６１８により駆動され一定回転数で回転するチョッパ板６１７により断続される。ここでチョッパ板６１７は不透明な材質により形成され、モータ６１８の軸を中心とする第１の光源６０１及び第２の光源６０５の光が通過する円周上に、互いに素な個数の開口部が形成されている。   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.

上記の構成により、第１の光源６０１及び第２の光源６０５の各々が出力する光は互いに素な変調周波数ｆ１及び変調周波数ｆ２で強度変調された後、合波部６０９により合波され、１の光束として被測定物６１０に照射される。 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.

被測定物６１０の内部には第１の光源６０１の光により周波数ｆ１の光音響信号が発生し、第２の光源６０５の光により周波数ｆ２の光音響信号が発生し、これらの光音響信号は、音響センサ６１９により検出され、音圧に比例した電気信号に変換され、その周波数スペクトルが、周波数解析器６２１により観測される。本例においては、複数の光源の波長は全てグルコースの吸収波長に設定されており、各波長に対応する光音響信号の強度は、血液中に含まれるグルコースの量に対応した電気信号として測定される。 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

ここで、予め光音響信号の測定値の強度と別途採血した血液によりグルコースの含有量を測定した値との関係を記憶しておいて、前記光音響信号の測定値からグルコースの量を測定している。
特開平１０−１８９号公報 オウル大学（Ｕｎｉｖｅｒｓｉｔｙ ｏｆ Ｏｕｌｕ、Ｆｉｎｌａｎｄ）学位論文「Ｐｕｌｓｅｄ ｐｈｏｔｏａｃｏｕｓｔｉｃ ｔｅｃｈｎｉｑｕｅｓ ａｎｄ ｇｌｕｃｏｓｅ ｄｅｔｅｒｍｉｎａｔｉｏｎ ｉｎ ｈｕｍａｎ ｂｌｏｏｄ ａｎｄ ｔｉｓｓｕｅ」（ＩＢＳ ９５１−４２−６６９０−０、ｈｔｔｐ：／／ｈｅｒｋｕｌｅｓ．ｏｕｌｕ．ｆｉ／ｉｓｂｎ９５１４２６６９００／、２００２年） Here, the relationship between the intensity of the measured value of the photoacoustic signal and the value obtained by measuring the glucose content with blood collected separately 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, hlk / 95.

上述の従来例においては以下のような課題がある。光音響法による２波長の差分検出方式では、２波長間での光音響信号の強度差が被測定物の成分濃度の測定と係わる。光伝搬経路における偏波回転や光学部品の偏波依存性のために、２波の光の強度が別々に変動してしまい、成分濃度測定装置の測定精度が低下する問題がある。   The conventional example described above has the following problems. In the two-wavelength difference detection method using the photoacoustic method, the difference in the intensity of the photoacoustic signal between the two wavelengths is related to the measurement of the component concentration of the object to be measured. Due to the polarization rotation in the light propagation path and the polarization dependence of the optical component, the intensity of the two waves varies separately, and there is a problem that the measurement accuracy of the component concentration measuring device is lowered.

本発明は、偏波依存性による測定誤差を減少させ、被測定物の成分濃度を高精度に測定可能な成分濃度測定装置を提供することを目的とする。   An object of the present invention is to provide a component concentration measuring apparatus capable of reducing a measurement error due to polarization dependence and measuring a component concentration of an object to be measured with high accuracy.

上記の課題を解決するために、本発明に係る成分濃度測定装置は、光の偏波状態を保持したまま被測定物に出射することを特徴とする成分濃度測定装置である。   In order to solve the above problems, a component concentration measuring apparatus according to the present invention is a component concentration measuring apparatus that emits light to a measurement object while maintaining the polarization state of light.

具体的には、本発明に係る成分濃度測定装置は、互いに異なる波長の２波の光を同一周波数で逆位相の信号によりそれぞれ電気的に強度変調する光変調手段と、前記光変調手段で変調された前記２波の光の偏波状態を保持しつつ前記光変調手段で変調された前記２波の光を合波する偏波保持光合波手段と、前記光変調手段と前記偏波保持光合波手段とを接続し、前記２波の光の偏波状態を保持しつつ前記２波の光のそれぞれを伝搬する偏波保持光伝搬手段と、前記偏波保持光合波手段で合波された光の偏波状態を保持しつつ前記偏波保持光合波手段で合波された光を被測定物に出射する偏波保持光出射手段と、前記偏波保持光出射手段からの光によって前記被測定物から発生する光音響信号を検出する音波検出手段と、を備えることを特徴とする。   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. A polarization-maintaining optical multiplexing unit that combines the two-wave light modulated by the optical modulation unit while maintaining a polarization state of the two-wave light, and the optical modulation unit and the polarization-maintaining optical multiplexing unit. The polarization maintaining light propagation means for propagating each of the two waves of light while maintaining the polarization state of the two waves of light, and multiplexed by the polarization maintaining optical multiplexing means A polarization maintaining light emitting means for emitting the light combined by the polarization maintaining light combining means to the object to be measured while maintaining the polarization state of the light, and the light from the polarization maintaining light emitting means by the light from the polarization maintaining light emitting means. A sound wave detecting means for detecting a photoacoustic signal generated from a measurement object, and That.

上記の成分濃度測定装置は、偏波に依存する光の強度の変動を抑制することで、偏波依存性による前記被測定物の成分濃度の測定誤差を減少させ、前記光音響信号を高精度で検出することができる。   The component concentration measuring apparatus reduces the measurement error of the component concentration of the object to be measured due to the polarization dependence by suppressing the fluctuation of the light intensity depending on the polarization, and the photoacoustic signal is highly accurate. Can be detected.

本発明に係る成分濃度測定装置では、前記偏波保持光出射手段の光路に偏波保持光切替手段がさらに挿入され、前記偏波保持光切替手段に偏波保持光分岐路がさらに接続され、前記偏波保持光切替手段は、前記偏波保持光出射手段を伝搬する光の偏波状態を保持しつつ前記偏波保持光出射手段を伝搬する光を前記偏波保持光出射手段又は前記偏波保持光分岐路のいずれか一方に分岐させ、前記偏波保持光分岐路は、前記偏波保持光切替手段で分岐された光の偏波状態を保持しつつ前記偏波保持光切替手段で分岐された光を標準試料に出射し、前記音波検出手段は、前記偏波保持光分岐路からの光によって前記標準試料から発生する光音響信号を検出することが好ましい。   In the component concentration measuring apparatus according to the present invention, a polarization maintaining light switching unit is further inserted in the optical path of the polarization maintaining light emitting unit, and a polarization maintaining light branching path is further connected to the polarization maintaining light switching unit, The polarization maintaining light switching unit is configured to transmit light propagating through the polarization maintaining light emitting unit while maintaining a polarization state of light propagating through the polarization maintaining light emitting unit. The polarization-maintaining optical branch is branched into one of the wave-maintaining optical branches, and the polarization-maintaining optical branch is maintained by the polarization-maintaining light switching unit while maintaining the polarization state of the light branched by the polarization-maintaining light switching unit It is preferable that the branched light is emitted to a standard sample, and the sound wave detecting means detects a photoacoustic signal generated from the standard sample by light from the polarization maintaining light branch path.

上記の成分濃度測定装置は、前記被測定物と前記標準試料を手で置き換えることによって生じる前記被測定物の成分濃度の測定誤差を減少させ、及び、前記標準試料を用いた校正精度を向上させることができる。さらに、上記の成分濃度測定装置は、校正時間を短縮し、校正精度を向上させることができる。   The component concentration measuring apparatus reduces a measurement error of the component concentration of the object to be measured which is caused by manually replacing the object to be measured and the standard sample, and improves calibration accuracy using the standard sample. be able to. Furthermore, the above-described component concentration measuring apparatus can shorten the calibration time and improve the calibration accuracy.

本発明に係る成分濃度測定装置では、前記偏波保持光出射手段の光路に偏波保持光分割手段がさらに挿入され、前記偏波保持光分割手段に偏波保持光分岐路がさらに接続され、前記偏波保持光分割手段は、前記偏波保持光出射手段を伝搬する光の偏波状態を保持しつつ前記偏波保持光出射手段を伝搬する光を前記偏波保持光出射手段及び前記偏波保持光分岐路のそれぞれに分割し、前記偏波保持光分岐路は、前記偏波保持光分割手段で分割された光の偏波状態を保持しつつ前記偏波保持光分割手段で分割された光を標準試料に出射し、前記音波検出手段は、前記偏波保持光分岐路からの光によって前記標準試料から発生する光音響信号を検出することが好ましい。   In the component concentration measurement apparatus according to the present invention, a polarization maintaining light splitting unit is further inserted in the optical path of the polarization maintaining light emitting unit, and a polarization maintaining light splitting path is further connected to the polarization maintaining light splitting unit, The polarization maintaining light splitting unit is configured to transmit light propagating through the polarization maintaining light emitting unit while maintaining a polarization state of light propagating through the polarization maintaining light emitting unit. The polarization-maintaining optical branch is divided by each of the polarization-maintaining optical splitters while maintaining the polarization state of the light split by the polarization-maintaining optical splitter. It is preferable that the emitted light is emitted to a standard sample, and the sound wave detecting means detects a photoacoustic signal generated from the standard sample by light from the polarization maintaining optical branch path.

上記の成分濃度測定装置は、前記被測定物と前記標準試料を手で置き換えることによって生じる前記被測定物の成分濃度の測定誤差を減少させ、及び、前記標準試料を用いた校正精度を向上させることができる。さらに、上記の成分濃度測定装置は、校正時間を短縮し、校正精度を向上させることができる。   The component concentration measuring apparatus reduces a measurement error of the component concentration of the object to be measured which is caused by manually replacing the object to be measured and the standard sample, and improves calibration accuracy using the standard sample. be able to. Furthermore, the above-described component concentration measuring apparatus can shorten the calibration time and improve the calibration accuracy.

本発明に係る成分濃度測定装置では、前記偏波保持光分岐路は、偏波保持光ファイバであることが好ましい。   In the component concentration measuring apparatus according to the present invention, the polarization maintaining optical branch path is preferably a polarization maintaining optical fiber.

上記の成分濃度測定装置は、外部の温度の変化や外部からの圧力によっても前記偏波保持光分岐路を伝搬する光の偏波が回転せず、かつ、偏波に依存する光の強度の変動を抑制できるので、前記光音響信号をより高精度で検出することができる。さらに、上記の成分濃度測定装置は、省スペース化を図ることができる。   The above-described component concentration measuring apparatus does not rotate the polarization of light propagating through the polarization maintaining optical branch path due to an external temperature change or an external pressure, and the intensity of light depending on the polarization Since fluctuations can be suppressed, the photoacoustic signal can be detected with higher accuracy. Furthermore, the above-described component concentration measuring device can save space.

本発明に係る成分濃度測定装置では、前記偏波保持光伝搬手段は、偏波保持光ファイバであることが好ましい。   In the component concentration measuring apparatus according to the present invention, the polarization maintaining light propagation means is preferably a polarization maintaining optical fiber.

上記の成分濃度測定装置は、外部の温度の変化や外部からの圧力によっても前記偏波保持光伝搬手段を伝搬する光の偏波が回転せず、かつ、偏波に依存する光の強度の変動を抑制できるので、前記光音響信号をより高精度で検出することができる。さらに、上記の成分濃度測定装置は、省スペース化を図ることができる。   The above component concentration measuring apparatus does not rotate the polarization of the light propagating through the polarization maintaining light propagation means due to an external temperature change or an external pressure, and the intensity of the light depending on the polarization does not rotate. Since fluctuations can be suppressed, the photoacoustic signal can be detected with higher accuracy. Furthermore, the above-described component concentration measuring device can save space.

本発明に係る成分濃度測定装置では、前記偏波保持光出射手段は、偏波保持光ファイバであることが好ましい。   In the component concentration measuring apparatus according to the present invention, the polarization maintaining light emitting means is preferably a polarization maintaining optical fiber.

上記の成分濃度測定装置は、外部の温度の変化や外部からの圧力によっても前記偏波保持光出射手段を伝搬する光の偏波が回転せず、かつ、偏波に依存する前記光の強度の変動を抑制できるので、前記光音響信号をより高精度で検出することができる。さらに、上記の成分濃度測定装置は、省スペース化を図ることができる。   The component concentration measuring device described above is such that the polarization of light propagating through the polarization maintaining light emitting means does not rotate due to a change in external temperature or pressure from the outside, and the intensity of the light depends on the polarization. Therefore, the photoacoustic signal can be detected with higher accuracy. Furthermore, the above-described component concentration measuring device can save space.

本発明は、偏波依存性による測定誤差を減少させ、被測定物の成分濃度を高精度に測定可能な成分濃度測定装置を提供することができる。   The present invention can provide a component concentration measuring apparatus that can reduce measurement errors due to polarization dependence and can measure the component concentration of a measurement object with high accuracy.

添付の図面を参照して本発明の実施の形態を説明する。以下に説明する実施の形態は本発明の構成の例であり、本発明は、以下の実施の形態に制限されるものではない。また、各実施形態に係る成分濃度測定装置において、電源、あるいは全体の動作を制御する制御部などの通常の技術により実現できる部分は図示せず、同一部材及び同一部位には同一符号を付した。   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. .

初めに、本発明の成分濃度測定装置の基本原理を説明する。被測定物の成分濃度の算定式を数１に示す。ここで、α１ （Ｗ），α２ （Ｗ）は、波長λ１の光及び波長λ２の光に対する背景（主に水）の吸収係数であり、α１ （ｇ），α２ （ｇ）は、波長λ１の光及び波長λ２の光に対する測定対象となる成分（例えば、血液）のモル吸収係数である。 First, the basic principle of the component concentration measuring apparatus of the present invention will be described. The formula for calculating the component concentration of the object to be measured is shown in Equation 1. Here, α 1 (W) and α 2 (W) are absorption coefficients of the background (mainly water) with respect to light of wavelength λ 1 and light of wavelength λ 2 , and α 1 (g) and α 2 (g ) Is the molar absorption coefficient of the component (for example, blood) to be measured for the light of wavelength λ 1 and the light of wavelength λ 2 .

Figure 2008125543
Figure 2008125543

上記の数１を解いて、被測定物の測定対象の成分濃度Ｍを求めることができる。ここで、Ｃは制御あるいは予想困難な係数、すなわち、被測定物と音波検出器の結合状態、音波検出器の感度、被測定物において光により音波が発生される位置と音波検出器との間の距離、被測定物の比熱及び熱膨張係数、被測定物の内部の音波の速度、波長λ１の光及び波長λ２の光の変調周波数、背景の吸収係数及び測定対象となる成分のモル吸収係数、などに依存する未知定数である。さらに、数１においてＣを消去すると数２が得られる。ここで、ｓ１及びｓ２は、波長λ１の光及び波長λ２の光によって被測定物が発生する光音響信号の大きさである。 By solving the above equation 1, the component concentration M of the measurement target of the object to be measured can be obtained. Here, C is a coefficient that is difficult to control or predict, that is, the coupling state between the object to be measured and the sound wave detector, the sensitivity of the sound wave detector, and the position between the position where the sound wave is generated by light in the object to be measured and the sound wave detector. Distance, specific heat and thermal expansion coefficient of the object to be measured, speed of sound wave inside the object to be measured, modulation frequency of light of wavelength λ 1 and light of wavelength λ 2 , absorption coefficient of background, and mole of component to be measured It is an unknown constant that depends on the absorption coefficient. Further, when C is deleted in Equation 1, Equation 2 is obtained. Here, s 1 and s 2 are the magnitudes of the photoacoustic signals generated by the object to be measured by the light of wavelength λ 1 and the light of wavelength λ 2 .

Figure 2008125543
Figure 2008125543

ここで、吸収係数α１ （Ｗ）及びα２ （Ｗ）が等しくなるよう２波の光を選択し、ｓ１≒ｓ２であることを用いれば、成分濃度Ｍは、数３で表される。 Here, if two light beams are selected so that the absorption coefficients α 1 (W) and α 2 (W) are equal, and s 1 ≈s 2 is used, the component concentration M is expressed by Equation 3. The

Figure 2008125543
Figure 2008125543

（第１実施形態）
図１に、第１実施形態に係る成分濃度測定装置の概略図を示す。第１実施形態に係る成分濃度測定装置１００は、互いに異なる波長の２波の光を同一周波数で逆位相の信号によりそれぞれ電気的に強度変調する光変調手段１１０と、光変調手段で変調された２波の光の偏波状態を保持しつつ光変調手段１１０で変調された２波の光を合波する偏波保持光合波手段１２０と、光変調手段１１０と偏波保持光合波手段１２０とを接続し、２波の光の偏波状態を保持しつつ２波の光のそれぞれを伝搬する偏波保持光伝搬手段１３０と、偏波保持光合波手段１２０で合波された光の偏波状態を保持しつつ偏波保持光合波手段１２０で合波された光を被測定物１９９に出射する偏波保持光出射手段１４０と、偏波保持光出射手段１４０からの光によって被測定物１９９から発生する光音響信号を検出する音波検出手段１５０と、を備える。さらに、図１の光変調手段１１０は、２個の駆動回路１１１ａ，１１１ｂ、２個の光源１１２ａ，１１２ｂ、遅延調整器１１３及び発信器１１４を有する。図１の音波検出手段１５０は、音波検出器１５１、前置増幅器１５２、位相検波増幅器１５３、光音響信号出力端子１５４及び成分濃度算出部１５５を有する。 (First embodiment)
FIG. 1 shows a schematic diagram of a component concentration measuring apparatus according to the first embodiment. The component concentration measuring apparatus 100 according to the first embodiment is modulated by the light modulating unit 110 that electrically modulates the intensity of two light beams having different wavelengths by signals having the same frequency and opposite phase, and the light modulating unit. A polarization-maintaining optical multiplexing unit 120 that combines the two light beams modulated by the optical modulation unit 110 while maintaining the polarization state of the two light beams, and the optical modulation unit 110 and the polarization-maintaining optical multiplexing unit 120. And polarization maintaining light propagation means 130 for propagating each of the two light waves while maintaining the polarization state of the two light lights, and polarization of the light combined by the polarization maintaining light combining means 120 While maintaining the state, the polarization-maintaining light emitting means 140 that emits the light combined by the polarization-maintaining light multiplexing means 120 to the object 199 to be measured, and the object 199 to be measured by the light from the polarization-maintaining light emitting means 140 Sound wave detecting means for detecting a photoacoustic signal generated from the sound wave It includes a 50, a. 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.

光源１１２としては、例えば、分布帰還型半導体レーザ（ＤＦＢ−ＬＤ）がある。ここでは、光源１１２ａ，１１２ｂは、互いに波長が異なり、かつ、被測定物１９９の吸収波長となる光を出力することが好ましい。図１の成分濃度測定装置１００では、光源１１２ａの発振波長が１．３８μｍであり、光源１１２ｂの発振波長が１．６１μｍである。また、光源１１２は、ヒーター又はペルチェ素子で加熱又は冷却することにより出力する光の波長を変化できることが好ましい。光源１１２は、例えば、波長安定度が０．１ｎｍであり、０．１℃単位で光源１１２の温度を安定化できる。   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.

例えば、光源１１２ａに電力を供給する駆動回路１１１ａが光源１１２ａに接続され、光源１１２ｂに電力を供給する駆動回路１１１ｂが光源１１２ｂに接続される。駆動回路１１１は、例えば、５００ｋＨｚの周波数で光源１１２が出力する光を直接変調する。また、発信器１１４は、任意の周波数、例えば、周波数が１ｋＨｚ〜１ＭＨｚのパルス列を発生させ、これを駆動回路１１１ａ，１１１ｂに出力する。遅延調整器１１３は、例えば、０．１ｎ秒単位の精度で遅延を付与でき、光源１１２ａ，１１２ｂを逆位相で駆動するために、発信器１１４が発生させたパルス列に周期の半分の遅延を付与するように調整する。   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

偏波保持光伝搬手段１３０ａは、例えば、光源１１２ａと偏波保持光合波手段１２０の光入力端子（不図示）との間を接続する。また、偏波保持光伝搬手段１３０ｂは、例えば、光源１１２ｂと偏波保持光合波手段１２０の光入力端子との間を接続する。偏波保持光合波手段１２０としては、例えば、光ファイバ結合型光カプラ又は空間型光フィルタがある。   For example, the polarization maintaining light propagation unit 130 a connects between the light source 112 a and an optical input terminal (not shown) of the polarization maintaining light multiplexing unit 120. The polarization maintaining light propagation unit 130b connects, for example, between the light source 112b and the light input terminal of the polarization maintaining light combining unit 120. Examples of the polarization maintaining optical multiplexing unit 120 include an optical fiber coupling type optical coupler and a spatial type optical filter.

第１実施形態に係る成分濃度測定装置では、偏波保持光伝搬手段１３０は、偏波保持光ファイバであることが好ましい。成分濃度測定装置１００は、外部の温度の変化や外部からの圧力によっても偏波保持光伝搬手段１３０を伝搬する光の偏波が回転せず、かつ、偏波に依存する光の強度の変動を抑制できるので、光音響信号をより高精度で検出することができる。さらに、成分濃度測定装置１００は、偏波保持光ファイバを用いることで偏波保持光伝搬手段１３０の取り回しの自由度が高くなり、省スペース化を図ることができる。   In the component concentration measuring apparatus according to the first embodiment, the polarization maintaining light propagation means 130 is preferably a polarization maintaining optical fiber. The component concentration measuring apparatus 100 does not rotate the polarization of light propagating through the polarization-maintaining light propagation means 130 due to a change in external temperature or pressure from the outside, and fluctuations in the intensity of light depending on the polarization. Therefore, the photoacoustic signal can be detected with higher accuracy. Furthermore, the component concentration measuring apparatus 100 uses a polarization maintaining optical fiber, so that the degree of freedom in handling the polarization maintaining light propagation means 130 is increased, and space can be saved.

偏波保持光出射手段１４０は、例えば、偏波保持光合波手段１２０の光出力端子（不図示）に接続される。第１実施形態に係る成分濃度測定装置では、偏波保持光出射手段１４０は、偏波保持光ファイバであることが好ましい。成分濃度測定装置１００は、外部の温度の変化や外部からの圧力によっても偏波保持光出射手段１４０を伝搬する光の偏波が回転せず、かつ、偏波に依存する前記光の強度の変動を抑制できるので、光音響信号をより高精度で検出することができる。さらに、成分濃度測定装置１００は、偏波保持光ファイバを用いることで偏波保持光出射手段１４０の取り回しの自由度が高くなり、省スペース化を図ることができる。   The polarization maintaining light emitting unit 140 is connected to, for example, an optical output terminal (not shown) of the polarization maintaining light combining unit 120. In the component concentration measuring apparatus according to the first embodiment, the polarization maintaining light emitting means 140 is preferably a polarization maintaining optical fiber. The component concentration measuring apparatus 100 does not rotate the polarization of the light propagating through the polarization-maintaining light emitting means 140 due to a change in external temperature or pressure from the outside, and the intensity of the light depending on the polarization does not rotate. Since fluctuation can be suppressed, the photoacoustic signal can be detected with higher accuracy. Furthermore, the component concentration measuring apparatus 100 uses a polarization-maintaining optical fiber, so that the degree of freedom in handling the polarization-maintaining light emitting means 140 is increased, and space can be saved.

偏波保持光出射手段１４０から光を受けた被測定物１９９は、光音響効果によって光音響信号を発生する。音波検出器１５１は、例えば、被測定物１９９が発生する光音響信号を検出して電気信号に変換する。ここで、音波検出器１５１は、検出感度が最高となる共振周波数を、光変調手段１１０の変調周波数に合せた周波数、例えば、５００ｋＨｚに合せることが好ましい。音波検出器１５１としては、例えば、超音波センサがある。前置増幅器１５２は、例えば、音波検出器１５１からの電気信号を増幅して出力する。位相検波増幅器１５３は、例えば、光変調手段１１０の変調周波数と同一周波数成分となる電気信号を抽出し、光音響信号出力端子１５４に出力する。光音響信号出力端子１５４には、例えば、成分濃度算出部１５５が接続される。成分濃度算出部１５５は、例えば、上記の基本原理を用いて、光音響信号出力端子１５４が出力する電気信号に基づいて被測定物１９９の成分濃度を算出する。   The device under test 199 that has received light from the polarization maintaining 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, the sound wave detector 151 preferably 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 the electrical signal output from the photoacoustic signal output terminal 154, for example, using the basic principle described above.

被測定物１９９としては、人体又は人体の一部、例えば、指がある。被測定物１９９が指であれば、成分濃度測定装置１００は、血液中のグルコースの濃度を測定できる。また、被測定物１９９としては、例えば、実験用ラット、みかん等の果実、或いは、人体又は実験用ラットから採取した採取物もある。被測定物１９９が果実であれば、成分濃度測定装置１００は、果実の糖度、すなわち、果実の甘さを測定できる。   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.

成分濃度測定装置１００は、光変調手段１１０で出力された光が被測定物１９９に出射されるまで、偏波保持光合波手段１２０、偏波保持光伝搬手段１３０及び偏波保持光出射手段１４０によって光の偏波状態を保持できるので、偏波依存性による被測定物１９９の成分濃度の測定誤差が減少する。これによって、成分濃度測定装置１００は、光音響信号を高精度で検出することができる。   The component concentration measuring apparatus 100 includes the polarization maintaining light combining unit 120, the polarization maintaining light propagation unit 130, and the polarization maintaining light emitting unit 140 until the light output from the light modulation unit 110 is output to the device under test 199. Since the polarization state of light can be maintained by this, the measurement error of the component concentration of the device under test 199 due to polarization dependence is reduced. Thereby, the component concentration measuring apparatus 100 can detect the photoacoustic signal with high accuracy.

（第２実施形態）
第２実施形態に係る成分濃度測定装置について、第１実施形態に係る成分濃度測定装置と異なる点を中心に説明する。図２に、第２実施形態に係る成分濃度測定装置の概略図を示す。第２実施形態に係る成分濃度測定装置１０１では、偏波保持光出射手段１４０の光路に偏波保持光切替手段１６０がさらに挿入され、偏波保持光切替手段１６０に偏波保持光分岐路１７０がさらに接続され、偏波保持光切替手段１６０は、偏波保持光出射手段１４０を伝搬する光の偏波状態を保持しつつ偏波保持光出射手段１４０を伝搬する光を偏波保持光出射手段１４０又は偏波保持光分岐路１７０のいずれか一方に分岐させ、偏波保持光分岐路１７０は、偏波保持光切替手段１６０で分岐された光の偏波状態を保持しつつ偏波保持光切替手段１６０で分岐された光を標準試料１９８に出射し、音波検出手段１５０は、偏波保持光分岐路１７０からの光によって標準試料１９８から発生する光音響信号を検出することが好ましい。図２の音波検出手段１５０は、２個の音波検出器１５１ａ，１５１ｂ、２個の前置増幅器１５２ａ，１５２ｂ、位相検波増幅器１５３及び光音響信号出力端子１５４、成分濃度算出部１５５及び電気スイッチ１５６を有する。 (Second Embodiment)
The component concentration measuring apparatus according to the second embodiment will be described focusing on differences from the component concentration measuring apparatus according to the first embodiment. FIG. 2 shows a schematic diagram of a component concentration measuring apparatus according to the second embodiment. In the component concentration measuring apparatus 101 according to the second embodiment, a polarization maintaining light switching unit 160 is further inserted in the optical path of the polarization maintaining light emitting unit 140, and the polarization maintaining light branching path 170 is connected to the polarization maintaining light switching unit 160. Are further connected, and the polarization maintaining light switching unit 160 outputs the light propagating through the polarization maintaining light emitting unit 140 while maintaining the polarization state of the light propagating through the polarization maintaining light emitting unit 140. The polarization-maintaining optical branch 170 is branched into either one of the means 140 or the polarization-maintaining optical branch 170, and the polarization-maintaining optical branch 170 maintains the polarization state of the light branched by the polarization-maintaining light switching unit 160. The light branched by the light switching means 160 is emitted to the standard sample 198, and the sound wave detection means 150 preferably detects the photoacoustic signal generated from the standard sample 198 by the light from the polarization maintaining light branching path 170. 2 includes two sound wave detectors 151a and 151b, two preamplifiers 152a and 152b, a phase detection amplifier 153, a photoacoustic signal output terminal 154, a component concentration calculation unit 155, and an electric switch 156. Have

偏波保持光切替手段１６０は、例えば、偏波保持光出射手段１４０の中間に挿入される。偏波保持光切替手段１６０としては、例えば、光ファイバ切替型スイッチ又はミラー反射型スイッチがある。偏波保持光切替手段１６０は、分岐した光の出力が低下しにくい利点がある。   For example, the polarization maintaining light switching unit 160 is inserted in the middle of the polarization maintaining light emitting unit 140. Examples of the polarization maintaining light switching means 160 include an optical fiber switching type switch and a mirror reflection type switch. The polarization maintaining light switching means 160 has an advantage that the output of the branched light is unlikely to decrease.

偏波保持光切替手段１６０は、１本の偏波保持光分岐路１７０が接続される。第２実施形態に係る成分濃度測定装置では、偏波保持光分岐路１７０は、偏波保持光ファイバであることが好ましい。成分濃度測定装置１０１は、外部の温度の変化や外部からの圧力によっても偏波保持光分岐路１７０を伝搬する光の偏波が回転せず、かつ、偏波に依存する光の強度の変動を抑制できるので、光音響信号をより高精度で検出することができる。さらに、成分濃度測定装置１０１は、偏波保持光ファイバを用いることで偏波保持光分岐路１７０の取り回しの自由度が高くなり、省スペース化を図ることができる。   The polarization maintaining light switching unit 160 is connected to one polarization maintaining light branching path 170. In the component concentration measuring apparatus according to the second embodiment, the polarization maintaining optical branching path 170 is preferably a polarization maintaining optical fiber. The component concentration measuring apparatus 101 does not rotate the polarization of the light propagating through the polarization maintaining optical branching path 170 due to a change in external temperature or pressure from the outside, and fluctuations in light intensity depending on the polarization. Therefore, the photoacoustic signal can be detected with higher accuracy. Further, the component concentration measuring apparatus 101 uses a polarization maintaining optical fiber, so that the degree of freedom in handling the polarization maintaining optical branching path 170 is increased, and space can be saved.

例えば、偏波保持光出射手段１４０の先端には出射口１４１が装着され、偏波保持光分岐路１７０の先端には出射口１７１が装着される。出射口１４１及び出射口１７１としては、例えば、光のビーム径が２ｍｍとなる光ファイバコリメータ、材料がＢＫ７（登録商標）、ＳＦＬ−１１（登録商標）、石英又はサファイアの全反射プリズム、或いは、フェルールがある。   For example, an exit port 141 is attached to the tip of the polarization maintaining light emitting means 140, and an exit port 171 is attached to the tip of the polarization maintaining light branching path 170. As the exit port 141 and the exit port 171, for example, an optical fiber collimator with a light beam diameter of 2 mm, a material made of BK7 (registered trademark), SFL-11 (registered trademark), quartz or sapphire total reflection prism, or There is a ferrule.

偏波保持光合波手段１２０で合波された光は、偏波保持光出射手段１４０の中間で偏波保持光切替手段１６０によって偏波保持光出射手段１４０の出射口１４１の側又は偏波保持光分岐路１７０の出射口１７１の側に分岐され、被測定物１９９及び標準試料１９８のいずれか一方に出射される。   The light combined by the polarization maintaining light combining unit 120 is provided between the polarization maintaining light emitting unit 140 and the polarization maintaining light switching unit 160 at the exit 141 side of the polarization maintaining light emitting unit 140 or polarization maintaining. The light is branched to the exit 171 side of the light branching path 170 and emitted to either the object to be measured 199 or the standard sample 198.

音波検出器１５１ａは、例えば、被測定物１９９が発生する光音響信号を検出して電気信号に変換する。前置増幅器１５２ａは、例えば、音波検出器１５１ａからの電気信号を増幅して出力する。また、電気スイッチ１５６は、例えば、前置増幅器１５２ａからの電気信号と前置増幅器１５２ｂからの電気信号とを切り替え、光音響信号出力端子１５４に出力する。被測定物１９９の成分濃度を測定する際は、偏波保持光切替手段１６０及び電気スイッチ１５６を被測定物１９９に光が出射されるように切り替える。これによって、第１実施形態に係る成分濃度測定装置と同様に、成分濃度測定装置１０１は、被測定物１９９の成分濃度を測定できる。   The sound wave detector 151a detects, for example, a photoacoustic signal generated by the device under test 199 and converts it into an electrical signal. For example, the preamplifier 152a amplifies and outputs an electric signal from the sound wave detector 151a. In addition, the electrical switch 156 switches, for example, an electrical signal from the preamplifier 152a and an electrical signal from the preamplifier 152b, and outputs the signal to the photoacoustic signal output terminal 154. When measuring the component concentration of the device under test 199, the polarization maintaining light switching means 160 and the electric switch 156 are switched so that light is emitted to the device under test 199. Thereby, the component concentration measuring apparatus 101 can measure the component concentration of the object 199 to be measured, like the component concentration measuring apparatus according to the first embodiment.

一方、音波検出器１５１ｂは、例えば、標準試料１９８が発生する光音響信号を検出して電気信号に変換する。前置増幅器１５２ｂは、例えば、音波検出器１５１ｂからの電気信号を増幅して出力する。標準試料１９８を用いて校正する際は、偏波保持光切替手段１６０及び電気スイッチ１５６を標準試料１９８に光が出射されるように切り替える。そして、数３における光音響信号の強度の差分（ｓ１‐ｓ２）がゼロ又は雑音の強度と略等しくなるように、発信器１１４及び駆動回路１１１の変調振幅、並びに、遅延調整器１１３の遅延を調整する。 On the other hand, the sound wave detector 151b detects, for example, a photoacoustic signal generated by the standard sample 198 and converts it into an electrical signal. For example, the preamplifier 152b amplifies and outputs an electric signal from the sound wave detector 151b. When calibrating using the standard sample 198, the polarization maintaining light switching means 160 and the electric switch 156 are switched so that light is emitted to the standard sample 198. Then, the modulation amplitudes of the transmitter 114 and the drive circuit 111 and the delay adjuster 113 are set so that the difference (s 1 -s 2 ) in the intensity of the photoacoustic signal in Equation 3 is zero or substantially equal to the noise intensity. Adjust the delay.

標準試料１９８としては、例えば、被測定物１９９と等価な吸光度、電熱特性及び音響特性を示すように調合した生体等価物質を封入したものがある。測定対象の成分が血液中のグルコースであれば、標準試料１９８としては、例えば、水溶液又は水分を含んだ軟化ゲル状の試料を封入したガラスセル、或いは、血液成分量を検査済みの血液又は血清を封入したガラスセルがある。成分濃度測定装置１００では、被検体１９９の測定対象とする成分に応じた標準試料１９８とすることにより、成分濃度測定値１００の校正を行うことができる。   As the standard sample 198, for example, there is a sample in which a bioequivalent material prepared so as to exhibit absorbance, electrothermal characteristics, and acoustic characteristics equivalent to the measurement object 199 is enclosed. If the component to be measured is glucose in the blood, the standard sample 198 may be, for example, a glass cell encapsulating a softened gel sample containing an aqueous solution or water, or blood or serum whose blood component amount has been examined. There is a glass cell in which is enclosed. In the component concentration measuring apparatus 100, the component concentration measurement value 100 can be calibrated by using the standard sample 198 corresponding to the component to be measured by the subject 199.

光変調手段１１０で出力された光が標準試料１９８に出射されるまで、偏波保持光合波手段１２０、偏波保持光伝搬手段１３０、偏波保持光出射手段１４０、偏波保持光切替手段１６０及び偏波保持光分岐路１７０によって光の偏波状態を保持できるので、成分濃度測定装置１０１は、偏波依存性による標準試料１９８の成分濃度の測定誤差が減少する
。 Until the light output from the light modulating unit 110 is emitted to the standard sample 198, the polarization maintaining light combining unit 120, the polarization maintaining light propagation unit 130, the polarization maintaining light emitting unit 140, and the polarization maintaining light switching unit 160 are used. Since the polarization state of the light can be held by the polarization maintaining optical branching path 170, the component concentration measuring apparatus 101 reduces the measurement error of the component concentration of the standard sample 198 due to the polarization dependency.

成分濃度測定装置１０１は、偏波保持光切替手段１６０及び偏波保持光分岐路１７０を備えるので、被測定物１９９と標準試料１９８を手で置き換える必要がなく、手の温度によって標準試料１９８及び被測定物１９９の温度は変動しない。これによって、成分濃度測定装置１０１は、被測定物１９９の成分濃度の測定誤差が減少させ、標準試料１９８を用いた校正精度を向上させることができる。また、手の温度の影響がないので、標準試料１９８の温度が規定値になるまでの時間を待つことなく校正を開始でき、成分濃度測定装置１０１は、校正時間を短縮することができる。   Since the component concentration measuring apparatus 101 includes the polarization maintaining light switching means 160 and the polarization maintaining light branching path 170, it is not necessary to replace the measurement object 199 and the standard sample 198 by hand. The temperature of the measurement object 199 does not vary. Thereby, the component concentration measuring apparatus 101 can reduce the measurement error of the component concentration of the measurement object 199 and improve the calibration accuracy using the standard sample 198. Further, since there is no influence of the temperature of the hand, the calibration can be started without waiting for the time until the temperature of the standard sample 198 reaches the specified value, and the component concentration measuring apparatus 101 can shorten the calibration time.

（第３実施形態）
第３実施形態に係る成分濃度測定装置について、第２実施形態に係る成分濃度測定装置と異なる点を中心に説明する。図３に、第３実施形態に係る成分濃度測定装置の概略図を示す。第３実施形態に係る成分濃度測定装置１０２では、偏波保持光出射手段１４０の光路に偏波保持光分割手段１８０がさらに挿入され、偏波保持光分割手段１８０に偏波保持光分岐路１７０がさらに接続され、偏波保持光分割手段１８０は、偏波保持光出射手段１４０を伝搬する光の偏波状態を保持しつつ偏波保持光出射手段１４０を伝搬する光を偏波保持光出射手段１４０及び偏波保持光分岐路１７０のそれぞれに分割し、偏波保持光分岐路１７０は、偏波保持光分割手段１８０で分割された光の偏波状態を保持しつつ偏波保持光分割手段１８０で分割された光を標準試料１９８に出射し、音波検出手段１５０は、偏波保持光分岐路１７０からの光によって標準試料１９８から発生する光音響信号を検出することが好ましい。 (Third embodiment)
The component concentration measuring apparatus according to the third embodiment will be described focusing on differences from the component concentration measuring apparatus according to the second embodiment. FIG. 3 shows a schematic diagram of a component concentration measuring apparatus according to the third embodiment. In the component concentration measurement apparatus 102 according to the third embodiment, a polarization maintaining light splitting unit 180 is further inserted in the optical path of the polarization maintaining light emitting unit 140, and the polarization maintaining light splitting path 170 is connected to the polarization maintaining light splitting unit 180. Are further connected, and the polarization maintaining light splitting unit 180 outputs the light propagating through the polarization maintaining light emitting unit 140 while maintaining the polarization state of the light propagating through the polarization maintaining light emitting unit 140. The polarization maintaining light branching path 170 is divided into the polarization maintaining light splitting section 170 while maintaining the polarization state of the light split by the polarization maintaining light splitting section 180. The light divided by the means 180 is emitted to the standard sample 198, and the sound wave detection means 150 preferably detects the photoacoustic signal generated from the standard sample 198 by the light from the polarization maintaining optical branching path 170.

偏波保持光分割手段１８０は、例えば、偏波保持光出射手段１４０の光路の中間に挿入される。偏波保持光分割手段１８０としては、例えば、光ファイバ結合型スプリッタ、又は、ビームスプリッタを用いた空間フィルタ型スプリッタがある。偏波保持光分割手段１８０は、分割した光が、繰り返し再現性に優れ、測定誤差が発生しにくい利点がある。   The polarization maintaining light splitting unit 180 is inserted in the middle of the optical path of the polarization maintaining light emitting unit 140, for example. As the polarization maintaining light splitting unit 180, for example, there is an optical fiber coupling type splitter or a spatial filter type splitter using a beam splitter. The polarization maintaining light splitting means 180 has an advantage that the split light is excellent in repeatability and hardly causes measurement errors.

偏波保持光合波手段１２０で合波された光は、偏波保持光出射手段１４０の中間で偏波保持光分割手段１８０によって偏波保持光出射手段１４０の出射口１４１の側及び偏波保持光分岐路１７０の出射口１７１の側に分割され、被測定物１９９及び標準試料１９８の両方に出射される。   The light combined by the polarization maintaining light combining unit 120 is provided between the polarization maintaining light emitting unit 140 and the polarization maintaining light splitting unit 180 in the middle of the polarization maintaining light emitting unit 140. The light is divided into the exit 171 side of the optical branching path 170 and emitted to both the object to be measured 199 and the standard sample 198.

光変調手段１１０で出力された光が標準試料１９８に出射されるまで、偏波保持光合波手段１２０、偏波保持光伝搬手段１３０、偏波保持光出射手段１４０、偏波保持光分岐路１７０及び偏波保持光分割手段１８０によって光の偏波状態が保持されるので、成分濃度測定装置１０２は、被測定物１９９の成分濃度の測定誤差が減少させ、標準試料１９８を用いた校正精度を向上させることができる。さらに、成分濃度測定装置１０２は、第２実施形態に係る成分濃度測定装置と同様に、校正時間を短縮し、校正精度を向上させることができる。   Until the light output from the light modulation means 110 is emitted to the standard sample 198, the polarization maintaining light multiplexing means 120, the polarization maintaining light propagation means 130, the polarization maintaining light emitting means 140, and the polarization maintaining light branching path 170 Since the polarization state of the light is held by the polarization maintaining light splitting unit 180, the component concentration measuring apparatus 102 reduces the measurement error of the component concentration of the object 199 to be measured, and the calibration accuracy using the standard sample 198 is improved. Can be improved. Furthermore, the component concentration measuring apparatus 102 can shorten the calibration time and improve the calibration accuracy, similarly to the component concentration measuring apparatus according to the second embodiment.

本発明に係る成分濃度測定装置は、日常の健康管理や美容上のチェックに利用することができる。また、人間ばかりでなく、動物についても健康管理に利用することができる。また、本発明に係る成分濃度測定装置は、人間や動物だけではなく、液体中の成分濃度を測定する分野、例えば果実の糖度測定にも適用することができる。   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.

第１実施形態に係る成分濃度測定装置の概略図である。It is the schematic of the component concentration measuring apparatus which concerns on 1st Embodiment. 第２実施形態に係る成分濃度測定装置の概略図である。It is the schematic of the component concentration measuring apparatus which concerns on 2nd Embodiment. 第３実施形態に係る成分濃度測定装置の概略図である。It is the schematic of the component concentration measuring apparatus which concerns on 3rd Embodiment. 従来の光音響法による従来の血液成分濃度測定装置の構成例を示す図である。It is a figure which shows the structural example of the conventional blood component concentration measuring apparatus by the conventional photoacoustic method. 従来の光音響法による従来の血液成分濃度測定装置の構成例を示す図である。It is a figure which shows the structural example of the conventional blood component concentration measuring apparatus by the conventional photoacoustic method.

符号の説明Explanation of symbols

１００，１０１，１０２：成分濃度測定装置
１１０：光変調手段
１１１，１１１ａ，１１１ｂ：駆動回路
１１２，１１２ａ，１１２ｂ：光源
１１３：遅延調整器
１１４：発振器
１２０：偏波保持光合波手段
１３０，１３０ａ，１３０ｂ：偏波保持光伝搬手段
１４０：偏波保持光出射手段
１４１，１７１：出射口
１５０：音波検出手段
１５１：音波検出器
１５２：前置増幅器
１５３：位相検波増幅器
１５４：光音響信号出力端子
１５５：成分濃度算出部
１５６：電気スイッチ
１６０：偏波保持光切替手段
１７０：偏波保持光分岐路
１８０：偏波保持光分割手段
１９８：標準試料
１９９：被測定物
６０１：第１の光源
６０４：駆動回路
６０５：第２の光源
６０８：駆動回路
６０９：合波部
６１０：被測定物
６１３：超音波検出器
６１６：パルス光源
６１７：チョッパ板
６１８：モータ
６１９：音響センサ
６２０：波形観測器
６２１：周波数解析器 100, 101, 102: Component concentration measuring device 110: Optical modulation means 111, 111a, 111b: Drive circuits 112, 112a, 112b: Light source 113: Delay adjuster 114: Oscillator 120: Polarization-maintaining optical multiplexing means 130, 130a, 130b: Polarization-maintaining light propagation means 140: Polarization-maintaining light emitting means 141, 171: Outlet 150: Sound wave detecting means 151: Sound wave detector 152: Preamplifier 153: Phase detection amplifier 154: Photoacoustic signal output terminal 155 : Component concentration calculator 156: electrical switch 160: polarization maintaining light switching means 170: polarization maintaining light branching path 180: polarization maintaining light splitting means 198: standard sample 199: object to be measured 601: first light source 604: Drive circuit 605: second light source 608: drive circuit 609: multiplexer 610: object to be measured 613: ultrasonic detector 616: pulsed light 617: chopper plate 618: Motor 619: acoustic sensor 620: waveform observer 621: Frequency analyzer

Claims (6)

互いに異なる波長の２波の光を同一周波数で逆位相の信号によりそれぞれ電気的に強度変調する光変調手段と、
前記光変調手段で変調された前記２波の光の偏波状態を保持しつつ前記光変調手段で変調された前記２波の光を合波する偏波保持光合波手段と、
前記光変調手段と前記偏波保持光合波手段とを接続し、前記２波の光の偏波状態を保持しつつ前記２波の光のそれぞれを伝搬する偏波保持光伝搬手段と、
前記偏波保持光合波手段で合波された光の偏波状態を保持しつつ前記偏波保持光合波手段で合波された光を被測定物に出射する偏波保持光出射手段と、
前記偏波保持光出射手段からの光によって前記被測定物から発生する光音響信号を検出する音波検出手段と、を備える成分濃度測定装置。 Light modulation means for electrically intensity-modulating two waves of different wavelengths with signals of the same frequency and opposite phase;
Polarization maintaining optical multiplexing means for multiplexing the two waves of light modulated by the light modulation means while maintaining the polarization state of the two waves of light modulated by the light modulation means;
Polarization maintaining light propagating means for propagating each of the two waves of light while connecting the optical modulation means and the polarization maintaining optical multiplexing means, and maintaining the polarization state of the two waves of light;
Polarization maintaining light emitting means for emitting the light combined by the polarization maintaining light combining means to the object to be measured while maintaining the polarization state of the light combined by the polarization maintaining light combining means;
A component concentration measuring apparatus comprising: a sound wave detecting unit that detects a photoacoustic signal generated from the object to be measured by light from the polarization maintaining light emitting unit. 前記偏波保持光出射手段の光路に偏波保持光切替手段がさらに挿入され、前記偏波保持光切替手段に偏波保持光分岐路がさらに接続され、
前記偏波保持光切替手段は、前記偏波保持光出射手段を伝搬する光の偏波状態を保持しつつ前記偏波保持光出射手段を伝搬する光を前記偏波保持光出射手段又は前記偏波保持光分岐路のいずれか一方に分岐させ、
前記偏波保持光分岐路は、前記偏波保持光切替手段で分岐された光の偏波状態を保持しつつ前記偏波保持光切替手段で分岐された光を標準試料に出射し、
前記音波検出手段は、前記偏波保持光分岐路からの光によって前記標準試料から発生する光音響信号を検出することを特徴とする請求項１に記載の成分濃度測定装置。 A polarization maintaining light switching means is further inserted in the optical path of the polarization maintaining light emitting means, and a polarization maintaining light branching path is further connected to the polarization maintaining light switching means,
The polarization maintaining light switching unit is configured to transmit light propagating through the polarization maintaining light emitting unit while maintaining a polarization state of light propagating through the polarization maintaining light emitting unit. Branch to one of the wave-holding optical branch paths,
The polarization maintaining light branch path emits the light branched by the polarization maintaining light switching unit to the standard sample while maintaining the polarization state of the light branched by the polarization maintaining light switching unit,
2. The component concentration measuring apparatus according to claim 1, wherein the sound wave detecting unit detects a photoacoustic signal generated from the standard sample by light from the polarization maintaining optical branching path. 前記偏波保持光出射手段の光路に偏波保持光分割手段がさらに挿入され、前記偏波保持光分割手段に偏波保持光分岐路がさらに接続され、
前記偏波保持光分割手段は、前記偏波保持光出射手段を伝搬する光の偏波状態を保持しつつ前記偏波保持光出射手段を伝搬する光を前記偏波保持光出射手段及び前記偏波保持光分岐路のそれぞれに分割し、
前記偏波保持光分岐路は、前記偏波保持光分割手段で分割された光の偏波状態を保持しつつ前記偏波保持光分割手段で分割された光を標準試料に出射し、
前記音波検出手段は、前記偏波保持光分岐路からの光によって前記標準試料から発生する光音響信号を検出することを特徴とする請求項１に記載の成分濃度測定装置。 A polarization maintaining light splitting means is further inserted in the optical path of the polarization maintaining light emitting means, and a polarization maintaining light branching path is further connected to the polarization maintaining light splitting means,
The polarization maintaining light splitting unit is configured to transmit light propagating through the polarization maintaining light emitting unit while maintaining a polarization state of light propagating through the polarization maintaining light emitting unit. Split into each of the wave-holding optical branch paths,
The polarization maintaining light branch path emits the light split by the polarization maintaining light splitting means to a standard sample while maintaining the polarization state of the light split by the polarization maintaining light splitting means,
2. The component concentration measuring apparatus according to claim 1, wherein the sound wave detecting unit detects a photoacoustic signal generated from the standard sample by light from the polarization maintaining optical branching path. 前記偏波保持光分岐路は、偏波保持光ファイバであることを特徴とする請求項２又は３に記載の成分濃度測定装置。   The component concentration measuring apparatus according to claim 2, wherein the polarization maintaining optical branch path is a polarization maintaining optical fiber. 前記偏波保持光伝搬手段は、偏波保持光ファイバであることを特徴とする請求項１から４のいずれかに記載の成分濃度測定装置。   The component concentration measuring apparatus according to claim 1, wherein the polarization maintaining light propagation means is a polarization maintaining optical fiber. 前記偏波保持光出射手段は、偏波保持光ファイバであることを特徴とする請求項１から５のいずれかに記載の成分濃度測定装置。   6. The component concentration measuring apparatus according to claim 1, wherein the polarization maintaining light emitting means is a polarization maintaining optical fiber.
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JP2013106874A (en) * 2011-11-24 2013-06-06 Nippon Telegr & Teleph Corp <Ntt> Component concentration measuring method and device

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JPH10267631A (en) * 1997-03-26 1998-10-09 Kowa Co Optical measuring instrument
JP2000037355A (en) * 1998-07-24 2000-02-08 Fuji Photo Film Co Ltd Method for measuring glucose concentration and apparatus therefor
WO2005107592A1 (en) * 2004-05-06 2005-11-17 Nippon Telegraph And Telephone Corporation Component concentration measuring device and method of controlling component concentration measuring device

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JPH10267631A (en) * 1997-03-26 1998-10-09 Kowa Co Optical measuring instrument
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WO2005107592A1 (en) * 2004-05-06 2005-11-17 Nippon Telegraph And Telephone Corporation Component concentration measuring device and method of controlling component concentration measuring device

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* Cited by examiner, † Cited by third party
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CN101799404A (en) * 2010-03-16 2010-08-11 中国科学院安徽光学精密机械研究所 Quartz tuning fork photoacoustic gas sensing device based on broadband light source dual-wavelength difference
JP2013106874A (en) * 2011-11-24 2013-06-06 Nippon Telegr & Teleph Corp <Ntt> Component concentration measuring method and device

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