JPH0588608B2 - - Google Patents
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- Publication number
- JPH0588608B2 JPH0588608B2 JP1196209A JP19620989A JPH0588608B2 JP H0588608 B2 JPH0588608 B2 JP H0588608B2 JP 1196209 A JP1196209 A JP 1196209A JP 19620989 A JP19620989 A JP 19620989A JP H0588608 B2 JPH0588608 B2 JP H0588608B2
- Authority
- JP
- Japan
- Prior art keywords
- light
- oxygen saturation
- wavelength
- absorbance
- blood
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
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- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 53
- 229910052760 oxygen Inorganic materials 0.000 claims description 53
- 239000001301 oxygen Substances 0.000 claims description 53
- 238000002835 absorbance Methods 0.000 claims description 24
- 239000008280 blood Substances 0.000 claims description 19
- 210000004369 blood Anatomy 0.000 claims description 19
- 238000004364 calculation method Methods 0.000 claims description 15
- 238000005259 measurement Methods 0.000 claims description 14
- 102100023170 Nuclear receptor subfamily 1 group D member 1 Human genes 0.000 description 7
- 108010054147 Hemoglobins Proteins 0.000 description 6
- 102000001554 Hemoglobins Human genes 0.000 description 6
- 230000009102 absorption Effects 0.000 description 5
- 238000010521 absorption reaction Methods 0.000 description 5
- 239000004576 sand Substances 0.000 description 5
- 238000001514 detection method Methods 0.000 description 4
- 238000011088 calibration curve Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- INGWEZCOABYORO-UHFFFAOYSA-N 2-(furan-2-yl)-7-methyl-1h-1,8-naphthyridin-4-one Chemical compound N=1C2=NC(C)=CC=C2C(O)=CC=1C1=CC=CO1 INGWEZCOABYORO-UHFFFAOYSA-N 0.000 description 1
- 108010064719 Oxyhemoglobins Proteins 0.000 description 1
- 238000000862 absorption spectrum Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 108010002255 deoxyhemoglobin Proteins 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 229910052736 halogen Inorganic materials 0.000 description 1
- 150000002367 halogens Chemical class 0.000 description 1
- 230000031700 light absorption Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000000241 respiratory effect Effects 0.000 description 1
- 210000003437 trachea Anatomy 0.000 description 1
Landscapes
- Investigating Or Analysing Materials By Optical Means (AREA)
- Measurement Of The Respiration, Hearing Ability, Form, And Blood Characteristics Of Living Organisms (AREA)
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、酸素飽和度測定装置、特に、光を用い
て血液の酸素飽和度を非観血的に測定するための
酸素飽和度測定装置に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an oxygen saturation measuring device, particularly an oxygen saturation measuring device for non-invasively measuring blood oxygen saturation using light. Regarding.
例えば、動脈血の酸素飽和度の検査は、呼吸作
用（ガス交換作用）の最終結果である静脈血の動
脈血化を知る上で重要な検査であり、臨床的に大
きな意味を持つ。ところで、血色素は、酸化ヘモ
グロビン（酸素化ヘモグロビン）と還元ヘモグロ
ビン（脱酸素化ヘモグロビン）とで、第２図に示
すように光の吸収スペクトラムが異なる。波長
805nmは、ヘモグロビンの酸素化、脱酸素化にか
かわらず同じ吸収を示し、等吸収点と呼ばれる。
805nmより短波長である赤領域の光（波長600〜
750nm程度）では脱酸素化ヘモグロビンによる吸
収が大きく、805nmより長波長である近赤外領域
の光（波長810nm〜850nm程度）では酸素化ヘモ
グロビンによる吸収が大きい。
For example, testing the oxygen saturation of arterial blood is an important test for understanding the conversion of venous blood to arterial blood, which is the final result of respiratory action (gas exchange action), and has great clinical significance. By the way, as shown in FIG. 2, hemoglobin has different light absorption spectra between oxyhemoglobin (oxygenated hemoglobin) and deoxyhemoglobin (deoxygenated hemoglobin). wavelength
805 nm shows the same absorption regardless of whether hemoglobin is oxygenated or deoxygenated, and is called the isosbestic point.
Light in the red region with a wavelength shorter than 805 nm (wavelength 600~
750 nm), absorption by deoxygenated hemoglobin is large, and light in the near-infrared region, which has a wavelength longer than 805 nm (wavelengths of about 810 nm to 850 nm), is largely absorbed by oxygenated hemoglobin.
上述の特性を利用した従来の酸素飽和度測定装
置は、生体に対して光を照射する発光部と、生体
を透過した発光部からの光の強さを測定する受光
部とを備えている。この発光部と受光部とによつ
て、従来は、２種類の波長の透過光量が測定され
ていた。それらの波長は、血液中の酸素飽和度が
変わつても吸光度が変わらない波長（例えば
805nm）と、吸光度が大きく変わる波長（例えば
730nm）とである。この２つの波長における透過
光量の比2／I1は血液の酸素飽和度と直線関係
にあるので、予めその比例定数を定めておき、そ
れに基づいて酸素飽和度を演算することができ
る。すなわち、
〔酸素飽和度〕＝Ａ−Ｂ（I2／I1）
が成立するので、予め実験的に係数Ａ，Ｂを定め
ておき、実際の透過光量I2，I1から酸素飽和度が
求められる。 A conventional oxygen saturation measuring device using the above characteristics includes a light emitting section that irradiates light onto a living body, and a light receiving section that measures the intensity of light from the light emitting section that has passed through the living body. Conventionally, the amounts of transmitted light of two different wavelengths have been measured using the light emitting section and the light receiving section. These wavelengths are those whose absorbance does not change even if the oxygen saturation in the blood changes (e.g.
805nm) and wavelengths at which the absorbance changes significantly (e.g.
730nm). Since the ratio 2 /I 1 of the amount of transmitted light at these two wavelengths has a linear relationship with the oxygen saturation of the blood, the proportionality constant can be determined in advance and the oxygen saturation can be calculated based on it. In other words, [oxygen saturation] = A - B (I 2 / I 1 ) holds, so the coefficients A and B are determined experimentally in advance, and the oxygen saturation is calculated from the actual transmitted light amounts I 2 and I 1 . Desired.
前記従来の構成では、透過光量の比I2／I1から
較正曲線を得、その較正曲線に基づいて実際の測
定値から酸素飽和度を演算するのであるが、得ら
れる較正曲線の勾配は小さく、それに基づく演算
の精度を十分に高めることができない。
In the conventional configuration, a calibration curve is obtained from the ratio of transmitted light amount I 2 /I 1 , and oxygen saturation is calculated from the actual measured value based on the calibration curve, but the slope of the obtained calibration curve is small. , it is not possible to sufficiently improve the accuracy of calculations based on it.
本発明の目的は、精度の良い酸素飽和度の測定
を行い易くすることにある。 An object of the present invention is to facilitate accurate measurement of oxygen saturation.
本発明に係る酸素飽和度測定装置は、光を用い
て生体中の血液の酸素飽和度を測定するための装
置である。この装置は、生体に対して光を照射す
る発光部と、生体を透過した発光部からの光の強
さを測定する受光部と、受光部からの信号を受け
て演算を行う演算手段とを備えている。前記演算
手段は、血液の酸素飽和度の変化に応じて吸光度
が逆に変化する波長780nm及び波長830nmと、血
液の酸素飽和度が変化しても吸光度が変化しない
波長805nmとに基づく受光部からの信号を受け、
酸素飽和度を演算する手段である。
The oxygen saturation measuring device according to the present invention is a device for measuring the oxygen saturation of blood in a living body using light. This device includes a light emitting part that irradiates light onto a living body, a light receiving part that measures the intensity of light from the light emitting part that has passed through the living body, and a calculation means that performs calculations based on signals from the light receiving part. We are prepared. The arithmetic means is configured to calculate from a light receiving section based on a wavelength of 780 nm and a wavelength of 830 nm, at which the absorbance changes inversely according to a change in the oxygen saturation of the blood, and a wavelength of 805 nm, at which the absorbance does not change even when the oxygen saturation of the blood changes. receive the signal of
This is a means of calculating oxygen saturation.
本発明に係る酸素飽和度測定装置では、発光部
が生体に対して光を照射する。受光部は、生体を
透過した発光部からの光の強さを測定する。そし
て、演算手段では、血液の酸素飽和の変化に応じ
て吸光度が逆に変化する波長780nm及び波長
830nmと、血液の酸素飽和度によつて吸光度が変
化しない波長805nmとに基づく受光部からの信号
を受け、酸素飽和度を演算する。
In the oxygen saturation measuring device according to the present invention, the light emitting section irradiates the living body with light. The light receiving section measures the intensity of light from the light emitting section that has passed through the living body. The calculation means uses a wavelength of 780 nm and a wavelength at which the absorbance changes inversely according to changes in blood oxygen saturation.
The oxygen saturation is calculated by receiving signals from the light receiving section based on 830 nm and a wavelength of 805 nm, the absorbance of which does not change depending on the oxygen saturation of the blood.
この場合には血液の酸素飽和度の変化に応じて
吸光度が逆に変化する波長780nm及び波長830nm
に基づいて演算を行うので、両波長を用いた測定
結果の差を取ることにより、変化をより大きくと
らえることが可能になる。このため、本発明によ
れば演算精度が向上する。 In this case, the wavelengths 780nm and 830nm, where the absorbance changes inversely according to changes in blood oxygen saturation, are used.
Since calculations are performed based on , it is possible to grasp changes more greatly by taking the difference between the measurement results using both wavelengths. Therefore, according to the present invention, calculation accuracy is improved.
また、使用する波長が780〜830nmの範囲内に
あるので、発光部として用い得る光源の自由度が
高く、必要に応じて適切な光源を使用できる。受
光部についても、受光波長領域は800nm前後と狭
いので、簡素な構成なものを使用できる。 Further, since the wavelength used is within the range of 780 to 830 nm, there is a high degree of freedom in the light source that can be used as the light emitting section, and an appropriate light source can be used as necessary. As for the light-receiving section, the light-receiving wavelength range is narrow, around 800 nm, so a simple structure can be used.
さらに、使用する波長が780〜830nmの範囲内
であれば、短波長のときに影響が大きいレーリー
散乱による減衰は小さく、しかも脂肪の吸収ピー
クからは低く外れているので、生体に対する測定
を行い易い。 Furthermore, if the wavelength used is within the range of 780 to 830 nm, the attenuation due to Rayleigh scattering, which has a large effect at short wavelengths, is small, and it is low and deviates from the absorption peak of fat, making it easy to perform measurements on living organisms. .
したがつて、精度の良い酸素飽和度の測定が容
易に行えるようになる。 Therefore, it becomes possible to easily measure oxygen saturation with high accuracy.
本発明の一実施例を第１図に示す。この実施例
は、人間の耳部分の血液の酸素飽和度を測定する
ための装置である。
An embodiment of the present invention is shown in FIG. This example is a device for measuring the oxygen saturation level of blood in the human ear.
第１図に示す酸素飽和度測定装置は、耳１にお
いて測定を行うための測定部２と、測定部２を制
御するための制御部３とを主として有している。
制御部３には、測定部２が電気的に接続されると
ともに、さらに表示用のLCD４と指令入力用の
キーボード５とが接続されている。 The oxygen saturation measurement device shown in FIG. 1 mainly includes a measurement section 2 for performing measurements in the ear 1 and a control section 3 for controlling the measurement section 2.
The control section 3 is electrically connected to the measuring section 2, and further connected to an LCD 4 for display and a keyboard 5 for inputting commands.
前記測定部２は、第１波長λ1（例えば780nm）
の光を発するLED６と、第２波長λ2（例えば
830nm）の光を発するLED７と、第３の波長λ3
（例えば805nm）の光を発するLED８とを有して
いる。これらLED６，７，８が発光部となる。
一方、発光部に対向して受光部９が配置されてい
る。LED６，７，８と受光部９との間には、カ
フ１０を介して耳１が挟まれるようになつてい
る。 The measurement unit 2 has a first wavelength λ 1 (for example, 780 nm)
LED 6 that emits light of λ 2 and a second wavelength λ 2 (e.g.
830nm) and a third wavelength λ 3
(for example, 805 nm). These LEDs 6, 7, and 8 serve as a light emitting section.
On the other hand, a light receiving section 9 is arranged opposite to the light emitting section. The ear 1 is sandwiched between the LEDs 6, 7, 8 and the light receiving section 9 via the cuff 10.
LED６，７，８は、ドライバ１１を介して制
御部３のＩ／Ｏポート１２に接続されている。ま
た、受光部９の出力端子は、Ａ／Ｄコンバータ１
３を介して制御部３のＩ／Ｏポート１２に接続さ
れている。さらに、カフ１０への加圧エアの調整
を行うためのエア圧調整装置１４も、Ｉ／Ｏポー
ト１２に接続されている。 The LEDs 6, 7, and 8 are connected to the I/O port 12 of the control unit 3 via the driver 11. Furthermore, the output terminal of the light receiving section 9 is connected to the A/D converter 1.
3 to the I/O port 12 of the control unit 3. Further, an air pressure adjustment device 14 for adjusting pressurized air to the cuff 10 is also connected to the I/O port 12.
制御部３は、CPU１５、ROM１５、RAM１
７等を備えたマイクロコンピユータを有しおり、
その入出力はＩ／Ｏポート１２を介して行われ
る。Ｉ／Ｏポートには、LCD４及びキーボード
５もそれぞれ接続されている。 The control unit 3 includes a CPU 15, a ROM 15, and a RAM 1.
It has a microcomputer equipped with 7 etc.
The input/output is performed via the I/O port 12. An LCD 4 and a keyboard 5 are also connected to the I/O ports.
次に、上述の実施例の動作を、第３図に示すフ
ローチヤートにしたがつて説明する。制御部３に
おけるプログラムがスタートすれば、第３図のス
テツプS1においてLCD４に「０」を表示する等
の初期設定が行われる。次に、ステツプS2にお
いてカフ１０がセツトされたか否かを判断する。
操作者は、耳１にカフ１０をセツトするととも
に、LED６，７，８及び受光部９をカフ１０及
び耳１を介して互いに対向させるように配置し、
そしてキーボード５からセツト完了指令を入力す
る。 Next, the operation of the above embodiment will be explained according to the flowchart shown in FIG. When the program in the control section 3 starts, initial settings such as displaying "0" on the LCD 4 are performed in step S1 in FIG. Next, in step S2, it is determined whether the cuff 10 is set.
The operator sets the cuff 10 on the ear 1, and arranges the LEDs 6, 7, 8 and the light receiving part 9 to face each other through the cuff 10 and the ear 1,
Then, a set completion command is input from the keyboard 5.
セツト完了指令が入力されれば、プログラムはス
テツプS3に移行する。If the set completion command is input, the program moves to step S3.
次に、ステツプS3において測定開始指令を待
つ。操作者がキーボード５から測定開始指令を入
力すれば、ステツプS4に移行する。ステツプS4
では、LED６が点灯し、LED６から波長λ1の光
が耳１に照射される。耳１を通過した光は受光部
９で検出される。受光部９では、光の強さに応じ
た電圧値を出力する。電圧値はＡ／Ｄコンパレー
タ１３でデジタル信号に変換された後、制御部３
に入力される。制御部３では、その電圧値を
RAM１７に記憶する。次に、ステツプS5におい
て、LED７を点灯させる。これによつて波長λ2
を用いた検出が行われ、その検出結果も制御部３
のRAM１７に記憶される。同様に、ステツプS6
では、LED８が点灯して波長λ3用いた検出が行
われ、その検出結果もRAM１７に記憶される。 Next, in step S3, a measurement start command is awaited. If the operator inputs a measurement start command from the keyboard 5, the process moves to step S4. Step S4
Then, the LED 6 is turned on, and the ear 1 is irradiated with light of wavelength λ 1 from the LED 6. The light passing through the ear 1 is detected by the light receiving section 9. The light receiving section 9 outputs a voltage value according to the intensity of light. After the voltage value is converted into a digital signal by the A/D comparator 13, the control unit 3
is input. In the control section 3, the voltage value is
Store in RAM17. Next, in step S5, the LED 7 is turned on. This makes the wavelength λ 2
Detection is performed using the control unit 3, and the detection result is also
is stored in the RAM 17 of. Similarly, step S6
Then, the LED 8 is turned on and detection using the wavelength λ 3 is performed, and the detection result is also stored in the RAM 17.
次に、ステツプS7では、エア圧調整装置１４
を駆動し、カフ１０をふくらませて所定圧で耳１
を圧止する。その状態で、ステツプS4，S5，S6
と同様に、波長λ1，λ2，λ3を用いた測定がそれぞ
れステツプS8，S9，S10で行われる。 Next, in step S7, the air pressure adjustment device 14
to inflate the cuff 10 and apply a predetermined pressure to the ear 1.
to suppress. In that state, step S4, S5, S6
Similarly, measurements using wavelengths λ 1 , λ 2 , and λ 3 are performed in steps S8, S9, and S10, respectively.
ステツプS11では、ステツプS5，S6，S7，S8，
S9，S10における測定結果に基づいて酸素飽和度
が演算される。演算結果は、ステツプS12におい
てLCD４に表示される。表示処理が終わればス
テツプS3に再び戻る。 In step S11, steps S5, S6, S7, S8,
Oxygen saturation is calculated based on the measurement results in S9 and S10. The calculation result is displayed on the LCD 4 in step S12. When the display processing is completed, the process returns to step S3.
ここで、ステツプS11における演算について説
明する。 Here, the calculation in step S11 will be explained.
780nm（波長λ1）を用いて吸光度を測定した場
合と、830nm（波長λ2）を用いて吸光度を測定し
た場合とでは、血液中の酸素飽和度が変化した際
に、一方の吸収が増大すれば他方の吸収が減少す
るという関係にある。そこで、ステツプS11にお
ける演算式の一例として、次式を用いる。 When absorbance is measured using 780nm (wavelength λ 1 ) and when absorbance is measured using 830nm (wavelength λ 2 ), when the oxygen saturation in the blood changes, one of the absorptions increases. If one does, the absorption of the other will decrease. Therefore, the following equation is used as an example of the calculation equation in step S11.
〔酸素飽和度〕＝Ａ−Ｂ（I780−I830）／I805 ここで、Ａ，Ｂは係数、Ｉは透過光量である。[Oxygen saturation] = AB (I 780 - I 830 )/I 805 where A and B are coefficients, and I is the amount of transmitted light.
上式のように、780nm（波長λ1）における吸光
度と830nm（波長λ2）における吸光度との差をと
ることにより、酸素飽和度の変化に対する吸光度
の変化を大きく捕らえることができる。なお、係
数Ａ，Ｂは、予め実験的に求められることがで
き、多数の実験結果から回帰的に決定される。こ
の係数は、予めROM１６に記憶されており、必
要に応じて演算の際に利用される。 As shown in the above equation, by taking the difference between the absorbance at 780 nm (wavelength λ 1 ) and the absorbance at 830 nm (wavelength λ 2 ), it is possible to largely capture changes in absorbance with respect to changes in oxygen saturation. Note that the coefficients A and B can be obtained experimentally in advance, and are determined recursively from a large number of experimental results. This coefficient is stored in the ROM 16 in advance and is used in calculations as necessary.
この実施例によれば、血液の酸素飽和度の変化
に応じて吸光度が逆に変化する第１及び第２波長
λ1，λ2と、血液の酸素飽和度の変化によつては吸
光度が変化しない第３波長λ3とから酸素飽和度を
演算するので、わずかな酸素飽和度の変化であつ
ても演算結果が大きく変化し、その結果得られた
酸素飽和度の値の精度が向上する。 According to this embodiment, the first and second wavelengths λ 1 and λ 2 have absorbances that change inversely depending on changes in blood oxygen saturation, and absorbance changes depending on changes in blood oxygen saturation. Since the oxygen saturation is calculated from the third wavelength λ 3 that does not change, even a slight change in the oxygen saturation causes a large change in the calculation result, and as a result, the accuracy of the obtained oxygen saturation value is improved.
なお、本発明を実施するにあたり、発光部とし
ては、LEDに限られることはなく、例えばレー
ザダイオード等のレーザーやハロゲンランプ等を
用いることもできる。白色光を光源とする場合に
は、所定の波長を得るためにフイルターを設ける
必要があるが、そのフイルターは発光部側あるい
は受光部側のいずれに設けられてもよい。また、
使用する波長としては780nm、830nm及び805nm
に限られることはない。第１波長及び第２波長
は、酸素飽和度により吸光度が逆に変化する波長
であれば他の波長を使用してもよい。第３波長と
しては、第１波長及び第２波長の変化よりも変化
が小さく、実質的に酸素飽和度が変化しても吸光
度は変化しないと見なしうる波長であればよい。
さらに、上述の実施例では、受光部９によつて透
過光測定を行つたが、反射光を測定する構成とし
てもよい。 In carrying out the present invention, the light emitting section is not limited to LEDs, and for example, lasers such as laser diodes, halogen lamps, and the like can also be used. When using white light as a light source, it is necessary to provide a filter in order to obtain a predetermined wavelength, but the filter may be provided on either the light emitting section side or the light receiving section side. Also,
The wavelengths used are 780nm, 830nm and 805nm.
It is not limited to. As the first wavelength and the second wavelength, other wavelengths may be used as long as the absorbance changes inversely depending on the oxygen saturation. The third wavelength may be any wavelength that changes less than the changes in the first wavelength and the second wavelength and can be considered to cause no change in absorbance even if the oxygen saturation changes substantially.
Furthermore, in the above-described embodiment, transmitted light was measured using the light receiving section 9, but a configuration may also be adopted in which reflected light is measured.
次に、本発明に係る実験例を説明する。 Next, an experimental example according to the present invention will be explained.
砂ネズミ（モンゴリアン・ジヤービル）の頭部
における透過光を測定した。第４図に示すよう
に、砂ネズミ２０の頭部上端にはレーザ発光部か
らの光を導くライトガイド２１を配置し、下端に
はレーザ受光部へ光を導くライトガイド２２を配
置した。発光部、受光部及びライトガイド２１，
２２は、第１図に示すLED６，７，８及び受光
部９に代えてこの実験では使用された。また、砂
ネズミ２０の気管を切開し、酸素供給用のカニユ
ーレ２３を接続した。そして、カニユーレ２３か
らの供給酸素濃度（吸入酸素濃度）を変化させ、
砂ネズミ２０の頭部における吸光度を測定した。
使用したレーザの波長は、780nm（第１波長λ1）
830nm（第２波長λ2）及び805nm（第３波長λ3）で
あつた。 The transmitted light in the head of a sand rat (Mongolian jaerbil) was measured. As shown in FIG. 4, a light guide 21 was placed at the upper end of the head of the sand mouse 20 to guide light from the laser light emitting section, and a light guide 22 was placed at the lower end to guide light to the laser light receiving section. light emitting section, light receiving section and light guide 21,
22 was used in this experiment in place of the LEDs 6, 7, 8 and light receiving section 9 shown in FIG. Further, the trachea of the sand mouse 20 was incised, and a cannula 23 for oxygen supply was connected thereto. Then, the supply oxygen concentration (inhaled oxygen concentration) from the cannula 23 is changed,
The absorbance at the head of sand rat 20 was measured.
The wavelength of the laser used was 780 nm (first wavelength λ 1 )
They were 830 nm (second wavelength λ 2 ) and 805 nm (third wavelength λ 3 ).
吸入酸素濃度を変化させて測定した結果を第５
図に示す。第５図から明らかなように、吸入酸素
濃度を上げれば、第１波長λ1を用いた場合の吸光
度は下がり、第２波長λ2を用いた場合の吸光度は
上昇した。また、第３波長のλ3での吸光度はほぼ
変化がなかつた。つまり、吸入酸素濃度が上がれ
ば、波長λ1による透過光量I1は上がり、波長λ2に
よる透過光量I2は下がり、波長λ3による透過光量
I3はほぼ変化がないことになる。なお、吸入酸素
濃度は、砂ネズミの血液中の酸素飽和度にほぼ対
応しているものと見なし得る。 The results measured by varying the inspired oxygen concentration are shown in the fifth section.
As shown in the figure. As is clear from FIG. 5, as the concentration of inspired oxygen was increased, the absorbance when using the first wavelength λ 1 decreased, and the absorbance when using the second wavelength λ 2 increased. Further, the absorbance at the third wavelength λ 3 remained almost unchanged. In other words, as the inspired oxygen concentration increases, the amount of transmitted light I 1 at wavelength λ 1 increases, the amount of transmitted light I 2 at wavelength λ 2 decreases, and the amount of transmitted light at wavelength λ 3 decreases.
I 3 will remain almost unchanged. Note that the inspired oxygen concentration can be considered to approximately correspond to the oxygen saturation level in the blood of the sand rat.
得られた第５図のデータを用いて、吸光度を透
過光量に換算し、ステツプS11（第３図）で使用
する演算式を適用して回帰式を得た。その回帰式
を第６図に示す。また、第１図波長及び第３波長
を用いて従来の演算方法によつて得た回帰式を第
７図に示す。第７図と比較すれば明らかなよう
に、第６図では回帰式の傾斜が大きく、したがつ
てわずかな透過光量の変化に基づいて酸素飽和度
の変化を精度良く検出することができた。 Using the obtained data in FIG. 5, the absorbance was converted into the amount of transmitted light, and the arithmetic equation used in step S11 (FIG. 3) was applied to obtain a regression equation. The regression equation is shown in FIG. Further, FIG. 7 shows a regression equation obtained by a conventional calculation method using the wavelengths in FIG. 1 and the third wavelength. As is clear from a comparison with FIG. 7, the slope of the regression equation is large in FIG. 6, and therefore changes in oxygen saturation can be detected with high accuracy based on slight changes in the amount of transmitted light.
本発明に係る酸素飽和度測定装置によれば、上
述のような演算手段によつて波長780nm，805nm
及び830nmを用いた演算を行うことから、精度の
良い酸素飽和度の測定を行い易くなる。
According to the oxygen saturation measuring device according to the present invention, the wavelengths of 780 nm and 805 nm can be determined by the above-mentioned calculation means.
Since calculations are performed using 830nm and 830nm, it becomes easier to measure oxygen saturation with high accuracy.
第１図は本発明の一実施例の概略ブロツク図、
第２図は波長と吸光度との関係を示すグラフ、第
３図は制御フローチヤート、第４図は実験状態を
示す側面図、第５図は実験結果を示すグラフ、第
６図は第５図の実験結果に基づいて得た本発明に
係る回帰式を示すグラフ、第７図は第５図の実験
結果から得た従来例に係る回帰式を示すグラフで
ある。
２……測定部、３……制御部、６，７，８……
LED、９……受光部、１５……CPU。
FIG. 1 is a schematic block diagram of an embodiment of the present invention;
Figure 2 is a graph showing the relationship between wavelength and absorbance, Figure 3 is a control flowchart, Figure 4 is a side view showing the experimental conditions, Figure 5 is a graph showing the experimental results, and Figure 6 is Figure 5. FIG. 7 is a graph showing the regression equation according to the present invention obtained based on the experimental results of FIG. 5. FIG. 7 is a graph showing the regression equation according to the conventional example obtained from the experimental results of FIG. 2... Measuring section, 3... Control section, 6, 7, 8...
LED, 9...light receiving section, 15...CPU.
Claims (1)
血的に測定するための酸素飽和度測定装置であつ
て、 生体に対して光を照射する発光部と、 生体を通過した前記発光部からの光の強さを測
定する受光部と、 血液の酸素飽和度の変化に応じて吸光度が逆に
変化する波長780nm及び波長830nmと、血液の酸
素飽和度が変化しても吸光度が変化しない波長
805nmとに基づく前記受光部からの信号を受け、
酸素飽和度を演算する演算手段と、 を備えた酸素飽和度測定装置。[Scope of Claims] 1. An oxygen saturation measurement device for non-invasively measuring the oxygen saturation of blood in a living body using light, comprising: a light emitting unit that irradiates light onto the living body; A light receiving part that measures the intensity of the light from the light emitting part that has passed through the living body, a wavelength of 780 nm and a wavelength of 830 nm whose absorbance changes inversely according to changes in the oxygen saturation of the blood, and a light receiving part that measures the intensity of light from the light emitting part that has passed through the living body. Wavelengths at which the absorbance does not change even when
receiving a signal from the light receiving section based on 805 nm;
An oxygen saturation measurement device comprising: a calculation means for calculating oxygen saturation; and an oxygen saturation measuring device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1196209A JPH0360646A (en) | 1989-07-28 | 1989-07-28 | Oxygen saturation measuring device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1196209A JPH0360646A (en) | 1989-07-28 | 1989-07-28 | Oxygen saturation measuring device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0360646A JPH0360646A (en) | 1991-03-15 |
| JPH0588608B2 true JPH0588608B2 (en) | 1993-12-22 |
Family
ID=16354019
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1196209A Granted JPH0360646A (en) | 1989-07-28 | 1989-07-28 | Oxygen saturation measuring device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0360646A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6992772B2 (en) * | 2003-06-19 | 2006-01-31 | Optix Lp | Method and apparatus for optical sampling to reduce interfering variances |
| JP2008032123A (en) * | 2006-07-28 | 2008-02-14 | Aisin Ai Co Ltd | Lubricating structure of power distribution and transmission device |
| US8700111B2 (en) * | 2009-02-25 | 2014-04-15 | Valencell, Inc. | Light-guiding devices and monitoring devices incorporating same |
| JP5616303B2 (en) * | 2010-08-24 | 2014-10-29 | 富士フイルム株式会社 | Electronic endoscope system and method for operating electronic endoscope system |
| EP2718680B1 (en) | 2011-06-07 | 2023-12-27 | Measurement Specialties, Inc. | Optical sensing device for fluid sensing and method therefor |
-
1989
- 1989-07-28 JP JP1196209A patent/JPH0360646A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0360646A (en) | 1991-03-15 |
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