JP3740527B2 - Method and apparatus for measuring brain activity by near infrared spectroscopy - Google Patents

Description

【００１６】
一方、ｆＭＲＩによる脳活動の計測と解析については、(1)装置は、Siemens VISION(Germany),1.5T System、(2)撮像法は、GER-EPI法、(3)撮像パラメーターは、TR 3.9sec,TE 55.24msec, FA 90 degree、(4)スライスは、Axialスライス 32（厚さmm／１枚、間隔 0mm)、(5)ピクセルサイズ 4mm×4mm×4mm (Fov 256mm×256mm Matrix 64×64)である。解析は、(6)Motion CorrectionはAIR3.0、(7)AVS/Express、(8)構造画像と機能画像の重ね合わせは、Analyze PC2.5(Mayo Fundation)及びＳＰＭ９９を使用した。
【００１７】
測定は、ＭＲＩ装置の被験者の頭部を乗せる部分に、近赤外分光法で測定することができるように近赤外マッピング装置のプローブを置いた。ここで、本発明による方法は、ｆＭＲＩの測定と同時でもよく、また、同条件下でｆＭＲＩの測定の前後でNIRSの測定を行ってもよい。NIRSの測定は、CW型近赤外分光装置、時間分解型近赤外分光装置、又は周波数領域を使った強度変調型を用いることが挙げられる。
【００１８】
測定結果は、NIRSの測定とｆＭＲＩの測定で、上述の条件による実験では、活動部位の検出については両測定とも、同じ領域が活動されていることが示された。次に、NIRSの測定では、視覚刺激に伴う後頭部ヘモグロビンの変化は、図３のグラフに示したように、0.5Hz及び14Hzの刺激で全ヘモグロビン量及び酸素化ヘモグロビン量の増加が大きいことが示された。
【００１９】
一方、ｆＭＲＩの測定では、図４に示すように1.4Hz及び4.7Hzで大きな信号強度が見られた。グラフ横軸は時間（秒）を表し、縦軸は当該活動部位の信号強度を表している。Correlation Coefficient（相関係数）はボックススカーフィッチングで、信号変化がタスク負荷にどれだけマッチしているのか相関を出したものであり、ｒが0.75以上であれば、相関が有ると示される。
【００２０】
また、図４では、fMRI信号と近赤外線を用いた測定（NIRS）の結果を同画面で表示したものである。ヘモグロビンパラメーターの測定は上述のように、７７６nm、８０４nm、８２８nmと４００msの間隔で順次測定した。ヘモグロビンパラメーターは、前記のModified Beer-Lambert法により算出した。上記式である（△Ｓ／Ｓ）rest= (TE・Ｒ2^*rest)・｛２△Ｙ/(1―Ｙrest) ― △［total-Hb］/［total-Hb］rest｝（第１式）若しくは、（△Ｓ／Ｓ）rest= (TE・Ｒ2^*rest)・｛△Ｙ/(1―Ｙrest) ― △［total-Hb］/［total-Hb］rest｝（第２式）に、これらヘモグロビンパラメーター等を代入して計算した。絶対値のヘモグロビン量は、時間分解型近赤外分光装置を用いることが適している。第１式は、細静脈での信号が反映される場合、第２式は、毛細血管での信号が反映される場合である。図４のfMRI信号はそのままのデータを表示し、細静脈と毛細血管の信号は、個々のヘモグロビンパラメーターを上記式に従って代入して算出されたグラフである。結果は２人の実験で同様の結果が得られ、本実施例では、ｆMRI信号は細静脈の信号が反映されていること、近赤外線の測定からｆMRI信号を算出できたことが示された。
【００２１】
【発明の効果】
本発明により、MRIの構造画像のデータ及び近赤外線の測定結果より、fMRIの測定でしか得られないfMRI信号強度（（△Ｓ／Ｓ）rest）を算出することができる。また、fMRI信号強度（（△Ｓ／Ｓ）rest）及び近赤外線の測定結果より、その信号の帰属部位が細静脈又は毛細血管であるかを判断することができる。
【図面の簡単な説明】
【図１】被験者に視覚刺激を与える手順を示す説明図
【図２】近赤外線を生体に照射及び受光するファイバー先端部を示す説明図
【図３】各視覚刺激におけるfMRI信号強度を示したグラフ
【図４】甲及び乙のfMRI及び近赤外線測定から算出したfMRI信号（細静脈・毛細血管）を経時的に示したグラフ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to brain activity measurement (hereinafter referred to as fMRI (functional MRI)) using a magnetic resonance imaging apparatus (hereinafter referred to as MRI) and brain activity activity means using light such as near infrared rays.
[0002]
[Prior art]
Non-invasive measurement of human biological functions includes a method for measuring electrical activity (MEG, EEG) and a method for measuring hemodynamics (fMRI, NIRS). The purpose of fMRI is to have a feature with high spatial resolution, to extract the activation region and grasp the functional distribution of the brain, and to observe the signal change rate in the activation region. From the measurement of this signal change rate, it can be used for research purposes such as elucidation of brain activity for a specific stimulus. In particular, in brain activity measurement, it is used as a routine means for identifying active sites.
[0003]
The principle of signal change in fMRI is based on the fact that the effective transverse relaxation time (T2 ^* ) of mobile protons in free water in the living body changes due to the change in magnetism based on the change in the amount of deoxygenated hemoglobin in the circulating blood. ing. For example, when oxygen binds to the iron atom of hemoglobin, it becomes oxygenated hemoglobin (corresponding to arterial blood), the magnetism disappears, and the effective lateral relaxation time (T2 ^* ) of mobile protons in free water in the living body increases. The parameter (ΔS / S) rest measured by fMRI reflects this change in T2 ^* . T2 relaxation called effective transverse relaxation in MRI is a time constant indicating a process in which the transverse magnetization component is attenuated, and means a signal obtained with an ideal uniform magnetic field. However, since the signal is actually attenuated faster than T2 due to the inhomogeneity of the magnetic field, this actual signal is expressed as T2 ^* (tea to star) and is distinguished from T2. fMRI captures signal changes in T2 ^* .
[0004]
If the brain is stimulated by vision, sound or the like, neurons in the cerebral cortex are excited and consume oxygen. Thereby, the amount of deoxygenated hemoglobin locally increases. Next, since the oxygen consumption is increased in the activated region, the blood flow and blood volume due to the inflow of arterial blood increase. That is, in the activated region, a change in magnetic properties due to an increase in oxyhemoglobin and a change in blood flow and blood volume occur simultaneously, which affect the fMRI signal.
Thus, T2 ^* is obtained as a result of mutually dependent parameters of blood flow, blood volume, and blood oxygenation state, which complicates interpretation of fMRI and causes confusion. However, the physiological information originally required is parameters of blood flow, blood volume, and blood oxygenation state from which these factors are separated, but the separation is impossible only by fMRI.
[0005]
In the past, qualitative transitions were predicted by substituting hypothetical values based on literature values for blood volume and blood oxygenation required for calculation models instead of actual measurement values. It was. Therefore, only such an fMRI signal estimation model has been proposed, and it is identified whether the information source is an arteriole region or a capillary region, and the blood flow and blood volume are determined from the fMRI signal change. The parameters of blood oxygenation status could not be separated and evaluated.
[0006]
On the other hand, in brain activity measurement using near-infrared light (near-infrared spectroscopy (NIRS)), information resulting from a change in light absorption characteristics of brain tissue can be obtained. Near-infrared rays refer to the wavelength region closest to the visible light region (about 400 to 700 nm) among infrared rays (about 700 to 3000 nm). Near-infrared light with a wavelength of around 800 nm has high biological permeability, light in the near-infrared region (700-1500 nm) has high biological permeability, and the light projected from the scalp passes through brain tissue, It becomes a reflector and can receive light from the scalp. Near-infrared spectroscopy uses the characteristic absorption band of hemoglobin in blood in this region, so that oxygenated hemoglobin (oxy-Hb), deoxygenated hemoglobin (deoxy-Hb) It has the feature that changes in Hb) and total hemoglobin ([total-Hb]) can be detected continuously. It has also been established as a measurement method that can handle changes in local cerebral blood volume (rCBV).
[0007]
[Problems to be solved by the invention]
Therefore, in the present invention, the (M / S) rest, which is an fMRI signal, is obtained from a brain function analysis using a signal obtained by MRI and near-infrared light, and the signal is obtained from venules, capillaries, etc. It is an object of the present invention to provide a means that contributes to providing a means for determining what kind of part the signal is.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problems, a brain activity measuring apparatus according to the present invention is a brain activity measuring apparatus using near infrared rays, in which an attached computer has at least an echo time (TE) and a resting time when MRI is input. Recorded the effective lateral relaxation time (T2 ^* rest), total hemoglobin measured by the brain activity measuring device ([total-Hb]), hemoglobin change at rest ([△ Hb]), blood oxygenation rate Means for recording at least the amount of change ([ΔY]), and applying these numerical values to the following equation, ΔS / Srest = (TE · T2 ^* rest) · {2ΔY / (1−Yrest ) ― △ [total-Hb] / [total-Hb] rest} (However, “rest” means “resting (resting)”, and [total-Hb] rest is “all resting” “Hemoglobin amount” and “Yrest” indicate the oxygenation rate of hemoglobin at rest) Δ is a functional MRI (fMRI) signal from the calculation result / Characterized by having a calculating means for calculating Srest the (variation ratio of from resting against MRI signal intensity at rest).
Similarly, the brain activity measuring method of the present invention is a brain activity measuring device using near infrared rays, and at least an input echo time (TE) at the time of MRI measurement and an effective lateral relaxation time at rest ( T2 ^* rest) is recorded, and the total hemoglobin measured by the brain activity measuring device ([total-Hb]), the amount of hemoglobin change at rest ([△ Hb]), and the change in blood oxygenation rate ([△ Y]) at least, and apply these numbers to one of the following formulas: △ S / Srest = (TE ・ T2 ^* rest) ・ {2 △ Y / (1-Yrest) ― △ [total -Hb] / [total-Hb] rest} or △ S / Srest = (TE ・ T2 ^* rest) ・ {△ Y / (1-Yrest) ― △ [total-Hb] / [total-Hb] rest} (However, “rest” means “resting state (resting)”, [total-Hb] rest is “total hemoglobin amount at resting”, and “Yrest” is oxygenation of resting hemoglobin. ΔS / Srest (ratio of change from rest to MRI signal intensity at rest), which is a functional MRI (fMRI) signal, is calculated from the calculation result.
In addition, the computer software of the present invention is a computer attached to a brain activity measuring apparatus using near infrared rays, and at least the input echo time (TE) at the time of MRI measurement and effective lateral relaxation time at rest (T2 ^* rest ) As well as the total hemoglobin measured by the brain activity measuring device ([total-Hb]), the amount of hemoglobin change at rest ([△ Hb]), and the change in blood oxygenation rate ([△ Y]) Apply at least one of the following formulas to the recording unit that records at least S / Srest = (TE · T2 ^* rest) · {2ΔY / (1−Yrest) —Δ [total- Hb] / [total-Hb] rest} or ΔS / Srest = (TE · T2 ^* rest) · {ΔY / (1-Yrest)-△ [total-Hb] / [total-Hb] rest} ( However, “rest” means “resting (resting)”, [total-Hb] rest is “total hemoglobin amount at rest”, and “Yrest” is resting hemoglobin. It has a calculation unit for calculating ΔS / Srest (ratio of change from rest to MRI signal intensity at rest) which is a functional MRI (fMRI) signal from the calculation result (indicating the oxygenation rate of globin) [0009]
When the formula part is (ΔS / S) rest = (TE · T2 ^* rest) · {2ΔY / (1-Yrest) -Δ [total-Hb] / [total-Hb] rest} Used when the fMRI signal reflects venules, or reflects venules when the formula is true. These meanings and definitions are the same below.
Specific when the mathematical part is (ΔS / S) rest = (TE · T2 ^* rest) · {ΔY / (1-Yrest) -Δ [total-Hb] / [total-Hb] rest} It can be used when the hemoglobin in the capillaries of the brain changes in response to the stimulation.
[0010]
According to the present invention, an fMRI signal (ΔS / S) rest that has been conventionally obtained only by fMRI can be automatically calculated from an MRI structure image and a measurement method using near infrared rays.
It is also possible to determine what component the obtained fMRI signal is. That is, the fMRI signal reflects the total hemoglobin amount, the oxidized hemoglobin amount, and the like, and can determine whether to reflect any part of the venule or capillary.
[0011]
Furthermore, fMRI and near infrared rays are used to measure brain activity in parallel, fMRI signal intensity display means for displaying the signal intensity obtained by the fMRI measurement over time, and changes in hemoglobin in the venule caused by the near infrared measurement. You may comprise with the apparatus which has a near-infrared venule hemoglobin change display means to display, and a near-infrared capillary venous hemoglobin change display means to display the change of hemoglobin in the capillary vein by the near-infrared measurement. Then, by displaying the fMRI signal and the signal obtained with the near infrared ray on the same screen, it is possible to determine to which of the signals obtained with the near infrared ray the fMRI signal belongs. The change in hemoglobin in the venule or capillary vein is calculated by the above formula.
[0012]
In brain activity measurement, a visual stimulus is applied by reversing the checkerboard, and at least one of the fMRI ((ΔS / S) rest) signal, oxygenated hemoglobin, deoxygenated hemoglobin, and total hemoglobin is measured. You may do it. The visual stimulus by reversing the checkerboard is a visual stimulus of 0.5 Hz or 14 Hz, and the change in the biological information of the measurement brain occipital region at fMRI and near infrared is large, which is suitable for measurement.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, the signal change of fMRI reflects the magnetic change of hemoglobin accompanying the change of cerebral circulation and metabolism, whereas the brain activity measurement using near infrared light (near infrared spectroscopy (NIRS)). ) Provides information resulting from changes in the light scattering characteristics of brain tissue. Near-infrared rays refer to the wavelength region closest to the visible light region (about 400 to 700 nm) among infrared rays (about 700 to 3000 nm). Near-infrared rays with a wavelength of around 800 nm have high biological permeability, and the near-infrared rays projected from the scalp pass through brain tissue and can be received from the scalp. Near-infrared spectroscopy uses the characteristic absorption band of hemoglobin in blood in this region, so that oxygenated hemoglobin (oxy-Hb), deoxygenated hemoglobin (deoxy-Hb) It has the feature that changes in Hb) and total hemoglobin ([total-Hb]) can be detected continuously. It has also been established as a measurement method that can handle changes in local cerebral blood volume (rCBV).
Therefore, in the present invention, NIRS measurement is performed in parallel with fMRI measurement, and means for assigning fMRI signal change by infrared spectroscopy is provided.
[0014]
【Example】
As an experimental condition, it was shown as an example that the change in hemodynamics obtained by fMRI during activation of the human visual cortex can be supplemented with the results obtained by NIRS by the method of the present invention. The subjects measure NIRS in parallel with the fMRI measurement for 6 healthy adult males (24 to 43 years old). For visual stimulation, a checker board (stimulation frequencies: blinking at 0.5, 1.4, 4.7 and 14 Hz) projected on a computer monitor was used. In the experiment, four types of stimulation frequencies were presented pseudo-randomly 16 times in total (measurement time was about 16 minutes) (FIG. 1).
The upper part of FIG. 1 shows the monitor display of the resting state and the stimulating state of the visual stimulus. The lower part of FIG. 1 shows the experimental conditions and shows that the intensity of the visual stimulus changes randomly. The visual stimulation hertz (Hz) is determined from the reversal speed of the checkerboard.
[0015]
The brain activity measurement by near infrared spectroscopy was performed using a CW type near infrared spectrometer. Measure the hemoglobin parameter using the near-infrared mapping device (OPTIM-A, Yu Yanagida Special Group, Communications Research Laboratory, 1999) for the back of the head (7 cm x 7 cm area) including the visual cortex. It was. The measurement channels were 4 × 4 16 channels (FIG. 2), and the measurement wavelengths were sequentially measured at intervals of 776 nm, 804 nm, 828 nm and 400 ms. The hemoglobin parameter was calculated by the Modified Beer-Lambert method expressed by the following formula 1.
By this measurement method / calculation method, Δoxy-Hb (oxygenated hemoglobin change amount), Δdeoxy-Hb (deoxygenated hemoglobin change amount), and Δtotal Hb (total hemoglobin change amount) can be calculated.
[Formula 1]

[0016]
On the other hand, regarding the measurement and analysis of brain activity by fMRI, (1) the device is Siemens VISION (Germany), 1.5T System, (2) the imaging method is the GER-EPI method, and (3) the imaging parameter is TR 3.9. sec, TE 55.24msec, FA 90 degree, (4) slice is Axial slice 32 (thickness mm / 1 sheet, interval 0mm), (5) pixel size 4mm × 4mm × 4mm (Fov 256mm × 256mm Matrix 64 × 64 ). For analysis, (6) Motion Correction used AIR3.0, (7) AVS / Express, and (8) Structured image and functional image were superimposed using Analyze PC2.5 (Mayo Fundation) and SPM99.
[0017]
In the measurement, the probe of the near-infrared mapping apparatus was placed on the portion of the MRI apparatus where the subject's head is placed so that the measurement can be performed by near-infrared spectroscopy. Here, the method according to the present invention may be performed simultaneously with the fMRI measurement, or the NIRS measurement may be performed before and after the fMRI measurement under the same conditions. NIRS can be measured by using a CW type near-infrared spectrometer, a time-resolved near-infrared spectrometer, or an intensity modulation type using a frequency domain.
[0018]
The measurement results were NIRS measurement and fMRI measurement. In the experiment under the above-mentioned conditions, it was shown that the same region was activated for both of the measurements for the detection of the active site. Next, NIRS measurement shows that the changes in occipital hemoglobin associated with visual stimulation show a large increase in total hemoglobin and oxygenated hemoglobin levels at 0.5 Hz and 14 Hz stimulation, as shown in the graph of FIG. It was done.
[0019]
On the other hand, in the fMRI measurement, as shown in FIG. 4, large signal intensities were observed at 1.4 Hz and 4.7 Hz. The horizontal axis of the graph represents time (seconds), and the vertical axis represents the signal intensity of the active site. Correlation Coefficient (correlation coefficient) is box scarf switching, and indicates how much the signal change matches the task load. If r is 0.75 or more, it indicates that there is a correlation.
[0020]
In FIG. 4, the result of measurement (NIRS) using the fMRI signal and near infrared rays is displayed on the same screen. As described above, hemoglobin parameters were measured sequentially at intervals of 776 nm, 804 nm, 828 nm and 400 ms. The hemoglobin parameter was calculated by the modified Beer-Lambert method. (ΔS / S) rest = (TE · R2 ^* rest) · {2ΔY / (1−Yrest) −Δ [total-Hb] / [total-Hb] rest} (the first equation) Or (△ S / S) rest = (TE ・ R2 ^* rest) ・ {△ Y / (1-Yrest) ― △ [total-Hb] / [total-Hb] rest} (Equation 2) It was calculated by substituting hemoglobin parameters. For the absolute amount of hemoglobin, it is suitable to use a time-resolved near-infrared spectrometer. The first expression is a case where a signal in a venule is reflected, and the second expression is a case where a signal in a capillary is reflected. The fMRI signal of FIG. 4 displays the data as it is, and the venule and capillary signal are graphs calculated by substituting individual hemoglobin parameters according to the above formula. As a result, similar results were obtained in two experiments. In this example, it was shown that the fMRI signal reflected the venule signal, and that the fMRI signal could be calculated from the near infrared measurement.
[0021]
【The invention's effect】
According to the present invention, the fMRI signal intensity ((ΔS / S) rest) that can be obtained only by the fMRI measurement can be calculated from the MRI structural image data and the near-infrared measurement result. Further, from the measurement result of the fMRI signal intensity ((ΔS / S) rest) and the near-infrared ray, it can be determined whether the part to which the signal belongs is a venule or a capillary.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a procedure for giving a visual stimulus to a subject. FIG. 2 is an explanatory diagram showing a fiber tip that irradiates and receives a near infrared ray on a living body. FIG. 3 is a graph showing fMRI signal intensity in each visual stimulus. FIG. 4 is a graph showing fMRI signals (fine veins / capillaries) calculated from fMRI and near-infrared measurements of A and B over time.

Claims (6)

In the brain activity measuring device using near infrared rays,
The attached computer records at least the input echo time (TE) at the time of MRI measurement and the effective transverse relaxation time (T2 * rest) at rest,
Record at least the amount of total hemoglobin ([total-Hb]) measured by the brain activity measuring device, the amount of change in total hemoglobin relative to rest ( △ [total-Hb]) , and the change in blood oxygenation rate (△ Y) Recording means,
Apply these numbers to the following formula:
△ S / Srest = (TE ・ T2 * rest) ・ {2 △ Y / (1-Yrest) ― △ [total-Hb] / [total-Hb] rest}
(However, “rest” means “resting (resting)”, [total-Hb] rest is “total amount of hemoglobin at rest”, and “Yrest” is the oxygenation rate of resting hemoglobin. Indicate)
A brain activity measuring device comprising a computing means for calculating ΔS / Srest (ratio of change from rest to MRI signal intensity at rest) which is a functional MRI (fMRI) signal from the calculation result . In the brain activity measuring device using near infrared rays,
The attached computer records at least the input echo time (TE) at the time of MRI measurement and the effective transverse relaxation time (T2 * rest) at rest,
Record at least the amount of total hemoglobin ([total-Hb]) measured by the brain activity measuring device, the amount of change in total hemoglobin relative to rest (△ [total-Hb]) , and the change in blood oxygenation rate (△ Y) Recording means,
Apply these numbers to the following formula:
△ S / Srest = (TE ・ T2 * rest) ・ {△ Y / (1-Yrest) ― △ [total-Hb] / [total-Hb] rest}
(However, “rest” means “resting (resting)”, [total-Hb] rest is “total amount of hemoglobin at rest”, and “Yrest” is the oxygenation rate of resting hemoglobin. Indicate)
A brain activity measuring device comprising a computing means for calculating ΔS / Srest (ratio of change from rest to MRI signal intensity at rest) which is a functional MRI (fMRI) signal from the calculation result . In the brain activity measuring device using near infrared rays,
With the attached computer, record at least the echo time (TE) at the time of MRI measurement and the effective transverse relaxation time (T2 * rest) at rest,
Record at least the amount of total hemoglobin ([total-Hb]) measured by the brain activity measuring device, the amount of change in total hemoglobin relative to rest ( △ [total-Hb]) , and the change in blood oxygenation rate (△ Y) And
These numbers can be any of the following formulas:
△ S / Srest = (TE ・ T2 * rest) ・ {2 △ Y / (1-Yrest) ― △ [total-Hb] / [total-Hb] rest}
Or
△ S / Srest = (TE ・ T2 * rest) ・ {△ Y / (1-Yrest) ― △ [total-Hb] / [total-Hb] rest}
(However, “rest” means “resting (resting)”, [total-Hb] rest is “total amount of hemoglobin at rest”, and “Yrest” is the oxygenation rate of resting hemoglobin. Indicate)
A method of measuring brain activity, comprising calculating ΔS / Srest (ratio of change from rest to MRI signal intensity at rest), which is a functional MRI (fMRI) signal, from the calculation result applied to. In the software on the computer attached to the brain activity measuring device using near infrared rays,
Record the echo time (TE) during MRI measurement and the effective lateral relaxation time (T2 * rest) at rest,
Total hemoglobin measured and input by the brain activity measuring device ([total-Hb]), change in total hemoglobin relative to rest ( △ [total-Hb]) , change in blood oxygenation rate (△ Y) A recording step for recording at least in the recording unit;
These numbers can be any of the following formulas:
△ S / Srest = (TE ・ T2 * rest) ・ {2 △ Y / (1-Yrest) ― △ [total-Hb] / [total-Hb] rest}
Or
△ S / Srest = (TE ・ T2 * rest) ・ {△ Y / (1-Yrest) ― △ [total-Hb] / [total-Hb] rest}
(However, “rest” means “resting (resting)”, [total-Hb] rest is “total amount of hemoglobin at rest”, and “Yrest” is the oxygenation rate of resting hemoglobin. Indicate)
Applying the calculation to the calculation unit, the calculation unit calculates the functional MRI (fMRI) signal ΔS / Srest (the ratio of the change from rest to the MRI signal intensity at rest) by the calculation unit. Computer software characterized by having. Measure brain activity in parallel using fMRI and near infrared,
FMRI signal intensity display means for displaying the signal intensity by the fMRI measurement over time;
A near-infrared venule hemoglobin change display means for displaying a change in hemoglobin in the venule by the near-infrared measurement,
The brain activity measuring device according to claim 1, further comprising a near-infrared capillary venous hemoglobin change display unit that displays a change in hemoglobin in the capillary vein by the near-infrared measurement. In brain activity measurement,
Give visual stimulus by reversing the checkerboard,
At least fMRI signal ((ΔS / S) rest), oxygenated hemoglobin ([oxy-Hb] and △ [oxy-Hb]) , deoxygenated hemoglobin ([deoxy-Hb] and △ [deoxy-Hb]) and total hemoglobin ([total-Hb] (= [oxy-Hb] + [deoxy-Hb]) And [total-Hb] (= Δ [oxy-Hb] + Δ [deoxy-Hb])) is used for brain function analysis.

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