JPH0919408A - Living body light measuring device and image forming method in the device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form an image of a biodynamic function by measuring it in a short time by using a simple detector. SOLUTION: Light 2a∼2d of plural wavelength whose intensity are modulated by means of different frequencies 1a∼1d are applied from plural irradiation positions on a living body 6 surface, and time change of a living body transmission light intensity on each wavelength and each radiation position re measured (7, 8, 9). Change of concentration of an absorbed body in the living body is determined from the living body transmitting light intensity of plural wavelengths which are measured at each detecting point after completion of measurement or during measurement (11), and an image 13 is formed by setting a measuring point on a perpendicular which passes through an intermediate point between each incident point and each detecting point.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a living body optical measuring device and an image forming method in the living body optical measuring device, that is, a living body optical measuring device and an image forming apparatus for measuring information inside a living body using light and imaging the measurement result. Regarding the method.

[0002]

2. Description of the Related Art An apparatus or method for simply measuring the inside of a living body without harming the living body is desired in clinical medicine.
For this demand, measurement using light is very effective.
The first reason is that the oxygen metabolism function inside the living body corresponds to the concentration of a specific dye (hemoglobin, cytochrome aa3, myoglobin, etc.) in the living body, that is, the concentration of the light absorber, and this specific dye concentration is light (from visible to near This is because it is calculated from the absorption amount (wavelength in the infrared region). The second reason is that light is easy to handle with an optical fiber. The third reason is
The optical measurement does not harm the living body when used within the range of safety standards.

Utilizing the advantages of living body measurement using such light, the living body is irradiated with light having a wavelength from visible to near infrared, and the living body is detected from reflected light at a position about 10-50 mm away from the irradiation position. A device for measuring the inside is, for example, an open patent publication,
JP-A-63-277038, JP-A-5-300878
No. etc. Also, thickness 100-200mm
A device for measuring a CT image of oxygen metabolism function from light transmitted through a living body, that is, an optical CT device is disclosed in, for example, Japanese Patent Laid-Open Publication No. 60-72542 and Japanese Patent Publication No. 62-2316.
No. 25.

[0004]

The clinical application by optical measurement of the living body includes, for example, measurement of the activated state of oxygen metabolism in the brain and local intracerebral hemorrhage when the head is a measurement target. Also, in relation to oxygen metabolism in the brain, exercise,
It is also possible to measure higher brain functions such as sensation and thinking. In such measurement, the effect is dramatically increased by measuring and displaying as an image rather than a non-image. For example, it is essential to measure and display as an image when detecting a local oxygen metabolism change site.

However, the prior art has the following problems. First, in the measurement using the reflected light, a measurement and display method for imaging is not presented. Therefore, when the oxygen metabolism locally changes, it is difficult to detect the changed part. An optical CT device using transmitted light can detect a local change as an image, but the transmitted light intensity of a living body is several orders of magnitude smaller than the reflected light intensity, which is extremely weak. The transmitted optical signal is buried in random noise components. Therefore, an expensive feeble light detector is required to measure the transmitted light signal to be sufficiently large with respect to noise, and the measurement time, that is, the measurement time, is required to remove the noise and extract the transmitted light signal. It also becomes necessary to increase the number of times of integration. As a result, the measurement time becomes long, which not only imposes a mental burden on the subject, but also reduces the operating efficiency of the device.

Therefore, the object of the present invention is to solve the above problems and to measure by using a biometric measuring device and a device for visualizing the state of biological function by using a simple detector and measuring in a shorter time. It is to realize a method of imaging the result.

[0007]

In order to achieve the above object, the bioinstrumentation apparatus of the present invention comprises a plurality of light irradiating means for irradiating a subject with light having a wavelength in the visible to near infrared region, and the above light irradiating means. A plurality of light receiving means for detecting the light emitted from the means and reflected inside the subject; a storage means for storing and storing the signals detected by the light receiving means for each of the plurality of light receiving means over time; Calculating means for converting the signals stored in the means into signals to be measured at a plurality of measuring points; and displaying the output of the calculating means as a topographic image represented as an intensity signal on the two-dimensional display surface representing the measurement position. An image creation unit was provided. In particular, each of the plurality of light irradiation means has a plurality of light sources with different wavelengths, a modulator that modulates the light of the plurality of light sources with different frequencies, and a guide that guides the plurality of modulated lights to the irradiation position. Wave means, and each of the plurality of light receiving means has a separating means for separating the intensity of light from the plurality of light sources having different wavelengths.

When the function inside the living body is measured using the living body measuring apparatus, the light irradiating positions of the plurality of light irradiating means are distributed and arranged on the measuring portion of the subject, and they are arranged in a distributed manner. A plurality of light receiving portions of the plurality of light receiving means are arranged in the peripheral portion of each light irradiation position, and an optical signal detected by the plurality of light receiving means is set at a midpoint between the light irradiation position and the detection position, and An arbitrary position on the perpendicular to the inside of the living body with respect to the living body surface is set as a measurement point. The measurement point and the detected optical signal intensity corresponding to the measurement point are displayed on the two-dimensional image. Further, when displaying as a topography image, a signal at a position that is not measured may be obtained by an interpolation signal at the measurement point. When the subject is a living body, the distance between the irradiation position and the detection position is 10 to 5
About 0 mm is desirable.

[0009]

According to the present invention, the information on the measurement position is almost uniquely determined by the light irradiation position of the light irradiation unit on the subject and the position of the light receiving unit, so that the signal processing for displaying as a topographic image is simple and easy. Can be done at high speed. Further, when the position of the light receiving means is about 10 to 50 mm from the light irradiation position, the reflected light is used, and 100 to 200 m
The detection intensity is sufficiently higher than that of light transmitted through a living body of about m. Therefore, it becomes possible to measure with a simple photodetector in a short time.

For example, when the measurement target (subject) is the head, the distance between the irradiation position and the detection position is at least 30 mm.
Then, it is known that the detected light passes through the skin and the skull to reach the surface part of the brain, that is, the cerebral cortex, for example, Patrick W. McCormick et al. By Intracerebral penetration of infrared ligh
t) ”, Journal of Neurosurgery, Vol. 76, pp. 315-318, published February 1992 (J Neurosur
g., 76, 315 (1992)). In addition, the information in the position on the normal line from the midpoint of the irradiation and detection position to the inside of the living body relative to the surface of the living body contains the most information in the light detected at such a position. It is known for its propagation characteristics. This property is described, for example, by Shechao Feng et al. In “Monte Carlo Simulation of Photon Transfer Path Distribution in Multiple Scattering Media (Mon.
te Carlosimulationsof photon path distribution in
multiple scattering media) ", Proceedings of Spiai Ie, 1993, Volume 1888, Photon migration and images in random media and biological tissues, paragraphs 78-89.
(SPIE, Proceedings of photon migration and imaging
in random media and tissues, 1888, 78 (1993)).

In the living body optical measurement system of the present invention, a large number of light irradiating means and a large number of light receiving means are required to measure a large number of positions. Is effective, and a topography image can be obtained at high speed by a simple calculation process of interpolating the measurement results obtained for a plurality of measurement points for each measurement point.

[0012]

Embodiments of the present invention will be described below. FIG. 1 shows the configuration of an embodiment of a biological optical measurement device according to the present invention. The present embodiment is an example in which the biological optical measurement device is applied to the measurement of hemodynamic changes (relative changes in oxygenated and reduced hemoglobin concentrations) associated with brain functions. The specific part of the brain is related to the control of a specific function of the living body (for example, moving a part of the body such as a finger), and by operating the specific function, the hemodynamics of the specific part of the brain are changed. It is possible to add a load that causes the specific function to work, for example, to move a finger, measure hemodynamic changes, and display as a contour map on a secondary plane image representing a region of the brain. Can be done using.

As shown in the figure, in this embodiment, a plurality of light sources 2a to 2d (light sources 2a and 2c and light source 2b) having different wavelengths are used.
And 2d are the same wavelengths in the visible to near-infrared region) and the light from the plurality of light sources 2a and 2b (2c and 2c) are respectively generated by oscillators 1a and 1b (1
c and 1d), and the optical fibers 3a and 3b (32c and 3b) for the intensity-modulated light, respectively.
The light from the coupler 4a (4b) that is coupled through c) is passed through the optical fiber 5a (5b) and the subject 6 is the subject.
A plurality of light irradiation means for irradiating different positions on the scalp of
The plurality of light detecting optical fibers 7a to 7a to 7a to 7n so that the tips are located at positions equidistant (here, 30 mm) from the light irradiation positions near the light irradiation positions of the plurality of light irradiation means.
7d and a plurality of light receiving means composed of photodetectors 8a to 8f provided on each of the optical fibers for light detection 7a to 7d. 6 optical fibers for light detection 7a-
At 7f, the living body passing light is condensed on an optical fiber, and the living body passing light is photoelectrically converted by the photodetectors 8a to 8f, respectively. The light receiving means detects the light reflected inside the subject and converts it into an electric signal, and a photomultiplier tube or a photoelectric conversion element represented by a photodiode is used as the photodetector 8.

The electric signals (hereinafter referred to as living body passing light intensity signals) representing the living body passing light intensity photoelectrically converted by the photodetectors 8a to 8f are input to lock-in amplifiers 9a to 9h, respectively. Here, since the photodetectors 8c and 8d detect the in-vivo light intensity collected by the photodetection optical fibers 7c and 7d equidistant from both the optical fibers 5a and 5b, the photodetectors 8c and 8d are detected. Signal from 2
The system is separated and input to the lock-in amplifiers 9c and 9e and 9d and 9f. The lock-in amplifiers 9a to 9d include oscillators 1a and 1b, and lock-in amplifiers 9e to 9h.
The intensity modulation frequencies from the oscillators 1c and 1d are input as reference frequencies. Therefore, the living body passing light intensity signals for the light sources 1a and 1b are separated and output from the lock-in amplifiers 9a to 9d.
From ~ 9h, living body passing light intensity signals for the light sources 1c and 1d are separated and output.

The separated transmitted light intensity signals for each wavelength, which are the outputs of the lock-in amplifiers 9e to 9h, are analog-digital converted by the analog-digital converter 10, and then are inside the computer 11 or outside the computer 11. Storage device 1
2 is stored. During or after the measurement, the calculator 11 uses the transmitted light intensity signal stored in the storage device to calculate the relative change amount of the oxyhemoglobin concentration and the reduced hemoglobin concentration obtained from the detection signal at each detection point, and the plurality of measurements are performed. It is stored in the storage device 12 as temporal information of the point m. The above calculation will be described later in detail. The display control unit 30 converts the signal stored in the storage unit 12 into a display signal of a display device 13 such as a CRT and displays it on the display device 13. The display signal is a signal for converting the measurement position into coordinates on the display plane of the subject and displaying the intensity signal (relative change amount of oxidative or reduced hemoglobin concentration) of the coordinate position by contour lines.

By using the living body light measuring apparatus according to this embodiment, the relative change amount of the oxidative and reduced hemoglobin concentrations in the living body can be measured easily and at high speed. The configuration for increasing the number of light incident points (light irradiation positions) and the number of light detection points can be easily expanded because it is sufficient to increase the intensity modulation frequency of the light source, the light source, the light detector, and the lock-in amplifier. With this biological light measurement device, the spectral and light irradiation positions can be separated by the intensity modulation frequency, so even if the light irradiation positions are increased, the number of wavelengths of irradiation light at each light irradiation position can be measured. It suffices that the number is the same as the number of absorbers to be used, and it is not particularly necessary to change the wavelength of irradiation light for each light irradiation position. Therefore, the number of wavelengths of the irradiation light used is small, and the error due to the influence of scattering that differs depending on the wavelength can be reduced.

FIG. 2 is a diagram for explaining an embodiment of an image creating method according to the present invention using a biological light measuring device.
The relationship between the light incident point, the light detection point, and the measurement point in the above method is shown. The image creating method of the present example is a method of creating a topographic image of the relative change amount of the oxyhemoglobin concentration and the reduced hemoglobin concentration in the head of the subject, and the left head that is involved in the motor function of the right finger of the subject. This is a method of providing four incident and detection points for each part, measuring the intensity of light passing through the living body, and imaging the measurement results when the motion of the right finger and the motion of the left finger are applied as loads.

As shown in the figure, light incident points 17a to 17d and detection points 18a to 18d are arranged on the left side of the head of the subject 16. Here, the correspondence relationship between each light incident point and each detection point is 1
7a-18a, 17a-18b, 17b-18a, 17
b-18b, 17b-18c, 17b-18d, 17c
-18b, 17c-18c, 17d-18c, 17d-
There are 10 sets of 18d. The distance between each corresponding light incident point and detection point is 30 mm. Furthermore, the time change of the relative change amount of the oxidized and reduced hemoglobin concentrations obtained from the measurement signals at each detection point is
Eng et al., “Monte Carlo simulations of photon migration path distributions in multiple scattering media.
of photon path distribution in multiple scattering
media) ”, Proceedings of Spy, I, 1993, Volume 1888, Photon migration and images in random media and biological tissues, paragraphs 78-89 (SPIE, Proceedings).
of photon migration and imaging in random media an
d tissues, 1888, 78 (1993)), most of the information between the corresponding incident points and the detection points is reflected, so that the measurement points 19a to 19j are detected as the incident points. Set to the center of the point correspondence. Measurement points 19a-1
The information of 9j is obtained, and the size of the information is displayed as a contour line, a shade, and a color identification diagram on a two-dimensional plane as shown in FIG.

Next, the relative change amount of each hemoglobin concentration from the measurement signal at each of the light detection points according to the present invention, that is, the function of the brain by operating a specific function of the living body (for example, moving a part of the body such as a finger). An example of a method for obtaining a change in the moglobin concentration at a specific portion will be described. FIG. 3 is a measurement signal 14 at one of the detection points 18a to 18d of the biological optical measurement device in the embodiment of FIG. 2 and a predicted no-load signal 15 obtained from the measurement signal 14.
It is a graph showing the time-dependent change of. The horizontal axis of the graph represents the measurement time, and the vertical axis represents the relative concentration change amount. The predicted no-load signal 15 is the pre-load time T excluding the signals from the measurement signal 14 at the load application time (load time) Tt and the post-load signal return time (relaxation time) T2.
It is obtained by fitting an arbitrary function to the measurement signal 14 at 1 and the post-loading time T2 by using the least square method. In the present embodiment, the arbitrary function is a linear polynomial of degree 5, each time is T1 = 40 seconds, T2 = 30 seconds, Tt = 30 seconds, T
Processing is performed with 3 = 30 seconds.

FIG. 4 shows the relative changes in the concentrations of oxyhemoglobin and deoxyhemoglobin at one measurement point (hereinafter, Δ
6 is a graph showing a temporal change of Coxy (t) signal 20 and ΔCdeoxy (t) signal 21. The horizontal axis of the graph represents the measurement time, and the vertical axis represents the relative concentration change amount. The time indicated by the diagonal lines is the load application time (movement period of the right finger). The relative change amount is the two-wavelength measurement signal 14 and the predicted no-load signal 15 shown in FIG.
From the above, the relative change amount of the concentration of oxidized and reduced hemoglobin (HbO ₂ , Hb) due to the load application is obtained by the following arithmetic processing.

Predicted no-load signal Str at wavelength λ
The relationship between (λ, t) and the light source intensity I0 (λ) is expressed by the following equation (2) by separating light attenuation in the living body into scattering and absorption. The equations (2) and (3) are described in “Biometrics Using Light-The Road to Optical CT”, 2nd O plus E 19
It can also be derived from the equation (8) on page 61, June 1987. -Ln {Str (λ, t) / I0 (λ)} = εoxy (λ) ・ Coxy (t) ・ d + εdeoxy (λ) ・ Cdeoxy (t) ・ d + A (λ) + S (λ) ・... (2) where εoxy (λ): absorption coefficient of oxyhemoglobin at wavelength λ εdeoxy (λ): absorption coefficient of reduced hemoglobin at wavelength λ A (λ): attenuation due to absorption other than hemoglobin at wavelength λ S (λ): Attenuation due to scattering at wavelength λ Coxy (t): Oxyhemoglobin concentration at measurement time t Cdeoxy (t): Reduced hemoglobin concentration at measurement time t d: Effective optical path length in the living body (in the region of interest) Is.

The relationship between the measurement signal Sm (λ, t) and the light source intensity I0 (λ) is expressed by the following equation (3). −Ln {Sm (λ, t) / I0 (λ)} = εoxy (λ) ・ {Coxy (t) + C'oxy (t) + Noxy (t)} ・ d + εdeoxy (λ) ・ {Cdeoxy ( t) + C'deoxy (t) + Ndeoxy (t)} ・ d + A '(λ) + S' (λ) ・ ・ ・ (3) where C'oxy (t): load at measurement time t Change in oxygenated hemoglobin concentration due to application C'deoxy (t): Change in reduced hemoglobin concentration due to load application at measurement time t Noxy (t): noise or high-frequency fluctuation of oxygenated hemoglobin concentration at measurement time t Ndeoxy (t): noise or High Frequency Fluctuation of Reduced Hemoglobin Concentration at Measurement Time t Here, assuming that A (λ) and S (λ) do not change under load application and load non-application, that is, the measurement signal change caused by load is oxidation and reduction. If only due to the change in the hemoglobin concentration, the difference between the equations (2) and (3) is shown by the following equation (4).

Ln {Str (λ, t) / Sm (λ, t)} = εoxy (λ) {C'oxy (t) + Noxy (t)} d + εdeoxy (λ) {C'deoxy (t) + Ndeoxy (t)} d (4) where ΔCoxy (t) and ΔCoxy (t) are the time-dependent changes in the relative changes in oxygenated and reduced hemoglobin concentrations due to load, respectively.
It is represented by Cdeoxy (t) and defined by the following formula. ΔCoxy (t) = {C'oxy (t) + Noxy (t)} d ΔCdeoxy (t) = {C'deoxy (t) + Ndeoxy (t)} d ... (5) Since it is usually difficult to specify d, the dimension of the density change amount is the product of the density and the distance d.

However, in the equation (5), the distance d is ΔCoxy and Δ
Since it acts like Cdeoxy, the expression (5) is defined as the relative change amount of each hemoglobin concentration. When two wavelengths are used for measurement, the obtained expression (4) is ΔCoxy (t) and ΔCdeoxy (t).
The simultaneous simultaneous equations with respect to are obtained, and ΔCoxy (t) and ΔCdeoxy (t) are obtained from the predicted no-load signal Str (λ, t) and the measurement signal Sm (λ, t) for each wavelength. Furthermore, ΔCoxy (t) other than the loading time and relaxation time
And ΔCdeoxy (t) represents C′oxy (t) =
Since 0, C'deoxy (t) = 0, it means that high-frequency fluctuations of oxyhemoglobin concentration and reduced hemoglobin due to noise or living body are expressed. The values obtained over the time of 0 to 140 seconds by the above-described processing are ΔCoxy (t) signal 20 and ΔCdeoxy of FIG.
(T) The signal 21.

FIG. 5 and FIG. 6 are contour image (topography image) created from the time change of the relative change amount of the oxygenated hemoglobin concentration at each of the above measurement points, with the load of the motion of the left and right fingers of the subject, respectively. Indicates. The method of creating a topography image is based on the load application time (the shaded period in FIG. 4).
The relative integrated amount ΔCoxy (t) signal 20 in the inside is calculated by the computer 11 with time integrated value (may be the time average value), and the values between the measurement points are linearly interpolated in the X-axis direction and the Y-axis direction. It was done. As the topography image, in addition to the contour lines as shown in FIGS. 5 and 6, a black and white gray image and a color-based identification display may be used. From the comparison of the images of FIGS. 5 and 6, it is apparent that the oxygenated hemoglobin concentration is increased at a specific position during the right-handed movement. By displaying such information of the spatial distribution as an image, the recognition of the measurement result is made quick and easy. The images shown in FIG. 5 and FIG. 6 were created by using the time-integrated value of the relative concentration change amount during the load application time. However, the images are similarly obtained by the relative change amount of the oxyhemoglobin concentration at each measurement point at the same measurement time. It is also possible to create topographic images. By displaying the plurality of created topographic images in the order of measurement time or as a moving image, it is possible to grasp the time change of the relative change amount of the oxygenated hemoglobin concentration.

Furthermore, the self- and cross-correlation functions of the time change of the relative change amount of the oxyhemoglobin concentration at any one measurement point and the time change of the relative change amount of the oxyhemoglobin concentration at the other measurement points are calculated, and at each measurement point It is also possible to create a topography image from the correlation function. Since the correlation function at each measurement point is a function defined by time lag τ, if a topography is created from the value of the correlation function at the same time lag τ and displayed in the order of τ or displayed as a moving image, hemodynamic changes Can be visualized as they propagate. Here, the relative change amount of the oxyhemoglobin concentration is described as a typical example, but the relative change amount of the reduced hemoglobin concentration or the total change of the total hemoglobin concentration calculated by the sum of the relative change amounts of the oxidized and reduced hemoglobin concentrations. Amounts can be topographically created as well.

FIG. 7 shows a display example in which the topography image 22 created by the method described above is superimposed on the brain surface image 23 of the subject. The topography image 22 is a change in the hemodynamics of the brain that changes in association with the function of the living body,
It is desirable to display it on top of the brain surface image. The brain surface image 23 is measured and displayed by three-dimensional MRI or three-dimensional X-ray CT. For the topography image 22, the coordinates of each measurement point are coordinate-converted so as to be located on the brain surface, and the values between the measurement points after the coordinate conversion are interpolated to create a topography image. Created topography image 22 and brain surface image 2
When 3 is superimposed and displayed, the color of the superimposed topography image 22 is made semitransparent so that the brain surface image located therebelow can be seen through.

FIG. 8 is a diagram for explaining the measuring point coordinate conversion method. When a morphological image of three-dimensional MRI or three-dimensional X-ray CT is photographed, a marker is placed at a measurement point set by the biological optical measurement device, and when the photograph is taken, skin and bone images 24 and brain images 25 are obtained from the photographed morphological information. The marker image 26 can be displayed. The photographed image has three-dimensional coordinate information. Therefore, the measurement point 27 indicated by the marker image 26
A perpendicular line 28 is calculated with respect to the skin surface at the measurement point 27 or the bottom surface of the marker image 26, and the point intersecting the brain image 25 is set as the coordinate-converted measurement point 29. As shown in this example, in the case of measuring brain function, it is known that hemodynamic changes correlated with load mainly occur on the brain surface (cerebral cortex). For the above reason, it is possible to know the depth of coordinate conversion of the measurement point by using the morphological information of the living body. However, when the measurement target is another biological organ such as a muscle, the depth at which the coordinate conversion is performed may not be known from the morphological information. When this method is used for the measurement as described above, the light propagation in the living body is preliminarily calculated by the numerical calculation by the Monte Carlo method, the depth that most contributes to the measurement signal is calculated, and the depth is calculated as described above. Coordinate conversion of measurement points.

[0029]

According to the present invention, a low-cost light irradiation means and a photodetector are used, and since the arithmetic processing is simple, high-speed processing can be performed with an economical device, and a planar image showing the shape of the object to be measured. Since the biological function associated with can be imaged, it becomes an effective means particularly for measuring a predetermined function of the biological body.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of a biological optical measurement device according to the present invention.

FIG. 2 is a diagram for explaining an embodiment of an image creating method using the biological optical measurement device.

FIG. 3 is a diagram showing a change with time of a measurement signal and a predicted no-load signal 15 obtained from the measurement signal at one measurement point in the above embodiment.

FIG. 4 is a diagram showing a temporal change of a relative change amount of hemoglobin concentration at one measurement point in the above-mentioned embodiment.

FIG. 5 is a diagram showing a topography image in an embodiment of the biological optical measurement device according to the present invention.

FIG. 6 is a diagram showing a topography image in an embodiment of the biological optical measurement device according to the present invention.

FIG. 7 is a diagram showing a display example of a topography image in an embodiment of the biological optical measurement device according to the present invention.

FIG. 8 is a diagram for explaining a coordinate conversion method according to another embodiment of the biological light measuring device according to the present invention.

[Explanation of symbols]

1: Oscillator, 2: Light source, 3: Optical fiber, 4: Coupler, 5: Optical fiber, 6: Subject, 7: Photodetection optical fiber, 8: Photodetector, 9: Lock-in amplifier, 10:
Analog-digital converter, 11: calculator, 12: storage device, 13: display device, 14: measurement signal, 15: predicted no-load signal, 16: subject, 17: incident point, 18: detection point, 19: Measurement point, 20: ΔCoxy (t) signal, 2
1: ΔCdeoxy (t) signal, 22: topography image, 23: brain surface image, 24: skin and bone image, 25: brain image, 26: marker image, 27: measurement point, 28: perpendicular line, 2
9: Coordinate-converted measurement point.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideaki Koizumi 1-280 Higashi Koikekubo, Kokubunji City, Tokyo Inside Hitachi Central Research Laboratory

Claims (10)

[Claims] 1. A plurality of light irradiating means for irradiating a subject with light having a wavelength in the visible to near-infrared region, and a plurality of light irradiating means for detecting the light emitted from the light irradiating means and reflected inside the subject. Light receiving means, storage means for storing and storing the signal detected by the light receiving means for each of the plurality of light receiving means over time, and signals to be measured at a plurality of measurement points using the signals stored in the storage means A living body optical measurement device, comprising: an arithmetic unit for converting into an optical image and an image creating unit for displaying the output of the arithmetic unit on a two-dimensional display surface representing the measurement position as a topography image represented as an intensity signal. 2. A plurality of light sources, each of which has a different wavelength, a modulator for modulating the light of the plurality of light sources at different frequencies, and an irradiation position of the plurality of modulated lights. A living body optical measurement device, characterized in that the living body optical measuring device comprises a waveguide means for guiding the light to each of the plurality of light receiving means, and each of the plurality of light receiving means has a separating means for separating the intensities of light from the plurality of light sources having different wavelengths. 3. The living body optical measurement system according to claim 2, wherein said separating means comprises a lock-in amplifier driven by a modulation signal of said modulator. 4. The living body optical measurement system according to claim 1, wherein the number of the plurality of light sources having different wavelengths is the same as the number of types of the light absorbers to be measured. 5. A plurality of light irradiation positions of a subject are irradiated with light having a wavelength in the visible to near-infrared region, and light passing through the inside of the subject is at least one for each of the plurality of light irradiation positions. The first step of obtaining the concentration of the light absorber contained in the subject at the measurement point in the vicinity of the plurality of light irradiation positions, and the light absorption of the plurality of measurement points obtained in the first step. And a second step of displaying the body concentration as a two-dimensional topography image representing the subject. 6. In the first step, the measurement point is set to an arbitrary position on the normal line from the midpoint of the light irradiation position and the light detection position to the inside of the subject and perpendicular to the surface of the subject, and in the second step. , Displaying the interpolated light absorber concentration obtained by interpolating the light absorber concentration obtained at the plurality of measurement points and the light absorber concentration obtained at the plurality of measurement points between each measurement point as a topography image. The image creating method according to claim 5, characterized in that 7. An image is obtained by using the light absorber concentration as a light absorber concentration at an arbitrary time point or a time-averaged variation amount of the light absorber concentration for a certain period of time. Alternatively, the image creating method described in item 6. 8. The method according to claim 5, wherein in the second step, the light absorber concentration or the amount of change in the light absorber concentration is obtained at arbitrary time intervals, and continuous time-lapse images are obtained at each time interval. 6. The image creating method described in 6. 9. In the second step, image information of the inside of the object measured by magnetic resonance and X-rays is displayed together with the information of the light absorber concentration on the same screen as the two-dimensional image. 9. The image creating method according to claim 6, further comprising: 10. In the second step, the light absorber concentration or the amount of change in the light absorber concentration is obtained at an arbitrary time interval,
It is characterized in that, with reference to the time change of the change amount at any one measurement point, a correlation with the time change of the change amount at another measurement point is obtained, and a temporal image of a continuous correlation function is obtained at each time interval. The image creating method according to claim 5.