JP2001153796A - Optical apparatus for measuring living matter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance reliability on measured data by compensating for effects by a change in quantity of light detected by a detector in an optical apparatus for measuring a living matter. SOLUTION: In the optical apparatus 1 for measuring the living matter, a light source 2 irradiates a body 10 to be inspected such as the living matter or the like with light, a spectroscopic means 3 spectroscopically measures the light emitted from the living matter, and a two-dimensional detector 4 detects the spectroscopically measured light and obtains spectroscopic pickup images. A control device 5 obtains information on the living matter by processing the spectroscopic pickup images. The optical apparatus 1 is constituted to compensate for effects by a change in quantity of light, with including a detecting means 6 for detecting a quantity of light emitted from the body 10 to be inspected and a compensating means 7 for compensating for the change in quantity of light based on a detected quantity of light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical living body measuring apparatus, and two-dimensionally measures the distribution of blood such as oxygenated hemoglobin and deoxygenated hemoglobin in a living tissue in each part of a living body. The present invention can be applied to diagnosis of normal or abnormal tissue of a living body.

[0002]

2. Description of the Related Art There is known an optical measuring device which irradiates a subject such as a living body with light, receives light scattered, reflected and absorbed by the subject, and optically measures a tissue of the subject. .
In this optical measurement device, it may be required to diagnose the state of blood vessels and blood flow in a shallow part of a living body such as the skin. In order to determine whether blood vessels and blood flow in such a shallow part of a living body are normal, two-dimensional information of the absolute amount at the time of the measurement is necessary in a part where the measurement depth is shallow.

Conventionally, there has been known an optical measurement in which reflected light or transmitted light from an object is detected by a two-dimensional detector to obtain a two-dimensional image. The values are relative and cannot give an absolute amount, and the image obtained simply shows the time change,
It is not meaningful for diagnosing vascular or blood flow conditions.

Further, in order to obtain two-dimensional information using a conventionally known absolute amount measurement, a plurality of detectors are arranged at different distances from the light source, and the absolute amount of each detector is determined. Is required, there is a problem that the device configuration is complicated and the calculation time is long.In addition, since the composition of the subject is assumed to be uniform, when the composition is non-uniform, However, there is also a problem that the measurement value cannot be said to be significant and an accurate diagnosis cannot be made. Therefore, the present applicant has proposed an optical applied biometric method that simply and quickly obtains an absolute amount at the time of measurement by using two-dimensional image information of a subject obtained by a single two-dimensional detector without requiring a large number of detectors. A device has been proposed (Japanese Patent Application No. Hei 11-210).
867).

[0005] In this optical applied biometric apparatus, two-dimensional measurement image data obtained by detecting a subject with a detector and reference image data obtained independently of the subject are obtained at a plurality of measurement wavelengths. The absolute value at the time of measurement is obtained by performing an operation using the measurement image data at the plurality of measurement wavelengths and the reference image data. It is known that the amount of hemoglobin (hemoglobin) contained in blood increases and decreases reflecting the expansion and contraction of blood vessels, and that the expansion and contraction of blood vessels is detected by measuring the amount of hemoglobin in tissues.
Hemoglobin binds to and separates from oxygen in the blood and transports oxygen. At this time, the spectrum is different between oxyhemoglobin bound to oxygen and deoxyhemoglobin separated from oxygen. A method has been proposed in which oxyhemoglobin and deoxyhemoglobin are non-invasively quantified based on this difference in spectrum, and a diagnosis of a tissue state of a living body such as a blood vessel state such as dilation / reduction of a blood vessel or a blood flow state has been proposed.

[0006]

In the optical biometric device proposed above, there is a problem that the reliability of the measurement data is reduced due to a change in the amount of light detected by the detector. Factors of the light quantity fluctuation include those attributable to the light source and those attributable to the subject. The amount of light emitted by the light source is
It changes due to a voltage fluctuation, a temporal change of a light emitting element or a circuit element, or the like. In a plurality of measurements, when the irradiation light amount changes, the detection intensity also changes, and the reference value cannot be determined.
It is difficult to compare a plurality of measurement data. Also,
Even in one measurement, if the amount of light emitted from the light source fluctuates during the measurement, it cannot be distinguished whether the fluctuation in the amount of light is due to the fluctuation of the subject or the amount of irradiation light from the light source.

[0007] Generally, the reflectance of each subject differs depending on the surface condition and composition. In particular, when the subject is a living body, the amount of reflected light varies depending on various measurement environments even if the subject is the same. The change in the amount of reflected light from the subject changes the detection intensity and affects the measurement data. Therefore, even when the amount of light emitted from the light source does not change, the measurement data may change depending on the subject.

[0008] Therefore, when comparing a plurality of subjects, it is difficult to accurately compare each measurement data because it is not possible to determine data serving as a comparison reference.
Further, even for the same subject, if the amount of reflected light changes, it becomes difficult to accurately determine the change over time in the measurement data. As described above, if the light amount detected by the detector fluctuates due to the light source or the subject, the reliability of the measurement data decreases. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned conventional problems and to improve the reliability of measurement data by compensating for the influence of fluctuations in the amount of light detected by a detector in an optical biometric device.

[0009]

SUMMARY OF THE INVENTION The present invention is directed to a spectrometer which irradiates a living body with light, splits light emitted from the living body with spectroscopic means, and detects the split light with a two-dimensional detector. A device for obtaining biological information using a captured image, comprising: a detecting unit for monitoring the amount of light emitted from a living body, and a compensating unit for compensating for a change in the amount of light based on the amount of light detected by the detecting unit. By doing
It compensates for the effect of fluctuations in the amount of light detected by the detector and increases the reliability of the measurement data.

FIG. 1 is a schematic block diagram for explaining an outline of an optical living body measuring apparatus according to the present invention. Optical biological measurement device 1
, The light source 2 irradiates a subject 10 such as a living body with light,
The spectroscopic unit 3 splits the light emitted from the living body, and the two-dimensional detector 4 detects the split light to obtain a spectrally captured image.
The control device 5 obtains biological information by performing image data processing on the spectrally captured image. The optical biometric device 1 of the present invention has a configuration for compensating for the influence of the light amount fluctuation, a detecting unit 6 for detecting the light amount of the light emitted from the subject 10, and a light amount fluctuation based on the detected light amount of the detecting unit 6. Compensation means 7 for compensating is provided. The detection means of the optical biometric device of the present invention can have two configurations. FIG. 2 is a schematic block diagram for explaining these two configurations.

The first configuration of the detecting means is shown in FIG.
As shown in the figure, the detector 6a is provided independently of the two-dimensional detector 4, and the two-dimensional detector 4 is provided by the detector 6a.
Detects the light amount of a part or the whole of the area to be detected, and performs light amount compensation based on the detected light amount. When detecting the light amount in a part of the area, the detection area of the detector is selected from the detection areas of the two-dimensional detector by adjusting the optical axis direction of the detector. Further, when detecting the light amount in the entire region, positioning is performed so that the detection region of the detector and the detection region of the two-dimensional detector become substantially the same, and light amount compensation is performed by averaging the detected light amounts. The detector 6a can use, for example, a photodiode or a photomultiplier.
As the two-dimensional detector, a CCD camera or the like can be used.

The second configuration of the detecting means is shown in FIG.
As shown in (2), the two-dimensional detector 4 also serves as the detector 6b, and a part of the detection signal of the two-dimensional detector 4 is used as a signal for detecting the amount of light. In the second configuration mode, one mode of extracting a signal for detecting the amount of light from the detection signal of the two-dimensional detector is to detect the amount of light in a specific region on the subject,
From the pixels of the two-dimensional detector, the light quantity is obtained from the data of the pixels corresponding to the specific area. The specific area is set by attaching a reference mark having a constant reflection characteristic on the subject,
By referring to the two-dimensional image, it is possible to select a portion where the reflection characteristics are stable on the subject, and set the selected region as a specific region.

In the second configuration, the signal for detecting the amount of light is extracted from the detection signal of the two-dimensional detector. In another aspect, the pixel of the two-dimensional detector includes a pixel region for detecting image data and a pixel for detecting the amount of light. The light quantity is obtained from the data of the pixel area for measuring the light quantity.

Next, the compensating means of the optical living body measuring apparatus according to the present invention may have two constitution modes. Figure 3 shows this 2
FIG. 2 is a schematic block diagram for describing one configuration mode.
As shown in FIG. 3A, the first configuration of the compensating means is to control the intensity of irradiation light emitted from the light source 2 by the compensating means 7. The light amount control 21 for controlling the irradiation light amount of the light source 2 can be performed by controlling the power for driving the light source, controlling the shutter time for opening and closing the irradiation light, controlling the focus of the irradiation light, and the like.

FIG. 3B shows a second configuration of the compensating means.
As shown in (1), the light amount correction of the image data is performed by the compensating means 7, and the signal intensity of the image data of the spectrally picked-up image picked up by the two-dimensional detector is corrected, whereby the light amount is compensated.

According to the present invention, even when the irradiation light quantity fluctuates during a plurality of measurements or one measurement, the measurement data can be compared by performing light quantity compensation. Further, the detecting means can adjust a detection position on the subject, and by adjusting the detection position, can select a position on the subject where the light amount fluctuates due to the fluctuation of the light source. Therefore, the detecting means selectively detects the change of the irradiation light amount due to the change of the light source, and the compensating means:
Based on the detection, it is possible to control the irradiation light amount or to correct the signal intensity of the image data of the spectrally picked-up image to compensate for the influence of the light amount fluctuation, thereby improving the reliability of the measurement data. In addition, each configuration of the above-mentioned detection means and each configuration of the compensation means may be combined.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings. First, the first and second detection means for detecting the amount of light having a two-dimensional detector and an independent detector.
A second configuration example will be described with reference to FIG.

FIG. 4A shows a first configuration example. The optical biological measurement device 1 irradiates the subject 10 from the light source 2 via the optical fiber 22. The spectroscopy unit 3 includes a rotating disk 31 provided with a plurality of filters (31a, 31b, 31c) having different wavelength characteristics and a motor 32 for rotating the rotating disk 31, and disperses light emitted from the subject 10 into light. Then, the two-dimensional detector 4 obtains spectrally picked-up images of a plurality of wavelengths.

The control device 5 has a function 52 of image data processing, performs image data processing of a spectrally picked-up image of a plurality of wavelengths,
An image distribution of hemoglobin (oxyhemoglobin, deoxyhemoglobin) or the like is obtained. FIG. 4C shows an example of the configuration of the rotating disk 31 constituting the spectral unit 3. A plurality of filters 31 having different wavelengths and / or wavelength ranges on the turntable 31
a, 31b, 31c, and by rotating the rotating disk 31 with the motor 32, the filters 31a, 31b, 31c
Is exchanged to change the spectral wavelength, and image data necessary for measuring the temporal change of hemoglobin is obtained.

The detector 6a is a detecting means for detecting the amount of light, and is provided independently of the two-dimensional detector 4. Photodetector 63
Is provided with a condensing lens 61 via an optical fiber 62, and condenses light from the subject 10. Photodetector 63
By changing the focal position of the condenser lens 61, the focusing position can be adjusted by displacing the optical fiber 62, and the focusing position on the irradiation range can be adjusted by changing the focal position of the focusing lens 61. In FIG. 4A, between the condenser lens 61 and the subject 10, a broken line indicates a case where the focusing range is widened, and a chain line indicates a case where the focusing range is narrowed.

By adjusting the light condensing position on the subject 10 or selecting the light converging range, it is possible to select the detection position of the light amount in the irradiation range. By selecting a portion where the light quantity variation is caused by the light source and not by the subject, it is possible to detect only the light quantity variation caused by the light source. Further, the light amount state of the entire irradiation area can be detected by widening the light collecting range, and the light amount can be compensated by averaging the light amounts. In general, the change in the subject is local and the light amount fluctuation is small, whereas the light amount fluctuation due to the light source is general and the light amount fluctuation is large. By using the obtained light amount average, light amount compensation for light amount fluctuation of the light source can be performed.

The signal of the light amount detected by the light detector 63 is sent from the light detector 63 to the light source 2 or the control device 5 (broken line connected to the light detector 63 in FIG. 4A),
Used for light amount compensation. On the other hand, when the light amount compensation is performed on the light source 2 side, for example, the voltage supplied to the light source is controlled, the opening / closing time of a shutter device for controlling the irradiation light amount of the irradiation light is controlled, or the focal position of the optical system is controlled. Can be adjusted by controlling the irradiation range. Further, when the light amount compensation is performed on the control device 5 side, the light amount correction function 51 is provided in the control device 5, and the signal intensity of the image data of the spectrally captured image captured by the two-dimensional detector 4 is corrected.

FIG. 4B shows a second configuration example. The detector 6a of the second configuration example has no
Is directly detected by the photodetector 63. The photodetector 63 includes a condenser lens (not shown), and can change the focal position by changing the focal position as in the first configuration example. Note that the second configuration example is different from the first configuration example only in the configuration of the detector 6a, and is common in other configurations. Therefore, the description of the other configurations is omitted.

Next, third and fourth structural examples of the light amount detecting means in which the two-dimensional detector also functions as the detector are shown in FIGS.
This will be described with reference to FIG. FIG. 5A shows a third configuration example. The optical biological measurement device 1 of the third configuration example is similar to the first configuration example.
0, irradiate the light emitted from the subject 10
Dimension detector 4 obtains spectrally picked-up images of a plurality of wavelengths. As shown in FIG. 5C, the spectroscopy unit 3 includes a turntable 31 having a plurality of filters (31a, 31b, 31c) having different wavelength characteristics, and is selected by rotation by a motor 32. The control device 5 has a function 5 for image data processing.
2, the image data processing is performed on the spectrally picked-up images of a plurality of wavelengths to obtain an image distribution of hemoglobin (oxyhemoglobin, deoxyhemoglobin) and the like.

The two-dimensional detector 4 also serves as the detector 6b,
Light amount detection is performed using a part of the image data detected by the dimension detector 4. The image data to be subjected to the light amount detection is image data of a specific area on the subject, and the light amount is detected using the image data. The specific area can be determined by arranging the reference mark 13 having a constant reflection characteristic within the imaging range of the two-dimensional detector. The arrangement position can be an arbitrary position on the subject 10 or the background portion within the imaging range of the two-dimensional detector. In addition, instead of the reference mark 13, it can be set by selecting a portion where the reflection characteristics are stable on the subject with reference to the captured image.

FIG. 6A is an example of a captured image of the third configuration example. The captured image 12a is obtained by capturing an image of the imaging range 12 within the irradiation range 11 in FIG.
The captured image 12a includes an image 10a of the subject 10 and an image 13a of the reference mark 13. The image data processing function 52 extracts image data from the image 10 a of the subject 10, while the light amount correction function 51 extracts the image 13 of the reference mark 13.
The correction data for correcting the intensity of the image data is extracted from a, and the light amount correction of the image data is performed.

FIG. 7 shows an outline of the light amount correction processing of the third configuration example.
This will be described with reference to the processing block diagram of FIG. In the image data processing means 52, the image data obtained by the two-dimensional detector 4 is separated by a reference data extraction function 53 into image data of a specific area such as a reference mark (reference data) and image data excluding the specific area. .

The reference data extraction function 53 automatically recognizes the shape of a predetermined specific area such as a reference mark, or selects a specific area visually from image data obtained by the two-dimensional detector 4. By setting, an area for extracting reference data can be obtained.

The light quantity determination function 54 determines the light quantity from the light intensity of the reference data. The light amount determination can be performed by comparing with a predetermined reference value or light amount range. The result of the light quantity determination is control of the irradiation intensity of the light source 2,
Alternatively, it is used for the image data intensity correction by the image data light amount correction function 51.

FIG. 5B shows a fourth configuration example. The optical biological measurement device 1 of the fourth configuration example has the same configuration as the third configuration example.
A two-dimensional detector is also used as a detector, and the pixels of the two-dimensional detector are divided into a pixel region for detecting image data and a pixel region for measuring the amount of light, and the data in the pixel region for measuring the amount of light is Find the light intensity. The two-dimensional detector 4 is a detector 6
b is also used, and a part of the pixel area of the two-dimensional detector 4 is used for light amount detection.

FIG. 6B shows a captured image example of the fourth configuration example. The captured image 12a is obtained by capturing the imaging range 12 within the irradiation range 11 in FIG. 5, and includes the image 10a of the subject 10. The two-dimensional detector 4 detects the captured image 12a with each pixel 41. Here, the pixel area 41 of the two-dimensional detector 4 includes a plurality of pixels, and includes a pixel area 41a for detecting image data and a pixel area 41b for detecting correction data (the shaded area in FIG. 6B). Are shown). The pixel area 41a and the pixel area 41b are
Although the pixel area 41 can be arbitrarily divided and set, since the pixel area 41b is an area for light quantity detection, it is desirable to select an area in which the light quantity change due to the subject is small.

The function 52 of the image data processing is the
Image data (first area image data) is extracted from 1a (first area). On the other hand, the light quantity correction function 51 extracts correction data (second area image data) from the pixel area 41b (second area). The correction data is data for correcting the light amount by correcting the intensity of the image data (first region image data).

FIG. 8 shows an outline of the light amount correction processing of the fourth configuration example.
This will be described with reference to the processing block diagram of FIG. In the image data processing means 52, a first area (pixel area 41a) reading function 55 extracts image data of the first area from the image data obtained by the two-dimensional detector 4, and reads the second area (pixel area 41b). The function 56 extracts the image data of the second area from the image data obtained by the two-dimensional detector 4. The light amount determination function 54 determines the light amount from the light intensity of the second area image data. The light amount determination can be performed by comparing the signal intensity of the second area image data with a predetermined reference value or light amount range. The light amount determination result is used for controlling the irradiation intensity of the light source 2 or for correcting the intensity of image data (first region image data) by the image data light amount correction function 51.

Further, in the light quantity determination function 54, the signal intensity of the second area image data read out in order is integrated, and when the integrated value reaches a preset image density ratio, the entire imaging is stopped. It is possible to shift to a process of performing light amount compensation. Note that, in the fourth configuration example, the second region image data is used only for determining the light amount, and the image data is obtained only by the first region image data. However, the first region image data and the second region image data are obtained. It is also possible to adopt a configuration in which image data is obtained by combining the image data.

The above-described light amount determination and light amount correction can be repeatedly performed at a predetermined cycle during the measurement, or can be performed only for the purpose of measurement such as initial setting of the light source light amount before the measurement.

According to the embodiment of the present invention, the optimum irradiation intensity of the light source can be set regardless of the type of the subject. Further, in the case of measuring a plurality of images such as a measurement of a plurality of subjects or a measurement of a change with time, it is possible to prevent fluctuation of measurement data due to light source fluctuation. According to the optical biometric device of the present invention, for example, a biological condition such as vascular occlusion can be diagnosed by observing the two-dimensional distribution state of deoxyhemoglobin or oxyhemoglobin.

[0037]

As described above, according to the optical living body measuring apparatus, it is possible to compensate for the influence of the fluctuation in the amount of light detected by the detector and to improve the reliability of the measurement data.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram for explaining an outline of an optical biometric device of the present invention.

FIG. 2 is a schematic block diagram for explaining an aspect of a detection unit of the optical biometric device of the present invention.

FIG. 3 is a schematic block diagram for explaining an aspect of a compensating means of the optical biometric device of the present invention.

FIG. 4 is a diagram of a first configuration example including a light amount detection unit independent of a two-dimensional detector of the optical biometric device of the present invention.

FIG. 5 is a diagram of a second configuration example including a two-dimensional detector and an independent light amount detection unit of the optical biometric device of the present invention.

FIG. 6 is an example of a captured image of a third configuration example of the optical biometric device of the present invention.

FIG. 7 is a processing block diagram for explaining an outline of a light quantity correction process of a third configuration example of the optical biometric device of the present invention.

FIG. 8 is a processing block diagram for explaining an outline of a light amount correction process of a fourth configuration example of the optical biometric device of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical biometric device, 2 ... Light source, 3 ... Spectroscope, 4 ... Two-dimensional detector, 5 ... Control device, 6 ... Detection means, 6a, 6b,
63: detector, 7: compensation means, 10: subject, 10a,
13a: image, 11: irradiation area, 12: imaging area, 12a
... a captured image, 13 ... a reference mark, 21 ... light amount control means,
22, 62 optical fiber, 31 rotating plate, 31a, 31
b, 31c: filter, 32: motor, 41: pixel area, 41a: first pixel area, 41b: second pixel area, 5
1: Image data light amount correction function, 52: Image data processing function, 53: Reference data extraction function, 54: Light amount judgment function,
55: first area read function; 56: second area read function; 61: condenser lens.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Ikuo Konishi 1 Nishinokyo Kuwaharacho, Nakagyo-ku, Kyoto City, Kyoto Prefecture Inside Shimadzu Corporation (72) Inventor Yoshio Tsunazawa 1 Kunishimachi Nishinokyo-ku, Nakagyo-ku Kyoto City, Kyoto Prefecture Shimadzu Corporation (72) Inventor Tetsuo Tamai 1 Nishinokyo Kuwabara-cho, Nakagyo-ku, Kyoto-shi, Kyoto Prefecture F-term in Shimadzu Corporation (reference) 2G059 AA05 BB13 CC18 EE12 FF01 JJ02 JJ11 JJ17 JJ23 KK04 MM01 MM09 MM14 MM17 NN05 NN09 NN09 NN09 4 KY10

Claims (6)

[Claims] 1. A living body is irradiated with light, light emitted from the living body is separated by spectral means, and biological information is obtained by using a spectral image obtained by detecting the separated light with a two-dimensional detector. An optical biometric device, comprising: a detection unit configured to detect a light amount of light emitted from a living body; and a compensation unit configured to compensate for a change in light amount based on the light amount detected by the detection unit. 2. The optical living body according to claim 1, wherein said detecting means includes a detector independent of the two-dimensional detector, and detects a light amount in a part or an entire detection area of the two-dimensional detector. measuring device. 3. The two-dimensional detector also serves as detecting means,
The optical biometric device according to claim 1, wherein the two-dimensional detector detects a light amount in a specific area on the subject. 4. The two-dimensional detector also serves as detecting means,
The optical biometric device according to claim 1, wherein the light amount is detected by one region of the two-dimensional detector. 5. The optical biometric device according to claim 1, wherein said compensating means compensates for a change in light amount by correcting an irradiation light intensity based on the detected light amount. 6. The apparatus according to claim 1, wherein said compensating means compensates for a change in light amount by correcting a signal intensity of the spectrally captured image based on the detected light amount.
The optical biological measurement device according to claim 1.