JPH0465684B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method and apparatus for measuring reflection characteristics of organs and tissues of a living body. In more detail,
The present invention relates to a method for measuring the reflection characteristics of organs and tissues of a living body, which is used for detecting the presence or absence of a lesion based on the reflection characteristics of the organs and tissues of the living body, and particularly to a diffuse reflection measurement method and an apparatus therefor.

<Problems to be solved by conventional techniques and inventions> Conventionally, in fields such as clinical diagnosis, light is irradiated onto a subject such as a living body's organs and tissues, such as skin, mucous membranes, and excised organs, and its reflection characteristics are measured. The method of diagnosing the presence or absence of lesions, symptoms, etc. is widely used. As a method and apparatus used for such diagnosis, light from a light source is transmitted using a first optical fiber, and a tip of the optical fiber facing the subject (hereinafter referred to as the irradiation tip) is transmitted to the subject. It irradiates the specimen and receives the reflected light from the specimen at the tip of the second optical fiber facing the specimen (hereinafter referred to as the light-receiving tip), and consists of a photodetector such as a light-receiving element and a spectrometer. A method for detecting the reflection characteristics of a subject by transmitting the information to a photometric means and a device equipped with such a reflection characteristics detection means are widely used.

In such a method and apparatus, if the positions of the irradiation tip and the light receiving tip of the optical fiber are set so that the incident angle and the reflection angle are equal to the subject, the amount of reflected light will be maximized and the S/N ratio will be the same. Capable of excellent measurements. However, in this case, a large amount of space is required because the two probes on the irradiation side and the light receiving side must be provided at a certain angle. Further, objects to be examined such as organs and tissues of living bodies usually have a glossy appearance, and when irradiated with light, the surface reflection is large. Therefore, when measuring the diffusely reflected light containing internal information unique to the subject from inside the organ or tissue, this large surface reflected light interferes with the measurement, resulting in a problem of poor measurement accuracy.

Therefore, as a method to reduce surface reflection as much as possible, a method has been proposed in which the light-receiving tip of the optical fiber is placed at an angle where specularly reflected light does not enter. Since the probe needs to be installed at a certain angle, the same problem as above occurs, and furthermore, the amount of diffusely reflected light that contains internal information of organs and tissues decreases, worsening the S/N ratio and increasing exposure. When the surface of the specimen is uneven, surface reflected light easily enters the specimen, resulting in unreliable measured values.

In order to solve these problems, a method was proposed in which the irradiating tip and the light receiving tip of the optical fiber are combined into a bundle, irradiating the subject with light from a substantially perpendicular direction, and measuring the reflected light in the vertical direction. has been done. According to this method, the space can be reduced, but there is a problem similar to the conventional method in terms of suppressing surface reflection from organs and tissues of the living body. That is,
Generally, when light is perpendicularly incident on the interface of two layers with different refractive indexes (refractive indexes are n1 and n2, respectively), the surface reflectance (R) at the interface is defined by the following general formula: Ru.

R=(n1-n2/n1+n2) ^2As is clear from the above equation, the smaller the difference in refractive index between the two layers, the lower the surface reflectance. Therefore, when a sample is irradiated with light through a gas phase with a low refractive index such as air, the difference in refractive index between the optical fiber and the sample and the gas is large, so the tip of the optical fiber and the gas phase Surface reflection becomes large at the interface between the object surface and the gas phase, and accurate measurement cannot be performed as in the case described above.

Therefore, an apparatus has been proposed in which the bundled irradiation tip and light-receiving tip are brought into contact with the surface of the subject and measured by compressing them, thereby minimizing surface reflection from the optical fiber tip and the subject. (Refer to Special Publication No. 60-43134). However, even in this case, air may be present between the tip of the optical fiber and the surface of the subject, causing surface reflection. In addition, when the organs and tissues of a living body are compressed, the degree of this compression changes the color of the organs and tissues, and the reflection spectrum also changes. Considering that it is difficult to maintain a uniform compression force, it is difficult to reproduce the There is a problem that certain measurements cannot be made. Furthermore, when performing fluorescence measurements of biological organs and tissues, it is necessary to use high-energy excitation light, and when the measurement is made in contact with the subject as described above, the temperature of the irradiated area increases and the surface This causes problems such as drying of the body and deterioration of living organs and tissues, making it impossible to accurately measure diffusely reflected light.

<Purpose> This invention was made in view of the above problems, and provides a method for measuring the diffuse reflection of organs and tissues of living bodies, which is simple and has excellent reproducibility, and allows measurement of diffuse reflection characteristics without adversely affecting the subject. The object of the present invention is to provide a method and device for measuring characteristics.

<Means for Solving the Problems> The first invention of the present invention, which was made to solve the above problems, is a method for measuring diffuse reflection characteristics of organs and tissues of a living body, which transmits light from a light source. , a first optical fiber that irradiates the light to an organ or tissue separated from a human body, or a subject consisting of an organ or tissue of a living body other than a human body, and a first optical fiber that receives reflected light from the subject and transmits it to a photometric means. A method for detecting reflection characteristics of a subject using a second optical fiber, comprising:
between the irradiation tip and the light receiving tip of the first optical fiber and the second optical fiber and the subject;
The second invention, a device for measuring diffuse reflection characteristics of living organs and tissues, is characterized in that measurement is performed in a state filled with a transparent liquid having a refractive index similar to the refractive index of the surface of the subject. a first optical fiber that transmits the light from the light source and irradiates it to the subject, and a second optical fiber that receives the reflected light from the subject and transmits it to the photometric means. a reflection characteristic detecting means for detecting the reflection characteristics of the object using a reflection characteristic detecting means; It is characterized by comprising means for supplying a transparent liquid having a refractive index similar to the refractive index to fill the refractive index.

Note that the above-mentioned transparent liquid includes, for example, water,
Examples include physiological saline, alcohols such as ethanol, and hydrous alcohols. Further, the irradiating tip portion and the light receiving tip portion may be formed as a bundle.

<Function> The present invention has the above configuration, in which light from the light source is transmitted through the first optical fiber, and is transmitted from the irradiation tip of the optical fiber to the transparent filter filled between the tip and the subject. The subject is irradiated via the liquid.
Furthermore, the light reflected by the subject is received by the light-receiving tip of the second optical fiber via the transparent liquid. Therefore, since there is no intervening gas such as air that has a large difference in refractive index from the refractive index of the optical fiber and the surface of the object, surface reflection at the tip of the optical fiber and surface reflection at the surface of the object during irradiation and reception of light is suppressed. Furthermore, since the refractive index of the transparent liquid is similar to the refractive index of the surface of the object, surface reflections on the surface of the object are further suppressed, making it possible to measure a large amount of diffusely reflected light that contains information inside the object. can.

Furthermore, since the light is irradiated onto the sample through the liquid as before, the sample does not dry out or undergo thermal denaturation even when irradiated with light with high energy, such as in fluorescence analysis, making it more accurate. information.

<Examples> Hereinafter, examples will be described in detail based on the accompanying drawings showing examples.

FIG. 1 is a conceptual diagram showing an embodiment of the measuring method which is the first invention of the present invention. , from the irradiation tip 3',) organs and tissues separated from the human body,
) A first optical fiber 3 that irradiates a subject 2 consisting of an organ or tissue of an animal other than a human or a tissue of a plant, and a light receiving tip 5' that receives reflected light from the subject 2
A second optical fiber 5 that receives light from the source and transmits it to a photometric means 4 consisting of a light receiving element, a spectroscopic analyzer, etc., and a mantle tube that bundles the irradiation tips 3' and light receiving tips 5' of the optical fibers 3 and 5 into a bundle. 6, and a transparent liquid 7 filled between the distal end of the mantle tube 6 and the subject 2 and having a refractive index similar to the refractive index of the surface of the subject 2, and a plurality of optical fibers 3 and 5, respectively. A bundle of book optical fibers is used. The measuring method of the present invention will be explained based on the figure. First, one drop of transparent liquid 7 is dropped onto the subject 2, which is a tissue such as skin separated from a human body. The irradiation tips 3' and light-receiving tips 5' of the optical fibers 3 and 5 are brought into contact with the dropped transparent liquid 7, and the distance between the irradiation tips 3' and the light-receiving tips 5' and the subject is maintained at a predetermined distance. Fix the distance so that the distance is . In this state, the emitted light from the light source 1 is incident on the optical fiber 3 and transmitted, and is irradiated onto the subject 2 from the irradiation tip 3' of the fiber 3 via the transparent liquid 7. The reflected light from the subject 2 is received by the light-receiving tip 5' of the optical fiber 5, transmitted through the optical fiber 5, and incident on a photometry means 4 such as a light-receiving element or a spectroscopic analyzer, where it is photometered. The signal from the photometric means 4 is input to a conventional processing means such as an arithmetic processing section (not shown), and the result is displayed on the surface section.

FIG. 2 shows the optical fiber 3 in the above embodiment.
5 is a schematic cross-sectional view showing a modified example of the irradiation tip 3' and the light reception tip 5' of the irradiation tip 3' and the light reception tip 5', which are bundled in the mantle tube 6. A thin tube 8 is provided approximately at the center of the optical fiber and parallel to the optical fiber. The transparent liquid 2 is dripped onto the subject 2 from the transparent liquid 7 supply source (not shown) through the thin tube 8 using a liquid feeding means such as a pump. The reflective properties of the subject are measured using a specific procedure. According to this modification, the transparent liquid 7 is dropped onto the subject 2 from the irradiation tip 3' and the light receiving tip 5' sides, so that
It is possible to prevent bubbles such as air from adhering to the irradiation tip 3' and the light receiving tip 5', and it is possible to reliably fill the space between the tip 3' and 5' and the subject with the transparent liquid 7. .

FIGS. 3a and 3b are a schematic vertical cross-sectional view of an embodiment of the apparatus for measuring reflection characteristics of living organs and tissues, which is the second invention of the present invention, and a schematic cross-sectional view taken along the line B-B' in FIG. 3a. The same reference numerals are given to the same members as those in the embodiment shown in FIG. 1. In this embodiment of the second invention, the subject 2 includes, in addition to the above-mentioned) to), organs and tissues that are not separated from the human body. The measuring tank 9 made of a material such as metal or plastic has a cylindrical hollow section formed therein from approximately the center toward the lower end surface. In addition, a bottom cover 11 is removably provided on the lower end surface of the measuring tank 9 via a commonly used fixing device 10, and when attached, the bottom cover 11 is attached to the lower end surface of the measuring tank 9 by a sealing member such as an O-ring. Closely attached,
The cylindrical hollow part and the bottom cover 11 form a filling part 12 that is filled with the transparent liquid 7. The filling part 12
In order to supply the transparent liquid 7 to the filling part 12, a supply pipe 13 for the transparent liquid 7 passes from the upper side wall of the measuring tank 9 through the main body of the measuring tank 9 to the lower side wall of the filling part 12. In order to discharge the transparent liquid 7 and/or gas such as air from the filling part 12, a discharge pipe 14 passes through the main body of the measurement tank 9 from the upper end surface of the filled part 12 and communicates with the upper side wall of the measurement tank 9. The transparent liquid 7 is supplied from a supply pipe (not shown) of the transparent liquid 7 to the filled part 12 via the supply pipe 13 by a liquid feeding means such as a pump, and the liquid level gradually rises, and the filled part Since the air and the like in 12 are discharged from the discharge pipe 14, the filling part 12 can finally be completely filled with the transparent liquid 7. In addition, the measurement tank 9
Above, from the center of the upper end surface of the measuring tank 9, using conventional members such as mounting members and sealing members,
The irradiating tips 3' and the light receiving tips 5' of the optical fibers 3 and 5 are provided to penetrate toward the filled part 12, and the irradiating tips 3' and the light receiving tips 5' are located at a distance from the subject. It is formed to be able to slide up and down so that it can be maintained at a predetermined interval. The tips of the irradiation tip 3' and the light receiving tip 5' are usually flush with the upper end surface of the filled part 12 or protrude slightly toward the filled part 12 from the upper end surface so that they are immersed in the transparent liquid 7. used.

Note that the irradiation tip 3' and the light reception tip 5' may be provided on the side wall of the filled portion 12, and light irradiation and light reception may be performed from the side of the subject. In addition, the filled part 1
2 may be provided with a temperature sensor that detects the temperature of the transparent liquid 7 in the filled portion 12, and the reflection characteristics can be measured while monitoring the liquid temperature.

Next, to explain specifically how to use the apparatus shown in FIG. 3, first, remove the fixing device 10, remove the bottom cover 11, and place the subject 2 such as an organ or tissue taken out from a living body into the measurement tank. accommodated in the filling part 12 of 9;
Next, the bottom cover 11 is attached and fixed with the fixing tool 10. After maintaining a predetermined distance from the subject by sliding the irradiation tip 3' and the light receiving tip 5' up and down and appropriately adjusting them, the transparent liquid 7 is supplied from the transparent liquid 7 supply pipe 13 to the filled part 12. is supplied to fill the plenum 12 with the transparent liquid 7. Next, light from a light source (not shown) is transmitted through the optical fiber 3 and irradiated onto the subject 2 from the irradiation tip 3' via the transparent liquid 7. The reflected light from the subject 2 is received by the light-receiving tip 5' of the optical fiber 5 via the transparent liquid 7, and the incident light is transmitted through the optical fiber 5 to a photometric means (not shown).
The reflection characteristics are measured photometrically.

In addition, in the above-mentioned measurement, the transparent liquid 7 supplied to the filling part 12 may be heated or cooled to an appropriate temperature and supplied, and the temperature change can be controlled by gradually increasing or decreasing the liquid temperature and supplying the transparent liquid 7. It is possible to measure changes in the reflective properties of a subject relative to the subject. In addition, when the transparent liquid 7 contains a medium such as physiological saline, the refractive index of the transparent liquid 7 in the filled part 12 can be adjusted appropriately by supplying liquids with different medium concentrations to the filled part 12. can do.

FIG. 4 shows a schematic vertical cross-sectional view of another embodiment of the measuring device of the present invention, in which the same members as those in the embodiment of FIG. 3 are given the same reference numerals. This device is a simplified version of the device of the embodiment shown in FIG. It is discharged from the discharge pipe 14. In addition, the bottom cover 11 is fixed to the measurement tank 9,
The subject 2 is accommodated in the filled portion 12 by removing the removably formed upper lid 15 . Below, the third
The reflection characteristics of the object are measured using the same procedure as in the example shown in the figure.

FIG. 5 shows a schematic vertical cross-sectional view of another embodiment of the measuring device of the present invention, in which the same members as those in the embodiment shown in FIG. 3 are given the same reference numerals.
This device is particularly preferably used when the subject 2 has movement, such as a living heart. Ru. optical fiber 3
and the irradiation tip 3' and the light receiving tip 5' of 5.
is provided on the bottom lid 11 side, and the light emitted from the irradiation tip 3' is irradiated onto the subject 2 from below, and the reflected light is received by the light receiving tip 5'. The measurement procedure is similar to that of the embodiment shown in FIG. 3 to measure the reflection characteristics. In this embodiment, since the subject 2 is suspended in the filled part 12, the movement of the subject 2 is not hindered and the movement of the subject 2 is not inhibited compared to the case where the subject 2 is accommodated at the bottom of the filled part 12. Since the influence of own weight can be removed by buoyancy, accurate information can be obtained from the subject 2.

Note that this invention is not limited to the above-mentioned embodiments, and the design can be changed as appropriate without changing the gist of the invention. For example, in the above embodiments, the optical fibers 3 and 5 each have a plurality of optical fibers. Although the fibers are made up of a bundle, each may be made up of a single optical fiber, and the irradiating tip 3' and the light receiving tip 5' can be made of a single bidirectional optical fiber. It may also be configured such that the optical fiber from the light emitting source and the photometry side is coupled to one end of the bidirectional optical fiber via an optical branching coupler.
Alternatively, a filter, prism, slit, or other spectroscopic means may be provided between the light source and the optical fiber 3 or between the optical fiber 5 and the photometric means 4 to produce monochromatic light, and the reflection characteristics at each wavelength may be measured. good.
Moreover, the measurement sample may be a plant or food.

Next, the present invention will be explained in more detail based on examples.

Experimental Example In the apparatus diagram shown in Figure 1, a spectrophotometer with a built-in light source (J = 50W) equipped with an optical fiber (manufactured by Otsuka Electronics Co., Ltd., MCDD-200) was used as the light source, photometric means, and optical fiber. The reflectance of the skin of a man's finger was measured with air or water interposed between the optical fiber tip and the subject.

The measurement temperature was 25° C., a white standard plate was used as a reference for reflectance, and the reflectance of the white standard plate in water or air was set as 100. Further, the distance between the tip of the optical fiber and the subject or white standard plate was 5 mm. The measurement time was 1 second, the measurement was repeated 8 times, and the average value was determined. The results are shown in FIG.

As is clear from the spectrum diagram in Figure 6, when air is present, the curve is gentle over all wavelengths and no specific peak is shown, but when water is present, cytochrome C appears at 560 nm. A peak based on this appeared, and the diffuse reflection characteristics unique to the subject were detected.

<Effects of the Invention> As described above, according to the first invention of the present invention, which is a method for measuring reflection characteristics of living organs and tissues, a transparent liquid, especially a transparent liquid, is placed between the light emitting/receiving tip and the subject. Since a transparent liquid with a refractive index similar to the refractive index of the specimen surface is present, surface reflection at the tip of the optical fiber and the specimen surface is suppressed, and a large amount of diffusely reflected light containing information about the specimen can be measured. It also prevents the temperature of the sample from rising and drying out even when irradiated with high-energy light such as in fluorescence analysis.
According to the second invention, an apparatus for measuring reflection characteristics of living organs and tissues, in addition to the above-mentioned effects, the refractive index of the transparent liquid to be supplied has a unique effect of being able to obtain accurate information. can be adjusted as appropriate, and furthermore, the temperature of the supplied transparent liquid can be controlled, so it has the unique effect of being able to measure changes in the reflection characteristics of the subject with respect to temperature changes.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of the measuring method of the present invention, FIG. 2 is a cross-sectional schematic diagram showing a main part of a modified example of the measuring method of the present invention, and FIG. 3 is a schematic diagram showing an embodiment of the measuring method of the present invention. FIGS. 4 and 5 are a schematic vertical cross-sectional view and a schematic cross-sectional view showing one embodiment of the device, and FIG. 6 is a schematic cross-sectional view showing another embodiment of the measuring device of the present invention.
The figure is a reflection spectrum diagram obtained in an experimental example. 1... Light source, 2... Subject, 3, 5... Optical fiber, 4... Photometric means, 7... Transparent liquid, 9...
Measuring tank, 11...bottom cover, 12...filled part, 13...
...supply pipe, 14...discharge pipe.

Claims (1)

[Claims] 1. A first optical fiber that transmits light from a light source and irradiates the light to an organ or tissue separated from a human body, or a subject consisting of an organ or tissue of a living body other than a human body. , a second optical fiber that receives reflected light from the subject and transmits it to a photometric means; and a second optical fiber that receives reflected light from the subject and transmits it to a photometric means. The method is characterized in that the measurement is performed with a transparent liquid having a refractive index similar to the refractive index of the surface of the subject being filled between the tip of the fiber and the second optical fiber facing the subject and the subject. A method for measuring the diffuse reflection characteristics of biological organs and tissues. 2. The method for measuring diffuse reflection characteristics of organs and tissues of a living body according to claim 1, wherein the first optical fiber and the second optical fiber are formed in a bundle at their distal ends facing the subject. 3 A measurement tank that accommodates at least a portion of the subject, and a first chamber that transmits light from a light source and irradiates the subject.
and a second optical fiber that receives reflected light from the subject and transmits it to the photometric means; A method for supplying a transparent liquid having a refractive index similar to that of the surface of the subject to be filled between the tip of the optical fiber for the subject and the subject. Device for measuring diffuse reflection characteristics of organs and tissues. 4. The apparatus for measuring diffuse reflection characteristics of organs and tissues of a living body according to claim 3, wherein the first optical fiber and the second optical fiber are formed in a bundle at their distal ends facing the subject. 5. The apparatus for measuring diffuse reflection characteristics of organs and tissues of a living body according to claim 3, wherein the measurement tank is a measurement tank having a transparent liquid supply pipe and a discharge pipe.