JP2009153654A - Living body observing apparatus and living body observing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To vividly detect a blood vessel existing in the deep part of body tissue regardless of the presence of the body tissue, especially fatty tissue. <P>SOLUTION: The living body observing apparatus 1 includes: a light source 2 for generating illumination light for irradiating the body tissue B; an illumination wavelength control part 6 for cyclically changing the wavelength of the illumination light generated from the light source 2 at a prescribed frequency fm in a wavelength band where the spectral characteristics of an observation object A inside the body tissue B are roughly monotonously changed and the change of the spectral characteristics of the other part inside the body tissue B is smaller than that; a light receiving part 4 for receiving scattering light transmitted inside the body tissue B among the illumination light emitted from the light source 2; and a signal processing part 7 for extracting the scattering light whose strength is changed at the frequency fm from the scattering light received by the light receiving part 4. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a living body observation apparatus and a living body observation method.

  2. Description of the Related Art Conventionally, an imaging system that detects a state of blood vessel travel by irradiating a living tissue with infrared light and taking an image of the living tissue is known (see, for example, Patent Document 1).

JP 2004-358051 A

  However, since living tissue, particularly adipose tissue, has strong scattering, infrared light is scattered by the adipose tissue existing around the observation target such as a blood vessel to be observed, and scattered light including information on the observation target is scattered by the adipose tissue. There is a problem that it is buried in the scattered strong scattered light and it is difficult to detect the state of blood vessel running in the deep part of the living tissue.

  The present invention has been made in view of the above-described circumstances, and is a living body observation apparatus and a living body that can more clearly detect a blood vessel existing in a deep part of a living tissue regardless of the presence of living tissue, particularly adipose tissue. The object is to provide an observation device.

In order to achieve the above object, the present invention provides the following means.
The present invention relates to a light source that generates illumination light that irradiates a biological tissue, and the wavelength of the illumination light emitted from the light source. An illumination wavelength control unit that periodically changes at a predetermined frequency in a wavelength band in which a change in spectral characteristics of the portion is smaller, and scattering that has passed through the living tissue out of the illumination light emitted from the light source There is provided a living body observation apparatus including a light receiving unit that receives light and a signal processing unit that extracts scattered light whose intensity changes at the frequency from the scattered light received by the light receiving unit.

  According to the present invention, the wavelength of the illumination light emitted from the light source is irradiated on the living tissue in a state where the wavelength of the illumination light is periodically changed at a predetermined frequency by the illumination wavelength control unit, and the scattered light transmitted through the living tissue is received. The light is received by the unit. In the illumination wavelength control unit, the spectral characteristic of the observation object changes substantially monotonously, and the frequency of the illumination light is changed in a wavelength band in which the change of the spectral characteristic of the other part in the biological tissue is smaller than that. Of the light that has passed through the tissue, the scattered light that has passed through the observation target varies in intensity at the same frequency due to the influence of the modulation of the illumination light.

  Therefore, in the signal processing unit, it is possible to extract only the scattered light transmitted through the observation target by extracting the scattered light whose intensity changes at the modulation frequency by the illumination wavelength control unit from the received scattered light. It is possible to grasp the existence of the observation target in the living tissue. In other words, even if a small amount of scattered light that has passed through the observation target is buried in the highly scattered light scattered in the tissue around the observation target, this should be easily extracted and visualized. Is possible.

In the above invention, the scanning unit that scans the living tissue with the illumination light from the light source, the irradiation position of the illumination light by the scanning unit, and the amplitude of the intensity of the scattered light extracted by the signal processing unit correspond to each other And a storage unit for storing the information.
By doing in this way, it becomes possible to grasp | ascertain distribution of the observation object inside a biological tissue.

Further, in the above invention, the observation target is a blood vessel, and the illumination wavelength control unit periodically changes at a predetermined frequency in a wavelength band in which absorption intensity by a substance contained in blood changes substantially monotonously. Also good.
By doing in this way, the blood vessel which exists in the deep part of a biological tissue can be grasped | ascertained clearly.

In the above invention, the image generation unit that generates the distribution image of the intensity amplitude of the scattered light based on the irradiation position of the illumination light stored in association with the storage unit and the amplitude of the intensity of the scattered light; And a display unit that displays the distribution image generated by the image generation unit.
By doing in this way, the distribution of the observation target in the living tissue can be displayed on the display unit as a distribution image and visualized.

In the above invention, the light source may be a wavelength tunable laser light source.
In the above invention, the light source may be a plurality of laser diodes that emit laser beams having different wavelengths, and the illumination wavelength controller may operate the laser diode in an interpolating manner.

In the above invention, the light source is a broadband light source that emits illumination light over a predetermined wavelength band, and the illumination wavelength control unit has an arbitrary wavelength from illumination light emitted from the illumination light emitted from the light source. A wavelength selection element capable of selecting illumination light may be used.
Moreover, in the said invention, the said light-receiving part may be a photodiode.
Moreover, in the said invention, the said light-receiving part may be a CCD camera.

  Further, the present invention provides a broadband light source that generates illumination light over a predetermined wavelength band to irradiate a living tissue, and arbitrary scattered light that has passed through the living tissue out of the illumination light emitted from the broadband light source. A wavelength selection element capable of selecting illumination light of a wavelength, a light receiving unit that receives scattered light of a wavelength selected by the wavelength selection element, and an observation of the wavelength of the scattered light selected by the wavelength selection element in a living tissue The light receiving wavelength control unit that changes the spectral characteristics of the target substantially monotonously and periodically changes the spectral characteristics of other parts in the living tissue at a predetermined frequency in a smaller wavelength band, and the light receiving unit There is provided a living body observation apparatus including a signal processing unit that extracts scattered light whose intensity changes at the frequency from received scattered light.

  According to the present invention, when a living tissue is irradiated with broadband illumination light having a predetermined wavelength band emitted from a broadband light source, the illumination light is scattered into scattered light while passing through the living tissue, The intensity of the scattered light changes for each wavelength according to the spectral characteristics of the observation target. Therefore, the wavelength of the scattered light selected by the wavelength selection element from the scattered light that has been transmitted through the living tissue changes the spectral characteristics of the observation target in the living tissue substantially monotonously by the operation of the light receiving wavelength control unit, When the scattered light that has passed through the observation target exists in the scattered light that has passed through the living tissue by periodically changing the spectral characteristics of other parts at a predetermined frequency in a smaller wavelength band. Can receive the scattered light whose intensity varies at the same frequency by the light receiving unit. Thereby, it becomes possible to grasp the existence of the observation target in the living tissue.

In the above invention, the scanning unit that scans the living tissue with the illumination light from the light source, the irradiation position of the illumination light by the scanning unit, and the amplitude of the intensity of the scattered light extracted by the signal processing unit correspond to each other And a storage unit for storing the information.
In the above invention, the observation target is a blood vessel, and the light receiving wavelength control unit may periodically change at a predetermined frequency in a wavelength band in which absorption intensity by a substance contained in blood changes substantially monotonously. Good.

In the above invention, the image generation unit that generates the distribution image of the intensity amplitude of the scattered light based on the irradiation position of the illumination light stored in association with the storage unit and the amplitude of the intensity of the scattered light; And a display unit that displays the distribution image generated by the image generation unit.
Moreover, in the said invention, the said light-receiving part may be a photodiode.
Moreover, in the said invention, the said light-receiving part may be a CCD camera.

  In addition, the present invention is configured to periodically change the wavelength of illumination light applied to a living tissue at a predetermined frequency in a wavelength band in which the spectral characteristics of an observation target in the living tissue change substantially monotonously, thereby changing the illumination light to the living body. Provided is a living body observation method for irradiating a tissue, receiving scattered light transmitted through the living tissue, and extracting scattered light whose intensity changes at the frequency from the received scattered light.

  Further, the present invention irradiates a living tissue with illumination light over a predetermined wavelength band, and from the scattered light transmitted through the living tissue, the spectral characteristics of the observation target in the living tissue change substantially monotonously, and the living tissue In the wavelength band where the change in spectral characteristics of other parts is smaller, the scattered light is selected by periodically changing the wavelength at a predetermined frequency, and the selected scattered light is received. There is provided a living body observation method for extracting scattered light whose intensity changes at the frequency from light.

  According to the present invention, there is an effect that an observation target existing deep in a living tissue can be detected more clearly regardless of the presence of a living tissue, particularly an adipose tissue.

Hereinafter, the biological observation apparatus 1 according to the first embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, the biological observation apparatus 1 according to the present embodiment has a variable wavelength that generates laser light (illumination light) that irradiates the surface of a fat tissue (biological tissue) B including a blood vessel (observation target) A. A light source 2, a scanning unit 3 for changing the irradiation position of the laser light to the fat tissue B, a light receiving element 4 for detecting scattered light transmitted through the fat tissue B, a frequency oscillator 5 for oscillating a reference frequency fm, In accordance with the reference frequency fm transmitted by the frequency oscillator 5, the wavelength control unit 6 that periodically changes the wavelength of the laser light generated from the wavelength tunable light source 2, and the scattered light received by the light receiving element 4, A synchronous detector (signal processing unit) 7 that extracts scattered light whose intensity varies at the same frequency as the reference frequency fm, and a computer that generates an amplitude distribution image of the intensity of the scattered light extracted by the synchronous detector 7 (Picture A generating unit) 8, and a monitor (display unit) 9 for displaying the distribution image generated by the computer 8.

  The wavelength variable light source 2 is, for example, an external resonator type wavelength variable semiconductor laser light source in the example shown in FIG. The wavelength tunable light source 2 emits light of a predetermined wavelength and performs stimulated emission, a semiconductor gain medium 2a that collects illumination light emitted from the semiconductor gain medium 2a, and a light that is collected by the lens 2b. A diffraction grating 2c that diffracts light and guides the diffracted light to the lens 2b again; a half mirror 2d that transmits a part of the light reflected by the diffraction grating 2c and transmitted through the lens 2b and the semiconductor gain medium 2a; A coupling lens 2e for allowing the light transmitted through the half mirror 2d to enter one end 10a of the optical fiber 10;

  The wavelength control unit 6 changes the angle of the diffraction grating 2 c at the reference frequency fm input from the frequency oscillator 5. As a result, the wavelength of the laser light incident on the optical fiber 10 can be changed continuously and periodically at the reference frequency fm. Specifically, the wavelength control unit 6 is configured to periodically change the wavelength of the laser light within a range of 950 nm to 1040 nm. This wavelength range is a wavelength band in which the absorption intensity of hemoglobin in the blood changes almost monotonously while the absorption intensity of the surrounding adipose tissue B hardly changes.

  The scanning unit 3 is configured by a slider that is moved relative to the surface of the adipose tissue B in the direction of arrow C, and fixes the other end 10 b of the optical fiber 10. Laser light emitted from the other end 10 b of the optical fiber 10 is irradiated onto the surface of the adipose tissue B in a state of being substantially parallel light by the collimator lens 11.

  Further, the scattered light that has passed through the adipose tissue B and is emitted again from the surface of the adipose tissue B is condensed by the condenser lens 12 that is also fixed to the scanning unit 3 and is incident on one end 13 a of the optical fiber 13. The light receiving element 4 disposed at the other end 13b of the optical fiber 13 receives light. The light receiving element 4 is, for example, a photodiode.

The synchronous detection device 7 is a lock-in amplifier that extracts a voltage component that fluctuates at the reference frequency fm from the frequency oscillator 5 input as a reference signal from the input voltage signal.
The computer 8 includes a storage unit 8 a that instructs the scanning unit 3 to specify a scanning position and stores the amplitude value of the voltage component output from the synchronous detector 7 and the scanning position of the scanning unit 3 in association with each other. ing. In the figure, reference numeral 14 is an amplifier, and reference numeral 15 is an A / D converter.

Here, the principle of the living body observation method by the living body observation apparatus 1 according to the present embodiment will be described.
When the adipose tissue B is a scattering medium that is not desired to be visualized and includes a blood vessel A that is an observation target that is desired to be visualized, if illumination light is incident on the inside of the adipose tissue B from the surface of the adipose tissue B As shown in FIG. 2, a part of the light is again released from the surface of the adipose tissue B through the first optical path L1 that transmits only the adipose tissue B. The other part passes through the fat tissue B and the blood vessel A, and is emitted from the surface of the fat tissue B to the outside via the second optical path L2 that passes through the fat tissue B again.

  In this case, as shown in FIG. 3, the wavelength characteristics of the absorption intensity are greatly different between the blood vessel A and the fat tissue B. That is, the blood vessel A has a wavelength band that is strongly absorbed by hemoglobin and water contained in blood flowing in the blood vessel A. On the other hand, in the same wavelength band, there is no significant change in the wavelength characteristics of the absorption intensity of the adipose tissue B.

  Therefore, as shown in FIG. 3, when the wavelength of the laser beam to be irradiated is periodically changed at a constant frequency fm in a wavelength band where the wavelength characteristic of the absorption intensity of the blood vessel A changes substantially monotonically, the blood vessel A The transmitted scattered light has its wavelength component intensity I2 varying at the same frequency fm. On the other hand, for scattered light that has not passed through the blood vessel A, the intensity I1 does not vary even if the wavelength of the laser beam to be irradiated varies.

  That is, the scattered light passing through the first optical path L1 does not change in intensity, and as shown in FIG. 4A, the scattered light has a temporally constant intensity I1 and is scattered via the second optical path L2. As shown in FIG. 4B, the light becomes scattered light having an intensity I2 = I2AC + I2DC that periodically varies with time. Here, I2AC is an AC component, and I2DC is a DC component. The light receiving element 4 receives the scattered light in a synthesized state, and the intensity I1 of the scattered light passing through the first optical path L1 increases as the blood vessel A becomes deeper in the fat tissue B.

In this case, if only the intensity information of the scattered light received by the light receiving element 4 is imaged as it is, the scattered light transmitted through the blood vessel A becomes a background noise from the scattered light having a large intensity by the adipose tissue B. It will be buried.
In the present embodiment, the synchronous detector 7 extracts the AC component I2AC of the scattered light that fluctuates at the same frequency fm as the reference frequency fm of the laser light from the intensity signal of the scattered light obtained by the light receiving element 4. By doing so, it is possible to remove the direct current components I1 and I2DC from the intensity signal of the scattered light and extract only the alternating current component I2AC of the scattered light transmitted through the second optical path L2.

The operation of the biological observation apparatus 1 according to the present embodiment configured as described above will be described below.
In order to observe the running state of the blood vessel A in the adipose tissue B using the living body observing method by the living body observing apparatus 1 according to this embodiment, an AC signal having a predetermined frequency fm from the frequency oscillator 5 is sent to the wavelength control unit 6. The laser light having a wavelength periodically changed at a predetermined frequency fm within a range of 950 nm to 1040 nm is emitted from the variable wavelength light source 2.

  Further, the computer 8 outputs a command signal for the scanning position of the laser beam to the scanning unit 3. Thereby, the scanning part 3 is moved to the scanning position according to the command signal along the surface of the fat tissue B. Since the other end 10 b of the optical fiber 10 that emits laser light is fixed to the slider that constitutes the scanning unit 3, the laser light emitted from the wavelength variable light source 2 is transmitted through the optical fiber 10 by the collimator lens 11. The light is substantially parallel light and is irradiated onto the surface of the adipose tissue B at a position corresponding to the scanning position.

  The laser light applied to the surface of the adipose tissue B is emitted from the surface of the adipose tissue B as scattered light after passing through the first optical path L1 and the second optical path L2, and is collected by the condenser lens 12. Light is received by the light receiving element 4 through the optical fiber 13. A voltage signal corresponding to the intensity of the received scattered light is output from the light receiving element 4, amplified by the amplifier 14, and then input to the synchronous detector 7.

  In the synchronous detection device 7, synchronous detection of the intensity signal of the scattered light input from the amplifier 14 is performed using the AC signal of the predetermined frequency fm input from the frequency oscillator 5 as a reference signal. As a result, only the AC component I2AC contained in the scattered light intensity signal is extracted, A / D converted, and input to the computer 8. In the computer 8, the amplitude value is detected, and the scanning position information output to the scanning unit 3 is associated with the detected amplitude value and stored in the storage unit 8a.

  While the scanning unit 3 scans the surface of the adipose tissue B with laser light, the scattered light output from the surface of the adipose tissue B is received, so that each scanning position and the AC component in the scattered light at that position can be detected. The amplitude value is sequentially associated. Then, by scanning the laser beam two-dimensionally along the surface of the adipose tissue B, a two-dimensional distribution image of the amplitude value of the AC component I2AC in the scattered light can be obtained, and the obtained distribution image Is visualized by being displayed on the monitor 9.

  As described in the above description of the principle, the amplitude value of the AC component I2AC in the scattered light is large in the region where the blood vessel A exists, and is small in the region where the blood vessel A does not exist. An image having a large amplitude value is obtained in a region where the blood vessel A exists in B. Further, when the blood vessel A is arranged in the deep part of the adipose tissue B, the amplitude value is smaller than that in the case where the blood vessel A is arranged in the shallow part.

  As described above, according to the living body observation apparatus 1 according to the present embodiment, since the fluctuation of the intensity of the scattered light generated only in the region where the blood vessel A exists is extracted, the fatty tissue B arranged around the blood vessel A Even if the scattered light transmitted through the blood vessel A is buried in the scattered light having a large intensity due to the above, it can be efficiently extracted to obtain a clear distribution image. Therefore, the running state of the blood vessel A existing deep in the fat tissue B can be clearly visualized, and there is an advantage that the abdominal tissue B can be incised without damaging the blood vessel A.

  In the present embodiment, the wavelength of the laser beam is continuously and periodically changed at the reference frequency fm from the frequency oscillator 5 using the wavelength tunable light source 2 composed of an external resonator type wavelength tunable semiconductor laser light source. However, instead of this, as shown in FIG. 5, two laser diodes 16 and 17 that oscillate different wavelengths λ1 and λ2, respectively, and laser beams emitted from the two laser diodes 16 and 17 are transmitted in the same optical path. The wavelength tunable light source 2 having the coupler 18 to be joined may be adopted. In the wavelength tunable light source 2, the wavelength control unit 6 switches on and off the two laser diodes 16 and 17 alternately according to the reference frequency fm from the frequency oscillator 5. The number of laser diodes 16 and 17 may be three or more.

  In addition, as shown in FIG. 6, the wavelength tunable light source 2 may be configured by a broadband light source 19 that emits broadband illumination light and a wavelength tunable filter 20 that selects a wavelength to be cut out from the broadband light source 19. . Also in this case, the wavelength of the illumination light selected by the wavelength tunable filter 20 may be changed by the reference frequency fm from the frequency oscillator 5. As the broadband light source 19, an ultrashort pulse light source or a supercontinuum light source (for example, an LED or a superluminescent diode) can be employed. As the wavelength tunable filter 20, a diffraction grating filter, a Fabry-Perot filter, a fiber Bragg grating, or the like can be used.

  Further, in this embodiment, the laser light is irradiated to one point and the operation of receiving the scattered light output from the other point is repeated to acquire the distribution image of the amplitude value. Irradiating the surface of the adipose tissue B with a line-shaped laser beam, and moving the laser beam in a direction perpendicular to the line, and receiving scattered light emitted in a line from a position slightly away from the irradiation position It may be. Thereby, a distribution image can be acquired more rapidly.

  In this embodiment, the distribution of amplitude values is acquired by repeating the operation of irradiating laser light to one point and receiving the scattered light output from the other point by the light receiving element 4 made of a photodiode. However, instead of this, as shown in FIG. 7, a light receiving element including a CCD camera 21 may be adopted. In this way, a wider range of scattered light can be imaged at once, and by performing synchronous detection on the voltage signal indicating each pixel value of the CCD camera 21, it is quicker than in the first embodiment. There is an advantage that a distribution image of the blood vessel A can be acquired.

Next, a living body observation apparatus 30 and a living body observation method according to a second embodiment of the present invention will be described below with reference to FIG.
In the description of the present embodiment, portions having the same configuration as those of the biological observation apparatus 1 according to the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.

  The living body observation apparatus 30 according to the present embodiment uses a broadband light source that irradiates the surface of the adipose tissue B with broadband illumination light having a wide wavelength band instead of changing the wavelength of the laser beam applied to the adipose tissue B. 31 and a wavelength selection element 32 capable of selecting scattered light having a desired wavelength from scattered light emitted from the surface of the adipose tissue B.

The broadband light source 31 is, for example, an LED.
The wavelength selection element 32 is, for example, a dielectric multilayer film type wavelength tunable bandpass filter.
The wavelength control unit 6 is connected to the wavelength selection element 32. The wavelength control unit 6 periodically changes the center wavelength of light that can be transmitted by the wavelength selection element 32 at the reference frequency fm from the frequency transmitter 5. The change range of the center wavelength is in the range of 950 nm to 1040 nm, as in the first embodiment.

  According to the living body observation apparatus 30 according to the present embodiment configured as described above, the broadband illumination light emitted from the broadband light source 31 is converted into substantially parallel light by the collimator lens 11 via the optical fiber 10, and adipose tissue The surface of B is irradiated. The irradiated illumination light enters the adipose tissue B, becomes scattered light through the first optical path L1 and the second optical path L2, and is emitted from the surface of the adipose tissue B again. A portion of the scattered light passes through the wavelength selection element 32 and is then collected by the condenser lens 12 and photographed by the CCD camera 21.

  In this case, the center wavelength of the scattered light allowed to pass through the wavelength selection element 32 is periodically changed by the wavelength control unit 6 based on the reference frequency fm from the frequency transmitter 5. Since the wavelength characteristic of the absorption intensity does not change in the wavelength range, there is almost no intensity fluctuation with respect to the scattered light passing through the first optical path L1 that passes only through the adipose tissue B. On the other hand, in the wavelength range, the wavelength characteristic of the absorption intensity of hemoglobin monotonously changes, and therefore, the scattered light that has passed through the second optical path L2 that passes through the blood vessel A passes through the wavelength selection element 32. The intensity fluctuates every time.

  Therefore, in the same manner as in the first embodiment, the luminance value signal of each pixel of the scattered light imaged by the CCD camera 21 is subjected to synchronous detection with the reference frequency fm from the frequency transmitter 5 by the synchronous detector 7. By doing so, only the alternating current component of the scattered light is extracted for each pixel and input to the computer 8. In the computer 8, the amplitude value of the alternating current component of the scattered light is acquired for each pixel, and the distribution value is generated by storing the amplitude value for each pixel.

  As described above, the living body observation apparatus 30 according to the present embodiment also extracts fluctuations in the intensity of the scattered light generated only in the region where the blood vessel A exists, so that it is large due to the fat tissue B arranged around the blood vessel A. Even if the scattered light transmitted through the blood vessel A is buried in the scattered light with high intensity, it can be efficiently extracted to obtain a clear distribution image. Therefore, the running state of the blood vessel A existing deep in the fat tissue B can be clearly visualized, and there is an advantage that the abdominal tissue B can be incised without damaging the blood vessel A.

  In each of the above embodiments, the blood vessel A is exemplified as the observation target, and the fatty tissue B is exemplified as the living tissue composed of the scattering medium. However, the present invention is not limited to this, and the other tissue in any other living tissue is exemplified. You may decide to apply when observing an observation object.

It is a whole lineblock diagram showing the living body observation device concerning a 1st embodiment of the present invention. It is an optical path diagram explaining the operation principle of the living body observation apparatus of FIG. It is a graph which shows the transmittance | permeability characteristic of the observation object in the scattering medium observed by the biological observation apparatus of FIG. (A) It is a graph which shows the intensity | strength of the light which permeate | transmitted only the scattering medium, (b) The intensity | strength of the light which permeate | transmitted the scattering medium and the observation object. It is a figure which shows the 1st modification of the wavelength variable light source of the biological observation apparatus of FIG. It is a figure which shows the 2nd modification of the wavelength variable light source of the biological observation apparatus of FIG. It is a whole block diagram which shows the modification which employ | adopted the CCD camera as a light receiving element of the biological observation apparatus of FIG. It is a whole block diagram which shows the biological observation apparatus which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

A Blood vessel (object to be observed)
B Fat tissue (living tissue)
fm Frequency 1,30 Living body observation device 2 Wavelength variable light source (light source)
3 Scanning unit 4 Light receiving element (light receiving unit)
6 Wavelength control unit (illumination wavelength control unit, received light wavelength control unit)
7 Synchronous detector (signal processor)
8 Computer (image generator)
8a Storage unit 9 Monitor (display unit)
16, 17 Laser diode 19, 31 Broadband light source 20 Wavelength variable filter (wavelength selection element)
21 CCD camera (receiver)
32 wavelength selection element

Claims (17)

A light source that generates illumination light for irradiating a living tissue;
The wavelength of the illumination light emitted from the light source is set to a predetermined value in a wavelength band in which the spectral characteristics of the observation target in the biological tissue change substantially monotonously and the spectral characteristics of other parts in the biological tissue change less than that. An illumination wavelength controller that periodically changes in frequency;
A light receiving unit that receives scattered light transmitted through the living tissue among the illumination light emitted from the light source;
A biological observation apparatus comprising: a signal processing unit that extracts scattered light whose intensity changes at the frequency from scattered light received by the light receiving unit. A scanning unit that scans the living tissue with illumination light from the light source;
The living body observation apparatus according to claim 1, further comprising: a storage unit that stores the irradiation position of the illumination light by the scanning unit and the amplitude of the intensity of the scattered light extracted by the signal processing unit in association with each other. The observation object is a blood vessel;
The living body observation apparatus according to claim 1, wherein the illumination wavelength control unit periodically changes at a predetermined frequency in a wavelength band in which absorption intensity by a substance contained in blood changes substantially monotonously. An image generation unit that generates a distribution image of the intensity amplitude of the scattered light based on the irradiation position of the illumination light stored in association with the storage unit and the amplitude of the intensity of the scattered light;
The living body observation apparatus according to claim 1, further comprising: a display unit that displays the distribution image generated by the image generation unit.   The living body observation apparatus according to claim 1, wherein the light source is a tunable laser light source. The light source is a plurality of laser diodes emitting laser light having different wavelengths;
The living body observation apparatus according to claim 1, wherein the illumination wavelength control unit operates the laser diode in an interpolation manner. The light source is a broadband light source that emits illumination light over a predetermined wavelength band,
The living body observation apparatus according to claim 1, wherein the illumination wavelength control unit includes a wavelength selection element capable of selecting illumination light having an arbitrary wavelength from illumination light emitted from illumination light emitted from a light source.   The living body observation apparatus according to claim 1, wherein the light receiving unit is a photodiode.   The living body observation apparatus according to claim 1, wherein the light receiving unit is a CCD camera. A broadband light source that generates illumination light over a predetermined wavelength band for irradiating a biological tissue;
A wavelength selection element capable of selecting illumination light of an arbitrary wavelength from scattered light transmitted through the living tissue among illumination light emitted from the broadband light source;
A light receiving unit for receiving scattered light having a wavelength selected by the wavelength selection element;
The wavelength of the scattered light selected by the wavelength selection element is predetermined in a wavelength band in which the spectral characteristics of the observation target in the biological tissue change substantially monotonously and the spectral characteristics of other parts of the biological tissue change less than that. A received light wavelength control unit that periodically changes at a frequency of
A biological observation apparatus comprising: a signal processing unit that extracts scattered light whose intensity changes at the frequency from scattered light received by the light receiving unit. A scanning unit that scans the living tissue with illumination light from the light source;
The living body observation apparatus according to claim 10, further comprising: a storage unit that stores the irradiation position of the illumination light by the scanning unit and the amplitude of the intensity of the scattered light extracted by the signal processing unit in association with each other. The observation object is a blood vessel;
The biological observation apparatus according to claim 10, wherein the light reception wavelength control unit periodically changes at a predetermined frequency in a wavelength band in which absorption intensity due to a substance contained in blood changes substantially monotonously. An image generation unit that generates a distribution image of the intensity amplitude of the scattered light based on the irradiation position of the illumination light stored in association with the storage unit and the amplitude of the intensity of the scattered light;
The biological observation apparatus according to claim 10, further comprising a display unit that displays the distribution image generated by the image generation unit.   The living body observation apparatus according to claim 10, wherein the light receiving unit is a photodiode.   The living body observation apparatus according to claim 10, wherein the light receiving unit is a CCD camera. The wavelength of the illumination light that illuminates the living tissue is set to a predetermined frequency in a wavelength band in which the spectral characteristics of the observation target in the living tissue change substantially monotonously and the spectral characteristics of other parts of the living tissue change less than that. And periodically illuminate the living tissue with illumination light,
Receives scattered light that has passed through living tissue,
A living body observation method for extracting scattered light whose intensity changes at the frequency from received scattered light. Illuminate the living tissue with illumination light over a predetermined wavelength band,
From the scattered light transmitted through the living tissue, the spectral characteristics of the observation target in the living tissue change substantially monotonously, and the change in the spectral characteristics of other parts in the living tissue is smaller than that in the wavelength band. Is selected periodically by changing the frequency at a predetermined frequency,
Receive the selected scattered light,
A living body observation method for extracting scattered light whose intensity changes at the frequency from received scattered light.

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