JP2015177812A - biological observation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a biological observation system capable of generating, when narrow-band light is radiated on a subject, a white light image of a color tone suitable for observation.SOLUTION: The biological observation system comprises: a light source unit that is capable of radiating, within a predetermined wavelength band, narrow-band light having a plurality of wavelength bands corresponding to the absorption property of hemoglobins in blood and wide-band light outside the predetermined wavelength band; an imaging unit that receives light from the subject on which light from the light source unit is radiated and generates an imaging signal; a control unit that performs control for switching between a first mode of sequentially generating the narrow-band light for each of the plurality of the wavelength bands and a second mode of simultaneously generating the narrow-band light and the wide-band light; a light source drive unit that drives in the seconde mode the light source unit so as to irradiate the subject with the narrow-band light and the wide-band light, and light in the predetermined wavelength band and not in the wavelength band in which the narrow-band light has the largest intensity; and an image generation unit that generates an image by using the imaging signal.

Description

  The present invention relates to a living body observation system, and more particularly to a living body observation system capable of generating an observation image by irradiating a subject such as a living body mucous membrane with white light.

  In the medical field, for example, a mode for irradiating a subject such as a biological mucous membrane with white light to generate an observation image and a method for generating an observation image by irradiating a subject with narrow band light of a predetermined wavelength band A living body observation system capable of switching between modes is conventionally known.

  Specifically, for example, Patent Document 1 discloses a normal light image mode in which a subject in a body cavity is irradiated with white light to generate a broadband light image, and narrowband light in a predetermined wavelength band is applied to a subject in the body cavity. An electronic living body observation system capable of switching between a special light image mode in which a blood vessel depth image and an oxygen saturation image are generated by irradiation is disclosed.

  However, Patent Document 1 does not particularly disclose a specific method for generating a broadband optical image by irradiating a subject with narrowband light used in the special light image mode. As a result, according to the configuration disclosed in Patent Document 1, there is a problem that a broadband optical image having a color tone that is not suitable for observation may be generated.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a living body observation system capable of generating a white light image having a color tone suitable for observation when a subject is irradiated with narrowband light. It is said.

  The biological observation system according to one aspect of the present invention includes a narrowband light having a plurality of mutually different wavelength bands in accordance with an absorption characteristic of blood hemoglobin within a predetermined wavelength band, and a broadband light outside the predetermined wavelength band. A light source unit capable of irradiating light, a light received from a subject irradiated with light from the light source unit, a pixel having sensitivity in the predetermined wavelength band, and a sensitivity in the wavelength band of the broadband light. A first mode for sequentially generating the narrowband light from the light source unit for each of the plurality of wavelength bands, or an imaging unit that generates an imaging signal of the subject corresponding to each pixel, or A control unit that performs control for switching to one of the second modes in which the narrowband light and the broadband light are simultaneously generated from the light source unit, and the second mode based on the control of the control unit In addition, the light source unit is driven to irradiate the subject with the narrowband light and the broadband light and light in a wavelength range other than the wavelength band that is the maximum intensity in the narrowband light. A narrowband light image is generated using a light source driving unit and a plurality of imaging signals of the subject generated in the first mode, and a wideband is generated using the imaging signal of the subject generated in the second mode. An image generation unit that generates an optical image.

  The biological observation system according to one aspect of the present invention includes a narrowband light having a plurality of mutually different wavelength bands in accordance with an absorption characteristic of blood hemoglobin within a predetermined wavelength band, and a broadband light outside the predetermined wavelength band. A light source unit capable of irradiating light, a light received from a subject irradiated with light from the light source unit, a pixel having sensitivity in the predetermined wavelength band, and a sensitivity in the wavelength band of the broadband light. A first mode for sequentially generating the narrowband light from the light source unit for each of the plurality of wavelength bands, or an imaging unit that generates an imaging signal of the subject corresponding to each pixel, or A control unit that performs control for switching to one of the second modes in which the narrow band light and the broadband light are simultaneously generated from the light source unit, and corresponds to the narrow band light in the first mode. A narrowband light image is generated using a plurality of imaging signals, and in the second mode, broadband light is obtained using a calculation result obtained by performing arithmetic processing on the plurality of imaging signals and an imaging signal corresponding to the broadband light. An image generation unit that generates an image.

  According to the living body observation system of the present invention, when a subject is irradiated with narrowband light, a white light image having a color tone suitable for observation can be generated.

The figure which shows the structure of the principal part of the biological observation system which concerns on an Example. The figure which shows an example of the spectral sensitivity of a primary color filter. The figure for demonstrating an example of the wavelength of the light emitted from a light source device in narrow band light mode. The figure which shows an example of a structure of the image signal process part in the biological observation system which concerns on an Example. The figure for demonstrating an example of spectrum FW1. The figure for demonstrating an example of spectrum FW2. The figure for demonstrating an example of the light control process according to spectrum FW1. The figure for demonstrating an example of the light control process according to spectrum FW2. The figure which shows an example of the look-up table used for the process which concerns on acquisition of an oxygen saturation value. The figure for demonstrating the process performed when acquiring oxygen saturation using the lookup table of FIG. The figure which shows an example of the display mode at the time of alert | reporting presence of a low oxygen area | region.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 to 11 relate to an embodiment of the present invention. FIG. 1 is a diagram illustrating a configuration of a main part of the living body observation system according to the embodiment.

  As shown in FIG. 1, the living body observation system 101 includes an elongated insertion portion that can be inserted into a subject that is a living body, and also captures an imaging signal by imaging a subject such as a living tissue in the subject. Output from the endoscope 1 that outputs the light, the light source device 2 that supplies illumination light used for observing the subject via the light guide 6 that is inserted and disposed inside the endoscope 1, and the endoscope 1. A processor 3 that generates and outputs an observation image or the like corresponding to the imaging signal, a display device 4 that displays an observation image or the like output from the processor 3, and an instruction or the like corresponding to a user input operation to the processor 3 And an input device 5 having switches and / or buttons that can be performed.

  The endoscope 1 images an illumination optical system 11 that irradiates the subject with light transmitted by the light guide 6 and reflected light (return light) emitted from the subject in accordance with the light emitted from the illumination optical system 11. The imaging unit 12 that outputs the obtained imaging signal is provided at the distal end of the insertion unit. In addition, the endoscope 1 stores a scope switch 13 that can give various instructions to the processor 3 in accordance with user operations, and imaging light information (described later) unique to each endoscope 1. And a memory 14.

  The imaging unit 12 is configured to capture reflected light (return light) from a subject illuminated by illumination light emitted from the light source device 2 and output an imaging signal. Specifically, the imaging unit 12 matches the imaging surface of the objective optical system 12a with an objective optical system 12a that forms an image of reflected light (returned light) emitted from the subject and a primary color filter 121. The image pickup device 12b is arranged.

  The image pickup device 12b includes, for example, a CCD and is driven according to the image pickup device drive signal output from the processor 3, and images reflected light (return light) from the subject imaged on the image pickup surface. The obtained imaging signal is output.

  The primary color filter 121 has a spectral sensitivity as illustrated in FIG. 2 in each wavelength band of the red color range, the green color range, and the blue color range. FIG. 2 is a diagram illustrating an example of the spectral sensitivity of the primary color filter.

  For example, the scope switch 13 is instructed to the processor 3 to set (switch) the observation mode of the living body observation system 101 to either the white light observation mode or the narrowband light observation mode in accordance with a user operation. An observation mode switch (not shown) that can be performed is provided.

  The memory 14 includes a spectrum RS indicating a correlation between a wavelength band and a light amount value of red light suitable for imaging by the imaging unit 12, and a wavelength band and light amount value of green light suitable for imaging by the imaging unit 12. Imaging light information including a spectrum GS indicating a correlation between the wavelength band and a spectrum BS indicating a correlation between a wavelength band and a light amount value of blue light suitable for imaging by the imaging unit 12 is stored.

  Specifically, the above-described spectrum RS represents, for example, the spectrum of the return light emitted from the reference subject CW when the reference subject CW, which is a white subject, is irradiated with broadband red light, and the imaging element of the endoscope 1. 12b is shown as an adjusted spectrum adjusted based on the spectral sensitivity of 12b and the optical characteristics of each optical member (light guide 6, illumination optical system 11, and objective optical system 12a) of the endoscope 1.

  Further, the above-described spectrum GS is, for example, the spectrum of the return light emitted from the reference subject CW when the reference subject CW is irradiated with broadband green light, the spectral sensitivity of the imaging device 12b of the endoscope 1, and the endoscope. It is shown as an adjusted spectrum adjusted based on the optical characteristics of each optical member (light guide 6, illumination optical system 11 and objective optical system 12a) of the mirror 1.

  In addition, the spectrum BS described above represents, for example, the spectrum of the return light emitted from the reference subject CW when the reference subject CW is irradiated with broadband blue light, the spectral sensitivity of the imaging device 12b of the endoscope 1, and the endoscope. It is shown as an adjusted spectrum adjusted based on the optical characteristics of each optical member (light guide 6, illumination optical system 11 and objective optical system 12a) of the mirror 1.

  The light source device 2 includes a light source driving unit 21, a light emitting unit 22, and a memory 23.

  The light source drive unit 21 includes, for example, a drive circuit. Further, the light source driving unit 21 generates a light source driving signal for controlling the light emission state of each light source of the light emitting unit 22 and the arrangement state of a fluorescent element 22f described later based on the illumination control signal output from the processor 3. The light source drive signal is generated and output to the light emitting unit 22.

  Specifically, the light source drive unit 21 is based on the illumination control signal output from the processor 3, for example, when the observation mode of the living body observation system 101 is set to the white light observation mode, which will be described later. The light emitting device 22f is disposed on the optical path of the light source, and a light source driving signal for simultaneously emitting light sources of the light emitting unit 22 is generated based on a light amount value after dimming described later, and the generated light source driving signal is emitted. It is configured to output to the unit 22.

  Further, the light source driving unit 21 is based on the illumination control signal output from the processor 3, for example, when the observation mode of the living body observation system 101 is set to the narrow band light observation mode, the optical path of the narrow band light source 22a described later The fluorescent element 22f is arranged outside, a light source driving signal for causing each light source of the light emitting unit 22 to emit light in a predetermined order is generated, and the generated light source driving signal is output to the light emitting unit 22. Yes.

  The light emitting unit 22 includes narrow band light sources 22a, 22b and 22c, a green light source 22d, a red light source 22e, and a fluorescent element 22f.

  The narrow-band light source 22a includes, for example, a blue LED (light emitting diode) or a blue LD (laser diode), and is configured to generate NB1 light that is narrow-band blue light. FIG. 3 is a diagram for explaining an example of the wavelength of light emitted from the light source device in the narrow-band light mode.

  For example, as shown in FIG. 3, the NB1 light has a peak wavelength and a wavelength band such that the amount of change in the absorption coefficient with respect to the amount of oxygen saturation of blood hemoglobin is lower than that of the NB2 light and NB3 light described later. It has.

  The peak wavelength λP1 of the NB1 light is set as a wavelength such that a difference value ΔA1 obtained by subtracting the absorption coefficient of reduced hemoglobin from the absorption coefficient of oxyhemoglobin is smaller than later-described difference values ΔA2 and ΔA3. In the present embodiment, the peak wavelength λP1 is preferably set to a wavelength around 400 nm.

  For example, as shown in FIG. 3, the wavelength band of the NB1 light is set to a shorter wavelength side than the wavelength bands of the NB2 light and the NB3 light in the blue region. Further, for example, as shown in FIG. 3, the wavelength band of the NB1 light is set as a wavelength band that does not overlap with the wavelength bands of the NB2 light and the NB3 light in the blue region. In the present embodiment, preferably, the wavelength band of the NB1 light is set as a wavelength band including a wavelength of 415 nm.

  The narrow-band light source 22b includes, for example, a blue LED or a blue LD, and is configured to generate NB2 light that is narrow-band blue light.

  For example, as shown in FIG. 3, the NB2 light has a peak wavelength and a wavelength band such that the amount of change in the absorption coefficient relative to the amount of change in oxygen saturation of blood hemoglobin is higher than that of the NB1 light.

  The peak wavelength λP2 of the NB2 light is set as a wavelength such that a difference value ΔA2 obtained by subtracting the absorption coefficient of oxyhemoglobin from the absorption coefficient of reduced hemoglobin is larger than the above-described difference value ΔA1. In the present embodiment, the peak wavelength λP2 is preferably set to a wavelength around 440 nm.

  For example, as shown in FIG. 3, the wavelength band of the NB2 light is set to a longer wavelength side than the wavelength band of the NB1 light and to a shorter wavelength side than the wavelength band of the NB3 light in the blue region. Further, for example, as shown in FIG. 3, the wavelength band of the NB2 light is set as a wavelength band that does not overlap with the wavelength bands of the NB1 light and the NB3 light in the blue region.

  That is, the wavelength band of NB2 light is set as a wavelength band in which the absorption coefficient changes in the visible region (blue region) according to the oxygen saturation of blood hemoglobin.

  The narrow-band light source 22c includes, for example, a blue LED or a blue LD, and is configured to generate NB3 light that is narrow-band blue light.

  For example, as shown in FIG. 3, the NB3 light has a peak wavelength and a wavelength band such that the amount of change in the absorption coefficient with respect to the amount of change in oxygen saturation of blood hemoglobin is higher than that of the NB1 light.

  The peak wavelength λP3 of NB3 light is set as a wavelength at which a difference value ΔA3 obtained by subtracting the absorption coefficient of reduced hemoglobin from the absorption coefficient of oxyhemoglobin is larger than the above-described difference value ΔA1. In the present embodiment, the peak wavelength λP3 is preferably set to a wavelength in the vicinity of 470 nm.

  For example, as shown in FIG. 3, the wavelength band of the NB3 light is set to a longer wavelength side than the wavelength bands of the NB2 light and the NB3 light in the blue region. Further, for example, as shown in FIG. 3, the wavelength band of the NB3 light is set as a wavelength band that does not overlap with the wavelength bands of the NB1 light and the NB2 light in the blue region.

  That is, the wavelength band of NB3 light is set as a wavelength band in which the absorption coefficient changes in the visible region (blue region) according to the oxygen saturation level of blood hemoglobin.

  The green light source 22d includes, for example, a green LED. Further, the green light source 22d is configured to generate G light, which is broadband green light having a wider wavelength band than the NB1 light, NB2 light, and NB3 light as illustrated in FIG. It is assumed that the wavelength band of G light is set so as not to overlap with the wavelength band of NB3 light. In the present embodiment, the wavelength band of G light is preferably set as a wavelength band including a wavelength of 540 nm.

  The red light source 22e includes, for example, a red LED. The red light source 22e is configured to generate R light, which is broadband red light having a wider wavelength band than the NB1 light, NB2 light, and NB3 light, as illustrated in FIG.

  The fluorescent element 22f functions as a wavelength conversion member that emits light having a wavelength different from the incident wavelength when a predetermined wavelength is incident. Specifically, the fluorescent element 22f includes, for example, at least a wavelength band other than the wavelength band having the maximum intensity of the NB1 light, the NB2 light, and the NB3 light in the blue region when the NB1 light is irradiated as the excitation light. It is formed using a fluorescent material that emits FL light, which is a set of broadband fluorescence having a spectrum FW. Further, the fluorescent element 22f is configured to be disposed on or outside the optical path of the NB1 light emitted from the narrow band light source 22a based on the light source driving signal output from the light source driving unit 21.

  That is, the broadband light generation unit of the present embodiment includes the narrow band light source 22a and the fluorescent element 22f.

  The light emitting unit 22 of the present embodiment is configured to include an optical element formed of a photonic crystal that emits FL light in response to irradiation with NB1 light, for example, instead of the fluorescent element 22f described above. Also good.

  The memory 23 includes a spectrum NW1 indicating a correlation between the wavelength band of the NB1 light and the light amount value, a spectrum NW2 indicating a correlation between the wavelength band of the NB2 light and the light amount value, and a wavelength band and the light amount of the NB3 light. A spectrum NW3 indicating a correlation between values, a spectrum GW indicating a correlation between a wavelength band of G light and a light amount value, a spectrum RW indicating a correlation between a wavelength band of R light and a light amount value, Is stored. The memory 23 also has excitation wavelength information indicating the excitation wavelength of the fluorescent element 22f and FL light emitted from the fluorescent element 22f when NB1 light, which is excitation light including the excitation wavelength, is irradiated with a predetermined light amount value PL. Fluorescence information having the spectrum FW of the above is stored.

  The processor 3 includes a preprocessing unit 31, an image signal processing unit 32, a display image generation unit 33, and a control unit 34.

  The preprocessing unit 31 includes, for example, a noise reduction circuit, an A / D conversion circuit, and the like, and performs digital processing by performing processing such as noise removal and A / D conversion on the imaging signal output from the endoscope 1. An image signal is generated, and the generated image signal is output to the image signal processing unit 32.

  The image signal processing unit 32 is configured to operate based on a system control signal output from the control unit 34. Further, for example, as shown in FIG. 4, the image signal processing unit 32 includes a color component separation unit 32A, a memory 32B, an oxygen saturation information acquisition unit 32C, and a determination unit 32D. Yes. FIG. 4 is a diagram illustrating an example of the configuration of the image signal processing unit in the biological observation system according to the embodiment.

  Based on the system control signal output from the control unit 34, the color component separation unit 32A is, for example, an image output from the preprocessing unit 31 when the observation mode of the living body observation system 101 is set to the white light observation mode. The signal is separated into R (red) component, G (green) component, and B (blue) component color components obtained by imaging reflected light (returned light) of white light, and output to the display image generation unit 33. Is configured to do.

  Based on the system control signal output from the control unit 34, the color component separation unit 32A is output from the preprocessing unit 31, for example, when the observation mode of the living body observation system 101 is set to the narrowband light observation mode. NB1 component obtained by imaging image signal reflected light (returned light) of NB1, light, NB2 component obtained by imaging reflected light (returned light) of NB2 light, reflected light (returned light) of NB3 light For each of the NB3 component obtained by imaging, the G component obtained by imaging the reflected light (return light) of G light, and the R component obtained by imaging the reflected light of R light (return light) It is configured to perform color separation processing for separation. Further, the color component separation unit 32A is based on the system control signal output from the control unit 34, for example, when the observation mode of the living body observation system 101 is set to the narrowband light observation mode, by the color separation process described above. Each obtained color component is output to the oxygen saturation information acquisition unit 32C and the display image generation unit 33 for each frame.

  The memory 32B stores a lookup table (described later) used for processing of the oxygen saturation information acquisition unit 32C.

  The oxygen saturation information acquisition unit 32C includes each pixel included in an image for one frame based on each color component output for each frame from the color component separation unit 32A and a lookup table stored in the memory 32B. A process (to be described later) for obtaining an oxygen saturation value is performed every time. Further, the oxygen saturation information acquisition unit 32C indicates oxygen saturation information indicating the magnitude of the oxygen saturation of the subject illuminated by the illumination light emitted from the light source device 2 based on the oxygen saturation value acquired by the above-described processing. And processing for outputting the acquired oxygen saturation information to the determination unit 32D. Further, the oxygen saturation information acquisition unit 32C performs processing related to acquisition of oxygen saturation information and output to the determination unit 32D in each frame when the observation mode of the living body observation system 101 is set to the narrowband light observation mode. It is configured to be performed every time.

  Based on the oxygen saturation information output from the oxygen saturation information acquisition unit 32C, the determination unit 32D determines whether or not a low oxygen region in which the magnitude of the oxygen saturation is less than a predetermined threshold TH exists in the image. It is comprised so that the determination process for determining may be performed. In addition, when the observation mode of the living body observation system 101 is set to the narrow-band light observation mode, the determination unit 32D performs the above-described determination process for each frame and displays the determination result obtained by the above-described determination process. It is configured to output to the display image generation unit 33.

  The display image generation unit 33 has a function as an observation image generation unit, and includes a system control signal output from the control unit 34 and each color component output from the image signal processing unit 32 (output from the color component separation unit 32A). And an image corresponding to each color component), and the generated observation image is output to the display device 4.

  The display image generation unit 33 is output from the image signal processing unit 32 when, for example, the observation mode of the biological observation system 101 is set to the white light observation mode based on the system control signal output from the control unit 34. The luminance value of the R component is assigned to the R channel corresponding to the red color of the display device 4, the luminance value of the G component output from the image signal processing unit 32 is assigned to the G channel corresponding to the green color of the display device 4, and image signal processing is performed. The white light observation image is generated by assigning the luminance value of the B component output from the unit 32 to the B channel corresponding to the blue color of the display device 4.

  The display image generation unit 33 is output from the image signal processing unit 32 based on the system control signal output from the control unit 34, for example, when the observation mode of the living body observation system 101 is set to the narrowband light observation mode. The luminance value obtained by adding the NB1 component and the NB2 component output from the image signal processing unit 32 to the G channel and NB1 output from the image signal processing unit 32 A narrow band light observation image is generated by assigning a luminance value obtained by adding the component and the NB2 component to the B channel.

  Based on the system control signal output from the control unit 34 and the determination result output from the determination unit 32D, the display image generation unit 33, for example, has no low oxygen region in the image in the narrowband light observation mode. If this is detected, the narrow-band light observation image generated as described above is output to the display device 4 as it is.

  Based on the system control signal output from the control unit 34 and the determination result output from the determination unit 32D, the display image generation unit 33 includes, for example, a low oxygen region in the image in the narrowband light observation mode. If this is detected, visual information including a predetermined symbol or a predetermined character string for notifying the presence of the hypoxic region in the image is generated, and the generated visual information is used as a narrowband light observation image. In addition, a process for outputting to the display device 4 is performed.

  The control unit 34 is configured to generate and output an image sensor driving signal for driving the image sensor 12b.

  Based on the operation of the scope switch 13, for example, when the control unit 34 detects that the observation mode of the living body observation system 101 is set to the white light observation mode, the imaging light information read from the memory 14 and the memory 23. The light control processing (described later) is performed based on the light source light information and the fluorescence information read from. In addition, when the control unit 34 detects that the observation mode of the living body observation system 101 is set to the white light observation mode, the control unit 34 arranges the fluorescent element 22f on the optical path of the narrowband light source 22a and controls the dimming described above. It is configured to generate an illumination control signal for simultaneously generating light from each light source of the light emitting unit 22 using the light amount value after dimming obtained by the processing, and to output it to the light source driving unit 21.

  For example, when the control unit 34 detects that the observation mode of the living body observation system 101 is set to the narrowband light observation mode based on the operation of the scope switch 13, the fluorescent element 22f is placed outside the optical path of the narrowband light source 22a. Are arranged, and an illumination control signal for generating NB1 light, NB2 light, NB3 light, G light, and R light in a predetermined order is generated and output to the light source driving unit 21. .

  The control unit 34 includes, for example, a CPU or a control circuit, and generates a system control signal for performing an operation corresponding to the observation mode set in the observation mode switching switch of the scope switch 13 to generate an image signal processing unit. 32 and the display image generation unit 33.

  Then, the effect | action of the biological observation system 101 which concerns on a present Example is demonstrated. In the following, for the sake of simplicity, NB1 image, NB2 image, NB3 image, B image, G image, and R image corresponding to each color component described above are obtained by the color separation processing of the color component separation unit 32A. The explanation will proceed as a thing.

  The user performs an operation on the scope switch 13 to set the observation mode of the biological observation system 101 to the white light observation mode after turning on the power of each part of the biological observation system 101.

  The control unit 34 reads the imaging light information from the memory 14 of the endoscope 1 connected to the processor 3 as the processor 3 is turned on, and the light source from the memory 23 of the light source device 2 connected to the processor 3. Read light information and fluorescence information.

  Based on the light source light information and the fluorescence information read from the memory 23, the controller 34 emits the FL light having the spectrum FW when the NB1 light having the spectrum NW1 is irradiated with the predetermined light amount value PL. Detects that it is emitted from.

  Based on the light source light information and the fluorescence information read from the memory 23, the control unit 34 having a function as a dimming target setting unit is not involved in the generation of FL light in each spectrum included in the light source light information. In addition, a spectrum that is at least partially overlapped with the spectrum FW is set as a spectrum to be dimmed.

  Specifically, when the control unit 34 irradiates the NB1 light having the spectrum NW1 with the predetermined light amount value PL, for example, the FL light having the blue spectrum FW1 as shown in FIG. When it is detected that the light is emitted from the fluorescent element 22f, the spectra NW2 and NW3 included in the light source light information read from the memory 23 are set as the light control target spectrum. FIG. 5 is a diagram for explaining an example of the spectrum FW1.

  Further, in response to the irradiation of the NB1 light having the spectrum NW1, the control unit 34 emits FL light having the spectrum FW2 from the blue range to the green range as shown in FIG. 6 from the fluorescent element 22f, for example. Is detected, the spectra NW2, NW3, and GW included in the light source light information read from the memory 23 are set as the light control target spectra. FIG. 6 is a diagram for explaining an example of the spectrum FW2.

  Based on the imaging light information read from the memory 14, the control unit 34 sets the spectrum corresponding to the color gamut of the spectrum to be dimmed among the spectra included in the imaging light information as the dimming target spectrum.

  Specifically, for example, when the spectra NW2 and NW3 are set as dimming target spectra, the control unit 34 sets the spectrum BS included in the imaging light information read from the memory 14 as the dimming target spectrum. To do.

  In addition, for example, when the spectra NW2, NW3, and GW are set as dimming target spectra, the control unit 34 uses the spectrum BS and GS included in the imaging light information read from the memory 14 as the dimming target spectrum. Set.

  That is, the control unit 34 having a function as a dimming target value setting unit sets a dimming target value corresponding to the wavelength band of the light to be dimmed based on the imaging light information read from the memory 14.

  The control unit 34 having a function as a dimming unit performs an operation of subtracting the light amount value of the spectrum FW from the light amount value of the spectrum of the dimming target at the peak wavelength of each spectrum to be dimmed. The light intensity value after dimming of the light corresponding to the spectrum is acquired, and an illumination control signal including the acquired light intensity value after dimming is generated and output to the light source drive unit 21.

  Specifically, for example, when the control unit 34 detects that FL light having the spectrum FW1 is emitted from the fluorescent element 22f, the light amount of the spectrum FW1 is calculated from the light amount value of the spectrum BS at the peak wavelength λP2 of the spectrum NW2. By performing the operation of subtracting the value, the light amount value PN2 after dimming of the NB2 light is obtained, and by performing the operation of subtracting the light amount value of the spectrum FW1 from the light amount value of the spectrum BS at the peak wavelength λP3 of the spectrum NW3, A light amount value PN3 after light dimming is acquired (see FIG. 7). Thereafter, the control unit 34 generates an illumination control signal including the light amount values PN2 and PN3 acquired as described above and the light amount value PL of the NB1 light, and outputs the illumination control signal to the light source driving unit 21. FIG. 7 is a diagram for explaining an example of the light control processing according to the spectrum FW1.

  The light source driving unit 21 arranges the fluorescent element 22f on the optical path of the narrow band light source 22a based on the illumination control signal output from the control unit 34, and also includes NB1 light having a light amount value PL and NB2 light having a light amount value PN2. The light source drive signal for simultaneously generating the NB3 light having the light amount value PN3, the G light having the light amount value corresponding to the spectrum GS, and the R light having the light amount value corresponding to the spectrum RS is generated and sent to the light emitting unit 22. Output.

  On the other hand, for example, when the control unit 34 detects that FL light having the spectrum FW2 is emitted from the fluorescent element 22f, the control unit 34 changes the light amount value of the spectrum FW2 from the light amount value of the spectrum BS at the peak wavelength λP2 of the spectrum NW2. The light amount value PN2 after dimming of the NB2 light is obtained by performing a subtracting calculation, and the light amount value of the spectrum FW2 is subtracted from the light amount value of the spectrum BS at the peak wavelength λP3 of the spectrum NW3. The light amount value PN3 after dimming is obtained, and the light amount value PG after dimming of the G light is calculated by subtracting the light amount value of the spectrum FW2 from the light amount value of the spectrum GS at the peak wavelength λPG of the spectrum GW. Obtain (see FIG. 8). Thereafter, the control unit 34 generates an illumination control signal including the light amount values PN2, PN3, and PG acquired as described above and the light amount value PL of the NB1 light, and outputs the illumination control signal to the light source driving unit 21. FIG. 8 is a diagram for explaining an example of the light control processing according to the spectrum FW2.

  The light source driving unit 21 arranges the fluorescent element 22f on the optical path of the narrow band light source 22a based on the illumination control signal output from the control unit 34, and also includes NB1 light having a light amount value PL and NB2 light having a light amount value PN2. A light source driving signal for simultaneously generating NB3 light having a light amount value PN3, G light having a light amount value PG, and R light having a light amount value corresponding to the spectrum RS is generated and output to the light emitting unit 22.

  According to the present embodiment, in the white light observation mode, the subject is irradiated with white light having each light subjected to the dimming process described above as illumination light, and reflected light from the subject. An imaging signal obtained by imaging (return light) is output from the imaging device 12b, and an image signal generated based on the imaging signal is output from the preprocessing unit 31, and obtained by separating the image signal. A white light observation image based on the R image, the G image, and the B image is generated. Therefore, according to the present embodiment, when a subject is irradiated with narrowband light, a white light image having a color tone suitable for observation can be generated.

  According to the present embodiment, for example, in the white light observation mode, NB1 light, NB2 light, and NB3 light are emitted from the light source device 2 at the same time, and the missing portions of the spectra NW1, NW2, and NW3 with respect to the spectrum BS are complemented. Such a spectral estimation process may be performed by the display image generation unit 33.

  On the other hand, the user sets the observation mode of the living body observation system 101 to the narrow-band light observation mode in a state where the distal end portion of the insertion portion of the endoscope 1 is disposed in the vicinity of a desired observation site in the subject. The operation is performed on the scope switch 13.

  When the control unit 34 detects that the observation mode of the living body observation system 101 is set to the narrow-band light observation mode, the control unit 34 arranges the fluorescent element 22f outside the optical path of the narrow-band light source 22a and the first timing ta. NB1 light and G light are generated at the same time, NB2 light and R light are simultaneously generated at a second timing tb after the first timing ta, and a third timing tc after the second timing tb. Then, an illumination control signal for sequentially repeating the operation for generating the NB3 light is generated and output to the light source driving unit 21.

  Based on the illumination control signal output from the control unit 34, for example, the light source driving unit 21 causes only the narrow-band light source 22a and the green light source 22d to emit light at the first timing ta, and the narrow-band light source 22b at the second timing tb. Then, a light source driving signal is generated so that only the red light source 22e emits light and only the narrow-band light source 22c emits light at the third timing tc, and is output to the light emitting unit 22. Then, according to the operation of the light source driving unit 21, in the narrow band light observation mode, NB1 light and G light, NB2 light and R light, and NB3 light are sequentially irradiated through the illumination optical system 11, An imaging signal obtained by imaging reflected light (return light) from the subject is output from the imaging element 12b, and an image signal generated based on the imaging signal from the imaging element 12b is output from the preprocessing unit 31. The

  The color component separation unit 32A performs color separation processing for separating the image signal output from the preprocessing unit 31 into the NB1 image, the NB2 image, the NB3 image, the G image, and the R image, and performs the color separation processing. Each image obtained by the above is output to the oxygen saturation information acquisition unit 32C and the display image generation unit 33 by one frame.

  Based on the NB1 image and the NB2 image output from the color component separation unit 32A, the oxygen saturation information acquisition unit 32C subtracts the luminance value of the target pixel Pi in the NB1 image from the luminance value of the target pixel Pi in the NB2 image. The division value DA is calculated by Further, the oxygen saturation information acquisition unit 32C removes the luminance value of the target pixel Pi in the NB1 image from the luminance value of the target pixel Pi in the NB3 image based on the NB1 image and the NB3 image output from the color component separation unit 32A. Thus, a process for calculating the division value DB is performed.

  Here, the lookup table stored in the memory 32B includes, for example, an X axis that defines the division value DA as the X coordinate value, and a Y axis that defines the division value DB as the Y coordinate value, as shown in FIG. Are expressed as a result of adding a V-axis defining an oxygen saturation value indicated as a value of 0% to 100% as a V coordinate value with respect to an orthogonal coordinate system (hereinafter abbreviated as XY coordinate system). The Further, the V axis in FIG. 9 is represented as a line segment having a negative slope in the XY coordinate system. Therefore, according to the lookup table illustrated in FIG. 9, for example, when the division value DA is larger than the division value DB, a relatively large oxygen saturation value is acquired, while the division value DA is divided. If it is smaller than the value DB, a relatively small oxygen saturation value is acquired. FIG. 9 is a diagram illustrating an example of a look-up table used for processing related to acquisition of oxygen saturation values.

  Based on the division values DA and DB and the lookup table including the XY coordinate system and the V axis as shown in FIG. 9, the oxygen saturation information acquisition unit 32C has coordinates (Xd, Yd) corresponding to the division values DA and DB. ) Is specified in the XY coordinate system, and the V coordinate value at the intersection of the perpendicular line from the specified coordinates (Xd, Yd) to the V axis and the V axis is acquired as the oxygen saturation value Vdi of the pixel of interest Pi. Such processing is performed (see FIG. 10). FIG. 10 is a diagram for explaining processing performed when oxygen saturation is acquired using the lookup table of FIG. 9.

  The oxygen saturation information acquisition unit 32C acquires the oxygen saturation value Vd for each pixel included in the image for one frame by repeatedly performing the process described above while changing the pixel of interest Pi. .

  Then, the oxygen saturation information acquisition unit 32C outputs the oxygen saturation value Vd for each pixel included in the image for one frame to the determination unit 32D as oxygen saturation information. Alternatively, the oxygen saturation information acquisition unit 32C calculates an average oxygen saturation value AVd that is an average value of the oxygen saturation values Vd for each pixel included in an image for one frame, and calculates the calculated average oxygen saturation. The value AVd is output to the determination unit 32D as oxygen saturation information. Alternatively, the oxygen saturation information acquisition unit 32C calculates an average oxygen saturation value RVd that is an average value of the oxygen saturation values Vd for each pixel included in a predetermined region of interest set in an image for one frame. Then, the calculated average oxygen saturation value RVd is output to the determination unit 32D as oxygen saturation information. In the present embodiment, preferably, the predetermined region of interest is set as a region including the central portion of the image.

  The determination unit 32D performs a determination process for determining whether or not a low oxygen region exists in the image based on the oxygen saturation information output from the oxygen saturation information acquisition unit 32C in the narrow-band light observation mode. Do.

  Specifically, the determination unit 32D, based on the oxygen saturation information output from the oxygen saturation information acquisition unit 32C, satisfies, for example, less than the threshold TH in each oxygen saturation value Vd in the oxygen saturation information. If it is detected that one or more objects are included, it is determined that a hypoxic region exists in the image, and each oxygen saturation value Vd in the oxygen saturation information is less than the threshold value TH. When it is detected that no object exists, it is determined that there is no hypoxic region in the image.

  Alternatively, the determination unit 32D, based on the oxygen saturation information output from the oxygen saturation information acquisition unit 32C, for example, one of the average oxygen saturation value AVd or the average oxygen saturation value RVd included in the oxygen saturation information. If the value is less than the threshold value TH, it is determined that a hypoxic region is present in the image, and if the one value included in the oxygen saturation information is greater than or equal to the threshold value TH, It is determined that there is no hypoxic region inside.

  Then, the determination unit 32D outputs the determination result obtained by performing the determination process as described above to the display image generation unit 33.

  In the present embodiment, for example, by setting the threshold value TH used in the determination process of the determination unit 32D to 30%, the presence or absence of a lesion such as cancer that exhibits an oxygen saturation level of about 20 to 30% is suitably set. Can be detected.

  When the display image generation unit 33 detects that the low oxygen region does not exist in the image based on the determination result output from the determination unit 32D in the narrow band light observation mode, the display image generation unit 33 directly displays the narrow band light observation image. Output to the display device 4.

  In addition, when the display image generation unit 33 detects the presence of a low oxygen region in the image based on the determination result output from the determination unit 32D in the narrowband light observation mode, the display image generation unit 33 displays a low level in the image. Visual information including a predetermined symbol or a predetermined character string for notifying the presence of the oxygen region is generated, and processing for outputting the generated visual information to the display device 4 together with the narrowband light observation image is performed. . Then, according to such processing of the display image generation unit 33, for example, as shown in FIG. 11, a narrowband light observation image and an icon that lights or blinks at a predetermined position outside the narrowband light observation image. 71 are also displayed in the screen of the display device 4. FIG. 11 is a diagram illustrating an example of a display mode when the presence of the low oxygen region is notified.

  The display image generation unit 33 according to the present embodiment is configured to notify the presence of the low oxygen region in the image when the low oxygen region is detected in the image in the narrow-band light observation mode. The present invention is not limited to processing for generating visual information and outputting the generated visual information to the display device 4 together with the narrow-band light observation image. For example, the presence of a low oxygen region in the image is notified. Audio information may be generated and a process for outputting the narrowband light observation image to the display device 4 may be performed while outputting the generated audio information to an audio output device such as a speaker.

  As described above, according to the present embodiment, in the narrowband light observation mode, the oxygen saturation is lower than that of arterial blood and venous blood without changing the color tone of the entire image in the narrowband light observation image. The operator can be notified of the presence or absence of a lesion. Therefore, according to the present embodiment, the burden on the operator when diagnosing a lesion can be reduced in the narrow-band light observation mode.

  On the other hand, according to the present embodiment, in the narrow-band observation mode, instead of the narrow-band light observation image and the icon 71, for example, it is included in the image for one frame as visual information for notifying the presence of the low oxygen region. Alternatively, an oxygen saturation image that can visually recognize the oxygen saturation value Vd for each pixel may be displayed on the display device 4. An example of specific processing in such a case will be described below.

  When the control unit 34 detects that the observation mode of the living body observation system 101 is set to the narrow-band light observation mode, the control unit 34 arranges the fluorescent element 22f outside the optical path of the narrow-band light source 22a and the first timing ta. NB1 light is generated, NB2 light is generated at the second timing tb after the first timing ta, and NB3 light is generated at the third timing tc after the second timing tb. An illumination control signal for sequentially repeating the operation is generated and output to the light source driving unit 21.

  Based on the illumination control signal output from the control unit 34, for example, the light source driving unit 21 causes only the narrow-band light source 22a to emit light at the first timing ta and causes only the narrow-band light source 22b to emit light at the second timing tb. Then, a light source drive signal for causing only the narrow-band light source 22c to emit light at the third timing tc is generated and output to the light emitting unit 22. Then, according to the operation of the light source driving unit 21, in the narrow-band light observation mode, NB1 light, NB2 light, and NB3 light are sequentially irradiated through the illumination optical system 11, and reflected light from the subject. An imaging signal obtained by imaging the (return light) is output from the imaging device 12b, and an image signal generated based on the imaging signal from the imaging device 12b is output from the preprocessing unit 31.

  The oxygen saturation information acquisition unit 32C acquires the oxygen saturation value Vd for each pixel included in an image for one frame by performing the above-described processing. Then, the oxygen saturation information acquisition unit 32C outputs the oxygen saturation value Vd for each pixel included in the image for one frame to the determination unit 32D as oxygen saturation information.

  The determination unit 32D does not perform the determination process related to the presence or absence of the low oxygen region in the image as described above, and directly uses the oxygen saturation information output from the oxygen saturation information acquisition unit 32C to the display image generation unit 33. Output.

  The display image generation unit 33 visually recognizes the oxygen saturation value Vd for each pixel included in the image for one frame based on the oxygen saturation information output from the determination unit 32D in the narrowband light observation mode. A possible oxygen saturation image is generated and output to the display device 4.

  Specifically, the display image generation unit 33, for example, the luminance according to the multiplication value obtained by multiplying the maximum value of the gradation value in the A / D conversion process of the preprocessing unit 31 by the oxygen saturation value Vd An image having values is generated as the aforementioned oxygen saturation image. According to such processing, for example, when the maximum value of the gradation value in the A / D conversion processing of the preprocessing unit 31 is 255, the luminance value of the pixel having the oxygen saturation value Vd = 98%. An oxygen saturation image such that is 250 is generated.

  The present invention is not limited to the above-described embodiments, and various modifications and applications can be made without departing from the spirit of the invention.

DESCRIPTION OF SYMBOLS 1 Endoscope 2 Light source device 3 Processor 4 Display apparatus 5 Input device 6 Light guide 11 Illumination optical system 12 Imaging part 13 Scope switch 14 Memory 21 Light source drive part 22 Light emission unit 22a, 22b, 22c Narrow band light source 22d Green light source 22e Red Light source 22f Fluorescent element 23 Memory 31 Preprocessing unit 32 Image signal processing unit 33 Display image generation unit 34 Control unit 101 Living body observation system 121 Primary color filter

Japanese Unexamined Patent Publication No. 2012-66065

Claims (6)

Within a predetermined wavelength band, a light source unit capable of irradiating narrow band light having a plurality of different wavelength bands according to absorption characteristics of blood hemoglobin, and broadband light outside the predetermined wavelength band, and
Each pixel includes a pixel that receives light from a subject irradiated with light from the light source unit and has sensitivity in the predetermined wavelength band, and a pixel that has sensitivity in the wavelength band of the broadband light. An imaging unit that generates an imaging signal of the subject corresponding to
Either the first mode in which the narrow-band light is sequentially generated from the light source unit for each of the plurality of wavelength bands, or the second mode in which the narrow-band light and the broadband light are simultaneously generated from the light source unit. A control unit that performs control for switching;
Based on the control of the control unit, in the second mode, the narrowband light and the broadband light, and light other than the wavelength band within the predetermined wavelength band and the maximum intensity in the narrowband light, A light source driving unit that drives the light source unit to irradiate the subject;
A narrowband optical image is generated using a plurality of imaging signals of the subject generated in the first mode, and a broadband optical image is generated using the imaging signal of the subject generated in the second mode. An image generator;
A living body observation system comprising: Within a predetermined wavelength band, a light source unit capable of irradiating narrow band light having a plurality of different wavelength bands according to absorption characteristics of blood hemoglobin, and broadband light outside the predetermined wavelength band, and
Each pixel includes a pixel that receives light from a subject irradiated with light from the light source unit and has sensitivity in the predetermined wavelength band, and a pixel that has sensitivity in the wavelength band of the broadband light. An imaging unit that generates an imaging signal of the subject corresponding to
Either the first mode in which the narrow-band light is sequentially generated from the light source unit for each of the plurality of wavelength bands, or the second mode in which the narrow-band light and the broadband light are simultaneously generated from the light source unit. A control unit that performs control for switching;
A calculation result obtained by generating a narrowband light image using a plurality of imaging signals corresponding to the narrowband light in the first mode, and performing arithmetic processing on the plurality of imaging signals in the second mode; An image generation unit that generates a broadband optical image using an imaging signal corresponding to the broadband light;
A living body observation system comprising: The image generation unit generates visual information for notifying the presence of a hypoxic region in the subject by performing arithmetic processing between the plurality of imaging signals in the first mode, and generating the second information The living body according to claim 2, wherein the broadband optical image is generated by allocating the plurality of imaging signals and imaging signals corresponding to the broadband light to different color channels of the display device in the mode. Observation system. In the second mode, the image generation unit performs arithmetic processing on the imaging signal to supplement a wavelength band other than the wavelength band of the narrowband light within the predetermined wavelength band. The endoscope system according to claim 2. A wavelength conversion member that receives light having the shortest wavelength among the plurality of wavelength bands, and generates light having a wavelength characteristic that is longer than the light having the shortest wavelength and that has a broad wavelength;
A storage unit storing information of an emission spectrum of the wavelength conversion member,
The light source driving unit arranges the fluorescent element on an optical path of the light having the shortest wavelength in the second mode, and out of the optical path of the light having the shortest wavelength in the first mode. The fluorescent element is arranged in
In the second mode, the control unit sets a dimming target value based on an emission spectrum of the wavelength conversion member stored in the storage unit, and based on the set dimming target value, the shortest The living body observation system according to claim 3, wherein the light amount of light in a wavelength band other than the wavelength side light is adjusted. The predetermined wavelength band is a blue wavelength band,
The wavelength band other than the predetermined wavelength band is a green wavelength band,
The imaging unit further includes a pixel having sensitivity in a red wavelength band,
The light source unit includes a plurality of semiconductor light emitting elements that emit light in a blue wavelength band for measuring oxygen saturation of the subject as the narrow band light, light having a peak in the green wavelength band, and the red color A plurality of semiconductor light emitting elements that emit light having a peak in the wavelength band of the light as the broadband light,
The image generation unit performs arithmetic processing between a plurality of imaging signals corresponding to the narrowband light generated in time series in pixels having sensitivity in the predetermined wavelength band in the first mode. Generating visual information for notifying the existence of a hypoxic region in the subject, and pixels having sensitivity in the blue wavelength band and pixels having sensitivity in the green wavelength band in the second mode, The broadband optical image is generated by assigning imaging signals generated in the pixel having sensitivity in the red wavelength band to different color channels of the display device, respectively. Living body observation system.

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