Medical image processing device and medical observation system

Abstract

A medical image processing device 9 comprises an image processing unit 92 for processing pixel signals acquired from the pixels of an imaging element 513. The pixel signals include: a first pixel signal having an unnecessary light component including autofluorescence generated by light from a member forming an optical path for observation when light emitted from a light source device propagates through the optical path for observation, and an observation target fluorescence component emitted from a substance included in an observation target that is excited by the light; and a second pixel signal having at least an unnecessary light component. The image processing unit 92 comprises a signal correction unit 923 that generates a corrected pixel signal on the basis of the first and second pixel signals and a correction coefficient set on the basis of the spectral characteristics of the observation target fluorescence.

Description

Medical image processing device and medical observation system

[0001] The present disclosure relates to a medical image processing device and a medical observation system.

[0002] Conventionally, a medical observation system has been known that irradiates an observation target (such as a human subject) with a first light including visible light, such as narrow-band excitation light or broad-band white light, emitted from a light source device, and observes the fluorescence (hereinafter referred to as "observation target fluorescence") emitted from a substance contained in the observation target in response to the irradiation of the excitation light (see, for example, Patent Document 1). This type of fluorescence observation makes it possible to grasp tissue conditions, which are difficult to recognize using white light, through the observation target fluorescence. Therefore, fluorescence observation can be used for various purposes and applications, such as identifying lesions.

[0003] Japanese Patent Application Laid-Open No. 2021-132695

[0004] A medical observation system has an observation optical path including a first optical path through which first light propagates from a light source device to an observation object, and a second optical path through which second light propagates, the second light being return light (including observation object fluorescence) of the first light from the observation object irradiated with the first light. When the first and second lights propagate through the observation optical path, autofluorescence may be generated from components forming the observation optical path due to the first and second lights being irradiated onto the components. Such autofluorescence may have a wavelength band that includes the wavelength band of the observation object fluorescence that is the target of fluorescence observation, and may result in noise during the fluorescence observation. Therefore, there is a demand for technology that enables satisfactory fluorescence observation.

[0005] The present disclosure has been made in view of the above, and has an object to provide a medical image processing device and a medical observation system that are capable of performing satisfactory fluorescence observation.

[0006] In order to solve the above-mentioned problems and achieve the object, a medical image processing device according to the present disclosure includes an image processing unit that processes pixel signals corresponding to pixels of an imaging element, the pixel signals including a first pixel signal having unwanted light components including autofluorescence generated from a member that forms an observation optical path by light emitted from a light source device when the light propagates through the observation optical path, and an observation object fluorescence component emitted from a substance included in the observation object and excited by the light, and a second pixel signal having at least the unwanted light components, and the image processing unit includes a signal correction unit that generates a corrected pixel signal based on a correction coefficient set based on the spectral characteristics of the observation object fluorescence and on the first pixel signal and the second pixel signal.

[0007] A medical observation system according to the present disclosure comprises: a light source device that emits first light including narrowband light that excites a substance contained in an observation object; an imaging device having an imaging element that captures second light, which is return light of the first light from the observation object; and a medical image processing device having an image processing unit that processes pixel signals corresponding to pixels of the imaging element, wherein the pixel signals include a first pixel signal having an unwanted light component including autofluorescence generated from a member that forms an observation optical path by the first light when the first light emitted from the light source device propagates through the observation optical path, and an observation object fluorescence component emitted from a substance contained in the observation object that is excited by the first light, and a second pixel signal having at least the unwanted light component, and the image processing unit comprises a signal correction unit that generates a corrected pixel signal based on a correction coefficient set based on the spectral characteristics of the observation object fluorescence and on the first pixel signal and the second pixel signal.

[0008] The medical image processing device and medical observation system according to the present disclosure enable excellent fluorescence observation.

[0009] FIG. 1 is a diagram illustrating a configuration of a medical observation system according to an embodiment. FIG. 2 is a block diagram illustrating the configuration of a camera head and a control device. FIG. 3 is a diagram illustrating a configuration of a color filter. FIG. 4 is a diagram illustrating a configuration of a color filter. FIG. 5 is a diagram illustrating a first modification of the embodiment. FIG. 6 is a diagram illustrating a first modification of the embodiment. FIG. 7 is a diagram illustrating a first modification of the embodiment. FIG. 8 is a diagram illustrating a first modification of the embodiment. FIG. 9 is a diagram illustrating a second modification of the embodiment. FIG. 10 is a diagram illustrating a second modification of the embodiment. FIG. 11 is a diagram illustrating a third modification of the embodiment. FIG. 12 is a diagram illustrating a fourth modification of the embodiment. FIG. 13 is a diagram illustrating a fourth modification of the embodiment. FIG. 14 is a diagram illustrating a fourth modification of the embodiment. FIG. 15 is a diagram illustrating a fifth modification of the embodiment. FIG. 16 is a diagram illustrating a fifth modification of the embodiment. FIG. 17 is a diagram illustrating a sixth modification of the embodiment. FIG. 18 is a diagram illustrating a sixth modification of the embodiment. FIG. 19 is a diagram illustrating a seventh modification of the embodiment. FIG. 20 is a diagram illustrating an eighth modification of the embodiment. FIG. 21 is a diagram illustrating a ninth modification of the embodiment. FIG. 22 is a diagram illustrating a ninth modification of the embodiment.

[0010] Hereinafter, modes for carrying out the present disclosure (hereinafter, referred to as embodiments) will be described with reference to the drawings. Note that the present disclosure is not limited to the embodiments described below. Furthermore, in the description of the drawings, the same parts are assigned the same reference numerals.

[0011] [Configuration of Medical Observation System] Figure 1 is a diagram showing the configuration of a medical observation system 1 according to an embodiment. In this embodiment, the medical observation system 1 is a medical endoscope system that uses an endoscope to observe an observation object OB (Figure 1) inside a living body. As shown in Figure 1, this medical observation system 1 includes an insertion section 2, a light source device 3, a light guide 4, a camera head 5, a first transmission cable 6, a display device 7, a second transmission cable 8, a control device 9, and a third transmission cable 10.

[0012] In this embodiment, the insertion section 2 is a rigid endoscope. That is, the insertion section 2 has an elongated shape that is rigid as a whole or has a flexible and rigid portion, and is inserted into the observation object OB. The insertion section 2 includes an optical system that includes one or more lenses and focuses second light (subject image) from the observation object OB, which will be described later.

[0013] One end of the light guide 4 is connected to the light source device 3. The light source device 3 includes a first light source 31 ( FIG. 1 ) that supplies first light to one end of the light guide 4 under the control of the control device 9. In this embodiment, excitation light (narrowband light) that excites a substance contained in the observation object OB is used as the first light. The first light source 31 may be configured with an LED (Light Emitting Diode) or a semiconductor laser. The number of first light sources 31 that emit the first light may be one or more. The excitation light may be visible light or invisible light. The light source device 3 may be configured to include a second light source that emits broadband light such as white light in addition to the first light source 31.

[0014] Here, examples of substances contained in the observation object OB that are excited by the excitation light include drugs or fluorescent dyes attached to the observation object OB, or fluorescent substances derived from the observation object OB that constitute the observation object OB itself.

[0015] Examples of the above-mentioned drugs administered to the observation subject OB include "5-ALA (PP-IX)", "ADS780WS", "ADS830WS", "aggregation-induced emission dots allophycocyanin (APC)", "boron-dipyrromethane (BODIPY)", "CLR 1502", "Flavins", "fluorescamine", "Fluorescein", "fluoro-gold", "green fluorescence protein", "ICG (indocyanine green)", "IRDye 78", "IR-PEG nanoparticles", "Isothiocyanate", "rose Bengal", "SGM-101", and "trypan blue".

[0016] The above-mentioned fluorescent dyes applied to the observation target OB include "coumarine," "Cy3," "DyLight547," "GE3126," "metal nanoclusters," "oxacarbocyanine," "rhodamine," "riboflavin," "fluorescein," "AlexaFluor660," "AlexaFluor680," "AlexaFluor700," "Cy5," "Cy5.5," "Dy677," "Dy682," "Dy752," "DyLight647," "HiLyte Fluor 647," "HiLyte Fluor 680," "IRDye 700DX," "methylene blue," "Porphyrins," "Porphysomes," "VivoTag-680," "VivoTag-S680," "AlexaFluor750," "AlexaFluor790," "carbocyanine," "conjugated copolymers," "CW800-CA," "Cy7," "Cy7.5," "cyanine dyes," "Dy780," and "HiLyte Fluor 750," "Indocarbocyanine," "IR-786," ​​"IRDye 800CW," "IRDye 800RS," "IRDye 800BK," "Nervelight," "OTL-38 (Pafolacianine)," "Polymethine," "VivoTag-S750," "Xanthene," and "LUM-015" can be cited as examples.

[0017] Furthermore, examples of fluorescent substances derived from the observation object OB that constitute the observation object OB itself include "collagen," "elastin," and "NADH."

[0018] In this embodiment, the light source device 3 is configured as a separate entity from the control device 9, but this is not limited to this, and a configuration in which the light source device 3 and the control device 9 are provided in the same housing may also be adopted.

[0019] One end of the light guide 4 is detachably connected to the light source device 3. The other end of the light guide 4 is detachably connected to the insertion section 2. The light guide 4 propagates first light supplied from the light source device 3 (first light source 31) from one end to the other end, supplying the first light to the insertion section 2. The first light supplied to the insertion section 2 is emitted from the tip of the insertion section 2 and irradiated onto the observation object OB. The second light (subject image), which is the return light of the first light irradiated onto the observation object OB and returned from the observation object OB, is collected by the optical system within the insertion section 2. The second light includes, in addition to the first light reflected by the observation object OB, fluorescence (hereinafter referred to as observation object fluorescence) emitted from a substance contained in the observation object OB when the first light (excitation light) is irradiated onto the observation object OB and the substance is excited.

[0020] The camera head 5 corresponds to the imaging device according to the present disclosure. The camera head 5 is detachably connected to the eyepiece 21 of the insertion section 2. Under the control of the control device 9, the camera head 5 captures an image of the second light collected by the insertion section 2 to generate a pixel signal. Hereinafter, for the sake of convenience, the pixel signal will be referred to as a captured image. The detailed configuration of the camera head 5 will be described later in the section "Configuration of the Camera Head."

[0021] One end of the first transmission cable 6 is detachably connected to the control device 9 via a connector CN1 (FIG. 1). The other end of the first transmission cable 6 is detachably connected to the camera head 5 via a connector CN2 (FIG. 1). The first transmission cable 6 transmits captured images and other signals output from the camera head 5 to the control device 9, and also transmits control signals, synchronization signals, clocks, power, and other signals output from the control device 9 to the camera head 5.

[0022] The captured images and the like transmitted from the camera head 5 to the control device 9 via the first transmission cable 6 may be transmitted as optical signals or as electrical signals. The same applies to the transmission of control signals, synchronization signals, and clocks from the control device 9 to the camera head 5 via the first transmission cable 6.

[0023] The display device 7 is configured with a display using a liquid crystal or an organic EL (Electro Luminescence) display, and displays an image based on a video signal from the control device 9 under the control of the control device 9. The display device also includes a wearable display.

[0024] One end of the second transmission cable 8 is detachably connected to the display device 7. The other end of the second transmission cable 8 is detachably connected to the control device 9. The second transmission cable 8 transmits the video signal processed by the control device 9 to the display device 7.

[0025] The control device 9 corresponds to the medical image processing device according to the present disclosure. This control device 9 is composed of a central processing unit (CPU), a graphics processing unit (GPU), a field-programmable gate array (FPGA), etc., and comprehensively controls the operations of the light source device 3, the camera head 5, and the display device 7. The detailed configuration of the control device 9 will be described later in the section "Configuration of the control device."

[0026] One end of the third transmission cable 10 is detachably connected to the light source device 3. The other end of the third transmission cable 10 is detachably connected to the control device 9. The third transmission cable 10 transmits a control signal from the control device 9 to the light source device 3.

[0027] [Configuration of Camera Head] Next, a description will be given of the configuration of the camera head 5. Fig. 2 is a block diagram showing the configuration of the camera head 5 and the control device 9. As shown in Fig. 2, the camera head 5 includes an imaging unit 51 and a communication unit 52.

[0028] The imaging unit 51 captures an image of the observation object OB under the control of the control device 9. As shown in FIG. 2 , the imaging unit 51 includes an excitation light cut filter 511, a lens unit 512, an imaging element 513, a color filter 514, and a signal processing unit 515.

[0029] The excitation light cut filter 511 is a filter that partially, substantially, or completely suppresses the excitation light contained in the second light (subject image) collected by the insertion portion 2. The excitation light cut filter 511 is not limited to being disposed in the camera head 5, but may also be disposed in the insertion portion 2 (for example, the eyepiece 21).

[0030] The lens unit 512 focuses the second light (subject image) that is collected by the insertion portion 2 and passes through the excitation light cut filter 511 onto the light receiving surface of the image sensor 513 .

[0031] In this embodiment, only one image sensor 513 is provided. This image sensor 513 is configured with a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) that receives the second light (subject image) that has passed through the excitation light cut filter 511 and been focused by the lens unit 512, and converts the received light into an electrical signal. The image sensor 513 then captures the second light (subject image) under the control of the control device 9. This generates pixel signals (captured image).

[0032] The color filter 514 corresponds to a spectroscopic member according to the present disclosure. The color filter 514 is provided on the light receiving surface of the image sensor 513. The detailed configuration of the color filter 514 will be described later in the section "Configuration of Color Filter."

[0033] The signal processing unit 515 performs signal processing on the captured image (analog signal) generated by the image sensor 513 and outputs the captured image (digital signal) under the control of the control device 9. For example, the signal processing unit 515 performs signal processing on the captured image (analog signal) generated by the image sensor 513, such as processing to remove reset noise, processing to multiply the analog signal by an analog gain that amplifies the analog signal, and A / D conversion.

[0034] The communication unit 52 functions as a transmitter that transmits the captured images sequentially output from the imaging unit 51 to the control device 9 via the first transmission cable 6. The communication unit 52 is configured, for example, with a high-speed serial interface that communicates captured images with the control device 9 at a transmission rate of 1 Gbps or more via the first transmission cable 6. Note that the communication unit 52 may communicate at a transmission rate lower than 1 Gbps, for example, when the imaging element 513 is an image sensor with HD resolution or lower.

[0035] [Color Filter Configuration] Next, the configuration of the color filter 514 will be described. FIGS. 3 and 4 are diagrams illustrating the configuration of the color filter 514. Specifically, FIG. 3 is a diagram illustrating the color filter 514. FIG. 4 is a diagram illustrating the spectral characteristics of the color filter 514. The spectral characteristics of a filter such as the color filter 514 are also called transmission spectral characteristics. In FIG. 4, the horizontal axis represents wavelength [nm], and the vertical axis represents relative response [%]. The color filter 514 is a color filter in which three filter groups, each grouped according to the wavelength band of light to be transmitted (red, green, blue), are arranged in a specific format (for example, a Bayer array).

[0036] Specifically, as shown in Fig. 3, the color filter 514 includes an R filter group 514r that primarily transmits light in the red wavelength band, a B filter group 514b that primarily transmits light in the blue wavelength band, a first G filter group (arranged in the same column as the R filter group 514r) that primarily transmits light in the green wavelength band, and a second G filter group (arranged in the same column as the B filter group 514b) that primarily transmits light in the green wavelength band. In Fig. 3, the first and second G filter groups are collectively referred to as a G filter group 514g. In Fig. 3, the R filter group 514r is labeled with the letter "R," the G filter group 514g is labeled with the letter "G," and the B filter group 514b is labeled with the letter "B." 4, the spectral characteristics of the R filter group 514r are shown by a curve CR, the spectral characteristics of the G filter group 514g are shown by a curve CG, and the spectral characteristics of the B filter group 514b are shown by a curve CB. As can be seen from the curves CR, CG, and CB, the spectral characteristics of the filter groups 514r, 514g, and 514b are different from each other in terms of peak wavelengths that are transmitted, but overlap with each other in some wavelength bands.

[0037] 4, the symbol "SPF1" indicates the spectrum of the fluorescence to be observed. Also, in FIG. 4, the symbol "SPU" indicates the wavelength range in which unwanted light, as described below, can be generated.

[0038] The first light emitted from the light source device 3 is irradiated onto the observation object OB via a first optical path P1 ( FIG. 1 ). The first optical path P1 is an optical path that travels from the light source device 3 to the light guide 4 to the insertion section 2 to the observation object OB. When the first light is irradiated onto the observation object OB, substances contained in the observation object OB are excited, and the substances emit observation object fluorescence. The observation object fluorescence is the observation object light in fluorescence observation. Then, the second light, which is the return light of the first light containing the observation object light, propagates to the image sensor 513 via a second optical path P2 ( FIG. 1 ). The second optical path P2 is an optical path that travels from the observation object OB to the insertion section 2 to the image sensor 513. Note that the excitation light contained in the second light is partially, substantially, or completely suppressed by the excitation light cut filter 511 as it propagates along the second optical path P2.

[0039] Here, when the first light propagates through the first optical path P1 and the second light propagates through the second optical path P2, the first light and the second light may be irradiated onto a component (hereinafter referred to as an unwanted light-generating component) that forms the observation optical path P0 ( FIG. 1 ) of the first and second optical paths P1 and P2, resulting in the generation of autofluorescence (hereinafter referred to as unwanted light) from the unwanted light-generating component. Examples of such unwanted light-generating components include components contained in multi-component glass such as optical fibers and lenses, material components contained in color filters, adhesives used to bond lenses or other optical components together, and oil adhering to optical components such as lenses. Such unwanted light has a wavelength band that includes the wavelength band of the target fluorescence, which is the light to be observed in fluorescence observation, as shown in the wavelength range SPU in which unwanted light can be generated in FIG. 4 , and can cause noise during fluorescence observation.

[0040] In particular, when the fluorescence of the object of observation from the object of observation OB is weak, in order to separate the fluorescence of the object of observation from the unnecessary light described above and perform good fluorescence observation, it is necessary to adjust the signal value based on the fluorescence of the object of observation imaged by the image sensor 513. However, adjusting the signal value based on the fluorescence of the object of observation is difficult because of the influences of the following (1) to (4):

[0041] (1) Drugs Generally, the intensity of the fluorescence emitted from the observation object OB varies depending on the type and dosage of the drug. The type of drug administered to the observation object OB is selected according to the observation object OB (cancer, blood, lymph, etc.). Furthermore, in order to image the fluorescence emitted from the drug in the medical observation system 1, drugs are selected that can separate the wavelength of the excitation light that excites the drug from the wavelength of the fluorescence emitted from the drug. Drugs selected in this manner emit different intensities of fluorescence from the observation object. Furthermore, while the intensity of fluorescence from the observation object can be adjusted by the dosage of the drug, it is difficult to increase the dosage more than necessary to achieve minimally invasive treatment. In other words, it is difficult to adjust the intensity of fluorescence from the observation object by selecting the type of drug and adjusting the dosage. As a result, it is difficult to adjust the signal value based on the fluorescence from the observation object imaged by the image sensor 513 by selecting the type of drug and adjusting the dosage.

[0042] (2) Observation Object The amount of observation object fluorescence emitted from the observation object OB varies depending on the location and condition of the observation object OB. Specifically, if the observation object OB is located in a location or condition where the drug is likely to remain, the amount of observation object fluorescence emitted from the observation object OB increases. On the other hand, if the observation object OB is located in a location or condition where the drug is likely to flow and not remain, the amount of observation object fluorescence emitted from the observation object OB decreases and the afterglow time also becomes shorter. Furthermore, if the observation object OB is a tumor, the amount of observation object fluorescence received by the image sensor 513 changes depending on its spread, size, and depth. In other words, it is difficult to adjust the amount of observation object fluorescence depending on the type and condition of the observation object OB. As a result, it is difficult to adjust the signal value based on the observation object fluorescence imaged by the image sensor 513 depending on the type and condition of the observation object OB.

[0043] (3) Light Source Device The intensity of the fluorescence emitted from the observation object varies depending on the intensity of the excitation light emitted from the light source device 3. Increasing the intensity of the excitation light may require adjusting the power supplied to the light source device 3. However, the power that can be supplied to the light source device 3 is limited by the upper limit of the power required to operate the entire medical observation system 1. Furthermore, the intensity of the excitation light must be adjusted taking into account factors such as heat generation in components constituting the optical path of the excitation light (e.g., heat generation between the light guide 4 and the insertion section 2), compatibility with the laser class, the amount of light energy received by the observation object OB and surrounding living tissue (high light energy levels pose a risk of burns), and the rate of fading of the fluorescence emitted from the drug. Furthermore, the intensity of the excitation light can also be adjusted by changing the number of excitation light sources installed in the light source device 3. However, the number of light sources may affect the size of the light source device 3. The size of the light source device 3 may be limited by the size of a cart used to transport the light source device 3. In other words, it is difficult to adjust the intensity of the fluorescence emitted from the observation object by adjusting the intensity of the excitation light. As a result, it is difficult to adjust the signal value based on the fluorescence from the observation object imaged by the image sensor 513 by adjusting the amount of excitation light.

[0044] (4) Imager The signal value based on the observation target fluorescence generated by the imager 513 varies depending on the amount of the observation target fluorescence received by the imager 513. To adjust the signal value based on the observation target fluorescence, it is desirable to select an imager 513 with optimal sensitivity and configuration for imaging the observation target fluorescence. However, the imager 513 may be required not only to output an image for fluorescence observation based on receiving observation target fluorescence in a predetermined wavelength band, but also to output an image for normal light observation based on receiving visible light, such as white light. Furthermore, the imager 513 may be required to output an image for fluorescence observation corresponding to a wide wavelength band or multiple wavelength bands within a wavelength band including visible light and invisible light. Furthermore, even when the same drug is used, the amount of observation target fluorescence may change depending on the procedure or the observation target OB, and the imager 513 may be required to output an image for fluorescence observation that corresponds to such changes in the amount of observation target fluorescence. In such cases, the imager 513 must be selected to accommodate such observations, and it may not be possible to use an imager with optimal characteristics for imaging fluorescence in a predetermined wavelength band. Furthermore, the image sensor 513 is disposed inside the camera head 5, but because the size and weight of the camera head 5 are appropriate for observation, this may limit the type of image sensor 513, including its size. Note that the image sensor 513 is not limited to being disposed inside the camera head 5, and even when disposed at the tip of a rigid endoscope or a flexible endoscope, the size and weight are appropriate for observation, and this may limit the type of image sensor 513, including its size. In other words, it is difficult to adjust the signal value based on the fluorescence of the observation object imaged by the image sensor 513 by selecting the type of image sensor 513.

[0045] As described above, the signal value based on the fluorescence from the observation object captured by the image capturing element 513 is determined within the above-mentioned constraints, and therefore cannot be easily adjusted.

[0046] In this embodiment, the fluorescence to be observed has spectral characteristics in a wavelength band with a center wavelength of approximately 650 nm, as shown by spectrum SPF1 in FIG. 4 . That is, in this embodiment, the fluorescence to be observed is light in the wavelength band of visible light. Furthermore, the unwanted light has spectral characteristics in a wavelength band spanning the entire visible light wavelength band and the invisible light wavelength band, as shown by the wavelength range SPU in FIG. 4 where the unwanted light may be generated. The spectral characteristics of light such as the fluorescence to be observed and the unwanted light are also referred to as emission spectral characteristics. Note that, in this embodiment, the spectral characteristics of the fluorescence to be observed and the unwanted light are shown in FIG. 4 , but these spectral characteristics may vary depending on the type and concentration of the fluorescent agent, the wavelength characteristics and intensity of the excitation light, the type and amount of components forming the optical path, and so on. That is, the spectral characteristics of the fluorescence to be observed and the unwanted light are not limited to those shown in FIG. 4 and may have other spectral characteristics.

[0047] Therefore, based on the spectral characteristics of the R filter group 514r and the spectral characteristics of the fluorescence of the observation object and the unnecessary light, the signal value of the pixel signal corresponding to the R filter group 514r (hereinafter referred to as the r value) includes a component of the fluorescence of the observation object and a component of the unnecessary light. Furthermore, based on the spectral characteristics of the G filter group 514g and the spectral characteristics of the fluorescence of the observation object and the unnecessary light, the signal value of the pixel signal corresponding to the pixel corresponding to the G filter group 514g (hereinafter referred to as the g value) mainly includes a component of the unnecessary light. Furthermore, based on the spectral characteristics of the B filter group 514b and the spectral characteristics of the fluorescence of the observation object and the unnecessary light, the signal value of the pixel signal corresponding to the pixel corresponding to the B filter group 514b (hereinafter referred to as the b value) also mainly includes a component of the unnecessary light. In other words, the r value contains a larger component of the fluorescence of the observation object than the g value and the b value.

[0048] As described above, the r-value, g-value, and b-value contain unwanted light components. In this embodiment, in order to perform good fluorescence observation, the control device 9 performs image processing (correction matrix processing) described below to generate corrected pixel signals in which the unwanted light components that become noise in fluorescence observation are suppressed (signals in which the signal value based on the unwanted light is reduced).

[0049] The filter groups constituting the color filter 514 are not limited to the filter groups 514r, 514g, and 514b that mainly transmit light in the wavelength bands of R, G, and B. In other words, the color filter 514 is not limited to color filters having the above-mentioned spectral characteristics, and may be composed of a plurality of filter groups each having other spectral characteristics.

[0050] [Configuration of Control Device] Next, the configuration of the control device 9 will be described with reference to Fig. 2. As shown in Fig. 2, the control device 9 includes a communication unit 91, an image processing unit 92, a control unit 93, an input unit 94, an output unit 95, and a storage unit 96.

[0051] The communication unit 91 functions as a receiver that receives captured images sequentially transmitted from the camera head 5 (communication unit 52) ​​via the first transmission cable 6. This communication unit 91 is configured, for example, with a high-speed serial interface that communicates captured images at a transmission rate of 1 Gbps or more with the communication unit 52. Note that the communication unit 91 may communicate at a transmission rate lower than 1 Gbps, for example, when the imaging element 513 is an image sensor with HD resolution or lower.

[0052] Under the control of the control unit 93, the image processing unit 92 processes the captured images that are sequentially output from the camera head 5 (communication unit 52) ​​and received by the communication unit 91. As shown in FIG. 2 , the image processing unit 92 includes a WB processing unit 921, a demosaic processing unit 922, a correction matrix processing unit 923, a gamma processing unit 924, and a YC conversion unit 925.

[0053] The WB processing unit 921 performs WB (white balance) processing by multiplying the r value, g value, and b value of the captured image by a specific gain. In the following, the r value of the captured image output from the WB processing unit 921 is referred to as R ９２１ , g value G ９２１ , b value is B ９２１ (Figure 2).

[0054] The demosaic processing unit 922 interpolates the r, g, and b signal values ​​(R ９２２ , G ９２２ , B９２２ ) is demosaic processed.

[0055] In this embodiment, as described above, the r value contains a larger amount of the fluorescence component of the object of observation than the g value and the b value, based on the spectral characteristics of the color filter 514 and the spectral characteristics of the fluorescence component of the object of observation and the unnecessary light. ９２２ , G ９２２ , B ９２２ ), the signal value (R ９２２ ) is the signal value (G ９２２ , B ９２２ ), the component of the fluorescence to be observed is larger than that of the signal value (R ９２２ ) corresponds to the first pixel signal (signal value) according to the present disclosure. ９２２ , B ９２２ ) corresponds to the second pixel signal (signal value) according to the present disclosure. ９２２ ) is a signal value in which the component of the fluorescence of the object of observation is greater than the component of the unnecessary light, and the component of the fluorescence of the object of observation is dominant. ９２２ , B ９２２ ) is a signal value where the unnecessary light component is dominant.

[0056] In the WB processing described above, the r value, the g value, and the b value are multiplied by specific gains, respectively, to perform processing so that the unnecessary light components contained in the r value, the g value, and the b value become approximately the same (processing to adjust the magnitude relationship of the unnecessary light components). In other words, in the WB processing, a signal value (R ９２２ ), signal value (G ９２２ ), and the signal value (B ９２２ ) are processed so that the unnecessary light components included in the WB processing unit 921 are substantially the same. Therefore, the WB processing unit 921 corresponds to the spectral sensitivity correction unit according to the present disclosure. Furthermore, the WB processing corresponds to the spectral sensitivity correction processing according to the present disclosure.

[0057] The correction matrix processing unit 923 corresponds to the signal processing unit according to the present disclosure. The correction matrix processing unit 923 calculates the correction coefficients and the signal value (R ９２２ , G ９２２ , B ９２２ ) and generates a corrected pixel signal.

[0058] In this embodiment, the correction matrix processing unit 923 calculates the signal value (R ９２２ , G ９２２ , B ９２２ ) as matrix elements of the input matrix M ９２２ is the correction matrix M, which is the correction coefficient according to the present disclosure. Ｃ A correction matrix process is performed to generate a corrected pixel signal by multiplying the

[0059] Specifically, in the correction matrix processing, the correction matrix processing unit 923 calculates the signal value (R ９２２ , G ９２２ , B ９２２ ) to the signal value (R ９２３ , G ９２３ , B ９２３ ) and correct the signal value (R ９２３ , G ９２３ , B ９２３ ) corresponds to the signal value of the corrected pixel signal.

[0060]

[0061] In addition, the correction matrix M Ｃ For details of the correction matrix M Ｃ This will be explained in "About"

[0062] The gamma processing unit 924 processes the captured image (signal value for each pixel (R ９２３ , G ９２３ , B ９２３ )) and perform gamma processing (γ correction).

[0063] The YC conversion unit 925 converts the gamma-processed captured image (RGB signal) into a luminance signal and a color difference signal (Y, C Ｂ / C Ｒ Then, the image processing unit 92 outputs the YC converted captured image to the display device 7 via the second transmission cable 8. As a result, the display device 7 displays the captured image.

[0064] The image processing unit 92 is not limited to a configuration in which demosaic processing is performed between WB processing and correction matrix processing. The demosaic processing may be performed at any timing as long as it is performed before gamma processing. In other words, the image processing unit 92 may be configured such that the processing units 921 to 925 are arranged in an order different from that shown in FIG. 2.

[0065] The control unit 93 is realized by a controller such as a CPU or an MPU (Micro Processing Unit) executing various programs stored in the storage unit 96, and controls the operations of the light source device 3, the camera head 5, and the display device 7, as well as the operation of the entire control device 9. Note that the control unit 93 is not limited to being a CPU or an MPU, and may be configured by an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA.

[0066] The input unit 94 is configured using operation devices such as a mouse, a keyboard, and a touch panel, and receives user operations from a user such as a surgeon. The input unit 94 then outputs an operation signal corresponding to the user operation to the control unit 93.

[0067] The output unit 95 is configured using a speaker, a printer, etc., and outputs various information.

[0068] The storage unit 96 stores the programs executed by the control unit 93, information necessary for the processing of the control unit 93, and the like.

[0069] [Correction matrix M Ｃ Next, the correction matrix M Ｃ The correction matrix M Ｃ is set based on at least the spectral characteristics of the fluorescence to be observed. In this embodiment, the correction matrix M Ｃ is set based on the spectral characteristics of the fluorescence of the observation object, the spectral characteristics of the unwanted light, and the spectral characteristics of the color filter 514.

[0070] Specifically, the correction matrix M ＣIn this embodiment, as described above, the matrix elements by which the first pixel signal (signal value) is multiplied are set to 0 or a positive value. ９２２ ), which is a signal value with a relatively large component of fluorescence from the observation object. Ｃ The signal value (R ９２２ The matrix elements "a", "d", and "g" (see equation (1)) by which the matrix is ​​multiplied are set to 0 or positive values.

[0071] On the other hand, the correction matrix M Ｃ In this embodiment, as described above, the matrix elements by which the second pixel signal (signal value) is multiplied are set to 0 or a negative value. ９２２ , B ９２２ ), which is a signal value that mainly contains unnecessary light components. Ｃ The signal value (G ９２２ , B ９２２ The matrix elements "b", "c", "e", "f", "h", and "i" (see equation (1)) by which .times. ...

[0072] Furthermore, the correction matrix M Ｃ The matrix elements in can be set by the following first to third setting methods.

[0073] The first setting method is to use the correction matrix M Ｃ In this embodiment, the correction matrix M set by the first setting method is Ｃ An example of the correction matrix is ​​the following formula (2).

[0074]

[0075] The second setting method is to use the correction matrix M Ｃ In each row, the sum of the matrix elements is set to be greater than 0 (a+b+c=d+e+f=g+h+i>0).

[0076] The third setting method is to use the correction matrix M Ｃ In each row, the sum of the matrix elements is set to be smaller than 0 (a+b+c=d+e+f=g+h+i<0).

[0077] In addition, the correction matrix M Ｃ In this case, the ratios of "a", "d", and "g" in the first column, "b", "e", and "h" in the second column, and "c", "f", and "i" in the third column may be set taking into consideration the spectral sensitivity ratios of each filter group 514r, 514g, and 514b.

[0078] If you want to strengthen the observed fluorescent component or express the observed fluorescent component as a pseudo color, you can use the correction matrix M Ｃ In this example, "a", "b", and "c" on the first line, "d", "e", and "f" on the second line, and "g", "h", and "i" on the third line may each be multiplied by a different gain coefficient.

[0079] According to the present embodiment described above, the following effects are achieved. In the control device 9 according to the present embodiment, the correction matrix processing unit 923 calculates the correction coefficient (in this embodiment, the correction matrix M Ｃ ), and a first pixel signal (signal value (R ９２２ )) and a second pixel signal (in this embodiment, a signal value (G ９２２ , B ９２２ )) based on the corrected pixel signal (in this embodiment, the signal value (R ９２３ , G ９２３ , B ９２３ )) is generated. Therefore, the control device 9 according to this embodiment can subtract the second pixel signal, in which the unwanted light component is dominant, from the first pixel signal, in which the observation object fluorescence component is dominant, to generate a corrected pixel signal in which the unwanted light component that becomes noise in fluorescence observation is suppressed. In other words, fluorescence observation can be performed satisfactorily.

[0080] In particular, the correction matrix processing unit 923 calculates the first and second pixel signals (signal values ​​(R ９２２ , G ９２２ , B ９２２)) as matrix elements of the input matrix M ９２２ is the correction matrix M, which is the correction coefficient according to the present disclosure. Ｃ The corrected pixel signal (in this embodiment, the signal value (R ９２３ , G ９２３ , B ９２３ )) is generated. Therefore, the correction pixel signal can be easily generated by simple processing.

[0081] Correction matrix M Ｃ In the first setting method, the matrix element by which the signal value of the first pixel signal is multiplied is set to 0 or a positive value, and the matrix element by which the signal value of the second pixel signal is multiplied is set to 0 or a negative value. Furthermore, by setting the matrix elements using the first to third setting methods, the following effects are achieved. Ｃ In the second setting method, when the matrix elements in the correction matrix M are set, it is possible to generate a corrected pixel signal in which unnecessary light components are substantially removed or suppressed. Ｃ When the matrix elements in the correction matrix M are set, it is possible to generate a corrected pixel signal in which only a part of the unnecessary light component is substantially removed or suppressed. Ｃ When the matrix elements in the above formula are set, it is possible to generate a corrected pixel signal in which unnecessary light components including variations are substantially removed or suppressed.

[0082] The control device 9 also includes a WB processing unit 921 that performs WB processing to make the unnecessary light component contained in the first pixel signal and the unnecessary light component contained in the second pixel signal approximately the same. Then, a correction matrix processing unit 923 corrects the first and second pixel signals (signal values ​​(R ９２２ , G ９２２ , B ９２２ )) is used to generate a correction pixel signal. Therefore, by subtracting the second pixel signal in which the unnecessary light component is dominant from the first pixel signal in which the observation object fluorescence component is dominant, a correction pixel signal in which the unnecessary light component is efficiently suppressed can be generated.

[0083] Other Embodiments Although the embodiments for implementing the present disclosure have been described above, the present disclosure should not be limited to the above-described embodiments. In the above-described embodiments, the light source device 3 emits only excitation light. However, this is not limited to this configuration. A configuration that emits white light in addition to the excitation light may also be adopted. In this case, the camera head 5 generates a captured image (hereinafter referred to as a fluorescence image) capturing the observation target fluorescence generated in the observation target OB in response to the excitation light, and a captured image (hereinafter referred to as a white light image) capturing the white light reflected from the observation target OB. The control device 9 then superimposes the fluorescence image on the white light image, displays the white light image and the fluorescence image side by side, displays the white light image and the fluorescence image in PinP mode, or displays the white light image and the fluorescence image on different monitors. Even with such a configuration, the same effects as those of the above-described embodiments can be achieved. Furthermore, the above-described embodiments may employ the following modifications 1 to 10.

[0084] (Variation 1) In this variation 1, a case where ALM-488 is used as the drug will be described. FIGS. 5 to 8 are diagrams illustrating variation 1 of the embodiment. Specifically, FIG. 5 shows the absorption spectrum and emission spectrum of ALM-488. Note that in FIG. 5, the horizontal axis represents wavelength [nm], and the vertical axis represents absorbance (absorbance) and fluorescence emission (fluorescence emission). Also, in FIG. 5, the absorption spectrum of ALM-488 is shown by a dashed line, and the emission spectrum of ALM-488 is shown by a solid line. FIG. 6 is a diagram corresponding to FIG. 4. FIG. 7 shows a captured image F1 obtained by placing a test tube TU containing the drug DR of ALM-488 in front of a blackout curtain, irradiating the drug DR with excitation light, and capturing a region containing the drug DR as the subject. FIG. 8(a) shows the frequency distribution of r, g, and b values ​​within the first region Ar1 in the captured image F1 shown in FIG. 7. Fig. 8(b) is a diagram showing the frequency distribution of the r value, g value, and b value of the second region Ar2 in the captured image F1 shown in Fig. 7. In Fig. 8, the r value, g value, and b value are shown on the horizontal axis, and the number of pixels (frequency) of the r value, g value, and b value are shown on the vertical axis.

[0085] The peak wavelength of the absorption spectrum of ALM-488 is about 480 nm, as shown in Fig. 5. Therefore, the excitation light emitted from the light source device 3 is preferably in a wavelength band including a wavelength of about 480 nm, in order to increase the intensity of the fluorescence to be observed emitted from ALM-488.

[0086] Furthermore, as shown in FIG. 5 , the peak wavelength of the emission spectrum of ALM-488 is approximately 530 nm. Therefore, the fluorescence under observation emitted from ALM-488 has spectral characteristics in a wavelength band centered around approximately 530 nm, as shown by spectrum SPF2 in FIG. 6 . The g value, derived from the spectral characteristics of the G filter group 514g and the spectral characteristics of the fluorescence under observation and the unnecessary light, includes both the fluorescence under observation and the unnecessary light. The r value, derived from the spectral characteristics of the R filter group 514r and the spectral characteristics of the fluorescence under observation and the unnecessary light, includes primarily the unnecessary light. Similarly, the b value, derived from the spectral characteristics of the B filter group 514b and the spectral characteristics of the fluorescence under observation and the unnecessary light, includes primarily the unnecessary light. In other words, the g value contains a larger amount of the fluorescence under observation than the r and b values.

[0087] The following experiment also demonstrated that "when ALM-488 was used, the g value was higher in the fluorescence component of the object of observation than the r value and b value." In this experiment, a test tube TU containing the drug DR (ALM-488) was placed in front of a black screen, and the drug DR was irradiated with excitation light. Under this condition, the imaging unit 51 captured an area containing the drug DR as a subject, and the frequency distributions of the r value, g value, and b value in the first and second areas Ar1 and Ar2 in the captured image F1 generated by the imaging were compared ( FIG. 8 ). Here, the first area Ar1 is the area in the captured image F1 where the drug DR is captured, as shown in FIG. 7 . On the other hand, the second area Ar2 is the background area (black screen) other than the drug DR in the captured image F1. That is, because the drug DR emits fluorescence of the object of observation upon irradiation with excitation light, the first area Ar1 is brighter than the second area Ar2.

[0088] In FIG. 8 , the symbol "FR" denotes the frequency distribution of r values. The symbol "FG" denotes the frequency distribution of g values. The symbol "FB" denotes the frequency distribution of b values. As a result, as shown in FIG. 8A, the frequency distribution FG of g values ​​appears in the bright areas (areas with large values ​​on the horizontal axis in FIG. 8 ), and the frequency distributions FR and FB of r and b values ​​appear in areas darker than the frequency distribution FG (areas with small values ​​on the horizontal axis in FIG. 8 ). This indicates that "when ALM-488 is used, the g value contains more fluorescence components than the r and b values." The frequency distributions FR and FB of r and b values ​​in the first region Ar1 shown in FIG. 8A and the frequency distributions FR, FG, and FB of r, g, and b values ​​in the second region Ar2 shown in FIG. 8B are primarily composed of unwanted light components.

[0089] As described above, the g value has a larger component of the fluorescence of the observation object than the r and b values. ９２２ , G ９２２ , B ９２２ ), the signal value (G ９２２ ) is the signal value (R ９２２ , B ９２２ ), the component of the fluorescence to be observed is larger than that of the signal value (G ９２２ ) corresponds to the first pixel signal (signal value) according to the present disclosure. ９２２ , B ９２２ ) corresponds to the second pixel signal (signal value) according to the present disclosure. ９２２ ) is a signal value in which the component of the fluorescence of the object to be observed is greater than the component of the unnecessary light, and the component of the fluorescence of the object to be observed is dominant. ９２２ , B ９２２ ) is a signal value where the unnecessary light component is dominant.

[0090] Even when ALM-488 is used, the correction matrix M Ｃ The matrix elements by which the first pixel signal (signal value) in the matrix are multiplied are set to 0 or a positive value. Specifically, when ALM-488 is used, as described above, the first pixel signal (signal value) is multiplied by the signal value (G ９２２), which is a signal value with a relatively large component of fluorescence from the observation object. Ｃ The signal value (G ９２２ The matrix elements "b", "e", and "h" (see equation (1)) by which the matrix is ​​multiplied are set to 0 or a positive value.

[0091] Even when ALM-488 is used, the correction matrix M Ｃ The matrix elements by which the second pixel signal (signal value) in ９２２ , B ９２２ ), which is a signal value that mainly contains unnecessary light components. Ｃ The signal value (R ９２２ , B ９２２ The matrix elements "a", "d", "g", "c", "f", and "i" (see equation (1)) by which the matrix is ​​multiplied are set to 0 or negative values.

[0092] And the correction matrix M when using ALM-488 Ｃ As in the above-described embodiment, the correction matrix M can be set by the first to third setting methods. Ｃ As an example, the correction matrix of the following formula (3) can be given.

[0093]

[0094] Even when ALM-488 is used as the drug as in the first modification described above, the same effects as those of the above-described embodiment are achieved.

[0095] (Variation 2) In this variation 2, a case where LUM-015 is used as the drug will be described. FIGS. 9 and 10 are diagrams illustrating variation 2 of the embodiment. Specifically, FIG. 9 is a diagram showing the absorption spectrum and emission spectrum of LUM-015. Note that in FIG. 9, the horizontal axis represents wavelength [nm], and the vertical axis represents absorbance in the absorption spectrum and fluorescence emission in the emission spectrum. In addition, in FIG. 9, the absorption spectrum of LUM-015 is shown by a dashed line, and the emission spectrum of LUM-015 is shown by a solid line, and FIG. 10 is a diagram corresponding to FIG. 4.

[0096] The peak wavelength of the absorption spectrum of LUM-015 is approximately 650 nm, as shown in Fig. 9. Therefore, the excitation light emitted from the light source device 3 is preferably in a wavelength band including a wavelength of approximately 650 nm, in order to increase the intensity of the fluorescence to be observed emitted from LUM-015.

[0097] Furthermore, the peak wavelength of the emission spectrum of LUM-015 is approximately 670 nm, as shown in FIG. 9 . Therefore, the fluorescence of the object of observation emitted from LUM-015 has spectral characteristics in a wavelength band centered around approximately 670 nm, as shown by spectrum SPF3 in FIG. 10 . The r-value, derived from the spectral characteristics of the R filter group 514r and the spectral characteristics of the fluorescence of the object of observation and the unnecessary light, includes both the fluorescence of the object of observation and the unnecessary light. The g-value, derived from the spectral characteristics of the G filter group 514g and the spectral characteristics of the fluorescence of the object of observation and the unnecessary light, includes primarily the unnecessary light. Similarly, the b-value, derived from the spectral characteristics of the B filter group 514b and the spectral characteristics of the fluorescence of the object of observation and the unnecessary light, includes primarily the unnecessary light. In other words, the r-value contains a larger amount of the fluorescence of the object of observation than the g-value and the b-value.

[0098] As described above, the r value has a larger component of the fluorescence of the observation object than the g value and the b value. ９２２ , G ９２２ , B ９２２ ), the signal value (R ９２２ ) is the signal value (G ９２２ , B ９２２), the component of the fluorescence to be observed is larger than that of the signal value (R ９２２ ) corresponds to the first pixel signal (signal value) according to the present disclosure. ９２２ , B ９２２ ) corresponds to the second pixel signal (signal value) according to the present disclosure. ９２２ ) is a signal value in which the component of the fluorescence of the object of observation is greater than the component of the unnecessary light, and the component of the fluorescence of the object of observation is dominant. ９２２ , B ９２２ ) is a signal value where the unnecessary light component is dominant.

[0099] That is, when LUM-015 is used, the signal value (R ９２２ ) corresponds to the first pixel signal (signal value) according to the present disclosure, and the signal value (G ９２２ , B ９２２ ) corresponds to the second pixel signal (signal value) according to the present disclosure. Therefore, the correction matrix M Ｃ As the correction matrix, the correction matrix explained in the above embodiment can be used.

[0100] Even when LUM-015 is used as the drug as in the second modified example described above, the same effects as those of the above-described embodiment are achieved.

[0101] (Variation 3) In this variation 3, a case where multiple drugs are used will be described. FIG. 11 is a diagram illustrating variation 3 of the embodiment. Specifically, FIG. 11 is a diagram corresponding to FIG. 1. Note that FIG. 11 illustrates a medical observation system 1 in which two drugs are used. For ease of explanation, the following description will assume that two drugs are used. When two drugs are used, as shown in FIG. 11 , the medical observation system 1 needs to be configured to include a first light source 31 that emits excitation light to excite the first drug of the two drugs, and a second light source 32 that emits excitation light to excite the second drug. Note that when three or more drugs are used, the number of light sources may be three or more, corresponding to the number of drugs.

[0102] The medical observation system 1 turns on the first and second light sources 31 and 32 in a time-division manner for the observation object OB to which the first and second drugs have been applied. When the medical observation system 1 performs correction matrix processing on the captured image generated by capturing an image with the image sensor 513 at the timing when the first light source 31 is turned on, the correction matrix M corresponding to the first drug is used. Ｃ On the other hand, when the medical observation system 1 performs correction matrix processing on the captured image generated by capturing an image with the image capturing element 513 at the lighting timing of the second light source 32, the correction matrix M corresponding to the second drug is used. Ｃ is used.

[0103] Even when a plurality of drugs are used as in the third modified example described above, the same effects as those of the above-described embodiment can be achieved.

[0104] (Modification 4) Figs. 12 to 14 are diagrams illustrating Modification 4 of the embodiment. Specifically, Fig. 12 is a diagram corresponding to Fig. 4. Fig. 13 shows the correction matrix M Ｃ 14 is a flowchart showing a method for calculating the correction matrix M shown in FIG. Ｃ 1 is a diagram showing a white chart WC used in the calculation method of the correction matrix M Ｃ However, the present invention is not limited to this. For example, a 3*8 correction matrix M Ｃ , a 3*7 correction matrix M Ｃ , a 3*6 correction matrix M Ｃ , a 3*5 correction matrix M Ｃ , or the 3*4 correction matrix M shown in the following equation (8) Ｃ It is acceptable to adopt this method.

[0105]

[0106]

[0107]

[0108]

[0109]

[0110] The input matrix M shown in equation (4) ９２２ is the signal value (R ９２２ , G ９２２ , B ９２２ ) as matrix elements, and also includes signal values ​​(R ９２２ ) and signal value (G ９２２ ) multiplied by "R ９２２ *G ９２２ " and the signal value (G ９２２ ) and signal value (B ９２２ ) multiplied by "G ９２２ *B ９２２ " and the signal value (R ９２２ ) and signal value (B ９２２ ) multiplied by "R ９２２ *B ９２２ " and the signal value (R ９２２ ), signal value (G ９２２ ), and the signal value (B ９２２ ) multiplied by "R ９２２ *G ９２２ *B ９２２ " and "1" as matrix elements, respectively.

[0111] The input matrix M shown in equation (5) ９２２ is the input matrix M ９２２ "R" in ９２２ *G ９２２ *B ９２２ " matrix elements are omitted.

[0112] In equation (6), the input matrix M ９２２ Three input matrices M ９２２ The three input matrices M ９２２ is the input matrix M ９２２ "R" in ９２２ *G ９２２ "," "G ９２２ *B ９２２ " and "R ９２２ *B ９２２ " is obtained by omitting one of the matrix elements.

[0113] In equation (7), the input matrix M ９２２ Three input matrices M ９２２ The three input matrices M ９２２ is the input matrix M ９２２ "R" in ９２２ *G ９２２ "," "G ９２２ *B ９２２ " and "R ９２２ *B ９２２ " is obtained by omitting any two matrix elements.

[0114] The input matrix M shown in equation (8) ９２２ is the input matrix M ９２２ is obtained by adding a matrix element of "1" to

[0115] By the way, the input matrix M ９２２ For example, if the spectral characteristics of the fluorescence to be observed are those of a wavelength band with a center wavelength of about 580 [nm] as shown in spectrum SPF4 in FIG. 12, the signal value (R ９２２ ) and signal value (G ９２２ ) is a signal value where the component of the fluorescence of the object to be observed is dominant. ９２２ ) is a signal value where the unnecessary light component is dominant. In this case, the signal value (R ９２２ ) and signal value (G ９２２ ) corresponds to the first pixel signal (signal value) according to the present disclosure. ９２２ ) corresponds to the second pixel signal (signal value) according to the present disclosure. ９２２ ) and signal value (G ９２２ ) multiplied by "R ９２２ *G ９２２ " is a value in which the component of the fluorescence to be observed is extremely dominant. ９２２ *G ９２２ " into the input matrix M ９２２(for example, equations (4) to (7)), a corrected pixel signal in which unnecessary light components are efficiently suppressed can be generated.

[0116] In the fourth modification, as shown in the flowchart of FIG. 13, the correction matrix M Ｃ First, the operator brings the tip of the insertion portion 2 close to a white chart WC ( FIG. 14 ), irradiates the white chart WC with the first light emitted from the light source device 3, and then causes the imaging unit 51 to capture an image of the white chart WC (step S1). Here, the white chart WC is a white chart with a light reflectance of approximately 1. That is, the first light (excitation light) reflected by the white chart WC and unwanted light generated in the observation optical path P0 are incident on the imaging unit 51. Of these, the first light (excitation light) is partially, substantially, or completely suppressed by the excitation light cut filter 511 in the imaging unit 51. That is, only unwanted light is incident on the imaging element 513 via the color filter 514.

[0117] After step S1, the operator uses the image processing unit 92 to perform WB processing (step S2) and demosaic processing (step S3) on the captured image generated by the imaging unit 51, thereby obtaining a signal value (R ９２２ , G ９２２ , B ９２２ Then, the operator obtains the signal value (R ９２２ , G ９２２ , B ９２２ ) to the signal value (R ９２２ ), signal value (G ９２２ ), and the signal value (B ９２２ ) and the average signal value (R ９２２_AVE , G ９２２_AVE , B ９２２_AVE ) is obtained (step S4).

[0118] After step S4, the operator calculates the input matrix M ９２２ (Step S5). Specifically, the operator selects the type of 3*3 correction matrix M ＣWhen calculating the input matrix M ９２２ In addition, the operator selects a 3*8 correction matrix M Ｃ When calculating the input matrix M ９２２ Furthermore, the operator selects a 3*7 correction matrix M Ｃ When calculating the input matrix M ９２２ In addition, the operator selects a 3*6 correction matrix M Ｃ When calculating the three input matrices M ９２２ Furthermore, the operator selects either one of the 3*5 correction matrix M Ｃ When calculating the three input matrices M ９２２ In addition, the operator selects either one of the 3*4 correction matrix M Ｃ When calculating the input matrix M ９２２ Select .

[0119] After step S5, the operator calculates the average signal value (R ９２２_AVE , G ９２２_AVE , B ９２２_AVE ) the input matrix M selected in step S5 ９２２ is calculated (step S6).

[0120] After step S6, the operator uses the input matrix M ９２２ is input into the following equation (9) (step S7). That is, in step S7, the correction matrix M Ｃ Equation (9) is generated with variables.

[0121]

[0122] After step S7, the worker uses the correction matrix M Ｃ The correction matrix M is calculated by the least squares method from the equation (9) with variables Ｃ (Step S8). Note that the correction matrix M Ｃ The calculation method is not limited to the least squares method, and other methods may be used.

[0123] As described above, only unwanted light is incident on the image sensor 513 via the color filter 514. Therefore, the input matrix M ９２２ The matrix elements in (9) include only the unnecessary light components. Then, by setting the left side of the equation (9) to "0", in step S8, a correction matrix M Ｃ Calculate.

[0124] According to the fourth modification described above, in addition to the same effects as those of the above-described embodiment, the following effects are achieved. Ｃ Besides, 3*8, 3*7, 3*6, 3*5, and 3*4 correction matrices M Ｃ In other words, the number of correction parameters increases, and it is possible to generate a corrected pixel signal in which unnecessary light components are effectively suppressed. In addition, the value obtained by multiplying the signal values ​​of at least two first pixel signals is used as an input matrix M ９２２ By including the unnecessary light component in the matrix element in, it is possible to generate a corrected pixel signal in which the unnecessary light component is efficiently suppressed.

[0125] In the above-described embodiment and the fourth modification, the second pixel signal according to the present disclosure has a signal value (G ９２２ ) and signal value (B ９２２ ) and the correction matrix M Ｃ However, when only one second pixel signal is used, a correction matrix M of 2*m (m is 2 or more) is used. Ｃ It is acceptable to adopt this method.

[0126] (Modification 5) FIGS. 15 and 16 are diagrams illustrating Modification 5 of the embodiment. Specifically, FIG. 15 is a diagram illustrating the configuration of a prism 516 and image sensors 513r, 513g, and 513b according to Modification 5. In FIG. 15, light in the red wavelength band separated by the prism 516 is referred to as "R," light in the green wavelength band separated by the prism 516 is referred to as "G," and light in the blue wavelength band separated by the prism 516 is referred to as "B." FIG. 16 is a diagram illustrating the spectral characteristics of the prism 516. The spectral characteristics of a prism such as the prism 516 are also referred to as wavelength spectral characteristics. In FIG. 16, the horizontal axis represents wavelength [nm], and the vertical axis represents relative response [%]. 16 , the spectral characteristics of the prism 516 are shown by the curve CR, the curve CG, and the curve CB, respectively, as the spectrum of light in the red wavelength band dispersed by the prism 516, the curve CG, and the curve CB, respectively. Note that, in this fifth modification, the spectral characteristics of the fluorescence to be observed are the same as those in the above-described embodiment, as shown by the spectrum SPF1 in FIG. 16 , but the spectral characteristics may be other spectral characteristics. Similarly, the wavelength range SPU in which unwanted light can be generated may be other wavelength ranges different from those in the above-described embodiment.

[0127] In the above-described embodiment, instead of the image sensor 513 and color filter 514, a prism 516 and image sensors 513r, 513g, and 513b according to the fifth modified example shown in FIG. 15 may be employed.

[0128] The prism 516 corresponds to a spectroscopic member according to the present disclosure. The prism 516 separates the second light (subject image) formed by the lens unit 512 after passing through the excitation light cut filter 511 into light R, G, and B in the red, green, and blue wavelength bands, respectively.

[0129] The image sensor 513 r has the same configuration as the image sensor 513 , and captures an image of light R in the red wavelength band separated by the prism 516 .

[0130] The image sensor 513 g has the same configuration as the image sensor 513 , and captures an image of light G in the green wavelength band separated by the prism 516 .

[0131] The image sensor 513 b has the same configuration as the image sensor 513 , and captures an image of light B in the blue wavelength band separated by the prism 516 .

[0132] Based on the spectral characteristics of the prism 516 (curve CR) and the spectral characteristics of the fluorescence of the object of observation and the unnecessary light, the signal value (r value) of the pixel signal output from the image sensor 513r includes a component of the fluorescence of the object of observation and a component of the unnecessary light. Based on the spectral characteristics of the prism 516 (curve CG) and the spectral characteristics of the fluorescence of the object of observation and the unnecessary light, the signal value (g value) of the pixel signal output from the image sensor 513g includes mainly the component of the unnecessary light. Based on the spectral characteristics of the prism 516 (curve CB) and the spectral characteristics of the fluorescence of the object of observation and the unnecessary light, the signal value (b value) of the pixel signal output from the image sensor 513b includes mainly the component of the unnecessary light. In other words, the r value contains a larger component of the fluorescence of the object of observation than the g value and the b value. From the above, the pixel signal output from the image sensor 513r corresponds to a first pixel signal according to the present disclosure. Based on the pixel signals output from the image sensors 513g and 513b, the signal values ​​(b value) of the pixel signal output from the image sensor 513r correspond to a second pixel signal according to the present disclosure.

[0133] The image processing unit 92 according to the fifth modification does not need to be provided with the demosaic processing unit 922 described in the above embodiment. The correction matrix processing unit 923 according to the fifth modification calculates signal values ​​(R ９２２ , G ９２２ , B ９２２ ) to perform correction matrix processing to generate a corrected pixel signal, as in the above-described embodiment. Ｃ is set based on the spectral characteristics of the fluorescence of the object of observation, the spectral characteristics of the unwanted light, and the spectral characteristics of the prism 516.

[0134] The same effects as those of the above-described embodiment can be achieved even when the configuration of the present modified example 5 described above is adopted. Note that the configuration of the present modified example 5 may also be adopted as the configuration of the above-described modified example 4.

[0135] (Variation 6) Figures 17 and 18 are diagrams illustrating Variation 6 of the embodiment. Specifically, Figure 17 is a perspective view showing an image sensor 513 according to Variation 6. Figure 18 is a side view showing the image sensor 513 according to Variation 6. Note that in Figure 18, light in the red wavelength band is designated "R," light in the green wavelength band is designated "G," and light in the blue wavelength band is designated "B." In the above-described embodiment, the image sensor 513 according to Variation 6 shown in Figures 17 and 18 may be used instead of the image sensor 513 and color filter 514.

[0136] The image sensor 513 according to Modification 6 is a Foveon type image sensor (e.g., an organic CMOS). Specifically, as shown in Figures 17 and 18, the image sensor 513 has a configuration in which first to third light receiving layers 5131b, 5131g, and 5131r are stacked.

[0137] The first light receiving layer 5131b receives only light in the blue wavelength band and converts it into an electrical signal. The first light receiving layer 5131b is provided as the top layer and receives light B in the blue wavelength band from the second light (subject image) formed by the lens unit 512 after passing through the excitation light cut filter 511, and converts it into an electrical signal.

[0138] The second light receiving layer 5131g receives only light in the green wavelength band and converts it into an electrical signal. The second light receiving layer 5131g is provided below the first light receiving layer 5131b, and receives light G in the green wavelength band among the light transmitted through the first light receiving layer 5131b and converts it into an electrical signal.

[0139] The third light receiving layer 5131r is provided as the bottom layer, and receives light R in the red wavelength band that has passed through the first and second light receiving layers 5131b and 5131g, and converts it into an electrical signal.

[0140] For example, if the spectral characteristics of the fluorescence under observation are those of a wavelength band included in the red wavelength band of light R, the electrical signal (pixel signal (r value)) output from the third light receiving layer 5131r mainly contains components of the fluorescence under observation and therefore corresponds to the first pixel signal according to the present disclosure. On the other hand, the electrical signals (pixel signals (g value, b value)) output from the first and second light receiving layers 5131b and 5131g mainly contain components of unwanted light and therefore correspond to the second pixel signal according to the present disclosure.

[0141] The image processing unit 92 according to the sixth modification does not need to be provided with the demosaic processing unit 922 described in the above embodiment. The correction matrix processing unit 923 according to the sixth modification calculates signal values ​​(R ９２２ , G ９２２ , B ９２２ ) to perform correction matrix processing to generate a corrected pixel signal, as in the above-described embodiment. Ｃ is set based on the spectral characteristics of the fluorescence of the object of observation, the spectral characteristics of the unwanted light, and the spectral characteristics of the image sensor 513 according to Modification 6. The spectral characteristics of a Foveon type image sensor such as the image sensor 513 according to Modification 6 are also called received light spectral characteristics.

[0142] The same effects as those of the above-described embodiment can be achieved even when the configuration of the present modified example 6 described above is adopted. Note that the configuration of the present modified example 6 may also adopt the configuration of the above-described modified example 4.

[0143] (Variation 7) The medical observation system according to Variation 7 is a medical observation system that uses a so-called videoscope (flexible endoscope) that has an imaging unit at the tip of an insertion section. For ease of explanation, the medical observation system 1 according to Variation 7 will be referred to as medical observation system 1A below.

[0144] Fig. 19 is a diagram illustrating a seventh modification of the embodiment. As shown in Fig. 19, the medical observation system 1A includes an endoscope 100 that captures an in-vivo image of an observation site by inserting an insertion section 2A into a living body and outputs the captured image, a light source device 3 that generates a first light that is emitted from the tip of the endoscope 100, a control device 9 that processes the captured image output from the endoscope 100, and a display device 7 that is connected to the control device 9 via a second transmission cable 8 and displays an image based on a video signal processed by the control device 9.

[0145] 19 , the endoscope 100 includes a flexible, elongated insertion section 2A, an operation section 101 connected to the base end side of the insertion section 2A and accepting various operations, and a universal cord 102 extending from the operation section 101 in a direction different from the direction in which the insertion section 2A extends and incorporating various cables connecting to the light source device 3 and the control device 9. As shown in FIG. 19 , the insertion section 2A includes a tip section 22, a freely bendable bending section 23 connected to the base end side of the tip section 22 and made up of a plurality of bending pieces, and a flexible, elongated flexible tube section 24 connected to the base end side of the bending section 23.

[0146] Although not specifically shown in the drawings, the tip portion 22 has a built-in configuration substantially similar to that of the camera head 5 described in the above embodiment. An image captured by the tip portion 22 (imaging unit) is output to the control device 9 via the operation unit 101 and the universal cord 102.

[0147] Even when the configuration of the seventh modified example described above is adopted, the same effects as those of the above-described embodiment are achieved.

[0148] (Variation 8) The medical observation system according to Variation 8 is a medical observation system that uses a surgical microscope to magnify and capture images of a predetermined field of view inside a subject (inside a living body) or on the surface of a subject (surface of a living body). For ease of explanation, the medical observation system 1 according to Variation 7 will be referred to as medical observation system 1B below.

[0149] Fig. 20 is a diagram illustrating an eighth modification of the embodiment. As shown in Fig. 20, the medical observation system 1B includes a surgical microscope 12 that captures images for observing a subject and outputs the captured images, a control device 9 that processes the captured images output from the surgical microscope 12, and a display device 7 that is connected to the control device 9 via a second transmission cable 8 and displays images based on video signals processed by the control device 9.

[0150] As shown in Fig. 20 , the surgical microscope 12 includes a microscope unit 121 that captures a magnified image of a minute portion of a subject and outputs the captured image, a support unit 122 that is connected to the base end of the microscope unit 121 and includes an arm that rotatably supports the microscope unit 121, and a base unit 123 that rotatably holds the base end of the support unit 122 and is movable on the floor. The control device 9 is mounted on the base unit 123 as shown in Fig. 20 . Although not specifically shown, the base unit 123 also has a light source device 3 that generates illumination light to be irradiated from the surgical microscope 12 to the subject. The base unit 123 may be fixed to a ceiling, wall, or the like to support the support unit 122, rather than being movable on the floor.

[0151] Although not specifically shown in the drawings, the microscope unit 121 has a built-in configuration substantially similar to that of the camera head 5 described in the above-described embodiment. An image captured by the microscope unit 121 (imaging unit) is output to the control device 9 via a first transmission cable 6 wired along the support unit 122.

[0152] Even when the configuration of the eighth modified example described above is adopted, the same effects as those of the above-described embodiment are achieved.

[0153] (Modification 9) FIGS. 21 and 22 are diagrams illustrating Modification 9 of the embodiment. Specifically, FIG. 21 is a side view of the ring light 15. The ring light 15 corresponds to an open-field observation device for observing biological tissue. The open-field observation device is a device used in open surgery. FIG. 22 is a front view of the ring light 15 (left side in FIG. 21). In Modification 9, in addition to the insertion section 2 described in the above-mentioned embodiment, the ring light 15 shown in FIGS. 21 and 22 is detachably connected to the camera head 5. That is, depending on the user's usage state, as shown in FIG. 21, the insertion section 2 or the ring light 15 may be connected to the camera head 5.

[0154] The ring light 15 is not inserted into the observation object OB like the insertion section 2, but supplies a first light to the surgical site and captures a second light (subject image) that is a return light of the first light from the surgical site. As shown in Figures 21 and 22, the ring light 15 includes an illumination section 151 and a subject image capture section 152 that captures the subject image.

[0155] 21 and 22 , the illumination unit 151 includes a housing 1511 and a plurality of illumination lenses 1512. The housing 1511 has an annular shape centered on the optical axis Ax. The other end of the light guide 4 is detachably connected to the housing 1511.

[0156] 22, the plurality of illumination lenses 1512 are arranged at predetermined intervals along the circumferential direction centered on the optical axis Ax on the front end surface of the housing 1511. The plurality of illumination lenses 1512 each irradiate the first light, which is supplied from the light source device 3 and introduced into the housing 1511 via the light guide 4, toward the surgical site.

[0157] The subject image capture unit 152 extends along the optical axis Ax. An optical system configured with one or more lenses is provided within the subject image capture unit 152, and focuses second light (subject image) that is irradiated from the multiple illumination lenses 1512 and passes through the surgical site. A connector 1521 is provided at the end on the proximal side (right side in FIG. 21 ) of the subject image capture unit 152. This connector 1521 has a design (shape) compatible with the eyepiece 21 of the insertion unit 2, and is detachably connected to the camera head 5.

[0158] Even when the configuration of the present modified example 9 described above is adopted, the same effects as those of the above-described embodiment are achieved.

[0159] (Modification 10) In the above-described embodiment, the fluorescence to be observed is visible light, but this is not limiting and it may be invisible light.

[0160] In this case, the imaging element according to this modification 10 may be only one, as long as it has the sensitivity to capture not only visible light but also invisible light, like the imaging element 513 of the above-described embodiment, and is also capable of capturing the invisible fluorescence of the object to be observed.

[0161] Furthermore, an imaging element that captures only invisible light, such as an infrared imaging element, may be used as the imaging element according to Modification Example 10. In this case, as long as the imaging element that captures only invisible light has sensitivity to multiple wavelength bands and is capable of outputting a first pixel signal that mainly contains an invisible component of the fluorescence of the object of observation and a second pixel signal that mainly contains an unwanted invisible light component, a configuration in which only one imaging element is provided may be used. Alternatively, a configuration in which two imaging elements, one that captures invisible light and one that captures visible light, are provided may be used, with the imaging element that captures invisible light capturing the fluorescence of the object of observation and the imaging element that captures visible light capturing the unwanted visible light.

[0162] Even when the configuration of the present modified example 10 described above is adopted, the same effects as those of the above-described embodiment are achieved.

[0163] Note that the following configurations also fall within the technical scope of the present disclosure: (1) A medical image processing device including an image processing unit that processes pixel signals acquired from pixels of an image sensor, the pixel signals including a first pixel signal having an unwanted light component including autofluorescence generated from a member forming an observation optical path by light emitted from a light source device when the light propagates through the observation optical path, and an observation object fluorescence component emitted from a substance included in the observation object and excited by the light, and a second pixel signal having at least the unwanted light component, the image processing unit including a signal correction unit that generates a corrected pixel signal based on a correction coefficient set based on the spectral characteristics of the observation object fluorescence and the first pixel signal and the second pixel signal. (2) The medical image processing device according to (1), wherein the observation object fluorescence component is contained more abundantly in the first pixel signal than in the second pixel signal. (3) The medical image processing device according to (1) or (2), wherein the signal correction unit generates the corrected pixel signal by multiplying an input matrix containing, as matrix elements, the signal values ​​of the first pixel signal and the signal values ​​of the second pixel signal by a correction matrix serving as the correction coefficient. (4) The medical image processing device according to (3), wherein at least two first pixel signals are provided, and the input matrix contains, as matrix elements, values ​​obtained by multiplying the signal values ​​of the at least two first pixel signals. (5) The medical image processing device according to (3) or (4), wherein the matrix elements by which the signal values ​​of the first pixel signal are multiplied in the correction matrix are set to 0 or a positive value, and the matrix elements by which the signal values ​​of the second pixel signal are multiplied in the correction matrix are set to 0 or a negative value. (6) The medical image processing device according to (5), wherein the sum of the matrix elements in each row of the correction matrix is ​​0. (7) The medical image processing device according to (5), wherein the sum of the matrix elements in each row of the correction matrix is ​​greater than 0. (8) The medical image processing device according to (5), wherein the sum of the matrix elements in each row of the correction matrix is ​​less than zero.(9) The medical image processing device according to any one of (1) to (8), wherein the image sensor captures each light beam obtained by dispersing light from the object of observation by a dispersing element, and the correction coefficient is set based on the spectral characteristics of the object of observation fluorescence and the spectral characteristics of the dispersing element. (10) The medical image processing device according to any one of (1) to (9), wherein the correction coefficient is set based on the spectral characteristics of the object of observation fluorescence and the spectral characteristics of the unnecessary light. (11) The medical image processing device according to (9), wherein the image processing unit further includes a spectral sensitivity correction unit that performs spectral sensitivity correction processing on the first pixel signal and the second pixel signal based on the spectral characteristics of the dispersing element, and the signal correction unit generates the corrected pixel signal using the first pixel signal and the second pixel signal after the spectral sensitivity correction processing has been performed by the spectral sensitivity correction unit. (12) The medical image processing device according to any one of (1) to (11), wherein the first pixel signal and the second pixel signal are acquired from the same image sensor. (13) The medical image processing device according to any one of (1) to (11), wherein a plurality of image sensors are provided, and the first pixel signal and the second pixel signal are acquired from different image sensors. (14) The medical image processing device according to any one of (1) to (13), wherein the observation object fluorescence is generated from a drug, a fluorescent dye, or a fluorescent substance derived from the observation object, applied to the observation object. (15) The medical image processing device according to any one of (1) to (14), wherein a member forming the observation optical path that generates the autofluorescence is an optical fiber, a lens, glass, a bonding material, or a filter. (16) The medical image processing device according to any one of (1) to (15), wherein the corrected pixel signal is a signal in which a signal value based on the unnecessary light is reduced.(17) A medical observation system comprising: a light source device including a first light source that emits first light that includes narrowband light that excites a substance contained in an observation object; an imaging device having an imaging element that captures second light that is return light of the first light from the observation object; and a medical image processing device having an image processing unit that processes pixel signals corresponding to pixels of the imaging element, wherein the pixel signals include a first pixel signal having a component of unwanted light that includes autofluorescence generated from a member that forms the observation optical path by the first light when the first light emitted from the light source device propagates through the observation optical path, and a component of observation object fluorescence emitted from a substance contained in the observation object that is excited by the first light; and a second pixel signal having at least the component of unwanted light, wherein the image processing unit comprises a signal correction unit that generates a corrected pixel signal based on the first pixel signal and the second pixel signal and a correction coefficient set based on the spectral characteristics of the observation object fluorescence. (19) The medical observation system according to (17) or (18), wherein the first light source is configured by an LED or a semiconductor laser. (20) The medical observation system according to any one of (17) to (19), wherein the first light is configured by broadband light or narrowband light.

[0164] REFERENCE SIGNS LIST 1, 1A, 1B Medical observation system 2, 2A Insertion section 3 Light source device 4 Light guide 5 Camera head 6 First transmission cable 7 Display device 8 Second transmission cable 9 Control device 10 Third transmission cable 12 Surgical microscope 15 Ring light 21 Eyepiece 22 Tip 23 Bending section 24 Flexible tube section 31 First light source 51 Imaging section 52 Communication section 91 Communication section 92 Image processing section 93 Control section 94 Input section 95 Output section 96 Memory section 100 Endoscope 101 Operation section 102 Universal cord 121 Microscope section 122 Support section 123 Base section 151 Illumination section 152 Subject image capture section 511 Excitation light cut filter 512 Lens unit 513, 513b, 513g, 513r Image sensor 514 Color filter 514b B filter group 514g G filter group 514r R filter group 515 Signal processing unit 516 Prism 921 WB processing unit 922 Demosaic processing unit 923 Correction matrix processing unit 924 Gamma processing unit 925 YC conversion unit 1511 Housing 1512 Illumination lens 5131b First light receiving layer 5131g Second light receiving layer 5131r Third light receiving layer Ar Area Ar1 First area Ar2 Second area Ax Optical axis CB, CG, CR Curve CN1, CN2 Connector DG Medication F1 Captured image FR, FG, FB Power distribution OB Observation object P0 Observation light path P1 First light path P2 Second light path SPF1, SPF2, SPF3, SPF4 Spectrum of fluorescence to be observed SPU Wavelength range in which unwanted light can be generated TU Test tube WC White chart

Claims

1. A medical image processing device comprising: an image processing unit that processes pixel signals acquired from pixels of an imaging element, the pixel signals including: a first pixel signal having an unwanted light component including autofluorescence generated from a member forming an observation optical path by light emitted from a light source device as the light propagates through the observation optical path, and an observation object fluorescence component emitted from a substance contained in the observation object excited by the light; and a second pixel signal having at least the unwanted light component, the image processing unit comprising: a signal correction unit that generates a corrected pixel signal based on a correction coefficient set based on the spectral characteristics of the observation object fluorescence and the first pixel signal and the second pixel signal.

2. A medical image processing device according to claim 1, wherein the fluorescence component of the object to be observed is contained more in the first pixel signal than in the second pixel signal.

3. The medical image processing device according to claim 1, wherein the signal correction unit generates the corrected pixel signal by multiplying an input matrix containing the signal value of the first pixel signal and the signal value of the second pixel signal as matrix elements by a correction matrix which is the correction coefficient.

4. A medical image processing device as described in claim 3, wherein at least two first pixel signals are provided, and the input matrix includes values ​​obtained by multiplying the signal values ​​of at least two of the first pixel signals as matrix elements.

5. A medical image processing device as described in claim 3, wherein a matrix element in the correction matrix by which the signal value of the first pixel signal is multiplied is set to 0 or a positive value, and a matrix element in the correction matrix by which the signal value of the second pixel signal is multiplied is set to 0 or a negative value.

6. The medical image processing device according to claim 5, wherein the sum of the matrix elements in each row of the correction matrix is ​​zero.

7. The medical image processing device according to claim 5, wherein the sum of the matrix elements in each row of the correction matrix is ​​greater than zero.

8. The medical image processing device according to claim 5, wherein the sum of the matrix elements in each row of the correction matrix is ​​less than zero.

9. A medical image processing device as described in claim 1, wherein the imaging element captures each light beam obtained by dispersing light from the object of observation by a spectroscopic element, and the correction coefficient is set based on the spectral characteristics of the fluorescence from the object of observation and the spectral characteristics of the spectroscopic element.

10. A medical image processing device according to claim 1, wherein the correction coefficient is set based on the spectral characteristics of the fluorescence of the object of observation and the spectral characteristics of the unnecessary light.

11. The medical image processing device of claim 9, further comprising a spectral sensitivity correction unit that performs spectral sensitivity correction processing on the first pixel signal and the second pixel signal based on the spectral characteristics of the spectroscopic element, and the signal correction unit generates the corrected pixel signal using the first pixel signal and the second pixel signal after the spectral sensitivity correction processing has been performed by the spectral sensitivity correction unit.

12. The medical image processing device according to claim 1, wherein the first pixel signal and the second pixel signal are acquired from the same imaging element.

13. The medical image processing device according to claim 1, wherein a plurality of the imaging elements are provided, and the first pixel signal and the second pixel signal are acquired from different imaging elements.

14. A medical image processing device according to claim 1, wherein the fluorescence of the object is generated from a drug or fluorescent dye applied to the object, or from a fluorescent substance derived from the object.

15. The medical image processing device according to claim 1, wherein the member forming the observation optical path that generates the autofluorescence is an optical fiber, a lens, glass, a bonding material, or a filter.

16. The medical image processing device according to claim 1, wherein the corrected pixel signal is a signal in which a signal value based on the unnecessary light is reduced.

17. A medical observation system comprising: a light source device including a first light source that emits first light including narrowband light that excites a substance contained in an observation object; an imaging device having an imaging element that captures second light, which is return light of the first light from the observation object; and a medical image processing device having an image processing unit that processes pixel signals corresponding to pixels of the imaging element, wherein the pixel signals include a first pixel signal having an unwanted light component including autofluorescence generated from a member that forms the observation optical path by the first light when the first light emitted from the light source device propagates through the observation optical path, and an observation object fluorescence component emitted from a substance contained in the observation object that is excited by the first light, and a second pixel signal having at least the unwanted light component, and the image processing unit comprises a signal correction unit that generates a corrected pixel signal based on a correction coefficient set based on the spectral characteristics of the observation object fluorescence, the first pixel signal, and the second pixel signal.

18. The medical observation system according to claim 17, wherein the first light source is composed of one or more light sources.

19. The medical observation system according to claim 17, wherein the first light source is an LED or a semiconductor laser.

20. The medical observation system according to claim 17, wherein the first light is broadband light or narrowband light.

Images