Medical control device, medical control method, and medical observation system

Abstract

To generate an image suitable for observation.SOLUTION: A medical control device 9 includes: a driving mode switch 94 configured to switch a driving mode of a rolling shutter type image sensor 521 in which multiple pixels are two-dimensionally arrayed in units of horizontal lines; and a dimming controller 94 configured to control a light emitting element 31 configured to emit light according to a supplied current. The dimming controller 94 switches control of the light emitting element 31 according to the driving mode.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a medical control device and a medical observation system. [Background technology]

[0002] BACKGROUND ART Conventionally, there is known a medical observation system that uses an imaging element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) to capture an image of an observation target, such as the inside of a living body, and observes the observation target (see, for example, Patent Document 1). In the medical observation system described in Patent Document 1, the control of the light emitting elements is switched depending on the type of the imaging element, such as CCD or CMOS. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-60860 Summary of the Invention [Problem to be solved by the invention]

[0004] When a CMOS image sensor is used, changing the drive mode of the image sensor also changes the all-line exposure period during which all horizontal lines in the effective pixel area of ​​the image sensor are simultaneously exposed, and the readout period during which charges accumulated in multiple pixels of the image sensor are read out. If the light-emitting elements are controlled in the same way in all drive modes, stripes due to uneven exposure may appear in the captured image. Therefore, there is a demand for a technology that can suppress the occurrence of stripes and generate an image suitable for observation even when the drive mode of the imaging element is changed.

[0005] The present disclosure has been made in view of the above, and aims to provide a medical control device and a medical observation system that are capable of generating images suitable for observation. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the objectives, the medical control device of the present disclosure includes a drive mode switching unit that switches the drive mode of a rolling shutter type image sensor in which multiple pixels are arranged two-dimensionally in horizontal line units, and a dimming control unit that controls a light-emitting element that emits light in accordance with a supplied current, and the dimming control unit switches control of the light-emitting element in accordance with the drive mode.

[0007] Furthermore, the medical observation system according to the present disclosure comprises an imaging device including a rolling shutter type imaging element in which a plurality of pixels are arranged two-dimensionally in horizontal line units, a light source device including a light emitting element that emits light in response to a supplied current, and a medical control device that controls the operation of the imaging device and the light source device, wherein the medical control device comprises a drive mode switching unit that switches the drive mode of the imaging element and a dimming control unit that controls the light emitting element, and the dimming control unit switches control of the light emitting element in response to the drive mode. [Effects of the Invention]

[0008] The medical control device and medical observation system according to the present disclosure can generate images suitable for observation. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing the configuration of a medical observation system according to the first embodiment. [Figure 2] FIG. 2 is a block diagram showing the configuration of the camera head and the control device. [Figure 3] FIG. 3 is a diagram illustrating dimming control in the first driving mode. [Figure 4] FIG. 4 is a diagram illustrating dimming control in the first driving mode. [Figure 5] FIG. 5 is a diagram illustrating dimming control in the second driving mode. [Figure 6] FIG. 6 is a diagram illustrating dimming control in the third driving mode. [Figure 7] FIG. 7 is a diagram showing the configuration of a medical observation system according to the second embodiment. [Figure 8] FIG. 8 is a diagram illustrating the function of the control unit (drive mode switching unit and light adjustment control unit) in the second observation mode. DETAILED DESCRIPTION OF THE INVENTION

[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 drawings, the same parts are denoted by the same reference numerals.

[0011] (Embodiment 1) [General configuration of medical observation system] FIG. 1 is a diagram showing the configuration of a medical observation system 1 according to the first embodiment. The medical observation system 1 is a system used in the medical field for capturing (observing) images of the inside of a living body (observation target) as a subject. As shown in Fig. 1, the 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 the first embodiment, the insertion section 2 is configured as a rigid endoscope. That is, the insertion section 2 has an elongated shape that is entirely rigid or has a soft portion and a rigid portion, and is inserted into a living body. The insertion section 2 includes an optical system configured using one or more lenses that collects light from a subject.

[0013] The light source device 3 is connected to one end of the light guide 4, and supplies light to be irradiated into the living body to the one end of the light guide 4 under the control of the control device 9. As shown in FIG. 1, the light source device 3 includes a first light source 31. The first light source 31 corresponds to the light emitting element and the first light emitting element according to the present disclosure. The first light source 31 emits (emits) normal light in the visible wavelength band (first wavelength band) in response to a supplied current. In the first embodiment, the first light source 31 is configured by an LED (Light Emitting Diode) that emits white light. In the first embodiment, the light source device 3 is configured as a separate unit from the control device 9, but the present invention is not limited to this, and the light source device 3 may be configured to be provided inside the control device 9.

[0014] One end of the light guide 4 is detachably connected to the light source device 3, and the other end is detachably connected to the insertion portion 2. The light guide 4 transmits light (normal light) supplied from the light source device 3 from one end to the other end, and supplies it to the insertion portion 2. The normal light that is irradiated into the living body and passes through the living body (normal light reflected within the living body) is collected by an optical system in the insertion portion 2.

[0015] The camera head 5 corresponds to the imaging device according to the present disclosure. The camera head 5 is detachably connected to the base end (eyepiece 21 (FIG. 1)) of the insertion section 2. Under the control of the control device 9, the camera head 5 captures light collected by the insertion section 2 to generate a captured image. The detailed configuration of the camera head 5 will be explained later in the section "Configuration of the Camera Head."

[0016] One end of the first transmission cable 6 is detachably connected to the control device 9 via a connector CN1 (FIG. 1), and the other end is detachably connected to the camera head 5 via a connector CN2 (FIG. 1). The first transmission cable 6 transmits captured images and the like output from the camera head 5 to the control device 9, and also transmits control signals, synchronization signals, clocks, power, and the like output from the control device 9 to the camera head 5. The captured images and the like may be transmitted as optical signals or electrical signals from the camera head 5 to the control device 9 via the first transmission cable 6. 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.

[0017] The display device 7 is configured with a display using liquid crystal or organic EL (Electro Luminescence) or the like, and displays an image based on a video signal from the control device 9 under the control of the control device 9. One end of the second transmission cable 8 is detachably connected to the display device 7, and the other end 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.

[0018] The control device 9 corresponds to the medical control device according to the present disclosure. The control device 9 is configured with a CPU (Central Processing Unit), an FPGA (Field-Programmable Gate Array), etc., and controls the overall 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 explained later in the section "Configuration of the Control Device." One end of the third transmission cable 10 is detachably connected to the light source device 3, and the other end 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.

[0019] [Camera head configuration] Next, the configuration of the camera head 5 will be described. FIG. 2 is a block diagram showing the configuration of the camera head 5 and the control device 9. As shown in FIG. As shown in FIG. 2, the camera head 5 includes a lens unit 51, an imaging unit 52, and a communication unit 53. The lens unit 51 is configured using one or more lenses, and forms an image on the imaging surface of the imaging unit 52 (image sensor 521) of the light (normal light) collected by the insertion portion 2. For ease of explanation, hereinafter, the normal light (white light) directed from the lens unit 51 to the image sensor 521 will be referred to as a subject image.

[0020] The imaging unit 52 captures images of the inside of a living body under the control of the control device 9. The imaging unit 52 includes an imaging element 521 and a signal processing unit 522, as shown in FIG. The image sensor 521 receives a subject image and converts it into an electrical signal (analog signal). In the first embodiment, the image sensor 521 is configured with a CMOS, which is a rolling shutter type image sensor in which a plurality of pixels are two-dimensionally arranged in horizontal line units. Here, although specific illustrations are omitted, the image sensor 521 is composed of an invalid area that is not electrically guaranteed, an optical black area (OB area), and an effective pixel area that converts the subject image formed by the lens unit 51 into an image signal and outputs it. In the following, for convenience of explanation, a captured image generated by capturing an object image (in normal light) by the image sensor 521 will be referred to as a normal light image. The signal processing unit 522 performs signal processing on the normal light image generated by the image sensor 521 as an analog signal, and outputs the normal light image as a digital signal.

[0021] The communication unit 53 functions as a transmitter that transmits the normal light image output from the imaging unit 52 to the control device 9 via the first transmission cable 6. The communication unit 53 is configured, for example, with a high-speed serial interface that communicates the normal light image with the control device 9 via the first transmission cable 6 at a transmission rate of 1 Gbps or more.

[0022] [Configuration of the control device] Next, the configuration of the control device 9 will be described with reference to FIG. As shown in FIG. 2, the control device 9 includes a communication unit 91, a memory 92, an observation image generation unit 93, a control unit 94, an input unit 95, an output unit 96, and a storage unit 97. The communication unit 91 functions as a receiver that receives the normal light image output from the camera head 5 (communication unit 53) via the first transmission cable 6. This communication unit 91 is configured, for example, with a high-speed serial interface that communicates the normal light image with the communication unit 53 at a transmission rate of 1 Gbps or more. The memory 92 is configured, for example, with a DRAM (Dynamic Random Access Memory), etc. This memory 92 is capable of temporarily storing multiple frames of normal light images sequentially output from the camera head 5 (communication unit 53).

[0023] Under the control of the control unit 94, the observation image generation unit 93 processes the normal light images sequentially output from the camera head 5 (communication unit 53) and received by the communication unit 91. As shown in FIG. 2 , the observation image generation unit 93 includes a memory controller 931, a normal light image processing unit 932, and a display control unit 933.

[0024] The memory controller 931 controls the writing and reading of normal light images to the memory 92. More specifically, the memory controller 931 sequentially writes the normal light images that are sequentially output from the camera head 5 (communication unit 53) and received by the communication unit 91 into the memory 92. The memory controller 931 also reads the normal light images from the memory 92 at specific times, and inputs the read normal light images to the normal light image processing unit 932.

[0025] The normal light image processing unit 932 performs a first image processing on the input normal light image. Examples of the first image processing include optical black subtraction processing, white balance adjustment processing, demosaic processing, color correction matrix processing, gamma correction processing, and YC processing that converts RGB signals (normal light images) into luminance color difference signals (Y, Cb / Cr signals).

[0026] Under the control of the control unit 94, the display control unit 933 generates a video signal for displaying the normal light image after the first image processing has been performed by the normal light image processing unit 932. Then, the display control unit 933 outputs the video signal to the display device 7 via the second transmission cable 8.

[0027] The control unit 94 is configured using, for example, a CPU, an FPGA, etc., 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, by outputting control signals via the first to third transmission cables 6, 8, and 10. This control unit 94 has the functions of a drive mode switching unit and a dimming control unit according to the present disclosure. The functions of the drive mode switching unit and the dimming control unit will be described later in the section "Operation of the Control Device."

[0028] The input unit 95 is configured using operation devices such as a mouse, a keyboard, and a touch panel, and receives user operations by a user such as a doctor. The input unit 95 then outputs an operation signal to the control unit 94 in response to the user operation. The output unit 96 is configured using a speaker, a printer, etc., and outputs various information. The storage unit 97 stores programs executed by the control unit 94, information necessary for the processing of the control unit 94, and the like.

[0029] [Control device operation] Next, the operation of the control device 9 will be described. For the sake of convenience, the following description will mainly focus on the function of the drive mode switching section in the control section 94 and the function of the dimming control section in the control section 94. The control unit 94 controls the image pickup element 521 as follows. Specifically, the control unit 94 performs exposure control using a so-called rolling shutter method, in which exposure of the image sensor 521 is started sequentially for each horizontal line during one field period, and reading is performed sequentially for each horizontal line after a predetermined period (so-called shutter speed) has elapsed since the start of exposure. Then, the control unit 94 (drive mode switching unit) switches the control pattern (drive mode) of the exposure control described above. In the first embodiment, the control unit 94 (drive mode switching unit) switches the drive mode to one of the first to third drive modes in response to a user operation on the input unit 95 by a user such as an operator, for example. The first to third driving modes will be described in detail later.

[0030] Furthermore, the control unit 94 (dimming control unit) executes dimming control to adjust the normal light image to a reference brightness based on the brightness (average luminance value, etc.) of a specific region (detection region) in the normal light image. In the first embodiment, the control unit 94 is capable of executing the following dimming controls: first control to adjust the supply time of current supplied to the first light source 31 (current application pulse width); second control to adjust the value of the current supplied to the first light source 31; and third control to adjust the electronic shutter of the image sensor 521. The control unit 94 switches the dimming control depending on the drive mode of the image sensor 521. The dimming control in the first drive mode, the dimming control in the second drive mode, and the dimming control in the third drive mode will be described below in this order.

[0031] [Dimming control in the first driving mode] 3 and 4 are diagrams illustrating the dimming control in the first drive mode. Specifically, FIGS. 3(a) and 4(a) are diagrams illustrating the exposure timing of the image sensor 521, with the vertical axis representing the horizontal line of the image sensor 521 (the top row represents the highest horizontal line (first horizontal line) and the bottom row represents the lowest horizontal line (last line)), and the horizontal axis representing time. The parallelogram area is the area that contributes to the generation of one field of a normal light image. FIGS. 3(b) and 4(b) are diagrams illustrating the dimming control, with the vertical axis representing the current value supplied to the first light source 31 and the horizontal axis representing time (the supply time of the current supplied to the first light source 31). Note that in FIGS. 3(b) and 4(b), the third control (electronic shutter adjustment) of the dimming control is represented by diagonal lines. FIG. 3 shows a case where the brightness of the normal light image is increased by light adjustment control, and FIG. 4 shows a case where the brightness of the normal light image is decreased by light adjustment control.

[0032] 3(a) and 4(a), the first driving mode is a driving mode in which the readout period TR for reading out charges accumulated in multiple pixels of the image sensor 521 is long and an all-line exposure period cannot be secured. Here, the all-line exposure period is a period during which all horizontal lines in the effective pixel area of ​​the image sensor 521 are exposed simultaneously.

[0033] When the drive mode of the image sensor 521 is the first drive mode, the control unit 94 (light adjustment control unit) executes the light adjustment control described below. First, let us consider a case where the brightness of a normal light image is increased by light adjustment control. In this case, as shown in Figure 3(b), the control unit 94 (dimming control unit) fixes the supply time of the current supplied to the first light source 31 for each field (supply time: 1 field), fixes the electronic shutter of the image sensor 521 (in the case of NTSC system: 1 / 60 [second]), and increases the current value supplied to the first light source 31 using the second control, thereby increasing the brightness of the normal light image.

[0034] Next, a case will be considered in which the brightness of the normal light image is gradually decreased by light adjustment control. In this case, as shown in Figure 4(b), the control unit 94 (dimming control unit) fixes the supply time of the current supplied to the first light source 31 for each field (the supply time: 1 field), and while fixing the current value supplied to the first light source 31 at the minimum rated current value Imin, adjusts the electronic shutter using the third control to darken the brightness of the normal light image. In Fig. 4(b), the hatched parallelogram area indicates the area where the electric charge is swept away by the electronic shutter, and the open parallelogram area indicates the area where the effective exposure period is. As described above, when the drive mode of the imaging element 521 is the first drive mode, the control unit 94 (light adjustment control unit) executes only the second and third controls out of the first to third controls as light adjustment controls.

[0035] [Dimming control in the second driving mode] Fig. 5 is a diagram illustrating dimming control in the second driving mode, specifically, Fig. 5 is a diagram corresponding to Figs. Here, as shown by the dashed line in FIG. 5(a), it is assumed that the readout period is long and an exposure period for all lines cannot be secured. The second driving mode is a driving mode called long-term exposure or long-second exposure in which a plurality of fields (two in the example of FIG. 5(a)) are treated as one pseudo-field. That is, when the driving mode of the image sensor 521 is switched from the driving mode shown by the dashed line in FIG. 5(a) to the second driving mode, a pseudo-all-line exposure period TE is generated for each pseudo-grouped field, as shown by the solid line in FIG. 5(a).

[0036] When the drive mode of the image sensor 521 is the second drive mode, the control unit 94 (light adjustment control unit) executes the light adjustment control described below. 5(b), the control unit 94 (dimming control unit) sets the current value supplied to the first light source 31 for the entire all-line exposure period TE generated pseudo by the second driving mode to the maximum rated current value Imax while fixing the electronic shutter of the image sensor 521 for each pseudo-grouped field.The control unit 94 (dimming control unit) then adjusts the brightness of the normal light image by adjusting the supply time of the current supplied to the first light source 31 using the first control during the readout period TR generated pseudo by the second driving mode for each pseudo-grouped field. Here, the amount of light emitted by the first light source 31 during the all-line exposure period TE (value of current supplied to the first light source 31×time for which the current is supplied) is higher than the amount of light emitted by the first light source 31 during the readout period TR. As described above, when the drive mode of the imaging element 521 is the second drive mode, the control unit 94 (light adjustment control unit) executes only the first and second controls out of the first to third controls as light adjustment controls.

[0037] [Dimming control in the third driving mode] FIG. 6 is a diagram illustrating dimming control in the third driving mode. Specifically, FIG. 6 corresponds to FIGS. 3 to 5. In FIG. 6(a), Here, as shown by the dashed line in FIG. 6(a), it is assumed that the readout period is long and an exposure period for all lines cannot be secured. The third driving mode is a driving mode that includes binning. The binning is not limited to adding adjacent pixels together, but also includes thinning out some pixels while reading them out. That is, when the driving mode of the image sensor 521 is switched from the driving mode indicated by the dashed line in FIG. 6A to the third driving mode, the readout speed can be increased, as indicated by the solid line in FIG. 6A, and a pseudo all-line exposure period TE is generated for each field.

[0038] When the drive mode of the image sensor 521 is the third drive mode, the control unit 94 (light adjustment control unit) executes the light adjustment control described below. 6(b), the control unit 94 (dimming control unit) sets the current value supplied to the first light source 31 for the entire all-line exposure period TE generated in a pseudo manner by the third driving mode to the maximum rated current value Imax for each field while fixing the electronic shutter of the image sensor 521. Then, the control unit 94 (dimming control unit) adjusts the supply time of the current supplied to the first light source 31 by the first control in the readout period TR generated in a pseudo manner by the third driving mode for each field, thereby adjusting the brightness of the normal light image. Here, the amount of light emitted by the first light source 31 during the all-line exposure period TE (value of current supplied to the first light source 31×time for which the current is supplied) is higher than the amount of light emitted by the first light source 31 during the readout period TR. As described above, when the drive mode of the imaging element 521 is the third drive mode, the control unit 94 (light adjustment control unit) executes only the first and second controls out of the first to third controls as light adjustment controls.

[0039] According to the first embodiment described above, the following effects are achieved. The control device 9 according to the first embodiment switches between the first to third controls (light adjustment controls) depending on the drive mode of the imaging element 521. Specifically, when the drive mode of the imaging element 521 is the first drive mode, the control device 9 executes only the second and third controls out of the first to third controls as the light adjustment control. Here, when the brightness of the normal light image is increased, a second control is executed. That is, the difference in brightness between the upper and lower positions in the normal light image increases in accordance with the increase in the amount of light emitted between adjacent fields (the value of the current supplied to the first light source 31 × the time for which the current is supplied). In other words, the difference in brightness in the normal light image can be suppressed by reducing the increase in the amount of light emitted between adjacent fields. Furthermore, when the brightness of the normal light image is decreased, the amount of light emitted by the first light source 31 is fixed, while the electronic shutter of the image sensor 521 is adjusted. That is, the electronic shutter sweeps out charge for all lines of the image sensor 521 at the same time, so no difference in brightness occurs in the normal light image.

[0040] Furthermore, when the drive mode of the imaging element 521 is the second or third drive mode, the control device 9 executes only the first or second control out of the first to third controls as the light adjustment control. Here, the control device 9 sets the current value supplied to the first light source 31 to the maximum rated current value Imax throughout the entire pseudo-generated all-line exposure period TE, and executes the first control during the pseudo-generated readout period TR. That is, by causing the first light source 31 to emit full light during the all-line exposure period TE, it is possible to make the luminance difference in the normal light image due to the first control during the readout period TR less noticeable. From the above, even when the drive mode of the image sensor 521 is changed, it is possible to suppress the brightness difference in the normal light image and generate a normal light image suitable for observation.

[0041] (Embodiment 2) Next, a second embodiment will be described. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted or simplified. FIG. 7 is a diagram showing the configuration of a medical observation system 1A according to the second embodiment. The medical observation system 1A according to the second embodiment is capable of performing a first observation mode and a second observation mode. The first observation mode is an observation mode in which the inside of a living body illuminated with normal light is imaged by the image sensor 521 to obtain a normal light image (first captured image), similar to the medical observation system 1 of the first embodiment described above. The second observation mode is an observation mode in which a normal light image is obtained and a second captured image (hereinafter referred to as a fluorescent image) is obtained by capturing an image of the inside of a living body illuminated with light of a second wavelength band, which is a different wavelength band from the normal light, using the imaging element 521.

[0042] 7, in the medical observation system 1A, the configurations of the light source device 3, camera head 5, and control device 9 are changed from those of the medical observation system 1 described in the above-mentioned embodiment 1. For ease of explanation, the light source device 3, camera head 5, and control device 9 according to embodiment 2 will be referred to as the light source device 3A, camera head 5A, and control device 9A below.

[0043] As shown in FIG. 7, in the light source device 3A, a second light source 32 is added to the light source device 3 described in the first embodiment above. The second light source 32 corresponds to the light-emitting element and second light-emitting element according to the present disclosure. The second light source 32 is configured with a semiconductor laser or an LED that emits near-infrared excitation light in a near-infrared wavelength band (e.g., a wavelength band of approximately 750 nm to 800 nm), which is a second wavelength band. The near-infrared excitation light is excitation light that excites fluorescent substances such as indocyanine green. When excited by the near-infrared excitation light, the fluorescent substance such as indocyanine green emits fluorescence in a wavelength band outside the visible range (e.g., a wavelength band around 830 nm) that has a center wavelength longer than the center wavelength of the wavelength band of the near-infrared excitation light. The wavelength band of the near-infrared excitation light and the wavelength band of the fluorescence may be set to partially overlap or not overlap at all.

[0044] In the light source device 3A according to the second embodiment, in the first observation mode, only the first light source 31 is driven under the control of the control device 9A, as shown in Figures 3 to 6 in the first embodiment described above. In the light source device 3A according to the second embodiment, in the second observation mode, the first light source 31 is driven during the first period of alternately repeated first and second periods under the control of the control device 9A. That is, during the first period, the light source device 3 emits normal light (white light). In the light source device 3A, the second light source 32 is driven during the second period under the control of the control device 9A. That is, during the second period, the light source device 3A emits near-infrared excitation light. When the near-infrared excitation light is irradiated into a living body via the light guide 4 and the insertion section 2, the near-infrared excitation light transmitted through the living body (near-infrared excitation light reflected within the living body) and the fluorescence emitted from the fluorescent substance, which is excited by the near-infrared excitation light and accumulates in a lesion within the living body, are collected by the optical system in the insertion section 2.

[0045] As shown in FIG. 7, in the camera head 5A, an excitation light cut filter 523 is added to the imaging section 52 in comparison with the camera head 5 described in the first embodiment. The excitation light cut filter 523 is provided between the lens unit 51 and the image sensor 521, and is configured as a band-stop filter that removes a specific wavelength band. For ease of explanation, hereinafter, the wavelength band that is cut (removed) by the excitation light cut filter 523 will be referred to as a cut band, the wavelength band that is shorter in wavelength than the cut band and that passes through the excitation light cut filter 523 will be referred to as a short-wave transmission region, and the wavelength band that is longer in wavelength than the cut band and that passes through the excitation light cut filter 523 will be referred to as a long-wave transmission region. Here, the cutoff band includes at least a part of the wavelength band of near-infrared excitation light. In the first embodiment, the cutoff band includes the entire wavelength band of near-infrared excitation light. The long-wave transmission band includes the wavelength band of fluorescent light. Furthermore, the short-wave transmission region includes the wavelength band of normal light (white light).

[0046] That is, the excitation light cut filter 523 transmits the subject image (normal light) traveling from the lens unit 51 to the image sensor 521. On the other hand, with regard to near-infrared excitation light and fluorescence traveling from the lens unit 51 to the image sensor 521, the excitation light cut filter 523 removes the near-infrared excitation light and transmits the fluorescence. For ease of explanation, the fluorescence traveling through the excitation light cut filter 523 and traveling toward the image sensor 521 will be referred to as a fluorescent image below. The image sensor 521 then captures an image of the subject to generate a normal light image, and captures a fluorescent image to generate a fluorescent light image.

[0047] As shown in FIG. 7, the control device 9A is configured such that a fluorescence image processing unit 934 and a superimposed image generation unit 935 are added to the observation image generation unit 93 in comparison with the control device 9A described in the first embodiment above. Here, in the first observation mode, the memory controller 931 operates in the same manner as described in the first embodiment. Moreover, the memory controller 931 operates as follows in the second observation mode. The memory controller 931 sequentially writes the captured images (normal light images and fluorescent images) that are sequentially output from the camera head 5A (communication unit 53) and received by the communication unit 91 into the memory 92. The memory controller 931 also reads out the normal light images from the memory 92 at specific timing, and inputs the read-out normal light images to the normal light image processing unit 932. The memory controller 931 also reads out the fluorescent images from the memory 92 at specific timing, and inputs the read-out fluorescent images to the fluorescent image processing unit 934.

[0048] In the second observation mode, the fluorescence image processing unit 934 performs second image processing on the input fluorescence image, which is different from the first image processing performed by the normal light image processing unit 932. As with the first image processing, examples of the second image processing include optical black subtraction processing, white balance adjustment processing, demosaic processing, color correction matrix processing, gamma correction processing, and YC processing that converts RGB signals (fluorescence images) into luminance color difference signals (Y, Cb / Cr signals).

[0049] In the second observation mode, the superimposed image generation unit 935 performs superimposition processing to generate a superimposed image by superimposing the fluorescent image after the second image processing has been performed by the fluorescent image processing unit 934 on the normal light image after the first image processing has been performed by the normal light image processing unit 932. Here, examples of the superimposition process include the first and second superimposition processes shown below. Note that, hereinafter, a region in a fluorescence image that is composed of pixels whose brightness value is equal to or greater than a specific threshold value is referred to as a fluorescent region. The first superimposition process is a process of replacing an area in the normal light image that has the same pixel positions as the fluorescent area with an image of the fluorescent area in the fluorescent image. The second superimposition process is a process (so-called alpha blending process) that changes the brightness of the color indicating fluorescence applied to each pixel in the area that is at the same pixel position as the fluorescent area in the normal light image, depending on the brightness value of each pixel position in the fluorescent area of ​​the fluorescent image.

[0050] Then, in the first observation mode, the display control unit 933 generates a video signal for displaying the normal light image after the first image processing has been performed by the normal light image processing unit 932, as described in the above-mentioned embodiment 1. Furthermore, the display control unit 933 generates a video signal for displaying the superimposed image generated by the superimposed image generation unit 935 in the second observation mode.

[0051] Furthermore, the control unit 94 according to the second embodiment has the functions of an observation mode switching unit in addition to the functions of the drive mode switching unit and the light adjustment control unit according to the present disclosure.

[0052] Next, the operation of the above-mentioned control device 9A will be described. For convenience of explanation, the following mainly describes the function of the drive mode switching unit in the control unit 94, the function of the light adjustment control unit in the control unit 94, and the function of the observation mode switching unit in the control unit 94. The control unit 94 (observation mode switching unit) switches the observation mode to either the first or second observation mode in response to a user operation on the input unit 95 by a user such as an operator, for example. In the first observation mode, the control unit 94 (drive mode switching unit and dimming control unit) operates in the same manner as the operations described in "dimming control in the first drive mode," "dimming control in the second drive mode," and "dimming control in the third drive mode" in the above-mentioned embodiment 1. Therefore, only the functions of the control unit 94 (drive mode switching unit and dimming control unit) in the second observation mode will be described below.

[0053] Fig. 8 is a diagram illustrating the function of the control unit 94 (drive mode switching unit and dimming control unit) in the second observation mode. Specifically, Fig. 8 corresponds to Figs. 3 to 6. Here, the dashed dotted line shown in Fig. 8(a) indicates the drive mode before switching. Furthermore, the solid line shown in Fig. 8(b) indicates the drive mode after switching (the second drive mode). Here, as shown by the dashed line in FIG. 8(a), it is assumed that the readout period is long and the all-line exposure period TE0 is short. In this case, when the observation mode is switched to the second observation mode, the control unit 94 (drive mode switching unit) switches the drive mode of the image sensor 521 to the second drive mode. Then, when the drive mode of the image sensor 521 is switched from the drive mode indicated by the dashed line in Fig. 8(a) to the second drive mode, a pseudo all-line exposure period TE1 that is longer than the all-line exposure period TE0 is generated for each pseudo-grouped field, as indicated by the solid line in Fig. 8(a).

[0054] Thereafter, the control unit 94 (light control unit) alternately controls the emission of light from the first light source 31 and the second light source 32 for each pseudo-grouped field, as shown in FIG. 8(b). In FIG. 8(a), the solid-line parallelogram region of each pseudo-grouped field that contributes to the generation of a normal light image is referred to as a WLI (White Light Imaging) field, and the solid-line parallelogram region that contributes to the generation of a fluorescent image is referred to as an IR (Infra-Red) field. In FIG. 8(b), the normal light emission is referred to as WLI, and the excitation light emission is referred to as IR.

[0055] Specifically, the control unit 94 (dimming control unit) causes the first light source 31 to emit light for the entire first period TE11' within the all-line exposure period TE11, which is generated pseudo-by the second drive mode, in the WLI field of the alternating WLI and IR fields. Note that FIG. 8(b) illustrates a case in which the current supply time is maximized and the current value is set to the maximum rated current value Imax. Therefore, the first period TE11' is the same duration as the all-line exposure period TE11. Meanwhile, the control unit 94 (dimming control unit) causes the second light source 32 to emit light for the entire second period TE12' within the all-line exposure period TE12, which is generated pseudo-by the second drive mode, in the IR field of the alternating WLI and IR fields. Note that FIG. 8(b) illustrates a case in which the current supply time is maximized and the current value is set to the maximum rated current value Imax. Therefore, the second period TE12' is the same duration as the all-line exposure period TE12.

[0056] According to the second embodiment described above, in addition to the same effects as those of the first embodiment, the following effects are achieved. When the observation mode is the second observation mode, the control device 9A according to the second embodiment switches the drive mode of the image sensor 521 to the second drive mode. Furthermore, the control device 9A causes the first and second light sources 31 and 32 to emit light for each all-line exposure period TE that is pseudo-generated by the second drive mode. That is, while a configuration in which the first and second light sources 31, 32 are each made to emit light for each all-line exposure period TE0 results in insufficient brightness for the normal light image and the fluorescence image, by artificially generating an all-line exposure period TE1 that is longer than the all-line exposure period TE0 and making the first and second light sources 31, 32 each emit light for each all-line exposure period TE1, it is possible to ensure sufficient brightness for the normal light image and the fluorescence image, thereby generating images suitable for observation.

[0057] (Other embodiments) Although the embodiments for carrying out the present disclosure have been described above, the present disclosure should not be limited to only the first and second embodiments described above. In the above-described first and second embodiments, the function of the dimming control unit according to the present disclosure includes a function for adjusting the electronic shutter of the image sensor 521, but this is not limited thereto, and the function may be to control only the first light source 31 (second light source 32). In the first and second embodiments described above, the number of drive modes of the imaging element 521 is three, but this is not limitative and the number may be only two, or may be four or more.

[0058] In the first and second embodiments described above, the light source control device according to the present disclosure is installed in a medical observation system 1 in which the insertion section 2 is configured as a rigid endoscope, but this is not limiting. For example, the light source control device according to the present disclosure may be installed in a medical observation system in which the insertion section 2 is configured as a flexible endoscope. Furthermore, the light source control device according to the present disclosure may be installed in a medical observation system such as a surgical microscope (see, for example, JP 2016-42981 A) that magnifies and observes a predetermined field of view inside a subject (inside a living body) or on the surface of a subject (surface of a living body). In the first and second embodiments described above, a part of the configuration of the camera head 5 and a part of the configuration of the control device 9 may be provided in, for example, the connector CN1 and the connector CN2.

[0059] Incidentally, photodynamic diagnosis (PDD) has been known as one of the cancer diagnostic methods for detecting cancer cells. In photodynamic diagnosis, a photosensitizer such as 5-aminolevulinic acid (hereinafter referred to as 5-ALA) is used. 5-ALA is a natural amino acid originally found in the living organisms of animals and plants. After administration, 5-ALA is taken up into cells and biosynthesized into protoporphyrin in mitochondria. This protoporphyrin then accumulates in excess in cancer cells. Furthermore, the protoporphyrin that accumulates in excess in cancer cells is photoactive. Therefore, when excited with excitation light (e.g., blue visible light in the wavelength range of 375 nm to 445 nm), the protoporphyrin emits fluorescence (e.g., red fluorescence in the wavelength range of 600 nm to 740 nm). This cancer diagnostic method, which uses a photosensitizer to cause cancer cells to emit fluorescence, is called photodynamic diagnosis. In the second embodiment described above, the first light source 31 may be configured with an LED that emits white light, and the second light source 32 may be configured with a semiconductor laser that emits excitation light that excites protoporphyrin (for example, blue visible light in the wavelength band of 375 nm to 445 nm). Even in this configuration, the same effects as those of the second embodiment described above can be achieved.

[0060] In the above-described second embodiment, the first and second periods are set to alternately repeat in the second observation mode, but this is not limited thereto. Alternatively, at least one of the first and second periods may be consecutive, and the frequency ratio between the first and second periods may be a ratio other than 1:1.

[0061] The following configurations also fall within the technical scope of the present disclosure. (1) A driving mode switching unit that switches the driving mode of a rolling shutter type image sensor in which multiple pixels are arranged two-dimensionally in horizontal line units, and a dimming control unit that controls a light-emitting element that emits light in accordance with a supplied current, the dimming control unit switching the control of the light-emitting element in accordance with the driving mode. (2) The dimming control unit is capable of executing dimming control including a first control for adjusting the supply time of the current supplied to the light-emitting element, a second control for adjusting the current value supplied to the light-emitting element, and a third control for adjusting the electronic shutter of the imaging element, and switches the dimming control depending on the drive mode. (3) The medical control device described in (2) above, wherein the dimming control unit executes only the second control and the third control among the first control, the second control, and the third control when the driving mode is a first driving mode in which there is no full-line exposure period in which all horizontal lines of the effective pixel area of ​​the imaging element are exposed simultaneously. (4) The dimming control unit of the medical control device described in (2) or (3) executes only the first control and the second control among the first control, the second control, and the third control when the drive mode is a second drive mode of long exposure in which multiple fields are pseudo-as one field. (5) The medical control device described in (4) above, wherein when the driving mode is the second driving mode, the dimming control unit increases the light emission amount of the light-emitting element during a full line exposure period, which is a period pseudo-generated by the second driving mode and in which all lines of the effective pixel area of ​​the imaging element are exposed simultaneously, compared to other periods. (6) A medical control device described in any one of (2) to (5), wherein the dimming control unit executes only the first control and the second control among the first control, the second control, and the third control when the driving mode is a third driving mode including binning. (7) The medical control device described in (6) above, wherein when the driving mode is the third driving mode, the dimming control unit increases the light emission amount of the light-emitting element during a full line exposure period, which is a period pseudo-generated by the third driving mode and in which all lines of the effective pixel area of ​​the imaging element are exposed simultaneously, compared to other periods. (8) The light-emitting element includes a first light-emitting element that emits light in a first wavelength band and a second light-emitting element that emits light in a second wavelength band different from the first wavelength band, and the medical control device further includes an observation mode switching unit that switches the observation mode between a first observation mode and a second observation mode, the first observation mode being an observation mode in which an observation object irradiated with light in the first wavelength band is imaged by the image sensor to obtain a first image, and the second observation mode being an observation mode in which the first image is obtained and an observation object irradiated with light in the second wavelength band is imaged by the image sensor to obtain a second image. and when the observation mode is the second observation mode, the drive mode switching unit switches the drive mode to a second drive mode of long exposure in which a plurality of fields are treated as a single field, and when the drive mode is the second drive mode, the dimming control unit causes the first light-emitting element and the second light-emitting element to emit light for each full line exposure period, which is a period that is pseudo-generated by the second drive mode and in which all lines of an effective pixel area of ​​the imaging element are exposed simultaneously. (9) A medical observation system comprising an imaging device including a rolling shutter type imaging element in which multiple pixels are arranged two-dimensionally in horizontal line units, a light source device including a light-emitting element that emits light in accordance with a supplied current, and a medical control device that controls the operation of the imaging device and the light source device, wherein the medical control device comprises a drive mode switching unit that switches the drive mode of the imaging element and a dimming control unit that controls the light-emitting element, and the dimming control unit switches control of the light-emitting element in accordance with the drive mode. [Explanation of symbols]

[0062] 1,1A Medical Observation System 2 Insertion section 3,3A light source device 4 Light Guide 5,5A camera head 6. First Transmission Cable 7 Display device 8 Second Transmission Cable 9,9A Control device 10 Third Transmission Cable 21 Eyepiece 31 First Light Source 32 Second Light Source 51 Lens unit 52 Imaging unit 53 Communications Department 91 Communications Department 92 memory 93 Observation image generation unit 94 Control Unit 95 Input section 96 Output section 97 Memory section 521 Image sensor 522 Signal Processing Unit 523 Excitation light cut filter 931 Memory Controller 932 Normal light image processing section 933 Display control unit 934 Fluorescence Image Processing Unit 935 Superimposed Image Generation Unit CN1, CN2 connectors TE0,TE1,TE11,TE12 All line exposure period TE11´ 1st period TE12´ Second Period TR read period

Claims

1. a driving mode switching unit that switches driving modes of a rolling shutter imaging element in which a plurality of pixels are two-dimensionally arranged in horizontal line units; a light control unit that executes light control including a first control that adjusts a supply time of a current supplied to a light emitting element that emits light in accordance with the supplied current, a second control that adjusts a current value supplied to the light emitting element, and a third control that adjusts an electronic shutter of the image sensor; The light control unit When the driving mode is a first driving mode in which pixels in an area that contributes to image generation of the imaging element are read out in a first period that is shorter than the period for reading out all of the pixels by a method that includes binning, the medical control device executes at least one of the first control and the second control out of the first control, the second control, and the third control.

2. The drive mode switching unit The medical control device according to claim 1, wherein the driving mode is switched by changing the length of a full line exposure period in which all horizontal lines in an area contributing to image generation of the imaging element are simultaneously exposed, or a readout period in which exposed charges in the imaging element are read out.

3. The binning may include: The medical control device according to claim 1 , wherein the medical control device includes adding a plurality of pixels or thinning out some of the pixels.

4. The light control unit The medical control device according to claim 1 , wherein when the drive mode is the first drive mode, only the first control and the second control are executed.

5. The light control unit 2. The medical control device according to claim 1, wherein when the drive mode is the first drive mode, the electronic shutter of the image pickup device is fixed.

6. In the first driving mode, 2. The medical control device according to claim 1, wherein there is a full line exposure period in which all horizontal lines in an area of ​​the imaging element that contributes to image generation are exposed simultaneously.

7. The light control unit 7. The medical control device according to claim 6, wherein when the drive mode is the first drive mode, the current value supplied to the light emitting element is fixed to a specific current value during the all-line exposure period.

8. The specific current value is The medical control device according to claim 7, wherein the maximum current value is a maximum current value.

9. The light control unit The medical control device according to claim 1 , wherein when the drive mode is the first drive mode, the supply time of the current supplied to the light-emitting element is adjusted by the first control during the first period.

10. The light control unit 10. The medical control device according to claim 9, wherein, when the drive mode is the first drive mode, the first control and the second control cause the light emission amount of the light-emitting element during a full line exposure period in which all horizontal lines of an area contributing to image generation of the imaging element are simultaneously exposed to be higher than the light emission amount of the light-emitting element during the first period.

11. The light-emitting element is The medical control device according to claim 1, which emits light in the visible wavelength band.

12. The light in the visible wavelength range is 12. The medical control device of claim 11, wherein the light is white.

13. The first period of time comprises: The medical control device according to claim 1 , wherein the exposure period is shorter than the exposure period of the horizontal line.

14. The light control unit 2. The medical control device according to claim 1, wherein, when the drive mode is a second drive mode in which exposure is performed within one field and pixels in an area contributing to image generation of the imaging element are read out in a second period longer than the first period, at least one of the second control and the third control is executed among the first control, the second control, and the third control.

15. The one field is: The medical control device according to claim 14 , wherein the period is from the start of readout of the top horizontal line of the imaging element to the end of readout of the bottom horizontal line that contributes to generating the image.

16. The light control unit The medical control device according to claim 14 , wherein when the drive mode is the second drive mode, the supply time of the current supplied to the light emitting element is fixed to a specific supply time.

17. The specific supply time is 17. The medical control device of claim 16, wherein the period is one field.

18. The light control unit 15. The medical control device according to claim 14, wherein when the drive mode is the second drive mode, when the brightness of the generated image is increased, the effective exposure period by the electronic shutter of the image sensor is fixed to 1 / 60 [second] while the current value supplied to the light-emitting element is increased by the second control.

19. The light control unit 15. The medical control device according to claim 14, wherein when the driving mode is the second driving mode, when the brightness of the generated image is darkened, the current value supplied to the light-emitting element is fixed to a specific minimum current value, while the electronic shutter of the imaging element is adjusted by the third control.

20. In the second driving mode, The medical control device according to claim 14 , wherein there is no all-line exposure period in which all horizontal lines of the area of ​​the imaging element that contributes to image generation are exposed simultaneously.

21. The second period of time is 15. The medical control device of claim 14, wherein the effective exposure period of the horizontal line is equal to or longer than the effective exposure period of the horizontal line.

22. The light control unit 15. The medical control device according to claim 14, wherein, when the driving mode is a third driving mode in which exposure is performed for each field that is a pseudo-group of multiple fields of the one field of the second driving mode, at least one of the first control and the second control is executed among the first control, the second control, and the third control.

23. In the third driving mode, The medical control device according to claim 22, wherein pixels in an area of ​​the imaging element that contributes to image generation are read out during a third period that is shorter than the exposure period of the horizontal line.

24. The light control unit 2. The medical control device according to claim 1, wherein, when the driving mode is a third driving mode in which exposure is performed for each field that is a pseudo-group of multiple fields, at least one of the first control and the second control is executed among the first control, the second control, and the third control.

25. The light control unit The medical control device according to claim 24, wherein when the drive mode is the third drive mode, only the first control and the second control are executed.

26. The light control unit 25. The medical control device according to claim 24, wherein when the driving mode is the third driving mode, the electronic shutter of the image pickup device is fixed for each pseudo-grouped field.

27. In the third driving mode, 25. The medical control device of claim 24, wherein there is a full line exposure period in which all horizontal lines of the area of ​​the imaging element that contributes to image generation are exposed simultaneously.

28. The light control unit 28. The medical control device according to claim 27, wherein when the drive mode is the third drive mode, the current value supplied to the light-emitting element is fixed to a specific current value during the all-line exposure period.

29. The specific current value is 29. The medical control device of claim 28, wherein the maximum current value is a maximum current value.

30. The light control unit 25. The medical control device of claim 24, wherein when the driving mode is the third driving mode, the first control adjusts the supply time of current supplied to the light-emitting element during a third period in which pixels of an area contributing to image generation of the imaging element are read out for each pseudo-summarized field.

31. A medical control method executed by a medical control device, a driving mode switching step of switching a driving mode of a rolling shutter type image sensor in which a plurality of pixels are two-dimensionally arranged in units of horizontal lines; a light control step of executing light control including a first control for adjusting a supply time of a current supplied to a light emitting element that emits light in accordance with the supplied current, a second control for adjusting a current value supplied to the light emitting element, and a third control for adjusting an electronic shutter of the image sensor; In the dimming control step, A medical control method, wherein when the drive mode is a first drive mode in which pixels in an area that contributes to image generation of the imaging element are binned and read out in a first period that is shorter than the period for reading out all of the pixels, at least one of the first control and the second control is executed among the first control, the second control, and the third control.

32. an imaging device including a rolling shutter type imaging element in which a plurality of pixels are two-dimensionally arranged in horizontal line units; a light source device including a light emitting element that emits light in response to a supplied current; a medical control device that controls operations of the imaging device and the light source device, The medical control device includes: a drive mode switching unit that switches a drive mode of the image sensor; a light control unit that executes light control including first control for adjusting a supply time of a current supplied to the light emitting element, second control for adjusting a current value supplied to the light emitting element, and third control for adjusting an electronic shutter of the image sensor; The light control unit a medical observation system that executes at least one of the first control and the second control among the first control, the second control, and the third control when the drive mode is a first drive mode in which pixels in an area that contributes to image generation of the image sensor are read out in a first period that is shorter than a period for reading out all of the pixels by a method that includes binning the pixels;

33. The medical observation system includes:

33. The medical observation system according to claim 32, which is a medical observation system using a rigid endoscope, a flexible endoscope, or a microscope.

34. The light-emitting element is 33. The medical observation system of claim 32, wherein the light source is an LED.

35. A medical observation system as described in claim 32, further comprising an input unit configured to be able to input a user operation to switch the drive mode.

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