Medical imaging device and medical observation system

Abstract

To suppress an increase in circuit scale and power consumption.SOLUTION: A medical imaging device 5 includes: a plurality of imaging elements 531, 532 which acquire a subject image, and each of which outputs respective pixel signals; and a signal integration unit 535 which converts the pixel signal output from each of the plurality of imaging elements 531, 532 into a pixel signal corresponding to a specific transmission standard.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to medical imaging devices and medical observation systems. [Background technology]

[0002] Conventionally, there has been known a medical observation system that irradiates an observation target (a subject such as a human) with visible light such as white light or excitation light, which is narrow-band light, emitted from a light source device, and observes the observation target (see, for example, Patent Document 1). The medical observation system described in Patent Document 1 has a normal observation mode and a fluorescent observation mode. In the normal observation mode, the medical observation system irradiates an observation target with visible light such as white light, captures the return light (reflected light) of the visible light from the observation target with an imaging element, and displays the normal light image captured by the imaging element on a display device. On the other hand, in the fluorescent observation mode, the medical observation system irradiates an observation target with excitation light, which is narrow-band light, and captures the fluorescence emitted from a substance contained in the observation target by the irradiation of the excitation light with the imaging element, and displays the fluorescent image captured by the imaging element on a display device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2021 / 039869 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the medical observation system described in Patent Document 1, the return visible light and the fluorescence are captured by only one imaging element. When only one imaging element is used in this way, it is necessary to use an imaging element with sensitivity capable of capturing both visible light and fluorescence, and the sensitivity is not sufficient to capture weak fluorescence, making it difficult to generate a fluorescence image suitable for observation.

[0005] Therefore, it may be possible to provide two imaging elements, one for capturing an image of the returning visible light and the other for capturing an image of the fluorescent light, depending on the wavelength of the light to be captured. However, if a circuit is provided that processes pixel signals from the two image sensors independently in accordance with a transmission standard appropriate for each image sensor, there is a problem that the circuit size becomes large and power consumption becomes high.

[0006] The present disclosure has been made in view of the above, and has an object to provide a medical imaging apparatus and a medical observation system that can suppress increases in circuit size and power consumption. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems and achieve the objective, the medical imaging device disclosed herein includes a plurality of imaging elements that capture an image of a subject and output pixel signals, and a signal integration unit that converts the pixel signals output from the plurality of imaging elements into pixel signals that correspond to a specific transmission standard.

[0008] The medical observation system according to the present disclosure comprises a medical imaging device that captures an image of a subject and outputs pixel signals, and a signal processing device that processes the pixel signals output from the medical imaging device, the medical imaging device comprising a plurality of imaging elements that capture the image of the subject and output pixel signals, respectively, and a signal integration unit that converts the plurality of pixel signals output respectively from the plurality of imaging elements into pixel signals corresponding to a specific transmission standard. Effect of the Invention

[0009] According to the medical imaging apparatus and medical observation system according to the present disclosure, it is possible to suppress an increase in circuit size and power consumption. [Brief description of the drawings]

[0010] [Figure 1]FIG. 1 is a diagram showing the configuration of a medical observation system according to an embodiment. [Diagram 2] FIG. 2 is a block diagram showing the configuration of the camera head and the control device. [Diagram 3] FIG. 3 is a diagram for explaining the functions of the first and second signal receiving units. [Figure 4] FIG. 4 is a diagram illustrating the buffer process. [Diagram 5] FIG. 5 is a diagram illustrating a first modified example of the embodiment. [Figure 6] FIG. 6 is a diagram illustrating a second modification of the embodiment. [Figure 7] FIG. 7 is a diagram illustrating a third modification of the embodiment. [Figure 8] FIG. 8 is a diagram illustrating a fourth modified example of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, a mode for carrying out the present disclosure (hereinafter, referred to as an embodiment) will be described with reference to the drawings. Note that the present disclosure is not limited to the embodiment described below. Furthermore, in the description of the drawings, the same parts are given the same reference numerals.

[0012] [Overview of medical observation system] FIG. 1 is a diagram showing the configuration of a medical observation system 1 according to an embodiment. A medical observation system 1 according to this embodiment is used in the medical field to observe inside a living body. 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.

[0013] In this 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 partially flexible and other rigid, and is inserted into a living body. The insertion section 2 includes an optical system (not shown) that is configured using one or more lenses and focuses light from a subject (subject image).

[0014] The light source device 3 is connected to one end of the light guide 4, and supplies light to be irradiated into a 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 and a second light source 32.

[0015] The first light source 31 emits light in a first wavelength band. In the present embodiment, the first light source 31 is configured with an LED (Light Emitting Diode) that emits white light (light in the first wavelength band (visible light)).

[0016] The second light source 32 emits excitation light in a second wavelength band different from the first wavelength band. In this embodiment, the second light source 32 is configured with a semiconductor laser that emits near-infrared excitation light in a near-infrared wavelength band (light in a second wavelength band (narrowband light)). Note that the excitation light is not limited to near-infrared excitation light, and excitation light in other wavelength bands may be used.

[0017] The near-infrared excitation light emitted by the second light source 32 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 having a central wavelength on the longer wavelength side than the central wavelength of the wavelength band of the near-infrared excitation light.

[0018] In the present embodiment, the light source device 3 is configured as a separate entity from the control device 9, but the present invention 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 be adopted.

[0019] The light guide 4 has one end detachably connected to the light source device 3 and the other end detachably connected to the insertion section 2. The light guide 4 transmits light (white light or near-infrared excitation light) supplied from the light source device 3 from one end to the other end and supplies it to the insertion section 2. The light (white light or near-infrared excitation light) supplied to the insertion section 2 is emitted from the tip of the insertion section 2 and irradiated into the living body. When the white light is irradiated into the living body, the white light reflected in the living body is collected by the optical system in the insertion section 2. For convenience of explanation, the white light collected by the optical system in the insertion section 2 will be referred to as a first subject image below. When the near-infrared excitation light is irradiated into the living body, the near-infrared excitation light reflected in the living body and the fluorescence emitted from the fluorescent substance, which is excited by a fluorescent substance such as indocyanine green that accumulates in a lesion in the living body, are collected by the optical system in the insertion section 2. In the following, for convenience of explanation, the near-infrared excitation light and the fluorescent light collected by the optical system in the insertion portion 2 will be referred to as a second subject image.

[0020] The camera head 5 corresponds to the medical 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 portion 2. Under the control of the control device 9, the camera head 5 captures a first subject image (white light) and a second subject image (near-infrared excitation light and fluorescent light) focused by the insertion portion 2 to generate pixel signals (hereinafter referred to as captured images). 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), 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.

[0022] The captured image and the like may be transmitted as an optical signal or as an electrical signal when transmitted from the camera head 5 to the control device 9 via the first transmission cable 6. The same applies to the transmission of a control signal, a synchronization signal, and a clock 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 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.

[0024] 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.

[0025] The control device 9 corresponds to a signal processing device according to the present disclosure. The control device 9 is composed of a central processing unit (CPU), a field-programmable gate array (FPGA), 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 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, 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.

[0027] [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, a prism 52, an imaging unit 53, and a communication unit .

[0028] The lens unit 51 is configured using one or more lenses. The lens unit 51 forms a first subject image (white light) collected by the insertion portion 2 on the imaging surface of a first imaging element 531 (FIG. 2), and forms a second subject image (near-infrared excitation light and fluorescent light) collected by the insertion portion 2 on the imaging surface of a second imaging element 532 (FIG. 2).

[0029] The prism 52 separates the first subject image (white light) and the second subject image (near-infrared excitation light and fluorescence) via the lens unit 51. Then, the prism 52 causes the first subject image (white light) to proceed toward the first imaging element 531. Also, the prism 52 causes the second subject image (near-infrared excitation light and fluorescence) to proceed toward the second imaging element 532.

[0030] The imaging unit 53 captures images of the inside of a living body under the control of the control device 9. As shown in FIG. 2 , the imaging unit 53 includes a first imaging element 531, a second imaging element 532, a first signal receiving unit 533, a second signal receiving unit 534, and a signal combining unit 535.

[0031] The first and second imaging elements 531 and 532 are configured with a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) that receives incident light and converts it into an electrical signal, etc. Note that the number of imaging elements according to the present disclosure is not limited to two, the first and second imaging elements 531 and 532, and may be three or more imaging elements.

[0032] Here, the first imaging element 531, although not specifically shown, is made up of an invalid area that is not electrically guaranteed, an optical black area (OB area), and an effective pixel area that converts the first subject image formed by the lens unit 51 into an imaging signal and outputs it. Similarly, the second imaging element 532 is made up of an invalid area, an optical black area (OB area), and an effective pixel area.

[0033] Then, under the control of the control device 9, the first imaging element 531 captures a first subject image (white light) through the prism 52. For ease of explanation, hereinafter, a captured image generated by capturing the first subject image (white light) by the first imaging element 531 will be referred to as a normal light image. In this embodiment, the first imaging element 531 has a number of pixels capable of capturing an image at a 4K resolution. That is, the normal light image is a 4K image with 4K pixels. Note that the first imaging element 531 may be an imaging element having a number of pixels capable of capturing an image at another resolution, not limited to 4K.

[0034] Further, the second imaging element 532 captures a second subject image (near-infrared excitation light and fluorescence) through the prism 52 under the control of the control device 9. Hereinafter, for convenience of explanation, a captured image generated by capturing the second subject image (near-infrared excitation light and fluorescence) by the second imaging element 532 will be referred to as a fluorescence image. In this embodiment, the second imaging element 532 has a number of pixels capable of capturing an image at HD resolution. That is, the fluorescence image is an HD image having a number of HD pixels. Note that the second imaging element 532 is not limited to HD, and an imaging element having a number of pixels capable of capturing an image at other resolutions may be adopted. Furthermore, an excitation light cut filter for removing only at least a part of the near-infrared excitation light directed toward the second imaging element 532 may be disposed on the upstream side of the optical path of the second imaging element 532.

[0035] As described above, the camera head 5 includes the first and second imaging elements 531, 532 that respectively output different types of images (normal light image (4K image) and fluorescent image (HD image)).

[0036] The first signal receiving unit 533 reads out pixel signals (normal light image) from each pixel in the first imaging element 531 based on signals related to the timing and cycle of imaging in the first imaging element 531. Here, the signals related to the timing and cycle of imaging in the first imaging element 531 are a clock and a synchronization signal (vertical / horizontal synchronization signal).

[0037] The second signal receiving unit 534 reads out pixel signals (fluorescence images) from each pixel in the second imaging element 532 based on signals related to the timing and cycle of imaging in the second imaging element 532. Here, the signals related to the timing and cycle of imaging in the second imaging element 532 are a clock and a synchronization signal (vertical / horizontal synchronization signal). The detailed functions of the first and second signal receiving units 533 and 534 will be described later in "Functions of the First and Second Signal Receiving Units."

[0038] Under the control of the control device 9, the signal integration unit 535 performs signal processing such as removing reset noise from the pixel signals (normal light image, fluorescent image) read out by the first and second signal receiving units 533, 534, multiplying the pixel signals (analog signals) by an analog gain to amplify the pixel signals, A / D conversion, and the integration and buffering processes described below.

[0039] Here, the integration process is a process of converting the pixel signals (normal light image, fluorescent image) read out by the first and second signal receiving units 533, 534, respectively, into pixel signals corresponding to a specific transmission standard. In this embodiment, the specific transmission standard is a transmission standard corresponding to the imaging element having the fastest transmission rate or the imaging element having the largest amount of signal data of the pixel signals among the first and second imaging elements 531, 532. That is, the specific transmission standard is the 4K transmission standard. The transmission standard includes the vertical and horizontal sizes of the captured image, the transmission time required to transmit one frame, the horizontal and vertical synchronization timing, the reference clock, and the like. Therefore, in the integration process according to this embodiment, the fluorescent image signal of the HD transmission standard is converted into a pixel signal of the 4K transmission standard. Note that the specific transmission standard according to the present disclosure is not limited to the 4K transmission standard, and other transmission standards may be adopted.

[0040] The buffer process uses a buffer 5351 (FIG. 2) provided in the signal combining unit 535. Details of the buffering process will be described later in the section "Buffering Process."

[0041] The communication unit 54 functions as a transmitter that transmits the captured images sequentially output from the imaging unit 53 to the control device 9 via the first transmission cable 6. The communication unit 54 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. In this embodiment, the communication unit 54 transmits the normal light images and fluorescent images that have been subjected to signal processing including integrating processing in the signal integrating unit 535 alternately to the control device 9 in a time-division manner.

[0042] [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 reference signal generating unit 91, a communication unit 92, an image memory 93, a processing module 94, a control unit 95, an input unit 96, an output unit 97, and a storage unit 98.

[0043] The reference signal generating unit 91 generates a reference signal necessary for the operation of the camera head 5 and the control device 9. The reference signal is a clock and a synchronization signal (vertical / horizontal synchronization signal). In this embodiment, the reference signal generating unit 91 generates different clock and synchronization signals as the clock and synchronization signals to be output to the first and second imaging elements 531 and 532.

[0044] The communication unit 92 functions as a receiver that receives captured images sequentially output from the camera head 5 (communication unit 54) via the first transmission cable 6. The communication unit 92 is configured, for example, with a high-speed serial interface that communicates captured images with the communication unit 54 at a transmission rate of 1 Gbps or more.

[0045] The image memory 93 is configured, for example, with a dynamic random access memory (DRAM), etc. This image memory 93 is capable of temporarily storing multiple frames of captured images sequentially output from the camera head 5.

[0046] The processing module 94 processes the captured images sequentially received via the communication unit 92. The processing module 94 includes a memory controller 941 and an image processing unit 942, as shown in FIG.

[0047] The memory controller 941 controls the writing of captured images to the image memory 93 and the reading of the captured images from the image memory 93. More specifically, the memory controller 941 writes normal light images received by the communication unit 92 to the image memory 93, reads the normal light images from the image memory 93 at a specific timing, and inputs them to a first image processing block 9421 in the image processing unit 942. The memory controller 941 also writes fluorescent images received by the communication unit 92 to the image memory 93, and reads the fluorescent images from the image memory 93 at a specific timing, and inputs them to a second image processing block 9422 in the image processing unit 942.

[0048] The image processing unit 942 performs image processing on the captured images sequentially received via the communication unit 92 and read out from the image memory 93 by the memory controller 941. The image processing unit 942 also generates a display image (video signal for display) for displaying the captured image after image processing. Then, the image processing unit 942 outputs the display image to the display device 7. As a result, the display image is displayed on the display device 7.

[0049] As shown in FIG. 2, the image processing unit 942 includes a first image processing block 9421 that performs image processing on the input normal light image, and a second image processing block 9422 that performs image processing on the input fluorescent light image.

[0050] Here, the image processing performed by the first and second image processing blocks 9421, 9422 includes, for example, optical black subtraction processing, white balance adjustment processing, demosaic processing, color correction matrix processing, gamma correction processing, YC processing for converting RGB signals into luminance color difference signals (Y, Cb / Cr signals), gain adjustment, noise removal, and filter processing for structural enhancement.

[0051] The image processing performed by the first image processing block 9421 and the image processing performed by the second image processing block 9422 may be different from each other, or may be the same.

[0052] The control unit 95 is realized by a controller such as a CPU or an MPU (Micro Processing Unit) executing various programs stored in a storage unit 98, 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 95 is not limited to a CPU or an MPU, and may be configured by an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA.

[0053] The input unit 96 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 surgeon. Then, the input unit 96 outputs an operation signal to the control unit 95 in response to the user operation.

[0054] The output unit 97 is configured using a speaker, a printer, etc., and outputs various information.

[0055] The storage unit 98 stores the programs executed by the control unit 95, information necessary for the processing of the control unit 95, and the like.

[0056] [Functions of the first and second signal receiving units] Next, the functions of the first and second signal receiving units 533 and 534 will be described. FIG. 3 is a diagram for explaining the functions of the first and second signal receiving units 533 and 534. Specifically, FIG. 3(a) is a diagram for explaining the function of the first signal receiving unit 533 that reads out a pixel signal (normal light image) having a pixel number of 4K. FIG. 3(b) and FIG. 3(c) are diagrams for explaining the function of the second signal receiving unit 534 that reads out a pixel signal (fluorescence image) having a pixel number of HD. In FIG. 3, the normal light image and the fluorescence image to be read out are each represented by a rectangle. In FIG. 3(a), the shaded area in the rectangle showing the normal light image indicates a pixel signal from the effective pixel area of ​​the first imaging element 531. In addition, in FIG. 3(b) and FIG. 3(c), the shaded area in the rectangle showing the fluorescence image indicates a pixel signal from the effective pixel area of ​​the second imaging element 532.

[0057] The first signal receiving unit 533 reads out pixel signals (normal light image) from each pixel in the first imaging element 531, based on the clock and synchronization signals (vertical / horizontal synchronization signals) generated by the reference signal generating unit 91. Here, in (a) of Fig. 3, the symbol "TS1" is the start timing of a pixel signal from the effective pixel area in the first imaging element 531. In the normal light image, the data amount of the pixel signal from the readout start timing to the start timing TS1 is the data amount D1.

[0058] The second signal receiving unit 534 reads out pixel signals (fluorescence image) from each pixel in the second imaging element 532, based on the clock and synchronization signals (vertical / horizontal synchronization signals) generated by the reference signal generating unit 91. Here, in Fig. 3(b) and Fig. 3(c), the symbol "TS2" is the start timing of a pixel signal from the effective pixel area in the second imaging element 532. In the fluorescence image, the amount of data of the pixel signal from the readout start timing to the start timing TS2 is the data amount D2.

[0059] However, data amount D2 is larger than data amount D1. Therefore, if the readout start timing for both the normal light image and the fluorescent image is set to the same timing, the start timings TS1 and TS2 will be different timings, as shown in Figures 3(a) and 3(b).

[0060] Therefore, in this embodiment, the second signal receiving unit 534 advances the read start timing by an amount of time corresponding to the difference between the data amounts D1 and D2, as shown in (c) of Figure 3, so that the start timings TS1 and TS2 are the same.

[0061] Note that the start timing of reading by the first signal receiving unit 533 may be delayed by a time period corresponding to the difference between the data amounts D1 and D2, so that the head timings TS1 and TS2 may be made the same timing.

[0062] [About buffer processing] Next, the buffering process executed by the signal combining unit 535 will be described. FIG. 4 is a diagram for explaining the buffer processing. Specifically, FIG. 4(a) corresponds to FIG. 3(a). Note that in FIG. 4(a), pixel signals from the effective pixel region of the first imaging element 531 are omitted. FIG. 4(b) corresponds to FIG. 3(b). Note that in FIG. 4(b), pixel signals from the effective pixel region of the second imaging element 532 are omitted. In order to distinguish between normal light images and fluorescent images, normal light images are represented by white rectangles, and fluorescent images are represented by shaded rectangles. FIG. 4(c) shows normal light images and fluorescent images alternately transmitted from the communication unit 54 in a time-division manner.

[0063] Incidentally, when the clock and synchronization signals output from the reference signal generating unit 91 to the first and second imaging elements 531, 532 are clock and synchronization signals of the recommended specifications for the first and second imaging elements 531, 532, that is, when the clock and synchronization signals input to the first and second imaging elements 531, 532 are not identical, the readout time T2 of the fluorescence image will be shorter than the readout time T1 of the normal light image, as shown in Figures 4(a) and 4(b). In other words, the readout time T2 of the fluorescence image will be shorter than each of the transmission times T3 of the normal light image and the fluorescence image.

[0064] Therefore, in order to absorb the difference between readout time T2 and transmission time T3, the signal combining unit 535 executes a buffer process in which the pixel signals (fluorescence image) read from the second signal receiving unit 534 are temporarily stored in the buffer 5351 while being read out. In other words, the signal combining unit 535 uses the buffer process to absorb the difference between the clock and synchronization signals input to the first and second imaging elements 531, 532. As a result, the fluorescence image can also be transmitted in the transmission time T3, like the normal light image, as shown in FIG. 4(c).

[0065] According to the present embodiment described above, the following effects are achieved. Camera head 5 according to the present embodiment includes a signal integrating unit 535 that converts pixel signals output from first and second imaging elements 531 and 532, respectively, into pixel signals compatible with the 4K transmission standard. Therefore, there is no need to provide circuits for independently processing pixel signals from the first and second imaging elements 531 and 532 in accordance with a transmission standard corresponding to the imaging elements. Therefore, according to the camera head 5 of this embodiment, it is possible to prevent the circuit size and power consumption from increasing.

[0066] Furthermore, the signal combining unit 535 absorbs the difference between the clock and synchronization signals input to the first and second imaging elements 531 and 532 by buffering. Therefore, when the normal light image and the fluorescent light image are processed on the control device 9 side, the processing can be performed at a specified frequency, making it unnecessary to change the design of the control device 9 side.

[0067] Furthermore, the camera head 5 includes first and second signal receiving units 533 and 534 that respectively read out pixel signals from the first and second imaging elements 531 and 532. The first and second signal receiving units 533 and 534 respectively read out the pixel signals from the effective pixel areas of the first and second imaging elements 531 and 532 so that the start timings TS1 and TS2 of the pixel signals are the same. Therefore, the control device 9 receives data from the effective pixel areas of the first and second imaging elements 531, 532 at a specified frequency, and can perform processing at the specified frequency, eliminating the need for design changes on the control device 9 side.

[0068] (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 above-described embodiments. The configurations of the following modified examples 1 to 4 may also be adopted.

[0069] (Variation 1) 5 is a diagram for explaining a first modified example of the embodiment. Specifically, FIG. 5 corresponds to FIG. In the above-described embodiment, the reference signal generating unit 91 generates different clock and synchronization signals as the clock and synchronization signals to be output to the first and second imaging elements 531 and 532, but the present invention is not limited to this. The reference signal generating section 91 according to the present first modification generates the same clock and synchronization signals as the clock and synchronization signals to be output to the first and second imaging elements 531 and 532.

[0070] As a result, the readout time T2 of the fluorescence image is the same as the readout time T1 of the normal light image, as shown in Fig. 5. In other words, the readout time T2 of the fluorescence image is the same as each of the transmission times T3 of the normal light image and the fluorescence image.

[0071] According to the above-described first modification, in addition to the same effects as those of the above-described embodiment, the following effects are achieved. According to the present modified example 1, the buffer processing described in the above embodiment is unnecessary, so that the buffer 5351 does not need to be provided.

[0072] (Variation 2) Fig. 6 is a diagram for explaining the second modified example of the embodiment. Specifically, Fig. 6 shows a schematic diagram of images transmitted to the control device 9 by the communication unit 54, with the horizontal axis representing time. Note that in Fig. 6, images with a pixel count of 4K are marked with the letters "4K," and images with a pixel count of HD are marked with the letters "HD," "HD1," and "HD2." In the above-described embodiment, for example, a first mode and a second mode that can be switched to one of them by the control unit 95 in response to a user operation on the input unit 96 may be employed.

[0073] The first mode, similar to the embodiment described above, is a mode in which a fluorescent substance such as indocyanine green is used, and fluorescence from the fluorescent substance is caused to travel toward the second image sensor 532 by the prism 52. In this first mode, similar to the embodiment described above, the normal light image and the fluorescent image simultaneously captured by the first and second image sensors 531, 532 are converted into a 4K transmission standard by the signal integrating unit 535, and then transmitted alternately in a time-division manner to the control device 9 by the communication unit 54 ((a) of FIG. 6).

[0074] The second mode is a mode in which a fluorescent material different from that of the above-mentioned embodiment is used. In this second mode, the fluorescence from the fluorescent material is caused to proceed toward the first image pickup element 531 by the prism 52 in the same manner as the white light. That is, the wavelength band of the fluorescence overlaps with the wavelength band of the white light. In the second mode, the control unit 95 turns on the first light source 31 during the first period and turns on the second light source 32 during the second period of the first and second periods that are alternately repeated. In addition, the first image pickup element 531 performs imaging for each of the first and second periods that are alternately repeated in synchronization with the timing of turning on the first and second light sources 31 and 32. As a result, the imaging unit 53 performs imaging during the first period and generates a normal light image with a HD number of pixels by thinning-out readout and pixel addition. In addition, the imaging unit 53 performs imaging during the second period and generates a fluorescent image with a HD number of pixels by thinning-out readout and pixel addition. Furthermore, the imaging unit 53 (signal integration unit 535) converts the normal light image with an HD pixel count and the fluorescent image with an HD pixel count into a 4K transmission standard and outputs them. The communication unit 54 then simultaneously transmits the normal light image (HD image) and the fluorescent image (HD image) generated by the imaging unit 53 (FIG. 6(b)). Note that in FIG. 6(b), the normal light image (HD image) is labeled "HD1" and the fluorescent image (HD image) is labeled "HD2."

[0075] According to the present modified example 2 described above, in addition to the same effects as those of the above-mentioned embodiment, the following effects are achieved. According to the present modified example 2, the first and second modes can be selected according to the type of fluorescent material, thereby improving convenience.

[0076] (Variation 3) The medical observation system according to the present modified example 3 is a medical observation system using a so-called videoscope (flexible endoscope) having an imaging unit at the tip side of an insertion part. For convenience of explanation, the medical observation system 1 according to the present modified example 3 will be referred to as a medical observation system 1A below.

[0077] FIG. 7 is a diagram illustrating a third modification of the embodiment. As shown in FIG. 7, the medical observation system 1A includes an endoscope 100 that captures in-vivo images of an observation site by inserting an insertion portion 2A into a living body and outputs the captured images, a light source device 3 that generates illumination light to be emitted from the tip of the endoscope 100, a control device 9 that processes the captured images 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.

[0078] As shown in FIG. 7, the endoscope 100 includes an insertion section 2A having a flexible, elongated shape, 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 connected to the light source device 3 and the control device 9. As shown in FIG. 7, the insertion section 2A includes a tip portion 22, a freely bendable bending section 23 connected to the base end side of the tip portion 22 and composed of a plurality of bending pieces, and a long, flexible tube section 24 connected to the base end side of the bending section 23 and having flexibility.

[0079] 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.

[0080] Even when the configuration of the present modified example 3 described above is adopted, the same effects as those of the above-mentioned embodiment are achieved.

[0081] (Variation 4) The medical observation system according to the present modification 4 is a medical observation system using a surgical microscope that enlarges and captures a predetermined field of view of the inside of a subject (inside a living body) or the surface of a subject (surface of a living body). For convenience of explanation, the medical observation system 1 according to the present modification 4 will be referred to as a medical observation system 1B below.

[0082] FIG. 8 is a diagram illustrating a fourth modified example of the embodiment. As shown in FIG. 8, 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 an image based on a video signal processed by the control device 9.

[0083] As shown in FIG. 8, the surgical microscope 12 comprises a microscope unit 121 that captures a magnified image of a minute part 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 surface. The control device 9 is mounted on a base unit 123 as shown in Fig. 8. Although not specifically shown in the drawings, the base unit 123 also has a light source device 3 mounted thereon, which generates illumination light to be irradiated from the surgical microscope 12 to the subject. The base portion 123 may be configured to support the support portion 122 by being fixed to a ceiling or a wall surface, rather than being provided so as to be movable on the floor surface.

[0084] 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 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.

[0085] Even when the configuration of the present modified example 4 described above is adopted, the same effects as those of the above-mentioned embodiment are achieved.

[0086] Note that the following configurations also fall within the technical scope of the present disclosure. (1) A medical imaging device comprising: a plurality of imaging elements that capture an image of a subject and output pixel signals, and a signal integration unit that converts the pixel signals output from the plurality of imaging elements into pixel signals that correspond to a specific transmission standard. (2) The medical imaging device described in (1), wherein the specific transmission standard is a transmission standard corresponding to the imaging element having the fastest transmission rate among the plurality of imaging elements, or the imaging element having the largest amount of signal data of the pixel signal. (3) The medical imaging device described in (1) or (2) further includes a communication unit that transmits, in a time-division manner, the multiple pixel signals output from the multiple imaging elements and converted to the specific transmission standard by the signal integration unit. (4) The medical imaging apparatus according to any one of (1) to (3), wherein signals relating to timing and period of imaging in the plurality of imaging elements are set to be the same. (5) The medical imaging device described in any one of (1) to (3), wherein the signal integration unit includes a buffer that temporarily stores at least one of the plurality of pixel signals, and when signals related to the timing and period of imaging at the plurality of imaging elements are not identical, at least one of the plurality of pixel signals is stored in the buffer to absorb differences in signals related to the timing and period of imaging at the plurality of imaging elements. (6) A medical imaging device as described in any one of (1) to (5), further comprising a plurality of signal receiving units each reading out a plurality of the pixel signals from the plurality of imaging elements, wherein the plurality of signal receiving units each read out the plurality of the pixel signals so that the start timing of the pixel signals from the effective pixel areas of the plurality of imaging elements is the same. (7) The medical imaging device described in any one of (1) to (6) is switchable between a first mode and a second mode, and in the first mode, the medical imaging device further includes a communication unit that simultaneously transmits, in the second mode, a plurality of pixel signals captured simultaneously by the plurality of imaging elements in a time-division manner and converted to the specific transmission standard by the signal integration unit, and simultaneously transmits, in the second mode, a plurality of pixel signals captured in a time-division manner by any one of the plurality of imaging elements, in accordance with the specific transmission standard. (8) The medical imaging device according to any one of (1) to (7), wherein the plurality of imaging elements include a first imaging element that outputs a pixel signal of a 4K image and a second imaging element that outputs a pixel signal of an HD image. (9) A medical observation system comprising: a medical imaging device that captures an image of a subject and outputs pixel signals; and a signal processing device that processes the pixel signals output from the medical imaging device, wherein the medical imaging device comprises a plurality of imaging elements that capture the image of the subject and output pixel signals, respectively; and a signal integration unit that converts the plurality of pixel signals output respectively from the plurality of imaging elements into pixel signals corresponding to a specific transmission standard. [Explanation of symbols]

[0087] 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 21 Eyepiece 22 Tip 23 Curved section 24 Flexible tube section 31 First Light Source 32 Second Light Source 51 Lens unit 52 Prism 53 Imaging unit 54 Communications Department 91 Reference signal generation section 92 Communications Department 93 Image Memory 94 Processing Module 95 Control Unit 96 Input section 97 Output section 98 Memory section 100 Endoscope 101 Operation section 102 Universal Code 121 Microscope Section 122 Support part 123 Base 531 First imaging element 532 Second imaging element 533 First signal receiving unit 534 Second signal receiving unit 535 Signal Integration Section 941 Memory Controller 942 Image Processing Unit 5351 Buffer 9421 1st Image Processing Block 9422 2nd Image Processing Block CN1,CN2 connector D1, D2 data volume T1, T2 Read time T3 Transmission Time TS1, TS2 start timing

Claims

1. a plurality of image pickup elements each for capturing an image of a subject and outputting a pixel signal; a signal integration unit that converts each of the pixel signals output from the imaging elements into a pixel signal that complies with a specific transmission standard.

2. The specific transmission standard is 2. The medical imaging apparatus according to claim 1, wherein the transmission standard corresponds to an imaging element having the fastest transmission rate or an imaging element having the largest amount of signal data of the pixel signal among the plurality of imaging elements.

3. The medical imaging apparatus according to claim 1 , further comprising a communication unit that transmits, in a time-division manner, the plurality of pixel signals that are output from the plurality of imaging elements and converted into the specific transmission standard by the signal integration unit.

4. A signal related to the timing and period of imaging in the plurality of imaging elements is 2. The medical imaging device of claim 1, wherein the imaging devices are configured identically.

5. The signal integration unit includes:

2. The medical imaging device of claim 1, further comprising a buffer for temporarily storing at least one of the plurality of pixel signals, and in a case where signals related to the timing and period of imaging at the plurality of imaging elements are not identical, at least one of the plurality of pixel signals is stored in the buffer to absorb differences in signals related to the timing and period of imaging at the plurality of imaging elements.

6. a plurality of signal receiving units each reading out a plurality of pixel signals from the plurality of image pickup elements, The plurality of signal receiving units include The medical imaging apparatus according to claim 1 , wherein the pixel signals are read out so that the start timings of the pixel signals from effective pixel regions of the imaging elements are the same.

7. The medical imaging device includes:

2. The medical imaging device of claim 1, further comprising a communication unit that is switchable between a first mode and a second mode, and in the first mode, transmits in a time-division manner a plurality of pixel signals that are simultaneously captured by the plurality of imaging elements and converted to the specific transmission standard by the signal integration unit, and in the second mode, transmits in a time-division manner a plurality of pixel signals that are captured by any one of the plurality of imaging elements in a time-division manner by the specific transmission standard.

8. The plurality of image pickup elements include A first imaging element that outputs a pixel signal of a 4K image; 2. The medical imaging apparatus according to claim 1, further comprising a second imaging element that outputs pixel signals of an HD image.

9. a medical imaging device that captures an image of a subject and outputs a pixel signal; a signal processing device for processing pixel signals output from the medical imaging device, The medical imaging device includes: a plurality of image pickup elements each capturing an image of the subject and outputting a pixel signal; a signal integration unit that converts each of the pixel signals output from the imaging elements into a pixel signal that complies with a specific transmission standard.

Images