JP2011010879A - Electronic endoscope system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic endoscope system capable of transmitting the large capacity of sound signals and character signals without changing a transmission route.SOLUTION: In the electronic endoscope system including an image signal processor for outputting the image signals of observation images imaged by an imaging element as digital video signals according to a prescribed format, a transmission system for transmitting the digital video signals according to the prescribed format, and a receiver for demodulating the observation images received through the transmission system and outputting them to a monitor, the image signal processor includes a means for determining that the observation images are to be sent and displayed frame by frame, a means for writing image signals to the leading frame of the digital video signal and writing prescribed signals in a post-stage frame, a means for generating identification signals indicating the kinds of the signals written to the respective frames, and a means for allocating the image signals, the prescribed signals and the identification signals to the digital video signals, and the receiver demodulates the signals on the basis of the identification signals.

Description

  The present invention relates to an electronic endoscope system that outputs an endoscope observation image, sound, and text information and displays them on a monitor.

  In the conventional electronic endoscope system, as shown in Patent Document 1, analog RGB, composite sync signal, composite video signal, S video signal, and digital video signal are employed as output signal formats. In addition, a configuration has been proposed in which voice information such as a practitioner's findings and character information about a patient are added to an endoscopic observation image and output. For example, as shown in Patent Document 2, a digital video signal output block is proposed. There is also a configuration in which an audio signal or the like is assigned during the ranking period. In these electronic endoscope systems, there are cases where a digital video signal of a frame-by-frame image is transmitted to a remote monitor using an electronic endoscope whose image processing frame rate is smaller than a predetermined value.

JP-A-8-214290 Japanese Patent Laid-Open No. 9-9109

  In recent years, observation images taken with an electronic endoscope at the time of surgery are transmitted in real time to another room, hospital, laboratory, etc., and a remote doctor provides remote guidance and remote support to the practitioner while checking the observation images It is desired that an electronic endoscope can be used also in telemedicine.

  However, in the conventional configuration as described above, when the amount of information to be transmitted to a remote location such as a voice signal other than an image signal, a character signal, or a control signal for controlling the operation of a peripheral device at a remote location increases There may be a case where these information signals cannot be received during the blanking period of the digital video signal to be transmitted. When such a case occurs, there is a possibility that necessary information cannot be transmitted to a remote place. For this reason, there is a possibility that it may be inconvenient for telemedicine, for example, it becomes difficult for the doctor in the remote place to confirm and judge from what viewpoint the image displayed on the monitor should be confirmed.

  In addition, if a transmission cable signal line is added to increase the amount of information transmitted, or if a transmission cable capable of transferring a larger capacity is introduced, the transmission of the transmission cable or the electronic endoscope corresponding to the new transmission cable will be performed. Costs such as construction of a mirror system are generated.

  The present invention has been made in view of the above. The object of the present invention is to increase the capacity of audio signals, character signals, control signals, etc. without reducing the amount of information of the endoscopic observation image without incurring the cost of adding a signal line of the transmission cable. It is another object of the present invention to provide an electronic endoscope system that can supply the auxiliary data of a remote controller to a remote receiving device.

  An electronic endoscope system according to the present invention includes an image signal processing device that processes an image signal of an observation image captured by an image sensor in accordance with a predetermined format and outputs the processed image signal as a digital video signal, and the digital video signal A transmission system for transmitting the digital video signal corresponding to the predetermined format, and a receiving device for demodulating the observation image received through the transmission system and outputting the demodulated image to a monitor. A determination unit that determines whether or not an observation image is displayed frame by frame when the frame rate of the element is smaller than a predetermined value, and a continuous digital video signal when the determination unit determines that the observation image is frame-by-frame display. In a plurality of frames, an image signal is written in the first frame, and a predetermined signal other than the image signal is written in a subsequent frame following the first frame. A signal writing means for writing, an identification signal generating means for generating an identification signal indicating the type of signal written in each frame, and a signal allocation means for assigning an image signal, a predetermined signal and the identification signal to the digital video signal. The receiving device demodulates the image signal and the predetermined signal based on the identification signal.

  Preferably, the image signal processing apparatus further includes an audio signal generation unit that generates an audio signal as a predetermined signal. The image signal processing apparatus further includes character signal generation means for generating a character signal as a predetermined signal. Furthermore, the identification signal is assigned to the blanking period of the digital video signal. For this reason, when image display is frame-by-frame, various data can be assigned to frames where image data overlaps, so that not only information essential for endoscopic observation but also more efficient observation can be performed. Information for realization can also be sent to remote locations.

  More preferably, the image signal processing device is configured so that a plurality of types of electronic endoscopes can be connected. Therefore, even when using an electronic endoscope that can only perform frame advance for image display or when using an electronic endoscope that can switch image display to frame advance, the above-described processing can be performed in the same apparatus.

  According to the present invention, when transmitting auxiliary data such as voice, character information, etc. as well as an observation image to a remote monitor using an electronic endoscope whose image processing frame rate is smaller than a predetermined value, Data can be transmitted without increasing the number of signal lines of the transmission cable and without reducing signals. Therefore, it is possible to receive a large volume of auxiliary data while displaying a high-quality endoscopic observation image equivalent to a monitor in the operation room even in a remote place, and realize a highly economical electronic endoscope system. can do. Furthermore, since it is not necessary to transmit the same image over a plurality of frames, transmission efficiency can be improved.

1 is a block diagram illustrating an outline of an entire electronic endoscope system according to an embodiment of the present invention. It is a block diagram which shows the structure of the electronic endoscope system which is one Embodiment of this invention. (A) And (b) is a figure which shows the flame | frame of the digital video signal transmitted in the electronic endoscope system which is one Embodiment of this invention. It is a flowchart which shows the outline of the signal processing in the electronic endoscope system which is one Embodiment of this invention. (A) And (b) is a schematic diagram which shows an analog video signal and a digital video signal. It is a figure which shows the multiplexing of the image signal in a digital video signal.

  Hereinafter, an electronic endoscope system according to an embodiment of the present invention will be described with reference to the drawings. In addition, the same number is attached | subjected, when showing the same member over several figures.

  FIG. 1 is a block diagram showing an outline of the entire electronic endoscope system according to an embodiment of the present invention. In the present embodiment, due to the performance of the image sensor, the electronic endoscope 1 (for example, a confocal endoscope or an enlarged endoscope) in which the frame rate of image processing is 5 fps (frames per second) and the image display is frame advance. A endoscope or the like) is connected to the video processor 2. The digital video signal output from the video processor 2 is transferred to the remote receiving device 3 by the NTSC (National Television System Committee) method. In the case of the NTSC rate, 30 images are transferred per second. However, in the case of frame advance display in this embodiment, only 5 frames can be transferred per second, and 6 identical images are transferred per frame. The electrically erasable read-only memory (EEPROM) 10 of the electronic endoscope 1 stores property information unique to the image sensor 6 such as the number of pixels and the frame rate. When the electronic endoscope 1 is connected to the video processor 2, property information stored in the EEPROM 10 is read into the peripheral drive 14 and then sent to the system control unit 15. Of the property information in the EEPROM 10, information such as the number of pixels and the frame rate necessary for demodulating and outputting the digital video signal transmitted from the video processor 2 is sent to the receiving device 3.

  The light generated by the light source unit 17 of the video processor 2 is propagated to the distal end of the insertion unit of the electronic endoscope 1 by the light guide 7 and irradiated as an illumination light onto the observation target in the patient's body cavity. Although not shown, the light source unit 17 includes various light sources such as a halogen lamp, a xenon lamp, and a white LED, a condensing lens that collects light from the light source, and white light from the light source as red (R) and green ( G), a color filter for sequentially separating the light into blue (B) light, and the speed of the color filter so that the color filter rotates in synchronization with a timing pulse or a vertical synchronization signal when the image signal is written in the frame memory. It has a color filter rotation control circuit for controlling the phase, a light amount diaphragm for adjusting the amount of illumination light, a circuit for controlling the light amount diaphragm, and the like, and generates illumination light by a frame sequential method. The imaging surface of the imaging device 6 is disposed at a position where an image of the observation object is formed by an objective optical system (not shown) provided at the distal end of the insertion portion in the insertion portion of the electronic endoscope 1. Further, by operating various operation buttons 8 provided in the operation unit of the endoscope, an operation signal is sent to the system control unit 15 in the video processor 2 to record a still image or a moving image, supply air, Various treatments such as water supply are performed.

  The imaging signal photoelectrically converted by the imaging element 6 is sent to the preprocessing unit 11 by the drive circuit 9. The preprocessing unit 11 extracts an image signal by performing preprocessing such as amplification, sample hold processing, A / D conversion, and noise removal on the imaging signal. The extracted image signal is sent to the host process unit 13 via the timing circuit 12. The host process unit 13 performs processing such as assigning character information and audio information to the image signal, and displays an analog video to display an image on a television monitor (not shown) or the like installed in the treatment room, for example. In addition to outputting a signal, a digital video signal is output to display an image on a remote television monitor 4. In addition, when displaying an image in a remote place, the output digital video signal is received by the receiving device 3. The receiving device 3 extracts an image signal, a character signal, and an audio signal from the digital video signal. The receiving device 3 converts the image signal into a digital video signal, an RGB video signal, a composite video signal, an S video signal, etc., displays an image on various monitors, displays character information, and reproduces sound. To go. In addition, the VTR 5 can be connected to the receiving device 3 to record images, text information, voice, and the like.

  The system control unit 15 determines whether or not image display is frame-by-frame based on information about the frame rate of the image sensor 6 obtained from the EEPROM 10 of the electronic endoscope 1 and controls the image sensor 6 and the video processor 2. Switch. In addition, the system control unit 15 is based on information stored in the EEPROM 10 in the electronic endoscope 1, operation of the buttons 8 and the panel switch 18, and input from the keyboard 19, the preprocessing unit 11, the timing circuit 12, The operation of the host process unit 13 and the audio signal processing circuit 16 is controlled. For example, the system control unit 15 controls the operation of the timing circuit 12 based on the frame rate information. When it is determined that the image display is not frame advance, the system control unit 15 controls the operation of each unit in the image processing apparatus so as to output a signal according to conventional image processing.

  On the display unit (not shown) of the video processor 2, character information indicating the current operation status of the electronic endoscope and the processing status of the observation image is displayed according to the setting in the panel switch 18. In addition to the endoscope observation image, various character information such as the current time, patient name, practitioner's findings and comments are displayed on the TV monitor 4 and the remote TV monitor 4 installed in the operation room. It is displayed automatically or in accordance with an input from the keyboard 19. Further, information related to the treatment of the practitioner is input to the audio signal processing circuit 16 via a microphone or the like.

  FIG. 2 is a block diagram specifically showing the above-described configuration in one embodiment of the present invention. An imaging signal output from the imaging device 6 is amplified by an amplifier (AMP) 20 of the preprocessing unit 11, and then an image signal is extracted by a sample hold circuit 21 and converted into a digital signal by an analog / digital conversion circuit 22. It is sent to the timing circuit 12. The timing circuit 12 is sequentially controlled by the system control unit 15 in synchronization with the timing at which the accumulated charge is sent from the image sensor 6, and sequentially outputs image signals of red (R), green (G), and blue (B). Are stored in the corresponding frame memory R23a, frame memory G23b, and frame memory B23c, respectively. The three-color image signals are simultaneously read from the frame memories 23a, 23b, and 23c, and the character signals output from the character signal processing circuit 25 are superimposed, while the digital / analog conversion circuits 24a, 24b, and 24c and the matrix circuit are superimposed. 27. The image signals sent to the digital / analog conversion circuits 24a, 24b, and 24c for the R, G, and B frame memories are converted into analog signals and then output as RGB video signals as they are, or the RGB encoder 25 is used. Or output as a composite video signal or an S video signal, and displayed on a monitor in the treatment room.

  In the matrix circuit 27, each of the R, G, and B digital signals has a luminance signal Y and a color difference signal Cr ((r) such that the ratio of the sampling frequency of the luminance signal Y and the color difference signals Cr and Cb is 4: 2: 2, for example. = R−Y) and Cb (= B−Y). Here, the sampling frequency is 13.5 MHz for Y, 6.75 MHz for Cr and Cb, and the clock frequency is 27 MHz, which is twice the sampling frequency of Y. Sampling is performed in the order of Cb, Y, Cr. In addition, the number of samples in the effective image period of each scanning line of each signal is 720 samples for Y, 360 samples for Cr and Cb, and 1440 samples in total.

  The luminance signal Y, the color difference signals Cr and Cb, and the character signal output from the matrix circuit 27 are sent to the digital signal processing circuit 28. The audio signal output from the audio signal processing circuit 16 is also sent to the digital signal processing circuit 28. The digital signal processing circuit 28 determines the type of signal assigned to the effective image period of the digital video signal based on information such as the frame rate.

  FIGS. 3A and 3B are schematic diagrams showing a transmission state of a digital video signal output from the video processor when the image display is frame advance. For convenience, the two frames between the frames 103 and 106 and the two frames between the frames 203 and 206 are omitted. As shown in FIG. 3A, conventionally, when a frame rate of an imaging device is 5 fps and a frame-advanced digital video signal is transmitted, the same image is continuously transmitted by a predetermined number of frames. Therefore, for example, when considering the frames 101 to 206, the same image data is written in the six frames 101 to 106 and the frames 201 to 206, respectively. For this reason, the signal transmission efficiency is low. Therefore, as shown in FIG. 3B, in the present embodiment, the displayed image is assigned only to the first frames 101 and 201, and the subsequent frame transmitted until the next displayed image is assigned. In 102 to 106 and 202 to 206, auxiliary data such as a voice signal, a character signal, and a control signal is assigned to an effective image period. Note that these processes are performed in the same manner for frames after the frame 301. Thereby, even when the information amount of auxiliary data does not completely enter the blanking period, the auxiliary data can be transmitted without omission without changing the transmission path and the configuration of the video processor. When the process of assigning auxiliary data to the effective image period is not performed, the effective image period is transmitted as an empty area with a synchronization word added before and after that period. The timing for assigning the next image to be displayed to the frame is determined by the system control unit 15 based on the frame rate of the image sensor 6.

  FIG. 4 is a flowchart showing an outline of processing of an image signal and auxiliary data in the digital signal processing circuit 28. Since the system control unit 15 acquires the information stored in the EEPROM 10, the number of frames included in one frame is 6, and the data size that can be written in the subsequent frame is 5 frames. I know that. In step S <b> 101, the digital signal processing circuit 28 determines whether an image signal is received from the matrix circuit 27. S101 is repeated until an image signal is received. When the image signal is received, in step S102, the received image signal is written in the first frame. Next, the process proceeds to step S103, and character information superimposed by the character signal processing circuit 25 and voice information input from the voice signal processing circuit 16 are used as auxiliary data to determine whether or not such auxiliary data exists. If auxiliary data exists, the process proceeds to step S104, and auxiliary data of either character information or voice information is written in the subsequent frame. If there is no auxiliary data, the loop process in this flowchart is terminated. After the auxiliary data is written in the subsequent frame in step S104, the process proceeds to step S105, and it is determined whether or not there is an empty area in the effective image period of the subsequent frame. If there is still a free area, the process proceeds to step S103, and steps S103 to S105 are repeated again. If there is no free area, the process ends. By executing the above processing for each frame, the digital signal processing circuit 28 writes the received image signal and auxiliary data signal to each frame in one frame. The auxiliary data is arbitrarily divided into an appropriate size by the digital signal processing circuit 28 and written in the subsequent frame. Therefore, voice information or character information may be written across a plurality of frames in one frame or may be written across a plurality of frames.

  The digital signal processing circuit 28 writes the signal in the frame as described above, generates an identification signal indicating the type of the written signal, and sends it to the multiplexer 29 together with the image signal, the character signal, and the audio signal. In the multiplexer 29, the synchronization word output from the synchronization word generation circuit 31 is added before and after the effective image period. The identification signal is assigned to the blanking period of the digital video signal. Then, the image signal, the character signal, the sound signal, and the identification signal are multiplexed. Here, the blanking period is a synchronization word that specifies an effective image period corresponding to one line of an image, that is, a synchronization word indicating the end of a certain effective image period and the next effective image in the digital video signal. It means a period that is interposed between the synchronization word indicating the start of the period and originally has no information. Therefore, even if a signal as described above is assigned to the blanking period of the digital video signal, the signal assigned to the effective image period has no effect.

  FIGS. 5A and 5B are diagrams illustrating the relationship between the effective image period, the blanking period, and the synchronization word in the analog video signal and the digital video signal. FIG. 5A shows an analog video signal, and FIG. 5B shows a digital video signal corresponding to the analog video signal. By the above processing, an analog image signal as shown in FIG. 5A is converted into a digital image signal as shown in FIG. In the digital image signal, the synchronization word output from the synchronization word generation circuit 31 is recorded before and after the effective image period for one scanning line. The receiving device 3 detects this synchronization word and extracts a signal sandwiched between the synchronization words as image data.

  FIG. 6 is a diagram illustrating signal multiplexing in the effective image period. The luminance signals Y1, Y2, Y3, Y4... And the color difference signals Cr1, Cr2, Cr3... And Cb1, Cb2, Cb3... Output from the matrix circuit 27 via the digital signal processing circuit 28 are multiplexers. 29, multiplexing is performed in the order of Cb1, Y1, Cr1, Y2, Cb2, Y3, Cr2, Y4, Cb3. By this multiplexing processing, one parallel digital signal is generated.

  The multiplexed signal is sent to the digital output circuit 30 as a parallel digital video signal, converted into a serial digital video signal by the digital output circuit 30, and then SD from the least significant bit (LSB) toward the remote location. It is transmitted in a format compatible transmission system. Note that whether or not to add a character signal, a voice signal, or the like can be performed from a button provided on the electronic endoscope 1, a panel switch 18 on the video processor 2 side, a keyboard 19, or the like.

  Each of the digital luminance signal Y and the color difference signals Cb and Cr is composed of a 10-bit bit string, and is transmitted through the 10 signal lines (buses) in the host process unit 13. Since the digital output circuit 30 outputs the digital video signal to the outside bit by bit, the bit data reading from the LSB of the bit string and the right shift operation toward the most significant bit (MSB) are alternately executed. As a result, the digital video signal is serially transmitted to the receiving device 3. Note that the digital video signal may be compressed and output in accordance with the IEEE 1394 standard.

  Next, processing in the receiving device 3 at the remote site will be described with reference to FIG. 2 again. The video decoder circuit 32 and the timing circuit 34 of the receiving device 3 perform signal processing based on property information regarding the image sensor 6 sent from the video processor 2. The received serial digital video signal is reconverted into a parallel digital video signal in the video decoder circuit 32. The video decoder circuit 32 detects a blanking period and a synchronization word in the video signal based on the synchronization signal output from the timing circuit 34, and separates an image signal, an identification signal, and the like from the video signal. The separated image signal is demodulated and stored in an image memory (not shown) in the video decoder circuit 32, and then sent to the digital encoder 33 to receive analog signals such as RGB video signal, composite video signal, and S video signal. It is converted into a component signal and output. The separated voice signal and character signal are demodulated and then output through the voice signal output circuit 35 and the character signal processing circuit 36, respectively. The separated control information is sent to the target peripheral device. The video decoder circuit 32 can also output the parallel digital video signal as it is to a monitor compatible with the digital video signal.

  The above is the description regarding the electronic endoscope system of the present invention. In the above description, only the case of using an electronic endoscope in which image display is frame-by-frame is described, but it is possible to connect a plurality of types of electronic endoscopes having different image sensor frame rates to a video processor. A possible configuration may be used. Further, it is possible to determine whether or not to perform frame advance display in consideration of the frame rate of a video device such as a monitor in addition to the frame rate of the image sensor. In implementing the present invention, the number and frequency of the digital video signal and the frame rate of the image sensor are not limited to the above-described values, and can be changed as appropriate according to the mode of the system to which the present invention is applied. . In the above description, it is assumed that an image is captured by the frame sequential method, but a simultaneous imaging method may be adopted. In other words, the white light of the light source is collected as it is on the light guide and transmitted to irradiate the object to be observed, and the complementary color signal is separated by an on-chip complementary color filter on the image sensor, and this complementary color signal is converted into the RGB primary color. It is possible to obtain color difference signals RY and BY by converting the primary color signal into a signal and using a color difference matrix.

DESCRIPTION OF SYMBOLS 1 Electronic endoscope 6 Image pick-up element 12 Timing circuit 15 System control part 16 Audio | voice signal processing circuit 28 Digital signal processing circuit 29 Multiplexer 30 Digital output circuit 31 Synchronous word generation circuit

Claims (5)

An image signal processing apparatus that processes an image signal of an observation image picked up by the image pickup device according to a predetermined format and outputs the processed signal as a digital video signal, and transmits the digital video signal corresponding to the predetermined format In an electronic endoscope system comprising: a transmission system; and a reception device that demodulates an observation image received through the transmission system and outputs the image to a monitor.
The image signal processing apparatus includes:
A determination unit that determines whether or not the observation image is frame-by-frame displayed with a frame rate of the image sensor smaller than a predetermined value;
When the determination means determines that the observation image is displayed frame by frame, the image signal is written in a leading frame in a plurality of consecutive frames of the digital video signal, and the subsequent frame following the leading frame Signal writing means for writing a predetermined signal other than the image signal;
Identification signal generating means for generating an identification signal indicating the type of signal written in each frame;
Signal allocating means for allocating the image signal, the predetermined signal, and the identification signal to the digital video signal;
With
The receiver demodulates the image signal and the predetermined signal based on the identification signal;
An electronic endoscope system characterized by that. The image signal processing apparatus further includes an audio signal generating means for generating an audio signal as the predetermined signal;
The electronic endoscope system according to claim 1. The image signal processing device further includes a character signal generating means for generating a character signal as the predetermined signal;
The electronic endoscope system according to claim 1 or 2, characterized by the above.   The electronic endoscope system according to any one of claims 1 to 3, wherein the identification signal is assigned to a blanking period of the digital video signal. The image signal processing device is configured to connect a plurality of types of electronic endoscopes.
The electronic endoscope system according to any one of claims 1 to 4, wherein the electronic endoscope system is characterized in that:

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