Patent Publication Number: US-2022218181-A1

Title: Processing apparatus, processing method, and computer readable recording medium

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation-in-part of International Application No. PCT/JP2019/038842, filed on Oct. 2, 2019, the entire contents of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a processing apparatus, a processing method, and a computer readable recording medium. 
     2. Related Art 
     In the relater art, an endoscope has been in widespread use as a medical observation apparatus that is introduced into an inside of a body of a subject, such as a patient, and observes the inside of the body of the subject. Further, in recent years, a capsule endoscope as a swallow-type image acquisition apparatus that includes, inside a capsule-shaped casing, an imaging apparatus, a communication apparatus that wirelessly transmits an image signal captured by the imaging apparatus to outside the body, and the like has been developed (see, for example, Japanese Laid-open Patent Publication No. 2007-75161). The capsule endoscope, after being swallowed through a mouth of a patient for observation of an inside of the body of the subject and until being naturally excreted from the subject, moves inside of organs, such as an esophagus, a stomach, and a small intestine, in accordance with peristaltic movement of the organs and sequentially captures images. 
     While the capsule endoscope moves inside the body of the subject, image data captured by the capsule endoscope is sequentially transmitted to the outside of the body by wireless communication, and stored in a memory provided inside or outside of a receiving apparatus located outside the body via a receiving antenna or displayed as an image on a display that is arranged on the receiving apparatus. A doctor or a nurse is able to load the image data stored in the memory onto an information processing apparatus via a cradle to which the receiving apparatus is inserted and make a diagnosis on the basis of an image displayed on the information processing apparatus. 
     A plurality of receiving antennas, each of which receives image data transmitted by the capsule endoscope, are attached to the subject. The information processing apparatus selects a receiving antenna with the highest reception strength and acquires image data that has been received by the selected receiving antenna. 
     SUMMARY 
     In some embodiments, a processing apparatus includes: a processor configured to: acquire, for each of receiving antennas receiving wireless signals that are transmitted from a medical apparatus configured to capture an image of an inside of a subject, a plurality of pieces of line data that constitute first image data from the wireless signals, count numbers related to acquisition of synchronous signals included in the plurality of pieces of line data, and collect a plurality of pieces of line data that constitute second image data from the plurality of pieces of line data that are acquired by the receiving antennas and that constitute a plurality of pieces of the first image data, based on the numbers related to acquisition. 
     In some embodiments, provided is a processing method implemented by a processor. The processing method includes: acquiring, for each of receiving antennas receiving wireless signals that are transmitted from a medical apparatus configured to capture an image of an inside of a subject, a plurality of pieces of line data that constitute first image data from the wireless signals; counting numbers related to acquisition of synchronous signals included in the plurality of pieces of line data; and collecting a plurality of pieces of line data that constitute second image data from the plurality of pieces of line data that are acquired by the receiving antennas and that constitute a plurality of pieces of the first image data, based on the numbers related to acquisition. 
     In some embodiments, provided is a non-transitory computer readable recording medium having an executable program recorded thereon. The program instructs a processor to execute: acquiring, for each of receiving antennas receiving wireless signals that are transmitted from a medical apparatus configured to capture an image of an inside of a subject, a plurality of pieces of line data that constitute first image data from the wireless signals; counting numbers related to acquisition of synchronous signals included in the plurality of pieces of line data; and collecting a plurality of pieces of line data that constitute second image data from the plurality of pieces of line data that are acquired by the receiving antennas and that constitute a plurality of pieces of the first image data, based on the numbers related to acquisition. 
     The above and other features, advantages and technical and industrial significance of this disclosure will be better understood by reading the following detailed description of presently preferred embodiments of the disclosure, when considered in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram illustrating a schematic configuration of a capsule endoscope system according to a first embodiment of the present disclosure; 
         FIG. 2  is a block diagram illustrating a schematic configuration of the capsule endoscope system according to the first embodiment of the present disclosure; 
         FIG. 3  is a block diagram illustrating a configuration of a receiving antenna in the capsule endoscope system according to the first embodiment of the present disclosure; 
         FIG. 4  is a diagram for explaining a configuration of data stored in a storage unit according to the first embodiment of the present disclosure; 
         FIG. 5  is a flowchart illustrating an image data acquisition process performed by the capsule endoscope system according to the first embodiment of the present disclosure; 
         FIG. 6  is a flowchart illustrating an image data acquisition process performed by a capsule endoscope system according to a second embodiment of the present disclosure; 
         FIG. 7  is a flowchart illustrating an image data acquisition process performed by a capsule endoscope system according to a third embodiment of the present disclosure; 
         FIG. 8  is a flowchart illustrating an image data acquisition process performed by a capsule endoscope system according to a fourth embodiment of the present disclosure; 
         FIG. 9  is a diagram for explaining a configuration of line data used in the fourth embodiment of the present disclosure; 
         FIG. 10  is a schematic diagram illustrating a schematic configuration of an endoscope system according to a fifth embodiment of the present disclosure; and 
         FIG. 11  is a block diagram illustrating the schematic configuration of the endoscope system according to the fifth embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     A capsule endoscope system using a medical capsule endoscope will be described below as embodiments of the present disclosure. In description of the drawings, the same components are denoted by the same reference symbols. Further, it is necessary to note that the drawings are schematic, and a relation between a thickness and a width of each of the components, ratios among the components, and the like are different from actual ones. 
     First Embodiment 
       FIG. 1  is a schematic diagram illustrating a schematic configuration of a capsule endoscope system according to a first embodiment of the present disclosure. A capsule endoscope system  1  illustrated in  FIG. 1  includes a capsule endoscope  2  that is introduced into a subject H, that generates image data by capturing an image of an inside of the subject H, that superimposes the image data on a wireless signal, and that transmits the wireless signal by radio waves, a receiving apparatus  4  that receives the wireless signal transmitted from the capsule endoscope  2  via a receiving antenna unit  3  including a plurality of receiving antennas (receiving antennas  3   a  to  3   h ) attached to the subject H, and a processing apparatus  5  that loads the image signal captured by the capsule endoscope  2  from the receiving apparatus  4  via a cradle  5   a , that performs processing on the image data, and that generates image data representing an image of the inside of the subject H. The image data generated by the processing apparatus  5  is displayed and output by a display apparatus  6 , for example. A receiving system is configured with the plurality of receiving antennas and the receiving apparatus  4 . 
       FIG. 2  is a block diagram illustrating a schematic configuration of the capsule endoscope system according to the first embodiment of the present disclosure. The capsule endoscope  2  includes an imaging unit  21 , an illumination unit  22 , a control unit  23 , a wireless communication unit  24 , a memory  26 , and a power supply unit  27 . The capsule endoscope  2  is an apparatus in which the components as described above are incorporated in a capsule-shaped casing with a size that can be swallowed by the subject H. 
     The imaging unit  21  includes an image sensor that generates, from an optical image formed on a light receiving surface, image data in which the inside of the subject H is captured and outputs the image data, and an optical system, such as an objective lens, that is arranged at a side of the light receiving surface of the image sensor, for example. The image sensor includes a plurality of pixels that are arranged in a matrix manner and that receive light from the subject H, and generates image data by performing photoelectric conversion on light received by the pixels. The imaging unit  21  reads pixel values of the plurality of pixels, which are arranged in a matrix manner, for each of horizontal lines, and generates image data including a plurality of pieces of line data to each of which a synchronous signal is assigned for each of the horizontal lines. The imaging unit  21  is configured with a charge coupled device (CCD) image sensor or a complementary metal oxide semiconductor (CMOS) image sensor. 
     The illumination unit  22  is configured with a white light emitting diode (LED) or the like that generates white light as illumination light. Meanwhile, it may be possible to adopt a configuration that generates white light by combining light from a plurality of LEDs or laser light sources with different emission wavelength bands or a configuration using a xenon lamp, a halogen lamp, or the like, instead of the white LED. 
     The control unit  23  controls an operation process of each of the components of the capsule endoscope  2 . For example, when the imaging unit  21  performs an imaging process, the control unit  23  causes the image sensor to perform an exposure process and a read process and causes the illumination unit  22  to emit illumination light in accordance with an exposure timing of the imaging unit  21 . The control unit  23  is configured with a general-purpose processor, such as a central processing unit (CPU), or a dedicated processor, such as various arithmetic circuits including an application specific integrated circuit (ASIC) or the like, that implements specific functions. 
     The wireless communication unit  24  performs a modulation process on the image data that is output from the imaging unit  21 , and transmits the image data to outside. The wireless communication unit  24  performs analog to digital (A/D) conversion and predetermined signal processing on the image data that is output from the imaging unit  21 , acquires image data in a digital format, superimposes the image data together with related information on a wireless signal, and transmits the wireless signal from an antenna  25 . The related information includes identification information (for example, a serial number) on the capsule endoscope  2 , which is assigned to identify the individual capsule endoscope  2 , identification information (for example, a captured image number to be described later) on image data to be transmitted, and the like. Meanwhile, the wireless communication unit  24  may be configured to receive a control signal transmitted from the receiving apparatus  4  via the antenna  25 . 
     The memory  26  stores therein an execution program and a control program that are used by the control unit  23  to execute various kinds of operation and a parameter, such as a threshold. The memory  26  is configured with a volatile memory, a non-volatile memory, or a combination of a volatile memory and a non-volatile memory. The memory  26  is configured with a random access memory (RAM), a read only memory (ROM), or the like. 
     The power supply unit  27  includes a battery including a button battery or the like, a power supply circuit that supplies electric power to each of the units, and a power switch for switching between an ON state and an OFF state of the power supply unit  27 , and supplies electric power to each of the units in the capsule endoscope  2  after the power switch is turned on. Meanwhile, the power switch is configured with, for example, a reed switch for which an ON state and an OFF state are switched by an external magnetic force, and is switched to the ON state by external application of a magnetic force to the capsule endoscope  2  before use of the capsule endoscope  2  (before the capsule endoscope  2  is swallowed by the subject H). 
     The capsule endoscope  2  as described above, after being swallowed by the subject H, moves inside a digestive tract of the subject H by peristaltic movement or the like of organs and sequentially captures images of living body sites (an esophagus, a stomach, a small intestine, a large intestine, and the like) with a predetermined cycle (for example, with a cycle of 0.5 second). Further, an image signal and related information that are acquired by the imaging operation as described above are sequentially and wirelessly transmitted to the receiving apparatus  4 . 
     Configurations of the receiving antennas  3   a  to  3   h  will be described below with reference to  FIG. 3 .  FIG. 3  is a block diagram illustrating a configuration of a receiving antenna in the capsule endoscope system according to the first embodiment of the present disclosure. The receiving antennas  3   a  to  3   h  have the same configurations. In  FIG. 3 , a configuration example of a certain receiving antenna is illustrated and is applied to the receiving antennas  3   a  to  3   h . A receiving antenna  30  illustrated in  FIG. 3  includes an antenna unit  31 , a radio frequency (RF) processing unit  32 , a demodulation processing unit  33 , a signal processing unit  34 , a data transmitting/receiving unit  35 , a storage unit  36 , and a control unit  37 . 
     The antenna unit  31  receives a wireless signal from the capsule endoscope  2 . The antenna unit  31  is configured with, for example, a dipole antenna, a monopole antenna, a chip antenna, or the like. 
     The RF processing unit  32  performs processing on an RF signal that is received by the antenna unit  31 . The RF processing unit  32  extracts, from the RF signal, a signal with a frequency corresponding to data to be acquired. The RF processing unit  32  is configured with one or more of a general-purpose processor, such as a CPU, and a dedicated processor, such as various arithmetic circuits including an ASIC or the like, that implements specific functions. 
     The demodulation processing unit  33  demodulates the signal processed by the RF processing unit  32 . The demodulation processing unit  33  performs a demodulation process on the basis of the signal with the frequency extracted from the RF signal. The demodulation processing unit  33  is configured with a general-purpose processor, such as a CPU, or a dedicated processor, such as various arithmetic circuits including an ASIC or the like, that implements specific functions. 
     The signal processing unit  34  performs processing on the data that has been subjected to the demodulation process. The signal processing unit  34  includes a strength information generation unit  341 , an error counting unit  342 , and a line signal processing unit  343 . The signal processing unit  34  is configured with a general-purpose processor, such as a CPU, or a dedicated processor, such as various arithmetic circuits including an ASIC or the like, that implements specific functions. The error counting unit  342  corresponds to a counting unit. 
     The strength information generation unit  341  generates strength information on the RF signal that is received by the antenna unit  31 . The strength information generation unit  341  measures a received signal strength indicator (RSSI) of a wireless signal that is received by each of the receiving antennas  3   a  to  3   h . The strength information generation unit  341  outputs the measured RSSI of each of the receiving antennas  3   a  to  3   h  as the strength information. 
     The error counting unit  342  counts the number of bit errors of image data that is included in the signal subjected to the demodulation process, and outputs a counting result as bit error information. Specifically, the error counting unit  342  determines whether synchronous signals of a plurality of pieces of line data included in the image data are accurately received, and counts the number of bit errors in accordance with a determination result. The line data corresponds to data of a pixel sequence in a pixel array of the imaging unit  21 , and a synchronous signal is added at the top or the end of the line data, for example. 
     The line signal processing unit  343  performs a process of associating the line data included in the image data with a frame number or a receiving antenna from the RF signal, and stores the processed line data in the storage unit  36 . 
     The data transmitting/receiving unit  35 , when being connected to the receiving apparatus  4  in a communicable manner, transmits the image data stored in the storage unit  36 , information on a reception strength, or the like to the receiving apparatus  4 . The data transmitting/receiving unit  35  is configured with a communication interface, such as a serial peripheral interface (SPI). 
     The storage unit  36  stores therein a program for causing the receiving antenna  30  to operate and implement various functions, image data received by the antenna unit  31 , and the like. The storage unit  36  is configured with a RAM, a ROM, a volatile memory, or the like. 
     The control unit  37  controls each of the structural units of the receiving antenna  30 . The control unit  37  is configured with a general-purpose processor, such as a CPU, or a dedicated processor, such as various arithmetic circuits including an ASIC or the like, that implements specific functions. 
     Referring back to  FIG. 2 , the receiving apparatus  4  includes a receiving unit  41 , a data processing unit  42 , an operating unit  43 , an output unit  44 , a data transmitting/receiving unit  45 , a storage unit  46 , a control unit  47 , and a power supply unit  48 . 
     The receiving unit  41  receives a wireless signal that is wirelessly transmitted by the capsule endoscope  2 . Specifically, the receiving unit  41  receives image data and related information that are wirelessly transmitted by the capsule endoscope  2  via the receiving antenna unit  3 . 
     The data processing unit  42  performs processing on the data that is received by the receiving unit  41 . The data processing unit  42  includes a reception strength processing unit  421 , a selection unit  422 , and a data collection unit  423 . The data processing unit  42  is configured with a general-purpose processor, such as a CPU, or a dedicated processor, such as various arithmetic circuits including an ASIC or the like, that implements specific functions. 
     The reception strength processing unit  421  acquires the RSSI of each of the receiving antennas and determines a magnitude relationship. 
     The selection unit  422  selects a receiving antenna that meets a predetermined condition on the basis of the magnitude relationship determined by the reception strength processing unit  421 . For example, if a receiving antenna with the largest RSSI is to be selected, the selection unit  422  selects a receiving antenna with the largest RSSI on the basis of the magnitude relationship as described above. Further, the selection unit  422  selects line data corresponding to the set receiving antenna. For example, the selection unit  422  selects line data of the receiving antenna selected by the selection unit  422  from among the pieces of line data of all of the receiving antennas. 
     The data collection unit  423  refers to the storage unit  46  or the storage unit  36  of each of the receiving antennas, acquires the line data selected by the selection unit  422 , and collects a plurality of pieces of line data that constitute image data. The data collection unit  423  collects the line data of the selected (sorted) receiving antenna, for each of line numbers. 
     The operating unit  43  is an input device that is used when a user inputs various kinds of setting information or instruction information to the receiving apparatus  4 . The operating unit  43  is configured with, for example, a switch, a button, or the like that is arranged on an operation panel of the receiving apparatus  4 . 
     The output unit  44  displays an image, outputs sound or light, or generates vibration. The output unit  44  displays a notification image corresponding to an interference level, or generates sound, light, or vibration. The output unit  44  is configured with at least one of a display, such as a liquid crystal display or an organic electro luminescence (EL) display, a speaker, a light source, and a vibration generator, such as a vibration motor. 
     The data transmitting/receiving unit  45 , when being connected to the processing apparatus  5  in a communicable manner, transmits the image data and the related information that are stored in the storage unit  46  to the processing apparatus  5 . The data transmitting/receiving unit  45  is configured with a communication interface, such as a universal serial bus (USB) or a local area network (LAN). 
     The storage unit  46  stores therein a program for causing the receiving apparatus  4  to operate and implement various functions, image data acquired by the capsule endoscope  2 , a threshold for a determination process, and the like. The storage unit  46  is configured with a RAM, a ROM, or the like. 
       FIG. 4  is a diagram for explaining a configuration of data stored in the storage unit according to the first embodiment of the present disclosure. In the first embodiment, the storage unit  46  stores therein, for each of the receiving antennas, strength data D_ 0  related to the RSSI of the receiving antenna and pieces of line data D_ 1  to D_N related to a plurality of lines that constitute an image. Each piece of the line data D_ 1  to D_N includes information on an image (Image data) and information on the number of bit errors in the line data. 
     The control unit  47  controls each of the structural units of the receiving apparatus  4 . The control unit  47  is configured with a general-purpose processor, such as a CPU, or a dedicated processor, such as various arithmetic circuits including an ASIC or the like, that implements specific functions. 
     The power supply unit  48  supplies electric power to each of the units of the receiving apparatus  4 . The power supply unit  48  is configured with, for example, a battery including an electric battery or the like. 
     The receiving apparatus  4  as described above is attached to and carried with the subject H while the capsule endoscope  2  is performing imaging, in particular, after the capsule endoscope  2  is swallowed by the subject H and until the capsule endoscope  2  is excreted through digestive tracts. During this period, the receiving apparatus  4  stores image data that is received via the receiving antenna unit  3  in the storage unit  46 . 
     After the capsule endoscope  2  completes imaging, the receiving apparatus  4  is detached from the subject H and set to the cradle  5   a  (see  FIG. 1 ) that is connected to the processing apparatus  5 . Accordingly, the receiving apparatus  4  is connected to the processing apparatus  5  in a communicable manner, and transfers (downloads) the image data and the related information stored in the storage unit  46  to the processing apparatus  5 . 
     The processing apparatus  5  is configured with, for example, a workstation including the display apparatus  6 , such as a liquid crystal display. The processing apparatus  5  includes a data transmitting/receiving unit  51 , an image processing unit  52 , a control unit  53 , a display control unit  54 , an input unit  55 , and a storage unit  56 . 
     The data transmitting/receiving unit  51  is connected to the receiving apparatus  4  via the cradle  5   a , and transmits and received data to and from the receiving apparatus  4 . The data transmitting/receiving unit  51  is configured with a communication interface, such as a USB or a LAN. 
     The image processing unit  52  reads a predetermined program stored in a storage unit  58  (to be described later) and performs predetermined image processing for generating an image corresponding to image data that is input from the data transmitting/receiving unit  51  or image data that is stored in the storage unit  58 . The image processing unit  52  is implemented by a general-purpose processor, such as a CPU, or a dedicated processor, such as various arithmetic circuits including an ASIC or the like, that implements specific functions. 
     The control unit  53  reads various programs stored in the storage unit  56 , transfers an instruction or data to each of the units included in the processing apparatus  5  on the basis of a signal that is input from the input unit  55  or image data that is input from the data transmitting/receiving unit  51 , and comprehensively controls entire operation of the processing apparatus  5 . The control unit  53  is implemented by a general-purpose processor, such as a CPU, or a dedicated processor, such as various arithmetic circuits including an ASIC or the like, that implements specific functions. 
     The display control unit  54  performs predetermined processing, such as data decimation corresponding to an image display range of the display apparatus  6  or gradation processing, on the image generated by the image processing unit  52 , and displays and outputs the obtained image together with display target information, such as a final score, on the display apparatus  6 . The display control unit  54  is implemented by a general-purpose processor, such as a CPU, or a dedicated processor, such as various arithmetic circuits including an ASIC or the like, that implements specific functions. 
     The input unit  55  receives input of information or a command corresponding to operation performed by a user. The input unit  55  is implemented by, for example, an input device, such as a keyboard, a mouse, a touch panel, or various switches. 
     The storage unit  56  stores therein a program for causing the processing apparatus  5  to operate and implement various functions, various kinds of information used during execution of the program, the image data and the related information acquired from the receiving apparatus  4 , an endoscopic image generated by the image processing unit  52 , and the like. The storage unit  56  is implemented by a semiconductor memory, such as a flash memory, a RAM, or a ROM, a recording medium, such as a hard disk drive (HDD), a magneto-optical disk (MO), a compact disc-recordable (CD-R), or a digital versatile disk-recordable (DVD-R), a driving apparatus that drives the recording medium, or the like. 
     An image data acquisition process performed by the capsule endoscope system  1  will be described below.  FIG. 5  is a flowchart illustrating the image data acquisition process performed by the capsule endoscope system according to the first embodiment of the present disclosure. The flowchart illustrated in  FIG. 5  is one example of acquiring a plurality of pieces of line data as image data of a single frame. 
     First, at Step S 101 , the data processing unit  42  acquires information on the RSSI from each of the receiving antennas. The reception strength processing unit  421  determines a magnitude relationship on the basis of the acquired RSSI of each of the receiving antennas. For example, the reception strength processing unit  421  acquires the strength data D_ 0  (see  FIG. 4 ) of each of the receiving antennas from the storage unit  46 , and determines the magnitude relationship among the RSSIs of all of the receiving antennas. 
     At Step S 102  following Step S 101 , the selection unit  422  selects a receiving antenna with the largest RSSI on the basis of the magnitude relationship determined by the reception strength processing unit  421 . The selection unit  422  sets a selection order K of the receiving antenna with the largest RSSI such that K=1, where the selection order K is for selecting the receiving antenna. The selection unit  422  determines the selection orders with respect to the receiving antennas other than the receiving antenna with the largest RSSI, on the basis of a condition that is preset. For example, the selection unit  422  assigns numbers to the receiving antennas in descending order of the RSSIs (in this example, K=2, 3, . . . , 8). Hereinafter, a maximum value of K (the number of the receiving antennas) is denoted by Ma. In the first embodiment, Ma=8. 
     At Step S 103 , the selection unit  422  acquires the bit error information on the selected receiving antenna. The selection unit  422  acquires the number of bit errors of each piece of line data of the selected receiving antenna. 
     At Step S 104 , the selection unit  422  determines whether a piece of line data for which the number of bit errors is equal to or larger than a predetermined threshold is present. If the selection unit  422  determines that a piece of line data for which the number of bit errors is equal to or larger than the threshold is present (Step S 104 : Yes), the process goes to Step S 106 . In contrast, if the selection unit  422  determines that a piece of line data for which the number of bit errors is equal to or larger than the threshold is not present (Step S 104 : No), the process goes to Step S 105 . The threshold is set on the basis of the number of bit errors corresponding to allowable image definition. The threshold is stored in the storage unit  46  in advance. In the first embodiment, a predetermined criterion (first criterion) is that the number of bit errors is smaller than the threshold. 
     At Step S 105 , the selection unit  422  associates the receiving antenna with the largest RSSI, with numbers of pieces of line data to be collected, and stores the associated information in the storage unit  46 . At Step S 105 , pieces of line data acquired by the same receiving antenna constitute image data of a single frame. After completion of the association by the selection unit  422 , the data processing unit  42  goes to Step S 117 . 
     Further, at Step S 106 , the selection unit  422  selects, as a collection target that is line data to be collected, a piece of line data for which the number of bit errors is smaller than the threshold. The data collection unit  423  stores the line data selected by the selection unit  422  in the storage unit  46  in association with the number of the receiving antenna. In this example, the selected line data and the number of the receiving antenna selected at Step S 102  are associated with each other. 
     At Step S 107 , the selection unit  422  sets the selection order K of the receiving antenna such that K=2. 
     At Step S 108 , the selection unit  422  extracts a number (hereinafter, may be simply referred to as a line number) of line data for which the number of bit errors is determined as being equal to or larger than the threshold at Step S 104 . The selection unit  422  assigns En to the extracted line number. For example, the selection unit  422  assigns En in ascending order of the line numbers such that En=1, 2, 3, . . . Q (Q is the number of extractions). 
     At Step S 109 , the selection unit  422  acquires information on the numbers of bit errors for all pieces of line data to which the line numbers En are assigned with respect to the K-th receiving antenna. 
     At Step S 110 , the selection unit  422  determines whether a piece of line data for which the acquired number of bit errors is equal to or larger than a predetermined threshold is present. If the selection unit  422  determines that a piece of line data for which the number of bit errors is equal to or larger than the threshold is present (Step S 110 : Yes), the process goes to Step S 112 . In contrast, if the selection unit  422  determines that a piece of line data for which the number of bit errors is equal to or larger than the threshold is not present (Step S 110 : No), the process goes to Step S 111 . 
     At Step S 111 , the data collection unit  423  acquires En-th line data that is acquired by the K-th receiving antenna. The data collection unit  423  stores the acquired En-th line data as image data of the subject frame in the storage unit  46 . 
     Further, at Step S 112 , the selection unit  422  selects, as a collection target that is line data to be collected, a piece of line data for which the number of bit errors is smaller than the threshold. The data collection unit  423  stores the line data selected by the selection unit  422  in the storage unit  46  in association with the number of the receiving antenna. In this example, a piece of line data for which the number of bit errors is smaller than the threshold among the pieces of line data assigned with the numbers En with respect to the K-th receiving antenna is associated with the number of the receiving antenna. 
     At Step S 113 , the selection unit  422  extracts the line number for which the number of bit errors is determined as being equal to or larger than the threshold at Step S 110 , and re-defines En. The selection unit  422  re-assigns En to the extracted line number. For example, the selection unit  422  assigns En in ascending order of the line numbers such that En=1, 2, 3, . . . Z (Z is the number of extractions). 
     At Step S 114 , the selection unit  422  increments a value of the selection order K of the receiving antenna by one. 
     At Step S 115 , the selection unit  422  determines whether the set selection order K is smaller than the maximum value Ma that is allowable for K. If the selection order K is smaller than the maximum value Ma (Step S 115 : No), the selection unit  422  returns to Step S 108  and the above-described processes are repeated for the receiving antenna corresponding to the updated selection order K. In contrast, if the selection order K is equal to the maximum value Ma (Step S 115 : Yes), the selection unit  422  goes to Step S 116 . 
     At Step S 116 , the selection unit  422  associates line data of the receiving antenna having the smallest number of bit errors, with all pieces of line data assigned with the numbers En, and stores the associated information in the storage unit  46 . At this time, if a plurality of receiving antennas having the smallest numbers of bit errors are present, the selection unit  422  associates the receiving antenna with the largest RSSI. At Step  3116 , each piece of line data is associated with the receiving antenna corresponding to the selection order K or the receiving antenna with the largest RSSI. After completion of the association by the selection unit  422 , the data processing unit  42  goes to Step S 117 . 
     At Step S 117 , the data collection unit  423  collects line data of the receiving antenna associated with each of the line numbers. The data collection unit  423  collects line data that is acquired by the associated receiving antenna, for each of the line numbers. 
     Through the process as described above, image data of a single frame that is formed of pieces of line data with the line numbers selected from among all of the receiving antennas is generated. The receiving apparatus  4 , by repetition of the process as described above, acquires image data of a plurality of frames captured by the capsule endoscope  2 . 
     In the first embodiment as described above, image data of a single frame is generated by pieces of line data each having a high reception strength and the small number of bit errors, on the basis of line data received by each of the receiving antennas. According to the first embodiment, it is possible to obtain image data in which noise is suppressed. 
     Second Embodiment 
     A second embodiment of the present disclosure will be described below.  FIG. 6  is a flowchart illustrating an image data acquisition process performed by a capsule endoscope system according to the second embodiment of the present disclosure. The capsule endoscope system according to the second embodiment has the same configuration as that of the first embodiment. A process different from the first embodiment will be described below with reference to  FIG. 6 . 
     First, at Step S 201 , the data processing unit  42  acquires information on the RSSI from each of the receiving antennas. Subsequently, the reception strength processing unit  421  determines priorities on the basis of the acquired RSSI of each of the receiving antennas (Step S 202 ). In the second embodiment, the priorities are determined in descending order of the RSSIs. 
     At Step S 203  following Step S 202 , the selection unit  422  acquires the number of bit errors of each piece of line data of each of the receiving antennas. A line number M is set such that M=1. 
     At Step S 204 , the selection unit  422  extracts a receiving antenna that has line data with the smallest number of bit errors (best line data) among the receiving antennas with respect to the M-th line data. 
     At Step S 205  following Step S 204 , the selection unit  422  determines whether a plurality of receiving antennas with the smallest numbers of bit errors are present with respect to each of line numbers of the collection target. If the selection unit  422  determines that a plurality of receiving antennas with the smallest number of bit errors are present (Step S 205 : Yes), the process goes to Step S 206 . If the selection unit  422  determines that only a single receiving antenna with the smallest number of bit errors is present (Step S 205 : No), the process goes to Step S 207 . A first condition is that a plurality of antennas with the smallest numbers of bit errors are not present at Step S 205 . 
     At Step S 206 , the selection unit  422  determines an antenna number with the smallest number of bit errors in order of priorities based on the RSSIs, from among the plurality of antennas with the smallest numbers of bit errors. Meanwhile, a second condition is that the priority is the highest when the plurality of receiving antennas with the smallest numbers of bit errors are present at Step S 206 . 
     At Step S 207 , the selection unit  422  associates, with respect to each piece of line data, the line data number with an antenna number that has the synchronous signal for which the number of bit errors is the smallest. The selection unit  422  stores the associated information in the storage unit  46 . After completion of the association, the control unit  47  goes to Step S 208 . 
     At Step S 208 , the selection unit  422  increments a value of the line number M by one. 
     At Step S 209  following Step S 208 , if the line number M is larger than a maximum value L (Step S 209 : Yes), the selection unit  422  goes to Step S 210 . In contrast, if the line number M is equal to or smaller than the maximum value L (Step S 209 : No), the selection unit  422  goes to Step S 204 . 
     The selection unit  422  repeats the processes from Step S 204  to Step S 209  until all of the line data numbers are associated with the antenna numbers. 
     At Step S 210 , the data collection unit  423  collects line data of the receiving antenna associated with each of the line numbers. The data collection unit  423  collects line data that is acquired by the associated receiving antenna, for each of the line numbers. 
     Through the process as described above, image data of a single frame that is formed of pieces of line data with the line numbers selected from among all of the receiving antennas is generated. 
     In the second embodiment as described above, if the receiving antennas that have the same numbers of bit errors are present with respect to line data with the same number, the receiving antenna with the higher priority that is determined based on the RSSI is selected. In the second embodiment, image data of a single frame is generated by pieces of line data each having a high reception strength and the small number of bit errors, on the basis of the line data received by each of the receiving antennas. 
     According to the second embodiment, it is possible to obtain image data in which noise is suppressed. 
     Third Embodiment 
     A third embodiment of the present disclosure will be described below.  FIG. 7  is a flowchart illustrating an image data acquisition process performed by a capsule endoscope system according to the third embodiment of the present disclosure. The capsule endoscope system according to the third embodiment has the same configuration as that of the first embodiment. A process different from the first embodiment will be described below with reference to  FIG. 7 . 
     First, at Step S 301 , the data processing unit  42  acquires information on the RSSI from each of the receiving antennas. Subsequently, the reception strength processing unit  421  determines priorities on the basis of the acquired RSSI of each of the receiving antennas (Step S 302 ). In the third embodiment, priorities N are determined in descending order of the RSSIs (N=1, 2, 3, . . . , Ma). The selection unit  422  assigns numbers to all of the receiving antennas in descending order of the RSSIs, for example. The priorities in the third embodiment are the same as the selection orders as described above. 
     At Step S 303  following Step S 302 , the selection unit  422  sets an association target line number M such that M=1. In the third embodiment, a maximum value of the line number is denoted by L. 
     At Step S 304  following Step S 303 , the selection unit  422  selects a receiving antenna with the largest RSSI on the basis of the magnitude relationship determined by the reception strength processing unit  421 . The selection unit  422  sets the priority N of the receiving antenna with the largest RSSI such that N=1. 
     At Step S 305 , the selection unit  422  acquires the bit error information on the M-th line number of the receiving antenna with the priority N. 
     At Step S 306 , the selection unit  422  determines whether the acquired number of bit errors is equal to or smaller than a predetermined threshold. If the selection unit  422  determines that the number of bit errors is larger than the threshold (Step S 306 : No), the process goes to Step S 310 . In contrast, if the selection unit  422  determines that the number of bit errors is equal to or smaller than the threshold (Step S 306 : Yes), the process goes to Step S 307 . Meanwhile, a first condition is that the number of bit errors is equal to or smaller than the threshold at Step S 306 . 
     At Step S 307 , the data collection unit  423  stores line data with the line number M of the N-th receiving antenna in the storage unit  46 . After the selection unit  422  completes the association, the data processing unit  42  goes to Step S 308 . 
     At Step S 308  following Step S 307 , the selection unit  422  increments a value of the line number M by one. 
     At Step S 309  following Step S 308 , the selection unit  422  determines whether the set line number M is equal to or smaller than the maximum value L that is allowable for M. If the line number M is larger than the maximum value L (Step S 309 : Yes), the selection unit  422  goes to Step S 318 . In contrast, if the line number M is equal to or smaller than the maximum value L (Step S 309 : No), the selection unit  422  returns to Step S 304 . 
     Further, at Step S 310 , the selection unit  422  determines whether the priority N of the set receiving antenna is set such that N=1. If the selection unit  422  determines that N is not set such that N=1 (Step S 310 : No), the process goes to Step S 312 . In contrast, if the selection unit  422  determines that N is set such that N=1 (Step S 310 : Yes), the process goes to Step S 311 . 
     At Step S 311 , the selection unit  422  associates the number of bit errors E of the line number M of the receiving antenna for which N=1 with the number of the receiving antenna, and stores the associated information in the storage unit  46 . 
     Further, at Step S 312 , the selection unit  422  acquires the bit error information on the line number M of the N-th receiving antenna, and determines whether the acquired number of bit errors is equal to or larger than the stored number of bit errors E. If the selection unit  422  determines that the acquired number of bit errors is smaller than the stored number of bit errors E (Step S 312 : No), the process goes to Step S 314 . In contrast, if the selection unit  422  determines that the acquired number of bit errors is equal to or larger than the stored number of bit errors E (Step S 312 : Yes), the process goes to Step S 313 . 
     At Step S 313 , the selection unit  422  maintains the stored number of bit errors E. 
     Further, at Step S 314 , the selection unit  422  updates the number of bit errors E with the number of bit errors acquired at Step S 311 . 
     At Step S 315  following Step S 314 , the selection unit  422  determines whether the set priority N is equal to or larger than the maximum value Ma that is allowable for N. If the selection unit  422  determines that the priority N is smaller than the maximum value Ma (Step S 315 : No), the process goes to Step S 317 . In contrast, if the selection unit  422  determines that the priority N is equal to the maximum value Ma (Step S 315 : Yes), the process goes to Step S 316 . 
     At Step S 316 , the selection unit  422  selects, as an acquisition target, a piece of line data with the line number M of the receiving antenna corresponding to the number of bit errors E. After selection of the receiving antenna, the data processing unit  42  goes to Step S 307 . Meanwhile, a second condition is that if the first condition is not met, the number of bit errors is the smallest among all of the receiving antennas at Steps S 307  to S 316 . 
     At Step S 317 , the selection unit  422  sets the priority N such that N=N+1. After setting the priority, the data processing unit  42  goes to Step S 305  and repeats the process as described above. 
     Through the process as described above, image data of a single frame that is formed of pieces of line data with the line numbers selected from among all of the receiving antennas is generated. 
     In the third embodiment as described above, line data of the receiving antenna with the largest RSSI is used as a base, and line data of a different receiving antenna is selected as line data with the large number of bit errors. In the third embodiment, image data of a single frame is generated by pieces of line data each having the small number of bit errors, on the basis of the line data received by each of the receiving antennas. According to the third embodiment, it is possible to obtain image data in which noise is suppressed. 
     Fourth Embodiment 
     A fourth embodiment of the present disclosure will be described below. In the first to the third embodiments as described above, acquisition target line data is selected by using the RSSI of each of the receiving antennas and the bit error information on the synchronous signals of a plurality of pieces of line data included in the image data. In contrast, in the fourth embodiment, acquisition target line data is selected by using only the RSSI that is measured every time each piece of line data included in image data is received. A capsule endoscope system according to the fourth embodiment is configured by removing the error counting unit  342  from the configuration of the capsule endoscope  1  according to the first embodiment. Other configurations of the capsule endoscope system according to the fourth embodiment are the same as those of the first embodiment. 
       FIG. 8  is a flowchart illustrating an image data acquisition process performed by the capsule endoscope system according to the fourth embodiment of the present disclosure. A process according to the fourth embodiment will be described below with reference to  FIG. 8 . 
     First, at Step S 401 , the data processing unit  42  acquires information on the RSSI for each piece of line data, from each of the receiving antennas.  FIG. 9  is a diagram for explaining a configuration of line data used in the fourth embodiment of the present disclosure. In the fourth embodiment, the data processing unit  42  acquires each piece of line data (LD_ 1  to LD_N) that includes information on an image (Image data) and RSSI information (RSSI), and extracts the RSSI information from each piece of the acquired line data. In the fourth embodiment, the information illustrated in  FIG. 9  is stored in the storage unit  46 . 
     At Step S 402 , the selection unit  422  acquires the number of bit errors of line data of each of the receiving antennas. The line number M is set such that M=1. 
     At Step S 403  following Step S 402 , the selection unit  422  extracts the antenna number of the receiving antenna having line data with the largest RSSI with respect to the M-th line data. 
     At Step S 404  following Step S 403 , the selection unit  422  associates the M-th line data with the antenna number of the receiving antenna with the largest RSSI. The selection unit  422  stores the associated information in the storage unit  46 . After the association, the control unit  47  goes to Step S 405 . 
     At Step S 405  following Step S 404 , the selection unit  422  increments a value of the line number M by one. 
     At Step S 406  following Step S 405 , if the line number M is larger than the maximum value L (Step S 406 : Yes), the selection unit  422  goes to Step S 407 . In contrast, if the line number M is not larger than the maximum value L (Step S 406 : No), the selection unit  422  goes to Step S 403 . 
     The selection unit  422  repeats the processes from Step S 403  to Step S 406  until all of the line data numbers are associated with the antenna numbers. 
     At Step S 407 , the data collection unit  423  collects line data of the receiving antenna associated with each of the line numbers. The data collection unit  423  collects line data that is acquired by the associated receiving antenna, for each of the line numbers. 
     Through the process as described above, image data of a single frame that is formed of pieces of line data with the line numbers selected from among all of the receiving antennas is generated. 
     In the fourth embodiment as described above, the receiving antenna from which image data is to be acquired is selected based on the RSSI. In the fourth embodiment, image data of a single frame is generated by pieces of line data each having a high reception strength, on the basis of the line data received by each of the receiving antennas. According to the fourth embodiment, it is possible to obtain image data in which noise is suppressed. 
     Meanwhile, if a difference between the RSSI of the line data with the line number M−1 and the RSSI of the line data with the line number M is equal to or smaller than a reference value, it may be possible to adopt the receiving antenna of the line data that is selected as an acquisition target for the line number M−1, as the receiving antenna of the line data to be selected as an acquisition target for the line number M. 
     Specifically, if a difference between the RSSI of a receiving antenna N of the line data that is selected as an acquisition target for the line number M−1 and the RSSI of the same receiving antenna for the line number M is equal to or smaller than a reference value, line data that is assigned with the line number M and that is received by the same receiving antenna N is selected as an acquisition target. 
     In the fourth embodiment as described above, image data of a single frame is generated by selecting line data of the receiving antenna with the largest RSSI, for each piece of line data. According to the fourth embodiment, it is possible to obtain image data in which noise is suppressed. 
     While the embodiments of the present disclosure have been explained above, the present disclosure is not limited to the embodiments and the modifications as described above. The present disclosure is not limited to the embodiments and the modifications as described above, and includes various other embodiments within a scope not departing from the technical idea described in the appended claims. Further, the configurations of the embodiments and the modifications may be combined appropriately. 
     Meanwhile, in the first to the fourth embodiments as described above, the capsule endoscope  2  has been described as an example of the medical apparatus, but the present disclosure is not limited to this example. For example, a medical apparatus, such as an implant medical device or a catheter, that is introduced into a subject, that acquires pH information, and that outputs the acquired information as a wireless signal may be adopted. Furthermore, a medical apparatus that outputs, as a wireless signal, an image signal that is captured by an endoscope having a different system from a capsule type, e.g., an endoscope that performs wireless communication with a processing apparatus, may be adopted. 
     Fifth Embodiment 
     A fifth embodiment of the present disclosure will be described below.  FIG. 10  is a schematic diagram illustrating a schematic configuration of an endoscope system according to the fifth embodiment of the present disclosure.  FIG. 11  is a block diagram illustrating a schematic configuration of the endoscope system according to the fifth embodiment of the present disclosure. In the first to the fourth embodiments as described above, the capsule endoscope system including the capsule endoscope  2  has been described, but in the fifth embodiment, an example of an endoscope system that includes a wireless endoscope  2 A capable of performing wireless communication and a receiver  7  capable of performing communication with the wireless endoscope  2 A will be described. 
     The wireless endoscope  2 A (hereinafter, may be simply referred to as the “endoscope  2 A”) includes, for example, an imaging unit  212  at a distal end portion of a thin and elongated insertion portion thereof. The receiver  7  that is a portable monitor includes receiving antennas  71  and a display  72  that displays an endoscopic image. Transmitting antennas  211  of the endoscope  2 A and the receiving antennas  71  of the receiver  7  perform wireless communication using a 5 GHz band or a 60 GHz band. 
     The endoscope  2 A includes the transmitting antennas  211  (transmitting antennas  211 A to  211 C), the imaging unit  212 , a first image processing unit  213 , a first control unit  214 , a signal generation unit  215 , and a first transmitting/receiving unit  216 . 
     The imaging unit  212  includes an image sensor and acquires an endoscopic image. The first image processing unit  213  performs predetermined image processing, such as image compression processing, on the endoscopic image, and outputs an image signal. The first control unit  214  controls the entire operation of the endoscope  2 A and controls wireless transmission and reception, for example, performs switching control on the transmitting antennas  211  as will be described later. The signal generation unit  215  generates a signal for acquiring a second sensitivity to be described later. The first transmitting/receiving unit  216  transmits and receives a signal by using the transmitting antennas  211 . A wireless signal transmitted and received by the first transmitting/receiving unit  216  includes a main signal including the image signal and includes a signal (sub signal) that is generated by the signal generation unit  215  and that is transmitted at a carrier frequency different from the main signal. 
     The receiver  7  includes the receiving antennas  71  (receiving antennas  71 A to  71 C), the display  72 , a second image processing unit  73 , a second control unit  74 , a first sensitivity acquisition unit  75 , a second transmitting/receiving unit  76 , a second sensitivity acquisition unit  77 , a comparing unit  78 , and a setting unit  79 . The receiver  7  includes a storage unit in the receiver  7  or the second control unit  74 . 
     The second transmitting/receiving unit  76  transmits and receives a signal by using the receiving antennas  71 . The second image processing unit  73  performs predetermined image processing on a received image signal, and displays an image on the display  72  under the control of the second control unit  74 . The second control unit  74  controls the entire receiver  7  and controls wireless transmission and reception, for example, performs switching control on the receiving antennas  71 . The first sensitivity acquisition unit  75 , the second sensitivity acquisition unit  77 , the comparing unit  78 , and the setting unit  79  acquire data for performing the switching control on antenna pairs that are sets of the transmitting antennas  211  and the receiving antennas  71 . Meanwhile, as for the antenna pairs, sets of the receiving antennas and the transmitting antennas may be preset or setting of the pairs may be changed appropriately. 
     The first sensitivity acquisition unit  75  acquires a first communication sensitivity that is a communication sensitivity (that is, reception strength or RSSI) of a first antenna pair that is formed of a first transmitting antenna and a first receiving antenna and that is a set of a transmitting antenna and a receiving antenna for transmitting and receiving an image signal that is a main signal having largest transmission quantity among wireless signals. The second sensitivity acquisition unit  77  acquires, by using a sub signal, second communication sensitivities of a plurality of second antenna pairs each being formed of any of the transmitting antennas and any of the receiving antennas that do not transmit and receive the main signal. Further, if a communication sensitivity between a second transmitting antenna and a second receiving antenna, which is the highest among the plurality second communication sensitivities, is higher than the first communication sensitivity, the setting unit  79  sets the antenna pair formed of the second transmitting antenna and the second receiving antenna as the first antenna pair that transmits and receives the main signal. 
     In the fifth embodiment, similarly to the image data acquisition process of the first embodiment, an image data acquisition process is performed (see  FIG. 5 ). Specifically, the second control unit  74  acquires the RSSI information received by each of the receiving antennas (the receiving antennas  71 A to  71 C) of the receiver  7 , selects a receiving antenna with the largest RSSI, adopts the selected receiving antenna as the first receiving antenna, and acquires the bit error information on the synchronous signals of the receiving antenna. At this time, if the numbers of bit errors of the selected receiving antenna are smaller than a threshold, the second control unit  74  stores all pieces of line data acquired by the receiving antenna in the storage unit. In contrast, if the number of bit errors of the selected receiving antenna is equal to or larger than the threshold, the second control unit  74  stores, in the storage unit, line data of a receiving antenna that is one of the other receiving antennas (the second receiving antennas), that has the smaller number of bit errors than the threshold among the receiving antennas having smaller RSSIs than the selected antenna, and that has the largest RSSI among the other receiving antennas. 
     In the fifth embodiment as described above, similarly to the first embodiment, image data of a single frame is generated by pieces of line data each having a high reception strength and the small number of bit errors, on the basis of line data received by each of the receiving antennas. Therefore, it is possible to obtain image data in which noise is suppressed. 
     Furthermore, an endoscope system  1 A according to the fifth embodiment suppresses reduction in the communication sensitivity by transmitting and receiving the image signal by using an antenna pair with the highest communication sensitivity among the plurality of antennas. According to the endoscope system  1 A, even if relative positions of the endoscope  2 A and the receiver  7  are changed or an object that disturbs radio wave transmission is provided between the endoscope  2 A and the receiver, it is possible to transmit a high quality endoscopic image. 
     Meanwhile, in the first to the third embodiments as described above, the example has been described in which the error counting unit  342  counts the number of bit errors in the synchronous signal as pattern data, but it may be possible to count the number of bits of a normally acquired synchronous signal. In this case, line data for which the counted value is larger than a threshold is selected as an acquisition target. In this case, a second criterion is that the counted value is larger than the threshold. Further, the error counting unit  342  may be configured to count the number of fixed patterns or the number of pieces of block data included in each piece of line data, instead of the synchronous signal. 
     Furthermore, in the first to the fifth embodiments as described above, the example has been described in which the data processing unit  42  performs processing for each piece of line data, but the collection target is not limited to data of each line, but a plurality of pieces of line data may be collected as a single set. For example, three consecutive pieces of line data may be grouped into a single set, the error counting unit  342  may count a representative count value of each of the sets, and the data collection unit  423  may collect line data for each of the sets. In the present embodiment, each piece of partial image data that constitutes image data of a single frame may be adopted as a single piece of line data or may be adopted as a single set of line data. 
     Moreover, in the first to the fifth embodiments as described above, the example has been described in which the process of counting the number of bit errors or the like is performed for all of the receiving antennas, but it may be possible to perform the process for a part of the receiving antennas. For example, it may be possible to perform the process on only the receiving antennas for which the RSSIs are equal to or larger than a predetermined value. In other words, it may be possible to generate groups of receiving antennas based on the RSSIs, and perform the process on only a group of the receiving antennas having large RSSIs. 
     Furthermore, an execution program implemented by each of the structural units of the capsule endoscope systems  1  and  1 A in the embodiments may be provided by being recorded in a computer readable recording medium, such as a compact disc-read only memory (CD-ROM), a flexible disk (FD), a CD-R, or a digital versatile disk (DVD), in an installable or an executable file format, or may be provided by being stored in a computer connected to a network, such as the Internet, and by being downloaded via the network. Moreover, the execution program may be provided or distributed via a network, such as the Internet. 
     As described above, the receiving system according to the present disclosure is useful for acquiring image data in which noise is suppressed. 
     According to the present disclosure, it is possible to acquire image data in which noise is suppressed. 
     Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the disclosure in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.