JP2005223427A - Receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a receiver which has a simple configuration, and reliably selects and switches an optimum antenna with high reception electric field strength even in a short reception electric field strength measurement period. <P>SOLUTION: A connection unit CON detects the connection state of each antenna wherein each antenna is connected corresponding to the arrangement positions of reception antennas A1 to An. A selection control section C1 sets reception antennas whose antenna connection states are detected as strength reception antennas, allows the strength reception antennas to sequentially detect the reception electric field strength during the strength reception period in a single frame, and selects the strength reception antenna from which the highest reception electric field strength is detected as a video reception antenna. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a receiving apparatus that receives a radio signal having a frame structure including an information main body including an information main body and an additional unit including at least information for measuring received field strength using a plurality of antennas. The present invention relates to a receiving apparatus that receives a wireless video signal transmitted from a capsule endoscope in a specimen using a plurality of antennas outside the subject.

  In recent years, swallowable capsule endoscopes have appeared in the field of endoscopes. This capsule endoscope is provided with an imaging function and a wireless communication function. Capsule endoscopes are peristaltic in the body cavity, for example, the stomach, small intestine, etc., after being swallowed from the patient's mouth for observation (examination) and before being spontaneously discharged from the human body. It has the function to move according to and to image sequentially.

  While moving inside the body cavity, image data imaged inside the body by the capsule endoscope is sequentially transmitted to the outside by wireless communication and stored in a memory provided in an external receiver. When the patient carries the receiver having the wireless communication function and the memory function, the patient can freely act even during the period from swallowing the capsule endoscope until it is discharged. Thereafter, the doctor or nurse can make a diagnosis by displaying an organ image on the display based on the image data stored in the memory.

  Generally, a receiver distributes a plurality of antennas for receiving a video signal transmitted from a capsule endoscope outside the body, and selects and receives one antenna with few reception errors of the video signal. ing. In Patent Document 1, reception switching of a plurality of antennas arranged outside the body is performed, and the position of the capsule endoscope in the body, which is a transmission source of the video signal, based on the electric field intensity received by each antenna. A receiver for detecting is described.

Japanese Patent Laid-Open No. 2003-19111

  However, in the conventional receiver, when one antenna is selectively switched from a plurality of antennas and one receiving unit (tuner) is used, the received electric fields of the plurality of antennas are received within a reception field strength measurement period such as a preamble. There was a problem that the strength had to be measured.

  Here, when the number of antennas increases, in order to measure the received field strength of all antennas within the received field strength measurement period described above, a changeover switch capable of high-speed switching of antennas and high-speed received field strength measurement processing are realized. There was a problem that a circuit configuration to be required.

  The present invention has been made in view of the above, and has a simple configuration and a receiving device that can reliably select and switch an optimum antenna having a large received electric field strength even in a short received electric field strength measurement period. The purpose is to provide.

  In order to solve the above-described problems and achieve the object, a receiving apparatus according to claim 1 is a wireless signal transmitted from a moving transmitting apparatus, and includes an information main body including at least an information main body and a received electric field strength measurement. In a receiving apparatus that receives a frame-structured radio signal having an additional unit including information for using a plurality of antennas, each antenna can be connected corresponding to the arrangement position of the plurality of antennas An antenna switching unit that detects a connection state of each antenna and switches the connected antenna according to an instruction; and an antenna whose connection is detected by the antenna switching unit during reception of the additional unit is sequentially switched to detect a received electric field strength, Control means for switching to the antenna that has detected the largest received electric field strength and receiving the radio signal of the information main body. It is characterized in.

  In the receiving device according to claim 2, in the above invention, the number of the plurality of antennas is less than the number of the plurality of connection portions, and the plurality of antennas is one of the plurality of already connected antennas. The part is used by being replaced with another connection part.

  According to a third aspect of the present invention, in the above invention, the control means measures the received electric field strengths of a plurality of antennas during the reception period of the additional unit.

  In the receiving apparatus according to the present invention, the control means sequentially switches only the antenna whose connection is detected by the antenna switching means at the time of reception by the adding unit to detect the received electric field strength, and switches to the antenna that has detected the largest received electric field strength. Since the radio signal of the information main body is received, the total number of antennas to be switched can be reduced, and the time required for the antenna switching process can be shortened.

  Hereinafter, a wireless in-vivo information acquiring system provided with a receiving apparatus which is the best mode for carrying out the present invention will be described.

(Embodiment 1)
First, a wireless in-vivo information acquiring system including the receiving apparatus according to the first embodiment will be described. This wireless intra-subject information acquisition system uses a capsule endoscope as an example of the intra-subject introduction apparatus.

  FIG. 1 is a schematic diagram showing an overall configuration of a wireless in-vivo information acquiring system. As shown in FIG. 1, the wireless in-vivo information acquisition system includes a receiving device 2 having a wireless receiving function, and a body cavity image that is introduced into the body of the subject 1 to capture an image of the body cavity. A capsule endoscope (intra-subject introduction device) 3 that transmits data such as signals. In addition, the wireless in-vivo information acquiring system performs data exchange between the display device 4 that displays the intra-body cavity image based on the video signal received by the receiving device 2 and the receiving device 2 and the display device 4. The portable recording medium 5 is provided. The receiving device 2 includes a receiving jacket 2a worn by the subject 1 and an external device 2b that performs processing of a radio signal received through the receiving jacket 2a.

  The display device 4 is for displaying an in-vivo image captured by the capsule endoscope 3, and has a configuration such as a workstation that displays an image based on data obtained by the portable recording medium 5. Have Specifically, the display device 4 may be configured to directly display an image by a CRT display, a liquid crystal display, or the like, or may be configured to output an image to another medium such as a printer.

  The portable recording medium 5 can be attached to and detached from the external device 2b and the display device 4, and has a structure capable of outputting or recording information when being inserted into both. Specifically, the portable recording medium 5 is inserted into the external device 2 b and transmitted from the capsule endoscope 3 while the capsule endoscope 3 is moving in the body cavity of the subject 1. Record the data. Then, after the capsule endoscope 3 is ejected from the subject 1, that is, after imaging of the inside of the subject 1 is finished, the capsule endoscope 3 is taken out from the external device 2b and inserted into the display device 4 to be attached to the display device. The data recorded by 4 is read out. When data is transferred between the external device 2b and the display device 4 by a portable recording medium 5 such as a compact flash (registered trademark) memory, and the external device 2b and the display device 4 are connected by wire. Rather, the subject 1 can freely move during imaging inside the body cavity. Here, the portable recording medium 5 is used for data transfer between the external device 2b and the display device 4. However, the present invention is not limited to this, and the external device 2b has another built-in recording device. In order to exchange data with the display device 4, both may be connected by wire or wirelessly.

  Here, the receiving apparatus 2 will be described with reference to FIG. The receiving device 2 also has a function of receiving body cavity image data wirelessly transmitted from the capsule endoscope 3. FIG. 2 is a block diagram schematically showing the configuration of the receiving device 2. As shown in FIG. 2, the receiving device 2 has a shape that can be worn by the subject 1, a receiving jacket 2a having receiving antennas A1 to An, and an external device that performs processing of received radio signals and the like. 2b. Each of the receiving antennas A1 to An may not be provided in the receiving jacket 2a so as to be directly attached to the outer surface of the subject, and may be detachable from the receiving jacket 2a.

  The external device 2b has a function of processing a radio signal transmitted from the capsule endoscope 3. Specifically, as shown in FIG. 2, the external device 2b is connected to the selector switch SW for switching the connection of the receiving antennas A1 to An and the subsequent stage of the selector switch SW, and is switched and connected by the selector switch SW. The receiving circuit 11 amplifies and demodulates the radio signals from the receiving antennas A1 to An, and a signal processing circuit 12 and a sample hold circuit 15 are connected to the subsequent stage of the receiving circuit 11. An A / D converter 16 is further connected to the subsequent stage of the sample hold circuit 15. The control unit C includes a selection control unit C1 as control means, and includes a signal processing circuit 12, an A / D conversion unit 16, a storage unit 13 corresponding to the portable storage medium 5, a display unit 14, and a switching control unit SC. Connecting. The switching control unit SC has an intensity receiving antenna number N1 and a video receiving antenna number N2. Based on these pieces of number information, the switching control unit SC issues a switching instruction of the changeover switch SW, and the sample hold circuit 15 and the A / D conversion unit. 16 and the processing timing of the selection control unit C1 are instructed. The power supply unit 17 supplies power to each unit described above, and is realized by, for example, a battery.

  The change-over switch SW of the external device 2b selectively switches any one of the receiving antennas A1 to An based on the switching instruction from the switching control unit SC, and the radio signal from the switched receiving antennas A1 to An. Is output to the receiving circuit 11. Here, the changeover switch SW has a connection part CON as antenna switching means for connecting the reception antennas A1 to An in correspondence with the arrangement positions of the reception antennas A1 to An, respectively. On the other hand, each of the receiving antennas A1 to An has connectors CON1 to CONn connected to the connection part CON.

  The connection part CON has a detection function for detecting the connection state of the connectors CON1 to CONn. For example, the connector CON1 has a detection circuit as shown in FIG. 3 for the connector CON1, and has similar detection circuits for the other connectors CON2 to CONn. In FIG. 3, the connector CON1 connects the signal line LS and the ground line LG from the receiving antenna A1 to the connection part CON, and branches and outputs the ground line LG. The connection unit CON outputs the signal line LS as it is to the switching unit SW1, and is switched based on the signal S5 instructing switching and outputs it to the receiving circuit 11. On the other hand, one of the ground lines LG is grounded as it is, and the other of the ground lines LG is connected to the constant voltage source VDD. When the connector CON1 is connected to the connection part CON, the voltage signal from the constant voltage source VDD flows to one side of the ground line LG, so that the signal S6 is not output to the selection control part C1 of the control part C that is external, When the connector CON1 is not connected to the connection part CON, the voltage signal from the constant voltage source VDD is output as it is to the selection control part C1 as the signal S6. Therefore, the selection control unit C1 can determine whether or not the connector CON1, that is, the receiving antenna A1 is connected, by detecting the presence or absence of the signal S6 that is the voltage signal. By providing a similar detection circuit corresponding to each of the connectors CON2 to CONn, the selection control unit C1 can detect the connection state of each of the receiving antennas A1 to An.

  In FIG. 2, the receiving circuit 11 amplifies the radio signal and outputs the demodulated video signal S1 to the signal processing circuit 12 as described above, and receives the received intensity signal that is the received electric field strength of the amplified radio signal. S2 is output to the sample hold circuit 15. The video data processed by the signal processing circuit 12 is stored in the storage unit 13 by the control unit C and displayed and output by the display unit 14. The signal sampled and held by the sample and hold circuit 15 is converted into a digital signal by the A / D conversion unit 16 and taken into the control unit C. The selection control unit C1 of the control unit C is received during an intensity reception period to be described later. The receiving antenna that received the largest receiving field strength among the received receiving field strengths is selected as the receiving antenna for the video signal period, and receiving antennas other than the selected receiving antenna are sequentially received during the strength receiving period. And the reception antenna number is output to the switching control unit SC as a signal S4 having a video reception antenna number N2 and an intensity reception antenna number N1. Here, the selection control unit C1 sets the reception antennas to be switched only for the reception antennas A1 to An that are currently connected based on the signal S6. Further, the control unit C stores the received electric field strength in the intensity receiving period and the received electric field strength in the video receiving period in the storage unit 13 together with the video data in association with the reception antenna selected at that time. The stored received electric field strength of each receiving antenna becomes information for calculating the position of the capsule endoscope 3 in the body when the video data is received.

  The switching control unit SC holds the strength receiving antenna number N1 and the video receiving antenna number N2 instructed by the selection control unit C1, and sets the receiving antennas A1 to An corresponding to the strength receiving antenna number N1 during the strength receiving period. The changeover switch SW is instructed to make a selective connection, and a signal S5 that instructs the changeover switch SW to make a selective connection of the receiving antennas A1 to An corresponding to the video reception antenna number N2 is given to the changeover switch SW during the video reception period. A signal S3a for instructing sample hold timing by the sample hold circuit 15, a signal S3b for instructing A / D conversion timing by the A / D conversion unit 16, and a signal S3c for instructing selection control timing by the selection control unit C1 are output. Output.

  Here, the intensity reception period and the video reception period described above with reference to FIGS. 4 and 5, that is, the frame configuration of the radio signal will be described, and an outline of the selection switching process of the receiving antennas A1 to An will be described. The radio signal sent from the capsule endoscope 3 is sent in units of frames. As shown in FIG. 4, this frame includes an intensity reception period and an information body as an additional unit including information for measuring the received electric field strength. And a video signal period as an information main body part. The strength reception period is a period corresponding to a preamble signal period for reception adjustment. The video signal period can include a control signal necessary for receiving the video signal in addition to the video signal itself. The intensity reception period and the video reception period may be provided as independent periods or may be provided as overlapping periods.

  Each frame is sent as shown in FIG. 5, and there may be a no-signal state between the frames, or each frame may be sent continuously. Considering the effective use of the battery of the capsule endoscope 3, the frame period TT of the frame transmission is shortened in an imaging region to be noticed or a region where the capsule endoscope 3 is moving fast, and the frame cycle TT is short or long. Is flexibly adjusted.

  As shown in FIG. 5, when the nth frame (n) and the (n + 1) th frame (n + 1) are transmitted in order, the same frame (n) in the period ta corresponding to the intensity reception period of the frame (n). Is switched to another receiving antenna (strength receiving antenna) different from the receiving antenna (video receiving antenna) that is received during the video signal period until the start of the video receiving period and the intensity receiving period of the next frame (n + 1) When the period tb including the period is reached, the video receiving antenna is switched. Similarly, in a period ta ′ corresponding to the intensity reception period of the frame (n + 1), the intensity reception antenna is switched during the video signal period of the same frame (n + 1), and the intensity reception period of the video reception period and the next frame (n + 2) When the period tb ′ including the period until the start of is reached, the video receiving antenna is switched.

  In addition, at the timings t1 and t1 ′ within the intensity reception period of the frame (n) and the frame (n + 1), the intensity detection processing by the sample hold circuit 15 and the A / D converter 16 is executed, and the result is the selection controller C1. Is output. If high-speed switching of reception antennas or high-speed reception field strength measurement processing is possible, a plurality of reception field strengths may be measured by switching between a plurality of strength reception antennas within the strength reception period. For example, as shown in FIG. 4, the received electric field strength may be measured sequentially at timings t2 and t3 after the timing t1, and the received electric field strength may be measured sequentially at timings t2 ′ and t3 ′ after the timing t1 ′. .

  Here, the antenna switching processing procedure will be described with reference to the flowchart shown in FIG. In FIG. 6, first, the selection control unit C1 detects the connection state of the connectors CON1 to CONn based on the signal S6 (step S101). Thereafter, the receiving antennas A1 to An corresponding to the connected connectors CON1 to CONn are set as strength receiving antennas (step S102). Thereafter, the reception field strength of each of the set strength reception antennas is measured (step S103), and the strength reception antenna having the highest reception field strength is set as the video reception antenna (step S104). Thereafter, a video signal of one frame is received by this video receiving antenna (step S105).

  Thereafter, it is determined whether or not the connection state of the connectors CON1 to CONn has changed (step S106). If there is a change in the connection state (YES in step S106), the process proceeds to step S102, the connected reception antenna after the change is reset as the strength reception antenna, and then the above-described processing is repeated. On the other hand, if there is no change in the connection state (step S106, NO), the process proceeds to step S103, the above-described processing is repeated, and the switching process to the optimum video receiving antenna is performed.

  For example, as shown in FIG. 7A, there are receiving antennas A1 to A6 corresponding to six arrangement positions “1” to “6”, and each of the receiving antennas A1 to A6 includes connectors CON1 to CON6. Assume that the connectors CON1 to CON4 are connected to the connection portions of the corresponding connection portions CON, and the connectors CON5 and 6 are not connected. In this case, since it is detected that only the receiving antennas A1 to A4 are connected, the receiving antennas A1 to A4 are set as strength receiving antennas, and the received electric field intensity is selected from the receiving antennas A1 to A4. The video receiving antenna with the largest is selected.

  Thereafter, as shown in FIG. 7B, when the connectors CON1 and CON2 are disconnected and the connectors CON5 and CON6 are newly connected, the selection control unit C1 uses only the receiving antennas A3 to A6 as the strength receiving antennas. The strength receiving antenna having the highest received electric field strength is selected from the strength receiving antennas as the video receiving antenna.

  In the first embodiment, only the connected receiving antennas A1 to An of the connectors CON1 to CONn are set as the strength receiving antennas, so that the time for measuring the received electric field strengths of all the strength receiving antennas is short. Thus, the time required for the antenna switching process can be shortened. In particular, when only the antenna at the position corresponding to the observation site in the body is connected, or when the number of antennas to be used is reduced in a patient with a small physique, the necessary received image can be reliably obtained by a simple switching process. it can.

(Embodiment 2)
Next, a second embodiment of the present invention will be described. In the first embodiment described above, all the receiving antennas A1 to An corresponding to the arrangement positions “1” to “6” are provided, and the strength receiving antenna is selected depending on whether or not the corresponding connectors CON1 to CONn are connected. However, in this second embodiment, only the minimum receiving antenna necessary for obtaining the antenna received electric field strength that is the basis for receiving the image and calculating the position of the capsule endoscope 3 is connected. Thus, the number of receiving antennas A1 to An is reduced, and the reduced number of receiving antennas are reused to efficiently obtain a received image and antenna received electric field strength. For example, with the movement of the capsule endoscope 3 in the body, the receiving antenna at a position that is no longer necessary for reception is changed to a position that is necessary for reception as the capsule endoscope 3 continues to move. Make use.

  That is, the configurations of the connectors CON1 to CONn of the receiving antennas A1 to An are made the same so that the connectors CON1 to CONn can be connected to any connection position of the arrangement position, and the minimum receiving antenna is used. Yes.

  As shown in FIG. 8A, the receiving antennas A1 to A4 are arranged at positions corresponding to the arrangement positions “1” to “4” where the received images are to be obtained, and the connectors CON1 to CON4 are arranged at the corresponding connection locations. Connect. As a result, the receiving antennas A1 to A4 are set as strength receiving antennas, and a desired received image and the received electric field strength of each antenna can be obtained by a simple switching process with the minimum number of receiving antennas.

  In addition, in the case of trying to obtain received images corresponding to the other arrangement positions “3” to “6” from the arrangement state shown in FIG. The antenna antenna part is moved to the part corresponding to the arrangement positions “5” and “6”, and the connectors CON1 and CON2 are replaced and connected to the connection points of the connectors CON5 and CON6, respectively. In this way, the four receiving antennas can be reused to function as six receiving antennas. Even in this case, the number of strength receiving antennas does not increase, and switching processing can be performed with the minimum necessary receiving antennas. Furthermore, the time required for the process of switching the intensity receiving antenna is shortened, and the optimum video receiving antenna can be selected quickly and reliably. In addition, since the number of antennas attached to the patient at a time can be reduced, the burden on the patient can be reduced.

  In the first and second embodiments described above, since the connectors CON1 to CONn correspond to the arrangement positions of the receiving antennas A1 to An, this switching information corresponds to the received image when there is a change in the connection. Thus, it can be used as index information indicating the position of the received image.

  In addition, since the antenna can be replaced, the antenna at the position that is no longer necessary for reception as the capsule endoscope moves inside the body can be received as the capsule endoscope continues to move inside the body. By switching to the required position and reusing it, it is possible to obtain the required received image and the antenna received electric field strength that is the basis for calculating the position of the capsule endoscope with a small total number of antennas.

It is a schematic diagram which shows the whole structure of the radio | wireless type in-vivo information acquisition system containing the receiver concerning Embodiment 1 of this invention. It is a block diagram which shows the structure of the receiver shown in FIG. It is a figure which shows the structure of the connection part in a changeover switch. It is a figure which shows the frame format of the radio signal sent from the capsule type endoscope shown in FIG. 3 is a time chart showing reception field strength measurement processing for each frame by the reception device shown in FIG. 1. 4 is a flowchart illustrating an antenna switching processing procedure by a selection control unit of the receiving apparatus illustrated in FIG. 1. It is a figure which shows an example of the connection relation of the receiving antenna and external apparatus by Embodiment 1 of this invention. It is a figure which shows an example of the connection relation of the receiving antenna and external device by Embodiment 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Subject 2 Reception apparatus 2a Reception jacket 2b External apparatus 3 Capsule type | mold endoscope 4 Display apparatus 5 Portable recording medium 11 Reception circuit 12 Signal processing circuit 13 Memory | storage part 14 Display part 15 Sample hold circuit 16 A / D conversion part 17 Power supply unit SW selector switch SW1 switching unit C control unit C1 to C3 selection control unit SC switching control unit CON connection unit CON1 to CONn connector N1 strength receiving antenna number N2 video receiving antenna number A1 to An receiving antenna

Claims (3)

A radio signal transmitted from a moving transmission apparatus and having a frame structure radio signal having at least an information main body including an information main body and an additional unit including information for reception field strength measurement, using a plurality of antennas In the receiving device that receives
Antenna switching means that can connect each antenna corresponding to the arrangement position of the plurality of antennas and detects a connection state of each antenna, and switches the connected antenna according to an instruction;
The reception unit strength is detected by sequentially switching the antenna whose connection is detected by the antenna switching means during reception by the additional unit, and the radio signal of the information main body unit is received by switching to the antenna that has detected the largest reception field strength. Control means;
A receiving apparatus comprising:   The number of the plurality of antennas is less than the number of the plurality of connection portions, and the plurality of antennas are used by replacing a part of the plurality of already connected antennas with another connection portion. The receiving device according to claim 1.   The receiving apparatus according to claim 1, wherein the control unit measures received electric field strengths of a plurality of antennas during a receiving period of the adding unit.

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