JP2005192819A - Receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To switch to an optimal antenna of large receiving electric field intensity by selecting it even in a short reception electric field intensity measuring period by simple constitution. <P>SOLUTION: A switch control part SC switches to receiving antennas A1 to An for receiving the video signal within a video signal period in a present frame, and switches to receiving antennas A1 to An other than the receiving antennas A1 to An for receiving the video signal of the present frame within an intensity reception period within the present frame to respectively measure the reception electric field intensity through a sample hold circuit 15 and an A/D conversion part 16. When the reception electric field intensity within the intensity reception period exceeds the reception electric field intensity within the video signal period, a selection control part C1 selects the reception antennas A1 to An switched within the intensity reception period as the reception antennas A1 to An within the video signal period of the next frame. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a receiving apparatus that selectively receives a radio signal having a frame configuration having 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 subject 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.

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

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

  In order to solve the above-described problems and achieve the object, a receiving apparatus according to claim 1 includes a frame configuration including at least an information main body including an information main body and an additional section including information for reception field strength measurement. In a receiving apparatus that selectively receives a radio signal using a plurality of antennas, the received electric field of a second antenna other than the first antenna that receives the information body within the transmission period of the additional unit in the current frame In addition to measuring the strength, the received electric field strength of the first antenna is measured within the transmission period of the information main body in the current frame, and the received electric field strength of the second antenna is received by the first antenna. Control means is provided for selecting and switching the second antenna as the first antenna of the next frame when the electric field strength is exceeded.

  Further, in the receiving device according to claim 2, in the above invention, the control unit may be configured to receive the second antenna when the received electric field strength of the second antenna does not exceed the received electric field strength of the first antenna. It is characterized by switching to the antennas in order.

  In the receiver according to claim 3, in the above invention, the control means provides the timing of measuring the received electric field strength of the second antenna in the vicinity of the transmission period start timing of the information main body. It is characterized by.

  According to a fourth aspect of the present invention, in the above invention, the control unit causes the reception electric field strength of the plurality of second antennas to be measured within the transmission period of the additional unit, and the plurality of the second antennas. When the received field strength of the second antenna having the largest received field strength of the first antenna exceeds the received field strength of the first antenna, the second antenna is connected to the first frame of the next frame. The antenna is selected and switched.

  According to a fifth aspect of the present invention, there is provided a receiving apparatus that transmits a radio signal having a frame configuration that is transmitted from the inside of a subject and includes a video signal unit that transmits at least a video signal and an additional unit that includes information for measuring received field strength. In a receiving apparatus that receives using a plurality of antennas provided outside the subject, the wireless signal is received within a transmission period of the switching unit that selectively switches the plurality of antennas and the additional unit in the current frame. Measuring the received electric field strength of the second antenna other than the first antenna and measuring the received electric field strength of the first antenna during the transmission period of the video signal portion in the current frame. And when the received field strength of the second antenna measured by the field strength measuring means exceeds the received field strength of the first antenna, the second antenna is moved to the next frame. Selection control means for selecting as the first antenna, and antennas other than the first antenna selected by the selection control means are sequentially switched and connected during the transmission period of the additional section of the next frame, and the selected first antenna is selected. Switching control means for switching and connecting one antenna during the transmission period of the video signal section.

  In the intra-subject introduction device according to the present invention, the control means measures the received electric field strength of the second antenna other than the first antenna that receives the information body within the transmission period of the additional unit in the current frame. And the received electric field strength of the first antenna is measured within the transmission period of the information main body in the current frame, and the received electric field strength of the second antenna is equal to the received electric field strength of the first antenna. If exceeded, this second antenna is selected and switched as the first antenna of the next frame, so even with a simple configuration that does not require high-speed processing and a short reception field strength measurement period. There is an effect that an optimum antenna having a high received electric field strength can be selected and switched reliably.

  A wireless in-vivo information acquiring system that is the best mode for carrying out the present invention will be described below.

(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 an image in the body cavity 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, and connects the signal processing circuit 12, the A / D conversion unit 16, the storage unit 13 corresponding to the portable storage medium 5, the display unit 14, and the switching control unit SC. 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. As described above, the receiving circuit 11 amplifies the radio signal, outputs the demodulated video signal S1 to the signal processing circuit 12, and also receives the received intensity signal S2 that is the received electric field intensity of the amplified radio signal as the sample hold circuit 15. Output to. 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. If the field strength received during the strength reception period exceeds the field strength received during the video signal period, it is switched to this strength reception period. Selected as the receiving antenna for the video signal period, and sequentially select receiving antennas other than the selected receiving antenna as the receiving antenna for the strength receiving period. , The video receiving antenna number N2 and the intensity receiving antenna number N1 are output to the switching controller SC as a signal S4. 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. 3 and 4, that is, the frame configuration of the radio signal will be described, and the outline of the selection switching process of the reception antennas A <b> 1 to An will be described. The radio signal sent from the capsule endoscope 3 is sent in frame units, and this frame is composed of an intensity reception period and a video signal period as shown in FIG. 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.

  Each frame is sent as shown in FIG. 4, 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. 4, 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 timing t1 within the intensity reception period of the frame (n), the intensity detection process by the sample hold circuit 15 and the A / D conversion unit 16 is executed, and the result is output to the selection control unit C1. Similarly, at the timing t2 in the video signal period of the frame (n), the intensity detection process by the sample hold circuit 15 and the A / D conversion unit 16 is executed, and the result is output to the selection control unit C1. . Therefore, a margin period until the antenna switching process of the next frame (n + 1) is a switching margin time T from this timing t2 to the start of the intensity reception period of the next frame (n + 1). For this reason, the switching allowance time T can be lengthened by bringing the timing t2 to the early stage of the video signal period. The increase in the switching allowance time T eliminates the need for high-speed performance of the sample hold circuit 15, the A / D converter 16, the selection switching control unit C1, the switching control unit SC, and the changeover switch SW. Can be realized by using. In addition, the reception electric field strength of the receiving antenna for receiving the video signal is received and measured during the video signal period, and does not have to be measured during the strength reception period, so it is not necessary to perform high-speed switching of the antenna. . Furthermore, when measuring the received field strength of a plurality of receiving antennas during the strength reception period, it is not necessary to measure the received field strength of the self-video signal, so that there is a margin for switching.

  Here, the antenna switching processing procedure will be described with reference to the flowchart shown in FIG. This antenna switching process is performed by the selection control unit C1 and the switching control unit SC. In FIG. 5, as an initial setting, the selection control unit C1 first sets the video receiving antenna number, which is the video receiving antenna number, to No. 1 and the strength receiving antenna number which is the number of the strength receiving antenna is set to No. 1. 2 are registered in the video receiving antenna number N2 and the strength receiving antenna number N1 of the switching control unit SC (step S101). Here, the video receiving antenna number and the strength receiving antenna number No. 1-No. n is a number corresponding to each of the receiving antennas A1 to An.

  Thereafter, the switching control unit SC determines whether or not the intensity reception period has started (step S102). When the strength reception period starts (YES in step S102), the switching control unit SC outputs an instruction to switch to the reception antenna corresponding to the strength reception antenna number registered in the strength reception antenna number N1 to the changeover switch SW ( In step S103), the changeover switch SW switches to the designated reception antenna. Thereafter, the switching control unit SC causes the sample-and-hold circuit 15 and the A / D conversion unit 16 to perform detection processing of the received electric field strength of the strength receiving antenna at timing t1 (step S104), and matches the start of the video reception period. The switch SW is instructed to switch to the receiving antenna registered in the video receiving antenna number N2 (step S105), and the switching switch SW switches to the instructed receiving antenna. Note that the switching time of step S105 may be within the intensity reception period as long as the electric field intensity measurement process of the intensity reception antenna is completed, even if it is not the start of the video signal period.

  Thereafter, the switching control unit SC determines whether or not the video signal period has started (step S106). The video signal period here may be a period in which the video signal is transmitted when a control signal or the like is included in the video signal period. Thereafter, when the video signal period starts (step S106, YES), the sample hold circuit 15 and the A / D converter 16 are caused to detect the received electric field strength of the strength receiving antenna at timing t2 (step S107). ).

  Thereafter, the selection control unit C1 compares the received electric field strength (video receiving antenna strength) of the video receiving antenna received during the video signal period with the received electric field strength (strength receiving antenna strength) of the strength receiving antenna received during the strength receiving period. It is then determined whether it is small (step S108). When the video receiving antenna strength is smaller than the strength receiving antenna strength (step S108, YES), the video receiving antenna number is registered in the strength receiving antenna number N1 as the strength receiving antenna number (step S109), and step S110. Migrate to On the other hand, when the video receiving antenna strength is not smaller than the strength receiving antenna strength (NO in step S108), that is, when the video receiving antenna strength exceeds the strength receiving antenna strength, the strength receiving antenna number N1 is kept as it is. Is incremented (step S110).

  Thereafter, it is determined whether or not the value of the strength receiving antenna number matches the value of the video receiving antenna number (step S111). If they match (step S111, YES), the process proceeds to step S110 to further increase the strength. If the value of the receiving antenna number is incremented and does not match (step S111, NO), the strength receiving antenna number is further set to No. It is determined whether or not n (step S112). Here, the strength receiving antenna number is “No. If it is not n (step S112, NO), the process proceeds to step S102 and the above processing is repeated, and the strength receiving antenna number is No. n (step S112, YES), the video receiving antenna number is No. It is determined whether or not 1 (step S113). The video receiving antenna number is No. If it is not 1 (step S113, NO), the strength receiving antenna number is set to No. 1. 1 is registered (step S114), and the video receiving antenna number is No. 1. 1 (step S113, YES), the strength receiving antenna number is set to No. 1. 2 is set and registered (step S115), and then the process proceeds to step S102 to repeat the above-described processing.

  In the first embodiment, the received electric field strength of the video signal is measured in the video signal period, and the received electric field strength is measured by sequentially switching to a receiving antenna other than the receiving antenna that receives the video signal in the strength receiving period. When the received field strength measured during the reception period exceeds the received field strength measured during the video reception period, the reception antenna switched to this strength reception period is switched to the reception antenna during the video reception period. In addition to shortening the intensity reception period, it is possible to allow time for switching the receiving antenna in the intensity reception period, and to switch the antenna between frames by advancing the intensity detection timing in the video reception period. Setting time is born, and the configuration related to receiving field strength measurement is fast. Not determined, it can be a simple structure.

(Embodiment 2)
Next, a second embodiment of the present invention will be described. In the second embodiment, a peak hold circuit 18 is further provided between the receiving circuit 11 and the sample hold circuit 15 in the first embodiment.

  FIG. 6 is a block diagram showing a configuration of a receiving apparatus according to Embodiment 2 of the present invention. As shown in FIG. 6, this receiving apparatus is provided with a peak hold circuit 18 and holds the peak value of the received intensity signal S <b> 2 output from the receiving circuit 11.

  Therefore, as shown in FIG. 7, the switching control unit SC outputs the signal Sr to the peak hold circuit 18 at the start time of the intensity reception period, and resets it at the timing tr1. Thereafter, the switching controller SC acquires the peak value held by the peak hold circuit 18 at the detection timing t3 of the sample hold circuit 15, and resets the peak hold circuit 18 again at the timing tr2 at the start timing of the video signal period. At timing t4 after this timing tr2, the sample hold circuit 15 acquires the peak value held by the peak hold circuit 18. That is, the sample hold circuit 15 can sample the peak value between the timing tr1 and the timing t3 and can sample the peak value between the timing tr2 and the timing t4. Can be done well.

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 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. It is a flowchart which shows the antenna switching process procedure by the receiver shown in FIG. It is a block diagram which shows the structure of the receiver concerning Embodiment 1 of this invention. It is a time chart which shows the received electric field strength measurement process for every flame | frame by the reception sparse knowledge shown in FIG.

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 18 Peak hold circuit SW changeover switch C control unit C1 selection control unit SC switching control unit N1 intensity reception antenna number N2 video reception antenna number A1 to An reception antenna

Claims (5)

In a receiving apparatus that selectively receives a radio signal having a frame configuration having an information main body including at least an information main body and an additional unit including information for receiving field strength measurement using a plurality of antennas,
The reception electric field strength of the second antenna other than the first antenna receiving the information body is measured within the transmission period of the additional section in the current frame, and the transmission period of the information body section in the current frame is measured. If the received electric field strength of the first antenna exceeds the received electric field strength of the first antenna, the second antenna is moved to the first frame in the next frame. A receiving apparatus comprising control means for selecting and switching as one antenna.   2. The control unit according to claim 1, wherein when the received electric field strength of the second antenna does not exceed the received electric field strength of the first antenna, the control unit sequentially switches to the other second antenna. Receiver device.   The receiving apparatus according to claim 1, wherein the control means sets the timing of measuring the received electric field strength of the second antenna in the vicinity of the start time of the transmission period of the information main body.   The control means measures the reception field strength of a plurality of second antennas within a transmission period of the additional unit, and has a second reception field strength having the largest reception field strength of the plurality of second antennas. The second antenna is selected and switched as the first antenna of the next frame when the received electric field strength of the antenna exceeds the received electric field strength of the first antenna. The receiving device according to any one of the above. A plurality of antennas provided outside a subject with a frame-structured radio signal transmitted from the inside of the subject and having at least a video signal portion for transmitting a video signal and an additional portion including information for receiving electric field strength measurement In a receiving device that receives using
Switching means for selectively switching the plurality of antennas;
The reception electric field strength of the second antenna other than the first antenna receiving the radio signal is measured within the transmission period of the additional unit in the current frame, and the transmission of the video signal unit in the current frame is performed. Electric field strength measuring means for measuring the received electric field strength of the first antenna within a period;
When the received field strength of the second antenna measured by the field strength measuring means exceeds the received field strength of the first antenna, the second antenna is selected as the first antenna of the next frame Control means;
Antennas other than the first antenna selected by the selection control means are sequentially switched and connected during the transmission period of the additional section of the next frame, and the selected first antenna is switched and connected during the transmission period of the video signal section. Switching control means for
A receiving apparatus comprising:

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