JP2005260750A - Receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To receive a video signal so that power can be saved in a transmitter side such as capsule type endoscope. <P>SOLUTION: A receiver 2 selectively receives the radio signal of a frame configuration having a video signal period for receiving a video signal and an intensity receiving period including information for measuring reception electric field intensity by using a plurality of reception antennas A1-An. In this receiver, one part in a synchronization period in the video signal period is set on one part or the entire of the intensity receiving period, and an antenna for measuring the reception electric field and an antenna for receiving a video signal are switched in the synchronization period, using a synchronization signal in the synchronization period as a signal for measuring the receiving electric field intensity. <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, the conventional receiver provides a reception electric field strength measurement period and a video signal reception period when one antenna is selected from a plurality of antennas and one reception unit (tuner) is used. Although the synchronization processing of the receiving device is performed using the synchronization signal provided at the beginning of the video signal reception period after the electric field strength measurement period, the video signal transmitted from the capsule endoscope or the like is Since the power supply of the endoscope is limited, there is a problem in that the video signal becomes intermittent and the power required for the received reception field strength measurement period cannot be ignored.

  The present invention has been made in view of the above, and an object of the present invention is to provide a receiving apparatus that can at least save power on the transmitting apparatus side.

  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 the receiving apparatus that selectively receives the wireless signal according to each received electric field strength using a plurality of antennas, a part of the synchronization period of the information body part is part or all of the received electric field strength measurement period of the additional unit And the synchronization signal in the synchronization period is used as a signal for receiving electric field measurement.

  According to a second aspect of the present invention, there is provided a receiving apparatus that uses a plurality of antennas to transmit a radio signal having a frame structure having at least an information main body including an information main body and an additional unit including information for measuring received field strength. In the receiving apparatus that selectively receives according to the received electric field strength, a part of the synchronization period of the information body unit is set to a part or all of the received electric field strength measurement period of the additional unit, and the synchronization signal of the synchronization period is received Used as an electric field measurement signal, and switches between the received electric field measurement antenna and the antenna that receives the information main body within the synchronization period according to the measurement result of the received electric field strength for each of the plurality of antennas. It is characterized by that.

  According to a third aspect of the present invention, in the above invention, the reception device according to the third aspect is characterized in that the reception electric field measurement antenna is switched within the reception electric field intensity measurement period, and the reception electric field intensity of each antenna is measured. .

  In the receiving apparatus according to the present invention, a part of the synchronization period of the information main body is set to a part or all of the reception electric field strength measurement period of the additional unit, and the synchronization signal of the synchronization period is used as a signal for measuring the received electric field. Since it is used, there is an effect that at least power saving on the transmission device side can be achieved.

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

(Embodiment)
First, a wireless in-vivo information acquiring system including a receiving apparatus according to an 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. In addition, the subject 1 can freely operate during imaging in the body cavity, and also contributes to shortening of data transfer time with the display device 4. 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 strength receiving antenna number information N1 and video receiving antenna number information N2. Based on these number information, the switching control unit SC issues a switching instruction of the changeover switch SW, and the sample hold circuit 15, A / D Instruct the processing timing of the conversion unit 16 and the selection control unit C1. 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 converter 16 and taken in by the controller C. The selection controller C1 of the controller C receives the intensity reception period of the synchronization period described later. The receiving antenna having the largest received electric field strength is selected as the receiving antenna for the video signal period from the received electric field strengths received at the same time, and the receiving antenna number received during the strength receiving period is used as the strength receiving antenna number information N1. And a signal S4 having the reception antenna number in the video signal period as the video reception antenna number information N2 is output to the switching control unit SC. The switching control unit SC holds the strength reception antenna number information N1 and the video reception antenna number information N2 instructed by the selection control unit C1, and the reception antenna A1 corresponding to the strength reception antenna number information N1 during the strength reception period. A signal S5 for instructing the changeover switch SW to selectively connect the receiving antennas A1 to An corresponding to the video receiving antenna number information N2 is instructed to selectively connect to An. 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 selection control timing by the selection control unit C1. The signal S3c to be output is output.

  Here, with reference to FIG. 3 and FIG. 4, the detailed configuration of the sample hold circuit 15 and the changeover switch SW will be described. First, in FIG. 3, a sample hold circuit 15 includes a pulse generator 15a that generates a sample hold pulse, an intensity reception sample hold circuit 15b that samples and holds the received electric field intensity during the intensity reception period, and a received electric field intensity during the video reception period. A video reception sample and hold circuit 15c for sample and hold is provided.

  The pulse generator 15a generates a pulse SH_KYODO and a pulse SH_EIZO that indicate the timing and period of sample hold by the intensity reception sample hold circuit 15b based on the signal S3a input from the switching control unit SC. The pulse SH_KYODO and the pulse SH_EIZO are output to the switch SW1 of the intensity reception sample / hold circuit 15b and the switch SW2 of the video reception sample / hold circuit 15c, respectively.

  The intensity reception sample / hold circuit 15b buffers the reception intensity signal S2 input from the reception circuit 11 by the amplifier Amp1. On the other hand, the switch SW1 is turned on for the period indicated from the timing indicated by the pulse SH_KYODO, and the signal buffered by the amplifier Amp1 is accumulated by the charge being accumulated in the capacitor C1 and being turned off. The charges are buffered by the amplifier Amp2 and output to the A / D converter 16 as a signal KYODO_LVL indicating the received electric field strength during the strength receiving period.

  On the other hand, the video reception sample / hold circuit 15c receives the signal buffered by the amplifier Amp1 from the intensity reception sample / hold circuit 15b. The switch SW2 is turned on for a period indicated from the timing indicated by the pulse SH_EIZO, and the signal buffered by the amplifier Amp1 accumulates charges in the capacitor C2 and is turned off. Are buffered by the amplifier Amp3 and output to the A / D converter 16 as a signal EIZO_LVL indicating the received electric field strength during the video signal period.

  Next, a detailed configuration of the changeover switch SW will be described. In FIG. 4, this changeover switch SW is connected to a decoder D1 that decodes a 3-bit signal S5 input from the changeover controller SC into an 8-bit signal S51, and reception antennas A1 to A4. Of the signals Sa and Sb respectively connected to the switch SW11 that selects the switch SW11 and the receiving antennas A5 to A8, connected to the switch SW12 that selects any one of the switches SW11 and SW12, and output from the switches SW11 and SW12, respectively. The switch SW13 that selects and outputs one of them and the inverting circuit I1 that ensures the exclusive logic of the switch SW13 based on the most significant bit input to the decoder.

  The signal S5 is input to the decoder D1 as a 3-bit signal for selecting one of the eight receiving antennas A1 to A8. The 3-bit signal S5 is a signal ANT_SELECT [0], a signal ANT_SELECT [1], and a signal ANT_SELECT [2], and a signal indicating the most significant bit is a signal ANT_SELECT [2]. The decoder D1 decodes the 3-bit signal S5 into the 8-bit signal S51, outputs the lower 4-bit signal S51a to the switch SW11 that switches the lower-order receiving antennas A1 to A4, and receives the upper-order signal. The upper 4-bit signal S51b is output to the switch SW12 that switches the antennas A5 to A8. The switches SW11 and SW12 select one of the receiving antennas A1 to A8 according to the signals S51a and S51b, respectively. The switch SW13 selects one of the signals Sa and Sb output from the switches SW11 and SW12 based on the most significant bit signal ANT_SELECT [2]. Here, when the switch SW11 selects any one of the receiving antennas A1 to A4, the switch SW12 does not select the receiving antennas A5 to A8. However, in order to increase the selection accuracy, the inversion is performed. An inversion signal of the most significant bit signal ANT_SELECT [2] from the circuit I1 is input to perform exclusion processing. The signals of the receiving antennas A1 to A8 finally selected by the switch SW13 are output to the receiving circuit 11. Here, the receiving antennas A1 to An are described as eight receiving antennas A1 to A8. The antenna numbers of the receiving antennas A1 to A8 are identification information unique to each receiving antenna, and “1” to “8” are set to “0” to “7” for information processing.

  Here, the strength reception period and the video reception period described above with reference to FIGS. 5 and 6, that is, the frame configuration of the radio signal will be described, and the 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, and this frame is conventionally provided with a video signal period after the intensity reception period TS1, as shown in FIG. A synchronization period TS is provided, and a video period TM including m lines is provided following the synchronization period TS. In this embodiment, the intensity reception period TS1 is shifted to the synchronization period TS, and the synchronization signal is used as a signal for measuring the received electric field strength. The synchronization signal is a pulse signal having a duty ratio of 50%, for example. Further, when the receiving circuit 11 is configured to be separated into an RF module that performs RF signal processing and a demodulation circuit that performs baseband demodulation, synchronization processing of the RF module is performed in the first half of the synchronization period TS. Thereafter, the demodulation process of the demodulation circuit is performed in the latter half of the synchronization period TS.

  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. 6, the synchronization period TS of the nth frame (n) includes a strength reception period TS1 for selecting a receiving antenna having the highest received electric field strength using a synchronization signal, and a video signal synchronization period TS2. The antenna switching is executed between the intensity reception period TS1 and the synchronization period TS2. In FIG. 6, two reception antennas are switched using a synchronization signal in the intensity reception period TS1, and the received electric field strength of each reception antenna is sampled and measured at timings t1 and t2 corresponding to the switched states. ing. Thereafter, at timing tc within the synchronization period TS, the antenna is switched to a receiving antenna that receives a video signal. In the switched synchronization period TS2, the reception circuit 11 performs synchronization processing following the synchronization period corresponding to the intensity reception period TS1. Thereafter, the video signal of m lines is received in the video period TM. Within the synchronization period TS2 and the video period TM, for example, the received electric field strength of the video receiving antenna is measured at timing tt1. Note that sample hold pulses at the timings t1, t2, tt1, and tta are generated by the pulse generator 15a.

  Here, the selection control unit C1 selects the receiving antenna having the largest received electric field strength from the received electric field strengths received in the strength receiving period TS1, but is not limited thereto. First, the receiving antenna having the largest receiving electric field strength is selected as the video receiving antenna including the receiving electric field strength of the video receiving antenna in addition to the receiving electric field strength of the receiving antenna received within the synchronization period TS1. Also good.

  In the above-described embodiment, the intensity reception period TS1 is included in the synchronization period TS. However, the present invention is not limited to this, and a part of the intensity reception period TS1 may be related to the synchronization period TS.

  In this embodiment, the strength reception period TS1 is provided in the synchronization period TS, and the received electric field strength measurement is performed using the synchronization signal in the strength reception period TS1, so there is no need to newly provide a strength reception period. It is possible to reduce the transmission power on the capsule endoscope 3 side consumed for the frame.

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. FIG. 3 is a block diagram showing a detailed configuration of a sample and hold circuit shown in FIG. 2. FIG. 3 is a block diagram illustrating a detailed configuration of a changeover switch illustrated in FIG. 2. It is a figure explaining a frame format. 3 is a timing chart for explaining antenna switching processing by the receiving apparatus shown in FIG. 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Subject 2 Reception apparatus 2a Reception jacket 2b External apparatus 3 Capsule 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 15a Pulse generator 15b Intensity reception Sample hold circuit 15c Video reception sample hold circuit 16 A / D conversion unit 17 Power supply unit 18 Peak hold circuit SW changeover switch C control unit C1 selection control unit SC change control unit D1 decoder I1 inversion circuit SW changeover switch SW11, SW12, SW13 Switch N1 Strength receiving antenna number information N2 Video receiving antenna number information A1-An receiving antenna

Claims (3)

A receiving apparatus that selectively receives a radio signal having a frame structure having an information main body including at least an information main body and an additional unit including information for measuring received electric field strength according to each received electric field strength using a plurality of antennas In
A part of the synchronization period of the information body part is set to a part or all of the reception field strength measurement period of the additional part, and the synchronization signal of the synchronization period is used as a signal for reception field measurement apparatus. A receiving apparatus that selectively receives a radio signal having a frame structure having an information main body including at least an information main body and an additional unit including information for measuring received electric field strength according to each received electric field strength using a plurality of antennas In
A part of the synchronization period of the information body part is set to a part or all of the reception electric field strength measurement period of the additional unit, and the synchronization signal of the synchronization period is used as a signal for reception electric field measurement. A receiving apparatus that switches between the antenna for receiving electric field measurement and the antenna for receiving the information main body within the synchronization period according to the measurement result of the received electric field strength for each.   The receiving apparatus according to claim 2, wherein the antenna for receiving electric field measurement is switched within the reception electric field intensity measurement period, and the received electric field intensity of each antenna is measured.

Images