JP4451163B2 - Receiver - Google Patents

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 selected from a plurality of antennas and one receiving unit (tuner) is used, the received field strength of the antenna is measured within the received field strength measurement period such as a preamble. However, since this reception field strength measurement period is short, multiple frames must be received before the optimum antenna having a large reception field strength is finally selected. There was a problem that it took.

  In particular, a video signal transmitted from a capsule endoscope or the like becomes an intermittent video signal because the power source of the capsule endoscope is limited, and the video signal is reliably transmitted in a short time on the receiving device side. It is desired to be able to receive.

  The present invention has been made in view of the above, and an object thereof is to provide a receiving apparatus capable of obtaining a reliable video signal in a short time.

In order to solve the above-described problems and achieve the object, a receiving apparatus according to the present invention has a frame configuration having at least an information main body including an information main body and an additional section including information for measuring received electric field strength. In a receiving apparatus that selectively receives a radio signal using a plurality of antennas, the reception field strength of two or more antennas is measured by the additional unit of the current frame, and the maximum received electric field of the two or more antennas Control means for selecting and switching an antenna having strength as an antenna for receiving the information main body in the current frame is provided.

In the receiver according to the present invention as set forth in the invention described above, the two or more antennas are all of the plurality of antennas.

The receiving apparatus according to the present invention selectively receives 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 reception field strength measurement using a plurality of antennas. In the receiving apparatus, the first received electric field strength of the antenna that has received the information body in the previous frame and the received electric field strength of two or more antennas other than the antenna are measured by the additional unit in the current frame. Control means for comparing the second received electric field strength, which is the maximum received electric field strength in the measurement result, and selecting and switching an antenna having a larger received electric field strength as an antenna for receiving the information main body in the current frame. It is provided with.

In the receiver according to the present invention as set forth in the invention described above, the two or more antennas are all antennas other than the antenna having the first reception electric field strength.

In the receiver according to the present invention as set forth in the invention described above, the two or more antennas are an antenna group obtained by grouping the plurality of antennas.

In the receiving apparatus according to the present invention as set forth in the invention described above, the two or more antennas are antenna groups in the vicinity of the antenna receiving the information body in the previous frame.

Further, in the receiving device according to the present invention , in the above invention, the plurality of antennas have a series of numbers according to a moving path of the transmitting device, and the two or more antennas are the information in the previous frame. It is an antenna group after the order of the antennas receiving the main body.

  In the receiving apparatus according to the present invention, the control unit causes the additional field of the current frame to measure the received electric field strength of two or more antennas, and selects the antenna having the maximum received electric field strength of the two or more antennas. Since the information main body in the frame is selected and switched as an antenna for receiving, there is an effect that a reliable video signal can be obtained in a short time.

  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, for example, 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 for display. Data recorded by the device 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 holds the strength receiving antenna number information N1 and the video receiving antenna number information N2, and instructs the switching of the changeover switch SW based on these number information, 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 among the received electric field strengths received at the same time, and the receiving antenna number received during the strength receiving period is set as the strength receiving antenna number N1. Then, the signal is output to the switching controller SC as a signal S4 in which the receiving antenna number during the video signal period is N2. 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, 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 amplifies 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 a period indicated from the timing indicated by the pulse SH_KYODO, and the signal amplified by the amplifier Amp1 is accumulated as a voltage value in the capacitor C1 and accumulated by being turned off. The amplified voltage value is amplified by the amplifier Amp2, and is output to the A / D conversion unit 16 as the signal KYODO_LVL indicating the received electric field strength in the strength receiving period.

  On the other hand, the video reception sample / hold circuit 15c receives the signal amplified 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 amplified by the amplifier Amp1 is accumulated as a voltage value in the capacitor C2, and the accumulated voltage is obtained by being turned off. The value is amplified by the amplifier Amp3 and output to the A / D conversion unit 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 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 signal ANT_SELECT [2] of the most significant bit by the circuit is input and exclusive processing is performed. 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 “0” to “7” from “1” to “8” in terms of information processing.

  Here, the intensity reception period and the video reception period described above with reference to FIG. 5, that is, the frame configuration of the radio signal will be described, and the outline of the selection switching process of the reception antennas A1 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 a synchronization period and a video signal period as shown in FIG. The synchronization 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. 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, the synchronization period TS of the nth frame (n) has an intensity reception period TS1 for selecting a receiving antenna having the highest received electric field intensity and a video signal synchronization period TS2. Antenna switching is executed between the intensity reception period TS1 and the synchronization period TS2. Here, when the receiving antennas A1 to An are eight receiving antennas, the antenna switching of all the receiving antennas A1 to A8 is performed within the intensity receiving period TS1, and each of the switched antennas is within the switched period. Received electric field strength measurement is performed at timings t1 to t8. The peak hold pulse at the timings t1 to t8 is generated by the pulse generator 15a.

  When the reception field strength measurement of all the reception antennas A1 to A8 is completed, the selection control unit C1 selects the reception antenna having the highest reception field strength at that time, and selects this reception antenna as the synchronization period TS2 and the video. Select as a video receiving antenna in the signal period TM. Then, in the video signal period TM or the synchronization period TS2, reception field strength measurement by the video reception antenna is performed at timing tt1 or timing tta. However, the reception field strength measurement by the video reception antenna may not be performed if it is not necessary. In the first embodiment, the reception state is confirmed.

  In the first embodiment, the reception field strength of all reception antennas is measured in the strength reception period TS1, and the reception antenna having the highest reception field strength is selected as the video reception antenna. It is possible to reliably receive a small number of video signals without transmitting signals. As a result, power saving on the capsule endoscope 3 side can be promoted.

(Embodiment 2)
Next, a second embodiment of the present invention will be described. In the second embodiment, the selection process of the video receiving antenna is further performed by effectively using the result of the measurement of the received electric field strength by the video receiving antenna.

  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 selection control unit C2 instead of the selection control unit C1. Other configurations are the same as those of the first embodiment, and the same reference numerals are given to the same components.

  As shown in FIG. 7, the selection control unit C2 excludes the reception antenna selected as the video signal antenna in the frame (n−1) from the strength reception antennas, and uses the remaining seven reception antennas as the strength reception antennas. In the intensity reception period TS1, the reception electric field intensity of each reception antenna is measured. The selection control unit C2 determines a receiving antenna having the largest received electric field strength in the strength receiving period TS1, and determines the received electric field strength of the determined receiving antenna and the video receiving antenna of the frame (n−1). The reception field strength is compared, and the reception antenna with the higher reception field strength is selected as the video reception antenna for frame (n). The selected video receiving antenna measures the received electric field strength within the synchronization period TS2 or the video signal period TM, and the result is used to determine the video receiving antenna of the frame (n + 1).

  In the second embodiment, the received electric field strength of the video receiving antenna is measured within the previous video signal period TM in which time is available, and only this receiving antenna is excluded from the strength receiving antenna in the strength receiving period TS1. Since the receiving antenna having the highest received electric field strength is selected as the video receiving antenna from these received electric field strengths, a reliable video signal can be received in a short time.

  In Embodiments 1 and 2 described above, all receiving antennas are basically strength receiving antennas. For example, when all receiving antennas are grouped in advance, this grouping is performed. Basically, only the antenna group should be the target of the intensity receiving antenna. Further, not all receiving antennas but neighboring receiving antennas determined in advance with respect to the video receiving antenna may be targeted. For example, when all receiving antennas are assigned a series of numbers corresponding to the movement path of the capsule endoscope 3, a receiving antenna having a series of numbers up to two in the vicinity of the video receiving antenna, for example, It may be a target. Further, in the case of receiving antennas assigned with a series of numbers, all of the receiving antennas having numbers after the number of the current video receiving antenna may be targeted for the strength receiving antenna.

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. 3 is a timing chart for explaining antenna switching processing by the receiving apparatus shown in FIG. 2. It is a block diagram which shows the structure of the receiver concerning Embodiment 2 of this invention. It is a timing chart explaining the antenna switching process by the receiver shown in FIG.

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 switching switch C control unit C1, C2 selection control unit SC switching control unit D1 decoder I1 inversion circuit SW switching switch SW11, SW12 , SW13 switch N1 strength receiving antenna number N2 video receiving antenna number A1-An receiving antenna

Claims (4)

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,
An antenna for measuring the reception field strength of two or more antennas at the additional portion of the current frame and receiving the antenna having the maximum reception field strength of the two or more antennas from the information main body portion in the current frame Control means to select and switch as
The receiving apparatus according to claim 1, wherein the two or more antennas are an antenna group obtained by grouping nearby antennas determined in advance with respect to the antenna selected by the control means in the previous frame. 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,
An antenna for measuring the reception field strength of two or more antennas at the additional portion of the current frame and receiving the antenna having the maximum reception field strength of the two or more antennas from the information main body portion in the current frame Control means to select and switch as
The plurality of antennas have a series of numbers according to the moving path of the transmission device, and the two or more antennas are antenna groups after the order of the antennas that received the information body in the previous frame. A receiving device. 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 first received electric field strength of the antenna that has received the information body in the previous frame and the received electric field strength of two or more antennas other than the antenna are measured by the additional unit in the current frame, and within the measurement result A control means for comparing the second received electric field strength, which is the maximum received electric field strength, and selecting and switching an antenna having a larger received electric field strength as an antenna for receiving the information body in the current frame,
The two or more antennas are antenna groups obtained by grouping nearby antennas determined in advance with respect to the antenna for which the first reception electric field strength selected by the control unit in the previous frame is measured. Receiving device. 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 first received electric field strength of the antenna that has received the information body in the previous frame and the received electric field strength of two or more antennas other than the antenna are measured by the additional unit in the current frame, and within the measurement result A control means for comparing the second received electric field strength, which is the maximum received electric field strength, and selecting and switching an antenna having a larger received electric field strength as an antenna for receiving the information body in the current frame,
The plurality of antennas have a series of numbers according to the moving path of the transmission device, and the two or more antennas are antenna groups after the order of the antennas that received the information body in the previous frame. A receiving device.

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