The present invention relates to a signal processing apparatus capable of communicating using a two dimensional diffusive signal-transmission technology, and a method to determine an optimum receiving device among two dimensional diffusive signal-transmission devices provided in the signal processing apparatus.
Japanese Unexamined Patent Publication No. 2003-188882 discloses a two dimensional diffusive signal-transmission technology (hereinafter, simply referred to as a 2D-DST technology) for transmitting a signal with a plurality of communication devices (hereinafter, referred to as 2D-DST devices) serving as transmission sites, without forming patterned wiring.
Japanese Unexamined Patent Publication No. 2003-188882 proposes a signal communication apparatus including a plurality of 2D-DST devices scattered on two-dimensional plane therein. Each of the plurality of 2D-DST devices is configured to communicate only with adjacent 2D-DST devices thereto within a predetermined communication distance. By means of such a local communication, a signal is transmitted in sequence from one of the 2D-DST devices to another. This makes it possible to transmit a signal to an intended 2D-DST device. The plurality of 2D-DST devices are categorized into hierarchies based on their predetermined management functions. In each of the hierarchies, a transmission channel data is set such that a signal can be efficiently transmitted to a final destination.
As an application example of the 2D-DST technology, there is cited a system that receives a image signal outputted from an imaging device of a capsule endoscope through wireless communication to transmit the image signal to a predetermined destination using the 2D-DST technology. In the 2D-DST technology, it is desirable to reduce an output of an electromagnetic wave as much as possible in view of electrical power consumption and/or effects on a living body. On the other hand, in order to receive a signal with a high S/N ratio, it is desirable to receive the signal at a position closer to a signal transmitting source. One of solutions to satisfy such requirements, for instance, is to receive a signal with an optimum 2D-DST device being determined. However, as the number of 2D-DST devices increases, a process for determining the optimum 2D-DST device is more complicated, and takes longer time.
The present invention is advantageous in that a method to determine an optimum receiving device for receiving a signal through wireless communication while reducing the burden on a control system, in a signal processing apparatus using a 2D-DST technology, is provided.
According to an aspect of the invention, there is provided a method to determine an optimum receiving device, which receives a signal outputted from a separate device through wireless communication, among a plurality of communication devices two-dimensionally arranged on a two dimensional diffusive signal-transmission board, the plurality of communication devices being configured to communicate with each other using a two dimensional diffusive signal-transmission technology, the method including first selecting a first plurality of receiving devices, of which received signal intensities are to be measured, among the plurality of communication devices, first measuring the received signal intensities of the first plurality of receiving devices, first comparing the received signal intensities of the first plurality of receiving devices, second selecting a second plurality of receiving devices based on the results of the first comparing the received signal intensities, second measuring the received signal intensities of the second plurality of receiving devices, second comparing the received signal intensities of the second plurality of receiving devices, and determining the optimum receiving device based on the results of the second comparing the received signal intensities.
Optionally, the selected second plurality of receiving devices may include neighboring communication devices of a receiving device with the highest received signal intensity among the first plurality of receiving devices.
Alternatively or optionally, the second selecting the second plurality of receiving devices may include calculating the ratio of the second highest received signal intensity to the highest received signal intensity among the received signal intensities of the first plurality of receiving devices, and comparing the calculated ratio with a predetermined ratio. Optionally, when the calculated ratio is the predetermined ratio or more, the second plurality of receiving devices may include a receiving device with the highest received signal intensity among the first plurality of receiving devices, neighboring communication devices of the receiving device with the highest received signal intensity, a receiving device with the second highest received signal intensity among the first plurality of receiving devices, and neighboring communication devices of the receiving device with the second highest received signal intensity. Optionally, when the calculated ratio is less than the predetermined ratio, the second plurality of receiving devices may include the receiving device with the highest received signal intensity among the first plurality of receiving devices, and neighboring communication devices of the receiving device with the highest received signal intensity.
Optionally, in the determining the optimum receiving device, a receiving device with the highest received signal intensity among the second plurality of receiving devices may be defined as the optimum receiving device.
Still optionally, the method may further include re-determining a different optimum receiving device when at least one predetermined condition is satisfied after the determining the optimum receiving device.
Optionally, the at least one predetermined condition may include a condition that the received signal intensity of the optimum receiving device is less than a predetermined intensity.
Alternatively or optionally, the at least one predetermined condition may include a condition that a predetermined time period has passed.
Alternatively or optionally, the at least one predetermined condition may include a condition that the absolute time rate of change of the received signal intensity of the optimum receiving device is a predetermined value or more.
Optionally, the re-determining a different optimum receiving device may include third selecting a third plurality of receiving devices, of which received signal intensities are to be measured, among the plurality of communication devices, third measuring the received signal intensities of the third plurality of receiving devices, third comparing the received signal intensities of the third plurality of receiving devices, and re-determining the different optimum receiving device based on the results of the third comparing the received signal intensities.
Yet optionally, the selected third plurality of receiving devices may include neighboring communication devices of the optimum receiving device.
Optionally, the third plurality of receiving devices is selected based on a moving direction, of the external device, presumed from the history of past optimum receiving devices.
According to another aspect of the invention, there is provided a method to determine an optimum receiving device, which receives a signal outputted from a separate device through wireless communication, among a plurality of communication devices two-dimensionally arranged on a two dimensional diffusive signal-transmission board, the plurality of communication devices being configured to communicate with each other using a two dimensional diffusive signal-transmission technology, the method including measuring received signal intensities of all the plurality of communication devices, comparing the received signal intensities of all the plurality of communication devices with each other, and determining the optimum receiving device based on the results of the comparing the received signal intensities.
Optionally, in the determining the optimum receiving device, a communication device with the highest received signal intensity may be defined as the optimum receiving device.
According to a further aspect of the invention, there is provided a method to determine an optimum receiving device, which receives a signal outputted from a separate device through wireless communication, among a plurality of communication devices two-dimensionally arranged on a two dimensional diffusive signal-transmission board, the plurality of communication devices being configured to communicate with each other using a two dimensional diffusive signal-transmission technology, the method including measuring received signal intensities of all the plurality of communication devices, comparing the received signal intensities of all the plurality of communication devices with a predetermined intensity, specifying a region in which communication devices with received signal intensities of the predetermined intensity or more are included, and determining the optimum receiving device among the communication devices in the specified region.
Optionally, in the determining the optimum receiving device, a communication device located substantially at the center of the region may be defined as the optimum receiving device.
Alternatively or optionally, in the determining the optimum receiving device, a communication device located the closest to a control unit, which is configured to implement the method to determine the optimum receiving device, provided at the two dimensional diffusive signal-transmission board, may be defined as the optimum receiving device.
According to a different aspect of the invention, there is provided a signal processing apparatus, which is provided with a two dimensional diffusive signal-transmission board, a plurality of communication devices, two-dimensionally arranged in the two dimensional diffusive signal-transmission board, which are configured to communicate with each other using a two dimensional diffusive signal-transmission technology, and a control unit configured to control the whole of the signal processing apparatus. The signal processing apparatus is configured to implement a method to determine an optimum receiving device, which receives a signal outputted from a separate device through wireless communication, among the plurality of communication devices. The method includes first selecting a first plurality of receiving devices, of which received signal intensities are to be measured, among the plurality of communication devices, first measuring the received signal intensities of the first plurality of receiving devices, first comparing the received signal intensities of the first plurality of receiving devices, second selecting a second plurality of receiving devices based on the results of the first comparing the received signal intensities, second measuring the received signal intensities of the second plurality of receiving devices, second comparing the received signal intensities of the second plurality of receiving devices, and determining the optimum receiving device based on the results of the second comparing the received signal intensities.
Optionally, the selected second plurality of receiving devices may include neighboring communication devices of a receiving device with the highest received signal intensity among the first plurality of receiving devices.
Alternatively or optionally, the second selecting the second plurality of receiving devices may include calculating the ratio of the second highest received signal intensity to the highest received signal intensity among the received signal intensities of the first plurality of receiving devices, and comparing the calculated ratio with a predetermined ratio. Optionally, when the calculated ratio is the predetermined ratio or more, the second plurality of receiving devices may include a receiving device with the highest received signal intensity among the first plurality of receiving devices, neighboring communication devices of the receiving device with the highest received signal intensity, a receiving device with the second highest received signal intensity among the first plurality of receiving devices, and neighboring communication devices of the receiving device with the second highest received signal intensity. Optionally, when the calculated ratio is less than the predetermined ratio, the second plurality of receiving devices may include the receiving device with the highest received signal intensity among the first plurality of receiving devices, and neighboring communication devices of the receiving device with the highest received signal intensity.
Optionally, in the determining the optimum receiving device, a receiving device with the highest received signal intensity among the second plurality of receiving devices may be defined as the optimum receiving device.
A signal communication apparatus and a method to determine an optimum receiving device according to each of embodiments of the present invention is assumed to be applied to clothing provided with an antenna function that receives an image signal outputted from a capsule endoscope. The clothing provided with an antenna function includes circuits incorporated thereon for obtaining information on a physical condition and/or a body cavity image of a patient without using any wired cable or patterned copper film. In addition, the clothing provides better flexibility and durability, and reduces the weight and design limitation thereof, more densely incorporating antennas therein, and obtaining an image signal with a higher S/N ratio. Referring to the accompanying drawings, configurations and operations of endoscope systems, each of which includes such clothing provided with an antenna function, will be explained.
The jacket 200 with the antenna function, which is shaped so as to cover a part of the body of the patient 1, has a plurality of devices 230 scattered therein. The plurality of devices 230 are 2D-DST devices, each of which includes various functions such as a function to obtain the image signal outputted from the capsule endoscope 100, a function to send out electromagnetic waves for providing an electrical power to the capsule endoscope 100 and/or a control signal, and a function to obtain the information on the physical condition of the patient 1. Hereinafter, such a 2D-DST device is simply referred to as a device. In addition, the jacket 200 includes a control unit 220 attached thereto so as to be located around the waist of the patient 1 while being worn, which controls the whole of the circuits.
When the capsule endoscope 100 is put into the body cavity of the patient 1 with the power supply portion 102 being powered on, the body cavity is illuminated by the illuminating portion 108. Illuminating light reflected by a reflecting surface such as a wall of the body cavity is incident to the objective optical system 110, and is received by a light receiving surface of the solid-state image sensor 112 that is provided on a focal plane at the imaging side of the objective optical system 110. The solid-state image sensor 112 photoelectrically-converts the received light to generate an image signal. The controlling portion 104 controls the transmitting portion 114, so that the generated image signal is modulated to be superimposed on a signal with a predetermined frequency, and is then transmitted externally via the antenna portion 116. The transmitted image signal is received by the jacket 200 with the antenna function. In addition, the receiving portion 115 is configured to receive a radio wave from an external device. The controlling portion 104 provides on-off control of the illuminating portion 108 and drive control of the capsule endoscope 100.
Next, the configuration and operation of a 2D-DST circuit incorporated in the jacket 200 with the antenna function will be described.
In the aforementioned configuration, for example, when the receiving device 22 receives an image signal outputted from the capsule endoscope 100, the control unit 220 determines transmission devices 24 for transmitting the received signal to the control unit 220 and a transmission channel 28. Based on the determination, the signal received by the receiving device 22 is transmitted to the control unit 220 via the receiving device 22 by means of a predetermined algorithm.
The 2D-DST board 20 shown in
The above configuration is for explaining a first embodiment to seventh embodiment described below. Next, referring to
As an example of the method to determine the optimum receiving device among the devices A11-A69 capable of receiving an image signal, there is cited a method to determine the optimum receiving device based on results obtained by comparing the intensities of all the devices receiving an image signal with the control unit 220. That is to say, a receiving device receiving an image signal with the highest received signal intensity is defined as the optimum receiving device.
In another example of the method, the optimum receiving device may be determined among receiving devices located within a range in which each of the receiving devices can receive an image signal with predetermined received signal intensity or more. For instance, the receiving devices receiving an image with predetermined received signal intensity or more are assumed to be A34-A36, A44-A46, and A54-A56 in
Next, the methods to determine the optimum receiving device among the receiving devices in the area 23 defined according to the aforementioned first embodiment will be explained more specifically. The method to determine the optimum receiving device may be the following one.
Next, referring to
Next, a method to determine the optimum receiving device applied to a second embodiment according to the present invention will be described.
If all the receiving devices carry out measurement of the received signal intensities thereof, the comparing-judging process will be more cumbersome and take more time, as the number of the receiving devices is larger. The following method can simplify the comparing-judging process. First, among all the devices 230 on the 2D-DST board 20, a plurality of receiving devices, which measure the received signal intensities thereof, is selected at a predetermined interval. Thereafter, the receiving device with the highest received signal intensity and the devices around the receiving device with the highest received signal intensity selectively measure their received signal intensities. By the number of the receiving device being thus decreased, an effective comparing-judging process and a reduced necessary time for such a process are achieved.
First, among all the devices 230 on the 2D-DST board 20, a plurality of receiving devices is selected. In this embodiment, for instance, the receiving devices are selected every three devices at even intervals. In this case, the devices A22, A25, A28, A52, A55, and A58 are selected as shown in
Next, the control unit 220 commands the selected receiving devices A22, A25, A28, A52, A55, and A58 to measure the received signal intensities (S1). When receiving the signal, each of the selected receiving devices measures the received signal intensity thereof. The measurement results by the selected receiving devices are transmitted and gathered to the control unit 220, which then compares the received signal intensities to determine a receiving device with the highest received signal intensity (S2). In this case, for example, the receiving device A55 is identified as a receiving device with the highest received signal intensity.
Thereafter, the devices located around (adjacent to) the receiving device A55 are selected. Then, the control unit 220 commands these selected receiving devices including the receiving device A55 to measure their received signal intensities (S3). According to this command, each of the receiving devices measures the received signal intensity thereof. It is noted that hereinafter, the term “adjacent” includes the meaning of “adjacent in a diagonal direction” or “within a range in which direct communication is possible” (here, the term “direct communication”, for example, means “communication between the first-order devices” or “such communication that the third-order device sends data to a communication device within an effective communication range” described in Japanese Unexamined Patent Publication No. 2003-188882). In this case, the receiving devices A44, A45, A46, A54, A56, A64, A65, and A66 adjacent to the receiving device A55, and the receiving device A55 are selected, as shown in
The measurement results by the receiving devices are transmitted to the control unit 220, which then compares the received signal intensities (S4), so as to define a receiving device with the highest received signal intensity as the optimum receiving device (S5). In this case, for example, the receiving device A55 is defined as the optimum receiving device. Thereafter, the optimum transmission channel is set between the optimum receiving device and the control unit 220 (S6). The optimum transmission channel is determined such that the transmission channel is the shortest, or such that the number of transmission sites on the transmission channel is the minimum.
It is noted that in the process of S2 for comparing the received signal intensities, the above-mentioned first method is applicable. In addition, in the process of S4 for comparing the received signal intensities, any of the first, second, and third methods is applicable.
Next, a third embodiment, in which a method to determine the optimum receiving device is employed to receive an image signal, will be explained. The method employed in the third embodiment, for example, is applied in the case where the difference between the highest received signal intensity and the second highest one is small in the comparison result in S2 of the flowchart shown in
First, processes S11 and S12, which are the same as S1 and S2 shown in
When the calculated ratio is judged to be the predetermined ratio or more in S13 (S13: YES), the control unit 220 commands receiving devices including the aforementioned two receiving devices A25 and A55 in a first area to measure their received signal intensities (S14). In this case, the predetermined ratio, for instance, is 80%, yet any ratio can be set as the predetermined ratio. In the first area, there are included the receiving devices A24, A25, A26, A34, A35, A36, A44, A45, A46, A54, A55, and A56, as shown in
A method to set the first area will be described below. First, the receiving devices A35 and A45 are selected, which are located on a line connecting the receiving device A25 of the highest received signal intensity with the receiving device A55 of the second highest received signal intensity. Next, the receiving devices A24, A26, A34, A36, A44, A46, A54, and A56 are selected, which are located at both adjacent sides of A25, A35, A45, and A55 in a direction perpendicular to the above line. In this embodiment, an area including these twelve receiving devices is thus set as the first area.
According to the aforementioned command, the above twelve receiving devices measure their received signal intensities to transmit the measurement results to the control unit 220. The control unit 220 compares the received signal intensities (S16) to define a receiving device with the highest received signal intensity as the optimum receiving device (S17). In this case, for example, the receiving device A25 is defined as the optimum receiving device. Thereafter, the optimum transmission channel is set (S18), and the process of the flowchart is terminated.
On the other hand, when the calculated ratio is judged to be less than the predetermined ratio in S13 (S113: NO), the control unit 220 commands receiving devices in a second area to measure their received signal intensities (S15). Thereafter, the process of S16 to S18 is carried out as described above. The second area, in this case, is an area including all the devices adjacent to the receiving device with the highest received signal intensity in the same way as the second embodiment.
It is noted that in the process of S12 for comparing the received signal intensities, the aforementioned first method is applicable. In addition, in the process of S16 for comparing the received signal intensities, any of the first, second, and third methods is applicable.
In the above-mentioned first to third embodiments, the method to determine the optimum receiving device in the case where the location of the optimum receiving device before a re-determining operation is unknown has been explained. In the present invention, the “re-determining operation” represents an operation that is carried out every predetermined timing to re-determine the optimum receiving device. For example, since the optimum receiving device would be shifted from the current one to another, accompanied by reduction of the received signal intensity of the current one and/or movement of the capsule endoscope 100, such a re-determining operation is required.
Next, a method to determine the optimum receiving device, which is employed in a fourth embodiment according to the present invention, will be explained. In the fourth embodiment, a method, which is effective in the case where the location of the optimum receiving device before the re-determining operation is known, is employed, and the capsule endoscope 100 is anticipated to move by short distance for a short time. In the fourth embodiment, the received signal intensities of neighboring devices of the optimum receiving device before the re-determining operation are selectively measured. In the case of a capsule endoscope, when it is passing through esophagus, its velocity is relatively high, yet its velocity is low while moving in other regions. For example, its typical velocity, which depends on the condition in an intestine, though, is 2 cm/min. in a small intestine.
By any of the methods in the first to third embodiments, for example, it is assumed that the receiving device A33 is defined as the optimum receiving device, and receives an image signal from the capsule endoscope 100. Since the capsule endoscope 100 is moving, the optimum receiving device after the re-determining operation is anticipated reasonably likely to be any of the receiving device A33 and the receiving devices adjacent thereto A22, A23, A24, A32, A34, A42, A43, A44 in an area 27. The optimum receiving device is determined using any of the aforementioned first to third methods. By selectively measuring the received signal intensities of the receiving devices in the area 27, a process in the re-determining operation can be simplified. The followings can mainly be considered as conditions (timing) for starting the re-determining operation.
A first condition for starting the redetermining operation (a first starting condition) will be described.
Accordingly, even though the redetermining operation is not frequently carried out, while the optimum receiving device once determined keeps the received signal intensity thereof more than the predetermined level, the optimum receiving device and the transmission channel can be continuously used. The redetermining operation is carried out only in the case where the received signal intensity becomes less than the predetermined level, and thereby the S/N ratio is reduced, so that the optimum receiving device and the transmission channel are re-determined.
Next, a second starting condition will be described.
A third starting condition will be described.
Next, a method to determine the optimum receiving device, which is employed in a fifth embodiment according to the present invention, will be explained. In the fifth embodiment, a method, which is effective when a plurality of locations of the successive optimum receiving devices before the re-determining operation is known, is employed, and thereby, the moving direction of the capsule endoscope 100 is presumable. In the fifth embodiment, the received signal intensities of receiving devices located around a presumed moving direction of the optimum receiving device are selectively measured.
It is assumed that the receiving device A33 is the closest to the signal source (the capsule endoscope 100), and receives an image signal. In other words, the receiving device A33 is the current optimum receiving device in this case. In addition, it is assumed that the optimum receiving device before the last re-determining operation (the previous optimum receiving device) is the receiving device A34. The moving direction of the capsule endoscope 100 can be presumed by monitoring the successive optimum receiving devices through time. In this case, the capsule endoscope 100 is presumed to move in a direction going from the previous optimum receiving device A34 to the current optimum receiving device A33. Based on such a presumption, the capsule endoscope 100, for instance, is anticipated reasonably likely to move to a neighboring part around an extension of the moving direction, in addition to the circumference of the receiving device A33, at a time of the next re-determining operation. By selectively measuring the received signal intensities of receiving devices located in an area to which the capsule endoscope 100 is anticipated to move at a time of the next re-determining operation, a process carried out in the re-determining operation can be simplified.
Here, a method to select receiving devices located around an area to which the capsule endoscope 100 is anticipated to move will be explained. First, receiving devices A31 and A32 are selected, which are an extension of a line extending from the receiving device A34 to the receiving device A33. Next, the receiving devices A21, A22, A23, A24, A41, A42, A43, and A44 are selected, which are located at both adjacent sides of the receiving devices A31, A32, A33, and A34 in a direction perpendicular to the aforementioned line.
As mentioned above, after setting an area to which the capsule endoscope 100 is anticipated to move, the optimum receiving device is determined using any of the aforementioned first, second, and third methods. In addition, the re-determining operation is carried out under any of the above first, second, and third starting conditions.
Hereinbefore, the embodiments in which the devices 230 are arranged on a two-dimensional plane have been explained. However, in order to receive a signal outputted from the capsule endoscope 100 inside a patient, it is necessary to take into consideration the not two-dimensional but three-dimensional positional relationship between the capsule endoscope 100 and the devices 230.
A method to determine the optimum receiving device, employed in a sixth embodiment according to the present invention, will be explained. In the sixth embodiment, the devices 230 are two-dimensionally arranged on the 2D-DST board 20, yet the 2D-DST board 20 is bent to form a three-dimensional shape.
In the 2D-DST board 20 shown in
Hereinafter, a concrete method to determine the optimum receiving device in the sixth embodiment will be explained. First, a plurality of receiving devices are selected, with a predetermined distance being spaced, among all the devices on the 2D-DST board 20, and the received signal intensities thereof are measured. Some receiving devices in the first row and some receiving devices, at the same location as the above receiving devices in the X-Y coordinates, in the third row are selected. For example, a receiving device B101 in the first row is selected. Next, a receiving device 107, which faces the receiving device B101 across the Z axis, is selected. In addition, receiving devices B104 and B110, which are located on a line perpendicular to the Z axis and a line extending from the receiving device B101 to the receiving device B107, are selected. Further, receiving devices, in the third row, at the same location as the above four receiving devices in the X-Y coordinates, are selected. In this case, receiving devices B301, B304, B307, and B310 are selected. The receiving devices are thus selected to search the position of the capsule endoscope 100.
Hereinafter, referring to
First, the control unit 220 commands the receiving devices B101, B104, B107, B110, B301, B304, B307, and B310, selected in the aforementioned way, to measure their received signal intensities (S21). According to this command, each of the receiving devices measures the received signal intensity thereof to transmit the measurement result to the control unit 220.
The control unit 220 compares the received signal intensities (S22), and narrows down a region in which the capsule endoscope 100 is likely to be in the following way (S23). First, the control unit 220 adds the received signal intensity of each of the receiving devices in the first row to the received signal intensity of a corresponding one of the receiving devices in the third row. In particular, a sum B01 of the received signal intensities of the receiving devices B101 and B301, a sum B04 of the received signal intensities of the receiving devices B104 and B304, a sum B07 of the received signal intensities of the receiving devices B107 and B307, and a sum B110 of the received signal intensities of the receiving devices B110 and B310 are calculated.
Thereafter, the control unit 220 selects the largest value and the second largest value among the sums B01, B04, B07, and B130, and narrows down the region, in which the capsule endoscope 100 is likely to be, based on the largest value and the second largest value. For example, it is assumed that the largest value is the sum B10, and the second largest value is the sum B07. In this case, the region, in which the capsule endoscope 100 is likely to be, is limited in the third quadrant of the X-Y plane.
In addition, since the sum B10 is larger than the sum B07, the region in which the capsule endoscope 100 is likely to be can be narrowed to a neighboring region of the receiving devices B310, B210, B310, B109, B209, and B309.
Furthermore, the control unit 220 compares the receiving devices B110 and B310. Thereby, the location of the capsule endoscope 100 can be narrowed to the side of the first row or the side of the third row. For example, in this case, the received signal intensity of the receiving device B310 is higher than that of the receiving device B110. Therefore, the capsule endoscope 100 can be presumed to be located closer to the third row as shown in
After the aforementioned process for narrowing down the location of the capsule endoscope 100, the control unit 220 commands the receiving devices B210, B310, B209, and B309 to measure their received signal intensities (S24). According to such a command, each of the receiving devices measures the received signal intensity thereof, and the measurement result is transmitted to the control unit 220. Then, the control unit 220 compares the received signal intensity with any other received signal intensities (S25), and a receiving device with the highest received signal intensity is defined as the optimum receiving device (S26). For example, in this case, the closest receiving devices to the capsule endoscope 100 in the X-Y plane are the receiving devices B109, B209, and B309, as shown in
In the 2D-DST board 20 with the three-dimensional structure in the sixth embodiment, the first optimum receiving device has been selected. A method, which is carried out based upon the first optimum receiving device in the next re-determining operation, of determining the optimum receiving device in a seventh embodiment, will be explained.
The control unit 220 judges based on the measurement results whether the received signal intensity of the receiving device B207 is higher than that of the receiving device B201 by a predetermined value or more (S32). When the control unit 220 has judged that the received signal intensity of the receiving device B207 is higher than that of the receiving device B201 by a predetermined value or more (S32: YES), the capsule endoscope 100 is judged closer to the receiving device B207 than to the receiving device B201, and the process goes to S33. When the control unit 220 has not judged that the received signal intensity of the receiving device B207 is higher than that of the receiving device B201 by a predetermined value or more (S32: NO), a receiving device that is the closest to the capsule endoscope 100 is judged to be one of receiving devices other than the receiving device B207, and the process in the flowchart shown in
The steps of S33 and later in the flowchart shown in
In S32, it has already been clear that the capsule endoscope 100 is located in a neighboring region of the receiving device B207. Therefore, the control unit 220 commands the receiving device B207, the receiving devices B206 and B208 adjacent thereto in the second row, and the receiving devices B106, B107, B108, B306, B307, B308 that are at the same location as the receiving devices B206, B207, and B208 in the X-Y coordinates to measure their received signal intensities (S33). Each of the receiving devices measures the received signal intensity thereof according to such a command to transmit the measurement result to the control unit 220. The control unit 220 compares the received signal intensities with each other (S34) to determine the optimum receiving device (S35). As shown in
It is noted that any of the aforementioned first, second, and third methods is applicable to the processes of comparing the received signal intensities in S25 shown in
The present disclosure relates to the subject matter contained in Japanese Patent Application No. P2004-351474, filed on Dec. 3, 2004, which is expressly incorporated herein by reference in its entirely.
Number | Date | Country | Kind |
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2004-351474 | Dec 2004 | JP | national |