JP6590398B2 - Wireless device, detection device, detection system, and wireless communication method - Google Patents

Description

  The present invention relates to a wireless device, a detection device, a detection system, and a wireless communication method.

  There is known a wireless communication system in which an external device located outside a living body receives a signal transmitted wirelessly by a wireless device introduced into the living body (for example, Non-Patent Document 1 and Non-Patent Document 2). reference).

  By the way, the living body contains a considerable amount of water. Therefore, the propagation of the signal from the inside of the living body to the outside of the living body is expressed with sufficiently high accuracy by the propagation of the signal in water. In addition, it is considered that the loss caused by propagation in the water of the signal transmitted by the wireless device increases as the frequency of the signal increases.

  For this reason, the wireless communication system uses frequencies from 1 MHz to 400 MHz as frequencies used for signal transmission by the wireless device.

Yoshida and two others, “Transmission path characteristics and BER evaluation of 30 MHz / 400 MHz band dual mode communication in human body”, IEICE Technical Report, IEICE, December 2014, Vol. 114, No. 381 No., p. 19-24 Ishiwatari, 4 others, “Capacitively coupled wireless information transmission between the deep body and the outside of the body -Evaluation of voltage gain characteristics in air and liquid simulated living body-”, IEICE Technical Report, IEICE, Heisei Heisei May 26, 114, 61, p. 9-12

By the way, the wavelength of a 400 MHz signal is about 75 cm. The length of the dipole antenna is about one quarter of the wavelength. For this reason, when a dipole antenna is used for signal transmission, the size of the wireless device becomes considerably large.
Thus, in the above wireless device, there is a possibility that the size of the wireless device becomes excessive.

  One of the objects of the present invention is to provide a wireless device that can be reduced in size while reducing loss of signal power.

In one aspect, the wireless device is introduced inside the living body ,
UHF (Ultra High Frequency), SHF (Super High Frequency), EHF (Extremely High Frequency), and THF (the frequency part of Tremendously High Frequency) This is a device that wirelessly transmits a signal to the outside of the living body at a frequency that has a loss factor, which is a ratio of the dielectric constant to the real part, higher than a maximum frequency having a maximum value due to dipole polarization.
Furthermore, the wireless device is formed on a coil surface and used for at least one of reception of a wireless signal from the outside of the living body and reception of wireless power from the outside of the living body,
A directional antenna used for the transmission and having a signal strength in a direction orthogonal to the coil surface higher than the signal strength in the other direction;
Is provided.

In another aspect, the detection device is a device that is located outside the living body, includes an antenna, and receives a signal transmitted wirelessly by the wireless device using the antenna .
Furthermore, the detection device, on the basis of the intensity of the upper Symbol received signal from the antenna, a position on the straight line extending in a direction perpendicular to the antenna surface, is detected as the position of the wireless device.
In another aspect, the detection device is located outside the living body, receives a signal transmitted wirelessly by the wireless device, and detects the position of the wireless device based on the intensity of the received signal. It is a device to do.
Further, the detection device is wound on a coil surface parallel to the antenna surface, and is at least one of wireless signal transmission into the living body and wireless power transmission into the living body. The coil used for is provided.

In another aspect, a detection system includes a wireless device introduced inside a living body and a detection device located outside the living body.
On Symbol wireless device,
Of the frequencies included in the frequency band consisting of UHF, SHF, EHF, and THF, the loss coefficient, which is the ratio of the imaginary part of the dielectric constant of water to the real part of the dielectric constant, has a maximum value due to dipole polarization. at a frequency higher than the maximum value frequency with the transmission of signals by wireless to the outside of the living body a row of Umono,
Furthermore, the wireless device is formed on a coil surface, and is used for at least one of reception of a wireless signal from the outside of the living body and reception of wireless power from the outside of the living body, and
A directional antenna used for the transmission and having a signal strength in a direction orthogonal to the coil surface higher than the signal strength in the other direction;
Is provided.
The detection device is
A signal transmitted wirelessly by the wireless device is received, and the position of the wireless device is detected based on the strength of the received signal.

In another aspect, a wireless communication method includes:
A coil formed on the coil surface and used for at least one of reception of a wireless signal from the outside of the living body and reception of wireless power from the outside of the living body, and a coil used for transmission and the coil A wireless device including a directional antenna having a signal strength in a direction orthogonal to a plane higher than that of a signal in the other direction ;
The above wireless device has a dipole whose loss coefficient is a ratio of the imaginary part of the dielectric constant of water to the real part of the dielectric constant of the frequencies included in the frequency band consisting of UHF, SHF, EHF, and THF. A signal is wirelessly transmitted to the outside of the living body at a frequency higher than a maximum frequency having a maximum value due to polarization.

  The size of the wireless device can be reduced while reducing the loss of signal power.

It is a graph showing the change with respect to the frequency of the power loss of water. It is a graph showing the change with respect to the frequency of the dielectric constant of water. It is a graph showing the change with respect to the frequency of the power loss of the water measured by experiment. It is a figure showing the structure of the detection system of 1st Embodiment. FIG. 5 is a diagram illustrating a configuration of a wireless device in FIG. 4. It is a figure showing the structure of the detection system of 2nd Embodiment. It is a figure showing the structure of the radio | wireless apparatus of FIG.

A signal power loss P caused by signal propagation in the dielectric is expressed by Equation 1. The loss P of the signal power caused by the propagation of the signal in the dielectric is also expressed as the lost power. α represents a coefficient that is constant with respect to the frequency of the signal. f represents the frequency of the signal. ε _r ′ represents the real part of the dielectric constant of the dielectric. ε _r ″ represents the imaginary part of the dielectric constant of the dielectric. A value ε _r ″ / ε _r ′ obtained by dividing the imaginary part ε _r ″ of the dielectric constant by the real part ε _r ′ of the dielectric constant is also expressed as a loss coefficient or a dielectric loss tangent.

  For example, when the loss coefficient is constant with respect to the frequency f, the loss P increases in proportion to the frequency f as represented by Equation 1. The dotted line in FIG. 1 represents the change of the loss P with respect to the frequency f when the loss coefficient is constant with respect to the frequency f. In FIG. 1, a logarithmic scale is used for both the horizontal axis and the vertical axis.

As an example, the real part ε _r ′ of the dielectric constant of water and the imaginary part ε _r ″ of the dielectric constant of water correspond to the frequencies included in the frequency band composed of UHF, SHF, EHF, and THF. As shown in FIG. UHF is a frequency band from 300 MHz to 3 GHz. SHF is a frequency band from 3 GHz to 30 GHz. EHF is a frequency band from 30 GHz to 300 GHz. THF is a frequency band from 300 GHz to 3 THz. Therefore, the frequency band consisting of UHF, SHF, EHF, and THF is a frequency band from 300 MHz to 3 THz.

In FIG. 2, the horizontal axis uses a logarithmic scale, and the vertical axis uses a linear scale. The solid line in FIG. 2 represents the real part ε _r ′ of the dielectric constant of water, and the dotted line in FIG. 2 represents the imaginary part ε _r ″ of the dielectric constant of water. The imaginary part of the dielectric constant of water epsilon _{r '',} as well as having a maximum value by the dipole polarization at a frequency f _m near the 22 GHz, with a maximum value by atomic polarization in the vicinity of 2 THz.

  Based on the change in the dielectric constant of water represented by FIG. 2, the inventors of the present application are dipolar with respect to the frequency in which the water loss coefficient is included in the frequency band consisting of UHF, SHF, EHF, and THF. The knowledge that it changes so that it may have a maximum value with a certain maximum frequency by a child polarization was acquired. Furthermore, the inventor of the present application has a ratio of the water loss coefficient to the maximum frequency of the water loss coefficient for the frequency of interest higher than the maximum frequency in the frequency band composed of UHF, SHF, EHF, and THF. The knowledge that the ratio of the maximum frequency to the frequency of interest is smaller.

  According to the above knowledge, the power of the signal generated by the propagation of the signal in the water with respect to the frequency higher than the maximum frequency among the frequencies included in the frequency band consisting of UHF, SHF, EHF, and THF. The loss P is smaller than the power loss with respect to the maximum frequency.

The solid line in FIG. 1 represents a change in the signal power loss P with respect to the frequency f caused by the propagation of the signal in the water in the frequency band composed of UHF, SHF, EHF, and THF. The loss P changes so as to have a maximum value at the maximum value frequency f _m in the frequency band composed of UHF, SHF, EHF, and THF.
FIG. 3 shows a signal power loss P caused by propagation of a signal in water to a frequency higher than the maximum frequency f _m among the frequencies included in the frequency band composed of UHF, SHF, EHF, and THF. Represents the result measured experimentally. In FIG. 3, the horizontal axis uses a linear scale, and the vertical axis uses a logarithmic scale.

  Therefore, in each embodiment to be described later, the wireless device introduced into the living body is an imaginary part of the dielectric constant of water among the frequencies included in the frequency band consisting of UHF, SHF, EHF, and THF. A signal is wirelessly transmitted to the outside of the living body at a frequency where a loss coefficient, which is a ratio of the dielectric constant to the real part, is higher than a maximum frequency having a maximum value due to dipole polarization.

According to this, the loss caused by the propagation of the power of the signal transmitted by the wireless device from the inside of the living body to the outside of the living body can be reduced as compared with the case where the signal is transmitted at the maximum frequency. Furthermore, the radio circuit including the antenna used for transmission can be made smaller than when the signal is transmitted at a frequency lower than the maximum frequency. As a result, the size of the wireless device can be made smaller than when signals are transmitted at a frequency lower than the maximum frequency.
In this manner, according to the wireless device of each embodiment described later, the size of the wireless device can be reduced while reducing the loss of signal power.

  Hereinafter, embodiments of the present invention relating to a wireless device, a detection device, a detection system, and a wireless communication method will be described with reference to FIGS. 4 to 7.

<First Embodiment>
(Constitution)
As illustrated in FIG. 4, the detection system 1 of the first embodiment includes a wireless device 10, a power feeding device 20, and a detection device 30.

  In this example, the wireless device 10 is a wireless chip. The wireless device 10 may be a wireless tag, an IC (Integrated Circuit) tag, an RF (Radio Frequency) tag, or an RFID (Radio Frequency Identifier). For example, the wireless device 10 is formed using a semiconductor.

  The wireless device 10 is introduced into the living body LB. The ingestion of the wireless device 10 by the living body LB is an example in which the wireless device 10 is introduced into the living body LB. For example, the wireless device 10 may be ingested by the living body LB through the mouth of the living body LB. The wireless device 10 may be attached to medicine or food. Moreover, the radio | wireless apparatus 10 may be mixed in a chemical | medical agent or a foodstuff.

Further, the wireless device 10 may be directly introduced into a blood vessel or an organ via a needle or a tube. Further, the wireless device 10 may be introduced into the living body LB by being embedded in the living body LB.
The wireless device 10 may be a device accommodated in a container such as a capsule. For example, the wireless device 10 may be a capsule endoscope device.

  As illustrated in FIG. 5, the wireless device 10 has a flat plate shape and a square shape. For example, the length of each side of the wireless device 10 is 1 mm. Note that the wireless device 10 may have a shape (for example, a circular shape, an elliptical shape, or a polygonal shape) different from the square shape.

The wireless device 10 includes a coil 11 and an antenna 12.
The coil 11 is located at the outer edge of the wireless device 10. The coil 11 is wound along the outer edge of the wireless device 10 on a predetermined coil surface.

  The wireless device 10 receives the wireless signal from the outside of the living body LB and the wireless power from the outside of the living body LB in accordance with the electromagnetic induction method using the coil 11 in the state introduced into the living body LB. Receive power. In this example, the wireless device 10 receives and receives power from the power feeding device 20 located outside the living body LB.

  The frequency (in other words, the first frequency) used for wirelessly receiving signals from outside the living body LB and receiving power from the outside of the living body LB is wireless to the outside of the living body LB, which will be described later. Is lower than the frequency used for signal transmission (in other words, the second frequency). In this example, the frequency used for the reception and the power reception is 100 kHz or more and 50 MHz or less. In this example, the frequency used for the reception and the power reception is 13.56 MHz. Note that the frequency used for the reception may be different from the frequency used for the power reception.

  The wireless device 10 operates with the power received from the power supply device 20. Further, the wireless device 10 controls the operation of the wireless device 10 according to the signal received from the power supply device 20.

  The antenna 12 is located inside the coil 11. In this example, the antenna 12 is a set of dipole antennas extending along a diagonal line of the wireless device 10. The antenna 12 is an example of an omnidirectional antenna (in other words, an omni antenna). An omnidirectional antenna has a constant signal strength with respect to a direction in a specific plane. The antenna 12 may be two sets of dipole antennas extending along two diagonal lines of the wireless device 10. The antenna 12 may be an omnidirectional antenna different from the dipole antenna.

  In a state where the wireless device 10 is introduced into the living body LB, the antenna 12 is used to transmit a signal wirelessly to the outside of the living body LB in accordance with a radio wave system. In this example, the wireless device 10 performs transmission to the detection device 30 located outside the living body LB.

  In this example, the wireless device 10 includes a memory (not shown), and transmits a signal representing information stored in advance in the memory to the outside of the living body LB. For example, the information is information unique to the wireless device 10 or information for identifying the wireless device 10.

  Note that the wireless device 10 may include a sensor and transmit a signal representing a physical quantity detected by the sensor. For example, the physical quantity is temperature, pH, or the amount or concentration of a specific substance. In addition, the wireless device 10 may include a camera and transmit a signal representing a video or an image captured by the camera.

  The frequency used for wireless signal transmission to the outside of the living body LB is the dielectric constant of the imaginary part of the dielectric constant of water among the frequencies included in the frequency band consisting of UHF, SHF, EHF, and THF. The loss coefficient, which is a ratio to the real part, is a frequency higher than the maximum frequency having a maximum value due to dipole polarization. In this example, the maximum value frequency is 22 GHz. Therefore, in this example, the frequency used for the transmission is higher than 22 GHz and lower than 3 THz. In this example, the frequency used for the transmission is 60 GHz.

As illustrated in FIG. 4, the power feeding device 20 includes a coil 21 and a control device 22.
The coil 21 is wound around a predetermined coil surface. For example, the coil surface is arranged so as to be orthogonal to the direction toward the front or back surface of the living body LB.

  The power feeding device 20 uses the coil 21 to perform wireless signal transmission to the inside of the living body LB and power transmission to the inside of the living body LB in accordance with the electromagnetic induction method. In this example, the power feeding device 20 performs transmission and power transmission to the wireless device 10 located inside the living body LB.

  In this example, the power supply device 20 transmits a signal for controlling the wireless device 10 to the inside of the living body LB. For example, a signal for controlling the wireless device 10 is a signal for starting the wireless device 10 (in other words, causing the wireless device 10 to start an operation), a signal for causing the wireless device 10 to transmit a signal, and causing the wireless device 10 to detect a physical quantity. A signal, or a signal that causes the wireless device 10 to capture a video or an image.

In the power supply device 20, the frequency used for wirelessly transmitting a signal to the inside of the living body LB and transmitting the wireless power to the inside of the living body LB is a wireless signal from the outside of the living body LB in the wireless device 10. And the frequency used for receiving electric power by radio from the outside of the living body LB.
The control device 22 controls the current flowing through the coil 21.

The detection device 30 includes an antenna 31 and a control device 32.
The antenna 31 is a set of dipole antennas located on the antenna surface. For example, the antenna surface is arranged so as to be orthogonal to the direction toward the surface of the living body LB.

  The detection device 30 receives a signal from the inside of the living body LB wirelessly using the antenna 31 according to a radio wave system. In this example, the detection device 30 performs reception from the wireless device 10 located inside the living body LB.

  In the detection device 30, the frequency used for wireless signal reception from the inside of the living body LB is the same as the frequency used for wireless transmission of the signal to the outside of the living body LB in the wireless device 10.

  The control device 32 detects the position of the wireless device 10 based on the strength of the signal received using the antenna 31. In this example, when the intensity of the received signal is larger than a predetermined threshold, the control device 32 determines the position on the straight line extending from the antenna 31 in the direction orthogonal to the antenna surface as the position of the wireless device 10. Detect as.

  In this example, the threshold value is determined in advance. Note that the threshold value may be determined based on the strength of a signal received in a predetermined period. In this case, for example, the threshold value may be determined based on an average value of the strengths of signals received in a predetermined period.

  In this example, the control device 22 and the control device 32 are realized by an integrated circuit (for example, LSI (Large Scale Integration) or the like). Note that each of the control device 22 and the control device 32 may include a processing device and a storage device, and the processing device may implement the above functions by executing a program stored in the storage device.

(Operation)
Next, the operation of the detection system 1 will be described.
First, the wireless device 10 is introduced into the living body LB. Thereafter, at a predetermined timing, the power feeding device 20 transmits power to the wireless device 10 located inside the living body LB wirelessly and transmits a signal wirelessly to the wireless device 10 located inside the living body LB. Is performed using the coil 21 at the first frequency (13.56 MHz in this example).

  Thereby, the radio | wireless apparatus 10 receives the electric power of the radio | wireless from the electric power feeder 20 located outside the biological body LB at the 1st frequency using the coil 11. FIG. By operating with the received power, the wireless device 10 receives a wireless signal from the power supply device 20 located outside the living body LB at the first frequency using the coil 11.

  Then, the wireless device 10 operates with the received power and controls the operation of the wireless device 10 according to the received signal, thereby transmitting the signal wirelessly to the outside of the living body LB using the antenna 12. This is performed at the second frequency (60 GHz in this example).

  In this example, the detection device 30 is held by a user of the detection device 30. The user moves the detection device 30 so as to scan the surface of the living body LB while arranging the antenna surface of the detecting device 30 so as to be orthogonal to the direction toward the surface of the living body LB.

The detection device 30 performs radio signal reception from the inside of the living body LB using the antenna 31 at the second frequency.
When the wireless device 10 is located in the vicinity of a straight line extending in a direction orthogonal to the antenna surface from the antenna 31, the detection device 30 uses the antenna 31 to output a signal whose intensity is greater than the threshold value. Receive at frequency. Therefore, in this case, the detection device 30 detects a position on a straight line extending from the antenna 31 in a direction orthogonal to the antenna surface as the position of the wireless device 10.

  As described above, the wireless device 10 according to the first embodiment has the dielectric constant of the imaginary part of the dielectric constant of water among the frequencies included in the frequency band composed of UHF, SHF, EHF, and THF. A signal is wirelessly transmitted to the outside of the living body LB at a frequency whose loss coefficient, which is a ratio to the real part, is higher than a maximum frequency having a maximum value due to dipole polarization.

According to this, the loss caused by the propagation of the power of the signal transmitted by the wireless device 10 from the inside of the living body LB to the outside of the living body LB can be reduced as compared with the case where the signal is transmitted at the maximum value frequency. . Furthermore, the radio circuit including the antenna 12 used for transmission can be made smaller than when signal transmission is performed at a frequency lower than the maximum frequency. As a result, the size of the wireless device 10 can be reduced as compared with the case where signal transmission is performed at a frequency lower than the maximum frequency.
In this manner, according to the wireless device 10, the size of the wireless device 10 can be reduced while reducing the loss of signal power.

  Furthermore, in the wireless device 10 according to the first embodiment, the antenna 12 used for wireless signal transmission to the outside of the living body LB is an omnidirectional antenna.

  According to this, the detection device 30 located outside the living body LB can increase the probability of receiving the signal transmitted by the wireless device 10. As a result, for example, the detection device 30 can detect the position of the wireless device 10 with high accuracy.

  In addition, the wireless device 10 according to the first embodiment receives the wireless signal from the outside of the living body LB at a frequency lower than the frequency used for wirelessly transmitting the signal to the outside of the living body LB, and the living body LB. Both power reception by radio from outside the LB is performed.

  According to this, both the probability of receiving a signal from the outside of the living body LB and the probability of receiving power from the outside of the living body LB can be increased.

  Furthermore, the detection device 30 of the first embodiment is a ratio of the imaginary part of the dielectric constant of water to the real part of the dielectric constant of the frequencies included in the frequency band consisting of UHF, SHF, EHF, and THF. The position of the wireless device 10 is detected based on the intensity of the signal received at a frequency higher than the maximum frequency at which the loss coefficient is a maximum value due to the dipole polarization.

According to this, the loss caused by the propagation of the power of the signal transmitted by the wireless device 10 from the inside of the living body LB to the outside of the living body LB can be reduced as compared with the case where the signal is received at the maximum frequency. . Furthermore, the correlation between the intensity of the received signal and the position of the wireless device 10 can be increased as compared with the case where the signal is received at a frequency lower than the maximum frequency. As a result, the position of the wireless device 10 can be detected with higher accuracy than when the signal is received at a frequency lower than the maximum frequency.
Thus, according to the detection device 30, the position of the wireless device 10 can be detected with high accuracy.

Note that the detection system 1 may be configured not to perform one or both of power reception and reception from the outside of the living body LB by the wireless device 10.
When neither power reception nor reception from the outside of the living body LB is performed by the wireless device 10, the detection system 1 may omit the power supply device 20. Further, in this case, the wireless device 10 may omit the coil 11.
Further, when the wireless device 10 does not receive power from the outside of the living body LB, the wireless device 10 may include a capacity for storing electric power. In this case, the wireless device 10 may operate with electric power stored in the capacity.
In addition, when the wireless device 10 does not receive power from the outside of the living body LB, the wireless device 10 may generate power. In this case, the wireless device 10 may operate with the generated power.

  The detection system 1 may be configured not to detect the position of the wireless device 10 by the detection device 30.

Second Embodiment
Next, the detection system of the second embodiment will be described. The detection system of the second embodiment is different from the detection system of the first embodiment in that the detection device includes a power supply device. Hereinafter, the difference between the detection system of the second embodiment and the first embodiment will be mainly described. In the description of the second embodiment, the same reference numerals as those in the first embodiment are used.

  As illustrated in FIG. 6, the detection system 1 </ b> A of the second embodiment omits the power feeding device 20, and replaces the wireless device 10 and the detection device 30 of the first embodiment with the wireless device 10 </ b> A and the detection device 30 </ b> A. Is provided.

As illustrated in FIG. 7, the wireless device 10A is different from the wireless device 10 according to the first embodiment in that an antenna 12A is provided instead of the antenna 12.
The antenna 12 </ b> A is located inside the coil 11. In this example, the antenna 12A is a patch antenna having a circular shape. Note that the patch antenna may have a shape different from a circular shape (for example, an elliptical shape, a regular shape, or a polygonal shape).

  The antenna 12A is an example of a directional antenna. A directional antenna has a signal strength in a specific direction higher than the signal strength in another direction. In this example, the antenna 12A has a higher signal strength in a direction orthogonal to the coil surface of the wireless device 10A than in other directions. The antenna 12A may be a directional antenna different from the patch antenna.

  As illustrated in FIG. 6, the detection device 30 </ b> A is different from the detection device 30 of the first embodiment in that a control device 32 </ b> A and a coil 33 </ b> A are provided instead of the control device 32.

The coil 33A is wound on a coil surface parallel to the antenna surface of the detection device 30A. In this example, the coil surface coincides with the antenna surface.
The detection device 30A uses the coil 33A to perform wireless signal transmission into the living body LB and wireless power transmission into the living body LB in accordance with the electromagnetic induction method. In this example, the detection device 30A performs transmission and power transmission to the wireless device 10A located inside the living body LB.

In the detection device 30A, the frequency used for the wireless signal transmission to the inside of the living body LB and the power transmission to the inside of the living body LB is the signal used by the wireless device 10A for the wireless signal from the outside of the living body LB. And the frequency used for receiving electric power by radio from the outside of the living body LB.
The control device 32A has a function of controlling the current flowing through the coil 33A in addition to the function of the control device 32 of the first embodiment.

  According to the detection system 1A of the second embodiment, the same operation and effect as the detection system 1 of the first embodiment can be achieved.

  Furthermore, in the wireless device 10A of the second embodiment, the antenna 12A is used for wireless signal transmission to the outside of the living body LB, and the signal strength in the direction orthogonal to the coil surface is the signal in the other direction. It is a directional antenna higher than strength.

  According to this, when at least one of reception and power reception from the detection device 30A located outside the living body LB is performed, the probability that the detection device 30A receives a signal transmitted by the wireless device 10A is increased. Can do. As a result, for example, the detection device 30A can detect the position of the wireless device 10A with high accuracy.

  In addition, the detection apparatus 30A of the second embodiment includes a coil 33A that is used for both wireless signal transmission into the living body LB and wireless power transmission into the living body LB. Furthermore, in the detection apparatus 30A, the antenna 31 used for receiving a wireless signal from the inside of the living body LB is an omnidirectional antenna.

  According to this, when at least one of transmission and power transmission to the wireless device 10A introduced into the living body LB is performed, it is possible to increase the probability of receiving the signal transmitted by the wireless device 10A.

  In addition, this invention is not limited to embodiment mentioned above. For example, various modifications that can be understood by those skilled in the art may be added to the above-described embodiments without departing from the spirit of the present invention. For example, any combination of the above-described embodiment and modification may be adopted as another modification of the above-described embodiment without departing from the spirit of the present invention.

1, 1A detection system 10, 10A wireless device 11 coil 12, 12A antenna 20 power supply device 21 coil 22 control device 30, 30A detection device 31 antenna 32, 32A control device 33A coil LB living body

Claims (11)

Introduced into the body ,
UHF (Ultra High Frequency), SHF (Super High Frequency), EHF (Extremely High Frequency), and THF (the frequency part of Tremendously High Frequency) A wireless device that wirelessly transmits a signal to the outside of the living body at a frequency higher than a local maximum frequency at which a loss factor that is a ratio of the dielectric constant to a real part has a local maximum due to dipole polarization ,
The wireless device includes:
A coil formed on a coil surface and used for at least one of reception of a wireless signal from the outside of the living body and reception of wireless power from the outside of the living body;
A directional antenna used for the transmission and having a signal strength in a direction orthogonal to the coil surface higher than the signal strength in the other direction;
A wireless device comprising: The wireless device according to claim 1,
The local maximum frequency is 22 GHz . The wireless device according to claim 1 or 2 , wherein
A wireless device that performs at least one of reception of a wireless signal from the outside of the living body and reception of wireless power from the outside of the living body at a frequency lower than the frequency used for the transmission. The wireless device according to claim 3 ,
A wireless device, wherein a frequency used for at least one of the reception and the power reception is 100 kHz or more and 50 MHz or less. Located outside the living body ,
With an antenna,
A detection device that receives a signal transmitted wirelessly by the wireless device according to claim 1 using the antenna .
Based on the strength before Symbol received signal from the antenna, a position on the straight line extending in a direction perpendicular to the antenna surface, is detected as the position of the wireless device, the detection device. The detection device according to claim 5 ,
The transmission of the radio by the signal to the interior of the living body, and includes a coil for use in at least one of electric power transmission by radio to the interior of the living body,
The detection device, wherein the antenna is an omnidirectional antenna .   A detection device that is located outside a living body, receives a signal transmitted wirelessly by the wireless device according to claim 1, and detects the position of the wireless device based on the intensity of the received signal,
  The coil is wound around a coil surface parallel to the antenna surface, and includes a coil used for at least one of transmission of a wireless signal to the inside of the living body and transmission of wireless power to the inside of the living body. Detection device.   The detection device according to claim 7, further comprising an omnidirectional antenna used for the reception. A wireless device introduced inside the living body;
A detection device located outside the living body;
A detection system comprising:
The wireless device includes:
UHF (Ultra High Frequency), SHF (Super High Frequency), EHF (Extremely High Frequency), and THF (the frequency part of Tremendously High Frequency) the loss factor is the ratio of the real part of the dielectric constant at a frequency higher than the maximum value frequency having the maximum value by dipole polarization, the transmission of the radio by the signal to the outside of the living body a row of Umono,
Furthermore, the wireless device comprises:
A coil formed on a coil surface and used for at least one of reception of a wireless signal from the outside of the living body and reception of wireless power from the outside of the living body;
A directional antenna used for the transmission and having a signal strength in a direction orthogonal to the coil surface higher than the signal strength in the other direction;
With
The detection device includes:
The detection system which receives the signal transmitted by the radio | wireless by the said radio | wireless apparatus, and detects the position of the said radio | wireless apparatus based on the intensity | strength of the received signal. A coil formed on a coil surface and used for at least one of reception of a wireless signal from outside the living body and reception of wireless power from the outside of the living body; and a coil used for transmission and the coil A wireless device including a directional antenna having a signal strength in a direction orthogonal to a plane higher than that of a signal in the other direction ;
The wireless device includes UHF (Ultra High Frequency), SHF (Super High Frequency), EHF (Extremely High Frequency), and THF (Trequently High Frequency Frequency). Wirelessly transmits a signal to the outside of the living body at a frequency where the loss coefficient, which is the ratio of the imaginary part to the real part of the dielectric constant, is higher than the local maximum frequency having a local maximum due to dipole polarization. Communication method. The wireless communication method according to claim 10, comprising:
The detection device located outside the living body receives a signal transmitted wirelessly by the wireless device,
The detection device detects the position of the wireless device based on the strength of the received signal;
Wireless communication method.

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