Sensor system, sensor, reader, and measurement method

Abstract

A sensor system (30) comprises a sensor (10) and a reader (20). The sensor (10) comprises a first coil (11) and a second coil (12) separated from the first coil (11). The reader (20) comprises a third coil (23). The reader (20) is capable of wirelessly performing reading from the sensor (10) by causing an alternating magnetic field generated in the third coil (23) to act on the first coil (11) and the second coil (12). The reader (20) detects information relating to the positional relationship between at least two coils among the first coil (11), the second coil (12), and the third coil (23) on the basis of the result of the reading.

Description

Sensor system, sensor, reader, and measurement method

[0001] The present invention relates to a sensor system, a sensor, a reader, and a measurement method.

[0002] Sensor technologies using magnetic resonance coupling (also referred to as magnetic resonance coupling) have been developed.

[0003] Patent Document 1 describes a sensor system in which a gain-loss coupling circuit formed by a reader-side resonance circuit and a sensor-side resonance circuit is configured to have parity-time symmetry.

[0004] International Publication No. 2022 / 202773

[0005] The technology of Patent Document 1 was for detecting a change in resistance of a sensor element as a resistance portion included in the sensor-side resonance circuit.

[0006] The present invention provides a sensor technology capable of highly sensitively detecting information regarding the positional relationship between coils.

[0007] According to one aspect of the present invention, the following sensor system, sensor, reader, and measurement method are provided.

[0008] (1) A sensor system comprising a sensor having a first coil and a second coil spaced apart from the first coil, and a reader having a third coil, wherein the reader can wirelessly read from the sensor by applying an alternating magnetic field generated in the third coil to the first coil and the second coil, and the reader detects information regarding the positional relationship between at least two of the coils, the first coil, the second coil, and the third coil, based on the result of the reading. (2) The sensor system according to (1), wherein the sensor comprises a first resonator including the first coil and a second resonator including the second coil, the reader comprises a third resonator including the third coil, and the reader can perform the reading in a coupled state in which the first resonator, the second resonator, and the third resonator are electrically coupled by applying an alternating magnetic field generated in the third coil to the first coil and the second coil. (3) The sensor system described in (2), wherein the reader further comprises a measuring unit connected to the third resonator for measuring the real part of the impedance, and the reading can be performed by performing a measurement by the measuring unit in the coupled state. (4) The sensor system described in (3), wherein the reader, in the coupled state, measures a predetermined frequency f by the measuring unit. ｍ A sensor system that can perform the reading by measuring the real part of the impedance at (5) In the sensor system described in (4), the frequency f ｍ(1) A sensor system having a frequency of 0.1 MHz or more and 10 THz or less. (6) A sensor system according to (3) or (4), wherein the Q value of the resonance peak measured by the measuring unit in the coupled state is 1 or more and 1,000,000 or less. (7) A sensor system according to any one of (3) to (6), wherein the reader further comprises a support part for supporting the third coil, the reader is capable of replacing a first combination of the third coil and the support part with a second combination of another third coil and another support part, reference information is predetermined for each of the first and second combinations, the measuring unit identifies information regarding the positional relationship using the result of the reading and the reference information for the first combination when the reading is made with the first combination, and identifies information regarding the positional relationship using the result of the reading and the reference information for the second combination when the reading is made with the second combination. (8) A sensor system according to any one of (2) to (7), wherein the first resonator and the second resonator are both loss circuits, and the third resonator is a gain circuit. (9) A sensor system according to (8), wherein in the coupled state, the first resonator, the second resonator, and the third resonator constitute a gain-loss coupled circuit having parity-time symmetry. (10) A sensor system according to (8) or (9), wherein the resonant frequency f of the first resonator １ , the resonant frequency f of the second resonator ２ , and the resonant frequency f of the third resonator ３ (11) A sensor system in which the third resonator includes negative resistance, wherein the value obtained by subtracting the lowest frequency from the highest frequency is 10 THz or less. １is set, and the resonance frequency of the second resonator is f ２ When it is set as such, |f １ - f ２A sensor system in which the value obtained by | is 1 THz or less. (13) A sensor system in which, in any one of (2) to (12), both the first resonator and the second resonator are LCR series resonant circuits. (14) A sensor system in which, in any one of (2) to (12), both the first resonator and the second resonator are LCR parallel resonant circuits. (15) A sensor system in which, in any one of (1) to (14), the distance between the first coil and the second coil is 0 mm or more and 50 mm or less. (16) A sensor system in which, in any one of (1) to (15), the inclination of the axis of the second coil with respect to the axis of the first coil is 12° or less. (17) A sensor system in which, in any one of (1) to (16), when viewed with the line of sight in a direction parallel to the axis of the first coil, at least a part of the internal region of the first coil and the internal region of the second coil overlap. (18) A sensor system according to any one of (1) to (17), wherein the reader detects at least one of the distance and the change in distance between the first coil and the second coil based on the reading result. (19) A sensor system according to any one of (1) to (18), wherein the sensor further comprises a contact portion that is attachable to the eyeball and is extendable, and the first coil and the second coil are attached to the contact portion. (20) A sensor system according to (19) for measuring intraocular pressure. (21) A sensor used in a sensor system according to any one of (1) to (20). (22) A reader used in a sensor system according to any one of (1) to (20).(23) A measurement method for wirelessly reading from a sensor by applying an alternating magnetic field generated in a third coil provided in a reader to a first coil provided in a sensor and a second coil provided in the sensor at a distance from the first coil, and detecting information regarding the positional relationship between at least two of the first coil, the second coil, and the third coil based on the reading result. (24) The measurement method according to (23), wherein the sensor comprises a first resonator including the first coil and a second resonator including the second coil, the reader comprises a third resonator including the third coil, and the reading is performed in a coupled state in which the first resonator, the second resonator, and the third resonator are electrically coupled by applying an alternating magnetic field generated in the third coil to the first coil and the second coil. (25) The measurement method described in (24), wherein the reader further comprises a measuring unit connected to the third resonator to measure the real part of the impedance, and the measurement is performed by measuring with the measuring unit in the coupled state to perform the reading. (26) The measurement method described in (25), wherein in the coupled state, the measuring unit measures a predetermined frequency f. ｍ A measurement method in which the reading is performed by measuring the real part of the impedance at (27) In the measurement method described in (26), the frequency f ｍ(28) A measurement method in which the frequency is 0.1 MHz or more and 10 THz or less. (25) A measurement method in which the Q value of the resonance peak measured by the measurement unit in the coupled state is 1 or more and 1,000,000 or less. (29) A measurement method in which the reading method in which any one of (25) to (28) is characterized in that the reader can replace the first combination of the third coil and the support part that supports the third coil with a second combination of another third coil and another support part that supports the other third coil, and reference information for each of the first and second combinations is predetermined, and when the reading is made with the first combination, the reading result and the reference information for the first combination are used to identify the positional relationship, and when the reading is made with the second combination, the reading result and the reference information for the second combination are used to identify the positional relationship. (30) A measurement method according to any one of (24) to (29), wherein the first resonator and the second resonator are both loss circuits, and the third resonator is a gain circuit. (31) A measurement method according to (30), wherein in the coupled state, the first resonator, the second resonator, and the third resonator constitute a gain-loss coupled circuit having parity-time symmetry. (32) A measurement method according to (30) or (31), wherein the resonant frequency f of the first resonator １ , the resonant frequency f of the second resonator ２ , and the resonant frequency f of the third resonator ３ Of these, the value obtained by subtracting the lowest frequency from the highest frequency is 10 THz or less, and the third resonator is a measurement method including negative resistance. (33) A measurement method in which the third resonator is an LCC resonant circuit in which the third resonator is a measurement method in which the third resonator is an LCC resonant circuit. (34) A measurement method in which the resonant frequency of the first resonator is f １ Let the resonant frequency of the second resonator be f ２ When this is the case, |f １ -f２ A measurement method in which the value obtained by | is 1 THz or less. (35) A measurement method in which, in any one of (24) to (34), both the first resonator and the second resonator are LCR series resonant circuits. (36) A measurement method in which, in any one of (24) to (34), both the first resonator and the second resonator are LCR parallel resonant circuits. (37) A measurement method in which, in any one of (23) to (36), the distance between the first coil and the second coil is 0 mm or more and 50 mm or less. (38) A measurement method in which, in any one of (23) to (37), the inclination of the axis of the second coil with respect to the axis of the first coil is 12° or less. (39) A measurement method according to any one of (23) to (38), wherein, when viewed with the line of sight in a direction parallel to the axis of the first coil, the internal region of the first coil and the internal region of the second coil overlap in at least a portion. (40) A measurement method according to any one of (23) to (39), wherein, based on the reading result, at least one of the distance and the change in distance between the first coil and the second coil is detected. (41) A measurement method according to any one of (23) to (40), wherein the sensor further comprises a contact portion that can be attached to the eyeball and is expandable, and the first coil and the second coil are attached to the contact portion. (42) A measurement method according to (41), wherein intraocular pressure is measured.

[0009] According to the present invention, it is possible to provide a sensor technology that can detect information regarding the positional relationship between coils with high sensitivity.

[0010] This is a schematic diagram illustrating the configuration of the sensor system according to the first embodiment. This is a diagram illustrating the relationship between the first coil, the second coil, and the third coil according to the first embodiment. This is a diagram illustrating the image of mode splitting. This is a schematic diagram illustrating the configuration of the sensor system when both the first and second resonators are LCR series resonant circuits. This is a diagram illustrating the computer included in the measurement unit. This is a diagram illustrating the circuit diagrams of the first, second, and third resonators. This is a diagram illustrating the sensor and the third coil of the sensor system according to the second embodiment. This is a diagram illustrating the measurement configuration according to Example 1-1. This is a diagram showing the frequency spectra obtained with multiple simulated intraocular pressures P in Example 1-1 superimposed. This is a diagram showing the frequency spectra obtained with multiple simulated intraocular pressures P in Comparative Example 1-1 superimposed. This is a diagram showing the frequency spectra obtained with multiple simulated intraocular pressures P in Example 1-2 superimposed. This is a diagram showing the frequency spectra obtained with multiple simulated intraocular pressures P in Comparative Example 1-2 superimposed. This graph summarizes the measurement results from Example 1-1, Comparative Example 1-1, Example 1-2, and Comparative Example 1-2. This is a photograph taken with the sensor attached to the eyeball. This is a photograph taken with the intraocular pressure being read by a reader equipped with a third coil. This is a graph showing the measurement results in Example 2. This is a diagram illustrating the configuration of the reader according to the third embodiment.

[0011] Embodiments of the present invention will be described below with reference to the drawings. In all drawings, similar components are denoted by the same reference numerals, and their descriptions are omitted as appropriate.

[0012] (First Embodiment) Figure 1 is a schematic diagram illustrating the configuration of the sensor system 30 according to this embodiment. Figure 2 is a diagram illustrating the relationship between the first coil 11, the second coil 12, and the third coil 23 according to this embodiment.

[0013] The sensor system 30 according to the first embodiment includes a sensor 10 and a reader 20. The sensor 10 includes a first coil 11 and a second coil 12 spaced apart from the first coil 11. The reader 20 includes a third coil 23. The reader 20 can wirelessly read from the sensor 10 by applying an alternating magnetic field generated in the third coil 23 to the first coil 11 and the second coil 12. Based on the reading results, the reader 20 detects information regarding the positional relationship between at least two of the coils, the first coil 11, the second coil 12, and the third coil 23.

[0014] The measurement method according to this embodiment wirelessly reads from the sensor 10 by applying an alternating magnetic field generated in the third coil 23 to the first coil 11 and the second coil 12. Based on the reading results, information regarding the positional relationship between at least two of the first, second, and third coils is detected. Here, the first coil 11 is provided in the sensor 10. The second coil 12 is provided in the sensor 10 at a distance from the first coil 11. The third coil 23 is provided in the reader 20.

[0015] The measurement method according to this embodiment can be realized by the sensor system 30 according to this embodiment. The sensor system 30 and the measurement method according to this embodiment will be described in detail below.

[0016] Sensor 10 includes a first resonator 110 containing a first coil 11 and a second resonator 120 containing a second coil 12. Reader 20 includes a third resonator 230 containing a third coil 23. Reader 20 can perform readings in a coupled state where the first resonator 110, the second resonator 120, and the third resonator 230 are electrically coupled by applying the alternating magnetic field generated in the third coil 23 to the first coil 11 and the second coil 12. Hereinafter, the first coil 11 and the second coil 12 will be collectively referred to as the "sensor-side coil". During reading, the distance between the first coil 11 and the third coil 23 is assumed to be less than or equal to the distance between the second coil 12 and the third coil 23.

[0017] The reader 20 includes a measuring unit 21. The measuring unit 21 is connected to the third resonator 230 to measure the real part of the impedance. The dashed lines in Figure 1 and Figure 4 (described later) show the connection lines between the measuring unit 21 and the third resonator 230. By performing measurements with the measuring unit 21 in the above-described coupling state, readings can be performed. Note that the ability to read from the sensor 10 wirelessly means that the sensor 10 and the reader 20 are not connected by a wire and readings can be performed even when they are separated. Furthermore, the first resonator 110 and the second resonator 120 of the sensor 10 do not require wired connections from other devices, and no wired power supply is required.

[0018] The actual impedance measured by the measurement unit 21, i.e., the resistance R, changes depending on the extent to which the alternating magnetic field from the third coil 23 acts on the first coil 11 and the second coil 12. Furthermore, the resistance R also changes depending on the relationship between the first coil 11 and the second coil 12. In other words, the resistance R can change as the positional relationship between the first coil 11, the second coil 12, and the third coil 23 changes. Based on this change in resistance R, changes in the positional relationship between the first coil 11, the second coil 12, and the third coil 23 can be detected.

[0019] In particular, the sensor 10 according to this embodiment has a first coil 11 and a second coil 12, that is, two inductively coupled antennas. When the first coil 11 and the second coil 12 are close together, mode splitting (frequency splitting) occurs depending on the distance between the first coil 11 and the second coil 12. Figure 3 is a diagram illustrating the image of mode splitting. When the resistance R at a certain frequency f (for example, the dashed line frequency in Figure 3) is observed, it can be seen that the resistance R also changes due to the effect of mode splitting. By performing readings with the third resonator 230 under conditions in which such mode splitting occurs, the detection sensitivity can be synergistically increased.

[0020] The high detection sensitivity of the sensor system 30 means that wireless reading over longer distances is possible. The degree to which the alternating magnetic field from the third coil 23 acts on the first coil 11 and the second coil 12 decreases as the distance between the third coil 23 and the sensor 10 increases. Because the sensor system 30 according to this embodiment has high detection sensitivity, detection results can be obtained with the desired accuracy even when the third coil 23 and the sensor 10 are separated by a certain distance.

[0021] As described above, the reader 20 detects information regarding the positional relationship between the coils. Based on the reading results, the reader 20 can detect at least one of the positional relationship and changes in the positional relationship between at least two of the coils among the first coil 11, the second coil 12, and the third coil 23. More specifically, based on the reading results, the reader 20 can detect the distance d between the first coil 11 and the second coil 12. １２ The distance d between the first coil 11 and the second coil 12. １２ Changes in the distance d between the first coil 11 and the third coil 23. ３１ The distance d between the first coil 11 and the third coil 23. ３１ Changes in the distance d between the second coil 12 and the third coil 23. ３２ , and the distance d between the second coil 12 and the third coil 23 ３２ At least one of these changes can be detected. However, the sensor system 30 may be configured so that the reader 20 detects not only the distance between coils, i.e., the positional relationship in the direction parallel to the coil axis, but also the positional relationship and changes in the positional relationship in the direction perpendicular to the coil axis. Furthermore, the information regarding the positional relationship between coils includes information that can be associated with the positional relationship or changes in the positional relationship between coils, such as values ​​that fluctuate depending on the distance between coils.

[0022] As an example, if the position of the first coil 11 changes while the relative positions of the second coil 12 and the third coil 23 are fixed, the distance d between the first coil 11 and the second coil 12... １２ , and the distance d between the first coil 11 and the third coil 23 ３１As both of these change, the measurement result of the measurement unit 21 changes. Using this measurement result, the reader 20 can detect changes in the positional relationship of the first coil 11 with respect to the third coil 23 and the second coil 12. Because highly sensitive detection is possible due to the effect of mode splitting described above, it is preferable that the target of detection by the reader 20 is a value that changes with the change in distance between the first coil 11 and the second coil 12. In particular, based on the reading result, the reader 20 determines the distance d between the first coil 11 and the second coil 12. １２ and distance d １２ It is preferable to detect at least one of the changes in the following:

[0023] The sensor 10 used in the sensor system 30 will be explained in more detail.

[0024] In the example shown in Figure 2, the axis of the first coil 11 and the axis of the second coil 12 are almost identical. In Figure 2, the axes of the first coil 11 and the second coil 12 are shown by dashed lines. The inclination of the axis of the second coil 12 with respect to the axis of the first coil 11 is not particularly limited, but from the viewpoint of improving detection sensitivity, it is preferably 12° or less, more preferably 10° or less, and even more preferably 5° or less.

[0025] From the viewpoint of improving detection sensitivity, it is preferable that, when viewed from a direction parallel to the axis of the first coil 11 as the line of sight, at least a portion of the internal region of the first coil 11 and the internal region of the second coil 12 overlap. The internal region of a coil refers to the region surrounded by the coil's conductors.

[0026] For the first coil 11, the coil radius, number of turns, material, and wire thickness can be set according to the application of the sensor system 30 and the object to be measured. For the second coil 12, the coil radius, number of turns, material, and wire thickness can be set according to the application of the sensor system 30 and the object to be measured. Furthermore, the inductance of the first coil 11 and the inductance of the second coil 12 can be selected so as to achieve a coupled state between the third coil 23 and the sensor-side coil, as will be described later.

[0027] The coil radii of the first coil 11 and the coil radii of the second coil 12 are not particularly limited, but can be, for example, 300 mm or less. From the viewpoint of miniaturizing the sensor 10, it is preferable that the coil radii of the first coil 11 and the coil radii of the second coil 12 are both 150 mm or less, more preferably 50 mm or less, and even more preferably 8 mm or less. On the other hand, it is preferable that the coil radii of the first coil 11 and the coil radii of the second coil 12 are both 1 mm or more, more preferably 2 mm or more, and even more preferably 3 mm or more.

[0028] The first coil 11 and the second coil 12 may have the same coil radius, the coil radius of the first coil 11 may be smaller than that of the second coil 12, or the coil radius of the first coil 11 may be larger than that of the second coil 12. The shapes of the first coil 11 and the second coil 12 when viewed from a direction parallel to the axis as the line of sight are not particularly limited and can be, for example, a circle, an ellipse, or a polygon (triangle, quadrilateral, etc.).

[0029] The number of turns of the first coil 11 and the second coil 12 are not particularly limited; both may be 1 or 2 or more. From the viewpoint of miniaturizing the sensor 10, it is preferable that both the number of turns of the first coil 11 and the second coil 12 be 10 or less, and more preferably 5 or less.

[0030] The materials of the first coil 11 and the second coil 12 are not particularly limited, but metal wires such as copper can be used. The first coil 11 may or may not have a ferromagnetic core. The second coil 12 may or may not have a ferromagnetic core.

[0031] The distance d between the first coil 11 and the second coil 12 １２ The distance d between the first coil 11 and the second coil 12 is not particularly limited, but may be 0 mm or more, more than 0 mm, 10 mm or more, or 100 mm or more. １２The distance d between the first coil 11 and the second coil 12 is preferably 50 mm or less, preferably 10 mm or less, and more preferably 5 mm or less. １２ This represents the distance between the center of the first coil 11 and the center of the second coil 12. １２ The state where the distance is 0 mm means that one of the first coil 11 and the second coil 12 is located inside the other, and the centers of the two coils coincide. The first coil 11 and the second coil 12 are not electrically short-circuited.

[0032] In the example in Figure 1, both the first resonator 110 and the second resonator 120 are LCR parallel resonant circuits. However, both the first resonator 110 and the second resonator 120 may be LCR series resonant circuits. Figure 4 is a schematic diagram illustrating the configuration of the sensor system 30 when both the first resonator 110 and the second resonator 120 are LCR series resonant circuits. When both the first resonator 110 and the second resonator 120 are LCR series resonant circuits, the resistance value can be lowered and energy loss can be reduced compared to when they are LCR parallel resonant circuits. In other words, the wireless power supply efficiency from the reader 20 to the sensor 10 can be increased.

[0033] The resonant frequency of the first resonator 110 is f １ The resonant frequency of the second resonator 120 is set to f ２ When this is the case, |f １ -f ２ The value obtained by | may be, for example, 1 THz or less. However, from the viewpoint of improving detection sensitivity due to the mode splitting effect of the first resonator 110 and the second resonator 120, the resonant frequency f of the first resonator 110 １ And the resonant frequency f of the second resonator 120 ２ It is preferable that they be somewhat close. For example, |f １ -f ２ The value obtained by | is preferably 1 MHz or less, more preferably 1 kHz or less, and even more preferably 100 Hz or less. Resonant frequency f of the first resonator 110 １ and the resonant frequency f of the second resonator 120 ２These can be calculated using the resistance of the resistor, the capacitance of the capacitor, and the inductance of the coil, respectively, used in the resonant circuit.

[0034] The reader 20 used in the sensor system 30 will be explained in more detail.

[0035] As described above, the leader 20 includes a third resonator 230 and a measuring unit 21. The coil radius, number of turns, material, and wire thickness of the third coil 23 can be set according to the application of the sensor system 30 and the object to be measured. Furthermore, the inductance of the third coil 23 can be selected so that the third coil 23 and the sensor-side coil are coupled, as will be described later.

[0036] The coil radius of the third coil 23 is not particularly limited, but can be, for example, 300 mm or less. From the viewpoint of miniaturizing the leader 20, the coil radius of the third coil 23 is preferably 150 mm or less, more preferably 50 mm or less, and even more preferably 8 mm or less. On the other hand, the coil radius of the third coil 23 is preferably 1 mm or more, more preferably 2 mm or more, and even more preferably 3 mm or more.

[0037] The third coil 23 may have the same coil radius as the first coil 11, the coil radius of the third coil 23 may be smaller than that of the first coil 11, or the coil radius of the third coil 23 may be larger than that of the first coil 11. The third coil 23 may have the same coil radius as the second coil 12, the coil radius of the third coil 23 may be smaller than that of the second coil 12, or the coil radius of the third coil 23 may be larger than that of the second coil 12.

[0038] The number of turns of the third coil 23 is not particularly limited and may be 1 or 2 or more. From the viewpoint of miniaturizing the leader 20, the number of turns of the third coil 23 is preferably 10 or less, and more preferably 5 or less. The shape of the third coil 23 when viewed with the line of sight parallel to the axis is not particularly limited and can be, for example, a circle, an ellipse, or a polygon (triangle, quadrilateral, etc.).

[0039] The material of the third coil 23 is not particularly limited, but metal wire such as copper can be used. The third coil 23 may or may not have a ferromagnetic core.

[0040] The measurement unit 21 measures a predetermined frequency f ｍ In this system, the resistivity R can be measured, but it is not particularly limited, for example, by including a vector network analyzer (VNA). The measurement unit 21 applies an AC signal to the connected third resonator 230 and measures the impedance by measuring the amplitude and phase of the reflected and traveling waves, thereby obtaining the resistivity R. It can also be said that the measurement unit 21 supplies AC power to the third resonator 230 and the sensor 10 using the AC signal.

[0041] The measurement unit 21 may include a computer. Figure 5 illustrates a computer 1000 included in the measurement unit 21. The computer 1000 is any computer. For example, the computer 1000 may be a SoC (System on Chip), a Personal Computer (PC), a server machine, a tablet terminal, or a smartphone. The computer 1000 may be a dedicated computer designed to implement the sensor 10, or it may be a general-purpose computer. Furthermore, the sensor 10 may be implemented by a single computer 1000, or by a combination of multiple computers 1000.

[0042] Computer 1000 includes a bus 1020, a processor 1040, a memory 1060, a storage device 1080, an input / output interface 1100, and a network interface 1120. The bus 1020 is a data transmission path for the processor 1040, memory 1060, storage device 1080, input / output interface 1100, and network interface 1120 to send and receive data to and from each other. However, the method of connecting the processor 1040 and the other components is not limited to bus connection. The processor 1040 is a variety of processor such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or an FPGA (Field-Programmable Gate Array). The memory 1060 is a main memory device implemented using RAM (Random Access Memory), etc. The storage device 1080 is an auxiliary storage device implemented using a hard disk, SSD (Solid State Drive), memory card, or ROM (Read Only Memory), etc.

[0043] The input / output interface 1100 is an interface for connecting the computer 1000 with input / output devices. For example, input devices such as a keyboard and output devices such as a display are connected to the input / output interface 1100. The method by which the input / output interface 1100 connects to the input and output devices may be wireless or wired.

[0044] The network interface 1120 is an interface for connecting the computer 1000 to a network. Examples of such networks include LANs (Local Area Networks) and WANs (Wide Area Networks). The network interface 1120 may connect to the network via a wireless connection or a wired connection.

[0045] The storage device 1080 stores a program module for implementing the measurement unit 21. The processor 1040 reads the program module into the memory 1060 and executes it, thereby realizing the function corresponding to the program module.

[0046] In the coupled state, the leader 20 measures a predetermined frequency f by the measuring unit 21. ｍ The reading can be obtained by measuring the real part of the impedance (i.e., resistance R) at the frequency f. ｍ For example, it can be 0.1 MHz or more and 10 THz or less. However, the leader 20 has a predetermined frequency f ｍ Alternatively, the frequency spectrum of the resistance R can be obtained by sweeping the frequency. For example, the positional relationship between coils can be determined using the peak values ​​of the frequency spectrum. ｍ The frequency at which the maximum peak occurs in the frequency spectrum of the resistance R is f ｒ It is preferable that it be close to |f. ｍ -f ｒ It is preferable that the value calculated by | be 10 MHz or less, and more preferably 1 MHz or less.

[0047] The Q value of the resonance peak measured by the measurement unit 21 in the coupled state may be between 1 and 1,000,000. However, from the viewpoint of improving detection sensitivity, the Q value of the resonance peak measured by the measurement unit 21 in the coupled state is preferably 10 or more, more preferably 100 or more, and even more preferably 1,000 or more. The Q value is obtained by dividing the peak frequency by the full width at half maximum (FWHM) of the peak.

[0048] In the example in Figure 1, the third resonator 230 is an LCR parallel resonant circuit. In the example in Figure 4, the third resonator 230 is an LCR series resonant circuit. However, the third resonator 230 is not limited to these examples. From the viewpoint of increasing the Q factor and improving detection sensitivity, it is preferable that the third resonator 230 is an LCC resonant circuit.

[0049] As another example, it is preferable that the first resonator 110 and the second resonator 120 are both loss circuits, and the third resonator 230 is a gain circuit. Furthermore, in the coupled state, it is preferable that the first resonator 110, the second resonator 120, and the third resonator 230 constitute a gain-loss coupled circuit with parity-time symmetry. This enables highly sensitive detection with a high Q factor.

[0050] A gain-loss coupled circuit can be constructed when a gain circuit and a loss circuit are wirelessly connected to each other by magnetic field resonant coupling. The state in which magnetic field resonant coupling occurs is a state in which the resonant circuit on the sensor side (first resonator 110 and second resonator 120) and the third resonator 230 on the reader side are electrically connected to each other by electromagnetic induction between the coils on the sensor side (first coil 11 and second coil 12) and the third coil 23 on the reader side. In this state, the first resonator 110 and second resonator 120 on the sensor side and the third resonator 230 on the reader side, whose resonant frequencies have been set to be approximately matched in advance, are energetically connected using a high-frequency magnetic field as a medium.

[0051] Furthermore, a gain-loss coupled circuit is said to have parity and time symmetry because the energy dissipated by the resonant load on the loss circuit side is compensated for by the gain circuit side. As a result, a conservative system (Hamiltonian system) is constructed near the resonant frequency, and the system configured as a gain-loss coupled circuit behaves similarly to an ideal, lossless LC circuit.

[0052] For a gain-loss coupled circuit to have parity and time symmetry, the absolute values ​​of the resistance component of the loss-side resonant circuit and the negative resistance component of the gain-side resonant circuit must be designed to be approximately equal. Furthermore, the inductance and capacitance components of each must be designed to exhibit equivalent values ​​in the circuit.

[0053] The resonant frequency f of the first resonator 110 １ , the resonant frequency f of the second resonator 120 ２ , and the resonant frequency f of the third resonator 230 ３ The relationship is not particularly limited; for example, the resonant frequency f １, resonant frequency f ２ , and the resonant frequency f ３ The value obtained by subtracting the lowest frequency from the highest frequency can be 10 THz or less. However, the resonant frequency f of the first resonator 110 １ , the resonant frequency f of the second resonator 120 ２ , and the resonant frequency f of the third resonator 230 ３ It is preferable that these are relatively close to each other. Specifically, the resonant frequency f １ , resonant frequency f ２ , and the resonant frequency f ３ The value obtained by subtracting the lowest frequency from the highest frequency is preferably 10 MHz or less, preferably 100 kHz or less, and more preferably 1 kHz or less. Resonant frequency f of the third resonator 230 ３ These can be calculated using the resistance of the resistor, the capacitance of the capacitor, and the inductance of the coil, respectively, used in the resonant circuit.

[0054] Furthermore, in order to configure the gain-loss coupling circuit to have parity-time symmetry, it is preferable that the third resonator 230 includes a negative resistor.

[0055] Figure 6 illustrates the circuit diagrams of the first resonator 110, the second resonator 120, and the third resonator 230. In Figure 6, P1 corresponds to the measurement unit 21. In the example of Figure 6, the resistance component of the third resonator 230 is negative resistance, and in the coupled state, the first resonator 110, the second resonator 120, and the third resonator 230 can constitute a gain-loss coupled circuit with parity-time symmetry.

[0056] In the circuit of Figure 6, the resistance components of the loss-side resonant circuits (first resonator 110 and second resonator 120) and the negative resistance component of the gain-side resonant circuit (third resonator 230) can be designed so that their absolute values ​​are approximately equal. Specifically, it is preferable that the difference between the maximum and minimum values ​​of the absolute values ​​of the resistance component of the third resonator 230, the resistance component of the first resonator 110, and the resistance component of the second resonator 120 is 10Ω or less. The inductance components of the three resonators can be designed so that they exhibit approximately the same values ​​in terms of the circuit. Specifically, it is preferable that the difference between the maximum and minimum values ​​of the inductance components of the third resonator 230, the inductance component of the first resonator 110, and the inductance component of the second resonator 120 is 10nH or less. Furthermore, the capacitance components of the three resonators can be designed so that they exhibit approximately the same values ​​in terms of the circuit. Specifically, it is preferable that the difference between the maximum and minimum capacitance components of the third resonator 230, the first resonator 110, and the second resonator 120 is 10 pF or less.

[0057] The measurement process using the sensor system 30 according to this embodiment will be described below.

[0058] The sensor 10 is attached to the object to be measured in advance. Of the sensor 10, one or both of the first coil 11 and the second coil 12 are attached to the surface or inside the object to be measured. One of the first coil 11 and the second coil 12 may be attached to the object to be measured, and the other may be placed outside the object to be measured. The object to be measured is not particularly limited and may be a living organism or not. Examples of objects to be measured include organs such as the eyeball and heart. The sensor system 30 can measure intraocular pressure or measure the movement of organs. For example, the reader 20 can read the sensor 10 placed inside the body from outside the body. The sensor system 30 for measuring intraocular pressure will be described in more detail in the second embodiment.

[0059] For reading, the third coil 23 of the reader 20 is brought close to the sensor 10 to a predetermined distance. However, the third coil 23 may be attached to the object to be measured in advance at a distance from the sensor 10. During reading, it is preferable to position the third coil 23 opposite the first coil 11. That is, it is preferable to position the third coil 23 so that its axis and the axis of the first coil 11 coincide as much as possible. For example, during reading, it is preferable that the inclination of the axis of the third coil 23 with respect to the axis of the first coil 11 be 12° or less, and more preferably 10° or less. Also, when viewed in a direction parallel to the axis of the third coil 23 as the line of sight, it is preferable that at least a portion of the internal region of the first coil 11 and the internal region of the third coil 23 overlap.

[0060] The distance d between the third coil 23 and the first coil 11 during reading. ３１ While not particularly limited, it can be, for example, 10 cm or less. From the viewpoint of improving sensitivity, the distance d between the third coil 23 and the first coil 11 during reading is important. ３１ The distance between the third coil 23 and the first coil 11 during reading may be 0.5 cm or more, or 1 cm or more. ３１ This refers to the distance between the center of the third coil 23 and the center of the first coil 11. Because the sensor system 30 according to this embodiment is highly sensitive, readings can be performed even when the third coil 23 and the sensor 10 are far apart.

[0061] In the reading process, the measuring unit 21 measures a predetermined frequency f ｍ The AC signal is input to the third resonator 230. The input impedance of the third resonator 230 is then measured by measuring the amplitude and phase of the reflected and traveling waves with respect to the input signal, and the real part of the input impedance is obtained as the resistance R.

[0062] The measuring unit 21 measures resistance R and the target value (for example, distance d). １２Reference information (e.g., a table or formula) that shows the relationship (i.e., correspondence) between the measurement unit 21 and the reference information is stored in advance. This information can be prepared through prior trial experiments and stored in the storage unit (e.g., storage device 1080) of the computer 1000 provided in the measurement unit 21. The measurement unit 21 can identify the target value to be detected using the measured resistance R and the reference information.

[0063] Furthermore, the reference information is not limited to the relationship between resistance R and the target value, but also includes the change in resistance R and the target value (for example, distance d). １２ The information may also show the relationship with the change in resistance R. In that case, based on the change in resistance R, for example, the change in distance from a predetermined initial state can be identified. Also, if the distance in the initial state is known, the measurement unit 21 can identify the distance after the change using the distance in the initial state and the change in distance.

[0064] Next, the operation and effects of this embodiment will be described. According to this embodiment, the sensor 10 comprises a first coil 11 and a second coil 12 spaced apart from the first coil 11. This allows for highly sensitive detection of information regarding the positional relationship between the coils.

[0065] (Second Embodiment) Figure 7 is a diagram illustrating the sensor 10 and third coil 23 according to the second embodiment. The sensor system 30 according to this embodiment has the same configuration as the sensor system 30 according to the first embodiment. The sensor system 30 according to the second embodiment is a sensor system for measuring intraocular pressure.

[0066] The sensor 10 includes a contact portion 15. The contact portion 15 is retractable and can be attached to the eyeball. The first coil 11 and the second coil 12 are attached to the contact portion 15.

[0067] The contact portion 15 is transparent and made of a resin that allows moisture to penetrate, for example. The contact portion 15 may be a soft contact lens. The first coil 11 and the second coil 12 may be attached to the surface of the contact portion 15 or enclosed within the contact portion 15. In the example in Figure 7, the first coil 11 is located on the top side of the contact portion 15, and the second coil 12 is located on the bottom side of the contact portion 15. The coil radius of the first coil 11 is smaller than the coil radius of the second coil 12. The coil radius of the first coil 11 is suitable for providing the first coil 11 in the contact portion 15 if, for example, 1 mm or more and 10 mm or less. The coil radius of the second coil 12 is suitable for providing the second coil 12 in the contact portion 15 if, for example, 8 mm or more and 20 mm or less. The distance d between the first coil 11 and the second coil 12 １２ If the measurement is 0 mm or more and 30 mm or greater than 0 mm and less than or equal to 30 mm, the first coil 11 and the second coil 12 are provided in the contact portion 15, which is suitable for measuring intraocular pressure.

[0068] The first resonator 110 and the second resonator 120 are each configured in a ring shape as a whole and are attached to the contact portion 15.

[0069] When the sensor 10 is attached to the eye, the contact portion 15 expands and contracts in accordance with the change in the surface shape of the eyeball when the intraocular pressure changes. Accordingly, the distance d between the first coil 11 and the second coil 12 changes. １２ The intraocular pressure changes. The sensor system 30 detects the change in intraocular pressure at this distance d. １２ This can be detected as a change in intraocular pressure. １２ Furthermore, the distance d between the first coil 11 and the third coil 23 ３１ It can be said that this also changes. In other words, the change in the measured resistance R is equal to the distance d １２ Changes in distance d ３１ It can be said that this reflects both changes.

[0070] The third coil 23 according to this embodiment is attached to, for example, eyeglasses. The distance between typical eyeglasses and contact lenses when worn is about 1 cm, and the sensor system 30 according to this embodiment can detect intraocular pressure with sufficient accuracy.

[0071] Since the sensor 10 is configured to be attached to the eyeball, the subject can perform any activity while the measurement is being taken. In other words, the sensor system 30 according to this embodiment enables continuous intraocular pressure measurement.

[0072] The measurement unit 21 according to this embodiment may pre-store information indicating the relationship between resistance R and intraocular pressure as reference information. The measurement unit 21 can determine the intraocular pressure using the measured resistance R and the reference information.

[0073] Next, the operation and effects of this embodiment will be described. According to this embodiment, the same operation and effects as those of the first embodiment can be obtained. In addition, according to this embodiment, the first coil 11 and the second coil 12 are attached to the contact portion 15. Therefore, continuous intraocular pressure measurement becomes possible.

[0074] (Third Embodiment) Figure 17 is a diagram illustrating the configuration of the reader 20 according to the third embodiment. The sensor system 30 according to this embodiment has the same configuration as the sensor system 30 according to the first embodiment. The sensor system 30 according to this embodiment may also have the same configuration as the sensor system 30 according to the second embodiment.

[0075] In this embodiment, the reader 20 further includes a support portion 29a that supports the third coil 23. In the reader 20, the first combination of the third coil 23 and the support portion 29a can be replaced with a second combination of another third coil 23 and another support portion 29b. In this embodiment, reference information for both the first and second combinations is predetermined. When a reading is made with the first combination, the measuring unit 21 uses the reading result and the reference information for the first combination to identify information regarding the positional relationship. On the other hand, when a reading is made with the second combination, the measuring unit 21 uses the reading result and the reference information for the second combination to identify information regarding the positional relationship.

[0076] Hereinafter, support parts 29a and 29b will be collectively referred to simply as "support parts." The support parts may have the function of holding the third coil 23 in a position where it can be read from the sensor 10. As described in the second embodiment, when the first coil 11 and the second coil 12 are attached to the contact part 15, the support parts may be, for example, eyeglasses, goggles, or an eye mask. However, the support parts are not limited to these examples, such as when the object to be measured is something other than intraocular pressure.

[0077] If the support is eyeglasses or goggles, the third coil 23 is provided in the light-transmitting part (e.g., the lens) of the eyeglasses or goggles that faces the eyeball to which the contact part 15 is attached. The person wearing the eyeglasses or goggles can see their surroundings through this light-transmitting part. If the support is an eye mask, the third coil 23 is provided in the part of the eye mask that blocks light from entering the eye. In either case, when a person wearing the sensor 10 on their eye puts on the support, the third coil 23 is held by the support so as to face the first coil 11 and the second coil 12.

[0078] The sensor system 30 allows subjects to have their intraocular pressure measured using, for example, a glasses-type support 29a during the day and an eye mask-type support 29b while they are sleeping. This allows for continuous 24-hour monitoring of intraocular pressure.

[0079] The entire third resonator 230, including the third coil 23, may be attached to the support portion 29a and the support portion 29b, respectively. The measuring unit 21 is configured to be connectable to and detachable from the third resonator 230 of each support portion in a measurable manner. Therefore, one measuring unit 21 can be used for multiple support portions and third resonators 230.

[0080] However, the resistance R measured for the same intraocular pressure may differ between support section 29a and support section 29b, for example, if the distance between the sensor 10 and the third coil 23 is different. Therefore, it is preferable to prepare the above-mentioned reference information for each support section and use it accordingly. This makes it possible to compensate for differences in measurement results due to differences in the support sections.

[0081] The sensor system 30 according to this embodiment may have multiple combinations of support parts and third coils 23 (hereinafter referred to as "sets"). The user can use any of the multiple sets. For example, the set including the support part 29a will be called "set A," and the set including the support part 29b will be called "set B," and these will be described below.

[0082] The storage unit provided in the measurement unit 21 (for example, the storage device 1080 of the computer 1000 included in the measurement unit 21) has reference information A for set A and reference information B for set B stored in it beforehand. As described above, each piece of reference information can be prepared through prior trial experiments, etc.

[0083] Prior to calculating the target value, the measurement unit 21 identifies which set is being used. The identification of the set may be performed by the user inputting information into the measurement unit 21, or it may be performed by automatic detection by the measurement unit 21.

[0084] The measurement unit 21 reads reference information prepared for the specified set from the storage unit. Then, using the read reference information, it converts the resistance R into a target value (for example, intraocular pressure).

[0085] Figure 17 shows an example where the support parts 29a (glasses type) and 29b (eye mask type) are of different types. However, the support parts 29a and 29b may be of the same type. Even in that case, by using different reference information depending on whether support part 29a or support part 29b is used, it is possible to compensate for the influence of individual differences that may occur in the measurement results of resistance R.

[0086] Furthermore, the number of replaceable support parts is not limited to two. The leader 20 may have three or more support parts, and the user may choose to use any of them.

[0087] Next, the operation and effects of this embodiment will be described. According to this embodiment, the same operation and effects as those of the first embodiment can be obtained. In addition, according to this embodiment, in the reader 20, the first combination of the third coil 23 and the support part 29a can be replaced with a second combination of another third coil 23 and another support part 29b. Therefore, the support part can be used differently depending on the user's situation, measurement environment, etc.

[0088] This embodiment will be described in detail below with reference to the examples provided. However, this embodiment is not limited in any way to the examples described.

[0089] (Example 1-1) Measurements were taken using a sensor system having the same configuration as described in the second embodiment.

[0090] Figure 8 shows the measurement configuration according to Example 1-1. A sensor 91, which has two coils arranged on an expandable contact lens, was attached to an eyeball-sized balloon 92. By pumping air into the balloon 92 with a syringe pump 93, the internal pressure of the balloon 92 (i.e., simulated intraocular pressure P) was changed. The simulated intraocular pressure P was measured with a pressure sensor 94 and confirmed with a monitor 95. In addition, a third coil 96 included in a third resonator was opposed to the sensor 91. A vector network analyzer 97 was connected to the third resonator, and the frequency spectrum was obtained by sweeping the frequency and measuring the real part R of the input impedance. The measurement results from the vector network analyzer 97 were input into a computer 98 and displayed on a display. In this way, frequency spectra for multiple simulated intraocular pressures P were obtained. Furthermore, frequency spectra were obtained for each of the following distances between the sensor 91 and the third coil 96, i.e., the distance between the first coil and the third coil: 1 cm, 1.5 cm, and 3 cm.

[0091] In Example 1-1, the first, second, and third resonators were configured to form a gain-loss coupled circuit with parity-time symmetry in the coupled state. The first coil was placed on the top side of the contact lens, and the second coil was placed on the bottom side of the contact lens. In the initial state, the distance between the first and second coils was 4 mm. The axes of the first and second coils were approximately aligned. The radius of the first coil was 2.5 mm, the radius of the second coil was 8 mm, and the radius of the third coil was 8 mm. The first and second resonators were LCR parallel resonant circuits. The resonant frequency f of the first resonator used was... １ , the resonant frequency f of the second resonator ２ , and the resonant frequency f of the third resonator ３ Both were set to 73 MHz.

[0092] Figure 9 shows the frequency spectra obtained at multiple simulated intraocular pressures P in Example 1-1, superimposed on each other. During the measurement of these spectra, the distance between the sensor 91 and the third coil 96 was 1 cm. In Figure 9, R ０f is the peak value of the maximum peak in the frequency spectrum acquired at P = 0 mmHg. In the frequency spectrum acquired at P = 0 mmHg, the frequency at which the maximum peak occurs (resonance frequency) is f ｒ Let ΔR be the frequency f ｒ From R to R ０ It is the absolute value of the value obtained by subtracting. "Pressure" is the simulated intraocular pressure P. The same applies to Figures 10 to 13. The Q value of the resonance peak (i.e., maximum peak) of Example 1-1 shown in Figure 9 was 1850.

[0093] (Comparative Example 1-1) In the sensor system according to Comparative Example 1-1, a second coil was not provided in the contact lens. In other respects, the sensor system and measurement configuration were the same in Comparative Example 1-1 and Example 1-1. That is, in Comparative Example 1-1, in the coupled state, the first resonator and the third resonator were configured to form a gain-loss coupling circuit having parity-time symmetry.

[0094] Figure 10 shows the frequency spectra obtained at multiple simulated intraocular pressures P in Comparative Example 1-1, superimposed on each other. During the measurement of these spectra, the distance between the sensor 91 and the third coil 96 was 1 cm. The Q value of the resonance peak (i.e., maximum peak) in Comparative Example 1-1, shown in Figure 10, was 1470.

[0095] (Example 1-2) In the coupled state, instead of the first, second, and third resonators forming a gain-loss coupled circuit with parity-time symmetry, in Example 1-2 the third resonator was made into an LCC resonant circuit. In other respects, the sensor system and measurement configuration were the same in Example 1-2 and Example 1-1.

[0096] Figure 11 shows the frequency spectra obtained at multiple simulated intraocular pressures P in Example 1-2, superimposed on each other. During the measurement of these spectra, the distance between the sensor 91 and the third coil 96 was 1 cm. The Q value of the resonance peak (i.e., maximum peak) in Example 1-2, shown in Figure 11, was 65.3.

[0097] (Comparative Example 1-2) In the sensor system of Comparative Example 1-2, a second coil was not provided in the contact lens. In other respects, the sensor system and measurement configuration were the same in Comparative Example 1-2 and Example 1-2. Specifically, in Comparative Example 1-2, the third resonator was an LCC resonant circuit.

[0098] Figure 12 shows the frequency spectra obtained at multiple simulated intraocular pressures P in Comparative Examples 1-2, superimposed on each other. During the measurement of these spectra, the distance between the sensor 91 and the third coil 96 was 1 cm. The Q value of the resonance peak (i.e., maximum peak) in Comparative Examples 1-2, shown in Figure 12, was 72.9.

[0099] Figure 13 is a graph summarizing the measurement results for Example 1-1, Comparative Example 1-1, Example 1-2, and Comparative Example 1-2. Example 1-1 corresponds to "PT-double coil", Comparative Example 1-1 corresponds to "PT-single coil", Example 1-2 corresponds to "WPT-double coil", and Comparative Example 1-2 corresponds to "WPT-single coil".

[0100] In the graph in Figure 13, "Distance" on the axis represents the distance between the sensor 91 and the third coil 96. ΔP is the value obtained by subtracting 6 mmHg from the simulated intraocular pressure P at the measurement point. Pmax = 42 mmHg - 6 mmHg.

[0101] As can be seen from the graph in Figure 13, the sensitivity of the sensor system according to Example 1-1, which used both the first and second coils, was significantly higher than the sensitivity of the sensor system according to Comparative Example 1-1, which did not have the second coil. Furthermore, the sensitivity of the sensor system according to Example 1-2, which used both the first and second coils, was higher than the sensitivity of the sensor system according to Comparative Example 1-2, which did not have the second coil.

[0102] (Example 2) A sensor with two coils arranged in a stretchable contact lens was attached to a rabbit's eyeball to measure intraocular pressure. FIG. 14 is a photograph of the state where the sensor was attached to the rabbit's eyeball. FIG. 15 is a photograph of the state where the intraocular pressure was being read by a reader equipped with a third coil.

[0103] In Example 2, in the coupled state, the first resonator, the second resonator, and the third resonator were configured to form a gain-loss coupling circuit having parity-time symmetry. The first coil was arranged on the top side of the contact lens, and the second coil was arranged on the bottom side of the contact lens. In the initial state, the distance between the first coil and the second coil was 10 mm. The distance between the sensor and the third coil was set to 14 mm. The axes of the first coil and the second coil were made to substantially coincide. The radius of the first coil was 2.5 mm, the radius of the second coil was 8 mm, and the radius of the third coil was 8 mm. The first resonator and the second resonator were each an LCR parallel resonance circuit. The resonance frequency f １ of the first resonator used, the resonance frequency f ２ of the second resonator, and the resonance frequency f ３ of the third resonator were all set to 73 MHz.

[0104] The frequency f ｍ was set to 74 MHz. The value calculated by |f ｍ - f ｒ | was 10 MHz or less. Here, f ｒ is the frequency at which the maximum peak occurs in the frequency spectrum of the measured resistance R. And the value of R at the frequency f ｍ was measured for 6 minutes. FIG. 16 is a graph showing the measurement results in Example 2. As can be seen from FIG. 16, the change in intraocular pressure could be continuously measured. In the first measurement (to the left of the broken line in the graph), the average value of the intraocular pressure was calculated to be 22 mmHg. In the second measurement (to the right of the broken line in the graph), the average value of the intraocular pressure was calculated to be 32 mmHg.

[0105] The embodiments of the present invention have been described above with reference to the drawings, but these are merely examples of the present invention, and various other configurations can be adopted. Furthermore, the embodiments described above can be combined to the extent that their contents do not conflict.

[0106] This application claims priority based on Japanese Patent Application No. 2024-189985, filed on 29 October 2024, and incorporates all of its disclosures herein.

[0107] 10 Sensor 11 First coil 12 Second coil 15 Contact section 20 Reader 21 Measurement section 23 Third coil 30 Sensor system 91 Sensor 92 Balloon 96 Third coil 97 Vector network analyzer 98 Computer 110 First resonator 120 Second resonator 230 Third resonator 1000 Computer 1020 Bus 1040 Processor 1060 Memory 1080 Storage device 1100 Input / output interface 1120 Network interface

Claims

1. A sensor system comprising a sensor having a first coil and a second coil spaced apart from the first coil, and a reader having a third coil, wherein the reader can wirelessly read from the sensor by applying an alternating magnetic field generated in the third coil to the first and second coils, and the reader detects information regarding the positional relationship between at least two of the first, second, and third coils based on the reading results.

2. The sensor system according to claim 1, wherein the sensor comprises a first resonator including the first coil and a second resonator including the second coil, the reader comprises a third resonator including the third coil, and the reader is capable of performing the reading in a coupled state in which the first resonator, the second resonator, and the third resonator are electrically coupled by applying an alternating magnetic field generated in the third coil to the first coil and the second coil.

3. The sensor system according to claim 2, wherein the reader further comprises a measuring unit connected to the third resonator for measuring the real part of the impedance, and the reading can be performed by performing a measurement by the measuring unit in the coupled state.

4. In the sensor system according to claim 3, the reader, in the coupled state, measures a predetermined frequency f by the measuring unit. ｍ A sensor system capable of performing the reading by measuring the actual part of the impedance in the given region.

5. In the sensor system according to claim 4, the frequency f ｍ This is a sensor system with a frequency range of 0.1 MHz to 10 THz.

6. A sensor system according to claim 3 or 4, wherein the Q value of the resonance peak measured by the measuring unit in the coupled state is 1 or more and 1,000,000 or less.

7. A sensor system according to any one of claims 3 to 6, wherein the reader further comprises a support portion for supporting the third coil, the reader is replaceable with a first combination of the third coil and the support portion for a second combination of another third coil and another support portion, reference information is predetermined for each of the first and second combinations, the measuring unit identifies information regarding the positional relationship using the reading result and the reference information for the first combination when the reading is made with the first combination, and identifies information regarding the positional relationship using the reading result and the reference information for the second combination when the reading is made with the second combination.

8. A sensor system according to any one of claims 2 to 7, wherein the first resonator and the second resonator are both loss circuits, and the third resonator is a gain circuit.

9. A sensor system according to claim 8, wherein in the coupled state, the first resonator, the second resonator, and the third resonator constitute a gain-loss coupled circuit having parity-time symmetry.

10. In the sensor system according to claim 8 or 9, the resonant frequency f of the first resonator １ , the resonant frequency f of the second resonator ２ , and the resonant frequency f of the third resonator ３ Of these, the value obtained by subtracting the lowest frequency from the highest frequency is 10 THz or less, and the third resonator is a sensor system including negative resistance.

11. A sensor system according to any one of claims 2 to 10, wherein the third resonator is an LCC resonant circuit.

12. In the sensor system according to any one of claims 2 to 11, the resonance frequency of the first resonator is f １ and the resonance frequency of the second resonator is f ２ When, |f １ - f ２ | is a sensor system in which the value obtained is 1 THz or less.

13. A sensor system according to any one of claims 2 to 12, wherein both the first resonator and the second resonator are LCR series resonant circuits.

14. A sensor system according to any one of claims 2 to 12, wherein both the first resonator and the second resonator are LCR parallel resonant circuits.

15. A sensor system according to any one of claims 1 to 14, wherein the distance between the first coil and the second coil is 0 mm or more and 50 mm or less.

16. A sensor system according to any one of claims 1 to 15, wherein the inclination of the axis of the second coil with respect to the axis of the first coil is 12° or less.

17. A sensor system according to any one of claims 1 to 16, wherein, when viewed with the line of sight in a direction parallel to the axis of the first coil, the internal region of the first coil and the internal region of the second coil overlap in at least a portion of each other.

18. A sensor system according to any one of claims 1 to 17, wherein the reader detects at least one of the distance and the change in distance between the first coil and the second coil based on the result of the reading.

19. A sensor system according to any one of claims 1 to 18, wherein the sensor further comprises a retractable contact portion that can be attached to the eyeball, and the first coil and the second coil are attached to the contact portion.

20. A sensor system for measuring intraocular pressure, according to claim 19.

21. A sensor used in the sensor system according to any one of claims 1 to 20.

22. A reader used in the sensor system according to any one of claims 1 to 20.

23. A measurement method for wirelessly reading from a sensor by applying an alternating magnetic field generated in a third coil provided in a reader to a first coil provided in a sensor and a second coil provided in the sensor at a distance from the first coil, and detecting information regarding the positional relationship between at least two of the first coil, the second coil, and the third coil based on the reading results.

24. The measurement method according to claim 23, wherein the sensor comprises a first resonator including the first coil and a second resonator including the second coil, the reader comprises a third resonator including the third coil, and the measurement method is performed in a coupled state in which the first resonator, the second resonator and the third resonator are electrically coupled by applying an alternating magnetic field generated in the third coil to the first coil and the second coil.

25. The measurement method according to claim 24, wherein the reader further comprises a measuring unit connected to the third resonator for measuring the real part of the impedance, and the measurement method is performed by performing a measurement by the measuring unit in the coupled state to perform the reading.

26. In the measurement method according to claim 25, in the coupled state, the measurement unit measures a predetermined frequency f ｍ A measurement method for performing the reading by measuring the actual part of the impedance in the given region.

27. In the measurement method according to claim 26, the frequency f ｍ This is a measurement method where the frequency is between 0.1 MHz and 10 THz.

28. A measurement method according to claim 25 or 26, wherein the Q value of the resonance peak measured by the measurement unit in the coupled state is 1 or more and 1,000,000 or less.

29. A measurement method according to any one of claims 25 to 28, wherein the reader is replaceable with a first combination of the third coil and a support portion supporting the third coil for a second combination of another third coil and another support portion supporting the other third coil, wherein reference information is predetermined for each of the first and second combinations, and when the reading is performed with the first combination, the measurement method identifies information regarding the positional relationship using the result of the reading and the reference information for the first combination, and when the reading is performed with the second combination, the measurement method identifies information regarding the positional relationship using the result of the reading and the reference information for the second combination.

30. A measurement method according to any one of claims 24 to 29, wherein both the first resonator and the second resonator are loss circuits, and the third resonator is a gain circuit.

31. A measurement method according to claim 30, wherein in the coupled state, the first resonator, the second resonator, and the third resonator constitute a gain-loss coupled circuit having parity-time symmetry.

32. In the measurement method according to claim 30 or 31, the resonant frequency f of the first resonator １ , the resonant frequency f of the second resonator ２ , and the resonant frequency f of the third resonator ３ The value obtained by subtracting the lowest frequency from the highest frequency is 10 THz or less, and the third resonator is a measurement method including negative resistance.

33. A measurement method according to any one of claims 24 to 32, wherein the third resonator is an LCC resonant circuit.

34. In the measurement method according to any one of claims 24 to 33, the resonant frequency of the first resonator is f １ Let the resonant frequency of the second resonator be f ２ When this is the case, |f １ -f ２ The value obtained using the | operator is less than or equal to 1 THz.

35. A measurement method according to any one of claims 24 to 34, wherein both the first resonator and the second resonator are LCR series resonant circuits.

36. A measurement method according to any one of claims 24 to 34, wherein both the first resonator and the second resonator are LCR parallel resonant circuits.

37. A measurement method according to any one of claims 23 to 36, wherein the distance between the first coil and the second coil is 0 mm or more and 50 mm or less.

38. A measurement method according to any one of claims 23 to 37, wherein the inclination of the axis of the second coil with respect to the axis of the first coil is 12° or less.

39. A measurement method according to any one of claims 23 to 38, wherein, when viewed with the line of sight in a direction parallel to the axis of the first coil, the internal region of the first coil and the internal region of the second coil overlap in at least a portion.

40. A measurement method according to any one of claims 23 to 39, wherein, based on the reading result, at least one of the distance and the change in distance between the first coil and the second coil is detected.

41. A measurement method according to any one of claims 23 to 40, wherein the sensor further comprises a contact portion that is attachable to the eyeball and is extendable, and the first coil and the second coil are attached to the contact portion.

42. A measurement method for measuring intraocular pressure, as described in claim 41.

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