Sensor system, reader, and sensor
A sensor system includes a reader side resonant circuit ( 10 ) and a sensor side resonant circuit ( 20 ). The reader side resonant circuit ( 10 ) is an LCR parallel resonant circuit and a gain circuit. The sensor side resonant circuit ( 20 ) is an LCR parallel resonant circuit and a loss circuit having, as a resistance portion, a sensor element whose resistance value changes according to an object to be sensed. The reader side resonant circuit ( 10 ) and the sensor side resonant circuit ( 20 ) are wirelessly connected to each other through magnetic field resonant coupling to constitute a gain-loss coupling circuit, and the reader side resonant circuit ( 10 ) and the sensor side resonant circuit ( 20 ) are formed such that the gain-loss coupling circuit has parity-time symmetry.
1 . A sensor system comprising a reader side resonant circuit and a sensor side resonant circuit, wherein
the reader side resonant circuit is an LCR parallel resonant circuit and a gain circuit,
the sensor side resonant circuit is an LCR parallel resonant circuit and a loss circuit having, as a first resistance portion, a sensor element having a first resistance that changes according to a target object to be sensed,
the reader side resonant circuit and the sensor side resonant circuit are wirelessly connected to each other through magnetic field resonant coupling to constitute a gain-loss coupling circuit, and
the reader side resonant circuit and the sensor side resonant circuit are formed so that the gain-loss coupling circuit has parity-time symmetry.
2 . The sensor system according to claim 1 , wherein
the sensor side resonant circuit includes a first inductance portion having a first inductance, a first capacitance portion having a first capacitance, and the first resistance portion,
at least one of a second resistance of a second resistance portion in the reader side resonant circuit, a second inductance of a second coil portion in the reader side resonant circuit, and a second capacitance of a second capacitor portion in the reader side resonant circuit is variable, and
at least one of the second resistance, the second inductance, and the second capacitance in the reader side resonant circuit is adjusted based on the first resistance that changes according to the target object to be sensed to maintain the parity-time symmetry.
3 . The sensor system according to claim 1 , wherein the first resistance changes according to a chemical reaction with the target object to be sensed or a physical quantity received from the target object to be sensed.
4 . The sensor system according to claim 1 , wherein the target object to be sensed is a substance contained in a fluid, and the fluid is one or more fluids selected from the group consisting of tears, saliva, sweat, urine, feces, exhaled breath, blood, lymph, interstitial fluid, cell fluid, tissue fluid, organ fluid, and other body fluids.
5 . The sensor system according to claim 1 , wherein the target object to be sensed includes at least one of glucose, lactate, urea, sodium, potassium, calcium, magnesium, chlorine, cortisol, catechol, exosomes, matrix metalloproteinase, procalcitonin, and ferritin.
6 . The sensor system according to claim 1 , wherein the sensor side resonant circuit is adapted to be located over a surface of or inside an object.
7 . The sensor system according to claim 6 , wherein the sensor side resonant circuit is located over a contact lens.
8 . The sensor system according to claim 6 , wherein the sensor side resonant circuit is adapted to be located inside a body.
9 . The sensor system according to claim 1 , further comprising
a contact lens, wherein
the sensor side resonant circuit is located over the contact lens or inside the contact lens, and
the sensor side resonant circuit comprises a coil portion, a number of turns of the coil portion in the sensor side resonant circuit being one.
10 . The sensor system according to claim 1 , wherein
the sensor element includes at least one of an enzyme-modified fiber, an enzyme electrode, a chemical resistor, a cell-type sensor using a working electrode, and an FET-type sensor using a graphene surface modified with an enzyme as a channel.
11 . A reader used in a sensor system including a reader side resonant circuit and a sensor side resonant circuit, the reader comprising the reader side resonant circuit, wherein
the reader side resonant circuit is an LCR parallel resonant circuit and a gain circuit,
the sensor side resonant circuit is an LCR parallel resonant circuit and a loss circuit having, as a first resistance portion, a sensor element having a first resistance that changes according to a target object to be sensed,
the reader side resonant circuit and the sensor side resonant circuit are wirelessly connected to each other through magnetic field resonant coupling to constitute a gain-loss coupling circuit, and
the reader side resonant circuit and the sensor side resonant circuit are formed so that the gain-loss coupling circuit has parity-time symmetry.
12 . The reader according to claim 11 , wherein
the sensor side resonant circuit includes a first inductance portion having a first inductance, a first capacitance portion having a first capacitance, and the first resistance portion,
at least one of a second resistance of a second resistance portion in the reader side resonant circuit, a second inductance of a coil portion in the reader side resonant circuit, and a second capacitance of a second capacitor portion in the reader side resonant circuit is variable, and
at least one of the second resistance, the second inductance, and the second capacitance in the reader side resonant circuit is adjusted based on the first resistance that changes according to the target object to be sensed to maintain the parity-time symmetry.
13 . The reader according to claim 11 , wherein the first resistance changes according to a chemical reaction with the target object to be sensed or a physical quantity received from the target object to be sensed.
14 . The reader according to claim 11 , wherein the target object to be sensed is a substance contained in a fluid, and the fluid is one or more fluids selected from the group consisting of tears, saliva, sweat, urine, feces, exhaled breath, blood, lymph, interstitial fluid, cell fluid, tissue fluid, organ fluid, and other body fluids.
15 . The reader according to claim 11 , wherein the target object to be sensed includes at least one of glucose, lactate, urea, sodium, potassium, calcium, magnesium, chlorine, cortisol, catechol, exosomes, matrix metalloproteinase, procalcitonin, and ferritin.
16 . The reader according to claim 11 , wherein the sensor side resonant circuit is adapted to be located over a surface of or inside an object.
17 . The reader according to claim 16 , wherein the sensor side resonant circuit is located over a contact lens.
18 . The reader according to claim 16 , wherein the sensor side resonant circuit is adapted to be located inside a body.
19 . A sensor used in a sensor system including a reader side resonant circuit and a sensor side resonant circuit, the sensor comprising the sensor side resonant circuit, wherein
the reader side resonant circuit is an LCR parallel resonant circuit and a gain circuit,
the sensor side resonant circuit is an LCR parallel resonant circuit and a loss circuit having, as a first resistance portion, a sensor element having a first resistance that changes according to a target object to be sensed,
the reader side resonant circuit and the sensor side resonant circuit are wirelessly connected to each other through magnetic field resonant coupling to constitute a gain-loss coupling circuit, and
the reader side resonant circuit and the sensor side resonant circuit are formed such-so that the gain-loss coupling circuit has parity-time symmetry.
20 . The sensor according to claim 19 , wherein
the sensor side resonant circuit includes a first inductance portion having a first inductance, a first capacitance portion having a first capacitance, and the first resistance portion,
at least one of a second resistance of a second resistance portion in the reader side resonant circuit, a second inductance of a coil portion in the reader side resonant circuit, and a second capacitance of a second capacitor portion in the reader side resonant circuit is variable, and
at least one of the second resistance, the second inductance, and the second capacitance in the reader side resonant circuit is adjusted based on the first resistance that changes according to the target object to be sensed to maintain the parity-time symmetry.
21 . The sensor according to claim 19 , wherein the first resistance changes according to a chemical reaction with the target object to be sensed or a physical quantity received from the target object to be sensed.
22 . The sensor according to claim 19 , wherein the target object to be sensed is a substance contained in a fluid, and the fluid is one or more fluids selected from the group consisting of tears, saliva, sweat, urine, feces, exhaled breath, blood, lymph, interstitial fluid, cell fluid, tissue fluid, organ fluid, and other body fluids.
23 . The sensor according to claim 19 , wherein the target object to be sensed includes at least one of glucose, lactate, urea, sodium, potassium, calcium, magnesium, chlorine, cortisol, catechol, exosomes, matrix metalloproteinase, procalcitonin, and ferritin.
24 . The sensor according to claim 19 , wherein the sensor side resonant circuit is adapted to be located over a surface of or inside an object.
25 . The sensor according to claim 24 , wherein the sensor side resonant circuit is located over a contact lens.
26 . The sensor according to claim 24 , wherein the sensor side resonant circuit is adapted to be located inside a body.
27 . The sensor system according to claim 3 , wherein the physical quantity received from the target object to be sensed includes at least one of heat, light, current, voltage, electric field, magnetic field, speed, vibration, force including pressure, and shape change including strain.
28 . The reader according to claim 13 , wherein the physical quantity received from the target object to be sensed includes at least one of heat, light, current, voltage, electric field, magnetic field, speed, vibration, force including pressure, and shape change including strain.
29 . The sensor according to claim 21 , wherein the physical quantity received from the target object to be sensed includes at least one of heat, light, current, voltage, electric field, magnetic field, speed, vibration, force including pressure, and shape change including strain.