Biosensor and biological management system

Abstract

A biosensor according to an embodiment of the present technology includes a first antenna conductor, a second antenna conductor, and a power detection unit. The second antenna conductor is a different conductor than the first antenna conductor and is electrically coupled to an organism connected to earth ground directly or by capacitive coupling. The power detection unit detects AC power generated between the first antenna conductor and the second antenna conductor in accordance with a resistance component of the living body with respect to earth ground.

Description

TECHNICAL FIELD

[0001] The present technology relates to a biological sensor that detects a state of a living body and a biological management system. BACKGROUND

[0002] Techniques for detecting a state of a living body have been developed to date. For example, Patent Literature 1 describes a growth diagnosis device applied to a vascular plant. This growth diagnosis device is provided with an internal information measuring sensor that measures data on internal information indicating a growth state of the vascular plant. As the internal information measuring sensor, for example, a sensor that measures acoustic emission used for evaluating a health condition of the vascular plant and a sensor that measures data on transpiration flow rate, diameter of a stem, hardness of the stem, bioelectric potential, and the like of the vascular plant are used (paragraphs

[0002] ,

[0020] ,

[0029] ,

[0135] , and the like of the specification of Patent Literature 1).

[0003] LIST OF CITATIONS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Laid-Open No. 2017-51125 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] The sensor described in Patent Literature 1 detects a state of a plant. Also, for humans and other animals, techniques for detecting a state thereof have also been developed. Such techniques for detecting a state of a living body are expected to be applied to various fields.

[0008] As an example of a method of detecting a state of a living body, there is a method of directly detecting a weak signal emitted by the living body itself. However, this method can be difficult to achieve sufficient detection accuracy. In addition, in order to detect such a signal, for example, a dedicated measuring instrument or the like can be required, which complicates the configuration of the device.

[0009] In view of the circumstances as described above, the present technology has been made to achieve the object of providing a biological sensor and a biological management system that can easily and highly accurately detect a state of a living body.

[0010] SOLUTION TO PROBLEM

[0011] In order to achieve the above-mentioned object, a biological sensor according to an embodiment of the present technology includes a first antenna conductor, a second antenna conductor, and a power detection unit.

[0012] The second antenna conductor is a different conductor from the first antenna conductor, and is electrically coupled to a living body connected to an earth ground directly or through a capacitive coupling.

[0013] The power detection unit detects AC power generated between the first antenna conductor and the second antenna conductor according to a resistance component of the living body with respect to the earth ground.

[0014] This biosensor is provided with a first antenna conductor and a second antenna conductor connected to an earth ground via a living body. AC power generated between these antenna conductors according to a resistance component of the living body with respect to the earth ground is detected. This makes it possible to obtain relatively high AC power while the configuration is simple, and the state of the living body can be detected easily and highly accurately.

[0015] The biosensor can further include

[0016] A signal generator that applies a predetermined AC signal to the first antenna conductor.

[0017] The frequency of the predetermined AC signal can be set according to a frequency characteristic of a resistance component of the living body with respect to the earth ground.

[0018] The living body can be a plant.

[0019] In this case, the frequency of the predetermined AC signal can be set to a frequency of 5 Hz or higher and 3 MHz or lower.

[0020] The predetermined AC signal can have any one of a rectangular wave, a sinusoidal wave, and a triangular wave.

[0021] The signal generator can include a ground portion that provides a reference potential of the predetermined AC signal.

[0022] In this case, the ground portion can be electrically coupled to the living body.

[0023] The signal generator can include a ground portion that provides a reference potential of the predetermined AC signal.

[0024] In this case, the ground portion can be connected to an earth ground.

[0025] The signal generator can include a ground portion that provides a reference potential of the predetermined AC signal.

[0026] In this case, the ground portion can be in a state of being electrically floating from an earth ground.

[0027] The power detection unit can include

[0028] a rectifier circuit that rectifies AC power generated between the first antenna conductor and the second antenna conductor, and

[0029] a DC detection circuit that detects DC power output from the rectifier circuit.

[0030] The DC detection circuit can be either of a voltage meter that detects an output voltage of the rectifier circuit and a current meter that detects an output current of the rectifier circuit.

[0031] The DC detection circuit can be a voltage meter that detects an output voltage of the rectifier circuit.

[0032] In this case, an internal resistor of the voltage meter can be adjusted to achieve a predetermined sensor sensitivity.

[0033] The living organism can be a plant.

[0034] In this case, a resistance value of the internal resistor of the voltage meter can be 1 kΩ or more and 10 MΩ or less.

[0035] The living organism can be a plant.

[0036] In this case, the second antenna conductor can be attached to an aboveground portion of the plant.

[0037] The second antenna conductor can have either of a contact structure that presses an end portion of the second antenna conductor against the outside of the plant and a needle structure that inserts the end portion of the second antenna conductor into the inside of the plant.

[0038] The living organism can be a human or an animal.

[0039] In this case, the second antenna conductor can be attached to a body of the human or the body of the animal.

[0040] The first antenna conductor can be disposed to have a length corresponding to 1 / 4 of a wavelength of a predetermined AC component among AC components induced in the living organism.

[0041] The biosensor can use the energy harvesting device as a power source.

[0042] A living organism management system according to another embodiment of the present technology includes at least one biosensor and a management device.

[0043] The at least one biosensor includes

[0044] a first antenna conductor,

[0045] a second antenna conductor that is different from the first antenna conductor and is electrically coupled to a living organism connected to an earth ground directly or through a capacitive coupling, and

[0046] a power detection unit that detects AC power generated between the first antenna conductor and the second antenna conductor in accordance with a resistance component of the living body with respect to the earth ground.

[0047] The management device performs a management operation based on a detection result of the at least one biological sensor. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 is a schematic diagram showing an example of a configuration of a biological sensor according to a first embodiment of the present technology.

[0049] Figure 2 is a schematically explanatory circuit diagram showing an operation of a monopole antenna.

[0050] Figure 3 is a schematically explanatory circuit diagram showing an operation of a biological sensor.

[0051] Figure 4 is a block diagram showing an example of a configuration of a biological sensor.

[0052] Figure 5 is a circuit diagram showing an example of a configuration of a power detection unit.

[0053] Figure 6 is an explanatory graph showing characteristics of diodes of a rectifier circuit.

[0054] Figure 7 is an explanatory table showing characteristics of diodes of a rectifier circuit.

[0055] Figure 8 is a schematically circuit diagram showing an example of a connection between a biological sensor and a plant.

[0056] Figure 9 is a schematic diagram illustrating an example of a connection between a biological sensor and a plant, which is shown in Figure 8 .

[0057] Figure 10 is a graph showing an example of a monitoring result of a biological sensor.

[0058] Figure 11 is a schematic diagram showing an example of a configuration of a biological management system using a biological sensor.

[0059] Figure 12 is a schematically circuit diagram showing another example of a connection between a biological sensor and a plant.

[0060] Figure 13 is a schematically circuit diagram showing another example of a connection between a biological sensor and a plant.

[0061] Figure 14 is a schematic circuit diagram showing an example of a configuration of a biosensor according to a second embodiment.

[0062] Figure 15 is a schematic diagram illustrating an example of applying a biosensor to a human body.

[0063] Figure 16 is a schematic diagram illustrating an example of applying a biosensor to an animal.

[0064] Figure 17 is a schematic circuit diagram showing an example of a configuration of a biosensor according to another embodiment. DETAILED DESCRIPTION

[0065] Hereinafter, an embodiment according to the present technology is described with reference to the drawings.

[0066] [Outline of Biosensor]

[0067] Figure 1 is a schematic diagram showing an example of a configuration of a biosensor according to a first embodiment of the present technology. The biosensor 100 is a sensor that detects a state of a living body 1. The living body 1 includes a resistance component 10 that functions as a resistor. The state of the living body 1, which is detected by the biosensor 100, includes internal and external states of the living body 1, which are estimated from the resistance component 10 of the living body 1 to be detected. The biosensor 100 detects the state of the living body 1 by detecting a change in the resistance component 10 as an electric signal.

[0068] In this embodiment, the living body 1 is a plant 2. For example, the resistance component 10 changes in response to a change in a water content and a concentration of an electrolyte such as sap contained in the plant 2 (hereinafter, referred to as electrolyte concentration). According to this change in the resistance component 10, the biosensor 100 detects the state of the water content, the electrolyte concentration, and the like of the plant 2. In Figure 1 In the drawing, a tree growing on the ground is schematically illustrated as an example of the plant 2. Further, the resistance component 10 of the plant 2 to be detected by the biosensor 100 is schematically shown using a symbol for a resistor element. Hereinafter, a resistance value of the resistance component 10 can be denoted by Rt.

[0069] The biosensor 100 includes a first antenna conductor 11, a second antenna conductor 12, a power detection unit 20, and a signal generator 25. Further, the biosensor 100 is connected to a power supply 28 and operates based on power supplied from the power supply 28. In the biosensor 100, AC power generated between the first antenna conductor 11 and the second antenna conductor 12 is detected by the power detection unit 20.

[0070] The first antenna conductor 11 is an antenna that receives a signal to generate the above-mentioned AC electric power. In this embodiment, the first antenna conductor 11 is connected to the signal generator 25. In this case, the first antenna conductor 11 can be regarded as an antenna to which a signal from the signal generator 25 is inputted.

[0071] The second antenna conductor 12 is electrically coupled to the plant 2 connected to the earth ground directly or through a capacitive coupling. It can also be said that the second antenna conductor 12 is connected to the earth ground (hereinafter, referred to as the earth ground 6) via the plant 2. The resistance component 10 of the plant 2 is, for example, a component that functions as a resistor from a connecting portion between the second antenna conductor 12 and the plant 2 to the earth ground 6.

[0072] In the example shown in Figure 1 , the ground on which the plant 2 grows is used as the earth ground 6. In this case, the plant 2 is directly connected to the earth ground 6. Note that the present technology is also applicable to other plants than the plant 2 growing on the ground. For example, when the plant 2 grows in a container such as a flowerpot, the roots, trunk, branches, leaves, and the like of the plant 2 are connected to the earth ground 6 through a capacitive coupling. In this case, the second antenna conductor 12 is connected to the earth ground 6 via the plant 2 through a capacitive coupling.

[0073] Further, the earth ground 6 does not necessarily need to be an actual ground. For example, when the plant 2 grows indoors, a portion among portions around the plant 2 whose electric potential is substantially constant, such as a metal structural member or a ground wire prepared together with an electrical wiring, is used as the earth ground 6.

[0074] The electric power detection unit 20 detects the AC electric power generated between the first antenna conductor 11 and the second antenna conductor 12 in accordance with the resistance component 10 of the plant 2. As described below with reference to, for example, Figure 3 , an AC electric signal (hereinafter, referred to as a detection signal) that varies in accordance with the resistance component 10 of the plant 2 is generated between the first antenna conductor 11 and the second antenna conductor 12. By detecting the AC electric power of the detection signal, the electric power detection unit 20 detects the state of the plant 2, such as the state of the water content and the electrolyte concentration, which is indicated by the resistance component 10.

[0075] As shown in Figure 1 , the electric power detection unit 20 rectifies the detection signal generated between the first antenna conductor 11 and the second antenna conductor 12 via its rectifier circuit 21, and measures the voltage level of a DC electric signal outputted from the rectifier circuit 21 via its voltage meter 22. In this way, in the electric power detection unit 20, the AC electric power of the detection signal is detected by detecting the voltage level of the rectified detection signal.

[0076] The signal generator 25 applies a predetermined AC signal to the first antenna conductor 11. In the following, this predetermined AC signal is referred to as an applied signal. In this embodiment, in response to the applied signal being applied from the signal generator 25 to the first antenna conductor 11, an AC electric signal (a detection signal) in conformity with the applied signal and the electric resistance component 10 of the plant 2 is generated between the first antenna conductor 11 and the second antenna conductor 12. It can be said that the biosensor 100 is a sensor that generates the detection signal by using the signal generator 25 in such a manner to generate the detection signal.

[0077] [Operation of monopole antenna]

[0078] Figure 2 is a schematic explanatory circuit diagram showing the operation of the monopole antenna. Here, in order to describe the operation of the biosensor 100, the operation of the monopole antenna 30 is first described. The monopole antenna 30 is an antenna including a feed point 7 between its single receiving antenna 31 and the earth ground 6. Note that the feed point 7 is a pair of terminal portions of a current path. Specifically, the feed point 7 includes an antenna-side feed point 7a connected to the receiving antenna and a ground-side feed point 7b connected to the earth ground 6.

[0079] In the monopole antenna 30 shown in Figure 2 , a resistor 33 is connected between the feed point 7 and the earth ground 6. In other words, the feed point 7 is formed between the resistor 33 connected to the earth ground 6 and the receiving antenna 31. In this monopole antenna 30, for example, in response to the receiving antenna 31 receiving an electromagnetic wave, a current corresponding to this electromagnetic wave flows through the receiving antenna 31. Further, a mirror current corresponding to the current flowing through the receiving antenna 31 flows through the resistor 33 connected to the earth ground 6. Thus, an AC electric signal is generated at the feed point 7 (between the antenna-side feed point 7a and the ground-side feed point 7b).

[0080] The power (AC electric power) of the AC electric signal to be generated at the feed point 7 has a value corresponding to the resistance value of the resistor 33. For example, as the resistance value R of the resistor 33 becomes smaller, the mirror current flowing through the resistor 33 becomes higher. Thus, the AC electric power to be generated at the feed point 7 becomes higher. In contrast, as the resistance value R of the resistor 33 becomes higher, the mirror current flowing through the resistor 33 becomes lower. Thus, the AC electric power to be generated at the feed point 7 becomes lower. In this way, in the monopole antenna 30, the AC electric power to be generated at the feed point 7 serves as a parameter indicating the resistance value R of the resistor 33.

[0081] The inventors of the present technology have found that the resistance component 10 of the living body 1 can be detected by taking advantage of this characteristic of the monopole antenna 30, and have developed a biological sensor 100. When the configuration of the monopole antenna 30 is applied to the biological sensor 100, the receiving antenna 31 corresponds to the first antenna conductor 11, and the conductive portion connecting the feed point 7 (the ground side feed point 7b) and the resistor 33 to each other corresponds to the second antenna conductor 12. Further, the resistor 33 can be regarded as the resistance component 10 of the living body 1 (the plant 2) that is connected to the earth ground 6 directly or through capacitive coupling.

[0082] Here, the case where an electromagnetic wave is received through the monopole antenna 30 is studied. In general, in order to maximize the energy of the electric signal induced at the feed point 7, it is necessary to set the length of the receiving antenna 31 to correspond to 1 / 4 of the wavelength λ of the electromagnetic wave to be received.

[0083] Note that when the resistance value (impedance) of the resistor 33 is sufficiently high at the frequency of the electromagnetic wave to be received, it can not be possible to induce an electric signal of sufficient strength at the feed point 7. Therefore, in order for the living body 1 having the resistance component 10 to function as part of the monopole antenna 30, it is necessary to adjust the frequency of the electromagnetic wave to be received to a frequency corresponding to the resistance component 10 of the living body 1. This means that the length of the receiving antenna 31 is set in accordance with the resistance component 10 of the living body 1.

[0084] When the living body 1 to be measured is the plant 2, it can be said that the resistance value Rt of the resistance component 10 is generally low within the AM band (1 kHz to 3 MHz). In other words, in order for the plant 2 to function as part of the monopole antenna 30, it is desirable that the frequency of the electromagnetic wave to be received be 3 MHz or lower.

[0085] As in the case where the plant 2 functions as an antenna in the AM band, the wavelength of the electromagnetic wave to be received is very long. For example, when the frequency is 3 MHz, 1 / 4 of the wavelength λ is approximately 25 m. Therefore, it is difficult to configure the receiving antenna 31 corresponding to this wavelength. In view of this situation, in this embodiment, a configuration is adopted in which an AC signal at a frequency such that the plant 2 can function as part of an antenna is directly applied to the first antenna conductor 11 corresponding to the receiving antenna 31.

[0086] [Operation of Biological Sensor]

[0087] Figure 3 is a schematic explanatory circuit diagram showing the operation of the biological sensor. Figure 3 The biological sensor 100 shown in Figure 2 The diagram of the monopole antenna 30 shown in Figure 1 is a simplified diagram of the biological sensor 100. Note that the power detection unit 20 is not shown.

[0088] The first antenna conductor 11 connects the feed point 7 (antenna-side feed point 7a) and the signal generator 25 to each other. In addition, the signal generator 25 applies an AC signal (applied signal) at a frequency that enables the plant 2 to function as a part of an antenna to the first antenna conductor 11. Thereby, the first antenna conductor 11 and the signal generator 25 function as a receiving antenna 31 in a monopole antenna structure.

[0089] The second antenna conductor 12 is electrically coupled to the plant 2 and connects the feed point 7 (ground-side feed point 7b) and the plant 2 to each other. In addition, the plant 2 as the resistor 33 is connected to the earth ground 6 via its root. Thereby, in a monopole antenna structure, the second antenna conductor 12 and the plant 2 function as a part of connecting the feed point 7 to the earth ground 6 via the resistor 33.

[0090] The applied signal at a frequency suitable for the plant 2 is output from the signal generator 25. In the example shown in Figure 3 , a rectangular wave with a frequency of 1 kHz and an amplitude of 5 V is output as the applied signal and applied to the first antenna conductor 11. In this case, the earth ground 6 is connected to the feed point 7 of the biosensor 100 in a manner including the resistance value Rt of the plant 2. In addition, the resistance value Rt is the resistance value of the resistance component 10 of the plant 2 with respect to an AC signal at a frequency of the applied signal (specifically, 1 kHz).

[0091] In this way, in the biosensor 100, the first antenna conductor 11 is connected to the signal generator 25, and the second antenna conductor 12 is electrically coupled to the plant 2. In addition, the applied signal at a frequency suitable for the plant 2 is applied from the signal generator 25 to the first antenna conductor 11. Thereby, similarly to the monopole antenna 30 shown in Figure 2 , a structure is provided in which AC power corresponding to the resistance component 10 (resistance value Rt) of the plant 2 is generated at the feed point 7 between the first antenna conductor 11 and the second antenna conductor 12.

[0092] The resistance value Rt of the plant 2 (resistance component 10) with respect to the earth ground 6 is determined by the water content and the electrolyte concentration of the plant 2. Therefore, the resistance value Rt changes in response to a change in the water content and the electrolyte concentration of the plant 2. To this end, by observing the power such as voltage or current of the detection signal induced at the feed point 7 after the applied signal is applied, the amount of change in the water content and the electrolyte concentration of the plant 2 can be observed.

[0093] As a reference to Figure 1Described is that, in this embodiment, the energy of the AC detection signal induced at the feeding point 7 is rectified by the rectifier circuit 21, and the DC voltage output from the rectifier circuit 21 is detected by the voltage meter 22. Monitoring the DC voltage generated in this way by rectification of the detection signal makes it possible to visualize the state of the water content, electrolyte concentration, etc. of the plant 2 as a voltage value.

[0094] [Configuration of biosensor]

[0095] Figure 4 is a block diagram showing an example of the configuration of the biosensor 100. Now, the respective configurations of the first antenna conductor 11, the second antenna conductor 12, the power detection unit 20, and the signal generator 25 that constitute the biosensor 100 will be described in detail.

[0096] [First antenna conductor]

[0097] The first antenna conductor 11 is a conductor to which the applied signal from the signal generator 25 is applied and which functions as a current path connecting the signal generator 25 and the feeding point 7 to each other. One of the end portions of the first antenna conductor 11 is connected to the output terminal 26 of the signal generator 25. Meanwhile, the other end portion of the first antenna conductor 11 functions as the antenna-side feeding point 7a and is connected to one of the input terminals of the rectifier circuit 21.

[0098] In this embodiment, the first antenna conductor 11 functions as an input antenna to which the applied signal is directly input from the signal generator 25. In other words, in the biosensor 100, it is not necessary to receive, for example, an electromagnetic wave at a frequency suitable for the plant 2. Therefore, the length of the first antenna conductor 11 can be arbitrarily set in accordance with, for example, the size and circuit configuration of the biosensor 100.

[0099] [Signal generator]

[0100] The signal generator 25 is a signal generation circuit that outputs an applied signal that is a predetermined AC signal, and includes an output terminal 26 and a ground terminal 27. The output terminal 26 is a terminal that outputs the applied signal and is connected to the first antenna conductor 11. The ground terminal 27 is a terminal that is connected to the ground of the signal generator 25. The potential of the ground terminal 27 is a reference potential of the applied signal, such as a level at which the voltage is zero. The connection destination of the ground terminal 27 is described in detail below with reference to, for example, Figure 8 、 Figure 12 and Figure 13 In this embodiment, the ground terminal 27 corresponds to a ground portion that provides the reference potential of the applied signal.

[0101] The frequency of the applied signal is set in accordance with the frequency characteristics of the resistance component 10 of the plant 2 with respect to the earth ground 6. As described above, in order for the resistance value Rt (impedance) of the resistance component 10 included in the plant 2 to be sufficiently low and for the plant 2 to function as an antenna, the frequency is desirably within the AM band or lower. Therefore, in this embodiment, the frequency of the applied signal is set to 5 Hz or higher and 3 MHz or lower. This enables a mirror current at the same frequency as the frequency of the applied signal to flow through the plant 2 and induces a detection signal of sufficient strength at the feeding point 7. This enables a change in the resistance value Rt to be reliably detected.

[0102] In addition, the waveform of the applied signal is, for example, rectangular. In this case, a logic source such as a pulse generator can be used as the signal generator 25, which simplifies the circuit configuration of the signal generator 25. Note that the waveform of the applied signal is not limited and a sine wave, a triangular wave, or the like can be used. In this case, for example, a function generator that outputs a signal having an arbitrary waveform is used as the signal generator 25. This enables an appropriate waveform to be selected in accordance with the characteristics and type of the plant 2, for example.

[0103] Furthermore, the center voltage of the amplitude of the applied signal is not limited. For example, the center voltage can be set to a zero level at which the voltage value is zero, or can be set to a voltage other than the zero level by applying a DC offset. In addition, the waveform of the applied signal is not limited and an applied signal having an arbitrary waveform mentioned above can be used.

[0104] [Second antenna conductor]

[0105] The second antenna conductor 12 is a conductor electrically coupled to the plant 2 and functions as a current path that connects the plant 2 and the feeding point 7 to each other. The second antenna conductor 12 is constituted by using a metal cable or the like, for example. One of the end portions of the second antenna conductor 12 functions as an attachment portion 15 that is attached to the plant 2. Meanwhile, the other end portion of the second antenna conductor 12 functions as the ground-side feeding point 7b and is connected to the other input terminal of the rectifier circuit 21.

[0106] The second antenna conductor 12 is attached to the above-ground portion of the plant 2. The above-ground portion of the plant 2 refers to a portion that is higher than the ground. For example, the trunk, branches, leaves, and the like of the plant 2 correspond to the above-ground portion. For example, in the case of a tree, the above-ground portion corresponds to the trunk, branches, and leaves of the tree. Figure 1 In the embodiment, the attachment portion 15 of the second antenna conductor 12 is attached to the branch of the plant 2. Note that the roots of the plant 2 are the below-ground portion of the plant 2. Attaching the second antenna conductor 12 to the above-ground portion eliminates the need for a direct connection between the second antenna conductor 12 and the earth ground 6. This enables the resistance value Rt of the resistance component 10 of the plant 2 to be appropriately measured.

[0107] The attachment portion 15 is a probe electrode for maintaining the end portion of the cable constituting the second antenna conductor 12 in contact with the plant 2. In general, a metal is used for a portion of the attachment portion 15 that is maintained in contact with the plant 2. The attachment portion 15 includes, for example, either a contact structure that presses the end portion of the second antenna conductor 12 against the outside of the plant 2 or a needle structure that inserts the end portion of the second antenna conductor 12 into the inside of the plant 2.

[0108] The attachment portion 15 with a contact structure is a type of probe electrode that presses a metal electrode (the end portion of the second antenna conductor 12) against an attachment object, for example, by using a spring, a fastener, or the like. For example, a clip structure that uses a spring (for example, a metal clip such as a crocodile clip) is used as the attachment portion 15 with a contact structure. Alternatively, the attachment portion 15 can be configured as a structure that presses a metal electrode against an attachment object by tightening a wire that is wound around the attachment object, for example, or a structure that presses a metal electrode against an attachment object by using a resin tie. Still alternatively, the contact structure to be used as the contact structure of the attachment portion 15 can be any structure that is capable of maintaining a metal electrode in contact with an attachment object. The use of the attachment portion 15 with a contact structure enables the second antenna conductor 12 to be easily attached to the plant 2. For example, in indoor cultivation within a greenhouse, the attachment portion 15 with a contact structure can be used without any problems in a case where the electrode is not directly exposed to moisture such as rainwater.

[0109] The attachment portion 15 with a needle structure is a type of probe electrode that inserts a needle-shaped electrode into the inside of a trunk or a branch of the plant 2, for example. In this case, direct contact with the inside of the plant 2 is possible. For example, in the attachment portion 15 with a clip structure, moisture such as rainwater enters between the electrodes that are pinching the plant 2, causing a change in contact resistance. In contrast, since the attachment portion 15 with a needle structure is used by inserting a needle-shaped electrode or the like into the plant 2, the second antenna conductor 12 can be maintained in direct contact with the plant 2. Therefore, the influence of moisture such as rainwater can be reduced. This enables stable contact even outdoors, for example.

[0110] In order to reduce the possibility of corrosion by moisture, for example, a gold-plated metal material, stainless steel, or the like is desirably used as the material of the metal that constitutes the attachment portion 15. In addition to the structure of the attachment portion 15, any other structure that is capable of electrically coupling the main body (cable portion) of the second antenna conductor 12 and the plant 2 to each other can be used.

[0111] By attaching the second antenna conductor 12 of the biosensor 100 to the plant 2, an antenna unit 16 including two antenna elements is formed. Specifically, the signal generator 25 and the first antenna conductor 11 connected to the signal generator 25 serve as an antenna element connected to the antenna-side feed point 7a and receiving an AC signal. Further, the plant 2 and the second antenna conductor 12 connected to the plant 2 serve as another antenna element connecting the ground-side feed point 7b to the earth ground 6. The antenna unit 16 including these two antenna elements enables induction of an AC electric power corresponding to the resistance component 10 of the plant 2 at the feed point 7.

[0112] Figure 5 is a circuit diagram showing an example of a configuration of the electric power detection unit 20. The electric power detection unit 20 is a circuit that rectifies the AC electric power generated at the feed point 7 and detects the level of the electric power. The electric power detection unit 20 includes a rectifier circuit 21 and a voltage meter 22.

[0113] [Rectifier Circuit]

[0114] The rectifier circuit 21 rectifies the AC electric power generated between the first antenna conductor 11 and the second antenna conductor 12 (feed point 7). In other words, the rectifier circuit 21 converts the power of the AC detection signal generated at the feed point 7 into a DC electric power. Thus, the output from the rectifier circuit 21 is a DC signal indicating the power level of the detection signal.

[0115] In the biosensor 100, when detecting a change in the power level of the detection signal, the accuracy of the detection can be enhanced as the output voltage from the rectifier circuit 21 becomes higher. For example, a full-wave rectifier circuit is able to increase the voltage of the AC signal and capture the entire waveform, and thus is efficient even when including a loss in the diode used for rectification. Further, in the rectifier circuit 21, it is important that the leakage current of the diode under reverse bias be very small. A full-wave rectifier circuit is suitable for use when there is a leakage current. For this reason, it is desirable to use a full-wave rectifier circuit as the rectifier circuit 21. Note that the configuration of the rectifier circuit 21 is not limited to this, and a half-wave rectifier circuit, a voltage doubler circuit, a Cockcroft-Walton circuit, or the like can also be used.

[0116] Figure 5The rectifier circuit 21 shown in FIG. 6 is configured as a full-wave rectifier circuit. The rectifier circuit 21 includes four diodes 41a, 41b, 41c, and 41d, a Zener diode 42, and output terminals 43a and 43b. The diodes 41a and 41b are connected in series, and the diodes 41c and 41d are connected in series. A connection point between the anode of the diode 41a and the cathode of the diode 41b corresponds to the antenna-side feed point 7a to which the first antenna conductor 11 is connected. Further, a connection point between the anode of the diode 41c and the cathode of the diode 41d corresponds to the ground-side feed point 7b to which the second antenna conductor 12 is connected.

[0117] A connection point between the cathode of the diode 41a and the cathode of the diode 41c is connected to one of the output terminals 43a, and a connection point between the anode of the diode 41b and the anode of the diode 41d is connected to the other of the output terminals 43b. Although the rectifier diodes 41a, 41b, 41c, and 41d are configured by discrete diodes, these diodes can be configured by a dedicated IC.

[0118] Further, the Zener diode 42 is connected in parallel between the output terminals 43a and 43b. The Zener diode 42 serves as an electrostatic protection component that releases static electricity in the event of occurrence of a high voltage such as static electricity. Instead of the Zener diode 42, a pressure-sensitive resistor for electrostatic protection can be provided. Note that, depending on the configuration of the biosensor 100, it is not necessary to provide an electrostatic protection component such as the Zener diode 42.

[0119] Figure 6 is an explanatory graph showing the characteristics of the diodes of the rectifier circuit 21. Figure 7 is an explanatory table showing the characteristics of the diodes of the rectifier circuit 21. Figure 6 and Figure 7 Measurement results of the forward voltage Vf and the reverse current Is of the rectifier diodes used in the rectifier circuit 21 are shown. Measurements were made for a silicon diode of type 1N60 and a germanium diode, and an evaluation was performed for another type of germanium diode 1SS108 from a different manufacturer. In Figure 6 In FIG. 6, the curve 44a shows the characteristics of 1N60 (silicon), the curve 44b shows the characteristics of 1N60 (germanium), and the curve 44c shows the characteristics of 1SS108 (germanium).

[0120] The current that flows in response to the application of a voltage in the reverse direction of the diode is the reverse current Is. Figure 7 The measurement data shown in FIG. 6 is data when 10 V is applied in the reverse direction of the diode. The forward voltage Vf is the voltage when a forward current (1 mA) starts to flow through the diode.

[0121] It was found that, when rectifying the output of the above-described antenna unit 16, a 1N60 (silicon) diode that blocks the flow of reverse current is able to extract more power than a diode with a lower forward on-voltage. Furthermore, the reverse current Is generated in response to the application of the forward voltage Vf of the diode in the reverse direction was also evaluated. Given that the signal to be rectified is AC, and Figure 7 The data shown in FIG. 8 is for 10 V, so the reverse current Is in response to the application of the same voltage Vf was calculated to be 0.036 μA for the 1N60 (silicon), 0.21 μA for the 1N60 (germanium), and 0.5 μA for the 1SS108 (germanium).

[0122] Therefore, the ratio of the reverse current Is at the forward voltage Vf to the forward current (1 mA) is 1 / 27778 for the 1N60 (silicon), 1 / 4762 for the 1N60 (germanium), and 1 / 2000 for the 1SS108 (germanium). In other words, the ratio of the diode used in the rectifier circuit 21 must be approximately 4700 times or more. The ratio desirably is 10000 times or more. Therefore, of the three diodes exemplified, the 1N60 (silicon) has the most suitable characteristics.

[0123] Furthermore, in consideration of the characteristics of the diode, the reverse current Is in response to the application of the voltage in the reverse direction should be low. Using the data at 10 V, the reverse resistance value was calculated to be 100 MΩ for the 1N60 (silicon), 1.43 MΩ for the 1N60 (germanium), and 0.38 MΩ for the 1SS108 (germanium). In other words, the resistance value that blocks the flow of current in the reverse direction is desirably high. The resistance value of the diode used in the rectifier circuit 21 must be greater than 1.43 MΩ. The resistance value desirably is 10 MΩ or more. Therefore, of the three diodes exemplified, the 1N60 (silicon) has the most suitable characteristics.

[0124] [Voltage meter]

[0125] Referring again to Figure 5 , the voltage meter 22 detects the output voltage of the rectifier circuit 21. An internal resistor 45 is provided in the voltage meter 22. This internal resistor 45 is connected between the output terminal 43a and the output terminal 43b of the rectifier circuit 21. Hereinafter, the resistance value of the internal resistor 45 is denoted by Ri. The resistance value Ri of the internal resistor 45 corresponds to the input impedance of the voltage meter 22, which is set to a relatively high value such as 1 MΩ or more.

[0126] In the voltage meter 22, the voltage between the output terminal 43a and the output terminal 43b is detected as a DC voltage applied to the internal resistor 45. This makes it possible to detect the DC power output from the rectifier circuit 21 as a voltage. In this embodiment, the voltage meter 22 corresponds to a DC detection circuit that detects the DC power output from the rectifier circuit 21.

[0127] Further, the resistance value Ri of the internal resistor 45 is a parameter that affects the sensitivity of the voltage meter 22. In other words, the sensitivity of the voltage meter 22 depends on the resistance value Ri. For example, as the resistance value Ri becomes higher, the level of the voltage detected by the voltage meter 22 becomes higher, which increases the sensitivity to changes in the output of the rectifier circuit 21. Therefore, the internal resistor 45 of the voltage meter 22 is adjusted to achieve a predetermined sensor sensitivity.

[0128] For example, it is desirable that the resistance value Ri of the internal resistor 45 of the voltage meter 22 be 1 kΩ or higher and 10 MΩ or lower. By setting the resistance value Ri to 1 kΩ or higher, it is possible to maintain the voltage level for detecting changes in the resistance component 10 of the plant 2, and it is possible to appropriately detect the water content and the like of the plant 2. Further, by setting the resistance value Ri to 10 MΩ or lower, it is possible to prevent the sensor sensitivity of the voltage meter 22 from unnecessarily increasing, and it is possible to detect significant changes in the output of the rectifier circuit 21.

[0129] For example, in order to closely observe changes in the state of the plant 2, the resistance value Ri of the internal resistor 45 is set to approximately 10 MΩ. In this case, not only changes in the water content and the electrolyte concentration of the plant 2, but also, for example, the contact state of the plant 2 with other living organisms can be detected. For example, this makes it possible to detect a case where a wild animal such as a wild boar or a monkey approaches and, for example, damages the plant 2.

[0130] Note that when the resistance value Ri is set to 10 MΩ, the reading of the voltage meter 22 responds sensitively, which can make it difficult to appropriately detect changes in the water content and the like. Therefore, in order to observe the water content, the electrolyte concentration, and the like of the plant 2, it is desirable that the resistance value Ri of the internal resistor 45 be set to approximately 2 MΩ. This adjustment of the resistance value Ri makes it possible to perform sensitivity adjustment in accordance with, for example, the characteristics of the plant 2 and the application of the biological sensor 100. The resistance value Ri of the internal resistor 45 can be set to other values. For example, even outside the above-described resistance value range, the resistance value Ri can be appropriately set in accordance with, for example, the state of the living organism 1 (specifically, the plant 2) to be measured and the application and use environment of the biological sensor 100.

[0131] [Power supply]

[0132] As Figure 4As shown, the signal generator 25 and voltmeter 22 of the biosensor 100 are powered by electricity supplied from the power source 28. For example, a battery is used as the power source 28. In this case, there are no restrictions on where the biosensor 100 is installed, and the application range of the biosensor 100 can be expanded. Alternatively, a commercial power supply can be used as the power source 28. In this case, concerns such as battery depletion are eliminated, and the status of the plant 2 can be reliably monitored.

[0133] The biosensor 100 can use an energy harvesting device as its power source. Examples of such energy harvesting devices include solar panels and energy harvesters that generate electricity through vibration. The electricity generated by these devices is charged into a battery, which is then used to supply power to the biosensor 100. Alternatively, for example, AC power generated at the feed point 7 of the biosensor 100 can be used to charge the battery. Using an energy harvesting device as a power source in this way allows the biosensor 100 to operate for extended periods in various environments. Furthermore, the configuration of the power source 28 is not limited.

[0134] In addition, such as Figure 4 As shown, in the biosensor 100, the signal generator 25, the first antenna conductor 11, and the rectifier circuit 21 can be configured as a sensor module 17. In this case, the sensor module 17 has an input terminal (the terminal connected to the ground-side feed point 7b) for connecting the second antenna conductor 12, and a pair of output terminals (output terminals 43a and 43b of the rectifier circuit 21) for connecting the signal generator 25. Furthermore, the sensor module 17 has a power terminal for connecting the power supply 28. Using the sensor module 17 makes it easy to configure the biosensor 100 according to the organism 1 being targeted (e.g., plant 2, human body, or animal).

[0135] [Connection between biosensors and plants]

[0136] Figure 8 This is a schematic circuit diagram illustrating an example of the connection between the biosensor 100 and the plant 2. Figure 9 This is a schematic diagram illustrating an example of the connection between the biosensor 100 and the plant 2, as shown in the diagram. Figure 8 As shown. In Figure 8 and Figure 9 In the signal generator 25, the ground terminal 27 is electrically coupled to the plant 2. Note that... Figure 8 The part enclosed by the dashed line corresponds to plant 2, and the resistance component 10 (resistance components 10a, 10b and 10c) shown in the dashed line can be regarded as a variable resistor whose value varies according to the water content and electrolyte concentration of plant 2.

[0137] The ground terminal 27 of the signal generator 25 is electrically coupled to a portion of the plant 2 other than the portion to which the second antenna conductor 12 is connected. The ground terminal 27 is connected to the plant 2, for example, via a cable provided with an attachment portion 15 similar to the attachment portion of the second antenna conductor 12. For example, in Figure 9 , the ground terminal 27 of the signal generator 25 is connected to a branch on the left side of the plant 2 in the illustration, while the second antenna conductor 12 is connected to a branch on the right side of the plant 2 in the illustration.

[0138] In this way, both the second antenna conductor 12 and the ground terminal 27 of the signal generator 25 are connected to the plant 2. This connection state is represented by three resistance components 10a, 10b, and 10c that constitute the plant 2. The resistance component 10a is a resistance component connected to the second antenna conductor 12. The resistance component 10b is a resistance component connected to the ground terminal 27 of the signal generator 25. Furthermore, the resistance component 10a and the resistance component 10b are connected to the earth ground 6 via the resistance component 10c. Therefore, it can be said that the resistance component 10c is a resistance component common to the second antenna conductor 12 and the ground terminal 27 of the signal generator 25.

[0139] Connecting the ground terminal 27 of the signal generator 25 to the plant 2 enables the signal generator 25 to output an applied signal with respect to a common potential of the plant 2. Furthermore, a portion (a connection point between the resistance components 10a and 10b) that functions as a common potential is formed in the plant 2. Thereby, a component of the applied signal is easily reflected in a detection signal to be excited at the feeding point 7. As a result, the power level of the detection signal increases. This can also be said to be because the plant 2 itself functions as a large ground, so the power level of the detection signal increases.

[0140] In this way, in the connection configuration shown in Figure 8 and Figure 9 , the electric power to be excited at the feeding point 7 increases, which clearly manifests a change in the plant 2. This enables a change in the resistance components 10 (the resistance components 10a, 10b, and 10c) to be detected with high accuracy. Furthermore, the electrode connected to the ground terminal 27 of the signal generator 25 is not buried in the ground, so there is no risk of soil contamination. Note that if the electrode is buried in the ground such that the ground terminal 27 is connected to the earth ground 6 (refer to Figure 12 ), it is necessary to take into account the effect of a potential difference between the ground on which the plant 2 grows and the ground in which the electrode is buried. In contrast, if the ground terminal 27 is connected to the plant 2, it is not necessary to take into account the effect of such a potential difference.

[0141] In fact, both the second antenna conductor 12 and the ground terminal 27 of the signal generator 25 were connected to a potted ornamental plant, blue daze, and the output of the voltmeter 22 was measured. The output of the voltmeter 22 was the value of the DC induced voltage output from the rectifier circuit 21. In this measurement, as the applied signal, a rectangular wave with a frequency of 1 kHz and an amplitude of 5 V was output, and the resistance value Ri of the internal resistor 45 of the voltmeter 22 was set to 2 MΩ. Thus, the output of the voltmeter 22 was approximately 0.7 V. This is at a relatively higher level than those in the other connection examples described below Figure 12 and Figure 13 This enabled changes in the resistance component 10 (resistance components 10a, 10b, and 10c) of the plant 2 to be detected with sufficient accuracy.

[0142] [Results of monitoring]

[0143] Figure 10 is a graph showing an example of the results of monitoring by the biosensor 100. Figure 10 The graph shown in FIG. 8 was generated by the biosensor 100 connected to a potted blue daze via the connection method shown in FIG. 7. Figure 8 and Figure 9 In this measurement, as the applied signal, a rectangular wave with a frequency of 1 kHz and an amplitude of 5 V was output, and the resistance value Ri of the internal resistor 45 of the voltmeter 22 was set to 2 MΩ.

[0144] The horizontal axis indicates time. The solid line indicates 0:00 when the date changes, and the broken line indicates 12:00 noon each day. In addition, the weather, maximum temperature, and minimum temperature each day are also shown. The vertical axis indicates the reading of the voltmeter 22 (voltage [V]). Also, the thick arrow shown on the graph indicates the timing of watering. The hatched arrow indicates the timing at which photosynthesis is presumed to occur during the day. Also, it rained on the 8th and 9th days, so an arrow indicating this period is also shown.

[0145] During the day, there is a general tendency for the voltage to decrease during the day and increase at night. For example, it is presumed that the stomata of the leaves open during the day to perform transpiration, thereby reducing the water content. In this case, the resistance value Rt of the resistance component 10 increases, and the voltage level (power level of the detected signal) detected by the voltmeter 22 decreases. In contrast, it is presumed that the stomata close at night to suppress transpiration, thereby causing water to be stored in the plant 2. In this case, the resistance value Rt decreases, and the voltage level increases. It is presumed that this graph reflects such detected activities of the plant 2.

[0146] Further, for example, on a rainy day, the voltage changes little. This is presumed because the humidity is kept high throughout the day, so the stomata are closed, and the moisture content and the like change little. In addition, it was found that even if watering is performed, the voltage does not immediately rise, but there is a time lag. Using the biosensor 100 in this way makes it possible to check various states of the plant 2 that involve changes in the resistance component 10. For example, this makes it possible to determine the optimal timing of fertilization or watering. Note that, although Figure 10 The experimental results shown in FIG. 6 are obtained by measuring potted plants, but the present technology is also applicable to cases of open field cultivation and the like.

[0147] Further, the biosensor 100 does not directly apply a voltage to the plant 2, but induces a mirror current on the side where the plant 2 is located, which corresponds to the frequency of the applied signal applied to the side of the feeding point 7. Although this method does not cause serious damage to the plant 2, the mirror current flowing through the plant 2 causes moderate stress to the plant 2. Thus, for example, an advantage of an increase in the sweetness of fruits such as tomatoes can be expected. Further, since a voltage corresponding to the mirror current flowing through the plant 2 is induced, an advantage of repelling pests can be expected.

[0148] Note that it was found that, when the biosensor 100 is used, the level of the output voltage varies depending on the soil composition or the type of the plant 2. Thus, for example, before starting monitoring, it is desirable to set a reference value of the voltage level in accordance with the measurement system. The reference value of the voltage level is a voltage level used to determine the level of the moisture content and the electrolyte concentration of the plant 2 in the measurement system.

[0149] For example, an average value of the voltage level measured in a proper watering and fertilization state is set as the reference value. Further, the amount of change in the voltage level measured in the same state can be set as a threshold value. Thereby, for example, if the voltage level falls below the threshold value in relation to the reference value, it can be determined that watering is needed. Further, if the voltage level falls below the threshold value in relation to the reference value, it can be determined that watering is excessive. In this way, the voltage level of the biosensor 100 can be calibrated.

[0150] Basically, the biosensor 100 detects the state of the plant 2 to which the biosensor 100 is attached. For example, for a plant group in which the plants contact each other with their roots in the ground, it is presumed that the state of each plant within the plant group is detected as a whole.

[0151] For example, if the plants 2 include plants planted in flowerpots, such as tomatoes planted relatively densely, or if the plants 2 include plants grown side by side, such as grapevines, it is presumed that the roots of the plants 2 overlap each other. In these cases, instead of installing the biosensor 100 on each of the plants 2, the biosensor 100 can be arranged, for example, in the flowerpots, or at both ends and in the middle of a hedge, respectively. In this way, even if the biosensor 100 is not installed on each of the plants 2, it is possible to collectively detect the states of the plants 2 if the roots of the plants 2 contact each other, and manage the entire plant group.

[0152] [biological management system]

[0153] Figure 11 is a schematic diagram showing an example of a configuration of a biological management system using a biosensor. This biological management system 110 is a system for managing plants 2 as biological organisms 1 with at least one biosensor 100.

[0154] Here, as an example of the biological management system 110, a system in which the biosensor 100 is arranged in an orchard in which citrus trees or the like are planted is shown. In this case, the plants 2 detected by the biosensor 100 are fruit trees such as citrus trees. The biological management system 110 includes at least one biosensor 100, a host device 50, a management device 51, a watering device 52, and a pesticide spraying device 53.

[0155] Further, in the biological management system 110, the biosensor 100, a communication device (not shown) for communicating with the host device 50, and a power supply 28 for the biosensor 100 and the communication device are configured as a single sensor unit 55. The second antenna conductor 12 of the biosensor 100 and the ground terminal 27 of the signal generator 25 are connected to the plants 2 in the orchard via respective cables. Note that the orchard is located outdoors, and therefore the second antenna conductor 12 and the ground terminal 27 (both not shown) are connected to the plants 2 via, for example, probe electrodes having a needle structure that is not affected by, for example, rain.

[0156] For example, a solar panel is used as the power supply 28. Here, the electric power from the solar panel is charged to an energy storage device (not shown), such as a secondary battery or a capacitor, and is appropriately supplied to the biosensor 100 and the communication device. Further, as the communication device, a communication module capable of communicating using a short-range communication method such as BLE (Bluetooth Low Energy) or a long-range communication method such as LPWA (Low Power Wide Area Network) is used.

[0157] The detected data from the biosensor 100 is transmitted to the host device 50 via a communication device. The transmission frequency of the detected data is set according to, for example, the amount of electrical power to be obtained from the solar panel, the characteristics of the plant 2, and the application of the biomanagement system 110. For example, the detected data can be transmitted at intervals of, for example, 5 minutes, 1 hour, or 1 day. The host device 50 receives the detected data transmitted from each sensor unit 55 (biosensor 100) and uploads the detected data to a cloud network (cloud 54). The detected data is analyzed in the cloud 54, or transmitted as is to the management device 51 for analysis.

[0158] The management device 51 is a device that performs management operations based on the detection results of at least one biosensor 100. Note that management operations refer to operations that manage plants such as the plant 2 to which the biosensor 100 is connected. Examples of management operations include controlling a dedicated device for managing the plant 2 and notifying an administrator of the status of the plant 2. Here, the management operations are performed based on the results of analysis of the data detected by the biosensor 100.

[0159] For example, if it is determined that plant 2 has insufficient water content, a notification of insufficient water content is transmitted to a terminal device (such as a PC, smartphone, or tablet) used by the administrator. In this way, an alert is issued to the administrator. In this case, the administrator can manually operate the watering device 52. Alternatively, the management device 51 can operate the watering device 52 automatically. In automatic mode, for example, the host device 50 communicates with the watering device 52 via the cloud 54 to automatically open the watering valve. In this way, water is supplied to the plant. Furthermore, similar management operations can be performed if the leaves of plant 2 are damaged by pests or other pests. For example, if pest damage is determined, the pesticide spraying device 53 is activated to spray pesticides as in the case of watering.

[0160] As described above, in the biological management system 110, the use of biosensors 100 enables direct detection of the corresponding state of plant 2. Until now, humans have judged the state of plants based on humidity, temperature, weather, etc. Now, it is possible to automatically provide data to support these judgments and determine the state of plant 2. Furthermore, management operations can be performed at appropriate time intervals based on the plant's state, and in some cases, automatically. This allows plant 2 to be properly managed to maintain its healthy growth.

[0161] [Other examples of connections]

[0162] Figure 12 This is a schematic circuit diagram illustrating another example of the connection between the biosensor 100 and the plant 2. Figure 12In the biosensor 100 shown in FIG. 1, the ground terminal 27 of the signal generator 25 is connected to the earth ground 6. In this state, the ground terminal 27 of the signal generator 25 is connected to the common ground of the plant 2. Note that the second antenna conductor 12 is electrically coupled to the plant 2. The electrode to be connected to the earth ground 6 can be exposed to rain, for example. For precaution, it is desirable to use stainless steel, gold-plated metal, or the like that is not easily subject to moisture corrosion for the electrode portion.

[0163] In Figure 12 the example shown in FIG. 2, the signal generator 25 is allowed to output an applied signal with respect to the potential of the earth ground 6 serving as the common ground of the plant 2. This increases the power level of the detection signal to be excited at the feeding point 7. In addition, by using the earth ground 6 as a reference, the output of the voltage meter 22 is stabilized. When the ground terminal 27 is connected to the earth ground, the output of the voltage meter 22 is higher than, for example, Figure 13 the output in the floating state shown in FIG. 1. The output of the voltage meter 22 (which is obtained by a similar measurement method to the measurement method in the connection configuration shown in FIG. 1) is approximately 0.4 V. Figure 8

[0164] Figure 13 is a schematic circuit diagram showing still another example of the connection between the biosensor 100 and the plant 2. In Figure 13 the biosensor 100 shown in FIG. 3, the ground terminal 27 of the signal generator 25 is used in a state of being electrically floating from the earth ground 6. In this case, the ground terminal 27 is not connected to any location. Note that the second antenna conductor 12 is electrically connected to the plant 2.

[0165] In the state where the ground terminal 27 is electrically floating, the difference between the potential of the ground-side feeding point 7b and the potential of the antenna-side feeding point 7a appears to be small with respect to the earth ground 6. Therefore, a component of the applied signal is unlikely to be reflected in the detection signal to be excited at the feeding point 7. Thus, the power of the detection signal to be induced at the feeding point 7 is relatively small. For example, in order to detect a slight change in the resistance component 10 of the plant 2, it is desirable to improve the sensitivity of the voltage meter 22 in advance by setting the internal resistor 45 of the voltage meter 22 to have a high resistance value such as 10 MΩ.

[0166] When the ground terminal 27 is floating, the output of the voltage meter 22 (which is obtained by a similar measurement method to the measurement method in the connection configuration shown in FIG. 1) is approximately 0.4 V. Figure 8 ​The measurement method in the connection configuration shown in the middle (a similar measurement method to that obtained) is approximately 0.2 V. In this way, the output of the voltmeter 22 (which is lower than the output in other connection configurations) is much higher than the output in a configuration in which the bioelectric potential is directly detected. Therefore, it is easy to detect a change in the output. Furthermore, this method eliminates the need for a cable for the wiring ground terminal 27, and thus can simplify the device configuration.

[0167] As described above, the bio sensor 100 according to this embodiment is provided with the first antenna conductor 11 and the second antenna conductor 12 connected to the earth ground 6 via the plant 2. The AC power generated between these antenna conductors is detected in accordance with the electrical resistance component 10 of the plant 2 with respect to the earth ground 6. Thereby, even with a simple configuration, it is made possible to obtain a relatively high AC power, and the state of the plant 2 can be easily and with high accuracy detected.

[0168] In this context, for example, a method of observing the state of a plant is described, which is different from the method of the present application. Generally, in order to observe the bioelectric potential of a plant, two electrodes are attached to a part such as a leaf and a stem, and a weak electric signal generated between the electrodes is amplified and examined. In this case, the energy generated between the two electrodes is observed, and thus it is possible to at least read a local potential change accompanying, for example, photosynthesis. At the same time, the state of the plant as a whole is not clear, and it is difficult to convert the result of the measurement into, for example, the water content of the plant as a whole.

[0169] In addition, as another method of observing the bioelectric potential of a plant, a method of observing the potential of the plant as a whole with respect to the earth ground is also conceivable. In this case, among two electrodes, one electrode is connected to a plant, and the other electrode is connected to the earth. The distance between the plant to be measured and the earth or the weather has an influence thereon. Furthermore, the electric signal to be measured is weak, and thus it is difficult to accurately measure.

[0170] Further, there are known methods of promoting the growth of a plant or repelling a pest by directly applying an electric signal to a plant, and a known method of using a plant as a human motion sensor. In these methods, for example, two electrodes are attached to a plant to be an object, and a DC or AC signal is applied between the electrodes. Therefore, it is difficult to simultaneously measure, for example, a bioelectric potential.

[0171] In this embodiment, the AC power generated between the first antenna conductor 11 and the second antenna conductor 12 connected to the earth ground 6 via the plant 2 is detected. Furthermore, a signal to be applied is applied from the signal generator 25 to the first antenna conductor 11. This configuration functions as a monopole antenna in which the plant 2 (the electrical resistance component 10 having an electrical resistance value of Rt) is inserted between the feeding point 7 and the earth ground 6.

[0172] Therefore, in the biological sensor 100, by detecting the AC power generated between the first antenna conductor 11 and the second antenna conductor 12 (at the feeding point 7), a change in the electrical resistance component 10 of the plant 2 can be detected. The electrical resistance value Rt of the electrical resistance component 10 of the plant 2 changes in accordance with the water content and the electrolyte concentration of the plant 2 as a whole. Therefore, by observing a change in the AC power generated at the feeding point 7, the state of the plant 2 as a whole can be determined.

[0173] In addition, the output (voltage level of the voltage meter 22) of the biological sensor 100 is, for example, much higher than a bioelectric potential or the like. This makes it possible for a change in the output of the biological sensor 100 to be easily detected. Therefore, a change in the water content and the electrolyte concentration of the plant 2 can be detected with high accuracy. Also, a special probe electrode, an amplifier circuit, or the like for capturing a weak signal such as a bioelectric potential is not necessary. Therefore, it is possible to simplify the device configuration.

[0174] The biological sensor 100 induces a potential corresponding to the applied signal in the electrical resistance component 10 of the plant 2 and does not directly apply an electric signal. This speculatively makes it possible not only to visualize a change in the electrical resistance component 10 caused by a change in the water content and the electrolyte concentration of the plant 2 itself but also to promote growth or drive away pests by inducing a potential in the plant 2 itself. This makes it possible to realize an advantage such as promoting growth while monitoring the state of the plant 2.

[0175] <Second Embodiment>

[0176] A biological sensor according to a second embodiment of the present technology is described. Hereinafter, a description of configurations and functions similar to those of the biological sensor 100 described in the above-described embodiments is omitted or simplified.

[0177] Figure 14 is a schematic circuit diagram showing an example of a configuration of a biological sensor according to the second embodiment. In this embodiment, the living body 1 to be detected using the biological sensor 200 is a human or an animal. In this case, the second antenna conductor 12 is attached to the body of the human or the body of the animal.

[0178] The electrical resistance value Rt of the electrical resistance component 10 (specifically, the electrical resistance components 10a, 10b, and 10c) constituting the living body 1 such as a human, an animal, or the like changes in accordance with the water content and the electrolyte (such as blood and lymph) concentration contained in the living body 1. Therefore, detecting a change in the electrical resistance component 10 (10a, 10b, and 10c), specifically, a change in the AC power to be generated in the biological sensor 200 in accordance with the electrical resistance component 10 (10a, 10b, and 10c) makes it possible to monitor the state of the water content and the electrolyte concentration contained in the human or the animal.

[0179] As Figure 14The circuit configuration of the biological sensor 200 is substantially similar to that of the biological sensor 100 for plants, which has been described with reference to Figure 8 Not only the second antenna conductor 12 but also the ground terminal 27 of the signal generator 25 is connected to the biological object 1 as the subject. Note that in the biological sensor 200, the attachment portion 15 of the second antenna conductor 12 and the ground terminal 27 are configured to be attachable to the body of a human or an animal. Further, the biological object 1 is connected to the earth ground 6, for example, by capacitive coupling.

[0180] The frequency of the applied signal is set in accordance with the frequency characteristics of the resistance component 10 (10a, 10b, and 10c) of the biological object 1. For example, at a frequency of 1 GHz or lower, the resistance component 10 (10a, 10b, and 10c) is low, which enables the body of a human to be used as part of an antenna. Therefore, when the detection subject is a human, a 1 GHz or lower applied signal is used. In addition, the amplitude of the applied signal is appropriately set in accordance with, for example, the resistance value Rt of the resistance component 10 (10a, 10b, and 10c), for example, within a range that does not affect the biological object 1. Also, the frequency or amplitude of the applied signal can be set in accordance with the characteristics of the biological object 1 or the application of the biological sensor 200.

[0181] In the biological object 1 such as a human or an animal, the resistance component 10a connected to the second antenna conductor 12, the resistance component 10b connected to the ground terminal 27 of the signal generator 25, and the resistance component 10c connecting the resistance component 10a and the resistance component 10b to the earth ground 6 are configured. This is similar to the case of the plant 2 shown in Figure 8 This enables the signal generator 25 to output an applied signal with respect to the common potential of the biological object 1. Therefore, the power level of the detection signal increases. Therefore, it is possible to maintain high detection accuracy without interfering with the movement or action of a human or an animal.

[0182] Figure 15 is a schematic diagram illustrating an example of applying the biological sensor 200 shown in Figure 14 Here, the cable connecting the ground terminal 27 and the human body 3 is referred to as a ground cable 29. Figure 15 The second antenna conductor 12 and the ground cable 29 connected to the human body 3 via the attachment portion 15 are schematically illustrated. Note that the earth ground 6 and the human body 3 are capacitively coupled to each other through space, and thus the resistance between the earth ground 6 and the human body 3 can be regarded as constant.

[0183] Figure 15 The left side of FIG. 8 illustrates a case in which Figure 14The example shown illustrates the attachment of the biosensor 200 to the wrist and ankle of the human body 3. Here, although the second antenna conductor 12 is attached to the wrist and the grounding cable 29 is attached to the ankle, the attachment could be reversed. Thus, in Figure 14 The biosensor 200 shown senses a voltage at its feed point 7 that corresponds to the water content and electrolyte concentration between the wrist and ankle. For example, this allows for the determination of when the wearer drinks or eats, thereby enabling the management of the wearer's physical condition.

[0184] at the same time, Figure 15 The right side of the diagram illustrates an example of attaching a biosensor 200 via both ends of the wearer's hand muscles. In this example, although the second antenna conductor 12 and the ground cable 29 are attached sequentially from the side closest to the torso, the attachment could be reversed. Thus, for example, the amount of change in the resistance component 10 due to muscle contraction can be detected. This allows the biosensor 200 to be used, for example, like an electromyography (EMG) sensor. Furthermore, since the second antenna conductor 12 and the ground cable 29 are attached close to each other, for example, the local moisture content between the corresponding attachment portions 15 can be detected. In this case, the biosensor 200 can be used, for example, like a skin sensor.

[0185] Figure 16 The diagram shows... Figure 14 The diagram illustrates an example of the biosensor 200 being applied to an animal. Here, the biosensor 200 is attached to animal 4. This allows the state of animal 4 to be monitored, just as in the case of humans. Although a cow 5 is illustrated here as an example of animal 4, the type of animal 4 is not limited to this. For example, applications to livestock such as horses, pigs, and birds, as well as to wild animals to be observed, are also possible. Note that in the case of animal 4, the resistance between earth ground 6 and animal 4 can also be considered constant due to capacitive coupling with earth ground 6.

[0186] The second antenna conductor 12 of the biosensor 200 is connected to the neck collar 18 of the cow 5. In this case, the neck collar 18 serves as an attachment portion 15 for the second antenna conductor 12. Simultaneously, the ground terminal 27 of the signal generator 25 is connected to the ear 19 of the cow 5, for example, via a probe electrode having a clip structure. Note that the connection positions of the second antenna conductor 12 and the ground terminal 27 can be reversed. This allows the biosensor 200 to detect changes in the resistance component 10 from the neck of the cow 5 to the ear 19.

[0187] Further, the detected data detected by the biosensor 200 is transmitted to the satellite 35 via the communication module that performs satellite communication. For example, a GPS sensor that acquires the current position of the cow 5, a temperature sensor that measures the environmental temperature, and the like can be provided together with the biosensor 200. In this case, in addition to the detected data of the biosensor 200 (data indicating the state of the cow 5), information on the position of the cow 5, information on the environmental temperature around the cow 5, and the like can also be transmitted to the satellite 35. This makes it possible to closely monitor and manage the state of the grazing cow 5 and the like, for example.

[0188] Further, as the power source of the biosensor 200, a battery can be used, or vibration power generation using vibrations to be generated by the ear of the cow 5 can be used. For example, a vibration power generation unit can be provided in the main body of the biosensor 200, and the main body with this unit can be attached to the ear of the cow 5. Alternatively, only the vibration power generation unit can be attached to the ear of the cow 5. This eliminates the need to replace the battery, and makes it possible to provide a biosensing system that is easy to maintain, for example.

[0189] [Other Embodiments]

[0190] The present technology is not limited to the embodiments described above, and can be implemented in various other embodiments.

[0191] In the embodiments described above, an example in which the applied signal is applied from the signal generator 25 to the first antenna conductor 11 is mainly described. This makes it possible to utilize a stable applied signal, and thus the state of the living body 1 can be stably detected. Meanwhile, since such a configuration is provided with the signal generator 25, the circuit with such a configuration can be complex, or the power consumption can increase.

[0192] Incidentally, as described with reference to Figure 2 , configuring the first antenna conductor 11 as an antenna that receives electromagnetic waves also makes it possible to induce AC power from the resistance component 10 of the living body 1. Therefore, appropriately configuring the first antenna conductor 11 makes it possible to configure the biosensor without providing the signal generator 25.

[0193] Figure 17 is a schematic circuit diagram that shows an example of a configuration of a biosensor according to another embodiment. In Figure 17 This biosensor 300 shown in FIG. 8 is not provided with the signal generator 25, and the first antenna conductor 11 is configured as an antenna that receives electromagnetic waves. Note that, in the biosensor 300, the configurations other than the configuration of the first antenna conductor 11 are similar to those in the other biosensors described above, for example.

[0194] The first antenna conductor 11 is provided to have a length corresponding to 1 / 4 of the wavelength of a predetermined AC component among the AC components induced in the living body 1. Note that the AC components induced in the living body 1 refer to, for example, an AC electric signal that can be induced in the living body 1 when the living body 1 is used as an antenna. For example, when the living body 1 is a human body, as described above, the human body functions as a part of an antenna at a frequency of 1 GHz or lower. In other words, at a frequency of 1 GHz or lower, the electric resistance component 10 of the human body is relatively low and functions as a path connecting the feeding point 7 to the earth ground 6. The same applies to animals other than the human body.

[0195] When the living body sensor 300 is applied to a human body or an animal, the length of the first antenna conductor 11 is set to have a length corresponding to 1 / 4 of the wavelength of a predetermined AC component among the AC components at 1 GHz or lower. This makes it possible to maximize the efficiency of receiving the predetermined AC component. The predetermined AC component is set, for example, in accordance with the frequency characteristics of the electric resistance component of the living body 1, the intensity of electromagnetic waves present in the surroundings of the living body 1, and the like. For example, by selecting a frequency at which the electric resistance component of the living body 1 is low, or by selecting a frequency at which the intensity of electromagnetic waves is high, it is possible to increase the AC electric power induced in the living body 1. Note that in a frequency band of 1 GHz or higher, the electric resistance value Rt of the electric resistance component 10 is too high. Therefore, the living body 1 cannot function as a part of an antenna.

[0196] For example, when the frequency of the predetermined AC component is set to 500 MHz, the wavelength λ thereof is 60 cm, and thus the length of the first antenna conductor 11 is 15 cm. This is the antenna length of the first antenna conductor 11, which is, for example, the length of the current path from the antenna-side feeding point 7a to the tip of the antenna. In order to reduce the actual size of the first antenna conductor 11, there are methods such as winding the antenna having a length of 15 cm in the form of a coil. The first antenna conductor 11 can be constituted by other methods. For example, the first antenna conductor 11 can be constituted by using a meander line, a chip inductor, or the like.

[0197] Note that the intensity of the electromagnetic wave received by the living body sensor 300 (the first antenna conductor 11) can not be constant. Therefore, for example, a method of calibrating a reference value for electric power detection in accordance with the level of the surrounding electromagnetic wave before using the living body sensor 300 can be conceivable. Alternatively, for example, a method of calibrating the output of the living body sensor 300 by referring to the electric power at the feeding point of another monopole antenna that is prepared separately and connected to the earth ground 6 without the interposition of the living body 1 can be employed.

[0198] Although Figure 17The biosensor 300 shown in the above embodiment is generally intended for use in humans and animals that are capable of receiving electromagnetic waves of approximately 1 GHz high frequency, but the biosensor 300 can also be applied to plants 2. For example, the biosensor 300 having the first antenna conductor 11 that receives electromagnetic waves can also be applied to plants 2 in a case where there is no problem even if the size of the housing is large and the length of the antenna is long, or in a case where low reception sensitivity is acceptable.

[0199] In the above-described embodiment, as a method of detecting the AC power generated at the feeding point 7 between the first antenna conductor 11 and the second antenna conductor 12, a method of detecting the output of the rectifier circuit 21 connected to the feeding point 7 via the voltmeter 22 is described. The method of detecting the AC power generated at the feeding point 7 is not limited thereto.

[0200] For example, a current meter that detects the output current of the rectifier circuit 21 can be provided. In other words, the value of the DC current output from the rectifier circuit 21 is detected as the AC power generated at the feeding point 7. In this case, the current meter functions as a DC detection circuit that detects the DC power output from the rectifier circuit 21. In this way, when the value of the DC current is detected, it is also possible to detect the state of the living body 1 that changes depending on the resistance component 10.

[0201] Further, the rectifier circuit 21 is not necessarily provided, and it is possible to directly detect the AC power generated at the feeding point 7. In this case, an AC voltmeter capable of detecting an AC voltage or an AC current meter capable of detecting an AC current is connected to the feeding point 7. Other arbitrary configurations capable of detecting the AC power generated at the feeding point 7 can be employed.

[0202] It is also possible to combine at least two features according to the features of the present technology described above. In other words, the respective features respectively described in the embodiments can be arbitrarily combined with each other regardless of the embodiments. Further, the various advantages described above are merely examples and are not limited thereto, and other advantages can be achieved.

[0203] The terms same, equal, orthogonal, and the like used herein encompass the concepts of substantially same, substantially equal, substantially orthogonal, and the like. For example, the terms also encompass a state that is within a predetermined range, such as a range of ±10%, based on a criterion such as exactly same, exactly equal, exactly orthogonal, and the like.

[0204] Note that the present technology can also employ the following configurations.

[0205] (1) A biosensor comprising:

[0206] a first antenna conductor;

[0207] a second antenna conductor that is a different conductor from the first antenna conductor and is electrically coupled to the living body connected to the earth ground directly or through a capacitive coupling; and

[0208] a power detection unit that detects AC power generated between the first antenna conductor and the second antenna conductor according to a resistance component of the living body with respect to the earth ground.

[0209] (2) The biosensor according to (1), further comprising

[0210] a signal generator that applies a predetermined AC signal to the first antenna conductor.

[0211] (3) The biosensor according to (2), wherein

[0212] a frequency of the predetermined AC signal is set according to a frequency characteristic of the resistance component of the living body with respect to the earth ground.

[0213] (4) The biosensor according to (3), wherein

[0214] the living body is a plant, and

[0215] the frequency of the predetermined AC signal is set to a frequency of 5 Hz or more and 3 MHz or less.

[0216] (5) The biosensor according to any one of (2) to (3), wherein

[0217] the predetermined AC signal has any one of a rectangular wave, a sinusoidal wave, and a triangular wave.

[0218] (6) The biosensor according to any one of (2) to (5), wherein

[0219] the signal generator includes a ground portion that provides a reference potential of the predetermined AC signal, and

[0220] the ground portion is electrically coupled to the living body.

[0221] (7) The biosensor according to any one of (2) to (5), wherein

[0222] the signal generator includes a ground portion that provides a reference potential of the predetermined AC signal, and

[0223] the ground portion is connected to the earth ground.

[0224] (8) The biosensor according to any one of (2) to (5), wherein

[0225] the signal generator includes a ground portion that provides a reference potential of the predetermined AC signal, and

[0226] The grounding part is in a state of being suspended from the earth's grounding voltage.

[0227] (9) A biosensor based on any one of (1) to (8), wherein

[0228] The power detection unit includes

[0229] A rectifier circuit that rectifies the AC power generated between the first antenna conductor and the second antenna conductor, and

[0230] A DC detection circuit is used to detect the DC power output from the rectifier circuit.

[0231] (10) Based on the biosensor in (9), where

[0232] A DC detection circuit is either a voltmeter that detects the output voltage of a rectifier circuit or a galvanometer that detects the output current of a rectifier circuit.

[0233] (11) Based on the biosensor in (9), where

[0234] A DC detection circuit is a voltmeter used to detect the output voltage of a rectifier circuit.

[0235] Adjust the internal resistor of the voltmeter to achieve the predetermined sensor sensitivity.

[0236] (12) Based on the biosensor in (11), where

[0237] The organisms are plants, and

[0238] The internal resistor of the voltmeter has a resistance value of 1kΩ or higher and 10MΩ or lower.

[0239] (13) A biosensor based on any one of (1) to (12), wherein

[0240] The organisms are plants, and

[0241] The second antenna conductor is attached to the above-ground part of the plant.

[0242] (14) Based on the biosensor in (13), where

[0243] The second antenna conductor has either a clip structure that presses the end portion of the second antenna conductor against the outside of the plant or a needle structure that inserts the end portion of the second antenna conductor into the inside of the plant.

[0244] (15) A biosensor based on any one of (1) to (3) and (5) to (11), wherein

[0245] a living body is a human or an animal, and

[0246] The second antenna conductor is attached to the body of a human or the body of an animal.

[0247] (16) The biosensor according to any one of (1) to (15), wherein

[0248] The first antenna conductor is provided to have a length corresponding to 1 / 4 of a wavelength of a predetermined AC component among the AC components induced in the living body.

[0249] (17) The biosensor according to any one of (1) to (16), wherein

[0250] The energy harvesting device is used as a power source.

[0251] (18) A living body management system, comprising:

[0252] at least one biosensor including

[0253] a first antenna conductor,

[0254] a second antenna conductor different from the first antenna conductor and electrically coupled to a living body connected to an earth ground directly or through a capacitive coupling, and

[0255] a power detection unit that detects AC power generated between the first antenna conductor and the second antenna conductor in accordance with a resistance component of the living body with respect to the earth ground; and

[0256] a management device that performs a management operation based on a detection result of the at least one biosensor.

[0257] List of Reference Numerals

[0258] 1 living body

[0259] 2 plant

[0260] 3 human body

[0261] 4 animal

[0262] 6 earth ground

[0263] 7 feeding point

[0264] 10 resistance component

[0265] 11 first antenna conductor

[0266] 12 second antenna conductor

[0267] 20 power detection unit

[0268] 21 rectifier circuit

[0269] 22 voltage meter

[0270] 25 signal generator

[0271] 27 ground terminal

[0272] 28 power supply

[0273] 45 internal resistor

[0274] 51 management device

[0275] 100, 200, 300 biosensor

[0276] 110 biosensor management system

Claims

1. A biosensor, comprising: First antenna conductor; The second antenna conductor is a different conductor from the first antenna conductor and is electrically coupled to an organism that is directly or capacitively connected to the earth ground. as well as A power detection unit detects the AC power generated between the first antenna conductor and the second antenna conductor based on the resistive component of the organism relative to the grounding of the earth.

2. The biosensor according to claim 1, further comprising: A signal generator that applies a predetermined AC signal to a first antenna conductor.

3. The biosensor according to claim 2, wherein... The frequency of the predetermined AC signal is set based on the frequency characteristics of the resistive component of the organism relative to the ground.

4. The biosensor according to claim 3, wherein... The organisms are plants, and The frequency of the predetermined AC signal is set to 5Hz or higher and 3MHz or lower.

5. The biosensor according to claim 2, wherein... The predetermined AC signal can be any of a rectangular wave, a sine wave, or a triangular wave.

6. The biosensor according to claim 2, wherein... The signal generator includes a grounded portion that provides a reference potential for a predetermined AC signal, and The grounding part is electrically coupled to the organism.

7. The biosensor according to claim 2, wherein... The signal generator includes a grounded portion that provides a reference potential for a predetermined AC signal, and The grounding part is connected to the earth ground.

8. The biosensor according to claim 2, wherein... The signal generator includes a grounded portion that provides a reference potential for a predetermined AC signal, and The grounding part is in a state of being suspended from the earth's grounding voltage.

9. The biosensor according to claim 1, wherein... The power detection unit includes A rectifier circuit that rectifies the AC power generated between the first antenna conductor and the second antenna conductor, and A DC detection circuit is used to detect the DC power output from the rectifier circuit.

10. The biosensor according to claim 9, wherein... A DC detection circuit is either a voltmeter that detects the output voltage of a rectifier circuit or a galvanometer that detects the output current of a rectifier circuit.

11. The biosensor according to claim 9, wherein... A DC detection circuit is a voltmeter used to detect the output voltage of a rectifier circuit. Adjust the internal resistor of the voltmeter to achieve the predetermined sensor sensitivity.

12. The biosensor of claim 11, wherein... The organisms are plants, and The internal resistor of the voltmeter has a resistance value of 1kΩ or higher and 10MΩ or lower.

13. The biosensor according to claim 1, wherein... The organisms are plants, and The second antenna conductor is attached to the above-ground part of the plant.

14. The biosensor according to claim 13, wherein... The second antenna conductor has either a contact structure that presses the end portion of the second antenna conductor against the outside of the plant or a needle structure that inserts the end portion of the second antenna conductor into the inside of the plant.

15. The biosensor according to claim 1, wherein... The organism is a human or an animal, and The second antenna conductor is attached to the human or animal body.

16. The biosensor according to claim 1, wherein... The first antenna conductor is configured to have a length corresponding to 1 / 4 of the wavelength of a predetermined AC component in the AC component induced in the organism.

17. The biosensor according to claim 1, wherein... The energy harvesting device is used as a power source.

18. A biological management system, comprising: At least one biosensor, including First antenna conductor, The second antenna conductor, which differs from the first antenna conductor, is electrically coupled to a living organism directly or capacitively connected to the earth's ground. A power detection unit that detects the AC power generated between the first antenna conductor and the second antenna conductor based on the resistance component of the organism relative to the ground. as well as A management device that performs management operations based on the detection results of the at least one biosensor.

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