KR20240088530A - Device for wirelessly transmitting power to neural signal processing device - Google Patents

Abstract

According to various embodiments, a wireless power transmission apparatus includes: a first antenna for power input; and a second antenna spaced upwardly from the first antenna by a predetermined first distance to amplify the power input, wherein the first antenna and the second antenna surround a cage accommodating an experimental animal. It has a shape, the second antenna is located at a point spaced upward by a predetermined second distance from the footrest of the cage for supporting the experimental animal, and the second antenna is located around the brain of the experimental animal. Power is transmitted wirelessly to a wireless power reception module, where the wireless power reception module may include a litz wire coil. Various other embodiments may also be possible.

Description

DEVICE FOR WIRELESSLY TRANSMITTING POWER TO NEURAL SIGNAL PROCESSING DEVICE}

Various embodiments of this document relate to a device for wirelessly transmitting power to a device embedded around the brain of a laboratory animal and processing neural signals.

The majority of information related to metabolic regulation, such as movement, sensation, language, learning, memory, and hormones, is concentrated in the brain, processed by the brain, and transmitted to each part of the body. The brain controls body mechanisms by providing electrical signals to each part of the body through the central nervous system. Animal behavior is caused by electrical signals provided by the brain, and there is a close relationship between electrical signals provided by the brain and animal behavior.

In analyzing animal behavior patterns, methods using electrical signals such as electroencephalogram (EEG), electrocortigram (ECoG), and local field potential can be used. In particular, local field potential refers to an electrical signal formed not only on the surface of the brain but also deep in the brain using a probe. It can be measured deep in the brain by cutting a part of the skull and infiltrating the exposed brain with a probe. At this time, by comparing the animal's behavior pattern with the nerve signal measured in the brain, changes in the nerve signal according to the animal's behavior pattern can be known.

Recently, in order to effectively analyze animal behavior patterns, there is a need to steadily and stably collect neural signals formed deep in the animal brain even when the animal is moving.

Meanwhile, as the efficiency of wireless power transmission technology has recently increased, wireless power transmission technology is being used in various fields. Wireless power transmission includes inductive charging, magnetic resonance, and electromagnetic wave methods. For example, wireless power transmission technology is applied to a bio-implantable neural signal processing device, collecting neural signals from a specific area (e.g. the brain) through a neural signal processing device inserted into the body and transmitting the processed signals to an external device. Meanwhile, the power required for neural signal processing devices can be solved using wireless power transmission technology.

(Non-patent Document 1) Document Name: Wright J, etc., A Fully Implantable Wireless Bidirectional Neuromodulation System for Mice. bioRxiv. doi: https://doi.org/10.1101/2021.06.02.446797, pp.1~17, published date: 2021.06.02 Korean Patent Publication No. 10-2021-0055610 (Title of invention: Reconfigurable modular wireless power transmission device, Publication date: 2021.05.17) Korean Patent No. 10-2469310 (Title of invention: Wireless power transmission device, electronic device that receives power wirelessly and method of operation thereof, Publication date: 2019.05.31)

Previously, in the process of collecting nerve signals deep in the animal brain, the nerve signals collected from the nerve signal processing device had to be transmitted by wire to an external electronic device, so there were time constraints on signal collection, and the nerve signals collected in the nerve signal processing device had to be transmitted to an external electronic device by wire. There is also a problem of limited power supply to various hardware of the signal processing device.

Various embodiments of the present invention provide a neural signal processing device that transmits collected neural signals to an external electronic device without noise using a low-power Bluetooth module and stably supplies power to various hardware using a wireless power receiving module. can do.

Various embodiments of the present invention can provide a wireless power transmission device capable of transmitting wireless power with high efficiency to a neural signal processing device using a power input antenna and a repeater antenna.

According to various embodiments, a device that is embedded around the brain of an experimental animal and processes neural signals includes a brain-insertable flexible probe (flexible) that is inserted into the brain and includes 32 electrodes for collecting 32 channels of neural signals. probe); A communication module including a Bluetooth Low Energy (BLE) module; A sensor module including an acceleration sensor; A wireless power reception module including a litz wire coil for wirelessly receiving power from a wireless power transmission device; A processor; and, while receiving power wirelessly through the Ritz wire coil, the processor acquires the 32 channels of nerve signals collected through the flexible probe, and selects a predetermined number of the 32 channels of nerve signals. Four channels of nerve signals can be selected according to a standard, and the four channels of nerve signals can be set to be transmitted to an external electronic device through the low-power Bluetooth module.

According to various embodiments, in a method of operating a neural signal processing device that is embedded around the brain of a laboratory animal and processes neural signals, the neural signal processing device is inserted into the brain to collect 32 channels of neural signals. A brain-implantable flexible probe containing 32 electrodes, a communication module including a Bluetooth Low Energy (BLE) module, a sensor module including an acceleration sensor, and REITs for wirelessly receiving power from a wireless power transmitter. A wireless power reception module including a litz wire coil, and a processor; and a method of operating a neural signal processing device, while receiving power wirelessly through the litz wire coil, using the processor: An operation of acquiring the 32 channels of nerve signals collected through the flexible probe, an operation of selecting 4 channels of nerve signals among the 32 channels of nerve signals according to a predetermined standard, and the 4 channels of nerve signals through the low-power Bluetooth module. It may include an operation of transmitting a neural signal to an external electronic device.

According to various embodiments, in a storage medium for storing computer-readable instructions, the instructions are embedded around the brain of an experimental animal and, when executed by a processor of a neural signal processing device that processes neural signals, Causes a neural signal processing device to perform at least one operation, wherein the neural signal processing device includes a brain-implantable flexible probe inserted into the brain and including 32 electrodes for collecting 32 channels of neural signals. ), a communication module including a low-power Bluetooth (BLE) module, a sensor module including an acceleration sensor, and a wireless power receiving module including a litz wire coil for wirelessly receiving power from a wireless power transmitting device. Comprising: the at least one operation: using the processor while receiving power wirelessly through the Ritz wire coil: acquiring the 32 channels of neural signals collected through the flexible probe, 32 It may include an operation of selecting nerve signals of four channels according to a predetermined standard among nerve signals of channels, and an operation of transmitting the nerve signals of four channels to an external electronic device through the low-power Bluetooth module.

According to various embodiments, a wireless power transmission apparatus includes: a first antenna for power input; and a second antenna spaced upwardly from the first antenna by a predetermined first distance to amplify the power input, wherein the first antenna and the second antenna surround a cage accommodating an experimental animal. It has a shape, the second antenna is located at a point spaced upward by a predetermined second distance from the footrest of the cage for supporting the experimental animal, and the second antenna is located around the brain of the experimental animal. Power is transmitted wirelessly to a wireless power reception module, where the wireless power reception module may include a litz wire coil.

According to various embodiments of the present invention, the neural signal processing device adopts a low-power Bluetooth module and a wireless power reception module to wirelessly transmit the collected neural signals to an external electronic device and stably supply power to various hardware, It allows researchers to collect and analyze neural signals related to various behaviors of laboratory animals without time constraints.

According to various embodiments of the present invention, a wireless power transmission device implements a first antenna for power input and a second antenna for amplifying the power input to have an appropriate distance interval, thereby enabling wireless power transmission with high efficiency in a neural signal processing device. It can provide the effect of transmitting power.

1 illustrates a neural signal processing system using wireless power transmission and reception according to various embodiments.
FIG. 2A shows the structure of a neural signal processing device according to various embodiments.
FIG. 2B shows an actual photograph of a neural signal processing device according to various embodiments and a photograph of the neural signal processing device embedded around the brain of a laboratory animal.
FIG. 3 illustrates an example in which a neural signal processing device operates according to various embodiments.
FIG. 4 illustrates the formats of a 4-channel neural signal and a 32-channel neural signal transmitted by a neural signal processing device to an external electronic device, according to various embodiments.
FIG. 5A shows the results of static evaluation of the noise removal performance of neural signal processing devices according to various embodiments.
Figure 5b shows the results of dynamic evaluation of the noise removal performance of neural signal processing devices according to various embodiments.
FIG. 5C shows neural signals collected by a neural signal processing device before and after a specific movement of a laboratory animal according to various embodiments.
Figure 6 shows the structure of a wireless power transmission device according to various embodiments.
FIG. 7 shows equivalent circuits of a first antenna and a second antenna of a wireless power transmission device according to various embodiments.
FIG. 8 is a graph showing a change in current generated in the second antenna according to a change in the coupling coefficient (k) between the first and second antennas according to various embodiments.
Figure 9 is a diagram to explain the difference between a solid coil and a litz coil and the difference between a Single-Tx structure and a Repeater-Tx structure according to various embodiments.
Figure 10 shows a concept diagram of a wireless power transmission device according to various embodiments.
Figure 11 shows a biodegradable nerve electrode needle inserted into the brain according to various embodiments.
Figure 12 shows a sugar-coated brain implantable flexible probe according to various embodiments.
Figure 13 shows a circuit diagram for measuring the change in impedance of an electrode according to coating according to various embodiments.
Figure 14 shows a graph of impedance change of a nerve electrode according to the biodegradation process according to various embodiments.
Figure 15 shows a graph of physical changes and impedance changes of a biodegradable nerve electrode needle according to brain tissue insertion time according to various embodiments.
In relation to the description of the drawings, identical or similar reference numerals may be used for identical or similar components.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. Examples of the present invention are provided to more completely explain the present invention to those with average knowledge in the art. Since the present invention can be subject to various changes and can have various forms, specific embodiments will be illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to a specific disclosed form, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention. When describing each drawing, similar reference numerals are used for similar components. In the attached drawings, the dimensions of the structures are enlarged or reduced from the actual size to ensure clarity of the present invention.

The terms used in this application are only used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that it does not exclude in advance the existence or possibility of addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having meanings consistent with the meanings they have in the context of the related technology, and unless clearly defined in the present application, should not be interpreted in an ideal or excessively formal sense. No.

FIG. 1 illustrates a neural signal processing system 100 using wireless power transmission and reception according to various embodiments.

According to various embodiments, the neural signal processing system 100 may include a neural signal processing device 101 and a wireless power transmission device 201. The neural signal processing system 100 collects neural signals generated in the brain of an experimental animal using the neural signal processing device 101, and transmits the collected neural signals to an external electronic device (e.g., computing device). An operation of analyzing the behavior of an experimental animal by transmitting a command to the neural signal processing device 101 may be sequentially performed. In particular, the neural signal processing device 101 may include a flexible probe that can be inserted into the brain of an experimental animal, and may collect neural signals occurring in the brain using a plurality of electrodes implemented in the flexible probe. there is. At this time, the neural signal processing device 101 may be implemented as a battery-free structure, and the power required for operation of the neural signal processing device 101 is supplied from the wireless power transmission device 201. Transmitted wireless power can be used. The wireless power transmission device 201 may include a first antenna 211 for power input and a second antenna 212 (eg, a repeater antenna) for amplifying the power input. A detailed description of the structure of the neural signal processing device 101 will be described later with reference to FIG. 2A, and a detailed description of the structure of the wireless power transmission device 201 will be described later with reference to FIG. 6.

FIG. 2A shows the structure of a neural signal processing device 101 according to various embodiments.

FIG. 2B shows an actual photograph of the neural signal processing device 101 according to various embodiments and a photograph of the neural signal processing device 101 embedded around the brain of an experimental animal.

According to various embodiments, the neural signal processing device 101, which is embedded around the brain of an experimental animal and processes neural signals, is inserted into the brain and includes 32 electrodes for collecting 32 channels of neural signals. An insertable flexible probe, a communication module including a Bluetooth Low Energy (BLE) module, a sensor module including an acceleration sensor, and a litz wire coil for wirelessly receiving power from a wireless power transmitter. It may include a wireless power reception module, and a processor operatively connected to the modules.

According to one embodiment, referring to FIG. 2A, the neural signal processing device 101 may be implemented in a stacked structure of the following components when implementing the product, and each component will be described in detail below. Meanwhile, referring to FIG. 2B, the neural signal processing device 101 may adopt a structure suitable for being embedded in the brain of an experimental animal.

1st Parylene-PDMS (111): Encapsulation layer of biocompatible material that prevents absorption of body fluids and biochemical reactions in a bioembedded environment and has soft physical properties

Full-wave rectifier (112): A circuit that receives wireless power and changes AC voltage to DC voltage.

Indicator LED (113): Red, Green LED that displays the status of the device

Super capacitor (114): A super capacitor with a large capacitance that maintains voltage so that the device can still operate when the height of the device is distant or the angle is wrong.

Circuit traces(115): Copper conductors on the PCB that make up the circuit

Polyimide substrate (116): A layer for electrical insulation between the conductors of the circuit and other layers.

Litz wire coil (117): A wireless power receiving coil made of Litz wire that increases wireless power efficiency and softens mechanical properties.

Flexible ferrite (118): A soft magnetic material layer to increase the efficiency of wireless power reception by guiding the magnetic field and increasing the amount of magnetic flux passing inside the coil.

Copper magnetic shield (119): A thin magnetic field protection layer made of copper to prevent EMI noise in the circuit caused by strong magnetic fields.

Electrical ground plane (120): A wide electrical ground layer made of copper to effectively remove noise originating from the input terminal and circuit.

Polyimide substrate (121): A layer for electrical insulation between the conductors of the circuit and other layers.

Circuit traces(122): Layer for efficient radiation of electrical conductors and Bluetooth RF signals that make up the circuit

BLE microcontroller unit(123): Bluetooth low-power microcontroller

3-axis accelerometer(124): 3-axis accelerometer IC

Neural signal amplifier (125): IC for amplifying cranial nerve signals

RFI filter components (126): Filter elements made up of R and C to remove RF noise flowing from the input terminal.

2nd Parylene-PDMS (127): Encapsulation layer of biocompatible material that prevents absorption of body fluids and biochemical reactions in a bioembedded environment and has soft physical properties

Brain implantable flexible probe (130): A device inserted into the brain of an experimental animal to collect 32 channels of neural signals

According to one embodiment, referring to FIG. 2A, the flexible probe 130 may include the following components.

3D porous electrode (131): 3D porous electrode to lower the electrochemical impedance of nerve electrodes

32Ch electrode(132): Electrodes consisting of 32 channels to measure signals from various parts of the brain area

Encapsulant (133): A layer for electrical insulation between electrodes, conductors, and biological tissues.

Biodegradable needle (134): A soluble needle made of a material that temporarily maintains hardness in order to place a flexible, long nerve electrode probe in a target area deep in the brain and melts and disappears in the body.

According to one embodiment, the processor included in the neural signal processing device 101, for example, executes software (e.g., a program) to execute at least one other component of the neural signal processing device 101 connected to the processor ( e.g. hardware or software components) and can perform various data processing or computations. According to one embodiment, as at least part of data processing or computation, the processor stores instructions or data received from another component (e.g., a sensor module or communication module) in a volatile memory, and stores the instructions or data stored in the volatile memory. It can be processed and the resulting data can be stored in non-volatile memory. According to one embodiment, the processor may include a main processor (eg, a central processing unit or an application processor) or an auxiliary processor (eg, a sensor hub processor or a communication processor) that can operate independently or together with the main processor. For example, when a neural signal processing device includes a main processor and a co-processor, the co-processor may be set to use less power than the main processor or to specialize in a designated function. The auxiliary processor may be implemented separately from the main processor or as part of it. According to one embodiment, the BLE microcontroller unit 123 may be implemented as an example of a processor of the neural signal processing device 101.

According to one embodiment, the sensor module included in the neural signal processing device 101 detects the operating state of the neural signal processing device 101 or the external environmental state, and electrical signals or data values corresponding to the detected state. can be created. According to one embodiment, the sensor module may include, for example, an acceleration sensor, a gyro sensor, a biometric sensor, or a temperature sensor.

According to one embodiment, the communication module included in the neural signal processing device 101 is configured to establish a communication channel between the neural signal processing device 101 and an external electronic device (e.g., a computing device or an external server), and the established communication channel. It can support communication through . According to one embodiment, the low-power Bluetooth module may be implemented as an example of a communication module of the neural signal processing device 101.

According to one embodiment, the wireless power reception module included in the neural signal processing device 101 may include a Litz wire coil 117, a rectifier circuit, and a converter. The power generated from the power source of the wireless power transmission device is transmitted to the Litz wire coil 117 through the resonance coil of the wireless power transmission device, and resonates with the resonance coil by a self-resonance phenomenon, that is, the wireless power having the same resonance frequency value It is transmitted to the power receiving module. The power delivered to the wireless power receiving module is transferred to various hardware of the neural signal processing device 101 through a rectifier circuit and converter. The rectifier circuit can rectify alternating current power into direct current power, and the converter can convert direct current power into a required voltage and provide it to various hardware. Power transmission by magnetic resonance is a phenomenon in which power is transmitted between two LC circuits with matched impedances, and can transmit power over a longer distance with higher efficiency than power transmission by electromagnetic induction. According to one embodiment, the Litz wire coil 117 may be composed of individual insulated wires twisted or braided in a uniform pattern, which has the primary advantage of reducing AC losses in high frequency windings. . The reason for using the Litz wire coil 117 is to increase the surface area because the time-varying current due to the skin effect has the property of flowing only toward the surface of the wire, so the current hardly flows in the center of the wire. Since the surface area can be expanded while preventing the skin effect of the wire, the resistance component of the coil can be prevented from increasing.

FIG. 3 illustrates an example in which a neural signal processing device (eg, the neural signal processing device 101 of FIG. 1 ) operates according to various embodiments.

According to various embodiments, the neural signal processing device 101 collects 32 channels of neural signals through 32 electrodes of a flexible probe (e.g., flexible probe 130 in FIG. 2) inserted into the brain of an experimental animal. You can. The neural signal processing device 101 can amplify a small voltage signal in uV units through the neural signal amplifier 125, remove RF noise through RFI filter components 126, and perform analog-to-digital converter (ADC). Digital signals can be converted through a digital converter. The neural signal processing device 101 may transmit data converted into a digital signal to a processor (eg, BLE MCU).

According to one embodiment, referring to FIG. 3, the processor of the neural signal processing device 101 may transmit 32 channels of neural signals to an external electronic device (e.g., a personal computer or smartphone) through a low-energy Bluetooth module. .

According to one embodiment, referring to FIG. 3, the processor of the neural signal processing device 101 may select 4-channel neural signals from 32-channel neural signals according to a predetermined standard. According to one embodiment, the processor may check a request to select four specific channels from a user command generated from an external electronic device and select neural signals of four channels based on the request. According to one embodiment, the processor can check the number of spikes during a specific time for the 32-channel neural signal, and divides the 4-channel signals in the order of the number of spikes (i.e., the order of the most active areas) during a specific time. Neural signals can be selected. At this time, the 4-channel neural signal may be in the form of a raw signal. An external electronic device that receives the four-channel nerve signal can analyze the signal using a technique such as spike sorting, which determines the level of activity of the nerve signal.

During the process of performing the above-described operation, the neural signal processing device 101 may wirelessly receive power from a wireless power transmission device (e.g., the wireless power transmission device 201 of FIG. 1), and use the received power as It can be supplied to various hardware within the neural signal processing device 101. Specifically, in the wireless power reception process, wireless power transmitted from the repeater antenna system may be received through the Litz wire coil 117 of the wireless power reception module, a rectifier in the neural signal processing device 101, and A stable DC voltage of 3.3V can be supplied to the neural signal processing device 101 through a regulator.

FIG. 4 illustrates the formats of a 4-channel neural signal and a 32-channel neural signal transmitted by a neural signal processing device (e.g., the neural signal processing device 101 of FIG. 1) to an external electronic device, according to various embodiments.

According to various embodiments, the processor of the neural signal processing device 101 may transmit a 4-channel neural signal or a 32-channel neural signal to an external electronic device through a low-power Bluetooth module. According to one embodiment, the processor may allocate a size of 2 bytes per cycle to the neural signal of each channel. For example, referring to FIG. 4, the processor may allocate a high byte (1 byte) and a low byte (1 byte) to the first to fourth channels, respectively. According to one embodiment, referring to FIG. 4, the processor calculates acceleration sensor data (ACC A size of 4 bytes can be allocated to the level).

According to one embodiment, when transmitting a 4-channel neural signal to an external electronic device, the processor transmits one packet with a size of 244 bytes including 30 cycles of the neural signal, acceleration sensor data, and voltage value. can do. For example, referring to FIG. 4, the processor generates 30 cycles of data for 4-channel neural signals with a size of 8 bytes per cycle, acceleration sensor data and voltage value data with a size of 4 bytes. It can be created as one packet with a size of 244 bytes and transmitted to an external electronic device.

According to one embodiment, when transmitting a 32-channel neural signal to an external electronic device, the processor transmits one packet with a size of 196 bytes including 3 cycles of the neural signal, acceleration sensor data, and voltage value. can do. For example, referring to FIG. 4, the processor generates 3 cycles of data, 4 bytes of acceleration sensor data, and voltage value data for 32-channel neural signals with a size of 64 bytes per cycle. It can be created as one packet with a size of 196 bytes and transmitted to an external electronic device.

According to one embodiment, the 4-channel neural signal may be a raw signal composed only of AP (Action Potential) or AP and LFP (Local Field Potential), and the 32-channel neural signal may be a raw signal composed only of LFP. .

FIG. 5A shows the results of static evaluation of the noise removal performance of a neural signal processing device (e.g., the neural signal processing device 101 of FIG. 1) according to various embodiments.

FIG. 5B shows the results of dynamic evaluation of the noise removal performance of the neural signal processing device 101 according to various embodiments.

FIG. 5C shows neural signals collected by the neural signal processing device 101 before and after a specific movement of an experimental animal according to various embodiments.

5A and 5B show stable operation and signals of the signal processing device 101 when wireless power is transmitted in various situations by inputting signals simulating brain nerve signals using equipment called FB128 to the neural signal processing device 101 before animal experiments. It shows the results of an experiment conducted to determine the level of noise.

Referring to FIG. 5A, under wireless power transmission by a wireless power transmission device (e.g., the wireless power transmission device 201 of FIG. 1), the height of the neural signal processing device 101 is measured based on the repeater antenna 212. You can see the configuration and signal results of the experiment to check whether signal measurement and Bluetooth communication are working well. With the neural signal processing device 101 fixed at each height within the range of -20cm to +40cm, it can be confirmed that the neural signal processing device 101 receives sufficient wireless power and measures the signal well without the influence of noise. .

Referring to FIG. 5B, the experiment is the same as the situation in FIG. 5A, but the signal is measured while moving the neural signal processing device 101 at slow and fast speeds within the range of -20 cm to +40 cm, assuming that the actual experimental animal is moving. Shows one result. It can be confirmed that the neural signal processing device 101 operates stably without generating noise depending on movement and speed even in moving situations.

Referring to FIG. 5C, it can be seen that the neural signal processing device 101 according to the present invention properly supplies power and stably transmits neural signal data to an external electronic device under wireless power transmission. Specifically, signal analysis can be performed using techniques such as spike sorting, which stably collects nerve signals before and after a laboratory animal eats food, receives the data from an external electronic device, and determines the level of activity of the nerve signals. .

FIG. 6 illustrates the structure of a wireless power transmission device (eg, the wireless power transmission device 201 of FIG. 1) according to various embodiments.

According to various embodiments, the wireless power transmission device 201 includes a first antenna 211 for power input and a second antenna 211 spaced upward by a predetermined first distance from the first antenna to amplify the power input. It may include an antenna 212. For example, referring to FIG. 6, the second antenna 212 moves upward by a predetermined first distance d1 from the first antenna 211 in order to generate a high current value in relation to the first antenna 211. It may be spaced apart and installed in the wireless power transmission device 201. The first antenna 211 and the second antenna 212 have a shape surrounding a cage 213 for accommodating the experimental animal, and the second antenna 212 is in contact with the experimental animal to use the experimental animal. It is located at a point spaced upward by a predetermined second distance from the footrest of the cage 213 for supporting the animal, and the second antenna 212 is a wireless power reception module located around the brain of the experimental animal. Power is transmitted wirelessly, and the wireless power reception module may include a litz wire coil. According to one embodiment, the second antenna 212 may be located within a third predetermined distance from the central point of the cage 213. For example, referring to FIG. 6, the second antenna 212 is used to transmit high wireless power to the neural signal processing device 101 embedded in the head of an experimental animal in relation to the neural signal processing device 101. It may be located at a point spaced apart by a specific distance d2 from the center point of the cage 213 within a predetermined third distance from the center point of the cage 213.

FIG. 7 shows a first antenna (e.g., the first antenna 211 of FIG. 1) and a second antenna (e.g., the wireless power transmission device 201 of FIG. 1) according to various embodiments. : shows the equivalent circuit of the first antenna 212 in FIG. 1.

FIG. 8 is a graph showing a change in current generated in the second antenna 212 according to a change in the coupling coefficient (k) between the first antenna 211 and the second antenna 212 according to various embodiments.

Parameters that can be derived from the equivalent circuit of FIG. 7 may be as follows. At this time, the Tx antenna refers to the first antenna 211, and the repeater antenna refers to the second antenna 212.

= Current flowing in Tx antenna

= Current flowing in the repeater antenna

= Total resistance of Tx antenna system (Rs+Rtp)

= Total resistance of the repeater antenna system

= output resistance of power source

= Resistance of Tx antenna coil

= Voltage supplied to Tx antenna

= Inductance of Tx antenna

= Inductance of repeater antenna

= Capacitance of the capacitor to match the resonant frequency of the Tx antenna

= Capacitance of the capacitor to match the resonance frequency of the repeater antenna

= Coupling coefficient between Tx antenna and Repeater antenna

= resonant frequency

According to one embodiment, the current (Itx) flowing through the first antenna 211 and the current (Irep) flowing through the second antenna 212 may be calculated according to [Equation 1] below.

Regarding the parameters of [Equation 1], the newly added parameters may be as follows.

= Quality factor of Tx antenna

= Quality factor of repeater antenna

According to one embodiment, k can be calculated according to [Equation 2] below.

M represents the mutual inductance of Ltx and Lrep.

Referring to <801> in FIG. 8, the wireless power transmission device 201 according to the present invention adopts both the first antenna 211 and the second antenna 212 (Repeater-Tx structure), so that the first antenna ( Compared to the Single-Tx structure that only adopts 211), it can be seen that the wireless power transmission efficiency is high in a specific region (critically-coupled region) of the k value.

According to one embodiment, the distance d between the first antenna 211 and the second antenna 212 is greater than the current flowing through the first antenna 211 (Itx). It may be a distance that has a k value that generates a higher Irep). According to one embodiment, the distance d between the first antenna 211 and the second antenna 212 may be a distance that has a k value that generates the maximum value of Irep. Referring to <802> and <803> of FIG. 8, the k value can be adjusted by adjusting the distance (d) between the first antenna 211 and the second antenna 212, and when there is an appropriate distance ( That is, when the k value is in an appropriate range), the Repeater-Tx structure adopting both the first antenna 211 and the second antenna 212 has a larger current than the Single-Tx structure adopting only the first antenna 211. It can be seen that a stronger magnetic field is generated. At this time, normalized B means normalized magnetic flux density. Specifically, referring to <802>, it can be seen that a stronger magnetic field is generated in the Repeater-Tx structure compared to the Single-Tx structure at the k value when the distance between the first antenna 211 and the second antenna 212 is 80 cm. Able to know.

According to one embodiment, the wireless power transmission device 201 may adopt an Rtx of 50 ohms and an Rrep of less than 10 ohms to increase power transmission efficiency.

Figure 9 is a diagram to explain the difference between a solid coil and a litz coil and the difference between a Single-Tx structure and a Repeater-Tx structure according to various embodiments.

Figure 9(a) is a graph showing the degree of wireless power reception according to the shape of the receiving unit coil in the case of a repeater antenna. A Litz coil is a coil made up of 100 thin wires bundled together. A solid coil is wound with a wire with the same diameter as the Litz coil, but consists of one thick wire. A planar coil is a coil made up of a thin pattern on a PCB. represents. In terms of reception efficiency, it can be seen that Planar coil is the worst, and Solid coil and Litz coil show similar wireless power reception performance. However, referring to (b) of Figure 9, in the case of the Solid coil, it is made of a single thick conductor, so it has high mechanical rigidity and does not bend, but on the other hand, the Litz coil is made of 100 thin strands, so it is mechanically strong. Since the rigidity is relatively weak and can be bent, it can be seen that the soft and bendable Litz coil has an advantage when used as a wireless power receiving coil for an implantable device.

Figures 9 (c) and (d) show the output voltage of the receiving coil according to the height from the antenna in the case of the Single-Tx structure and the Repeater-Tx structure, respectively, according to the size of the load (0.1k, 1k, 10k ohm). This is a graph shown accordingly. Overall, it can be seen that the repeater antenna can transmit greater power to a relatively high point. The height area shaded in green represents the range in which the Amplifier IC for measuring neural signals in the circuit of the neural signal processing device 101 can operate, and represents the area where the received voltage in the circuit is 3.2V or more. The height area shaded in blue represents the range in which the BLE MCU can operate in the circuit of the neural signal processing device 101, and represents the area where the received voltage in the circuit is 1.7V or more. For example, selecting a monkey as an experimental animal means that the neural signal processing device 101 must operate up to a height of about 30 cm, and only when a repeater antenna is used, wireless power transmission over a wider area is possible, making monkey experiments possible. You can see that it is possible.

FIG. 10 shows a concept diagram of a wireless power transmission device 201 according to various embodiments.

The wireless power transmission device 201 according to an embodiment may be designed and implemented in various ways, as shown in FIG. 10. Referring to FIG. 10 according to one embodiment, the second antenna 212 is located at a point spaced upward by a predetermined second distance d3 from the footrest 214 of the cage 213 for supporting the experimental animal. You can.

Figure 11 shows a brain-implantable flexible probe inserted into the brain according to various embodiments.

The brain-insertable flexible probe 130 according to one embodiment may be coated with a biodegradable material and have different rigidity before and after being inserted into the brain.

The biodegradable material may include sugar. However, it is not limited to this, and any biodegradable material that can maintain a certain shape until it is inserted into the brain is sufficient.

According to one embodiment, referring to FIG. 11, the brain-insertable flexible probe maintains its sugar-coated appearance when inserted into the brain. Afterwards, sugar, a biodegradable substance, dissolves in the brain over time. When the sugar is dissolved, the 3D porous electrode and 32-channel electrode within the brain-implantable flexible probe can receive signals from the cranial nerves.

Figure 12 shows a sugar-coated brain implantable flexible probe according to various embodiments.

The outside of the brain-insertable flexible probe according to one embodiment may be coated with a biodegradable material in a U-shape. Referring to Figure 12, the brain-insertable flexible probe has excellent rigidity as sugar, a biodegradable material, is dissolved, changing from a rigid form to a soft form, which has the effect of preventing damage to the brain. .

By coating the outside of the brain implantable flexible probe with sugar, a U-shaped biodegradable material, the bending rigidity of the brain implantable flexible probe can be increased while the cross-sectional area can be minimized. This has the effect of allowing the brain-insertable flexible probe to be inserted into the desired area when inserted into the brain. Once inserted into the brain, the flexible probe has the effect of reducing brain damage as the biodegradable material becomes mushy upon recording.

Figure 13 shows a circuit diagram for measuring the change in impedance of an electrode according to coating according to various embodiments.

Changes in the impedance of the electrode that change as the biodegradable material coated on the brain-insertable flexible probe according to various embodiments decompose in the brain were measured.

Figure 13 shows a circuit diagram for measuring the change in impedance of an electrode according to coating according to various embodiments.

<Conditions>

Agarose gel

1mM PBS

pH: 7.4

Electrochemical impedance spectroscopy

Open circuit delay: 120 seconds

Sine wave AC: 10 mV

Direct current component (offset DC): 0 V

Electrode size: 300㎛ ²

The change in electrode impedance was measured using Equation 3 below.

Z _a-e' : Value of Amplifier input impedance

Z _e' : Value of effective electrode impedance

V _e' : Voltage value applied to resistance Z _a-e'-

V _e : Voltage value across the entire resistance

The signal loss before and after the biodegradable material was dissolved was measured according to Equation 3 above.

Z _e' value is 1M When Ω (at 1kHz), signal loss occurred about 7%. In contrast,

Z _e' value is 3M At Ω (at 1kHz), signal loss occurred at approximately 19%. Through this, it was confirmed that the larger the resistance value, the more signal loss occurs.

According to various embodiments, the 32-channel electrode may be made of polystyrene, platinum, and iridium oxide. The electrode may have a macro-porous structure. This has the effect of reducing the resistance of the electrode.

Figure 14 shows a graph of impedance change of a nerve electrode according to the biodegradation process according to various embodiments.

According to one embodiment, the electrode impedance within the brain-insertable flexible probe had the effect of lowering the impedance over time as the coated biodegradable material was directly exposed to the brain during recording.

Referring to Figure 14, the impedance of the electrode 7 minutes after being inserted into the brain at 1 kHz is 1.505M. Ω, but it was confirmed that the impedance of the electrode 28 minutes after being inserted into the brain was 1.121 MΩ, which lowered the impedance by about 25%.

Figure 15 shows a graph of physical changes and impedance changes of a nerve electrode according to brain tissue insertion time according to various embodiments.

Referring to Figure 15, it can be seen that the rigidity of the brain-insertable flexible probe before being inserted into the brain tissue is in a rigid form, and that the rigidity is in a soft form as the biodegradable material is recorded after being inserted into the brain tissue. You can check it.

In addition, the electrochemical impedance of the electrode before insertion into the brain tissue was ^10-4 kΩ, but after insertion into the brain tissue, the electrochemical impedance of the electrode decreased to 10 ² kΩ.

Through this, it is possible to check the stiffness of the brain-inserted flexible probe and the change in electrochemical impedance of the electrode depending on the brain tissue insertion time.

According to various embodiments, a device that is embedded around the brain of an experimental animal and processes neural signals includes a brain-insertable flexible probe (flexible) that is inserted into the brain and includes 32 electrodes for collecting 32 channels of neural signals. probe); A communication module including a Bluetooth Low Energy (BLE) module; A sensor module including an acceleration sensor; A wireless power reception module including a litz wire coil for wirelessly receiving power from a wireless power transmission device; A processor; and, while receiving power wirelessly through the Ritz wire coil, the processor acquires the 32 channels of nerve signals collected through the flexible probe, and selects a predetermined number of the 32 channels of nerve signals. Four channels of nerve signals can be selected according to a standard, and the four channels of nerve signals can be set to be transmitted to an external electronic device through the low-power Bluetooth module.

According to various embodiments, the processor may be further configured to transmit the 32-channel neural signal to the external electronic device through the low-power Bluetooth module.

According to various embodiments, the processor determines the number of spikes for the 32-channel nerves during a specific time, and, as the predetermined standard, selects the 4 channels in the order of the highest number of spikes during the specific time. It can be set to select neural signals.

According to various embodiments, the neural signal processing device further includes a neural signal amplifier, and the processor selects the four-channel neural signal having a raw signal form according to the predetermined standard. It can be set to control the neural signal amplifier to do so.

According to various embodiments, the 4-channel neural signal is a raw signal composed only of AP (Action Potential) or AP and LFP (Local Field Potential), and the 32-channel neural signal is a raw signal composed only of LFP. You can.

According to various embodiments, the flexible probe may include a three-dimensional porous electrode to lower the electrochemical impedance of the 32 electrodes.

According to various embodiments, the processor allocates a size of 2 bytes per cycle to the neural signal of each channel, and calculates the acceleration sensor data obtained through the acceleration sensor and the power received through the wireless power receiving module. A size of 4 bytes is assigned to the voltage value, and when transmitting the 32-channel neural signal to the external electronic device, 3 cycles of the neural signal, the acceleration sensor data, and the voltage value are included to create a size of 196 bytes. When transmitting one packet having and transmitting the 4-channel neural signal to the external electronic device, one packet having a size of 244 bytes including 30 cycles of the neural signal, the acceleration sensor data, and the voltage value can be set to transmit.

According to various embodiments, in a method of operating a neural signal processing device that is embedded around the brain of a laboratory animal and processes neural signals, the neural signal processing device is inserted into the brain to collect 32 channels of neural signals. A brain-implantable flexible probe containing 32 electrodes, a communication module including a Bluetooth Low Energy (BLE) module, a sensor module including an acceleration sensor, and REITs for wirelessly receiving power from a wireless power transmitter. A wireless power reception module including a litz wire coil, and a processor; and a method of operating a neural signal processing device, while receiving power wirelessly through the litz wire coil, using the processor: An operation of acquiring the 32 channels of nerve signals collected through the flexible probe, an operation of selecting 4 channels of nerve signals among the 32 channels of nerve signals according to a predetermined standard, and the 4 channels of nerve signals through the low-power Bluetooth module. It may include an operation of transmitting a neural signal to an external electronic device.

According to various embodiments, the method may further include transmitting the 32-channel neural signal to the external electronic device through the low-power Bluetooth module.

According to various embodiments, the operation of selecting the 4-channel nerve signal is an operation of checking the number of spikes during a specific time for the 32-channel nerve, and, as the predetermined standard, the spike during the specific time. It may include an operation of selecting the neural signals of the four channels in the order of the largest number.

According to various embodiments, the operation of selecting the four-channel neural signal may include controlling the neural signal amplifier to select the four-channel neural signal having a raw signal form according to the predetermined standard. You can.

According to various embodiments, the method includes an operation of allocating a size of 2 bytes per cycle to the neural signal of each channel, and acceleration sensor data acquired through the acceleration sensor and received through the wireless power reception module. It further includes an operation of allocating a size of 4 bytes to the voltage value of the generated power, and the operation of transmitting the 32-channel neural signal to the external electronic device includes transmitting the 32-channel neural signal to the external electronic device. An operation of transmitting one packet with a size of 196 bytes including 3 cycles of neural signals, the acceleration sensor data, and the voltage value, and transmitting the 4-channel neural signals to the external electronic device. The operation of transmitting the 4-channel neural signal to the external electronic device includes transmitting one packet with a size of 244 bytes including 30 cycles of the neural signal, the acceleration sensor data, and the voltage value. may include.

According to various embodiments, in a storage medium for storing computer-readable instructions, the instructions are embedded around the brain of an experimental animal and, when executed by a processor of a neural signal processing device that processes neural signals, Causes a neural signal processing device to perform at least one operation, wherein the neural signal processing device includes a brain-implantable flexible probe inserted into the brain and including 32 electrodes for collecting 32 channels of neural signals. ), a communication module including a low-power Bluetooth (BLE) module, a sensor module including an acceleration sensor, and a wireless power receiving module including a litz wire coil for wirelessly receiving power from a wireless power transmitting device. Comprising: the at least one operation: using the processor while receiving power wirelessly through the Ritz wire coil: acquiring the 32 channels of neural signals collected through the flexible probe, 32 It may include an operation of selecting nerve signals of four channels according to a predetermined standard among nerve signals of channels, and an operation of transmitting the nerve signals of four channels to an external electronic device through the low-power Bluetooth module.

According to various embodiments, a wireless power transmission apparatus includes: a first antenna for power input; and a second antenna spaced upwardly from the first antenna by a predetermined first distance to amplify the power input, wherein the first antenna and the second antenna surround a cage accommodating an experimental animal. It has a shape, the second antenna is located at a point spaced upward by a predetermined second distance from the footrest of the cage for supporting the experimental animal, and the second antenna is located around the brain of the experimental animal. Power is transmitted wirelessly to a wireless power reception module, where the wireless power reception module may include a litz wire coil.

According to various embodiments, the predetermined first distance is a distance that has a k value that generates a second current (Irep) flowing through the second antenna higher than a first current (Itx) flowing through the first antenna. , the first current and the second current can each be calculated by Equation 1 below.

[Equation 1]

= Total resistance of the Tx antenna (the first antenna)

= Total resistance of the repeater antenna (the second antenna)

= Voltage supplied to Tx antenna

= Inductance of Tx antenna

= Inductance of repeater antenna

= Coupling coefficient between Tx antenna and Repeater antenna

= resonant frequency

= Quality factor of Tx antenna

= Quality factor of repeater antenna

According to various embodiments, the predetermined first distance may be a distance that has a k value that generates the maximum value of the second current.

According to various embodiments, the Rtx may be 50 ohms and the Rrep may be less than 10 ohms.

According to various embodiments, the second antenna may be located within a third predetermined distance from the central point of the cage.

The various embodiments of this document and the terms used herein are not intended to limit the technical features described in this document to specific embodiments, but should be understood to include various changes, equivalents, or replacements of the embodiments. In connection with the description of the drawings, similar reference numbers may be used for similar or related components. The singular form of a noun corresponding to an item may include one or more of the items, unless the relevant context clearly indicates otherwise. As used herein, “A or B”, “at least one of A and B”, “at least one of A or B”, “A, B or C”, “at least one of A, B and C”, and “A Each of phrases such as “at least one of , B, or C” may include any one of the items listed together in the corresponding phrase, or any possible combination thereof. Terms such as "first", "second", or "first" or "second" may be used simply to distinguish one component from another, and to refer to those components in other respects (e.g., importance or order) is not limited. One (e.g., first) component is said to be “coupled” or “connected” to another (e.g., second) component, with or without the terms “functionally” or “communicatively.” Where mentioned, it means that any of the components can be connected to the other components directly (e.g. wired), wirelessly, or through a third component.

100: Neural signal processing system using wireless power transmission and reception
101: neural signal processing device, 201: wireless power transmission device
211: first antenna, 212: second antenna

Claims (5)

In the wireless power transmission device,
a first antenna for power input; and
It includes a second antenna spaced upwardly from the first antenna by a predetermined first distance to amplify the power input,
The first antenna and the second antenna have a shape surrounding a cage accommodating experimental animals,
The second antenna is located at a point spaced upward by a predetermined second distance from the footrest of the cage for supporting the experimental animal,
The second antenna wirelessly transmits power to a wireless power reception module, wherein the wireless power reception module is located at the top of the brain of the experimental animal and includes a litz wire coil,
The predetermined first distance is a distance that has a k value that causes the second current (I _REP ) flowing through the second antenna to be higher than the first current (I _TX ) flowing through the first antenna,
Wireless power transmission device.
According to claim 1,
The first current and the second current are each calculated by Equation 1 below,
Wireless power transmission device.
[Equation 1]


= Total resistance of the Tx antenna (the first antenna)
= Total resistance of the repeater antenna (the second antenna)
= Voltage supplied to Tx antenna
= Inductance of Tx antenna
= Inductance of repeater antenna
k = coupling coefficient between Tx antenna and Repeater antenna
= resonant frequency
= Quality factor of Tx antenna
= Quality factor of repeater antenna
According to clause 2,
The predetermined first distance is a distance that has a k value that generates the maximum value of the second current,
Wireless power transmission device.
According to clause 3,
The R _TX is 50 ohms, and the R _REP is less than 10 ohms,
Wireless power transmission device.
According to claim 1,
The second antenna is located within a third predetermined distance from the central point of the cage,
Wireless power transmission device.