Portable frontotemporal lobe electroencephalogram acquisition system and method
Through a portable EEG acquisition system using FPC flexible dry electrodes and input impedance lifting unit, the problem of wearable EEG devices compatibility with signal accuracy is solved, long-term, high-quality EEG signal acquisition and monitoring is achieved, and application scenarios are expanded.
Patent Information
- Application Number
- CN202510930826.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-07
- Publication Date
- 2025-08-15
AI Technical Summary
Existing portable EEG devices are difficult to take into account wear comfort and signal accuracy, especially the problem of high contact impedance between dry electrodes and skin, resulting in a decrease in measurement accuracy.
The FPC flexible dry electrode and input impedance lifting unit are adopted, combined with the analog filtering unit, signal amplification unit and analog-to-digital conversion unit, and the integrated design of elastic and elastic intelligent headbands can achieve comfortable and disturbance-free EEG signal acquisition and accurate transmission.
It realizes long-term and high-quality EEG signal acquisition, expands the application scenarios of EEG monitoring, is suitable for communities and families, and reduces user burden.
Smart Images
Figure CN120477785A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of portable brain health monitoring, and in particular relates to a portable frontotemporal lobe electroencephalogram (EEG) acquisition system and method. Background Art
[0002] Brain science is the ultimate frontier of human science, and understanding the structure and function of the brain is one of the most challenging frontier scientific issues of the 21st century. EEG signals, a neurophysiological signal that reflects the collective electrical activity of brain neurons, contain rich information about brain activity and demonstrate enormous potential for application in fields such as disease monitoring, emotion recognition, fatigue detection, and brain-computer interfaces. They are of great significance in brain science research and applications.
[0003] Currently, the mainstream clinical EEG monitoring method is whole-brain EEG monitoring. This type of EEG equipment uses wet electrodes and requires the injection of conductive gel. The operation is cumbersome and time-consuming. The equipment is bulky and has limited application scenarios. At the same time, it suffers from poor user comfort and low user cooperation. Therefore, it is only suitable for short-term monitoring in hospital clinical settings or laboratory settings. In recent years, with the expansion of EEG monitoring scenarios and the increasing demand for long-term EEG monitoring, portable and wearable EEG acquisition devices have become a research hotspot.
[0004] However, current portable EEG devices have compatibility issues between wearing comfort and signal accuracy. Mainstream sensing electrodes for EEG devices mainly include wet electrodes and dry electrodes. Wet electrodes have good contact conditions with the scalp and high signal accuracy, but are less comfortable for long-term monitoring. Dry electrodes have good contact comfort with the skin, but the contact impedance between the dry electrodes and the scalp is high. After the contact impedance is divided by the input impedance of the subsequent acquisition circuit, the accuracy of EEG signal measurement is reduced, affecting subsequent data analysis and practical applications. Therefore, portable EEG acquisition systems that balance comfort and accuracy will remain a focus of future attention. Summary of the Invention
[0005] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a portable frontotemporal EEG acquisition system and method, aiming to solve the pain point problem that the portable EEG acquisition system in the prior art cannot take into account both wearing comfort and signal accuracy.
[0006] In order to achieve the above object, the present invention adopts the following technical solutions:
[0007] A portable frontotemporal EEG acquisition system comprises a signal sensing module, a signal processing module, a signal control module, a signal transmission module, a power supply module and a back-end data processing module; wherein the signal sensing module comprises an EEG electrode unit and an input impedance enhancement unit connected to the EEG electrode unit; the signal processing module comprises an analog filtering unit, a signal amplification unit, a right leg drive unit and an analog-to-digital conversion unit connected to the input impedance enhancement unit; the signal control module comprises a microcontroller unit connected to the signal processing module; the signal transmission module comprises a Bluetooth unit connected to the microcontroller unit; the power supply module comprises an analog power supply unit and a digital power supply unit for supplying power to each module; the back-end data processing module comprises a digital filtering unit and an artifact removal unit of a host computer; the frontotemporal EEG signals are acquired by the signal sensing module, and then the signal processing module performs signal preprocessing such as filtering, amplification, and analog-to-digital conversion, and then transmits the data to the host computer through the Bluetooth unit of the signal transmission module under the control of the signal control module, and the host computer further performs back-end data processing to obtain high-quality EEG data.
[0008] Furthermore, the EEG electrode unit utilizes flexible dry electrodes (FPCs), which are made of gold and polyimide as a substrate. These electrodes combine material flexibility, stability, and conductivity, enabling comfortable and undisturbed EEG signal acquisition through contact with the human scalp. The EEG signal lead layout follows the international 10-10 standard system for eight frontal and temporal lobe channels (FT7, F7, AF7, Fp1, Fp2, AF8, F8, FT8), utilizing a reference electrode, eight measurement electrodes, and a right leg drive electrode to synchronously acquire eight channels of EEG analog signals.
[0009] The input impedance enhancement unit adopts an AC bootstrap buffer circuit designed based on an instrumentation operational amplifier. The input impedance of the EEG acquisition unit is increased to tens or even hundreds of GΩ through the input impedance enhancement unit. The contact impedance between the FPC flexible dry electrode and the frontal and temporal scalp or hair is tens of kΩ to MΩ. The input impedance is more than 1,000 times the electrode-skin contact impedance, and the EEG signal is coupled out in the back-end circuit.
[0010] Furthermore, the signal processing unit includes an analog filtering unit, a signal amplifying unit, a right leg driving unit, and an analog-to-digital conversion unit. The analog filtering unit is connected to the EEG signal sensing module, and the original input EEG signal is passed through the low-pass filter and anti-aliasing filter of the analog filtering unit to obtain a filtered EEG analog signal; the signal amplifying unit is connected to the analog filtering unit, and the filtered measurement channel EEG analog signal and the filtered reference channel EEG analog signal are differentially amplified; the right leg driving unit draws out the common-mode interference signal of each measurement channel, amplifies it inversely, and then feeds it back to the human body through the right leg driving FPC flexible dry electrode to achieve common-mode interference suppression; the analog-to-digital conversion unit is connected to each output pin of the signal amplifying unit, and converts the EEG analog signal of each channel into a digital signal.
[0011] Furthermore, the micro control unit of the signal control module is connected to the output end of the analog-to-digital conversion unit to exchange data, and the Bluetooth unit of the signal transmission module is connected to the micro control unit to transmit data to the host computer via Bluetooth.
[0012] Furthermore, the power module is powered by a 3.7V rechargeable lithium battery, and the voltage of the 3.7V rechargeable lithium battery is converted into the required level voltage through a voltage regulator chip to supply power to various modules of the system.
[0013] Furthermore, the portable frontotemporal EEG acquisition system is in the form of an elastic and tight smart headband. The FPC flexible dry electrode and the headband are integrated into an integrated design. The elastic structure of the headband makes close contact with the scalp. The signal sensing module, signal processing module, signal control module, signal transmission module and power supply module are encapsulated in the shell, and the encapsulation shell is integrated with the elastic and tight smart headband through a Velcro structure.
[0014] A data processing method for a portable frontotemporal lobe electroencephalogram (EEG) acquisition system comprises the following steps:
[0015] S1, eight-channel EEG signals were acquired through a portable frontotemporal EEG acquisition system;
[0016] S2, removes noise from the eight-channel EEG signal through digital filters such as notch and bandpass filtering of the analog filtering unit;
[0017] S3, decompose the EEG signals of each channel into multiple intrinsic mode functions through multivariate variational mode decomposition, and regard the intrinsic mode functions with sample entropy values lower than the threshold as components containing electrooculographic artifacts and motion artifacts;
[0018] S4, clearing the components above the threshold in the intrinsic mode function containing eye artifacts and motion artifacts, reconstructing the EEG signal, and obtaining high-quality EEG data;
[0019] S5, extracts time domain features, frequency domain features, time-frequency features and nonlinear dynamic features from high-quality EEG data to obtain the multi-dimensional information state of the brain.
[0020] Compared with the prior art, the present invention has the following beneficial technical effects:
[0021] 1. The present invention provides a portable frontotemporal EEG acquisition system, which can comfortably and undisturbedly acquire long-term, high-quality EEG signals, and obtain processed EEG data through a data processing method to provide information on the activity status of the human brain.
[0022] 2. The EEG electrode unit uses FPC flexible dry electrodes, which do not require the injection of conductive glue and do not require cumbersome operating steps. This avoids the damage of conductive glue to the skin during long-term EEG monitoring, increases the comfort and non-interference during EEG signal acquisition, and broadens the application possibilities of long-term EEG monitoring.
[0023] 3. The input impedance enhancement unit increases the input impedance of the EEG electrode circuit to the GΩ level, overcoming the problem of high contact impedance between the FPC flexible dry electrode and the skin or hair, which leads to reduced measurement accuracy. It accurately senses the EEG signal from the scalp surface to the circuit measurement channel, meeting the accuracy of portable EEG monitoring.
[0024] 4. The signal transmission module uses a Bluetooth unit to wirelessly transmit data, expanding the application scenarios of EEG monitoring from clinical to community and family.
[0025] 5. The system adopts an elastic smart headband, which can be adaptively adjusted according to the individual head circumference, is comfortable, and has good contact with the scalp. The signal sensing module, signal processing module, signal control module, signal transmission module and power module are integrated into a package design with a small size and light weight, which reduces the burden on the human head and is suitable for long-term, comfortable and non-disturbing EEG monitoring. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 Schematic diagram of the module composition of the portable frontotemporal EEG acquisition system in an embodiment of the present invention.
[0027] Figure 2 Schematic diagram of the FPC flexible dry electrode unit structure in an embodiment of the present invention.
[0028] Figure 3 Schematic diagram of the structure of the input impedance boosting circuit unit in an embodiment of the present invention.
[0029] Figure 4 Schematic diagram of the signal processing module structure in an embodiment of the present invention.
[0030] Figure 5Schematic diagram of the integrated structure of the portable frontotemporal EEG acquisition system in an embodiment of the present invention.
[0031] In the figure, 1. elastic band, 2. packaging shell, 3. Velcro hook surface, 4. Velcro loop surface. DETAILED DESCRIPTION
[0032] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:
[0033] like Figure 1 As shown, a portable frontotemporal EEG acquisition system includes a signal sensing module, a signal processing module, a signal control module, a signal transmission module, a power supply module, and a back-end data processing module. The signal sensing module includes an EEG electrode unit and an input impedance boosting unit connected to the EEG electrode unit; the signal processing module includes an analog filtering unit, a signal amplification unit, a right leg drive unit, and an analog-to-digital conversion unit connected to the input impedance boosting unit; the signal control module includes a microcontroller unit connected to the signal processing module; the signal transmission module includes a Bluetooth unit connected to the microcontroller unit; the power supply module includes an analog power supply unit and a digital power supply unit for each module; and the back-end data processing module includes a digital filtering unit and an artifact removal unit for a host computer. The frontotemporal EEG signals are acquired by the signal sensing module, then pre-processed by the signal processing module through filtering, amplification, and analog-to-digital conversion. The data is then transmitted to the host computer via the Bluetooth unit of the signal transmission module under the control of the signal control module. The host computer further performs back-end data processing to obtain high-quality EEG data.
[0034] Specifically, such as Figure 2 As shown, the EEG electrode unit uses FPC flexible dry electrodes. The FPC flexible dry electrodes use gold as the electrode material and polyimide as the substrate, taking into account the material's flexibility, stability, and conductivity. The FPC flexible dry electrodes contact the human scalp to achieve comfortable and undisturbed EEG signal acquisition. EEG signal measurement uses unipolar leads. The lead layout is the international 10-10 standard system of eight-channel frontotemporal lobe leads, using one reference electrode, eight measurement electrodes, and one right leg drive electrode. The specific reference electrode is located behind the left mastoid process, the right leg drive electrode is located behind the right mastoid process, and the measurement channel electrodes are located in the frontotemporal lobe regions FT7, F7, AF7, Fp1, Fp2, AF8, F8, and FT8. Eight-channel frontotemporal EEG analog signals are synchronously acquired.
[0035] like Figure 3As shown in the figure, the input impedance boosting unit adopts an AC bootstrap buffer circuit designed based on an instrumentation operational amplifier. The input impedance of the EEG electrode unit is increased to tens or even hundreds of GΩ through the input impedance boosting unit, which is much higher than the contact impedance between the FPC flexible dry electrode and the skin or hair of the frontal and temporal lobes, and the EEG signal is coupled out in the back-end circuit.
[0036] like Figure 4 As shown, the signal processing module includes an analog filtering unit, a signal amplification unit, a right leg drive unit, and an analog-to-digital conversion unit. The analog filtering unit is connected to the signal sensing module, specifically a first-order low-pass filter circuit with a cutoff frequency of 6.77kHz. The original input EEG signal with impedance boost is passed through the low-pass filter to obtain a filtered EEG analog signal; the signal amplification unit is connected to the analog filtering unit, specifically using the ADS1299 chip, to differentially amplify the filtered measurement channel EEG analog signal and the filtered reference channel EEG analog signal, with an amplification factor of 24 times; the right leg drive unit draws out the common-mode interference signal of each measurement channel, amplifies it inversely, and then feeds it back to the human body through the right leg drive FPC flexible dry electrode to achieve common-mode interference suppression; the analog-to-digital conversion unit is connected to each output pin of the signal amplification unit to convert the EEG analog signal of each channel into a digital signal.
[0037] The signal control module's microcontroller unit is connected to the output of the analog-to-digital conversion unit for data exchange. The signal transmission module's Bluetooth unit is connected to the microcontroller unit and transmits data to the host computer via Bluetooth. The Bluetooth unit uses a Bluetooth 4.0 low-power module with a serial communication baud rate of 115,200 bit / s.
[0038] The power module is powered by a 3.7V rechargeable lithium battery. The voltage of the 3.7V rechargeable lithium battery is converted into the required voltage level through a voltage regulator chip to supply power to the system's signal sensing module, signal processing module, signal control module, and signal transmission module respectively.
[0039] like Figure 5 As shown, the portable frontotemporal EEG acquisition system takes the form of an elastic smart headband. Specifically, the FPC flexible dry electrodes are integrated with the elastic headband, ensuring close contact with the scalp via elastic strap 1. The signal sensing module, signal processing module, signal control module, signal transmission module, and power module are encapsulated in a housing 2, which is integrated with the elastic headband via a Velcro structure. In the figure, 3 represents the hook surface, and 4 represents the loop surface.
[0040] When using the portable frontotemporal EEG acquisition system of the present invention, the user only needs to wear the elastic and tight smart headband on the head, ensure that the electrode position is correct and the electrode is in close contact with the skin, and perform EEG signal acquisition and measurement. The collected EEG analog signal is filtered, amplified, and converted into analog to digital form, and the data is transmitted to the host computer via Bluetooth. The host computer obtains high-quality EEG data after digital filtering and artifact removal. By extracting time domain features, frequency domain features, time-frequency features, and nonlinear dynamic features from the EEG data, the multi-dimensional information state assessment of the brain is realized.
[0041] The portable frontotemporal EEG acquisition system proposed in this invention comfortably and non-disturbingly acquires long-term, high-quality EEG signals. Data processing methods are used to obtain processed EEG data, providing information on brain activity status. The EEG electrode unit utilizes flexible dry electrodes (FPCs), ensuring comfortable and non-disturbing EEG signal acquisition, broadening the application possibilities of long-term EEG monitoring. The input impedance boost circuit unit increases the input impedance of the EEG acquisition circuit to the GΩ level, overcoming the issue of reduced measurement accuracy caused by the high contact impedance of FPC dry electrodes with skin or hair. This allows EEG signals to be accurately sensed from the scalp surface to the circuit measurement channel, ensuring the accuracy of portable EEG monitoring. The signal transmission module uses Bluetooth for wireless data transmission, expanding the application scenarios of EEG monitoring. The system utilizes an elastic smart headband that can be adaptively adjusted to individual head circumference, providing excellent comfort and close contact with the scalp. The integrated device is compact and lightweight, reducing head strain, making it suitable for long-term, comfortable, and non-disturbing EEG monitoring, expanding EEG monitoring applications from the laboratory and clinical setting to community and home use.
Claims
1. A portable frontotemporal EEG acquisition system, characterized in that: It includes a signal sensing module, a signal processing module, a signal control module, a signal transmission module, a power supply module and a back-end data processing module; wherein the signal sensing module includes an EEG electrode unit and an input impedance enhancement unit connected to the EEG electrode unit; the signal processing module includes an analog filtering unit, a signal amplification unit, a right leg drive unit and an analog-to-digital conversion unit connected to the input impedance enhancement unit; the signal control module includes a microcontroller unit connected to the signal processing module; the signal transmission module includes a Bluetooth unit connected to the microcontroller unit; the power supply module includes an analog power supply unit and a digital power supply unit for powering each module; the back-end data processing module includes a digital filtering unit and an artifact removal unit of a host computer; the frontal and temporal lobe EEG signals are collected by the signal sensing module, and then filtered, amplified and analog-to-digital converted by the signal processing module for signal preprocessing, and then the data is transmitted to the host computer through the Bluetooth unit of the signal transmission module under the control of the signal control module, and the host computer further performs back-end data processing to obtain high-quality EEG data; The EEG electrode unit uses an FPC flexible dry electrode, which uses gold as the electrode material and polyimide as the substrate. The EEG signal lead layout is the international 10-10 standard system of eight frontal and temporal lobe channels, namely FT7, F7, AF7, Fp1, Fp2, AF8, F8, and FT8. It uses a reference electrode, eight measurement electrodes, and a right leg drive electrode to synchronously collect eight-channel EEG simulation signals. The input impedance enhancement unit increases the input impedance of the EEG acquisition unit to tens or even hundreds of GΩ. The contact impedance between the FPC flexible dry electrode and the frontal and temporal scalp or hair is tens of kΩ to MΩ. The input impedance is more than 1,000 times the electrode-skin contact impedance, and the EEG signal is coupled out in the back-end circuit.
2. A portable frontotemporal EEG acquisition system according to claim 1, characterized in that: The input impedance enhancement unit adopts an AC bootstrap buffer circuit designed based on an instrumentation operational amplifier.
3. The portable frontotemporal EEG acquisition system according to claim 1, characterized in that: The analog filtering unit is connected to the signal sensing module, and the original input EEG signal is passed through the low-pass filter of the analog filtering unit to obtain a filtered EEG analog signal; the signal amplification unit is connected to the analog filtering unit, and the filtered EEG analog signal of the measurement channel and the filtered EEG analog signal of the reference channel are differentially amplified; the right leg driving unit draws out the common-mode interference signal of each measurement channel, amplifies it inversely, and then feeds it back to the human body through the right leg driving FPC flexible dry electrode to achieve common-mode interference suppression; the analog-to-digital conversion unit is connected to each output pin of the signal amplification unit, and converts the EEG analog signal of each channel into a digital signal.
4. The portable frontotemporal EEG acquisition system according to claim 1, characterized in that: The micro control unit of the signal control module is connected to the output end of the analog-to-digital conversion unit to exchange data, and the Bluetooth unit of the signal transmission module is connected to the micro control unit to transmit data to the host computer via Bluetooth.
5. The portable frontotemporal EEG acquisition system according to claim 1, characterized in that: The power module is powered by a 3.7V rechargeable lithium battery, and the voltage of the 3.7V rechargeable lithium battery is converted into the required level voltage through a voltage regulator chip to supply power to each module of the system.
6. The portable frontotemporal EEG acquisition system according to claim 1, characterized in that: The portable frontotemporal EEG acquisition system is in the form of an elastic and tight smart headband, with an FPC flexible dry electrode and the headband integrated into one design. The elastic structure of the headband allows close contact with the scalp. The signal sensing module, signal processing module, signal control module, signal transmission module and power supply module are encapsulated in a shell, and the encapsulation shell is integrated with the elastic and tight smart headband through a Velcro structure.
7. The data processing method of the portable frontotemporal EEG acquisition system according to any one of claims 1 to 6, characterized in that: The steps include: S1, eight-channel EEG signals were acquired through a portable frontotemporal EEG acquisition system; S2, removes noise from the eight-channel EEG signal through the notch and bandpass digital filters of the analog filtering unit; S3, decompose the EEG signals of each channel into multiple intrinsic mode functions through multivariate variational mode decomposition, and regard the intrinsic mode functions with sample entropy values lower than the threshold as components containing electrooculographic artifacts and motion artifacts; S4, clearing the components above the threshold in the intrinsic mode function containing eye artifacts and motion artifacts, reconstructing the EEG signal, and obtaining high-quality EEG data; S5, extracts time domain features, frequency domain features, time-frequency features and nonlinear dynamic features from high-quality EEG data to obtain the multi-dimensional information state of the brain.