CN109009105B - Performance characterization method of scalp electroencephalogram sensing electrode interface material - Google Patents
Performance characterization method of scalp electroencephalogram sensing electrode interface material Download PDFInfo
- Publication number
- CN109009105B CN109009105B CN201810831114.9A CN201810831114A CN109009105B CN 109009105 B CN109009105 B CN 109009105B CN 201810831114 A CN201810831114 A CN 201810831114A CN 109009105 B CN109009105 B CN 109009105B
- Authority
- CN
- China
- Prior art keywords
- test
- electrode interface
- electrodes
- interface material
- group
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000000463 material Substances 0.000 title claims abstract description 103
- 210000004761 scalp Anatomy 0.000 title claims abstract description 51
- 238000012512 characterization method Methods 0.000 title claims abstract description 31
- 238000012360 testing method Methods 0.000 claims abstract description 211
- 230000003321 amplification Effects 0.000 claims abstract description 32
- 238000003199 nucleic acid amplification method Methods 0.000 claims abstract description 32
- 239000011540 sensing material Substances 0.000 claims abstract description 8
- 230000010287 polarization Effects 0.000 claims description 57
- 238000000034 method Methods 0.000 claims description 25
- 238000012935 Averaging Methods 0.000 claims description 12
- 210000004556 brain Anatomy 0.000 claims description 12
- 238000003754 machining Methods 0.000 claims description 5
- 229910000838 Al alloy Inorganic materials 0.000 claims description 4
- 229910000975 Carbon steel Inorganic materials 0.000 claims description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 4
- 239000010962 carbon steel Substances 0.000 claims description 4
- 229910052802 copper Inorganic materials 0.000 claims description 4
- 239000010949 copper Substances 0.000 claims description 4
- 230000009286 beneficial effect Effects 0.000 description 10
- 238000010586 diagram Methods 0.000 description 10
- 238000013461 design Methods 0.000 description 6
- 206010061296 Motor dysfunction Diseases 0.000 description 3
- 208000037265 diseases, disorders, signs and symptoms Diseases 0.000 description 2
- 230000001537 neural effect Effects 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- 208000024827 Alzheimer disease Diseases 0.000 description 1
- 208000019430 Motor disease Diseases 0.000 description 1
- 206010039966 Senile dementia Diseases 0.000 description 1
- 208000006011 Stroke Diseases 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000004590 computer program Methods 0.000 description 1
- 238000003745 diagnosis Methods 0.000 description 1
- 201000010099 disease Diseases 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 239000007772 electrode material Substances 0.000 description 1
- 206010015037 epilepsy Diseases 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000009897 systematic effect Effects 0.000 description 1
Images
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/24—Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
- A61B5/25—Bioelectric electrodes therefor
- A61B5/279—Bioelectric electrodes therefor specially adapted for particular uses
- A61B5/291—Bioelectric electrodes therefor specially adapted for particular uses for electroencephalography [EEG]
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Medical Informatics (AREA)
- Biophysics (AREA)
- Pathology (AREA)
- Engineering & Computer Science (AREA)
- Biomedical Technology (AREA)
- Heart & Thoracic Surgery (AREA)
- Physics & Mathematics (AREA)
- Molecular Biology (AREA)
- Surgery (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Measurement And Recording Of Electrical Phenomena And Electrical Characteristics Of The Living Body (AREA)
Abstract
The invention relates to a performance characterization method of a scalp electroencephalogram sensing electrode interface material, belongs to the technical field of testing, and solves the problem that the comprehensive performance of the scalp electroencephalogram sensing electrode interface material cannot be quantitatively and systematically and effectively characterized in the prior art. The performance characterization method disclosed by the invention comprises the following steps of: aiming at an electrode interface material to be characterized, preparing a plurality of scalp electroencephalogram sensing test electrodes; carrying out calibration test on the test electrode groups to obtain electrochemical index parameters of each group of test electrodes so as to obtain the electrochemical index parameters of the electrode interface material to be characterized; and connecting each group of test electrodes with an electroencephalogram amplification acquisition system, acquiring a scalp electroencephalogram analog signal to obtain the input impedance of the acquisition system, and combining the obtained electrochemical index parameters of the electrode interface material to be characterized to obtain quantitative comprehensive characterization parameters of the scalp electroencephalogram sensing material. The comprehensive characterization parameters provide a basis for reasonable selection of scalp electroencephalogram sensing electrode interface materials.
Description
Technical Field
The invention relates to the technical field of testing, in particular to a performance characterization method of a scalp electroencephalogram sensing electrode interface material.
Background
The brain-computer interface system can be widely used for diagnosis, treatment or auxiliary rehabilitation of diseases such as motor disorder, senile dementia, epilepsy and stroke, and can improve the life quality of patients suffering from motor dysfunction diseases. For example, a patient suffering from motor dysfunction can assist walking by controlling the movement of a wheelchair through signals given by his brain waves.
With the increasing population of motor dysfunction patients and aging, brain-computer interface systems are also growing rapidly. In the brain-computer interface system, an electrode made of scalp electroencephalogram sensing materials plays an important role, and performance indexes of the electrode have restrictive influence on the whole brain-computer interface system. Researches find that the electrochemical property of the scalp electroencephalogram sensing material has an extremely important influence on the sensing conversion performance of the electrode, and the quality of the electrode is determined.
At present, in the design and preparation of the scalp electroencephalogram sensing electrode, a quantitative and systematic method is lacked to represent the performance of alternative scalp electroencephalogram sensing materials in advance, and the processability, durability and the like of the materials are comprehensively considered, so that the appropriate scalp electroencephalogram sensing materials can be selected, and the design of the electrode is guided.
Disclosure of Invention
In view of the above analysis, the embodiment of the invention aims to provide a method for characterizing the performance of a scalp electroencephalogram sensing electrode interface material, so as to solve the problem that the comprehensive performance of the scalp electroencephalogram sensing material cannot be quantitatively and systematically effectively characterized in the prior art.
On one hand, the embodiment of the invention provides a performance characterization method of a scalp electroencephalogram sensing electrode interface material, which comprises the following steps:
preparing N scalp bioelectricity sensing test electrodes aiming at an electrode interface material to be characterized;
carrying out calibration test on the prepared test electrode groups to obtain electrochemical index parameters of each group of test electrodes so as to obtain the electrochemical index parameters of the electrode interface material to be characterized; the electrochemical index parameters comprise direct current offset potential, alternating current impedance and polarization voltage amplitude;
and connecting each group of test electrodes with an electroencephalogram amplification acquisition system, acquiring electroencephalogram analog signals of human scalp to obtain input impedance of the acquisition system, and combining the obtained electrochemical index parameters of the electrode interface material to be characterized to obtain quantitative comprehensive characterization parameters of the electrode interface material to be characterized.
The beneficial effects of the above technical scheme are as follows: according to the technical scheme, three electrochemical parameter indexes of direct-current offset potential, alternating-current impedance and polarization voltage amplitude are reasonably integrated to obtain a quantized comprehensive characterization parameter, namely a comprehensive performance parameter, so that the comprehensive performance of the electrode interface material is characterized, and a foundation is provided for reasonable selection of the electrode interface material. When the method is implemented, for a plurality of electrode interface materials to be characterized, the excellent performance of the electrode interface materials can be known through the quantitative comprehensive characterization parameters, and the optimal electrode interface materials can be selected by combining the realization difficulty and the cost of the process.
In another embodiment based on the method, the obtaining of the quantified comprehensive characterization parameter of the scalp electroencephalogram sensing material by combining the obtained electrochemical index parameter of the electrode interface material to be characterized includes obtaining the comprehensive characterization parameter of the electrode interface material by using the following formula:
in the formula, V1Voltage amplitude, V, representing an electroencephalogram analog signal2Representing the amplitude, V, of the polarization voltage of the material of the electrode interface to be characterized3Representing the DC offset potential, Z, of the material of the electrode interface to be characterised1Representing the AC impedance, Z, of the material of the electrode interface to be characterised2And the input impedance of the electroencephalogram amplification acquisition system is shown.
The beneficial effects of the above technical scheme are: through the quantitative comprehensive characterization parameters, namely comprehensive performance parameters, technicians can intuitively understand the comprehensive performance of the electrode interface material integrally, and specifically, the closer the quantitative comprehensive characterization parameters are to 1, the more excellent the electrode interface material performance is. The scalp and brain electrical sensing electrode material is convenient to select and use, and the design quality and efficiency of the electrode are improved.
Further, the scalp electroencephalogram sensing electrode interface material comprises at least one of copper, carbon steel and aluminum alloy;
the testing electrode adopts a sheet structure, and the cross section of the testing electrode adopts at least one of a circle, a square, a rectangle, a triangle, a pentagon and a hexagon.
The beneficial effects of the further scheme are as follows: the range of the interface material of the scalp electroencephalogram sensing electrode is limited by the further scheme, and at least one of copper, carbon steel and aluminum alloy is generally adopted. Meanwhile, the cross section of the electrode generally adopts at least one of a circle, a square, a rectangle, a triangle, a pentagon and a hexagon.
Further, the step of performing calibration test on the prepared test electrodes in groups to obtain the electrochemical index parameters of each group of test electrodes comprises:
building a direct current offset potential test circuit, and acquiring the direct current offset potential of each group of test electrodes through the direct current offset potential test circuit;
building an alternating current impedance test circuit, and acquiring alternating current impedance of each group of test electrodes through the alternating current impedance test circuit;
and (4) building a polarization voltage test circuit, and acquiring the polarization voltage amplitude of each group of test electrodes through the polarization voltage test circuit.
The beneficial effects of the further scheme are as follows: the direct current offset potential has an important influence on an electroencephalogram signal acquisition circuit system, and the lower the numerical value of the direct current offset potential is, the better the electrode interface material is. The alternating-current impedance is an external electrical embodiment of the electrode interface charge transfer capability, and has very important influence on the signal-to-noise ratio of the extracted neural signal. The smaller the ac impedance, the less thermal noise the electrode itself generates, the more conducive to the collected signal having a high signal-to-noise ratio, i.e., the better the performance of the electrode interface material. The polarization voltage amplitude is the amplitude of the polarization voltage generated by the electrode interface material itself when the electrode interface has external input voltage. The smaller the polarization voltage amplitude, the better the sensing performance of the electrode.
Further, the step of connecting each group of test electrodes with an electroencephalogram amplification and acquisition system to acquire the electroencephalogram analog signals of the human scalp to obtain the input impedance of the acquisition system comprises the following steps:
carrying out calibration test on the electroencephalogram amplification acquisition system to obtain the input impedance of the electroencephalogram amplification acquisition system; or,
each group of test electrodes are respectively connected with the electroencephalogram amplification and acquisition system to acquire electroencephalogram analog signals of human scalp, and input voltage and current of the electroencephalogram amplification and acquisition system corresponding to each group of test electrodes are obtained;
respectively averaging the input voltage and the current of the electroencephalogram amplification acquisition system corresponding to all groups of test electrodes to obtain the average input voltage and the average current of the electroencephalogram amplification acquisition system;
and dividing the average input voltage by the average current to obtain the input impedance of the electroencephalogram amplification and acquisition system.
The beneficial effects of the further scheme are as follows: by the two methods, the input impedance of the electroencephalogram amplification and acquisition system can be obtained, and the method is simple and easy to operate.
Further, the step of preparing N scalp electroencephalogram sensing test electrodes aiming at the electrode interface material to be characterized comprises the following steps:
preparing N from the electrode interface material to be characterized by machining1The prepared electrodes are the same in size and shape;
and performing calibration test on the prepared electrodes, and after removing the prepared electrodes with the resistance values exceeding the preset range, selecting N residual electrodes as scalp electroencephalogram sensing test electrodes.
The beneficial effects of the further scheme are as follows: some unqualified test electrodes may appear in the preparation process, the unqualified test electrodes can be removed through calibration test, and only qualified test electrodes are reserved, so that the success rate and the accuracy of subsequent tests can be improved.
Further, the step of building a dc offset potential test circuit and acquiring the dc offset potential of each group of test electrodes through the dc offset potential test circuit includes:
building a direct current offset potential test circuit, wherein the direct current offset potential test circuit comprises any group of test electrodes and a high-precision voltage tester, and the test electrodes are arranged on the surface of the skin of a human body at preset intervals; the preset distance is 5-10 cm;
and measuring each group of test electrodes by using the direct current offset potential test circuit respectively, and obtaining the direct current offset potential of each group of test electrodes after the reading of the high-precision voltage tester is stable for 30-60 s.
The beneficial effects of the further scheme are as follows: the testing method is simple, and the testing method is repeated with the testing equipment selected by the alternating current impedance testing circuit and the polarization voltage testing circuit, so that the testing cost can be saved to a certain extent.
Further, the step of building an alternating current impedance test circuit and acquiring the alternating current impedance of each group of test electrodes through the alternating current impedance test circuit comprises:
building an alternating current impedance test circuit, wherein the alternating current impedance test circuit comprises any one group of test electrodes, a signal generator, a high-precision current tester and a high-precision voltage tester; the signal generator is connected in series with the high-precision current tester and then connected in parallel with the high-precision voltage tester; the test electrodes are arranged on the surface of the skin of the human body and are spaced by a preset distance; the preset distance is 5-10 cm;
sinusoidal alternating-current voltage signals of 5-20 mV and 1-100 Hz are applied between the two electrodes of any one group through a signal generator, and the alternating-current impedance test circuit is adopted to measure N/2 groups of test electrodes respectively to obtain the alternating-current impedance of each group of test electrodes.
The beneficial effects of the further scheme are as follows: the testing method is simple and is repeated with the testing equipment selected by the direct current offset potential testing circuit and the polarization voltage testing circuit, so that the testing cost can be saved to a certain extent.
Further, the step of setting up the polarization voltage test circuit and acquiring the polarization voltage amplitude of each group of test electrodes through the polarization voltage test circuit comprises:
a polarization voltage test circuit is set up, and the polarization voltage test circuit comprises any group of test electrodes, a signal generator, a high-precision current tester and a high-precision voltage tester; the signal generator is connected in series with the high-precision current tester and then connected in parallel with the high-precision voltage tester; the test electrodes are arranged on the surface of the skin of the human body and are spaced by a preset distance; the preset distance is 5-10 cm;
and applying sinusoidal alternating voltage signals of 10-100 muV and 1-100 Hz between the two electrodes of any group through a signal generator, and measuring N/2 groups of test electrodes by adopting a polarization voltage test circuit respectively to obtain the polarization voltage amplitude of each group of test electrodes.
The beneficial effects of the further scheme are as follows: the testing method is simple and is repeated with the testing equipment selected by the direct current offset potential testing circuit and the alternating current impedance testing circuit, so that the testing cost can be saved to a certain extent.
Further, the step of obtaining an electrochemical index parameter of the electrode interface material to be characterized comprises:
averaging the DC offset potentials of all groups of test electrodes, and taking the result as the DC offset potential of the electrode interface material to be characterized;
averaging the alternating current impedance of all groups of test electrodes, and taking the result as the alternating current impedance of the electrode interface material to be characterized;
and averaging the polarization voltage amplitudes of all groups of test electrodes, and taking the result as the polarization voltage amplitude of the electrode interface material to be characterized.
The beneficial effects of the further scheme are as follows: the average calculation method is accurate in result, can eliminate the influence caused by a certain misoperation to the maximum extent, is simple, can accurately represent the respective overall level of the three data, and omits the difference between the individual data.
In the invention, the technical schemes can be combined with each other to realize more preferable combination schemes. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
Drawings
The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention, wherein like reference numerals are used to designate like parts throughout.
FIG. 1 is a schematic diagram of the steps of a method for characterizing the properties of a scalp electroencephalogram sensing electrode interface material according to embodiment 1 of the present invention;
FIG. 2 is a schematic diagram of the procedure of obtaining the electrochemical index parameters of each group of test electrodes of the electrode interface material to be characterized in example 2 of the present invention;
FIG. 3 is a schematic diagram of the steps for preparing N scalp electroencephalogram sensing test electrodes in embodiment 2 of the present invention;
FIG. 4 is a schematic diagram of the step of obtaining the DC offset potential of the electrode interface material to be characterized in embodiment 2 of the present invention;
FIG. 5 is a schematic diagram of a DC offset potential testing circuit according to embodiment 2 of the present invention;
FIG. 6 is a schematic diagram of the AC impedance of the electrode interface material to be characterized obtained in example 2 of the present invention;
FIG. 7 is a schematic diagram of an AC impedance testing circuit according to embodiment 2 of the present invention;
FIG. 8 is a schematic diagram of the polarization voltage amplitude obtained from the electrode interface material to be characterized in example 2 of the present invention;
fig. 9 is a schematic diagram of a polarization voltage test circuit according to embodiment 2 of the present invention.
Detailed Description
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate preferred embodiments of the invention and together with the description, serve to explain the principles of the invention and not to limit the scope of the invention.
Example 1
As shown in fig. 1, a specific embodiment of the present invention discloses a method for characterizing the performance of a scalp electroencephalogram sensing electrode interface material, comprising the following steps:
s1, aiming at an electrode interface material to be characterized, machining is carried out, and N scalp electroencephalogram sensing test electrodes are prepared.
S2, performing calibration test on the prepared test electrode groups to obtain electrochemical parameters of each group of test electrodes, and further obtaining the electrochemical parameters of the electrode interface material to be characterized; the electrochemical parameters include a dc offset potential, an ac impedance, and a polarization voltage amplitude.
And S3, connecting each group of test electrodes with an electroencephalogram amplification acquisition system, acquiring electroencephalogram analog signals of human scalp to obtain input impedance of the acquisition system, and combining the obtained electrochemical index parameters to obtain quantized comprehensive characterization parameters of electrode interface materials to be characterized.
Compared with the prior art, the embodiment provides a method for effectively integrating three electrochemical parameter indexes of direct current offset potential, alternating current impedance and polarization voltage amplitude so as to obtain a quantitative comprehensive characterization parameter, namely a comprehensive performance parameter. And the comprehensive characterization parameters are used for characterizing the comprehensive performance of the electrode interface material, and providing a basis for reasonably selecting the electrode interface material. When the method is implemented, for a plurality of electrode interface materials to be characterized, the corresponding excellent degree of performance can be known through the corresponding comprehensive characterization parameters, and the optimal electrode interface material can be selected by combining other factors such as process realization difficulty, cost and the like. The performance characterization method can improve the design quality and efficiency of the electrode.
Example 2
And optimizing on the basis of the embodiment, wherein the electrode interface material to be characterized, namely the scalp electroencephalogram sensing electrode interface material, comprises at least one of copper, carbon steel and aluminum alloy. The test electrode made of the electrode interface material to be characterized generally adopts a sheet structure, and the cross section of the test electrode adopts at least one of a circle, a square, a rectangle, a triangle, a pentagon and a hexagon, or other suitable structures.
As shown in fig. 3, step S1 can be subdivided into the following steps:
s11, preparing N from the electrode interface material to be characterized through machining1And the prepared electrodes are completely the same in size and shape. Specifically, in this step, electrodes having sizes and shapes different from the standard need to be removed by limiting errors.
S12, performing calibration test on the prepared electrodes, and after removing the prepared electrodes with the resistance values exceeding the preset range, selecting N residual electrodes as scalp electroencephalogram sensing test electrodes.
Specifically, in the present embodiment, for each material to be characterized, N test electrode pieces having the same size and shape are manufactured by machining. The number of the test electrode plates of each material is not less than 6, namely N is not less than 6, N is an even number, and the test electrode plates are selected according to actual requirements. The cross section of the test strip is used as a test contact surface and is directly attached and contacted with the skin surface of a human body, and the area of the cross section is not less than 10mm2And the height is not more than 1 cm. During testing, the cross section of the electrode plate is selected to be circular, the diameter of the cross section is 6mm, and the height is 2 mm.
As shown in fig. 2, the step S2 of obtaining the electrochemical index parameter of the electrode interface material to be characterized can be further detailed as the following steps:
and S21, building a direct current offset potential testing circuit, acquiring the direct current offset potential of each group of testing electrodes through the direct current offset potential testing circuit, and averaging the direct current offset potentials of all groups of testing electrodes to obtain the direct current offset potential of the electrode interface material to be represented. The direct current offset potential is a voltage formed at two ends of the electrode pair due to the difference of the potentials of the two electrodes, and has an important influence on an electroencephalogram signal acquisition circuit system, and the lower the numerical value is, the better the electrode interface material is.
S22, an alternating current impedance test circuit is built, alternating current impedance of each group of test electrodes is collected through the alternating current impedance test circuit, and the alternating current impedance of all groups of test electrodes is averaged to obtain alternating current impedance of the electrode interface material to be characterized. The alternating-current impedance is an external electrical embodiment of the electrode interface charge transfer capability, and has very important influence on the signal-to-noise ratio when extracting the neural signal. The smaller the alternating current impedance is, the smaller the thermal noise generated by the electrode is, the higher the signal-to-noise ratio of the acquired signal is, and the better the performance of the electrode interface material is. The alternating current impedance is directly related to the contact area of the electrode and the skin of the human body, and the larger the contact area is, the smaller the corresponding alternating current impedance is.
S23, a polarization voltage test circuit is set up, the polarization voltage amplitude of each group of test electrodes is collected through the polarization voltage test circuit, and the polarization voltage amplitudes of all groups of test electrodes are averaged to obtain the polarization voltage amplitude of the electrode interface material to be represented.
As shown in fig. 4, step S21 can be subdivided into the following steps:
s211, a direct current offset potential testing circuit is built, the direct current offset potential testing circuit comprises any one group of testing electrodes and a high-precision voltage tester, and the testing electrode groups are arranged on the surface of the skin of a human body at preset intervals. The preset distance is 5-10 cm.
S212, each group of test electrodes are respectively measured by the direct current offset potential test circuit, and after the reading of the high-precision voltage tester is stable for 30-60 s, the direct current offset potential corresponding to each group of test electrodes is obtained.
S213, averaging the direct-current offset potentials corresponding to all the groups of test electrodes, and taking the result as the direct-current offset potential of the electrode interface material to be characterized. The polarization voltage amplitude is the condition that the electrode interface has external input voltage, and the fluctuation is generated by the electrode interface material, namely the polarization voltage amplitude. The smaller the polarization voltage amplitude, the better the sensing performance of the electrode.
Specifically, 6 test electrode pieces of each material are randomly selected and divided into 3 groups of 2 pieces, and the test is performed. And respectively arranging each group of electrodes on the surface of the skin of a human body, wherein the interval between the two electrodes is 5cm, and respectively testing the direct current offset potential between 2 electrodes of each group. The circuit diagram of the direct current offset potential testing is shown in fig. 5, 2 electrodes are connected to a high-precision voltage measuring instrument such as an oscilloscope, and after the reading of the high-precision voltage measuring instrument is stable for 30-60 s, the direct current offset potential is recorded.
As shown in fig. 6, step S22 can be subdivided into the following steps:
s221, an alternating current impedance test circuit is built, and the alternating current impedance test circuit comprises any one group of test electrodes, a signal generator, a high-precision current tester and a high-precision voltage tester. The signal generator is connected with the high-precision current tester in series and then connected with the high-precision voltage tester in parallel. The test electrodes are arranged on the surface of the skin of the human body and are spaced by a preset distance; the preset distance is 5-10 cm.
S222, sinusoidal alternating current voltage signals of 5-20 mV and 1-100 Hz are applied between two electrodes of any group through a signal generator, and N/2 groups of test electrodes are respectively measured by the alternating current impedance test circuit to obtain alternating current impedance of each group of test electrodes.
And S223, averaging the alternating current impedance of all the groups of test electrodes, and taking the average result as the alternating current impedance of the electrode interface material to be characterized.
Specifically, as shown in fig. 7, a sinusoidal ac voltage signal of 5 to 20mV and 1 to 100Hz is applied between two electrodes of each group as a disturbance input signal of the electrode system through a signal generator, the magnitude of the voltage and current signals applied between the two electrodes is measured by a high-precision test instrument such as an oscilloscope, and the effective voltage is divided by the effective current to record the respective ac impedance.
As shown in fig. 8, step S23 can be subdivided into the following steps:
s231, a polarization voltage testing circuit is set up, and the polarization voltage testing circuit comprises any group of testing electrodes, a signal generator, a high-precision current tester and a high-precision voltage tester. The signal generator is connected with the high-precision current tester in series and then connected with the high-precision voltage tester in parallel. The testing electrodes are arranged on the surface of the skin of the human body at intervals of preset distances. The preset distance is 5-10 cm.
S232, sinusoidal alternating-current voltage signals of 10-100 mu V and 1-100 Hz are applied between two electrodes of any group through a signal generator, and N/2 groups of test electrodes are respectively measured by adopting a polarization voltage test circuit to obtain polarization voltage amplitudes corresponding to each group of test electrodes.
And S233, averaging the polarization voltage amplitudes corresponding to all the groups of test electrodes, and taking the average result as the polarization voltage amplitude of the electrode interface material to be characterized.
Specifically, as shown in fig. 9, in the polarization voltage amplitude test process, a sinusoidal alternating voltage signal of 10-100 μ V and 1-100 Hz is applied between 2 electrodes through a signal generator, the voltage magnitude and the change thereof between 2 electrodes within 1-10 min are recorded and saved through a high-precision voltmeter, and the highest voltage signal of the recording period is subtracted from the lowest voltage signal to record as the polarization voltage amplitude.
When the method is implemented, the smaller the direct current offset potential characterization parameter, the smaller the unit area alternating current impedance and the polarization voltage amplitude characterization parameter are, the more excellent the corresponding electrode interface material performance is. The test electrode is connected with an electroencephalogram amplification and acquisition system to acquire data of electroencephalogram signals, and the input of the electroencephalogram amplification and acquisition system is obtained
In the formula, V1Voltage amplitude, V, representing an electroencephalogram analog signal2Representing the amplitude, V, of the polarization voltage of the material of the electrode interface to be characterized3Representing the DC offset potential, Z, of the material of the electrode interface to be characterised1Representing the AC impedance, Z, of the material of the electrode interface to be characterised2And the input impedance of the electroencephalogram amplification acquisition system is shown.
Wherein,
is an alternating current part input by the electroencephalogram amplification and acquisition system,
the direct current part is input by the electroencephalogram amplification and acquisition system. When the AC impedance Z1And V2The smaller the input signal obtained from the electroencephalogram amplification and acquisition system is, the closer to the original electroencephalogram signal V1The signal assurance degree is better, and the electrode interface material performance is more excellent. When V is3The smaller the size, the more suitable the design of the brain electricity amplification and collection system.
Dividing the input of the brain electrical amplification acquisition system by the brain electrical signal V1The obtained parameter value
As a quantitative comprehensive characterization parameter of the electrode interface material, namely a comprehensive performance parameter, the closer P is to 1, namely the closer the input of the electroencephalogram amplification and acquisition system is to the original electroencephalogram signal, the more excellent the electrode interface material performance is.
Therefore, quantitative comprehensive characterization of the performance of the electrode interface material to be characterized is realized.
Compared with the prior art, the performance characterization method provided by the embodiment fully utilizes three electrochemical parameters, namely direct current offset potential, unit area alternating current impedance and polarization voltage amplitude, so as to complete quantitative comprehensive characterization of the electrode interface material performance, and the characterization method can improve the electrode design quality and efficiency.
Those skilled in the art will appreciate that all or part of the flow of the method implementing the above embodiments may be implemented by a computer program, which is stored in a computer readable storage medium, to instruct related hardware. The computer readable storage medium is a magnetic disk, an optical disk, a read-only memory or a random access memory.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.
Claims (9)
1. A performance characterization method of a scalp electroencephalogram sensing electrode interface material is characterized by comprising the following steps:
preparing N scalp bioelectricity sensing test electrodes aiming at an electrode interface material to be characterized;
carrying out calibration test on the prepared test electrode groups to obtain electrochemical index parameters of each group of test electrodes so as to obtain the electrochemical index parameters of the electrode interface material to be characterized; the electrochemical index parameters comprise direct current offset potential, alternating current impedance and polarization voltage amplitude;
connecting each group of test electrodes with an electroencephalogram amplification and acquisition system, acquiring electroencephalogram analog signals of human scalp to obtain input impedance of the acquisition system, and combining the obtained electrochemical index parameters of the electrode interface material to be characterized to obtain quantitative comprehensive characterization parameters of the electrode interface material to be characterized;
the method for obtaining the quantified comprehensive characterization parameters of the scalp electroencephalogram sensing material by combining the obtained electrochemical index parameters of the electrode interface material to be characterized comprises the following steps of calculating to obtain the comprehensive characterization parameters of the electrode interface material by using the following formula:
in the formula, V1Voltage amplitude, V, representing an electroencephalogram analog signal2Representing the amplitude, V, of the polarization voltage of the material of the electrode interface to be characterized3Representing the DC offset potential, Z, of the material of the electrode interface to be characterised1Representing the AC impedance, Z, of the material of the electrode interface to be characterised2And the input impedance of the electroencephalogram amplification acquisition system is shown.
2. The method for characterizing the performance of a scalp brain electrical sensing electrode interface material according to claim 1, wherein the scalp brain electrical sensing electrode interface material comprises at least one of copper, carbon steel, and aluminum alloy;
the testing electrode adopts a sheet structure, and the cross section of the testing electrode adopts at least one of a circle, a square, a rectangle, a triangle, a pentagon and a hexagon.
3. The method for characterizing the performance of the scalp electroencephalogram sensing electrode interface material according to claim 1, wherein the step of performing calibration tests on the groups of prepared test electrodes to obtain electrochemical index parameters of each group of test electrodes comprises the following steps:
building a direct current offset potential test circuit, and acquiring the direct current offset potential of each group of test electrodes through the direct current offset potential test circuit;
building an alternating current impedance test circuit, and acquiring alternating current impedance of each group of test electrodes through the alternating current impedance test circuit;
and (4) building a polarization voltage test circuit, and acquiring the polarization voltage amplitude of each group of test electrodes through the polarization voltage test circuit.
4. The method for characterizing the performance of the scalp electroencephalogram sensing electrode interface material according to claim 1, wherein the step of connecting each group of test electrodes with an electroencephalogram amplification and acquisition system to acquire an electroencephalogram analog signal of a human scalp and obtain the input impedance of the acquisition system comprises the following steps:
carrying out calibration test on the electroencephalogram amplification acquisition system to obtain the input impedance of the electroencephalogram amplification acquisition system; or,
each group of test electrodes are respectively connected with the electroencephalogram amplification and acquisition system to acquire electroencephalogram analog signals of human scalp, and input voltage and current of the electroencephalogram amplification and acquisition system corresponding to each group of test electrodes are obtained;
respectively averaging the input voltage and the current of the electroencephalogram amplification acquisition system corresponding to all groups of test electrodes to obtain the average input voltage and the average current of the electroencephalogram amplification acquisition system;
and dividing the average input voltage by the average current to obtain the input impedance of the electroencephalogram amplification and acquisition system.
5. The method for characterizing the performance of a scalp brain electrical sensing electrode interface material according to claim 1, wherein the step of preparing N scalp brain electrical sensing test electrodes for the electrode interface material to be characterized comprises:
preparing N from the electrode interface material to be characterized by machining1The prepared electrodes are the same in size and shape;
and performing calibration test on the prepared electrodes, and after removing the prepared electrodes with the resistance values exceeding the preset range, selecting N residual electrodes as scalp electroencephalogram sensing test electrodes.
6. The method for characterizing the performance of the scalp electroencephalogram sensing electrode interface material according to claim 3, wherein the step of building a DC offset potential test circuit and acquiring the DC offset potential of each group of test electrodes through the DC offset potential test circuit comprises the following steps:
building a direct current offset potential test circuit, wherein the direct current offset potential test circuit comprises any group of test electrodes and a high-precision voltage tester, and the test electrodes are arranged on the surface of the skin of a human body at preset intervals; the preset distance is 5-10 cm;
and measuring each group of test electrodes by using the direct current offset potential test circuit respectively, and obtaining the direct current offset potential of each group of test electrodes after the reading of the high-precision voltage tester is stable for 30-60 s.
7. The method for characterizing the performance of the scalp brain electrical sensing electrode interface material according to claim 3 or 6, wherein the step of constructing an alternating current impedance test circuit and acquiring the alternating current impedance of each group of test electrodes through the alternating current impedance test circuit comprises the steps of:
building an alternating current impedance test circuit, wherein the alternating current impedance test circuit comprises any one group of test electrodes, a signal generator, a high-precision current tester and a high-precision voltage tester; the signal generator is connected in series with the high-precision current tester and then connected in parallel with the high-precision voltage tester; the test electrodes are arranged on the surface of the skin of the human body and are spaced by a preset distance; the preset distance is 5-10 cm;
sinusoidal alternating-current voltage signals of 5-20 mV and 1-100 Hz are applied between the two electrodes of any one group through a signal generator, and the alternating-current impedance test circuit is adopted to measure N/2 groups of test electrodes respectively to obtain the alternating-current impedance of each group of test electrodes.
8. The method for characterizing the performance of a scalp brain electrical sensing electrode interface material according to claim 7, wherein the step of building a polarization voltage test circuit, and the step of collecting the polarization voltage amplitude of each group of test electrodes by the polarization voltage test circuit, comprises:
a polarization voltage test circuit is set up, and the polarization voltage test circuit comprises any group of test electrodes, a signal generator, a high-precision current tester and a high-precision voltage tester; the signal generator is connected in series with the high-precision current tester and then connected in parallel with the high-precision voltage tester; the test electrodes are arranged on the surface of the skin of the human body and are spaced by a preset distance; the preset distance is 5-10 cm;
and applying sinusoidal alternating voltage signals of 10-100 muV and 1-100 Hz between the two electrodes of any group through a signal generator, and measuring N/2 groups of test electrodes by adopting a polarization voltage test circuit respectively to obtain the polarization voltage amplitude of each group of test electrodes.
9. The method for characterizing the performance of a scalp brain electrical sensing electrode interface material according to claim 8, wherein the step of obtaining electrochemical index parameters of the electrode interface material to be characterized comprises:
averaging the DC offset potentials of all groups of test electrodes, and taking the result as the DC offset potential of the electrode interface material to be characterized;
averaging the alternating current impedance of all groups of test electrodes, and taking the result as the alternating current impedance of the electrode interface material to be characterized;
and averaging the polarization voltage amplitudes of all groups of test electrodes, and taking the result as the polarization voltage amplitude of the electrode interface material to be characterized.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810831114.9A CN109009105B (en) | 2018-07-26 | 2018-07-26 | Performance characterization method of scalp electroencephalogram sensing electrode interface material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810831114.9A CN109009105B (en) | 2018-07-26 | 2018-07-26 | Performance characterization method of scalp electroencephalogram sensing electrode interface material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109009105A CN109009105A (en) | 2018-12-18 |
| CN109009105B true CN109009105B (en) | 2021-01-01 |
Family
ID=64645375
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810831114.9A Active CN109009105B (en) | 2018-07-26 | 2018-07-26 | Performance characterization method of scalp electroencephalogram sensing electrode interface material |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109009105B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110074778A (en) * | 2019-05-29 | 2019-08-02 | 北京脑陆科技有限公司 | A kind of extensive brain electrosleep monitoring system based on EEG equipment |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101726518A (en) * | 2009-12-24 | 2010-06-09 | 福建师范大学 | Method for measuring electrical conductivity of solution |
| CN107468241A (en) * | 2016-06-07 | 2017-12-15 | 汪子锋 | Brain electricity cap |
| CN107485786A (en) * | 2017-09-18 | 2017-12-19 | 电子科技大学 | Implantation evaluation system of full subcutaneous implantation type cardioverter defibrillator S _ ICD |
| CN108186013A (en) * | 2012-06-08 | 2018-06-22 | 美敦力迷你迈德公司 | Application of the electrochemical impedance spectroscopy in sensing system, equipment and associated method |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6696844B2 (en) * | 1999-06-04 | 2004-02-24 | Engineering & Research Associates, Inc. | Apparatus and method for real time determination of materials' electrical properties |
| US6577112B2 (en) * | 2001-03-09 | 2003-06-10 | The Lubrizol Corporation | Method and apparatus for on-line monitoring of quality and/or condition of highly resistive fluids |
| US10285617B2 (en) * | 2013-06-06 | 2019-05-14 | Lifelens Technologies, Llc | Modular physiologic monitoring systems, kits, and methods |
-
2018
- 2018-07-26 CN CN201810831114.9A patent/CN109009105B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101726518A (en) * | 2009-12-24 | 2010-06-09 | 福建师范大学 | Method for measuring electrical conductivity of solution |
| CN108186013A (en) * | 2012-06-08 | 2018-06-22 | 美敦力迷你迈德公司 | Application of the electrochemical impedance spectroscopy in sensing system, equipment and associated method |
| CN107468241A (en) * | 2016-06-07 | 2017-12-15 | 汪子锋 | Brain electricity cap |
| CN107485786A (en) * | 2017-09-18 | 2017-12-19 | 电子科技大学 | Implantation evaluation system of full subcutaneous implantation type cardioverter defibrillator S _ ICD |
Non-Patent Citations (3)
| Title |
|---|
| 6种生物电极在颅脑电阻抗成像中的性能比较研究;徐世伟,等;《医疗卫生装备》;20111231;全文 * |
| Quantitative Studies on Electrode Material Properties by Means of the Cavity Microelectrode;Locatelli C , 等;《Analytical Chemistry》;20111231;全文 * |
| 面向穿戴式脑电系统的主动干电极传感器;黄涌,等;《仪表技术与传感器》;20171231(第2期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109009105A (en) | 2018-12-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Otto et al. | Voltage pulses change neural interface properties and improve unit recordings with chronically implanted microelectrodes | |
| Prasad et al. | Quantifying long-term microelectrode array functionality using chronic in vivo impedance testing | |
| Zhou et al. | Characterizing the complexity of spontaneous motor unit patterns of amyotrophic lateral sclerosis using approximate entropy | |
| CA2278520C (en) | A medical device for the diagnosis of cartilage degeneration via spatial mapping of compression-induced electrical potentials | |
| US20140350432A1 (en) | Assessment of relative proportions of adrenergic and cholinergic nervous receptors with non-invasive tests | |
| CN86105980A (en) | Bioelectric signal measuring apparatus | |
| MacIsaac et al. | Fatigue estimation with a multivariable myoelectric mapping function | |
| CN103405225A (en) | Method, apparatus and device for obtaining pain feeling evaluation indexes | |
| Zhou et al. | MUAP number estimates in surface EMG: template-matching methods and their performance boundaries | |
| CN109009105B (en) | Performance characterization method of scalp electroencephalogram sensing electrode interface material | |
| Hernan et al. | Methodological standards and functional correlates of depth in vivo electrophysiological recordings in control rodents. A TASK 1‐WG 3 report of the AES/ILAE Translational Task Force of the ILAE | |
| Rohlén et al. | Optimization and comparison of two methods for spike train estimation in an unfused tetanic contraction of low threshold motor units | |
| Blok et al. | Motor unit action potential topography and its use in motor unit number estimation | |
| CN104523271A (en) | Myoelectricity pain measurement method and device for clinical use | |
| Amorim et al. | Application of surface electromyography in the dynamics of human movement | |
| CN101856221A (en) | Detection system for determining damage degree and damage positions of spinal cord | |
| CN115966308A (en) | Method, system and device for detecting and quantifying sleep memory activity level | |
| EP0833585A1 (en) | Method and apparatus for use in imaging a body | |
| CN2645609Y (en) | Brain wave psychological tester | |
| Holobar et al. | A signal-based approach for assessing the accuracy of high-density surface EMG decomposition | |
| CN203208022U (en) | Electroencephalograph | |
| CN1611183A (en) | Subhealth detecting device and method based on human body channel biological electric signal | |
| CN2315900Y (en) | Measurer for organ pathologic change | |
| CN113017618A (en) | Rapid diagnosis instrument for upper limb myotonic dyskinesia | |
| CN112568912A (en) | Depression biomarker identification method based on non-invasive electroencephalogram signals |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |