Method for testing analog-to-digital conversion performance of electroencephalogram acquisition equipment

Abstract

The invention relates to a method for testing analog-to-digital conversion performance of electroencephalogram acquisition equipment, belongs to the technical field of testing, and solves the problem that an existing method for testing the analog-to-digital conversion performance of the electroencephalogram acquisition equipment mainly uses a special electroencephalograph detector to test according to a method specified by an electroencephalograph type evaluation outline. The evaluation equipment is single, the coverage is narrow, and the accuracy is not high. The test method comprises the following steps: sequentially carrying out acquisition precision test, noise test, common-mode rejection ratio test and channel number test on each channel of the electroencephalogram acquisition equipment with multiple channels; if a certain channel is unqualified in the certain test, stopping the test and judging that the electroencephalogram acquisition equipment is unqualified; and if all the channels pass all the tests, determining that the electroencephalogram acquisition equipment is qualified. The test method has the advantages that the evaluation equipment for the analog-to-digital conversion performance of the electroencephalogram acquisition equipment is free, the test coverage is wide, the accuracy rate is high, and the adaptability to different electroencephalogram acquisition equipment is good.

Description

Technical Field

[0001] The present invention relates to the field of testing technology, and in particular to a method for testing analog-to-digital conversion performance of electroencephalogram (EEG) acquisition equipment. Background Art

[0002] The signal acquisition principle of EEG acquisition equipment is the process of collecting weak electrical signals emitted by the human brain and converting them into digital signals. Brain waves are electrical signals emitted by brain neurons, and these signals can be measured through the scalp.

[0003] The principle of EEG signal acquisition is an important part of neuroscience research. It can help us gain a deeper understanding of the function and behavior of the human brain and help treat various neurological diseases.

[0004] The current test method for the analog-to-digital conversion performance of EEG acquisition equipment mainly uses a dedicated EEG detector and performs tests according to the methods specified in the EEG type evaluation outline. This method has the disadvantages of single evaluation equipment, narrow coverage, and low accuracy. Summary of the invention

[0005] In view of the above analysis, an embodiment of the present invention aims to provide a method for testing the analog-to-digital conversion performance of an EEG acquisition device, so as to solve the problem that the evaluation equipment for the analog-to-digital conversion performance of the existing EEG acquisition device is single, has a narrow coverage, and has a low accuracy.

[0006] On the one hand, an embodiment of the present invention provides a method for testing the analog-to-digital conversion performance of an EEG acquisition device, wherein the EEG acquisition device includes multiple channels, and each channel of the EEG acquisition device is sequentially tested for acquisition accuracy, noise, and common mode rejection ratio, and the next test is performed after all channels pass the previous test;

[0007] If one of the channels of the EEG acquisition device fails the acquisition accuracy test, noise test, and common mode rejection ratio test, the test is terminated and the EEG acquisition device is determined to be unqualified; if all channels of the EEG acquisition device pass the above tests, a channel number test is performed to obtain the number of available channels of the EEG acquisition device.

[0008] Furthermore, in the acquisition accuracy test, common mode rejection ratio test, and channel number test, a signal calibrator with an acquisition accuracy one order of magnitude higher than that of the EEG acquisition device under test is used as a signal input source to test the EEG acquisition device under test.

[0009] Furthermore, the acquisition accuracy test includes:

[0010] The following tests are performed on each channel of the EEG acquisition device under test:

[0011] Get the minimum voltage value ACQ that can be collected by the EEG acquisition device under testmin ;According to the minimum voltage value ACQ that can be collected by the EEG acquisition device under test min The signal calibrator outputs voltage values ​​of n×ACQ in the order of n=1,2…k. min The DC voltage signal is sent to the signal input terminal of the current channel of the EEG acquisition device under test. After the voltage is collected by the EEG acquisition device under test, the collected voltage is recorded as VC n ; According to the collected voltage VC n And the minimum voltage value ACQ that can be collected min Determine whether the current channel acquisition accuracy is qualified; where 11≤k≤50;

[0012] If the acquisition accuracy of all channels is qualified, it is determined that the acquisition accuracy of the tested EEG acquisition device is qualified.

[0013] Furthermore, the minimum voltage ACQ that can be collected by the EEG acquisition device under test is obtained. min for:

[0014] ACQ min =(V2-V1) / (2 M );

[0015] Among them, V2 and V1 are the upper and lower limits of the input voltage range of the EEG acquisition device under test, and M is the expected resolution of the EEG acquisition device under test.

[0016] Furthermore, the voltage VC collected n And the minimum voltage value ACQ that can be collected min Judging whether the current channel acquisition accuracy is qualified includes:

[0017] Subtract the difference between the acquisition results of the current channel based on two adjacent different input voltages and the minimum voltage value that can be collected to obtain VC m -VC m-1 -ACQ min ; Where m = 2, 3…k; if all VC m -VC m-1 -ACQ min If the values ​​are all within the inherent noise range of the signal calibrator, the acquisition accuracy of the current channel is qualified.

[0018] Furthermore, the noise test includes:

[0019] Short-circuit the differential input positive terminal and the differential input negative terminal of each channel of the EEG acquisition device that has passed the acquisition accuracy test. Calculate the root mean square Vrms of the N voltage values ​​collected by each channel within the set first acquisition time. Then the input noise of the channel is Where V 1 、V 2 ...Vn is the N voltages collected within the set collection time period;

[0020] If the root mean square values ​​Vrms of all channels are within the first threshold, it is determined that the input noise of the tested EEG acquisition device is qualified.

[0021] Furthermore, the common mode rejection ratio test includes:

[0022] The following tests are performed on each channel of the EEG acquisition device under test:

[0023] The positive and negative ends of the signal output of the signal calibrator are respectively connected to the positive input end and the reverse input end of the current channel of the measured EEG acquisition device; the signal calibrator outputs a periodic signal, the maximum amplitude of which is the maximum input voltage that can be collected by the measured EEG acquisition device; the peak-to-peak value of the voltage collected by the measured EEG acquisition device is recorded as V2';

[0024] Keep the signal generated inside the signal calibrator unchanged, turn off the output, keep the positive input terminal of the current channel of the EEG acquisition device under test connected unchanged, ground the reverse input terminal, turn on the output of the signal calibrator, and record the peak-to-peak voltage collected by the EEG acquisition device under test as V1';

[0025] Calculate the common mode rejection ratio of the current channel based on the peak-to-peak voltages V1' and V2';

[0026] If the common mode rejection ratios of all channels of the tested EEG acquisition device are greater than the second threshold, it is determined that the common mode rejection ratio of the tested EEG acquisition device is qualified.

[0027] Furthermore, the periodic signal output by the signal calibrator is a sinusoidal signal with a frequency of 10 Hz, and the amplitude of the sinusoidal signal is the maximum input voltage that can be collected by the measured EEG acquisition device.

[0028] Furthermore, the channel number test includes:

[0029] The positive terminal of the signal output of the signal calibrator is simultaneously connected to the positive input terminals of all channels of the tested EEG acquisition device, and the reverse input terminals of all channels of the tested EEG acquisition device are grounded. If the current channel of the tested EEG acquisition device can restore the input signal of the signal calibrator, the current channel of the tested EEG acquisition device is determined to be qualified; otherwise, the current channel of the tested EEG acquisition device is determined to be unqualified and marked;

[0030] Record the number of channels of the EEG acquisition device that pass the test.

[0031] Furthermore, the peak-to-peak value of the output sinusoidal signal of the signal calibrator does not exceed the maximum input range of the tested EEG acquisition device, and the frequency does not exceed the maximum acquisition frequency of the tested EEG acquisition device; the tested EEG acquisition device continuously acquires the sinusoidal voltage signal within the second acquisition time, and records the voltage values ​​collected by all channels. If the voltage signals collected by the tested channels can be restored to sinusoidal signals with the input peak-to-peak value and frequency, it proves that the channels meet the requirements.

[0032] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0033] 1. The present invention proposes a method for testing the analog-to-digital conversion performance of EEG acquisition equipment, and standardizes the testing process for the analog-to-digital conversion performance of EEG acquisition equipment; first, the acquisition accuracy of the EEG acquisition equipment is tested, and after determining that the equipment accuracy meets the requirements, an input noise test is performed. Only after the acquisition accuracy is determined, the subsequent noise test is accurate, ensuring that the input noise of the tested EEG acquisition equipment is within the expected range and will not affect the accuracy of subsequent tests. Then a common-mode rejection ratio test is performed to ensure the common-mode anti-interference capability of the tested EEG acquisition equipment, and finally a channel number test is performed. Only when the first three are passed, the channel number test is meaningful. After completing the entire test cycle in accordance with the prescribed process and test method, a comprehensive test of the analog-to-digital conversion performance of the EEG acquisition equipment can be achieved. Through verified standard test methods, various performance evaluations of analog-to-digital conversion are carried out, providing a set of reliable and effective means for evaluating the analog-to-digital conversion performance of EEG acquisition equipment;

[0034] 2. In the acquisition accuracy test, common mode rejection ratio test, and channel number test, a signal calibrator with an acquisition accuracy one order of magnitude higher than that of the EEG acquisition device under test is used as the signal input source to test the EEG acquisition device under test. Performance testing can be carried out according to different EEG acquisition devices by selecting test equipment with corresponding accuracy, and objective performance evaluation results can be given; compared with the existing EEG acquisition device analog-to-digital conversion performance test method, it has the advantages of free evaluation equipment, high accuracy, and good adaptability to different EEG acquisition devices.

[0035] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0037] Figure 1 The present invention is a flow chart of a method for testing the analog-to-digital conversion performance of an EEG acquisition device. DETAILED DESCRIPTION

[0038] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0039] A specific embodiment of the present invention discloses a method for testing the analog-to-digital conversion performance of an electroencephalogram acquisition device. Figure 1 shown.

[0040] The EEG acquisition device includes multiple channels, and each channel of the EEG acquisition device is sequentially subjected to an acquisition accuracy test, a noise test, and a common mode rejection ratio test, and the next test is performed only after all channels pass the previous test;

[0041] If one of the channels of the EEG acquisition device fails the acquisition accuracy test, noise test, and common mode rejection ratio test, the test is terminated and the EEG acquisition device is determined to be unqualified; if all channels of the EEG acquisition device pass the above tests, a channel number test is performed to obtain the number of available channels of the EEG acquisition device.

[0042] During implementation, the test process of the present invention is linked one by one, and changing the order will distort the test results. First, the acquisition accuracy of the EEG acquisition device is tested. After determining that the equipment accuracy meets the requirements, the input noise test is performed. Only after the acquisition accuracy is determined first, the subsequent noise test is accurate, ensuring that the input noise of the tested EEG acquisition device is within the expected range and will not affect the accuracy of subsequent tests. Then, the common mode rejection ratio test is performed to ensure the common mode anti-interference ability of the tested EEG acquisition device. Finally, the number of channels test is performed. Only when the first three are passed, the number of channels test is meaningful to determine the number of effective channels of the tested EEG acquisition device. At this point, the analog-to-digital conversion performance test of the EEG acquisition device is completed. In addition, all channels must pass a certain test before performing the next test to improve the test efficiency.

[0043] After completing the entire test cycle according to the prescribed process and test methods, the coverage test of the analog-to-digital conversion performance of the EEG acquisition equipment can be achieved.

[0044] In the acquisition accuracy test, common mode rejection ratio test, and channel number test, a signal calibrator with an acquisition accuracy one order of magnitude higher than that of the EEG acquisition device under test is used as a signal input source to test the EEG acquisition device under test.

[0045] The acquisition accuracy test includes:

[0046] The following tests are performed on each channel of the EEG acquisition device under test:

[0047] Get the minimum voltage value ACQ that can be collected by the EEG acquisition device under test min ;According to the minimum voltage value ACQ that can be collected by the EEG acquisition device under test min The signal calibrator outputs voltage values ​​of n×ACQ in the order of n=1,2…k. min The DC voltage signal is sent to the signal input terminal of the current channel of the EEG acquisition device under test. After the voltage is collected by the EEG acquisition device under test, the collected voltage is recorded as VC n ; According to the collected voltage VC n And the minimum voltage value ACQ that can be collected min Determine whether the current channel acquisition accuracy is qualified; where 11≤k≤50;

[0048] If the acquisition accuracy of all channels is qualified, it is determined that the acquisition accuracy of the tested EEG acquisition device is qualified.

[0049] The minimum voltage value ACQ that can be collected by the measured EEG acquisition device is obtained min for:

[0050] ACQ min =(V2-V1) / (2 M );

[0051] Among them, V2 and V1 are the upper and lower limits of the input voltage range of the EEG acquisition device under test, and M is the expected resolution of the EEG acquisition device under test.

[0052] The voltage VC collected n And the minimum voltage value ACQ that can be collected min Judging whether the current channel acquisition accuracy is qualified includes:

[0053] Subtract the difference between the acquisition results of the current channel based on two adjacent different input voltages and the minimum voltage value that can be collected to obtain VC m -VC m-1 -ACQ min ; Where m = 2, 3…k; if all VC m -VC m-1 -ACQ min If the values ​​are all within the inherent noise range of the signal calibrator, the acquisition accuracy of the current channel is qualified.

[0054] If the acquisition accuracy of each channel of the tested EEG acquisition device is qualified, it is determined that the acquisition accuracy test of the tested EEG acquisition device is qualified.

[0055] The present invention inputs different voltages n×ACQ min, and collect data at different voltages, by calculating VC m -VC m-1 -ACQ min To judge the acquisition accuracy of the channel, the input voltage range covered by the test can be wider, and whether the acquisition accuracy of the device under various voltages can meet the requirements can be examined, so as to better verify the acquisition linearity and acquisition accuracy of the device under test.

[0056] The noise test includes:

[0057] Short-circuit the differential input positive terminal and the differential input negative terminal of each channel of the EEG acquisition device that has passed the acquisition accuracy test. Calculate the root mean square Vrms of the N voltage values ​​collected by each channel within the set first acquisition time. Then the input noise of the channel is Where V 1 、V 2 ...V n is the N voltages collected within the set collection time period;

[0058] If the root mean square values ​​Vrms of all channels are within the first threshold, it is determined that the input noise of the tested EEG acquisition device is qualified.

[0059] Specifically, the first threshold is 1-5 μV, and the first acquisition time is 10 seconds.

[0060] The common mode rejection ratio test includes:

[0061] The following tests are performed on each channel of the EEG acquisition device under test:

[0062] The positive and negative ends of the signal output of the signal calibrator are respectively connected to the positive input end and the reverse input end of the current channel of the measured EEG acquisition device; the signal calibrator outputs a periodic signal; the maximum amplitude of the periodic signal is the maximum input voltage that can be collected by the measured EEG acquisition device; the peak-to-peak value of the voltage collected by the measured EEG acquisition device is recorded as V2';

[0063] Keep the signal generated inside the signal calibrator unchanged, turn off the output, keep the positive input terminal of the current channel of the EEG acquisition device under test connected unchanged, ground the reverse input terminal, turn on the output of the signal calibrator, and record the peak-to-peak voltage collected by the EEG acquisition device under test as V1';

[0064] Calculate the common mode rejection ratio CMRR1 of the current channel based on the peak-to-peak voltages V1' and V2';

[0065] If the common mode rejection ratios of all channels of the tested EEG acquisition device are greater than the second threshold, it is determined that the common mode rejection ratio of the tested EEG acquisition device is qualified.

[0066] The signal calibrator outputs a periodic signal which is a sinusoidal signal with a frequency of 10 Hz, and the amplitude of the sinusoidal signal is the maximum input voltage that can be collected by the measured EEG acquisition device.

[0067] Specifically, the common mode rejection ratio CMRR1 is defined as:

[0068] CMRR1=20log(V1' / V2')dB;

[0069] Specifically, the second threshold is 80dB.

[0070] The purpose of this connection is to better simulate differential mode signals and common mode signals, and eliminate the interference of the test cable length and the surrounding electromagnetic environment on the test. The 10Hz sine signal can better simulate the representation of real EEG signals, and can more accurately reflect the common mode suppression ability of the EEG acquisition system under test when collecting actual human brain signals.

[0071] At the same time, in order to measure the upper limit of the performance of the measured EEG acquisition device during measurement, it is necessary to obtain the maximum common mode rejection ratio; to obtain the maximum common mode rejection ratio, the maximum amplitude of the periodic signal is set to the maximum input voltage that can be collected by the measured EEG acquisition device;

[0072] The channel number test includes:

[0073] The positive terminal of the signal output of the signal calibrator is simultaneously connected to the positive input terminals of all channels of the tested EEG acquisition device, and the reverse input terminals of all channels of the tested EEG acquisition device are grounded. If the current channel of the tested EEG acquisition device can restore the input signal of the signal calibrator, the current channel of the tested EEG acquisition device is determined to be qualified; otherwise, the current channel of the tested EEG acquisition device is determined to be unqualified and marked;

[0074] Record the number of channels of the EEG acquisition device that pass the test.

[0075] The peak-to-peak value of the output sinusoidal signal of the signal calibrator does not exceed the maximum input range of the tested EEG acquisition device, and the frequency does not exceed the maximum acquisition frequency of the tested EEG acquisition device; the tested EEG acquisition device continuously acquires the sinusoidal voltage signal within the second acquisition time, and records the voltage values ​​collected by all channels. If the voltage signals collected by the tested channels can be restored to sinusoidal signals with the input peak-to-peak value and frequency, it proves that the channels meet the requirements.

[0076] Specifically, the second acquisition time is 10 minutes. The output sinusoidal signal of the signal calibrator is a sinusoidal voltage signal with a peak-to-peak value of 1 mV and a frequency of 10 Hz.

[0077] This test method is not only used in delivered products, but can also be applied to pre-research projects. When a channel is found to be unqualified, it is marked and subsequently repaired or the unqualified channel is not used.

[0078] Compared with the prior art, the present embodiment provides a method for testing the analog-to-digital conversion performance of an EEG acquisition device. By standardizing the testing process for the analog-to-digital conversion performance of the EEG acquisition device, the method comprehensively evaluates the analog-to-digital conversion performance of the EEG acquisition device from different angles according to the acquisition accuracy test, input noise test, common mode rejection ratio test, and number of channels test. The method also uses verified standard testing methods to evaluate various performances of analog-to-digital conversion, thereby providing a set of reliable and effective means for evaluating the analog-to-digital conversion performance of the EEG acquisition device. The method can select test equipment with corresponding accuracy according to different EEG acquisition devices to carry out performance testing and provide objective performance evaluation results. Compared with the prior method for testing the analog-to-digital conversion performance of the EEG acquisition device, the method has the advantages of wide test coverage, freedom of evaluation equipment, high accuracy, and good adaptability to different EEG acquisition devices.

[0079] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0080] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for testing the analog-to-digital conversion performance of an electroencephalogram acquisition device, characterized in that: The EEG acquisition device includes multiple channels, and each channel of the EEG acquisition device is sequentially subjected to an acquisition accuracy test, a noise test, and a common mode rejection ratio test, and the next test is performed only after all channels pass the previous test; If one of the channels of the EEG acquisition device fails the acquisition accuracy test, noise test, and common mode rejection ratio test, the test is terminated and the EEG acquisition device is determined to be unqualified; if all channels of the EEG acquisition device pass the above tests, a channel number test is performed to obtain the number of available channels of the EEG acquisition device.

2. The method for testing the analog-to-digital conversion performance of an electroencephalogram acquisition device according to claim 1, characterized in that: In the acquisition accuracy test, common mode rejection ratio test, and channel number test, a signal calibrator with an acquisition accuracy one order of magnitude higher than that of the EEG acquisition device under test is used as a signal input source to test the EEG acquisition device under test.

3. The method for testing the analog-to-digital conversion performance of an electroencephalogram acquisition device according to claim 2, characterized in that: The acquisition accuracy test includes: The following tests are performed on each channel of the EEG acquisition device under test: Get the minimum voltage value ACQ that can be collected by the EEG acquisition device under test min ;According to the minimum voltage value ACQ that can be collected by the EEG acquisition device under test min The signal calibrator outputs voltage values ​​of n×ACQ in the order of n=1,2…k. min The DC voltage signal is sent to the signal input terminal of the current channel of the EEG acquisition device under test. After the voltage is collected by the EEG acquisition device under test, the collected voltage is recorded as VC n ; According to the collected voltage VC n And the minimum voltage value ACQ that can be collected min Determine whether the current channel acquisition accuracy is qualified; where 11≤k≤50; If the acquisition accuracy of all channels is qualified, it is determined that the acquisition accuracy of the tested EEG acquisition device is qualified.

4. The method for testing the analog-to-digital conversion performance of an electroencephalogram acquisition device according to claim 3, characterized in that: The minimum voltage value ACQ that can be collected by the measured EEG collection device is obtained min for: ACQ min =(V2-V1) / (2 M ); Among them, V2 and V1 are the upper and lower limits of the input voltage range of the EEG acquisition device under test, and M is the expected resolution of the EEG acquisition device under test.

5. The method for testing the analog-to-digital conversion performance of an electroencephalogram acquisition device according to claim 4, characterized in that: The voltage VC collected n And the minimum voltage value ACQ that can be collected min Judging whether the current channel acquisition accuracy is qualified includes: Subtract the difference between the acquisition results of the current channel based on two adjacent different input voltages and the minimum voltage value that can be collected to obtain VC m -VC m-1 -ACQ min ; Where m = 2, 3…k; if all VC m -VC m-1 -ACQ min If the values ​​are all within the inherent noise range of the signal calibrator, the acquisition accuracy of the current channel is qualified.

6. The method for testing the analog-to-digital conversion performance of an electroencephalogram acquisition device according to claim 1, characterized in that: The noise test includes: Short-circuit the differential input positive terminal and the differential input negative terminal of each channel of the EEG acquisition device that has passed the acquisition accuracy test. Calculate the root mean square (Vrms) of the N voltage values ​​collected by each channel within the set first acquisition time. Then, the input noise of the channel is Among them, V1, V2...V n is the N voltages collected within the set collection time period; If the root mean square values ​​Vrms of all channels are within the first threshold, it is determined that the input noise of the tested EEG acquisition device is qualified.

7. The method for testing the analog-to-digital conversion performance of an electroencephalogram acquisition device according to claim 2, characterized in that: The common mode rejection ratio test includes: The following tests are performed on each channel of the EEG acquisition device under test: The positive and negative ends of the signal output of the signal calibrator are respectively connected to the positive input end and the reverse input end of the current channel of the measured EEG acquisition device; the signal calibrator outputs a periodic signal, the maximum amplitude of which is the maximum input voltage that can be collected by the measured EEG acquisition device; the peak-to-peak value of the voltage collected by the measured EEG acquisition device is recorded as V2'; Keep the signal generated inside the signal calibrator unchanged, turn off the output, keep the positive input terminal of the current channel of the EEG acquisition device under test connected unchanged, ground the reverse input terminal, turn on the output of the signal calibrator, and record the peak-to-peak voltage collected by the EEG acquisition device under test as V1'; Calculate the common mode rejection ratio of the current channel based on the peak-to-peak voltages V1' and V2'; If the common mode rejection ratios of all channels of the tested EEG acquisition device are greater than the second threshold, it is determined that the common mode rejection ratio of the tested EEG acquisition device is qualified.

8. The method for testing the analog-to-digital conversion performance of an electroencephalogram acquisition device according to claim 7, characterized in that: The signal calibrator outputs a periodic signal which is a sinusoidal signal with a frequency of 10 Hz, and the amplitude of the sinusoidal signal is the maximum input voltage that can be collected by the measured EEG acquisition device.

9. The method for testing the analog-to-digital conversion performance of an electroencephalogram acquisition device according to claim 2, characterized in that: The channel number test includes: The positive terminal of the signal output of the signal calibrator is simultaneously connected to the positive input terminals of all channels of the tested EEG acquisition device, and the reverse input terminals of all channels of the tested EEG acquisition device are grounded. If the current channel of the tested EEG acquisition device can restore the input signal of the signal calibrator, the current channel of the tested EEG acquisition device is determined to be qualified; otherwise, the current channel of the tested EEG acquisition device is determined to be unqualified and marked; Record the number of channels of the EEG acquisition device that pass the test.

10. The method for testing the analog-to-digital conversion performance of an electroencephalogram acquisition device according to claim 9, characterized in that: The peak-to-peak value of the output sinusoidal signal of the signal calibrator does not exceed the maximum input range of the EEG acquisition device under test, and the frequency does not exceed the maximum acquisition frequency of the EEG acquisition device under test; The EEG acquisition device under test continuously acquires the sinusoidal voltage signal within the second acquisition time, and records the voltage values ​​acquired by all channels. If the voltage signals acquired by the channels under test can be restored to sinusoidal signals with the input peak-to-peak value and frequency, it proves that the channel meets the requirements.

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