Frequency-phase brain-computer interface decoding method and device based on fft spectrum correction

Abstract

The invention discloses a frequency phase brain-computer interface decoding method based on FFT spectrum correction. The method comprises the steps that digital sampling is carried out on collected SSVEP signals to obtain N discrete samples, windowing is carried out on the discrete samples for FFT analysis, and the spectrum of the SSVEP signals is obtained; a peak value spectrum is sought out, the phase value of the peak value spectrum is recorded, the secondary high spectrum position needs to be determined, and a ratio is obtained; a frequency offset estimated value is obtained through the ratio, and corresponding phase estimated values are obtained based on the frequency offset estimated value; a stimulation object is recognized by solving measurement phase errors of two corrected stimulation frequencies. According to the decoding device, the collected signals are sampled by an analog-digital converter to obtain a sample sequence, the collected signals enter into a DSP device in a parallel digital input mode, internal processing is carried out, and parameter estimation of the signals is obtained; then a command sent by a tested person is displayed through an output drive and a display module of the output drive, and finally external equipment responds to the corresponding command.

Description

technical field

[0001] The invention relates to the field of digital signal processing, in particular to a frequency-phase brain-computer interface decoding method and device based on FFT spectrum correction. , and the command decoding is realized by extracting the phase information through the FFT spectrum correction method. Background technique

[0002] brain-computer interface [1] (Brain-Computer Interface, abbreviated as BCI) is a direct information exchange and control channel established between the human brain and a computer or other electronic devices. It does not depend on the normal output pathways of the brain (peripheral nervous system and muscle tissue). ), is a new communication and control method [2] . It aims to establish a direct communication channel between the human brain and the outside world, identify brain instructions by extracting the characteristics of EEG signals, and finally complete the direct control of external devices by the brain. [0003...

Examples

Embodiment Construction

[0036] In order to make the objectives, technical solutions and advantages of the present invention clearer, the embodiments of the present invention are further described in detail below.

[0037] In order to break through this bottleneck, the present invention uses frequency and phase to mix and encode the SSVEP signal on the basis of the mixed-frequency phase-difference excitation method and perform decoding processing, and proposes a new type of frequency-phase brain computer based on FFT spectrum correction. Interface decoding method and device thereof. This method can improve the problem of inaccurate phase measurement due to the leakage of FFT spectrum when the SSVEP excitation signal has a frequency offset, accurately calculate the corresponding excitation phase value, and identify the target block, and finally relax the limit on the target excitation frequency and increase the The purpose of motivating target numbers.

[0038] figure 1 This is the basic block diagra...

technical field

[0001] The invention relates to the field of digital signal processing, in particular to a frequency-phase brain-computer interface decoding method and device based on FFT spectrum correction. , and the command decoding is realized by extracting the phase information through the FFT spectrum correction method. Background technique

[0002] brain-computer interface [1] (Brain-Computer Interface, abbreviated as BCI) is a direct information exchange and control channel established between the human brain and a computer or other electronic devices. It does not depend on the normal output pathways of the brain (peripheral nervous system and muscle tissue). ), is a new communication and control method [2] . It aims to establish a direct communication channel between the human brain and the outside world, identify brain instructions by extracting the characteristics of EEG signals, and finally complete the direct control of external devices by the brain. [0003...

Examples

Embodiment Construction

[0036] In order to make the objectives, technical solutions and advantages of the present invention clearer, the embodiments of the present invention are further described in detail below.

[0037] In order to break through this bottleneck, the present invention uses frequency and phase to mix and encode the SSVEP signal on the basis of the mixed-frequency phase-difference excitation method and perform decoding processing, and proposes a new type of frequency-phase brain computer based on FFT spectrum correction. Interface decoding method and device thereof. This method can improve the problem of inaccurate phase measurement due to the leakage of FFT spectrum when the SSVEP excitation signal has a frequency offset, accurately calculate the corresponding excitation phase value, and identify the target block, and finally relax the limit on the target excitation frequency and increase the The purpose of motivating target numbers.

[0038] figure 1 This is the basic block diagra...

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