Development of Biofeedback System Adapting EEG and Evaluation of its Response Quality

Transcription

1 Development of Biofeedback System Adapting EEG and Evaluation of its Response Quality Tsuruoka National College of Technology Shishido Laboratory Keiji WATARAI

2 1 Background B C I (Brain Computer Interface) New Human Interface E E G (Electroencephalogram) Emotional states of humans

3 1 Background Brain New Human Interface Signal to control Use of senses Send electricity Moving muscle Control Directly Operate joystick Send electricity Machine

4 2 What s EEG? E E G FFT EEG is the recording of electronic activity produced by neurons within the brain Range of Frequency [Hz] Type of EEG 0.1 ~ 3 δ 3 ~ 7 θ 8~12 12~20 21~30 30~50 α Low β High β γ

5 3 Purpose of research To Develop BCI models adapting EEG Biofeedback system which is able to show humans Emotional states Control actuators understanding vital signs Examine Response Quality of actuator from the point of using Emotion as Input

6 4 Experimental procedure Examinee Measure EEG Cut Artifact Evaluate Emotional states Bluetooth Microcomputer Control motor USB PC Record data Receive Value of Emotional states Control motor Biofeedback Right:Attention Left:Meditation

7 5 Instrumentation Reference electrode EEG Sensor Measuring electrode Mindset / Neurosky 512 Sampling per second One EEG Channel Classify brainwave to five Evaluate Emotional States of Attention and Meditation Component Arduino / Smart Projects DC Motor / TAMIYA BlueSMiRF / Sparkfun Module

8 Experimental scenery

9 6 Result 6-1 Relationship between Artifact and Operability Artifact stagnated in 13, hardly converged to 0 Value of Emotional states and Artifact Feedback system was uncertain Unstable Input Signal Output was intermitted, Operability was limited

10 6 Result 6-2 Relationship between Emotions and EEG Attention High Frequency of EEG Beta(β), Gamma(γ) Meditation Low Frequency of EEG Delta(δ), Theta(θ), Alpha(α) Prevalence of EEG were reflected to Emotional Values

11 7 Discussion To improve Operability, Setting border line of Artifact under 13 Using Prevalence of EEG as Input signal to actuator Circulate Biofeedback system Output is reflective of User s intention Improvement of Response Quality

12 8 Conclusion 1 Evaluation of Operability If Artifact is the criteria of Input, Output system is restricted, examinee feel stress 2 Relationship between Emotional states and EEG Low frequency of EEG reflect to Meditation High frequency of EEG reflect to Attention Prevalence of each EEG type reflect to Emotional states

13 The author would like to thank, 4I Kazuki TAMURA Yu SAITO with technical supports and analysis

14 Thank you for your attention

15 Artifact Value Reasons of Artifact value Countermeasure Non - contact an electrode Not enough to connect an electrode Blinking Eye movement ~40 12~13 Press the electrode pad Close eyes Perspiration 13~25 Wiping with alcohols Electromyogram 12~40 Remain stationary Other electronic devices influence 12~13 Separate electronic device

16 What s FFT? X k = Discrete Fourier Transform N 1 X n n=0 e i2πkn/n k = 1, 2, N 1 Fast Fourier Transform O( N 2 ) O( N logn )

17 5 Scenery of Remote control

18 1 Background Technical problems of BCI New Human Interface 1 Accuracy of EEG 2 Reliability of Measurement 3 Responsibility from Machine Amplification Noise Spatial Resolution EEG Problems