Design And Implementation Of Brain-computer Interface Visual Stimulator Based On DirectShow

Brain-computer interface (BCI) is an EEG-based communication and control system between human and computer or other electric devices, which does not depend on the brain's normal output channels of peripheral nerves and muscles. It's a novel kind of human interface. Now dozens of the world BCI research group have different ideas on the study of BCI, and their ideas can be classified into two categories based on ways of signal generation: one is the BCI based on evoked EEG and the other is the BCI based on spontaneous EEG. In this paper, the BCI system we researched is based on the spontaneous EEG. This paper mainly talks about visual stimulator's design and implementation, and aims to do some preliminary research for the application of BCI in the field of rehabilitation medicine engineering.This paper introduces some basic principles of BCI and imagine movement, conducts a study on the stimulator and proposed two design solutions for visual stimulator. Then this paper achieves the stimulator for specific needs and design. Finally this paper designs the experimental procedure of brain-computer interface and completes the experiment of brain-computer interface. Specific tasks of this paper are as follows:1. Research and design the stimulator. In this paper, the principles of BCI and imagine movement is studied and two visual stimulators are designed: video visual stimulator and image visual stimulator. According to its characteristics and difficulties, this paper studies and compares various techniques, chooses a better technology solution—DirectShow, and makes the depth study for the application of DirectShow.2. Implement two visual stimulators. This paper uses DirectShow technology for video stimulator in the video playback control of video files, capture, frame operation, video frame and parallel data communication, and video file's custom play process; Image visual stimulator implement precise timing of image sequence playback, image and parallel data communication and add some voice prompts. What's more, technical program use a custom DirectShow filter method. To achieve it can solve the precise timing of image sequence playback and custom image sequence playback process problems. Stimulator time precision experiments show that this method achieved the expected requirements and provided a good guarantee for data analysis of EEG.3. Study on the experiment of brain-computer interface system, design experimental procedure of brain-computer interface system based on imagine movement, set up some controlled parameters of experiments such as sample number cycle number, interval time interval picture color and so on. Then this paper successfully completes a number of experiments. Finally, the experiments which analyze and identify the EEG data of imaging left-right hands movement show that two stimulators design and implementation is successful.