Auditory Brain Computer Interface Research Based On Bone Conduction

Brain Computer Interface(BCI)is a kind of system for direct communication between brain and computers or other electric devices without using peripheral nerves and muscles.BCI is the only way to communicate with the outside world for the locked in syndrome patients.The research institutions at home and abroad have conducted a lot of research on the brain computer interface technology based on the visual paradigm and auditory paradigm of air conduction.They have achieved great achievements.Locked-in syndrome patients,however,as the illness aggravating,seeing and hearing ability also can appear a certain degree of degradation,or the patient itself under the influence of middle ear disease,air conduction hearing pathway is completely blocked,it makes the way of brain-computer interface system running effect,or even completely unable to work.In the presence of air conduction hearing pathway exists obstacle,based on the bone conduction mode as the breakthrough point,auditory brain computer interface technology was studied.Bone conduction mode relative to the air conduction mode,and is featured by strong anti-interference,the characteristics of the unaffected by middle ear disease.The research of this technology,which can widen the scope of application to auditory BCI,improve the operation efficiency of BCI system.In this paper,the bone conduction and air conduction of BCI has carried on the contrast research.The main contributions this paper have been listed as below:1.The dichotic listening paradigm was brought to the auditory BCI experiments.The bone conduction and air conduction of auditory ERPs were extracted from subjects.2.The bone conduction and air conduction of auditory ERP waveform were analyzed.The results show that in the two kinds of sound conduction mode,target stimulation evoked the waveform of N200,P300 and N2 ac.The peak of N200 and N2 ac in bone conduction were significantly higher than air conduction.But the peak of P300 between air conduction and bone conduction has no significant difference.3.Compared the difference of brain networks and EEG map based on the two sound conduction ways during different time period and spatial distribution.4.The Coherent averaging method were used to exacted auditory ERPs of N200 and P300 were extracted.To complete the pattern recognition based on support vector machine,has carried on the research of brain-computer interface technology.The results showed that the classification accuracy of bone conduction in significantly higher than the classification accuracy of air conduction in a single lead.On the lead in adopting multiple classification,the bone conduction classification accuracy was still significantly higher than the air conduction.The result also showed that the accuracy of bone conduction in optimal electrode or combination electrode at all subjects can reach more than 80%.It proved that the way of bone conduction brain-computer interface technology is feasible and effective.