An online three-class Transcranial Doppler ultrasound brain computer interface

作者：Goyal Anuja; Samadani Ali Akbar; Guerguerian Anne Marie; Chau Tom^*

来源：Neuroscience Research, 2016, 107: 47-56.

DOI：10.1016/j.neures.2015.12.013

• Transcranial Doppler ultrasound
• Brain computer interface
• Spatial task
• Motor imagery task
• Lateralization
• Online

Brain computer interfaces (BCI) can provide communication opportunities for individuals with severe motor disabilities. Transcranial Doppler ultrasound (TCD) measures cerebral blood flow velocities and can be used to develop a BCI. A previously implemented TCD BCI system used verbal and spatial tasks as control signals; however, the spatial task involved a visual cue that awkwardly diverted the user's attention away from the communication interface. Therefore, vision-independent right-lateralized tasks were investigated. Using a bilateral TCD BCI, ten participants controlled online, an on-screen keyboard using a left-lateralized task (verbal fluency), a right-lateralized task (fist motor imagery or 3D-shape tracing), and unconstrained rest. 3D-shape tracing was generally more discernible from other tasks than was fist motor imagery. Verbal fluency, 3D-shape tracing and unconstrained rest were distinguished from each other using a linear discriminant classifier, achieving a mean agreement of K = 0.43 + 0.17. These rates are comparable to the best offline three-class TCD BCI accuracies reported thus far. The online communication system achieved a mean information transfer rate (ITR) of 1.08+ 0.69 bits/min with values reaching up to 2.46 bits/min, thereby exceeding the ITR of previous online TCD BCIs. These findings demonstrate the potential of a three-class online TCD BCI that does not require visual task cues.

• 出版日期2016-6