Evaluation of Switch and Continuous Navigation Paradigms to Command a Brain-Controlled Wheelchair

Area of Science:

• Neuroscience
• Rehabilitation Engineering
• Human-Computer Interaction

Background:

• Brain-computer interfaces (BCIs) enable communication for individuals with severe motor dysfunction using electroencephalographic (EEG) signals.
• Brain-controlled wheelchairs (BCWs) offer mobility but face challenges with continuous control, particularly for sustained forward movement using sensorimotor rhythms (SMR).

Purpose of the Study:

• To evaluate the feasibility of continuous versus switch control modes for BCWs.
• To compare user performance and experience with SMR-modulated right-hand motor imagery tasks in BCW navigation.

Main Methods:

• 10 able-bodied users navigated a BCW using continuous and switch control paradigms after achieving a 30% error rate threshold.
• Navigation involved a straight path with alternating forward and stationary sections.
• Usability was assessed via effectiveness, efficiency, satisfaction, time, command selection, confusion matrix, NASA-TLX, and custom questionnaires.

Main Results:

• Switch control demonstrated higher accuracy (0.72 ± 0.05) compared to continuous control (0.59 ± 0.17).
• Users completed forward sections faster with switch control (15.47 ± 3.43 s) versus continuous control (42.2 ± 28.7 s).
• Continuous control was more effective for maintaining stationary positions (42.45 ± 16.01 s) compared to switch control (24.35 ± 10.94 s).

Conclusions:

• The optimal BCW control mode depends on individual user abilities and task requirements.
• Switch control is recommended for forward navigation segments due to improved speed and accuracy.
• Continuous control may be preferable for tasks requiring precise stopping and holding positions.