Comparing the Use of Single vs. Multiple Combined Abilities in Conducting Complex Computer Tasks Hands-free

Area of Science:

• Rehabilitation Engineering
• Human-Computer Interaction
• Assistive Technology

Background:

• Assistive technologies often focus on a single remaining ability for individuals with physical disabilities.
• Improving computer access for users with severe motor impairments, such as tetraplegia, remains a significant challenge.
• Multimodal systems offer a potential avenue to enhance computer interaction by integrating diverse user abilities.

Purpose of the Study:

• To investigate if combining multiple user abilities via a multimodal Tongue Drive System (mTDS) can improve computer access quality.
• To compare the performance of mTDS against a unimodal tongue drive system (TDS) and a traditional keyboard and mouse (KnM) setup.
• To evaluate the effectiveness of mTDS across various computer access tasks, including tapping, maze navigation, gaming, and email composition.

Main Methods:

• 15 able-bodied subjects performed four computer access tasks without using their hands.
• Subjects utilized the multimodal Tongue Drive System (mTDS) for proportional cursor control (head motion), discrete clicks (tongue gestures), and speech recognition typing.
• Performance was benchmarked against a unimodal tongue drive system (TDS) and the gold standard keyboard and mouse (KnM).

Main Results:

• mTDS and TDS achieved 21-22.4% of mouse throughput in center-out tapping, with mTDS showing lower error rates.
• Maze navigation throughput for mTDS and TDS was 16.6% and 21.8% of mouse throughput, respectively.
• Participants scored 72.32% higher in a game using mTDS than TDS; email generation time with mTDS was approximately twice as long as KnM, with 78.1% typing accuracy.

Conclusions:

• Engaging multimodal abilities significantly improved performance in complex tasks like email composition compared to unimodal systems.
• Multimodal input enhanced interaction accuracy, though performance on simpler tasks was comparable to unimodal systems.
• Head motion for cursor control in mTDS led to better performance in less constrained tasks (game) than in highly constrained tasks (maze).