Testing the usability of a voice control system for assistive robotic arms in people with neurological conditions.

The acceptance and effective use of assistive robotic arms by people with neurological conditions strongly depend on the usability of the control interface. This study evaluated the usability of a voice control system for an assistive robotic arm in both healthy participants and individuals with neurological disorders, and compared its applicability and effectiveness with conventional joystick control. A voice control module based on automatic speech recognition and text-to-speech feedback was developed for a commercially available 6-degree-of-freedom assistive robotic arm. The system was implemented using the Robot Operating System (ROS) and an Italian speech-recognition knowledge base. Voice control was tested in 20 healthy subjects and 20 individuals with varying levels of upper-limb impairment due to neurological diseases. Participants performed representative activities of daily living, including (i) pressing an elevator button, (ii) picking up a TV remote control, and (iii) pouring water into a glass. Task completion time, usability, and speech recognition accuracy were assessed and compared between voice and joystick control. All participants except one with neurological impairment were able to successfully use the voice interface, whereas only 11 could operate the joystick. Voice control achieved a recognition accuracy of 87% and a System Usability Scale (SUS) score corresponding to a “Good” adjective rating. Overall, these results indicate that voice control represents a promising and inclusive access modality, with the potential to improve the usability of assistive robotic arms, particularly for individuals with severe motor impairments.