Angela Abreu Rosa de Sá

Introduction: Driving a powered wheelchair is a complex task that requires the integration of motor, visual, and cognitive skills. The development of assistive technologies without appropriate assessment methods that help bridge the gap between users and developers may lead to abandonment and reduced engagement. Most assessments rely on explicit measures, such as performance metrics, or subjective tools like interviews and questionnaires. In contrast, implicit measures allow continuous inference of mental states during task execution. This study proposes the use of blink indices derived from electroencephalographic (EEG) signals as implicit metrics to estimate cognitive load during the use of a virtual reality wheelchair training simulator. Methods: A total of 25 participants (14 females and 11 males; mean age 26.50 ± 5.7 years) completed a predefined route using a virtual wheelchair simulator. Blink parameters, including frequency, duration, and velocity, were extracted from EEG signals during task performance. After completing the simulation, participants responded to the NASA Task Load Index (NASA-TLX) to assess subjective cognitive load, as well as the System Usability Scale (SUS) and the Igroup Presence Questionnaire (IPQ). Results: The findings showed that higher mental-visual demand was associated with decreases in blink frequency, duration, and velocity. Correlation analyses between NASA-TLX scores and blink parameters revealed weak to moderate associations. These results suggest partial convergence between subjective and physiological measures of cognitive load. Discussion: Blink-based indices derived from EEG signals provide relevant information regarding cognitive demand during wheelchair simulator use. However, blink parameters alone are insufficient to reliably infer cognitive load. When combined with subjective questionnaires, implicit physiological metrics may offer a more comprehensive assessment than questionnaires alone, supporting the development and refinement of assistive training technologies.

(1) Background: One of the main cardinal signs of Parkinson’s disease (PD) is rigidity, whose assessment is important for monitoring the patient’s recovery. The wrist is one of the joints most affected by this symptom, which has a great impact on activities of daily living and consequently on quality of life. The assessment of rigidity is traditionally made by clinical scales, which have limitations due to their subjectivity and low intra- and inter-examiner reliability. (2) Objectives: To compile the main methods used to assess wrist rigidity in PD and to study their validity and reliability, a scope review was conducted. (3) Methods: PubMed, IEEE/IET Electronic Library, Web of Science, Scopus, Cochrane, Bireme, Google Scholar and Science Direct databases were used. (4) Results: Twenty-eight studies were included. The studies presented several methods for quantitative assessment of rigidity using instruments such as force and inertial sensors. (5) Conclusions: Such methods present good correlation with clinical scales and are useful for detecting and monitoring rigidity. However, the development of a standard quantitative method for assessing rigidity in clinical practice remains a challenge.

Normal gait patterns allow the identification of the normal movement pattern, such as the gait of people with cerebral palsy. Paralympic classification systems aim to include the participation in sports of people with cerebral palsy, minimizing the impact of the injury on the result of the competition. In this context, this study aims to investigate, functionally, the linear and angular kinetic parameters of gait in individuals with cerebral palsy. 15 participants with cerebral palsy were classified into three groups according to the classification of the International Paralympic Committee: 1) T35- diplegic; 2) T36- athetoid ataxic; 3) T37- hemiplegic. For data acquisition, we used a motion capture system in 3 dimensions. The results showed significant differences between the three groups in some linear and angular gait variables, corroborating the qualitative classification process already used by the International Paralympics Committee. In addition, we identified the existence of people with different levels of cerebral palsy within a single functional class of International Paralympics Committee. We found significant differences in some linear and angular gait variables among the classes T35, T36 e T37, which suggest "subgroups" inside each category, and this would prevent a athlete from competing on equal terms with the other competitors.