The effect of differences in powered wheelchair joystick shape on subjective and objective operability

Research on wheelchair form design based on Kansei engineering and GWO-BP neural network

With the increasing emphasis on humanistic care in society, consumers are no longer only concerned about the functional needs of products but also about the spiritual, cultural, and emotional needs that products bring to people. This study proposes a wheelchair form design method based on the Kansei engineering approach, which integrates the evaluation grid method (EGM), grey wolf optimization (GWO) algorithm, and back propagation neural network (BPNN) technology. The aim is to explore the connection between wheelchair form design elements and user emotions and help industrial designers find designs with emotional preferences. In this study method, firstly, the collected wheelchair samples were evaluated using the EGM, extracting upper-level Kansei vocabulary driven by user attractiveness, middle-level original attractiveness items, and lower-level specific design elements and extracting nine sets of Kansei vocabulary mentioned frequently by users. Meanwhile, the morphological analysis method is used to construct a sample library of product morphological elements. Secondly, the semantic difference and factor analysis methods were used to analyze the ratings of 9 pairs of Kansei words, and the weights of Kansei factors were calculated to identify three critical Kansei demand factors. Thirdly, based on the analysis results of the orthogonal experiment, a conceptual plan for the wheelchair was constructed using computer-aided technology Rhinoceros 3D modelling software. Fourthly, the semantic difference method is used to collect users' ratings of critical Kansei words for wheelchair concept schemes, and the evaluation values of critical Kansei words are calculated by weighting. Fifth, a BPNN based on the GWO algorithm will establish a predictive model between wheelchair design elements and vital Kansei images. Finally, the predictive performance of BPNN and GWO-BPNN models will be compared to verify their superiority. The results indicate that the GWO-BPNN model has better predictive ability and performance. The method proposed by this research institute can more effectively help industrial designers create products that meet users' emotional needs, providing a new perspective for wheelchair algorithm design.

Quantifying joystick interactions and movement patterns of toddlers with disabilities using powered mobility with an instrumented Explorer Mini

Powered mobility technology can be a powerful tool to facilitate self-initiated exploration and play for toddlers with motor disabilities. The joystick-controlled Permobil Explorer Mini is currently the only commercially available powered mobility device for children ages 1-3 years in the United States. However, many open questions persist regarding how joystick-based mobility technologies should be designed to optimally suit the developmental needs of toddlers. The purpose of this study was to quantify how toddlers with motor disabilities use the Explorer Mini during free exploration and play. For this work, we developed a custom-instrumented Explorer Mini with embedded sensors to measure joystick interactions and wheel rotations. Nine children with motor disabilities (ages 12-36 months) participated in 12 in-lab visits, and during each visit they engaged in two 15-20 minute play sessions. For each session, we calculated several quantitative outcome metrics, including the time spent using the joystick, distance traveled, and the number, duration, and complexity of joystick interactions. Every participant independently interacted with the joystick and moved the Explorer Mini during every session. Over 12 visits, participants significantly increased their distance traveled and the time spent with the joystick active. Surprisingly, we found that only 48% of joystick interactions resulted in device movement, which has important implications for learning. These results can serve as a benchmark for caregivers and clinicians to understand early device use patterns. Furthermore, this knowledge can be used to inform the design of new powered mobility technologies for toddlers with disabilities or support the refinement of existing devices.

Customised joystick-making and training service of power wheelchair using rapid prototyping in rehabilitation centre for people with cervical spinal cord injury: findings from two case studies

PURPOSE

This study aimed to evaluate the clinical applicability of a customised power wheelchair joystick using rapid prototyping with 3D modeling and printing technology within a rehabilitation centre for patients with cervical spinal cord injury.

MATERIALS AND METHODS

Two male participants with tetraplegia following cervical-level spinal cord injury who had difficulty operating a powered wheelchair were recruited. The procedure of the joystick-making and training service consists of four steps: (1) driving evaluation; (2) digital fabrication; (3) functional test; and (4) driving training. K-QUEST 2.0 (Korean-Quebec User Evaluation of Satisfaction version 2.0) was used to measure the usability of the off-the-shelf and customised joystick.

RESULTS

During the application process, several redesign stages were required to obtain the final customised joystick. After participants attended a 30-min driving training five times per week for 8 weeks, the usability of the customised joystick was higher than that of the off-the-shelf one.

CONCLUSION

Providing the customised joystick-making and training service can be used in hospitalised rehabilitation centre before the hospital discharge of patients and returns to their everyday lives.