Abstract
It is a known fact that aging adults experience a decline in muscle mass along with a decrease in function of the musculoskeletal system, which could lead to musculoskeletal disorders and disabilities. To address said problem, we developed two key wearable technologies: 1) a motion-assist exosuit and 2) a wearable motion sensor technology for activity recognition for the elderly. In the initial phase of this study, we developed and tested the first prototype of the soft exosuit with active elders to determine and improve upon the effectiveness and efficiency of the prototype. The results showed a reduction in rectus abdominis activation of 33%, and the activity energy expenditure was reduced by 5.7%, exceeding our targets of > 20% and > 5%, respectively. The exosuit also improved user posture, especially in the shoulder and upper back areas. After design improvement, the second prototype showed improvements in support of muscle function: the biceps femoris and multifidus were reduced by 16.5% and 3.5%, respectively, compared to tests without the exosuit. The elderly subjects gave the exosuit an 80% satisfaction rate. The exosuit allowed them to smoothly continue their daily lives and, in some, the exosuit reduced back, waist, and upper leg pain. A third prototype was developed, and preliminary test results revealed satisfactory muscle function support, especially in the rectus abdominis, which had ca. 74% reduction in muscle activation in STS. These results demonstrate that the exosuit is ready to be developed for commercial development, production, and product launch. For the wearable sensor technology, we developed sensors that can be installed on the exosuit, at the thoracic spine (T8) and vastus lateralis (VL) areas. The motion prediction model had an accuracy of 96% to 100% and calculation speed of < 1 s, meeting targets. The mobile application was developed with the elderly in mind, can report “risky” activities within 3 s and has 100% detection accuracy, exceeding the set project goal. The wearable sensors and application were tested for use during daily activities, and using user feedback, the technologies were modified for greater user satisfaction. Overall, the motion-assist exosuit and wearable motion sensor technologies developed in this project have been verified in the laboratory and validated in real-life settings, satisfying the key objective of this study. However, further studies must be carried out to determine their capabilities in improving musculoskeletal function in various target groups. Furthermore, we have started collaborative work with a leading undergarment manufacturer in Thailand to further develop the soft exosuit, with a plan for commercialization within this year.
