Combined active wrist and hand orthosis for home use: Lessons learned

In this paper, we present our design of an active hand and wrist orthosis, SCRIPT Active Orthosis Iteration 3 (SAO-i3), for rehabilitation after stroke at home. Impairments in the hand decrease the quality of life of stroke patients drastically by limiting activities of daily living such as eating, drinking, buttoning, etc. Since there is a high correlation between therapy intensity and functional recovery, it is logical to bring robot-assisted therapy to patients´ homes in order to let them customize their own therapy schedules in a more time-effective, affordable and motivational way. In the EU-FP7 SCRIPT project, we developed a passive hand and wrist orthosis and tested it with 24 patients from three countries (NL, IT, UK) at their homes for six weeks. Based on the lessons we learned, we developed an active hand and wrist orthosis for home use to enable better control over the assist-as-needed characteristics of the orthosis, which is beneficial to adjust the assistance according to patients´ recovery progress. The results are mixed. Passive assistive forces, combined with compliant independent interaction with fingers and wrist, create a solid gaming interface for motivated rehabilitation at home, which was one of the primary goals of the project. However, complex mechanics and mechatronics provide theoretical benefits but result in significant practical limitations. Perhaps, having a compliant active wrist and finger orthosis that is useable independently at home, is a step too far.