Biomechanics and Ergonomics

Although much research is being developed on hand exoskeletons (HEx), very few reach TRL 9. This gives an idea of the deficiencies they present in usability and safety. The target population largely determines the suitability and usability level of each HEx. Depending on the user's pathology, it would be necessary to act in one direction or another: limiting or not the range of motion of certain joints, facilitating control through EMG or other sensor-based mechanisms or by means of a pushbutton, or giving more weight to the versatility of the device, ease of use and cleaning, and the possible stigma of using it.
Evaluations of HEx are usually partial, tested on few subjects and rarely on patients. These include measurement of ranges of motion, grip strength, and user feedback, but there is a lack of standard protocols, making accurate comparison between different exoskeletons difficult. In general, current assistive HEx can perform simple tasks (basically cylindrical and pinch grips), but lack the precision for fine motor control and sensing capabilities.
On the other hand, virtual therapies in rehabilitation are gaining relevance for their potential in neurological patients, especially when combined with upper limb exoskeletons. Upper limb exoskeletons used in rehabilitation focused on activities of daily living (ADL) do not include the hand. However, hand rehabilitation would be more efficient by training ADLs directly, using virtual reality and exoskeletons with assistant capabilities that allow patients to face the development of ADLs in very early stages where it would not be possible on their own, without assistance.
With all this, the proposal of this grant is to contribute to fill the identified gaps. On the one hand, in relation to the lack of protocols for systematic evaluation of the usability of HEx, we propose to adapt the protocols and metrics used by the group to compare artificial hands and prostheses, which measure grasping and manipulation capacity, to also consider other more ergonomic and biomechanical aspects, and thus consider, in addition to coordination and dexterity tests, usability aspects such as safety, invasiveness, efficiency, cleanliness, or cognitive effort for use. On the other hand, it is proposed to use assistive HEx for rehabilitation, focused on the performance of ADLs using serious virtual reality games, in order to: (i) motivate patients, (ii) make it possible to start rehabilitation by simulating ADLs much earlier, (iii) allow a more accurate monitoring of progress that helps to adapt rehabilitation specifically to the patient.