The Myoshirt is a textile-based soft wearable robot that supports the shoulder against gravity. The Myoshirt basically acts as an external layer of muscles that you can wear like a vest, which is why we call it an exomuscle. The design of the Myoshirt was based on considerations around activities of daily living, which makes it particularly suitable for assistance in home environments. Nevertheless, the Myoshirt can also be used for rehabilitation and training in clinics.
I developed the Myoshirt during my PhD at the Sensory-Motor Systems lab at ETH Zurich, together with my students and collaborators. Based on a meta-analysis of the literature, we used a data-driven approach to define a one-dimensional movement path on which the Myoshirt supports arm elevation, namely a coupled elevation and external rotation of the shoulder. This greatly helped us to reduce the complexity of the final device.
The Myoshirt attaches to the user via a textile thorax harness and an arm cuff system. Between the two, a tendon transmits a tensile force from an actuation box that is located behind the user.
Through the implementation of an autonomous gravity assistance controller, the Myoshirt follows and supports the user’s movement intuitively. The gravity estimation model is thereby fitted to each user using a data-driven system identification approach. Using inertial measurement units and load cells, the gravitational load can be estimated and compensated at the end effector in real time.
In a study, the Myoshirt was able to assist both people with and without impairments by reducing their muscular effort in a daily life-inspired task, and increasing their muscular endurance time in a fatigue task.