CoEx
Co-adaptation to enable and improve exoskeleton-based (tele-) rehabilitation
Dr.-Ing. Dennis Mronga
The CoEx project is concerned with the development of methods and systems for robot-assisted (tele)rehabilitation. The first goal is to enable exoskeleton-assisted forms of therapy for people with muscle spasticity, which often occurs as a consequence of a stroke. The second goal is to develop methods for robot-assisted telerehabilitation, in which one patient and one therapist wear an exoskeleton. To this end, methods for bidirectional telepresence are being researched, i.e. the bidirectional coupling of movements and forces between two separate robotic systems. The third main objective is the optimization of a lower body exoskeleton using the co-design approach.
Project details
The use of robots in rehabilitation for people with sensorimotor impairments is being discussed intensively as an approach to cope with demographic change and the increasing need for therapeutic staff. The aim is to develop systems that can increase the efficiency of therapy and relieve the burden on therapists. However, robot-assisted therapy cannot be used for all patients, e.g., due to the presence of muscle spasticity. Spasticity is observed in 25% to 44% of stroke patients and is characterized by an increase in muscle tone leading to muscle stiffness and resistance to passive joint movements. Current robotic assistance systems are not able to recognize this, which is why patients with spasticity cannot benefit from robot-assisted therapy. CoEx aims to change this by developing methods for online detection of the spasticity level and corresponding automatic adaptation of the robot-assisted therapy exercises.
The second aim of CoEx is to take the first steps towards robot-assisted telerehabilitation. This involves a therapist and a patient each wearing an exoskeleton as part of a robotic tele-rehabilitation session. The two exoskeletons are coupled bidirectionally. The therapist teaches the patient's exoskeleton how to support the patient until the next session. The interaction with the patient takes place through feedback of movements and forces to the therapist's exoskeleton, i.e., via bidirectional telepresence. The development of bidirectional telepresence approaches has many other applications, for example, telemanipulation in space, intuitive programming of robots, teleworking in industrial manufacturing, or the provision of physiotherapy services during a pandemic and in rural, poorly served areas. The potential of teletherapy for gait rehabilitation is also being investigated, using a lower body exoskeleton to control a bipedal robot.
In order to develop teletherapy approaches involving the lower body in future projects, the first version of a lower body exoskeleton called LEEDD is currently being developed. This first design will be improved in CoEx by applying co-design approaches for robots. The design and integration of an optimized lower body exoskeleton based on quasi-direct drives that can be safely used for bidirectional teleoperation tasks with force feedback will therefore be the third goal of CoEx.