In the past years the number of people affected by stroke has grown dramatically, leading survivors to long–term disabilities in the 50% of the cases. To these people rehabilitation is the only possibility to achieve a total or, at least, partial recovery from their motor impairment. In this context robotic rehabilitation has been developing greatly, contributing to the restoration of the functional capacity of high number of patients. Despite being a useful tool for recovery, mechanisms are bulky, uncomfortable for the patients and expensive, so that they are still not widely used in many cases during therapies. Furthermore, in a great variety of situations, the robot is utilized to move the arm of the patient in a passive way, wasting the great potential of these devices.

This work aims at developing a new inexpensive tool for rehabilitation, completely passive, composed only by elastic elements, such as springs, highly and simply customizable by a therapist and able to exert torque to the upper limbs of a patient;​ moreover, it will be able to achieve different kinds of therapies, based, for example, on the concept of error augmentation or gravity compensation.

In particular, this research concentrates on the development of an optimization algorithm able to find the set of optimal parameters needed for the customization of the system, performed according to a patient’s specific motor deficits.