Soft robotic for technologies for a novel generation of supernumerary limbs

Thanks to the continuous progress of technology, the interaction between humans and robots have become more and more frequent nowadays. This is visible in wearable robotics, where the physical distance between the user and the robotic device is completely reduced. Within this category, a new trend is emerging which aims at expanding the natural ability of the user. This is the case of the Supernumerary Robotic Limbs (SRL), where the features of a robot (as e.g. power and precision) are merged with the natural abilities of a human (e.g. cognitive and manipulation capabilities), in an attempt to augment performance, increase safety or compensate deficiencies of the user. In this thesis, different aspects related to the generation of novel Supernumerary Robotic systems will be addressed in terms of hardware technologies, control techniques, and usability assessment. In particular, I’ll present two different versions, resulted from the combination of passive gravity compensator arms with an under-actuated soft robotic hand and oriented respectively to improve safety for workers and compensating impairment in stroke subjects. A wide range of input interfaces for controlling both systems will be introduced as well, based on several sensor technologies and different body placements. Two important use cases will be defined, tested, and discussed. The first will focus on the capacity of this new approach for reducing joint loads and suppressing vibration transmitted on the worker’s arms in industrial environments. The second will be oriented to the impairment assistance in stroke subjects. For this purpose, a placement optimization analysis will be presented first, conducted to ease the use of the system and optimize final performances in subjects with reduced mobility. Then, the system potentiality with chronic and acute stroke subjects will be reported and examined. Two main approaches will be proposed, according to the subject condition: compensating the upper limb functionality deficiency in chronic subjects and training for rehabilitation in acute patients. Before presenting the clinical trials related to this last approach, some considerations about different neuroscientific results will be discussed for supporting it.