An innovative design for lower-limb prosthesis actuation and sensory system

Over the past decade, wearable robotics has received increasing attention as a solution to mitigate the consequences of an aging and growing population. Those devices are designed to act symbiotically with the human body and, similar to humans, are composed of a physical part – i.e., the physical human-robot interface (pHRi) – and a cognitive part – i.e., the cognitive human-robot interface (cHRi). The scenarios where humans cope with everyday are diverse, unstructured, dynamic, and oftentimes, require a considerable amount of flexibility which is difficult to implement in a robot. To operate in these scenarios along with their users, wearable robots need to have an effective combination of pHRi and a cHRi in order to find the most appropriate compromises to meet various requirements such as lightweight design, kinematic compatibility, and system adaptability. This presents a challenge for exoskeleton designers. To overcome these design challenges, the main goal of this dissertation was to present innovative mechatronic concepts to boost the design of new systems with effective pHRi and cHRi. Those systems were conceived to operate in the field of lower limb amputation and upper-limb rehabilitation. Three topics were addressed in the thesis. The first topic involved a design concept for wearable sensors for both motor intention detection and human-robot force interaction estimation. The second topic addressed a disruptive actuation system for robotic transfemoral prosthesis based on a differential under-actuated principle. Here, the mechanical principle was tested on the bench and with a preliminary healthy subject showed the feasibility of the paradigm. The last topic regarded the application of a novel kinematic chain to match the mobilization of the metacarpophalangeal joint of fingers by boosting the kinematic compatibility of hand exoskeletons. In the first phase, we concentrated on a fixed platform to validate the kinematic principle with healthy subjects, by demonstrating the promising applicability to the rehabilitation scenario, and then we imported the technology into a multi-finger concept by showing preliminary but promising results in terms of weight and encumbrance. Overall results advanced the current state of the art in terms of mechatronic innovation, and they are also promising for the motor enhancement of impaired people even though further clinical investigations are needed.