Stroke patients are often affected by hand impairment. Literature shows different experiences of robotic rehabilitation that is able to prove an intensive and effective therapy. A preliminary analysis of the state of the art evidenced lacks in hand robotic rehabilitation devices. Thus, this work proposes a new rehabilitation device for hand rehabilitation based on a compliant transmission. The mechanical power generator is not on the hand to reduce the weight of the device. The mechanical model of the system is descripted. Experimental results on 126 stroke patients evidenced the efficacy of this device

The investigated cantilever beam is characterized by a constant rectangular cross-section and is subjected to a concentrated vertical constant load at the free end. The same beam is made by an elastic non-linear asymmetric Ludwick type material with different behavior in tension and compression. Namely the constitutive law of the proposed material is characterized by two different elastic moduli and two different strain exponential coefficients. The aim of this study is to describe the deformation of the beam neutral surface and particularly the horizontal and vertical displacements of the free end cross-section. The analysis of large deflection is based on the Euler-Bernoulli bending beam theory, for which cross-sections, after the deformation, remain plain and perpendicular to the neutral surface; furthermore their shape and area do not change. On the stress viewpoint, the shear stress effect and the axial force effect are considered negligible in comparison with the bending effect. The mechanical model deduced from the identified hypotheses includes two kind of non-linearity: the first due to the material and the latter due to large deformations. The mathematical problem associated with the mechanical model, i.e. to compute the bending deformations, consists in solving a non-linear algebraic system and a non-liner second order ordinary differential equation. Thus a numerical algorithm is developed and some examples of specific results are shown in this paper. Precisely, the proposed problem is a generalization of similar cases in literature, consequently numerical comparisons are performed with these previous works, i.e. assuming linear elastic materials or assuming symmetric Ludwick type material with same behavior in tension and compression like aluminum alloy and annealed copper. After verifying a proper agreeing with the literature, in order to investigate the effect of the different material behavior on the horizontal and vertical displacements of the free end cross-section, numerical results are obtained for different values of elastic moduli and strain exponential coefficients. The arising conclusions are coherent with the assumed hypotheses and with similar works in literature.

This paper aims at proposing a structured approach in reliability design and analysis for mechatronic devices. Mechatronic systems are a complex integration of extremely advanced technological components able to perform tasks with high accuracy and flexibility. This complexity at all levels increases the risks of malfunction, failures and issues. The definition of an effective roadmap is necessary to provide prompt solutions in terms of product performances and duration. This study presents a set of reliability activities to be integrated in the product process development and during its cycle life. This approach may contribute to improve the mechatronic product functionalities and duration.

Physical rehabilitation based on robotic systems has the potential to cover the patient's need of improvement of upper extremity functionalities. In this article, the state of the art of resistant and assistive upper limb exoskeleton robots and their control are thoroughly investigated. Afterward, a single-degree-of-freedom exoskeleton matching the elbowforearm has been advanced to grant a valid rehabilitation therapy for persons with physical disability of upper limb motion. The authors have focused on the control system based on the use of electromyography signals as an input to drive the joint movement and manage the robotics arm. The correlation analysis between surface electromyography signal and the force exerted by the subject was studied in objects' grasping tests with the purpose of validating the methodology. The authors developed an innovative surface electromyography force-based active control that adjusts the force exerted by the device during rehabilitation. The control was validated by an experimental campaign on healthy subjects simulating disease on an arm, with positive results that confirm the proposed solution and that open the way to future researches.