02408nas a2200241   4500008004100000245007300041210006900114260001200183520171500195653001201910653001301922100001801935700001601953700001501969700001501984700001401999700001302013700001802026700002002044700001602064700001502080856007102095       2017                        eng d00aPostural Hand Synergies during Environmental Constraint Exploitation0 aPostural Hand Synergies during Environmental Constraint Exploita  c08/20173 a<p>Humans are able to intuitively exploit the shape of an object and environmental constraints to achieve stable grasps and perform dexterous manipulations. In doing that, a vast range of kinematic strategies can be observed. However, in this work we formulate the hypothesis that such ability can be described in terms of a synergistic behavior in the generation of hand postures, i.e., using a reduced set of commonly used kinematic patterns. This is in analogy with previous studies showing the presence of such behavior in different tasks, such as grasping. We investigated this hypothesis in experiments performed by six subjects, who were asked to grasp objects from a flat surface. We quantitatively characterized hand posture behavior from a kinematic perspective, i.e., the hand joint angles, in both pre-shaping and during the interaction with the environment. To determine the role of tactile feedback, we repeated the same experiments but with subjects wearing a rigid shell on the fingertips to reduce cutaneous afferent inputs. Results show the persistence of at least two postural synergies in all the considered experimental conditions and phases. Tactile impairment does not alter significantly the first two synergies, and contact with the environment generates a change only for higher order Principal Components. A good match also arises between the first synergy found in our analysis and the first synergy of grasping as quantified by previous work. The present study is motivated by the interest of learning from the human example, extracting lessons that can be applied in robot design and control. Thus, we conclude with a discussion on implications for robotics of our findings.</p>
10aHaptics10aRobotics1 aDella Santina1 aBianchi, M.1 aAverta, G.1 aCiotti, S.1 aArapi, V.1 aFani, S.1 aBattaglia, E.1 aCatalano, M. G.1 aSantello, M1 aBicchi, A.  uhttps://www.frontiersin.org/articles/10.3389/fnbot.2017.00041/full00655nas a2200145   4500008004100000245014000041210006900181260003700250100001700287700001400304700001600318700002000334700001600354856013900370       2016                        eng d00aOn the Pleasantness of a Haptic Stimulation: How Different Textures can be Recognized through Heart Rate Variability Nonlinear Analysis0 aPleasantness of a Haptic Stimulation How Different Textures can   aOrlando, USA, August 16-20, 20161 aNardelli, M.1 aGreco, A.1 aBianchi, M.1 aScilingo, E. P.1 aValenza, G.  uhttps://www.centropiaggio.unipi.it/publications/pleasantness-haptic-stimulation-how-different-textures-can-be-recognized-through-heart