Istituto Italiano di Tecnologia

About: Istituto Italiano di Tecnologia is a facility organization based out in Genoa, Italy. It is known for research contribution in the topics: Robot & Humanoid robot. The organization has 4561 authors who have published 14595 publications receiving 437558 citations. The organization is also known as: Italian Institute of Technology & IIT.

Rationale, Implementation and Evaluation of Assistive Strategies for an Active Back-Support Exoskeleton.

Abstract: Active exoskeletons are potentially more effective and versatile than passive ones, but designing them poses a number of additional challenges. An important open challenge in the field is associated to the assistive strategy, by which the actuation forces are modulated to the user's needs during the physical activity. This paper addresses this challenge on an active exoskeleton prototype aimed at reducing compressive low-back loads, associated to risk of musculoskeletal injury during manual material handling (i.e., repeatedly lifting objects). An analysis of the biomechanics of the physical task reveals two key factors that determine low-back loads. For each factor, a suitable control strategy for the exoskeleton is implemented. The first strategy is based on user posture and modulates the assistance to support the wearer's own upper body. The second one adapts to the mass of the lifted object and is a practical implementation of electromyographic control. A third strategy is devised as a generalized combination of the first two. With these strategies, the proposed exoskeleton can quickly adjust to different task conditions (which makes it versatile compared to using multiple, task-specific, devices) as well as to individual preference (which promotes user acceptance). Additionally, the presented implementation is potentially applicable to more powerful exoskeletons, capable of generating larger forces. The different strategies are implemented on the exoskeleton and tested on 11 participants in an experiment reproducing the lifting task. The resulting data highlights that the strategies modulate the assistance as intended by design, i.e., they effectively adjust the commanded assistive torque during operation based on user posture and external mass. The experiment also provides evidence of significant reduction in muscular activity at the lumbar spine (around 30%) associated to using the exoskeleton. The reduction is well in line with previous literature and may be associated to lower risk of injury. © 2018 Toxiri, Koopman, Lazzaroni, Ortiz, Power, de Looze, O'Sullivan and Caldwell.

Propagation and amplification dynamics of 1D polariton condensates.

Abstract: The dynamics of propagating polariton condensates in one-dimensional microcavities is investigated through time resolved experiments. We find a strong increase in the condensate intensity when it travels through the nonresonantly excited area. This amplification is shown to come from bosonic stimulated relaxation of reservoir excitons into the polariton condensate, allowing for the repopulation of the condensate through nonresonant pumping. Thus, we experimentally demonstrate a polariton amplifier with a large band width, opening the way towards the transport of polaritons with high densities over macroscopic distances.

Simultaneous two-photon imaging of intracellular chloride concentration and pH in mouse pyramidal neurons in vivo

Abstract: Intracellular chloride ([Cl-]i) and pH (pHi) are fundamental regulators of neuronal excitability They exert wide-ranging effects on synaptic signaling and plasticity and on development and disorders of the brain The ideal technique to elucidate the underlying ionic mechanisms is quantitative and combined two-photon imaging of [Cl-]i and pHi, but this has never been performed at the cellular level in vivo Here, by using a genetically encoded fluorescent sensor that includes a spectroscopic reference (an element insensitive to Cl- and pH), we show that ratiometric imaging is strongly affected by the optical properties of the brain We have designed a method that fully corrects for this source of error Parallel measurements of [Cl-]i and pHi at the single-cell level in the mouse cortex showed the in vivo presence of the widely discussed developmental fall in [Cl-]i and the role of the K-Cl cotransporter KCC2 in this process Then, we introduce a dynamic two-photon excitation protocol to simultaneously determine the changes of pHi and [Cl-]i in response to hypercapnia and seizure activity

On the effect of process parameters on properties of AlSi10Mg parts produced by DMLS

Abstract: Purpose – The aim of this research is to reach a deep understanding on the effect of the process parameters of Direct Metal Laser Sintering process (DMLS) on macroscopic properties (hardness and density) of AlSi10Mg parts and resulting microstructure. Design/methodology/approach – A full factorial design of experiment (DOE) was applied to determine the most significant process parameter influencing macroscopic properties of AlSi10Mg parts manufactured by DMLS process. The analysis aims to define the optimum process parameters and deduce the process window that provides better macroscopic properties of AlSi10Mg parts. Optical microscopy observations are carried out to link the microstructure to macroscopic properties. Findings – Macroscopic properties of DMLS parts are influenced by the change in process parameters. There is a close correlation between the geometry of scan tracks and macroscopic properties of AlSi10Mg parts manufactured by DMLS process. Originality/value – The knowledge of utilizing optimi...