Laser-induced thermoelastic effects can evoke tactile sensations

Humans process a plethora of sensory information that is provided by various entities in the surrounding environment. Among the five major senses, technology for touch, haptics, is relatively young and has relatively limited applications largely due to its need for physical contact. In this article, we suggest a new way for non-contact haptic stimulation that uses laser, which has potential advantages such as mid-air stimulation, high spatial precision, and long working distance. We demonstrate such tactile stimulation can be enabled by laser-induced thermoelastic effects by means of physical and perceptual studies, as well as simulations. In the physical study, the mechanical effect of laser on a human skin sample is detected using low-power radiation in accordance with safety guidelines. Limited increases (< similar to 2.5 degrees C) in temperature at the surface of the skin, examined by both thermal camera and the Monte Carlo simulation, indicate that laser does not evoke heat-induced nociceptive sensation. In the human EEG study, brain responses to both mechanical and laser stimulation are consistent, along with subjective reports of the non-nociceptive sensation of laser stimuli.close1

Low-thrust Transfers for the Vega Electric Upper Stage

On February 2012 the small European space transportation system Vega successfully lifted off for its maiden flight from the Kourou spaceport. Vega was specifically developed for placing small-weight satellites into low Earth orbits from the European spaceport. This study aims at designing minimum-time low-thrust transfer solutions from the reference Vega target orbits up to the geostationary Earth orbit, in order to evaluate the possibility of extending the Vega reach to GEO using an electric propulsion thruster. The continuous optimization problem is translated into a nonlinear programming problem using the direct multiple shooting method. To reduce the computational load and rapidly generate optimal trajectories, we apply averaging techniques and semi-analytic relations to describe the vehicle motion. The effects of the more significant disturbing forces are also considered during the entire transfer. It is shown that 1310 kg can be delivered to the target geostationary orbit in 252 days, using a state of the art Hall thruster. The mission is in the range of 5000 m/s, with a typical propellant mass consumption of the order of 25 %. The combination of averaging techniques with a direct optimization method provides optimal transfer solutions, sufficiently accurate for a first order study, in less than 7 hours using a 2.66 GHz processor

Worry and anger rumination in fibromyalgia syndrome

The aim of the present study was twofold: 1) to investigate the psychological profile of patients with fibromyalgia syndrome (FS) as compared to patients with other chronic pain syndromes (CP) and healthy subjects (HS); 2) to examine the associations between anxiety, depression, worry and angry rumination in FS patients. FS patients (N=30), CP patients (N=30) and HS (N=30) completed measurements of anxiety, depression, worry and angry rumination. FS patients showed higher levels of state and trait anxiety, worry and angry rumination than CP patients and HS, and higher levels of depression than HS. Worry and angry rumination were strongly associated in the FS group. FS patients may use worry and rumination as coping strategies to deal with their negative emotional experience, which might impair their emotional wellbeing. Findings from the present study add to our understanding of the psychological profile of FS patients, and have important implications for developing a tailored CBT protocol for pain management in FS patients