Design and evaluation of a new mechatronic platform for assessment and prevention of fall risks.

BACKGROUND: Studying the responses in human behaviour to external perturbations during daily motor tasks is of key importance for understanding mechanisms of balance control and for investigating the functional response of targeted subjects. Experimental platforms as far developed entail a low number of perturbations and, only in few cases, have been designed to measure variables used at run time to trigger events during a certain motor task. METHODS: This work introduces a new mechatronic device, named SENLY, that provides balance perturbations while subjects carry out daily motor tasks (e.g., walking, upright stance). SENLY mainly consists of two independently-controlled treadmills that destabilize balance by suddenly perturbing belts movements in the horizontal plane. It is also provided with force sensors, which can be used at run time to estimate the ground reaction forces and identify events along the gait cycle in order to trigger the platform perturbation. The paper also describes the customized procedures adopted to calibrate the platform and the first testing trials aimed at evaluating its performance. RESULTS: SENLY allows to measure both vertical ground reaction forces and their related location more precisely and more accurately than other platforms of the same size. Moreover, the platform kinematic and kinetic performance meets all required specifications, with a negligible influence of the instrumental noise. CONCLUSION: A new perturbing platform able to reproduce different slipping paradigms while measuring GRFs at run time in order to enable the asynchronous triggering during the gait cycle was designed and developed. Calibration procedures and pilot tests show that SENLY allows to suitably estimate dynamical features of the load and to standardize experimental sessions, improving the efficacy of functional analysis.

Preliminary experiments on the acceptability of animaloid companion robots by older people with early dementia.

Animaloid companion robots represent a very interesting paradigm. An increasing number of studies on this topic has been carried out in the past, involving such robots and older users affected by some kind of cognitive disease, from mild cognitive impairment (MCI) to more severe stages of Alzheimer's disease and other types of dementia. In the study described in this paper, an AIBO robotic dog was programmed and used to show simple reactive behaviors during the interaction with old adults. Experimental sessions were carried out with a group of 24 older subjects with cognitive deficits of relatively small entity (MMSE>23). Preliminary results seem to show the acceptability of this approach especially in subjects with a good relationship with technology. In the next future, the interaction between the robot and the old adults will be tested in more complex situations.