Development of a novel wearable system for real-time measurement of the inter-foot distance during gait

The combination of magneto-inertial measurement unit (MIMU) and distance sensor (DS) represents smart solution for evaluating the distance between feet during various daily-life activities. In particular, when analyzing gait, the latter technology can be used for estimating the instantaneous or average distance between selected points of the feet (IFD) during mid-swing and mid-stance phases. The aim of this preliminary work is twofold: a) to develop and validate a novel wearable system for the measurement of the IFD during gait; b) to investigate the optimal positioning of the DS on the foot. Preliminary results showed that the innovative wearable system can be effectively used for accurately measuring the IFD during gait. Interestingly, the accuracy of the IFD estimation is highly affected by the position of the DS on the foot

A wearable solution for accurate step detection based on the direct measurement of the inter-foot distance

Accurate step detection is crucial for the estimation of gait spatio-temporal parameters. Although several step detection methods based on the use of inertial measurement units (IMUs) have been successfully proposed, they may not perform adequately when the foot is dragged while walking, when walking aids are used, or when walking at low speed. The aim of this study was to test an original step-detection method, the inter-foot distance step counter (IFOD), based on the direct measurement of the distance between feet. Gait data were recorded using a wearable prototype system (SWING2DS), which integrates an IMU and two time-of-flight distance sensors (DSs). The system was attached to the medial side of the right foot with one DS positioned close to the forefoot (FOREDS) and the other close to the rearfoot (REARDS). Sixteen healthy adults were asked to walk over ground for two minutes along a loop, including both rectilinear and curvilinear portions, during two experimental sessions. The accuracy of the IFOD step counter was assessed using a stereo-photogrammetric system as gold standard. The best performance was obtained for REARDS with an accuracy higher than 99.8% for the instrumented foot step and 88.8% for the non-instrumented foot step during both rectilinear and curvilinear walks. Key features of the IFOD step counter are that it is possible to detect both right and left steps by instrumenting one foot only and that it does not rely on foot impact dynamics. The IFOD step counter can be combined with existing IMU-based methods for increasing step-detection accuracy

Systematic numerical investigation of the role of hierarchy in heterogeneous bio-inspired materials

It is well known that hierarchical structure is an important feature in biological materials to optimise various properties, including mechanical ones. It is however still unclear how these hierarchical architectures can improve material characteristics, for example strength. Also, the transposition of these structures from natural to artificial bioinspired materials remains to be perfected. In this paper, we introduce a numerical method to evaluate the strength of fibre-based heterogeneous biological materials and systematically investigate the role of hierarchy. Results show that hierarchy indeed plays an important role and that it is possible to “tune” the strength of bio-inspired materials in a wide range of values, in some cases improving the strength of non-hierarchical structures considerably

Interpretations of Progressive Education: A Comparative Study of the Philosophies of Education of the Municipal Early Childhood Schools of Reggio Emilia and the Bank Street College of Education

Compares the progressive philosophies of education of the municipal infant-toddler centers and preprimary schools of Reggio Emilia, and Bank Street College of Education and its School for Children. The histories and theoretical origins of each philosophy of education are introduced. Elaborations on the fundamental principles of each are provided, including discussions of the creation of learning environments, the perception of children\u27s learning, the roles of teachers, and the place of the community. Throughout the text, cultural frameworks are made evident, in order to reflect on the influence that culture and history have on the ways in which progressive philosophies of education take form

An objective assessment to investigate the impact of turning angle on freezing of gait in Parkinson's disease

Freezing of gait (FoG) is often described in subjects with Parkinson's disease (PD) as a sudden inability to continue the forward walking progression. FoG occurs most often during turning, especially at sharp angles. Here, we investigated 180 and 360 degrees turns in two groups: PD subjects reporting FoG (FoG+), and PD subjects without FoG (FoG-). Forty-three subjects (25 FoG+, 18 FoG-) wore an inertial sensor on their back while walking back and forth continuously for 2 min (reversing direction with a 180° turn), and while turning in place for 1 min (alternating 360° turning in opposite directions). Objective measures (turn duration, peak velocity, jerkiness and range of acceleration) were computed during the turns and compared across FoG+ and FoG-groups. Results showed that FoG+ compared to FoG-took significantly a longer time to complete 360° turns than 180° turns. A significant lower turn peak velocity, higher jerkiness and an increased range of medio-lateral acceleration was also found in FoG+. Significant differences between the two groups across the two turning tasks validated the hypothesis that sharper turns might cause higher instability in FoG+ compared to FoG-