A Novel Wearable Foot and Ankle Monitoring System for the Assessment of Gait Biomechanics

Walking is the most basic form of human activity for achieving mobility. As an essential function of the human body, the examination of walking is directed towards the assessment of body mechanics in posture and during movement. This work proposes a wearable smart system for the monitoring and objective evaluation of foot biomechanics during gait. The proposed solution assumes the cross-correlation of the plantar pressure with lower-limb muscular activity, throughout the stance phase of walking. Plantar pressure is acquired with an array of resistive pressure sensors deployed onto a shoe insole along the center of gravity progression line. Lower-limb muscular activity is determined from the electromyogram of the tibialis anterior and gastrocnemius lower limb muscles respectively. Under this scenario, physiological gait assumes the interdependency of plantar pressure on the heel area with activation of the tibialis anterior, as well as plantar pressure on the metatarsal arch/toe area with activation of the gastrocnemius. As such, assessment of gait physiology is performed by comparison of a gait map, formulated based on the footprint–lower-limb muscle cross-correlation results, to a reference gait template. A laboratory proof of concept validates the proposed solution in a test scenario which assumes a normal walking and two pathological walking patterns

A highly linear low pass filter for low voltage reconfigurable wireless application

This paper presents a reconfigurable and programmable analogue low pass filter for low voltage wireless applications. The proposed filter may be used for channel or band selection in multi-mode receiver front ends employing direct frequency conversion. The circuit has been synthesized using state variables and leapfrog OTA-C techniques, features programmable order, digitally variable frequency parameters and wide linear range. The fundamental OTA cell has been implemented with fully balanced second-generation current conveyors, suitable for operating with low supply voltages. Transistor level simulations based on a 180 nm digital CMOS technology have demonstrated the functionality of the design