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Latest trends in communication and consumer electronics target the development of fully adaptive systems on mixed signal systems-on-chip. This paper proposes an evolutionary approach to adaptive filter design. The hardware support of the evolutionary design algorithm is a field programmable analog array (FPAA). The FPAA has been implemented with OTA-C techniques. The synthesis algorithm has been developed considering the particularities of the proposed FPAA and of the supported filter structures. Topological reconfiguration is performed with a lookup table, parametric design is performed with evolutionary computation methods and wide-band self-calibration is achieved by means of a phase locked loop. The filter sizing algorithm is suitable for both intrinsic or extrinsic evolution and has the potential to be hard-wired in dedicated digital circuitry. Extensive transistor level simulations performed on the evolved adaptive filters prove the functionality of the proposed software and the underlying circuitry.

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.

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