The goal of this work is to develop deeper insight into the method of damping vibrations by means of parametric excitation in mechanical systems - employing the concept of the so-called parametric anti-resonance. Mechanical systems with simultaneously varying time-periodic stiffness, damping and inertia coefficients are examined. At least two vibration modes are necessary to achieve damping. For these minimum systems a thorough stability analysis is carried out using a perturbation technique. Parametric excitation may lead to a coupling of just two modes of a vibrating system, while the...

Functional electrical stimulation (FES) is a technique to artificially activate motor nerves and muscles by applying electrical current pulses to pairs of electrodes placed near the activation region. FES can be used for sports, fitness, rehabilitation, restoration of lost motor functions or muscles, e.g. in subjects with brain or spinal cord injuries. The main objective of the present work was to perform a numerical feasibility study of stimulating long term denervated muscles in the human thigh for different electrode arrangements placed on the skin surface (transcutaneous) or implanted in...