We present efficient reduced basis (RB) methods for the simulation of a coupled problem consisting of a rigid robot hand interacting with soft tissue material. The soft tissue is modeled by the linear elasticity equat...
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The functioning of the neuromuscular system is an important factor for quality of life. With the aim of restoring neuromuscular function after limb amputation, novel clinical techniques such as the agonist-antagonist ...
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The number of Finite Element Active Human Body Model (FE aHBM) applications for the design and test of vehicle safety systems is growing. Primarily they are used for simulations of the accident pre-crash phase where t...
The number of Finite Element Active Human Body Model (FE aHBM) applications for the design and test of vehicle safety systems is growing. Primarily they are used for simulations of the accident pre-crash phase where the influence of occupants active movements is significant. Such models are capable of accounting for dynamic human behaviour and reflexes by incorporating bio-inspired muscle controllers. These controllers need to govern hundreds of active muscle elements during simulation in every time-step thereby dramatically increasing runtime compared to passive HBMs. As runtime is an essential element of the entire research and development process of a new vehicle, new approaches for its reduction are required. The current contribution presents methods for the tuning of controller and active muscle element parameters using a reduced multibody (MB) model with a subsequent transfer to a fully deformable FE model.
Training exercise produces skeletal muscle adaptation: at the organ scale, as anatomical changes; and at the myofiber scale, as mitochondrial and protein type content. The protein content of a myofiber is controlled b...
Training exercise produces skeletal muscle adaptation: at the organ scale, as anatomical changes; and at the myofiber scale, as mitochondrial and protein type content. The protein content of a myofiber is controlled by the calcineurin-NFATc signaling pathway: exercise triggers the pathway, and its final product is the translocation of dephosphorylated NFATc to the nucleus. Once in the nucleus, NFATc controls the state of the gene program to encode the slow or the fast fiber type characteristics. In the long term, the adaptation of the fiber type characteristics produces a shift in muscle fiber type: an increase in the number of myofibers of the fast type (which means that myofibers of the slow type shift to fast type) is related to force production; and an increase in the number of myofibers of the slow type (myofibers of the fast type shift to slow type) is related to fatigue resistance. These macroscopic features, i.e. force production and fatigue resistance, are the main target of most training protocols; however, little attention is focused on the limitations imposed by the fiber distribution of muscles at the organ scale. Based on the calcineurin-NFATc signaling pathway, we represented an exercise stimulus by a cytosolic calcium signal, and simulated the dynamics of NFATc in the nucleus. In this contribution, we present a dynamical model for the calcineurin-NFATc signaling pathway to describe the time course of dephosphorilated NFATc in the nucleus. We used an experimental report of a continuous stimulation pattern for calibration, and an experimental report of a pulsed stimulation pattern for comparison; we obtained a good agreement between the simulations and the experimental measurements.
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