PUMA publications for /group/simtech/processingFri Jul 05 14:59:56 CEST 2024Frontiers in Bioengineering and BiotechnologyDetermination of muscle shape deformations of the tibialis anterior during dynamic contractions using 3D ultrasound1220243d image fibres shape muscle deformation processing contraction dynamic movement ultrasound Wed Jun 05 15:26:27 CEST 2024Frontiers in Bioengineering and Biotechnology06Determination of muscle shape deformations of the tibialis anterior during dynamic contractions using 3D ultrasound. Front. Bioeng. Biotechnol. 12:1388907. 1220243D image muscle deformation processing contraction dynamic movement ultrasound Purpose: In this paper, we introduce a novel method for determining 3D deformations of the human tibialis anterior (TA) muscle during dynamic movements using 3D ultrasound. Materials and Methods: An existing automated 3D ultrasound system is used for data acquisition, which consists of three moveable axes, along which the probe can move. While the subjects perform continuous plantar- and dorsiflexion movements in two different controlled velocities, the ultrasound probe sweeps cyclically from the ankle to the knee along the anterior shin. The ankle joint angle can be determined using reflective motion capture markers. Since we considered the movement direction of the foot, i.e., active or passive TA, four conditions occur: slow active, slow passive, fast active, fast passive. By employing an algorithm which defines ankle joint angle intervals, i.e., intervals of range of motion (ROM), 3D images of the volumes during movement can be reconstructed. Results: We found constant muscle volumes between different muscle lengths, i.e., ROM intervals. The results show an increase in mean cross-sectional area (CSA) for TA muscle shortening. Furthermore, a shift in maximum CSA towards the proximal side of the muscle could be observed for muscle shortening. We found significantly different maximum CSA values between the fast active and all other conditions, which might be caused by higher muscle activation due to the faster velocity. Conclusion: In summary, we present a method for determining muscle volume deformation during dynamic contraction using ultrasound, which will enable future empirical studies and 3D computational models of skeletal muscles.Tue Apr 02 12:17:45 CEST 2024Biomechanics and Modeling in Mechanobiology033D ultrasound-based determination of skeletal muscle fascicle orientations2024Image Skeletal ultrasound 3D Inspo PN2-8 Pennation muscle angle processing Siebert architecture 26Architectural parameters of skeletal muscle such as pennation angle provide valuable information on muscle function, since they can be related to the muscle force generating capacity, fiber packing, and contraction velocity. In this paper, we introduce a 3D ultrasound-based workflow for determining 3D fascicle orientations of skeletal muscles. We used a custom-designed automated motor driven 3D ultrasound scanning system for obtaining 3D ultrasound images. From these, we applied a custom-developed multiscale-vessel enhancement filter-based fascicle detection algorithm and determined muscle volume and pennation angle. We conducted trials on a phantom and on the human tibialis anterior (TA) muscle of 10 healthy subjects in plantarflexion (157 {\textpm} 7{\$}{\$}^{\backslash}circ{\$}{\$}), neutral position (109 {\textpm} 7{\$}{\$}^{\backslash}circ{\$}{\$}, corresponding to neutral standing), and one resting position in between (145 {\textpm} 6{\$}{\$}^{\backslash}circ{\$}{\$}). The results of the phantom trials showed a high accuracy with a mean absolute error of 0.92 {\textpm} 0.59{\$}{\$}^{\backslash}circ{\$}{\$}. TA pennation angles were significantly different between all positions for the deep muscle compartment; for the superficial compartment, angles are significantly increased for neutral position compared to plantarflexion and resting position. Pennation angles were also significantly different between superficial and deep compartment. The results of constant muscle volumes across the 3 ankle joint angles indicate the suitability of the method for capturing 3D muscle geometry. Absolute pennation angles in our study were slightly lower than recent literature. Decreased pennation angles during plantarflexion are consistent with previous studies. The presented method demonstrates the possibility of determining 3D fascicle orientations of the TA muscle in vivo.Thu Mar 24 15:53:08 CET 20222021 IEEE/ACM International Workshop on Hierarchical Parallelism for Exascale Computing (HiPar)1--9Distributing Higher-Dimensional Simulations Across Compute Systems: A Widely Distributed Combination Technique2021parallelism myown simulation processing combination_technique hpc sparse_grids The numerical solution of high-dimensional {PDE} problems is essential for many research questions, such as understanding relativistic astrophysics, quantum physics, or hot fusion plasmas. At the same time, it is haunted by the curse of dimensionality, rendering finely resolved simulations infeasible even on modern architectures. The Sparse Grid Combination Technique helps to break the curse of dimensionality for high-dimensional {PDE} problems to some extent. But even then, simulations are restricted by the size of {HPC} systems. A new implementation based on the open-source code {DisCoTec} allows to distribute existing solvers even across compute systems: The widely distributed combination technique enables simulations at scales that would otherwise be intractable.This paper introduces the extended algorithm and showcases a proof of concept for the remote communication set-up. The scaling properties for the single-system and two-system cases are presented, and the numerical correctness of the implementation is validated.The widely distributed combination technique is useful in cases where the memory and/or compute resources are not sufficient for a particular problem to fit on one single available system, but multiple systems are able to accommodate it.Wed Feb 14 21:53:58 CET 2018Future Generation Computer Systems228 - 238A characterization of workflow management systems for extreme-scale applications752017forschungsdaten systems management software Workflow processing workflowTracking