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https://www.readbyqxmd.com/read/28541192/real-time-error-control-for-surgical-simulation
#1
Huu Phuoc Bui, Satyendra Tomar, Hadrien Courtecuisse, Stephane Cotin, Stephane Bordas
OBJECTIVE: To present the first real-time a posteriori error-driven adaptive finite element approach for realtime simulation and to demonstrate the method on a needle insertion problem. METHODS: We use corotational elasticity and a frictional needle/tissue interaction model. The problem is solved using finite elements within SOFA1. The refinement strategy relies upon a hexahedron-based finite element method, combined with a posteriori error estimation driven local h-refinement, for simulating soft tissue deformation...
May 23, 2017: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/28516345/performance-and-cost-evaluation-of-health-information-systems-using-micro-costing-and-discrete-event-simulation
#2
Olfa Rejeb, Claire Pilet, Sabri Hamana, Xiaolan Xie, Thierry Durand, Saber Aloui, Anne Doly, Pierre Biron, Lionel Perrier, Vincent Augusto
Innovation and health-care funding reforms have contributed to the deployment of Information and Communication Technology (ICT) to improve patient care. Many health-care organizations considered the application of ICT as a crucial key to enhance health-care management. The purpose of this paper is to provide a methodology to assess the organizational impact of high-level Health Information System (HIS) on patient pathway. We propose an integrated performance evaluation of HIS approach through the combination of formal modeling using the Architecture of Integrated Information Systems (ARIS) models, a micro-costing approach for cost evaluation, and a Discrete-Event Simulation (DES) approach...
May 17, 2017: Health Care Management Science
https://www.readbyqxmd.com/read/28510575/electro-mechanical-dynamics-of-spiral-waves-in-a-discrete-2d-model-of-human-atrial-tissue
#3
Paul Brocklehurst, Haibo Ni, Henggui Zhang, Jianqiao Ye
We investigate the effect of mechano-electrical feedback and atrial fibrillation induced electrical remodelling (AFER) of cellular ion channel properties on the dynamics of spiral waves in a discrete 2D model of human atrial tissue. The tissue electro-mechanics are modelled using the discrete element method (DEM). Millions of bonded DEM particles form a network of coupled atrial cells representing 2D cardiac tissue, allowing simulations of the dynamic behaviour of electrical excitation waves and mechanical contraction in the tissue...
2017: PloS One
https://www.readbyqxmd.com/read/28493110/bem-based-simulation-of-lung-respiratory-deformation-for-ct-guided-biopsy
#4
Dong Chen, Weisheng Chen, Lipeng Huang, Xuegang Feng, Terry Peters, Lixu Gu
PURPOSE: Accurate and real-time prediction of the lung and lung tumor deformation during respiration are important considerations when performing a peripheral biopsy procedure. However, most existing work focused on offline whole lung simulation using 4D image data, which is not applicable in real-time image-guided biopsy with limited image resources. In this paper, we propose a patient-specific biomechanical model based on the boundary element method (BEM) computed from CT images to estimate the respiration motion of local target lesion region, vessel tree and lung surface for the real-time biopsy guidance...
May 10, 2017: International Journal of Computer Assisted Radiology and Surgery
https://www.readbyqxmd.com/read/28472465/precise-integration-of-inducible-transcriptional-elements-priite-enables-absolute-control-of-gene-expression
#5
Rita Pinto, Lars Hansen, John Hintze, Raquel Almeida, Sylvester Larsen, Mehmet Coskun, Johanne Davidsen, Cathy Mitchelmore, Leonor David, Jesper Thorvald Troelsen, Eric Paul Bennett
Tetracycline-based inducible systems provide powerful methods for functional studies where gene expression can be controlled. However, the lack of tight control of the inducible system, leading to leakiness and adverse effects caused by undesirable tetracycline dosage requirements, has proven to be a limitation. Here, we report that the combined use of genome editing tools and last generation Tet-On systems can resolve these issues. Our principle is based on precise integration of inducible transcriptional elements (coined PrIITE) targeted to: (i) exons of an endogenous gene of interest (GOI) and (ii) a safe harbor locus...
May 4, 2017: Nucleic Acids Research
https://www.readbyqxmd.com/read/28464970/advanced-identification-and-quantification-of-in-bearing-minerals-by-scanning-electron-microscope-based-image-analysis
#6
Kai Bachmann, Max Frenzel, Joachim Krause, Jens Gutzmer
The identification and accurate characterization of discrete grains of rare minerals in sulfide base-metal ores is usually a cumbersome procedure due to the small grain sizes (typically <10 μm) and complex mineral assemblages in the material. In this article, a new strategy for finding and identifying indium minerals, and quantifying their composition and abundance is presented, making use of mineral liberation analysis (MLA) and electron probe microanalysis (EPMA). The method was successfully applied to polymetallic massive sulfide ores from the Neves-Corvo deposit in Portugal...
May 3, 2017: Microscopy and Microanalysis
https://www.readbyqxmd.com/read/28464438/social-skills-training-for-children-with-autism-spectrum-disorder-using-a-robotic-behavioral-intervention-system
#7
Sang-Seok Yun, JongSuk Choi, Sung-Kee Park, Gui-Young Bong, HeeJeong Yoo
We designed a robot system that assisted in behavioral intervention programs of children with autism spectrum disorder (ASD). The eight-session intervention program was based on the discrete trial teaching protocol and focused on two basic social skills: eye contact and facial emotion recognition. The robotic interactions occurred in four modules: training element query, recognition of human activity, coping-mode selection, and follow-up action. Children with ASD who were between 4 and 7 years old and who had verbal IQ ≥ 60 were recruited and randomly assigned to the treatment group (TG, n = 8, 5...
May 2, 2017: Autism Research: Official Journal of the International Society for Autism Research
https://www.readbyqxmd.com/read/28433790/a-strain-mediated-corrosion-model-for-bioabsorbable-metallic-stents
#8
E Galvin, D O'Brien, C Cummins, B J Mac Donald, C Lally
This paper presents a strain-mediated phenomenological corrosion model, based on the discrete finite element modelling method which was developed for use with the ANSYS Implicit finite element code. The corrosion model was calibrated from experimental data and used to simulate the corrosion performance of a WE43 magnesium alloy stent. The model was found to be capable of predicting the experimentally observed plastic strain-mediated mass loss profile. The non-linear plastic strain model, extrapolated from the experimental data, was also found to adequately capture the corrosion-induced reduction in the radial stiffness of the stent over time...
April 19, 2017: Acta Biomaterialia
https://www.readbyqxmd.com/read/28427653/thermolysis-synthesis-of-pure-phase-nio-from-novel-sonochemical-synthesized-ni-ii-nano-metal-organic-supramolecular-architecture
#9
Younes Hanifehpour, Ali Morsali, Babak Mirtamizdoust, Sang Woo Joo, Behzad Soltani
Nano-structures of a new supramolecular coordination compound of divalent nickel with the pyrazol (pzH) containing the terminal azide anions, [Ni(pzH)2(N3)2] (1), with discrete molecular architecture (DMA) in solid state was synthesized via sonochemical method. The new nanostructure was characterized by scanning electron microscopy, X-ray powder diffraction, IR, and elemental analysis. Compound 1 was structurally characterized by single crystal X-ray diffraction and the single-crystal X-ray data shows that the coordination number of Ni (II) ions is six, (NiN6), with four N-donor atoms from neutral "pzH" ligands and two N-donors from two terminal azide anions...
July 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28425900/mobiliser-des-repr%C3%A3-sentations-ethnoculturelles-pour-expliquer-les-disparit%C3%A3-s-d%C3%A2-acc%C3%A3-s-aux-soins-de-sant%C3%A3-au-burkina-faso
#10
Loubna Belaid, Patrick Cloos, Valéry Ridde
OBJECTIFS: Cette étude vise à décrire la mobilisation des représentations ethnoculturelles par des agents et des gestionnaires de santé pour expliquer l'échec partiel d'une politique de santé maternelle et discuter des conséquences potentielles de ces représentations sur l'accès aux soins de santé des populations.MÉTHODES : Il s'agit d'une recherche qualitative de type socio-anthropologique mobilisant des entretiens approfondis, des discussions informelles, des observations non participantes menées dans les centres de santé et une analyse documentaire...
April 20, 2017: Canadian Journal of Public Health. Revue Canadienne de Santé Publique
https://www.readbyqxmd.com/read/28425587/hybrid-finite-difference-finite-element-immersed-boundary-method
#11
Boyce E Griffith, Xiaoyu Luo
The immersed boundary method is an approach to fluid-structure interaction that uses a Lagrangian description of the structural deformations, stresses, and forces along with an Eulerian description of the momentum, viscosity, and incompressibility of the fluid-structure system. The original immersed boundary methods described immersed elastic structures using systems of flexible fibers, and even now, most immersed boundary methods still require Lagrangian meshes that are finer than the Eulerian grid. This work introduces a coupling scheme for the immersed boundary method to link the Lagrangian and Eulerian variables that facilitates independent spatial discretizations for the structure and background grid...
April 20, 2017: International Journal for Numerical Methods in Biomedical Engineering
https://www.readbyqxmd.com/read/28380864/transient-polarized-radiative-transfer-analysis-in-a-scattering-medium-by-a-discontinuous-finite-element-method
#12
Cun-Hai Wang, Hong-Liang Yi, He-Ping Tan
Transient (time-dependent) polarized radiative transfer in a scattering medium exposed to an external collimated beam illumination is conducted based on the time-dependent polarized radiative transfer theory. The transient term, which persists the nanosecond order time and cannot be ignored for the time-dependent radiative transfer problems induced by a short-pulsed beam, is considered as well as the polarization effect of the radiation. A discontinuous finite element method (DFEM) is developed for the transient vector radiative transfer problem and the derivation of the discrete form of the governing equation is presented...
April 3, 2017: Optics Express
https://www.readbyqxmd.com/read/28365300/comparison-of-video-analysis-and-simulations-of-a-drum-coating-process
#13
P Boehling, G Toschkoff, R Dreu, S Just, P Kleinebudde, A Funke, H Rehbaum, J G Khinast
Tablet coating is a common unit operation in the pharmaceutical industry. To improve currently established processes, it is important to understand the influence of the process parameters on the coating quality. One of the critical parameters is the tablet velocity. In this work, numerical results are compared to results obtained experimentally. Tablet movement in the drums was simulated using the Discrete Element Method (DEM). The simulation parameters were adapted to fit the simulation to the experimental data...
March 30, 2017: European Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/28350406/power-free-digital-and-programmable-dispensing-of-picoliter-droplets-using-a-digit-chip
#14
A Mepham, J D Besant, A W Weinstein, I B Burgess, E H Sargent, S O Kelley
There is a growing need for power-free methods to manipulate small volumes of liquids and thereby enable use of diagnostic assays in resource-limited settings. Most existing self-powered devices provide analog manipulation of fluids using paper, capillary or pressure-driven pumps. These strategies are well-suited to manipulating larger micro- and milliliter-scale volumes at constant flow rates; however, they fail to enable the manipulation of nanoliter and picoliter volumes required in assays using droplets, capillary sampling (e...
April 11, 2017: Lab on a Chip
https://www.readbyqxmd.com/read/28297998/splash-detail-due-to-a-single-grain-incident-on-a-granular-bed
#15
Takahiro Tanabe, Takashi Shimada, Nobuyasu Ito, Hiraku Nishimori
Using the discrete element method, we study the splash processes induced by the impact of a grain on a randomly packed bed. Good correspondence is obtained between our numerical results and the findings of previous experiments for the movement of ejected grains. Furthermore, the distributions of the ejection angle and ejection speed for individual grains vary depending on the relative timing at which the grains are ejected after the initial impact. Obvious differences are observed between the distributions of grains ejected during the earlier and later splash periods: the form of the vertical ejection-speed distribution varies from a power-law form to a lognormal form with time; this difference may determine grain trajectory after ejection...
February 2017: Physical Review. E
https://www.readbyqxmd.com/read/28294574/phase-field-boundary-conditions-for-the-voxel-finite-cell-method-surface-free-stress-analysis-of-ct-based-bone-structures
#16
L H Nguyen, S K F Stoter, T Baum, J S Kirschke, M Ruess, Z Yosibash, D Schillinger
The voxel finite cell method employs unfitted finite element meshes and voxel quadrature rules to seamlessly transfer CT data into patient-specific bone discretizations. The method, however, still requires the explicit parametrization of boundary surfaces to impose traction and displacement boundary conditions, which constitutes a potential roadblock to automation. We explore a phase-field based formulation for imposing traction and displacement constraints in a diffuse sense. Its essential component is a diffuse geometry model generated from metastable phase-field solutions of the Allen-Cahn problem that assumes the imaging data as initial condition...
March 11, 2017: International Journal for Numerical Methods in Biomedical Engineering
https://www.readbyqxmd.com/read/28289574/digital-morphing-wing-active-wing-shaping-concept-using-composite-lattice-based-cellular-structures
#17
Benjamin Jenett, Sam Calisch, Daniel Cellucci, Nick Cramer, Neil Gershenfeld, Sean Swei, Kenneth C Cheung
We describe an approach for the discrete and reversible assembly of tunable and actively deformable structures using modular building block parts for robotic applications. The primary technical challenge addressed by this work is the use of this method to design and fabricate low density, highly compliant robotic structures with spatially tuned stiffness. This approach offers a number of potential advantages over more conventional methods for constructing compliant robots. The discrete assembly reduces manufacturing complexity, as relatively simple parts can be batch-produced and joined to make complex structures...
March 1, 2017: Soft Robotics
https://www.readbyqxmd.com/read/28280517/mixed-total-variation-and-l-1-regularization-method-for-optical-tomography-based-on-radiative-transfer-equation
#18
Jinping Tang, Bo Han, Weimin Han, Bo Bi, Li Li
Optical tomography is an emerging and important molecular imaging modality. The aim of optical tomography is to reconstruct optical properties of human tissues. In this paper, we focus on reconstructing the absorption coefficient based on the radiative transfer equation (RTE). It is an ill-posed parameter identification problem. Regularization methods have been broadly applied to reconstruct the optical coefficients, such as the total variation (TV) regularization and the L(1) regularization. In order to better reconstruct the piecewise constant and sparse coefficient distributions, TV and L(1) norms are combined as the regularization...
2017: Computational and Mathematical Methods in Medicine
https://www.readbyqxmd.com/read/28269628/development-of-an-open-source-cosimulation-method-of-the-knee
#19
Anne Schmitz, Davide Piovesan
Rigid body dynamics and soft tissue loads are solved simultaneously in a cosimulation framework to couple musculoskeletal dynamics and tissue mechanics. The goal of this work was to implement a validated, open-source cosimulation framework of the knee to determine how this coupling affects computed cartilage loads. The kinematic knee joint of a generic whole body model in the open-source software OpenSim was replaced by a previously developed discrete element knee model that consisted of a six degree of freedom (dof) tibiofemoral joint and one dof patellofemoral joint...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28268867/fea-modeling-and-fluid-flow-simulation-of-human-rectum-with-inserted-bowel-catheters
#20
Yong Zhang, Tina VanRiper, Brian Rague, Drew Weidman
In this project, fluid flow and fluid-structure interaction are studied for the human lower gastrointestinal (GI) region. The study consists of two steps. First, we apply meshing methods to discretize both the human lower GI model and the catheter model at sufficient resolution suitable for importing into a Finite Element Analysis (FEA) tool. For model discretization, 3D models of the colon reconstructed from human MRI slices are used to obtain the valid inlet and outlet boundary surfaces. To resolve the viscous boundary layer in flow studies, a special structure of the near-wall volumetric mesh is built by triangular prisms that construct quasi-structured, multiple near-boundary sub-layers...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
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