Left ventricle hydatid cyst of heart removed under cardiopulmonary bypass: anesthesia management

Hydatid cyst uncommon in heart, echinococcosis is endemine in our country. Hydatid cyst in a heart may causes disturbances in conducting system, Pericarditis congestive cardiac failure. The surgery and anesthetic management become very challenging in this case. We are describing the successful management of such a case of left ventricle hydatid cyst remove under cardio pulmonary bypass in a middle age female

Comportement mécanique de nano poudres métalliques consolidées et impactées à vitesse intermédiaire

Un procédé combinant la métallurgie des poudres et la déformation plastique sévère en régime dynamique intermédiaire a été mise au point pour élaborer des matériaux à grains ultrafins. Le matériau massif résultant de la compaction isostatique à chaud d'une poudre d'aluminium de pureté commerciale montre une microstructure homogène de grains équiaxes, dont la taille moyenne micro-m, sans orientation préférentielle. La microstructure après impact d'un poids tombant à la vitesse de 100s-1 induit une légère anisotropie de forme des grains et une texture cristallographique marquée. La taille moyenne des grains, mesurée par microscopie électronique en transmission et par diffraction des rayons X est de 500 nm et 80 nm respectivement. Des éprouvettes prélevées dans les directions parallèle (DN) et perpendiculaire (DT) à la direction de l'impact ont été déformées à température ambiante, en compression uniaxiale à 10-4s-1. Par rapport au matériau initial, un gain important en terme de limite d'élasticité est observé, s'accompagnant toutefois d'un adoucissement marqué après quelques % de déformation

A simple and effective 1D-element discrete-based method for computational bone remodeling

This is an Accepted Manuscript of an article published by Taylor & Francis Group in Computer Methods in Biomechanics and Biomedical Engineering on 2022, available online at: http://www.tandfonline.com/10.1080/10255842.2021.1943370.In-silico models applied to bone remodeling are widely used to investigate bone mechanics, bone diseases, bone-implant interactions, and also the effect of treatments of bone pathologies. This paper proposes a new methodology to solve the bone remodeling problem using one-dimensional (1D) elements to discretize trabecular structures more efficiently for 2D and 3D domains. An Euler integration scheme is coupled with the momentum equations to obtain the evolution of material density at each step. For the simulations, the equations were solved by using the finite element method, and two benchmark tests were solved varying mesh parameters. Proximal femur and calcaneus bone were selected as study cases given the vast research available on the topology of these bones, and compared with the anatomical features of trabecular bone reported in the literature. The presented methodology has proven to be efficient in optimizing topologies of lattice structures; It can predict the trend of formation patterns of the main trabecular groups from two different cancellous bones (femur and calcaneus) using domains set up by discrete elements as a starting point. Preliminary results confirm that the proposed approach is suitable and useful in bone remodeling problems leading to a considerable computational cost reduction. Characteristics similar to those encountered in topological optimization (TO) algorithms were identified in the benchmark tests as well, showing the viability of the proposed approach in other applications such as bio-inspired design.Peer ReviewedPostprint (author's final draft

Remodeling of the bone material containing microcracks: A theoretical analysis

The question is, what happens when the bone loses its ability for load-driven adaptation, when damage is no longer repaired as it seems to be the case for bone loss associated with age, medication or disease? In this study, we tempt to show how damage can influence the remodeling process. A thermodynamic theoretical framework is therefore provided as a basis for a consistent formulation of bone remodeling involving a chemical reaction and mass transfer between two constituents in presence of microcracks

Contribution to the study of the bone remodeling theory using n unit-elements model

Our work presents the study of bone remodeling scheme in the general case of n unit-elements model. The analytical result for the stationary states presented here as original was obtained and a condition which is necessary for the stability of the remodeling theory was derived. Forward finite-difference time-stepping is used to verify the prediction of the analytical study. This numerical study appears to confirm the analytical results

Anti-cytoskeletal drugs and time culture effects upon mechanical behavior of dermal equivalent tissue submitted to unconfined compression loading

International audienc

Internal bone remodeling induced by metallic pin fitted into medulla of a long bone having cylindrical anisotropy: Theoretical predictions

International audienc

Mechanical properties of polyurethane foam for potential application in the prevention and treatment of pressure ulcers

The viscoelastic property is a crucial parameter for evaluating the feasibility of the foam to be used as pressure relief. This work aims to perform experimental measurements to determine the dependence of the viscous behavior of polyurethane foam on density and energy dissipation. Experimental measurements were realized for three types of polyurethane foams with different densities soft, medium and hard. The compression tests at room temperature characterized the mechanical properties of these samples. Furthermore, the structures of the samples were characterized using scanning electron microscopy (SEM). A proportional relationship was observed between the density of polyurethane (PU) foam and the tolerated strength at 90% compression. This material has an excellent remanence (persistence) which showed by the creep experiments at constant stress (2, 5, 10 N) for 6 h. Young Modulus, relaxation time and dissipation coefficient (DE) were also calculated from the stress-strain curve. Moreover, softening behavior, which is responsible for pressure relief, was measured by a cyclic compression test. This paper assesses the capacity of polyurethane to effectively maintain interfacial pressure below the critical threshold of 32 mm of mercury, which represents a significant risk level for the development of pressure sores