Download or read book Quantitative Comparisons of Experimentally Measured Inhomogeneous Trabecular Bone Strain Distributions with Finite Element Predictions written by Brent Leonard Ulrey and published by . This book was released on 2000 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Quantitative Computed tomography Based Bone strength Indicators for the Identification of Low Bone strength Individuals in a Clinical Environment written by Bino Abel Varghese and published by . This book was released on 2011 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of the current study was to develop quantitative computed-tomography (QCT)-based bone-strength indicators that highly correlate with finite-element (FE)-based strength. We perform a combined numerical-experimental study, comparing FE-predicted surface strains with strain gauge measurements, to validate the FE models of 36 long bones (humerus, radius, femur and tibia) under three-point bending and torsion. The FE models were constructed from trans-axial volumetric CT scans, and the segmented bone images were corrected for partial-volume effects. The material properties (Young's modulus for cortex, density-modulus relationship for trabecular bone and Poisson's ratio) were calibrated by minimizing the error between experiments and simulations among all bones. The resultant R2 values of the measured strains versus load under three-point bending and torsion were 0.96-0.99 and 0.61-0.99, respectively, for all bones in our data set. The errors of the calculated FE strains in comparison to those measured using strain gauges in the mechanical tests ranged from -6% to 7% under bending and from -37% to 19% under torsion. The observation of comparatively low errors and high correlations between the FE-predicted strains and the experimental strains, across the various types of bones and loading conditions (bending and torsion), validates our approach to bone segmentation and our choice of material properties. Based on the analysis of the various FE models of the long bones, the location of the CT slice on the bone that showed the highest propensity to fracture was identified for four loading conditions (compression, three-point bending, cantilever bending and torsion). The identified CT slice was then used to derive novel and improved bone-strength indicators. We evaluated the performance of area-weighted (AW), density-weighted (DW) and modulus-weighted (MW) rigidity measures as well as popular strength indicators like section modulus and stress-strain index. We have also developed a novel strength metric, the centroid deviation, which takes into consideration the spatial distribution of the centroids. Here, we observed that the MW polar moment of inertia and the MW moment of inertia were the two top-performers (average r

Download or read book Imaging based Numerical Study of Biomechanics and Bone Density Distribution in Human Alveolar Bone written by Kangning Su and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Bone adapts to the changes of mechanical stimulus by bone remodeling activities. Bone remodeling results in the variation of bone density. This study presents the results of numerical simulations of biomechanics and mechanically adaptive bone remodeling in the human alveolar bone. Finite element models were built based on the micro X-ray computed tomography (micro-CT) images or clinical cone-beam computed tomography (CBCT) images. Strain in the alveolar bone under tooth loading or implant loading was calculated. Bone density distribution as a response to the mechanical stimulus was also computed. The results were in good agreement with experimentally measured strain using mechanical testing coupled with micro-CT and with the bone density distribution measured using clinical CBCT images. The models were used to predict the strain field with different implant positions. A number of numerical algorithms have been developed to model the adaptive bone remodeling under mechanical loads for orthopedic and dental applications. The parametric study examines the effects of several model parameters on the computed apparent bone density in mandible under normal chewing and biting forces. The density change rate was based on the strain energy density per unit mass. The algorithms used in this study containing an equilibrium zone (lazy zone) and saturated values of density change rate provided certain stability to result in convergence without discontinuous checkerboard patterns. The parametric study shows that when different boundary conditions were applied, the bone density distributions at convergence were very different, except in the vicinity of the applied loads. Compared with the effects of boundary conditions, the models are less sensitive to the choice of initial density values. Several models starting from different initial density values resulted in similar but not exactly the same bone density distribution at convergence. The results also show that, a higher reference value of mechanical stimulus resulted in lower average bone density at convergence. The width of equilibrium zone did not substantially affect the average density at convergence. However, with increasing width, the areas with the highest and the lowest bone density areas were all reduced. Moreover, the results of mechanically adaptive bone remodeling algorithms were compared with the information extracted from clinical images. Cone-beam computed tomography (CBCT) images of multiple patients were collected and processed to obtain the standard outline of mandible and average bone density distribution on the sagittal cross-sectional at the center of lateral incisors. Finite element models were built to compute the strain and stress in mandible under normal chewing and biting forces. Bone remodeling algorithm was carried out using strain energy density per unit bone mass as the mechanical stimulus to compute the bone density distribution at equilibrium. The computed bone density distribution exhibited close agreement with that obtained from CBCT image analysis with a coefficient of correlation of 0.87. The bite forces applied on teeth were transmitted through the tooth roots to the bone surrounding them, thus stimulated high trabecular bone density (1.6 g/cm3) near the tooth roots. The bending and torsion moments on the sagittal section of mandible resulted in lower bone density near the center (0.5 g/cm3) than those towards the edge of the section. The results add new knowledge of anatomy and biomechanics of mandibles and provide a new method to compare the results of numerical simulations of mechanically adaptive bone remodeling to in vivo data. Also, 3D finite element models were built based on micro-CT images and the results were compared with those obtained from mechanical testing coupled with micro-CT. Bone-implant mechanics is one of the factors that contribute to implant stability and success. In this work, voxel-based finite element models were built based on the micro-CT images of human cadaveric mandible specimens before and after implant placement. The elastic moduli of bone elements were assigned based on the intensity values in the micro-CT images of bone-tooth specimens before implant placement to avoid the beam hardening artifacts and to increase the connectivity and accuracy of the models. The implant positions in the models were determined by the micro-CT images of bone-implant specimens after implant placement. The computed results show that high strain appeared at the bone-implant contact locations and manifested into the supporting bone, including the buccal and lingual bone plates, which were not in direct contact with the implants. The strain concentration in the buccal bone plates was more substantial than that in the lingual bone plate, because the buccal bone plates were thinner than the lingual bone plates. The average values of maximum principal strain in the buccal and lingual regions of interest (ROI) were in good agreement with those experimentally measured using mechanical testing coupled with micro-CT and digital volume correlation. The implant positions were then virtually changed in the models by translating the implant towards the buccal or the lingual direction. The computed strain in the buccal bone decreased when the implant was virtually placed in the models away from the buccal bone plate. The strain in lingual bone also deceased when the implant was virtually moved in the model from the center of the alveolar socket towards the lingual or buccal plate. The results indicate that the distance of implant to the buccal bone plate can affect the mechanical stimuli in bone, especially in the buccal bone plate, which may subsequently affect the bone remodeling process and buccal bone resorption.

Download or read book Using Texture Correlation to Measure Strain in Trabecular Bone written by Tina Maree Herrera and published by . This book was released on 1994 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Microstructure based Characterization and Modeling of Trabecular Bone Deformation and Failure written by Hang Yao and published by . This book was released on 2011 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: A variety of micro-finite element (muFE) modeling meshes and tissue material models are investigated using ANSYS. An elasto-plastic muFE model of trabecular bone based on muCT reconstruction is validated and verified. The tissue material model of trabecular bone is predicted using the method of fitting the experimental nominal stress-strain curve. More measurements could be performed from muFE model, and a few examples are demonstrated.

Download or read book Fundamentals of Medical Imaging written by Paul Suetens and published by Cambridge University Press. This book was released on 2009-08-06 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamentals of Medical Imaging, second edition, is an invaluable technical introduction to each imaging modality, explaining the mathematical and physical principles and giving a clear understanding of how images are obtained and interpreted. Individual chapters cover each imaging modality – radiography, CT, MRI, nuclear medicine and ultrasound – reviewing the physics of the signal and its interaction with tissue, the image formation or reconstruction process, a discussion of image quality and equipment, clinical applications and biological effects and safety issues. Subsequent chapters review image analysis and visualization for diagnosis, treatment and surgery. New to this edition: • Appendix of questions and answers • New chapter on 3D image visualization • Advanced mathematical formulae in separate text boxes • Ancillary website containing 3D animations: www.cambridge.org/suetens • Full colour illustrations throughout Engineers, clinicians, mathematicians and physicists will find this an invaluable aid in understanding the physical principles of imaging and their clinical applications.

Download or read book Index Medicus written by and published by . This book was released on 2004 with total page 1810 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vols. for 1963- include as pt. 2 of the Jan. issue: Medical subject headings.

Download or read book Image Based Multilevel Biomechanical Modeling for Fall Induced Hip Fracture written by Yunhua Luo and published by Springer. This book was released on 2017-01-05 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fall-induced hip fracture is an epidemic health risk among elderly people. This book presents an image-based multilevel modeling approach to understanding the biomechanics involved in fall-induced hip fracture. By hierarchically integrating a body-level dynamics model, a femur-level finite element model, and a local bone failure model, the biomechanics approach is able to simulate all stages in sideways falls and to incorporate all biomechanical variables affecting hip fracture. This book is useful for clinicians to accurately evaluate fracture risk, for biomechanical engineers to virtually test hip protective devices, and for biomedical students to learn image-based biomechanical modeling techniques. This book also covers: Biomechanical viewing on bone composition, bone remodeling, and bone strength Bone imaging and information captured for constructing biomechanical models Bone mechanical testing and mechanical properties required for biomechanical modeling

Download or read book Cumulated Index Medicus written by and published by . This book was released on 1997 with total page 1912 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experimental Stress Analysis for Materials and Structures written by Alessandro Freddi and published by Springer. This book was released on 2015-03-19 with total page 509 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book summarizes the main methods of experimental stress analysis and examines their application to various states of stress of major technical interest, highlighting aspects not always covered in the classic literature. It is explained how experimental stress analysis assists in the verification and completion of analytical and numerical models, the development of phenomenological theories, the measurement and control of system parameters under operating conditions, and identification of causes of failure or malfunction. Cases addressed include measurement of the state of stress in models, measurement of actual loads on structures, verification of stress states in circumstances of complex numerical modeling, assessment of stress-related material damage, and reliability analysis of artifacts (e.g. prostheses) that interact with biological systems. The book will serve graduate students and professionals as a valuable tool for finding solutions when analytical solutions do not exist.

Download or read book Biomimetics written by Mehmet Sarikaya and published by American Institute of Physics. This book was released on 1995 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: Market: Students and researchers in geophysics, astronomy, and astrophysics. This book reports on the timely Earth Observing System (EOS) Program's wide range of scientific investigations, observational capabilities, vast data and information system, and educational activities. Because its primary goal is to determine the extent, causes, and regional consequences of global climate change, this program provides the scientific knowledge needed by world leaders to formulate sound and equitable environmental policies.

Download or read book Bones written by John D. Currey and published by Princeton University Press. This book was released on 2006-07-23 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a comprehensive and accessible overview of what is known about the structure and mechanics of bone, bones, and teeth. In it, John Currey incorporates critical new concepts and findings from the two decades of research since the publication of his highly regarded The Mechanical Adaptations of Bones. Crucially, Currey shows how bone structure and bone's mechanical properties are intimately bound up with each other and how the mechanical properties of the material interact with the structure of whole bones to produce an adapted structure. For bone tissue, the book discusses stiffness, strength, viscoelasticity, fatigue, and fracture mechanics properties. For whole bones, subjects dealt with include buckling, the optimum hollowness of long bones, impact fracture, and properties of cancellous bone. The effects of mineralization on stiffness and toughness and the role of microcracking in the fracture process receive particular attention. As a zoologist, Currey views bone and bones as solutions to the design problems that vertebrates have faced during their evolution and throughout the book considers what bones have been adapted to do. He covers the full range of bones and bony tissues, as well as dentin and enamel, and uses both human and non-human examples. Copiously illustrated, engagingly written, and assuming little in the way of prior knowledge or mathematical background, Bones is both an ideal introduction to the field and also a reference sure to be frequently consulted by practicing researchers.

Download or read book Bioinspired Structures and Design written by Wole Soboyejo and published by Cambridge University Press. This book was released on 2020-09-17 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt: Master simple to advanced biomaterials and structures with this essential text. Featuring topics ranging from bionanoengineered materials to bio-inspired structures for spacecraft and bio-inspired robots, and covering issues such as motility, sensing, control and morphology, this highly illustrated text walks the reader through key scientific and practical engineering principles, discussing properties, applications and design. Presenting case studies for the design of materials and structures at the nano, micro, meso and macro-scales, and written by some of the leading experts on the subject, this is the ideal introduction to this emerging field for students in engineering and science as well as researchers.

Download or read book Biomechanics Current Interdisciplinary Research written by European Society of Biomechanics. Meeting and published by Springer. This book was released on 1985-10-31 with total page 776 pages. Available in PDF, EPUB and Kindle. Book excerpt: Selected proceedings of the Fourth Meeting of the European Society of Biomechanics in collaboration with the European Society of Biomaterials, September 24-26, 1984, Davos

Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1992 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Introductory Biomechanics written by C. Ross Ethier and published by Cambridge University Press. This book was released on 2007-03-12 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introductory Biomechanics is a new, integrated text written specifically for engineering students. It provides a broad overview of this important branch of the rapidly growing field of bioengineering. A wide selection of topics is presented, ranging from the mechanics of single cells to the dynamics of human movement. No prior biological knowledge is assumed and in each chapter, the relevant anatomy and physiology are first described. The biological system is then analyzed from a mechanical viewpoint by reducing it to its essential elements, using the laws of mechanics and then tying mechanical insights back to biological function. This integrated approach provides students with a deeper understanding of both the mechanics and the biology than from qualitative study alone. The text is supported by a wealth of illustrations, tables and examples, a large selection of suitable problems and hundreds of current references, making it an essential textbook for any biomechanics course.

Download or read book Principles of Bone Biology written by John P. Bilezikian and published by Academic Press. This book was released on 2008-09-29 with total page 2074 pages. Available in PDF, EPUB and Kindle. Book excerpt: Principles of Bone Biology provides the most comprehensive, authoritative reference on the study of bone biology and related diseases. It is the essential resource for anyone involved in the study of bone biology. Bone research in recent years has generated enormous attention, mainly because of the broad public health implications of osteoporosis and related bone disorders. - Provides a "one-stop" shop. There is no need to search through many research journals or books to glean the information one wants...it is all in one source written by the experts in the field - The essential resource for anyone involved in the study of bones and bone diseases - Takes the reader from the basic elements of fundamental research to the most sophisticated concepts in therapeutics - Readers can easily search and locate information quickly as it will be online with this new edition