Article
Mechanics
Farzam Dadgar-Rad, Amirhossein N. Dorostkar, Mokarram Hossain
Summary: This paper presents a finite growth formulation for shell-like soft tissues under mechanical loading, and demonstrates that the present formulation can successfully predict the finite growth and deformation of the tissues under mechanical input.
INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS
(2023)
Article
Mechanics
Jay J. Shim, Gerard A. Ateshian
Summary: The study aims to establish theoretical foundations for a solid-fluid biphasic mixture domain accommodating inertial effects and a viscous interstitial fluid, interfacing with a dynamic viscous fluid domain. Proposing a hybrid framework where the porous solid skeleton is intrinsically incompressible while the interstitial fluid is compressible, a state variable as a measure of fluid volumetric strain is defined. Utilizing isothermal framework and Clausius-Duhem inequality, a fluid pressure function related to the strain measure is derived across hybrid biphasic interfaces.
ARCHIVE OF APPLIED MECHANICS
(2022)
Review
Engineering, Biomedical
Yali Zhao, Guohuang Hu, Yuwei Yan, Zhen Wang, Xiaohua Liu, Huanhuan Shi
Summary: Ocular diseases are closely related to physiological changes in the eye sphere and its contents. Using biomechanical methods to explore the structure-function relationship of ocular tissue helps reveal pathological processes and contributes to the diagnosis and treatment of ocular diseases.
BIOMEDICAL ENGINEERING ONLINE
(2022)
Article
Polymer Science
Yuchen Liu, Ming Fang, Ruifeng Zhao, Hengyan Liu, Min Tian, Sheng Zhong, Shizhu Bai
Summary: This study evaluated the effect of periodontal splints made from different materials on stress distributions in compromised periodontal tissues and cement layers. Using a computer simulation of mastication, it was found that the use of splints effectively distributed loads and reduced stress. Splinting materials with low elastic moduli reduced stress concentration at the connectors, but increased tensile stress in the cement layer.
Article
Biology
Sarah Broyde, Matthew Dempsey, Linjie Wang, Philip G. Cox, Michael Fagan, Karl T. Bates
Summary: Biomechanical modelling is a useful tool for studying the evolution of functional performance in extinct animals, but reconstructions of soft tissue properties in current models face challenges. The qualitative and quantitative differences in reconstructions have a significant impact on predicting evolutionary patterns in macroevolutionary studies.
PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES
(2021)
Article
Chemistry, Multidisciplinary
Emily Sanchez-Real, Diego Otuna-Hernandez, Alisson Fajardo-Cabrera, Rosemary Davies-Alcivar, Mario Madrid-Perez, Carolina Cadena-Morejon, Diego Almeida-Galarraga, Cesar Guevara, Andres Tirado-Espin, Fernando Villalba-Meneses
Summary: This study analyzed the effect of increasing intraocular pressure on eyes with different severity of keratoconus using patient-specific models. The findings revealed differences in corneal deformation and stress between normal eyes and eyes with keratoconus, highlighting the importance of biomechanics in ophthalmology. Further research is needed to confirm the role of these differences in the diagnosis of keratoconus.
APPLIED SCIENCES-BASEL
(2023)
Article
Engineering, Mechanical
Yu-Fei Wang, Song Cen, Chen-Feng Li, Qun Zhang
Summary: In this paper, the authors modify the US-ATFH8 hexahedral solid element for the analysis of anisotropic nearly-incompressible hyperelastic soft tissues. The modified formulation employs linear analytical general solutions and consistent tangent modulus for formulating the trial functions, resulting in attractive properties such as absence of locking and insensitivity to mesh distortions. Numerical tests demonstrate high accuracy and faster convergence rates compared to existing models.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Mechanics
Nasser Firouzi, Marco Amabili
Summary: The aim of this work is to develop a non-linear finite element formulation for two-dimensional growth of soft tissues, and several examples are provided to validate the proposed model.
EUROPEAN JOURNAL OF MECHANICS A-SOLIDS
(2024)
Article
Computer Science, Interdisciplinary Applications
Alireza Karimi, Rafael Grytz, Seyed Mohammadali Rahmati, Christopher A. Girkin, J. Crawford Downs
Summary: This study investigated the effects of different element types on the resulting ONH stresses and strains. Results showed that 10-noded tetrahedral elements yielded similar results to 20-noded hexahedral elements with significantly lower computational time, while linear element types did not yield acceptable results.
COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE
(2021)
Article
Engineering, Multidisciplinary
Bruno Klahr, Jose Luis Medeiros Thiesen, Otavio Teixeira Pinto, Thiago Andre Carniel, Eduardo Alberto Fancello
Summary: This study investigated the numerical performance of five biphasic solution algorithms in the context of soft biological tissues. The results showed that iterative techniques perform well for weak coupling cases but lack convergence when the coupling strength increases. Therefore, the monolithic scheme is the most reliable choice for problems related to soft biological tissues mechanics.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2022)
Article
Mechanics
Bruno Klahr, Jose Luis Medeiros Thiesen, Otavio Teixeira Pinto, Thiago Andre Carniel, Eduardo Alberto Fancello
Summary: Investigations on the micromechanics of soft biological tissues can contribute significantly to the fields of mechanobiology and tissue engineering. Multiscale models are valuable numerical tools for providing insights into the micromechanics of these tissues. Due to the multiple multiphysics phenomena observed, the coupling between fluid transport and solid phases is of great interest. Poromechanical models are commonly used to represent fluid diffusion in deformable porous media. This study presents an extension of the variational single-field multiscale formulation considering poromechanical phases at finite strain for applications to soft biological tissues. Numerical examples comparing with direct simulations are provided to verify the proposed formulation, considering both undrained and drained conditions. The results suggest that the minimally constrained boundary condition is suitable for the undrained condition, but multiscale boundary conditions need to be developed for the drained condition.
EUROPEAN JOURNAL OF MECHANICS A-SOLIDS
(2023)
Article
Mechanics
Yuwaraj M. Ghugal, Sanjay K. Kulkarni, Rahul D. Borate
Summary: The present study focuses on the flexural analysis of cross ply laminated beams under combined thermal and transverse mechanical loads. Trigonometric, hyperbolic and 5th order shear deformation theories are utilized, which do not require shear correction factor and satisfy stress free condition. The governing equations are developed using the principle of virtual work to determine transverse shear stresses. Stresses and displacements are investigated under uniformly distributed nonlinear thermal load combined with uniformly distributed transverse mechanical load. Comparisons are made among the results obtained from these theories due to the absence of exact solutions for these problems.
Article
Biophysics
Katherine R. Knaus, AnnMarie Hipsley, Silvia S. Blemker
Summary: The ciliary muscle consists of three sections with different orientations that contract to deform and translate the lens during accommodation. A finite element model was created to predict the actions of the ciliary muscle sections in lens displacement. The model was calibrated and validated using experimental data to study the mechanical actions of each section.
BIOMECHANICS AND MODELING IN MECHANOBIOLOGY
(2021)
Article
Engineering, Multidisciplinary
Ankush Aggarwal, Bjorn Sand Jensen, Sanjay Pant, Chung-Hao Lee
Summary: Data-based approaches are a promising alternative to traditional analytical constitutive models for solid mechanics. This study proposes a Gaussian process-based constitutive modeling framework for planar, hyperelastic, and incompressible soft tissues. The strain energy density of soft tissues is modeled as a Gaussian process and can be regressed to experimental stress-strain data. The proposed framework can be trained with limited experimental data and provides a straightforward way of quantifying uncertainty in simulation-based predictions.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2023)
Article
Biotechnology & Applied Microbiology
Anqi Xue, Zuming Mao, Xiaoyu Zhu, Qiang Yang, Peichen Wang, Zimu Mao, Mingze Du, Xu Ma, Dong Jiang, Yubo Fan, Feng Zhao
Summary: This study aimed to investigate the biomechanical effects of horizontal meniscal tears and different resection strategies on a rabbit knee joint using finite element analysis. The results showed that the horizontal meniscal tears had little biomechanical impact on the rabbit knee joint, and some of the partial meniscectomy strategies also had minimal effect on joint stress. It is recommended to preserve the posterior root and the remaining peripheral edge of the meniscus during surgery for a horizontal meniscal tear.
FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY
(2023)
Article
Ophthalmology
Satish K. Panda, Haris Cheong, Tin A. Tun, Sripad K. Devella, Vijayalakshmi Senthil, Ramaswami Krishnadas, Martin L. Buist, Shamira Perera, Ching-Yu Cheng, Tin Aung, Alexandre H. Thiery, Michael J. A. Girard
Summary: This study develops a novel deep-learning approach for describing the structural phenotype of the glaucomatous optic nerve head (ONH) and serving as a robust glaucoma diagnosis tool. By analyzing the latent parameters, it reveals the changes in ONH morphology during the transition from a non-glaucoma to a glaucoma condition.
AMERICAN JOURNAL OF OPHTHALMOLOGY
(2022)
Article
Ophthalmology
Xiaofei Wang, Stanley Chang, Jack Grinband, Lawrence A. Yannuzzi, K. Bailey Freund, Quan Hoang, Michael J. A. Girard
Summary: The axial length is longer in highly myopic eyes and the adjusted tortuosity of the optic nerve is lower, suggesting higher traction forces during eye movements. Optic nerve displacements differ significantly between adduction and abduction, with smaller displacements in highly myopic eyes. Additionally, posterior segment displacements are smaller in highly myopic eyes in both gaze directions, with larger displacements in the anterior-most segment during adduction.
BRITISH JOURNAL OF OPHTHALMOLOGY
(2022)
Article
Ophthalmology
Thanadet Chuangsuwanich, Tin A. Tun, Fabian A. Braeu, Xiaofei Wang, Zhi Yun Chin, Satish Kumar Panda, Martin Buist, Nicholas Strouthidis, Shamira Perera, Monisha Nongpiur, Tin Aung, Michael J. A. Girard
Summary: The purpose of this study was to investigate the associations between optic nerve head strains under intraocular pressure elevation and retinal sensitivity in glaucoma patients. A clinic-based cross-sectional study was conducted on 229 patients with primary open-angle glaucoma, divided into high-tension glaucoma (HTG) and normal-tension glaucoma (NTG) groups. The results showed significant negative associations between optic nerve head strains and retinal sensitivity in patients with HTG, while no significant associations were observed in patients with NTG except in certain regions of the lamina cribrosa.
Meeting Abstract
Critical Care Medicine
Christopher James, Michael J. Girard, Alejandro Dominguez, Adam Koller, Raul Alonso
Meeting Abstract
Critical Care Medicine
Joseph Knipe, Shannon N. Mohabir, Michael J. Girard, Marquand Patton
Article
Clinical Neurology
Michael J. A. Girard, Satish Panda, Tin Aung Tun, Elisabeth A. Wibroe, Raymond P. Najjar, Tin Aung, Alexandre H. Thiery, Steffen Hamann, Clare Fraser, Dan Milea
Summary: This study developed a deep learning algorithm to automatically identify major structures of the optic nerve head (ONH) in 3D optical coherence tomography (OCT) scans and differentiate between optic disc drusen (ODD), papilledema, and healthy ONHs. The algorithm was able to accurately isolate tissues and regions associated with ODD and achieved high classification performance.
Article
Ophthalmology
Fabian A. Braeu, Alexandre H. Thiery, Tin A. Tun, Aiste Kadziauskiene, George Barbastathis, Tin Aung, Michael J. A. Girard
Summary: This study compares the performance of two recent geometric deep learning techniques in diagnosing glaucoma from a single optical coherence tomographic scan of the optic nerve head, and identifies the critical 3D structural features of the optic nerve head for glaucoma diagnosis. Both deep learning approaches accurately detected glaucoma from the 3D optic nerve head point clouds, with critical points located within the neuroretinal rim in the inferior and superior quadrants. This approach has strong potential for clinical applications in diagnosing and prognosing ophthalmic disorders.
AMERICAN JOURNAL OF OPHTHALMOLOGY
(2023)
Article
Ophthalmology
Fabian A. Braeu, Thanadet Chuangsuwanich, Tin A. Tun, Shamira Perera, Rahat Husain, Alexandre H. Thiery, Tin Aung, George Barbastathis, Michael J. A. Girard
Summary: Using artificial intelligence techniques, the study aims to assess the robustness of the optic nerve head (ONH) by analyzing biomechanical knowledge through optical coherence tomography (OCT). Three AI algorithms were compared to predict ONH robustness and the DGCNN algorithm outperformed the others. The study suggests that ONH robustness can be assessed from a single OCT scan, providing potential insights into identifying fast visual field loss progressors.
BRITISH JOURNAL OF OPHTHALMOLOGY
(2023)
Article
Computer Science, Interdisciplinary Applications
Alireza Karimi, Devon J. Crouch, Reza Razaghi, J. Crawford Downs, Ted S. Acott, Mary J. Kelley, Julia G. Behnsen, Lucy A. Bosworth, Carl M. Sheridan
Summary: This study used X-ray computed tomography and scanning electron microscopy to reconstruct 3D microstructural finite element models of the healthy and glaucoma outflow tissues. The results showed that the primary site of outflow resistance in glaucoma eyes is the trabecular meshwork, while in healthy eyes, it is the juxtacanalicular connective tissue and the inner wall of Schlemm's canal. The glaucoma eyes had thicker trabecular meshwork and juxtacanalicular connective tissue and smaller trabecular space compared to healthy eyes.
COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE
(2023)
Article
Ophthalmology
Nick Grissom, Stuart K. Gardiner, Jack P. Rees, Facundo G. Sanchez, Steven L. Mansberger, Emmett T. Cunningham Jr, Claude F. Burgoyne, Karen Rice, Christina Belter, Robert M. Kinast
Summary: This study evaluated eye drop self-administration in low-vision patients and found that a nose-pivoted drop delivery device (NPDD) can improve eye drop delivery. The use of NPDD increased the success rate of eye drop delivery and reduced bottle tip contact. Patients reported higher satisfaction and increased confidence in independently using eye drops with NPDD.
OPHTHALMOLOGY GLAUCOMA
(2023)
Article
Ophthalmology
Claude f. Burgoyne, Ya xing Wang, Jin wook Jeoung, S. E. U. N. G. W. O. O. Hong, S. T. U. A. R. T. Gardiner, J. U. A. N. Reynaud, B. R. A. D. Fortune, Michael j. a. Girard, G. L. E. N. Sharpe, M. A. R. C. E. L. O. Nicolela, Balwantray c. Chauhan, H. O. N. G. L. Yang
Summary: This study used OCT to compare highly myopic and normal eyes and found that pNC-SB increased and pNC-CT decreased in highly myopic eyes, with the greatest changes in the inferior sectors. The results support the hypothesis that sectors of maximum pNC-SB may predict areas of greatest susceptibility to aging and glaucoma in future longitudinal studies of highly myopic eyes.
AMERICAN JOURNAL OF OPHTHALMOLOGY
(2023)
Article
Health Care Sciences & Services
Yiying Cai, Nuraini Nazeha, Shamira Perera, Alexandre H. Thiery, Michael J. A. Girard, Chen E. E. Lee, Weiwei Hong, Nicholas Graves
Summary: This study aimed to design and implement an assessment tool for informing funding decisions for competing health innovations in a tertiary hospital. The assessment tool consists of three components: value to the institution, novelty, and potential for adoption and scaling. The results demonstrated the usefulness of the assessment tool in the decision-making process.
INTERNATIONAL JOURNAL OF TECHNOLOGY ASSESSMENT IN HEALTH CARE
(2023)
Meeting Abstract
Ophthalmology
Michael J. A. Girard, Satish Kumar Panda, Tin Aung Tun, Raymond Najjar, Tin Aung, Alexandre Thiery, Steffen Hamann, Clare Louise Fraser, Dan Milea
INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE
(2022)
Meeting Abstract
Ophthalmology
Fabian Albert Braeu, Thanadet Chuangsuwanich, Tin A. Tun, Alexandre Thiery, George Barbastathis, Tin Aung, Michael J. A. Girard
INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE
(2022)
Article
Ophthalmology
Jeong-Ah Kim, Seung Hyen Lee, Dong Hwan Son, Tae-Woo Kim, Eun Ji Lee, Michael J. A. Girard, Jean Martial Mari
Summary: This study aimed to investigate whether the curve of the lamina cribrosa changes in eyes with normal tension glaucoma after receiving topical ocular hypotensive eye drops. OCT scans were used to measure the lamina cribrosa curvature in each eye before and after intraocular pressure (IOP)-lowering treatment. The results showed that there were significant changes in the lamina cribrosa curvature in some eyes after IOP reduction.
INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE
(2022)