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A Practical Subject-specific FE Model of Human Knee Joint for Pre-planning of Tibial Osteotomy Surgery
, M.Sc. Thesis Sharif University of Technology ; Farahmand, Farzam (Supervisor)
Abstract
Knee joint simulation to analyze the process of osteotomy surgery has been studied in several researches and its effectiveness has been shown. However, these models include many components and details that impose significant time and cost on the patient due to the need for multiple data as well as extensive specialized activity to build and analyze the model. Thus, this study aims to provide a practical finite-element patient-specific model for predicting the outcome and planning of knee osteotomy surgery, such a way that it can be made and processed with little data and in a short time, and also requires little specialized activity. For this purpose, first, a detailed model of the knee...
Design and Manufacturing of a Patient-specific Drill Guide Template for Thoracic Pedicle Screw Placement
,
M.Sc. Thesis
Sharif University of Technology
;
Arjmand, Navid
(Supervisor)
Abstract
Spinal instrumentation with pedicle screws has become a widespread surgical procedure in the treatment of spinal disease. The traditional way of placing pedicle screws is to use the anatomical landmarks which at many times can be a best guess resulting in breaches of the pedicle and causing neurological injuries. Additional modalities used include the intra-operative fluoroscopy or navigation systems, which results in radiation exposure and more intra-operative time. In order to solve the technical problems, a pedicle screw navigation template that guarantees the correct implantation position and direction of vertebral pedicle screws, can be used. Compared to pedicles in the lumbar spine,...
Analysis, Design and Manufacturing of Custom Osteotomy Implants Forming Machine
, M.Sc. Thesis Sharif University of Technology ; Farahmand, Farzam (Supervisor) ; Farkhondeh, Hassan (Supervisor)
Abstract
Knee arthritis is a painful disease from which millions of people around the world are suffering. One of the main causes of osteoarthritis and joint damage that starts from a young age, is that bones around the knee are not in a straight line. As a result, this situation causes additional pressure to the knee. This should be corrected with surgery. There are two procedures for this operation, a conventional method and a customized method. In conventional method, surgical planning is based on 2d X-ray images and plates are formed and fixed approximately at the desired location. This method is not precise enough and may cause problems for the patient. A new developing method, is that all the...
3D Finite Element Modeling of Head for Studying Subdural Hemorrhage Induced by Impact
, M.Sc. Thesis Sharif University of Technology ; Naghdabadi, Reza (Supervisor) ; Sohrabpour, Saeed (Supervisor)
Abstract
Subdural hemorrhage (SDH) is one of the most common traumatic brain injuries. The mortality rate of SDH is over 30 percent. In addition, patients require to visit hospital for treatment and further healthcare. According to the costs of treatment and frequency of injuries, prevention of SDH is essential. 3D-Finite element modeling of human head is an appropriate tool for evaluation of injury risk and setting up a prevention tolerance criteria. The aim of this study is to create a 3D finite element model of human head with special consideration of vessels. Vessels are modeled by truss elements at current finite element models of human head; however, geometry of vessels is regarded as simple...
Pull-out Strength Test Simulation and Stability Study of a Patient-Specific Drill Guide Template of Thoracic Pedicle Screw Placement for Patients with Spinal Deformity Using Finite Element Analysis
, M.Sc. Thesis Sharif University of Technology ; Arjmand, Navid (Supervisor)
Abstract
We have recently designed/fabricated novel bilateral vertebra- and patient-specific drill guides for pedicle screw (PS) placements and tested their accuracy for both nondeformed and deformed thoracic spines. PS placement deviations from their preplanned positions significantly reduced when guide template were used; the success rate improved from ~72% (freehand placements) to 94% (guided placements). In the present study, we aim to use finite element (FE) analyses to evaluate the pull-out strength of these PSs inserted via either the freehand technique or our drill-guide templates. Two 3D-printed T1-T12 thoracic models of a severe scoliosis patient with a 47° thoracic dextro-scoliotic curve...
Mechanical characterization of the ligaments in subject-specific models of the patellofemoral joint using in vivo laxity tests
, Article Knee ; Volume 26, Issue 6 , 2019 , Pages 1220-1233 ; 09680160 (ISSN) ; Farahmand, F ; Arjmand, N ; Sharif University of Technology
Elsevier B.V
2019
Abstract
Background: The purpose of this study was to propose a methodology for mechanical characterization of the ligaments in subject-specific models of the patellofemoral joint (PFJ) of living individuals. Method: PFJ laxity tests were performed on a healthy volunteer using a specially designed loading apparatus under biplane fluoroscopy. A three-dimensional (3D) parametric model of the PFJ was developed in the framework of the rigid body spring model using the geometrical data acquired from the subject's computed tomography and magnetic resonance images. The stiffness and pre-strains of the medial and lateral PFJ ligaments were characterized using a two-step optimization procedure which minimized...
Effect of body weight on spinal loads in various activities: A personalized biomechanical modeling approach
, Article Journal of Biomechanics ; Volume 48, Issue 2 , 2015 , Pages 276-282 ; 00219290 (ISSN) ; Arjmand, N ; Shirazi Adl, A ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
Epidemiological studies are divided over the causative role of body weight (BW) in low back pain. Biomechanical modeling is a valuable approach to examine the effect of changes in BW on spinal loads and risk of back pain. Changes in BW have not been properly simulated by previous models as associated alterations in model inputs on the musculature and moment arm of gravity loads have been neglected. A detailed, multi-joint, scalable model of the thoracolumbar spine is used to study the effect of BW (varying at five levels, i.e., 51, 68, 85, 102, and 119kg) on the L5-S1 spinal loads during various static symmetric activities while scaling moment arms and physiological cross-sectional areas of...
Personalised deposition maps for micro- and nanoparticles targeting an atherosclerotic plaque: attributions to the receptor-mediated adsorption on the inflamed endothelial cells
, Article Biomechanics and Modeling in Mechanobiology ; Volume 18, Issue 3 , 2019 , Pages 813-828 ; 16177959 (ISSN) ; Forouzandehmehr, M ; Sharif University of Technology
Springer Verlag
2019
Abstract
Endothelial inflammation as a prominent precursor to atherosclerosis elicits a distinct pathological surface expression of particular vascular proteins. To exhibit a site-specific behaviour, micro- and nanoparticles, as carriers of therapeutics or imaging agents, can distinguish and use these proteins as targeted docking sites. Here, a computational patient-specific model capturing the exclusive luminal qualities has been developed to study the transport and adsorption of particles decorated with proper antibodies over an atherosclerotic plaque located in the LAD artery of the patient. Particles, in nano- and micron sizes, have been decorated with Sialyl Lewisx (sLex), P-selectin aptamer...