A Hyrid EMG-optimization Based Model of the Lumbar Spine to Estimate Muscle Forces in Different Tasks

, M.Sc. Thesis Sharif University of Technology Mohammadi, Yousef (Author) ; Arjmand, Navid (Supervisor)

Abstract

Low back pains (LBP) are prevalent and costly. One of the important factors causing LBP is excessive axial compression and shear forces that are applied on the intervertebral discs during different activities. Due to lack of direct in vivo measurement methods for estimating these loads, musculoskeletal biomechanical models have been emerged as indispensable tools under various activities. Different biomechanical models have been suggested to estimate muscle forces and spinal loads base on optimization, EMG and hybrid (EMG assisted optimization, EMGAO) methods. Although there have been a number of studies on the differences between various optimization and EMG-based methods, there has been no...

Estimation of Spinal Loads in Static Activities by Considering Trunk Muscle Forces in a Detailed Nonlinear Finite Element Model

, Ph.D. Dissertation Sharif University of Technology Khodam Khorasani, Pooria (Author) ; Arjmand, Navid (Supervisor) ; Shirazi-Adl, Aboulfazl (Co-Supervisor)

Abstract

Spine biomechanical models suffers from either simplification in passive disc components modeling (modeling via torsional spring or beam elements) in musculoskeletal (MS) models or shortcomings in detailed muscles modeling (via a simple force and torque vector) in detailed finite element (FE) models. Considering these, that is aimed in this study to develop a hybrid MS-FE model which the calculated muscle forces by a MS model (developed based on geometrical and mechanical properties of FE model) for a desired static posture, being applied to a detailed FE model. Considering the change of discs stiffness in FE model under the applied muscles and gravity forces, the equivalent stiffness in MS...

Development of Photocured Bioinks Based on GelMa and MXene for Muscle and Neural Tissue Engineering

, Ph.D. Dissertation Sharif University of Technology Lotfi Ghameshlou, Roya (Author) ; Simchi, Abdolreza (Supervisor) ; Purjavadi, Ali (Supervisor) ; Tamjid, Elnaz (Supervisor)

Abstract

Despite the promising potential of 3D bioprinting for personalized medicine, this technology is still under development and faces challenges, such as the lack of bioinks capable of precise printing while maintaining high cell viability. The physical and chemical properties of bioinks, including mechanical, rheological, and biological characteristics, play a key role in the success of printing targeted scaffolds. In this study, photo-crosslinkable Gelatin methacrylate (GelMa)-Ti3C2 MXene (MX) bioinks were developed for muscle and nerve tissue engineering. Two-dimensional MX phase was synthesized using an in-situ HF generation method. To prepare photo-crosslinkable hydrogels, type I (IG and...