MSc Thesis

With technological advances in fabrication and control of prosthesis and assistive devices the importance of such systems has increased drastically. On the other hand the appropriate coupling of these devices, especially the exoskeletal systems with the upper or lower extremities is of immense importance as it is an integral part of the control system. In particular, the control strategy and its ability to adapt the exoskeletal system with the existing and physiological functionality of the user, is an integral part of the system requirement. In the controller implementation, a number of methods are proposed including using the excitation signal, similar to the existing neuromuscular system. However as the control system of such exoskeletal structures does not consider the complexity of the adjacent neuromuscular system and its intrinsic control system, it may not fully comply with its counterpart. In fact, due to the varying nature of the neuromuscular systems for different users, such exoskeletal controllers are not practically feasible in comprehensive functionalities. In my thesis we developed a reliable model of neuromuscular and musculoskeletal system and its coupling with the exoskeleton system. Based on this model, proper controllers for the exoskeleton as an aiding device for the upper extremity was proposed.

BSc Project

Magnetic Resonance Imaging (MRI) can be used for evaluating the diffusion in different mediums, as the only non-invasive in-vivo technique. On the other hand thanks to the dependence of diffusion in tissue on its structure, we can assess the structure of tissue through measuring its fusion and use the derived information for research and diagnosis purposes. Nowadays there exists several methods to measure diffusion by MRI that their output includes a wide spectrum from an image for amplitude of diffusion in just a direction to a 3D image of probability of diffusion in every voxel. These characteristics has led to development of a variety of tools to facilitate the manipulation of such enormous amount of information provided by this modern instrument. These tools span from different features representing different aspects of diffusion, hence depicting a characteristic of structure of tissue, to tracers capable of locating tissues and local evaluation of features. In this project first I studied the principles of diffusion and MRI beside their relation and the evaluation of diffusion through MRI. Next the illustration methods of Diffusion MRI and their applications was surveyed. In the end DTI method was used in practice in tractography and experimental diagnosis of epilepsy.