Biomechanics of Bone / Bone Biomechanics
Sara Sadat Farshidfar; Mohammad Reza Mallakzadeh; Hamid Reza Yazdi
Volume 6, Issue 1 , June 2012, , Pages 49-55
Abstract
The aim of this study was to compare the contact area and pressure within medial and lateral compartments of tibiofemoral joint during internal and external rotational deformities of tibia bone. Methods: five lower extremities of fresh frozen human cadavers were tested by using a mechanical system was ...
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The aim of this study was to compare the contact area and pressure within medial and lateral compartments of tibiofemoral joint during internal and external rotational deformities of tibia bone. Methods: five lower extremities of fresh frozen human cadavers were tested by using a mechanical system was designed for the first time in IRAN to simulate the static position loading of standing on two legs in full extension knee under 400N loading along the longitudinal axis of each foot. The contact area and pressure were measured by FUJIfilm Prescale films under axial loading in neutral rotation and serial mal-rotations of tibia from 40 degrees external to 40 degrees internal mal-rotations in 10 degrees increments by tibial osteotomy. Results: contact area and lateral compartment contact pressure was not significantly affected by mal-rotations. Medial compartment contact pressure increased with external and decreased with internal mal-rotations. Changing the medial compartment contact pressure of tibiofemoral joint in various rotational alignments of tibia can be very effective in rapid growth of knee osteoarthritis symptoms specially in people with unilateral medial knee osteoarthritis.
Rehabilitation Engineering
Diako Mardanbeigi; Mohammad Reza Mallakzadeh
Volume 4, Issue 4 , June 2010, , Pages 267-278
Abstract
This paper investigates prototyping an online, low-cost, video based and applicable eye tracker, which is called "Dias Eye Tracker". Disabled people can use the proposed system to communicate with computer. What have made the system different from the other low-cost eye trackers, are the accuracy of ...
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This paper investigates prototyping an online, low-cost, video based and applicable eye tracker, which is called "Dias Eye Tracker". Disabled people can use the proposed system to communicate with computer. What have made the system different from the other low-cost eye trackers, are the accuracy of gaze estimation, the different application parts of the software and the lightweight wireless hardware, which can be mounted on the user’s head. This paper introduces the software/hardware and the methods of the system. In addition, two methods of pupil tracking have been compared together, and an uncertainty analysis on the mapping function of the system has been done. The performance of the designed eye tracker has been evaluated by analyzing the answers to the three questionnaires, which were filled by disabled people after performing three specific tasks. The results show that the system performs well for interaction with computer.