بررسي عملكرد طناب نخاعي (spinal cord) در برابر ضربه هاي ناشي از تصادف با استفاده از مدل سازي المان محدود

چكيده انگليسي :

73Finite Element Study of the Mechanical Response in Spinal Cord during the Traumatic Injuries in accidents Maede Mousavi Maede mousavi@me iut ac ir Date of Submission 2018 14 1 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Saeid Ziaei Rad Szrad@cc iut ac ir and Reza Tikani r tikani@cc iut ac irAbstract Considering the extent of the disability caused by spinal cord injury and the increasing incidence of it many attempts have been made to understand how this lesion is repaired Most of the spinal cord injuriesare traumatic injuries that usually caused by road accidents The annual incidence of this damage isestimated between 15 40 cases per million people worldwide So considering the extent of this incident theneed for study of the effects of spinal cord injuries in particular on traumatic injuries is necessary Due tothe ethical and practical difficulties and limitations as well as the high cost of performing empirical studieson the living and corpse the use of finite element modeling is a powerful and complementary tool for thestudy of spinal biomechanics This method is able to predict how the spinal cord injuries are in differentloads and can theoretically determine the amount of spinal cord strain and the critical level for spinal cordinjuries so this prediction can play an important role in treating these lesions and improving patients In this study detailed three dimensional FE model of the cervical spine and spinal cord was created to studythe spinal cord biomechanical response against traumatic injuries The modeled injury mechanisms weretransverse contusion as would occur in a burst fracture usually in accidents distraction as would occur ina column distortion or distraction injury usually occur in accident and dislocation as would occur in afracture dislocation usually in accident For dislocation injury three case of dislocation injury are studied Case 1 1mm dislocation in 0 17 ms case2 1mm dislocation in 0 3 ms case 3 1mm dislocation in 0 17 ms The results indicate that critical section of spinal cord is near C5 C6 vertebrae and stress distribution inwhite matter is more than gray matter Stress in the cord was substantially elevated when dislocationdisplacement fixed time duration of dislocation or dislocation duration increased fixed dislocationdisplacement In case1 and case2 axonal injury occurs For distraction injury the results indicate criticalsection of spinal cord is near C6 vertebrae and stress distribution in white matter is more than gray matter Strain distribution in critical section of spinal cord indicates axonal injury may occur in this injurymechanism For contusion injury the results indicate that maximum deformation of the spinal cord wassubstantially elevated when impact velocity increased In this injury mechanism critical initial impactvelocity is 6m s and if impact velocity is more than these spinal cord lesion and axonal injury can occur Tovalidate the results of finite element model experimental data from other studies are used Theseexperimental studies have been done on animal specimens so finite element model of animal specimens wascreated too At last the results of finite element model animal specimen and experimental test werecompared and there was good agreement between the results The methods in human and animal finiteelement models are the same so it was concluded the human finite element model is correct and the resultsare valid Keywords Finite element model Traumatic injuries Accident Spinal cord injuries SCI Spinal cord

موسوي، مائده

بررسي عملكرد طناب نخاعي (spinal cord) در برابر ضربه هاي ناشي از تصادف با استفاده از مدل سازي المان محدود

مدل سازي المان محدود , بافت نخاعي , آسيب ستون فقرات , آسيب نخاعي , آسيب ضربه اي