scholarly journals Effects of Impactor Size on Biomechanical Characteristics of Spinal Cord in Hemicontusion Injury Model Using Finite Element Analysis

2020 ◽  
Vol 10 (12) ◽  
pp. 4097
Author(s):  
Batbayar Khuyagbaatar ◽  
Kyungsoo Kim ◽  
Temuujin Batbayar ◽  
Yoon Hyuk Kim
Keyword(s):  
Spinal Cord ◽  
Finite Element ◽  
Infinite Horizon ◽  
Experimental Studies ◽  
Contralateral Side ◽  
Cervical Region ◽  
Fe Model ◽  
New York University ◽  
Ipsilateral Side ◽  
Cord Injury

A cervical hemicontusion spinal cord injury (SCI) produces forelimb deficits on the ipsilateral side of the injury while sparing the function of the limbs on the contralateral side of the injury, allowing for the evaluation of experimental therapeutics for functional recovery. Although the effects of contusion force on the functional and behavioral outcomes were adequately described in previous experimental studies, the size of the impactor tip also had significant effects on the extent of the lesion on the contralateral side of the injury in the hemicontusion rat model. However, studies regarding the effects of impactor size on the spinal cord for the hemicontusion model are limited. In this study, a finite element (FE) model of the rat cervical spinal cord was developed to investigate the effects of impactor size in the hemicontusion SCI model on the stress, strain, and displacement of the spinal cord for the New York University (NYU) and Infinite Horizon (IH) impactors. The impactor tip diameters of 1.2 mm and 1.6 mm with high impact loading resulted in the highest stresses and strains in the right (ipsilateral) side of the spinal cord. Thus, impactor tip diameters between 1.2 mm and 1.6 mm would be convenient to use in the rat hemicontusion SCI models for the cervical region without damaging the left (contralateral) side of the spinal cord. Our findings provide an insight into SCI mechanisms in the rat cervical hemicontusion model.

Spinal Cord Stress and Strain Predictions in a Ligamentous C5-C6 Segment

2000 ◽  
Author(s):  
J. Scifert ◽  
K. Totoribe ◽  
V. Goel ◽  
C. Clark ◽  
J. Reinhardt ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Cervical Spinal Cord ◽  
Experimental Studies ◽  
Stress And Strain ◽  
Fe Model ◽  
Spinal Disorders ◽  
Significant Damage ◽  
Cord Injury ◽  
Bony Segment

Abstract Several spinal disorders and traumatic loading situations are known to inflict damage to neurovascular components of the cervical spinal cord. Studies have shown that damage to the spinal cord can occur regardless of significant damage to surrounding structures. To understand the mechanics of spinal cord injury, one needs to quantify stresses and strains within the spinal cord and its components in response to exterrnal loads applied to the bony spine. Experimental studies can not address this issue. This study presents a Finite Element (FE) model to quantify the physiologic strains and stresses in the cervical spinal cord placed in the ligamentous C5-C6 motion segment, with loads applied to the bony segment and not the the cord itself, as have been done in experimental studies reported in the literature.

Analysis of equivalent parameters of two spinal cord injury devices: the New York University impactor versus the Infinite Horizon impactor

2016 ◽  
Vol 16 (11) ◽  
pp. 1392-1403 ◽  
Author(s):  
Jin Hoon Park ◽  
Jeong Hoon Kim ◽  
Sun-Kyu Oh ◽  
Se Rim Baek ◽  
Joongkee Min ◽  
...  
Keyword(s):  
Spinal Cord ◽  
New York ◽  
Spinal Cord Injury ◽  
Infinite Horizon ◽  
New York University ◽  
Cord Injury

scholarly journals Effects of cervical rotatory manipulation on the cervical spinal cord: a finite element study

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Fan Xue ◽  
Zujiang Chen ◽  
Han Yang ◽  
Taijun Chen ◽  
Yikai Li
Keyword(s):  
Spinal Cord ◽  
Finite Element ◽  
Cervical Spinal Cord ◽  
Von Mises Stress ◽  
Published Data ◽  
Fe Model ◽  
Cross Sectional ◽  
Flexion Extension ◽  
Cord Injury

Abstract Background Little information is available concerning the biomechanism involved in the spinal cord injury after cervical rotatory manipulation (CRM). The primary purpose of this study was to explore the biomechanical and kinematic effects of CRM on a healthy spinal cord. Methods A finite element (FE) model of the basilaris cranii, C1–C7 vertebral bodies, nerve root complex and vertebral canal contents was constructed and validated against in vivo and in vitro published data. The FE model simulated CRM in the flexion, extension and neutral positions. The stress distribution, forma and relative position of the spinal cord were observed. Results Lower von Mises stress was observed on the spinal cord after CRM in the flexion position. The spinal cord in CRM in the flexion and neutral positions had a lower sagittal diameter and cross-sectional area. In addition, the spinal cord was anteriorly positioned after CRM in the flexion position, while the spinal cord was posteriorly positioned after CRM in the extension and neutral positions. Conclusion CRM in the flexion position is less likely to injure the spinal cord, but caution is warranted when posterior vertebral osteophytes or disc herniations exist.

scholarly journals Arrow-Shot Injury to Pediatric Spinal Cord

2021 ◽  
Author(s):  
Vijayveer Singh ◽  
Sharad Thanvi
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injuries ◽  
Pediatric Population ◽  
Cervical Region ◽  
Cervical Cord ◽  
Cord Injury ◽  
Dural Suturing ◽  
Stab Injuries ◽  
Early Surgical Intervention

AbstractPenetrating spinal cord injuries (PSCI) in cervical region are extremely rare in pediatric population. Most injuries in pediatric population are accidental due to gunshot or a stab injury with a sharp or pointed object. Gun shots may result into a severe wound which is usually fatal and may result in death, quadriplegia, or serious long-term disability. Stab injuries are less severe and may result in neurological sequalae. In this paper, an unusual case of pediatric arrow shot partial cervical cord injury is reported which was managed by aggressive neurosurgical management. The arrow lodged in the cervical cord was very near to the vertebral artery leading to parapariesis which recovered well without any complications. Diagnostic imaging at admission included radiographs, computed tomography (CT), and CT angiography of the cervical region. The patient underwent early surgical intervention with removal of foreign body from the cord and subsequent dural suturing.

Development of Upper Extremity Finite Element Model for Elderly Female: Validated Against Dynamic Loading Conditions

2017 ◽  
Author(s):  
Anand Hammad ◽  
Anil Kalra ◽  
Prashant Khandelwal ◽  
Xin Jin ◽  
King H. Yang
Keyword(s):  
Finite Element ◽  
Upper Extremity ◽  
Injury Risk ◽  
Experimental Studies ◽  
Upper Extremities ◽  
Whole Body ◽  
Crash Test ◽  
Fe Model ◽  
Long Term Effects ◽  
Elderly Female

Injuries to the upper extremities that are caused by dynamic impacts in crashes, including contact with internal instrument panels, has been a major concern, especially for smaller female occupants, and the problem worsens with increasing age due to reduced strength of the bones. From the analysis of 1988–2010 CDS unweighted data, it was found that risk of AIS ≥ 2 level for the arm was 58.2±20.6 percent higher in females than males, and the injury risk for a 75-year-old female occupant relative to a 21-year-old subjected to a similar physical insult was 4.2 times higher. Although injuries to upper extremities are typically not fatal, they can have long-term effects on overall quality of life. Therefore, it is important to minimize risks of injuries related to upper extremities, especially for elderly females, who are most at risk. Current anthropomorphic surrogates, like crash-test dummies, cannot be directly used to study injury limits, as these dummies were developed mainly to represent the younger population. The current study is focused on the development of a finite element (FE) model representing the upper extremity of an elderly female. This can be further used to analyze the injury mechanisms and tolerance limits for this vulnerable population. The FE mesh was developed through Computer Tomography (CT) scanned images of an elderly female cadaver, and the data included for validation of the developed model were taken from the experimental studies published in scientific literature, but only the data directly representing elderly females were used. It was found that the developed model could predict fractures in the long bones of elderly female specimens and could be further used for analyzing injury tolerances for this population. Further, it was determined that the developed segmental model could be integrated with the whole body FE model of the elderly female.

A Biomechanical Model of Lumbar Spine

2000 ◽  
Author(s):  
Subramanya Uppala ◽  
Robert X. Gao ◽  
Scott Cowan ◽  
K. Francis Lee
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Biomechanical Model ◽  
Element Model ◽  
Fe Model ◽  
Flexion Extension ◽  
Cortical Shell ◽  
Three Dimensional Finite Element

Abstract The strength and stability of the lumbar spine are determined not only by the bone and muscles, but also by the visco-elastic structures and the interplay between the different components of the spine, such as ligaments, capsules, annulus fibrosis, and articular cartilage. In this paper we present a non-linear three-dimensional Finite Element model of the lumbar spine. Specifically, a three-dimensional FE model of the L4-5 one-motion segment/2 vertebrae was developed. The cortical shell and the cancellous bone of the vertebral body were modeled as 3D isoparametric eight-nodal elements. Finite element models of spinal injuries with fixation devices are also developed. The deformations across the different sections of the spine are observed under the application of axial compression, flexion/extension, and lateral bending. The developed FE models provided input to both the fixture design and experimental studies.

Automotive Glass Exciter Technology for Acoustic Application

2014 ◽  
Author(s):  
Babak Ebrahimi ◽  
Amir Khajepour ◽  
Todd Deaville
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Experimental Studies ◽  
Element Model ◽  
Fe Model ◽  
Component Level ◽  
Modeling And Analysis ◽  
Electric Actuator ◽  
Conventional Systems ◽  
Fine Tune

This paper discusses the modeling and analysis of a novel audio subwoofer system for automotive applications using the automobile windshield glass. The use of a piezo-electric actuator coupled with a mechanical amplifier linked to a large glass panel provides a highly efficient method of producing sound. The proposed subwoofer system has the advantage over existing conventional systems of not only reducing the weight of the automobile, but also a significant power savings resulting in an increase of expected fuel economy. Among various design challenges, the glass-sealing design is of huge importance, as it affects the system dynamic response and so the output sound characteristics. The main goal in this manuscript is to evaluate different glass-sealing design configurations by providing a comprehensive Finite Element model of the system. To do so, a comprehensive, yet simplified FE model is developed, and experimental studies are performed in the component level to fine-tune and verify the model. Harmonic response of the system for each sealing configuration design is obtained in the frequency range of 0–200 Hz, and the results are compared and discussed. The finite element model is also beneficial in preliminary design of other components as well as the exciter placement, and predicting the performance of the overall system.

scholarly journals History of spinal cord localization

2004 ◽  
Vol 16 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Sait Naderi ◽  
Uğur Türe ◽  
T. Glenn Pait
Keyword(s):  
Spinal Cord ◽  
Muscle Tone ◽  
Experimental Studies ◽  
Gross Anatomy ◽  
Posterior Longitudinal Ligament ◽  
Spinal Nerve ◽  
Detailed Account ◽  
Pia Mater ◽  
Thin Sections ◽  
Cord Injury

The first reference to spinal cord injury is recorded in the Edwin Smith papyrus. Little was known of the function of the cord before Galen's experiments conducted in the second century AD. Galen described the protective coverings of the spinal cord: the bone, posterior longitudinal ligament, dura mater, and pia mater. He gave a detailed account of the gross anatomy of the spinal cord. During the medieval period (AD 700–1500) almost nothing of note was added to Galen's account of spinal cord structure. The first significant work on the spinal cord was that of Blasius in 1666. He was the first to differentiate the gray and white matter of the cord and demonstrated for the first time the origin of the anterior and posterior spinal nerve roots. The elucidation of the various tracts in the spinal cord actually began with demonstrations of pyramidal decussation by Mistichelli (1709) and Pourfoir du Petit (1710). Huber (1739) recorded the first detailed account of spinal roots and the denticulate ligaments. In 1809, Rolando described the substantia gelati-nosa. The microtome, invented in 1824 by Stilling, proved to be one of the fundamental tools for the study of spinal cord anatomy. Stilling's technique involved slicing frozen or alcohol-hardened spinal cord into very thin sections and examining them unstained by using the naked eye or a microscope. With improvements in histological and experimental techniques, modern studies of spinal cord anatomy and function were initiated by Brown-Séquard. In 1846, he gave the first demonstration of the decussation of the sensory tracts. The location and direction of fiber tracts were uncovered by the experimental studies of Burdach (1826), Türck (1849), Clarke (1851), Lissauer (1855), Goll (1860), Flechsig (1876), and Gowers (1880). Bastian (1890) demonstrated that in complete transverse lesions of the spinal cord, reflexes below the level of the lesion are lost and muscle tone is abolished. Flatau (1894) observed the laminar nature of spinal pathways. The 20th century ushered in a new era in the evaluation of spinal cord function and localization; however, the total understanding of this remarkable organ remains elusive. Perhaps the next century will provide the answers to today's questions about spinal cord localization.

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