1
|
Li R, Su Z, Li Z, Li D, Luo R, Qiu J, Lan H. Experimental investigation of brain contusion characteristics and dynamic response in low-age children using an animal model. Injury 2024; 55:111589. [PMID: 38704918 DOI: 10.1016/j.injury.2024.111589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 04/11/2024] [Accepted: 04/20/2024] [Indexed: 05/07/2024]
Abstract
INTRODUCTION Brain contusion is a prevalent traumatic brain injury (TBI) in low-age children, bearing the potential for coma and fatality. Hence, it is imperative to undertake comprehensive research in this field. METHODS This study employed 4-week-old piglets as surrogates for children and introduced self-designed devices for both free-fall drop impact tests and drop-hammer impact tests. The study explored the characteristics of brain contusion and dynamic responses of brain under these distinct testing conditions. RESULTS Brain contusions induced by free-fall and drop-hammer conditions both were categorized as the coup injury, except that slight difference in the contusion location was observed, with contusion occurring mainly in the surrounding regions beneath the impact location under free-fall condition and the region just right beneath the impact location under drop-hammer condition. Analysis of impact force and intracranial pressure (ICP) curves indicated similar trends in impact forces under both conditions, yet different trends in ICPs. Further examination of the peak impact forces and ICPs elucidated that, with increasing impact energy, the former followed a combined power and first-order polynomial function, while the latter adhered to a power function. The brain contusion was induced at the height (energy) of 2 m (17.2 J), but not at the heights of 0.4, 0.7, 1, 1.35 and 1.7 m, when the vertex of the piglet head collided with a rigid plate. In the case of a cylindrical rigid hammer (cross-sectional area constituting 40 % of the parietal bone) striking the head, the brain contusion was observed under the energy of 21.9 J, but not under energies of 8.1 J, 12.7 J and 20.3 J. Notably, the incidence of brain contusion was more pronounced under the free-fall condition. CONCLUSIONS These findings not only facilitate a comprehensive understanding of brain contusion dynamics in pediatric TBIs, but also contribute to the validation of theories and finite element models for piglet heads, which are commonly employed as surrogates for children.
Collapse
Affiliation(s)
- Rui Li
- School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing, 100044, PR China
| | - Zhongqing Su
- School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing, 100044, PR China
| | - Zhigang Li
- School of Mechanical Engineering, University of Science and Technology Beijing, Beijing, 100083, PR China.
| | - Dapeng Li
- Department of Neurosurgery, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, 100045, PR China
| | - Rutao Luo
- Department of Neurosurgery, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, 100045, PR China
| | - Jinlong Qiu
- Daping Hospital of Army Medical University, PLA, 400042, PR China
| | - Huiqing Lan
- School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing, 100044, PR China
| |
Collapse
|
2
|
Garate Andikoetxea B, Ajami S, Rodriguez-Florez N, Jeelani NUO, Dunaway D, Schievano S, Borghi A. Towards a radiation free numerical modelling framework to predict spring assisted correction of scaphocephaly. Comput Methods Biomech Biomed Engin 2023:1-10. [PMID: 38108140 DOI: 10.1080/10255842.2023.2294262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 12/08/2023] [Indexed: 12/19/2023]
Abstract
Sagittal Craniosynostosis (SC) is a congenital craniofacial malformation, involving premature sagittal suture ossification; spring-assisted cranioplasty (SAC) - insertion of metallic distractors for skull reshaping - is an established method for treating SC. Surgical outcomes are predictable using numerical modelling, however published methods rely on computed tomography (CT) scans availability, which are not routinely performed. We investigated a simplified method, based on radiation-free 3D stereophotogrammetry scans.Eight SAC patients (age 5.1 ± 0.4 months) with preoperative CT and 3D stereophotogrammetry scans were included. Information on osteotomies, spring model and post-operative spring opening were recorded. For each patient, two preoperative models (PREOP) were created: i) CT model and ii) S model, created by processing patient specific 3D surface scans using population averaged skin and skull thickness and suture locations. Each model was imported into ANSYS Mechanical (Analysis System Inc., Canonsburg, PA) to simulate spring expansion. Spring expansion and cranial index (CI - skull width over length) at times equivalent to immediate postop (POSTOP) and follow up (FU) were extracted and compared with in-vivo measurements.Overall expansion patterns were very similar for the 2 models at both POSTOP and FU. Both models had comparable outcomes when predicting spring expansion. Spring induced CI increase was similar, with a difference of 1.2%±0.8% for POSTOP and 1.6%±0.6% for FU.This work shows that a simplified model created from the head surface shape yields acceptable results in terms of spring expansion prediction. Further modelling refinements will allow the use of this predictive tool during preoperative planning.
Collapse
Affiliation(s)
| | - Sara Ajami
- University College London, United Kingdom
- Great Ormond Street Hospital, London, United Kingdom
| | | | | | - David Dunaway
- Great Ormond Street Hospital, London, United Kingdom
| | - Silvia Schievano
- University College London, United Kingdom
- Great Ormond Street Hospital, London, United Kingdom
| | - Alessandro Borghi
- University College London, United Kingdom
- Great Ormond Street Hospital, London, United Kingdom
- Department of Engineering, Durham University, Durham, United Kingdom
| |
Collapse
|
3
|
Torimitsu S, Nishida Y, Takano T, Yajima D, Inokuchi G, Makino Y, Motomura A, Chiba F, Yamaguchi R, Hoshioka Y, Iwase H. Statistical analysis of the thickness and biomechanical properties of Japanese children's skulls. Forensic Sci Int 2023; 344:111580. [PMID: 36753838 DOI: 10.1016/j.forsciint.2023.111580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 01/15/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023]
Abstract
OBJECTIVE The structure and strength of a child's skull are important in accurately determining what and how external forces were applied when examining head injuries. The aims of this study were to measure skull thickness and strength in children, evaluate sex differences, and investigate the correlation between skull thickness and strength and age. MATERIALS AND METHODS Skulls were obtained from 42 Japanese dead bodies under 20 years of age. During the autopsies, bone samples were taken from each skull. The length, width, and central thickness of the skulls were measured using calipers. Three-point bending tests were conducted, and bending load and displacement were recorded. Bending stress and bending strain were calculated, and Young's modulus, 0.2% proof stress, and maximum stress were obtained. RESULTS In cases under 1.5 years old, 14 out of 46 male samples and 20 out of 40 female samples did not fracture during the three-point bending test, though no significant sex differences were detected. No significant differences in age, sample thickness, Young's modulus, 0.2% proof stress, or maximum stress were detected between the sexes. The sample thickness, Young's modulus, 0.2% proof stress, and maximum stress increased significantly and logarithmically with age (R2 = 0.761-0.899). Although age correlated with thickness, Young's modulus, and maximum stress more in females than in males, 0.2% proof stress correlated slightly better in males than in females. CONCLUSION The skulls of preschool children, in particular, are thin, have low strength, and are at high risk of fracturing even with relatively small external forces. Unlike adults, no significant sex differences in skull thickness or strength were observed in children.
Collapse
Affiliation(s)
- Suguru Torimitsu
- Department of Forensic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; Education and Research Center of Legal Medicine, Graduate School of Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba 260-8670, Japan.
| | - Yoshifumi Nishida
- Department of Mechanical Engineering, Tokyo Institute of Technology, 2-12-1, O-okayama, Meguro-ku, Tokyo 152-8552, Japan; Artificial Intelligence Research Center (AIRC), The National Institute of Advanced Industrial Science and Technology (AIST), 2-4-7, Aomi, Koto-ku, Tokyo 135-0064, Japan.
| | - Tachio Takano
- Artificial Intelligence Research Center (AIRC), The National Institute of Advanced Industrial Science and Technology (AIST), 2-4-7, Aomi, Koto-ku, Tokyo 135-0064, Japan.
| | - Daisuke Yajima
- Education and Research Center of Legal Medicine, Graduate School of Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba 260-8670, Japan; Department of Forensic Medicine, School of Medicine, International University of Health and Welfare, 4-3, Kozunomori, Narita, Chiba 286-8686, Japan.
| | - Go Inokuchi
- Department of Forensic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; Education and Research Center of Legal Medicine, Graduate School of Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba 260-8670, Japan.
| | - Yohsuke Makino
- Department of Forensic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; Education and Research Center of Legal Medicine, Graduate School of Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba 260-8670, Japan.
| | - Ayumi Motomura
- Department of Forensic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; Education and Research Center of Legal Medicine, Graduate School of Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba 260-8670, Japan; Department of Forensic Medicine, School of Medicine, International University of Health and Welfare, 4-3, Kozunomori, Narita, Chiba 286-8686, Japan.
| | - Fumiko Chiba
- Department of Forensic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; Education and Research Center of Legal Medicine, Graduate School of Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba 260-8670, Japan.
| | - Rutsuko Yamaguchi
- Department of Forensic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; Education and Research Center of Legal Medicine, Graduate School of Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba 260-8670, Japan.
| | - Yumi Hoshioka
- Education and Research Center of Legal Medicine, Graduate School of Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba 260-8670, Japan.
| | - Hirotaro Iwase
- Department of Forensic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; Education and Research Center of Legal Medicine, Graduate School of Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba 260-8670, Japan.
| |
Collapse
|
4
|
Su ZQ, Li DP, Li R, Wang GL, Liu L, Wang YF, Guo YZ, Li ZG. Development and global validation of a 1-week-old piglet head finite element model for impact simulations. Chin J Traumatol 2022:S1008-1275(22)00081-5. [PMID: 35985904 DOI: 10.1016/j.cjtee.2022.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 06/21/2022] [Accepted: 07/08/2022] [Indexed: 02/04/2023] Open
Abstract
PURPOSE Child head injury under impact scenarios (e.g. falling, vehicle crashing, etc.) is an important topic in the field of injury biomechanics. The head of piglet was commonly used as the surrogate to investigate the biomechanical response and mechanisms of pediatric head injuries because of the similar cellular structures and material properties. However, up to date, piglet head models with accurate geometry and material properties, which have been validated by impact experiments, are seldom. We aimed to develop such a model for future research. METHODS In this study, first, the detailed anatomical structures of the piglet head, including the skull, suture, brain, pia mater, dura mater, cerebrospinal fluid, scalp, and soft tissue, were constructed based on CT scans. Then, a structured butterfly method was adopted to mesh the complex geometries of the piglet head to generate high-quality elements and each component was assigned corresponding constitutive material models. Finally, the guided drop tower tests were conducted and the force-time histories were ectracted to validate the piglet head finite element model. RESULTS Simulations were conducted on the developed finite element model under impact conditions and the simulation results were compared with the experimental data from the guided drop tower tests and the published literature. The average peak force and duration of the guide drop tower test were similar to that of the simulation, with an error below 10%. The inaccuracy was below 20%. The average peak force and duration reported in the literature were comparable to those of the simulation, with the exception of the duration for an impact energy of 11 J. The results showed that the model was capable to capture the response of the pig head. CONCLUSION This study can provide an effective tool for investigating child head injury mechanisms and protection strategies under impact loading conditions.
Collapse
Affiliation(s)
- Zhong-Qing Su
- School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing, 100044, China
| | - Da-Peng Li
- Department of Neurosurgery, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, 100045, China
| | - Rui Li
- School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing, 100044, China
| | - Guang-Liang Wang
- School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing, 100044, China
| | - Lang Liu
- School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing, 100044, China
| | - Ya-Feng Wang
- Aviation Key Laboratory of Science and Technology on Structures Impact Dynamics, China Aircraft Strength Research Institute, Xi'an, 710065, China
| | - Ya-Zhou Guo
- Aviation Key Laboratory of Science and Technology on Structures Impact Dynamics, China Aircraft Strength Research Institute, Xi'an, 710065, China
| | - Zhi-Gang Li
- School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing, 100044, China.
| |
Collapse
|
5
|
Bertocci G, Smalley C, Brown N, Dsouza R, Hilt B, Thompson A, Bertocci K, McKinsey K, Cory D, Pierce MC. Head biomechanics of video recorded falls involving children in a childcare setting. Sci Rep 2022; 12:8617. [PMID: 35597795 PMCID: PMC9124183 DOI: 10.1038/s41598-022-12489-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 05/11/2022] [Indexed: 12/04/2022] Open
Abstract
The objective of this study was to characterize head biomechanics of video-recorded falls involving young children in a licensed childcare setting. Children 12 to < 36 months of age were observed using video monitoring during daily activities in a childcare setting (in classrooms and outdoor playground) to capture fall events. Sensors (SIM G) incorporated into headbands worn by the children were used to obtain head accelerations and velocities during falls. The SIM G device was activated when linear acceleration was ≥ 12 g. 174 video-recorded falls activated the SIM G device; these falls involved 31 children (mean age = 21.6 months ± 5.6 SD). Fall heights ranged from 0.1 to 1.2 m. Across falls, max linear head acceleration was 50.2 g, max rotational head acceleration was 5388 rad/s2, max linear head velocity was 3.8 m/s and max rotational head velocity was 21.6 rad/s. Falls with head impact had significantly higher biomechanical measures. There was no correlation between head acceleration and fall height. No serious injuries resulted from falls—only 1 child had a minor injury. In conclusion, wearable sensors enabled characterization of head biomechanics during video-recorded falls involving young children in a childcare setting. Falls in this setting did not result in serious injury.
Collapse
Affiliation(s)
- Gina Bertocci
- Department of Bioengineering, University of Louisville, Louisville, KY, USA.
| | - Craig Smalley
- Department of Bioengineering, University of Louisville, Louisville, KY, USA
| | - Nathan Brown
- Department of Bioengineering, University of Louisville, Louisville, KY, USA
| | - Raymond Dsouza
- Department of Bioengineering, University of Louisville, Louisville, KY, USA
| | - Bret Hilt
- Department of Bioengineering, University of Louisville, Louisville, KY, USA
| | - Angela Thompson
- Engineering Fundamentals Department, University of Louisville, Louisville, KY, USA
| | - Karen Bertocci
- Department of Bioengineering, University of Louisville, Louisville, KY, USA
| | - Keyonna McKinsey
- Department of Bioengineering, University of Louisville, Louisville, KY, USA
| | - Danielle Cory
- Department of Bioengineering, University of Louisville, Louisville, KY, USA
| | - Mary Clyde Pierce
- Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.,Division of Emergency Medicine, Ann & Robert H. Lurie Children's Hospital, Chicago, IL, USA
| |
Collapse
|
6
|
Li Z, Pang Z, Qiu J, Zhang Z, Liu X, Bai C, Wang Y, Guo Y. Quantification and statistical analysis on the cranial vault morphology for Chinese children 3-10 years old. Comput Methods Programs Biomed 2022; 215:106591. [PMID: 34979294 DOI: 10.1016/j.cmpb.2021.106591] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 10/14/2021] [Accepted: 12/14/2021] [Indexed: 06/14/2023]
Abstract
BACKGROUND AND OBJECTIVE Head injury is the leading cause of fatalities and disabilities in children. Characterizing the variation in cranial size/shape and thickness during growth is important for developing finite element models of child heads and evaluating head injury risk at different ages. However, the quantitative morphological features of the cranial vault (size/shape and non-uniform thickness distribution) have not been accounted for in children aged between 3 and 10 years old (YO). METHODS Geometrically equivalent discrete points were identified on 42 head CT scans of 3-10 YO children by separation, curve dividing, and point fitting. Based on discrete points, the principal component analysis and regression (PCA&R) method was used to develop a statistical model of the cranial vault as a function of age and head circumference. RESULTS The ontogeny of three-dimensional cranial morphology and non-uniform thickness from 3 to 10 years of age was quantified and cranial vault morphologies for 3-10 YO children were generated in 1 year intervals. CONCLUSIONS The automatic method, the procedure of identifying discrete points from CT scans, and the developed quantitative cranial vault model are reliable and accurate.
Collapse
Affiliation(s)
- Zhigang Li
- School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, No.3 Shangyuancun, Haidian District, Beijing 100044, China; Key Laboratory of Vehicle Advanced Manufacturing, Ministry of Education, Measuring and Control Technology, Beijing Jiaotong University, China.
| | - Ziqiang Pang
- School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, No.3 Shangyuancun, Haidian District, Beijing 100044, China
| | - Jinlong Qiu
- Daping Hospital of Army Medical University, PLA, 400042, China
| | - Zhenhao Zhang
- School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, No.3 Shangyuancun, Haidian District, Beijing 100044, China
| | - Xiaochuan Liu
- Aviation Key Laboratory of Science and Technology on Structures Impact Dynamics, China Aircraft Strength Research Institute, Xi'an 710065, China
| | - Chunyu Bai
- Aviation Key Laboratory of Science and Technology on Structures Impact Dynamics, China Aircraft Strength Research Institute, Xi'an 710065, China
| | - Yafeng Wang
- Aviation Key Laboratory of Science and Technology on Structures Impact Dynamics, China Aircraft Strength Research Institute, Xi'an 710065, China
| | - Yazhou Guo
- Aviation Key Laboratory of Science and Technology on Structures Impact Dynamics, China Aircraft Strength Research Institute, Xi'an 710065, China
| |
Collapse
|
7
|
Abstract
Considering that the Pc-Crash multibody dynamics software can reproduce the accident process accurately and obtain the collision parameters of pedestrian heads at the moment of head landing, the finite element analysis method can accurately analyze the injury of the pedestrian head when the boundary conditions are known. This paper combines the accident reconstruction method with the finite element analysis method to study the injury mechanism of pedestrian head impact on the ground in vehicle pedestrian collision accidents to provide a theoretical basis for pedestrian protection and the improvement of vehicle shapes. First, a real-life vehicle pedestrian collision is reproduced by Pc-Crash. The simulation results show that the rigid multibody model can accurately simulate the scene of the accident, then the speed and angle of the pedestrian head landing moment can be obtained at the same time. Second, the finite element model of human heads with a detailed facial structure is established and verified. Finally, the collision parameters obtained from the accident reconstruction are used as the boundary conditions to analyze the collision between the pedestrian head and the ground, and the biomechanical parameters, such as intracranial pressure, von Mises stress, shear stress and strain, can be determined. The results show that the stress wave will propagate inside and outside the skull and cause stress concentration in the skull and the brain tissue to varying degrees after the pedestrian head strikes the ground. When the stress exceeds a certain limit, it will cause different degrees of brain tissue injury.
Collapse
|
8
|
Li Z, Wang J, Wang J, Wang J, Ji C, Wang G. Experimental and numerical study on the mechanical properties of cortical and spongy cranial bone of 8-week-old porcines at different strain rates. Biomech Model Mechanobiol 2020; 19:1797-808. [PMID: 32086636 DOI: 10.1007/s10237-020-01309-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Accepted: 02/13/2020] [Indexed: 10/25/2022]
Abstract
Pediatric porcines have widely been used as substitute for children in biomechanical research. Previous studies have used entire piglet cranium when testing their properties. Here, the piglet craniums from the frontal and parietal locations were carefully dissected into spongy and cortical part, and tensile tests at different strain rates were then conducted on these two bone types. It is found that the elastic modulus, yield stress, and ultimate stress of the cortical bone were all significantly higher than those of the spongy bone. The ultimate strains of the cortical and spongy bone were similar. Overall, the effect of the position on the mechanical properties did not reach significance. Cortical bone strength from the frontal location was slightly higher than that obtained from the parietal location; however, spongy bone did not show this location difference. The mechanical properties of both the cortical and spongy bone are significantly strain-rate dependent. Specifically, the elastic modulus, yield stress, and the ultimate stress of the cortical bone increased by approximately 123%, 63%, and 50%, respectively, with strain rates ranging from 0.001 to 10/s. For spongy bone, increases were approximately 128%, 73%, and 77%, respectively. Ultimate strain decreased by approximately 37% and 7% for cortical and spongy bone, respectively. An elastic-plastic constitutive model incorporating with strain rate based on a combined exponential and logarithmic function was proposed and implemented into LS-DYNA through user-defined material. The developed model and the subroutine code successfully simulated the strain-rate characteristics and the fracture process of the bone samples.
Collapse
|
9
|
Abstract
Background and Objective: To simulate infant skull trauma after low height falls when variable degrees of ossification of the sutures are present. Methods: A finite elements model of a four-week-old infant skull was developed for simulating low height impact from 30 cm and 50 cm falls. Two impacts were simulated: An occipito-parietal impact on the lambdoid suture and a lateral impact on the right parietal and six cases were considered: unossified and fully ossified sutures, and sagittal, metopic, right lambdoid and right coronal craniosynostosis. Results: 26 simulations were performed. Results showed a marked increase in strain magnitudes in skulls with unossified sutures and fontanels. Higher deformations and lower Von Mises stress in the brain were found in occipital impacts. Fully ossified skulls showed less overall deformation and lower Von Mises stress in the brain. Results suggest that neonate skull impact when falling backward has a higher probability of resulting in permanent damage. Conclusion: This work shows an initial approximation to the mechanisms underlying TBI in neonates when exposed to low height falls common in household environments, and could be used as a starting point in the design and development of cranial orthoses and protective devices for preventing or mitigating TBI.
Collapse
Affiliation(s)
- F J Burgos-Flórez
- Biomimetics Laboratory, Instituto De Biotecnología, Universidad Nacional De Colombia , Bogotá, Colombia.,Mathematical Modelling and Numerical Methods Research Group (GNUM), Universidad Nacional De Colombia , Bogotá, Colombia.,Rational Use of Energy and Preservation of the Environment Group (UREMA), Universidad Del Norte , Barranquilla, Colombia
| | - Diego Alexander Garzón-Alvarado
- Biomimetics Laboratory, Instituto De Biotecnología, Universidad Nacional De Colombia , Bogotá, Colombia.,Mathematical Modelling and Numerical Methods Research Group (GNUM), Universidad Nacional De Colombia , Bogotá, Colombia
| |
Collapse
|
10
|
He J, Yan J, Margulies S, Coats B, Spear AD. An adaptive-remeshing framework to predict impact-induced skull fracture in infants. Biomech Model Mechanobiol 2020; 19:1595-1605. [DOI: 10.1007/s10237-020-01293-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 01/14/2020] [Indexed: 11/30/2022]
|
11
|
Li Z, Ji C, Li D, Luo R, Wang G, Jiang J. A comprehensive study on the mechanical properties of different regions of 8-week-old pediatric porcine brain under tension, shear, and compression at various strain rates. J Biomech 2019; 98:109380. [PMID: 31630775 DOI: 10.1016/j.jbiomech.2019.109380] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 07/11/2019] [Accepted: 10/06/2019] [Indexed: 12/15/2022]
Abstract
Young porcine brain is often used as a surrogate for studying the mechanical factors affecting traumatic brain injury in children. However, the mechanical properties of pediatric brain tissue derived from humans and piglets are very scarce, and this seriously detracts from the biofidelity of the developed finite element (FE) models of the pediatric head/brain. The present study addresses this issue by subjecting the cerebrum (white matter and gray matter), cerebellum, and brainstem specimens derived from 8-week-old piglets to tension and shear testing at strain rates of 0.01, 1, and 50/s. The experimental data are combined with the corresponding data derived from a previous study under compression to obtain comprehensive stress-strain curves of the pediatric porcine cerebrum, cerebellum, and brainstem tissue specimens. In general, the average stress level of the white matter is somewhat higher than that of the gray matter under the tension, shear and compression conditions, however, this difference does not reach a significant level. The stiffness of the cerebellum and the cerebrum does not differ significantly under tension and shear conditions, but the stiffness of the cerebellum is greater than that of the cerebrum under compression. The brainstem has significantly higher stiffness than the cerebrum and the cerebellum under all loading modes. In addition, the mechanical properties of brain tissue exhibit significant strain-rate dependences. With increasing strain rate from 0.01/s to 50/s, the average stress at a strain of 0.5 for all of the brain tissue increased by about 2.2 times under tension, about 2.4 times under shearing and about 2.2 times under compression. The variations in the stress as a function of the strain rate for brain tissue specimens were well characterized by exponential functions at strains of 0.25 and 0.5 under all three loading modes. The results of this study are useful for developing biofidelic FE models of the pediatric brain.
Collapse
Affiliation(s)
- Zhigang Li
- School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, China.
| | - Cheng Ji
- School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, China
| | - Dapeng Li
- Department of Neurosurgery, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China
| | - Rutao Luo
- Department of Neurosurgery, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China
| | - Guangliang Wang
- School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, China
| | - Jinzhong Jiang
- Cangzhou Hospital of Integrated Traditional and Western Medicine of Hebei Province, Cangzhou 061001, Hebei, China
| |
Collapse
|
12
|
Borghi A, Rodriguez Florez N, Ruggiero F, James G, O'Hara J, Ong J, Jeelani O, Dunaway D, Schievano S. A population-specific material model for sagittal craniosynostosis to predict surgical shape outcomes. Biomech Model Mechanobiol 2019; 19:1319-1329. [PMID: 31571084 PMCID: PMC7424404 DOI: 10.1007/s10237-019-01229-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 09/17/2019] [Indexed: 11/26/2022]
Abstract
Sagittal craniosynostosis consists of premature fusion (ossification) of the sagittal suture during infancy, resulting in head deformity and brain growth restriction. Spring-assisted cranioplasty (SAC) entails skull incisions to free the fused suture and insertion of two springs (metallic distractors) to promote cranial reshaping. Although safe and effective, SAC outcomes remain uncertain. We aimed hereby to obtain and validate a skull material model for SAC outcome prediction. Computed tomography data relative to 18 patients were processed to simulate surgical cuts and spring location. A rescaling model for age matching was created using retrospective data and validated. Design of experiments was used to assess the effect of different material property parameters on the model output. Subsequent material optimization-using retrospective clinical spring measurements-was performed for nine patients. A population-derived material model was obtained and applied to the whole population. Results showed that bone Young's modulus and relaxation modulus had the largest effect on the model predictions: the use of the population-derived material model had a negligible effect on improving the prediction of on-table opening while significantly improved the prediction of spring kinematics at follow-up. The model was validated using on-table 3D scans for nine patients: the predicted head shape approximated within 2 mm the 3D scan model in 80% of the surface points, in 8 out of 9 patients. The accuracy and reliability of the developed computational model of SAC were increased using population data: this tool is now ready for prospective clinical application.
Collapse
Affiliation(s)
- Alessandro Borghi
- UCL Great Ormond Street Institute of Child Health and Great Ormond Street Hospital for Children, London, UK.
| | - Naiara Rodriguez Florez
- Surface Technologies Group, Department of Biomedical Engineering, Mondragon Unibertsitatea, Mondragón, Spain
| | - Federica Ruggiero
- UCL Great Ormond Street Institute of Child Health and Great Ormond Street Hospital for Children, London, UK
| | - Greg James
- UCL Great Ormond Street Institute of Child Health and Great Ormond Street Hospital for Children, London, UK
| | - Justine O'Hara
- UCL Great Ormond Street Institute of Child Health and Great Ormond Street Hospital for Children, London, UK
| | - Juling Ong
- UCL Great Ormond Street Institute of Child Health and Great Ormond Street Hospital for Children, London, UK
| | - Owase Jeelani
- UCL Great Ormond Street Institute of Child Health and Great Ormond Street Hospital for Children, London, UK
| | - David Dunaway
- UCL Great Ormond Street Institute of Child Health and Great Ormond Street Hospital for Children, London, UK
| | - Silvia Schievano
- UCL Great Ormond Street Institute of Child Health and Great Ormond Street Hospital for Children, London, UK
| |
Collapse
|
13
|
Khalid GA, Prabhu RK, Arthurs O, Jones MD. A coupled physical-computational methodology for the investigation of short fall related infant head impact injury. Forensic Sci Int 2019; 300:170-186. [DOI: 10.1016/j.forsciint.2019.04.034] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 04/03/2019] [Accepted: 04/25/2019] [Indexed: 11/26/2022]
|
14
|
Li Z, Wang G, Ji C, Jiang J, Wang J, Wang J. Characterization of the mechanical properties for cranial bones of 8-week-old piglets: the effect of strain rate and region. Biomech Model Mechanobiol 2019; 18:1697-1707. [DOI: 10.1007/s10237-019-01169-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Accepted: 05/12/2019] [Indexed: 11/25/2022]
|
15
|
Li Z, Yang H, Wang G, Han X, Zhang S. Compressive properties and constitutive modeling of different regions of 8-week-old pediatric porcine brain under large strain and wide strain rates. J Mech Behav Biomed Mater 2019; 89:122-131. [DOI: 10.1016/j.jmbbm.2018.09.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Revised: 08/15/2018] [Accepted: 09/07/2018] [Indexed: 11/15/2022]
|
16
|
Brooks T, Choi JE, Garnich M, Hammer N, Waddell JN, Duncan W, Jermy M. Finite element models and material data for analysis of infant head impacts. Heliyon 2018; 4:e01010. [PMID: 30582038 PMCID: PMC6288411 DOI: 10.1016/j.heliyon.2018.e01010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Revised: 10/31/2018] [Accepted: 11/30/2018] [Indexed: 11/06/2022] Open
Abstract
Finite element (FE) models of the infant human head may be used to discriminate injury patterns resulting from accidents (e.g. falls) and from abusive head trauma (AHT). Existing FE models of infant head impacts are reviewed. Reliability of the material models is the major limitation currently. Infant head tissue properties differ from adults (notably in suture stiffness and strain-to-failure), change with age, and experimental data is scarce. The available data on scalp, cranial bone, dura, and brain are reviewed. Data is most scarce for living brain. All infant head model to date, except one, have used linear elastic models for all tissues except the brain (viscoelastic or Ogden hyperelastic), and do not capture the full complexity of tissue response, but the predicted whole-head response may be of acceptable accuracy. Recent work by Li, Sandler and Kleiven has used hyperelastic models for scalp and dura, and an orthotropic model for bone. There is a need to simulate falls from greater than one metre, and blunt force impacts.
Collapse
Affiliation(s)
- Tom Brooks
- Department of Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
| | - Jung Eun Choi
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, PO Box 56, Dunedin, 9054, New Zealand
| | - Mark Garnich
- Department of Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
| | - Niels Hammer
- Department of Anatomy, University of Otago, PO Box 56, Dunedin, 9054, New Zealand
- Department of Orthopaedic and Trauma Surgery, University of Leipzig, Liebigstr. 20, 04103, Leipzig, Germany
- Fraunhofer Institute for Machine Tools and Forming Technology, Medical Division, Nöthnitzer Str. 44, 01187, Dresden, Germany
| | - John Neil Waddell
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, PO Box 56, Dunedin, 9054, New Zealand
| | - Warwick Duncan
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, PO Box 56, Dunedin, 9054, New Zealand
| | - Mark Jermy
- Department of Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
| |
Collapse
|
17
|
Li Z, Ji C, Wang L. Development of a child head analytical dynamic model considering cranial nonuniform thickness and curvature - Applying to children aged 0-1 years old. Comput Methods Programs Biomed 2018; 161:181-189. [PMID: 29852960 DOI: 10.1016/j.cmpb.2018.04.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 04/10/2018] [Accepted: 04/26/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND AND OBJECTIVE Although analytical models have been used to quickly predict head response under impact condition, the existing models generally took the head as regular shell with uniform thickness which cannot account for the actual head geometry with varied cranial thickness and curvature at different locations. The objective of this study is to develop and validate an analytical model incorporating actual cranial thickness and curvature for child aged 0-1YO and investigate their effects on child head dynamic responses at different head locations. METHODS To develop the new analytical model, the child head was simplified into an irregular fluid-filled shell with non-uniform thickness and the cranial thickness and curvature at different locations were automatically obtained from CT scans using a procedure developed in this study. The implicit equation of maximum impact force was derived as a function of elastic modulus, thickness and radius of curvature of cranium. RESULTS The proposed analytical model are compared with cadaver test data of children aged 0-1 years old and it is shown to be accurate in predicting head injury metrics. According to this model, obvious difference in injury metrics were observed among subjects with the same age, but different cranial thickness and curvature; and the injury metrics at forehead location are significant higher than those at other locations due to large thickness it owns. CONCLUSIONS The proposed model shows good biofidelity and can be used in quickly predicting the dynamics response at any location of head for child younger than 1 YO.
Collapse
Affiliation(s)
- Zhigang Li
- School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, PR China.
| | - Cheng Ji
- School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, PR China.
| | - Lishu Wang
- Hebei University of Engineering, Handan 056021, PR China.
| |
Collapse
|
18
|
Borghi A, Rodgers W, Schievano S, Ponniah A, Jeelani O, Dunaway D. Proof of Concept Study for the Design, Manufacturing, and Testing of a Patient-Specific Shape Memory Device for Treatment of Unicoronal Craniosynostosis. J Craniofac Surg 2018; 29:45-8. [PMID: 29040141 DOI: 10.1097/SCS.0000000000004025] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Treatment of unicoronal craniosynostosis is a surgically challenging problem, due to the involvement of coronal suture and cranial base, with complex asymmetries of the calvarium and orbit. Several techniques for correction have been described, including surgical bony remodeling, early strip craniotomy with orthotic helmet remodeling and distraction. Current distraction devices provide unidirectional forces and have had very limited success. Nitinol is a shape memory alloy that can be programmed to the shape of a patient-specific anatomy by means of thermal treatment.In this work, a methodology to produce a nitinol patient-specific distractor is presented: computer tomography images of a 16-month-old patient with unicoronal craniosynostosis were processed to create a 3-dimensional model of his skull and define the ideal shape postsurgery. A mesh was produced from a nitinol sheet, formed to the ideal skull shape and heat treated to be malleable at room temperature. The mesh was afterward deformed to be attached to a rapid prototyped plastic skull, replica of the patient initial anatomy. The mesh/skull construct was placed in hot water to activate the mesh shape memory property: the deformed plastic skull was computed tomography scanned for comparison of its shape with the initial anatomy and with the desired shape, showing that the nitinol mesh had been able to distract the plastic skull to a shape close to the desired one.The shape-memory properties of nitinol allow for the design and production of patient-specific devices able to deliver complex, preprogrammable shape changes.
Collapse
|
19
|
Libby J, Marghoub A, Johnson D, Khonsari RH, Fagan MJ, Moazen M. Modelling human skull growth: a validated computational model. J R Soc Interface 2018; 14:rsif.2017.0202. [PMID: 28566514 DOI: 10.1098/rsif.2017.0202] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 05/09/2017] [Indexed: 11/12/2022] Open
Abstract
During the first year of life, the brain grows rapidly and the neurocranium increases to about 65% of its adult size. Our understanding of the relationship between the biomechanical forces, especially from the growing brain, the craniofacial soft tissue structures and the individual bone plates of the skull vault is still limited. This basic knowledge could help in the future planning of craniofacial surgical operations. The aim of this study was to develop a validated computational model of skull growth, based on the finite-element (FE) method, to help understand the biomechanics of skull growth. To do this, a two-step validation study was carried out. First, an in vitro physical three-dimensional printed model and an in silico FE model were created from the same micro-CT scan of an infant skull and loaded with forces from the growing brain from zero to two months of age. The results from the in vitro model validated the FE model before it was further developed to expand from 0 to 12 months of age. This second FE model was compared directly with in vivo clinical CT scans of infants without craniofacial conditions (n = 56). The various models were compared in terms of predicted skull width, length and circumference, while the overall shape was quantified using three-dimensional distance plots. Statistical analysis yielded no significant differences between the male skull models. All size measurements from the FE model versus the in vitro physical model were within 5%, with one exception showing a 7.6% difference. The FE model and in vivo data also correlated well, with the largest percentage difference in size being 8.3%. Overall, the FE model results matched well with both the in vitro and in vivo data. With further development and model refinement, this modelling method could be used to assist in preoperative planning of craniofacial surgery procedures and could help to reduce reoperation rates.
Collapse
Affiliation(s)
- Joseph Libby
- Medical and Biological Engineering, School of Engineering and Computer Science, University of Hull, Hull HU6 7RX, UK
| | - Arsalan Marghoub
- UCL Mechanical Engineering, University College London, London WC1E 7JE, UK
| | - David Johnson
- Oxford Craniofacial Unit, Oxford Radcliffe Hospitals NHS Trust, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Roman H Khonsari
- Assistance Publique-Hôpitaux de Paris, Hôpital Universitaire Necker-Enfants Malades, Service de Chirurgie Maxillofaciale et Plastique & Université Paris Descartes, Paris, France
| | - Michael J Fagan
- Medical and Biological Engineering, School of Engineering and Computer Science, University of Hull, Hull HU6 7RX, UK
| | - Mehran Moazen
- UCL Mechanical Engineering, University College London, London WC1E 7JE, UK
| |
Collapse
|
20
|
Marghoub A, Libby J, Babbs C, Pauws E, Fagan MJ, Moazen M. Predicting calvarial growth in normal and craniosynostotic mice using a computational approach. J Anat 2018; 232:440-448. [PMID: 29243252 PMCID: PMC5807955 DOI: 10.1111/joa.12764] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/21/2017] [Indexed: 11/26/2022] Open
Abstract
During postnatal calvarial growth the brain grows gradually and the overlying bones and sutures accommodate that growth until the later juvenile stages. The whole process is coordinated through a complex series of biological, chemical and perhaps mechanical signals between various elements of the craniofacial system. The aim of this study was to investigate to what extent a computational model can accurately predict the calvarial growth in wild-type (WT) and mutant type (MT) Fgfr2C342Y/+ mice displaying bicoronal suture fusion. A series of morphological studies were carried out to quantify the calvarial growth at P3, P10 and P20 in both mouse types. MicroCT images of a P3 specimen were used to develop a finite element model of skull growth to predict the calvarial shape of WT and MT mice at P10. Sensitivity tests were performed and the results compared with ex vivo P10 data. Although the models were sensitive to the choice of input parameters, they predicted the overall skull growth in the WT and MT mice. The models also captured the difference between the ex vivoWT and MT mice. This modelling approach has the potential to be translated to human skull growth and to enhance our understanding of the different reconstruction methods used to manage clinically the different forms of craniosynostosis, and in the long term possibly reduce the number of re-operations in children displaying this condition and thereby enhance their quality of life.
Collapse
Affiliation(s)
- Arsalan Marghoub
- Department of Mechanical EngineeringUniversity College LondonLondonUK
| | - Joseph Libby
- Medical and Biological EngineeringSchool of Engineering and Computer ScienceUniversity of HullHullUK
| | - Christian Babbs
- MRC Molecular Haematology UnitMRC Weatherall Institute of Molecular MedicineUniversity of OxfordOxfordUK
| | - Erwin Pauws
- Institute of Child HealthGreat Ormond StreetUniversity College LondonLondonUK
| | - Michael J. Fagan
- Medical and Biological EngineeringSchool of Engineering and Computer ScienceUniversity of HullHullUK
| | - Mehran Moazen
- Department of Mechanical EngineeringUniversity College LondonLondonUK
| |
Collapse
|
21
|
Borghi A, Rodriguez-Florez N, Rodgers W, James G, Hayward R, Dunaway D, Jeelani O, Schievano S. Spring assisted cranioplasty: A patient specific computational model. Med Eng Phys 2018; 53:58-65. [DOI: 10.1016/j.medengphy.2018.01.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Revised: 12/19/2017] [Accepted: 01/03/2018] [Indexed: 11/29/2022]
|
22
|
Li X, Sandler H, Kleiven S. The importance of nonlinear tissue modelling in finite element simulations of infant head impacts. Biomech Model Mechanobiol 2017; 16:823-840. [PMID: 27873038 PMCID: PMC5422506 DOI: 10.1007/s10237-016-0855-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 11/11/2016] [Indexed: 11/14/2022]
Abstract
Despite recent efforts on the development of finite element (FE) head models of infants, a model capable of capturing head responses under various impact scenarios has not been reported. This is hypothesized partially attributed to the use of simplified linear elastic models for soft tissues of suture, scalp and dura. Orthotropic elastic constants are yet to be determined to incorporate the direction-specific material properties of infant cranial bone due to grain fibres radiating from the ossification centres. We report here on our efforts in advancing the above-mentioned aspects in material modelling in infant head and further incorporate them into subject-specific FE head models of a newborn, 5- and 9-month-old infant. Each model is subjected to five impact tests (forehead, occiput, vertex, right and left parietal impacts) and two compression tests. The predicted global head impact responses of the acceleration-time impact curves and the force-deflection compression curves for different age groups agree well with the experimental data reported in the literature. In particular, the newly developed Ogden hyperelastic model for suture, together with the nonlinear modelling of scalp and dura mater, enables the models to achieve more realistic impact performance compared with linear elastic models. The proposed approach for obtaining age-dependent skull bone orthotropic material constants counts both an increase in stiffness and decrease in anisotropy in the skull bone-two essential biological growth parameters during early infancy. The profound deformation of infant head causes a large stretch at the interfaces between the skull bones and the suture, suggesting that infant skull fractures are likely to initiate from the interfaces; the impact angle has a profound influence on global head impact responses and the skull injury metrics for certain impact locations, especially true for a parietal impact.
Collapse
Affiliation(s)
- Xiaogai Li
- Division of Neuronic Engineering, School of Technology and Health, Royal Institute of Technology-KTH, 141 52, Huddinge, Sweden.
| | - Håkan Sandler
- Department of Surgical Sciences/Forensic Medicine, Uppsala University, Uppsala, Sweden
- National Board of Forensic Medicine, Uppsala, Sweden
| | - Svein Kleiven
- Division of Neuronic Engineering, School of Technology and Health, Royal Institute of Technology-KTH, 141 52, Huddinge, Sweden
| |
Collapse
|
23
|
Jiang B, Zhu F, Cao L, Presley BR, Shen M, Yang KH. Computational Study of Fracture Characteristics in Infant Skulls Using a Simplified Finite Element Model. J Forensic Sci 2016; 62:39-49. [DOI: 10.1111/1556-4029.13241] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2015] [Revised: 01/10/2016] [Accepted: 03/19/2016] [Indexed: 11/26/2022]
Affiliation(s)
- Binhui Jiang
- The State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body; Hunan University; Hunan 410082 China
- Bioengineering Center; Wayne State University; MI 48201 China
| | - Feng Zhu
- The State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body; Hunan University; Hunan 410082 China
- Bioengineering Center; Wayne State University; MI 48201 China
| | - Libo Cao
- The State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body; Hunan University; Hunan 410082 China
| | | | - Ming Shen
- Bioengineering Center; Wayne State University; MI 48201 China
| | - King H. Yang
- Bioengineering Center; Wayne State University; MI 48201 China
| |
Collapse
|
24
|
Li Z, Han X, Ge H, Ma C. A semi-automatic method of generating subject-specific pediatric head finite element models for impact dynamic responses to head injury. J Mech Behav Biomed Mater 2016; 60:557-567. [DOI: 10.1016/j.jmbbm.2016.03.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Revised: 03/14/2016] [Accepted: 03/19/2016] [Indexed: 10/22/2022]
|
25
|
Zhou Z, Jiang B, Cao L, Zhu F, Mao H, Yang KH. Numerical simulations of the 10-year-old head response in drop impacts and compression tests. Comput Methods Programs Biomed 2016; 131:13-25. [PMID: 27265045 DOI: 10.1016/j.cmpb.2016.04.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 04/10/2016] [Accepted: 04/11/2016] [Indexed: 06/05/2023]
Abstract
BACKGROUND AND OBJECTIVE Studies on traumatic injuries of children indicate that impact to the head is a major cause of severe injury and high mortality. However, regulatory and ethical concerns very much limit development and validation of computer models representing the pediatric head. The purpose of this study was to develop a child head finite element model with high-biofidelity to be used for studying pediatric head injury mechanisms. METHODS A newly developed 10-year-old (YO) pediatric finite element head model was limitedly validated for kinematic and kinetic responses against data from quasi-static compressions and drop tests obtained from an experimental study involving a child-cadaver specimen. The validated model was subsequently used for a fall accident reconstruction and associated injury analysis. RESULTS The model predicted the same shape of acceleration-time histories as was found in drop tests with the largest discrepancy of -8.2% in the peak acceleration at a drop height of 15 cm. Force-deflection responses predicted by the model for compression loading had a maximum discrepancy of 7.5% at a strain rate of 0.3 s(-1). The model-predicted maximum von Mises stress (σv) and principal strain (εp) in the skull, intracranial pressure (ICP), maximum σv and maximum εp in the brain, head injury criterion (HIC), brain injury criterion (BrIC), and head impact power (HIP) were used for analyzing risks of injury in the accident reconstruction. CONCLUSIONS Based on the results of the injury analyses, the following conclusions can be drawn: (1) ICP cannot be used to accurately predict the locations of brain injury, but it may reflect the overall energy level of the impact event. (2) The brain regions predicted by the model to have high σv coincide with the locations of subdural hematoma with transtentorial herniation and the impact position of an actual injury. (3) The brain regions with high εp predicted by the model coincide with locations commonly found where diffuse axonal injuries (DAI) due to blunt-impact and rapid acceleration have taken place.
Collapse
Affiliation(s)
- Zhou Zhou
- The State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha, Hunan, 410082, China
| | - Binhui Jiang
- The State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha, Hunan, 410082, China; Bioengineering Center, Wayne State University, Detroit, MI 48201, USA.
| | - Libo Cao
- The State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha, Hunan, 410082, China
| | - Feng Zhu
- The State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha, Hunan, 410082, China; Department of Mechanical Engineering, Embry-Riddle Aeronautical University, FL 32114, USA
| | - Haojie Mao
- Bioengineering Center, Wayne State University, Detroit, MI 48201, USA
| | - King H Yang
- Bioengineering Center, Wayne State University, Detroit, MI 48201, USA
| |
Collapse
|
26
|
Wang J, Zou D, Li Z, Huang P, Li D, Shao Y, Wang H, Chen Y. Mechanical properties of cranial bones and sutures in 1-2-year-old infants. Med Sci Monit 2014; 20:1808-13. [PMID: 25279966 PMCID: PMC4199403 DOI: 10.12659/msm.892278] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 09/15/2014] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND The mechanical properties of 1-2-year-old pediatric cranial bones and sutures and their influential factors were studied to better understand how the pediatric calvarium reacts to loading. MATERIAL AND METHODS Cranial bone and suture specimens were extracted from seven fresh-frozen human infant cadavers (1.5±0.5 years old). Eight specimens were obtained from each subject: two frontal bones, two parietal bones, two sagittal suture samples, and two coronal suture samples. The specimens were tested in a three-point bend setup at 1.5 mm/s. The mechanical properties, such as ultimate stress, elastic modulus, and ultimate strain, were calculated for each specimen. RESULTS The ultimate stress and elastic modulus of the frontal bone were higher than those of the parietal bone (P<0.05). No differences were found between the coronal and sagittal sutures in ultimate stress, elastic modulus, or ultimate strain (P>0.05). The ultimate stress and elastic modulus of the frontal and parietal bones were higher than those of the sagittal and coronal sutures (P<0.05), whereas the opposite ultimate strain findings were revealed (P<0.05). CONCLUSIONS There was no significant difference in ultimate stress, elastic modulus, or ultimate strain between the sagittal and coronal sutures. However, there were significant differences in ultimate stress, elastic modulus, and ultimate strain between the frontal and parietal bones as well as between the cranial bones and sutures.
Collapse
Affiliation(s)
- Jiawen Wang
- Department of Forensic Science, Basic Medical College, Southern Medical University, Guangzhou, China
- Shanghai Key Laboratory of Forensic Medicine, Institute of Forensic Science, Ministry of Justice, Shanghai, China
- Department of Pathology Teaching and Research Section, Basic Medical College, Foshan University, Foshan, China
| | - Donghua Zou
- Shanghai Key Laboratory of Forensic Medicine, Institute of Forensic Science, Ministry of Justice, Shanghai, China
| | - Zhengdong Li
- Shanghai Key Laboratory of Forensic Medicine, Institute of Forensic Science, Ministry of Justice, Shanghai, China
| | - Ping Huang
- Shanghai Key Laboratory of Forensic Medicine, Institute of Forensic Science, Ministry of Justice, Shanghai, China
| | - Dongri Li
- Department of Forensic Science, Basic Medical College, Southern Medical University, Guangzhou, China
| | - Yu Shao
- Shanghai Key Laboratory of Forensic Medicine, Institute of Forensic Science, Ministry of Justice, Shanghai, China
| | - Huijun Wang
- Department of Forensic Science, Basic Medical College, Southern Medical University, Guangzhou, China
| | - Yijiu Chen
- Department of Forensic Science, Basic Medical College, Southern Medical University, Guangzhou, China
- Shanghai Key Laboratory of Forensic Medicine, Institute of Forensic Science, Ministry of Justice, Shanghai, China
| |
Collapse
|