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Hirst JN, Phung BR, Johnsson BT, He J, Coats B, Spear AD. Predicting fall parameters from infant skull fractures using machine learning. Biomech Model Mechanobiol 2025; 24:521-537. [PMID: 39826035 DOI: 10.1007/s10237-024-01922-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2024] [Accepted: 12/26/2024] [Indexed: 01/20/2025]
Abstract
When infants are admitted to the hospital with skull fractures, providers must distinguish between cases of accidental and abusive head trauma. Limited information about the incident is available in such cases, and witness statements are not always reliable. In this study, we introduce a novel, data-driven approach to predict fall parameters that lead to skull fractures in infants in order to aid in determinations of abusive head trauma. We utilize a state-of-the-art finite element fracture simulation framework to generate a unique dataset of skull fracture patterns from simulated falls. We then extract features from the resulting fracture patterns in this dataset to be used as input into machine learning models. We compare seven machine learning models on their abilities to predict two fall parameters: impact site and fall height. The results from our best-performing models demonstrate that while predicting the exact fall height remains challenging ( R 2 0.27 for the ridge regression model), we can effectively identify potential impact sites ( R 2 between 0.65 and 0.76 for the random forest regression model). This work not only provides a tool to enhance the ability to assess abuse in cases of pediatric head trauma, but also advocates for advancements in computational models to simulate complex skull fractures.
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Affiliation(s)
- Jacob N Hirst
- Department of Mechanical Engineering, University of Utah, Salt Lake City, UT, 84112, USA
| | - Brian R Phung
- Department of Mechanical Engineering, University of Utah, Salt Lake City, UT, 84112, USA
| | - Bjorn T Johnsson
- Department of Mechanical Engineering, University of Utah, Salt Lake City, UT, 84112, USA
| | - Junyan He
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61820, USA
| | - Brittany Coats
- Department of Mechanical Engineering, University of Utah, Salt Lake City, UT, 84112, USA
| | - Ashley D Spear
- Department of Mechanical Engineering, University of Utah, Salt Lake City, UT, 84112, USA.
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2
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Narang SK, Haney S, Duhaime AC, Martin J, Binenbaum G, de Alba Campomanes AG, Barth R, Bertocci G, Care M, McGuone D. Abusive Head Trauma in Infants and Children: Technical Report. Pediatrics 2025; 155:e2024070457. [PMID: 39992695 DOI: 10.1542/peds.2024-070457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/26/2025] Open
Affiliation(s)
- Sandeep K Narang
- Professor of Pediatrics, Medical College of Wisconsin; Chief, Section of Child Advocacy and Protection, Child Advocacy and Protection Services, Children's Wisconsin, Milwaukee, Wisconsin
| | - Suzanne Haney
- Children's Nebraska and University of Nebraska Medical Center, Omaha, Nebraska
| | - Ann-Christine Duhaime
- Department of Neurosurgery, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Jonathan Martin
- Division Head, Neurosurgery, Connecticut Children's; Professor, Surgery and Pediatrics, UConn School of Medicine, Farmington, Connecticut
| | - Gil Binenbaum
- Division of Ophthalmology at Children's Hospital of Philadelphia; Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | | | - Rich Barth
- Department of Radiology, Lucile Packard Children's Hospital, Stanford University, Stanford, California
| | - Gina Bertocci
- Department of Bioengineering, University of Louisville, Louisville, Kentucky
| | - Margarite Care
- Department of Radiology and Medical Imaging, Cincinnati Children's Hospital Medical Center; Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Declan McGuone
- Department of Pathology, Yale School of Medicine; Associate Medical Examiner, Connecticut Office of the Chief Medical Examiner, New Haven, Connecticut
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3
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Wei Y, Oldroyd J, Haste P, Jayamohan J, Jones M, Casey N, Peña JM, Baylis S, Gilmour S, Jérusalem A. A mechanics-informed machine learning framework for traumatic brain injury prediction in police and forensic investigations. COMMUNICATIONS ENGINEERING 2025; 4:29. [PMID: 40011627 DOI: 10.1038/s44172-025-00352-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2024] [Accepted: 01/21/2025] [Indexed: 02/28/2025]
Abstract
Police forensic investigations are not immune to our society's ubiquitous search for better predictive ability. In the particular and very topical case of Traumatic Brain Injury (TBI), police forensic investigations aim at evaluating whether a given impact or assault scenario led to the clinically observed TBI. This question is traditionally answered by means of forensic biomechanics and neurosurgical expertise which cannot provide a fully objective probabilistic measure. To this end, we propose here a numerical framework-based solution coupling biomechanical simulations of a variety of injurious impacts to machine learning training of police reports provided by the UK's Thames Valley Police and the National Crime Agency's National Injury Database. In this approach, the biomechanical predictions of mechanical metrics such as strain and stress distributions are interpreted by the machine learning model by additionally considering assault specific metadata to predict brain injury outcomes. The framework, only taking as input information typically available in police reports, reaches prediction accuracies exceeding 94% for skull fracture, 79% for loss of consciousness and intracranial haemorrhage, and is able to identify the best predictive features for each targeted injury. Overall, the proposed framework offers new avenues for the prediction, directly from police reports, of any TBI related symptom as required by forensic law enforcement investigations.
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Affiliation(s)
- Yuyang Wei
- Department of Engineering Science, University of Oxford, Oxford, UK
| | | | - Phoebe Haste
- The Podium Institute for Sports Medicine and Technology, Department of Engineering Science, University of Oxford, Oxford, UK
| | | | - Michael Jones
- School of Engineering, Cardiff University, Cardiff, UK
| | | | - Jose-Maria Peña
- Lurtis Ltd., Wood Centre for Innovation Stansfeld Park, Oxford, UK
| | | | - Stan Gilmour
- Thames Valley Police, Oxford, UK.
- Keele University, Newcastle, UK.
| | - Antoine Jérusalem
- Department of Engineering Science, University of Oxford, Oxford, UK.
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4
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Seidi M, Caccese V, Memar M. Impact testing methods to simulate head impacts due to falls from standing height. Med Eng Phys 2025; 136:104299. [PMID: 39979011 DOI: 10.1016/j.medengphy.2025.104299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 12/12/2024] [Accepted: 02/05/2025] [Indexed: 02/22/2025]
Abstract
Fall is one of the leading causes of traumatic brain injury (TBI), and thus, there is an increasing interest in validated tools and protective devices to prevent fall-related TBI. Developing head protective technologies for fall requires a reliable testing method to realistically mimic kinematics of head impacts due to fall to evaluate the injury attenuation of such protective headgears. The objective of this study is to recommend an appropriate and repeatable testing method for simulating fall-related head impacts due to standing height falls. To that end, several impact testing methods that commonly use to assess the efficacy of protective headgear were evaluated and compared. The four different test methods include: (1) a whole-body anthropomorphic test device (ATD) drop; (2) a drop-tower equipped with a Hybrid III head and neck assembly; (3) ASTM F429/F1446 standard; and (4) a linear impactor equipped with a Hybrid III head and neck assembly. Although the ATD drop system simulates fall-related head impacts realistically by considering the whole-body kinematics during falls from standing height, this method showed low repeatability. Among the three repeatable testing methods, only the drop tower with Hybrid III head and neck assembly showed statistically similar results to the ATD drop system for front and rear head impacts for all parameters examined in this study including peak linear acceleration, Head Injury Criterion, peak angular acceleration and peak angular velocity. The results suggested that drop-tower with Hybrid III head and neck assembly can realistically captured both translational and rotational motions of the head during impact due to standing height falls in a repeatable manner.
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Affiliation(s)
- Morteza Seidi
- Department of Mechanical, Aerospace, and Industrial Engineering, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA.
| | - Vincent Caccese
- Department of Mechanical Engineering, University of Maine, Orono, ME, USA
| | - Marzieh Memar
- Department of Biomedical Engineering and Chemical Engineering, University of Texas at San Antonio, San Antonio, TX, USA.
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Chen S, Kleiven S, Li X. Infant skull fractures align with the direction of bone mineralization. Biomech Model Mechanobiol 2025; 24:153-168. [PMID: 39585528 PMCID: PMC11846741 DOI: 10.1007/s10237-024-01902-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2024] [Accepted: 10/18/2024] [Indexed: 11/26/2024]
Abstract
The geometry and mechanical properties of infant skull bones differ significantly from those of adults. Over the past decades, debates surrounding whether fractures in infants come from deliberate abuse or accidents have generated significant impacts in both legal and societal contexts. However, the etiology of infant skull fractures remains unclear, which motivates this study with two main components of work. Firstly, we present and implement a progressive unidirectional fabric composite damage model for infant cranial vaults to represent ductile and anisotropic properties-two typical mechanical characteristics of infant skulls. Secondly, we hypothesize that these intrinsic material properties cause injuries perpendicular to the fiber direction to dominate infant skull fractures, resulting in fracture lines that align with the direction of mineralization in the infant skull. The material model and the finite element (FE) model were verified hierarchically, and this hypothesis was verified by reconstructing two legal cases with known fall heights and implementing the above damage model into CT-based subject-specific infant FE head models. We discovered that the infant skull is more susceptible to injuries within planes perpendicular to the mineralization direction because of the anisotropic mechanical property caused by the direction of mineralization, leading to infant skull fractures aligning with the mineralization direction. Our findings corroborated the several previously reported observations of fractures on cranial vaults, demonstrating that these fractures were closely associated with sutures and oriented along the mineralization direction, and revealed the underlying mechanisms of infant skull fracture pattern. The modeling methods and results of this study will serve as an anchor point for more rigorous investigations of infant skull fractures, ultimately aiming to provide convincing biomechanical evidence to aid forensic diagnoses of abusive head trauma.
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Affiliation(s)
- Siyuan Chen
- Division of Neuronic Engineering, KTH Royal Institute of Technology, Stockholm, Sweden.
| | - Svein Kleiven
- Division of Neuronic Engineering, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Xiaogai Li
- Division of Neuronic Engineering, KTH Royal Institute of Technology, Stockholm, Sweden
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Haarbauer-Krupa J, Haileyesus T, Peterson AB, Womack LS, Hymel K, Hajiaghamemar M, Klevens J, Lindberg D, Margulies SS. Nonfatal Emergency Department Visits Associated with Fall-Related Fractured Skulls of Infants Aged 0-4 Months. J Emerg Med 2024; 67:e138-e145. [PMID: 38811271 PMCID: PMC11290962 DOI: 10.1016/j.jemermed.2024.03.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 02/17/2024] [Accepted: 03/06/2024] [Indexed: 05/31/2024]
Abstract
BACKGROUND Children aged 0-4 years have the highest rate of emergency department (ED) visits for traumatic brain injury (TBI); falls are the leading cause. Infants younger than 2 years are more likely to sustain a fractured skull after a fall. OBJECTIVE This study examined caregiver actions and products associated with ED visits for fall-related fractured skulls in infants aged 0-4 months. METHODS Data were analyzed from the 2001-2017 National Electronic Injury Surveillance System-All Injury Program. Case narratives of infants aged 0-4 months who visited an ED for a fall-related skull fracture were examined to code caregiver actions preceding the fall. Product codes determined fall location and product type involved (e.g., flooring, bed, or stairs). All national estimates were weighted. RESULTS There were more than 27,000 ED visits (weighted estimate) of infants aged 0-4 months for a nonfatal fall-related fractured skull between 2001 and 2017. Most were younger than 2 months (46.7%) and male (54.4%). Falls occurred primarily in the home (69.9%) and required hospitalization (76.4%). Primary caregiver actions coded involved placing (58.6%), dropping (22.7%), and carrying an infant (16.6%). Floor surfaces were the most common product (mentioned in 24.0% of the cases). CONCLUSIONS Fall-related fractured skulls are a health and developmental concern for infants, highlighting the importance of a comprehensive assessment at the time of the injury to better understand adult actions. Findings indicated the need to develop prevention messages that include safe carrying and placement of infants.
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Affiliation(s)
- Juliet Haarbauer-Krupa
- Division of Injury Prevention, National Center for Injury Prevention and Control, Centers for Disease Control and Prevention, Atlanta, Georgia.
| | - Tadesse Haileyesus
- Division of Injury Prevention, National Center for Injury Prevention and Control, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Alexis B Peterson
- Division of Injury Prevention, National Center for Injury Prevention and Control, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Lindsay S Womack
- Division of Injury Prevention, National Center for Injury Prevention and Control, Centers for Disease Control and Prevention, Atlanta, Georgia; U.S. Public Health Service, Rockville, Maryland
| | - Kent Hymel
- Department of Pediatrics, Penn State Health Children's Hospital, Hershey, Pennsylvania
| | - Marzieh Hajiaghamemar
- Department of Biomedical Engineering, University of Texas at San Antonio, San Antonio, Texas
| | - Joanne Klevens
- Division of Violence Prevention, National Center for Injury Prevention and Control, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Daniel Lindberg
- Department of Emergency Medicine, University of Colorado Medical School, Aurora, Colorado
| | - Susan S Margulies
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia
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Isaac R, Greeley C, Marinello M, Herman BE, Frazier TN, Carroll CL, Armijo-Garcia V, Musick M, Weeks K, Haney SB, Wang M, Hymel KP. Skeletal survey yields in low vs. high risk pediatric patients with skull fractures. CHILD ABUSE & NEGLECT 2023; 139:106130. [PMID: 36905686 PMCID: PMC10120383 DOI: 10.1016/j.chiabu.2023.106130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/17/2023] [Accepted: 03/01/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND To assess for occult fractures, physicians often opt to obtain skeletal surveys (SS) in young, acutely head-injured patients who present with skull fractures. Data informing optimal decision management are lacking. OBJECTIVE To determine the positive yields of radiologic SS in young patients with skull fractures presumed to be at low vs. high risk for abuse. PARTICIPANTS AND SETTING 476 acutely head injured, skull-fractured patients <3 years hospitalized for intensive care across 18 sites between February 2011 and March 2021. METHODS We conducted a retrospective, secondary analysis of the combined, prospective Pediatric Brain Injury Research Network (PediBIRN) data set. RESULTS 204 (43 %) of 476 patients had simple, linear, parietal skull fractures. 272 (57 %) had more complex skull fracture(s). Only 315 (66 %) of 476 patients underwent SS, including 102 (32 %) patients presumed to be at low risk for abuse (patients who presented with a consistent history of accidental trauma; intracranial injuries no deeper than the cortical brain; and no respiratory compromise, alteration or loss of consciousness, seizures, or skin injuries suspicious for abuse). Only one of 102 low risk patients revealed findings indicative of abuse. In two other low risk patients, SS helped to confirm metabolic bone disease. CONCLUSIONS Less than 1 % of low risk patients under three years of age who presented with simple or complex skull fracture(s) revealed other abusive fractures. Our results could inform efforts to reduce unnecessary skeletal surveys.
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Affiliation(s)
- Reena Isaac
- Department of Pediatrics, Baylor College of Medicine, Texas Children's Hospital, 6621 Fannin St., Houston, TX 77030, USA.
| | - Christopher Greeley
- Department of Pediatrics, Baylor College of Medicine, Texas Children's Hospital, 6621 Fannin St., Houston, TX 77030, USA
| | - Mark Marinello
- Department of Pediatrics, Children's Hospital of Richmond at VCU, 1250 East Marshall Street, Richmond, VA 23219, USA
| | - Bruce E Herman
- Department of Pediatrics, University of Utah School of Medicine, Primary Children's Hospital, Salt Lake City, UT 84113, USA
| | - Terra N Frazier
- Department of Pediatrics, Children's Mercy Hospital, 2401 Gillham Road, Kansas City, MO 64108, USA
| | - Christopher L Carroll
- Department of Pediatrics, Connecticut Children's Medical Center, 282 Washington Street, Hartford, CT 06106, USA
| | - Veronica Armijo-Garcia
- University of Texas Health Sciences Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA
| | - Matthew Musick
- Department of Pediatrics, Baylor College of Medicine, Texas Children's Hospital, 6621 Fannin St., Houston, TX 77030, USA
| | - Kerri Weeks
- Department of Pediatrics, University of Kansas School of Medicine, 3243 East Murdoch, Wichita, KS 67208, USA
| | - Suzanne B Haney
- Department of Pediatrics, University of Nebraska Medical Center, Children's Hospital and Medical Center, 8200 Dodge Street, Omaha, NE 68114, USA
| | - Ming Wang
- Department of Public Health Sciences, Penn State College of Medicine, 700 HMC Crescent Road, Hershey, PA 17033, USA
| | - Kent P Hymel
- Department of Pediatrics, Penn State College of Medicine, Penn State Health Children's Hospital, 600 University Drive, Hershey, PA 17033, USA
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Peter C, Stranzinger E, Heverhagen JT, Keitel K, Romano F, Busch JD, Slavova N. Minor head trauma in infants - how accurate is cranial ultrasound performed by trained radiologists? Eur J Pediatr 2023:10.1007/s00431-023-04939-9. [PMID: 37093305 DOI: 10.1007/s00431-023-04939-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 03/08/2023] [Accepted: 03/15/2023] [Indexed: 04/25/2023]
Abstract
Correct management of infants after minor head trauma is crucial to minimize the risk to miss clinically important traumatic brain injury (ciTBI). Current practices typically involve CT or in-hospital surveillance. Cranial ultrasound (CUS) provides a radiation-free and fast alternative. This study examines the accuracy of radiologist-performed CUS to detect skull fracture (SF) and/or intracranial hemorrhage (ICH). An inconspicuous CUS followed by an uneventful clinical course would allow exclusion of ciTBI with a great certainty. This monocentric, retrospective, observational study analyzed CUS in infants (< 12 months) after minor head trauma at Bern University Children's Hospital, between 7/2013 and 8/2020. The primary outcome was the sensitivity and specificity of CUS in detecting SF and/or ICH by comparison to the clinical course and to additional neuroimaging. Out of a total of 325 patients, 73% (n = 241) had a normal CUS, 17% (n = 54) were found with SF, and ICH was diagnosed in 2.2% patients (n = 7). Two patients needed neurosurgery and three patients deteriorated clinically during surveillance. Additional imaging was performed in 35 patients. The sensitivity of CUS was 93% ([0.83, 0.97] 95% CI) and the specificity 98% ([0.95, 0.99] 95% CI). All false-negative cases originated in missed SF without clinical deterioration; no ICH was missed. Conclusion: This study shows high accuracy of CUS in exclusion of SF and ICH, which can cause ciTBI. Therefore, CUS offers a reliable method of neuroimaging in infants after minor head trauma and gives reassurance to reduce the duration of in-hospital surveillance. What is Known: • Minor head trauma can cause clinically important traumatic brain injury in infants, and the management of these cases is a challenge for the treating physician. • Cranial ultrasound (CUS) is regularly used in neonatology, but its accuracy after head trauma in infants is controversial. What is New: • CUS performed by a trained radiologist can exclude findings related to clinically important traumatic brain injury (ciTBI) with high sensitivity and specificity. It therefore offers reassurance in the management of infants after minor head trauma.
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Affiliation(s)
- Claudia Peter
- Department of Diagnostic, Interventional and Pediatric Radiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
| | - Enno Stranzinger
- Department of Diagnostic, Interventional and Pediatric Radiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Johannes T Heverhagen
- Department of Diagnostic, Interventional and Pediatric Radiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Kristina Keitel
- Division of Paediatric Emergency Medicine, Department of Paediatrics, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Fabrizio Romano
- Division of Paediatric Emergency Medicine, Department of Paediatrics, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Jasmin D Busch
- Department of Diagnostic, Interventional and Pediatric Radiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Nedelina Slavova
- Department of Diagnostic, Interventional and Pediatric Radiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Pediatric Radiology, University Children's Hospital (UKBB) Basel and University of Basel, Basel, Switzerland
- Institute of Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
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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] [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.
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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
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Vinchon M, Noulé N, Karnoub MA. The legal challenges to the diagnosis of shaken baby syndrome or how to counter 12 common fake news. Childs Nerv Syst 2022; 38:133-145. [PMID: 34564748 DOI: 10.1007/s00381-021-05357-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 09/05/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND The shaken baby syndrome (SBS) is a common cause of severe traumatic lesions in infants. Although well established for almost five decades, SBS and its diagnosis are becoming more and more aggressively challenged in courts. These challenges feed on the scientific debate and controversies regarding the pathophysiology and the differential diagnoses, scientific uncertainty being readily exploited by specialized barristers. MATERIAL AND METHODS In the present review, we analyze the most common challenges to the concept of SBS and its diagnosis, as well as the scientific evidence available to counter these challenges, the differential diagnoses, and how SBS can be diagnosed with confidence. RESULTS We found that the pathophysiology of SBS is well documented, with stereotyped descriptions by perpetrators, in good correlation with experimental studies and computer models. SBS is a well-defined clinico-pathological entity with a characteristic constellation of lesions; with a rigorous evaluation protocol, its diagnosis can be made rapidly and with excellent accuracy beyond a reasonable doubt. CONCLUSION It is important that medical experts master an extensive knowledge regarding the pathophysiology of the lesions of SBS, in particular infantile subdural hematomas, as well as other CSF-related conditions. This emphasizes the role that pediatric neurosurgeons should play in the clinical and medicolegal management of these patients.
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Affiliation(s)
- Matthieu Vinchon
- Department of Pediatric Neurosurgery, Service de Neurochirurgie Pédiatrique, CHRU de Lille, Lille University Hospital, 59 037, Lille, France.
| | - Nathalie Noulé
- Department of Pediatric Neurosurgery, Service de Neurochirurgie Pédiatrique, CHRU de Lille, Lille University Hospital, 59 037, Lille, France
| | - Melodie-Anne Karnoub
- Department of Pediatric Neurosurgery, Service de Neurochirurgie Pédiatrique, CHRU de Lille, Lille University Hospital, 59 037, Lille, France
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11
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Wang Z, Hu Y, Peng F. Long-Term Trends in Unintentional Fall Mortality in China: A Population-Based Age-Period-Cohort Study. Front Public Health 2021; 9:749295. [PMID: 35024364 PMCID: PMC8744467 DOI: 10.3389/fpubh.2021.749295] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 10/05/2021] [Indexed: 11/22/2022] Open
Abstract
Background: Unintentional falls seriously threaten the life and health of people in China. This study aimed to assess the long-term trends of mortality from unintentional falls in China and to examine the age-, period-, and cohort-specific effects behind them. Methods: This population-based multiyear cross-sectional study of Chinese people aged 0–84 years was a secondary analysis of the mortality data of fall injuries from 1990 to 2019, derived from the Global Burden of Disease Study 2019. Age-standardized mortality rates of unintentional falls by year, sex, and age group were used as the main outcomes and were analyzed within the age-period-cohort framework. Results: Although the crude mortality rates of unintentional falls for men and women showed a significant upward trend, the age-standardized mortality rates for both sexes only increased slightly. The net drift of unintentional fall mortality was 0.13% (95% CI, −0.04 to 0.3%) per year for men and −0.71% (95% CI, −0.96 to −0.46%) per year for women. The local drift values for both sexes increased with age group. Significant age, cohort, and period effects were found behind the mortality trends of the unintentional falls for both sexes in China. Conclusions: Unintentional falls are still a major public health problem that disproportionately threatens the lives of men and women in China. Efforts should be put in place urgently to prevent the growing number of fall-related mortality for men over 40 years old and women over 70 years old. Gains observed in the recent period, relative risks (RRs), and cohort RRs may be related to improved healthcare and better education.
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Affiliation(s)
- Zhenkun Wang
- Outpatient Department, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Department of Scientific Research, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Youzhen Hu
- Outpatient Department, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Department of Emergency, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Fang Peng
- Outpatient Department, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- *Correspondence: Fang Peng
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12
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Li X. Subject-Specific Head Model Generation by Mesh Morphing: A Personalization Framework and Its Applications. Front Bioeng Biotechnol 2021; 9:706566. [PMID: 34733827 PMCID: PMC8558307 DOI: 10.3389/fbioe.2021.706566] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 09/03/2021] [Indexed: 11/30/2022] Open
Abstract
Finite element (FE) head models have become powerful tools in many fields within neuroscience, especially for studying the biomechanics of traumatic brain injury (TBI). Subject-specific head models accounting for geometric variations among subjects are needed for more reliable predictions. However, the generation of such models suitable for studying TBIs remains a significant challenge and has been a bottleneck hindering personalized simulations. This study presents a personalization framework for generating subject-specific models across the lifespan and for pathological brains with significant anatomical changes by morphing a baseline model. The framework consists of hierarchical multiple feature and multimodality imaging registrations, mesh morphing, and mesh grouping, which is shown to be efficient with a heterogeneous dataset including a newborn, 1-year-old (1Y), 2Y, adult, 92Y, and a hydrocephalus brain. The generated models of the six subjects show competitive personalization accuracy, demonstrating the capacity of the framework for generating subject-specific models with significant anatomical differences. The family of the generated head models allows studying age-dependent and groupwise brain injury mechanisms. The framework for efficient generation of subject-specific FE head models helps to facilitate personalized simulations in many fields of neuroscience.
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Affiliation(s)
- Xiaogai Li
- Division of Neuronic Engineering, Department of Biomedical Engineering and Health Systems, KTH Royal Institute of Technology, Stockholm, Sweden
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13
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Yan J, He J, Spear A, Coats B. The Effect of Impact Angle and Fall Height on Skull Fracture Patterns in Infants. J Biomech Eng 2021; 143:071004. [PMID: 33704377 DOI: 10.1115/1.4050460] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Indexed: 11/08/2022]
Abstract
Skull fracture is a common finding for both accidental and abusive head trauma in infants and young children, and may provide important clues as to the energy and directionality of the event leading to the skull fracture. However, little is understood regarding the mechanics of skull fracture in the pediatric skull, and how accidental fall parameters contribute to skull fracture patterns. The objectives of this research were to utilize a newly developed linear elastic fracture mechanics finite element model of infant skull fracture to investigate the effect of impact angle and fall height on the predictions of skull fracture patterns in infants. Nine impact angles of right parietal bone impacts were simulated from three different heights onto a rigid plate. The average ± standard deviation of the distance between the impact location and fracture initiation site was 8.0 ± 5.9 mm. Impact angle significantly affected the fracture initiation site (p < 0.0001) and orientation (p < 0.0001). A 15 deg variation in impact angle changed the initiation site up to 47 mm. The orientation of the fracture pattern was dependent on the impact location and ran either horizontal or vertical toward the ossification center of the bone. Fall height significantly affected the fracture length (p = 0.0356). Specifically, at the same impact angle, a 0.3 m increase in fall height increased the skull fracture length by 21.39 ± 34.26 mm. These data indicate that environmental variability needs to be carefully considered when evaluating infant skull fracture patterns from low-height falls.
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Affiliation(s)
- Jiawei Yan
- Department of Mechanical Engineering, University of Utah, Salt Lake City, UT 84112
| | - Junyan He
- Department of Mechanical Engineering, University of Utah, Salt Lake City, UT 84112
| | - Ashely Spear
- Department of Mechanical Engineering, University of Utah, Salt Lake City, UT 84112
| | - Brittany Coats
- Department of Mechanical Engineering, University of Utah, Salt Lake City, UT 84112
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14
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Metcalf RM, Comstock JM, Coats B. High-Rate Anisotropic Properties in Human Infant Parietal and Occipital Bone. J Biomech Eng 2021; 143:061010. [PMID: 33564856 DOI: 10.1115/1.4050127] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Indexed: 11/08/2022]
Abstract
Computational models of infant head impact are limited by the paucity of infant cranial bone material property data, particularly with regard to the anisotropic relationships created by the trabecular fibers in infant bone. We previously reported high-rate material property data for human infant cranial bone tested perpendicular to trabeculae fiber orientation. In this study, we measure the anisotropic properties of human infant cranial bone by analyzing bending modulus parallel to the trabeculae fibers. We tested human bone specimens from nine donors ranging in age from 32 weeks gestational age to 10 months at strain rates of 12.3-30.1 s-1. Bending modulus significantly increased with donor age (p=0.008) and was 13.4 times greater along the fiber direction compared to perpendicular to the fibers. Ultimate stress was greater by 5.1 times when tested parallel to the fibers compared to perpendicular (p=0.067). Parietal bone had a higher modulus and ultimate stress compared to occipital bone, but this trend was not significant, as previously shown perpendicular to fiber orientation. Combined, these data suggest that the pediatric skull is highly age-dependent, anisotropic, and regionally dependent. The incorporation of these characteristics in finite element models of infant head impact will be necessary to advance pediatric head injury research and further our understanding of the mechanisms of head injury in children.
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Affiliation(s)
- Robert M Metcalf
- Department of Mechanical Engineering, University of Utah, 1495 E 100 S (1550 MEK), Salt Lake City, UT 84112
| | - Jessica M Comstock
- Pediatric Pathology, Primary Children's Hospital, University of Utah, Salt Lake City, Utah 84112
| | - Brittany Coats
- Department of Mechanical Engineering, University of Utah, 1495 E 100 S (1550 MEK), Salt Lake City, UT 84112
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15
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Rowbotham SK, Blumenthal R, Delabarde T, Legrand L, van der Walt E, Sutherland T, Lockhat Z, Arthurs OJ. An evaluation of the differences in paediatric skeletal trauma between fatal simple short falls and physical abuse blunt impact loads: An international multicentre pilot study. Forensic Sci Int 2021; 323:110788. [PMID: 33915490 DOI: 10.1016/j.forsciint.2021.110788] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 03/13/2021] [Accepted: 04/07/2021] [Indexed: 11/15/2022]
Abstract
In cases where a deceased child exhibits trauma as a result of a physical abuse blunt impact load, a parent/caregiver may provide a simple short fall (SSF) as the justification for that trauma. The skeletal fractures remain difficult to differentiate between a SSF and physical abuse however, as both are the result of a blunt impact load, and are therefore biomechanically alike, and the rare nature of these fatalities means only anecdotal research has been available to validate such claims. The aim of this pilot study was to investigate if there may be differences in the skeletal fracture patterns and types resulting from SSFs compared with those resulting from physical abuse blunt impacts. Paediatric (<10 years) cases of fatal SSFs (≤1.5 m) and physical abuse were collected from the Victorian Institute of Forensic Medicine (Australia), Institut Médico-Légal de Paris (France), University of Pretoria (South Africa) and Great Ormond Street Hospital (England). For each case the intrinsic and extrinsic variables were recorded from medico-legal reports and skeletal trauma was documented using post-mortem computed tomography scans and/or skeletal surveys. Three SSFs and 18 physical abuse cases were identified. Of the SSF cases, two exhibited fractures; both of which were simple linear neurocranial fractures. Comparatively, 12 of the physical abuse cases exhibited fractures and these were distributed across the skeleton; 58% located only in the skull, 17% only in the post-cranial and 25% located in both. Skull fracture types were single linear, multiple linear and comminuted. This pilot study suggests, anecdotally, there may be differences in the fracture patterns and types between blunt impact loads resulting from a SSF and physical abuse. This data will form the foundation of the Registry of Paediatric Fatal Fractures (RPFF) which, with further multicentre contributions, would allow this finding to be validated.
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Affiliation(s)
- Samantha K Rowbotham
- Victorian Institute of Forensic Medicine, 65 Kavanagh St, Southbank, Victoria 3006, Australia; Department of Forensic Medicine, Monash University, 65 Kavanagh St, Southbank, Victoria 3006, Australia.
| | - Ryan Blumenthal
- Department of Forensic Medicine, University of Pretoria, Pathology Building, 5 Bophelo Rd, Prinshof Campus, 0084, South Africa
| | - Tania Delabarde
- Institut Médico-Légal de Paris, 2 Voie Mazas, 75012 Paris, France
| | - Laurence Legrand
- Université de Paris, INSERM U1266, Service d'Imagerie Morphologique et Fonctionnelle, GHU Paris Psychiatrie et Neurosciences, Centre Hospitalier Sainte-Anne, 1 Rue Cabanis, 75674 Paris Cedex 14, France
| | - Elizabeth van der Walt
- Department of Radiology, University of Pretoria, Steve Biko Academic Hospital, Malherbe St, Riviera, Pretoria 0001, South Africa
| | - Tom Sutherland
- St Vincent's Hospital, 9 Princes St, Fitzroy, Victoria 3065, Australia; Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Gratton St, Melbourne 3010, Australia; Victorian Institute of Forensic Medicine, 65 Kavanagh St, Southbank, Victoria 3006, Australia
| | - Zarina Lockhat
- Department of Radiology, University of Pretoria, Steve Biko Academic Hospital, Malherbe St, Riviera, Pretoria 0001, South Africa
| | - Owen J Arthurs
- NIHR Great Ormond Street Hospital Biomedical Research Centre, London WC1N 3JH, United Kingdom; UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, United Kingdom
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16
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Hajiaghamemar M, Margulies SS. Multi-Scale White Matter Tract Embedded Brain Finite Element Model Predicts the Location of Traumatic Diffuse Axonal Injury. J Neurotrauma 2020; 38:144-157. [PMID: 32772838 DOI: 10.1089/neu.2019.6791] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Finite element models (FEMs) are used increasingly in the traumatic brain injury (TBI) field to provide an estimation of tissue responses and predict the probability of sustaining TBI after a biomechanical event. However, FEM studies have mainly focused on predicting the absence/presence of TBI rather than estimating the location of injury. In this study, we created a multi-scale FEM of the pig brain with embedded axonal tracts to estimate the sites of acute (≤6 h) traumatic axonal injury (TAI) after rapid head rotation. We examined three finite element (FE)-derived metrics related to the axonal bundle deformation and three FE-derived metrics based on brain tissue deformation for prediction of acute TAI location. Rapid head rotations were performed in pigs, and TAI neuropathological maps were generated and colocalized to the FEM. The distributions of the FEM-derived brain/axonal deformations spatially correlate with the locations of acute TAI. For each of the six metric candidates, we examined a matrix of different injury thresholds (thx) and distance to actual TAI sites (ds) to maximize the average of two optimization criteria. Three axonal deformation-related TAI candidates predicted the sites of acute TAI within 2.5 mm, but no brain tissue metric succeeded. The optimal range of thresholds for maximum axonal strain, maximum axonal strain rate, and maximum product of axonal strain and strain rate were 0.08-0.14, 40-90, and 2.0-7.5 s-1, respectively. The upper bounds of these thresholds resulted in higher true-positive prediction rate. In summary, this study confirmed the hypothesis that the large axonal-bundle deformations occur on/close to the areas that sustained TAI.
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Affiliation(s)
- Marzieh Hajiaghamemar
- Department of Biomedical Engineering, University of Texas at San Antonio, San Antonio, Texas, USA.,Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA
| | - Susan S Margulies
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA
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17
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Brooks T, Zwirner J, Hammer N, Ondruschka B, Jermy M. Preliminary observations of the sequence of damage in excised human juvenile cranial bone at speeds equivalent to falls from 1.6 m. Int J Legal Med 2020; 135:527-538. [PMID: 32865692 DOI: 10.1007/s00414-020-02409-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 08/21/2020] [Indexed: 11/29/2022]
Abstract
There is much debate within the forensic community around the indications that suggest a head injury sustained by a child resulted from abusive head trauma, rather than from accidental causes, especially when a fall from low height is the explanation given by a caregiver. To better understand this problem, finite element models of the paediatric head have been and continue to be developed. These models require material models that fit the behaviour of paediatric head tissues under dynamic loading conditions. Currently, the highest loading rate for which skull data exists is 2.81 ms-1. This study improves on this by providing preliminary experimental data for a loading rate of 5.65 ± 0.14 ms-1, equivalent to a fall of 1.6 m. Eleven specimens of paediatric cranial bone (frontal, occipital, parietal and temporal) from seven donors (age range 3 weeks to 18 years) were tested in three-point bending with an impactor of radius 2 mm. It was found that prompt brittle fracture with virtually no bending occurs in all specimens but those aged 3 weeks old, where bending preceded brittle fracture. The maximum impact force increased with age (or thickness) and was higher in occipital bone. Energy absorbed to failure followed a similar trend, with values 0.11 and 0.35 mJ/mm3 for age 3 weeks, agreeing with previously published static tests, increasing with age up to 9 mJ/mm3 for 18-year-old occipital bone. The preliminary data provided here can help analysts improve paediatric head finite element models that can be used to provide better predictions of the nature of head injuries from both a biomechanical and forensic point of view.
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Affiliation(s)
- Tom Brooks
- Department of Mechanical Engineering, University of Canterbury, Christchurch, New Zealand
| | - Johann Zwirner
- Department of Anatomy, University of Otago, Dunedin, New Zealand
| | - Niels Hammer
- Department of Macroscopic and Clinical Anatomy, Medical University of Graz, Graz, Austria.,Department of Orthopedic and Trauma Surgery, University of Leipzig, Leipzig, Germany.,Fraunhofer IWU, Dresden, Germany
| | - Benjamin Ondruschka
- Institute of Legal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Mark Jermy
- Department of Mechanical Engineering, University of Canterbury, Christchurch, New Zealand.
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18
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Hajiaghamemar M, Wu T, Panzer MB, Margulies SS. Embedded axonal fiber tracts improve finite element model predictions of traumatic brain injury. Biomech Model Mechanobiol 2020; 19:1109-1130. [PMID: 31811417 PMCID: PMC7203590 DOI: 10.1007/s10237-019-01273-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 11/29/2019] [Indexed: 12/23/2022]
Abstract
With the growing rate of traumatic brain injury (TBI), there is an increasing interest in validated tools to predict and prevent brain injuries. Finite element models (FEM) are valuable tools to estimate tissue responses, predict probability of TBI, and guide the development of safety equipment. In this study, we developed and validated an anisotropic pig brain multi-scale FEM by explicitly embedding the axonal tract structures and utilized the model to simulate experimental TBI in piglets undergoing dynamic head rotations. Binary logistic regression, survival analysis with Weibull distribution, and receiver operating characteristic curve analysis, coupled with repeated k-fold cross-validation technique, were used to examine 12 FEM-derived metrics related to axonal/brain tissue strain and strain rate for predicting the presence or absence of traumatic axonal injury (TAI). All 12 metrics performed well in predicting of TAI with prediction accuracy rate of 73-90%. The axonal-based metrics outperformed their rival brain tissue-based metrics in predicting TAI. The best predictors of TAI were maximum axonal strain times strain rate (MASxSR) and its corresponding optimal fraction-based metric (AF-MASxSR7.5) that represents the fraction of axonal fibers exceeding MASxSR of 7.5 s-1. The thresholds compare favorably with tissue tolerances found in in-vitro/in-vivo measurements in the literature. In addition, the damaged volume fractions (DVF) predicted using the axonal-based metrics, especially MASxSR (DVF = 0.05-4.5%), were closer to the actual DVF obtained from histopathology (AIV = 0.02-1.65%) in comparison with the DVF predicted using the brain-related metrics (DVF = 0.11-41.2%). The methods and the results from this study can be used to improve model prediction of TBI in humans.
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Affiliation(s)
- Marzieh Hajiaghamemar
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, U.A. Whitaker Building, 313 Ferst Drive, Atlanta, GA, 30332, USA.
| | - Taotao Wu
- Department of Mechanical and Aerospace Engineering, University of Virginia, 4040 Lewis and Clark Dr., Charlottesville, VA, 22911, USA
| | - Matthew B Panzer
- Department of Mechanical and Aerospace Engineering, University of Virginia, 4040 Lewis and Clark Dr., Charlottesville, VA, 22911, USA
| | - Susan S Margulies
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, U.A. Whitaker Building, 313 Ferst Drive, Atlanta, GA, 30332, USA
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19
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Pasquesi SA, Seidi M, Hajiaghamemar M, Margulies SS. Predictions of neonatal porcine bridging vein rupture and extra-axial hemorrhage during rapid head rotations. J Mech Behav Biomed Mater 2020; 106:103740. [PMID: 32250951 DOI: 10.1016/j.jmbbm.2020.103740] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 02/07/2020] [Accepted: 02/26/2020] [Indexed: 11/17/2022]
Abstract
When the head is rotated rapidly, the movement of the brain lags that of the skull. Intracranial contents between the brain and skull include meninges, cerebrospinal fluid (CSF), and cerebral vasculature. Among the cerebral vasculature in this space are the parasagittal bridging veins (BVs), which drain blood from the brain into the superior sagittal sinus (SSS), which is housed within the falx cerebri, adhered to the inner surface of the skull. Differential motion between the brain and skull that may occur during a traumatic event is thought to stretch BVs, causing damage and producing extra-axial hemorrhage (EAH). Finite element (FE) modeling is a technique often used to aid in the understanding and prediction of traumatic brain injury (TBI), and estimation of tissue deformation during traumatic events provides insight into kinematic injury thresholds. Using a FE model of the newborn porcine head with neonatal porcine brain and BV properties, single and cyclic rapid head rotations without impact were simulated. Measured BV failure properties were used to predict BV rupture. By comparing simulation outputs to observations of EAH in a development group of in vivo studies of rapid non-impact head rotations in the piglet, it was determined that failure of 16.7% of BV elements was associated with a 50% risk of EAH, and showed in a separate validation group that this threshold predicted the occurrence of EAH with 100% sensitivity and 100% specificity for single rapid non-impact rotations. This threshold for failed BV elements performed with 90% overall correct prediction in simulations of cyclic rotational head injuries. A 50% risk of EAH was associated with head angular velocities of 94.74 rad/s and angular accelerations of 29.60 krad/s2 in the newborn piglet. Future studies may build on these findings for BV failure in the piglet to develop predictive models for BV failure in human infants.
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Affiliation(s)
| | - Morteza Seidi
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, USA
| | - Marzieh Hajiaghamemar
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, USA
| | - Susan S Margulies
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, USA.
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20
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Hajiaghamemar M, Seidi M, Margulies SS. Head Rotational Kinematics, Tissue Deformations, and Their Relationships to the Acute Traumatic Axonal Injury. J Biomech Eng 2020; 142:031006. [PMID: 32073595 PMCID: PMC7104750 DOI: 10.1115/1.4046393] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Revised: 02/07/2020] [Indexed: 12/11/2022]
Abstract
Head rotational kinematics and tissue deformation metrics obtained from finite element models (FEM) have the potential to be used as traumatic axonal injury (TAI) assessment criteria and headgear evaluation standards. These metrics have been used to predict the likelihood of TAI occurrence; however, their ability in the assessment of the extent of TAI has not been explored. In this study, a pig model of TAI was used to examine a wide range of head loading conditions in two directions. The extent of TAI was quantified through histopathology and correlated to the FEM-derived tissue deformations and the head rotational kinematics. Peak angular acceleration and maximum strain rate of axonal fiber and brain tissue showed relatively good correlation to the volume of axonal injury, with similar correlation trends for both directions separately or combined. These rotational kinematics and tissue deformations can estimate the extent of acute TAI. The relationships between the head kinematics and the tissue strain, strain rate, and strain times strain rate were determined over the experimental range examined herein, and beyond that through parametric simulations. These relationships demonstrate that peak angular velocity and acceleration affect the underlying tissue deformations and the knowledge of both help to predict TAI risk. These relationships were combined with the injury thresholds, extracted from the TAI risk curves, and the kinematic-based risk curves representing overall axonal and brain tissue strain and strain rate were determined for predicting TAI. After scaling to humans, these curves can be used for real-time TAI assessment.
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Affiliation(s)
- Marzieh Hajiaghamemar
- Wallace H. Coulter Department of Biomedical Engineering,
Georgia Institute of Technology and Emory University,
Atlanta, GA 30332
e-mail:
| | - Morteza Seidi
- Wallace H. Coulter Department of Biomedical Engineering,
Georgia Institute of Technology and Emory University,
Atlanta, GA 30332
e-mail:
| | - Susan S. Margulies
- Wallace H. Coulter Department of Biomedical Engineering,
Georgia Institute of Technology and Emory University,
Atlanta, GA 30332
e-mail:
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