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Experimental and computational approach to human brain modelling – aHEAD

Ptak Mariusz, Dymek Mateusz, Sawicki Marek, Fernandes Fábio A. O., Wnuk Maciej, Wilhelm Johannes, Ratajczak Monika, Witkowska Daria, Kwiatkowski Artur, Poźniak Błażej, Kubicki Konrad, Tikhomirov Marta, Druszcz Adam, Chybowski Leszek

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 3

art. no. e218, 2023

EN

The human head is a highly complex structure, with a combination of hard and soft tissues and a variety of materials and interactions. Many researchers have used computational approaches to model the head, and several human finite element head models can be found in the literature. However, most of them are not geometrically accurate – for instance, the brain is simplified to a smooth spherical volume, which poses some concerns regarding boundary conditions and geometrical accuracy. Therefore, an advanced head model of a 28-year-old, designated as aHEAD 28 yo (aHEAD: advanced Head models for safety Enhancement And medical Development), has been developed. The model consists entirely of hexahedral elements for 3D structures of the head such as the cerebellum, skull and cerebrum, with detailed geometry of the gyri and sulci. Additionally, it is one of the first human head approaches published in the literature that includes cerebrospinal fluid simulated by Smoothed Particle Hydrodynamics (SPH) and a detailed model of pressurized bridging veins. To support the model’s credibility, this study is focused on physical material testing. A novel comprehensive experimental-computational approach is presented, which involves the brain tissue’s response to induced vibrations. The experiment successfully aimed to validate the material models used in the numerical analysis. Additionally, the authors present a kinematical model validation based on the Hardy experimental cadaver test. The developed model, along with its verification, aims to establish a further benchmark in finite element head modelling and can potentially provide new insights into injury mechanisms.

2

Finite element head model for the crew injury assessment in a light armoured vehicle

Burkacki Michał, Wolański Wojciech, Suchoń Sławomir, Joszko Kamil, Gzik-Zroska Bożena, Sybilski Kamil, Gzik Marek

Acta of Bioengineering and Biomechanics

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2020

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Vol. 22, no. 2

173--183

EN

Purpose: The aim of this paper was the development of a finite element model of the soldier’s head to assess injuries suffered by soldiers during blast under a light armoured vehicle. Methods: The application of a multibody wheeled armoured vehicle model, including the crew and their equipment, aenabled the researchers to analyse the most dangerous scenarios of the head injury. These scenarios have been selected for a detailed analysis using the finite element head model which allowed for the examination of dynamic effects on individual head structures. In this paper, the authors described stages of the development of the anatomical finite element head model. Results: The results of the simulations made it possible to assess parameters determining the head injury of the soldier during the IED explosion. The developed model allows the determination of the parameters of stress, strain and pressure acting on the structures of the human head. Conclusion: In future studies, the model will be used to carry out simulations which will improve the construction of the headgear in order to minimize the possibility of the head injury.

3

Wpływ warunków testu odwzorowującego zderzenie boczne pojazdu w aspekcie zachowania antropomorficznego manekina dziecka

Baranowski P., Damaziak K., Małachowski J., Mazurkiewicz Ł., Muszyński A.

Logistyka

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2015

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nr 4

2364--2371, CD2

PL

W pracy przedstawiono numeryczne symulacje dwóch przypadków uderzenia bocznego i zachowanie ATD w obu tych przypadkach. Jeden przypadek odpowiada procedurze homologacji urządzeń przytrzymujących zdefiniowane według nowo wprowadzonego Regulaminu 129 EKG/ONZ. Drugi przypadek odpowiada uderzeniu od strony przeciwnej do strony mocowania fotelika. Uzyskane wyniki pokazują, że test homologacyjny zdefiniowany w regulacji nie musi odpowiadać najbardziej niekorzystnym warunkom zderzenia. Wskazano też, że ewentualna poprawa wyniku testu dla danego urządzenia przytrzymującego jest relatywnie prosta, podczas gdy poprawa bezpieczeństwa przy uderzeniu od strony przeciwnej wymaga znacznie większych nakładów związanych ze świadomym zaprojektowaniem stref o określonej sztywności.

EN

The paper presents numerical simulations of two cases of side impact and behavior of ATD in both cases. One case corresponds to the procedure of approval of restraining devices defined in the newly introduced UN / ECE Regulation 129. The second case corresponds to the impact from the side opposite the seat mounting. The results show that the side impact test defined in the new Regulation, does not necessarily correspond to the most unfavorable conditions of the collision. It was also indicated that the possible improvement of the restraint device with respect to test results is relatively simple. On the other hand, improving safety when hitting from the opposite side is far more difficult, since it is associated with the design of specific stiffness zones.

4

Analiza wpływu zastosowanego elementu energochłonnego mającego bezpośredni kontakt z głową dziecka w aspekcie minimalizacji obciążeń dynamicznych

Baranowski P., Bogusz P., Damaziak K., Małachowski J., Mazurkiewicz Ł., Muszyński A.

Logistyka

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2015

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nr 4

2355--2363, CD2

PL

W pracy przedstawiono numeryczne symulacje trzech przypadków uderzenia bocznego oraz zbadano zachowanie się manekina, a w szczególności obciążeń dynamicznych działających na jego głowę. Przeprowadzone symulacje numeryczne odpowiadają procedurze homologacji urządzeń przytrzymujących zdefiniowane według nowo wprowadzonego Regulaminu 129 EKG/ONZ. Przetestowano trzy rodzaje materiałów dla zagłówka o odmiennych parametrach sztywnościowych. Na drodze analiz komputerowych wykazano, że ewentualna modyfikacja cech materiałowych elementu wchodzącego bezpośrednio w kontakt z głową dziecka, może zminimalizować skutki zderzenia bocznego.

EN

In the paper numerical simulations of three cases of side impact are presented. Dummy behavior was also investigated with the particular attention pointed on the dynamic loads acting on its head. Analyses correspond to the procedure of approval of restraining devices defined in the newly introduced UN / ECE Regulation 129. Three materials with different stiffness properties were adopted for the headrest were tested and compared. Thanks to the computational methods it was shown that the possible modification of material properties of the energy-consuming element directly in contact with the head of child can minimize the effects of side impact.

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A comparison of neck bending and flexion measurement methods for assessment of ergonomic risk

Zare M., Biau S., Gourlay A., Roquelaure Y.

International Journal of Occupational Safety and Ergonomics

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2015

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Vol. 21, No. 3

330--335

EN

Head movements of workers were measured in the sagittal plane in order to establish a precise and accurate assessment method to be used in real work situations. Measurements were performed using two inclinometers connected to an embedded recording system. Two quantitative analysis methods were tested, i.e., measurement of bending with an inclinometer attached to the head, and measurement of flexion/extension by using an additional inclinometer located at C7/T1. The results were also compared with a video observation method (qualitative). The results showed that bending measurements were significantly different from those of flexion/extension for angles between 0° and 20°, and angles >45°. There were also significant differences between workers for flexion >45°, reflecting individual variability. Additionally, several limitations of observational methods were revealed by this study.

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An ellipsoidal model for studying response of head impacts

Heydari M., Jani S.

Acta of Bioengineering and Biomechanics

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2010

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Vol. 12, no. 1

47-53

EN

The objective of this study was to propose a new analytical model for studying response of head impacts. Head is modeled by fluidfilled ellipsoidal shell of inconstant thickness impacted by a solid elastic sphere. Modeling the head as an ellipsoid is more realistic than modeling it as a sphere, the previous model existing in the literature [3]–[8]. In this model, the effect of Hertzian contact stiffness and local shell stiffness are combined to derive explicit equations for impact duration, the peak force transmitted to head, and the head injury criterion. One of the advantages of the model presented is sensitivity to the site of impact. A comparison between the present analytical results with the analytical data from spherical model [8] has been done to verify the validation of the present model.

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The influence of hitting the head with a ball on cervical spine response

Gzik M., Tejszerska D., Wolański W., Potkowa P.

Modelling and Optimization of Physical Systems

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2007

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z. 6

65--70

EN

The researches concerning internal forces in cervical spine in situation corresponding to head hit with balls having different masses and sizes are presented in this paper. In order to aim research realization flat model of human upper body was formulated. The model consists: a head, cervical spine, torso and muscles. Risk of sustained injuries has been estimated qualitatively on the basis of results obtained from Working Model 2D software.

PL

W artykule przedstawiono badania dotyczące obciążeń wewnętrznych występujących w odcinku szyjnym kręgosłupa podczas uderzenia piłką w głowę. Ruch analizowano w płaszczyźnie czołowej na podstawie płaskiego modelu człowieka uwzględniającego głowę, kręgi odcinka szyjnego kręgosłupa oraz tułów sformułowanym w programie Working Model 2D. Rozpatrywano szereg przypadków uderzenia, zmieniając prędkości oraz rodzaje piłek (siatkowa, nożna oraz lekarska). Ocenę zagrożeń urazami przeprowadzono w oparciu o jakościową analizę otrzymanych wyników.