scholarly journals Ballistic trauma caused by military rifles: experimental study based on synthetic skull proxies

2022 ◽  
Author(s):  
Seth C. Taylor ◽  
Benjamin Ondruschka ◽  
David C. Kieser ◽  
Niels Hammer ◽  
Matthew Lee ◽  
...  
Keyword(s):  
Expert Knowledge ◽  
Experimental Studies ◽  
Human Head ◽  
Damage Pattern ◽  
Entrance Wound ◽  
Entry Wound ◽  
Close Range ◽  
Full Metal Jacket ◽  
Wound Morphology ◽  
Ballistic Trauma

AbstractRifles are often involved in violent deaths such as homicide and suicide. Consequently, expert knowledge and experimental forensic investigations are important to clarify the nature of ballistic trauma when applied to the human head and neurocranium. This study investigated differences in entrance wound morphology with Synbone® spheres which are described as being comparable to human flat bones. A series of ballistic experiments were conducted using two different rifle calibers (5.56 × 45 mm and 7.62 × 39 mm Full Metal Jacket (FMJ)). Synbone® spheres were used for close-range 0.3 m simulated executions as well as at 25 m and 35 m to simulate urban and military engagements. Results were compared with previously published experimental studies using similar military ammunition. In our study, entry wound morphology closely resembles real forensic cases compared to exit wound and overall shape morphology independently of the distance and the caliber. Circumferential delamination was clearly visible with full metal jacket (FMJ) rounds, yielding similar damage pattern morphology to the human crania. This study documented the presence of hydraulic burst or shock in all ten rounds from all three distances. Krönlein shots were also observed in some cases. Synbone® spheres constitute an acceptable synthetic surrogate for ballistic experiments. The present study offers new initial data on the behavior of Synbone® proxies in ballistic testing of military ammunitions; FMJ gunshot injuries to the human head, for distances that have not previously been published, suggesting that efficient tests can take place under these conditions. Further research on experimental ballistics with a larger number of controlled factors and multiple repetitions is recommended to verify the results of this pilot study before applied in forensic simulations.

Viability of Bos taurus scapulae as a flat bone proxy for ballistic testing

2020 ◽  
pp. jramc-2019-001369 ◽  
Author(s):  
Seth C Taylor ◽  
D C Kieser ◽  
N Hammer ◽  
B Ondruschka ◽  
E Kranioti ◽  
...  
Keyword(s):  
Bos Taurus ◽  
Closed Range ◽  
Exit Wound ◽  
Entrance Wound ◽  
Flat Bone ◽  
Bone Damage ◽  
Series Of Experiments ◽  
Full Metal Jacket ◽  
Bone Section ◽  
Wound Morphology

BackgroundHandguns and rifles are often involved in violent deaths such as homicide and suicide. Consequently, forensic investigations are important to clarify the nature of ballistic trauma.MethodsThis study investigated the differences in entrance and exit wound morphology with Bos taurus (bovine) scapulae that have two cortical layers surrounding a central cancellous bone section which are comparable with human flat bones, with a series of experiments using six different calibres (0.22 Long Rifle, 9×19 mm North Atlantic Treaty Organization, 0.40 Smith & Wesson, 0.45 Automatic Colt Pistol, 5.56×45 mm and 7.62×51 mm). B. taurus (bovine) scapulae were used for closed range 30 cm simulated executions.ResultsThe ballistic experiments presented similarities in entrance wound morphology and exit wound bevelling with that of recognised forensic cases. As muzzle velocity increased, bevelling increased. Circumferential delamination is clearly visible with full metal jacket rounds, yielding similar bone damage morphology as human crania.ConclusionBovine scapulae seem appropriate for ballistic simulations of flat bone injuries on the macroscopic level, if the correct portion of the scapulae is deployed. More research is needed to further substantiate these interpretations.

Microscopic and macroscopic comparisons of 0.223 soft point and full metal jacket ammunition with bos taurus scapulae as a proxy to human flat bones

2020 ◽  
pp. bmjmilitary-2020-001491
Author(s):  
Seth C Taylor ◽  
D C Kieser ◽  
N Hammer ◽  
A Pullen ◽  
G Hooper
Keyword(s):  
Bos Taurus ◽  
Mass Shootings ◽  
Entrance Wound ◽  
Flat Bone ◽  
Different Types ◽  
Low Costs ◽  
The Difference ◽  
Full Metal Jacket ◽  
Wound Morphology ◽  
Soft Point

BackgroundThe prevalence of civilian 0.223 ammunition is widespread. Due to low costs and the same dimensions as a 5.56×45 mm North Atlantic Treaty Organization, this round is exceptionally popular. However, recent mass shootings have employed soft point (SP) expanding ammunition to cause grievous wounds compared with military full metal jacket (FMJ) rounds that do not rapidly expand on impact.MethodsThe aim of this given study is to compare FMJ and SP rounds to determine if there are diagnostic differences between the bullet types in the wounds inflicted to flat bones. Bos taurus scapulae were used for 25 m simulated cranial gunshot injuries. Scanning electron microscopy was employed to assess the difference in wound morphology and elemental analysis between SP and FMJ rounds.ResultsEntrance and exit wound morphology change significantly between the two different types of ammunition as seen with circumferential delamination which is indicative of FMJ rounds and is not seen with the softer SP hunting rounds. Lead staining of the entrance wound is visible on only the SP rounds.ConclusionGunshot flat bone wound morphology is distinctively different between SP and FMJ rounds. Circumferential delamination is only seen with FMJ due to the hardness of the round. Lead staining is only seen with SP rounds due to bullet composition.

scholarly journals Effect of different helmet shell configurations on the protection against head trauma

2019 ◽  
Vol 54 (7-8) ◽  
pp. 408-415 ◽  
Author(s):  
Marta Palomar ◽  
Ricardo Belda ◽  
Eugenio Giner
Keyword(s):  
Head Trauma ◽  
High Speed ◽  
Composite Shell ◽  
Human Head ◽  
High Rate ◽  
Finite Element Models ◽  
High Speed Impact ◽  
Full Metal Jacket ◽  
The Impact ◽  
Single Combat

Head trauma following a ballistic impact in a helmeted head is assessed in this work by means of finite element models. Both the helmet and the head models employed were validated against experimental high-rate impact tests in a previous work. Four different composite ply configurations were tested on the helmet shell, and the energy absorption and the injury outcome resulting from a high-speed impact with full metal jacket bullets were computed. Results reveal that hybrid aramid–polyethylene configurations do not prevent bullet penetration at high velocities, while 16-layer aramid configurations are superior in dissipating the energy absorbed from the impact. The fabric orientation of these laminates proved to be determinant for the injury outcome, as maintaining the same orientations for all the layers led to basilar skull fractures (dangerous), while alternating orientation of the adjacent plies resulted in an undamaged skull. To the authors knowledge, no previous work in the literature has analysed numerically the influence of different stack configurations on a single combat helmet composite shell on human head trauma.

Model of local temperature changes in brain upon functional activation

2004 ◽  
Vol 97 (6) ◽  
pp. 2051-2055 ◽  
Author(s):  
Christopher M. Collins ◽  
Michael B. Smith ◽  
Robert Turner
Keyword(s):  
Brain Temperature ◽  
Human Subjects ◽  
Potential Temperature ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Human Head ◽  
Bioheat Equation ◽  
Three Dimensional Model ◽  
Temperature Changes ◽  
Blood Temperature

Experimental results for changes in brain temperature during functional activation show large variations. It is, therefore, desirable to develop a careful numerical model for such changes. Here, a three-dimensional model of temperature in the human head using the bioheat equation, which includes effects of metabolism, perfusion, and thermal conduction, is employed to examine potential temperature changes due to functional activation in brain. It is found that, depending on location in brain and corresponding baseline temperature relative to blood temperature, temperature may increase or decrease on activation and concomitant increases in perfusion and rate of metabolism. Changes in perfusion are generally seen to have a greater effect on temperature than are changes in metabolism, and hence active brain is predicted to approach blood temperature from its initial temperature. All calculated changes in temperature for reasonable physiological parameters have magnitudes <0.12°C and are well within the range reported in recent experimental studies involving human subjects.

scholarly journals Imaging of Conductivity Changes of Excitable Tissues Based on Focused Passive Microwave

2015 ◽  
Vol 9 (1) ◽  
pp. 138-145 ◽  
Author(s):  
Irene Karanasiou
Keyword(s):  
Functional Organization ◽  
Imaging System ◽  
Experimental Studies ◽  
Human Head ◽  
Black Body Radiation ◽  
Human Volunteer ◽  
Microwave Radiometry ◽  
Spatial Average ◽  
Ellipsoidal Cavity ◽  
Detection Depth

Aims:Modeling of ionic distribution fluctuations of excitable tissues based on data elicited using focused microwave radiometry.Methodology:Focused Microwave Radiometry implemented to carry out measurements of in depth body temperature distributions, may provide the capability of sensing local electrical conductivity fluctuations during the cycle of actions potentials in the case of brain excitable cell clusters. An analog beamformer consisting of a conductive inner-surface ellipsoidal cavity is used to focus the chaotic-black body radiation emerging from human tissues by providing convergence of the electromagnetic energy from one focus area where the phantom or subject is placed, to the other where the antennas of sensitive radiometric receivers are positioned. During the past 10 years numerous phantom, animal and human volunteer experiments have been performed with the focused radiometry imaging system. The results show that the detected changes of the output radiometric voltage are attributed to temperature and/or conductivity changes that occur locally concentrated at the areas of interest under measurement. Theoretical and experimental studies are continuously carried out at various frequency bands in conjunction with the use of matching materials placed around the human head or phantom to improve focusing and detection depth. It seems that the manipulation of the focusing area in the tissue in terms of detection depth and spatial resolution is feasible depending on the suitable combination of operation frequencies and matching material. In this paper, theoretical analysis of ion charge diffusion during the cycle of action potentials, propagating along the axons in case of measurements of specific cortical regions is presented. The ion charge diffusion modeling is based on electromagnetic diffusion analogies in the effort to explain the observed experimental results obtained under various psychophysiological conditions in the case of human volunteer measurements.Results:By implementing an analysis based on the continuity equations of ionic charges it is concluded that the microwave radiometry output voltage is not affected by the temporal and spatial average fluctuations of Na+, K+, and Cl-ions of neural cell axons.Conclusion:The analysis of conductivity fluctuations in the central neural system in conjunction with the electromagnetic analysis of the system, leads to the interpretation of the previously acquired experimental data. The application of this technique with other brain functional mapping methods, may provide complementary knowledge to the understanding of the functional organization of psychophysiological processes.

About the traumatic ring around the entrance hole of the gunshot wounds

1927 ◽  
Vol 23 (1) ◽  
pp. 132-133
Author(s):  
A. D. Grigoriev
Keyword(s):  
Centrifugal Force ◽  
Gunshot Wounds ◽  
Long Distance ◽  
Entrance Wound ◽  
Close Range ◽  
Entrance Hole

The author points out that when shots are fired at a long distance, the bullet, having traveled a long distance, loses its centrifugal force and acts only percussively, more slowly passing through the thickness of tissues and injuring them much more than when fired at close range, so that a traumatic ring is formed in the circumference of the entrance wound.

Approach for the Automated Analysis of Geometrical Clinch Joint Characteristics

2021 ◽  
Vol 883 ◽  
pp. 105-110
Author(s):  
Christoph Zirngibl ◽  
Benjamin Schleich
Keyword(s):  
Cost Efficiency ◽  
Expert Knowledge ◽  
Learning Algorithm ◽  
Experimental Studies ◽  
Automated Analysis ◽  
Environmental Friendliness ◽  
Mechanical Joining ◽  
Geometrical Characteristics ◽  
Analysis Process ◽  
Joint Characteristics

Due to their cost-efficiency and environmental friendliness, the demand of mechanical joining processes is constantly rising. However, the dimensioning and design of joints and suitable processes are mainly based on expert knowledge and few experimental data. Therefore, the performance of numerical and experimental studies enables the generation of optimized joining geometries. However, the manual evaluation of the results of such studies is often highly time-consuming. As a novel solution, image segmentation and machine learning algorithm provide methods to automate the analysis process. Motivated by this, the paper presents an approach for the automated analysis of geometrical characteristics using clinching as an example.

Mechanical Response of the Brain Under Blast: The Effect of Blast Direction and the Head Protection

2016 ◽  
Author(s):  
Hesam Sarvghad-Moghaddam ◽  
Asghar Rezaei ◽  
Ashkan Eslaminejad ◽  
Mariusz Ziejewski ◽  
Ghodrat Karami
Keyword(s):  
Brain Injury ◽  
Mechanical Response ◽  
Experimental Studies ◽  
Human Head ◽  
Blast Waves ◽  
Arbitrary Lagrangian Eulerian ◽  
Explosion Pressure ◽  
Head Protection ◽  
Coupling Algorithm ◽  
The Brain

Blast-induced traumatic brain injury (bTBI), is defined as a type of acquired brain injury that occurs upon the interaction of the human head with blast-generated high-pressure shockwaves. Lack of experimental studies due to moral issues, have motivated the researchers to employ computational methods to study the bTBI mechanisms. Accordingly, a nonlinear finite element (FE) analysis was employed to study the interaction of both unprotected and protected head models with explosion pressure waves. The head was exposed to the incoming shockwaves from front, back, and side directions. The main goal was to examine the effects of head protection tools and the direction of blast waves on the tissue and kinematical responses of the brain. Generation, propagation, and interactions of blast waves with the head were modeled using an arbitrary Lagrangian-Eulerian (ALE) method and a fluid-structure interaction (FSI) coupling algorithm. The FE simulations were performed using Ls-Dyna, a transient, nonlinear FE code. Side blast predicted the highest mechanical responses for the brain. Moreover, the protection assemblies showed to significantly alter the blast flow mechanics. Use of faceshield was also observed to be highly effective in the front blast due to hindering of shockwaves.

Experimental Studies of Side Impact to the Human Head

1980 ◽  
Author(s):  
A. Nahum ◽  
C. Ward ◽  
E. Raasch ◽  
S. Adams ◽  
D. Schneider
Keyword(s):  
Experimental Studies ◽  
Human Head ◽  
Side Impact

scholarly journals Study of backspatter using high-speed video of experimental gunshots

2020 ◽  
Author(s):  
Christian Schyma ◽  
Fabienne Baumann ◽  
Burkhard Madea ◽  
Walther Gotsmy
Keyword(s):  
Biological Material ◽  
Initial Velocity ◽  
High Speed ◽  
Edge Length ◽  
Surface Material ◽  
Experimental Conditions ◽  
High Speed Video ◽  
Entry Wound ◽  
Close Range ◽  
Wound Ballistic

AbstractBackspatter is biological material that is ejected from the entry wound against the line of fire. This phenomenon was also observed in wound ballistic simulations using so called "reference cubes" (12 cm edge length, 10% gelatin, 4 °C, paint pad beneath the cover). High-speed video records from 102 experimental shots to these target models using full metal jacketed bullets in the calibers .32 auto, .38 special, 9 mm Luger and .357 Magnum were analyzed for chronology, morphological appearance and velocity of fluid ejection. Generally, a short tail splashing of surface material occurred when the bullet was penetrating the target. In 51 shots from distance (≥ 5 cm), regardless of caliber and shot range, a linear jet of fluid started in connection with the first collapse of the temporary cavity. The initial velocity of the jet was measured between 6 and 45 m/s. The jet was streaming on for about 60 to 100 ms with a stochastic deviation of ± 13° to the horizontal. Close range and contact shots showed earlier and faster (up to 330 m/s) backspatter depending on the cartridge and the gap between muzzle and target. Gaseous aerosol-like spray and cone-like spatter indicated an increasing influence of muzzle gases with decreasing shot range. Even under standardized experimental conditions, variations of backspatter were observed in near/contact shots.

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