FIGURE 21 - uploaded by Candice F Cooper
Content may be subject to copyright.
Source publication
Light body armor development for the warfighter is based on trial-and-error testing of prototype designs against ballistic projectiles. Torso armor testing against blast is virtually nonexistent but necessary to ensure adequate mitigation against injury to the heart and lungs. In this paper, we discuss the development of a high-fidelity human torso...
Citations
... By incorporating experimentally observed connections between projectile impact parameters and wound formation, computational models may be developed that simulate an impact event with high fidelity to predict and optimize PPE effectiveness 37,41 . Previously reported ballistic models with lower fidelity concerning the biomechanical complexity of human skin have nonetheless aided PPE design by providing insights such as the human vulnerability and bullet effectiveness at different body locations 42,43 , the threat of behind armor blunt trauma 44 , and the depth of idealized soft tissue penetration by certain ballistic projectiles 45 . However, high-fidelity models of the body, including the skin and constructed with experimental data, represent the ideal platform to test PPE designs 14,41 . ...
Partial-thickness cutaneous injuries distributed over exposed body locations, such as the face and extremities, pose a significant risk of infection, function loss, and extensive scarring. These injuries commonly result from impact of kinetic debris from industrial accidents or blast weaponry such as improvised explosive devices. However, the quantitative connections between partial-thickness injuries and debris attributes (kinetic energy, shape, orientation, etc.) remain unknown, with little means to predict damage processes or design protection. Here we quantitatively characterize damage in near-live human skin after impact by debris-simulating kinetic projectiles at differing impact angles and energies. Impact events are monitored using high-speed and quantitative imaging to visualize skin injuries. These findings are utilized to develop a highly predictive, dynamic computational skin-injury model. Results provide quantitative insights revealing how the dermal-epidermal junction controls more severe wound processes. Findings can illuminate expected wound severity and morbidity risks to inform clinical treatment, and assess effectiveness of emerging personal protective equipment. Berkey and colleagues quantitatively characterized partial-thickness cutaneous injuries after impact from projectiles simulating ballistic fragments. A corresponding damage model was developed to simulate and predict the cutaneous damage from impact, which could guide protective equipment design and clinical treatment.
... V irtual medical avatars with complete internal anatomy can be constructed from medical imaging data and are important for computational analyses such as thermal analysis 1 or projectile injury simulation for design of protective equipment. 2 These medical avatars are generated from imaging data, such as magnetic resonance imaging or computed tomography, which require a substantial amount of time and expense to acquire, process, segment, and label. Recent advances have enabled personalization of avatars by morphing standard sex-specific anatomy to fit a three-dimensional (3D) body surface scan of a warfighter, 3,4 thus greatly accelerating the process of avatar generation. ...
Background:
Virtual representations of human internal anatomy are important for military applications such as protective equipment design, injury severity prediction, thermal analysis, and physiological simulations. High-fidelity volumetric models based on imaging data are typically in static postures, and difficult to utilize in simulations of realistic mission scenarios. This study aimed to investigate a hybrid approach to reposition medical avatars that preserves internal anatomy but allows rapid repositioning of full 3D meshes.
Methods:
A software framework was developed that accepts a medical avatar in a 3D tetrahedral mesh format representing 72 organs and tissues with an articulated skeleton. The skeleton is automatically resized and associated to the avatar using rigging and skinning algorithms inspired by computer animation techniques. Military relevant motions were used for animations. A motion retargeting algorithm was implemented to apply animation to avatars of various sizes, and a motion blending algorithm was implemented to smoothly transition between movements. These algorithms were incorporated into a path generation tool that accepts initial, intermediate, and final coordinates of a multi-segment action along with the specific motion for each segment to synthesize a realistic compound set of movements comprising the animation.
Results:
The developed pipeline for dynamic repositioning of medical avatars was demonstrated. Various complex motions were automatically animated. Retargeting was demonstrated on models of varying sizes. Movements along a path were animated to demonstrate smooth motion transitions. Animation of the full 3D avatar mesh ran in real-time on a standard desktop PC. The repositioning algorithm successfully preserved shape and volume of rigid structures such as bone.
Conclusions:
The developed software leverages techniques from various disciplines to create a hybrid approach enabling real-time 3D mesh repositioning appropriate for use in simulated military missions using avatars containing a complete anatomy representation. The workflow is largely automated, enabling rapid evaluation of new mission scenarios.
Level of evidence:
N/A.
Behind armour blunt trauma (BABT) is a body injury resulting from the deformation of the back surface of armour as a result of a bullet impact. In the case of textile body armour, the severity of the injury may depend on the material of the fibres, but also on the geometric structure of the fabric. The article focuses on experimental research into injuries of the human body protected by ballistic packets made of biaxial and triaxial fabrics, during a non-penetrating impact from a Parabellum 9 × 19 Full Metal Jacket (FMJ) bullet, at a speed of 406 ± 5 m/s. In experimental research, the fabrics had a comparable surface weight and were made of the same Kevlar 29 yarn. The ballistic packages were made of 30 layers. As part of the work, a physical model of the human body was developed. The human body model consisted of a model of the heart, lungs, and skeletal and muscular systems. During the bullet impact, the pressure forces were recorded using sensors located at selected points of the human body. The bullets hit five selected places on the body that were considered critical, from the point of view of maintaining a human’s vital functions. It was found that, during firing, pressure increases both at the site of impact and in the internal organs, which can lead to multi-organ damage. As a result of the experimental analysis, it has been shown that the pressures exerted on specific organs are always lower in the case of body protection with a ballistic packet made of triaxial fabrics, compared to a packet made of biaxial fabrics.
