scholarly journals THREE-DIMENSIONAL SPATIAL RECONSTRUCTION OF THE GUNSHOT INJURIES IN THE PRACTICE OF FORENSIC MEDICINE

2020 ◽  
Vol 43 (4) ◽  
pp. 43-46
Author(s):  
V. T. Bachynskyy ◽  
Y. H. Zmiyevska ◽  
I. H. Savka

Abstract During the recent years the number of the wounded and killed due to firearms use both in Ukraine and in the majority of the world countries has increased. Therefore, examination of gunshot injuries is rather topical issue now in forensic medicine, and it is a considerable comprehensive question.Transience of incidences with the use of firearms in the majority of cases does not enable to find a real picture of circumstances when these incidences occur. Therefore, the issues of traumatic factor identification in these cases, especially with perforating and tangential injuries, are very important in forensic medicine, but remain elucidated insufficiently.At the same time, a dynamic development of up-to-date computer technologies enables to increase the level of visualization, forensic diagnostics of injuries and substantiation of expert conclusions in case of gunshot injuries. Purpose of the study. To study diagnostic possibilities of three-dimensional spatial reconstruction method for forensic identification of the main traumatic factor in case of gunshot injuries. Materials and methods. Ballistic plasticine and gel, fragments of pig skin with subcutaneous fat, fragments of biological tissues with gunshot injuries were used as the material for the study. The obtained experimental gunshot injuries (45 cases) and cases of injuries from the expert practice (30 cases) were subjected to photogrammetric with possibility to obtain a three-dimensional spatial model of every injury by means of the computer program Agisoft Photoscan. Results. The studies conducted differ from the existing ones by their novelty, higher inventive and scientific-practical level. Three-dimensional spatial digital models of the injured biological tissues and their imitators will be designed, examined and analyzed for the first time, and the diagnostic criteria for forensic identification of the main traumatic factor of gunshot body injuries will be developed. The obtained textured models of gunshot injuries in «Obj» format can be imported into the program 3dsMax, which enables to examine linear sizes of every fragment of a wound canal with higher accuracy (to 0,001 cm) in comparison with classical methods of examination.The results obtained while conducting the study enable not only to develop computer three-dimensional digital models of gunshot body injuries, but examine their character and morphologic peculiarities in forensic practice on an up-to-date scientific level. All the mentioned above enables to formulate and substantiate new, more accurate forensic diagnostic identification criteria of the main traumatic factor of gunshot body injuries. Conclusion. Introduction of up-to date computer technologies into the practice of forensic medicine will enable to determine identifying peculiarities of the main traumatic factor in case of gunshot injuries with a higher accuracy. Keywords: spatial reconstruction, 3D modelling, gunshot injuries, forensic medicine.

2021 ◽  
pp. 3-10
Author(s):  
Yuliia Zmiievska ◽  
Ivan Savka

This article shows the role and contribution of individual forensic scientists and famous forensic academies in the development of learning gunshot injuries. The article presents an analysis of the national literary sources concerning development of possibilities and methods of forensic diagnostics of the main traumatic factor of gunshot injuries. The role of up-to-date digital technologies, particularly the method of three-dimensional spatial reconstruction of the gunshot wounds, which can empower possibilities of forensic diagnostics of the main traumatic factor of gunshot injuries are shown. Aim of the work. To analyze the development of diagnostic methods of a kind of the main traumatic factor of gunshot injuries in forensic medicine, to find the up-to-date and most diagnostically valuable methods for further investigation and implementation into experts’ practical work. Conclusions. Analysis of national forensic experts’ studies shows that forensic medical examination of gunshot body wounds has always been of current interest and become more and more actual. In every period of forensic medicine development new instrumental and laboratory methods of examination of gunshot wounds have appeared. One of the most topical and promising methods are means of the three-dimensional spatial reconstruction. It can improve the possibilities of forensic medical diagnostics of a kind and characteristic of the main traumatic factor of gunshot wounds.


Author(s):  
Lee D. Peachey ◽  
Clara Franzini-Armstrong

The effective study of biological tissues in thick slices of embedded material by high voltage electron microscopy (HVEM) requires highly selective staining of those structures to be visualized so that they are not hidden or obscured by other structures in the image. A tilt pair of micrographs with subsequent stereoscopic viewing can be an important aid in three-dimensional visualization of these images, once an appropriate stain has been found. The peroxidase reaction has been used for this purpose in visualizing the T-system (transverse tubular system) of frog skeletal muscle by HVEM (1). We have found infiltration with lanthanum hydroxide to be particularly useful for three-dimensional visualization of certain aspects of the structure of the T- system in skeletal muscles of the frog. Specifically, lanthanum more completely fills the lumen of the tubules and is denser than the peroxidase reaction product.


Author(s):  
Neng-Yu Zhang ◽  
Terence Wagenknecht ◽  
Michael Radermacher ◽  
Tom Obrig ◽  
Joachim Frank

We have reconstructed the 40S ribosomal subunit at a resolution of 4 nm using the single-exposure pseudo-conical reconstruction method of Radermacher et al.Small (40S) ribosomal subunits were Isolated from rabbit reticulocytes, applied to grids and negatively stained (0.5% uranyl acetate) in a manner that “sandwiches” the specimen between two layers of carbon. Regions of the grid exhibiting uniform and thick staining were identified and photographed twice (magnification 49,000X). The first micrograph was always taken with the specimen tilted by 50° and the second was of the Identical area untilted (Fig. 1). For each of the micrographs the specimen was subjected to an electron dose of 2000-3000 el/nm2.Three hundred thirty particles appearing in the L view (defined in [4]) were selected from both tilted- and untilted-specimen micrographs. The untilted particles were aligned and their rotational alignment produced the azimuthal angles of the tilted particles in the conical tilt series.


Author(s):  
Jonas F. Eichinger ◽  
Maximilian J. Grill ◽  
Iman Davoodi Kermani ◽  
Roland C. Aydin ◽  
Wolfgang A. Wall ◽  
...  

AbstractLiving soft tissues appear to promote the development and maintenance of a preferred mechanical state within a defined tolerance around a so-called set point. This phenomenon is often referred to as mechanical homeostasis. In contradiction to the prominent role of mechanical homeostasis in various (patho)physiological processes, its underlying micromechanical mechanisms acting on the level of individual cells and fibers remain poorly understood, especially how these mechanisms on the microscale lead to what we macroscopically call mechanical homeostasis. Here, we present a novel computational framework based on the finite element method that is constructed bottom up, that is, it models key mechanobiological mechanisms such as actin cytoskeleton contraction and molecular clutch behavior of individual cells interacting with a reconstructed three-dimensional extracellular fiber matrix. The framework reproduces many experimental observations regarding mechanical homeostasis on short time scales (hours), in which the deposition and degradation of extracellular matrix can largely be neglected. This model can serve as a systematic tool for future in silico studies of the origin of the numerous still unexplained experimental observations about mechanical homeostasis.


2021 ◽  
Vol 10 (7) ◽  
pp. 460
Author(s):  
Mario Matthys ◽  
Laure De Cock ◽  
John Vermaut ◽  
Nico Van de Weghe ◽  
Philippe De Maeyer

More and more digital 3D city models might evolve into spatiotemporal instruments with time as the 4th dimension. For digitizing the current situation, 3D scanning and photography are suitable tools. The spatial future could be integrated using 3D drawings by public space designers and architects. The digital spatial reconstruction of lost historical environments is more complex, expensive and rarely done. Three-dimensional co-creative digital drawing with citizens’ collaboration could be a solution. In 2016, the City of Ghent (Belgium) launched the “3D city game Ghent” project with time as one of the topics, focusing on the reconstruction of disappeared environments. Ghent inhabitants modelled in open-source 3D software and added animated 3D gamification and Transmedia Storytelling, resulting in a 4D web environment and VR/AR/XR applications. This study analyses this low-cost interdisciplinary 3D co-creative process and offers a framework to enable other cities and municipalities to realise a parallel virtual universe (an animated digital twin bringing the past to life). The result of this co-creation is the start of an “Animated Spatial Time Machine” (AniSTMa), a term that was, to the best of our knowledge, never used before. This research ultimately introduces a conceptual 4D space–time diagram with a relation between the current physical situation and a growing number of 3D animated models over time.


2021 ◽  
Vol 11 (10) ◽  
pp. 4612
Author(s):  
KweonSoo Seo ◽  
Sunjai Kim

Purpose: The aim of this study was to present a new method to analyze the three-dimensional accuracy of complete-arch dental impressions and verify the reliability of the method. Additionally, the accuracies of conventional and intraoral digital impressions were compared using the new method. Methods: A master model was fabricated using 14 milled polyetheretherketone cylinders and a maxillary acrylic model. Each cylinder was positioned and named according to its corresponding tooth position. Twenty-five definitive stone casts were fabricated using conventional impressions of the master model. An intraoral scanner was used to scan the master model 25 times to fabricate 25 digital models. A coordinate measuring machine was used to physically probe each cylinder in the master model and definitive casts. An inspection software was used to probe cylinders of digital models. A three-dimensional part coordinate system was defined and used to compute the centroid coordinate of each cylinder. Intraclass correlation coefficient (ICC) was evaluated to examine the reliability of the new method. Independent two sample t-test was performed to compare the trueness and precision of conventional and intraoral digital impressions (α = 0.05). Results: ICC results showed that, the new method had almost perfect reliability for the measurements of the master model, conventional and digital impression. Conventional impression showed more accurate absolute trueness and precision than intraoral digital impression for most of the tooth positions (p < 0.05). Conclusions: The new method was reliable to analyze the three-dimensional deviation of complete-arch impressions. Conventional impression was still more accurate than digital intraoral impression for complete arches.


2021 ◽  
Vol 11 (12) ◽  
pp. 5321
Author(s):  
Marcin Barszcz ◽  
Jerzy Montusiewicz ◽  
Magdalena Paśnikowska-Łukaszuk ◽  
Anna Sałamacha

In the era of the global pandemic caused by the COVID-19 virus, 3D digitisation of selected museum artefacts is becoming more and more frequent practice, but the vast majority is performed by specialised teams. The paper presents the results of comparative studies of 3D digital models of the same museum artefacts from the Silk Road area generated by two completely different technologies: Structure from Motion (SfM)—a method belonging to the so-called low-cost technologies—and by Structured-light 3D Scanning (3D SLS). Moreover, procedural differences in data acquisition and their processing to generate three-dimensional models are presented. Models built using a point cloud were created from data collected in the Afrasiyab museum in Samarkand (Uzbekistan) during “The 1st Scientific Expedition of the Lublin University of Technology to Central Asia” in 2017. Photos for creating 3D models in SfM technology were taken during a virtual expedition carried out under the “3D Digital Silk Road” program in 2021. The obtained results show that the quality of the 3D models generated with SfM differs from the models from the technology (3D SLS), but they may be placed in the galleries of the vitrual museum. The obtained models from SfM do not have information about their size, which means that they are not fully suitable for archiving purposes of cultural heritage, unlike the models from SLS.


Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3493
Author(s):  
Gahyeon Lim ◽  
Nakju Doh

Remarkable progress in the development of modeling methods for indoor spaces has been made in recent years with a focus on the reconstruction of complex environments, such as multi-room and multi-level buildings. Existing methods represent indoor structure models as a combination of several sub-spaces, which are constructed by room segmentation or horizontal slicing approach that divide the multi-room or multi-level building environments into several segments. In this study, we propose an automatic reconstruction method of multi-level indoor spaces with unique models, including inter-room and inter-floor connections from point cloud and trajectory. We construct structural points from registered point cloud and extract piece-wise planar segments from the structural points. Then, a three-dimensional space decomposition is conducted and water-tight meshes are generated with energy minimization using graph cut algorithm. The data term of the energy function is expressed as a difference in visibility between each decomposed space and trajectory. The proposed method allows modeling of indoor spaces in complex environments, such as multi-room, room-less, and multi-level buildings. The performance of the proposed approach is evaluated for seven indoor space datasets.


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