Augmented Reality in Forensics and Forensic Medicine - Current Status and Future Prospects

Forensic investigations require a vast variety of knowledge and expertise of each specialist involved. With the increase in digitization and advanced technical possibilities, the traditional use of a computer with a screen for visualization and a mouse and keyboard for interactions has limitations, especially when visualizing the content in relation to the real world. Augmented reality (AR) can be used in such instances to support investigators in various tasks at the scene as well as later in the investigation process. In this article, we present current applications of AR in forensics and forensic medicine, the technological basics of AR, and the advantages that AR brings for forensic investigations. Furthermore, we will have a brief look at other fields of application and at future developments of AR in forensics

Technical note: Semiautomated targeted postmortem computed tomography angiography of the pulmonary arteries using a robotic system

INTRODUCTION To better depict vascular lesions on postmortem computed tomography (PMCT), whole-body postmortem computed tomography angiography (PMCTA) can be used in forensic diagnostics. Targeted angiography, in which only a specific vessel is filled with contrast agent, might help in cases of traumatic changes that render whole-body PMCTA impossible. Moreover, in targeted PMCTA, the contrast agent does not affect the haptics of any other organs. In this article, we describe automated, CT-guided targeted angiography of the pulmonary artery (PA) using the Virtobot system. MATERIAL AND METHODS Our study group consisted of 8 deceased persons (3 males, 5 females). We first performed an unenhanced CT scan and used the data obtained to plan the needle trajectories with the Virtobot planning software. Then, the needle was fully automatically placed by the Virtobot system. Subsequently, 50 ml of contrast agent was injected manually, and the CT scan was repeated (targeted PMCTA). RESULTS AND DISCUSSION We tested a new method for performing semiautomated targeted postmortem angiography of the PAs using a robotic needle placement system (Virtobot). In 6 out of our 8 cases, the injection of contrast agent in the PA was successful. In five of the six successful cases, there was reflux of contrast agent to some extent, but the reflux did not affect the readout. In general, the procedure was easy to plan based on a PMCT data set, and the pulmonary trunk was easy to reach with a robotic needle placement system

An algorithm for automatically generating gas, bone and foreign body visualizations from postmortem computed tomography data

Post mortem computed tomography (PMCT) can aid in localizing foreign bodies, bone fractures, and gas accumulations. The visualization of these findings play an important role in the communication of radiological findings. In this article, we present an algorithm for automated visualization of gas distributions on PMCT image data of the thorax and abdomen. The algorithm uses a combination of region growing segmentation and layering of different visualization methods to automatically generate overview images that depict radiopaque foreign bodies, bones and gas distributions in one image. The presented method was tested on 955 PMCT scans of the thorax and abdomen. The algorithm managed to generate useful images for all cases, visualizing foreign bodies as well as gas distribution. The most interesting cases are presented in this article. While this type of visualization cannot replace a real radiological analysis of the image data, it can provide a quick overview for briefings and image reports

Comparison of superficial wound documentation using 2D forensic photography, 3D photogrammetry, Botscan© and VR with real-life examination

Evidence acquisition, interpretation and preservation are essential parts of forensic case work that make a standardized documentation process fundamental. The most commonly used method for the documentation and interpretation of superficial wounds is a combination of two modalities: two-dimensional (2D) photography for evidence preservation and real-life examination for wound analysis. As technologies continue to develop, 2D photography is being enhanced with three-dimensional (3D) documentation technology. In our study, we compared the real-life examination of superficial wounds using four different technical documentation and visualization methods.To test the different methods, a mannequin was equipped with several injury stickers, and then the different methods were applied. A total of 42 artificial injury stickers were documented in regard to orientation, form, color, size, wound borders, wound corners and suspected mechanism of injury for the injury mechanism. As the gold standard, superficial wounds were visually examined by two board-certified forensic pathologists directly on the mannequin. These results were compared to an examination using standard 2D forensic photography; 2D photography using the multicamera system Botscan©, which included predefined viewing positions all around the body; and 3D photogrammetric reconstruction based on images visualized both on screen and in a virtual reality (VR) using a head-mounted display (HMD).The results of the gold standard examination showed that the two forensic pathologists had an inter-reader agreement ranging from 69% for the orientation and 11% for the size of the wounds. A substantial portion of the direct visual documentation showed only a partial overlap, especially for the items of size and color, thereby prohibiting the statistical comparison of these two items. A forest plot analysis of the remaining six items showed no significant difference between the methods. We found that among the forensic pathologists, there was high variability regarding the vocabulary used for the description of wound morphology, which complicated the exact comparison of the two documentations of the same wound.There were no significant differences for any of the four methods compared to the gold standard, thereby challenging the role of real-life examination and 2D photography as the most reliable documentation approaches. Further studies with real injuries are necessary to support our evaluation that technical examination methods involving multicamera systems and 3D visualization for whole-body examination might be a valid alternative in future forensic documentation

MRI Segmentation of Cervical Muscle Volumes in Survived Strangulation: Is There an Association between Side Differences in Muscle Volume and the Handedness of the Perpetrator? A Retrospective Study

We evaluate the potential value of magnetic resonance imaging (MRI) in the examination of survivors of manual strangulation. Our hypothesis was that trauma-induced edema of the cervical muscles might lead to a side difference in the muscle volumes, associated with the handedness of the perpetrator. In 50 individuals who survived strangulation, we performed MRI-based segmentation of the cervical muscle volumes. As a control group, the neck MRIs of 10 clinical patients without prior trauma were used. The ratio of the right to left muscle volume was calculated for each muscle group of the control and strangulation groups. Cutoff values for the assumed physiological muscle volume ratios between the right and left sides were identified from our control group. There was no significant difference among the individuals in the pathological muscle volume ratio between right-handed versus both-handed strangulation for the sternocleidomastoid, pretracheal, anterior deep, or trapezoid muscle groups. Only the posterior deep muscle group showed a statistically significant difference in the pathological muscle volume ratio for both-handed strangulations (p = 0.011). Measurement of side differences in cervical muscle volume does not allow for a conclusion concerning the probable handedness of the perpetrator

Disparitäten im Wortschatzerwerb: Zum Einfluss des Arbeitsgedächtnisses und der Anregungsqualität in Kindergarten und Familie auf den Erwerb lexikalischen Wissens

Vor dem Hintergrund der Bedeutung von Sprache und Spracherwerb für die kindliche Entwicklung und für die Ausbildung sozialer Disparitäten in Schulleistungen und Bildungskarrieren werden innere und äußere Einflussvariablen auf die Wortschatzentwicklung bei 428 monolingual deutschsprachigen Vorschulkindern der BiKS-3-10 Studie untersucht. Die Entwicklung des im Alter von 3, 4 und 5 Jahren längsschnittlich erhobenen rezeptiven Wortschatzes der Kinder wurde mittels latenter linearer Wachstumsmodelle analysiert. Speziell geprüft wurde der relative Einfluss von Personvariablen (phonologisches Arbeitsgedächtnis) sowie von strukturellen und prozessbezogenen Merkmalen der Kindergartenqualität und familiärer Variablen (sozioökonomischer Status, Bildung der Mutter, „literacy“ Anregung) auf die Wortschatzentwicklung von Kindern mit vergleichsweise besserem versus schlechterem Sprachstand zu Beginn der Studie. Die Ergebnisse zeigen einen signifikanten Einfluss der phonologischen Arbeitsgedächtniskapazität, die sich bei der Gruppe der sprachlich schwächeren Kinder als besonders bedeutsam für die Wortschatzentwicklung erweist. Die Qualität und Varianz der „literacy“ Anregung im Kindergarten erwies sich insgesamt als eher niedrig; bedeutsame Effekte auf den Wortschatzanstieg waren nicht nachweisbar. Die Effekte der „literacy“ Förderung im Elternhaus variieren in Abhängigkeit vom Sprachstand der Kinder zu Beginn der Studie. Die Ergebnisse werden hinsichtlich ihrer theoretischen und praktischen Implikationen diskutiert.Language competencies are important for child development in general and have been suggested to play a major role for the emergence of social disparities in educational careers. Therefore, the aim of the present study is to investigate the impact of internal (phonological working memory) and external variables (measures of preschool quality, home learning environment, and family background) on vocabulary development in preschool children with relatively restricted or more advanced language competencies at the beginning of the study. A subsample of 428 monolingual German children (who took part in the larger BiKS-3-10 study) was tested for receptive vocabulary at three successive measurement points (age 3, 4, and 5). Using latent growth curve models the relative impact of phonological working memory capacity and various measures of preschool quality and home background (SES, mother’s educational level, literacy stimulation) was evaluated. The results show that the capacity of phonological working memory has a strong impact on vocabulary development in preschool children, especially in children with less advanced language competencies. The observed quality of and variance in literacy stimulation in preschool (domain specific preschool quality) proved to be rather low and had no significant impact on vocabulary growth. Home learning environment in the sense of literacy stimulation showed different effects depending on the child’s language status. The results are discussed with respect to developmental and educational consequences

Kompetenzentwicklung und Bildungsentscheidungen im Vor- und Grundschulalter

"In den meisten soziologischen Theorien zu Bildungsungleichheiten gehen die Verfasser davon aus, dass unterschiedliche Schulleistungen vor allem Resultat unterschiedlicher familiärer Bedingungen im Hinblick auf kulturelles Kapital sind. Allerdings wird in neueren soziologischen Studien konzediert, dass Schulleistungen auch als Ergebnis der unterschiedlich ausgeprägten Kompetenzgefüge der Kinder zu betrachten sind. Wenn jedoch überhaupt Kompetenzparameter in quantitative soziologische Analysen einfließen, dann meist in Form von Schulnoten. Diese sind aber nicht unbedingt ein valider Indikator für die kindliche Kompetenzlage, sondern das Ergebnis eines längeren und komplexen Prozesses, in dem auch die Bedingungen in Familie, Kindergarten und Schule wirksam werden. Um die Herausbildung von schichtspezifischen Bildungswegen besser zu verstehen und abschätzen zu können, welcher Stellenwert den Kompetenzen der Kinder zukommt, ist es erforderlich, verschiedene Aspekte kindlicher Kompetenzen zu unterscheiden und diese über einen längeren Zeitraum in ihrer Abhängigkeit von familiären und institutionellen Bedingungen zu untersuchen. In enger Zusammenarbeit von SoziologInnen, PsychologInnen und PädagogInnen wendet sich das BiKS-Projekt derzeit diesen Fragen zu. In dem Vortrag stellen sie zunächst die theoretische Konzeption und das Design der BiKS-Studie vor. Sodann thematisieren sie die Frage, wie in der modernen psychologischen Kompetenzforschung der Gegensatz zwischen angeborenem Potential und Umwelteinflüssen diskutiert wird, und isolieren darauf aufbauend unterschiedliche Aspekte der kognitiven und sprachlichen Kompetenz. Danach präsentieren sie erste empirische Ergebnisse aus dem BiKS-Schullängsschnitt und stellen dar, ob und in welcher Weise kindliche Kompetenzen und Schulnoten mit den familiären Bedingungen kovariieren und auf die Formation von Bildungsentscheidungen einwirken." (Autorenreferat

Electronic structure and spectroscopy of the quaternary Heusler alloy Co2_2Cr1−x_{1-x}Fex_{x}Al

Quaternary Heusler alloys Co$_2$Cr$_{1-x}$Fe$_{x}$Al with varying Cr to Fe ratio $x$ were investigated experimentally and theoretically. The electronic structure and spectroscopic properties were calculated using the full relativistic Korringa-Kohn-Rostocker method with coherent potential approximation to account for the random distribution of Cr and Fe atoms as well as random disorder. Magnetic effects are included by the use of spin dependent potentials in the local spin density approximation. Magnetic circular dichroism in X-ray absorption was measured at the $L_{2,3}$ edges of Co, Fe, and Cr of the pure compounds and the $x=0.4$ alloy in order to determine element specific magnetic moments. Calculations and measurements show an increase of the magnetic moments with increasing iron content. Resonant (560eV - 800eV) soft X-ray as well as high resolution - high energy ($\geq 3.5$keV) hard X-ray photo emission was used to probe the density of the occupied states in Co$_2$Cr$_{0.6}$Fe$_{0.4}$Al.Comment: J.Phys.D_Appl.Phys. accepte

Home and preschool learning environments and their relations to the development of early numeracy skills

This study examined the influence of the quality of home and preschool learning environments on the development of early numeracy skills in Germany, drawing on a sample of 532 children in 97 preschools. Latent growth curve models were used to investigate early numeracy skills and their development from the first (average age: 3 years) to the third year (average age: 5 years) of preschool. Several child and family background factors (e.g., gender, maternal education, socioeconomic status), measures of the home learning environment (e.g., literacy- and numeracy-related activities), and measures of preschool structural and process quality (e.g., ECERS-E, ECERS-R) were tested as predictors of numeracy skills and their development. The analyses identified child and family background factors that predicted numeracy skills in the first year of preschool and their development over the three points of measurement — particularly gender, parental native language status (German/other), socioeconomic status, and mother’s educational level. The quality of the home learning environment was strongly associated with numeracy skills in the first year of preschool, and this advantage was maintained at later ages. In contrast, the process quality of the preschool was not related to numeracy skills at the first measurement, but was significantly related to development over the period observed. The results underline the differential impact of the two learning environments on the development of numeracy skills. Interaction effects are explored and discussed