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Testing photogrammetry-based techniques for three-dimensional surface documentation in forensic pathology
... In recent years, photogrammetry has received more attention in research. Tests have been conducted using a single camera [47,[50][51][52], multi-camera sys-tems [53][54][55][56][57] or videos [58]. These techniques have been applied to deceased [47,51,52,55] and living individuals [54], documenting single lesions, organs or entire bodies. ...
... Tests have been conducted using a single camera [47,[50][51][52], multi-camera sys-tems [53][54][55][56][57] or videos [58]. These techniques have been applied to deceased [47,51,52,55] and living individuals [54], documenting single lesions, organs or entire bodies. ...
... Surface imaging techniques effectively document abrasions, bruises, imprint marks, teeth marks, lacerations and superficial cuts, which may be challenging to detect on PMCT and PMMR scans ( Figure 2). Both surface scanners and photogrammetry produce comparable results, each with its own advantages and disadvantages [31,[46][47][48][49]. The choice of technique depends on specific needs, budget, area size and desired level of accuracy. ...
In the last two decades, forensic pathology and crime scene investigations have seen a rapid increase in examination tools due to the implementation of several imaging techniques, e.g., CT and MR scanning, surface scanning and photogrammetry. These tools encompass relatively simple visualization tools to powerful instruments for performing virtual 3D crime scene reconstructions. A multi-modality and multiscale approach to a crime scene, where 3D models of victims and the crime scene are combined, offers several advantages. A permanent documentation of all evidence in a single 3D environment can be used during the investigation phases (e.g., for testing hypotheses) or during the court procedures (e.g., to visualize the scene and the victim in a more intuitive manner). Advanced computational approaches to understand what might have happened during a crime can also be applied by, e.g., performing a virtual animation of the victim in the actual context, which can provide important information about possible dynamics during the event. Here, we present an overview of the different techniques and modalities used in forensic pathology in conjunction with crime scene investigations. Based on our experiences, the advantages and challenges of an image-based multi-modality approach will be discussed, including how their use may introduce new visualization modalities in court, e.g., virtual reality (VR) and 3D printing. Finally, considerations about future directions in research will be mentioned.
... Photogrammetry is a 3D acquisition method whereby images of an object are taken from varying angles and then used to reconstruct a 3D model [15]. Photogrammetry has found application in some forensic fields such as documentation and measurement of forensic-relevant injuries [16][17][18]; recording crime scenes [19]; examining patterned injuries of skin, soft tissues and bones; and comparison of injuries with injurycausing instruments [20], and road accident reconstruction [21]; however, its application to forensic purposes has not been discussed extensively [22], especially in the context of forensic anthropology. ...
... All skull 3D models can be downloaded as digital supplementary files. Only visible parts of the surface could be documented [22]; therefore, a hole is visible where the mounting pole was located owing to post-reconstruction trimming (Fig. 3, F + L, norma basalis). ...
... Photogrammetry is safe and affordable enables the reproducibility of accurate data, collects data points in 3D coordinate format which can then be used for morphometric studies and outputs a high-resolution colour representation [10,15,22,41], a merit it has over surface and CT scanners which do not produce 3D models with texture and colour information [22] and are very costly. The fact that it is safe and affordable and gives accurate data is especially vital as this makes it readily available especially to developing countries which are still building forensic capability and cannot afford portable X-ray machinery and mobile CT scanners which are being increasingly incorporated in DVI operations [14]. ...
Osseous remains provide forensic anthropologists with morphological and osteometric information that can be used in building a biological profile. By conducting a visual and physical examination, an anthropologist can infer information such as the sex and age of the deceased. Traditionally, morphological and osteometric information is gathered by physically handling remains for analysis. With the advancement of digital technology, there has been a shift from direct to indirect methods of analysis by utilizing models generated from three-dimensional (3D) imaging, which includes computed tomography (CT) scanning and 3D photogrammetry. Although CT scanning is more common, photogrammetry has found application in a range of fields such as architecture, geography and road accident reconstruction. The application of modern-day photogrammetry for forensic anthropology purposes, however, has not been discussed extensively. The aim of this research was to validate the accuracy of 3D models generated by photogrammetry by comparing them to both 3D models generated by CT scanning and the actual physical models. In this study, six 3D models were created using photogrammetry (n = 3) and CT scanning (n = 3). The 3D models were generated from three different Bone Clone® human skulls. A mobile phone camera was used to capture images, which were then processed in Agisoft Metashape®. Intrarater, interrater, and intermethod reliability tests gave correlation coefficients of at least 0.9980, 0.9871, and 0.9862, respectively; rTEM results ranged from 0.250 to 6.55%; and an analysis of variance (ANOVA) yielded P values under 0.05 for all measurements except one. Statistical tests therefore showed photogrammetry to be a reliable and accurate alternative to more expensive CT scanning approaches.
... In addition, all the objects and people in a crime scene can always be visualized in the photographs, but their dimensions and actual location in the 3D space cannot be recovered from a single photograph. Recently, new forms of documentation such as laser scanners, structured-light scanners, and photogrammetry are increasingly used in forensic investigations [1][2][3][4][5][6][7][8]. These techniques enable a 3D documentation of the actual crime scene and of any evidence, including bodies. ...
... These techniques enable a 3D documentation of the actual crime scene and of any evidence, including bodies. Photogrammetry has been found comparable to 3D commercial surface scanner with the advantages of being a faster method and not requiring expensive equipment and training [5,8,9]. ...
... Photogrammetry has already been demonstrated a valuable tool in forensic and clinical pathology. Photogrammetry has been used to record skin lesions [5,13], imprint marks on the skin [14,15] and also internal organs and bones [5]. Entire bodies can also be 3D documented using a multi-camera system [16,17]. ...
Recently, new forms of documentation such as photogrammetry are increasingly used in forensic sciences. Photogrammetry enables an actual 3D recording of crime scenes. This technique can be used to extract 3D models of an object in digital form (coordinates and derived geometric elements, e.g. measurements, surface, area) or graphical form (sketches, maps). Photogrammetry can be applied on large and small scale, from landscape to fingerprints. The aim of this chapter is to introduce forensic experts to the principles and applications of photogrammetry for 3D recording of crime scenes, evidence, and people (living or deceased individuals). Some applications in forensic pathology, including the integration of photogrammetry with post-mortem computed tomography (PMCT), are presented.
... Since 1998 in Germany, the active scanning was acquainted to forensic pathology and later since 2003 in Switzerland ATOS -a multinational French company have applied light 3D scanners 8,9 in the respective research and development departments. In any case to produce high resolution results ATOS scanners 15 include more conditions. The active 3D surface scanning innovation has constrained its use within forensic medicine because of the market cost and the control of the casualty required. ...
... The active 3D surface scanning innovation has constrained its use within forensic medicine because of the market cost and the control of the casualty required. In this way, it isn't totally incorporated into the routine forensic work all over, despite the fact that the prospective technology shall have an awesome noteworthiness in coming 12,15 times. Though optional method such as photogrammetry do exist, but it is not unrivalled in recording forensic injuries since it can't get a similar level of exactness and point's thickness 8,11,12 when contrasted with the active 3D scanners. ...
... The scanning can be performed either by operating the scanner on the object or vice versa, but a significant multiplication of acquisitions can occur, resulting in 14 decreased efficiency. The surface scanner resolution is usually a component of pixel size of the camera, a charge-coupled [12][13][14][15] device (CCD). Both the parameters are inversely associated to one another that is smaller the FOV, higher the resolution for a [13][14][15] given CCD. ...
Imaging innovations assume a necessary part irrespective of the considerable evolution in the discipline of forensic anthropology. Thus, enables the anthropologist to record the site and anthropological remains in outstanding point of interest. With advancement in
innovations, virtual human studies are increasing pervasively replacing conventional radiographs that have been utilized to archive specimens. The forensic anthropologists have incorporated computed tomography (CT) and three-dimensional (3D) surface scans as advanced imaging methods for their case analyses and research to obtain process and dissect 3D information. Among these methods, three dimensional scanners have picked up a conspicuous place for an assortment of reasons that make them valuable to
anthropologists. These propelled imaging innovations give a way to report anthropological specimens, their injury patterns, and thus provides a platform to create virtual models for record purpose. Imaging specialists have also tried creating techniques for evaluating and utilizing various parameters from the virtual models like surface mapping and advanced methods of geomorphometric analysis. It stretches out our capacity to evaluate phenotypic variety, its non-damaging nature adds to specimen preservation, and it can turn into a basic piece of virtual human studies, along these lines accomplishing more than simply "beginning to expose what's 3D scanning is all about. The present paper provides an insight on the new scanning technology and discusses the possible future application of these techniques in forensic analysis.
... Limitations of photogrammetry include that hidden or covered parts are not captured [26], and that the condition of the surface affects the recording. For example, data capture can be problematic if a surface is covered in hair, is reflective or wet [26,96]. The documentation of smooth surfaces are also challenging as demonstrated by Peterson et al. [75] when imaging a pocket knife. ...
... However, novel applications within forensic medicine are emerging, for example, Ebert et al. [26] state that digital surface documentation of cadavers complements traditional photography and is commonplace in Switzerland. While forensic 2D photo-documentation is the gold standard for recording injuries [63], photogrammetry in particular is noted to be beneficial for external body documentation [96]. While laser scanning is discouraged for use on living individuals due to safety concerns, slow speed of capture and difficulty in imaging surfaces of dark colours [86]. ...
... Indeed, photogrammetry has been used to match surface injuries with instruments and to reconstruct patterned injures [63]. It has been demonstrated that this technique can produce high-resolution, realistic, and to-scale 3D surface models [96]. A case-report by Davy-Jow et al. [21] used laser scanning and photography to document evidence of abuse and starvation. ...
The Journal of Forensic Radiology and Imaging was launched in 2013 with the aim to collate the literature and
demonstrate high-quality case studies on image-based modalities across the forensic sciences. Largely, the focus of this journal has been on the transmissive aspect of forensic imaging, and therefore a significant number of high-quality case studies have been published focusing on computed tomography and magnetic resonance imaging. As a result, the ‘and imaging’ aspect is often neglected. Since 2013, technology has fundamentally evolved, and a number of new techniques have become accessible or have been demonstrated as particularly useful within many sub-disciplines of forensic science. These include active and passive surface scanning techniques, and the availability of three-dimensional printing. Therefore, this article discusses non-contact techniques, their applications, advantages, and considerations on the current state of play of imaging in forensic science.
https://authors.elsevier.com/c/1YPXj7t3okMgmu
... Slot et al. [4] found that photogrammetry could be used to determine the location of lesions and create models for recreation of body postures. Urbanová et al. [5] created 3D documentation upon a living and two dead people. The 3D documentations were made of internal and external parts of the body using single camera photogrammetry, without the use of reference points and a laser scanner. ...
... This study showed that measurements gained by photogrammetry were comparable with manually taken measures by the forensic pathologist within a margin of error around 0.1 cm. Photographs can be taken using a single camera [3][4][5][6] or a multi-camera system [7][8][9][10]. However, multiple-camera systems are expensive and require a rig to be built. ...
... These limits of agreement represent the largest expected differences between the two methods of measurements [12] and were calculated by calculating the mean difference ± 1.96 standard deviations of the differences. The manual measurements of photographs were used as a Bgolden standard^as this method has been proven accurate through various studies [2,3,5,6]. All statistics were performed using ...
Accurate and precise documentation of lesions is an important aspect of the forensic pathologists’ work. Photogrammetry provides a useful tool to take precise measurements from photographs. These photographs are normally acquired with single camera photographs, but the procedure is quite time-consuming. Video recording has the potential to record a larger amount of image data faster. We documented 33 cadaveric skin lesions, using photographs and video recordings. The dimensions of the lesions ranged between 0.27 and 21.8 cm. The measurements of the lesions were extracted with both manual and automatic point measurements from photographs and from video frames, respectively. Very small differences (mean and median < 1 mm) were found between measurements taken in photographs versus video frames. Video frames were often blurred, preventing clear demarcation of the edges of the lesions and presenting a larger amount of noise in the 3D models. The differences between the manual point and automatic point measurements were very small (mean and median < 1 mm), but the manual procedure is to be preferred, since automatic points were not always located on the edges of the lesions. The only aspect in which video frames were superior to photographs was the recording time: video recording was almost five times faster than the photo sessions. In conclusion, this study shows that precise and comparable measurements can be extracted both from photographs and video frames. The video is the fastest method, but the use of photographs is still recommended. Manual measurements are more precise than automatic measurements and equally time-consuming.
... Therefore, 3D scar surface area measurement is more valid and reliable than measurements with 2D techniques [15][16][17][18]. Devices range from stereo photogrammetry such as Vectra H1 (Canfield Scientific, Fairfield, NJ, USA) [19,20] and 3D Lifeviz™ (Quantificare S.A., Sophia Antipolis, France) [16] to (laser-assisted) three-dimensional imaging systems such as Artec Eva (Artec Group, Luxembourg, Luxembourg) [15]. These systems are the most advanced products in their product range. ...
... Moreover, these devices are time-consuming since the analysis of the 3D image is not performed directly on the cameras themselves. The images are mostly analyzed afterward on a computer with additional software [15,20]. These high costs and time-consuming procedures make it less feasible in a clinical setting. ...
Introduction:
The quality of scars has become an important outcome of burn care. Objective scar assessment through scar surface area measurement enables quantification of scar formation and evaluation of treatment efficacy. 3D technology has proven valid and reliable but often remains cumbersome, expensive, and time-consuming. 3D technology with depth sensors on mobile devices has become available and might surpass these limitations. This study provides a clinimetric assessment of the validity and reliability of a 3D system with a depth sensor for scar surface area measurement.
Methods:
A technology involving a depth sensor mounted on a mobile device was used. Images and analyses were made with a custom-made software application. A standardized one-keyframe image capturing procedure was followed. To assess validity, stickers with predefined dimensions (8.01 cm2 - 77.70 cm2) were imaged in a single observer setting on various body parts of healthy volunteers. To assess reliability, hypertrophic scars, keloids, and normotrophic scars were imaged and rated by two observers independently. Data are expressed as mean (+/-SD), Coefficient of Variation (CV), Intraclass Correlation Coefficients (ICC), and Limits of Agreements (LoA).
Results:
Eighty stickers placed on 20 healthy volunteers showed validity with CV between 0.62%- 1.67% for observer A and 0.75%- 1.19% for observer B. For the reliability study, 69 scars on 36 patients were included. Mean scar surface area ranged from 0.83 cm2 to 155.59 cm2. Mean scar surface area measurement was 13.83 cm2 (SD 23.06) for observer A and 13.59 cm2 (SD 23.31) for observer B. Adjusted interobserver CV for trained observers is estimated as 5.59%, with corresponding LoA = 0 ± 0.15 x mean surface area. Interobserver ICCs were 0.99-1.00.
Conclusion:
This 3D technology with a depth sensor for measuring scar surface area provides valid and reliable data and thereby surpasses expensive and time-consuming 3D cameras.
... However, the generation of a mesh with highest quality was a computationally demanding process that increased the processing time from an average of 2-3 h to more than 10 h, depending on the computer power. Similar processing times have been reported by other photogrammetry studies [75][76][77]. Our scanning protocol generated 3D models of either complete or fragmented crania and mandibles (Fig. 4), with the smallest fragment being a mandibular condyle of 9 cm. ...
... This is likely due the fragmented state of some cranial remains, which increases the difficulty of keeping the skull in the same position during different measurement sessions and explains the dispersion of measures in Bland-Altman plots (Fig. 7). Therefore, traditional measures should not be taken as a "gold-standard" because measuring fragmented non-glued skulls using calipers is technically challenging and can introduce substantial measurement bias [76]. ...
Biological and forensic anthropologists face limitations while studying skeletal remains altered by taphonomic alterations and perimortem trauma, such as in remains from the Spanish Civil War. However, virtual anthropology techniques can optimize the information inferred from fragmented and deformed remains by generating and restoring three-dimensional bone models. We applied a low-cost 3D modelling methodology based on photogrammetry to develop novel forensic applications of virtual 3D skull reconstruction, assembly, restoration and ancestry estimation. Crania and mandible fragments from five Spanish Civil War victims were reconstructed with high accuracy, and only one cranium could not be assembled due to extensive bone loss. Virtual mirroring successfully restored reconstructed crania, producing 3D models with reduced deformation and perimortem trauma. High correlation between traditional and virtual craniofacial measurements confirmed that 3D models are suitable for forensic applications. Craniometric databases of world-wide and Spanish populations were used to assess the potential of discriminant analysis to estimate population ancestry. Our protocol correctly estimated the continental origin of 86.7% of 15 crania of known origin, and despite low morphological differentiation within European populations, correctly identified 54.5% as Spanish and 27.3% of them with high posterior probabilities. Two restored crania from the Civil War were estimated as Spanish, and one as a non-Spanish European. Results were not conclusive for one cranium and did not confirm previous archeological hypotheses. Overall, our research shows the potential to assess the presence of foreign volunteers in the Spanish Civil War and highlights the added value of 3D-virtual techniques in forensic anthropology.
... Transmissive imaging modalities, however, depict osseous tissue while soft tissue is still attached and include sonography, Computed Tomography (CT), Magnetic Resonance Imaging (MRI), X-rays and low-dose X-ray [15,17,18]. Reflective imaging modalities, unlike transmissive imaging modalities, are not often used in medico-legal procedures [19,20]. This is mainly due to the fact that the actual skeletal remains are present and available for physical examination [21]. ...
... Photogrammetry can produce a photo-realistic appearance if a texture map is applied [22] and has been found to be beneficial in documenting the external body in forensic medicine [19]. Brüschweiler et al. (2003) recommended that photogrammetry be used to document bone trauma and noted that by recording the size, shape, and angle of the injury, photogrammetry may provide information pertaining to the tool used to inflict the injury [33]. ...
The use of imaging modalities is becoming increasingly popular in forensic anthropology. Imaging modalities that have been used in forensic anthropology to date include; surface scanning, photogrammetry, sonography, Computed Tomography (CT), Magnetic Resonance Imaging (MRI) and conventional X-rays. Little is however, known about low-dose X-rays and its potential use in forensic anthropology. The aim of this review article is to briefly introduce the imaging modalities that have been used in forensic anthropology, by introducing their advantages and disadvantages, as well as highlighting its specific use in forensic anthropology, with emphasis on low-dose Xrays. Low-dose X-ray produces high resolution, full-body 2D images, without the need for image stitching, in less than 13 seconds. It is a user-friendly system that requires minimal training to operate and the setup thereof is cheaper than other imaging modalities. It was also found that low-dose X-rays often outperformed other imaging modalities. The use of low-dose X-ray in forensic anthropology is still in its infancy and as it is more frequently available and easily accessible in medico-legal laboratories, its full potential should be further explored.
... However, these challenging surfaces have been tested by the structured light and their 3D results were found to be satisfactory (1). On the other hand, the algorithm of the photogrammetry and stereophotogrammetry (the passive 3D scanning) faced difficulties to scan these surfaces (3,10). ...
... Supporting this, Ebert et al. (8) stated that scanning is generally limited to the injury (injured surface) to reduce the total effort required, and to avoid the movement effect which can cause difficulty in a scan fusion. Moreover, Urbanova et al. (10) cited that in forensic examination a scan of small to medium area of the body surface is adequate. All the direct and 3D wound measurements were very close to each other in all measured dimensions (length, width and depth). ...
... With drone photogrammetry, larger image of crime scene can be acquired, subsequently defining the topographic information [39] and provide accurate outline of crime scene along with interpersonal distances of evidence [4,32]. Additionally, Urbanová et al. [56] reported that digital camera-based photogrammetry and stereophotogrammetry-based handheld scanners were proven to be very advantageous for post-mortem body documentation in forensic pathology. If combined with high resolution texture, they can also offer information on subtle external interferences and time-sensitive coloration, both of which are crucial for finding forensic evidence [21]. ...
Drones, formally known as Unmanned Aerial Vehicles (UAVs), are versatile technology increasingly associated with many modern-day applications. The advancements in technology have brought about a revolution in drones, extending their applications in various fields, including forensic science. Despite their potential, the full extent of drone capabilities in forensic science remains unclear and limited by a lack of defined evidence. Therefore, this article aims to provide a comprehensive review of the current literature on the use of drones in forensic science, while also highlighting the challenges and limitations of their deployment. This review seeks to identify areas for further research and development in the use of drones in forensic science by exploring the key issues. The use of Arksey and O’Malley’s framework updated by Joanna Briggs Institute for Scoping Reviews methodology shows that drones have proven to be a valuable technology in various forensic-related events, including clandestine graves detection, crime scene investigations, traffic accident investigations, disaster assistance, and pollution detection. However, there is still inadequate information on the use of drones in forensic science, particularly in enhancing the Disaster Victim Identification (DVI) procedure during the initial phase of a disaster. Therefore, this paper aims to provide insights into the potential applications of drones in forensic science and promote their integration into related fields.
... However, photogrammetry can be used as an inexpensive alternative for optical 3D imaging. In controlled environments, such as autopsy facilities and forensic laboratories, photogrammetry is applicable to document external and internal postmortem examinations as well as objects and various pieces of evidence [1][2][3][4][12][13][14][15][16][17][18][19][20][21][22][23]. However, optical 3D imaging in less controlled environments, such as at a collision scene, can easily become much more challenging. ...
Background
: Three-dimensional (3D) documentation of crime and crash scenes is common practice during forensic and medicolegal investigations. Such documentation at a scene is usually carried out by specially trained personnel using various 3D imaging devices and methods, such as terrestrial laser scanners. Unfortunately, this causes the implementation of 3D documentation at the scenes to be expensive and not readily accessible. In 2020, Apple introduced a light detection and ranging (LiDAR) sensor into their high-end mobile devices. In 2022, Recon-3D, an iOS application (app), was launched. This app turns an iPhone or iPad into a 3D scanner and is specifically targeted at crime and crash scene applications.
Objectives
: The aim of this study was to test the Recon-3D app based on exemplary scenarios to see whether this technology is generally applicable to document crime or crash scenes.
Materials and Methods
: An iPhone 13 Pro in combination with the Recon-3D app was used to document two indoor scenarios, a mock-up crime scene and a garage, as well as an outdoor scenario of a parked car. Each scenario was documented multiple times.
Results
: On average, data acquisition for one scene took less than 2 minutes. Known distances within the scenes were measured with a mean absolute error of 0.22 cm and a standard deviation of 0.18 cm.
Conclusion
: The imaging workflow was simple and quick, enabling any person to perform 3D documentation at a crime or crash scene. Overall, Recon-3D appeared to be a useful application for forensic investigators.
... Approaches based on photogrammetry [6][7][8][9][10][11][12][13][14][15] in most cases use 2D images as input to generate a 3D model. The big advantage of photogrammetry is that the input data can be generated easily and cheaply without the need for special hardware. ...
Due to the increasing trend of online shopping, shoes are more and more often bought without being tried on. This leads to a strong increase in returns, which results in a high financial as well as ecological burden. To prevent this, feet can be measured either in the store or at home by various systems to determine the exact dimensions of the foot and derive an optimal shoe size. In this paper, we want to present an overview of the methods currently available on the market for the measurement of feet. The most important commercial systems are classified according to the underlying basic technology. Subsequently, the most promising methods were implemented and tested. The results of the different methods were finally compared to find out the strengths and weaknesses of each technology. After determining the measurement accuracy of the length and width for each measurement method and also comparing the general shape of the 3D reconstruction with the GT, it can be said that the measurement using a ToF sensor is currently the most robust, the easiest and, among other methods, the most accurate method.
... The advantages of 3D reconstruction methods over photography in documenting and presenting injuries are already demonstrated [31,32]. Photogrammetry allows creating 3D textured surface models from a series of overlapping photographs taken from varying viewpoints [33]. ...
In stabbing related fatalities, the forensic pathologist has to assess the direction of wound track (thus, the direction of the stabbing) and the weapon’s possible characteristics by examining the stab wound. The determination of these characteristics can be made only with a high level of uncertainty, and the precise direction of the stabbing is often difficult to assess if only soft tissues are injured. Previously reported techniques used for the assessment of these wound characteristics have substantial limitations. This manuscript presents a method using today’s easily accessible three-dimensional (3D) printing technology for blade-wound comparison and wound track determination. Scanning and 3D printing of knives is a useful method to identify weapons and determine the precise stabbing direction in a stabbing incident without compromising the trace evidence or the autopsy results. Ballistic gel experiment, and dynamic stabbing test experiments prove the method can be applied in safety, without compromising the autopsy results. Identification of the exact knife is not possible with complete certainty but excluding certain knives will decrease the number of necessary DNA examinations, hence it can lower the burden on forensic genetic laboratories. The method addresses many of the shortcomings of previously used methods of probe insertion or post-mortem CT. Insertion of the printed knife into the wound gives a good visual demonstration of the stabbing direction, thus easing the forensic reconstruction of the stabbing incident. After combining the 3D printing with photogrammetry, the achieved 3D visualization is useful for courtroom demonstration and educational purposes.
... Forensic pathologists also benefit from 3D surface documentation, but usually complex, expensive, and/or unwieldy instrumentations are required [1,30,31]. The introduction of photogrammetry has made 3D documentation easier than in the past since the required equipment consists basically of a camera and a computer [2,3,[32][33][34][35]. However, this method has some limits. ...
Autopsy is a complex and unrepeatable procedure. It is essential to have the possibility of reviewing the autoptic findings, especially when it is done for medico-legal purposes. Traditional photography is not always adequate to record forensic practice since two-dimensional images could lead to distortion and misinterpretation. Three-dimensional (3D) reconstructions of autoptic findings could be a new way to document the autopsy. Besides, nowadays, smartphones and tablets equipped with a LiDAR sensor make it extremely easy to elaborate a 3D model directly in the autopsy room. Herein, a quality and trustworthiness evaluation of 3D models obtained during ten autopsies is made comparing 3D models and conventional autopsy photographic records. Threedimensional models were realistic and accurate and allowed precise measurements. The review of the autoptic report was facilitated by the 3D model. Conclusions: The LiDAR sensor and 3D models have been demonstrated to be a valid tool to introduce some kind of reproducibility into the autoptic practice.
... The documentation process is often standardized and includes a collection of written statements together with drawn sketches of the injury locations and photographic documentation of the evidence [2]. Such documentation preserves the forensic evidence and should be in a format that enables specialists to form a second opinion, which would ideal confirm the original conclusions and thus allow rigorous quality control for the prevention of misdiagnoses [3]. To characterize superficial injuries, information about their localization, color, size, form, orientation, wound angles and corners, as well as the suspected mechanism of injury involved, must be documented [1]. ...
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.
... The accuracy of this technique has been proven to be comparable to the laser scanners [38]. Photogrammetry has been routinely utilized in forensic 3D documentation of skin injuries [39][40][41]. ...
The global Covid-19 pandemic has forced forensic dentists to improve infection control methods. This search investigated the practical utilization of different 3D scanners to record and to analyze bite marks in the skin-and inanimate objects with this aim in mind. A systematic review of the literature using keywords like "human bite mark", "bite mark analyzes", "3D analyzes", "3D scanning", "forensic odontology", and "forensic dentistry" was performed in three scientific databases: MED-LINEOvid®, Pubmed® and Google Scholar. The initial search yielded 263 full-text articles, of which 15 were considered eligible and current within the last 10 years. 3D scanners and computer-assisted human bite mark analyzes showed potential advantages and can be effectively used in forensic odontology on skin and inanimate objects. These technologies minimize the number of people being exposed to pathogens, simplify the chain of evidence, facilitate immediate information exchange between the team members and enable the virtual presentation of the expert witnesses in a court of law.
... Photogrammetry is a technology that allows the creation of 3D textured surface models from a series of overlapping photographs taken from varying viewpoints [9]. Every aspect of the created model can be examined by rotating in 3D and zooming in and out. ...
As the coronavirus disease 2019 (COVID‐19) pandemic forced universities to switch to distance online education, there was an urgent need to find some virtual/digital alternatives in order to continue teaching. Opportunities such as watching pre‐recorded autopsy videos or creating and analyzing post‐mortem computed tomography or magnetic resonance imaging with various 3D surface imaging techniques are usually time‐consuming and cost‐intensive. Photogrammetry, which allows the creation of 3D textured surface models from a series of overlapping photographs taken from varying viewpoints, is a less common approach compared with post‐mortem imaging. We created 3D autopsy case models for a special online forensic pathology course in which students could try the models. Then, formal feedback was requested regarding the possible application of this method in education. Most of the students were satisfied with the new method and ranked photogrammetry higher than the other available methods. Our results indicate that photogrammetry has a high potential in undergraduate education, especially in the case of distance education or in those countries where declining autopsy rates have resulted in a decline in the use of the autopsy as an educational tool. Photogrammetry can also be used as a supplementary tool in traditional autopsy‐based education and has potential applications in various fields of medical education.
... Plastination is a technique pioneered by von Hagens (1979), in which formalin-fixed bodies or organs are infiltrated with silicone, plastic polymers, or resins to create anatomical specimens (Kamath and Avadhani, 2016). Digitized 3D models are virtual representations of physical objects, created using data acquired through methods like 3D scanning (Adams et al., 2015), photogrammetry (Hagood et al., 2005;Petersson et al., 2009;Urbanová et al., 2015;Salazar-Gamarra et al., 2016;Petriceks et al., 2018;Turchini et al., 2018;Burk and Johnson, 2019), computed tomography (CT) and magnetic resonance imaging (MRI) data sets (Venkatesh et al., 2013;McMenamin et al., 2014;Kiraly et al., 2019). The differences in data acquisition and quality of the final reconstruction between 3D scanning and photogrammetry were evaluated in a recent study (Dixit et al., 2019), which concluded that photogrammetry had a better texture preservation in the virtual model. ...
Several alternatives to formalin‐stored physical specimens have been described in medical literature, but only a few studies have addressed the issue of learning outcomes when these materials were employed. The aim of this study was to conduct a prospective controlled study to assess student performance in learning anatomic pathology when adding three‐dimensional (3D) virtual models as adjunct teaching materials in the study of macroscopic lesions. Third‐year medical students enrolled at the Victor Babes University of Medicine and Pharmacy in Timisoara, Romania, were recruited to participate. Student performance was assessed through questionnaires (n = 501). Students performed worse with new method, with poorer results in terms of overall (mean 77.6% ±SD 11.8 vs. 83.6% ±10.5) and individual question scores (percentage of questions with maximum score 34.6% ±25.6 vs. 47.7 ±24.6). This decreased performance was generalizable, as it was observed across all language divisions and was independent of the teaching assistant involved in the process. In an open‐ended feedback evaluation of the new 3D specimens, most students agreed that the new method was better, bringing arguments both for and against these models. Although subjectively the students found the novel teaching materials to be more helpful, their learning performance decreased. A wider implementation as well as exposure to the technique and use of virtual specimens in medical teaching could improve the students’ performance outcome by accommodating the needs for novel teaching materials for digital natives
... This method is also known as photogrammetry and 3D photo scan. Image-based 3D scanning is used in forensic medicine Urbanova, Hejna, & Jurda, 2015), modeling of historical and structures (Kersten, & Lindstaedt, 2012), damage detection (Allard, Lavoıe, & Fraser, 2013), reverse engineering (Hoffmann, Hermanek, Rybka, & Honzik, 2015)., architecture (Baik, & Alitany, 2018) and many other sectors. The models obtained by this method are used for many purposes such as manufacturing, design, digital arts and archiving of objects. ...
Image-based three dimensional (3D) scanning is a photogrammetry method. Photogrammetry is a scientific discipline used for obtaining dimensional information from photographs taken of objects. This discipline used in the mapping of geographical areas with photographs taken from airplanes at first, began to be used in obtaining the 3D model of objects with the development of the technology. Image-based 3D scanning method which is becoming increasingly widespread in the field of photogrammetry has become important like laser and optical scanning methods in areas of reverse engineering, personalized design, forensics, biomedical, industrial design, virtual reality. This method has some advantages such as low cost, color modeling compared to other 3D scanning methods, and yet is questioned in some aspects such as dimensional accuracy and surface integrity. In this study, as a result of the scanning operations on small size (125-1000 cm3) objects, the digitized models and the actual objects were compared dimensionally. In addition, glossy, transparent and matte surface objects were modeled by image-based 3D scanning method and the differences related to the process were revealed and the precautions to be taken were stated. This article is thought to be useful for researchers who want to use image-based 3D scanning in their study.
... Photogrammetric techniques have been introduced as an important medical imaging tool, providing higher accuracy and improving existing techniques (Mitchell and Newton, 2002;Patias, 2002). Imagebased solutions have also proved to be useful for external body documentation and easy to use for static targets (Urbanová et al., 2015). Image-based and range-based technologies can be used for purposes such as prosthetics design (Grazioso et al., 2019), surgery planning (Kournoutas et al., 2019), deformation assessment (Jodeh et al., 2018) or obtainment of anthropometric measurements (Heymsfield et al., 2018), among others. ...
Image-based and range-based solutions can be used for the acquisition of valuable data in medicine. However, most of these methods are not valid for non-static patients. Cranial deformation is a problem with high prevalence among infants and image-based solutions can be used to assess the degree of deformation and monitor the evolution of patients. However, it is required to deal with infants normal movement during the assessment in order to avoid sedation. Some high-end multiple-sensor image-based solutions allow the achievement of accurate 3D data for medical applications under unpredicted dynamic conditions in consultation. In this paper, a novel, single photogrammetric smartphone-based solution for cranial deformation assessment is presented. A coded cap is placed on the infant’s head and a guided smartphone app is used by the user to acquire the information, that is later processed on a server to obtain the 3D model. The smartphone app is designed to guide users with no knowledge of photogrammetry, computer vision or 3D modelling. The processing is fully automatic offline. The photogrammetric tool is also non-invasive, reacting well with quick and sudden infant’s movements. Therefore, it does not require sedation. This paper tackles the accuracy and repeatability analysis tested both for a single user (intrauser) and multiple non-expert user (interuser) on 3D printed head models. The results allow us to confirm an accuracy below 1.5 mm, which makes the system suitable for clinical practice by medical staff. The basic automatically-derived anthropometric linear magnitudes are also tested obtaining a mean variability of 0.6 ± 0.6 mm for the longitudinal and transversal distances and 1.4 ± 1.3 mm for the maximum perimeter.
... Due to its accuracy in elaborating detailed 3D models of human bodies, photogrammetry may become an essential tool in forensic pathology. This technique is simple, cost-effective, and its acceptance in the scientific community is increasing (2)(3)(4)(5)(6). ...
Photogrammetry is a technique that uses two-dimensional photographs taken from different angles and positions to determine three-dimensional coordinates and distances. Becoming familiar with the photography technique for photogrammetry purposes is the first step to obtaining high-quality results. Ten human cadavers were studied to develop this protocol. Appropriate equipment settings, measurements, and suitable ambient conditions were determined. Finally, the protocol was tested on one cadaver wherein a full postmortem examination was conducted, allowing accurate 3D modeling and measurements of the human body. This straightforward, step-by-step workflow will help users become familiar with this technique. A thorough description of the necessary steps is reported, including equipment, environment requirements, body placement, how to take photographs, and the minimum suggested number of photos. Numerous graphics show the protocol's main steps to help users understand and reproduce the entire process. Photogrammetry allows the permanent recording and storage of photographic evidence of conditions that existed at the time of autopsy and accurate measurements of the body. The 3D model can have a powerful effect in court, where the findings can be accurately depicted without elicitation of strong emotion that may influence the judge or jurors. The primary disadvantage of photogrammetry for forensic pathology is its time-consuming nature. However, the widespread use of the photogrammetry technique in postmortem rooms would allow in-depth testing to detect and fix potential pitfalls, making this technique more reproducible and verifiable, increasing its admissibility in courts.
... In such cases, the joint evaluation is of even higher importance. The morphometric 3D reconstruction [11,12] is based on the 3D documentation of the incident site [13,14], the involved cars and objects [15,16] and the deceased and / or injured [17][18][19][20][21][22][23]. Hence, it is a unique interdisciplinary approach for analysis and assessment. ...
In traffic accidents, the differentiation of run-over and other injuries is crucial because questions about the origin of fatal injuries often arise. It is sometimes difficult for forensic pathologists to answer them due to the superimposition of injuries or competing, potentially fatal findings. Therefore, using morphometric three-dimensional (3D) reconstructions offers new perspectives based on an interdisciplinary evaluation of all findings and traces.
The morphometric 3D reconstruction includes the allocation of patterned injuries or transferred material, the determination of the origin of injuries as well as the reconstruction of the incident. The generated 3D models of persons, clothes, vehicles, incident sites and relevant objects resulting from forensic imaging, photogrammetry, 3D structured-light and laser scanning are included, as are all detected traces and damages. Three case studies are presented to illustrate the possibilities and results of morphometric 3D reconstruction.
Run-over accidents have received less attention than the topic of pedestrian, bicycle and motorbike accident analysis for which there is a large body of literature. Our goal is to add to the understanding of run-over accidents using morphometric reconstruction in order to improve their analysis in the future.
The possibilities of morphometric reconstructions by means of 3D techniques in run-over accidents are wide-ranging and can provide new, unexpected and significant insights.
... First, the thumb volar surface was macrophotographed in diffuse light. A subset of the acquired images (altogether 40 photographs) were further processed using a photogrammetry protocol according to Urbanová et al. [25] and Jurda and Urbanová [26]. Once scaled, this produced a life-size textured three-dimensional model of the photographed surface. ...
Obtaining postmortem fingerprints from a mummified human corpse represents a challenging task. Mummification alters, often irreversibly, elasticity of the skin. It dries, hardens, and creases the body surface to a degree, making it very difficult to employ conventional fingerprinting techniques. The present paper introduces a contactless three-dimensional digital approach for re-establishing a crease-free skin surface and for acquiring a two-dimensional reproduction of the volar surface of a finger pad. The technique was developed while fingerprinting Baron Franz von der Trenck (1711-1749), an elite Austrian-Hungarian military officer, whose naturally mum-mified body rests in the Capuchin Crypt in Brno, Czech Republic. His disarticulated left thumb was documented using an Atos Capsule three-dimensional scanner and close-range photogrammetry. In order to obtain a f lat two-dimensional thumbprint, two techniques were proposed. One was based on digitally painted texture, which adheres on the ridges, but avoids the furrows. The other printed an enlarged physical replica of the volar surface built by employing PolyJet three-dimensional print technology. Both techniques successfully dealt with the rigidity and extensive wrinkling of the printed skin. The texture paint technique, however, depicted the skin characteristics uniformly and more clearly. The present case study lays down a foundation for incorporating an advanced three-dimensional virtual approach into fingerprint processing in the forensic context.
... У наш час у медицину та судово-медичну практику активно впроваджуються сучасні комп'ютерні програми та 3D технології. Це розширює можливості щодо пошуку нових і вдосконалення відомих методів візуалізації тілесних ушкоджень із метою ідентифікації знаряддя травми [3][4][5]. Більшість наукових розробок у галузі судової медицини з використанням елементів 3D моделювання спрямовані на відтворення місця злочину й обставин пригоди [6,7], створення тривимірних моделей переломів кісток для дистанцій- ного фрактологічного дослідження [8], просторової реконструкції площини перелому трубчастих кісток [9] тощо. Водночас, нез'ясованими на сьогодні залишаються питання щодо можливостей використання 3D технологій для ідентифікації знаряддя травми за морфологічними особливостями ушкоджень м'яких тканин і ранового каналу, спричинених колюче-ріжучими предметами. ...
... A recent study has shown that it can produce high quality 3d meshes, although no landmark-based analyses were performed. 25 The Pro-Face system is available as part of the ProMax cone-beam computed tomography scanning systems used in dental clinical settings. As the variety of commercially available imaging systems increases and before data can be compared for quantitative research studies of human facial shape, it is important to validate the different systems. ...
Numerous 3d imaging systems are now available commercially for the capture of facial shape data via landmarking or surface shape comparisons but it is not known whether these systems produce data of comparable quality. This study investigates the error associated with landmark coordinate data collected on facial surface images taken using three 3d imaging systems: the 3dMDface system (3dMD, Atlanta, GA), the Planmeca ProFace system (Planmeca, Roselle, IL), and the Vectra H1 handheld system (Canfield Scientific, Parsippany, NJ). This was a retrospective study involving 3d imaging data that used geometric morphometric analysis to assess overall shape differences as well as landmark-specific differences among the systems. Ten individuals evaluated at the NIDCR dental clinic on various protocols were imaged on all 3 systems. The subject pool consisted of syndromic and unaffected subjects, as disease status was irrelevant to the question of reproducibility and variability. Variation in landmark placement across systems was assessed by ANOVA, covariance matrix, and summary statistics. No overall shape or size differences were found among the systems. However, there was some landmark-specific variation and the 3dMD and Vectra systems were generally more similar to each other than either was to the Planmeca system. The data acquired by these 3 systems are comparable, although landmarks on the eyes and ears are noisy and most different among systems.
... 5,14,15 For these reasons it has been proven very effective in facial reconstructions, 16,17 assessment of skeletal features, 10,18 and trauma-related examinations. 5,12,19,20 Furthermore, because digital tools operate independently to the laws of physics, 5,11,21 they have enabled researchers to perform a wide range of operations unfeasible in real life. These operations, such as editing, analysis and visualization, have even reached various degrees of semior full automatization. ...
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Experts in forensic anthropology and medicine have become gradually accustomed to examining components of the human body in the virtual workspace. While the computer-assisted approach offers numerous benefits, the interactions with digital three-dimensional biological objects are often problematic, particularly if conducted with mouse, keyboard and flat-panel screen. The study focusses on feasibility of a virtual reality (VR) system for virtual restoration of fragmentary skeletal remains.
The VR system was confronted with three cases of fragmentary remains. The cases were reassembled manually by twenty participants using a HTC Vive headset combined with an in-house application A.R.T. The same task was performed using a CloudCompare software in conjunction with a desktop peripheral. The two systems were compared in terms of time efficiency, the geometric properties of the resulting restorations, and convenience of use.
Restoration using the VR system took approximately half the time the desktop set-up did. The VR system also yielded a lower error rate when a severely fragmented skull was reassembled. Ultimately, although the efficiency of the reassembling was shown to be strongly dependent on the operator's experience, the use of the VR system balanced out the uneven levels of proficiency in computer graphics.
The current generation of virtual reality headsets has a strong potential to facilitate and improve tasks relating to the virtual restoration of fragmented skeletal remains. A VR system offers an intuitive digital working environment which is less affected by an operator's computer skills and practical understanding of the technology than the desktop systems are.
... Similar methods, such as laser scanning and single-image photogrammetry (which uses similar principles to SfM), have been explored for forensic use. These applications include documentation of footwear and tool-mark impressions, skin and bone trauma modeling, blood spatter and motor vehicular accident reconstruction (6). ...
Applied SfM reconstructs models through image point comparisons. A 3D model is produced from a reference photoset that captures a 360-degree view of the subject, and the software employs triangulation to match specific points, datums, across individual photos. The datums are arranged into a point cloud that is then transformed into the final model. Modifying the point cloud into a final product requires algorithms that adjust the points by building a textured mesh from them. One of the disadvantages of SfM is that the point cloud can be “noisy,” meaning that the program is unable to distinguish the features of one datum from another due to similarities, creating coverage gaps within the meshed images. To compensate for this, the software can smooth portions of the model in a best-guess process during meshing. As commercial software does not disclose the adjustment algorithms, this documentation technique, while very useful in other disciplines that regularly apply SfM, such as archaeology, would fail to meet the standards of the Daubert and Kumho criteria.
A potential solution to this problem is to use open-source software, which discloses the adjustment algorithms to the user. It was hypothesized that the output of open-sourced software solutions would be as accurate as the models produced with commercial software and with total station mapping techniques. To evaluate this hypothesis, a series of mock outdoor crime scenes were documented using SfM and traditional mapping techniques. The scenes included a dispersed set of plastic human remains and various objects that might reasonably be associated with a crime scene. Ten of these scenes were laid out in 10m x 10m units in a New England forested environment, each grid with a slightly different composition, and then documented using a total station/data logger system and camera. The resulting models were built using PhotoScan® by AgiSoft®, the commercial software, and MicMac/Meshlab for Mac OSX as the open-source comparison software. However, accuracy is only part of the concern; the full utility of any one of the workflows is defined additionally by the overall cost effectiveness (affordability and accessibility) and the visual quality of the final model. Accuracy was measured by the amount of variance in fixed-datum measurements (example, femur length) that remained consistent, while visual quality of the photogrammetric model was determined by the ability to see non-fixed datums (example, a syringe) that moved locations between grids.
While there was variance in the metric outputs between the total station and photogrammetric models, the average total variance from an individual scene, regarding the fixed-datum lengths, fell within 0.635cm. This standard is the recommended measurement accuracy for scene documentation as suggested by “The Technical Working Group on Crime Scene Investigation.”1 However, the quality of the SfM model was extremely variable, with smaller objects and details being lost entirely. Conditions such as light, ground foliage, and topography were found to effect model quality significantly, as well as the amount of available computing power. There was no issue of losing objects or computing power when mapping by total station and processing the data in AutoCAD®. This research demonstrates that there is potential for SfM to be a rapid, accurate, and low-cost resource for research and forensic investigation, but there are limitations that must be taken into consideration.
... In the past two decades, photogrammetric techniques have been used in various studies to illustrate their applicability in the field of forensic medicine [10][11][12][13][14][15][16][17][18][19][20]. 3D imaging techniques are now commonly used and have become beneficial tools in keeping with the aims of forensic investigations [21][22][23][24][25][26][27][28][29][30][31]. ...
Two-dimensional photographic documentation is a substantial part of post-mortem examinations for legal investigations. Additional three-dimensional surface documentation has been shown to assist in the visualization of findings and contribute to the reconstruction of the sequence of events. However, 2D photo documentation and, especially, 3D surface documentation, are time-consuming procedures that require specially trained personnel. In this study a 3D imaging system, called VirtoScan-on-Rails, was developed to automate and facilitate 3D surface documentation for photo documentation in autopsy suites. The imaging system was built to quickly acquire photogrammetric image sets of whole bodies during different stages of external and internal examinations. VirtoScan-on-Rails was set up in the autopsy suite of the Zurich Institute of Forensic Medicine at the University of Zurich (Zurich, Switzerland). The imaging system is based on a movable frame that carries a multi-camera array. Data quality and the applicability of the system were analyzed and evaluated within two test series. Up to 200 overlapping photographic images were acquired at consecutive image-capturing positions over a distance of approximately 2000 mm. The image-capturing process took 1 min and 23 s to acquire a set of 200 images for one side of the body. During test series one and two, 53 photogrammetric image sets taken from 31 forensic cases were successfully reconstructed. VirtoScan-on-Rails is an automated, fast and easy-to-use 3D imaging setup for autopsy suits. It facilitates documenting bodies during different stages of forensic examinations and allows standardizing the procedure of photo documentation.
... Generally, the optical measurement techniques can be classified into two main categories: (a) approaches that use laser beams and (b) approaches that use white light. Laser surface scanners are based on laser beams, which move across the scanned surface and reflect back to a light sensor [27] . The second class works by using white light and is called image based systems. ...
Recently, fiber-reinforced composites are widely used in manufacturing of large storage tanks for transportation purposes, thanks to their excellent mechanical and chemical performance, and their good applicability to the shaping of particular geometries. In this contribution, a non-contact 3D optical deformation measurement technique is proposed for monitoring the deformation of carbon-fiber reinforced composite tank subjected to different loading scenarios, which could not be achieved by traditional displacement sensors and resistance strain gauges due to large measuring ranges. This technique is based on the close-range photogrammetry technology, wherein 3D information is extracted from two-dimensional photographs. This is done by positioning artificial reference point markers on the measuring tank before loading, and calculate the 3D coordinates of these markers through analyzing the group photos captured in each loading stage. By tracking and comparing the 3D coordinates of the point markers among different loading stages, the 3D deformation of the tank is obtained. The loading tests comprise both hydrostatic pressure and water-pressurizing tests. The performed in-situ measurements show that the proposed technique can fulfill the efficiency and accuracy requirement of deformation measurement in tank loading tests. This in turn significantly contributes to better understanding the mechanical response at the macroscopic scale, thus improving safety performance.
... However, using photography and image analysis to gauge removal rates does not produce perfect results, since the bowl's three-dimensional surface is analysed in a two-dimensional photograph. Photogrammetric methods to develop a three-dimensional image from several two-dimensional photographs of the same object, for example used in medical (Patias, 2002) and forensic research (Urbanová et al., 2015), could be used to deliver more accurate results. ...
A prototype of a non-fluid based mechanical toilet flush was tested in a semi-public, institutional setting and in selected peri-urban households in eThekwini municipality, Republic of South Africa. The mechanism’s functionality and users’ perception of the flush were assessed. User perception varied depending on background: Users accustomed to porcelain water flush toilets were open to, yet reserved about the idea of using a waterless flush in their homes. Those who commonly use Urine Diversion Dehydration Toilets were far more receptive. The user-centred field trials were complemented by a controlled laboratory experiment, using synthetic urine, -faeces, and -menstrual blood, to systematically assess the efficiency of three swipe materials to clean the rotating bowl of the flush. A silicone rubber with oil-bleed-effect was found to be the best performing material for the swipe. Lubrication of the bowl prior to use further reduced fouling. A mechanical waterless flush that does not require consumables, like plastic wrappers, is a novelty and could – implemented in existing dry toilet systems – improve acceptance and thus the success of waterless sanitation.
... After the capture process, all image data are imported into 3D software that will generate the 3D model step by step [102]. The first step is a fully automatic alignment of the images. ...
Modern post-mortem investigations use an increasing number of digital imaging methods, which can be collected under the term “post-mortem imaging”. Most methods of forensic imaging are from the radiology field and are therefore techniques that show the interior of the body with technologies such as X-ray or magnetic resonance imaging. To digitally image the surface of the body, other techniques are regularly applied, e.g. three-dimensional (3D) surface scanning (3DSS) or photogrammetry. Today's most frequently used techniques include post-mortem computed tomography (PMCT), post-mortem magnetic resonance imaging (PMMR), post-mortem computed tomographic angiography (PMCTA) and 3DSS or photogrammetry. Each of these methods has specific advantages and limitations. Therefore, the indications for using each method are different. While PMCT gives a rapid overview of the interior of the body and depicts the skeletal system and radiopaque foreign bodies, PMMR allows investigation of soft tissues and parenchymal organs. PMCTA is the method of choice for viewing the vascular system and detecting sources of bleeding. However, none of those radiological methods allow a detailed digital view of the body's surface, which makes 3DSS the best choice for such a purpose. If 3D surface scanners are not available, photogrammetry is an alternative. This review article gives an overview of different imaging techniques and explains their applications, advantages and limitations. We hope it will improve understanding of the methods.
... They also mention the long calculation times, which hampers the possibility of real-time visualization at the crime scene. These downsides were also mentioned by Urbanova et al., who demonstrated the use of SfM for the documentation of a human body during autopsy (18), which required long postprocessing times and failed when the body was covered with hair or reflective moist areas. The image collection however was fast, and high-resolution, photorealistic, real sized 3D surface models were easily created. ...
Photogrammetry is a method for obtaining virtual 3D models of objects and scenes. The technique is increasingly used to record the crime scene in its original, undisturbed state for mapping, analytical and reconstruction purposes. Recently, it was shown that it is possible to visualize and/or chemically analyze latent traces by using advanced cameras which either operate in wavelength ranges beyond the visible range, and/or are able to obtain spectrally resolved images. The combination of these advanced cameras and photogrammetric techniques enables the 3D registration of valuable information. We successfully explored the feasibility to obtain visible, infrared, hyperspectral and thermal 3D registrations of simulated crime scenes using photogrammetry, and demonstrate the possibilities and practical challenges for use in forensic practice.
Recreation of 3D crime scenes is critical for law enforcement in the investigation of serious crimes for criminal justice responses. This work presents a premier systematic literature review (SLR) that offers a structured, methodical, and rigorous approach to understanding the trend of research in 3D crime scene reconstruction as well as tools, technologies, methods, and techniques employed thereof in the last 17 years. Major credible scholarly database sources, Scopus, and Google Scholar, which index journals and conferences that are promoted by entities such as IEEE, ACM, Elsevier, and SpringerLink were explored as data sources. Of the initial 17, 912 papers that resulted from the first search string, 258 were found to be relevant to our research questions after implementing the inclusion and exclusion criteria. To summarize the existing efforts, we compared and analysed various classical 3D reconstruction approaches. This study presents the first comprehensive review of key milestones in the development of methods for 3D crime scene reconstruction, gaps for improvement and where immersive technology has been used to enhance crime scene findings. This study found that the implementation of light detection and ranging (LiDAR) scanners and immersive technologies, alongside traditional methods, has been beneficial in the recreation of crime scenes. The SLR is limited to existing applications with peer-reviewed papers published between 2005 and 2021. Results based on the analysed published data indicated that 20.2% of the articles implemented immersive technologies in crime scene reconstruction, of which Augmented Reality (AR) accounted for 15.3%, Virtual Reality (VR) accounted for 75%, Mixed reality (MR) accounted for 5.9% and VR and AR mixture accounted for 3.8%. Finally, we summarize the development trend of design and key technology prospects of crime scene recreation using immersive technology and provide insights into potential future research. To the best of the researchers’ knowledge, this is the first survey that accomplishes such goals.
Multispectral photography offers a wide range of applications for forensic investigations. It is commonly used to detect latent evidence and to enhance the visibility of findings. Additionally, three-dimensional (3D) full-body documentation has become much easier and more affordable in recent years. However, the benefits of performing 3D imaging beyond the visible (VIS) spectrum are not well known, and the technique has not been widely used in forensic medical investigations. A multicamera setup was used to employ multispectral photogrammetry between 365 and 960 nm in postmortem investigations. The multicamera setup included four modified digital cameras, ultraviolet (UV) and near-infrared (NIR) light sources and supplemental lens filters. Full-body documentation was performed in conjunction with the use of a medical X-ray computed tomography (CT) scanner to automate the imaging procedure. Textured 3D models based on multispectral datasets from four example cases were reconstructed successfully. The level of detail and overall quality of the 3D reconstructions varied depending on the spectral range of the image data. Generally, the NIR datasets showed enhanced visibility of vein patterns and specific injuries, whereas the UV-induced datasets highlighted foreign substances on the skin. Three-dimensional multispectral full-body imaging enables the detection of latent evidence that is invisible to the naked eye and allows visualization, documentation and analysis of evidence beyond the VIS spectrum.
Current approaches for assessment of acne scars are subjective. We aimed to evaluate the reliability and feasibility of a new objective stereoscopic optical system for atrophic acne scars cumulative depth and monitoring therapeutic response.
This retrospective case study aimed to validate accuracy and present initial data of a new, simple, non-contact, high-resolution 3D stereoscopic optical imaging system (Cherry Imaging, Yokneam, Israel) in the setting of acne scarring. Feasibility of the system was assessed by monitoring the cumulative depth of atrophic acne scars after a single treatment by means of various approaches. investigator’s Qualitative Scarring Grading Score (QSGS) and patient’s Self-Assessment of Clinical Acne-Related Scars (SCARS) were also calculated before and four weeks after the intervention.
Scar depth measured by the imaging system correlated significantly with the actual depth of printed surface depressions. The changes in SCARS and 3D optical imaging assessments correlated significantly (R=0.68, P = 0.012), but there were no correlations between changes in QSGS and 3D optical assessment measures, or between the QSGS and SCARS results.
The new stereoscopic optical system is a reliable and practical objective method for assessing the cumulative depth of atrophic acne scars and monitoring treatment response. It is more sensitive, accurate, and informative than subjective scales.
Worldwide advances in computer techniques are not yet recognised in the practice of forensic medicine. A promising application is their use in making a three-dimensional reconstruction of the crime scene. This study analyses this technique in a homicide by firearm. Queries regarding the direction and number of shots, position of the victim inside the car when shot at and presence of the accused at the crime scene were answered by a scientific model. Similar reconstruction of the scene, nailing the accused in a heinous crime, has not previously been reported as a study or a case. The paper anticipates impetus to the growth of literature in criminology and forensic sciences. It will also expedite the delivery of justice based on scientific evidence in controversial causes of death.
The spatial structure building is a type of building system; it is necessary to monitor deformation to determine its stability and robustness. Under the dynamic deformation of structures, it is challenging to determine appropriate zero image (the reference image) if we use the PST-IM- MP (photograph scale transformation-image matching-motion parallax) method to obtain the deformation of structures. This paper offers the Z-MP (zero-centered motion parallax) method to solve these problems and offers PDMS (Photography Dynamic Monitoring System) based on the digital photography system to monitor the dynamic deformation of the tennis stadium located in Jinan Olympic Sports Center. The results showed that the spatial structures of the tennis stadium were robust, and the deformations were elastic and within the permissible value. Compared with the PST-IM-MP method, the Z-MP method is more suitable for deformation monitoring structures under real-time deformation. This paper indicates PDMS has advantages of the simplicity of operations, automation, and the ability of non-contact dynamic deformation monitoring for multiple points in a short period. In the future, it will have broader application prospects.
A fotogrammetria – amely az objektumok fényképfelvételek felhasználásával történő háromdimenziós rekonstrukcióját lehetővé tévő technológia – egyre gyakrabban merül fel a nemzetközi szakirodalomban a 3D lézerszkennelés alternatívájaként. A módszer, amely speciális eszközt nem igényel, és amelynek alkalmazására a bűnügyi technikus is képes, alkalmas lehet helyszínek, holttestek, valamint egyes tárgyak háromdimenziós, kriminalisztikai célú rögzítésére is. Az így készült háromdimenziós modelleket mind a bűnüldöző szervek, mind pedig a bíróság vagy akár az igazságügyi szakértők is felhasználhatják a helyszínek és az egyéb rekonstruált objektumok megtekintésére. A módszer a jövőben alkalmas lehet oktatási célokra, bűnügyi nyilvántartásba vételre vagy akár helyszíni kihallgatások, illetve más bizonyítási cselekmények foganatosítására is. A magyar jogi szabályozás, valamint a jelenleg kidolgozás alatt álló európai szabványok tükrében előre láthatólag nincsen akadálya a fotogrammetriai eljárások gyakorlatban történő alkalmazásának. A szakszerű módszertani keret kialakítása érdekében további kutatások elvégzése szükséges.
Various dentistry fields such as teeth treatment, dental restoration, and denture
production require the application of three-dimensional intraoral scanners to create digital
impressions. This study presents a method to reconstruct a three-dimensional teeth crown by
utilizing a prototype intraoral custom design with publicly available software. The system
consists of custom containing an endoscope camera and two light sources (white LED and blue
laser), a personal control computer, and photogrammetric open source software packages
(VisualSFM, CMVS/PMVS, and MeshLab). Photogrammetry methods were used to acquire the
three-dimensional teeth model with high precision. Multi images have been captured of the
interesting teeth using the custom system from different angles. The capturing process was done
in two phases using one illumination source each time. The captured images are loading to
Photogrammetry software to generate the three-dimensional dense point cloud. A comparison
has been made of the resulted dense point cloud at each phase. Finally, the dense point cloud is
loading to MeshLab software to generate the three-dimensional mesh that can be utilized in
CAD/CAM software. The results have shown the superiority of using blue illumination with the
photogrammetry software that shows good accuracy of teeth crown details and measurements
that are related to the reconstruction algorithm which yields in more number of 3D points of the
object to generate good three-dimensional meshes of the teeth crown. This study helps to offer
low cost, simple design, and a user-friendly system to generate a three-dimensional teeth crown.
Over the years, digital photography in dermatology has been proven to be an indispensable tool for documenting various diseases for clinical, scientific, didactic, and medico-legal aims, for archiving and for medical-scientific communication. Three-dimensional imaging is a new branch of digital photography with countless advantages. Thanks to specific software, the elaboration of the image allows to evaluate in an objective way the pigmentation, the vascular characteristics, and the skin texture and to measure areas and volumes. The observation of the photographic images is of paramount importance both for a correct diagnosis aimed at the choice of the best therapeutic approach and for a correct evaluation in follow-up, through the comparison between the images “before and after.” The fields of application are from clinical medicine to surgery, from esthetics to the prevention of skin tumors. Today the focus is on new 3D systems that allow to store, to analyze, and to reproduce healthy and pathological skin in a more detailed way and in accordance with reality.
Objective
To evaluate the feasibility of a phone camera and cloud service-based workflow to image bone specimens and print their three-dimensional (3D) models for anatomical education.
Design
The images of four typical human bone specimens, photographed by a phone camera, were aligned and converted into digital images for incorporation into a digital model through the Get3D website and submitted to an online 3D printing platform to obtain the 3D printed models. The fidelity of the 3D digital, printed models relative to the original specimens, was evaluated through anatomical annotations and 3D scanning.
Setting
The Morphologic Science Experimental Center, Central South University, China.
Participants
Specimens of four typical bones—the femur, rib, cervical vertebra and skull—were used to evaluate the feasibility of the workflow.
Outcome measures
The gross fidelity of anatomical features within the digital models and 3D printed models was evaluated first using anatomical annotations in reference to Netter’s Atlas of Human Anatomy. The measurements of the deviation were quantised and visualised for analysis in Geomagic Control 2015.
Results
All the specimens were reconstructed in 3D and printed using this workflow. The overall morphology of the digital and 3D printed models displayed a large extent of similarity to the corresponding specimens from a gross anatomical perspective. A high degree of similarity was also noticed in the quantitative analysis, with distance deviations ≤2 mm present among 99% of the random sampling points that were tested.
Conclusion
The photogrammetric digitisation workflow adapted in the present study demonstrates fairly high precision with relatively low cost and fewer equipment requirements. This workflow is expected to be used in morphological/anatomical science education, particularly in institutions and schools with limited funds or in certain field research projects involving the fast acquisition of 3D digital data on human/animal bone specimens or on other remains.
The rapid proliferation of 3D imaging in mainstream science is changing the quality and quantity of data that can be obtained. In the study of human remains, the structures and variations of the skeleton holds significant probative value in reconstructing the biological and physical history of that individual. As such, these new 3D tools are being successfully applied in the visualisation and assessment of human remains across forensic and archaeological contexts. However, while the practical applications are being discussed in the published literature, there has been little to no consideration of the more conceptual issues around the widespread use of these novel technologies in human remains disciplines. 3D imaging is producing increasingly accurate and realistic models that share many physical traits, and cultural and societal significances with the original skeletal remains. These are serious causes of concern for the ownership, sharing, and use of these resultant 3D digitisations, especially since there are already unique ethical challenges in the study and use of human remains. This chapter will discuss these issues within the context of a survey which revealed conflicting opinions between researchers and curators concerning the use, ownership, and ethics of 3D digital data of human remains.
Extreme aerial sports are a large subgroup of extreme sports. Participation in these activities has grown exponentially in the last decades, often surpassing traditional sports. Although fatalities related to extreme aerial sports are often generically ascribed to polytrauma, an autopsy can reveal unexpected elements in many cases. Forensic studies may lead us to ascertain different causes of death, such as anaphylaxis or myocardial infarction and together with eyewitness reports, they may make it possible to clarify the chain of events that led to an accident. This review paper may be critical not only for medico-legal reasons but also to provide useful information for the development of preventive measures, specific recommendations and safety systems. The paper aims to review available data about fatality rates, causes and dynamics in extreme aerial sports and to draw some possible conclusions about the role of forensic examinations in these sports.
Crime scene reconstruction plays a significant role in crime solving by helping to determine the course of events. Non-invasive, high-resolution measurement and increased insight are always the goal of forensic crime scene documentation. However, entire crime scenes cannot be effectively reconstructed with traditional methods. In this study, we present a portable system that consists of a laser scanner, two hand-held structured light scanners and a low-cost virtual reality (VR) headset with a mobile power supply to conduct multi-angle and omnidirectional three-dimensional spatial data collection of crime scenes. To demonstrate practical use, a real case has been analysed to verify the feasibility and effectiveness of the system.
The system accurately obtains information on decedent injuries, possible injury-inflicting tools and on-site traces. Various types of evidence from the crime scene can be jointly studied by three-dimensional visualization to develop a cohesive story. The data are presented via immersive VR rather than displayed on computer screens. The relationship between evidence chains enables us to achieve a complete crime scene reconstruction, using the specialized knowledge of experts and computer-aided forensic tools to analyse the causes of damage and identify suspects. The use of three- dimensional imaging techniques allows a more insightful survey and several useful analyses, such as accurate measurement, relative blood source location determination and injury-inflicting tool comparison.
Adventure and extreme sports (AESs) are associated with high risk of injury and even death. This has important ramifications for sport, education, medical and health professions and has led to discussions about the appropriateness of AESs for young people. For some, participation in AESs reflects social deviance. Research from this perspective has focused on testing this notion. However, in recent years research has questioned the perceived link to risk arguing that many acceptable activities might be ‘riskier’. Research from this perspective focuses on the positive side of AESs. Evidence points to a growing interest in AESs by young people and that AES activities might be useful to enhance the uptake of and adherence to physical activity, and support mental wellbeing in young people. This perspective suggests (1) AESs are important for the overall development of young people, (2) policy makers across sectors should recognize AESs when considering future interventions.
Various imaging modalities, including conventional radiography, computed tomography, magnetic resonance, and surface scanning have been applied in the examination of skeletal injuries in the forensic context. Although still not a substitute for a full medico-legal autopsy or the examination of skeletal remains, imaging is now increasingly used as a complementary tool in the postmortem analysis of perimortem skeletal trauma. Facilitated by the progress in general computational capacity, multimodal imaging has been proposed for comprehensive forensic documentation. A major advantage of these imaging approaches is that stored digital or physical 3D models of skeletal injuries can be reviewed at any time by various experts as well as be presented in court as evidence to clarify potentially complex medical and forensic aspects of the case. Due to constant technical progress in imaging techniques and software, continuous education, training, and sharing of expertise among engineers, computer scientists, and forensic experts, including forensic pathologists, anthropologists, and radiologists needs to be warranted to maintain high-quality expertise in the detection and interpretation of traumatic injuries on postmortem imaging. The technical developments and ever-improving user-friendliness of 3D imaging and modeling techniques present an atttactive alternative to traditional forensic approaches, but as long as the techniques have not been sufficiently tested and validated for forensic trauma analysis, and best practice manuals for forensic practice are lacking for both the technical procedures and method selection, the use of imaging techniques needs to be reevaluated on a case-by-case basis. In addition, ethical, legal, and financial aspects of the use of imaging and 3D modeling for forensic purposes need to be well understood by all parties in legal proceedings.
With the current deterioration rate of existing infrastructure, the importance of intervention and preservation efforts such as on-site visual inspections, non-destructive evaluation, structural health monitoring (SHM), and building pathology are on the rise. A critical aspect of these intervention and preservation methods is the visualization and accessibility of large, heterogeneous data sets. To enable diverse stakeholders to make informed choices, data and metadata for the built environment needs to be directly integrated into a user's viewing environment. To address this challenge, a human-machine interface which organizes these types of data and provides actionable information is necessary. The main aim of this work is to develop a preliminary framework for documenting and visualizing data about the built environment both on and off site using a combination of image-based documentation and augmented reality (AR). While this work illustrates preliminary annotation mechanisms such as drawing, the concept of projecting data between the image-based environment and the AR environment is the main contribution of this work. This method was applied to test objects as well as case studies in SHM and building pathology.
Purposes: Accurate measurements of the cerebrospinal fluid that flows through the prepontine cistern (PPC) are challenging due to artefacts originating from basilar artery blood flow. We aim to accurately quantify cerebrospinal fluid (CSF) flow and stroke volume in the PPC, which is essential before endoscopic third ventriculostomy.
Materials and methods: We developed a new PC-MRI sequence prepared with Hadamard saturation bands to accurately quantify CSF flow in the PPC by suppressing the blood signal in the surrounding vessels. In total, 28 adult hydrocephalic patients (age 59 ± 20 years) were scanned using conventional PC-MRI and our developed sequence. CSF was separately extracted from the PPC and the foramen of Magendie, and flow (min and max) and stroke volume were quantified.
Results: Our modifications result in a complete deletion of signal from flowing blood, resulting in significantly reduced CSF stroke vol- ume (Conv = 446 ± 113 mm3, Dev = 390 ± 119 mm3, p = 0.006) and flow, both minimum (Conv = −1630 ± 486 mm3/s, Dev = −1430 ± 406 mm3/s, p = 0.005) and maximum (Conv = 2384 ± 657 mm3 /s, Dev = 1971 ± 62 mm3 /s, p = 0.002) compared with the conventional sequence, whereas no change in the area of interest was noted (Conv = 236 ± 65 mm2, Dev = 249 ± 75 mm2, p = 0.21).
Conclusions: Accurate and reproducible CSF flow and stroke volume measurements in the PPC can be achieved with sat-band prepared cine PC-MRI.
The shape of the orbital rim is one of the essential craniofacial features that play a
crucial role in face perception, recognition, or personal identification. As a consequence, it
continues to attract a large variety of researchers, e.g., skeletal or forensic anthropologists,
anatomists, physicians, psychologists etc. Despite being a focus since the rise of traditional
anthropometrics, the 3-D nature of the orbital rim has not been satisfactorily quantified. This
paper presents an approach to numerically describe the within- and among-population shape
variation of the orbital rim, its curviness and spatial orientation using elliptic Fourier
analysis. The sample consisted of 336 crania from present-day skeletal collections (Czech
Republic, Portugal). For each specimen, a pair of orbital outlines was recorded using the
MicroScribe G2X, a portable digitizer. Regardless of the body side, the trace line started and
ended at dacryon located on the inner margin of the orbital rim. Cartesian coordinates of
three fixed points defining a 3-D Frankfurt Horizontal plane were also acquired. In order to
align for spatial orientation of the orbits, each pair was rotated to the Frankfurt Horizontal.
The outlines were divided into 150 evenly distributed points and subsequently processed
using elliptic Fourier analysis with 20 harmonics. The results showed that the specimen’s
population affinity, sex, age and body size are factors responsible for the shape of the orbital
rim. In contrast to the generally assumed pattern of sex differences, the shape of frontallyviewed
orbits failed to act as a good sex predictor. Sex-related differences, as described by 3-
D shape analysis, were linked mostly to a specific “curviness” and to spatial arrangement of
orbits within the craniofacial skeleton. Whereas the male orbital outline is characteristically
curved and placed in the frontal plane, the female outline is flat and diverged. The results
demonstrate that elliptic Fourier analysis is a powerful methodological tool that can provide
new insights into the structural relationships within biological objects.
We present a real-time 3D face identification system using a consumer level depth camera (PrimeSensor). Our system takes a noisy sequence as input and produces reliable identification. Instead of registering a probe to all instances in the database, we propose to only register it with several intermediate references, which considerably reduces processing, while preserving the recognition rate. The presented system routinely achieves 100% identification rate when matching a (0.5-4 seconds) video sequence, and 97.9% for single frame recognition. These numbers refer to a real-world dataset of 20 people. The methodology extends directly to very large datasets. The process runs at 20fps on an off the shelf laptop.
In this paper we present the second prototype of a robotic system to be used in forensic medicine. The system is capable of performing automated surface documentation using photogrammetry, optical surface scanning and image-guided, post-mortem needle placement for tissue sampling, liquid sampling, or the placement of guide wires. The upgraded system includes workflow optimizations, an automatic tool-change mechanism, a new software module for trajectory planning and a fully automatic computed tomography-data-set registration algorithm. We tested the placement accuracy of the system by using a needle phantom with radiopaque markers as targets. The system is routinely used for surface documentation and resulted in 24 surface documentations over the course of 11 months. We performed accuracy tests for needle placement using a biopsy phantom, and the Virtobot placed introducer needles with an accuracy of 1.4 mm (±0.9 mm). The second prototype of the Virtobot system is an upgrade of the first prototype but mainly focuses on streamlining the workflow and increasing the level of automation and also has an easier user interface. These upgrades make the Virtobot a potentially valuable tool for case documentation in a scalpel-free setting that uses purely imaging techniques and minimally invasive procedures and is the next step toward the future of virtual autopsy.
In light of declining autopsy rates around the world, post-mortem MR imaging is a promising alternative to conventional autopsy in the investigation of infant death. A major drawback of this non-invasive autopsy approach is the fact that histopathological and microbiological examination of the tissue is not possible. The objective of this prospective study is to compare the performance of minimally invasive, virtual autopsy, including CT-guided biopsy, with conventional autopsy procedures in a paediatric population.Methods/design: Foetuses, newborns and infants that are referred for autopsy at three different institutions associated with the University of Zurich will be eligible for recruitment. All bodies will be examined with a commercial CT and a 3 Tesla MRI scanner, masked to the results of conventional autopsy. After cross-sectional imaging, CT-guided tissue sampling will be performed by a multifunctional robotic system (Virtobot) allowing for automated post-mortem biopsies. Virtual autopsy results will be classified with regards to the likely final diagnosis and major pathological findings and compared to the results of conventional autopsy, which remains the diagnostic gold standard.
There is an urgent need for the development of alternative post-mortem examination methods, not only as a counselling tool for families and as a quality control measure for clinical diagnosis and treatment but also as an instrument to advance medical knowledge and clinical practice. This interdisciplinary study will determine whether virtual autopsy will narrow the gap in information between non-invasive and traditional autopsy procedures.Trial Registration: ClinicalTrials.gov: NCT01888380.
Three-dimensional measurements made using photogrammetry have recently gained popularity with the development of real-time detection facilities and up-to-date equipment. The modelling of human bones presents a particular challenge as the measurements required are difficult to obtain, especially from uneven surfaces. In this study, the articular surfaces of 12 radius bones were evaluated using photogrammetry to obtain three-dimensional coordinates of certain points. Morphometric characteristics of the digital topography of the articular surface were analysed using three-dimensional data from more than 200 points for each specimen. The coronal plane curve, from the tip of the styloid process to the centre of the distal radioulnar articular notch, was found to be similar to the fourth degree polynomial function. A mathematical expression representing the sagittal curve passing through scapholunate border could not be found. Close-range photogrammetry is a safe and precise technique that can provide reliable, reproducible and accurate data for evaluating complex morphological surfaces.
Forensic Pathology for Police, Death Investigators, Attorneys, and Forensic Scientists is a forensic pathology book specifically written for professionals who interact with forensic pathologists. The book includes sections that address various general topics which are not normally present in the typical forensic pathology text, such as descriptions of medical, pathology and forensic pathology training, basic anatomy and physiology, an overview of other forensic science disciplines, and autopsy performance. Forensic Pathology for Police, Death Investigators, Attorneys, and Forensic Scientists also covers classic topics in forensic pathology, including death investigation, death certification, postmortem changes, and the entire range of case types, ranging from natural deaths to drug-related deaths to various types of violent death. The text is written in easy-to-understand language, and is complemented by hundreds of high-quality photographs. © Springer Science+Business Media, LLC 2010 All rights reserved.
In recent decades, three-dimensional (3D) surface-imaging technologies have gained popularity worldwide, but because most published articles that mention them are technical, clinicians often have difficulties gaining a proper understanding of them. This article aims to provide the reader with relevant information on 3D surface-imaging systems. In it, we compare the most recent technologies to reveal their differences.
We have accessed five international companies with the latest technologies in 3D surface-imaging systems: 3dMD, Axisthree, Canfield, Crisalix and Dimensional Imaging (Di3D; in alphabetical order). We evaluated their technical equipment, independent validation studies and corporate backgrounds.
The fastest capturing devices are the 3dMD and Di3D systems, capable of capturing images within 1.5 and 1 ms, respectively. All companies provide software for tissue modifications. Additionally, 3dMD, Canfield and Di3D can fuse computed tomography (CT)/cone-beam computed tomography (CBCT) images into their 3D surface-imaging data. 3dMD and Di3D provide 4D capture systems, which allow capturing the movement of a 3D surface over time. Crisalix greatly differs from the other four systems as it is purely web based and realised via cloud computing.
3D surface-imaging systems are becoming important in today's plastic surgical set-ups, taking surgeons to a new level of communication with patients, surgical planning and outcome evaluation. Technologies used in 3D surface-imaging systems and their intended field of application vary within the companies evaluated. Potential users should define their requirements and assignment of 3D surface-imaging systems in their clinical as research environment before making the final decision for purchase.
In this pilot study, the authors tested whether photogrammetry can replace or supplement physical measurements made during autopsies and, based on such measurements, whether virtual computer models may be applicable in forensic reconstructions. Photogrammetric and physical measurements of markers denoting wounds on five volunteers were compared. Virtual models of the volunteers were made, and the precision of the markers' locations on the models was tested. Twelve of 13 mean differences between photogrammetric and physical measurements were below 1 cm, which indicates that the photogrammetric method has a high accuracy. The precision of the markers' location on the models was somewhat less, although the method is still promising and potentially superior to the current procedures used for reconstructions. The possibility to measure any distance on a body, even after the autopsy is concluded and the corpse is no longer available, is one of the biggest benefits of photogrammetry.
The increasing availability of 3D data and tools offers new analytical perspectives in palaeoanthropology, such as the quantitative testing of opposing phylogenetic scenarios. Using optical surface scan data and geometric morphometric techniques, this study explores calvarial shape variation in the “Middle Pleistocene muddle”. The morphological variability between H. erectus on the one hand and H. sapiens/neanderthalensis on the other has long remained obscure: opposing views have attributed the known specimens to any of the three species and possibly one or two more. A large number of landmarks and semilandmarks was extracted from the braincase and the face, in order to quantify the calvarial shape differences among species and key fossils. The results are incompatible with the hypothesis that H. rhodesiensis is the exclusive ancestor of H. sapiens, and offer only weak support for an exclusively European ancestor of Neandertals.
Purpose:
This study evaluated the usefulness of multidetector computed tomography (MDCT) in the postmortem diagnosis of death by drowning in fresh water by measuring the difference of blood density within the cardiac chambers.
Materials and methods:
Twenty-two corpses including six cases of fresh-water drowning (group A) and 16 deaths by other causes (group B), among which were also different forms of mechanical asphyxia other than drowning, underwent MDCT and conventional autopsy. Blood density within the right and left heart chambers, the aorta and the pulmonary trunk was measured and values compared between groups and within each group between heart chambers.
Results:
Blood density in all cardiac chambers was lower in group A than in group B. The difference was statistically significant within the left atrium and ventricle and was significantly lower in the left than in the right heart chambers in group A only.
Conclusions:
MDCT, together with conventional autopsy, may contribute to the diagnosis of drowning, by measuring blood density in the heart chambers.
Thanks to recent advances, computed tomography is now seen as a tool of great value in the field of physical anthropology. In this study, we focused on the posterior pelvis and the auricular surface and evaluated the accuracy of 3D reconstructions of the auricular surface, using a methodology derived from a previous study by Lovejoy et al. We also looked for trabecular bone criteria expressing age-related changes. Forty-six coxal bones were scanned, and scoring of macroscopic criteria showed a good agreement between 3D reconstructions and photographs, especially for transverse organization (k = 0.90). The changes occurring in the posterior part of the sacropubic trabecular bundle were evaluated on CT reconstructions via three new criteria, which exhibited a good intra- and inter-observer agreement (k = 0.77–0.89), and were particularly useful in identifying older subjects. We concluded that these CT-evaluated trabecular bone criteria are promising and yield useful information about age at death.
Since the earliest days of photogrammetry, there have been photogrammetrists who have directed research effort towards medical measurement. Although the specific motivation for these studies has not always been disclosed, it is probably because of the various benefits that photogrammetry can offer to humanity as a painless and non-invasive means of providing medical practitioners with spatial measurement relating to the human body. The intention of this paper is to reflect on the place of the many medical developments within the photogrammetric world. The various photogrammetric applications in medicine are summarised to identify the characteristics of medical photogrammetry, and it becomes evident that medical photogrammetrists have developed a range of body measurements using widely varying photogrammetric techniques, in response to the demands for specialised spatial measurement tools for a wide variety of medical ends. This volume of research activity has made medical measurement a substantial and varied sector of non-mapping photogrammetry. It is also clear that there are numerous challenges to the design of medical photogrammetric systems. They must give paramount consideration to the human patients and their comfort; they must yield not simply spatial data about the body but rather specific medical information. At the same time, it is of concern that non-photogrammetric scientists and engineers have developed medical measurement systems based on both photogrammetric and other optical techniques. Fortunately, photogrammetrists can also contribute to medical problems through their spatial data experiences. It is concluded that the many distinctive challenges mean that medical photogrammetry has not yet been as successful at changing the world as the extensive efforts applied to it suggest, but nevertheless, medical photogrammetry deserves to be recognised as a category of close range photogrammetry which remains a valuable pursuit which should not be abandoned because of any difficulties.
Graphic and metric archaeological documentation is an activity that requires the capture of information from different sources, accurate processing and comprehensive analysis. If monitoring of the state of conservation is required, this task has to be performed before intervention, during and after the completion of the works in a repetitive way.This paper presents the use of terrestrial laser scanning (TLS) in order to effectively produce, prior to intervention, accurate and high-resolution 3D models of a cave with engravings dating back to the Upper Palaeolithic era. The processing of the TLS data is discussed in detail in order to create digital surface models. The complexity of the cave required the integration of two techniques, TLS and close range photogrammetry to yield not only traditional drawings such as sections and elevations, but also photo-realistic perspective views and visual navigation worlds fully operational in 3D environments. This paper demonstrates the potential of integrating TLS and close range photogrammetry to provide both accurate digital surface models and photo-realistic outputs. This processed data can be used to systematically improve archaeological understanding of complex caves and relief panels of prehistoric art with tiny engravings.
In its current status, medical imaging involves a wide range of imaging modalities and is faced with a range of interesting research questions, while trying to automatically convert the huge floods of image data to useful information. The major characteristic of the developed techniques is the exploitation of visual similarities or differences; that is basically qualitative treatment of the information inherent in the images. This proves to be a major shortcoming, leading to erroneous or unreliable results in many cases. To this end, technology transfer from the part of photogrammetry can be proven very beneficial. Such a contribution can be geared by the fact that photogrammetry has developed efficient tools for accounting for imaging formation geometry. These tools, appropriately tuned for medical applications, can accelerate the technology transfer across the involved disciplines. Understanding the possible photogrammetric contributions by the medical imaging experts, and realizing the medical problems in photogrammetric terms by the photogrammetrists, remains a major barrier to this transfer. The intended scope of this paper is to provide a foundation for exchange of ideas and provoke photogrammetric research interest in these issues.
Forensic anthropology involves the building of an antemortem profile of an individual from skeletal remains. This includes sex, race determination, and age and stature estimation. Because most bones that are conventionally used for sex determination are often recovered either in a fragmented or incomplete state, it has become necessary to use denser bones that are often recovered intact, eg, the maxillary sinus. The present work was performed to investigate the possibility of estimation of sex from some radiologic measurements among a known cross-section of Egyptian population. In this study, by the use of Multidetector Computed Tomography (MDCT) scan, eight maxillary sinus measurements were assessed in 96 living non-pathologic Egyptians comprising 48 males and 48 females aged 20-70 years referred to the Radiology Department. These were subjected to statistical analysis. Two variables showed significant differences: cephalo-caudal and size of the left maxillary sinus. The study concluded that the correct predictive accuracy was 70.8% in males and 62.5% in females. In conclusion, MDCT measurements of cephalo-caudal and size of the left maxillary sinuses are useful feature in gender determination in Egyptians.
The purpose of this retrospective study was to examine the reliability of virtually estimated abdominal blood volume using segmentation from postmortem computed tomography (PMCT) data.
Twenty-one cases with free abdominal blood were investigated by PMCT and autopsy. The volume of the blood was estimated using a manual segmentation technique (Amira, Visage Imaging, Germany) and the results were compared to autopsy data. Six of 21 cases had undergone additional post-mortem computed tomographic angiography (PMCTA).
The virtually estimated abdominal blood volumes did not differ significantly from those measured at autopsy. Additional PMCTA did not bias data significantly.
Virtual estimation of abdominal blood volume is a reliable technique. The virtual blood volume estimation is a useful tool to deliver additional information in cases where autopsy is not performed or in cases where a postmortem angiography is performed.
Identifying group affinity from human crania is a long-standing problem in forensic and physical anthropology. Many craniofacial differences used in forensic skeletal identification are difficult to quantify, although certain measurements of the midfacial skeleton have shown high predictive value for group classifications. This study presents a new method for analyzing midfacial shape variation between different geographic groups. Three-dimensional laser scan models of 90 crania from three populations were used to obtain cross-sectional midfacial contours defined by three standard craniometric landmarks. Elliptic Fourier transforms of the contours were used to extract Fourier coefficients for statistical analysis. After cross-validation, discriminant functions based on the Fourier coefficients provided an average of 86% correct classifications for crania from the three groups. The high rate of accuracy of this method indicates its usefulness for identifying group affinities among human skeletal remains and demonstrates the advantages of digital 3D model-based analysis in forensic research.
Several noninvasive methods are used for 3-dimensional (3D) morphologic facial and dental analysis to aid practitioners during diagnosis and treatment planning. Integrating dental and facial noninvasive 3D reproduction could improve the efficacy of treatment management.
Dental virtual model and soft-tissue facial morphology were digitally integrated from 11 adults with a 3D stereophotogrammetric imaging system (Vectra, Canfield Scientific, Fairfield, NJ). The digital 3D coordinates of 3 facial landmarks (N, nasion; Ftr, frontotemporale right; Ftl, frontotemporale left) and 3 dental landmarks (I, interincisor; Pr, PI, tips of the mesiovestibular cusps of the right and left first permanent premolars) were then obtained by using Vectra's software. Additionally, the coordinates of the same 6 landmarks were digitized directly on each subject by using a 3D computerized electromagnetic digitizer (in vivo). Seven linear measurements were made between the occlusal plane (Pr-I-Pl) and the facial landmarks (Ftr-N-Ftl). The accuracy and reliability of the reconstruction were tested by in-vivo measurements and repeated acquisitions.
The greatest mean relative error of measurements was smaller than 1.2%. No significant differences in repeatable reproductions were found.
Integration of facial stereophotogrammetry acquisition and dental laser scan reproduction is possible with marginal error.
In the field of the documentation of forensics-relevant injuries, from the reconstructive point of view, the forensic, CAD-supported photogrammetry plays an important role; particularly so when a detailed 3-D reconstruction is vital. This is demonstrated with a soft-tissue injury to the face caused by being run over by a car tire. Since the objects (injury and surface of the tire) to be investigated will be evaluated in virtual space, they must be series photographed. These photo sequences are then evaluated with the RolleiMetric multi-image evaluation system. This system measures and calculates the spatial location of points shown in the photo sequences, and creates 3-D data models of the objects. In a 3-D CAD program, the model of the injury is then compared against the model of the possible injury-causing instrument. The validation of the forensic, CAD-supported photogrammetry, as shown by the perfect 3-D match between the tire tread and the facial injury, demonstrates how greatly this 3-D method surpasses the classic 2-D overlay method (one-to-one photography).
Forensic three-dimensional/computer aided design (CAD)-supported photogrammetry (FPHG) plays an important role in the field of the documentation of forensic relevant injuries; particularly so when a detailed, 3D reconstruction is necessary. This is demonstrated in the case of a patterned blunt injury to the face of a victim, which injury was subsequently proven by FPHG to have been caused by a blow from the muzzle of a soft air gun. The objects to be evaluated had to be series photographed in order to be evaluated virtually on the computer. These photo series were then analyzed with the RolleiMetric system. This system measures and calculates the spatial location of distinctive points on the objects' surfaces, and creates 3D data models of the objects. In a 3D/CAD program, the "virtual 3D model of the injury" is then compared against the "virtual 3D model of the possible injury-causing instrument". The validation of FPHG, as shown by the 3D match between certain characteristics of the muzzle form and the facial injury, demonstrates how this 3D method can be used for patterned wound documentation and analysis.
Forensic 3D/CAD supported photogrammetry (FPHG) is a method of recording and documenting the surface of small objects, thus enabling a three-dimensional image of these objects in virtual space. With this representation on the computer screen the course of forensically relevant events can be reconstructed. The procedure allows for examining patterned injuries of skin, soft tissue or bones for matching potentially incriminated instruments in shape, size and angle.3D recording of objects to be examined requires taking series of photographs. A computer system then calculates the position in space of certain points on the surface of the objects and subsequently produces 3D data models of the objects. Using a 3D/CAD program these data models are used to generate graphic true-to-object volume models. The objects in question can then be moved against each other arbitrarily on the screen-depending on the questions to be answered-in order to compare them and possibly establish their congruence. This article covers the state of the art in FPHG procedures in the form of a step-by-step instruction. It also illustrates the wide range of FPHG applications.
Bite mark identification is based on the individuality of a dentition, which is used to match a bite mark to a suspected perpetrator. This matching is based on a tooth-by-tooth and arch-to-arch comparison utilising parameters of size, shape and alignment. The most common method used to analyse bite mark are carried out in 2D space. That means that the 3D information is preserved only two dimensionally with distortions. This paper presents a new 3D documentation, analysis and visualisation approach based on forensic 3D/CAD supported photogrammetry (FPHG) and the use of a 3D surface scanner. Our photogrammetric approach and the used visualisation method is, to the best to our knowledge, the first 3D approach for bite mark analysis in an actual case. The documentation has no distortion artifacts as can be found with standard photography. All the data are documented with a metric 3D measurement, orientation and subsequent analysis in 3D space. Beside the metrical analysis between bite mark and cast, it is possible using our method to utilise the topographical 3D feature of each individual tooth. This means that the 3D features of the biting surfaces and edges of each teeth are respected which is--as shown in our case--very important especially in the front teeth which have the first contact to the skin. Based upon the 3D detailed representation of the cast with the 3D topographic characteristics of the teeth, the interaction with the 3D documented skin can be visualised and analysed on the computer screen.
Photography process reduces a three-dimensional (3D) wound to a two-dimensional level. If there is a need for a high-resolution 3D dataset of an object, it needs to be three-dimensionally scanned. No-contact optical 3D digitizing surface scanners can be used as a powerful tool for wound and injury-causing instrument analysis in trauma cases. The 3D skin wound and a bone injury documentation using the optical scanner Advanced TOpometric Sensor (ATOS II, GOM International, Switzerland) will be demonstrated using two illustrative cases. Using this 3D optical digitizing method the wounds (the virtual 3D computer model of the skin and the bone injuries) and the virtual 3D model of the injury-causing tool are graphically documented in 3D in real-life size and shape and can be rotated in the CAD program on the computer screen. In addition, the virtual 3D models of the bone injuries and tool can now be compared in a 3D CAD program against one another in virtual space, to see if there are matching areas. Further steps in forensic medicine will be a full 3D surface documentation of the human body and all the forensic relevant injuries using optical 3D scanners.
Because the use of radiology in modern forensic medicine has been, until today, mostly restricted to conventional X-rays, which reduces a 3D body to a 2D projection, a detailed 3D documentation of a gunshot's wound ballistic effects was not possible. The aim of our study was to evaluate whether the progress in imaging techniques over the last years has made it possible to establish an observer-independent and reproducible forensic assessment using multi-slice computed tomography (MSCT) and magnetic resonance imaging (MRI) technologies for the documentation and analysis of gunshot wounds. The bodies of eight gunshot victims were scanned by MSCT and by MRI; the data of these imaging techniques were post-processed on a workstation, interpreted and subsequently correlated with the findings of classical autopsy. With the spiral CT and MRI examinations and the subsequent 2D multi-planar reformation (MPR) and 3D shaded surface display (SSD) reconstruction, the entire gunshot-created complex skull fractures and brain injuries (such as wound channels and deeply-driven bone splinters) could be documented in complete and graphic detail. CT and MRI also documented vital reaction to the gunshot by demonstrating air emboli in the heart and blood vessels and the classic pattern of blood aspiration to the lung. Gunshot residues deposited within and under the skin were visible. In conclusion, we think that the radiological methods of MSCT and MRI have the potential to become a routine "virtual autopsy" tool in the future. Bullets and relevant histological samples from specific sites then might be won in image-guided minimally invasive fashion via percutaneous biopsy. The rapid application of developing radiological methods may lead to new horizons in forensic documentation and intravital as well as postmortem examination.
A body was found behind a car with a noose tied around its neck, the other end of the rope tied to a tree. Apparently the man committed suicide by driving away with the noose tied around his neck and was dragged out of the car through the open hatchback. postmortem multislice-computed tomography (MSCT) and magnetic resonance imaging (MRI) indicated that the cause of death was cerebral hypoxia due to classic strangulation by hanging, and not due to a brainstem lesion because of a hang-man fracture as would be expected in such a dynamic situation. Furthermore, the MRI displayed intramuscular haemorrhage, bleeding into the clavicular insertions of the sternocleidomastoid muscles and subcutaneous neck tissue. We conclude that MSCT and MRI are useful instruments with an increased value compared with 2D radiographs to augment the external findings of bodies when an autopsy is refused. But further postmortem research and comparing validation is needed.
The examination of traffic accidents is daily routine in forensic medicine. An important question in the analysis of the victims of traffic accidents, for example in collisions between motor vehicles and pedestrians or cyclists, is the situation of the impact. Apart from forensic medical examinations (external examination and autopsy), three-dimensional technologies and methods are gaining importance in forensic investigations. Besides the post-mortem multi-slice computed tomography (MSCT) and magnetic resonance imaging (MRI) for the documentation and analysis of internal findings, highly precise 3D surface scanning is employed for the documentation of the external body findings and of injury-inflicting instruments. The correlation of injuries of the body to the injury-inflicting object and the accident mechanism are of great importance. The applied methods include documentation of the external and internal body and the involved vehicles and inflicting tools as well as the analysis of the acquired data. The body surface and the accident vehicles with their damages were digitized by 3D surface scanning. For the internal findings of the body, post-mortem MSCT and MRI were used. The analysis included the processing of the obtained data to 3D models, determination of the driving direction of the vehicle, correlation of injuries to the vehicle damages, geometric determination of the impact situation and evaluation of further findings of the accident. In the following article, the benefits of the 3D documentation and computer-assisted, drawn-to-scale 3D comparisons of the relevant injuries with the damages to the vehicle in the analysis of the course of accidents, especially with regard to the impact situation, are shown on two examined cases.
Background:
There has been a growing interest in three-dimensional (3D) surface imaging devices over the last few years.
Methods:
This comprehensive review discusses the various emerging technologies in this field of 3D imaging and applies the use of technology to oral and maxillofacial imaging.
Results:
The paper shows that there is increased awareness and application of technology to the field.
Conclusion:
3D surface acquisition technology is improving at a rapid pace and has a place in oral and maxillofacial surgery.
The transdisciplinary research project Virtopsy is dedicated to implementing modern imaging techniques into forensic medicine and pathology in order to augment current examination techniques or even to offer alternative methods. Our project relies on three pillars: three-dimensional (3D) surface scanning for the documentation of body surfaces, and both multislice computed tomography (MSCT) and magnetic resonance imaging (MRI) to visualise the internal body. Three-dimensional surface scanning has delivered remarkable results in the past in the 3D documentation of patterned injuries and of objects of forensic interest as well as whole crime scenes. Imaging of the interior of corpses is performed using MSCT and/or MRI. MRI, in addition, is also well suited to the examination of surviving victims of assault, especially choking, and helps visualise internal injuries not seen at external examination of the victim. Apart from the accuracy and three-dimensionality that conventional documentations lack, these techniques allow for the re-examination of the corpse and the crime scene even decades later, after burial of the corpse and liberation of the crime scene. We believe that this virtual, non-invasive or minimally invasive approach will improve forensic medicine in the near future.
The Virtopsy Approach. 3D Optical and Radiological Scanning and Reconstruction in Forensic Medicine