Construction Of 3D Model Research Articles

3D Soft Tissue Imaging: An Accurate and Economical Approach

Research work regarding 3 dimensional (3D) soft tissue imaging is very scarce, the reason behind that is that 3D imaging modalities are either invasive, or expensive, or lack accuracy to a great extent. Aim of the study: To develop a new, accurate and economical method for 3D soft tissue image construction to aid in the assessment of facial esthetics. Materials and Methods: Ten adult females were comprised in the current study. For each subject, a 3D video model was constructed based on facial measurements taken after patient positioning using custom made patient positioning as- sembly. To check the reliability of this method certain measurements were compared between the patients' faces and the constructed 3D models. Results: Excellent agreement was found in all measurements except for the Inter-pupillary width and the Frontal prominence. Conclusions: The presented technique proved to be an accurate, reproducible and economic method for 3D model con- struction.

A Method for Accurate Reconstructions of the Upper Airway Using Magnetic Resonance Images.

ObjectiveThe purpose of this study is to provide an optimized method to reconstruct the structure of the upper airway (UA) based on magnetic resonance imaging (MRI) that can faithfully show the anatomical structure with a smooth surface without artificial modifications.MethodsMRI was performed on the head and neck of a healthy young male participant in the axial, coronal and sagittal planes to acquire images of the UA. The level set method was used to segment the boundary of the UA. The boundaries in the three scanning planes were registered according to the positions of crossing points and anatomical characteristics using a Matlab program. Finally, the three-dimensional (3D) NURBS (Non-Uniform Rational B-Splines) surface of the UA was constructed using the registered boundaries in all three different planes.ResultsA smooth 3D structure of the UA was constructed, which captured the anatomical features from the three anatomical planes, particularly the location of the anterior wall of the nasopharynx. The volume and area of every cross section of the UA can be calculated from the constructed 3D model of UA.ConclusionsA complete scheme of reconstruction of the UA was proposed, which can be used to measure and evaluate the 3D upper airway accurately.

WAY-FINDING ASSISTANCE SYSTEM FOR UNDERGROUND FACILITIES USING AUGMENTED REALITY

Abstract. Way-finding is one of main challenges for pedestrians in large subterranean spaces with complex network of connected labyrinths. This problem is caused by the loss of their sense of directions and orientation due to the lack of landmarks that are occluded by ceilings, walls, and skyscraper. This paper introduces an assistance system for way-finding problem in large subterranean spaces using Augmented Reality (AR). It suggests displaying known landmarks that are invisible in indoor environments on tablet/handheld devices to assist users with relative positioning and indoor way-finding. The location and orientation of the users can be estimated by the indoor positioning systems and sensors available in the common tablet or smartphones devices. The constructed 3D model of a chosen landmark that is in the field of view of the handheld’s camera is augmented on the camera’s video feed. A prototype system has been implemented to demonstrate the efficiency of the proposed system for way-finding.

Expression in yeast, new substrates, and construction of a first 3D model of human orphan cytochrome P450 2U1: Interpretation of substrate hydroxylation regioselectivity from docking studies

BackgroundCytochrome P450 2U1 (CYP2U1) has been identified from the human genome and is highly conserved in the living kingdom. In humans, it has been found to be predominantly expressed in the thymus and in the brain. CYP2U1 is considered as an “orphan” enzyme as few data are available on its physiological function(s) and active site topology. Its only substrates reported so far were unsaturated fatty acids such as arachidonic acid, and, much more recently, N-arachidonoylserotonin. MethodsWe expressed CYP2U1 in yeast Saccharomyces cerevisiae, built a 3D homology model of CYP2U1, screened a library of compounds known to be substrates of CYP2 family with metabolite detection by high performance liquid chromatography–mass spectrometry, and performed docking experiments to explain the observed regioselectivity of the reactions. ResultsWe show that drug-related compounds, debrisoquine and terfenadine derivatives, subtrates of CYP2D6 and CYP2J2, are hydroxylated by recombinant CYP2U1 with regioselectivities different from those reported for CYP2D6 and 2J2. Docking experiments of those compounds and of arachidonic acid allow us to explain the regioselectivity of the hydroxylations on the basis of their interactions with key residues of CYP2U1 active site. Major conclusionOur results show for the first time that human orphan CYP2U1 can oxidize several exogenous molecules including drugs, and describe a first CYP2U1 3D model. General significanceThese results could have consequences for the metabolism of drugs particularly in the brain. The described 3D model should be useful to identify other substrates of CYP2U1 and help in understanding its physiologic roles.

Challenges in computational modelling of food breakdown and flavour release.

A dynamic, three dimensional (3D) computational model that predicts the breakdown of food and the release of tastants and aromas could enhance the understanding of how food is perceived during consumption. This model could also shorten the development process of new foods because many virtual foods could be assessed, and discarded if unsuitable, before any physical prototyping is required. The construction and testing of a complete 3D model of mastication presents many challenges including an accurate representation of: the anatomical movements of the oral cavity (including the teeth, tongue, cheeks and palates), the breakdown behaviour of the food, the interactions between comminuted food and saliva as the bolus is formed, the release and transport of taste and aromas and how these physical and chemical processes are perceived by a person. These challenges are discussed in reference to previous experimental and simulation work and using results of new applications of a coupled biomechanical-smoothed particle hydrodynamics (B-SPH) model. The B-SPH model is demonstrated to simulate several complicated aspects of mastication including: (1) the sensitivity of particle size to changes in the movements of the jaw and tongue; (2) large strain behaviour of food due to softening by heating; (3) interactions between solid and liquid food components; (3) the release of tastants into the saliva; and (4) the transport of tastants to the taste buds. These applications show the possibilities of a model to viably simulate mastication, but highlight the many modelling and experimental challenges that remain.

Exploration of digital technology in traumatic orthopedic clinical teaching for eight-year program medical students

A preliminary exploration of the application and effects of digital orthopaedic technique combined with the clinical practice in our clinical teaching of orthopaedics and trauma for 8-year program medical students has been made. Construction of 3D-model of bone and joint with the digital reconstruction technology, combination of 3D-display with detailed clinical cases, individual studying of knowledge, and fracture models performed by three dimensional printing, all have enhanced the students＇ understanding of the basics knowledge of orthopaedic trauma and accelerated the process of its joining into clinical practice. Related software has been used to realize the virtual design of fracture reduction and fixation and based on it, students have been guided to personally involve in the development and realization of surgical simulation program on a personal computer, thus improving students＇ capabilities of analysis, diagnosis and treatment of illness. Besides, students have been actively guided to use digital technology to conduct the finite element analysis of posterior malleolar fractures and calcaneus fractures, and to produce APP software for mobile devices such as ankle fracture classification and function scoring, which has aroused students＇ interest of clinical research and innovation Key words: Digtalorthopaedie; Traumatic orthopedic; Eight year program medical education

Non-preloaded bolted ring flange connections subjected to static loads

The ultimate behaviour of bolted connections in tubular members, such as chimneys, is studied and the interaction M-N curves are plotted, taking into account the main parameters of the problem. The proposed methodology is based on a classification of failure patterns of the L-stub main component (segmental behaviour) under compressive or axial tensile forces, considering non-preloaded bolts. Besides, the results of the theoretical analysis of the main L-shape component ultimate behaviour are compared with the corresponding obtained through finite element analysis of the constructed 3D models. Extending the local behaviour of the individual L-shape segments along the ring flange, the ultimate bearing capacity is derived, for each level of axial force, through a proposed analytical procedure and the corresponding interaction M-N curves are obtained. The parameters considered are the size and thickness of the flange and the tubular shell, the size and the location of the bolts, the quality of the materials and the amount of the applied axial load on the tubular element.

Advanced micro- and nanofabrication technologies for tissue engineering

The ability of the living body to heal and regenerate itself following trauma is astonishing. Numerous events of repair and regeneration occur during our lifetime, most of which we are never aware of. Unfortunately, in some cases, the injury or defect cannot be adequately repaired solely by nature and medical intervention is required.

Dynamic motion characteristics of the lower lumbar spine: implication to lumbar pathology and surgical treatment.

Many studies have reported on the segmental motion range of the lumbar spine using various in vitro and in vivo experimental designs. However, the in vivo weightbearing dynamic motion characteristics of the L4-5 and L5-S1 motion segments are still not clearly described in literature. This study investigated in vivo motion of the lumbar spine during a weight-lifting activity. Ten asymptomatic subjects (M/F: 5/5; age: 40-60 years) were recruited. The lumbar segment of each subject was MRI-scanned to construct 3D models of the L2-S1 vertebrae. The lumbar spine was then imaged using a dual fluoroscopic imaging system as the subject performed a weight-lifting activity from a lumbar flexion position (45°) to maximal extension position. The 3D vertebral models and the fluoroscopic images were used to reproduce the in vivo vertebral positions along the motion path. The relative translations and rotations of each motion segment were analyzed. All vertebral motion segments, L2-3, L3-4, L4-5 and L5-S1, rotated similarly during the lifting motion. L4-5 showed the largest anterior-posterior (AP) translation with 2.9 ± 1.5 mm and was significantly larger than L5-S1 (p < 0.05). L5-S1 showed the largest proximal-distal (PD) translation with 2.8 ± 0.9 mm and was significantly larger than all other motion segments (p < 0.05). The lower lumbar motion segments L4-5 and L5-S1 showed larger AP and PD translations, respectively, than the higher vertebral motion segments during the weight-lifting motion. The data provide insight into the physiological motion characteristics of the lumbar spine and potential mechanical mechanisms of lumbar disease development.

A thermomechanical constitutive model for an epoxy based shape memory polymer and its parameter identifications

This paper presents a three-dimensional (3D) finite deformation thermomechanical model to study the glass transition and shape memory behaviors of an epoxy based shape memory polymer (SMP) (Veriflex E) and a systematic material parameter identification scheme from a set of experiments. The model was described by viscoelastic elements placed in parallel to represent different active relaxation mechanisms around glass transition temperature in the polymer. A set of standard material tests was proposed and conducted to identify the model parameter values, which consequently enable the model to reproduce the experimentally observed shape memory (SM) behaviors. The parameter identification procedure proposed in this paper can be used as an effective tool to assist the construction and application of such 3D multi-branch model for general SMP materials.

Research on BSP Algorithm of Construction of Large-Scale 3D Point Model

For the construction of large-scale surface features 3D point model, a large number of point cloud data processing calculations is needed. Previous model construction calculation was treated non-parallel manner successively and mostly with one by one point cloud. This data processing method is complex, low efficiency and requires vast computing resource. Accordance with the BSP parallel computing ideas, we design a point cloud data modeling algorithm based on BSP and build a Hama parallel computing cluster consisted of ordinary PCs. The results indicate that, large-scale 3D point model BSP construction algorithm can improve the efficiency of modeling calculations and reduce computing resources requirements for processing construction computing.

Modelli tematici 3D della copertura del suolo a partire da DTM e immagini telerilevate ad alta risoluzione WorldView-2

The integration of thematic layers and DTM (Digital Terrain Model) becomes possible to achieve 3D models that can contextually display the variability of both the morphology and territorial and / or environmental components. WorldView-2 high resolution images, presenting a reduced size of the pixels on the ground (0.5 m in panchromatic and 2 m in multispectral) and a high spectral resolution (with 8 bands in the portion of the electromagnetic spectrum between wavelengths 400 nm and 1040 nm) allow the creation of very detailed maps of land cover. The simultaneous availability of DTM with appropriate cell size transforms these thematic layers in digital 3D models with high resolution.This paper is aimed to test positional and thematic accuracies that can be achieved in the construction of 3D models of land cover using WorldView-2 images. Phlegraean area (in Campania region, Italy), characterized by particular morphological configuration, mainly due to the presence of craters and volcanic cones, is considered. The dataset is firstly orthorectified, using rational polynomial functions, and then processed using supervised classification (Maximum Likelihood method) to identify several homogenous classes. The indices derived by confusion matrix (Producer Accuracy, User Accuracy, Overall Accuracy, Cohen Index) permit to check the thematic accuracy. DTM is derived from technical maps (at 1:5.000 scale) and used as the basis for 3D models of land cover.

Large-scale reconstruction of 3D structures of human chromosomes from chromosomal contact data

Chromosomes are not positioned randomly within a nucleus, but instead, they adopt preferred spatial conformations to facilitate necessary long-range gene–gene interactions and regulations. Thus, obtaining the 3D shape of chromosomes of a genome is critical for understanding how the genome folds, functions and how its genes interact and are regulated. Here, we describe a method to reconstruct preferred 3D structures of individual chromosomes of the human genome from chromosomal contact data generated by the Hi-C chromosome conformation capturing technique. A novel parameterized objective function was designed for modeling chromosome structures, which was optimized by a gradient descent method to generate chromosomal structural models that could satisfy as many intra-chromosomal contacts as possible. We applied the objective function and the corresponding optimization method to two Hi-C chromosomal data sets of both a healthy and a cancerous human B-cell to construct 3D models of individual chromosomes at resolutions of 1 MB and 200 KB, respectively. The parameters used with the method were calibrated according to an independent fluorescence in situ hybridization experimental data. The structural models generated by our method could satisfy a high percentage of contacts (pairs of loci in interaction) and non-contacts (pairs of loci not in interaction) and were compatible with the known two-compartment organization of human chromatin structures. Furthermore, structural models generated at different resolutions and from randomly permuted data sets were consistent.

The Design and Development of Indoor 3D Routing System

At present, the development and application of outdoor navigation is already quite mature. Car navigating system and mobile navigating system have been good to meet people's requirements to find the path in outdoor. With the development of outdoor navigation system, indoor navigation system is also being paid more attention, especially in an unfamiliar and complex indoor environment. This paper constructs 3D models of the building by SketchUP so as to provide a 3D scene for indoor navigation system, and builds 3D network model based on the building plan by ArcGIS. Finally, a indoor routing prototype system is developed based on ArcEngine, which does a preliminary study for indoor navigation.

Remote robotic assembly guided by 3D models linking to a real robot

This paper presents a 3D model-driven remote robotic assembly system. It constructs 3D models at runtime to represent unknown geometries at the robot side, where a sequence of images from a calibrated camera in different poses is used. Guided by the 3D models over the Internet, a remote operator can manipulate a real robot instantly for remote assembly operations. Experimental results show that the system is feasible to meet industrial assembly requirements with an acceptable level of modelling quality and relatively short processing time. The system also enables programming-free robotic assembly where the real robot follows the human's assembly operations instantly.

“Left Neglected,” but Only in Far Space: Spatial Biases in Healthy Participants Revealed in a Visually Guided Grasping Task

Hemispatial neglect is a common outcome of stroke that is characterized by the inability to orient toward, and attend to stimuli in contralesional space. It is established that hemispatial neglect has a perceptual component, however, the presence and severity of motor impairments is controversial. Establishing the nature of space use and spatial biases during visually guided actions amongst healthy individuals is critical to understanding the presence of visuomotor deficits in patients with neglect. Accordingly, three experiments were conducted to investigate the effect of object spatial location on patterns of grasping. Experiment 1 required right-handed participants to reach and grasp for blocks in order to construct 3D models. The blocks were scattered on a tabletop divided into equal size quadrants: left near, left far, right near, and right far. Identical sets of building blocks were available in each quadrant. Space use was dynamic, with participants initially grasping blocks from right near space and tending to “neglect” left far space until the final stages of the task. Experiment 2 repeated the protocol with left-handed participants. Remarkably, left-handed participants displayed a similar pattern of space use to right-handed participants. In Experiment 3 eye movements were examined to investigate whether “neglect” for grasping in left far reachable space had its origins in attentional biases. It was found that patterns of eye movements mirrored patterns of reach-to-grasp movements. We conclude that there are spatial biases during visually guided grasping, specifically, a tendency to neglect left far reachable space, and that this “neglect” is attentional in origin. The results raise the possibility that visuomotor impairments reported among patients with right hemisphere lesions when working in contralesional space may result in part from this inherent tendency to “neglect” left far space irrespective of the presence of unilateral visuospatial neglect.

Principal component analysis in construction of 3D human knee joint models using a statistical shape model method

The statistical shape model (SSM) method that uses 2D images of the knee joint to predict the three-dimensional (3D) joint surface model has been reported in the literature. In this study, we constructed a SSM database using 152 human computed tomography (CT) knee joint models, including the femur, tibia and patella and analysed the characteristics of each principal component of the SSM. The surface models of two in vivo knees were predicted using the SSM and their 2D bi-plane fluoroscopic images. The predicted models were compared to their CT joint models. The differences between the predicted 3D knee joint surfaces and the CT image-based surfaces were 0.30 ± 0.81 mm, 0.34 ± 0.79 mm and 0.36 ± 0.59 mm for the femur, tibia and patella, respectively (average ± standard deviation). The computational time for each bone of the knee joint was within 30 s using a personal computer. The analysis of this study indicated that the SSM method could be a useful tool to construct 3D surface models of the knee with sub-millimeter accuracy in real time. Thus, it may have a broad application in computer-assisted knee surgeries that require 3D surface models of the knee.

Building a 3D geomodel for water resources management: case study in the Regional Park of the lower courses of Manzanares and Jarama Rivers (Madrid, Spain)

Water resources management of protected sites requires a powerful tool to analyze the process and changes that are occurring in the environment. This paper describes a 3D geomodel design of the Jarama River Detrital Aquifer located in Madrid (Spain). That hydrogeological unit is included in the “Parque Regional de los Cursos Bajos de los Rios Manzanares y Jarama” (Regional Park of the Lower Courses of Manzanares and Jarama Rivers). The goal of this work is to define a method by which a three-dimensional (3D) model can be created with hydrogeologic geometry real of main aquifer, to accomplish an adequate management of the groundwater resources. All data used in this study were integrated in a geographic database: geological and hydrogeological information, geological map (1:25,000), eleven cross-sections, piezometric maps and a digital elevation model. The constructed 3D model of the Jarama Aquifer shows geometric features and spatial distribution and variations of geologic units. Thus, the 3D model allows the assessment of volumes of each unit, the depth and thickness variations of the main aquifer, and the spatial and temporal variations of water tables. From the 3D model, the most suitable areas (in terms of groundwater protection) for managed recharge and mining works have been identified.

The development of a 3D immunocompetent model of human skin

As the first line of defence, skin is regularly exposed to a variety of biological, physical and chemical insults. Therefore, determining the skin sensitization potential of new chemicals is of paramount importance from the safety assessment and regulatory point of view. Given the questionable biological relevance of animal models to human as well as ethical and regulatory pressure to limit or stop the use of animal models for safety testing, there is a need for developing simple yet physiologically relevant models of human skin. Herein, we describe the construction of a novel immunocompetent 3D human skin model comprising of dendritic cells co-cultured with keratinocytes and fibroblasts. This model culture system is simple to assemble with readily-available components and importantly, can be separated into its constitutive individual layers to allow further insight into cell–cell interactions and detailed studies of the mechanisms of skin sensitization. In this study, using non-degradable microfibre scaffolds and a cell-laden gel, we have engineered a multilayer 3D immunocompetent model comprised of keratinocytes and fibroblasts that are interspersed with dendritic cells. We have characterized this model using a combination of confocal microscopy, immuno-histochemistry and scanning electron microscopy and have shown differentiation of the epidermal layer and formation of an epidermal barrier. Crucially the immune cells in the model are able to migrate and remain responsive to stimulation with skin sensitizers even at low concentrations. We therefore suggest this new biologically relevant skin model will prove valuable in investigating the mechanisms of allergic contact dermatitis and other skin pathologies in human. Once fully optimized, this model can also be used as a platform for testing the allergenic potential of new chemicals and drug leads.

Construction and Application of 3D Model Based on the Lithologic Characteristics of Ore

Based on the 3D mine software platform and aimed at optimizing the ore blending process,according to the different lithological features of Molybdenum and Tungsten in Sandaozhuang open pit,the data integration of storage,update and management in different maps,images,tables,lithology was realized.Using the lithologic database and human-computer interaction technology,the complex lithology profile of exploration line has been drawn,and based on the technology of triangulation,the lithology model of skarn, hornfels, quartzite has been established. The construction shows that this model can provide theoretical basis and data foundation for ore blending method of lithology.