WorldWideScience

Sample records for 3-d voxel based

  1. Micromechanical analysis of nanocomposites using 3D voxel based material model

    Mishnaevsky, Leon

    2012-01-01

    A computational study on the effect of nanocomposite structures on the elastic properties is carried out with the use of the 3D voxel based model of materials and the combined Voigt–Reuss method. A hierarchical voxel based model of a material reinforced by an array of exfoliated and intercalated ...... probability of glass fibers in hybrid (hierarchical) composites, using the micromechanical voxel-based model of nanocomposites, it was observed that the nanoreinforcement in the matrix leads to slightly lower fiber failure probability....

  2. 3D sensitive voxel detector of ionizing radiation based on Timepix device

    Soukup, P.; Jakubek, J.; Vykydal, Z.

    2011-01-01

    Position sensitive detectors are evolving towards higher segmentation geometries from 0D (single pad) over 1D (strip) to 2D (pixel) detectors. Each step has brought up substantial expansion in the field of applications. The next logical step in this evolution is to design a 3D, i.e. voxel detector. The voxel detector can be constructed from 2D volume element detectors arranged in layers forming a 3D matrix of sensitive elements — voxels. Such detectors can effectively record tracks of energetic particles. By proper analysis of these tracks it is possible to determine the type, direction and energy of the primary particle. One of the prominent applications of such device is in the localization and identification of gamma and neutron sources in the environment. It can be also used for emission and transmission radiography in many fields where standard imagers are currently utilized. The qualitative properties of current imagers such as: spatial resolution, efficiency, directional sensitivity, energy sensitivity and selectivity (background suppression) can be improved. The first prototype of a voxel detector was built using a number of Timepix devices. Timepix is hybrid semiconductor detector consisting of a segmented semiconductor sensor bump-bonded to a readout chip. Each sensor contains 256x256 square pixels of 55 μm size. The voxel detector prototype was successfully tested to prove the concept functionality. The detector has a modular architecture with a daisy chain connection of the individual detector layers. This permits easy rearrangement due to its modularity, while keeping a single readout system for a variable number of detector layers. A limitation of this approach is the relatively large inter-layer distance (4 mm) compared to the pixel thickness (0.3 mm). Therefore the next step in the design is to decrease the space between the 2D detectors.

  3. 3D Segmentation Method for Natural Environments based on a Geometric-Featured Voxel Map

    Plaza, Victoria; Ababsa, Fakhr-Eddine; Garcia-Cerezo, Alfonso J.; Gomez-Ruiz, Jose Antonio

    2015-01-01

    This work proposes a new segmentation algorithm for three-dimensional dense point clouds and has been specially designed for natural environments where the ground is unstructured and may include big slopes, non-flat areas and isolated areas. This technique is based on a Geometric-Featured Voxel map (GFV) where the scene is discretized in constant size cubes or voxels which are classified in flat surface, linear or tubular structures and scattered or undefined shapes, usually corre...

  4. Segmentation Based Classification of 3D Urban Point Clouds: A Super-Voxel Based Approach with Evaluation

    Laurent Trassoudaine

    2013-03-01

    Full Text Available Segmentation and classification of urban range data into different object classes have several challenges due to certain properties of the data, such as density variation, inconsistencies due to missing data and the large data size that require heavy computation and large memory. A method to classify urban scenes based on a super-voxel segmentation of sparse 3D data obtained from LiDAR sensors is presented. The 3D point cloud is first segmented into voxels, which are then characterized by several attributes transforming them into super-voxels. These are joined together by using a link-chain method rather than the usual region growing algorithm to create objects. These objects are then classified using geometrical models and local descriptors. In order to evaluate the results, a new metric that combines both segmentation and classification results simultaneously is presented. The effects of voxel size and incorporation of RGB color and laser reflectance intensity on the classification results are also discussed. The method is evaluated on standard data sets using different metrics to demonstrate its efficacy.

  5. Topographic deformation patterns of knee cartilage after exercises with high knee flexion: an in vivo 3D MRI study using voxel-based analysis at 3T

    Horng, Annie; Stockinger, M.; Notohamiprodjo, M. [Ludwig-Maximilians-University Hospital Munich, Institute for Clinical Radiology, Munich (Germany); Raya, J.G. [New York University Langone Medical Center, Center for Biomedical Imaging, New York, NY (United States); Pietschmann, M. [Ludwig-Maximilians-University Hospital Munich, Department of Orthopedic Surgery, Munich (Germany); Hoehne-Hueckstaedt, U.; Glitsch, U.; Ellegast, R. [Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA), Sankt Augustin (Germany); Hering, K.G. [Miner' s Hospital, Department of Diagnostic Radiology, Dortmund (Germany); Glaser, C. [Ludwig-Maximilians-University Hospital Munich, Institute for Clinical Radiology, Munich (Germany); RZM Zentrum, Munich (Germany)

    2015-06-01

    To implement a novel voxel-based technique to identify statistically significant local cartilage deformation and analyze in-vivo topographic knee cartilage deformation patterns using a voxel-based thickness map approach for high-flexion postures. Sagittal 3T 3D-T1w-FLASH-WE-sequences of 10 healthy knees were acquired before and immediately after loading (kneeling/squatting/heel sitting/knee bends). After cartilage segmentation, 3D-reconstruction and 3D-registration, colour-coded deformation maps were generated by voxel-based subtraction of loaded from unloaded datasets to visualize cartilage thickness changes in all knee compartments. Compression areas were found bifocal at the peripheral medial/caudolateral patella, both posterior femoral condyles and both anterior/central tibiae. Local cartilage thickening were found adjacent to the compression areas. Significant local strain ranged from +13 to -15 %. Changes were most pronounced after squatting, least after knee bends. Shape and location of deformation areas varied slightly with the loading paradigm, but followed a similar pattern consistent between different individuals. Voxel-based deformation maps identify individual in-vivo load-specific and posture-associated strain distribution in the articular cartilage. The data facilitate understanding individual knee loading properties and contribute to improve biomechanical 3 models. They lay a base to investigate the relationship between cartilage degeneration patterns in common osteoarthritis and areas at risk of cartilage wear due to mechanical loading in work-related activities. (orig.)

  6. Topographic deformation patterns of knee cartilage after exercises with high knee flexion: an in vivo 3D MRI study using voxel-based analysis at 3T

    To implement a novel voxel-based technique to identify statistically significant local cartilage deformation and analyze in-vivo topographic knee cartilage deformation patterns using a voxel-based thickness map approach for high-flexion postures. Sagittal 3T 3D-T1w-FLASH-WE-sequences of 10 healthy knees were acquired before and immediately after loading (kneeling/squatting/heel sitting/knee bends). After cartilage segmentation, 3D-reconstruction and 3D-registration, colour-coded deformation maps were generated by voxel-based subtraction of loaded from unloaded datasets to visualize cartilage thickness changes in all knee compartments. Compression areas were found bifocal at the peripheral medial/caudolateral patella, both posterior femoral condyles and both anterior/central tibiae. Local cartilage thickening were found adjacent to the compression areas. Significant local strain ranged from +13 to -15 %. Changes were most pronounced after squatting, least after knee bends. Shape and location of deformation areas varied slightly with the loading paradigm, but followed a similar pattern consistent between different individuals. Voxel-based deformation maps identify individual in-vivo load-specific and posture-associated strain distribution in the articular cartilage. The data facilitate understanding individual knee loading properties and contribute to improve biomechanical 3 models. They lay a base to investigate the relationship between cartilage degeneration patterns in common osteoarthritis and areas at risk of cartilage wear due to mechanical loading in work-related activities. (orig.)

  7. Voxel-based statistical analysis of cerebral glucose metabolism in the rat cortical deafness model by 3D reconstruction of brain from autoradiographic images

    Animal models of cortical deafness are essential for investigation of the cerebral glucose metabolism in congenital or prelingual deafness. Autoradiographic imaging is mainly used to assess the cerebral glucose metabolism in rodents. In this study, procedures for the 3D voxel-based statistical analysis of autoradiographic data were established to enable investigations of the within-modal and cross-modal plasticity through entire areas of the brain of sensory-deprived animals without lumping together heterogeneous subregions within each brain structure into a large region of interest. Thirteen 2-[1-14C]-deoxy-D-glucose autoradiographic images were acquired from six deaf and seven age-matched normal rats (age 6-10 weeks). The deafness was induced by surgical ablation. For the 3D voxel-based statistical analysis, brain slices were extracted semiautomatically from the autoradiographic images, which contained the coronal sections of the brain, and were stacked into 3D volume data. Using principal axes matching and mutual information maximization algorithms, the adjacent coronal sections were co-registered using a rigid body transformation, and all sections were realigned to the first section. A study-specific template was composed and the realigned images were spatially normalized onto the template. Following count normalization, voxel-wise t tests were performed to reveal the areas with significant differences in cerebral glucose metabolism between the deaf and the control rats. Continuous and clear edges were detected in each image after registration between the coronal sections, and the internal and external landmarks extracted from the spatially normalized images were well matched, demonstrating the reliability of the spatial processing procedures. Voxel-wise t tests showed that the glucose metabolism in the bilateral auditory cortices of the deaf rats was significantly (P<0.001) lower than that in the controls. There was no significantly reduced metabolism in any

  8. Voxel-based statistical analysis of cerebral glucose metabolism in the rat cortical deafness model by 3D reconstruction of brain from autoradiographic images

    Lee, Jae Sung; Park, Kwang Suk [Seoul National University College of Medicine, Department of Nuclear Medicine, 28 Yungun-Dong, Chongno-Ku, Seoul (Korea); Seoul National University College of Medicine, Department of Biomedical Engineering, Seoul (Korea); Ahn, Soon-Hyun; Oh, Seung Ha; Kim, Chong Sun; Chung, June-Key; Lee, Myung Chul [Seoul National University College of Medicine, Department of Otolaryngology, Head and Neck Surgery, Seoul (Korea); Lee, Dong Soo; Jeong, Jae Min [Seoul National University College of Medicine, Department of Nuclear Medicine, 28 Yungun-Dong, Chongno-Ku, Seoul (Korea)

    2005-06-01

    Animal models of cortical deafness are essential for investigation of the cerebral glucose metabolism in congenital or prelingual deafness. Autoradiographic imaging is mainly used to assess the cerebral glucose metabolism in rodents. In this study, procedures for the 3D voxel-based statistical analysis of autoradiographic data were established to enable investigations of the within-modal and cross-modal plasticity through entire areas of the brain of sensory-deprived animals without lumping together heterogeneous subregions within each brain structure into a large region of interest. Thirteen 2-[1-{sup 14}C]-deoxy-D-glucose autoradiographic images were acquired from six deaf and seven age-matched normal rats (age 6-10 weeks). The deafness was induced by surgical ablation. For the 3D voxel-based statistical analysis, brain slices were extracted semiautomatically from the autoradiographic images, which contained the coronal sections of the brain, and were stacked into 3D volume data. Using principal axes matching and mutual information maximization algorithms, the adjacent coronal sections were co-registered using a rigid body transformation, and all sections were realigned to the first section. A study-specific template was composed and the realigned images were spatially normalized onto the template. Following count normalization, voxel-wise t tests were performed to reveal the areas with significant differences in cerebral glucose metabolism between the deaf and the control rats. Continuous and clear edges were detected in each image after registration between the coronal sections, and the internal and external landmarks extracted from the spatially normalized images were well matched, demonstrating the reliability of the spatial processing procedures. Voxel-wise t tests showed that the glucose metabolism in the bilateral auditory cortices of the deaf rats was significantly (P<0.001) lower than that in the controls. There was no significantly reduced metabolism in

  9. Design, fabrication, and implementation of voxel-based 3D printed textured phantoms for task-based image quality assessment in CT

    Solomon, Justin; Ba, Alexandre; Diao, Andrew; Lo, Joseph; Bier, Elianna; Bochud, François; Gehm, Michael; Samei, Ehsan

    2016-03-01

    In x-ray computed tomography (CT), task-based image quality studies are typically performed using uniform background phantoms with low-contrast signals. Such studies may have limited clinical relevancy for modern non-linear CT systems due to possible influence of background texture on image quality. The purpose of this study was to design and implement anatomically informed textured phantoms for task-based assessment of low-contrast detection. Liver volumes were segmented from 23 abdominal CT cases. The volumes were characterized in terms of texture features from gray-level co-occurrence and run-length matrices. Using a 3D clustered lumpy background (CLB) model, a fitting technique based on a genetic optimization algorithm was used to find the CLB parameters that were most reflective of the liver textures, accounting for CT system factors of spatial blurring and noise. With the modeled background texture as a guide, a cylinder phantom (165 mm in diameter and 30 mm height) was designed, containing 20 low-contrast spherical signals (6 mm in diameter at targeted contrast levels of ~3.2, 5.2, 7.2, 10, and 14 HU, 4 repeats per signal). The phantom was voxelized and input into a commercial multi-material 3D printer (Object Connex 350), with custom software for voxel-based printing. Using principles of digital half-toning and dithering, the 3D printer was programmed to distribute two base materials (VeroWhite and TangoPlus, nominal voxel size of 42x84x30 microns) to achieve the targeted spatial distribution of x-ray attenuation properties. The phantom was used for task-based image quality assessment of a clinically available iterative reconstruction algorithm (Sinogram Affirmed Iterative Reconstruction, SAFIRE) using a channelized Hotelling observer paradigm. Images of the textured phantom and a corresponding uniform phantom were acquired at six dose levels and observer model performance was estimated for each condition (5 contrasts x 6 doses x 2 reconstructions x 2

  10. Visualization using 3D voxelization of full lidar waveforms

    Park, Joong Yong; Ramnath, Vinod; Feygels, Victor

    2014-11-01

    Airborne bathymetric lidar (Light Detection and Ranging) systems measure photoelectrons on the optical path (range and angle) at the photocathode of a returned laser pulse at high rates, such as every nanosecond. The collected measurement of a single pulse in a time series is called a waveform. Based on the calibration of the lidar system, the return signal is converted into units of received power. This converted value from the lidar waveform data is used to compute an estimate of the reflectance from the returned backscatter, which contains environmental information from along the optical path. This concept led us to develop a novel tool to visualize lidar data in terms of the returned backscatter, and to use this as a data analysis and editing tool. The full lidar waveforms along the optical path, from laser points collected in the region of interest (ROI), are voxelized into a 3D image cube. This allows lidar measurements to be analyzed in three orthogonal directions simultaneously. The laser pulse return (reflection) from the seafloor is visible in the waveform as a pronounced "bump" above the volume backscatter. Floating or submerged objects in the water may also be visible. Similarly, forest canopies and tree branches can be identified in the 3D voxelization. This paper discusses the possibility of using this unique three-orthogonal volume visualizing tool to extract environmental information for carrying out rapid environmental assessments over forests and water.

  11. Automatic calibration method of voxel size for cone-beam 3D-CT scanning system

    For a cone-beam three-dimensional computed tomography (3D-CT) scanning system, voxel size is an important indicator to guarantee the accuracy of data analysis and feature measurement based on 3D-CT images. Meanwhile, the voxel size changes with the movement of the rotary stage along X-ray direction. In order to realize the automatic calibration of the voxel size, a new and easily-implemented method is proposed. According to this method, several projections of a spherical phantom are captured at different imaging positions and the corresponding voxel size values are calculated by non-linear least-square fitting. Through these interpolation values, a linear equation is obtained that reflects the relationship between the voxel size and the rotary stage translation distance from its nominal zero position. Finally, the linear equation is imported into the calibration module of the 3D-CT scanning system. When the rotary stage is moving along X-ray direction, the accurate value of the voxel size is dynamically exported. The experimental results prove that this method meets the requirements of the actual CT scanning system, and has virtues of easy implementation and high accuracy. (authors)

  12. Automatic Calibration Method of Voxel Size for Cone-beam 3D-CT Scanning System

    Yang, Min; Liu, Yipeng; Men, Fanyong; Li, Xingdong; Liu, Wenli; Wei, Dongbo

    2013-01-01

    For cone-beam three-dimensional computed tomography (3D-CT) scanning system, voxel size is an important indicator to guarantee the accuracy of data analysis and feature measurement based on 3D-CT images. Meanwhile, the voxel size changes with the movement of the rotary table along X-ray direction. In order to realize the automatic calibration of the voxel size, a new easily-implemented method is proposed. According to this method, several projections of a spherical phantom are captured at different imaging positions and the corresponding voxel size values are calculated by non-linear least square fitting. Through these interpolation values, a linear equation is obtained, which reflects the relationship between the rotary table displacement distance from its nominal zero position and the voxel size. Finally, the linear equation is imported into the calibration module of the 3D-CT scanning system, and when the rotary table is moving along X-ray direction, the accurate value of the voxel size is dynamically expo...

  13. Evaluation of brain perfusion in specific Brodmann areas in Frontotemporal dementia and Alzheimer disease using automated 3-D voxel based analysis

    Valotassiou, V.; Papatriantafyllou, J.; Sifakis, N.; Karageorgiou, C.; Tsougos, I.; Tzavara, C.; Zerva, C.; Georgoulias, P.

    2009-05-01

    Introduction. Brain perfusion studies with single-photon emission computed tomography (SPECT) have been applied in demented patients to provide better discrimination between frontotemporal dementia (FTD) and Alzheimer's disease (AD). Aim. To assess the perfusion of specific Brodmann (Br) areas of the brain cortex in FTD and AD patients, using NeuroGam processing program to provide 3D voxel-by-voxel cerebral SPECT analysis. Material and methods. We studied 34 consecutive patients. We used the established criteria for the diagnosis of dementia and the specific established criteria for the diagnosis of FTD and AD. All the patients had a neuropsychological evaluation with a battery of tests including the mini-mental state examination (MMSE).Twenty-six patients (16 males, 10 females, mean age 68.76±6.51 years, education 11.81±4.25 years, MMSE 16.69±9.89) received the diagnosis of FTD and 8 patients (all females, mean age 71.25±10.48 years, education 10±4.6 years, MMSE 12.5±3.89) the diagnosis of AD. All the patients underwent a brain SPECT. We applied the NeuroGam Software for the evaluation of brain perfusion in specific Br areas in the left (L) and right (R) hemispheres. Results. Statistically significant hypoperfusion in FTD compared to AD patients, was found in the following Br areas: 11L (pbrain perfusion SPECT could result in enhanced accuracy for the differential diagnosis between AD and FTD patients.

  14. Evaluation of brain perfusion in specific Brodmann areas in Frontotemporal dementia and Alzheimer disease using automated 3-D voxel based analysis

    Introduction. Brain perfusion studies with single-photon emission computed tomography (SPECT) have been applied in demented patients to provide better discrimination between frontotemporal dementia (FTD) and Alzheimer's disease (AD). Aim. To assess the perfusion of specific Brodmann (Br) areas of the brain cortex in FTD and AD patients, using NeuroGam processing program to provide 3D voxel-by-voxel cerebral SPECT analysis. Material and methods. We studied 34 consecutive patients. We used the established criteria for the diagnosis of dementia and the specific established criteria for the diagnosis of FTD and AD. All the patients had a neuropsychological evaluation with a battery of tests including the mini-mental state examination (MMSE).Twenty-six patients (16 males, 10 females, mean age 68.76±6.51 years, education 11.81±4.25 years, MMSE 16.69±9.89) received the diagnosis of FTD and 8 patients (all females, mean age 71.25±10.48 years, education 10±4.6 years, MMSE 12.5±3.89) the diagnosis of AD. All the patients underwent a brain SPECT. We applied the NeuroGam Software for the evaluation of brain perfusion in specific Br areas in the left (L) and right (R) hemispheres. Results. Statistically significant hypoperfusion in FTD compared to AD patients, was found in the following Br areas: 11L (p<0.0001), 11R, 20L, 20R, 32L, 38L, 38R, 44L (p<0.001), 32R, 36L, 36R, 45L, 45R, 47R (p<0.01), 9L, 21L, 39R, 44R, 46R, 47L (p<0.05). On the contrary, AD patients presented significant (p<0.05) hypoperfusion in 7R and 39R Br areas. Conclusion. NeuroGam processing program of brain perfusion SPECT could result in enhanced accuracy for the differential diagnosis between AD and FTD patients.

  15. 3D volume and SUV analysis of oncological PET studies. A voxel-based image processing tool with NSCLC as example

    Krohn, T.; Kaiser, H.J.; Boy, C.; Schaefer, W.M.; Buell, U.; Zimny, M. [Universitaetsklinikum Aachen (Germany). Klinik fuer Nuklearmedizin; Gagel, B. [Universitaetsklinikum Aachen (Germany). Klinik fuer Strahlentherapie

    2007-07-01

    Aim: The standardized uptake value (SUV) of {sup 18}FDG-PET is an important parameter for therapy monitoring and prognosis of malignant lesions. SUV determination requires delineating the respective volume of interest against surrounding tissue. The present study proposes an automatic image segmentation algorithm for lesion volume and FDG uptake quantitation. Methods: A region growing-based algorithm was developed, which goes through the following steps: 1. Definition of a starting point by the user. 2. Automatic determination of maximum uptake within the lesion. 3. Calculating a threshold value as percentage of maximum. 4. Automatic 3D lesion segmentation. 5. Quantitation of lesion volume and SUV. The procedure was developed using CTI CAPP and ECAT 7.2 software. Validation was done by phatom studies (Jaszczak phantom, various ''lesion'' sizes and contrasts) and on studies of NSCLC patients, who underwent clinical CT and FDG-PET scanning. Results: Phantom studies demonstrated a mean error of 3.5% for volume quantification using a threshold of 41% for contrast ratios {>=}5:1 and sphere volumes >5 ml. Comparison between CT- and PET-based volumetry showed a high correlation of both methods (r=0.98) for lesions with homogeneous FDG uptake. Radioactivity concentrations were underestimated by on average -41%. Employing an empirical threshold of 50% for SUV determination, the underestimation decreased to on average -34%. Conclusions: The algorithm facilitates an easy and reproducible SUV quantification and volume assessment of PET lesions in clinical practice. It was validated using NSCLC patient data and should also be applicable to other tumour entities. (orig.)

  16. A novel 3D volumetric voxel registration technique for volume-view-guided image registration of multiple imaging modalities

    Purpose: To provide more clinically useful image registration with improved accuracy and reduced time, a novel technique of three-dimensional (3D) volumetric voxel registration of multimodality images is developed. Methods and Materials: This technique can register up to four concurrent images from multimodalities with volume view guidance. Various visualization effects can be applied, facilitating global and internal voxel registration. Fourteen computed tomography/magnetic resonance (CT/MR) image sets and two computed tomography/positron emission tomography (CT/PET) image sets are used. For comparison, an automatic registration technique using maximization of mutual information (MMI) and a three-orthogonal-planar (3P) registration technique are used. Results: Visually sensitive registration criteria for CT/MR and CT/PET have been established, including the homogeneity of color distribution. Based on the registration results of 14 CT/MR images, the 3D voxel technique is in excellent agreement with the automatic MMI technique and is indicatory of a global positioning error (defined as the means and standard deviations of the error distribution) using the 3P pixel technique: 1.8 deg ± 1.2 deg in rotation and 2.0 ± 1.3 (voxel unit) in translation. To the best of our knowledge, this is the first time that such positioning error has been addressed. Conclusion: This novel 3D voxel technique establishes volume-view-guided image registration of up to four modalities. It improves registration accuracy with reduced time, compared with the 3P pixel technique. This article suggests that any interactive and automatic registration should be safeguarded using the 3D voxel technique

  17. Voxel-Based LIDAR Analysis and Applications

    Hagstrom, Shea T.

    One of the greatest recent changes in the field of remote sensing is the addition of high-quality Light Detection and Ranging (LIDAR) instruments. In particular, the past few decades have been greatly beneficial to these systems because of increases in data collection speed and accuracy, as well as a reduction in the costs of components. These improvements allow modern airborne instruments to resolve sub-meter details, making them ideal for a wide variety of applications. Because LIDAR uses active illumination to capture 3D information, its output is fundamentally different from other modalities. Despite this difference, LIDAR datasets are often processed using methods appropriate for 2D images and that do not take advantage of its primary virtue of 3-dimensional data. It is this problem we explore by using volumetric voxel modeling. Voxel-based analysis has been used in many applications, especially medical imaging, but rarely in traditional remote sensing. In part this is because the memory requirements are substantial when handling large areas, but with modern computing and storage this is no longer a significant impediment. Our reason for using voxels to model scenes from LIDAR data is that there are several advantages over standard triangle-based models, including better handling of overlapping surfaces and complex shapes. We show how incorporating system position information from early in the LIDAR point cloud generation process allows radiometrically-correct transmission and other novel voxel properties to be recovered. This voxelization technique is validated on simulated data using the Digital Imaging and Remote Sensing Image Generation (DIRSIG) software, a first-principles based ray-tracer developed at the Rochester Institute of Technology. Voxel-based modeling of LIDAR can be useful on its own, but we believe its primary advantage is when applied to problems where simpler surface-based 3D models conflict with the requirement of realistic geometry. To

  18. Pattern of cerebral hyperperfusion in Alzheimer's disease and amnestic mild cognitive impairment using voxel-based analysis of 3D arterial spin-labeling imaging: initial experience

    Ding B

    2014-03-01

    Full Text Available Bei Ding,1 Hua-wei Ling,1 Yong Zhang,2 Juan Huang,1 Huan Zhang,1 Tao Wang,3 Fu Hua Yan11Department of Radiology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, 2Applied Science Laboratory, GE Healthcare, 3Department of Gerontology, Shanghai Mental Health Center, Shanghai, People's Republic of ChinaPurpose: A three-dimensional (3D continuous pulse arterial spin labeling (ASL technique was used to investigate cerebral blood flow (CBF changes in patients with Alzheimer's disease (AD, amnestic mild cognitive impairment (aMCI, and age- and sex-matched healthy controls.Materials and methods: Three groups were recruited for comparison, 24 AD patients, 17 MCI patients, and 21 age- and sex-matched control subjects. Three-dimensional ASL scans covering the entire brain were acquired with a 3.0 T magnetic resonance scanner. Spatial processing was performed with statistical parametric mapping 8. A second-level one-way analysis of variance analysis (threshold at P<0.05 was performed on the preprocessed ASL data. An average whole-brain CBF for each subject was also included as group-level covariates for the perfusion data, to control for individual CBF variations.Results: Significantly increased CBF was detected in bilateral frontal lobes and right temporal subgyral regions in aMCI compared with controls. When comparing AD with aMCI, the major hyperperfusion regions were the right limbic lobe and basal ganglia regions, including the putamen, caudate, lentiform nucleus, and thalamus, and hypoperfusion was found in the left medial frontal lobe, parietal cortex, the right middle temporo-occipital lobe, and particularly, the left anterior cingulate gyrus. We also found decreased CBF in the bilateral temporo-parieto-occipital cortices and left limbic lobe in AD patients, relative to the control group. aMCI subjects showed decreased blood flow in the left occipital lobe, bilateral inferior temporal cortex, and right middle temporal cortex

  19. Goldberg-like Decompositions and Voxel Representation of 3D Space

    Kolcun, Alexej

    Ostrava: Ústav geoniky AV ČR, 2014 - (Blaheta, R.; Starý, J.; Sysalová, D.). s. 57-57 ISBN 978-80-86407-47-0. [Modelling 2014. 02.06.2014-06.06.2014, Rožnov pod Radhoštěm] Institutional support: RVO:68145535 Keywords : space decomposition * voxel representation * 3D space Subject RIV: BA - General Mathematics

  20. Voxel-based model and its application in advanced manufacturing

    Wu, Xiaojun; Liu, Weijun; Wang, Tianran

    2004-03-01

    Traditionally, 3D models, even so called solid ones, can only represent the object's surface information, and the interior is regarded as homogeneous. In most applications, it is necessary to represent the interior structures and attributes of an object, such as materials, density and color, etc. Surface model is incapable of bearing this task. In this case, voxel model is a good choice. Voxelization is the process of converting a geometrically represented 3D object into a three dimensional volume of dataset. In this paper, an algorithm is proposed to voxelize the polygonal meshes ported from current CAD modeling packages into volume datasets based on the easily indexing property of Octree structure. The minimal distance to the feature voxel (or voxels) is taken as criterion to distribute different material compositions to get a new kind of material called FGM (functionally graded material), which is suitable for the interface of RPM (Rapid Prototyping Manufacturing).

  1. X-ray color imaging with 3D sensitive voxel detector

    X-ray imaging is today widely used in a broad range of applications. Nevertheless some limitations are represented by the inability to distinguish between a thick layer of low Z material and a thin layer of high Z material, and by the beam hardening, where the incident X-ray spectrum is modified as the beam traverses the sample. Such effects cause problems in many applications (e.g. CT reconstruction) generating artifacts and worsening the spatial resolution. This work presents a new technique allowing spectral sensitivity using a new 3D voxel detector based on the Timepix pixel detector. The device is designed as a layered stack of several Timepix sensors. The readout chip is thinned down to reduce the amount of insensitive absorbing material. Every single layers in the stack act as a filter, i.e. each stack layer visualizes a different part of the spectrum attenuated by the object giving further information about the object composition. The comparison of attenuation levels observed in different detector layers can be used to estimate the extent of the beam hardening effect in the imaged object and thus point out differences in the material composition.

  2. Voxelization algorithms for geospatial applications: Computational methods for voxelating spatial datasets of 3D city models containing 3D surface, curve and point data models.

    Nourian, Pirouz; Gonçalves, Romulo; Zlatanova, Sisi; Ohori, Ken Arroyo; Vu Vo, Anh

    2016-01-01

    Voxel representations have been used for years in scientific computation and medical imaging. The main focus of our research is to provide easy access to methods for making large-scale voxel models of built environment for environmental modelling studies while ensuring they are spatially correct, meaning they correctly represent topological and semantic relations among objects. In this article, we present algorithms that generate voxels (volumetric pixels) out of point cloud, curve, or surface objects. The algorithms for voxelization of surfaces and curves are a customization of the topological voxelization approach [1]; we additionally provide an extension of this method for voxelization of point clouds. The developed software has the following advantages:•It provides easy management of connectivity levels in the resulting voxels.•It is not dependant on any external library except for primitive types and constructs; therefore, it is easy to integrate them in any application.•One of the algorithms is implemented in C++ and C for platform independence and efficiency. PMID:27408832

  3. Shallow subsurface control on earthquake damage patterns: first results from a 3D geological voxel model study (Tokyo Lowland, Japan)

    Stafleu, Jan; Busschers, Freek; Tanabe, Susumu

    2016-04-01

    The Tokyo Lowland is situated in a Neogene sedimentary basin near the triple junction of the North American, Pacific, and Philippine tectonic plates. The basin is filled with Neogene and Quaternary sediments up to a thickness of 3 km. In the upper 70 m of the basin, thick sequences of soft Holocene sediments occur which are assumed to have played a key role in the spatial variation of damage intensity during the 1923 Kanto earthquake (Magnitude 7.9 to 8.3). Historical records show this earthquake destroyed large parts of the Tokyo urban area which in that time was largely made up by wooden houses. Although the epicentre was 70 km to the southwest of Tokyo, severe damage occurred north of the city centre, presumably due to ground motion amplification in the soft Holocene sediments in the shallow subsurface. In order to assess the presumed relation between the damage pattern of the 1923 earthquake and the occurrence of soft Holocene sediments in the shallow subsurface, we constructed a 3D geological voxel model of the central part of the Tokyo Lowland. The model was constructed using a methodology originally developed for the lowlands of the Netherlands. The modelling workflow basically consists of three steps. First, some 10,000 borehole descriptions (gathered for geomechanical purposes), were subdivided into geological units that have uniform sediment characteristics, using both lithological and geomechanical (N-value) criteria. Second, 2D bounding surfaces were constructed, representing tops and bases of the geological units. These surfaces were used to place each voxel (100 by 100 by 1 m) within the correct geological unit. The N-values and lithological units in the borehole descriptions were subsequently used to perform a 3D stochastic interpolation of N-value and lithological class within each geological unit. Using a vertical voxel stack analysis, we were able to create a map showing the accumulated thickness of soft muds in the Holocene succession. A

  4. Voxel-based texture analysis of the brain.

    Maani, Rouzbeh; Yang, Yee Hong; Kalra, Sanjay

    2015-01-01

    This paper presents a novel voxel-based method for texture analysis of brain images. Texture analysis is a powerful quantitative approach for analyzing voxel intensities and their interrelationships, but has been thus far limited to analyzing regions of interest. The proposed method provides a 3D statistical map comparing texture features on a voxel-by-voxel basis. The validity of the method was examined on artificially generated effects as well as on real MRI data in Alzheimer's Disease (AD). The artificially generated effects included hyperintense and hypointense signals added to T1-weighted brain MRIs from 30 healthy subjects. The AD dataset included 30 patients with AD and 30 age/sex matched healthy control subjects. The proposed method detected artificial effects with high accuracy and revealed statistically significant differences between the AD and control groups. This paper extends the usage of texture analysis beyond the current region of interest analysis to voxel-by-voxel 3D statistical mapping and provides a hypothesis-free analysis tool to study cerebral pathology in neurological diseases. PMID:25756621

  5. Voxel-based texture analysis of the brain.

    Rouzbeh Maani

    Full Text Available This paper presents a novel voxel-based method for texture analysis of brain images. Texture analysis is a powerful quantitative approach for analyzing voxel intensities and their interrelationships, but has been thus far limited to analyzing regions of interest. The proposed method provides a 3D statistical map comparing texture features on a voxel-by-voxel basis. The validity of the method was examined on artificially generated effects as well as on real MRI data in Alzheimer's Disease (AD. The artificially generated effects included hyperintense and hypointense signals added to T1-weighted brain MRIs from 30 healthy subjects. The AD dataset included 30 patients with AD and 30 age/sex matched healthy control subjects. The proposed method detected artificial effects with high accuracy and revealed statistically significant differences between the AD and control groups. This paper extends the usage of texture analysis beyond the current region of interest analysis to voxel-by-voxel 3D statistical mapping and provides a hypothesis-free analysis tool to study cerebral pathology in neurological diseases.

  6. AR based ornament design system for 3D printing

    Hiroshi Aoki

    2015-01-01

    Full Text Available In recent years, 3D printers have become popular as a means of outputting geometries designed on CAD or 3D graphics systems. However, the complex user interfaces of standard 3D software can make it difficult for ordinary consumers to design their own objects. Furthermore, models designed on 3D graphics software often have geometrical problems that make them impossible to output on a 3D printer. We propose a novel AR (augmented reality 3D modeling system with an air-spray like interface. We also propose a new data structure (octet voxel for representing designed models in such a way that the model is guaranteed to be a complete solid. The target shape is based on a regular polyhedron, and the octet voxel representation is suitable for designing geometrical objects having the same symmetries as the base regular polyhedron. Finally, we conducted a user test and confirmed that users can intuitively design their own ornaments in a short time with a simple user interface.

  7. Crowdsourcing Based 3d Modeling

    Somogyi, A.; Barsi, A.; Molnar, B.; Lovas, T.

    2016-06-01

    Web-based photo albums that support organizing and viewing the users' images are widely used. These services provide a convenient solution for storing, editing and sharing images. In many cases, the users attach geotags to the images in order to enable using them e.g. in location based applications on social networks. Our paper discusses a procedure that collects open access images from a site frequently visited by tourists. Geotagged pictures showing the image of a sight or tourist attraction are selected and processed in photogrammetric processing software that produces the 3D model of the captured object. For the particular investigation we selected three attractions in Budapest. To assess the geometrical accuracy, we used laser scanner and DSLR as well as smart phone photography to derive reference values to enable verifying the spatial model obtained from the web-album images. The investigation shows how detailed and accurate models could be derived applying photogrammetric processing software, simply by using images of the community, without visiting the site.

  8. The Monte Carlo SRNA-VOX code for 3D proton dose distribution in voxelized geometry using CT data

    Ilic, Radovan D [Laboratory of Physics (010), Vinca Institute of Nuclear Sciences, PO Box 522, 11001 Belgrade (Serbia and Montenegro); Spasic-Jokic, Vesna [Laboratory of Physics (010), Vinca Institute of Nuclear Sciences, PO Box 522, 11001 Belgrade (Serbia and Montenegro); Belicev, Petar [Laboratory of Physics (010), Vinca Institute of Nuclear Sciences, PO Box 522, 11001 Belgrade (Serbia and Montenegro); Dragovic, Milos [Center for Nuclear Medicine MEDICA NUCLEARE, Bulevar Despota Stefana 69, 11000 Belgrade (Serbia and Montenegro)

    2005-03-07

    This paper describes the application of the SRNA Monte Carlo package for proton transport simulations in complex geometry and different material compositions. The SRNA package was developed for 3D dose distribution calculation in proton therapy and dosimetry and it was based on the theory of multiple scattering. The decay of proton induced compound nuclei was simulated by the Russian MSDM model and our own using ICRU 63 data. The developed package consists of two codes: the SRNA-2KG, which simulates proton transport in combinatorial geometry and the SRNA-VOX, which uses the voxelized geometry using the CT data and conversion of the Hounsfield's data to tissue elemental composition. Transition probabilities for both codes are prepared by the SRNADAT code. The simulation of the proton beam characterization by multi-layer Faraday cup, spatial distribution of positron emitters obtained by the SRNA-2KG code and intercomparison of computational codes in radiation dosimetry, indicate immediate application of the Monte Carlo techniques in clinical practice. In this paper, we briefly present the physical model implemented in the SRNA package, the ISTAR proton dose planning software, as well as the results of the numerical experiments with proton beams to obtain 3D dose distribution in the eye and breast tumour.

  9. The Monte Carlo SRNA-VOX code for 3D proton dose distribution in voxelized geometry using CT data

    Ilic, Radovan D.; Spasic-Jokic, Vesna; Belicev, Petar; Dragovic, Milos

    2005-03-01

    This paper describes the application of the SRNA Monte Carlo package for proton transport simulations in complex geometry and different material compositions. The SRNA package was developed for 3D dose distribution calculation in proton therapy and dosimetry and it was based on the theory of multiple scattering. The decay of proton induced compound nuclei was simulated by the Russian MSDM model and our own using ICRU 63 data. The developed package consists of two codes: the SRNA-2KG, which simulates proton transport in combinatorial geometry and the SRNA-VOX, which uses the voxelized geometry using the CT data and conversion of the Hounsfield's data to tissue elemental composition. Transition probabilities for both codes are prepared by the SRNADAT code. The simulation of the proton beam characterization by multi-layer Faraday cup, spatial distribution of positron emitters obtained by the SRNA-2KG code and intercomparison of computational codes in radiation dosimetry, indicate immediate application of the Monte Carlo techniques in clinical practice. In this paper, we briefly present the physical model implemented in the SRNA package, the ISTAR proton dose planning software, as well as the results of the numerical experiments with proton beams to obtain 3D dose distribution in the eye and breast tumour.

  10. The Monte Carlo SRNA-VOX code for 3D proton dose distribution in voxelized geometry using CT data

    This paper describes the application of the SRNA Monte Carlo package for proton transport simulations in complex geometry and different material compositions. The SRNA package was developed for 3D dose distribution calculation in proton therapy and dosimetry and it was based on the theory of multiple scattering. The decay of proton induced compound nuclei was simulated by the Russian MSDM model and our own using ICRU 63 data. The developed package consists of two codes: the SRNA-2KG, which simulates proton transport in combinatorial geometry and the SRNA-VOX, which uses the voxelized geometry using the CT data and conversion of the Hounsfield's data to tissue elemental composition. Transition probabilities for both codes are prepared by the SRNADAT code. The simulation of the proton beam characterization by multi-layer Faraday cup, spatial distribution of positron emitters obtained by the SRNA-2KG code and intercomparison of computational codes in radiation dosimetry, indicate immediate application of the Monte Carlo techniques in clinical practice. In this paper, we briefly present the physical model implemented in the SRNA package, the ISTAR proton dose planning software, as well as the results of the numerical experiments with proton beams to obtain 3D dose distribution in the eye and breast tumour

  11. Voxel-based morphometry and voxel-based diffusion tensor analysis in amyotrophic lateral sclerosis

    Objective: To evaluate gray matter volume, white matter volume and FA value changes in amyatrophic lateral sclerosis (ALS) patients by voxel-based morphometry (VBM) and voxel-based diffusion tensor analysis (VBDTA). Methods: Thirty-nine definite or probable ALS patients diagnosed by El Escorial standard and 39 healthy controls were recruited and underwent conventional MR scans and the neuropsychological evaluation. The 3D FSPGR T1WI and DTI data were collected on GE Medical 3.0 T MRI system. The 3DT1 structural images were normalized, segmented and smoothed, and then VBM analysis was performed. DTI data were acquired from 76 healthy controls, and FA map template was made. FA maps generated from the DTI data of ALS patients and healthy controls were normalized to the FA map template for voxel-based analysis. ANCOVA was applied, controlling with age and total intracranial volume for VBM and age for VBDDTA. A statistical threshold of P<0.01 (uncorrected) and cluster level of more than continuous 20 voxels determined significance. Results: Statistical results showed no significant difference in the global volumes of gray matter and white matter, total intracranial volumes and gray matter fraction between ALS patients and healthy controls, but the white matter fraction of ALS patients (0.29 ± 0.02) was significantly less than that of healthy controls (0.30 ± 0.02) statistically (P=0.003). There was significant reduction of gray matter volumes in bilateral superior frontal gyri and precentral gyri, right middle frontal gyrus, right middle and inferior temporal gyrus, left superior occipital gyrus and cuneus and left insula in ALS patients when compared with healthy controls; and the regional reduction of white matter volumes in ALS patients mainly located in genu of corpus callosum, bilateral medial frontal gyri, paracentral lobule and insula, right superior and middle frontal gyrus and left postcentral gyrus. VBDTA showed decrease in FA values in bilateral

  12. View-based 3-D object retrieval

    Gao, Yue

    2014-01-01

    Content-based 3-D object retrieval has attracted extensive attention recently and has applications in a variety of fields, such as, computer-aided design, tele-medicine,mobile multimedia, virtual reality, and entertainment. The development of efficient and effective content-based 3-D object retrieval techniques has enabled the use of fast 3-D reconstruction and model design. Recent technical progress, such as the development of camera technologies, has made it possible to capture the views of 3-D objects. As a result, view-based 3-D object retrieval has become an essential but challenging res

  13. Voxel Based Representation of Full-Waveform Airborne Laser Scanner Data for Forestry Applications

    Stelling, N.; Richter, K.

    2016-06-01

    The advantages of using airborne full-waveform laser scanner data in forest applications, e.g. for the description of the vertical vegetation structure or accurate biomass estimation, have been emphasized in many publications. To exploit the full potential offered by airborne full-waveform laser scanning data, the development of voxel based methods for data analysis is essential. In contrast to existing approaches based on the extraction of discrete 3D points by a Gaussian decomposition, it is very promising to derive the voxel attributes from the digitised waveform directly. For this purpose, the waveform data have to be transferred into a 3D voxel representation. This requires a series of radiometric and geometric transformations of the raw full-waveform laser scanner data. Thus, the paper deals with the geometric aspects and describes a processing chain from the raw waveform data to an attenuationcorrected volumetric forest stand reconstruction. The integration of attenuation-corrected waveform data into the voxel space is realised with an efficient parametric voxel traversal method operating on an octree data structure. The voxel attributes are derived from the amplitudes of the attenuation-corrected waveforms. Additionally, a new 3D filtering approach is presented to eliminate non-object voxel. Applying these methods to real full-waveform laser scanning data, a voxel based representation of a spruce was generated combining three flight strips from different viewing directions.

  14. Probabilistic Voxel-Fe model for single cell motility in 3D

    Borau, Carlos; Polacheck, William J; Kamm, Roger D; García-Aznar, José Manuel

    2015-01-01

    Background Cells respond to a variety of external stimuli regulated by the environment conditions. Mechanical, chemical and biological factors are of great interest and have been deeply studied. Furthermore, mathematical and computational models have been rapidly growing over the past few years, permitting researches to run complex scenarios saving time and resources. Usually these models focus on specific features of cell migration, making them only suitable to study restricted phenomena. Methods Here we present a versatile finite element (FE) cell-scale 3D migration model based on probabilities depending in turn on ECM mechanical properties, chemical, fluid and boundary conditions. Results With this approach we are able to capture important outcomes of cell migration such as: velocities, trajectories, cell shape and aspect ratio, cell stress or ECM displacements. Conclusions The modular form of the model will allow us to constantly update and redefine it as advancements are made in clarifying how cellular events take place. PMID:26290806

  15. Voxel-based morphometry and epilepsy.

    Yasuda, Clarissa Lin; Betting, Luiz Eduardo; Cendes, Fernando

    2010-06-01

    Voxel-based morphometry is an automated technique for MRI analyses, developed to study differences in brain morphology and frequently used to study patients with diverse disorders. In epilepsy, it has been used to investigate areas with reduction or increase of gray and white matter, in different syndromes (i.e., temporal lobe epilepsy, focal cortical dysplasia and generalized epilepsies). In temporal lobe epilepsy, voxel-based morphometry showed gray/white matter atrophy extending beyond the atrophic hippocampus. These widespread abnormalities have been associated with seizure frequency, epilepsy duration, incidence of precipitating factors, cognitive dysfunction and surgical outcome. In generalized epilepsies, gray matter abnormalities were identified mainly in the thalamus and frontal cortex, reinforcing the role of the thalamocortical network in the mechanisms of generalized seizures. PMID:20518612

  16. Retrieving Leaf Area Index and Foliage Profiles Through Voxelized 3-D Forest Reconstruction Using Terrestrial Full-Waveform and Dual-Wavelength Echidna Lidars

    Strahler, A. H.; Yang, X.; Li, Z.; Schaaf, C.; Wang, Z.; Yao, T.; Zhao, F.; Saenz, E.; Paynter, I.; Douglas, E. S.; Chakrabarti, S.; Cook, T.; Martel, J.; Howe, G.; Hewawasam, K.; Jupp, D.; Culvenor, D.; Newnham, G.; Lowell, J.

    2013-12-01

    Measuring and monitoring canopy biophysical parameters provide a baseline for carbon flux studies related to deforestation and disturbance in forest ecosystems. Terrestrial full-waveform lidar systems, such as the Echidna Validation Instrument (EVI) and its successor Dual-Wavelength Echidna Lidar (DWEL), offer rapid, accurate, and automated characterization of forest structure. In this study, we apply a methodology based on voxelized 3-D forest reconstructions built from EVI and DWEL scans to directly estimate two important biophysical parameters: Leaf Area Index (LAI) and foliage profile. Gap probability, apparent reflectance, and volume associated with the laser pulse footprint at the observed range are assigned to the foliage scattering events in the reconstructed point cloud. Leaf angle distribution is accommodated with a simple model based on gap probability with zenith angle as observed in individual scans of the stand. The DWEL instrument, which emits simultaneous laser pulses at 1064 nm and 1548 nm wavelengths, provides a better capability to separate trunk and branch hits from foliage hits due to water absorption by leaf cellular contents at 1548 nm band. We generate voxel datasets of foliage points using a classification methodology solely based on pulse shape for scans collected by EVI and with pulse shape and band ratio for scans collected by DWEL. We then compare the LAIs and foliage profiles retrieved from the voxel datasets of the two instruments at the same red fir site in Sierra National Forest, CA, with each other and with observations from airborne and field measurements. This study further tests the voxelization methodology in obtaining LAI and foliage profiles that are largely free of clumping effects and returns from woody materials in the canopy. These retrievals can provide a valuable 'ground-truth' validation data source for large-footprint spaceborne or airborne lidar systems retrievals.

  17. Nonlaser-based 3D surface imaging

    Lu, Shin-yee; Johnson, R.K.; Sherwood, R.J. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    3D surface imaging refers to methods that generate a 3D surface representation of objects of a scene under viewing. Laser-based 3D surface imaging systems are commonly used in manufacturing, robotics and biomedical research. Although laser-based systems provide satisfactory solutions for most applications, there are situations where non laser-based approaches are preferred. The issues that make alternative methods sometimes more attractive are: (1) real-time data capturing, (2) eye-safety, (3) portability, and (4) work distance. The focus of this presentation is on generating a 3D surface from multiple 2D projected images using CCD cameras, without a laser light source. Two methods are presented: stereo vision and depth-from-focus. Their applications are described.

  18. Web-based interactive visualization of 3D video mosaics using X3D standard

    CHON Jaechoon; LEE Yang-Won; SHIBASAKI Ryosuke

    2006-01-01

    We present a method of 3D image mosaicing for real 3D representation of roadside buildings, and implement a Web-based interactive visualization environment for the 3D video mosaics created by 3D image mosaicing. The 3D image mosaicing technique developed in our previous work is a very powerful method for creating textured 3D-GIS data without excessive data processing like the laser or stereo system. For the Web-based open access to the 3D video mosaics, we build an interactive visualization environment using X3D, the emerging standard of Web 3D. We conduct the data preprocessing for 3D video mosaics and the X3D modeling for textured 3D data. The data preprocessing includes the conversion of each frame of 3D video mosaics into concatenated image files that can be hyperlinked on the Web. The X3D modeling handles the representation of concatenated images using necessary X3D nodes. By employing X3D as the data format for 3D image mosaics, the real 3D representation of roadside buildings is extended to the Web and mobile service systems.

  19. Volume-Rendering-Based Interactive 3D Measurement for Quantitative Analysis of 3D Medical Images

    Yakang Dai; Jian Zheng; Yuetao Yang; Duojie Kuai; Xiaodong Yang

    2013-01-01

    3D medical images are widely used to assist diagnosis and surgical planning in clinical applications, where quantitative measurement of interesting objects in the image is of great importance. Volume rendering is widely used for qualitative visualization of 3D medical images. In this paper, we introduce a volume-rendering-based interactive 3D measurement framework for quantitative analysis of 3D medical images. In the framework, 3D widgets and volume clipping are integrated with volume render...

  20. Second generation anthropomorphic physical phantom for mammography and DBT: Incorporating voxelized 3D printing and inkjet printing of iodinated lesion inserts

    Sikaria, Dhiraj; Musinsky, Stephanie; Sturgeon, Gregory M.; Solomon, Justin; Diao, Andrew; Gehm, Michael E.; Samei, Ehsan; Glick, Stephen J.; Lo, Joseph Y.

    2016-03-01

    Physical phantoms are needed for the evaluation and optimization of new digital breast tomosynthesis (DBT) systems. Previously, we developed an anthropomorphic phantom based on human subject breast CT data and fabricated using commercial 3D printing. We now present three key advancements: voxelized 3D printing, photopolymer material doping, and 2D inkjet printing of lesion inserts. First, we bypassed the printer's control software in order to print in voxelized form instead of conventional STL surfaces, thus improving resolution and allowing dithering to mix the two photopolymer materials into arbitrary proportions. We demonstrated ability to print details as small as 150μm, and dithering to combine VeroWhitePlus and TangoPlus in 10% increments. Second, to address the limited attenuation difference among commercial photopolymers, we evaluated a beta sample from Stratasys with increased TiO2 doping concentration up to 2.5%, which corresponded to 98% breast density. By spanning 36% to 98% breast density, this doubles our previous contrast. Third, using inkjet printers modified to print with iopamidol, we created 2D lesion patterns on paper that can be sandwiched into the phantom. Inkjet printing has advantages of being inexpensive and easy, and more contrast can be delivered through overprinting. Printing resolution was maintained at 210 μm horizontally and 330 μm vertically even after 10 overprints. Contrast increased linearly with overprinting at 0.7% per overprint. Together, these three new features provide the basis for creating a new anthropomorphic physical breast phantom with improved resolution and contrast, as well as the ability to insert 2D lesions for task-based assessment of performance.

  1. Neural Network Based 3D Surface Reconstruction

    Vincy Joseph

    2009-11-01

    Full Text Available This paper proposes a novel neural-network-based adaptive hybrid-reflectance three-dimensional (3-D surface reconstruction model. The neural network combines the diffuse and specular components into a hybrid model. The proposed model considers the characteristics of each point and the variant albedo to prevent the reconstructed surface from being distorted. The neural network inputs are the pixel values of the two-dimensional images to be reconstructed. The normal vectors of the surface can then be obtained from the output of the neural network after supervised learning, where the illuminant direction does not have to be known in advance. Finally, the obtained normal vectors can be applied to integration method when reconstructing 3-D objects. Facial images were used for training in the proposed approach

  2. Finding significantly connected voxels based on histograms of connection strengths

    Kasenburg, Niklas; Pedersen, Morten; Darkner, Sune

    2016-01-01

    We explore a new approach for structural connectivity based segmentations of subcortical brain regions. Connectivity based segmentations are usually based on fibre connections from a seed region to predefined target regions. We present a method for finding significantly connected voxels based on...... the distribution of connection strengths. Paths from seed voxels to all voxels in a target region are obtained from a shortest-path tractography. For each seed voxel we approximate the distribution with a histogram of path scores. We hypothesise that the majority of estimated connections are false-positives...... and that their connection strength is distributed differently from true-positive connections. Therefore, an empirical null-distribution is defined for each target region as the average normalized histogram over all voxels in the seed region. Single histograms are then tested against the corresponding...

  3. Py3DFreeHandUS: A PURE PYTHON LIBRARY FOR 3D VOXEL-ARRAY RECONSTRUCTION BY USING 3D FREEHAND ULTRASOUND

    Monari, Davide; Cenni, Francesco; Aertbeliën, Erwin; Desloovere, Kaat

    2014-01-01

    INTRODUCTION and AIM 3D Freehand ultrasound (3DUS) is a technique that combines ultrasound images and position + orientation sensors (POS) with the aim to reconstruct large 3D anatomical parts. However, the few existing applications for applying this technique have at least one of the following disadvantages: i) not open-source; ii) only supporting data streams from a limited number of ultrasound or POS devices; iii) they are written in low-level languages such as C++, making rapid develop...

  4. A Visual Similarity-Based 3D Search Engine

    Lmaati, Elmustapha Ait; Oirrak, Ahmed El; M.N. Kaddioui

    2009-01-01

    Retrieval systems for 3D objects are required because 3D databases used around the web are growing. In this paper, we propose a visual similarity based search engine for 3D objects. The system is based on a new representation of 3D objects given by a 3D closed curve that captures all information about the surface of the 3D object. We propose a new 3D descriptor, which is a combination of three signatures of this new representation, and we implement it in our interactive web based search engin...

  5. Multilevel Solvers with Aggregations for Voxel Based Analysis of Geomaterials

    Blaheta, R. (Radim); V. Sokol

    2012-01-01

    Our motivation for voxel based analysis comes from the investigation of geomaterials (geocomposites) arising from rock grouting or sealing. We use finite element analysis based on voxel data from tomography. The arising finite element systems are large scale, which motivates the use of multilevel iterative solvers or preconditioners. Among others we concentrate on multilevel Schwarz preconditioners with aggregations. The aggregations are efficient even in the case of problems with hete...

  6. Microassembly for complex and solid 3D MEMS by 3D Vision-based control.

    Tamadazte, Brahim; Le Fort-Piat, Nadine; Marchand, Eric; Dembélé, Sounkalo

    2009-01-01

    This paper describes the vision-based methods developed for assembly of complex and solid 3D MEMS (micro electromechanical systems) structures. The microassembly process is based on sequential robotic operations such as planar positioning, gripping, orientation in space and insertion tasks. Each of these microassembly tasks is performed using a posebased visual control. To be able to control the microassembly process, a 3D model-based tracker is used. This tracker able to directly provides th...

  7. Direct 3D Painting with a Metaball-Based Paintbrush

    WAN Huagen; JIN Xiaogang; BAO Hujun

    2000-01-01

    This paper presents a direct 3D painting algorithm for polygonal models in 3D object-space with a metaball-based paintbrush in virtual environment.The user is allowed to directly manipulate the parameters used to shade the surface of the 3D shape by applying the pigment to its surface with direct 3D manipulation through a 3D flying mouse.

  8. Morphometric changes of whole brain in patients with alcohol addiction: a voxel-based morphometry study

    Objective: To evaluate morphometric changes of brain in patients with alcohol addiction by voxel-based morphometry. Methods: Fifteen patients with alcohol addiction and 15 health controls were recruited and underwent fluid attenuated inversion recovery (FLAIR) and 3D fast spoiled gradient echo (FSPGR) T1-weighted sequences on a 3.0 T MRI system. 3D FSPGR T1 structure images were normalized, segmented and smoothed, and then underwent voxel-based morphometry. An ANCOVA was applied with age, body mass index (BMI), and education years as covariates because of exact sex match. A statistical threshold of P 0.05). Conclusions: Regional gray and white matter atrophy can be the initial changes in patients with alcohol addiction and the frontal region is a relative specific damaged brain region. VBM has a potential value for the detection of subtle brain atrophy in patients with alcohol addiction. (authors)

  9. Two adult human voxel phantoms based on polygon mesh surfaces

    Among computational models used in radiation protection, voxel phantoms based on computer tomographic (CT), nuclear magnetic resonance (NMR) or colour photographic images, became very popular in recent years. Although being a true to nature representation of the scanned individual the scanning is usually made in supine position, which causes a shift of internal organs towards the ribcage, a compression of the lungs and a reduction of the sagittal diameter especially in the abdominal region compared to the anatomy of a person in upright standing position, which in turn can influence absorbed or equivalent dose estimates. This study proposes a method for human phantom design using tools recently developed in the areas of computer graphics and animated films and applies them to the creation and modeling of artificial 3D human organs and tissues. Two models, a male and a female adult human phantom have been developed based on anatomical atlases, observing at the same time the anatomical specifications published by the International Commission on Radiological Protection for the male and female reference adult. The phantoms are called FAXAA (Female Adult voXelAverage-Average) and MAXAA (Male Adult voXelAverage-Average) because they represent female and male adults with average weight and average height. (author)

  10. Coronary Arteries Segmentation Based on the 3D Discrete Wavelet Transform and 3D Neutrosophic Transform

    Shuo-Tsung Chen

    2015-01-01

    Full Text Available Purpose. Most applications in the field of medical image processing require precise estimation. To improve the accuracy of segmentation, this study aimed to propose a novel segmentation method for coronary arteries to allow for the automatic and accurate detection of coronary pathologies. Methods. The proposed segmentation method included 2 parts. First, 3D region growing was applied to give the initial segmentation of coronary arteries. Next, the location of vessel information, HHH subband coefficients of the 3D DWT, was detected by the proposed vessel-texture discrimination algorithm. Based on the initial segmentation, 3D DWT integrated with the 3D neutrosophic transformation could accurately detect the coronary arteries. Results. Each subbranch of the segmented coronary arteries was segmented correctly by the proposed method. The obtained results are compared with those ground truth values obtained from the commercial software from GE Healthcare and the level-set method proposed by Yang et al., 2007. Results indicate that the proposed method is better in terms of efficiency analyzed. Conclusion. Based on the initial segmentation of coronary arteries obtained from 3D region growing, one-level 3D DWT and 3D neutrosophic transformation can be applied to detect coronary pathologies accurately.

  11. STAR3D: a stack-based RNA 3D structural alignment tool.

    Ge, Ping; Zhang, Shaojie

    2015-11-16

    The various roles of versatile non-coding RNAs typically require the attainment of complex high-order structures. Therefore, comparing the 3D structures of RNA molecules can yield in-depth understanding of their functional conservation and evolutionary history. Recently, many powerful tools have been developed to align RNA 3D structures. Although some methods rely on both backbone conformations and base pairing interactions, none of them consider the entire hierarchical formation of the RNA secondary structure. One of the major issues is that directly applying the algorithms of matching 2D structures to the 3D coordinates is particularly time-consuming. In this article, we propose a novel RNA 3D structural alignment tool, STAR3D, to take into full account the 2D relations between stacks without the complicated comparison of secondary structures. First, the 3D conserved stacks in the inputs are identified and then combined into a tree-like consensus. Afterward, the loop regions are compared one-to-one in accordance with their relative positions in the consensus tree. The experimental results show that the prediction of STAR3D is more accurate for both non-homologous and homologous RNAs than other state-of-the-art tools with shorter running time. PMID:26184875

  12. Random-Profiles-Based 3D Face Recognition System

    Joongrock Kim; Sunjin Yu; Sangyoun Lee

    2014-01-01

    In this paper, a noble nonintrusive three-dimensional (3D) face modeling system for random-profile-based 3D face recognition is presented. Although recent two-dimensional (2D) face recognition systems can achieve a reliable recognition rate under certain conditions, their performance is limited by internal and external changes, such as illumination and pose variation. To address these issues, 3D face recognition, which uses 3D face data, has recently received much attention. However, the perf...

  13. Voxel-based frog phantom for internal dose evaluation

    A voxel-based frog phantom has been developed for radiation protection of the environment. The voxel-based frog phantom was applied to evaluating self-absorbed fractions (self-AFs), which are defined as the fraction of energy emitted by a radiation source that is absorbed within the source organ. The self-AFs were evaluated for both photons and electrons in the spleen, kidneys, and liver using Monte Carlo simulations. Furthermore, self-S values (μGy/MBq·s) for 18F and 90Y in the organs were calculated using the results of the self-AFs. Consequently, the voxel-based frog phantom was found to be useful for the organ dose evaluations, which have not been proposed by the International Commission on Radiological Protection (ICRP). It was also confirmed that the self-AFs and self-S values are largely dependent on the mass of the source organ. (author)

  14. Building Point Detection from Vehicle-Borne LiDAR Data Based on Voxel Group and Horizontal Hollow Analysis

    Yu Wang

    2016-05-01

    Full Text Available Information extraction and three-dimensional (3D reconstruction of buildings using the vehicle-borne laser scanning (VLS system is significant for many applications. Extracting LiDAR points, from VLS, belonging to various types of building in large-scale complex urban environments still retains some problems. In this paper, a new technical framework for automatic and efficient building point extraction is proposed, including three main steps: (1 voxel group-based shape recognition; (2 category-oriented merging; and (3 building point identification by horizontal hollow ratio analysis. This article proposes a concept of “voxel group” based on the voxelization of VLS points: each voxel group is composed of several voxels that belong to one single real-world object. Then the shapes of point clouds in each voxel group are recognized and this shape information is utilized to merge voxel group. This article puts forward a characteristic nature of vehicle-borne LiDAR building points, called “horizontal hollow ratio”, for efficient extraction. Experiments are analyzed from two aspects: (1 building-based evaluation for overall experimental area; and (2 point-based evaluation for individual building using the completeness and correctness. The experimental results indicate that the proposed framework is effective for the extraction of LiDAR points belonging to various types of buildings in large-scale complex urban environments.

  15. Random-Profiles-Based 3D Face Recognition System

    Joongrock Kim

    2014-03-01

    Full Text Available In this paper, a noble nonintrusive three-dimensional (3D face modeling system for random-profile-based 3D face recognition is presented. Although recent two-dimensional (2D face recognition systems can achieve a reliable recognition rate under certain conditions, their performance is limited by internal and external changes, such as illumination and pose variation. To address these issues, 3D face recognition, which uses 3D face data, has recently received much attention. However, the performance of 3D face recognition highly depends on the precision of acquired 3D face data, while also requiring more computational power and storage capacity than 2D face recognition systems. In this paper, we present a developed nonintrusive 3D face modeling system composed of a stereo vision system and an invisible near-infrared line laser, which can be directly applied to profile-based 3D face recognition. We further propose a novel random-profile-based 3D face recognition method that is memory-efficient and pose-invariant. The experimental results demonstrate that the reconstructed 3D face data consists of more than 50 k 3D point clouds and a reliable recognition rate against pose variation.

  16. MRI Volume Fusion Based on 3D Shearlet Decompositions.

    Duan, Chang; Wang, Shuai; Wang, Xue Gang; Huang, Qi Hong

    2014-01-01

    Nowadays many MRI scans can give 3D volume data with different contrasts, but the observers may want to view various contrasts in the same 3D volume. The conventional 2D medical fusion methods can only fuse the 3D volume data layer by layer, which may lead to the loss of interframe correlative information. In this paper, a novel 3D medical volume fusion method based on 3D band limited shearlet transform (3D BLST) is proposed. And this method is evaluated upon MRI T2* and quantitative susceptibility mapping data of 4 human brains. Both the perspective impression and the quality indices indicate that the proposed method has a better performance than conventional 2D wavelet, DT CWT, and 3D wavelet, DT CWT based fusion methods. PMID:24817880

  17. 3D multifocus astigmatism and compressed sensing (3D MACS) based superresolution reconstruction.

    Huang, Jiaqing; Sun, Mingzhai; Gumpper, Kristyn; Chi, Yuejie; Ma, Jianjie

    2015-03-01

    Single molecule based superresolution techniques (STORM/PALM) achieve nanometer spatial resolution by integrating the temporal information of the switching dynamics of fluorophores (emitters). When emitter density is low for each frame, they are located to the nanometer resolution. However, when the emitter density rises, causing significant overlapping, it becomes increasingly difficult to accurately locate individual emitters. This is particularly apparent in three dimensional (3D) localization because of the large effective volume of the 3D point spread function (PSF). The inability to precisely locate the emitters at a high density causes poor temporal resolution of localization-based superresolution technique and significantly limits its application in 3D live cell imaging. To address this problem, we developed a 3D high-density superresolution imaging platform that allows us to precisely locate the positions of emitters, even when they are significantly overlapped in three dimensional space. Our platform involves a multi-focus system in combination with astigmatic optics and an ℓ 1-Homotopy optimization procedure. To reduce the intrinsic bias introduced by the discrete formulation of compressed sensing, we introduced a debiasing step followed by a 3D weighted centroid procedure, which not only increases the localization accuracy, but also increases the computation speed of image reconstruction. We implemented our algorithms on a graphic processing unit (GPU), which speeds up processing 10 times compared with central processing unit (CPU) implementation. We tested our method with both simulated data and experimental data of fluorescently labeled microtubules and were able to reconstruct a 3D microtubule image with 1000 frames (512×512) acquired within 20 seconds. PMID:25798314

  18. Creation of voxel-based models for paediatric dosimetry from automatic segmentation methods

    Full text: The first computational models representing human anatomy were mathematical phantoms, but still far from accurate representations of human body. These models have been used with radiation transport codes (Monte Carlo) to estimate organ doses from radiological procedures. Although new medical imaging techniques have recently allowed the construction of voxel-based models based on the real anatomy, few children models from individual CT or MRI data have been reported [1,3]. For pediatric dosimetry purposes, a large range of voxel models by ages is required since scaling the anatomy from existing models is not sufficiently accurate. The small number of models available arises from the small number of CT or MRI data sets of children available and the long amount of time required to segment the data sets. The existing models have been constructed by manual segmentation slice by slice and using simple thresholding techniques. In medical image segmentation, considerable difficulties appear when applying classical techniques like thresholding or simple edge detection. Until now, any evidence of more accurate or near-automatic methods used in construction of child voxel models exists. We aim to construct a range of pediatric voxel models, integrating automatic or semi-automatic 3D segmentation techniques. In this paper we present the first stage of this work using pediatric CT data.

  19. Towards a voxel-based geographic automata for the simulation of geospatial processes

    Jjumba, Anthony; Dragićević, Suzana

    2016-07-01

    Many geographic processes evolve in a three dimensional space and time continuum. However, when they are represented with the aid of geographic information systems (GIS) or geosimulation models they are modelled in a framework of two-dimensional space with an added temporal component. The objective of this study is to propose the design and implementation of voxel-based automata as a methodological approach for representing spatial processes evolving in the four-dimensional (4D) space-time domain. Similar to geographic automata models which are developed to capture and forecast geospatial processes that change in a two-dimensional spatial framework using cells (raster geospatial data), voxel automata rely on the automata theory and use three-dimensional volumetric units (voxels). Transition rules have been developed to represent various spatial processes which range from the movement of an object in 3D to the diffusion of airborne particles and landslide simulation. In addition, the proposed 4D models demonstrate that complex processes can be readily reproduced from simple transition functions without complex methodological approaches. The voxel-based automata approach provides a unique basis to model geospatial processes in 4D for the purpose of improving representation, analysis and understanding their spatiotemporal dynamics. This study contributes to the advancement of the concepts and framework of 4D GIS.

  20. Vessel-guided airway segmentation based on voxel classification

    Lo, Pechin Chien Pau; Sporring, Jon; Ashraf, Haseem;

    2008-01-01

    surroundings of a voxel, estimated based on a tube model, is to that of a neighboring vessel. The proposed method is tested on 20 CT images from different subjects selected randomly from a lung cancer screening study. Length of the airway branches from the results of the proposed method are significantly...

  1. Voxel selection in FMRI data analysis based on sparse representation.

    Li, Yuanqing; Namburi, Praneeth; Yu, Zhuliang; Guan, Cuntai; Feng, Jianfeng; Gu, Zhenghui

    2009-10-01

    Multivariate pattern analysis approaches toward detection of brain regions from fMRI data have been gaining attention recently. In this study, we introduce an iterative sparse-representation-based algorithm for detection of voxels in functional MRI (fMRI) data with task relevant information. In each iteration of the algorithm, a linear programming problem is solved and a sparse weight vector is subsequently obtained. The final weight vector is the mean of those obtained in all iterations. The characteristics of our algorithm are as follows: 1) the weight vector (output) is sparse; 2) the magnitude of each entry of the weight vector represents the significance of its corresponding variable or feature in a classification or regression problem; and 3) due to the convergence of this algorithm, a stable weight vector is obtained. To demonstrate the validity of our algorithm and illustrate its application, we apply the algorithm to the Pittsburgh Brain Activity Interpretation Competition 2007 functional fMRI dataset for selecting the voxels, which are the most relevant to the tasks of the subjects. Based on this dataset, the aforementioned characteristics of our algorithm are analyzed, and a comparison between our method with the univariate general-linear-model-based statistical parametric mapping is performed. Using our method, a combination of voxels are selected based on the principle of effective/sparse representation of a task. Data analysis results in this paper show that this combination of voxels is suitable for decoding tasks and demonstrate the effectiveness of our method. PMID:19567340

  2. Whole-brain voxel-based morphometry of white matter in medial temporal lobe epilepsy

    Yu Aihong [Department of Radiology, Xuanwu Hospital, Capital University of Medical Sciences, Beijing 100053 (China); Li Kuncheng [Department of Radiology, Xuanwu Hospital, Capital University of Medical Sciences, Beijing 100053 (China)], E-mail: Likuncheng@vip.sina.com; Li Lin; Shan Baoci [Institute of High Energy Physics, Chinese Academy of Sciences (China); Wang Yuping; Xue Sufang [Department of Neurology, Xuanwu Hospital, Capital University of Medical Sciences (China)

    2008-01-15

    Purpose: The purpose of this study was to analyze whole-brain white matter changes in medial temporal lobe epilepsy (MTLE). Materials and methods: We studied 23 patients with MTLE and 13 age- and sex-matched healthy control subjects using voxel-based morphometry (VBM) on T1-weighted 3D datasets. The seizure focus was right sided in 11 patients and left sided in 12. The data were collected on a 1.5 T MR system and analyzed by SPM 99 to generate white matter density maps. Results: Voxel-based morphometry revealed diffusively reduced white matter in MTLE prominently including bilateral frontal lobes, bilateral temporal lobes and corpus callosum. White matter reduction was also found in the bilateral cerebellar hemispheres in the left MTLE group. Conclusion: VBM is a simple and automated approach that is able to identify diffuse whole-brain white matter reduction in MTLE.

  3. Whole-brain voxel-based morphometry of white matter in mild cognitive impairment

    Purpose: The purpose of this study was to analyze whole-brain white matter changes in mild cognitive impairment (MCI). Materials and methods: We studied 14 patients with MCI and 14 age- and sex-matched healthy control subjects using voxel-based morphometry (VBM) on T1-weighted 3D datasets. The data were collected on a 3T MR system and analyzed by SPM2 to generate white matter volume maps. Results: Voxel-based morphometry revealed diffusively reduced white matter in MCI prominently including the bilateral temporal gyrus, the right anterior cingulate, the bilateral superior and medial frontal gyrus and right parietal angular gyrus. White matter reduction was more prominent in anterior regions than that in posterior regions. Conclusion: Whole-brain white matter reduction in MCI patients detected with VBM has special distribution which is in line with the white matter pathology of MCI.

  4. Whole-brain voxel-based morphometry of white matter in mild cognitive impairment

    Wang Zhiqun [Department of Radiology, Xuanwu Hospital of Capital Medical University, 100053, Beijing (China); Guo Xiaojuan [College of Information Science and Technology, Beijing Normal University, 100875, Beijing (China); National Key Laboratory for Cognitive Neuroscience and Learning, Beijing Normal University, 100875, Beijing (China); Qi Zhigang [Department of Radiology, Xuanwu Hospital of Capital Medical University, 100053, Beijing (China); Yao Li [College of Information Science and Technology, Beijing Normal University, 100875, Beijing (China); National Key Laboratory for Cognitive Neuroscience and Learning, Beijing Normal University, 100875, Beijing (China); Li Kuncheng, E-mail: likuncheng@xwh.ccmu.edu.c [Department of Radiology, Xuanwu Hospital of Capital Medical University, 100053, Beijing (China)

    2010-08-15

    Purpose: The purpose of this study was to analyze whole-brain white matter changes in mild cognitive impairment (MCI). Materials and methods: We studied 14 patients with MCI and 14 age- and sex-matched healthy control subjects using voxel-based morphometry (VBM) on T1-weighted 3D datasets. The data were collected on a 3T MR system and analyzed by SPM2 to generate white matter volume maps. Results: Voxel-based morphometry revealed diffusively reduced white matter in MCI prominently including the bilateral temporal gyrus, the right anterior cingulate, the bilateral superior and medial frontal gyrus and right parietal angular gyrus. White matter reduction was more prominent in anterior regions than that in posterior regions. Conclusion: Whole-brain white matter reduction in MCI patients detected with VBM has special distribution which is in line with the white matter pathology of MCI.

  5. Whole-brain voxel-based morphometry of white matter in medial temporal lobe epilepsy

    Purpose: The purpose of this study was to analyze whole-brain white matter changes in medial temporal lobe epilepsy (MTLE). Materials and methods: We studied 23 patients with MTLE and 13 age- and sex-matched healthy control subjects using voxel-based morphometry (VBM) on T1-weighted 3D datasets. The seizure focus was right sided in 11 patients and left sided in 12. The data were collected on a 1.5 T MR system and analyzed by SPM 99 to generate white matter density maps. Results: Voxel-based morphometry revealed diffusively reduced white matter in MTLE prominently including bilateral frontal lobes, bilateral temporal lobes and corpus callosum. White matter reduction was also found in the bilateral cerebellar hemispheres in the left MTLE group. Conclusion: VBM is a simple and automated approach that is able to identify diffuse whole-brain white matter reduction in MTLE

  6. Inclined nanoimprinting lithography-based 3D nanofabrication

    We report a 'top–down' 3D nanofabrication approach combining non-conventional inclined nanoimprint lithography (INIL) with reactive ion etching (RIE), contact molding and 3D metal nanotransfer printing (nTP). This integration of processes enables the production and conformal transfer of 3D polymer nanostructures of varying heights to a variety of other materials including a silicon-based substrate, a silicone stamp and a metal gold (Au) thin film. The process demonstrates the potential of reduced fabrication cost and complexity compared to existing methods. Various 3D nanostructures in technologically useful materials have been fabricated, including symmetric and asymmetric nanolines, nanocircles and nanosquares. Such 3D nanostructures have potential applications such as angle-resolved photonic crystals, plasmonic crystals and biomimicking anisotropic surfaces. This integrated INIL-based strategy shows great promise for 3D nanofabrication in the fields of photonics, plasmonics and surface tribology

  7. Review: Polymeric-Based 3D Printing for Tissue Engineering

    Wu, Geng-Hsi; Hsu, Shan-hui

    2015-01-01

    Three-dimensional (3D) printing, also referred to as additive manufacturing, is a technology that allows for customized fabrication through computer-aided design. 3D printing has many advantages in the fabrication of tissue engineering scaffolds, including fast fabrication, high precision, and customized production. Suitable scaffolds can be designed and custom-made based on medical images such as those obtained from computed tomography. Many 3D printing methods have been employed for tissue ...

  8. Tablet-Based Interaction for Immersive 3D Data Exploration

    Lopez, David; Oehlberg, Lora; Doger, Candemir; Isenberg, Tobias

    2014-01-01

    Our overall vision is to enable researchers to explore 3D datasets with as much immersion as possible, arising both from visuals as well as from interaction . We therefore explore ways to combine an immersive large view of the 3D data with means to intuitively control this view with touch input on a separate mobile monoscopic tablet. This combination has the potential to increase people's acceptance of stereoscopic environments for 3D data visualization since--through touch-based interaction-...

  9. Shear wave velocity for the upper 30 m: Combining a 3D voxel model and seismic CPTS for the Groningen gas field, the Netherlands.

    Dambrink, Roula; Gunnink, Jan; Stafleu, Jan; de Lange, Ger; Kruiver, Pauline

    2016-04-01

    The Groningen gas field in the Netherlands is one of the largest gas fields of Europe and has been in production since the 1960's. Due to the progressive depletion of the reservoir, induced seismic activity has increased in recent years. In 2012, an earthquake of magnitude 3.6 initiated further research in prediction and management of risks related to man-induced earthquakes. Last year the government decided to reduce the gas extraction for this reason. One of the topics of concern is the large difference in earthquake-related damage to buildings which, in addition to the distance to the epicenter, appears to be also related to the composition of the shallow subsurface. To improve the spatial distribution of Shear Wave Velocities (Vs) in the shallow subsurface, used for hazard prediction, the Geological Survey of the Netherlands and Deltares constructed a Vs30 map of the upper 30 m of the gas field. In this map a high-resolution geological model (GeoTOP) is combined with seismic cone penetration tests (SCPT) from the area. The GeoTOP model is a 3D voxel model of the upper 50 m, in which each voxel (100x100x0.5 m) is attributed with lithostratigraphy and the most likely lithological class (peat, clay, fine sand, etc.). To obtain statistical distributions (with mean and standard deviation) of Vs for each combination of lithostratigraphical unit and lithoclass, 60 SCPTs were analyzed. In this way, it was possible to assign a specific Vs to each voxel in the model. For each voxel in the stack of voxels that covers the upper 30 m (i.e. 60 voxels), a Vs value was randomly drawn from the statistical distribution of the lithostratigraphical - lithoclass combination it belongs to. The Vs30 for each voxelstack is then calculated using the harmonic mean of the Vs of the 60 voxels. By repeating this procedure 100 times, an (average) Vs30 map and the uncertainty in Vs30 has been constructed. Using the procedure described above we were able to delineate zones with distinct Vs30

  10. 3D multifocus astigmatism and compressed sensing (3D MACS) based superresolution reconstruction

    Huang, Jiaqing; Sun, Mingzhai; Gumpper, Kristyn; Chi, Yuejie; Ma, Jianjie

    2015-01-01

    Single molecule based superresolution techniques (STORM/PALM) achieve nanometer spatial resolution by integrating the temporal information of the switching dynamics of fluorophores (emitters). When emitter density is low for each frame, they are located to the nanometer resolution. However, when the emitter density rises, causing significant overlapping, it becomes increasingly difficult to accurately locate individual emitters. This is particularly apparent in three dimensional (3D) localiza...

  11. Postured voxel-based human models for electromagnetic dosimetry

    High-resolution anatomically realistic whole-body voxel models have recently been developed for electromagnetic dosimetry. However, the posture of most models is similar to the standing one, which strongly limits electromagnetic dosimetry when simulating a realistic exposure scenario. In this paper, we present the development of postured models based on anatomically realistic voxel models with standing posture. Voxel models of the Japanese adult male and female were used as the original upright standing models. The Japanese models were composed of 2 mm cubic voxels, each of which was segmented into 51 different tissue types. We developed several different types of posture models using a novel posture transformation method. These posture models were smoothly transformed, while the continuity of the internal tissues and organs was maintained. In this paper, we also present our calculations of the whole-body averaged specific absorption rates (SARs) of sitting male and female models exposed to electromagnetic plane waves at very high (VHF) and ultra high frequency (UHF) bands.

  12. Octree-based Robust Watermarking for 3D Model

    Su Cai

    2011-02-01

    Full Text Available Three robust blind watermarking methods of 3D models based on Octree are proposed in this paper: OTC-W, OTP-W and Zero-W. Primary Component Analysis and Octree partition are used on 3D meshes. A scrambled binary image for OTC-W and a scrambled RGB image for OTP-W are separately embedded adaptively into the single child nodes at the bottom level of Octree structure. The watermark can be extracted without the original image and 3D model. Those two methods have high embedding capacity for 3D meshes. Meanwhile, they are robust against geometric transformation (like translation, rotation, uniform scaling and vertex reordering attacks. For Zero-W, higher nodes of Octree are used to construct ‘Zero-watermark’, which can resist simplification, noise and remeshing attacks. All those three methods are fit for 3D point cloud data and arbitrary 3D meshes.Three robust blind watermarking methods of 3D models based on Octree are proposed in this paper: OTC-W, OTP-W and Zero-W. Primary Component Analysis and Octree partition are used on 3D meshes. A scrambled binary image for OTC-W and a scrambled RGB image for OTP-W are separately embedded adaptively into the single child nodes at the bottom level of Octree structure. The watermark can be extracted without the original image and 3D model. Those two methods have high embedding capacity for 3D meshes. Meanwhile, they are robust against geometric transformation (like translation, rotation, uniform scaling and vertex reordering attacks. For Zero-W, higher nodes of Octree are used to construct ‘Zero-watermark’, which can resist simplification, noise and remeshing attacks. All those three methods are fit for 3D point cloud data and arbitrary 3D meshes.

  13. Spatial indices for measuring three-dimensional patterns in a voxel-based space

    Jjumba, Anthony; Dragićević, Suzana

    2016-07-01

    Spatial indices are used to quantitatively describe the spatial arrangements of the features within a study region. However, most of the indices used are two-dimensional in their representation of the surface characteristics, and this is insufficient to quantify the three-dimensional properties of an area or geospatial features. With the increased availability of 3D data from laser scanning and other collection methods, a voxel-based representation of space is an important methodology that allows for an intuitive visualization of geospatial features and their analysis with 3D GIS techniques. The objective of this study is to conceptualize, develop, and implement indices that can characterize three-dimensional space and can be used to analyze the structure of spatial features in a landscape. The indices for three-dimensional space that are implemented are, namely, surface area volume, fractal dimension, lacunarity, and Moran's I which are all useful in the quantification of spatial organization found in ecological landscapes. In addition to providing the quantitative descriptors, the results indicate that a voxel-based representation provides a straightforward means of characterizing the form and composition of the spatial features using 3D indices.

  14. 3D Wavelet-Based Filter and Method

    Moss, William C.; Haase, Sebastian; Sedat, John W.

    2008-08-12

    A 3D wavelet-based filter for visualizing and locating structural features of a user-specified linear size in 2D or 3D image data. The only input parameter is a characteristic linear size of the feature of interest, and the filter output contains only those regions that are correlated with the characteristic size, thus denoising the image.

  15. Image based 3D city modeling : Comparative study

    Singh, S. P.; Jain, K.; Mandla, V. R.

    2014-06-01

    3D city model is a digital representation of the Earth's surface and it's related objects such as building, tree, vegetation, and some manmade feature belonging to urban area. The demand of 3D city modeling is increasing rapidly for various engineering and non-engineering applications. Generally four main image based approaches were used for virtual 3D city models generation. In first approach, researchers were used Sketch based modeling, second method is Procedural grammar based modeling, third approach is Close range photogrammetry based modeling and fourth approach is mainly based on Computer Vision techniques. SketchUp, CityEngine, Photomodeler and Agisoft Photoscan are the main softwares to represent these approaches respectively. These softwares have different approaches & methods suitable for image based 3D city modeling. Literature study shows that till date, there is no complete such type of comparative study available to create complete 3D city model by using images. This paper gives a comparative assessment of these four image based 3D modeling approaches. This comparative study is mainly based on data acquisition methods, data processing techniques and output 3D model products. For this research work, study area is the campus of civil engineering department, Indian Institute of Technology, Roorkee (India). This 3D campus acts as a prototype for city. This study also explains various governing parameters, factors and work experiences. This research work also gives a brief introduction, strengths and weakness of these four image based techniques. Some personal comment is also given as what can do or what can't do from these softwares. At the last, this study shows; it concluded that, each and every software has some advantages and limitations. Choice of software depends on user requirements of 3D project. For normal visualization project, SketchUp software is a good option. For 3D documentation record, Photomodeler gives good result. For Large city

  16. A Legendre orthogonal moment based 3D edge operator

    ZHANG Hui; SHU Huazhong; LUO Limin; J. L. Dillenseger

    2005-01-01

    This paper presents a new 3D edge operator based on Legendre orthogonal moments. This operator can be used to extract the edge of 3D object in any window size,with more accurate surface orientation and more precise surface location. It also has full geometry meaning. Process of calculation is considered in the moment based method.We can greatly speed up the computation by calculating out the masks in advance. We integrate this operator into our rendering of medical image data based on ray casting algorithm. Experimental results show that it is an effective 3D edge operator that is more accurate in position and orientation.

  17. Knowledge Base Approach for 3D Objects Detection in Point Clouds Using 3D Processing and Specialists Knowledge

    Ben Hmida, Helmi; Cruz, Christophe; Boochs, Frank; Nicolle, Christophe

    2013-01-01

    International audience This paper presents a knowledge-based detection of objects approach using the OWL ontology language, the Semantic Web Rule Language, and 3D processing built-ins aiming at combining geometrical analysis of 3D point clouds and specialist's knowledge. Here, we share our experience regarding the creation of 3D semantic facility model out of unorganized 3D point clouds. Thus, a knowledge-based detection approach of objects using the OWL ontology language is presented. Thi...

  18. Investigation of mindfulness meditation practitioners with voxel-based morphometry

    Hölzel, Britta K.; Ott, Ulrich; Gard, Tim; Hempel, Hannes; Weygandt, Martin; Morgen, Katrin; Vaitl, Dieter

    2008-01-01

    Mindfulness meditators practice the non-judgmental observation of the ongoing stream of internal experiences as they arise. Using voxel-based morphometry, this study investigated MRI brain images of 20 mindfulness (Vipassana) meditators (mean practice 8.6 years; 2 h daily) and compared the regional gray matter concentration to that of non-meditators matched for sex, age, education and handedness. Meditators were predicted to show greater gray matter concentration in regions that are typically...

  19. Development and tests of a mouse voxel model dor MCNPX based on Digimouse images

    Mice have been widely used in experimental protocols involving ionizing radiation. Biological effects (Be) induced by radiation can compromise studies results. Good estimates of mouse whole body and organs absorbed dose could provide valuable information to researchers. The aim of this study was to create and test a new voxel phantom for mice dosimetry from -Digimouse- project images. Micro CT images from Digimouse project were used in this work. Corel PHOTOPAINT software was utilized in segmentation process. The three-dimensional (3-D) model assembly and its voxel size manipulation were performed by Image J. SISCODES was used to adapt the model to run in MCNPX Monte Carlo code. The resulting model was called DMBRA. The volume and mass of segmented organs were compared with data available in literature. For the preliminary tests the heart was considered the source organ. Photons of diverse energies were simulated and Saf values obtained through F6:p and + F6 MCNPX tallies. The results were compared with reference data. 3-D picturing of absorbed doses patterns and relative errors distribution were generated by a C++ -in house- made program and visualized through Amide software. The organ masses of DMBRA correlated well with two models that were based on same set of images. However some organs, like eyes and adrenals, skeleton and brain showed large discrepancies. Segmentation of an identical image set by different persons and/or methods can result significant organ masses variations. We believe that the main causes of these differences were: i) operator dependent subjectivity in the definition of organ limits during the segmentation processes; and i i) distinct voxel dimensions between evaluated models. Lack of reference data for mice models construction and dosimetry was detected. Comparison with other models originated from different mice strains also demonstrated that the anatomical and size variability can be significant. Use of + F6 tally for mouse phantoms

  20. Development and tests of a mouse voxel model dor MCNPX based on Digimouse images

    Melo M, B.; Ferreira F, C. [Centro de Desenvolvimento da Tecnologia Nuclear / CNEN, Pte. Antonio Carlos No. 6627, Belo Horizonte 31270-901, Minas Gerais (Brazil); Garcia de A, I.; Machado T, B.; Passos Ribeiro de C, T., E-mail: bmm@cdtn.br [Universidade Federal de Minas Gerais, Departamento de Engenharia Nuclear, Pte. Antonio Carlos 6627, Belo Horizonte 31270-901, Minas Gerais (Brazil)

    2015-10-15

    Mice have been widely used in experimental protocols involving ionizing radiation. Biological effects (Be) induced by radiation can compromise studies results. Good estimates of mouse whole body and organs absorbed dose could provide valuable information to researchers. The aim of this study was to create and test a new voxel phantom for mice dosimetry from -Digimouse- project images. Micro CT images from Digimouse project were used in this work. Corel PHOTOPAINT software was utilized in segmentation process. The three-dimensional (3-D) model assembly and its voxel size manipulation were performed by Image J. SISCODES was used to adapt the model to run in MCNPX Monte Carlo code. The resulting model was called DM{sub B}RA. The volume and mass of segmented organs were compared with data available in literature. For the preliminary tests the heart was considered the source organ. Photons of diverse energies were simulated and Saf values obtained through F6:p and + F6 MCNPX tallies. The results were compared with reference data. 3-D picturing of absorbed doses patterns and relative errors distribution were generated by a C++ -in house- made program and visualized through Amide software. The organ masses of DM{sub B}RA correlated well with two models that were based on same set of images. However some organs, like eyes and adrenals, skeleton and brain showed large discrepancies. Segmentation of an identical image set by different persons and/or methods can result significant organ masses variations. We believe that the main causes of these differences were: i) operator dependent subjectivity in the definition of organ limits during the segmentation processes; and i i) distinct voxel dimensions between evaluated models. Lack of reference data for mice models construction and dosimetry was detected. Comparison with other models originated from different mice strains also demonstrated that the anatomical and size variability can be significant. Use of + F6 tally for mouse

  1. Terahertz Quantum Cascade Laser Based 3D Imaging Project

    National Aeronautics and Space Administration — LongWave Photonics proposes a terahertz quantum-cascade laser based swept-source optical coherence tomography (THz SS-OCT) system for single-sided, 3D,...

  2. Thickness and clearance visualization based on distance field of 3D objects

    Masatomo Inui

    2015-07-01

    Full Text Available This paper proposes a novel method for visualizing the thickness and clearance of 3D objects in a polyhedral representation. The proposed method uses the distance field of the objects in the visualization. A parallel algorithm is developed for constructing the distance field of polyhedral objects using the GPU. The distance between a voxel and the surface polygons of the model is computed many times in the distance field construction. Similar sets of polygons are usually selected as close polygons for close voxels. By using this spatial coherence, a parallel algorithm is designed to compute the distances between a cluster of close voxels and the polygons selected by the culling operation so that the fast shared memory mechanism of the GPU can be fully utilized. The thickness/clearance of the objects is visualized by distributing points on the visible surfaces of the objects and painting them with a unique color corresponding to the thickness/clearance values at those points. A modified ray casting method is developed for computing the thickness/clearance using the distance field of the objects. A system based on these algorithms can compute the distance field of complex objects within a few minutes for most cases. After the distance field construction, thickness/clearance visualization at a near interactive rate is achieved.

  3. 3D Motion Parameters Determination Based on Binocular Sequence Images

    2006-01-01

    Exactly capturing three dimensional (3D) motion information of an object is an essential and important task in computer vision, and is also one of the most difficult problems. In this paper, a binocular vision system and a method for determining 3D motion parameters of an object from binocular sequence images are introduced. The main steps include camera calibration, the matching of motion and stereo images, 3D feature point correspondences and resolving the motion parameters. Finally, the experimental results of acquiring the motion parameters of the objects with uniform velocity and acceleration in the straight line based on the real binocular sequence images by the mentioned method are presented.

  4. Powder-based 3D printing for bone tissue engineering.

    Brunello, G; Sivolella, S; Meneghello, R; Ferroni, L; Gardin, C; Piattelli, A; Zavan, B; Bressan, E

    2016-01-01

    Bone tissue engineered 3-D constructs customized to patient-specific needs are emerging as attractive biomimetic scaffolds to enhance bone cell and tissue growth and differentiation. The article outlines the features of the most common additive manufacturing technologies (3D printing, stereolithography, fused deposition modeling, and selective laser sintering) used to fabricate bone tissue engineering scaffolds. It concentrates, in particular, on the current state of knowledge concerning powder-based 3D printing, including a description of the properties of powders and binder solutions, the critical phases of scaffold manufacturing, and its applications in bone tissue engineering. Clinical aspects and future applications are also discussed. PMID:27086202

  5. A Primitive-Based 3D Object Recognition System

    Dhawan, Atam P.

    1988-08-01

    A knowledge-based 3D object recognition system has been developed. The system uses the hierarchical structural, geometrical and relational knowledge in matching the 3D object models to the image data through pre-defined primitives. The primitives, we have selected, to begin with, are 3D boxes, cylinders, and spheres. These primitives as viewed from different angles covering complete 3D rotation range are stored in a "Primitive-Viewing Knowledge-Base" in form of hierarchical structural and relational graphs. The knowledge-based system then hypothesizes about the viewing angle and decomposes the segmented image data into valid primitives. A rough 3D structural and relational description is made on the basis of recognized 3D primitives. This description is now used in the detailed high-level frame-based structural and relational matching. The system has several expert and knowledge-based systems working in both stand-alone and cooperative modes to provide multi-level processing. This multi-level processing utilizes both bottom-up (data-driven) and top-down (model-driven) approaches in order to acquire sufficient knowledge to accept or reject any hypothesis for matching or recognizing the objects in the given image.

  6. Detailed Primitive-Based 3d Modeling of Architectural Elements

    Remondino, F.; Lo Buglio, D.; Nony, N.; De Luca, L.

    2012-07-01

    The article describes a pipeline, based on image-data, for the 3D reconstruction of building façades or architectural elements and the successive modeling using geometric primitives. The approach overcome some existing problems in modeling architectural elements and deliver efficient-in-size reality-based textured 3D models useful for metric applications. For the 3D reconstruction, an opensource pipeline developed within the TAPENADE project is employed. In the successive modeling steps, the user manually selects an area containing an architectural element (capital, column, bas-relief, window tympanum, etc.) and then the procedure fits geometric primitives and computes disparity and displacement maps in order to tie visual and geometric information together in a light but detailed 3D model. Examples are reported and commented.

  7. 3D Visual SLAM Based on Multiple Iterative Closest Point

    Chunguang Li; Chongben Tao; Guodong Liu

    2015-01-01

    With the development of novel RGB-D visual sensors, data association has been a basic problem in 3D Visual Simultaneous Localization and Mapping (VSLAM). To solve the problem, a VSLAM algorithm based on Multiple Iterative Closest Point (MICP) is presented. By using both RGB and depth information obtained from RGB-D camera, 3D models of indoor environment can be reconstructed, which provide extensive knowledge for mobile robots to accomplish tasks such as VSLAM and Human-Robot Interaction. Due...

  8. Contour-based 3d motion recovery while zooming

    Martínez Marroquín, Elisa; Torras Genís, Carme

    2003-01-01

    This paper considers the problem of 3D motion recovery from a sequence of monocular images while zooming. Unlike the common trend based on point matches, the proposed method relies on the deformation of an active contour fitted to a reference object. We derive the relation between the contour deformation and the 3D motion components, assuming time-varying focal length and principal point. This relation allows us to present a method to extract the rotation matrix and the scaled translation alo...

  9. Validation of voxel-based morphometry (VBM) based on MRI

    Yang, Xueyu; Chen, Kewei; Guo, Xiaojuan; Yao, Li

    2007-03-01

    Voxel-based morphometry (VBM) is an automated and objective image analysis technique for detecting differences in regional concentration or volume of brain tissue composition based on structural magnetic resonance (MR) images. VBM has been used widely to evaluate brain morphometric differences between different populations, but there isn't an evaluation system for its validation until now. In this study, a quantitative and objective evaluation system was established in order to assess VBM performance. We recruited twenty normal volunteers (10 males and 10 females, age range 20-26 years, mean age 22.6 years). Firstly, several focal lesions (hippocampus, frontal lobe, anterior cingulate, back of hippocampus, back of anterior cingulate) were simulated in selected brain regions using real MRI data. Secondly, optimized VBM was performed to detect structural differences between groups. Thirdly, one-way ANOVA and post-hoc test were used to assess the accuracy and sensitivity of VBM analysis. The results revealed that VBM was a good detective tool in majority of brain regions, even in controversial brain region such as hippocampus in VBM study. Generally speaking, much more severity of focal lesion was, better VBM performance was. However size of focal lesion had little effects on VBM analysis.

  10. A novel Hessian based algorithm for rat kidney glomerulus detection in 3D MRI

    Zhang, Min; Wu, Teresa; Bennett, Kevin M.

    2015-03-01

    The glomeruli of the kidney perform the key role of blood filtration and the number of glomeruli in a kidney is correlated with susceptibility to chronic kidney disease and chronic cardiovascular disease. This motivates the development of new technology using magnetic resonance imaging (MRI) to measure the number of glomeruli and nephrons in vivo. However, there is currently a lack of computationally efficient techniques to perform fast, reliable and accurate counts of glomeruli in MR images due to the issues inherent in MRI, such as acquisition noise, partial volume effects (the mixture of several tissue signals in a voxel) and bias field (spatial intensity inhomogeneity). Such challenges are particularly severe because the glomeruli are very small, (in our case, a MRI image is ~16 million voxels, each glomerulus is in the size of 8~20 voxels), and the number of glomeruli is very large. To address this, we have developed an efficient Hessian based Difference of Gaussians (HDoG) detector to identify the glomeruli on 3D rat MR images. The image is first smoothed via DoG followed by the Hessian process to pre-segment and delineate the boundary of the glomerulus candidates. This then provides a basis to extract regional features used in an unsupervised clustering algorithm, completing segmentation by removing the false identifications occurred in the pre-segmentation. The experimental results show that Hessian based DoG has the potential to automatically detect glomeruli,from MRI in 3D, enabling new measurements of renal microstructure and pathology in preclinical and clinical studies.

  11. Voxel-based comparison of whole brain gray matter of patients with mild Alzheimer's disease with normal aging volunteers

    Objective: To detect gray matter abnormalities of whole brain in patients with mild Alzheimer's disease (AD) by voxel-based morphometry (VBM). Methods: Thirteen patients with mild Alzheimer's disease and sixteen normal aging volunteers underwent 3D SPGR scanning. For every subject, data was transferred to PC to be normalized, segmented and smoothed using SPM99. Non-dependent samples T-tests were conducted to compare gray matter' density voxel to voxel between the two groups. Results Significant reductions in gray matter density were found in the bilateral hippocampi and nucleus amygdalae, bilateral insulae, bilateral medial thalami, bilateral rectus gyri, right superior temporal gyms, right caudate nucleus, fight prefrontal lobe, right basal forebrain and portions of right occipital lobe. Conclusion: VBM reveals significant gray matter' reductions of numeral cortices in mild Alzheimer's disease. It can be a useful method to evaluate the anatomical changes in the progress of the disease. (authors)

  12. MicroCT-Based Skeletal Models for Use in Tomographic Voxel Phantoms for Radiological Protection

    The University of Florida (UF) proposes to develop two high-resolution image-based skeletal dosimetry models for direct use by ICRP Committee 2's Task Group on Dose Calculation in their forthcoming Reference Voxel Male (RVM) and Reference Voxel Female (RVF) whole-body dosimetry phantoms. These two phantoms are CT-based, and thus do not have the image resolution to delineate and perform radiation transport modeling of the individual marrow cavities and bone trabeculae throughout their skeletal structures. Furthermore, new and innovative 3D microimaging techniques will now be required for the skeletal tissues following Committee 2's revision of the target tissues of relevance for radiogenic bone cancer induction. This target tissue had been defined in ICRP Publication 30 as a 10-(micro)m cell layer on all bone surfaces of trabecular and cortical bone. The revised target tissue is now a 50-(micro)m layer within the marrow cavities of trabecular bone only and is exclusive of the marrow adipocytes. Clearly, this new definition requires the use of 3D microimages of the trabecular architecture not available from past 2D optical studies of the adult skeleton. With our recent acquisition of two relatively young cadavers (males of age 18-years and 40-years), we will develop a series of reference skeletal models that can be directly applied to (1) the new ICRP reference voxel man and female phantoms developed for the ICRP, and (2) pediatric phantoms developed to target the ICRP reference children. Dosimetry data to be developed will include absorbed fractions for internal beta and alpha-particle sources, as well as photon and neutron fluence-to-dose response functions for direct use in external dosimetry studies of the ICRP reference workers and members of the general public

  13. MicroCT-Based Skeletal Models for Use in Tomographic Voxel Phantoms for Radiological Protection

    Wesley Bolch

    2010-03-30

    ABSTRACT The University of Florida (UF) proposes to develop two high-resolution image-based skeletal dosimetry models for direct use by ICRP Committee 2’s Task Group on Dose Calculation in their forthcoming Reference Voxel Male (RVM) and Reference Voxel Female (RVF) whole-body dosimetry phantoms. These two phantoms are CT-based, and thus do not have the image resolution to delineate and perform radiation transport modeling of the individual marrow cavities and bone trabeculae throughout their skeletal structures. Furthermore, new and innovative 3D microimaging techniques will now be required for the skeletal tissues following Committee 2’s revision of the target tissues of relevance for radiogenic bone cancer induction. This target tissue had been defined in ICRP Publication 30 as a 10-m cell layer on all bone surfaces of trabecular and cortical bone. The revised target tissue is now a 50-m layer within the marrow cavities of trabecular bone only and is exclusive of the marrow adipocytes. Clearly, this new definition requires the use of 3D microimages of the trabecular architecture not available from past 2D optical studies of the adult skeleton. With our recent acquisition of two relatively young cadavers (males of age 18-years and 40-years), we will develop a series of reference skeletal models that can be directly applied to (1) the new ICRP reference voxel man and female phantoms developed for the ICRP, and (2) pediatric phantoms developed to target the ICRP reference children. Dosimetry data to be developed will include absorbed fractions for internal beta and alpha-particle sources, as well as photon and neutron fluence-to-dose response functions for direct use in external dosimetry studies of the ICRP reference workers and members of the general public

  14. MicroCT-Based Skeletal Models for Use in Tomographic Voxel Phantoms for Radiological Protection

    Bolch, Wesley [Univ. of Florida, Gainesville, FL (United States)

    2010-03-30

    The University of Florida (UF) proposes to develop two high-resolution image-based skeletal dosimetry models for direct use by ICRP Committee 2’s Task Group on Dose Calculation in their forthcoming Reference Voxel Male (RVM) and Reference Voxel Female (RVF) whole-body dosimetry phantoms. These two phantoms are CT-based, and thus do not have the image resolution to delineate and perform radiation transport modeling of the individual marrow cavities and bone trabeculae throughout their skeletal structures. Furthermore, new and innovative 3D microimaging techniques will now be required for the skeletal tissues following Committee 2’s revision of the target tissues of relevance for radiogenic bone cancer induction. This target tissue had been defined in ICRP Publication 30 as a 10-μm cell layer on all bone surfaces of trabecular and cortical bone. The revised target tissue is now a 50-μm layer within the marrow cavities of trabecular bone only and is exclusive of the marrow adipocytes. Clearly, this new definition requires the use of 3D microimages of the trabecular architecture not available from past 2D optical studies of the adult skeleton. With our recent acquisition of two relatively young cadavers (males of age 18-years and 40-years), we will develop a series of reference skeletal models that can be directly applied to (1) the new ICRP reference voxel man and female phantoms developed for the ICRP, and (2) pediatric phantoms developed to target the ICRP reference children. Dosimetry data to be developed will include absorbed fractions for internal beta and alpha-particle sources, as well as photon and neutron fluence-to-dose response functions for direct use in external dosimetry studies of the ICRP reference workers and members of the general public

  15. Building Point Detection from Vehicle-Borne LiDAR Data Based on Voxel Group and Horizontal Hollow Analysis

    Yu Wang; Liang Cheng; Yanming Chen; Yang Wu; Manchun Li

    2016-01-01

    Information extraction and three-dimensional (3D) reconstruction of buildings using the vehicle-borne laser scanning (VLS) system is significant for many applications. Extracting LiDAR points, from VLS, belonging to various types of building in large-scale complex urban environments still retains some problems. In this paper, a new technical framework for automatic and efficient building point extraction is proposed, including three main steps: (1) voxel group-based shape recognition; (2) cat...

  16. Multilevel Solvers with Aggregations for Voxel Based Analysis of Geomaterials

    Blaheta, Radim; Sokol, V.

    Berlin, Heidelberg : Springer-Verlag, 2012, -, č. 7116 /2012/, s. 489-497. ISBN 978-3-642-29842-4. ISSN 0302-9743. [LSSC 2011. Sozopol (BG), 06.06.2011-10.06.2011] R&D Projects: GA ČR GA105/09/1830 Grant ostatní: GA ČR(CZ) GD103/09/H078 Institutional research plan: CEZ:AV0Z30860518 Keywords : voxel based analysis * finite element analysis * tomography Subject RIV: IN - Informatics, Computer Science http://www.springer.com/series/558?changeHeader

  17. A web-based 3D geological information visualization system

    Song, Renbo; Jiang, Nan

    2013-03-01

    Construction of 3D geological visualization system has attracted much more concern in GIS, computer modeling, simulation and visualization fields. It not only can effectively help geological interpretation and analysis work, but also can it can help leveling up geosciences professional education. In this paper, an applet-based method was introduced for developing a web-based 3D geological information visualization system. The main aims of this paper are to explore a rapid and low-cost development method for constructing a web-based 3D geological system. First, the borehole data stored in Excel spreadsheets was extracted and then stored in SQLSERVER database of a web server. Second, the JDBC data access component was utilized for providing the capability of access the database. Third, the user interface was implemented with applet component embedded in JSP page and the 3D viewing and querying functions were implemented with PickCanvas of Java3D. Last, the borehole data acquired from geological survey were used for test the system, and the test results has shown that related methods of this paper have a certain application values.

  18. 3D Medical Image Segmentation Based on Rough Set Theory

    CHEN Shi-hao; TIAN Yun; WANG Yi; HAO Chong-yang

    2007-01-01

    This paper presents a method which uses multiple types of expert knowledge together in 3D medical image segmentation based on rough set theory. The focus of this paper is how to approximate a ROI (region of interest) when there are multiple types of expert knowledge. Based on rough set theory, the image can be split into three regions:positive regions; negative regions; boundary regions. With multiple knowledge we refine ROI as an intersection of all of the expected shapes with single knowledge. At last we show the results of implementing a rough 3D image segmentation and visualization system.

  19. Design and development of a 3D cadastral prototype based on the LADM and 3D topology

    Ying, S.; Guo, R.; Li, L.; Van Oosterom, P.J.M.; Ledoux, H.; Stoter, J.E.

    2011-01-01

    In this paper the design and development of a prototype 3D Cadastral system will be presented. The key aspects of this system are that the model is based on Land Administration Domain Model (LADM) and that the spatial profile is based on a full 3D topological structure. The prototype development sta

  20. Voxel-based model construction from colored tomographic images

    This work presents a new approach in the construction of voxel-based phantoms that was implemented to simplify the segmentation process of organs and tissues reducing the time used in this procedure. The segmentation process is performed by painting tomographic images and attributing a different color for each organ or tissue. A voxel-based head and neck phantom was built using this new approach. The way as the data are stored allows an increasing in the performance of the radiation transport code. The program that calculates the radiation transport also works with image files. This capability allows image reconstruction showing isodose areas, under several points of view, increasing the information to the user. Virtual X-ray photographs can also be obtained allowing that studies could be accomplished looking for the radiographic techniques optimization assessing, at the same time, the doses in organs and tissues. The accuracy of the program here presented, called MCvoxEL, that implements this new approach, was tested by comparison to results from two modern and well-supported Monte Carlo codes. Dose conversion factors for parallel X-ray exposure were also calculated. (author)

  1. Optical 3D watermark based digital image watermarking for telemedicine

    Li, Xiao Wei; Kim, Seok Tae

    2013-12-01

    Region of interest (ROI) of a medical image is an area including important diagnostic information and must be stored without any distortion. This algorithm for application of watermarking technique for non-ROI of the medical image preserving ROI. The paper presents a 3D watermark based medical image watermarking scheme. In this paper, a 3D watermark object is first decomposed into 2D elemental image array (EIA) by a lenslet array, and then the 2D elemental image array data is embedded into the host image. The watermark extraction process is an inverse process of embedding. The extracted EIA through the computational integral imaging reconstruction (CIIR) technique, the 3D watermark can be reconstructed. Because the EIA is composed of a number of elemental images possesses their own perspectives of a 3D watermark object. Even though the embedded watermark data badly damaged, the 3D virtual watermark can be successfully reconstructed. Furthermore, using CAT with various rule number parameters, it is possible to get many channels for embedding. So our method can recover the weak point having only one transform plane in traditional watermarking methods. The effectiveness of the proposed watermarking scheme is demonstrated with the aid of experimental results.

  2. Monocular model-based 3D tracking of rigid objects

    Lepetit, Vincent

    2014-01-01

    Many applications require tracking complex 3D objects. These include visual serving of robotic arms on specific target objects, Augmented Reality systems that require real time registration of the object to be augmented, and head tracking systems that sophisticated interfaces can use. Computer vision offers solutions that are cheap, practical and non-invasive. ""Monocular Model-Based 3D Tracking of Rigid Objects"" reviews the different techniques and approaches that have been developed by industry and research. First, important mathematical tools are introduced: camera representation, robust e

  3. Geometric Deformations Based on 3D Volume Morphing

    JIN Xiaogang; WAN Huagen; PENG Qunsheng

    2001-01-01

    This paper presents a new geometric deformation method based on 3D volume morphing by using a new concept called directional polar coordinate. The user specifies the source control object and the destination control object which act as the embedded spaces.The source and the destination control objects determine a 3D volume morphing which maps the space enclosed in the source control object to that of the destination control object. By embedding the object to be deformed into the source control object, the 3D volume morphing determines the deformed object automatically without the tiring moving of control points.Experiments show that this deformation model is efficient and intuitive, and it can achieve some deformation effects which are difficult to achieve for traditional methods.

  4. Robust model-based 3d/3D fusion using sparse matching for minimally invasive surgery.

    Neumann, Dominik; Grbic, Sasa; John, Matthias; Navab, Nassir; Hornegger, Joachim; Ionasec, Razvan

    2013-01-01

    Classical surgery is being disrupted by minimally invasive and transcatheter procedures. As there is no direct view or access to the affected anatomy, advanced imaging techniques such as 3D C-arm CT and C-arm fluoroscopy are routinely used for intra-operative guidance. However, intra-operative modalities have limited image quality of the soft tissue and a reliable assessment of the cardiac anatomy can only be made by injecting contrast agent, which is harmful to the patient and requires complex acquisition protocols. We propose a novel sparse matching approach for fusing high quality pre-operative CT and non-contrasted, non-gated intra-operative C-arm CT by utilizing robust machine learning and numerical optimization techniques. Thus, high-quality patient-specific models can be extracted from the pre-operative CT and mapped to the intra-operative imaging environment to guide minimally invasive procedures. Extensive quantitative experiments demonstrate that our model-based fusion approach has an average execution time of 2.9 s, while the accuracy lies within expert user confidence intervals. PMID:24505663

  5. 3D ear identification based on sparse representation.

    Lin Zhang

    Full Text Available Biometrics based personal authentication is an effective way for automatically recognizing, with a high confidence, a person's identity. Recently, 3D ear shape has attracted tremendous interests in research field due to its richness of feature and ease of acquisition. However, the existing ICP (Iterative Closet Point-based 3D ear matching methods prevalent in the literature are not quite efficient to cope with the one-to-many identification case. In this paper, we aim to fill this gap by proposing a novel effective fully automatic 3D ear identification system. We at first propose an accurate and efficient template-based ear detection method. By utilizing such a method, the extracted ear regions are represented in a common canonical coordinate system determined by the ear contour template, which facilitates much the following stages of feature extraction and classification. For each extracted 3D ear, a feature vector is generated as its representation by making use of a PCA-based local feature descriptor. At the stage of classification, we resort to the sparse representation based classification approach, which actually solves an l1-minimization problem. To the best of our knowledge, this is the first work introducing the sparse representation framework into the field of 3D ear identification. Extensive experiments conducted on a benchmark dataset corroborate the effectiveness and efficiency of the proposed approach. The associated Matlab source code and the evaluation results have been made publicly online available at http://sse.tongji.edu.cn/linzhang/ear/srcear/srcear.htm.

  6. Voxel Based Morphometry in Optical Coherence Tomography: Validation & Core Findings

    Antony, Bhavna J.; Chen, Min; Carass, Aaron; Jedynak, Bruno M.; Al-Louzi, Omar; Solomon, Sharon D.; Saidha, Shiv; Calabresi, Peter A.; Prince, Jerry L.

    2016-01-01

    Optical coherence tomography (OCT) of the human retina is now becoming established as an important modality for the detection and tracking of various ocular diseases. Voxel based morphometry (VBM) is a long standing neuroimaging analysis technique that allows for the exploration of the regional differences in the brain. There has been limited work done in developing registration based methods for OCT, which has hampered the advancement of VBM analyses in OCT based population studies. Following on from our recent development of an OCT registration method, we explore the potential benefits of VBM analysis in cohorts of healthy controls (HCs) and multiple sclerosis (MS) patients. Specifically, we validate the stability of VBM analysis in two pools of HCs showing no significant difference between the two populations. Additionally, we also present a retrospective study of age and sex matched HCs and relapsing remitting MS patients, demonstrating results consistent with the reported literature while providing insight into the retinal changes associated with this MS subtype.

  7. Dixon imaging-based partial volume correction improves quantification of choline detected by breast 3D-MRSI

    Minarikova, Lenka; Gruber, Stephan; Bogner, Wolfgang; Trattnig, Siegfried; Chmelik, Marek [Medical University of Vienna, Department of Biomedical Imaging and Image-guided Therapy, MR Center of Excellence, Vienna (Austria); Pinker-Domenig, Katja; Baltzer, Pascal A.T.; Helbich, Thomas H. [Medical University of Vienna, Department of Biomedical Imaging and Image-guided Therapy, Division of Molecular and Gender Imaging, Vienna (Austria)

    2014-09-14

    Our aim was to develop a partial volume (PV) correction method of choline (Cho) signals detected by breast 3D-magnetic resonance spectroscopic imaging (3D-MRSI), using information from water/fat-Dixon MRI. Following institutional review board approval, five breast cancer patients were measured at 3 T. 3D-MRSI (1 cm{sup 3} resolution, duration ∝11 min) and Dixon MRI (1 mm{sup 3}, ∝2 min) were measured in vivo and in phantoms. Glandular/lesion tissue was segmented from water/fat-Dixon MRI and transformed to match the resolution of 3D-MRSI. The resulting PV values were used to correct Cho signals. Our method was validated on a two-compartment phantom (choline/water and oil). PV values were correlated with the spectroscopic water signal. Cho signal variability, caused by partial-water/fat content, was tested in 3D-MRSI voxels located in/near malignant lesions. Phantom measurements showed good correlation (r = 0.99) with quantified 3D-MRSI water signals, and better homogeneity after correction. The dependence of the quantified Cho signal on the water/fat voxel composition was significantly (p < 0.05) reduced using Dixon MRI-based PV correction, compared to the original uncorrected data (1.60-fold to 3.12-fold) in patients. The proposed method allows quantification of the Cho signal in glandular/lesion tissue independent of water/fat composition in breast 3D-MRSI. This can improve the reproducibility of breast 3D-MRSI, particularly important for therapy monitoring. (orig.)

  8. A Novel 3D Reconstruction Approach from Uncalibrated Multiple Views Based on Homography

    Shuai Liu

    2014-07-01

    Full Text Available In this paper, we focus on a kind of 3D object shape reconstruction from images and put forward a metric approach to recover the object based on slicing planes by homography transformation and image consistency between multiple images.  This approach done here eliminates the requirement for camera calibration, the estimation of the fundamental matrix, feature matches and pose estimation. We adopt a set of hypothetical planes to intersect the reconstructed object to obtain every slicing plane of the reconstructed object by homography transformation and recover it to 3D adding vanishing points by the constraints of silhouette and the scene. The experiment shows that the approach is much validated, and something useful is obtained. topological changes of 2D curves, we adopt a physically-based 2D level set model to animate the evolution and propagation of the interface. We build a level set equation to model the evolution of the interface. In addition, to handle the large scale virtual environment correctly in our physically-based level set model, an image-based 2D voxelization method is proposed in the paper. In the voxelization method, the virtual environment will be converted to boundary conditions when solving the level set equation. Finally, the water pollutants diffusion phenomenon is simulated on large scale water surface by merging the interface animation results as well as the large scale virtual environment. Animation results about the algae propagation phenomenon in Taihu Lake show that our method is intuitively to be implemented and very convenient to produce visually interesting results.

  9. The visible ear simulator: a public PC application for GPU-accelerated haptic 3D simulation of ear surgery based on the visible ear data

    Sørensen, Mads Sølvsten; Mosegaard, Jesper; Trier, Peter

    2009-01-01

    BACKGROUND: Existing virtual simulators for middle ear surgery are based on 3-dimensional (3D) models from computed tomographic or magnetic resonance imaging data in which image quality is limited by the lack of detail (maximum, approximately 50 voxels/mm3), natural color, and texture of the sour...

  10. 3D face recognition with asymptotic cones based principal curvatures

    Tang, Yinhang

    2015-05-01

    The classical curvatures of smooth surfaces (Gaussian, mean and principal curvatures) have been widely used in 3D face recognition (FR). However, facial surfaces resulting from 3D sensors are discrete meshes. In this paper, we present a general framework and define three principal curvatures on discrete surfaces for the purpose of 3D FR. These principal curvatures are derived from the construction of asymptotic cones associated to any Borel subset of the discrete surface. They describe the local geometry of the underlying mesh. First two of them correspond to the classical principal curvatures in the smooth case. We isolate the third principal curvature that carries out meaningful geometric shape information. The three principal curvatures in different Borel subsets scales give multi-scale local facial surface descriptors. We combine the proposed principal curvatures with the LNP-based facial descriptor and SRC for recognition. The identification and verification experiments demonstrate the practicability and accuracy of the third principal curvature and the fusion of multi-scale Borel subset descriptors on 3D face from FRGC v2.0.

  11. Probabilistic reasoning for assembly-based 3D modeling

    Chaudhuri, Siddhartha

    2011-01-01

    Assembly-based modeling is a promising approach to broadening the accessibility of 3D modeling. In assembly-based modeling, new models are assembled from shape components extracted from a database. A key challenge in assembly-based modeling is the identification of relevant components to be presented to the user. In this paper, we introduce a probabilistic reasoning approach to this problem. Given a repository of shapes, our approach learns a probabilistic graphical model that encodes semantic and geometric relationships among shape components. The probabilistic model is used to present components that are semantically and stylistically compatible with the 3D model that is being assembled. Our experiments indicate that the probabilistic model increases the relevance of presented components. © 2011 ACM.

  12. Rapidly 3D Texture Reconstruction Based on Oblique Photography

    ZHANG Chunsen

    2015-07-01

    Full Text Available This paper proposes a city texture fast reconstruction method based on aerial tilt image for reconstruction of three-dimensional city model. Based on the photogrammetry and computer vision theory and using the city building digital surface model obtained by prior treatment, through collinear equation calculation geometric projection of object and image space, to obtain the three-dimensional information and texture information of the structure and through certain the optimal algorithm selecting the optimal texture on the surface of the object, realize automatic extraction of the building side texture and occlusion handling of the dense building texture. The real image texture reconstruction results show that: the method to the 3D city model texture reconstruction has the characteristics of high degree of automation, vivid effect and low cost and provides a means of effective implementation for rapid and widespread real texture rapid reconstruction of city 3D model.

  13. Development Of 3D Woven Fabric Based Pressure Switch

    Shaker Khubab

    2015-06-01

    Full Text Available This paper introduces a 3D woven fabric-based approach for the development of pressure switch. A fabric substrate, being elastic and extendable is very useful in addition to its high breaking strength and low cost. The developed resistive-type switch is based on the multilayer interlock 3D fabrics. In the top and bottom layers, certain number of conductive yarns are woven separated by cotton yarns in both transversal and thickness direction. Application of pressure makes the layers of conductive yarn to come in contact, resulting in a short circuit, which may be recorded using multi-meters. Removing the pressure cause the connection points to separate away and it depends on the weave design. Such switch can be used as an on/off switch for usage in security systems, can be sewn into carpets and wearable garments for a number of purposes.

  14. 3-D model-based tracking for UAV indoor localization.

    Teulière, Céline; Marchand, Eric; Eck, Laurent

    2015-05-01

    This paper proposes a novel model-based tracking approach for 3-D localization. One main difficulty of standard model-based approach lies in the presence of low-level ambiguities between different edges. In this paper, given a 3-D model of the edges of the environment, we derive a multiple hypotheses tracker which retrieves the potential poses of the camera from the observations in the image. We also show how these candidate poses can be integrated into a particle filtering framework to guide the particle set toward the peaks of the distribution. Motivated by the UAV indoor localization problem where GPS signal is not available, we validate the algorithm on real image sequences from UAV flights. PMID:25099967

  15. Oedipe: a voxel-based tool for the assessment of internal dose, applications and new developments

    The development of voxel phantoms has expanded tremendously over the last ten years thanks to progress in medical imaging techniques and computer simulation speed-up. The voxel phantom approach allows the actual anatomy of the subject, which is particularly important for beta and low energy exposure to be taken into account. The paper aims to present a tool (OEDIPE) that manages the creation and application of voxel phantoms in internal dosimetry: whole body and organ measurements as well as absorbed dose calculation in the organs or at voxel level. The new version of Oedipe allows easy direct handling of medical images, segmenting the phantom and creating an MCNP(X) input file. Several applications and new developments concerning medical image management and 3-D visualization are also presented

  16. Method for 3D Rendering Based on Intersection Image Display Which Allows Representation of Internal Structure of 3D objects

    Kohei Arai

    2013-01-01

    Method for 3D rendering based on intersection image display which allows representation of internal structure is proposed. The proposed method is essentially different from the conventional volume rendering based on solid model which allows representation of just surface of the 3D objects. By using afterimage, internal structure can be displayed through exchanging the intersection images with internal structure for the proposed method. Through experiments with CT scan images, the proposed met...

  17. GPU-accelerated 3-D model-based tracking

    Model-based approaches to tracking the pose of a 3-D object in video are effective but computationally demanding. While statistical estimation techniques, such as the particle filter, are often employed to minimize the search space, real-time performance remains unachievable on current generation CPUs. Recent advances in graphics processing units (GPUs) have brought massively parallel computational power to the desktop environment and powerful developer tools, such as NVIDIA Compute Unified Device Architecture (CUDA), have provided programmers with a mechanism to exploit it. NVIDIA GPUs' single-instruction multiple-thread (SIMT) programming model is well-suited to many computer vision tasks, particularly model-based tracking, which requires several hundred 3-D model poses to be dynamically configured, rendered, and evaluated against each frame in the video sequence. Using 6 degree-of-freedom (DOF) rigid hand tracking as an example application, this work harnesses consumer-grade GPUs to achieve real-time, 3-D model-based, markerless object tracking in monocular video.

  18. Gesture Interaction Browser-Based 3D Molecular Viewer.

    Virag, Ioan; Stoicu-Tivadar, Lăcrămioara; Crişan-Vida, Mihaela

    2016-01-01

    The paper presents an open source system that allows the user to interact with a 3D molecular viewer using associated hand gestures for rotating, scaling and panning the rendered model. The novelty of this approach is that the entire application is browser-based and doesn't require installation of third party plug-ins or additional software components in order to visualize the supported chemical file formats. This kind of solution is suitable for instruction of users in less IT oriented environments, like medicine or chemistry. For rendering various molecular geometries our team used GLmol (a molecular viewer written in JavaScript). The interaction with the 3D models is made with Leap Motion controller that allows real-time tracking of the user's hand gestures. The first results confirmed that the resulting application leads to a better way of understanding various types of translational bioinformatics related problems in both biomedical research and education. PMID:27350455

  19. 3D Medical Image Interpolation Based on Parametric Cubic Convolution

    2007-01-01

    In the process of display, manipulation and analysis of biomedical image data, they usually need to be converted to data of isotropic discretization through the process of interpolation, while the cubic convolution interpolation is widely used due to its good tradeoff between computational cost and accuracy. In this paper, we present a whole concept for the 3D medical image interpolation based on cubic convolution, and the six methods, with the different sharp control parameter, which are formulated in details. Furthermore, we also give an objective comparison for these methods using data sets with the different slice spacing. Each slice in these data sets is estimated by each interpolation method and compared with the original slice using three measures: mean-squared difference, number of sites of disagreement, and largest difference. According to the experimental results, we present a recommendation for 3D medical images under the different situations in the end.

  20. Technical illustration based on 3D CSG models

    GENG Wei-dong; DING Lei; YU Hong-feng; PAN Yun-he

    2005-01-01

    This paper presents an automatic non-photorealistic rendering approach to generating technical illustration from 3D models. It first decomposes the 3D object into a set of CSG primitives, and then performs the hidden surface removal based on the prioritized list, in which the rendition order of CSG primitives is sorted out by depth. Then, each primitive is illustrated by the pre-defined empirical lighting model, and the system mimics the stroke-drawing by user-specified style. In order to artistically and flexibly modulate the illumination, the empirical lighting model is defined by three major components: parameters of multi-level lighting intensities, parametric spatial occupations for each lighting level, and an interpolation method to calculate the lighting units into the spatial occupation of CSG primitives, instead of"pixel-by-pixel" painting. This region-by-region shading facilitates the simulation of illustration styles.

  1. Voxel-based population analysis for correlating local dose and rectal toxicity in prostate cancer radiotherapy

    The majority of current models utilized for predicting toxicity in prostate cancer radiotherapy are based on dose–volume histograms. One of their main drawbacks is the lack of spatial accuracy, since they consider the organs as a whole volume and thus ignore the heterogeneous intra-organ radio-sensitivity. In this paper, we propose a dose-image-based framework to reveal the relationships between local dose and toxicity. In this approach, the three-dimensional (3D) planned dose distributions across a population are non-rigidly registered into a common coordinate system and compared at a voxel level, therefore enabling the identification of 3D anatomical patterns, which may be responsible for toxicity, at least to some extent. Additionally, different metrics were employed in order to assess the quality of the dose mapping. The value of this approach was demonstrated by prospectively analyzing rectal bleeding (⩾Grade 1 at 2 years) according to the CTCAE v3.0 classification in a series of 105 patients receiving 80 Gy to the prostate by intensity modulated radiation therapy (IMRT). Within the patients presenting bleeding, a significant dose excess (6 Gy on average, p < 0.01) was found in a region of the anterior rectal wall. This region, close to the prostate (1 cm), represented less than 10% of the rectum. This promising voxel-wise approach allowed subregions to be defined within the organ that may be involved in toxicity and, as such, must be considered during the inverse IMRT planning step. (paper)

  2. Voxel-based population analysis for correlating local dose and rectal toxicity in prostate cancer radiotherapy

    Acosta, Oscar; Drean, Gael; Ospina, Juan D.; Simon, Antoine; Haigron, Pascal; Lafond, Caroline; de Crevoisier, Renaud

    2013-04-01

    The majority of current models utilized for predicting toxicity in prostate cancer radiotherapy are based on dose-volume histograms. One of their main drawbacks is the lack of spatial accuracy, since they consider the organs as a whole volume and thus ignore the heterogeneous intra-organ radio-sensitivity. In this paper, we propose a dose-image-based framework to reveal the relationships between local dose and toxicity. In this approach, the three-dimensional (3D) planned dose distributions across a population are non-rigidly registered into a common coordinate system and compared at a voxel level, therefore enabling the identification of 3D anatomical patterns, which may be responsible for toxicity, at least to some extent. Additionally, different metrics were employed in order to assess the quality of the dose mapping. The value of this approach was demonstrated by prospectively analyzing rectal bleeding (⩾Grade 1 at 2 years) according to the CTCAE v3.0 classification in a series of 105 patients receiving 80 Gy to the prostate by intensity modulated radiation therapy (IMRT). Within the patients presenting bleeding, a significant dose excess (6 Gy on average, p < 0.01) was found in a region of the anterior rectal wall. This region, close to the prostate (1 cm), represented less than 10% of the rectum. This promising voxel-wise approach allowed subregions to be defined within the organ that may be involved in toxicity and, as such, must be considered during the inverse IMRT planning step.

  3. Voxel Based Analysis of Surgical Revascularization for Moyamoya Disease: Pre- and Postoperative SPECT Studies.

    Fushimi, Yasutaka; Okada, Tomohisa; Takagi, Yasushi; Funaki, Takeshi; Takahashi, Jun C; Miyamoto, Susumu; Togashi, Kaori

    2016-01-01

    Moyamoya disease (MMD) is a chronic, progressive, cerebrovascular occlusive disease that causes abnormal enlargement of collateral pathways (moyamoya vessels) in the region of the basal ganglia and thalamus. Cerebral revascularization procedures remain the preferred treatment for patients with MMD, improving the compromised cerebral blood flow (CBF). However, voxel based analysis (VBA) of revascularization surgery for MMD based on data from pre- and postoperative data has not been established. The latest algorithm called as Diffeomorphic Anatomical Registration Through Exponentiated Lie Algebra (DARTEL) has been introduced for VBA as the function of statistical parametric mapping (SPM8), and improved registration has been achieved by SPM8 with DARTEL. In this study, VBA was conducted to evaluate pre- and postoperative single photon emission computed tomography (SPECT) images for MMD by SPM8 with DARTEL algorithm, and the results were compared with those from SPM8 without DARTEL (a conventional method). Thirty-two patients with MMD who underwent superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery as the first surgery were included and all patients underwent pre- and postoperative 3D T1-weighted imaging and SPECT. Pre- and postoperative SPECT images were registered to 3D T1-weighted images, then VBA was conducted. Postoperative SPECT showed more statistically increased CBF areas in the bypassed side cerebral hemisphere by using SPM8 with DARTEL (58,989 voxels; P<0.001), and increased ratio of CBF after operation was less than 15%. Meanwhile, postoperative SPECT showed less CBF increased areas by SPM8 without DARTEL. In conclusion, VBA was conducted for patients with MMD, and SPM8 with DARTEL revealed that postoperative SPECT showed statistically significant CBF increases over a relatively large area and with at most 15% increase ratio. PMID:26867219

  4. 3D Visual SLAM Based on Multiple Iterative Closest Point

    Chunguang Li

    2015-01-01

    Full Text Available With the development of novel RGB-D visual sensors, data association has been a basic problem in 3D Visual Simultaneous Localization and Mapping (VSLAM. To solve the problem, a VSLAM algorithm based on Multiple Iterative Closest Point (MICP is presented. By using both RGB and depth information obtained from RGB-D camera, 3D models of indoor environment can be reconstructed, which provide extensive knowledge for mobile robots to accomplish tasks such as VSLAM and Human-Robot Interaction. Due to the limited views of RGB-D camera, additional information about the camera pose is needed. In this paper, the motion of the RGB-D camera is estimated by a motion capture system after a calibration process. Based on the estimated pose, the MICP algorithm is used to improve the alignment. A Kinect mobile robot which is running Robot Operating System and the motion capture system has been used for experiments. Experiment results show that not only the proposed VSLAM algorithm achieved good accuracy and reliability, but also the 3D map can be generated in real time.

  5. 3D GIS spatial operation based on extended Euler operators

    Xu, Hongbo; Lu, Guonian; Sheng, Yehua; Zhou, Liangchen; Guo, Fei; Shang, Zuoyan; Wang, Jing

    2008-10-01

    The implementation of 3 dimensions spatial operations, based on certain data structure, has a lack of universality and is not able to treat with non-manifold cases, at present. ISO/DIS 19107 standard just presents the definition of Boolean operators and set operators for topological relationship query, and OGC GeoXACML gives formal definitions for several set functions without implementation detail. Aiming at these problems, based mathematical foundation on cell complex theory, supported by non-manifold data structure and using relevant research in the field of non-manifold geometry modeling for reference, firstly, this paper according to non-manifold Euler-Poincaré formula constructs 6 extended Euler operators and inverse operators to carry out creating, updating and deleting 3D spatial elements, as well as several pairs of supplementary Euler operators to convenient for implementing advanced functions. Secondly, we change topological element operation sequence of Boolean operation and set operation as well as set functions defined in GeoXACML into combination of extended Euler operators, which separates the upper functions and lower data structure. Lastly, we develop underground 3D GIS prototype system, in which practicability and credibility of extended Euler operators faced to 3D GIS presented by this paper are validated.

  6. A voxel-based multiscale model to simulate the radiation response of hypoxic tumors

    Espinoza, I., E-mail: iespinoza@fis.puc.cl [Institute of Physics, Pontificia Universidad Católica de Chile, Santiago 7820436, Chile and Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg 69120 (Germany); Peschke, P. [Clinical Cooperation Unit Molecular Radiooncology, German Cancer Research Center (DKFZ), Heidelberg 69120 (Germany); Karger, C. P. [Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg 69120 (Germany)

    2015-01-15

    model, tumor shrinkage was found to be significantly more important for reoxygenation than angiogenesis or decreased oxygen consumption due to an increased fraction of dead cells. In the studied HNSSC-case, the TCD{sub 50} values (dose at 50% TCP) decreased from 71.0 Gy under hypoxic to 53.6 Gy under the oxic condition. Conclusions: The results obtained with the developed multiscale model are in accordance with expectations based on radiobiological principles and clinical experience. As the model is voxel-based, radiological imaging methods may help to provide the required 3D-characterization of the tumor prior to irradiation. For clinical application, the model has to be further validated with experimental and clinical data. If this is achieved, the model may be used to optimize fractionation schedules and dose distributions for the treatment of hypoxic tumors.

  7. Vision based error detection for 3D printing processes

    Baumann Felix

    2016-01-01

    Full Text Available 3D printers became more popular in the last decade, partly because of the expiration of key patents and the supply of affordable machines. The origin is located in rapid prototyping. With Additive Manufacturing (AM it is possible to create physical objects from 3D model data by layer wise addition of material. Besides professional use for prototyping and low volume manufacturing they are becoming widespread amongst end users starting with the so called Maker Movement. The most prevalent type of consumer grade 3D printers is Fused Deposition Modelling (FDM, also Fused Filament Fabrication FFF. This work focuses on FDM machinery because of their widespread occurrence and large number of open problems like precision and failure. These 3D printers can fail to print objects at a statistical rate depending on the manufacturer and model of the printer. Failures can occur due to misalignment of the print-bed, the print-head, slippage of the motors, warping of the printed material, lack of adhesion or other reasons. The goal of this research is to provide an environment in which these failures can be detected automatically. Direct supervision is inhibited by the recommended placement of FDM printers in separate rooms away from the user due to ventilation issues. The inability to oversee the printing process leads to late or omitted detection of failures. Rejects effect material waste and wasted time thus lowering the utilization of printing resources. Our approach consists of a camera based error detection mechanism that provides a web based interface for remote supervision and early failure detection. Early failure detection can lead to reduced time spent on broken prints, less material wasted and in some cases salvaged objects.

  8. Acceleration of EM-Based 3D CT Reconstruction Using FPGA.

    Choi, Young-Kyu; Cong, Jason

    2016-06-01

    Reducing radiation doses is one of the key concerns in computed tomography (CT) based 3D reconstruction. Although iterative methods such as the expectation maximization (EM) algorithm can be used to address this issue, applying this algorithm to practice is difficult due to the long execution time. Our goal is to decrease this long execution time to an order of a few minutes, so that low-dose 3D reconstruction can be performed even in time-critical events. In this paper we introduce a novel parallel scheme that takes advantage of numerous block RAMs on field-programmable gate arrays (FPGAs). Also, an external memory bandwidth reduction strategy is presented to reuse both the sinogram and the voxel intensity. Moreover, a customized processing engine based on the FPGA is presented to increase overall throughput while reducing the logic consumption. Finally, a hardware and software flow is proposed to quickly construct a design for various CT machines. The complete reconstruction system is implemented on an FPGA-based server-class node. Experiments on actual patient data show that a 26.9 × speedup can be achieved over a 16-thread multicore CPU implementation. PMID:26462240

  9. Influence of regional cerebral blood volume on voxel-based morphometry.

    Zheng, Lei; Cleppien, Dirk; Gass, Natalia; Falfan-Melgoza, Claudia; Vollmayr, Barbara; Hesser, Jürgen; Weber-Fahr, Wolfgang; Sartorius, Alexander

    2016-06-01

    The investigation of structural brain alterations is one focus in research of brain diseases like depression. Voxel-based morphometry (VBM) based on high-resolution 3D MRI images is a widely used non-invasive tool for such investigations. However, the result of VBM might be sensitive to local physiological parameters such as regional cerebral blood volume (rCBV) changes. In order to investigate whether rCBV changes may contribute to variation in VBM, we performed analyses in a study with the congenital learned helplessness (cLH) model for long-term findings. The 3D structural and rCBV data were acquired with T2 -weighted rapid acquisition with relaxation enhancement (RARE) pulse sequences. The group effects were determined by standard statistical parametric mapping (SPM) and biological parametric mapping (BPM) and examined further using atlas-based regions. In our genetic animal model of depression, we found co-occurrence of differences in gray matter volume and rCBV, while there was no evidence of significant interaction between both. However, the multimodal analysis showed similar gray matter differences compared with the standard VBM approach. Our data corroborate the idea that two group VBM differences might not be influenced by rCBV differences in genetically different strains. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27074152

  10. Evaluation of a deterministic grid-based Boltzmann solver (GBBS) for voxel-level absorbed dose calculations in nuclear medicine

    Mikell, Justin; Cheenu Kappadath, S.; Wareing, Todd; Erwin, William D.; Titt, Uwe; Mourtada, Firas

    2016-06-01

    To evaluate the 3D Grid-based Boltzmann Solver (GBBS) code ATTILA ® for coupled electron and photon transport in the nuclear medicine energy regime for electron (beta, Auger and internal conversion electrons) and photon (gamma, x-ray) sources. Codes rewritten based on ATTILA are used clinically for both high-energy photon teletherapy and 192Ir sealed source brachytherapy; little information exists for using the GBBS to calculate voxel-level absorbed doses in nuclear medicine. We compared DOSXYZnrc Monte Carlo (MC) with published voxel-S-values to establish MC as truth. GBBS was investigated for mono-energetic 1.0, 0.1, and 0.01 MeV electron and photon sources as well as 131I and 90Y radionuclides. We investigated convergence of GBBS by analyzing different meshes ({{M}0},{{M}1},{{M}2} ), energy group structures ({{E}0},{{E}1},{{E}2} ) for each radionuclide component, angular quadrature orders (≤ft. {{S}4},{{S}8},{{S}16}\\right) , and scattering order expansions ({{P}0} –{{P}6} ); higher indices imply finer discretization. We compared GBBS to MC in (1) voxel-S-value geometry for soft tissue, lung, and bone, and (2) a source at the interface between combinations of lung, soft tissue, and bone. Excluding Auger and conversion electrons, MC agreed within  ≈5% of published source voxel absorbed doses. For the finest discretization, most GBBS absorbed doses in the source voxel changed by less than 1% compared to the next finest discretization along each phase space variable indicating sufficient convergence. For the finest discretization, agreement with MC in the source voxel ranged from  ‑3% to  ‑20% with larger differences at lower energies (‑3% for 1 MeV electron in lung to  ‑20% for 0.01 MeV photon in bone); similar agreement was found for the interface geometries. Differences between GBBS and MC in the source voxel for 90Y and 131I were  ‑6%. The GBBS ATTILA was benchmarked against MC in the nuclear medicine regime. GBBS can be a

  11. Evaluation of a deterministic grid-based Boltzmann solver (GBBS) for voxel-level absorbed dose calculations in nuclear medicine.

    Mikell, Justin; Cheenu Kappadath, S; Wareing, Todd; Erwin, William D; Titt, Uwe; Mourtada, Firas

    2016-06-21

    To evaluate the 3D Grid-based Boltzmann Solver (GBBS) code ATTILA (®) for coupled electron and photon transport in the nuclear medicine energy regime for electron (beta, Auger and internal conversion electrons) and photon (gamma, x-ray) sources. Codes rewritten based on ATTILA are used clinically for both high-energy photon teletherapy and (192)Ir sealed source brachytherapy; little information exists for using the GBBS to calculate voxel-level absorbed doses in nuclear medicine. We compared DOSXYZnrc Monte Carlo (MC) with published voxel-S-values to establish MC as truth. GBBS was investigated for mono-energetic 1.0, 0.1, and 0.01 MeV electron and photon sources as well as (131)I and (90)Y radionuclides. We investigated convergence of GBBS by analyzing different meshes ([Formula: see text]), energy group structures ([Formula: see text]) for each radionuclide component, angular quadrature orders ([Formula: see text], and scattering order expansions ([Formula: see text]-[Formula: see text]); higher indices imply finer discretization. We compared GBBS to MC in (1) voxel-S-value geometry for soft tissue, lung, and bone, and (2) a source at the interface between combinations of lung, soft tissue, and bone. Excluding Auger and conversion electrons, MC agreed within  ≈5% of published source voxel absorbed doses. For the finest discretization, most GBBS absorbed doses in the source voxel changed by less than 1% compared to the next finest discretization along each phase space variable indicating sufficient convergence. For the finest discretization, agreement with MC in the source voxel ranged from  -3% to  -20% with larger differences at lower energies (-3% for 1 MeV electron in lung to  -20% for 0.01 MeV photon in bone); similar agreement was found for the interface geometries. Differences between GBBS and MC in the source voxel for (90)Y and (131)I were  -6%. The GBBS ATTILA was benchmarked against MC in the nuclear medicine regime. GBBS can be a

  12. Virtual reality 3D headset based on DMD light modulators

    Bernacki, Bruce E.; Evans, Allan; Tang, Edward

    2014-06-13

    We present the design of an immersion-type 3D headset suitable for virtual reality applications based upon digital micro-mirror devices (DMD). Our approach leverages silicon micro mirrors offering 720p resolution displays in a small form-factor. Supporting chip sets allow rapid integration of these devices into wearable displays with high resolution and low power consumption. Applications include night driving, piloting of UAVs, fusion of multiple sensors for pilots, training, vision diagnostics and consumer gaming. Our design is described in which light from the DMD is imaged to infinity and the user’s own eye lens forms a real image on the user’s retina.

  13. Fast vision-based catheter 3D reconstruction

    Moradi Dalvand, Mohsen; Nahavandi, Saeid; Howe, Robert D.

    2016-07-01

    Continuum robots offer better maneuverability and inherent compliance and are well-suited for surgical applications as catheters, where gentle interaction with the environment is desired. However, sensing their shape and tip position is a challenge as traditional sensors can not be employed in the way they are in rigid robotic manipulators. In this paper, a high speed vision-based shape sensing algorithm for real-time 3D reconstruction of continuum robots based on the views of two arbitrary positioned cameras is presented. The algorithm is based on the closed-form analytical solution of the reconstruction of quadratic curves in 3D space from two arbitrary perspective projections. High-speed image processing algorithms are developed for the segmentation and feature extraction from the images. The proposed algorithms are experimentally validated for accuracy by measuring the tip position, length and bending and orientation angles for known circular and elliptical catheter shaped tubes. Sensitivity analysis is also carried out to evaluate the robustness of the algorithm. Experimental results demonstrate good accuracy (maximum errors of  ±0.6 mm and  ±0.5 deg), performance (200 Hz), and robustness (maximum absolute error of 1.74 mm, 3.64 deg for the added noises) of the proposed high speed algorithms.

  14. 3D-Dixon MRI based volumetry of peri- and epicardial fat.

    Homsi, Rami; Meier-Schroers, Michael; Gieseke, Jürgen; Dabir, Darius; Luetkens, Julian A; Kuetting, Daniel L; Naehle, Claas P; Marx, Christian; Schild, Hans H; Thomas, Daniel K; Sprinkart, Alois M

    2016-02-01

    There is growing evidence that pericardial and epicardial fat volume (PFV, EFV) are associated with cardiovascular risk. We evaluated a novel method for accurate measurement of PFV and EFV using a 3D-Dixon based cardiac magnetic resonance (CMR) approach. An electrocardiography triggered and respiratory navigator gated 3D-gradient echo pulse sequence was used for cardiac Dixon imaging. Based on this sequence, voxels predominantly containing fat were identified and added up for volumetry. After accuracy assessment in phantoms, consisting of muscle tissue and seven different fat samples (50-200 ml), the sequence was acquired in 34 healthy volunteers (22 male, BMI range 14-42 kg/m(2), age range 21-79 years) at 1.5 T. Analysis was performed independently by two readers who draw two 3D-regions of interest, one for EFV and one for PFV. Additionally, EFV and PFV were compared between overweighted and non-overweighted subjects. The phantom study showed an excellent agreement of measured and true fat volumes (maximum difference = 6 %, linear correlation coefficient R = 1.00). PFV over all volunteers was 158.0 ± 126.4 ml and EFV was 77.0 ± 55.3 ml. PFV and EFV were highly correlated (R = 0.96). Inter-reader agreement was good with a mean difference of 0.2 ± 5.6 and 4.5 ± 4.2 ml for PFV/EFV, (R > 0.99, each). EFV and PFV differed significantly between subjects with BMI > 25 kg/m(2) and BMI Dixon based method allows accurate measurement of cardiac fat volumes. It provides a valuable tool for cardiovascular risk stratification by CMR. PMID:26424492

  15. Several 3D graphics software study based on Linux

    This paper introduces the request of single event display in BES III online data acquisition system and presents OpenGL, ROOT, VRML, Java3D 3D graphics software. After making comparison with these software in effect and performance, finally we choose Java3D technology for developing single event display. (authors)

  16. Realistic terrain visualization based on 3D virtual world technology

    Huang, Fengru; Lin, Hui; Chen, Bin; Xiao, Cai

    2010-11-01

    The rapid advances in information technologies, e.g., network, graphics processing, and virtual world, have provided challenges and opportunities for new capabilities in information systems, Internet applications, and virtual geographic environments, especially geographic visualization and collaboration. In order to achieve meaningful geographic capabilities, we need to explore and understand how these technologies can be used to construct virtual geographic environments to help to engage geographic research. The generation of three-dimensional (3D) terrain plays an important part in geographical visualization, computer simulation, and virtual geographic environment applications. The paper introduces concepts and technologies of virtual worlds and virtual geographic environments, explores integration of realistic terrain and other geographic objects and phenomena of natural geographic environment based on SL/OpenSim virtual world technologies. Realistic 3D terrain visualization is a foundation of construction of a mirror world or a sand box model of the earth landscape and geographic environment. The capabilities of interaction and collaboration on geographic information are discussed as well. Further virtual geographic applications can be developed based on the foundation work of realistic terrain visualization in virtual environments.

  17. 3D Printed Paper-Based Microfluidic Analytical Devices

    Yong He

    2016-06-01

    Full Text Available As a pump-free and lightweight analytical tool, paper-based microfluidic analytical devices (μPADs attract more and more interest. If the flow speed of μPAD can be programmed, the analytical sequences could be designed and they will be more popular. This reports presents a novel μPAD, driven by the capillary force of cellulose powder, printed by a desktop three-dimensional (3D printer, which has some promising features, such as easy fabrication and programmable flow speed. First, a suitable size-scale substrate with open microchannels on its surface is printed. Next, the surface of the substrate is covered with a thin layer of polydimethylsiloxane (PDMS to seal the micro gap caused by 3D printing. Then, the microchannels are filled with a mixture of cellulose powder and deionized water in an appropriate proportion. After drying in an oven at 60 °C for 30 min, it is ready for use. As the different channel depths can be easily printed, which can be used to achieve the programmable capillary flow speed of cellulose powder in the microchannels. A series of microfluidic analytical experiments, including quantitative analysis of nitrite ion and fabrication of T-sensor were used to demonstrate its capability. As the desktop 3D printer (D3DP is very cheap and accessible, this device can be rapidly printed at the test field with a low cost and has a promising potential in the point-of-care (POC system or as a lightweight platform for analytical chemistry.

  18. EEG-based usability assessment of 3D shutter glasses

    Wenzel, Markus A.; Schultze-Kraft, Rafael; Meinecke, Frank C.; Cardinaux, Fabien; Kemp, Thomas; Müller, Klaus-Robert; Curio, Gabriel; Blankertz, Benjamin

    2016-02-01

    Objective. Neurotechnology can contribute to the usability assessment of products by providing objective measures of neural workload and can uncover usability impediments that are not consciously perceived by test persons. In this study, the neural processing effort imposed on the viewer of 3D television by shutter glasses was quantified as a function of shutter frequency. In particular, we sought to determine the critical shutter frequency at which the ‘neural flicker’ vanishes, such that visual fatigue due to this additional neural effort can be prevented by increasing the frequency of the system. Approach. Twenty-three participants viewed an image through 3D shutter glasses, while multichannel electroencephalogram (EEG) was recorded. In total ten shutter frequencies were employed, selected individually for each participant to cover the range below, at and above the threshold of flicker perception. The source of the neural flicker correlate was extracted using independent component analysis and the flicker impact on the visual cortex was quantified by decoding the state of the shutter from the EEG. Main Result. Effects of the shutter glasses were traced in the EEG up to around 67 Hz—about 20 Hz over the flicker perception threshold—and vanished at the subsequent frequency level of 77 Hz. Significance. The impact of the shutter glasses on the visual cortex can be detected by neurotechnology even when a flicker is not reported by the participants. Potential impact. Increasing the shutter frequency from the usual 50 Hz or 60 Hz to 77 Hz reduces the risk of visual fatigue and thus improves shutter-glass-based 3D usability.

  19. Voxel-based morphometry in patients with idiopathic generalized epilepsies.

    Betting, Luiz Eduardo; Mory, Susana Barreto; Li, Li Min; Lopes-Cendes, Iscia; Guerreiro, Marilisa M; Guerreiro, Carlos A M; Cendes, Fernando

    2006-08-15

    Idiopathic generalized epilepsies (IGE) are a group of frequent age-related epilepsy syndromes. IGE are clinically characterized by generalized tonic-clonic, myoclonic and absence seizures. According to predominant seizure type and age of onset, IGE are divided in subsyndromes: childhood absence and juvenile absence epilepsy (AE), juvenile myoclonic epilepsy (JME) and generalized tonic-clonic seizures on awakening (GTCS). The limits between these subsyndromes are not well defined, supporting the existence of only one major syndrome. Visual assessment of routine magnetic resonance imaging (MRI) in patients with IGE is normal. MRI voxel-based morphometry (VBM) uses automatically segmented gray and white matter for comparisons, eliminating the investigator bias. We used VBM to study 120 individuals (47 controls, 44 with JME, 24 with AE and 15 with GTCS) to investigate the presence of subtle structural abnormalities in IGE subsyndromes. VBM was performed searching for abnormalities on gray matter concentration (GMC) between patients groups and controls. Compared to controls, JME presented increased GMC in frontobasal region and AE showed increased GMC in the superior mesiofrontal region. The GTCS group did not differ from controls. There were no areas of reduced GMC with the statistical level selected. Region of interest analysis showed increased GMC in the anterior portion of the thalamus in patients with absence seizures. Our results support subtle GMC abnormalities in patients with JME and AE when compared to controls. These findings suggest the existence of different patterns of cortical abnormalities in IGE subsyndromes. PMID:16702001

  20. Neuroanatomical voxel-based profile of schizophrenia and bipolar disorder.

    Maggioni, E; Bellani, M; Altamura, A C; Brambilla, P

    2016-08-01

    Although schizophrenia (SCZ) and bipolar disorder (BD) share elements of pathology (Ellison-Wright and Bullmore, 2009), the neural mechanisms underlying these disorders are still under investigation. Up until now, many neuroimaging studies investigated the brain structural differences of SCZ and BD compared with healthy controls (HC), trying to identify the possible neuroanatomical markers for the two disorders. However, just a few studies focused on the brain structural changes between the two diagnoses. The present review summarises the findings of the voxel-based grey matter (GM) comparisons between SCZ and BD, with the objective to highlight the possible consistent anatomical differences between the two disorders. While the comparisons between patients and HC highlighted overlapping areas of GM reduction in insula and anterior cingulate cortex, the SCZ-BD comparisons suggest the presence of more generalised GM deficits in SCZ compared with BD. Indeed, in a number of studies, SCZ patients showed lower GM volumes than BD patients in fronto-temporal cortex, thalamus, hippocampus and amygdala. Conversely, only a couple of studies reported GM deficits in BD compared with SCZ, both at the level of cerebellum. In summary, the two disorders exhibit both common and specific neuroanatomical characteristics, whose knowledge is mandatory to develop innovative diagnostic and treatment strategies. PMID:27095442

  1. A voxel-based MRI morphometric study of Alzheimer's disease

    Objective: To assess the diagnostic value of voxel-based Morphometry (VBM) in studying Alzheimer's disease (AD). Methods: Graymatter density were comprehensive assessed by means of VBM on T1-weighted MRI volume sets in 19 patients with AD and 15 healthy subjects of similar age and gender ratio, 15 healthy adults. The data were collected on Siemens 1.5 T Sonata MRI systems and analyzed by SPM 99 to generate gray matter density map. Results: Relative to healthy controls, significant clusters of reduced gray matter density were found to affect medial temporal lobe ( hippocampus) (P<0.001). For hippocampus, reduced gray matter density were 1529 in the right and 1281 in the left with right-sided predominance. Moreover, atrophy of right caudate head and left medial thalamus were showed. We demonstrate global asymmetrical cortical atrophy with sparing of the sensorimotor cortex, occipital lobe and cerebellum. Conclusion: The results from VBM are in perfect agreement with those of earlier neuroimaging, which confirmed its value in demonstrating neuroanatomy of AD. VBM, the simple and automatic approach providing a full-brain assessment of AD morphology, has a good clinical perspective. (authors)

  2. Method for 3D Rendering Based on Intersection Image Display Which Allows Representation of Internal Structure of 3D objects

    Kohei Arai

    2013-06-01

    Full Text Available Method for 3D rendering based on intersection image display which allows representation of internal structure is proposed. The proposed method is essentially different from the conventional volume rendering based on solid model which allows representation of just surface of the 3D objects. By using afterimage, internal structure can be displayed through exchanging the intersection images with internal structure for the proposed method. Through experiments with CT scan images, the proposed method is validated. Also one of other applicable areas of the proposed for design of 3D pattern of Large Scale Integrated Circuit: LSI is introduced. Layered patterns of LSI can be displayed and switched by using human eyes only. It is confirmed that the time required for displaying layer pattern and switching the pattern to the other layer by using human eyes only is much faster than that using hands and fingers.

  3. Modern voxel based data and geometry analysis software tools for industrial CT

    Computer Tomography has become a well recognized tool in industrial quality control. Modern computer tomography systems ranging from micro-CT to huge multi MeV systems allow us to generate more and more detailed views of the inner of nearly any object. With the scan resolution becoming smaller and smaller, and at the same time image matrices becoming larger and larger, we are able to localize smallest defects even in large scale objects. At the same time even with the same data set we are able to measure the outer and inner geometry of an object with a measurement point density never known before from classical tactile or optical techniques. However, scanning objects in high resolution generates huge amounts of data, easily exceeding two GByte per scan. These huge amounts of data have caused a major drawback of a wider acceptance of CT technology in industrial use. Either no software tools have been available at all or available software process chains haven't been able to process these amounts of data in reasonable time. This presentation will introduce a new generation of 3D visualization and analysis software tools for industrial CT users. Interactive visualization of huge data sets with several Gbyte in size has become possible on a standard PC. Automatic wall thickness analysis and internal defect/porosity analysis can be done within minutes. In addition this presentation will also demonstrate the latest generation of software tools for highly accurate 3D geometry analysis based on voxel data. (author)

  4. Ultra-realistic 3-D imaging based on colour holography

    Bjelkhagen, H. I.

    2013-02-01

    A review of recent progress in colour holography is provided with new applications. Colour holography recording techniques in silver-halide emulsions are discussed. Both analogue, mainly Denisyuk colour holograms, and digitally-printed colour holograms are described and their recent improvements. An alternative to silver-halide materials are the panchromatic photopolymer materials such as the DuPont and Bayer photopolymers which are covered. The light sources used to illuminate the recorded holograms are very important to obtain ultra-realistic 3-D images. In particular the new light sources based on RGB LEDs are described. They show improved image quality over today's commonly used halogen lights. Recent work in colour holography by holographers and companies in different countries around the world are included. To record and display ultra-realistic 3-D images with perfect colour rendering are highly dependent on the correct recording technique using the optimal recording laser wavelengths, the availability of improved panchromatic recording materials and combined with new display light sources.

  5. Improving 3D Wavelet-Based Compression of Hyperspectral Images

    Klimesh, Matthew; Kiely, Aaron; Xie, Hua; Aranki, Nazeeh

    2009-01-01

    Two methods of increasing the effectiveness of three-dimensional (3D) wavelet-based compression of hyperspectral images have been developed. (As used here, images signifies both images and digital data representing images.) The methods are oriented toward reducing or eliminating detrimental effects of a phenomenon, referred to as spectral ringing, that is described below. In 3D wavelet-based compression, an image is represented by a multiresolution wavelet decomposition consisting of several subbands obtained by applying wavelet transforms in the two spatial dimensions corresponding to the two spatial coordinate axes of the image plane, and by applying wavelet transforms in the spectral dimension. Spectral ringing is named after the more familiar spatial ringing (spurious spatial oscillations) that can be seen parallel to and near edges in ordinary images reconstructed from compressed data. These ringing phenomena are attributable to effects of quantization. In hyperspectral data, the individual spectral bands play the role of edges, causing spurious oscillations to occur in the spectral dimension. In the absence of such corrective measures as the present two methods, spectral ringing can manifest itself as systematic biases in some reconstructed spectral bands and can reduce the effectiveness of compression of spatially-low-pass subbands. One of the two methods is denoted mean subtraction. The basic idea of this method is to subtract mean values from spatial planes of spatially low-pass subbands prior to encoding, because (a) such spatial planes often have mean values that are far from zero and (b) zero-mean data are better suited for compression by methods that are effective for subbands of two-dimensional (2D) images. In this method, after the 3D wavelet decomposition is performed, mean values are computed for and subtracted from each spatial plane of each spatially-low-pass subband. The resulting data are converted to sign-magnitude form and compressed in a

  6. Modelling shallow urban geology using reservoir modelling techniques: voxel-based lithology and physical properties of the greater Glasgow area

    Kingdon, Andrew; Williams, John D. O.; Williamson, J. Paul; Lark, R. Murray; Dobbs, Marcus R.; Kearsey, Timothy; Finlayson, Andrew; Campbell, S. Diarmad G.

    2013-04-01

    Conventional 3D geological models of lithostratigraphy undertaken by BGS have facilitated a significant step forward in understanding of the 3D sedimentological and structural controls in the subsurface of the UK. However, when lithostratigraphic units are mapped or modelled in 3D, intra-unit variability is often not recognized and may be substantial, particularly in sedimentologically heterogeneous successions. Because of this BGS has been testing voxel grid-based approaches in urban areas with high borehole density. A city-scale lithology model of shallow, unconsolidated sediments in Glasgow, Scotland has been developed as a test of the applicability of these techniques to aid geological understanding and possible future applications. This is of particular significance in this location due to the complex fluvial and glacial history of the superficial geology which alternates between inter-fingering sedimentary packages and short-scale variability of subsurface materials. The model has been created by developing a stochastic model of clastic geology on a voxel support, based on upscaling of observed borehole lithology, independent of lithostratigraphy. Multiple realisations of lithology were generated, each honouring the borehole observations. Lithology information has therefore been used to both develop a model of the distribution of lithology throughout the grid, but also to develop an understanding of the associated uncertainty by providing estimates of the probability with which a particular lithology occurs at a given node. This lithological model compares well with 'traditional' deterministic lithostratigraphic 3D models created in the same area, and with field-based geological maps. This lithological voxel model has been used as a matrix through which physical property data can be attributed within the grid by stochastic modelling and simulation of the variability of properties within the lithological units. Several different property datasets have been

  7. Lossless 3D Steganography Based on MST and Connectivity Modification

    Amat, Philippe; Puech, William; Druon, Sébastien; Pedeboy, Jean-Pierre

    2010-01-01

    International audience Data hiding has become increasingly important for many applications, like confidential transmission, video surveillance, military and medical applications. In this paper we present a new approach of 3D object data hiding without changing the position of vertices in the 3D space. The main idea of the proposed method is to find and to synchronize particular areas of the 3D objects used to embed the message. The embedding is carried out by changing the connectivity of e...

  8. 3D Healpix-based Skymaps Visualization using Java

    Joliet, E.; O'Mullane, W.; Górski, K. M.; Banday, A. J.; Hivon, E.; Carr, R.

    2008-08-01

    HEALPix {http://healpix.jpl.nasa.gov/} is useful for data analysis and visualization. Gaia is the ESA space astrometry cornerstone mission the main objective of wich is to astrometrically and spectro-photometrically map 10^{9} celestial objects (mostly in our galaxy) with unprecedented accuracy. The data will be organized and stored in a central database at ESAC (Spain). The data treatment needs data analysis and visualization tools to accomplish a successful mission. The 3D Healpix-based skymaps are used as part of the interactive diagnostic tools as well as within the core processing. We present the HEALPix Java library and give some examples of its use within Gaia and Planck processing.

  9. Development of a computational system for radiotherapic planning with the IMRT technique applied to the MCNP computer code with 3D graphic interface for voxel models

    The Intensity Modulated Radiation Therapy - IMRT is an advanced treatment technique used worldwide in oncology medicine branch. On this master proposal was developed a software package for simulating the IMRT protocol, namely SOFT-RT which attachment the research group 'Nucleo de Radiacoes Ionizantes' - NRI at UFMG. The computational system SOFT-RT allows producing the absorbed dose simulation of the radiotherapic treatment through a three-dimensional voxel model of the patient. The SISCODES code, from NRI, research group, helps in producing the voxel model of the interest region from a set of CT or MRI digitalized images. The SOFT-RT allows also the rotation and translation of the model about the coordinate system axis for better visualization of the model and the beam. The SOFT-RT collects and exports the necessary parameters to MCNP code which will carry out the nuclear radiation transport towards the tumor and adjacent healthy tissues for each orientation and position of the beam planning. Through three-dimensional visualization of voxel model of a patient, it is possible to focus on a tumoral region preserving the whole tissues around them. It takes in account where exactly the radiation beam passes through, which tissues are affected and how much dose is applied in both tissues. The Out-module from SOFT-RT imports the results and express the dose response superimposing dose and voxel model in gray scale in a three-dimensional graphic representation. The present master thesis presents the new computational system of radiotherapic treatment - SOFT-RT code which has been developed using the robust and multi-platform C++ programming language with the OpenGL graphics packages. The Linux operational system was adopted with the goal of running it in an open source platform and free access. Preliminary simulation results for a cerebral tumor case will be reported as well as some dosimetric evaluations. (author)

  10. Hydrogel-based reinforcement of 3D bioprinted constructs.

    Melchels, Ferry P W; Blokzijl, Maarten M; Levato, Riccardo; Peiffer, Quentin C; Ruijter, Mylène de; Hennink, Wim E; Vermonden, Tina; Malda, Jos

    2016-01-01

    Progress within the field of biofabrication is hindered by a lack of suitable hydrogel formulations. Here, we present a novel approach based on a hybrid printing technique to create cellularized 3D printed constructs. The hybrid bioprinting strategy combines a reinforcing gel for mechanical support with a bioink to provide a cytocompatible environment. In comparison with thermoplastics such as [Formula: see text]-polycaprolactone, the hydrogel-based reinforcing gel platform enables printing at cell-friendly temperatures, targets the bioprinting of softer tissues and allows for improved control over degradation kinetics. We prepared amphiphilic macromonomers based on poloxamer that form hydrolysable, covalently cross-linked polymer networks. Dissolved at a concentration of 28.6%w/w in water, it functions as reinforcing gel, while a 5%w/w gelatin-methacryloyl based gel is utilized as bioink. This strategy allows for the creation of complex structures, where the bioink provides a cytocompatible environment for encapsulated cells. Cell viability of equine chondrocytes encapsulated within printed constructs remained largely unaffected by the printing process. The versatility of the system is further demonstrated by the ability to tune the stiffness of printed constructs between 138 and 263 kPa, as well as to tailor the degradation kinetics of the reinforcing gel from several weeks up to more than a year. PMID:27431861

  11. Monte Carlo-based diffusion tensor tractography with a geometrically corrected voxel-centre connecting method

    Diffusion tensor tractography (DTT) allows one to explore axonal connectivity patterns in neuronal tissue by linking local predominant diffusion directions determined by diffusion tensor imaging (DTI). The majority of existing tractography approaches use continuous coordinates for calculating single trajectories through the diffusion tensor field. The tractography algorithm we propose is characterized by (1) a trajectory propagation rule that uses voxel centres as vertices and (2) orientation probabilities for the calculated steps in a trajectory that are obtained from the diffusion tensors of either two or three voxels. These voxels include the last voxel of each previous step and one or two candidate successor voxels. The precision and the accuracy of the suggested method are explored with synthetic data. Results clearly favour probabilities based on two consecutive successor voxels. Evidence is also provided that in any voxel-centre-based tractography approach, there is a need for a probability correction that takes into account the geometry of the acquisition grid. Finally, we provide examples in which the proposed fibre-tracking method is applied to the human optical radiation, the cortico-spinal tracts and to connections between Broca's and Wernicke's area to demonstrate the performance of the proposed method on measured data.

  12. Energy harvesting “3-D knitted spacer” based piezoelectric textiles

    Anand, S.; Soin, N.; Shah, T. H.; Siores, E.

    2016-07-01

    The piezoelectric effect in Poly(vinylidene fluoride), PVDF, was discovered over four decades ago and since then, significant work has been carried out aiming at the production of high p-phase fibres and their integration into fabric structures for energy harvesting. However, little work has been done in the area of production of “true piezoelectric fabric structures” based on flexible polymeric materials such as PVDF. In this work, we demonstrate “3-D knitted spacer” technology based all-fibre piezoelectric fabrics as power generators and energy harvesters. The knitted single-structure piezoelectric generator consists of high p-phase (~80%) piezoelectric PVDF monofilaments as the spacer yarn interconnected between silver (Ag) coated polyamide multifilament yarn layers acting as the top and bottom electrodes. The novel and unique textile structure provides an output power density in the range of 1.105.10 gWcm-2 at applied impact pressures in the range of 0.02-0.10 MPa, thus providing significantly higher power outputs and efficiencies over the existing 2-D woven and nonwoven piezoelectric structures. The high energy efficiency, mechanical durability and comfort of the soft, flexible and all-fibre based power generator is highly attractive for a variety of potential applications such as wearable electronic systems and energy harvesters charged from ambient environment or by human movement.

  13. 3D Model Retrieval Based on Semantic and Shape Indexes

    Kassimi, My Abdellah

    2011-01-01

    The size of 3D models used on the web or stored in databases is becoming increasingly high. Then, an efficient method that allows users to find similar 3D objects for a given 3D model query has become necessary. Keywords and the geometry of a 3D model cannot meet the needs of users' retrieval because they do not include the semantic information. In this paper, a new method has been proposed to 3D models retrieval using semantic concepts combined with shape indexes. To obtain these concepts, we use the machine learning methods to label 3D models by k-means algorithm in measures and shape indexes space. Moreover, semantic concepts have been organized and represented by ontology language OWL and spatial relationships are used to disambiguate among models of similar appearance. The SPARQL query language has been used to question the information displayed in this language and to compute the similarity between two 3D models. We interpret our results using the Princeton Shape Benchmark Database and the results show ...

  14. A parallelized surface extraction algorithm for large binary image data sets based on an adaptive 3D delaunay subdivision strategy.

    Ma, Yingliang; Saetzler, Kurt

    2008-01-01

    In this paper we describe a novel 3D subdivision strategy to extract the surface of binary image data. This iterative approach generates a series of surface meshes that capture different levels of detail of the underlying structure. At the highest level of detail, the resulting surface mesh generated by our approach uses only about 10% of the triangles in comparison to the marching cube algorithm (MC) even in settings were almost no image noise is present. Our approach also eliminates the so-called "staircase effect" which voxel based algorithms like the MC are likely to show, particularly if non-uniformly sampled images are processed. Finally, we show how the presented algorithm can be parallelized by subdividing 3D image space into rectilinear blocks of subimages. As the algorithm scales very well with an increasing number of processors in a multi-threaded setting, this approach is suited to process large image data sets of several gigabytes. Although the presented work is still computationally more expensive than simple voxel-based algorithms, it produces fewer surface triangles while capturing the same level of detail, is more robust towards image noise and eliminates the above-mentioned "staircase" effect in anisotropic settings. These properties make it particularly useful for biomedical applications, where these conditions are often encountered. PMID:17993710

  15. 3D reconstruction based on spatial vanishing information

    Yuan Shu; Zheng Tan

    2005-01-01

    An approach for the three-dimensional (3D) reconstruction of architectural scenes from two un-calibrated images is described in this paper. From two views of one architectural structure, three pairs of corresponding vanishing points of three major mutual orthogonal directions can be extracted. The simple but powerful constraints of parallelism and orthogonal lines in architectural scenes can be used to calibrate the cameras and to recover the 3D information of the structure. This approach is applied to the real images of architectural scenes, and a 3D model of a building in virtual reality modelling language (VRML) format is presented which illustrates the method with successful performance.

  16. Virtual reality 3D headset based on DMD light modulators

    Bernacki, Bruce E.; Evans, Allan; Tang, Edward

    2014-06-01

    We present the design of an immersion-type 3D headset suitable for virtual reality applications based upon digital micromirror devices (DMD). Current methods for presenting information for virtual reality are focused on either polarizationbased modulators such as liquid crystal on silicon (LCoS) devices, or miniature LCD or LED displays often using lenses to place the image at infinity. LCoS modulators are an area of active research and development, and reduce the amount of viewing light by 50% due to the use of polarization. Viewable LCD or LED screens may suffer low resolution, cause eye fatigue, and exhibit a "screen door" or pixelation effect due to the low pixel fill factor. Our approach leverages a mature technology based on silicon micro mirrors delivering 720p resolution displays in a small form-factor with high fill factor. Supporting chip sets allow rapid integration of these devices into wearable displays with high-definition resolution and low power consumption, and many of the design methods developed for DMD projector applications can be adapted to display use. Potential applications include night driving with natural depth perception, piloting of UAVs, fusion of multiple sensors for pilots, training, vision diagnostics and consumer gaming. Our design concept is described in which light from the DMD is imaged to infinity and the user's own eye lens forms a real image on the user's retina resulting in a virtual retinal display.

  17. Location based augmented reality application on Unity 3D

    Serra Font, Antoni

    2013-01-01

    This document presents the development and steps taken in order to create an augmented reality application using the Unity 3D software using a mobile handheld device. The steps of the development will be explained and the performance evaluated.

  18. Symmetry-Based Conflict Detection and Resolution Method towards Web3D-based Collaborative Design

    Mingjiu Yu; Hongming Cai; Xiaoming Ma; Lihong Jiang

    2016-01-01

    In the process of web3D-based collaborative design, it is necessary to completely prevent operation conflicts among designers due to distributed environments and complex 3D models. Therefore, conflict detection and conflict resolution are of great significance to attain an acceptable result. In order to facilitate effective and smooth design work, a symmetry-based collaborative design framework is proposed using the X3D operation models. Combined considerations cover both models and operation...

  19. Vision based error detection for 3D printing processes

    Baumann Felix; Roller Dieter

    2016-01-01

    3D printers became more popular in the last decade, partly because of the expiration of key patents and the supply of affordable machines. The origin is located in rapid prototyping. With Additive Manufacturing (AM) it is possible to create physical objects from 3D model data by layer wise addition of material. Besides professional use for prototyping and low volume manufacturing they are becoming widespread amongst end users starting with the so called Maker Movement. The most prevalent type...

  20. Gis-Based Smart Cartography Using 3d Modeling

    Malinverni, E. S.; Tassetti, A. N.

    2013-08-01

    3D City Models have evolved to be important tools for urban decision processes and information systems, especially in planning, simulation, analysis, documentation and heritage management. On the other hand existing and in use numerical cartography is often not suitable to be used in GIS because not geometrically and topologically correctly structured. The research aim is to 3D structure and organize a numeric cartography for GIS and turn it into CityGML standardized features. The work is framed around a first phase of methodological analysis aimed to underline which existing standard (like ISO and OGC rules) can be used to improve the quality requirement of a cartographic structure. Subsequently, from this technical specifics, it has been investigated the translation in formal contents, using an owner interchange software (SketchUp), to support some guide lines implementations to generate a GIS3D structured in GML3. It has been therefore predisposed a test three-dimensional numerical cartography (scale 1:500, generated from range data captured by 3D laser scanner), tested on its quality according to the previous standard and edited when and where necessary. Cad files and shapefiles are converted into a final 3D model (Google SketchUp model) and then exported into a 3D city model (CityGML LoD1/LoD2). The GIS3D structure has been managed in a GIS environment to run further spatial analysis and energy performance estimate, not achievable in a 2D environment. In particular geometrical building parameters (footprint, volume etc.) are computed and building envelop thermal characteristics are derived from. Lastly, a simulation is carried out to deal with asbestos and home renovating charges and show how the built 3D city model can support municipal managers with risk diagnosis of the present situation and development of strategies for a sustainable redevelop.

  1. Math world: A game-based 3D Virtual Learning Environment (3D VLE) for second graders

    Jean Maitem; Rosmina Joy Cabauatan; Lorena Rabago; Bartolome Tanguilig III

    2012-01-01

    This paper intends to introduce a game-based 3D Virtual Learning Environment (VLE) to second graders. The impetus arose from the need to make learning in mathematics more effective and interesting through multimedia. Applied in a game, the basic mathematical operations such as addition, subtraction, multiplication, and division are expected to performed by learners as they represent themselves as avatars while they immerse in a quest of digital objects in the VLE called Math World. Educatio...

  2. Math World: A Game-Based 3D Virtual Learning Environment (3D VLE) for Second Graders

    Jean Maitem; Rosmina Joy Cabauatan; Lorena Rabago

    2012-01-01

    This paper intends to introduce a game-based 3D Virtual Learning Environment (VLE) to second graders. The impetus arose from the need to make learning in mathematics more effective and interesting through multimedia. Applied in a game, the basic mathematical operations such as addition, subtraction, multiplication, and division are expected to performed by learners as they represent themselves as avatars while they immerse in a quest of digital objects in the VLE called Math World...

  3. Two animated adult human voxel phantoms based on polygon mesh surfaces

    Among computational models used in radiation protection, voxel phantoms based on computer tomographic (CT), nuclear magnetic resonance (NMR) or colour photographic images, became very popular in recent years. Although being a true to nature representation of the scanned individual the scanning is usually made in supine position, which causes a shift of internal organs towards the ribcage, a compression of the lungs and a reduction of the sagittal diameter especially in the abdominal region compared to the anatomy of a person in upright standing position, which in turn can influence absorbed or equivalent dose estimates. This study proposes a method for human phantom design using tools recently developed in the areas of computer graphics and animated films and applies them to the creation and modelling of artificial 3 D human organs and tissues. Two animated models, a male and a female adult human phantom have been developed based on anatomical atlases, observing at the same time the anatomical specifications published by the International Commission on Radiological Protection for the male and female reference adult. The phantoms are called FAXAA (Female Adult voXelAverage-Average) and MAXAA (Male Adult voXelAverage-Average) because they represent female and male adults with average weight and average height. (author)

  4. Collaboration on Scene Graph Based 3D Data

    Ammon, Lorenz; Bieri, Hanspeter

    Professional 3D digital content creation tools, like Alias Maya or discreet 3ds max, offer only limited support for a team of artists to work on a 3D model collaboratively. We present a scene graph repository system that enables fine-grained collaboration on scenes built using standard 3D DCC tools by applying the concept of collaborative versions to a general attributed scene graph. Artists can work on the same scene in parallel without locking out each other. The artists' changes to a scene are regularly merged to ensure that all artists can see each others progress and collaborate on current data. We introduce the concept of indirect changes and indirect conflicts to systematically inspect the effects that collaborative changes have on a scene. Inspecting indirect conflicts helps maintaining scene consistency by systematically looking for inconsistencies at the right places.

  5. Toward a Network Based 3D Printing Service

    Ndikuriyo, Laurier; Abdulla, Mohammad

    2013-01-01

    This bachelor’s thesis has given us an opportunity to gain insight into how to create a service from scratch and to develop it into a fully functional service. The 3D printer service starts when a customer uploads a file containing the 3D design that they want to have made via a website. The file is stored and the printing request is placed into a queue. After that the client simply waits until the object is printed, with all of the various steps being handled automatically. The uploaded file...

  6. Microseismic network design assessment based on 3D ray tracing

    Näsholm, Sven Peter; Wuestefeld, Andreas; Lubrano-Lavadera, Paul; Lang, Dominik; Kaschwich, Tina; Oye, Volker

    2016-04-01

    There is increasing demand on the versatility of microseismic monitoring networks. In early projects, being able to locate any triggers was considered a success. These early successes led to a better understanding of how to extract value from microseismic results. Today operators, regulators, and service providers work closely together in order to find the optimum network design to meet various requirements. In the current study we demonstrate an integrated and streamlined network capability assessment approach. It is intended for use during the microseismic network design process prior to installation. The assessments are derived from 3D ray tracing between a grid of event points and the sensors. Three aspects are discussed: 1) Magnitude of completeness or detection limit; 2) Event location accuracy; and 3) Ground-motion hazard. The network capability parameters 1) and 2) are estimated at all hypothetic event locations and are presented in the form of maps given a seismic sensor coordinate scenario. In addition, the ray tracing traveltimes permit to estimate the point-spread-functions (PSFs) at the event grid points. PSFs are useful in assessing the resolution and focusing capability of the network for stacking-based event location and imaging methods. We estimate the performance for a hypothetical network case with 11 sensors. We consider the well-documented region around the San Andreas Fault Observatory at Depth (SAFOD) located north of Parkfield, California. The ray tracing is done through a detailed velocity model which covers a 26.2 by 21.2 km wide area around the SAFOD drill site with a resolution of 200 m both for the P-and S-wave velocities. Systematic network capability assessment for different sensor site scenarios prior to installation facilitates finding a final design which meets the survey objectives.

  7. Voxel-based morphometry in the parkinson variant of multiple system atrophy

    Objective: To assess patterns of the gray and white matter atrophy in patients with multiple system atrophy-P (MSA-P) variant of whole brain compared with normal controls. Methods: Three dimensional fast spoiled gradient echo (3D-FSPGR) T1WI of whole brain were obtained from 13 patients with probable MSA-P and 14 age-matched normal controls. The volume of gray matter (GM) and white matter (WM) of MSA-P patients and normal controls was analyzed with voxel-based morphometry (VBM) using statistical parametric mapping (SPM) 8. Results: Compared with the controls, the MSA-P patients showed decreased gray matter and white matter in broad areas. Gray matter loss mainly symmetrically distributed in bilateral supplementary motor area (SMA), dorsal posterior cingulate cortex (DPCC), medial frontal gyrus, superior temporal gyrus, cerebellum cortex, eta Unilateral involvement of cortices mainly located in right primary motor cortex, somatosensory association cortex (SAC), and left ventral anterior cingulate cortex (VACC). There was white matter loss in bilateral superior frontal gyrus, bilateral precuneus, bilateral sub-gyrus of frontal lobe, left superior temporal gyrus, left cingulate gyrus, right orbitofrontal area, right sub- gyrus of temporal lobe, etc. Conclusion: VBM method is an automatic and comprehensive volumetry method and can objectively detect the difference of the whole brain structure in patients with probable MSA- P comparing with normal controls. (authors)

  8. Grey matter abnormalities in untreated hyperthyroidism: A voxel-based morphometry study using the DARTEL approach

    Zhang, Wei, E-mail: will.zhang.1111@gmail.com [Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing 400038 (China); Department of Radiology, Sichuan Provincial Corps Hospital, Chinese People' s Armed Police Forces, Leshan 614000 (China); Song, Lingheng, E-mail: songlh1023@hotmail.com [Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing 400038 (China); Department of Radiology, No. 324 Hospital of PLA, Chongqing 400020 (China); Yin, Xuntao, E-mail: xuntaoyin@gmail.com [Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing 400038 (China); Zhang, Jiuquan, E-mail: jiuquanzhang@yahoo.com [Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing 400038 (China); Liu, Chen, E-mail: cqliuchen@foxmail.com [Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing 400038 (China); Wang, Jian, E-mail: wangjian_811@yahoo.com [Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing 400038 (China); Zhou, Daiquan, E-mail: zhoudq77@sina.com [Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing 400038 (China); Chen, Bing, E-mail: chenbing3@medmail.com.cn [Department of Endocrinology, Southwest Hospital, Third Military Medical University, Chongqing 400038 (China); Lii, Haitao, E-mail: haitaolii023@gmail.com [Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing 400038 (China)

    2014-01-15

    Objective: Hyperthyroidism is frequently associated with pronounced neuropsychiatric symptoms such as impulsiveness, irritability, poor concentration, and memory impairments. Functional neuroimaging has revealed changes in cerebral metabolism in hyperthyroidism, but regional changes in cortical morphology associated with specific neurological deficits have not been studied so far. To investigate the pathophysiology underlying hyperthyroid-associated neural dysfunction, we compared grey matter volume (GMV) between adult hyperthyroid patients and matched healthy controls using voxel-based morphometry (VBM). Materials and methods: High resolution 3D T1-weighted images were acquired by 3T MRI from 51 hyperthyroid patients and 51 controls. VBM analysis was performed using SPM8. Correlations between regional GMV and both serum free thyroid hormone (TH) concentrations and disease duration were assessed by multiple regression analysis. Results: Compared to controls, GM volumes in the bilateral hippocampus, parahippocampal gyrus, calcarine, lingual gyrus, and left temporal pole were lower and bilateral supplementary motor area GMV higher in hyperthyroid patients. Serum free triiodothyronine (FT3) concentration was negatively correlated with the normalized regional volume (NRV) of the left parahippocampal gyrus and serum free thyroxine (FT4) concentration negatively correlated with the NRV of the left hippocampus and right parahippocampal gyrus. Disease duration was negatively correlated with the NRV of the left hippocampus, bilateral parahippocampal gyrus, and left temporal pole. Conclusion: Hyperthyroid patients exhibited reduced GMV in regions associated with memory, attention, emotion, vision, and motor planning. Negative correlations between GMV and both free TH and disease duration suggest that chronic TH elevation induces abnormalities in the adult cortex.

  9. Grey matter abnormalities in untreated hyperthyroidism: A voxel-based morphometry study using the DARTEL approach

    Objective: Hyperthyroidism is frequently associated with pronounced neuropsychiatric symptoms such as impulsiveness, irritability, poor concentration, and memory impairments. Functional neuroimaging has revealed changes in cerebral metabolism in hyperthyroidism, but regional changes in cortical morphology associated with specific neurological deficits have not been studied so far. To investigate the pathophysiology underlying hyperthyroid-associated neural dysfunction, we compared grey matter volume (GMV) between adult hyperthyroid patients and matched healthy controls using voxel-based morphometry (VBM). Materials and methods: High resolution 3D T1-weighted images were acquired by 3T MRI from 51 hyperthyroid patients and 51 controls. VBM analysis was performed using SPM8. Correlations between regional GMV and both serum free thyroid hormone (TH) concentrations and disease duration were assessed by multiple regression analysis. Results: Compared to controls, GM volumes in the bilateral hippocampus, parahippocampal gyrus, calcarine, lingual gyrus, and left temporal pole were lower and bilateral supplementary motor area GMV higher in hyperthyroid patients. Serum free triiodothyronine (FT3) concentration was negatively correlated with the normalized regional volume (NRV) of the left parahippocampal gyrus and serum free thyroxine (FT4) concentration negatively correlated with the NRV of the left hippocampus and right parahippocampal gyrus. Disease duration was negatively correlated with the NRV of the left hippocampus, bilateral parahippocampal gyrus, and left temporal pole. Conclusion: Hyperthyroid patients exhibited reduced GMV in regions associated with memory, attention, emotion, vision, and motor planning. Negative correlations between GMV and both free TH and disease duration suggest that chronic TH elevation induces abnormalities in the adult cortex

  10. Voxel Based Morphometry Alterations in Mal de Debarquement Syndrome.

    Yoon-Hee Cha

    Full Text Available Mal de debarquement syndrome (MdDS is a disorder of chronic self-motion perception that occurs though entrainment to rhythmic background motion, such as from sea voyage, and involves the perception of low-frequency rocking that can last for months or years. The neural basis of this persistent sensory perception abnormality is not well understood.We investigated grey matter volume differences underlying persistent MdDS by performing voxel-based morphometry on whole brain and pre-specified ROIs in 28 individuals with MdDS and comparing them to 18 age, sex, and handedness matched controls.MdDS participants exhibited greater grey matter volume in the left inferior parietal lobule, right inferior occipital gyrus (area V3v, right temporal pole, bilateral cerebellar hemispheric lobules VIII/IX and left lobule VIIa/VIIb. Grey matter volumes were lower in bilateral inferior frontal, orbitofrontal, pregenual anterior cingulate cortex (pgACC and left superior medial gyri (t = 3.0, p<0.005uncorr. In ROI analyses, there were no volume differences in the middle occipital gyrus (region of V5/MT or parietal operculum 2 (region of the parietoinsular vestibular cortex. Illness duration was positively related to grey matter volume in bilateral inferior frontal gyrus/anterior insula (IFG/AI, right posterior insula, superior parietal lobule, left middle occipital gyrus (V5/MT, bilateral postcentral gyrus, anterior cerebellum, and left cerebellar hemisphere and vermian lobule IX. In contrast, illness duration was negatively related to volume in pgACC, posterior middle cingulate gyrus (MCC, left middle frontal gyrus (dorsolateral prefrontal cortex-DLPFC, and right cerebellar hemispheric lobule VIIIb (t = 3.0, p<0.005uncorr. The most significant differences were decreased volume in the pgACC and increased volume in the left IFG/AI with longer illness duration (qFDRcorr <0.05. Concurrent medication use did not correlate with these findings or have a relationship with

  11. Software-based geometry operations for 3D computer graphics

    Sima, M.; Iancu, D.; Glossner, J.; Schulte, M.; Mamidi, S.

    2006-01-01

    In order to support a broad dynamic range and a high degree of precision, many of 3D renderings fundamental algorithms have been traditionally performed in floating-point. However, fixed-point data representation is preferable over floatingpoint representation in graphics applications on embedded de

  12. Modeling Perception of 3D Forms Using Fuzzy Knowledge Bases

    Achiche, Sofiane; Ahmed, Saeema

    the aesthetics of their products are likely to be perceived are of value. In this paper the authors propose an approach to formalize the relationship between geometric information of a 3D object and the intended perception using fuzzy logic. 3D objects (shapes) created by design engineering students...... to evoke a certain perception were analysed. Three different fuzzy logic models, with different input variables, for evaluating massiveness and lightness in a form are proposed. The uthors identified geometric information as inputs of the fuzzy model and developed a set of fuzzy if/then rules to map...... the relationships between the fuzzy sets on each input premise and the output premise. In our case the output premise of the fuzzy logic model is the level of belonging to the design context (perception). An evaluation of how users perceived the shapes was conducted to validate the fuzzy logic models...

  13. 3D Spatial Data Infrastructures for web-based Visualization

    Schilling, Arne

    2014-01-01

    In this thesis, concepts for developing Spatial Data Infrastructures with an emphasis on visualizing 3D landscape and city models in distributed environments are discussed. Spatial Data Infrastructures are important for public authorities in order to perform tasks on a daily basis, and serve as research topic in geo-informatics. Joint initiatives at national and international level exist for harmonizing procedures and technologies. Interoperability is an important aspect in this context - as ...

  14. Single Monocular Moving Camera based 3-D Segmentation

    R. Senthilnathan

    2012-06-01

    Full Text Available Three dimensional (3-D vision techniques in the field of Computer Vision aims mainly at reconstructing a scene to find its three dimensional geometrical information. Passive 3-D vision techniques such as computational stereo vision method do surface reconstruction from disparities arising in images of the same scene taken from multiple views. For reconstruction leading to metrical information of the 3-D geometry of the scene the camera pose with respect to some world reference frame and the camera parameters such as the focal length, sensor size has to be accurately known. Such information especially the pose of the camera might not be known in many applications such as in agricultural, underwater explorations since a unique universal frame of reference is not possible. Also the constancy of the internal camera parameters will not be valid in many applications requiring good accuracy in reconstruction. In such cases the cameras used for passive triangulation is said to be un-calibrated. Stereo vision technique generally requires two images and which need not be from two different cameras. The paper is an attempt to use a single moving camera with which the image of the same scene is acquired from two different views. Since the scene geometry and the pose of the camera are unknown the problem to be addressed is close to so called Structure from Motion (SfM problem in Computer Vision. The reconstruction method developed in the paper is extended further to segment top surfaces of cuboid shaped object considered as the object of interest in the scene reconstruction process. Though the information in the case considered is non-metrical the applications that pose such un-calibrated camera as a demand are plenty.

  15. Camera Based 3D Mine-Shaft Inspection System

    Wohlfeil, Jürgen; Spreckels, Volker; Strackenbrock, Bernhard; Schlienkamp, Andreas; Choinowski, André

    2015-01-01

    This paper describes the development of an Optical 3D Shaft Inspection System needed for the survey and monitoring of Water Handling Shafts in the German Ruhrgebiet. The development is part of the RAG R&D project “ABSMon”. The end of the German hard coal mining at the end of 2018 has been determined with the Steinkohlefinanzierungsgesetz (SteinkohleFinG) from 2007-12-20. About three hundred years before now the near surface hard coal mining began in the southern Ruhr Area an...

  16. Image-Based 3D Face Modeling System

    Vladimir Vezhnevets

    2005-08-01

    Full Text Available This paper describes an automatic system for 3D face modeling using frontal and profile images taken by an ordinary digital camera. The system consists of four subsystems including frontal feature detection, profile feature detection, shape deformation, and texture generation modules. The frontal and profile feature detection modules automatically extract the facial parts such as the eye, nose, mouth, and ear. The shape deformation module utilizes the detected features to deform the generic head mesh model such that the deformed model coincides with the detected features. A texture is created by combining the facial textures augmented from the input images and the synthesized texture and mapped onto the deformed generic head model. This paper provides a practical system for 3D face modeling, which is highly automated by aggregating, customizing, and optimizing a bunch of individual computer vision algorithms. The experimental results show a highly automated process of modeling, which is sufficiently robust to various imaging conditions. The whole model creation including all the optional manual corrections takes only 2∼3 minutes.

  17. VOXEL-BASED APPROACH FOR ESTIMATING URBAN TREE VOLUME FROM TERRESTRIAL LASER SCANNING DATA

    C. Vonderach

    2012-07-01

    Full Text Available The importance of single trees and the determination of related parameters has been recognized in recent years, e.g. for forest inventories or management. For urban areas an increasing interest in the data acquisition of trees can be observed concerning aspects like urban climate, CO2 balance, and environmental protection. Urban trees differ significantly from natural systems with regard to the site conditions (e.g. technogenic soils, contaminants, lower groundwater level, regular disturbance, climate (increased temperature, reduced humidity and species composition and arrangement (habitus and health status and therefore allometric relations cannot be transferred from natural sites to urban areas. To overcome this problem an extended approach was developed for a fast and non-destructive extraction of branch volume, DBH (diameter at breast height and height of single trees from point clouds of terrestrial laser scanning (TLS. For data acquisition, the trees were scanned with highest scan resolution from several (up to five positions located around the tree. The resulting point clouds (20 to 60 million points are analysed with an algorithm based on voxel (volume elements structure, leading to an appropriate data reduction. In a first step, two kinds of noise reduction are carried out: the elimination of isolated voxels as well as voxels with marginal point density. To obtain correct volume estimates, the voxels inside the stem and branches (interior voxels where voxels contain no laser points must be regarded. For this filling process, an easy and robust approach was developed based on a layer-wise (horizontal layers of the voxel structure intersection of four orthogonal viewing directions. However, this procedure also generates several erroneous "phantom" voxels, which have to be eliminated. For this purpose the previous approach was extended by a special region growing algorithm. In a final step the volume is determined layer-wise based on the

  18. Characterization of tumor dose heterogeneity for 90Y microsphere therapies using voxel- based dosimetry

    Justin Mikell

    2014-03-01

    Full Text Available Purpose: Dosimetry for 90Y microsphere therapies (YMT with Standard (SM and Partition (PM models provide only uniform dose estimates to tumor and liver. Our objective is to calculate tumor dose heterogeneity, known to effect response, using voxel-based dosimetry and investigate the limitations of SM and PM.Methods: Voxel-based dosimetry was performed on 17 YMT patients using Monte Carlo DOSXYZnrc. 90Y activity and tissue/density distributions were based on quantitative 90Y bremsstrahlung SPECT/CT. Tumors (n=31, liver, and treatment lobe/segments were segmented on diagnostic CT or MR. Dose volume histograms (DVH were created for tumors and normal liver. Bland-Altman analysis compared voxel-based mean absorbed doses to tumor and liver with SM and PM. Tumor and normal liver absorbed dose heterogeneity were investigated through metrics: integral uniformity (IU, D10/D90, COV. Correlations of heterogeneity with voxel-based mean doses and volumes were evaluated.Results: Heterogeneity metrics (mean ± 1σ for tumor dose were COV = 0.48 ± 0.28, D10/D90 = 4.7 ± 3.9, and IU = 0.8 ± 0.18. Heterogeneity metrics correlated with tumor volume (r > 0.58 but not tumor mean doses (r < 0.20. Voxel-based tumor mean doses correlated with PM (r = 0.84 but not SM (r = 0.08. Both yielded poor limits of agreement with of 83 ± 174 and -28 ± 181 Gy, respectively. Normal liver heterogeneity metrics (mean ± 1σ were COV = 0.83 ± 0.29, D10/D90 = 12 ± 15, and IU = 0.97 ± 0.03. Only D10/D90 (r = 0.49 correlated with mean normal liver absorbed dose. Voxel-based normal liver/lobe mean doses correlated with PM (r = 0.96, but had poor limits of agreement (26 ± 29 Gy.Conclusion: Tumor doses have high levels of heterogeneity that increase with volume but are independent of dose. Voxel-based DVH and dose heterogeneity metrics will promote accurate characterization of tumor response following YMT.--------------------------------------Cite this article as: Mikell J, Mourtada F

  19. A Survey of Recent View-based 3D Model Retrieval Methods

    Liu, Qiong

    2012-01-01

    Extensive research efforts have been dedicated to 3D model retrieval in recent decades. Recently, view-based methods have attracted much research attention due to the high discriminative property of multi-views for 3D object representation. In this report, we summarize the view-based 3D model methods and provide the further research trends. This paper focuses on the scheme for matching between multiple views of 3D models and the application of bag-of-visual-words method in 3D model retrieval....

  20. 3D Image Sensor based on Parallax Motion

    Barna Reskó

    2007-12-01

    Full Text Available For humans and visual animals vision it is the primary and the most sophisticatedperceptual modality to get information about the surrounding world. Depth perception is apart of vision allowing to accurately determine the distance to an object which makes it animportant visual task. Humans have two eyes with overlapping visual fields that enablestereo vision and thus space perception. Some birds however do not have overlappingvisual fields, and compensate this lask by moving their heads, which in turn makes spaceperception possible using the motion parallax as a visual cue. This paper presents asolution using an opto-mechanical filter that was inspired by the way birds observe theirenvironment. The filtering is done using two different approaches:using motion blur duringmotion parallax, and using the optical flow algorithm. The two methods have differentadvantages and drawbacks, which will be discussed in the paper. The proposed system canbe used in robotics for 3D space perception.

  1. Coniferous Canopy BRF Simulation Based on 3-D Realistic Scene

    Wang, Xin-yun; Guo, Zhi-feng; Qin, Wen-han; Sun, Guo-qing

    2011-01-01

    It is difficulties for the computer simulation method to study radiation regime at large-scale. Simplified coniferous model was investigate d in the present study. It makes the computer simulation methods such as L-systems and radiosity-graphics combined method (RGM) more powerf ul in remote sensing of heterogeneous coniferous forests over a large -scale region. L-systems is applied to render 3-D coniferous forest scenarios: and RGM model was used to calculate BRF (bidirectional refle ctance factor) in visible and near-infrared regions. Results in this study show that in most cases both agreed well. Meanwhiie at a tree and forest level. the results are also good.

  2. 3D Wavelet-based Fusion Techniques for Biomedical Imaging

    Rubio Guivernau, José Luis

    2012-01-01

    Hoy en día las técnicas de adquisición de imágenes tridimensionales son comunes en diversas áreas, pero cabe destacar la relevancia que han adquirido en el ámbito de la imagen biomédica, dentro del cual encontramos una amplia gama de técnicas como la microscopía confocal, microscopía de dos fotones, microscopía de fluorescencia mediante lámina de luz, resonancia magnética nuclear, tomografía por emisión de positrones, tomografía de coherencia óptica, ecografía 3D y un largo etcétera. Un denom...

  3. Mobile gaze-based screen interaction in 3D environments

    Mardanbeigi, Diako; Witzner Hansen, Dan

    2011-01-01

    Head-mounted eye trackers can be used for mobile interaction as well as gaze estimation purposes. This paper presents a method that enables the user to interact with any planar digital display in a 3D environment using a head-mounted eye tracker. An effective method for identifying the screens in...... the field of view of the user is also presented which can be applied in a general scenario in which multiple users can interact with multiple screens. A particular application of using this technique is implemented in a home environment with two big screens and a mobile phone. In this application a...... user was able to interact with these screens using a wireless head-mounted eye tracker....

  4. 3D transient calculations of PGV-1000 based on TRAC

    Anatoly A Kazantsev; Andrey N Pozdnyakov [Simulation Systems Ltd., 133-208 Lenin str. 249030, Obninsk city, Kaluga reg. (Russian Federation); Vladimir V Sergeev; Valery A Evstifeev [Institute of Physics and Power Engineering (IPPE) 249020, Bondarenko square 1, Obninsk city, Kaluga reg., Russia, Government research center RF IPPE by A.I. Leipynski (Russian Federation)

    2005-07-01

    Full text of publication follows: During calculations of SAR accidents and transients it is necessary to perform steam generator simulation. Best accuracy is 3D transient calculations presented in report. Main outcomes of work was next: 1. There was shown by analysis the applicability of code TRAC (Los-Alamos laboratory) for thermal - hydraulic calculations of horizontal steam generator PGV-1000M. Special nodalization scheme was developed for it purposes. 2. Validation and selection of thermal-hydraulic correlations for improvement of using the code at calculation PGV-1000M were performed. As result Labuntsov formula is recommended for horizontal SG. 3. Calculations of nominal mode operation of PGV-1000M for cross-verification with code STEG (Electrogorsk Research and Engineering Center EREC) during its verification were performed. Solution by TRAC was obtained for transient problem after stabilization time. 4. Development of dynamic SG model as conjugate problem (thermal hydraulic of I and II circuits are calculated together) for research of the transient and accident processes stipulated by safety standards for NPP with VVER-1000 and VVER-1500. 5. Creating of calculation complex on the basis of code TRAC for the purposes of the analysis and optimization of a design. Development graphic pre- and post-processor for code TRAC. 6. The TRAC code allows to use correlation Zukauskas for friction factors in tube bundles through the initial data. Using postprocessing calculations and restart mode iterations allows to use Kolbasnikov's correlations for friction factors for biphasic mode in tube bundles. Developed nodalization model of PGV-1000M includes a conjugate hydrodynamical problem on I and to II circuits in view of thermal connection through packages of tubes. Thus primary circuit is considered in multichannel 1D approximation with hydraulic non-uniformity of flow rates between pre-settled groups of tubes. The hydrodynamics into shell of PG is presented as 3D

  5. 3-D Adaptive Sparsity Based Image Compression With Applications to Optical Coherence Tomography.

    Fang, Leyuan; Li, Shutao; Kang, Xudong; Izatt, Joseph A; Farsiu, Sina

    2015-06-01

    We present a novel general-purpose compression method for tomographic images, termed 3D adaptive sparse representation based compression (3D-ASRC). In this paper, we focus on applications of 3D-ASRC for the compression of ophthalmic 3D optical coherence tomography (OCT) images. The 3D-ASRC algorithm exploits correlations among adjacent OCT images to improve compression performance, yet is sensitive to preserving their differences. Due to the inherent denoising mechanism of the sparsity based 3D-ASRC, the quality of the compressed images are often better than the raw images they are based on. Experiments on clinical-grade retinal OCT images demonstrate the superiority of the proposed 3D-ASRC over other well-known compression methods. PMID:25561591

  6. Research on urban rapid 3D modeling and application based on CGA rule

    Li, Jing-wen; Jiang, Jian-wu; Zhou, Song; Yin, Shou-qiang

    2015-12-01

    Use CityEngine as the 3D modeling platform, research on urban rapid 3D modeling technology based on the CGA(Computer Generated Architectur) rule , solved the problem of the rapid creation of urban 3D model in large scenes , and research on building texture processing and 3D model optimization techniques based on CGA rule , using component modeling method , solved the problem of texture distortion and model redundancy in the traditional fast modeling 3D model , and development of a three-dimensional view and analysis system based on ArcGIS Engine , realization of 3D model query , distance measurement , specific path flight , 3D marking , Scene export,etc.

  7. Math World: A Game-Based 3D Virtual Learning Environment (3D VLE for Second Graders

    Jean Maitem

    2012-02-01

    Full Text Available This paper intends to introduce a game-based 3D Virtual Learning Environment (VLE to second graders. The impetus arose from the need to make learning in mathematics more effective and interesting through multimedia. Applied in a game, the basic mathematical operations such as addition, subtraction, multiplication, and division are expected to performed by learners as they represent themselves as avatars while they immerse in a quest of digital objects in the VLE called Math World. Educational attributes such as mentality change, emotional fulfillment, knowledge enhancement, thinking skills development, and bodily coordination are evaluated to ensure learning effectiveness. Also, game playability measured in terms of game plays, story, mechanics and interface usability are examined for its educative design. With an aggregate of these enhanced indices, results attest that objectives were met while making mathematics an interesting, motivating and enjoyable subject, hence VLE a significant tool to complement the conventional approaches of teaching.

  8. Math World: A Game-Based 3D Virtual Learning Environment (3D VLE for Second Graders

    Jean Maitem

    2012-03-01

    Full Text Available This paper intends to introduce a game-based 3D Virtual Learning Environment (VLE to second graders. The impetus arose from the need to make learning in mathematics more effective and interesting through multimedia. Applied in a game, the basic mathematical operations such as addition, subtraction, multiplication, and division are expected to performed by learners as they represent themselves as avatars while they immerse in a quest of digital objects in the VLE called Math World. Educational attributes such as mentality change, emotional fulfillment, knowledge enhancement, thinking skills development, and bodily coordination are evaluated to ensure learning effectiveness. Also, game playability measured interms of game plays, story, mechanics and interface usability are examined for its educative design. With an aggregate of these enhanced indices, results attest that objectives were met while making mathematics an interesting, motivating and enjoyable subject, hence VLE a significant tool to complement the conventional approaches of teaching.

  9. Math world: A game-based 3D Virtual Learning Environment (3D VLE) for second graders

    Maitem, Jean; Rabago, Lorena; Tanguilig, Bartolome

    2012-01-01

    This paper intends to introduce a game-based 3D Virtual Learning Environment (VLE) to second graders. The impetus arose from the need to make learning in mathematics more effective and interesting through multimedia. Applied in a game, the basic mathematical operations such as addition, subtraction, multiplication, and division are expected to performed by learners as they represent themselves as avatars while they immerse in a quest of digital objects in the VLE called Math World. Educational attributes such as mentality change, emotional fulfillment, knowledge enhancement, thinking skills development, and bodily coordination are evaluated to ensure learning effectiveness. Also, game playability measured in terms of game plays, story, mechanics and interface usability are examined for its educative design. With an aggregate of these enhanced indices, results attest that objectives were met while making mathematics an interesting, motivating and enjoyable subject, hence VLE a significant tool to complement th...

  10. Development of a computational system for radiotherapic planning with the IMRT technique applied to the MCNP computer code with 3D graphic interface for voxel models; Desenvolvimento de um sistema computacional para o planejamento radioterapico com a tecnica IMRT aplicado ao codigo MCNP com interface grafica 3D para modelos de voxel

    Fonseca, Telma Cristina Ferreira

    2009-07-01

    The Intensity Modulated Radiation Therapy - IMRT is an advanced treatment technique used worldwide in oncology medicine branch. On this master proposal was developed a software package for simulating the IMRT protocol, namely SOFT-RT which attachment the research group 'Nucleo de Radiacoes Ionizantes' - NRI at UFMG. The computational system SOFT-RT allows producing the absorbed dose simulation of the radiotherapic treatment through a three-dimensional voxel model of the patient. The SISCODES code, from NRI, research group, helps in producing the voxel model of the interest region from a set of CT or MRI digitalized images. The SOFT-RT allows also the rotation and translation of the model about the coordinate system axis for better visualization of the model and the beam. The SOFT-RT collects and exports the necessary parameters to MCNP code which will carry out the nuclear radiation transport towards the tumor and adjacent healthy tissues for each orientation and position of the beam planning. Through three-dimensional visualization of voxel model of a patient, it is possible to focus on a tumoral region preserving the whole tissues around them. It takes in account where exactly the radiation beam passes through, which tissues are affected and how much dose is applied in both tissues. The Out-module from SOFT-RT imports the results and express the dose response superimposing dose and voxel model in gray scale in a three-dimensional graphic representation. The present master thesis presents the new computational system of radiotherapic treatment - SOFT-RT code which has been developed using the robust and multi-platform C{sup ++} programming language with the OpenGL graphics packages. The Linux operational system was adopted with the goal of running it in an open source platform and free access. Preliminary simulation results for a cerebral tumor case will be reported as well as some dosimetric evaluations. (author)

  11. An Overview of 3d Topology for Ladm-Based Objects

    Zulkifli, N. A.; Rahman, A. A.; van Oosterom, P.

    2015-10-01

    This paper reviews 3D topology within Land Administration Domain Model (LADM) international standard. It is important to review characteristic of the different 3D topological models and to choose the most suitable model for certain applications. The characteristic of the different 3D topological models are based on several main aspects (e.g. space or plane partition, used primitives, constructive rules, orientation and explicit or implicit relationships). The most suitable 3D topological model depends on the type of application it is used for. There is no single 3D topology model best suitable for all types of applications. Therefore, it is very important to define the requirements of the 3D topology model. The context of this paper is a 3D topology for LADM-based objects.

  12. Shifting from region of interest (ROI) to voxel-based analysis in human brain mapping

    Current clinical studies involve multidimensional high-resolution images containing an overwhelming amount of structural and functional information. The analysis of such a wealth of information is becoming increasingly difficult yet necessary in order to improve diagnosis, treatment and healthcare. Voxel-wise analysis is a class of modern methods of image processing in the medical field with increased popularity. It has replaced manual region of interest (ROI) analysis and has provided tools to make statistical inferences at voxel level. The introduction of voxel-based analysis software in all modern commercial scanners allows clinical use of these techniques. This review will explain the main principles, advantages and disadvantages behind these methods of image analysis. (orig.)

  13. A new approach towards image based virtual 3D city modeling by using close range photogrammetry

    S. P. Singh; K. Jain; V. R. Mandla

    2014-01-01

    3D city model is a digital representation of the Earth's surface and it’s related objects such as building, tree, vegetation, and some manmade feature belonging to urban area. The demand of 3D city modeling is increasing day to day for various engineering and non-engineering applications. Generally three main image based approaches are using for virtual 3D city models generation. In first approach, researchers used Sketch based modeling, second method is Procedural grammar based m...

  14. Calculations of internal and external radiation exposure based on voxel models. Final report

    Dose estimations of internal and external radiation exposure were based so far on mathematical phantoms with rather simple geometrical descriptions of the human body and teh organs. Recently the mathematical phantoms are replaced by more realistic voxel models that allow a more realistic dose estimation for professional radiation exposed personnel, individuals and patients. The projects is aimed to calculate organ doses for exposure to environmental radiation, organ doses for patients during computed tomography and to develop a voxel model for pregnant (24th week of pregnancy) woman for the estimation of radiation doses for the unborn child.

  15. Diagnostic System for 3D Ultrasonography Based on Gabor Filter

    Wei-Ming Chen

    2010-12-01

    Full Text Available 800x600 Normal 0 0 2 false false false EN-US ZH-TW X-NONE MicrosoftInternetExplorer4 With the development of the times, people's lifestyle and eating habits are changed a lot. Worldwide, breast cancer is the second most common type of cancer after lung cancer and the fifth most common cause of cancer death. Diagnostic ultrasound (US of breast cancer is currently the major clinical detection method. It is recognized as a safe, effective, and highly flexible imaging modality capable of providing clinically relevant information about most parts of the body in a rapid and cost-effective fashion. However, ultrasound imaging usually contains a large number of noises and speckles. That will impact greatly on diagnosis by physicians. Therefore, we proposed a method to enhance the computer-aided diagnosis (CAD of the breast cancer tumors and to reduce detection time and error rate. Experimental investigations demonstrated that the texture variance of 3D ultrasound were effective and useful for differential diagnosis of breast tumors. Texture extraction with proposed method can find malignant more accurate than auto-correlation.

  16. Preliminary application of voxel-based morphometry technique on brain changes in neuromyelitis

    Objective: To investigate the changes of brain volumes in neuromyelitis optica (NMO) patients using voxel-based morphometry (VBM) method, and preliminarily explore the pattern of cerebral anatomical impairment. Methods: Twenty-three clinically defined NMO patients and 15 gender and age matched healthy volunteers underwent 3-dimensional (3D) fast spoiled gradient echo (FSPGR) sequence scanning on 3.0 Tesla MR system. Raw data was processed and analyzed using statistical parametric mapping (SPM) 5. Whole brain volumes included grey matter volume (GMV), white matter volume (WMV), total intracranial volume (TIV), grey matter fraction (GMF), white matter fraction (WMF), brain tissue fraction (BTF) and regional brain volumes between the two groups were compared by independent samples t-test and an Pearson were performed to compare the regional brain volumes and the ages. Results: GMV of NMO group [(610.2±55.0) ml] was significantly decreased comparing to healthy control group [(657.2±36.3) ml] (t=-2.915, P<0.05). The age of NMO patients [(40±9) years old] showed negative correlation with GMF [(42.5±2.6) %] (r=-0.673, P<0.05). Regional brain volume analysis showed decreased GMV in left insula and bilateral posterior cingutates in NMO patients, while decreased WMV was found in left frontal and left parietal white matter. Conclusion: VBM could detect brain volume changes sensitively. Total grey matter volume in NMO patients was decreased comparing to HC group. Regional grey matter atrophy in NMO patients occurred in left insular and bilateral posterior cingutates, regional white matter atrophy occurred in left frontal and left parietal lobe. (authors)

  17. MO-G-17A-03: MR-Based Cortical Bone Segmentation for PET Attenuation Correction with a Non-UTE 3D Fast GRE Sequence

    Purpose: To determine the feasibility of identifying cortical bone on MR images with a short-TE 3D fast-GRE sequence for attenuation correction of PET data in PET/MR. Methods: A water-fat-bone phantom was constructed with two pieces of beef shank. MR scans were performed on a 3T MR scanner (GE Discovery™ MR750). A 3D GRE sequence was first employed to measure the level of residual signal in cortical bone (TE1/TE2/TE3=2.2/4.4/6.6ms, TR=20ms, flip angle=25°). For cortical bone segmentation, a 3D fast-GRE sequence (TE/TR=0.7/1.9ms, acquisition voxel size=2.5×2.5×3mm3) was implemented along with a 3D Dixon sequence (TE1/TE2/TR=1.2/2.3/4.0ms, acquisition voxel size=1.25×1.25×3mm3) for water/fat imaging. Flip angle (10°), acquisition bandwidth (250kHz), FOV (480×480×144mm3) and reconstructed voxel size (0.94×0.94×1.5mm3) were kept the same for both sequences. Soft tissue and fat tissue were first segmented on the reconstructed water/fat image. A tissue mask was created by combining the segmented water/fat masks, which was then applied on the fast-GRE image (MRFGRE). A second mask was created to remove the Gibbs artifacts present in regions in close vicinity to the phantom. MRFGRE data was smoothed with a 3D anisotropic diffusion filter for noise reduction, after which cortical bone and air was separated using a threshold determined from the histogram. Results: There is signal in the cortical bone region in the 3D GRE images, indicating the possibility of separating cortical bone and air based on signal intensity from short-TE MR image. The acquisition time for the 3D fast-GRE sequence was 17s, which can be reduced to less than 10s with parallel imaging. The attenuation image created from water-fat-bone segmentation is visually similar compared to reference CT. Conclusion: Cortical bone and air can be separated based on intensity in MR image with a short-TE 3D fast-GRE sequence. Further research is required to optimize the strategy to reduce Gibbs artifacts

  18. MO-G-17A-03: MR-Based Cortical Bone Segmentation for PET Attenuation Correction with a Non-UTE 3D Fast GRE Sequence

    Ai, H; Pan, T [The University of Texas MD Anderson Cancer Center, Houston, TX (United States); The University of Texas Graduate School of Biomedical Science, Houston, TX (United States); Hwang, K [GE Healthcare, Houston, TX (United States)

    2014-06-15

    Purpose: To determine the feasibility of identifying cortical bone on MR images with a short-TE 3D fast-GRE sequence for attenuation correction of PET data in PET/MR. Methods: A water-fat-bone phantom was constructed with two pieces of beef shank. MR scans were performed on a 3T MR scanner (GE Discovery™ MR750). A 3D GRE sequence was first employed to measure the level of residual signal in cortical bone (TE{sub 1}/TE{sub 2}/TE{sub 3}=2.2/4.4/6.6ms, TR=20ms, flip angle=25°). For cortical bone segmentation, a 3D fast-GRE sequence (TE/TR=0.7/1.9ms, acquisition voxel size=2.5×2.5×3mm{sup 3}) was implemented along with a 3D Dixon sequence (TE{sub 1}/TE{sub 2}/TR=1.2/2.3/4.0ms, acquisition voxel size=1.25×1.25×3mm{sup 3}) for water/fat imaging. Flip angle (10°), acquisition bandwidth (250kHz), FOV (480×480×144mm{sup 3}) and reconstructed voxel size (0.94×0.94×1.5mm{sup 3}) were kept the same for both sequences. Soft tissue and fat tissue were first segmented on the reconstructed water/fat image. A tissue mask was created by combining the segmented water/fat masks, which was then applied on the fast-GRE image (MRFGRE). A second mask was created to remove the Gibbs artifacts present in regions in close vicinity to the phantom. MRFGRE data was smoothed with a 3D anisotropic diffusion filter for noise reduction, after which cortical bone and air was separated using a threshold determined from the histogram. Results: There is signal in the cortical bone region in the 3D GRE images, indicating the possibility of separating cortical bone and air based on signal intensity from short-TE MR image. The acquisition time for the 3D fast-GRE sequence was 17s, which can be reduced to less than 10s with parallel imaging. The attenuation image created from water-fat-bone segmentation is visually similar compared to reference CT. Conclusion: Cortical bone and air can be separated based on intensity in MR image with a short-TE 3D fast-GRE sequence. Further research is required

  19. The Relevance Voxel Machine (RVoxM): A Bayesian Method for Image-Based Prediction

    Sabuncu, Mert R.; Van Leemput, Koen

    2011-01-01

    This paper presents the Relevance VoxelMachine (RVoxM), a Bayesian multivariate pattern analysis (MVPA) algorithm that is specifically designed for making predictions based on image data. In contrast to generic MVPA algorithms that have often been used for this purpose, the method is designed to...

  20. Structural covariance in the hallucinating brain : a voxel-based morphometry study

    Modinos, Gemma; Vercammen, Ans; Mechelli, Andrea; Knegtering, Henderikus; McGuire, Philip K.; Aleman, Andre

    2009-01-01

    Background: Neuroimaging studies have indicated that a number of cortical regions express altered patterns of structural covariance in schizophrenia. The relation between these alterations and specific psychotic symptoms is yet to be investigated. We used voxel-based morphometry to examine regional

  1. Anatomical specificity of vascular endothelial growth factor expression in glioblastomas: a voxel-based mapping analysis

    Fan, Xing [Capital Medical University, Department of Neurosurgery, Beijing Tiantan Hospital, Beijing (China); Wang, Yinyan [Capital Medical University, Department of Neurosurgery, Beijing Tiantan Hospital, Beijing (China); Capital Medical University, Department of Neuropathology, Beijing Neurosurgical Institute, Beijing (China); Wang, Kai; Ma, Jun; Li, Shaowu [Capital Medical University, Department of Neuroradiology, Beijing Tiantan Hospital, Beijing (China); Liu, Shuai [Chinese Academy of Medical Sciences and Peking Union Medical College, Departments of Neurosurgery, Peking Union Medical College Hospital, Beijing (China); Liu, Yong [Chinese Academy of Sciences, Brainnetome Center, Institute of Automation, Beijing (China); Jiang, Tao [Capital Medical University, Department of Neurosurgery, Beijing Tiantan Hospital, Beijing (China); Beijing Academy of Critical Illness in Brain, Department of Clinical Oncology, Beijing (China)

    2016-01-15

    The expression of vascular endothelial growth factor (VEGF) is a common genetic alteration in malignant gliomas and contributes to the angiogenesis of tumors. This study aimed to investigate the anatomical specificity of VEGF expression levels in glioblastomas using voxel-based neuroimaging analysis. Clinical information, MR scans, and immunohistochemistry stains of 209 patients with glioblastomas were reviewed. All tumor lesions were segmented manually and subsequently registered to standard brain space. Voxel-based regression analysis was performed to correlate the brain regions of tumor involvement with the level of VEGF expression. Brain regions identified as significantly associated with high or low VEGF expression were preserved following permutation correction. High VEGF expression was detected in 123 (58.9 %) of the 209 patients. Voxel-based statistical analysis demonstrated that high VEGF expression was more likely in tumors located in the left frontal lobe and the right caudate and low VEGF expression was more likely in tumors that occurred in the posterior region of the right lateral ventricle. Voxel-based neuroimaging analysis revealed the anatomic specificity of VEGF expression in glioblastoma, which may further our understanding of genetic heterogeneity during tumor origination. This finding provides primary theoretical support for potential future application of customized antiangiogenic therapy. (orig.)

  2. Anatomical specificity of vascular endothelial growth factor expression in glioblastomas: a voxel-based mapping analysis

    The expression of vascular endothelial growth factor (VEGF) is a common genetic alteration in malignant gliomas and contributes to the angiogenesis of tumors. This study aimed to investigate the anatomical specificity of VEGF expression levels in glioblastomas using voxel-based neuroimaging analysis. Clinical information, MR scans, and immunohistochemistry stains of 209 patients with glioblastomas were reviewed. All tumor lesions were segmented manually and subsequently registered to standard brain space. Voxel-based regression analysis was performed to correlate the brain regions of tumor involvement with the level of VEGF expression. Brain regions identified as significantly associated with high or low VEGF expression were preserved following permutation correction. High VEGF expression was detected in 123 (58.9 %) of the 209 patients. Voxel-based statistical analysis demonstrated that high VEGF expression was more likely in tumors located in the left frontal lobe and the right caudate and low VEGF expression was more likely in tumors that occurred in the posterior region of the right lateral ventricle. Voxel-based neuroimaging analysis revealed the anatomic specificity of VEGF expression in glioblastoma, which may further our understanding of genetic heterogeneity during tumor origination. This finding provides primary theoretical support for potential future application of customized antiangiogenic therapy. (orig.)

  3. Voxel based statistical analysis method for microPET studies to assess the cerebral glucose metabolism in cat deafness model: comparison to ROI based method

    Imaging research on the brain of sensory-deprived cats using small animal PET scanner has gained interest since the abundant information about the sensory system of ths animal is available and close examination of the brain is possible due to larger size of its brain than mouse or rat. In this study, we have established the procedures for 3D voxel-based statistical analysis (SPM) of FDG PET image of cat brain, and confirmed using ROI based-method. FDG PET scans of 4 normal and 4 deaf cats were acquired for 30 minutes using microPET R4 scanner. Only the brain cortices were extracted using a masking and threshold method to facilitate spatial normalization. After spatial normalization and smoothing, 3D voxel-wise and ROI based t-test were performed to identify the regions with significant different FDG uptake between the normal and deaf cats. In ROI analysis, 26 ROIs were drawn on both hemispheres, and regional mean pixel value in each ROI was normalized to the global mean of the brain. Cat brains were spatially normalized well onto the target brain due to the removal of background activity. When cerebral glucose metabolism of deaf cats were compared to the normal controls after removing the effects of the global count, the glucose metabolism in the auditory cortex, head of caudate nucleus, and thalamus in both hemispheres of the deaf cats was significantly lower than that of the controls (P<0.01). No area showed a significantly increased metabolism in the deaf cats even in higher significance level (P<0.05). ROI analysis also showed significant reduction of glucose metabolism in the same region. This study established and confirmed a method for voxel-based analysis of animal PET data of cat brain, which showed high localization accuracy and specificity and was useful for examining the cerebral glucose metabolism in a cat cortical deafness model

  4. Voxel based statistical analysis method for microPET studies to assess the cerebral glucose metabolism in cat deafness model: comparison to ROI based method

    Kim, Jin Su; Lee, Jae Sung; Park, Min Hyun; Lee, Jong Jin; Kang, Hye Jin; Lee, Hyo Jeong; Oh, Seung Ha; Kim, Chong Sun; Jung, June Key; Lee, Myung Chul; Lee, Dong Soo [Seoul National University College of Medicine, Seoul (Korea, Republic of); Lim, Sang Moo [KIRAMS, Seoul (Korea, Republic of)

    2005-07-01

    Imaging research on the brain of sensory-deprived cats using small animal PET scanner has gained interest since the abundant information about the sensory system of ths animal is available and close examination of the brain is possible due to larger size of its brain than mouse or rat. In this study, we have established the procedures for 3D voxel-based statistical analysis (SPM) of FDG PET image of cat brain, and confirmed using ROI based-method. FDG PET scans of 4 normal and 4 deaf cats were acquired for 30 minutes using microPET R4 scanner. Only the brain cortices were extracted using a masking and threshold method to facilitate spatial normalization. After spatial normalization and smoothing, 3D voxel-wise and ROI based t-test were performed to identify the regions with significant different FDG uptake between the normal and deaf cats. In ROI analysis, 26 ROIs were drawn on both hemispheres, and regional mean pixel value in each ROI was normalized to the global mean of the brain. Cat brains were spatially normalized well onto the target brain due to the removal of background activity. When cerebral glucose metabolism of deaf cats were compared to the normal controls after removing the effects of the global count, the glucose metabolism in the auditory cortex, head of caudate nucleus, and thalamus in both hemispheres of the deaf cats was significantly lower than that of the controls (P<0.01). No area showed a significantly increased metabolism in the deaf cats even in higher significance level (P<0.05). ROI analysis also showed significant reduction of glucose metabolism in the same region. This study established and confirmed a method for voxel-based analysis of animal PET data of cat brain, which showed high localization accuracy and specificity and was useful for examining the cerebral glucose metabolism in a cat cortical deafness model.

  5. An automated voxelized dosimetry tool for radionuclide therapy based on serial quantitative SPECT/CT imaging

    Jackson, Price A.; Kron, Tomas [Department of Physical Sciences, Peter MacCallum Cancer Centre, East Melbourne 3002 (Australia); Beauregard, Jean-Mathieu [Department of Radiology, Université Laval, Quebec City G1V 0A6 (Canada); Hofman, Michael S.; Hogg, Annette; Hicks, Rodney J. [Department of Molecular Imaging, Peter MacCallum Cancer Centre, East Melbourne 3002 (Australia)

    2013-11-15

    Purpose: To create an accurate map of the distribution of radiation dose deposition in healthy and target tissues during radionuclide therapy.Methods: Serial quantitative SPECT/CT images were acquired at 4, 24, and 72 h for 28 {sup 177}Lu-octreotate peptide receptor radionuclide therapy (PRRT) administrations in 17 patients with advanced neuroendocrine tumors. Deformable image registration was combined with an in-house programming algorithm to interpolate pharmacokinetic uptake and clearance at a voxel level. The resultant cumulated activity image series are comprised of values representing the total number of decays within each voxel's volume. For PRRT, cumulated activity was translated to absorbed dose based on Monte Carlo-determined voxel S-values at a combination of long and short ranges. These dosimetric image sets were compared for mean radiation absorbed dose to at-risk organs using a conventional MIRD protocol (OLINDA 1.1).Results: Absorbed dose values to solid organs (liver, kidneys, and spleen) were within 10% using both techniques. Dose estimates to marrow were greater using the voxelized protocol, attributed to the software incorporating crossfire effect from nearby tumor volumes.Conclusions: The technique presented offers an efficient, automated tool for PRRT dosimetry based on serial post-therapy imaging. Following retrospective analysis, this method of high-resolution dosimetry may allow physicians to prescribe activity based on required dose to tumor volume or radiation limits to healthy tissue in individual patients.

  6. SU-E-J-01: 3D Fluoroscopic Image Estimation From Patient-Specific 4DCBCT-Based Motion Models

    Purpose: 3D motion modeling derived from 4DCT images, taken days or weeks before treatment, cannot reliably represent patient anatomy on the day of treatment. We develop a method to generate motion models based on 4DCBCT acquired at the time of treatment, and apply the model to estimate 3D time-varying images (referred to as 3D fluoroscopic images). Methods: Motion models are derived through deformable registration between each 4DCBCT phase, and principal component analysis (PCA) on the resulting displacement vector fields. 3D fluoroscopic images are estimated based on cone-beam projections simulating kV treatment imaging. PCA coefficients are optimized iteratively through comparison of these cone-beam projections and projections estimated based on the motion model. Digital phantoms reproducing ten patient motion trajectories, and a physical phantom with regular and irregular motion derived from measured patient trajectories, are used to evaluate the method in terms of tumor localization, and the global voxel intensity difference compared to ground truth. Results: Experiments included: 1) assuming no anatomic or positioning changes between 4DCT and treatment time; and 2) simulating positioning and tumor baseline shifts at the time of treatment compared to 4DCT acquisition. 4DCBCT were reconstructed from the anatomy as seen at treatment time. In case 1) the tumor localization error and the intensity differences in ten patient were smaller using 4DCT-based motion model, possible due to superior image quality. In case 2) the tumor localization error and intensity differences were 2.85 and 0.15 respectively, using 4DCT-based motion models, and 1.17 and 0.10 using 4DCBCT-based models. 4DCBCT performed better due to its ability to reproduce daily anatomical changes. Conclusion: The study showed an advantage of 4DCBCT-based motion models in the context of 3D fluoroscopic images estimation. Positioning and tumor baseline shift uncertainties were mitigated by the 4DCBCT-based

  7. Content-based similarity for 3D model retrieval and classification

    Ke Lü; Ning He; Jian Xue

    2009-01-01

    With the rapid development of 3D digital shape information,content-based 3D model retrieval and classification has become an important research area.This paper presents a novel 3D model retrieval and classification algorithm.For feature representation,a method combining a distance histogram and moment invariants is proposed to improve the retrieval performance.The major advantage of using a distance histogram is its invariance to the transforms of scaling,translation and rotation.Based on the premise that two similar objects should have high mutual information,the querying of 3D data should convey a great deal of information on the shape of the two objects,and so we propose a mutual information distance measurement to perform the similarity comparison of 3D objects.The proposed algorithm is tested with a 3D model retrieval and classification prototype,and the experimental evaluation demonstrates satisfactory retrieval results and classification accuracy.

  8. DPGL: The Direct3D9-based Parallel Graphics Library for Multi-display Environment

    Zhen Liu; Jiao-Ying Shi

    2007-01-01

    The emergence of high performance 3D graphics cards has opened the way to PC clusters for high performance multidisplay environment. In order to exploit the rendering ability of PC clusters, we should design appropriate parallel rendering algorithms and parallel graphics library interfaces. Due to the rapid development of Direct3D, we bring forward DPGL, the Direct3D9-based parallel graphics library in D3DPR parallel rendering system, which implements Direct3D9 interfaces to support existing Direct3D9 application parallelization with no modification. Based on the parallelism analysis of Direct3D9 rendering pipeline, we briefly introduce D3DPR parallel rendering system. DPGL is the fundamental component of D3DPR. After presenting DPGL three layers architecture,we discuss the rendering resource interception and management. Finally, we describe the design and implementation of DPGL in detail,including rendering command interception layer, rendering command interpretation layer and rendering resource parallelization layer.

  9. 3D Keypoint Detection Based on Deep Neural Network with Sparse Autoencoder

    Lin, Xinyu; Zhu, Ce; Zhang, Qian; Liu, Yipeng

    2016-01-01

    Researchers have proposed various methods to extract 3D keypoints from the surface of 3D mesh models over the last decades, but most of them are based on geometric methods, which lack enough flexibility to meet the requirements for various applications. In this paper, we propose a new method on the basis of deep learning by formulating the 3D keypoint detection as a regression problem using deep neural network (DNN) with sparse autoencoder (SAE) as our regression model. Both local information...

  10. Single view-based 3D face reconstruction robust to self-occlusion

    Lee, Youn Joo; Lee, Sung Joo; Park, Kang Ryoung; Jo, Jaeik; Kim, Jaihie

    2012-12-01

    State-of-the-art 3D morphable model (3DMM) is used widely for 3D face reconstruction based on a single image. However, this method has a high computational cost, and hence, a simplified 3D morphable model (S3DMM) was proposed as an alternative. Unlike the original 3DMM, S3DMM uses only a sparse 3D facial shape, and therefore, it incurs a lower computational cost. However, this method is vulnerable to self-occlusion due to head rotation. Therefore, we propose a solution to the self-occlusion problem in S3DMM-based 3D face reconstruction. This research is novel compared with previous works, in the following three respects. First, self-occlusion of the input face is detected automatically by estimating the head pose using a cylindrical head model. Second, a 3D model fitting scheme is designed based on selected visible facial feature points, which facilitates 3D face reconstruction without any effect from self-occlusion. Third, the reconstruction performance is enhanced by using the estimated pose as the initial pose parameter during the 3D model fitting process. The experimental results showed that the self-occlusion detection had high accuracy and our proposed method delivered a noticeable improvement in the 3D face reconstruction performance compared with previous methods.

  11. Volumetric 3D Display System with Static Screen

    Geng, Jason

    2011-01-01

    Current display technology has relied on flat, 2D screens that cannot truly convey the third dimension of visual information: depth. In contrast to conventional visualization that is primarily based on 2D flat screens, the volumetric 3D display possesses a true 3D display volume, and places physically each 3D voxel in displayed 3D images at the true 3D (x,y,z) spatial position. Each voxel, analogous to a pixel in a 2D image, emits light from that position to form a real 3D image in the eyes of the viewers. Such true volumetric 3D display technology provides both physiological (accommodation, convergence, binocular disparity, and motion parallax) and psychological (image size, linear perspective, shading, brightness, etc.) depth cues to human visual systems to help in the perception of 3D objects. In a volumetric 3D display, viewers can watch the displayed 3D images from a completely 360 view without using any special eyewear. The volumetric 3D display techniques may lead to a quantum leap in information display technology and can dramatically change the ways humans interact with computers, which can lead to significant improvements in the efficiency of learning and knowledge management processes. Within a block of glass, a large amount of tiny dots of voxels are created by using a recently available machining technique called laser subsurface engraving (LSE). The LSE is able to produce tiny physical crack points (as small as 0.05 mm in diameter) at any (x,y,z) location within the cube of transparent material. The crack dots, when illuminated by a light source, scatter the light around and form visible voxels within the 3D volume. The locations of these tiny voxels are strategically determined such that each can be illuminated by a light ray from a high-resolution digital mirror device (DMD) light engine. The distribution of these voxels occupies the full display volume within the static 3D glass screen. This design eliminates any moving screen seen in previous

  12. A cross-platform solution for light field based 3D telemedicine.

    Wang, Gengkun; Xiang, Wei; Pickering, Mark

    2016-03-01

    Current telehealth services are dominated by conventional 2D video conferencing systems, which are limited in their capabilities in providing a satisfactory communication experience due to the lack of realism. The "immersiveness" provided by 3D technologies has the potential to promote telehealth services to a wider range of applications. However, conventional stereoscopic 3D technologies are deficient in many aspects, including low resolution and the requirement for complicated multi-camera setup and calibration, and special glasses. The advent of light field (LF) photography enables us to record light rays in a single shot and provide glasses-free 3D display with continuous motion parallax in a wide viewing zone, which is ideally suited for 3D telehealth applications. As far as our literature review suggests, there have been no reports of 3D telemedicine systems using LF technology. In this paper, we propose a cross-platform solution for a LF-based 3D telemedicine system. Firstly, a novel system architecture based on LF technology is established, which is able to capture the LF of a patient, and provide an immersive 3D display at the doctor site. For 3D modeling, we further propose an algorithm which is able to convert the captured LF to a 3D model with a high level of detail. For the software implementation on different platforms (i.e., desktop, web-based and mobile phone platforms), a cross-platform solution is proposed. Demo applications have been developed for 2D/3D video conferencing, 3D model display and edit, blood pressure and heart rate monitoring, and patient data viewing functions. The demo software can be extended to multi-discipline telehealth applications, such as tele-dentistry, tele-wound and tele-psychiatry. The proposed 3D telemedicine solution has the potential to revolutionize next-generation telemedicine technologies by providing a high quality immersive tele-consultation experience. PMID:26689324

  13. Geofencing-Based Localization for 3d Data Acquisition Navigation

    Nakagawa, M.; Kamio, T.; Yasojima, H.; Kobayashi, T.

    2016-06-01

    Users require navigation for many location-based applications using moving sensors, such as autonomous robot control, mapping route navigation and mobile infrastructure inspection. In indoor environments, indoor positioning systems using GNSSs can provide seamless indoor-outdoor positioning and navigation services. However, instabilities in sensor position data acquisition remain, because the indoor environment is more complex than the outdoor environment. On the other hand, simultaneous localization and mapping processing is better than indoor positioning for measurement accuracy and sensor cost. However, it is not easy to estimate position data from a single viewpoint directly. Based on these technical issues, we focus on geofencing techniques to improve position data acquisition. In this research, we propose a methodology to estimate more stable position or location data using unstable position data based on geofencing in indoor environments. We verify our methodology through experiments in indoor environments.

  14. A new approach towards image based virtual 3D city modeling by using close range photogrammetry

    Singh, S. P.; Jain, K.; Mandla, V. R.

    2014-05-01

    3D city model is a digital representation of the Earth's surface and it's related objects such as building, tree, vegetation, and some manmade feature belonging to urban area. The demand of 3D city modeling is increasing day to day for various engineering and non-engineering applications. Generally three main image based approaches are using for virtual 3D city models generation. In first approach, researchers used Sketch based modeling, second method is Procedural grammar based modeling and third approach is Close range photogrammetry based modeling. Literature study shows that till date, there is no complete solution available to create complete 3D city model by using images. These image based methods also have limitations This paper gives a new approach towards image based virtual 3D city modeling by using close range photogrammetry. This approach is divided into three sections. First, data acquisition process, second is 3D data processing, and third is data combination process. In data acquisition process, a multi-camera setup developed and used for video recording of an area. Image frames created from video data. Minimum required and suitable video image frame selected for 3D processing. In second section, based on close range photogrammetric principles and computer vision techniques, 3D model of area created. In third section, this 3D model exported to adding and merging of other pieces of large area. Scaling and alignment of 3D model was done. After applying the texturing and rendering on this model, a final photo-realistic textured 3D model created. This 3D model transferred into walk-through model or in movie form. Most of the processing steps are automatic. So this method is cost effective and less laborious. Accuracy of this model is good. For this research work, study area is the campus of department of civil engineering, Indian Institute of Technology, Roorkee. This campus acts as a prototype for city. Aerial photography is restricted in many country

  15. ICER-3D: A Progressive Wavelet-Based Compressor for Hyperspectral Images

    Kiely, A.; Klimesh, M.; Xie, H.; Aranki, N.

    2005-01-01

    ICER-3D is a progressive, wavelet-based compressor for hyperspectral images. ICER-3D is derived from the ICER image compressor. ICER-3D can provide lossless and lossy compression, and incorporates an error-containment scheme to limit the effects of data loss during transmission. The three-dimensional wavelet decomposition structure used by ICER-3D exploits correlations in all three dimensions of hyperspectral data sets, while facilitating elimination of spectral ringing artifacts. Correlation is further exploited by a context modeler that effectively exploits spectral dependencies in the wavelet-transformed hyperspectral data. Performance results illustrating the benefits of these features are presented.

  16. Future of photorefractive based holographic 3D display

    Blanche, P.-A.; Bablumian, A.; Voorakaranam, R.; Christenson, C.; Lemieux, D.; Thomas, J.; Norwood, R. A.; Yamamoto, M.; Peyghambarian, N.

    2010-02-01

    The very first demonstration of our refreshable holographic display based on photorefractive polymer was published in Nature early 20081. Based on the unique properties of a new organic photorefractive material and the holographic stereography technique, this display addressed a gap between large static holograms printed in permanent media (photopolymers) and small real time holographic systems like the MIT holovideo. Applications range from medical imaging to refreshable maps and advertisement. Here we are presenting several technical solutions for improving the performance parameters of the initial display from an optical point of view. Full color holograms can be generated thanks to angular multiplexing, the recording time can be reduced from minutes to seconds with a pulsed laser, and full parallax hologram can be recorded in a reasonable time thanks to parallel writing. We also discuss the future of such a display and the possibility of video rate.

  17. 3D Surface Editing Based on Level-Sets

    Lin Maosong; Zhang Dianhua

    2005-01-01

    A novel method which integrates the topological flexibility of the level-set approach and the simphcity of point-sampled surfaces is proposed. The grid structure resulted from the level-set approach not only offers a wide range of powerful surface editing techniques for the point set surface editing, but also facilitates the topological change with ease. With the aid of point-based resampling,the method updates the surface shape of the point-based geometry quickly without worrying about point connectivity at all. The point set surface can also change its topology properly whenever a collision with other parts of itself is detected. The experiment demonstrates their effectiveness on several scanned objects and scan-converted models. Four examples of surface editing operations: smoothing, tapering, deforming, and Boolean operations, are presented.

  18. Status and perspectives of pixel sensors based on 3D vertical integration

    This paper reviews the most recent developments of 3D integration in the field of silicon pixel sensors and readout integrated circuits. This technology may address the needs of future high energy physics and photon science experiments by increasing the electronic functional density in small pixel readout cells and by stacking various device layers based on different technologies, each optimized for a different function. Current efforts are aimed at improving the performance of both hybrid pixel detectors and of CMOS sensors. The status of these activities is discussed here, taking into account experimental results on 3D devices developed in the frame of the 3D-IC consortium. The paper also provides an overview of the ideas that are being currently devised for novel 3D vertically integrated pixel sensors. - Highlights: • 3D integration is a promising technology for pixel sensors in high energy physics. • Experimental results on two-layer 3D CMOS pixel sensors are presented. • The outcome of the first run from the 3D-IC consortium is discussed. • The AIDA network is studying via-last 3D integration of heterogeneous layers. • New ideas based on 3D vertically integrated pixels are being developed for HEP

  19. The Martian Water Cycle Based on 3-D Modeling

    Houben, H.; Haberle, R. M.; Joshi, M. M.

    1999-01-01

    Understanding the distribution of Martian water is a major goal of the Mars Surveyor program. However, until the bulk of the data from the nominal missions of TES, PMIRR, GRS, MVACS, and the DS2 probes are available, we are bound to be in a state where much of our knowledge of the seasonal behavior of water is based on theoretical modeling. We therefore summarize the results of this modeling at the present time. The most complete calculations come from a somewhat simplified treatment of the Martian climate system which is capable of simulating many decades of weather. More elaborate meteorological models are now being applied to study of the problem. The results show a high degree of consistency with observations of aspects of the Martian water cycle made by Viking MAWD, a large number of ground-based measurements of atmospheric column water vapor, studies of Martian frosts, and the widespread occurrence of water ice clouds. Additional information is contained in the original extended abstract.

  20. Depth-based Multi-View 3D Video Coding

    Zamarin, Marco

    improved, both in terms of objective and visual evaluations. Depth coding based on standard H.264/AVC is explored for multi-view plus depth image coding. A single depth map is used to disparity-compensate multiple views and allow more efficient coding than H.264 MVC at low bit rates. Lossless coding of...... number of standard solutions for lossless coding. New approaches for distributed video-plus-depth coding are also presented in this thesis. Motion correlation between the two signals is exploited at the decoder side to improve the performance of the side information generation algorithm. In addition...... on edge-preserving solutions. In a proposed scheme, texture-depth correlation is exploited to predict surface shapes in the depth signal. In this way depth coding performance can be improved in terms of both compression gain and edge-preservation. Another solution proposes a new intra coding mode...

  1. 3D downscaling model for radar-based precipitation fields

    Llort, X.; Berenguer, M.; Franco, M.; Sanchez-Diezma, R.; Sempere-Torres, D. [Grup de Recerca Aplicada en Hidrometeorologia, Univ. Politecnica de Catalunya (Spain)

    2006-10-15

    The generating of rainfall fields with a higher resolution than so far observed and with realistic features is a challenge with multiple applications. In particular it could be useful to quantify the uncertainty introduced by the different sources of error affecting radar measurements, in a controlled simulation framework. This paper proposes a method to generate three-dimensional high-resolution rainfall fields based on downscaling meteorological radar data. The technique performs a scale analysis of the first radar tilt field combining a wavelet model with Fourier analysis. In order to downscale the upper radar elevations and with the aim of preserving the vertical structure, a homotopy of the observed vertical profiles of reflectivity is performed. Preliminary evaluation of the technique shows that it is able to generate realistic extreme values and, at the same time, partially reproduce the structure of small scales. (orig.)

  2. Literary and Historical 3D Digital Game-Based Learning: Design Guidelines

    Neville, David O.; Shelton, Brett E.

    2010-01-01

    As 3D digital game-based learning (3D-DGBL) for the teaching of literature and history gradually gains acceptance, important questions will need to be asked regarding its method of design, development, and deployment. This article offers a synthesis of contemporary pedagogical, instructional design, new media, and literary-historical theories to…

  3. Point Cloud Data Conversion into Solid Models via Point-Based Voxelization

    Hinks, Tommy; Carr, Hamish; Truong-Hong, Linh; et al.

    2013-01-01

    Automated conversion of point cloud data from laser scanning into formats appropriate for structural engineering holds great promise for exploiting increasingly available aerially and terrestrially based pixelized data for a wide range of surveying-related applications from environmental modeling to disaster management. This paper introduces a point-based voxelization method to automatically transform point cloud data into solid models for computational modeling. The fundamental viability of ...

  4. Age and gender effects on normal regional cerebral blood flow studied using two different voxel-based statistical analyses

    Fully automated analysis programs have been applied more and more to aid for the reading of regional cerebral blood flow SPECT study. They are increasingly based on the comparison of the patient study with a normal database. In this study, we evaluate the ability of Three-Dimensional Stereotactic Surface Projection (3 D-S.S.P.) to isolate effects of age and gender in a previously studied normal population. The results were also compared with those obtained using Statistical Parametric Mapping (S.P.M.99). Methods Eighty-nine 99mTc-E.C.D.-SPECT studies performed in carefully screened healthy volunteers (46 females, 43 males; age 20 - 81 years) were analysed using 3 D-S.S.P.. A multivariate analysis based on the general linear model was performed with regions as intra-subject factor, gender as inter-subject factor and age as co-variate. Results Both age and gender had a significant interaction effect with regional tracer uptake. An age-related decline (p < 0.001) was found in the anterior cingulate gyrus, left frontal association cortex and left insula. Bilateral occipital association and left primary visual cortical uptake showed a significant relative increase with age (p < 0.001). Concerning the gender effect, women showed higher uptake (p < 0.01) in the parietal and right sensorimotor cortices. An age by gender interaction (p < 0.01) was only found in the left medial frontal cortex. The results were consistent with those obtained with S.P.M.99. Conclusion 3 D-S.S.P. analysis of normal r.C.B.F. variability is consistent with the literature and other automated voxel-based techniques, which highlight the effects of both age and gender. (authors)

  5. Effects of CT based Voxel Phantoms on Dose Distribution Calculated with Monte Carlo Method

    Chen Chaobin; Huang Qunying; Wu Yican

    2005-01-01

    A few CT-based voxel phantoms were produced to investigate the sensitivity of Monte Carlo simulations of X-ray beam and electron beam to the proportions of elements and the mass densities of the materials used to express the patient's anatomical structure. The human body can be well outlined by air, lung, adipose, muscle, soft bone and hard bone to calculate the dose distribution with Monte Carlo method. The effects of the calibration curves established by using various CT scanners are not clinically significant based on our investigation. The deviation from the values of cumulative dose volume histogram derived from CT-based voxel phantoms is less than 1% for the given target.

  6. Effects of CT based Voxel Phantoms on Dose Distribution Calculated with Monte Carlo Method

    Chen, Chaobin; Huang, Qunying; Wu, Yican

    2005-04-01

    A few CT-based voxel phantoms were produced to investigate the sensitivity of Monte Carlo simulations of x-ray beam and electron beam to the proportions of elements and the mass densities of the materials used to express the patient's anatomical structure. The human body can be well outlined by air, lung, adipose, muscle, soft bone and hard bone to calculate the dose distribution with Monte Carlo method. The effects of the calibration curves established by using various CT scanners are not clinically significant based on our investigation. The deviation from the values of cumulative dose volume histogram derived from CT-based voxel phantoms is less than 1% for the given target.

  7. 3D-TV System with Depth-Image-Based Rendering Architectures, Techniques and Challenges

    Zhao, Yin; Yu, Lu; Tanimoto, Masayuki

    2013-01-01

    Riding on the success of 3D cinema blockbusters and advances in stereoscopic display technology, 3D video applications have gathered momentum in recent years. 3D-TV System with Depth-Image-Based Rendering: Architectures, Techniques and Challenges surveys depth-image-based 3D-TV systems, which are expected to be put into applications in the near future. Depth-image-based rendering (DIBR) significantly enhances the 3D visual experience compared to stereoscopic systems currently in use. DIBR techniques make it possible to generate additional viewpoints using 3D warping techniques to adjust the perceived depth of stereoscopic videos and provide for auto-stereoscopic displays that do not require glasses for viewing the 3D image.   The material includes a technical review and literature survey of components and complete systems, solutions for technical issues, and implementation of prototypes. The book is organized into four sections: System Overview, Content Generation, Data Compression and Transmission, and 3D V...

  8. A modular cross-platform GPU-based approach for flexible 3D video playback

    Olsson, Roger; Andersson, Håkan; Sjöström, Mårten

    2011-03-01

    Different compression formats for stereo and multiview based 3D video is being standardized and software players capable of decoding and presenting these formats onto different display types is a vital part in the commercialization and evolution of 3D video. However, the number of publicly available software video players capable of decoding and playing multiview 3D video is still quite limited. This paper describes the design and implementation of a GPU-based real-time 3D video playback solution, built on top of cross-platform, open source libraries for video decoding and hardware accelerated graphics. A software architecture is presented that efficiently process and presents high definition 3D video in real-time and in a flexible manner support both current 3D video formats and emerging standards. Moreover, a set of bottlenecks in the processing of 3D video content in a GPU-based real-time 3D video playback solution is identified and discussed.

  9. Gray matter atrophy in patients with Parkinson’s disease and those with mild cognitive impairment: a voxel-based morphometry study

    Zhang, Jing; Zhang, Yun-ting; Hu, Wei-dong; Li, Li; Liu, Guang-Yao; Bai, Yu-Ping

    2015-01-01

    Purpose: Mild cognitive impairment is common in Parkinson’s disease, but the underlying pathological mechanism has not been fully understood. To examine the gray matter changes in patients with Parkinson’s disease and those with mild cognitive impairment (MCI) using voxel based Morphometry (VBM). Methods: Magnetic resonance images were obtained from 35 patients with PD and 20 age and sex-matched healthy control subjects. In the PD group, 14 subjects had no MCI and 21 had MCI. MRI 3D structura...

  10. Low-Complexity Multiple Description Coding of Video Based on 3D Block Transforms

    Andrey Norkin

    2007-02-01

    Full Text Available The paper presents a multiple description (MD video coder based on three-dimensional (3D transforms. Two balanced descriptions are created from a video sequence. In the encoder, video sequence is represented in a form of coarse sequence approximation (shaper included in both descriptions and residual sequence (details which is split between two descriptions. The shaper is obtained by block-wise pruned 3D-DCT. The residual sequence is coded by 3D-DCT or hybrid, LOT+DCT, 3D-transform. The coding scheme is targeted to mobile devices. It has low computational complexity and improved robustness of transmission over unreliable networks. The coder is able to work at very low redundancies. The coding scheme is simple, yet it outperforms some MD coders based on motion-compensated prediction, especially in the low-redundancy region. The margin is up to 3 dB for reconstruction from one description.

  11. 3D reconstruction of worn parts for flexible remanufacture based on robotic arc welding

    Yin Ziqiang; Zhang Guangjun; Gao Hongming; Wu Lin

    2010-01-01

    3D reconstruction of worn parts is the foundation for remanufacturing system based on robotic arc welding,because it can provide 3D geometric information for robot task plan.In this investigation,a nocwl 3D reconstruction system based on linear structured light vision sensing is developed,This system hardware consists of a MTC368-CB CCD camera,a MLH-645laser projector and a DH-CG300 image grabbing card.This system software is developed to control the image data capture.In order to reconstruct the 3D geometric information from the captured image,a two steps rapid calibration algorithm is proposed.The 3D reconstruction experiment shows a satisfactory result.

  12. 3D Digital Design of Cranes' Structures Based on Hybrid Software Architecture

    WANG Chonghua; LI Hua

    2006-01-01

    3D digital design for cranes' structures based on hybrid software architecture of Client/Server and Browser/Server is introduced in this paper. Based on Pro/ENGINEER platform, 3D parametric model family is built to allow generation of feasible configurations of cranes' structures in Client/Server framework. Taking use of Visual C++, the second exploiting software kit provided by Pro/ENGINEER and ANSYS GUI/APDL modeling patterns, an integration method of 3D CAD and CAE is achieved, which includes regeneration of 3D parametric model, synchronous updating and analysis of FEA model. As in Browser/Server framework, the 3D CAD models of parts, components and the whole structure could also be displayed in the customer's browser in VRML format.

  13. Atlas and feature based 3D pathway visualization enhancement for skull base pre-operative fast planning from head CT

    Aghdasi, Nava; Li, Yangming; Berens, Angelique; Moe, Kris S.; Bly, Randall A.; Hannaford, Blake

    2015-03-01

    Minimally invasive neuroendoscopic surgery provides an alternative to open craniotomy for many skull base lesions. These techniques provides a great benefit to the patient through shorter ICU stays, decreased post-operative pain and quicker return to baseline function. However, density of critical neurovascular structures at the skull base makes planning for these procedures highly complex. Furthermore, additional surgical portals are often used to improve visualization and instrument access, which adds to the complexity of pre-operative planning. Surgical approach planning is currently limited and typically involves review of 2D axial, coronal, and sagittal CT and MRI images. In addition, skull base surgeons manually change the visualization effect to review all possible approaches to the target lesion and achieve an optimal surgical plan. This cumbersome process relies heavily on surgeon experience and it does not allow for 3D visualization. In this paper, we describe a rapid pre-operative planning system for skull base surgery using the following two novel concepts: importance-based highlight and mobile portal. With this innovation, critical areas in the 3D CT model are highlighted based on segmentation results. Mobile portals allow surgeons to review multiple potential entry portals in real-time with improved visualization of critical structures located inside the pathway. To achieve this we used the following methods: (1) novel bone-only atlases were manually generated, (2) orbits and the center of the skull serve as features to quickly pre-align the patient's scan with the atlas, (3) deformable registration technique was used for fine alignment, (4) surgical importance was assigned to each voxel according to a surgical dictionary, and (5) pre-defined transfer function was applied to the processed data to highlight important structures. The proposed idea was fully implemented as independent planning software and additional data are used for verification and

  14. Midsagittal plane extraction from brain images based on 3D SIFT

    Midsagittal plane (MSP) extraction from 3D brain images is considered as a promising technique for human brain symmetry analysis. In this paper, we present a fast and robust MSP extraction method based on 3D scale-invariant feature transform (SIFT). Unlike the existing brain MSP extraction methods, which mainly rely on the gray similarity, 3D edge registration or parameterized surface matching to determine the fissure plane, our proposed method is based on distinctive 3D SIFT features, in which the fissure plane is determined by parallel 3D SIFT matching and iterative least-median of squares plane regression. By considering the relative scales, orientations and flipped descriptors between two 3D SIFT features, we propose a novel metric to measure the symmetry magnitude for 3D SIFT features. By clustering and indexing the extracted SIFT features using a k-dimensional tree (KD-tree) implemented on graphics processing units, we can match multiple pairs of 3D SIFT features in parallel and solve the optimal MSP on-the-fly. The proposed method is evaluated by synthetic and in vivo datasets, of normal and pathological cases, and validated by comparisons with the state-of-the-art methods. Experimental results demonstrated that our method has achieved a real-time performance with better accuracy yielding an average yaw angle error below 0.91° and an average roll angle error no more than 0.89°. (paper)

  15. Development and Implementation of a Web-Enabled 3D Consultation Tool for Breast Augmentation Surgery Based on 3D-Image Reconstruction of 2D Pictures

    de Heras Ciechomski, Pablo; Constantinescu, Mihai; Garcia, Jaime; Olariu, Radu; Dindoyal, Irving; Le Huu, Serge; Reyes, Mauricio

    2012-01-01

    Background Producing a rich, personalized Web-based consultation tool for plastic surgeons and patients is challenging. Objective (1) To develop a computer tool that allows individual reconstruction and simulation of 3-dimensional (3D) soft tissue from ordinary digital photos of breasts, (2) to implement a Web-based, worldwide-accessible preoperative surgical planning platform for plastic surgeons, and (3) to validate this tool through a quality control analysis by comparing 3D laser scans of...

  16. Investigating Structural Brain Changes of Dehydration Using Voxel-Based Morphometry

    Streitbürger, Daniel-Paolo; Möller, Harald E.; Tittgemeyer, Marc; Hund-Georgiadis, Margret; Matthias L Schroeter; Mueller, Karsten

    2012-01-01

    Dehydration can affect the volume of brain structures, which might imply a confound in volumetric and morphometric studies of normal or diseased brain. Six young, healthy volunteers were repeatedly investigated using three-dimensional T 1-weighted magnetic resonance imaging during states of normal hydration, hyperhydration, and dehydration to assess volume changes in gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF). The datasets were analyzed using voxel-based morphometry (V...

  17. Correlation between voxel based morphometry and manual volumetry in magnetic resonance images of the human brain

    Ricardo R. Uchida; Cristina M. Del-Ben; David Araújo; Geraldo Busatto-Filho; Duran, Fábio L.S.; Crippa, José A. S.; Graeff, Frederico G.

    2008-01-01

    This is a comparative study between manual volumetry (MV) and voxel based morphometry (VBM) as methods of evaluating the volume of brain structures in magnetic resonance images. The volumes of the hippocampus and the amygdala of 16 panic disorder patients and 16 healthy controls measured through MV were correlated with the volumes of gray matter estimated by optimized modulated VBM. The chosen structures are composed almost exclusively of gray matter. Using a 4 mm Gaussian filter, statistical...

  18. Diffuse Decreased Gray Matter in Patients with Idiopathic Craniocervical Dystonia: A Voxel-Based Morphometry Study

    Piccinin, Camila C.; Luiza G. Piovesana; Santos, Maria C. A.; Rachel P. Guimarães; Campos, Brunno M.; Rezende, Thiago J. R.; Campos, Lidiane S.; Torres, Fabio R.; Amato-Filho, Augusto C.; França, Marcondes C.; Lopes-Cendes, Iscia; Cendes, Fernando; D’Abreu, Anelyssa

    2015-01-01

    Background: Recent studies have addressed the role of structures other than the basal ganglia in the pathophysiology of craniocervical dystonia (CCD). Neuroimaging studies have attempted to identify structural abnormalities in CCD but a clear pattern of alteration has not been established. We performed whole-brain evaluation using voxel-based morphometry (VBM) to identify patterns of gray matter (GM) changes in CCD. Methods: We compared 27 patients with CCD matched in age and gender to 54 ...

  19. Meditation effects within the hippocampal complex revealed by voxel-based morphometry and cytoarchitectonic probabilistic mapping

    Luders, Eileen; Kurth, Florian; Toga, Arthur W.; Narr, Katherine L.; Gaser, Christian

    2013-01-01

    Scientific studies addressing anatomical variations in meditators' brains have emerged rapidly over the last few years, where significant links are most frequently reported with respect to gray matter (GM). To advance prior work, this study examined GM characteristics in a large sample of 100 subjects (50 meditators, 50 controls), where meditators have been practicing close to 20 years, on average. A standard, whole-brain voxel-based morphometry approach was applied and revealed significant m...

  20. Meditation effects within the hippocampal complex revealed by voxel-based morphometry and cytoarchitectonic probabilistic mapping

    Eileen eLuders; Florian eKurth; Toga, Arthur W.; Narr, Katherine L.; Christian eGaser

    2013-01-01

    Scientific studies addressing anatomical variations in meditators’ brains have emerged rapidly over the last few years, where significant links are most frequently reported with respect to gray matter (GM). To advance prior work, this study examined GM characteristics in a large sample of 100 subjects (50 meditators, 50 controls), where meditators have been practicing close to twenty years, on average. A standard, whole-brain voxel-based morphometry approach was applied and revealed significa...

  1. The Neuroanatomical Basis of Panic Disorder and Social Phobia in Schizophrenia: A Voxel Based Morphometric Study

    Picado Rossi, Marisol; Carmona Cañabate, Susana; Hoekzema, Elseline; Pailhez Vindual, Guillem; Bergé Baquero, Daniel; Mané, Anna; Fauquet Ars, Jordi; Hilferty, Joseph; Moreno, Ana; Cortizo, Romina; Vilarroya Oliver, Óscar; Bulbena Vilarrasa, Antonio

    2015-01-01

    Objective: It is known that there is a high prevalence of certain anxiety disorders among schizophrenic patients, especially panic disorder and social phobia. However, the neural underpinnings of the comorbidity of such anxiety disorders and schizophrenia remain unclear. Our study aims to determine the neuroanatomical basis of the co-occurrence of schizophrenia with panic disorder and social phobia. Methods: Voxel-based morphometry was used in order to examine brain structure and to measure b...

  2. The neuroanatomical basis of panic disorder and social phobia in schizophrenia: a voxel based morphometric study.

    Picado, Marisol; Carmona, Susanna; Hoekzema, Elseline; Pailhez, Guillem; Berg?? Baquero, Daniel; Man?? Santacana, Anna; Fauquet, Jordi; Hilferty, Joseph; Moreno, Ana; Cortizo Vidal, Romina; Vilarroya, ??scar; Bulbena Vilarrasa, Antonio

    2015-01-01

    OBJECTIVE: It is known that there is a high prevalence of certain anxiety disorders among schizophrenic patients, especially panic disorder and social phobia. However, the neural underpinnings of the comorbidity of such anxiety disorders and schizophrenia remain unclear. Our study aims to determine the neuroanatomical basis of the co-occurrence of schizophrenia with panic disorder and social phobia. METHODS: Voxel-based morphometry was used in order to examine brain structure and to measure b...

  3. Brain structure in post-traumatic stress disorder: A voxel-based morphometry analysis

    Tan, Liwen; Zhang, Li; Qi, Rongfeng; Lu, Guangming; Li, Lingjiang; Liu, Jun; Li, Weihui

    2013-01-01

    This study compared the difference in brain structure in 12 mine disaster survivors with chronic post-traumatic stress disorder, 7 cases of improved post-traumatic stress disorder symptoms, and 14 controls who experienced the same mine disaster but did not suffer post-traumatic stress disorder, using the voxel-based morphometry method. The correlation between differences in brain structure and post-traumatic stress disorder symptoms was also investigated. Results showed that the gray matter v...

  4. The National 3-D Geospatial Information Web-Based Service of Korea

    Lee, D. T.; Kim, C. W.; Kang, I. G.

    2013-09-01

    3D geospatial information systems should provide efficient spatial analysis tools and able to use all capabilities of the third dimension, and a visualization. Currently, many human activities make steps toward the third dimension like land use, urban and landscape planning, cadastre, environmental monitoring, transportation monitoring, real estate market, military applications, etc. To reflect this trend, the Korean government has been started to construct the 3D geospatial data and service platform. Since the geospatial information was introduced in Korea, the construction of geospatial information (3D geospatial information, digital maps, aerial photographs, ortho photographs, etc.) has been led by the central government. The purpose of this study is to introduce the Korean government-lead 3D geospatial information web-based service for the people who interested in this industry and we would like to introduce not only the present conditions of constructed 3D geospatial data but methodologies and applications of 3D geospatial information. About 15% (about 3,278.74 km2) of the total urban area's 3D geospatial data have been constructed by the national geographic information institute (NGII) of Korea from 2005 to 2012. Especially in six metropolitan cities and Dokdo (island belongs to Korea) on level of detail (LOD) 4 which is photo-realistic textured 3D models including corresponding ortho photographs were constructed in 2012. In this paper, we represented web-based 3D map service system composition and infrastructure and comparison of V-world with Google Earth service will be presented. We also represented Open API based service cases and discussed about the protection of location privacy when we construct 3D indoor building models. In order to prevent an invasion of privacy, we processed image blurring, elimination and camouflage. The importance of public-private cooperation and advanced geospatial information policy is emphasized in Korea. Thus, the progress of

  5. Do we need a voxel-based approach for LiDAR data in geomorphology?

    Székely, Balázs; Dorninger, Peter; Faber, Robert; Nothegger, Clemens

    2010-05-01

    Generations of geomorphologists have developed a multi-faceted approach to model the Earth's (and planetary) surface and the corresponding processes. This set of models is based on data, more specifically on conspicuously increasing amount of data. Obviously, all geomorphologists wish themselves more accurate and increasingly high resolution data on, or related to the Earth surface. This evolution also means that the studied boundary is not anymore a single surface; instead it is considered mostly a 2.5D object, sometimes a real 3D object. LiDAR technology can cope with this challenge: the data accuracy and resolution requirements can be fulfilled by applying this method. Although it is yet somewhat still expensive, more and more areas will be scanned, and in some regions the topographic point clouds are already multitemporal (causing of course other types of processing and evaluation problems). It is rather obvious that for certain, geomorphologically very interesting areas very dense and severalfold multitemporal LiDAR data will be available in the near future. These data sets will have various differences concerning the data density, accuracy, data acquisition technique (conventional or full-waveform), and perhaps most importantly, concerning the actual state of the surface. Similar to the satellite imagery integration problems, soon we all have to face with the LiDAR data integration problem. What type of surface or surfaces can be derived from this multitude of data sources with acceptable ambiguity? What conclusions can be drawn from these data that were originally acquired for various other purposes using various acquisition concepts? Will it be advantageous for geomorphic use to have a coverage of the surface with 100-200 points/m² density? Clearly, these data are, if they are once collected, still too expensive not to be integrated for further analyses. Consequently, we need a data reduction concept that effectively decreases the computer capacity needed

  6. Compression of 3D meshes based on a decomposition into singular vectors

    El Mostafa RAJAALLAH

    2016-06-01

    Full Text Available Compression of 3D meshes is an important operation for many applications involving transfer and storage of 3D objects data in their process, such as research by content and navigation in 3D objects databases. Compression is to reduce the space needed to store and/or display the 3D mesh. To do that, we usually try to project it in a frequency space where information is less correlated. The approach suggested in this work is based on a decomposition into singular vectors of the laplacian transform of the adjacency matrix of the vertices of the 3D mesh. The obtained results show the invariance of this approach to a normalization and very encouraging performance semantically.

  7. 3D graphene-based hybrid materials: synthesis and applications in energy storage and conversion.

    Shi, Qiurong; Cha, Younghwan; Song, Yang; Lee, Jung-In; Zhu, Chengzhou; Li, Xiaoyu; Song, Min-Kyu; Du, Dan; Lin, Yuehe

    2016-08-25

    Porous 3D graphene-based hybrid materials (3D GBHMs) are currently attractive nanomaterials employed in the field of energy. Heteroatom-doped 3D graphene and metal, metal oxide, and polymer-decorated 3D graphene with modified electronic and atomic structures provide promising performance as electrode materials in energy storage and conversion. Numerous synthesis methods such as self-assembly, templating, electrochemical deposition, and supercritical CO2, pave the way to mass production of 3D GBHMs in the commercialization of energy devices. This review summarizes recent advances in the fabrication of 3D GBHMs with well-defined architectures such as finely controlled pore sizes, heteroatom doping types and levels. Moreover, current progress toward applications in fuel cells, supercapacitors and batteries employing 3D GBHMs is also highlighted, along with the detailed mechanisms of the enhanced electrochemical performance. Furthermore, current critical issues, challenges and future prospects with respect to applications of 3D GBHMs in practical devices are discussed at the end of this review. PMID:27531643

  8. A Gaussian Mixture Model-Based Continuous Boundary Detection for 3D Sensor Networks

    Mitsuji Matsumoto

    2010-08-01

    Full Text Available This paper proposes a high precision Gaussian Mixture Model-based novel Boundary Detection 3D (BD3D scheme with reasonable implementation cost for 3D cases by selecting a minimum number of Boundary sensor Nodes (BNs in continuous moving objects. It shows apparent advantages in that two classes of boundary and non-boundary sensor nodes can be efficiently classified using the model selection techniques for finite mixture models; furthermore, the set of sensor readings within each sensor node’s spatial neighbors is formulated using a Gaussian Mixture Model; different from DECOMO [1] and COBOM [2], we also formatted a BN Array with an additional own sensor reading to benefit selecting Event BNs (EBNs and non-EBNs from the observations of BNs. In particular, we propose a Thick Section Model (TSM to solve the problem of transition between 2D and 3D. It is verified by simulations that the BD3D 2D model outperforms DECOMO and COBOM in terms of average residual energy and the number of BNs selected, while the BD3D 3D model demonstrates sound performance even for sensor networks with low densities especially when the value of the sensor transmission range (r is larger than the value of Section Thickness (d in TSM. We have also rigorously proved its correctness for continuous geometric domains and full robustness for sensor networks over 3D terrains.

  9. Virtual radiographies and images of homogeneous dose regions taken from human voxel-based models

    Full text: This work describes the properties of the Monte Carlo program MCvoxEL, developed in a graphic environment, that calculates absorbed dose distributions in voxel-based phantoms. The segmentation of organs and tissues is performed by painting tomographic images, and by assigning a different color to each organ or tissue of interest. Two voxel-based models (head-and-neck and chest) were built using this new approach. The way the voxels are stored in the RAM allows for a fast access of these data by the Monte Carlo code MCvoxEL. The graphical capabilities of the McvoxEL code facilitate image reconstruction with a graphical output of results, like visualized regions of absorbed fractions, specific absorbed fractions, absorbed dose per emitted particle, and absorbed dose per activity, presented under different points of view, thereby increasing the information to the user. Visualized specific absorbed fractions, virtual monoenergetic X-ray radiographs, and absorbed dose conversion coefficients for photon exposure are presented. (orig.)

  10. Binding affinity prediction of novel estrogen receptor ligands using receptor-based 3-D QSAR methods.

    Sippl, Wolfgang

    2002-12-01

    We have recently reported the development of a 3-D QSAR model for estrogen receptor ligands showing a significant correlation between calculated molecular interaction fields and experimentally measured binding affinity. The ligand alignment obtained from docking simulations was taken as basis for a comparative field analysis applying the GRID/GOLPE program. Using the interaction field derived with a water probe and applying the smart region definition (SRD) variable selection procedure, a significant and robust model was obtained (q(2)(LOO)=0.921, SDEP=0.345). To further analyze the robustness and the predictivity of the established model several recently developed estrogen receptor ligands were selected as external test set. An excellent agreement between predicted and experimental binding data was obtained indicated by an external SDEP of 0.531. Two other traditionally used prediction techniques were applied in order to check the performance of the receptor-based 3-D QSAR procedure. The interaction energies calculated on the basis of receptor-ligand complexes were correlated with experimentally observed affinities. Also ligand-based 3-D QSAR models were generated using program FlexS. The interaction energy-based model, as well as the ligand-based 3-D QSAR models yielded models with lower predictivity. The comparison with the interaction energy-based model and with the ligand-based 3-D QSAR models, respectively, indicates that the combination of receptor-based and 3-D QSAR methods is able to improve the quality of prediction. PMID:12413831

  11. Web-Based 3D and Haptic Interactive Environments for e-Learning, Simulation, and Training

    Hamza-Lup, Felix G.; Sopin, Ivan

    Knowledge creation occurs in the process of social interaction. As our service-based society is evolving into a knowledge-based society, there is an acute need for more effective collaboration and knowledge-sharing systems to be used by geographically scattered people. We present the use of 3D components and standards, such as Web3D, in combination with the haptic paradigm, for e-Learning and simulation.

  12. Simulation of Natural Scene Based on 3-D IFS Theory%基于3-D IFS理论的自然景观模拟

    王兴元; 刘波

    2003-01-01

    This article elaborates the theory of Iterated Function System (IFS)and gives the stochastic algorithm and the deterministic algorithm with which to construct IFS attractor. Based on the technique of coloring, lighting, shadow and mist in computer graphics, the authors construct a series of 3 dimension IFS (3-D IFS)characterized with the feature of natural scene on computer. The changing rules of the 3-D IFS are also discussed when the parameters mentioned above are changed.

  13. Construction and evaluation of F-18 FDG PET probabilistic MAP for voxel based analysis of the rat brain

    Im, K. C.; Kim, J. S.; Na, Y. S.; Moon, D. H.; Ryu, J. S. [Asan Medical Center, Seoul (Korea, Republic of)

    2007-07-01

    The purpose of this study was to develop F-18 FDG PET and MRI template for normal rat brain. Also, feasibility of SPM in detailed regional analysis of molecular changes in the rat brain was explored for F-18 FDG PET imaging of a model of traumatic brain injury (TBI). Ten normal rats were scanned with PET and MRI. The PET images were acquired with 3D mode using microPET focus 120 scanner after injection of 37 MBq F-18 FDG. T2-weighted MR images were acquired using 4.7T MRI system. A MRI-based spatial normalization was used. The PET images were coregistered to T2-weighted MR images. Maximum mutual information (MMI) registrations and affine spatial normalizations were performed using SPM2. The spatial normalization of the MRI to the standard MRI was applied to the integral images. The normalized PET images were averaged voxel wise to create PET template. Eight TBI model rats were subjected to a moderate lateral fluid percussion injury. At 2 days, 1 week, 3 weeks and 5 weeks post FPI, PET images of 8 TBI rats were acquired 4 times. TBI PET images were realigned, spatially normalized to a created PET-template and smoothed (8 mm FWHM). To assess the extent and severity of significant hypo metabolic lesions in TBI compared to normal controls were obtained by a two-sided t-test of SPM (uncorrected p < 0.001, 50 voxels). Visually acceptable PET and MRI templates were created. Registration errors were negligible when MMI procedure was used to register a translated or rotated image volume. Thirty-two PET studies of 8 TBI model subjects were obtained. SPM analysis showed injured distribution of decrease F-18 FDG uptake in TBI rats compared with normal rats. In SPM analysis, the extent and severity of significant hypo metabolic lesions were decreased according to a significant effect of time. At 5 weeks injured animals showed F-18 FDG uptake recovery using SPM analysis. These results indicate that voxel-based method will be useful for future longitudinal studies of rat brain.

  14. Evaluation of absorbed doses in voxel-based and simplified models for small animals

    Internal dosimetry in non-human biota is desirable from the viewpoint of radiation protection of the environment. The International Commission on Radiological Protection (ICRP) proposed Reference Animals and Plants using simplified models, such as ellipsoids and spheres and calculated absorbed fractions (AFs) for whole bodies. In this study, photon and electron AFs in whole bodies of voxel-based rat and frog models have been calculated and compared with AFs in the reference models. It was found that the voxel-based and the reference frog (or rat) models can be consistent for the whole-body AFs within a discrepancy of 25 %, as the source was uniformly distributed in the whole body. The specific absorbed fractions (SAFs) and S values were also evaluated in whole bodies and all organs of the voxel-based frog and rat models as the source was distributed in the whole body or skeleton. The results demonstrated that the whole-body SAFs reflect SAFs of all individual organs as the source was uniformly distributed per mass within the whole body by about 30 % uncertainties with exceptions for body contour (up to -40 %) for both electrons and photons due to enhanced radiation leakages, and for the skeleton for photons only (up to +185 %) due to differences in the mass attenuation coefficients. For nuclides such as 90Y and 90Sr, which were concentrated in the skeleton, there were large differences between S values in the whole body and those in individual organs, however the whole-body S values for the reference models with the whole body as the source were remarkably similar to those for the voxel-based models with the skeleton as the source, within about 4 and 0.3 %, respectively. It can be stated that whole-body SAFs or S values in simplified models without internal organs are not sufficient for accurate internal dosimetry because they do not reflect SAFs or S values of all individual organs as the source was not distributed uniformly in whole body. Thus, voxel-based models

  15. Automated Image-Based Procedures for Accurate Artifacts 3D Modeling and Orthoimage Generation

    Marc Pierrot-Deseilligny

    2011-12-01

    Full Text Available The accurate 3D documentation of architectures and heritages is getting very common and required in different application contexts. The potentialities of the image-based approach are nowadays very well-known but there is a lack of reliable, precise and flexible solutions, possibly open-source, which could be used for metric and accurate documentation or digital conservation and not only for simple visualization or web-based applications. The article presents a set of photogrammetric tools developed in order to derive accurate 3D point clouds and orthoimages for the digitization of archaeological and architectural objects. The aim is also to distribute free solutions (software, methodologies, guidelines, best practices, etc. based on 3D surveying and modeling experiences, useful in different application contexts (architecture, excavations, museum collections, heritage documentation, etc. and according to several representations needs (2D technical documentation, 3D reconstruction, web visualization, etc..

  16. A Log-Based 3D Model Retrieval Relevance Feedback Scheme Using Biased SVMs

    Zhiyong Zhang

    2010-12-01

    Full Text Available Retrieval relevance feedback is an iterative search technique to bridge the semantic gap between the high level user intention and low level data representation. This technique interactively determines a user's desired output or query concept by asking the user whether certain proposed 3D models are relevant or not. In the past, most research efforts in 3D model retrieval field have focused on designing algorithms for traditional relevance feedback. Given a 3D model retrieval system, it can collect and store users’ relevance feedback information in a history log, 3D model retrieval system can take advantage of the log data of users’ feedback to enhance its retrieval performance. In this paper, we propose a unified 3D model retrieval relevance feedback framework that integrates the log data into the traditional relevance feedback schemes to learn effectively the correlation between low-level 3D model features and high-level concepts. In this 3D model retrieval relevance feedback scheme, we use a learning technique for relevance feedback, named biased support vector machine based relevance feedback.  Experimental results show that this log-based scheme can achieves higher search accuracy than traditional query refinement schemes.  

  17. Large bulk-yard 3D measurement based on videogrammetry and projected contour aiding

    Ou, Jianliang; Zhang, Xiaohu; Yuan, Yun; Zhu, Xianwei

    2011-07-01

    Fast and accurate 3D measurement of large stack-yard is important job in bulk load-and-unload and logistics management. Stack-yard holds its special characteristics as: complex and irregular shape, single surface texture and low material reflectivity, thus its 3D measurement is quite difficult to be realized by traditional non-contacting methods, such as LiDAR(LIght Detecting And Ranging) and photogrammetry. Light-section is good at the measurement of small bulk-flow but not suitable for large-scale bulk-yard yet. In the paper, an improved method based on stereo cameras and laser-line projector is proposed. The due theoretical model is composed from such three key points: corresponding point of contour edge matching in stereo imagery based on gradient and epipolar-line constraint, 3D point-set calculating for stereo imagery projected-contour edge with least square adjustment and forward intersection, then the projected 3D-contour reconstructed by RANSAC(RANdom SAmpling Consensus) and contour spatial features from 3D point-set of single contour edge. In this way, stack-yard surface can be scanned easily by the laser-line projector, and certain region's 3D shape can be reconstructed automatically by stereo cameras on an observing position. Experiment proved the proposed method is effective for bulk-yard 3D measurement in fast, automatic, reliable and accurate way.

  18. Neuroanatomy of auditory verbal hallucinations in schizophrenia : A quantitative meta-analysis of voxel-based morphometry studies

    Modinos, Gemma; Costafreda, Sergi G.; van Tol, Marie-Jose; McGuire, Philip K.; Aleman, Andre; Allen, Paul

    2013-01-01

    Introduction: Voxel-based morphometry (VBM) studies demonstrate grey matter volume (GMV) deficits in schizophrenia. This method is also applied for detecting associations between specific psychotic symptoms and brain structure, such as auditory verbal hallucinations (AVHs). However, due to differing

  19. A novel 3D wavelet based filter for visualizing features in noisy biological data

    Moss, W C; Haase, S; Lyle, J M; Agard, D A; Sedat, J W

    2005-01-05

    We have developed a 3D wavelet-based filter for visualizing structural features in volumetric data. The only variable parameter is a characteristic linear size of the feature of interest. The filtered output contains only those regions that are correlated with the characteristic size, thus denoising the image. We demonstrate the use of the filter by applying it to 3D data from a variety of electron microscopy samples including low contrast vitreous ice cryogenic preparations, as well as 3D optical microscopy specimens.

  20. An adaptive grid algorithm for 3-D GIS landform optimization based on improved ant algorithm

    Wu, Chenhan; Meng, Lingkui; Deng, Shijun

    2005-07-01

    The key technique of 3-D GIS is to realize quick and high-quality 3-D visualization, in which 3-D roaming system based on landform plays an important role. However how to increase efficiency of 3-D roaming engine and process a large amount of landform data is a key problem in 3-D landform roaming system and improper process of the problem would result in tremendous consumption of system resources. Therefore it has become the key of 3-D roaming system design that how to realize high-speed process of distributed data for landform DEM (Digital Elevation Model) and high-speed distributed modulation of various 3-D landform data resources. In the paper we improved the basic ant algorithm and designed the modulation strategy of 3-D GIS landform resources based on the improved ant algorithm. By initially hypothetic road weights σi , the change of the information factors in the original algorithm would transform from ˜τj to ∆τj+σi and the weights was decided by 3-D computative capacity of various nodes in network environment. So during the course of initial phase of task assignment, increasing the resource information factors of high task-accomplishing rate and decreasing ones of low accomplishing rate would make load accomplishing rate approach the same value as quickly as possible, then in the later process of task assignment, the load balanced ability of the system was further improved. Experimental results show by improving ant algorithm, our system not only decreases many disadvantage of the traditional ant algorithm, but also like ants looking for food effectively distributes the complicated landform algorithm to many computers to process cooperatively and gains a satisfying search result.

  1. Quantitative Analysis and Modeling of 3-D TSV-Based Power Delivery Architectures

    He, Huanyu

    As 3-D technology enters the commercial production stage, it is critical to understand different 3-D power delivery architectures on the stacked ICs and packages with through-silicon vias (TSVs). Appropriate design, modeling, analysis, and optimization approaches of the 3-D power delivery system are of foremost significance and great practical interest to the semiconductor industry in general. Based on fundamental physics of 3-D integration components, the objective of this thesis work is to quantitatively analyze the power delivery for 3D-IC systems, develop appropriate physics-based models and simulation approaches, understand the key issues, and provide potential solutions for design of 3D-IC power delivery architectures. In this work, a hybrid simulation approach is adopted as the major approach along with analytical method to examine 3-D power networks. Combining electromagnetic (EM) tools and circuit simulators, the hybrid approach is able to analyze and model micrometer-scale components as well as centimeter-scale power delivery system with high accuracy and efficiency. The parasitic elements of the components on the power delivery can be precisely modeled by full-wave EM solvers. Stack-up circuit models for the 3-D power delivery networks (PDNs) are constructed through a partition and assembly method. With the efficiency advantage of the SPICE circuit simulation, the overall 3-D system power performance can be analyzed and the 3-D power delivery architectures can be evaluated in a short computing time. The major power delivery issues are the voltage drop (IR drop) and voltage noise. With a baseline of 3-D power delivery architecture, the on-chip PDNs of TSV-based chip stacks are modeled and analyzed for the IR drop and AC noise. The basic design factors are evaluated using the hybrid approach, such as the number of stacked chips, the number of TSVs, and the TSV arrangement. Analytical formulas are also developed to evaluate the IR drop in 3-D chip stack in

  2. 3D microporous base-functionalized covalent organic frameworks for size-selective catalysis.

    Fang, Qianrong; Gu, Shuang; Zheng, Jie; Zhuang, Zhongbin; Qiu, Shilun; Yan, Yushan

    2014-03-10

    The design and synthesis of 3D covalent organic frameworks (COFs) have been considered a challenge, and the demonstrated applications of 3D COFs have so far been limited to gas adsorption. Herein we describe the design and synthesis of two new 3D microporous base-functionalized COFs, termed BF-COF-1 and BF-COF-2, by the use of a tetrahedral alkyl amine, 1,3,5,7-tetraaminoadamantane (TAA), combined with 1,3,5-triformylbenzene (TFB) or triformylphloroglucinol (TFP). As catalysts, both BF-COFs showed remarkable conversion (96% for BF-COF-1 and 98% for BF-COF-2), high size selectivity, and good recyclability in base-catalyzed Knoevenagel condensation reactions. This study suggests that porous functionalized 3D COFs could be a promising new class of shape-selective catalysts. PMID:24604810

  3. Fast and Precise 3D Fluorophore Localization based on Gradient Fitting

    Ma, Hongqiang; Xu, Jianquan; Jin, Jingyi; Gao, Ying; Lan, Li; Liu, Yang

    2015-09-01

    Astigmatism imaging approach has been widely used to encode the fluorophore’s 3D position in single-particle tracking and super-resolution localization microscopy. Here, we present a new high-speed localization algorithm based on gradient fitting to precisely decode the 3D subpixel position of the fluorophore. This algebraic algorithm determines the center of the fluorescent emitter by finding the position with the best-fit gradient direction distribution to the measured point spread function (PSF), and can retrieve the 3D subpixel position of the fluorophore in a single iteration. Through numerical simulation and experiments with mammalian cells, we demonstrate that our algorithm yields comparable localization precision to the traditional iterative Gaussian function fitting (GF) based method, while exhibits over two orders-of-magnitude faster execution speed. Our algorithm is a promising high-speed analyzing method for 3D particle tracking and super-resolution localization microscopy.

  4. Web-based 3-D GIS and its applications for pipeline planning and construction

    Tao, V.; Wang, T.Q.K. [Calgary Univ., Calgary, AB (Canada). Dept. of Geomatics Engineering

    2000-07-01

    The many benefits that web-based 3D geographical information system (GIS) technology can bring to pipeline planning and construction was discussed. GIS can effectively integrate and manage a variety of data sources including geological, geographical, environmental, engineering and socioeconomic data. The third dimension of geospatial data is also very significant for pipeline planning, construction and maintenance which explains the increased demand for the development of a 3D GIS for pipeline applications. The Internet has made it possible to integrate GIS, visualization and distributed object computing technologies for a web-based 3D GIS. While this offers many advantages, it also poses several technical challenges. The technology allows users to access, manipulate and analyze geospatial objects remotely. This has positive implications for pipeline operating companies in their collaborative decision making for large pipeline projects that cover large areas with multiple landowners and different government sections. The technology will enhance their capability and productivity by making it possible to run their operations more efficiently. The Department of Geomatics Engineering at the University of Calgary has developed a web-based 3D GIS, GeoEye 3D prototype using a pure Java solution. The system is based on an advanced client/server model for visualization, manipulation and analysis of spatial data such as 3D terrain, wells, linear objects such as roads or pipelines and solid objects such as buildings. The system can be linked to other databases for spatial inquiry. 7 refs., 3 figs.

  5. 3D Facial Similarity Measure Based on Geodesic Network and Curvatures

    Junli Zhao

    2014-01-01

    Full Text Available Automated 3D facial similarity measure is a challenging and valuable research topic in anthropology and computer graphics. It is widely used in various fields, such as criminal investigation, kinship confirmation, and face recognition. This paper proposes a 3D facial similarity measure method based on a combination of geodesic and curvature features. Firstly, a geodesic network is generated for each face with geodesics and iso-geodesics determined and these network points are adopted as the correspondence across face models. Then, four metrics associated with curvatures, that is, the mean curvature, Gaussian curvature, shape index, and curvedness, are computed for each network point by using a weighted average of its neighborhood points. Finally, correlation coefficients according to these metrics are computed, respectively, as the similarity measures between two 3D face models. Experiments of different persons’ 3D facial models and different 3D facial models of the same person are implemented and compared with a subjective face similarity study. The results show that the geodesic network plays an important role in 3D facial similarity measure. The similarity measure defined by shape index is consistent with human’s subjective evaluation basically, and it can measure the 3D face similarity more objectively than the other indices.

  6. 3D face recognition based on multiple keypoint descriptors and sparse representation.

    Zhang, Lin; Ding, Zhixuan; Li, Hongyu; Shen, Ying; Lu, Jianwei

    2014-01-01

    Recent years have witnessed a growing interest in developing methods for 3D face recognition. However, 3D scans often suffer from the problems of missing parts, large facial expressions, and occlusions. To be useful in real-world applications, a 3D face recognition approach should be able to handle these challenges. In this paper, we propose a novel general approach to deal with the 3D face recognition problem by making use of multiple keypoint descriptors (MKD) and the sparse representation-based classification (SRC). We call the proposed method 3DMKDSRC for short. Specifically, with 3DMKDSRC, each 3D face scan is represented as a set of descriptor vectors extracted from keypoints by meshSIFT. Descriptor vectors of gallery samples form the gallery dictionary. Given a probe 3D face scan, its descriptors are extracted at first and then its identity can be determined by using a multitask SRC. The proposed 3DMKDSRC approach does not require the pre-alignment between two face scans and is quite robust to the problems of missing data, occlusions and expressions. Its superiority over the other leading 3D face recognition schemes has been corroborated by extensive experiments conducted on three benchmark databases, Bosphorus, GavabDB, and FRGC2.0. The Matlab source code for 3DMKDSRC and the related evaluation results are publicly available at http://sse.tongji.edu.cn/linzhang/3dmkdsrcface/3dmkdsrc.htm. PMID:24940876

  7. 3D automatic anatomy segmentation based on iterative graph-cut-ASM

    Chen, Xinjian; Bagci, Ulas

    2011-01-01

    Purpose: This paper studies the feasibility of developing an automatic anatomy segmentation (AAS) system in clinical radiology and demonstrates its operation on clinical 3D images.Methods: The AAS system, the authors are developing consists of two main parts: object recognition and object delineation. As for recognition, a hierarchical 3D scale-based multiobject method is used for the multiobject recognition task, which incorporates intensity weighted ball-scale (b-scale) information into the...

  8. Extended Distance-based Phylogenetic Analyses Applied to 3D Homo Fossil Skull Evolution

    Waddell, Peter J.

    2014-01-01

    This article shows how 3D geometric morphometric data can be analyzed using newly developed distance-based evolutionary tree inference methods, with extensions to planar graphs. Application of these methods to 3D representations of the skullcap (calvaria) of 13 diverse skulls in the genus Homo, ranging from Homo erectus (ergaster) at about 1.6 mya, all the way forward to modern humans, yields a remarkably clear phylogenetic tree. Various evolutionary hypotheses are tested. Results of these te...

  9. Accuracy Investigation for Structured-light Based Consumer 3D Sensors

    J. Boehm

    2014-01-01

    This work focuses on the performance investigation of consumer 3D sensors with respect to their repeatability and accuracy. It explores currently available sensors based on the 3D sensing technology developed by PrimeSense and introduced to the market in the form of the Microsoft Kinect. Accuracy and repeatability can be crucial criteria for the use of these sensors outside their intended use for home entertainment. The test strategies for the study are motivated by the VDI/VDE 2634 guideline...

  10. Application to monitoring of tailings dam based on 3D laser scanning technology

    Ren, Fang; Zhang, Aiwu

    2011-06-01

    This paper presented a new method of monitoring of tailing dam based on 3D laser scanning technology and gave the method flow of acquiring and processing the tailing dam data. Taking the measured data for example, the author analyzed the dam deformation by generating the TIN, DEM and the curvature graph, and proved that it's feasible to global monitor the tailing dam using 3D laser scanning technology from the theory and method.

  11. View Based Methods can achieve Bayes-Optimal 3D Recognition

    Breuel, Thomas M.

    2007-01-01

    This paper proves that visual object recognition systems using only 2D Euclidean similarity measurements to compare object views against previously seen views can achieve the same recognition performance as observers having access to all coordinate information and able of using arbitrary 3D models internally. Furthermore, it demonstrates that such systems do not require more training views than Bayes-optimal 3D model-based systems. For building computer vision systems, these results imply tha...

  12. Graphene Oxide-Based Electrode Inks for 3D-Printed Lithium-Ion Batteries.

    Fu, Kun; Wang, Yibo; Yan, Chaoyi; Yao, Yonggang; Chen, Yanan; Dai, Jiaqi; Lacey, Steven; Wang, Yanbin; Wan, Jiayu; Li, Tian; Wang, Zhengyang; Xu, Yue; Hu, Liangbing

    2016-04-01

    All-component 3D-printed lithium-ion batteries are fabricated by printing graphene-oxide-based composite inks and solid-state gel polymer electrolyte. An entirely 3D-printed full cell features a high electrode mass loading of 18 mg cm(-2) , which is normalized to the overall area of the battery. This all-component printing can be extended to the fabrication of multidimensional/multiscale complex-structures of more energy-storage devices. PMID:26833897

  13. Uniform Local Binary Pattern Based Texture-Edge Feature for 3D Human Behavior Recognition

    Ming, Yue; Wang, Guangchao; Fan, Chunxiao

    2015-01-01

    With the rapid development of 3D somatosensory technology, human behavior recognition has become an important research field. Human behavior feature analysis has evolved from traditional 2D features to 3D features. In order to improve the performance of human activity recognition, a human behavior recognition method is proposed, which is based on a hybrid texture-edge local pattern coding feature extraction and integration of RGB and depth videos information. The paper mainly focuses on backg...

  14. 3D MODELLING AND INTERACTIVE WEB-BASED VISUALIZATION OF CULTURAL HERITAGE OBJECTS

    Koeva, M. N.

    2016-01-01

    Nowadays, there are rapid developments in the fields of photogrammetry, laser scanning, computer vision and robotics, together aiming to provide highly accurate 3D data that is useful for various applications. In recent years, various LiDAR and image-based techniques have been investigated for 3D modelling because of their opportunities for fast and accurate model generation. For cultural heritage preservation and the representation of objects that are important for tourism and their interact...

  15. Comparison of photon and electron absorbed fractions in voxel-based and simplified phantoms for small animals

    Internal dosimetry on non-human biota is getting more important from the view point of radiation protection of environment. The International Commission on Radiological Protection (ICRP) proposed the Reference Animals and Plants using simplified phantoms, such as ellipsoids and spheres, and assessed absorbed fractions (AFs) for the whole bodies. In this study, photon and electron AFs in whole body of voxel-based frog and mouse phantoms were evaluated and compared with AFs in simplified phantoms. The evaluations were done by Monte Carlo methods for voxel-based and simplified phantoms. The monoenergetic photon or electron source was considered to be distributed uniformly in whole body. There were very small differences (less than 2%) between whole-body AFs in voxel-based and simplified mouse phantoms however the differences were up to 24% for the voxel-based and the Reference Frog phantoms. Whole-body AFs in voxel-based and simplified phantoms demonstrated that not only mass but also shape of whole body effected on AFs significantly. The results of this study suggest the replacement of the Reference Animal phantoms by voxel-based animal phantoms to improve the accuracy of the whole-body AFs. (author)

  16. 3D Image Synthesis for B—Reps Objects

    黄正东; 彭群生; 等

    1991-01-01

    This paper presents a new algorithm for generating 3D images of B-reps objects with trimmed surface boundaries.The 3D image is a discrete voxel-map representation within a Cubic Frame Buffer (CFB).The definition of 3D images for curve,surface and solid object are introduced which imply the connectivity and fidelity requirements.Adaptive Forward Differencing matrix (AFD-matrix) for 1D-3D manifolds in 3D space is developed.By setting rules to update the AFD-matrix,the forward difference direction and stepwise can be adjusted.Finally,an efficient algorithm is presented based on the AFD-matrix concept for converting the object in 3D space to 3D image in 3D discrete space.

  17. Retrieval and Clustering from a 3D Human Database based on Body and Head Shape

    Godil, Afzal

    2011-01-01

    In this paper, we describe a framework for similarity based retrieval and clustering from a 3D human database. Our technique is based on both body and head shape representation and the retrieval is based on similarity of both of them. The 3D human database used in our study is the CAESAR anthropometric database which contains approximately 5000 bodies. We have developed a web-based interface for specifying the queries to interact with the retrieval system. Our approach performs the similarity based retrieval in a reasonable amount of time and is a practical approach.

  18. SEGMENTATION OF UAV-BASED IMAGES INCORPORATING 3D POINT CLOUD INFORMATION

    A. Vetrivel

    2015-03-01

    Full Text Available Numerous applications related to urban scene analysis demand automatic recognition of buildings and distinct sub-elements. For example, if LiDAR data is available, only 3D information could be leveraged for the segmentation. However, this poses several risks, for instance, the in-plane objects cannot be distinguished from their surroundings. On the other hand, if only image based segmentation is performed, the geometric features (e.g., normal orientation, planarity are not readily available. This renders the task of detecting the distinct sub-elements of the building with similar radiometric characteristic infeasible. In this paper the individual sub-elements of buildings are recognized through sub-segmentation of the building using geometric and radiometric characteristics jointly. 3D points generated from Unmanned Aerial Vehicle (UAV images are used for inferring the geometric characteristics of roofs and facades of the building. However, the image-based 3D points are noisy, error prone and often contain gaps. Hence the segmentation in 3D space is not appropriate. Therefore, we propose to perform segmentation in image space using geometric features from the 3D point cloud along with the radiometric features. The initial detection of buildings in 3D point cloud is followed by the segmentation in image space using the region growing approach by utilizing various radiometric and 3D point cloud features. The developed method was tested using two data sets obtained with UAV images with a ground resolution of around 1-2 cm. The developed method accurately segmented most of the building elements when compared to the plane-based segmentation using 3D point cloud alone.

  19. 3D web based learning of medical equipment employed in intensive care units.

    Cetin, Aydın

    2012-02-01

    In this paper, both synchronous and asynchronous web based learning of 3D medical equipment models used in hospital intensive care unit have been described over the moodle course management system. 3D medical equipment models were designed with 3ds Max 2008, then converted to ASE format and added interactivity displayed with Viewpoint-Enliven. 3D models embedded in a web page in html format with dynamic interactivity-rotating, panning and zooming by dragging a mouse over images-and descriptive information is embedded to 3D model by using xml format. A pilot test course having 15 h was applied to technicians who is responsible for intensive care unit at Medical Devices Repairing and Maintenance Center (TABOM) of Turkish High Specialized Hospital. PMID:20703738

  20. Status and perspectives of pixel sensors based on 3D vertical integration

    Re, V

    2014-01-01

    This paper reviews the most recent developments of 3D integration in the field of silicon pixel sensors and readout integrated circuits. This technology may address the needs of future high energy physics and photon science experiments by increasing the electronic functional density in small pixel readout cells and by stacking various device layers based on different technologies, each optimized for a different function. Current efforts are aimed at improving the performance of both hybrid pixel detectors and of CMOS sensors. The status of these activities is discussed here, taking into account experimental results on 3D devices developed in the frame of the 3D-IC consortium. The paper also provides an overview of the ideas that are being currently devised for novel 3D vertically integrated pixel sensors.

  1. Demonstration of three gorges archaeological relics based on 3D-visualization technology

    Xu, Wenli

    2015-12-01

    This paper mainly focuses on the digital demonstration of three gorges archeological relics to exhibit the achievements of the protective measures. A novel and effective method based on 3D-visualization technology, which includes large-scaled landscape reconstruction, virtual studio, and virtual panoramic roaming, etc, is proposed to create a digitized interactive demonstration system. The method contains three stages: pre-processing, 3D modeling and integration. Firstly, abundant archaeological information is classified according to its history and geographical information. Secondly, build up a 3D-model library with the technology of digital images processing and 3D modeling. Thirdly, use virtual reality technology to display the archaeological scenes and cultural relics vividly and realistically. The present work promotes the application of virtual reality to digital projects and enriches the content of digital archaeology.

  2. GTP-based Integral Real-3D Spatial Model for Engineering Excavation GIS

    WU Lixin; SHI Wenzhong

    2004-01-01

    Engineering excavation GIS (E2GIS) is a real-3D GIS serving for geosciences related to geo-engineering, civil engineering and mining engineering based on generalized tri-prism (GTP) model. As two instances of GTP model, G-GTP is used for the real-3D modeling of subsurface geological bodies, and E-GTP is used for the real-3D modeling of subsurface engineering excavations.In the light of the discussions on the features and functions of E2GIS, the modeling principles of G-GTP and E-GTP are introduced. The two models couple together seamlessly to form an integral model for subsurface spatial objects including both geological bodies and excavations. An object-oriented integral real-3D data model and integral spatial topological relations are discussed.

  3. Sensitivity Analysis of the Scattering-Based SARBM3D Despeckling Algorithm.

    Di Simone, Alessio

    2016-01-01

    Synthetic Aperture Radar (SAR) imagery greatly suffers from multiplicative speckle noise, typical of coherent image acquisition sensors, such as SAR systems. Therefore, a proper and accurate despeckling preprocessing step is almost mandatory to aid the interpretation and processing of SAR data by human users and computer algorithms, respectively. Very recently, a scattering-oriented version of the popular SAR Block-Matching 3D (SARBM3D) despeckling filter, named Scattering-Based (SB)-SARBM3D, was proposed. The new filter is based on the a priori knowledge of the local topography of the scene. In this paper, an experimental sensitivity analysis of the above-mentioned despeckling algorithm is carried out, and the main results are shown and discussed. In particular, the role of both electromagnetic and geometrical parameters of the surface and the impact of its scattering behavior are investigated. Furthermore, a comprehensive sensitivity analysis of the SB-SARBM3D filter against the Digital Elevation Model (DEM) resolution and the SAR image-DEM coregistration step is also provided. The sensitivity analysis shows a significant robustness of the algorithm against most of the surface parameters, while the DEM resolution plays a key role in the despeckling process. Furthermore, the SB-SARBM3D algorithm outperforms the original SARBM3D in the presence of the most realistic scattering behaviors of the surface. An actual scenario is also presented to assess the DEM role in real-life conditions. PMID:27347971

  4. A neural network based 3D/3D image registration quality evaluator for the head-and-neck patient setup in the absence of a ground truth

    Purpose: To develop a neural network based registration quality evaluator (RQE) that can identify unsuccessful 3D/3D image registrations for the head-and-neck patient setup in radiotherapy. Methods: A two-layer feed-forward neural network was used as a RQE to classify 3D/3D rigid registration solutions as successful or unsuccessful based on the features of the similarity surface near the point-of-solution. The supervised training and test data sets were generated by rigidly registering daily cone-beam CTs to the treatment planning fan-beam CTs of six patients with head-and-neck tumors. Two different similarity metrics (mutual information and mean-squared intensity difference) and two different types of image content (entire image versus bony landmarks) were used. The best solution for each registration pair was selected from 50 optimizing attempts that differed only by the initial transformation parameters. The distance from each individual solution to the best solution in the normalized parametrical space was compared to a user-defined error threshold to determine whether that solution was successful or not. The supervised training was then used to train the RQE. The performance of the RQE was evaluated using the test data set that consisted of registration results that were not used in training. Results: The RQE constructed using the mutual information had very good performance when tested using the test data sets, yielding the sensitivity, the specificity, the positive predictive value, and the negative predictive value in the ranges of 0.960-1.000, 0.993-1.000, 0.983-1.000, and 0.909-1.000, respectively. Adding a RQE into a conventional 3D/3D image registration system incurs only about 10%-20% increase of the overall processing time. Conclusions: The authors' patient study has demonstrated very good performance of the proposed RQE when used with the mutual information in identifying unsuccessful 3D/3D registrations for daily patient setup. The classifier had

  5. A GPU-based Monte Carlo dose calculation code for photon transport in a voxel phantom

    Bellezzo, M.; Do Nascimento, E.; Yoriyaz, H., E-mail: mbellezzo@gmail.br [Instituto de Pesquisas Energeticas e Nucleares / CNEN, Av. Lineu Prestes 2242, Cidade Universitaria, 05508-000 Sao Paulo (Brazil)

    2014-08-15

    As the most accurate method to estimate absorbed dose in radiotherapy, Monte Carlo method has been widely used in radiotherapy treatment planning. Nevertheless, its efficiency can be improved for clinical routine applications. In this paper, we present the CUBMC code, a GPU-based Mc photon transport algorithm for dose calculation under the Compute Unified Device Architecture platform. The simulation of physical events is based on the algorithm used in Penelope, and the cross section table used is the one generated by the Material routine, als present in Penelope code. Photons are transported in voxel-based geometries with different compositions. To demonstrate the capabilities of the algorithm developed in the present work four 128 x 128 x 128 voxel phantoms have been considered. One of them is composed by a homogeneous water-based media, the second is composed by bone, the third is composed by lung and the fourth is composed by a heterogeneous bone and vacuum geometry. Simulations were done considering a 6 MeV monoenergetic photon point source. There are two distinct approaches that were used for transport simulation. The first of them forces the photon to stop at every voxel frontier, the second one is the Woodcock method, where the photon stop in the frontier will be considered depending on the material changing across the photon travel line. Dose calculations using these methods are compared for validation with Penelope and MCNP5 codes. Speed-up factors are compared using a NVidia GTX 560-Ti GPU card against a 2.27 GHz Intel Xeon CPU processor. (Author)

  6. A GPU-based Monte Carlo dose calculation code for photon transport in a voxel phantom

    As the most accurate method to estimate absorbed dose in radiotherapy, Monte Carlo method has been widely used in radiotherapy treatment planning. Nevertheless, its efficiency can be improved for clinical routine applications. In this paper, we present the CUBMC code, a GPU-based Mc photon transport algorithm for dose calculation under the Compute Unified Device Architecture platform. The simulation of physical events is based on the algorithm used in Penelope, and the cross section table used is the one generated by the Material routine, als present in Penelope code. Photons are transported in voxel-based geometries with different compositions. To demonstrate the capabilities of the algorithm developed in the present work four 128 x 128 x 128 voxel phantoms have been considered. One of them is composed by a homogeneous water-based media, the second is composed by bone, the third is composed by lung and the fourth is composed by a heterogeneous bone and vacuum geometry. Simulations were done considering a 6 MeV monoenergetic photon point source. There are two distinct approaches that were used for transport simulation. The first of them forces the photon to stop at every voxel frontier, the second one is the Woodcock method, where the photon stop in the frontier will be considered depending on the material changing across the photon travel line. Dose calculations using these methods are compared for validation with Penelope and MCNP5 codes. Speed-up factors are compared using a NVidia GTX 560-Ti GPU card against a 2.27 GHz Intel Xeon CPU processor. (Author)

  7. Evaluation and assessment of the seismic responses of 3-D base-isolated structures

    Hueffmann, G.K.; Sutton, W.T. [GERB Vibration Control Systems, Inc., Westmont, IL (United States)

    1995-12-01

    The 1994 Northridge earthquake offered the opportunity to evaluate and assess the seismic response of several base-isolated buildings. Assessment of 2-D base isolation is straightforward comparing separately the uncoupled horizontal and vertical building motions to the corresponding ground motions. With 3-D systems characterized by low vertical natural frequencies, the system assessment must include rocking of the structure. Neglecting this consideration leads to an erroneous conclusion that the system greatly amplifies vertical ground accelerations. The paper evaluates the seismic response of a 3-D base-isolated building as compared to the same structure on a 2-D system. The paper also shows that the vertical accelerations measured at extreme locations in the building on a 3-D base-isolation system develop mainly from rocking responses to the horizontal ground motion.

  8. Diffuse Decreased Gray Matter in Patients with Idiopathic Craniocervical Dystonia: a Voxel-Based Morphometry Study

    Camila Callegari Piccinin

    2015-01-01

    Full Text Available Background: Recent studies have addressed the role of structures other than the basal ganglia in the pathophysiology of craniocervical dystonia. Neuroimaging studies have attempted to identify structural abnormalities in craniocervical dystonia but a clear pattern of alteration has not been established. We performed whole brain evaluation using voxel-based morphometry to identify patterns of gray matter changes in craniocervical dystonia.Methods: We compared 27 patients with craniocervical dystonia matched in age and gender to 54 healthy controls. Voxel-based morphometry was used to compare gray matter volumes. We created a two-sample t-test corrected for subjects’ age and we tested with a level of significance of p<0.001 and false discovery rate correction (p<0.05. Results: Voxel-based morphometry demonstrated significant reductions of gray matter using p<0.001 in the cerebellar vermis IV/V, bilaterally in the superior frontal gyrus, precuneus, anterior cingulate and paracingulate, insular cortex, lingual gyrus and calcarine fissure; in the left hemisphere in the supplemementary motor area (SMA, inferior frontal gyrus, inferior parietal gyrus, temporal pole, supramarginal gyrus, rolandic operculum , hippocampus, middle occipital gyrus, cerebellar lobules IV/V, superior and middle temporal gyri; in the right hemisphere, the middle cingulate and precentral gyrus. Our study did not report any significant result using the false discovery rate correction. We also detected correlations between gray matter volume and age, disease duration, duration of botulinum toxin treatment and the Marsden-Fahn dystonia scale scores.Conclusions: We detected large clusters of gray matter changes chiefly in structures primarily involved in sensorimotor integration, motor planning, visuospatial function and emotional processing.

  9. 3D printed microfluidic circuitry via multijet-based additive manufacturing†

    Sochol, R. D.; Sweet, E.; Glick, C. C.; Venkatesh, S.; Avetisyan, A.; Ekman, K. F.; Raulinaitis, A.; Tsai, A.; Wienkers, A.; Korner, K.; Hanson, K.; Long, A.; Hightower, B. J.; Slatton, G.; Burnett, D. C.; Massey, T. L.; Iwai, K.; Lee, L. P.; Pister, K. S. J.; Lin, L.

    2016-01-01

    The miniaturization of integrated fluidic processors affords extensive benefits for chemical and biological fields, yet traditional, monolithic methods of microfabrication present numerous obstacles for the scaling of fluidic operators. Recently, researchers have investigated the use of additive manufacturing or “three-dimensional (3D) printing” technologies – predominantly stereolithography – as a promising alternative for the construction of submillimeter-scale fluidic components. One challenge, however, is that current stereolithography methods lack the ability to simultaneously print sacrificial support materials, which limits the geometric versatility of such approaches. In this work, we investigate the use of multijet modelling (alternatively, polyjet printing) – a layer-by-layer, multi-material inkjetting process – for 3D printing geometrically complex, yet functionally advantageous fluidic components comprised of both static and dynamic physical elements. We examine a fundamental class of 3D printed microfluidic operators, including fluidic capacitors, fluidic diodes, and fluidic transistors. In addition, we evaluate the potential to advance on-chip automation of integrated fluidic systems via geometric modification of component parameters. Theoretical and experimental results for 3D fluidic capacitors demonstrated that transitioning from planar to non-planar diaphragm architectures improved component performance. Flow rectification experiments for 3D printed fluidic diodes revealed a diodicity of 80.6 ± 1.8. Geometry-based gain enhancement for 3D printed fluidic transistors yielded pressure gain of 3.01 ± 0.78. Consistent with additional additive manufacturing methodologies, the use of digitally-transferrable 3D models of fluidic components combined with commercially-available 3D printers could extend the fluidic routing capabilities presented here to researchers in fields beyond the core engineering community. PMID:26725379

  10. 3D printed microfluidic circuitry via multijet-based additive manufacturing.

    Sochol, R D; Sweet, E; Glick, C C; Venkatesh, S; Avetisyan, A; Ekman, K F; Raulinaitis, A; Tsai, A; Wienkers, A; Korner, K; Hanson, K; Long, A; Hightower, B J; Slatton, G; Burnett, D C; Massey, T L; Iwai, K; Lee, L P; Pister, K S J; Lin, L

    2016-02-21

    The miniaturization of integrated fluidic processors affords extensive benefits for chemical and biological fields, yet traditional, monolithic methods of microfabrication present numerous obstacles for the scaling of fluidic operators. Recently, researchers have investigated the use of additive manufacturing or "three-dimensional (3D) printing" technologies - predominantly stereolithography - as a promising alternative for the construction of submillimeter-scale fluidic components. One challenge, however, is that current stereolithography methods lack the ability to simultaneously print sacrificial support materials, which limits the geometric versatility of such approaches. In this work, we investigate the use of multijet modelling (alternatively, polyjet printing) - a layer-by-layer, multi-material inkjetting process - for 3D printing geometrically complex, yet functionally advantageous fluidic components comprised of both static and dynamic physical elements. We examine a fundamental class of 3D printed microfluidic operators, including fluidic capacitors, fluidic diodes, and fluidic transistors. In addition, we evaluate the potential to advance on-chip automation of integrated fluidic systems via geometric modification of component parameters. Theoretical and experimental results for 3D fluidic capacitors demonstrated that transitioning from planar to non-planar diaphragm architectures improved component performance. Flow rectification experiments for 3D printed fluidic diodes revealed a diodicity of 80.6 ± 1.8. Geometry-based gain enhancement for 3D printed fluidic transistors yielded pressure gain of 3.01 ± 0.78. Consistent with additional additive manufacturing methodologies, the use of digitally-transferrable 3D models of fluidic components combined with commercially-available 3D printers could extend the fluidic routing capabilities presented here to researchers in fields beyond the core engineering community. PMID:26725379

  11. Efficient and high speed depth-based 2D to 3D video conversion

    Somaiya, Amisha Himanshu; Kulkarni, Ramesh K.

    2013-09-01

    Stereoscopic video is the new era in video viewing and has wide applications such as medicine, satellite imaging and 3D Television. Such stereo content can be generated directly using S3D cameras. However, this approach requires expensive setup and hence converting monoscopic content to S3D becomes a viable approach. This paper proposes a depth-based algorithm for monoscopic to stereoscopic video conversion by using the y axis co-ordinates of the bottom-most pixels of foreground objects. This code can be used for arbitrary videos without prior database training. It does not face the limitations of single monocular depth cues nor does it combine depth cues, thus consuming less processing time without affecting the efficiency of the 3D video output. The algorithm, though not comparable to real-time, is faster than the other available 2D to 3D video conversion techniques in the average ratio of 1:8 to 1:20, essentially qualifying as high-speed. It is an automatic conversion scheme, hence directly gives the 3D video output without human intervention and with the above mentioned features becomes an ideal choice for efficient monoscopic to stereoscopic video conversion. [Figure not available: see fulltext.

  12. A novel 3D stitching method for WLI based large range surface topography measurement

    Lei, Zili; Liu, Xiaojun; Zhao, Li; Chen, Liangzhou; Li, Qian; Yuan, Tengfei; Lu, Wenlong

    2016-01-01

    3D image stitching is an important technique for large range surface topography measurement in White-Light Interferometry (WLI). However, the stitching accuracy is inevitably influenced by noise. To solve this problem, a novel method for 3D image stitching is proposed in this paper. In this method, based on noise mechanism analysis in WLI measurement, a new definition of noise in 3D image is given by an evaluation model for difference between the practical WLI interference signal and the ideal signal. By this new definition, actual noises in 3D image are identified while those practical singular heights on surface will not be wrongly attributed to noise. With the definition, a binary matrix for noise mark corresponding to 3D image is obtained. Then, the matrix is devoted, as an important component, to establish a series of new algorithms of capability for suppressing the adverse effects of noises in each process of the proposed stitching method. By this method, the influence of the noises on stitching is substantially reduced and the stitching accuracy is improved. Through 3D image stitching experiments with noises in WLI, effectiveness of the proposed method is verified.

  13. A Service-oriented FPGA-based 3D Model Acquisition System

    MACHIDON, O. M.

    2015-11-01

    Full Text Available This paper proposes a non-contact, low cost 3D scanning solution using laser striping. The solution is composed of two main parts: the hardware setup - used for acquiring the object's 3D surface information, and the software part - that processes the information and obtains the 3D model representation of the object. We propose two major improvements over the traditional scanning solutions: the 3D information acquisition is based on a reconfigurable hardware platform - a Xilinx Spartan 6 FPGA - which adds flexibility and scalability to the scanning process, while the 3D model reconstruction is remotely available "as a Service", by the means of a web interface that abstracts away the complexity of the underlying processes and improves the performance, while granting easy sharing between users. By separating data capture process from the 3D model reconstruction tasks the system gains in portability - a feature that is absent for most existing solutions. The service-oriented approach brings on a performance gain, since the computational intensive tasks are handled by dedicated servers and ease of use of the system, because the user does not have to bother managing and using the software tools locally.

  14. Front and rear projection autostereoscopic 3D displays based on lenticular sheets

    Wang, Qiong-Hua; Zang, Shang-Fei; Qi, Lin

    2015-03-01

    A front projection autostereoscopic display is proposed. The display is composed of eight projectors and a 3D-imageguided screen which having a lenticular sheet and a retro-reflective diffusion screen. Based on the optical multiplexing and de-multiplexing, the optical functions of the 3D-image-guided screen are parallax image interlacing and viewseparating, which is capable of reconstructing 3D images without quality degradation from the front direction. The operating principle, optical design calculation equations and correction method of parallax images are given. A prototype of the front projection autostereoscopic display is developed, which enhances the brightness and 3D perceptions, and improves space efficiency. The performance of this prototype is evaluated by measuring the luminance and crosstalk distribution along the horizontal direction at the optimum viewing distance. We also propose a rear projection autostereoscopic display. The display consists of eight projectors, a projection screen, and two lenticular sheets. The operation principle and calculation equations are described in detail and the parallax images are corrected by means of homography. A prototype of the rear projection autostereoscopic display is developed. The normalized luminance distributions of viewing zones from the measurement are given. Results agree well with the designed values. The prototype presents high resolution and high brightness 3D images. The research has potential applications in some commercial entertainments and movies for the realistic 3D perceptions.

  15. 3D finite element analysis of porous Ti-based alloy prostheses.

    Mircheski, Ile; Gradišar, Marko

    2016-11-01

    In this paper, novel designs of porous acetabular cups are created and tested with 3D finite element analysis (FEA). The aim is to develop a porous acetabular cup with low effective radial stiffness of the structure, which will be near to the architectural and mechanical behavior of the natural bone. For the realization of this research, a 3D-scanner technology was used for obtaining a 3D-CAD model of the pelvis bone, a 3D-CAD software for creating a porous acetabular cup, and a 3D-FEA software for virtual testing of a novel design of the porous acetabular cup. The results obtained from this research reveal that a porous acetabular cup from Ti-based alloys with 60 ± 5% porosity has the mechanical behavior and effective radial stiffness (Young's modulus in radial direction) that meet and exceed the required properties of the natural bone. The virtual testing with 3D-FEA of a novel design with porous structure during the very early stage of the design and the development of orthopedic implants, enables obtaining a new or improved biomedical implant for a relatively short time and reduced price. PMID:27015664

  16. Performance Analysis of a Low-Cost Triangulation-Based 3d Camera: Microsoft Kinect System

    . K. Chow, J. C.; Ang, K. D.; Lichti, D. D.; Teskey, W. F.

    2012-07-01

    Recent technological advancements have made active imaging sensors popular for 3D modelling and motion tracking. The 3D coordinates of signalised targets are traditionally estimated by matching conjugate points in overlapping images. Current 3D cameras can acquire point clouds at video frame rates from a single exposure station. In the area of 3D cameras, Microsoft and PrimeSense have collaborated and developed an active 3D camera based on the triangulation principle, known as the Kinect system. This off-the-shelf system costs less than 150 USD and has drawn a lot of attention from the robotics, computer vision, and photogrammetry disciplines. In this paper, the prospect of using the Kinect system for precise engineering applications was evaluated. The geometric quality of the Kinect system as a function of the scene (i.e. variation of depth, ambient light conditions, incidence angle, and object reflectivity) and the sensor (i.e. warm-up time and distance averaging) were analysed quantitatively. This system's potential in human body measurements was tested against a laser scanner and 3D range camera. A new calibration model for simultaneously determining the exterior orientation parameters, interior orientation parameters, boresight angles, leverarm, and object space features parameters was developed and the effectiveness of this calibration approach was explored.

  17. A Secret 3D Model Sharing Scheme with Reversible Data Hiding Based on Space Subdivision

    Tsai, Yuan-Yu

    2016-03-01

    Secret sharing is a highly relevant research field, and its application to 2D images has been thoroughly studied. However, secret sharing schemes have not kept pace with the advances of 3D models. With the rapid development of 3D multimedia techniques, extending the application of secret sharing schemes to 3D models has become necessary. In this study, an innovative secret 3D model sharing scheme for point geometries based on space subdivision is proposed. Each point in the secret point geometry is first encoded into a series of integer values that fall within [0, p - 1], where p is a predefined prime number. The share values are derived by substituting the specified integer values for all coefficients of the sharing polynomial. The surface reconstruction and the sampling concepts are then integrated to derive a cover model with sufficient model complexity for each participant. Finally, each participant has a separate 3D stego model with embedded share values. Experimental results show that the proposed technique supports reversible data hiding and the share values have higher levels of privacy and improved robustness. This technique is simple and has proven to be a feasible secret 3D model sharing scheme.

  18. 3D Model Based Pose Invariant Face Recognition from a Single Frontal View

    Chen, Qinran; Cham, Wai-kuen

    2007-01-01

    This paper proposes a 3D model based pose invariant face recognition method that can recognize a face of a large rotation angle from its single nearly frontal view. The proposed method achieves the goal by using an analytic-to-holistic approach and a novel algorithm for estimation of ear points. Firstly, the proposed method achieves facial feature detection, in which an edge map based algorithm is developed to detect the ear points. Based on the detected facial feature points 3D face models a...

  19. Generation of 3D Virtual Geographic Environment Based on Laser Scanning Technique

    DU Jie; CHEN Xiaoyong; FumioYamazaki

    2003-01-01

    This paper demonstrates an experiment on the generation of 3D virtual geographic environment on the basis of experimental flight laser scanning data by a set of algorithms and methods that were developed to automatically interpret range images for extracting geo-spatial features and then to reconstruct geo-objects. The algorithms and methods for the interpretation and modeling of laser scanner data include triangulated-irregular-network (TIN)-based range image interpolation ; mathematical-morphology(MM)-based range image filtering,feature extraction and range image segmentation, feature generalization and optimization, 3D objects reconstruction and modeling; computergraphics (CG)-based visualization and animation of geographic virtual reality environment.

  20. A voxel-based lesion study on facial emotion recognition after penetrating brain injury

    Dal Monte, Olga; Krueger, Frank; Solomon, Jeffrey M.; Schintu, Selene; Knutson, Kristine M.; Strenziok, Maren; Pardini, Matteo; Leopold, Anne; Raymont, Vanessa; Grafman, Jordan

    2012-01-01

    The ability to read emotions in the face of another person is an important social skill that can be impaired in subjects with traumatic brain injury (TBI). To determine the brain regions that modulate facial emotion recognition, we conducted a whole-brain analysis using a well-validated facial emotion recognition task and voxel-based lesion symptom mapping (VLSM) in a large sample of patients with focal penetrating TBIs (pTBIs). Our results revealed that individuals with pTBI performed signif...

  1. Supervised and unsupervised MRF based 3D scene classification in multiple view airborne oblique images

    Gerke, M.; Xiao, J.

    2013-10-01

    In this paper we develop and compare two methods for scene classification in 3D object space, that is, not single image pixels get classified, but voxels which carry geometric, textural and color information collected from the airborne oblique images and derived products like point clouds from dense image matching. One method is supervised, i.e. relies on training data provided by an operator. We use Random Trees for the actual training and prediction tasks. The second method is unsupervised, thus does not ask for any user interaction. We formulate this classification task as a Markov-Random-Field problem and employ graph cuts for the actual optimization procedure. Two test areas are used to test and evaluate both techniques. In the Haiti dataset we are confronted with largely destroyed built-up areas since the images were taken after the earthquake in January 2010, while in the second case we use images taken over Enschede, a typical Central European city. For the Haiti case it is difficult to provide clear class definitions, and this is also reflected in the overall classification accuracy; it is 73% for the supervised and only 59% for the unsupervised method. If classes are defined more unambiguously like in the Enschede area, results are much better (85% vs. 78%). In conclusion the results are acceptable, also taking into account that the point cloud used for geometric features is not of good quality and no infrared channel is available to support vegetation classification.

  2. Shape-based 3D vascular tree extraction for perforator flaps

    Wen, Quan; Gao, Jean

    2005-04-01

    Perforator flaps have been increasingly used in the past few years for trauma and reconstructive surgical cases. With the thinned perforated flaps, greater survivability and decrease in donor site morbidity have been reported. Knowledge of the 3D vascular tree will provide insight information about the dissection region, vascular territory, and fascia levels. This paper presents a scheme of shape-based 3D vascular tree reconstruction of perforator flaps for plastic surgery planning, which overcomes the deficiencies of current existing shape-based interpolation methods by applying rotation and 3D repairing. The scheme has the ability to restore the broken parts of the perforator vascular tree by using a probability-based adaptive connection point search (PACPS) algorithm with minimum human intervention. The experimental results evaluated by both synthetic and 39 harvested cadaver perforator flaps show the promise and potential of proposed scheme for plastic surgery planning.

  3. Novel 3-D Object Recognition Methodology Employing a Curvature-Based Histogram

    Liang-Chia Chen

    2013-07-01

    Full Text Available In this paper, a new object recognition algorithm employing a curvature-based histogram is presented. Recognition of three-dimensional (3-D objects using range images remains one of the most challenging problems in 3-D computer vision due to its noisy and cluttered scene characteristics. The key breakthroughs for this problem mainly lie in defining unique features that distinguish the similarity among various 3-D objects. In our approach, an object detection scheme is developed to identify targets underlining an automated search in the range images using an initial process of object segmentation to subdivide all possible objects in the scenes and then applying a process of object recognition based on geometric constraints and a curvature-based histogram for object recognition. The developed method has been verified through experimental tests for its feasibility confirmation.

  4. 3D facial expression recognition based on histograms of surface differential quantities

    Li, Huibin

    2011-01-01

    3D face models accurately capture facial surfaces, making it possible for precise description of facial activities. In this paper, we present a novel mesh-based method for 3D facial expression recognition using two local shape descriptors. To characterize shape information of the local neighborhood of facial landmarks, we calculate the weighted statistical distributions of surface differential quantities, including histogram of mesh gradient (HoG) and histogram of shape index (HoS). Normal cycle theory based curvature estimation method is employed on 3D face models along with the common cubic fitting curvature estimation method for the purpose of comparison. Based on the basic fact that different expressions involve different local shape deformations, the SVM classifier with both linear and RBF kernels outperforms the state of the art results on the subset of the BU-3DFE database with the same experimental setting. © 2011 Springer-Verlag.

  5. Development of 3-D fracture network visualization software based on graphical user interface

    Young-Hwan, Noh; Jeong-Gi, Um; Yosoon, Choi; Myong-Ho, Park; Jaeyoung, Choi

    2013-04-01

    A sound understanding of the structural characteristics of fractured rock masses is important in designing and maintaining earth structures because their strength, deformability, and hydraulic behavior depend mainly on the characteristics of discontinuity network structures. Despite considerable progress in understanding the structural characteristics of rock masses, the complexity of discontinuity patterns has prevented satisfactory analysis based on a 3-D rock mass visualization model. This research presents the results of studies performed to develop rock mass visualization in 3-D to analysis the mechanical and hydraulic behavior of fractured rock masses. General and particular solutions of non-linear equations of disk-shaped fractures have been derived to calculated lines of intersection and equivalent pipes. Also, program modules of DISK3D, FNTWK3D, BOUNDARY and BDM(borehole data management) have been developed to perform the visualization of fracture network and corresponding equivalent pipes for DFN based fluid flow model. The developed software for the 3-D fractured rock mass visualization model based on MS visual studio can be used to characterize rock mass geometry and network systems effectively. The results obtained in this study will be refined and then combined for use as a tool for assessing geomechanical problems related to strength, deformability and hydraulic behaviors of the fractured rock masses. Acknowledgements. This work was supported by the 2011 Energy Efficiency and Resources Program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant.

  6. An optimized voxel-based morphometry study in the evaluation of brain structural abnormalities in anisometropic amblyopia patients

    Objective: To investigate possible neural mechanism of anisometropic amblyopia by analysing the whole brain volume changes both in grey matter and white matter using optimized voxel-based morphometry (VBM). Methods: Twelve anisometropic amblyopia patients and 12 age,gender and handedness matched healthy volunteers underwent 3-dimensional (3D) fast spoiled gradient echo (FSPGR) sequence scanning on 1.5 Tesla MR system. Raw data was processed and analyzed using statistical parametric mapping (SPM) 5. Results: Compared to healthy controls,the grey matter exhibiting significantly decreased volume in patients included right cuneus, bilateral occipital gyrus, right middle frontal gyrus, left middle temporal gyrus, right superior temporal gyrus, right precuneus,and middle part of right cingulate gyrus (clusters > 10). The grey matter showing increased volume in patients included right cerebellum,right parahippocampal gyrus, left precentral gyrus,and left superior frontal gyrus (clusters > 10). The white matter volume in bilateral optic radiation and internal capsule, especially right optic radiation, decreased significantly in patient group (clusters > 10 ). No white matter showed significantly increased volume in patient group. Conclusion: VBM can be used to investigate the changes of grey matter volume and white matter volume in the whole brain of anisometropic amblyopia children, it provides a method to illustrate the presumed neuro-mechanism from a morphologic point of view. (authors)

  7. A voxel visualization and analysis system based on AutoCAD

    Marschallinger, Robert

    1996-05-01

    A collection of AutoLISP programs is presented which enable the visualization and analysis of voxel models by AutoCAD rel. 12/rel. 13. The programs serve as an interactive, graphical front end for manipulating the results of three-dimensional modeling software producing block estimation data. ASCII data files describing geometry and attributes per estimation block are imported and stored as a voxel array. Each voxel may contain multiple attributes, therefore different parameters may be incorporated in one voxel array. Voxel classification is implemented on a layer basis providing flexible treatment of voxel classes such as recoloring, peeling, or volumetry. A versatile clipping tool enables slicing voxel arrays according to combinations of three perpendicular clipping planes. The programs feature an up-to-date, graphical user interface for user-friendly operation by non AutoCAD specialists.

  8. QueryArch3D: Querying and Visualising 3D Models of a Maya Archaeological Site in a Web-Based Interface

    Giorgio Agugiaro

    2011-12-01

    Full Text Available Constant improvements in the field of surveying, computing and distribution of digital-content are reshaping the way Cultural Heritage can be digitised and virtually accessed, even remotely via web. A traditional 2D approach for data access, exploration, retrieval and exploration may generally suffice, however more complex analyses concerning spatial and temporal features require 3D tools, which, in some cases, have not yet been implemented or are not yet generally commercially available. Efficient organisation and integration strategies applicable to the wide array of heterogeneous data in the field of Cultural Heritage represent a hot research topic nowadays. This article presents a visualisation and query tool (QueryArch3D conceived to deal with multi-resolution 3D models. Geometric data are organised in successive levels of detail (LoD, provided with geometric and semantic hierarchies and enriched with attributes coming from external data sources. The visualisation and query front-end enables the 3D navigation of the models in a virtual environment, as well as the interaction with the objects by means of queries based on attributes or on geometries. The tool can be used as a standalone application, or served through the web. The characteristics of the research work, along with some implementation issues and the developed QueryArch3D tool will be discussed and presented.

  9. Structuring Narrative in 3D Digital Game-Based Learning Environments to Support Second Language Acquisition

    Neville, David O.

    2010-01-01

    The essay is a conceptual analysis from an instructional design perspective exploring the feasibility of using three-dimensional digital game-based learning (3D-DGBL) environments to assist in second language acquisition (SLA). It examines the shared characteristics of narrative within theories of situated cognition, context-based approaches to…

  10. 3D Game-Based Learning System for Improving Learning Achievement in Software Engineering Curriculum

    Su,Chung-Ho; Cheng, Ching-Hsue

    2013-01-01

    The advancement of game-based learning has encouraged many related studies, such that students could better learn curriculum by 3-dimension virtual reality. To enhance software engineering learning, this paper develops a 3D game-based learning system to assist teaching and assess the students' motivation, satisfaction and learning…

  11. HOSVD-Based 3D Active Appearance Model: Segmentation of Lung Fields in CT Images.

    Wang, Qingzhu; Kang, Wanjun; Hu, Haihui; Wang, Bin

    2016-07-01

    An Active Appearance Model (AAM) is a computer vision model which can be used to effectively segment lung fields in CT images. However, the fitting result is often inadequate when the lungs are affected by high-density pathologies. To overcome this problem, we propose a Higher-order Singular Value Decomposition (HOSVD)-based Three-dimensional (3D) AAM. An evaluation was performed on 310 diseased lungs form the Lung Image Database Consortium Image Collection. Other contemporary AAMs operate directly on patterns represented by vectors, i.e., before applying the AAM to a 3D lung volume,it has to be vectorized first into a vector pattern by some technique like concatenation. However, some implicit structural or local contextual information may be lost in this transformation. According to the nature of the 3D lung volume, HOSVD is introduced to represent and process the lung in tensor space. Our method can not only directly operate on the original 3D tensor patterns, but also efficiently reduce the computer memory usage. The evaluation resulted in an average Dice coefficient of 97.0 % ± 0.59 %, a mean absolute surface distance error of 1.0403 ± 0.5716 mm, a mean border positioning errors of 0.9187 ± 0.5381 pixel, and a Hausdorff Distance of 20.4064 ± 4.3855, respectively. Experimental results showed that our methods delivered significant and better segmentation results, compared with the three other model-based lung segmentation approaches, namely 3D Snake, 3D ASM and 3D AAM. PMID:27277277

  12. 3D printing of weft knitted textile based structures by selective laser sintering of nylon powder

    Beecroft, M.

    2016-07-01

    3D printing is a form of additive manufacturing whereby the building up of layers of material creates objects. The selective laser sintering process (SLS) uses a laser beam to sinter powdered material to create objects. This paper builds upon previous research into 3D printed textile based material exploring the use of SLS using nylon powder to create flexible weft knitted structures. The results show the potential to print flexible textile based structures that exhibit the properties of traditional knitted textile structures along with the mechanical properties of the material used, whilst describing the challenges regarding fineness of printing resolution. The conclusion highlights the potential future development and application of such pieces.

  13. Inertial Sensor-Based Touch and Shake Metaphor for Expressive Control of 3D Virtual Avatars

    Shashidhar Patil; Harinadha Reddy Chintalapalli; Dubeom Kim; Youngho Chai

    2015-01-01

    In this paper, we present an inertial sensor-based touch and shake metaphor for expressive control of a 3D virtual avatar in a virtual environment. An intuitive six degrees-of-freedom wireless inertial motion sensor is used as a gesture and motion control input device with a sensor fusion algorithm. The algorithm enables user hand motions to be tracked in 3D space via magnetic, angular rate, and gravity sensors. A quaternion-based complementary filter is implemented to reduce noise and drift...

  14. Dynamic WIFI-Based Indoor Positioning in 3D Virtual World

    Chan, S.; G. Sohn; Wang, L.; Lee, W.

    2013-01-01

    A web-based system based on the 3DTown project was proposed using Google Earth plug-in that brings information from indoor positioning devices and real-time sensors into an integrated 3D indoor and outdoor virtual world to visualize the dynamics of urban life within the 3D context of a city. We addressed limitation of the 3DTown project with particular emphasis on video surveillance camera used for indoor tracking purposes. The proposed solution was to utilize wireless local area net...

  15. SOFI-based 3D superresolution sectioning with a widefield microscope

    Dertinger, Thomas; Xu, Jianmin; Naini, Omeed Foroutan; Vogel, Robert; Weiss, Shimon

    2013-01-01

    Background Fluorescence-based biological imaging has been revolutionized by the recent introduction of superresolution microscopy methods. 3D superresolution microscopy, however, remains a challenge as its implementation by existing superresolution methods is non-trivial. Methods Here we demonstrate a facile and straightforward 3D superresolution imaging and sectioning of the cytoskeletal network of a fixed cell using superresolution optical fluctuation imaging (SOFI) performed on a conventional lamp-based widefield microscope. Results and Conclusion SOFI’s inherent sectioning capability effectively transforms a conventional widefield microscope into a superresolution ‘confocal widefield’ microscope. PMID:24163789

  16. Learning to Grasp Unknown Objects Based on 3D Edge Information

    Bodenhagen, Leon; Kraft, Dirk; Popovic, Mila;

    2010-01-01

    In this work we refine an initial grasping behavior based on 3D edge information by learning. Based on a set of autonomously generated evaluated grasps and relations between the semi-global 3D edges, a prediction function is learned that computes a likelihood for the success of a grasp using either...... an offline or an online learning scheme. Both methods are implemented using a hybrid artificial neural network containing standard nodes with a sigmoid activation function and nodes with a radial basis function. We show that a significant performance improvement can be achieved....

  17. 3DTS: A 3D tolerancing system based on mathematical definition

    CAO Yan-long; LIU Yu-sheng; MAO Jian; YANG Jiang-xin

    2006-01-01

    Tolerance is almost ubiquitous during the whole product lift cycle and is imperative for seamless integration of CAD and CAM. Based on the mathematical definition of tolerance, a 3D tolerancing system, 3DTS, is presented with its design principle, system architecture and key functions. The following functional modules, tolerance modeling, semantics interpretation, 3D tolerance analysis, are described in detail. To make the tolerancing system robust and efficient, many techniques such as hierarchical tolerance representation, rule-based evaluation and non-intersection determination of tolerance zone have been devised.Tested by many samples, this system shows good robustness and practicability.

  18. 3D video

    Lucas, Laurent; Loscos, Céline

    2013-01-01

    While 3D vision has existed for many years, the use of 3D cameras and video-based modeling by the film industry has induced an explosion of interest for 3D acquisition technology, 3D content and 3D displays. As such, 3D video has become one of the new technology trends of this century.The chapters in this book cover a large spectrum of areas connected to 3D video, which are presented both theoretically and technologically, while taking into account both physiological and perceptual aspects. Stepping away from traditional 3D vision, the authors, all currently involved in these areas, provide th

  19. 2D-3D Face Recognition Method Based on a Modified CCA-PCA Algorithm

    Patrik Kamencay

    2014-03-01

    Full Text Available This paper presents a proposed methodology for face recognition based on an information theory approach to coding and decoding face images. In this paper, we propose a 2D-3D face-matching method based on a principal component analysis (PCA algorithm using canonical correlation analysis (CCA to learn the mapping between a 2D face image and 3D face data. This method makes it possible to match a 2D face image with enrolled 3D face data. Our proposed fusion algorithm is based on the PCA method, which is applied to extract base features. PCA feature-level fusion requires the extraction of different features from the source data before features are merged together. Experimental results on the TEXAS face image database have shown that the classification and recognition results based on the modified CCA-PCA method are superior to those based on the CCA method. Testing the 2D-3D face match results gave a recognition rate for the CCA method of a quite poor 55% while the modified CCA method based on PCA-level fusion achieved a very good recognition score of 85%.

  20. Laser nanostructuring 3-D bioconstruction based on carbon nanotubes in a water matrix of albumin

    Gerasimenko, Alexander Y.; Ichkitidze, Levan P.; Podgaetsky, Vitaly M.; Savelyev, Mikhail S.; Selishchev, Sergey V.

    2016-04-01

    3-D bioconstructions were created using the evaporation method of the water-albumin solution with carbon nanotubes (CNTs) by the continuous and pulsed femtosecond laser radiation. It is determined that the volume structure of the samples created by the femtosecond radiation has more cavities than the one created by the continuous radiation. The average diameter for multi-walled carbon nanotubes (MWCNTs) samples was almost two times higher (35-40 nm) than for single-walled carbon nanotubes (SWCNTs) samples (20-30 nm). The most homogenous 3-D bioconstruction was formed from MWCNTs by the continuous laser radiation. The hardness of such samples totaled up to 370 MPa at the nanoscale. High strength properties and the resistance of the 3-D bioconstructions produced by the laser irradiation depend on the volume nanotubes scaffold forming inside them. The scaffold was formed by the electric field of the directed laser irradiation. The covalent bond energy between the nanotube carbon molecule and the oxygen of the bovine serum albumin aminoacid residue amounts 580 kJ/mol. The 3-D bioconstructions based on MWCNTs and SWCNTs becomes overgrown with the cells (fibroblasts) over the course of 72 hours. The samples based on the both types of CNTs are not toxic for the cells and don't change its normal composition and structure. Thus the 3-D bioconstructions that are nanostructured by the pulsed and continuous laser radiation can be applied as implant materials for the recovery of the connecting tissues of the living body.

  1. Unitary Matrix Pencil Algorithm for Range-Based 3D Localization of Wireless Sensor Network Nodes

    Chang Liu

    2012-09-01

    Full Text Available Most node localization algorithms for wireless sensor network (WSN are only applicable to two-dimensional networks. However, in most cases, nodes are placed in three-dimensional (3D terrains, such as forests, oceans, etc. In this paper, a range-based 3D localization method is put forward based on time-of-arrival (TOA estimation of ultra wideband signal using unitary matrix pencil (UMP algorithm. The proposed method combines UMP algorithm, multilateral localization with 3D Taylor algorithm. UMP algorithm is a matrix pencil (MP algorithm with utilization of a unitary transform, which is traditionally used to estimate angle-of-arrival (AOA. Here it is extended to estimate TOA to measure the propagation distance between an unknown node and an anchor node, which reduces the computational complexity significantly. By simulation, the accuracy of UMP algorithm is compared with MP algorithm to validate the effectiveness in positioning WSN nodes in a 3D space. This method has superiorities over conventional methods in many aspects, such as higher 3D positioning accuracy, smaller computational amount, suppression over non-Gaussian noise, energy saving, faster executing, etc.

  2. A method of 3D CAD model retrieval based on feature adjacent graph

    Shi, Min; Zhang, Shusheng

    2013-03-01

    To reuse the 3D CAD model, a new method of 3D CAD model retrieval based on feature adjacent graph is proposed. First, a representation of feature adjacent graph for the CAD model is extracted by automatic identification-based and interactive identification-assisted. Next, the vertex product graph of the two CAD model's feature adjacent graphs is constructed, and then the ant colony algorithm is employed to detect the maximum-cliques in the vertex product graph. At last, the similarity of the models is calculated by comparing the maximum-cliques. Experimental results show that this method can realize the 3D CAD model retrieval and its efficiency meets the requirements of applications.

  3. Computer-Assisted Hepatocellular Carcinoma Ablation Planning Based on 3-D Ultrasound Imaging.

    Li, Kai; Su, Zhongzhen; Xu, Erjiao; Guan, Peishan; Li, Liu-Jun; Zheng, Rongqin

    2016-08-01

    To evaluate computer-assisted hepatocellular carcinoma (HCC) ablation planning based on 3-D ultrasound, 3-D ultrasound images of 60 HCC lesions from 58 patients were obtained and transferred to a research toolkit. Compared with virtual manual ablation planning (MAP), virtual computer-assisted ablation planning (CAP) consumed less time and needle insertion numbers and exhibited a higher rate of complete tumor coverage and lower rate of critical structure injury. In MAP, junior operators used less time, but had more critical structure injury than senior operators. For large lesions, CAP performed better than MAP. For lesions near critical structures, CAP resulted in better outcomes than MAP. Compared with MAP, CAP based on 3-D ultrasound imaging was more effective and achieved a higher rate of complete tumor coverage and a lower rate of critical structure injury; it is especially useful for junior operators and with large lesions, and lesions near critical structures. PMID:27126243

  4. Stereo-vision based 3D modeling for unmanned ground vehicles

    Se, Stephen; Jasiobedzki, Piotr

    2007-04-01

    Instant Scene Modeler (iSM) is a vision system for generating calibrated photo-realistic 3D models of unknown environments quickly using stereo image sequences. Equipped with iSM, Unmanned Ground Vehicles (UGVs) can capture stereo images and create 3D models to be sent back to the base station, while they explore unknown environments. Rapid access to 3D models will increase the operator situational awareness and allow better mission planning and execution, as the models can be visualized from different views and used for relative measurements. Current military operations of UGVs in urban warfare threats involve the operator hand-sketching the environment from live video feed. iSM eliminates the need for an additional operator as the 3D model is generated automatically. The photo-realism of the models enhances the situational awareness of the mission and the models can also be used for change detection. iSM has been tested on our autonomous vehicle to create photo-realistic 3D models while the rover traverses in unknown environments. Moreover, a proof-of-concept iSM payload has been mounted on an iRobot PackBot with Wayfarer technology, which is equipped with autonomous urban reconnaissance capabilities. The Wayfarer PackBot UGV uses wheel odometry for localization and builds 2D occupancy grid maps from a laser sensor. While the UGV is following walls and avoiding obstacles, iSM captures and processes images to create photo-realistic 3D models. Experimental results show that iSM can complement Wayfarer PackBot's autonomous navigation in two ways. The photo-realistic 3D models provide better situational awareness than 2D grid maps. Moreover, iSM also recovers the camera motion, also known as the visual odometry. As wheel odometry error grows over time, this can help improve the wheel odometry for better localization.

  5. Robust Segmentation of Voxel Shapes using Medial Surfaces

    Reniers, Dennie; Telea, Alexandru

    2008-01-01

    We present a new patch-type segmentation method for 3D voxel shapes based on the medial surface, also called surface skeleton. The boundaries of the simplified fore- and background skeletons map one-to-one to increasingly fuzzy, soft convex, respectively concave, edges of the shape. Using this prope

  6. Investigating structural brain changes of dehydration using voxel-based morphometry.

    Daniel-Paolo Streitbürger

    Full Text Available Dehydration can affect the volume of brain structures, which might imply a confound in volumetric and morphometric studies of normal or diseased brain. Six young, healthy volunteers were repeatedly investigated using three-dimensional T(1-weighted magnetic resonance imaging during states of normal hydration, hyperhydration, and dehydration to assess volume changes in gray matter (GM, white matter (WM, and cerebrospinal fluid (CSF. The datasets were analyzed using voxel-based morphometry (VBM, a widely used voxel-wise statistical analysis tool, FreeSurfer, a fully automated volumetric segmentation measure, and SIENAr a longitudinal brain-change detection algorithm. A significant decrease of GM and WM volume associated with dehydration was found in various brain regions, most prominently, in temporal and sub-gyral parietal areas, in the left inferior orbito-frontal region, and in the extra-nuclear region. Moreover, we found consistent increases in CSF, that is, an expansion of the ventricular system affecting both lateral ventricles, the third, and the fourth ventricle. Similar degrees of shrinkage in WM volume and increase of the ventricular system have been reported in studies of mild cognitive impairment or Alzheimer's disease during disease progression. Based on these findings, a potential confound in GM and WM or ventricular volume studies due to the subjects' hydration state cannot be excluded and should be appropriately addressed in morphometric studies of the brain.

  7. Investigating structural brain changes of dehydration using voxel-based morphometry.

    Streitbürger, Daniel-Paolo; Möller, Harald E; Tittgemeyer, Marc; Hund-Georgiadis, Margret; Schroeter, Matthias L; Mueller, Karsten

    2012-01-01

    Dehydration can affect the volume of brain structures, which might imply a confound in volumetric and morphometric studies of normal or diseased brain. Six young, healthy volunteers were repeatedly investigated using three-dimensional T(1)-weighted magnetic resonance imaging during states of normal hydration, hyperhydration, and dehydration to assess volume changes in gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF). The datasets were analyzed using voxel-based morphometry (VBM), a widely used voxel-wise statistical analysis tool, FreeSurfer, a fully automated volumetric segmentation measure, and SIENAr a longitudinal brain-change detection algorithm. A significant decrease of GM and WM volume associated with dehydration was found in various brain regions, most prominently, in temporal and sub-gyral parietal areas, in the left inferior orbito-frontal region, and in the extra-nuclear region. Moreover, we found consistent increases in CSF, that is, an expansion of the ventricular system affecting both lateral ventricles, the third, and the fourth ventricle. Similar degrees of shrinkage in WM volume and increase of the ventricular system have been reported in studies of mild cognitive impairment or Alzheimer's disease during disease progression. Based on these findings, a potential confound in GM and WM or ventricular volume studies due to the subjects' hydration state cannot be excluded and should be appropriately addressed in morphometric studies of the brain. PMID:22952926

  8. Regional gray matter abnormalities in patients with schizophrenia determined with optimized voxel-based morphometry

    Guo, XiaoJuan; Yao, Li; Jin, Zhen; Chen, Kewei

    2006-03-01

    This study examined regional gray matter abnormalities across the whole brain in 19 patients with schizophrenia (12 males and 7 females), comparing with 11 normal volunteers (7 males and 4 females). The customized brain templates were created in order to improve spatial normalization and segmentation. Then automated preprocessing of magnetic resonance imaging (MRI) data was conducted using optimized voxel-based morphometry (VBM). The statistical voxel based analysis was implemented in terms of two-sample t-test model. Compared with normal controls, regional gray matter concentration in patients with schizophrenia was significantly reduced in the bilateral superior temporal gyrus, bilateral middle frontal and inferior frontal gyrus, right insula, precentral and parahippocampal areas, left thalamus and hypothalamus as well as, however, significant increases in gray matter concentration were not observed across the whole brain in the patients. This study confirms and extends some earlier findings on gray matter abnormalities in schizophrenic patients. Previous behavior and fMRI researches on schizophrenia have suggested that cognitive capacity decreased and self-conscious weakened in schizophrenic patients. These regional gray matter abnormalities determined through structural MRI with optimized VBM may be potential anatomic underpinnings of schizophrenia.

  9. Matching Aerial Images to 3d Building Models Based on Context-Based Geometric Hashing

    Jung, J.; Bang, K.; Sohn, G.; Armenakis, C.

    2016-06-01

    In this paper, a new model-to-image framework to automatically align a single airborne image with existing 3D building models using geometric hashing is proposed. As a prerequisite process for various applications such as data fusion, object tracking, change detection and texture mapping, the proposed registration method is used for determining accurate exterior orientation parameters (EOPs) of a single image. This model-to-image matching process consists of three steps: 1) feature extraction, 2) similarity measure and matching, and 3) adjustment of EOPs of a single image. For feature extraction, we proposed two types of matching cues, edged corner points representing the saliency of building corner points with associated edges and contextual relations among the edged corner points within an individual roof. These matching features are extracted from both 3D building and a single airborne image. A set of matched corners are found with given proximity measure through geometric hashing and optimal matches are then finally determined by maximizing the matching cost encoding contextual similarity between matching candidates. Final matched corners are used for adjusting EOPs of the single airborne image by the least square method based on co-linearity equations. The result shows that acceptable accuracy of single image's EOP can be achievable by the proposed registration approach as an alternative to labour-intensive manual registration process.

  10. MATCHING AERIAL IMAGES TO 3D BUILDING MODELS BASED ON CONTEXT-BASED GEOMETRIC HASHING

    J. Jung

    2016-06-01

    Full Text Available In this paper, a new model-to-image framework to automatically align a single airborne image with existing 3D building models using geometric hashing is proposed. As a prerequisite process for various applications such as data fusion, object tracking, change detection and texture mapping, the proposed registration method is used for determining accurate exterior orientation parameters (EOPs of a single image. This model-to-image matching process consists of three steps: 1 feature extraction, 2 similarity measure and matching, and 3 adjustment of EOPs of a single image. For feature extraction, we proposed two types of matching cues, edged corner points representing the saliency of building corner points with associated edges and contextual relations among the edged corner points within an individual roof. These matching features are extracted from both 3D building and a single airborne image. A set of matched corners are found with given proximity measure through geometric hashing and optimal matches are then finally determined by maximizing the matching cost encoding contextual similarity between matching candidates. Final matched corners are used for adjusting EOPs of the single airborne image by the least square method based on co-linearity equations. The result shows that acceptable accuracy of single image's EOP can be achievable by the proposed registration approach as an alternative to labour-intensive manual registration process.

  11. 3D resolution enhancement of deep-tissue imaging based on virtual spatial overlap modulation microscopy.

    Su, I-Cheng; Hsu, Kuo-Jen; Shen, Po-Ting; Lin, Yen-Yin; Chu, Shi-Wei

    2016-07-25

    During the last decades, several resolution enhancement methods for optical microscopy beyond diffraction limit have been developed. Nevertheless, those hardware-based techniques typically require strong illumination, and fail to improve resolution in deep tissue. Here we develop a high-speed computational approach, three-dimensional virtual spatial overlap modulation microscopy (3D-vSPOM), which immediately solves the strong-illumination issue. By amplifying only the spatial frequency component corresponding to the un-scattered point-spread-function at focus, plus 3D nonlinear value selection, 3D-vSPOM shows significant resolution enhancement in deep tissue. Since no iteration is required, 3D-vSPOM is much faster than iterative deconvolution. Compared to non-iterative deconvolution, 3D-vSPOM does not need a priori information of point-spread-function at deep tissue, and provides much better resolution enhancement plus greatly improved noise-immune response. This method is ready to be amalgamated with two-photon microscopy or other laser scanning microscopy to enhance deep-tissue resolution. PMID:27464077

  12. An Interactive 3D Graphics Modeler Based on Simulated Human Immune System

    Hiroaki Nishino

    2008-07-01

    Full Text Available We propose an intuitive computer graphics authoring method based on interactive evolutionary computation (IEC. Our previous systems employed genetic algorithm (GA and mainly focused on rapid exploration of a single optimum 3D graphics model. The proposed method adopts a different computation strategy called immune algorithm (IA to ease the creation of varied 3D models even if a user doesn’t have any specific idea of final 3D products. Because artistic work like graphics design needs a process to diversify the user’s imagery, a tool that allows the user to select his/her preferred ones from a broad range of possible design solutions is particularly desired. IA enables the user to effectively explore a wealth of solutions in a huge 3D parametric space by using its essential mechanisms such as antibody formation and self-regulating function. We conducted an experiment to verify the effectiveness of the proposed method. The results show that the proposed method helps the user to easily generating wide variety of 3D graphics models.

  13. Electro-bending characterization of adaptive 3D fiber reinforced plastics based on shape memory alloys

    Ashir, Moniruddoza; Hahn, Lars; Kluge, Axel; Nocke, Andreas; Cherif, Chokri

    2016-03-01

    The industrial importance of fiber reinforced plastics (FRPs) is growing steadily in recent years, which are mostly used in different niche products, has been growing steadily in recent years. The integration of sensors and actuators in FRP is potentially valuable for creating innovative applications and therefore the market acceptance of adaptive FRP is increasing. In particular, in the field of highly stressed FRP, structural integrated systems for continuous component parts monitoring play an important role. This presented work focuses on the electro-mechanical characterization of adaptive three-dimensional (3D)FRP with integrated textile-based actuators. Here, the friction spun hybrid yarn, consisting of shape memory alloy (SMA) in wire form as core, serves as an actuator. Because of the shape memory effect, the SMA-hybrid yarn returns to its original shape upon heating that also causes the deformation of adaptive 3D FRP. In order to investigate the influences of the deformation behavior of the adaptive 3D FRP, investigations in this research are varied according to the structural parameters such as radius of curvature of the adaptive 3D FRP, fabric types and number of layers of the fabric in the composite. Results show that reproducible deformations can be realized with adaptive 3D FRP and that structural parameters have a significant impact on the deformation capability.

  14. Design-for-test and test optimization techniques for TSV-based 3D stacked ICs

    Noia, Brandon

    2014-01-01

    This book describes innovative techniques to address the testing needs of 3D stacked integrated circuits (ICs) that utilize through-silicon-vias (TSVs) as vertical interconnects.  The authors identify the key challenges facing 3D IC testing and present results that have emerged from cutting-edge research in this domain.  Coverage includes topics ranging from die-level wrappers, self-test circuits, and TSV probing to test-architecture design, test scheduling, and optimization.  Readers will benefit from an in-depth look at test-technology solutions that are needed to make 3D ICs a reality and commercially viable.   • Provides a comprehensive guide to the challenges and solutions for the testing of TSV-based 3D stacked ICs; • Includes in-depth explanation of key test and design-for-test technologies, emerging standards, and test- architecture and test-schedule optimizations; • Encompasses all aspects of test as related to 3D ICs, including pre-bond and post-bond test as well as the test optimizatio...

  15. Interactive Cosmetic Makeup of a 3D Point-Based Face Model

    Kim, Jeong-Sik; Choi, Soo-Mi

    We present an interactive system for cosmetic makeup of a point-based face model acquired by 3D scanners. We first enhance the texture of a face model in 3D space using low-pass Gaussian filtering, median filtering, and histogram equalization. The user is provided with a stereoscopic display and haptic feedback, and can perform simulated makeup tasks including the application of foundation, color makeup, and lip gloss. Fast rendering is achieved by processing surfels using the GPU, and we use a BSP tree data structure and a dynamic local refinement of the facial surface to provide interactive haptics. We have implemented a prototype system and evaluated its performance.

  16. Medical image analysis of 3D CT images based on extensions of Haralick texture features

    Tesař, Ludvík; Shimizu, A.; Smutek, D.; Kobatake, H.; Nawano, S.

    2008-01-01

    Roč. 32, č. 6 (2008), s. 513-520. ISSN 0895-6111 R&D Projects: GA AV ČR 1ET101050403; GA MŠk 1M0572 Institutional research plan: CEZ:AV0Z10750506 Keywords : image segmentation * Gaussian mixture model * 3D image analysis Subject RIV: IN - Informatics, Computer Science Impact factor: 1.192, year: 2008 http://library.utia.cas.cz/separaty/2008/AS/tesar-medical image analysis of 3d ct image s based on extensions of haralick texture features.pdf

  17. Rio-H: historical 3D models in a web-based system

    Kós, José R.

    2005-01-01

    This paper aims to explore the use of information technology, particularly 3D models, for the city history research. Rio-H, a web-based system is as a digital alternative for the representation of the city history. Three systems developed by ABACUS research group, in Glasgow, are analyzed for its influence on Rio-H conception. The tool developed as a prototype is grounded on 3D models representing different periods of the city linked to a database of a great diversity of histor...

  18. Smartphone-based 3D real-time vision system for teleoperation

    Servetti, Antonio; Masala, Enrico

    2013-01-01

    We present a small form factor 3D vision system that can easily be mounted in any system for teleoperation and presents a low-latency suitable to perform interactive control. The proposed system is based on a commercial 3D smartphone that integrates a stereoscopic camera and a wireless connection. The smartphone has been customized to acquire and transmit stereoscopic video in real-time by means of a special purpose software that runs on the Android operating system. We believe that the choic...

  19. Antiproliferative Activity and Cellular Uptake of Evodiamine and Rutaecarpine Based on 3D Tumor Models

    Hui Guo; Dongmei Liu; Bin Gao; Xiaohui Zhang; Minli You; Hui Ren; Hongbo Zhang; Santos, Hélder A.; Feng Xu

    2016-01-01

    Evodiamine (EVO) and rutaecarpine (RUT) are promising anti-tumor drug candidates. The evaluation of the anti-proliferative activity and cellular uptake of EVO and RUT in 3D multicellular spheroids of cancer cells would better recapitulate the native situation and thus better reflect an in vivo response to the treatment. Herein, we employed the 3D culture of MCF-7 and SMMC-7721 cells based on hanging drop method and evaluated the anti-proliferative activity and cellular uptake of EVO and RUT i...

  20. A Simple Isolation Criterion based on 3D Redshift Space Mapping

    Spector, Oded; Brosch, Noah

    2009-01-01

    We selected a sample of galaxies, extremely isolated in 3D redshift space, based on data from NED and the ongoing ALFALFA HI (21cm) survey. A simple selection criterion was employed: having no neighbors closer than 300 km/s in 3D redshift space. The environments of galaxies, selected using this criterion and NED data alone, were analyzed theoretically using a constrained simulation of the local Universe, and were found to be an order of magnitude less dense than environments around randomly s...

  1. Hierarchical online appearance-based tracking for 3D head pose, eyebrows, lips, eyelids, and irises

    Orozco, Javier; Rudovic, Ognjen; Gonzàlez, Jordi; Pantic, Maja

    2013-01-01

    In this paper, we propose an On-line Appearance-Based Tracker (OABT) for simultaneous tracking of 3D head pose, lips, eyebrows, eyelids and irises in monocular video sequences. In contrast to previously proposed tracking approaches, which deal with face and gaze tracking separately, our OABT can also be used for eyelid and iris tracking, as well as 3D head pose, lips and eyebrows facial actions tracking. Furthermore, our approach applies an on-line learning of changes in the appearance of the...

  2. A voxel-based investigation for MRI-only radiotherapy of the brain using ultra short echo times

    Edmund, Jens Morgenthaler; Kjer, Hans Martin; Van Leemput, Koen;

    2014-01-01

    receiving cranial irradiation, each containing a co-registered MRI and CT scan, were included. An ultra short echo time MRI sequence for bone visualization was used. Six methods were investigated for three popular types of voxel-based approaches; (1) threshold-based segmentation, (2) Bayesian segmentation...... and (3) statistical regression. Each approach contained two methods. Approach 1 used bulk density assignment of MRI voxels into air, soft tissue and bone based on logical masks and the transverse relaxation time T2 of the bone. Approach 2 used similar bulk density assignments with Bayesian statistics......, however, need to be assigned to the MRI images for dose calculation and patient setup based on digitally reconstructed radiographs (DRRs). Here, we investigate the geometric and dosimetric performance for a number of popular voxel-based methods to generate a so-called pseudo CT (pCT). Five patients...

  3. Treatment plan modification using voxel-based weighting factors/dose prescription

    Under various clinical situations, it is desirable to modify the original treatment plan to better suit the clinical goals. In this work, a method to help physicians modify treatment plans based on their clinical preferences is proposed. The method uses a weighted quadratic dose objective function. The commonly used organ-/ROI-based weighting factors are expanded to a set of voxel-based weighting factors in order to obtain greater flexibility in treatment plan modification. Two different but equivalent modification schemes based on Rustem's quadratic programming algorithms -modification of a weighting matrix and modification of prescribed doses - are presented. Case studies demonstrated the effectiveness of the two methods with regard to their capability to fine-tune treatment plans

  4. Novel video coding algorithm based on 3D-binDCT

    NI Wei; GUO Bao-long; YANG Liu

    2005-01-01

    In this paper we propose a three dimensional multiplierless discrete cosine transform(DCT) with lifting scheme called 3D-binDCT.Based on 3D-binDCT,a novel video coding algorithm without motion estimation/compensation is proposed.It uses the 3D-binDCT to exploit spatial or temporal redundancy.The computation of binDCT only needs shift and addition operations,thus the computational complexity is minimized.DC coefficient prediction,modified scan mode and arithmetic coding techniques are also adopted.Extensive simulation results show that the proposed coding scheme provides higher coding efficiency and improves visual quality, and it is easy to be realized by software and hardware.

  5. 3D visualization based customer experiences of nuclear plant control room

    This paper employs virtual reality (VR) technology to develop an interactive virtual nuclear plant control room in which the general public could easily walk into the 'red zone' and play with the control buttons. The VR-based approach allows deeper and richer customer experiences that the real nuclear plant control room could not offer. When people know more about the serious process control procedures enforced in the nuclear plant control room, they will appropriate more about the safety efforts imposed by the nuclear plant and become more comfortable about the nuclear plant. The virtual nuclear plant control room is built using a 3D game development tool called Unity3D. The 3D scene is connected to a nuclear plant simulation system through Windows API programs. To evaluate the usability of the virtual control room, an experiment will be conducted to see how much 'immersion' the users could feel when they played with the virtual control room. (author)

  6. Novel Aerial 3D Mapping System Based on UAV Platforms and 2D Laser Scanners

    David Roca

    2016-01-01

    Full Text Available The acquisition of 3D geometric data from an aerial view implies a high number of advantages with respect to terrestrial acquisition, the greatest being that aerial view allows the acquisition of information from areas with no or difficult accessibility, such as roofs and tops of trees. If the aerial platform is copter-type, other advantages are present, such as the capability of displacement at very low-speed, allowing for a more detailed acquisition. This paper presents a novel Aerial 3D Mapping System based on a copter-type platform, where a 2D laser scanner is integrated with a GNSS sensor and an IMU for the generation of georeferenced 3D point clouds. The accuracy and precision of the system are evaluated through the measurement of geometries in the point clouds generated by the system, as well as through the geolocation of target points for which the real global coordinates are known.

  7. Single-pixel 3D imaging with time-based depth resolution

    Sun, Ming-Jie; Gibson, Graham M; Sun, Baoqing; Radwell, Neal; Lamb, Robert; Padgett, Miles J

    2016-01-01

    Time-of-flight three dimensional imaging is an important tool for many applications, such as object recognition and remote sensing. Unlike conventional imaging approach using pixelated detector array, single-pixel imaging based on projected patterns, such as Hadamard patterns, utilises an alternative strategy to acquire information with sampling basis. Here we show a modified single-pixel camera using a pulsed illumination source and a high-speed photodiode, capable of reconstructing 128x128 pixel resolution 3D scenes to an accuracy of ~3 mm at a range of ~5 m. Furthermore, we demonstrate continuous real-time 3D video with a frame-rate up to 12 Hz. The simplicity of the system hardware could enable low-cost 3D imaging devices for precision ranging at wavelengths beyond the visible spectrum.

  8. Development of an indirect solid freeform fabrication process based on microstereolithography for 3D porous scaffolds

    Kang, Hyun-Wook; Seol, Young-Joon; Cho, Dong-Woo

    2009-01-01

    Scaffold fabrication using solid freeform fabrication (SFF) technology is a hot topic in tissue engineering. Here, we present a new indirect SFF technology based on microstereolithography (MSTL), which has the highest resolution of all SFF methods, to construct a three-dimensional (3D) porous scaffold by combining SFF with molding technology. To realize this indirect method, we investigated and modified a water-soluble photopolymer. We used MSTL technology to fabricate a high-resolution 3D porous mold composed of the modified polymer. The mold can be removed using an appropriate solvent. We tested two materials, polycaprolactone and calcium sulfate hemihydrate, using the molding process, and developed a lost-mold shape forming process by dissolving the mold. This procedure demonstrated that the proposed method can yield scaffold pore sizes as small as 60-70 µm. In addition, cytotoxicity test results indicated that the proposed process is feasible for producing 3D porous scaffolds.

  9. Development of an indirect solid freeform fabrication process based on microstereolithography for 3D porous scaffolds

    Scaffold fabrication using solid freeform fabrication (SFF) technology is a hot topic in tissue engineering. Here, we present a new indirect SFF technology based on microstereolithography (MSTL), which has the highest resolution of all SFF methods, to construct a three-dimensional (3D) porous scaffold by combining SFF with molding technology. To realize this indirect method, we investigated and modified a water-soluble photopolymer. We used MSTL technology to fabricate a high-resolution 3D porous mold composed of the modified polymer. The mold can be removed using an appropriate solvent. We tested two materials, polycaprolactone and calcium sulfate hemihydrate, using the molding process, and developed a lost-mold shape forming process by dissolving the mold. This procedure demonstrated that the proposed method can yield scaffold pore sizes as small as 60–70 µm. In addition, cytotoxicity test results indicated that the proposed process is feasible for producing 3D porous scaffolds

  10. Size-based emphysema cluster analysis on low attenuation area in 3D volumetric CT: comparison with pulmonary functional test

    Lee, Minho; Kim, Namkug; Lee, Sang Min; Seo, Joon Beom; Oh, Sang Young

    2015-03-01

    To quantify low attenuation area (LAA) of emphysematous regions according to cluster size in 3D volumetric CT data of chronic obstructive pulmonary disease (COPD) patients and to compare these indices with their pulmonary functional test (PFT). Sixty patients with COPD were scanned by a more than 16-multi detector row CT scanner (Siemens Sensation 16 and 64) within 0.75mm collimation. Based on these LAA masks, a length scale analysis to estimate each emphysema LAA's size was performed as follows. At first, Gaussian low pass filter from 30mm to 1mm kernel size with 1mm interval on the mask was performed from large to small size, iteratively. Centroid voxels resistant to the each filter were selected and dilated by the size of the kernel, which was regarded as the specific size emphysema mask. The slopes of area and number of size based LAA (slope of semi-log plot) were analyzed and compared with PFT. PFT parameters including DLco, FEV1, and FEV1/FVC were significantly (all p-value< 0.002) correlated with the slopes (r-values; -0.73, 0.54, 0.69, respectively) and EI (r-values; -0.84, -0.60, -0.68, respectively). In addition, the D independently contributed regression for FEV1 and FEV1/FVC (adjust R sq. of regression study: EI only, 0.70, 0.45; EI and D, 0.71, 0.51, respectively). By the size based LAA segmentation and analysis, we evaluated the Ds of area, number, and distribution of size based LAA, which would be independent factors for predictor of PFT parameters.

  11. Permutation and parametric tests for effect sizes in voxel-based morphometry of gray matter volume in brain structural MRI.

    Dickie, David A; Mikhael, Shadia; Job, Dominic E; Wardlaw, Joanna M; Laidlaw, David H; Bastin, Mark E

    2015-12-01

    Permutation testing has been widely implemented in voxel-based morphometry (VBM) tools. However, this type of non-parametric inference has yet to be thoroughly compared with traditional parametric inference in VBM studies of brain structure. Here we compare both types of inference and investigate what influence the number of permutations in permutation testing has on results in an exemplar study of how gray matter proportion changes with age in a group of working age adults. High resolution T1-weighted volume scans were acquired from 80 healthy adults aged 25-64years. Using a validated VBM procedure and voxel-based permutation testing for Pearson product-moment coefficient, the effect sizes of changes in gray matter proportion with age were assessed using traditional parametric and permutation testing inference with 100, 500, 1000, 5000, 10000 and 20000 permutations. The statistical significance was set at PPFDR<0.05) declines in gray matter proportion with age identified with permutation testing inference (N≈6000) were approximately twice the size of those identified with parametric inference (N=3221voxels). Permutation testing with 10000 (N=6251voxels) and 20000 (N=6233voxels) permutations produced clusters that were generally consistent with each other. However, with 1000 permutations there were approximately 20% more statistically significant voxels (N=7117voxels) than with ≥10000 permutations. Permutation testing inference may provide a more sensitive method than traditional parametric inference for identifying age-related differences in gray matter proportion. Based on the results reported here, at least 10000 permutations should be used in future univariate VBM studies investigating age related changes in gray matter to avoid potential false findings. Additional studies using permutation testing in large imaging databanks are required to address the impact of model complexity, multivariate analysis, number of observations, sampling bias and data quality

  12. METHOD FOR ADAPTIVE MESH GENERATION BASED ON GEOMETRICAL FEATURES OF 3D SOLID

    HUANG Xiaodong; DU Qungui; YE Bangyan

    2006-01-01

    In order to provide a guidance to specify the element size dynamically during adaptive finite element mesh generation, adaptive criteria are firstly defined according to the relationships between the geometrical features and the elements of 3D solid. Various modes based on different datum geometrical elements, such as vertex, curve, surface, and so on, are then designed for generating local refmed mesh. With the guidance of the defined criteria, different modes are automatically selected to apply on the appropriate datum objects to program the element size in the local special areas. As a result, the control information of element size is successfully programmed coveting the entire domain based on the geometrical features of 3D solid. A new algorithm based on Delaunay triangulation is then developed for generating 3D adaptive fmite element mesh, in which the element size is dynamically specified to catch the geometrical features and suitable tetrahedron facets are selected to locate interior nodes continuously. As a result, adaptive mesh with good-quality elements is generated. Examples show that the proposed method can be successfully applied to adaptive finite element mesh automatic generation based on the geometrical features of 3D solid.

  13. Validation of SPAMM tagged MRI based measurement of 3D soft tissue deformation

    K.M. Moerman; A.M.J. Sprengers; C.K. Simms; R.M. Lamerichs; J. Stoker; A.J. Nederveen

    2011-01-01

    This study presents and validates a novel (non-ECG-triggered) MRI sequence based on spatial modulation of the magnetization (SPAMM) to noninvasively measure 3D (quasistatic) soft tissue deformations using only six acquisitions (three static and three indentations). In the current SPAMM tagged MRI ap

  14. A joint multi-view plus depth image coding scheme based on 3D-warping

    Zamarin, Marco; Zanuttigh, Pietro; Milani, Simone;

    2011-01-01

    scene structure that can be effectively exploited to improve the performance of multi-view coding schemes. In this paper we introduce a novel coding architecture that replaces the inter-view motion prediction operation with a 3D warping approach based on depth information to improve the coding...

  15. A Bioactive Carbon Nanotube-Based Ink for Printing 2D and 3D Flexible Electronics.

    Shin, Su Ryon; Farzad, Raziyeh; Tamayol, Ali; Manoharan, Vijayan; Mostafalu, Pooria; Zhang, Yu Shrike; Akbari, Mohsen; Jung, Sung Mi; Kim, Duckjin; Comotto, Mattia; Annabi, Nasim; Al-Hazmi, Faten Ebrahim; Dokmeci, Mehmet R; Khademhosseini, Ali

    2016-05-01

    The development of electrically conductive carbon nanotube-based inks is reported. Using these inks, 2D and 3D structures are printed on various flexible substrates such as paper, hydrogels, and elastomers. The printed patterns have mechanical and electrical properties that make them beneficial for various biological applications. PMID:26915715

  16. 3D Partition-Based Clustering for Supply Chain Data Management

    Suhaibah, A.; Uznir, U.; Anton, François;

    2015-01-01

    coverage are computed and compared with the original 3D R-Tree and other practical approaches. The experiments demonstrated in this paper substantiated that the hierarchical structure of the proposed partition-based clustering is capable of preserving minimal overlap and coverage. The query performance was...

  17. Multimedia software design of automobile construction based on 3D engine

    Xu, Guo-dong; Chi, Xiao-xia

    2013-03-01

    This paper introduces the methods of three-dimensional modeling, assembling and simulating design of an automobile based on 3D engine, Pro/Engineer and 3DSMax. Research is also carried out on the order and the route of virtual assembling as well the corresponding processes.

  18. Hierarchical online appearance-based tracking for 3D head pose, eyebrows, lips, eyelids, and irises

    Orozco, Javier; Rudovic, Ognjen; Gonzalez Garcia, Jordi; Pantic, Maja

    2013-01-01

    In this paper, we propose an On-line Appearance-Based Tracker (OABT) for simultaneous tracking of 3D head pose, lips, eyebrows, eyelids and irises in monocular video sequences. In contrast to previously proposed tracking approaches, which deal with face and gaze tracking separately, our OABT can als

  19. Impact of 3-D printed PLA- and chitosan-based scaffolds on human monocyte/macrophage responses: unraveling the effect of 3-D structures on inflammation.

    Almeida, Catarina R; Serra, Tiziano; Oliveira, Marta I; Planell, Josep A; Barbosa, Mário A; Navarro, Melba

    2014-02-01

    Recent studies have pointed towards a decisive role of inflammation in triggering tissue repair and regeneration, while at the same time it is accepted that an exacerbated inflammatory response may lead to rejection of an implant. Within this context, understanding and having the capacity to regulate the inflammatory response elicited by 3-D scaffolds aimed for tissue regeneration is crucial. This work reports on the analysis of the cytokine profile of human monocytes/macrophages in contact with biodegradable 3-D scaffolds with different surface properties, architecture and controlled pore geometry, fabricated by 3-D printing technology. Fabrication processes were optimized to create four different 3-D platforms based on polylactic acid (PLA), PLA/calcium phosphate glass or chitosan. Cytokine secretion and cell morphology of human peripheral blood monocytes allowed to differentiate on the different matrices were analyzed. While all scaffolds supported monocyte/macrophage adhesion and stimulated cytokine production, striking differences between PLA-based and chitosan scaffolds were found, with chitosan eliciting increased secretion of tumor necrosis factor (TNF)-α, while PLA-based scaffolds induced higher production of interleukin (IL)-6, IL-12/23 and IL-10. Even though the material itself induced the biggest differences, the scaffold geometry also impacted on TNF-α and IL-12/23 production, with chitosan scaffolds having larger pores and wider angles leading to a higher secretion of these pro-inflammatory cytokines. These findings strengthen the appropriateness of these 3-D platforms to study modulation of macrophage responses by specific parameters (chemistry, topography, scaffold architecture). PMID:24211731

  20. 3D Face Recognition based on Radon Transform, PCA, LDA using KNN and SVM

    P. S. Hiremath

    2014-06-01

    Full Text Available Biometrics (or biometric authentication refers to the identification of humans by their characteristics or traits. Bio-metrics is used in computer science as a form of identification and access control. It is also used to identify individuals in groups that are under surveillance. Biometric identifiers are the distinctive, measurable characteristics used to label and describe individuals. Three dimensional (3D human face recognition is emerging as a significant biometric technology. Research interest into 3D face recognition has increased during recent years due to the availability of improved 3D acquisition devices and processing algorithms. Three dimensional face recognition also helps to resolve some of the issues associated with two dimensional (2D face recognition. In the previous research works, there are several methods for face recognition using range images that are limited to the data acquisition and pre-processing stage only. In the present paper, we have proposed a 3D face recognition algorithm which is based on Radon transform, Principal Component Analysis (PCA and Linear Discriminant Analysis (LDA. The Radon transform (RT is a fundamental tool to normalize 3D range data. The PCA is used to reduce the dimensionality of feature space, and the LDA is used to optimize the features, which are finally used to recognize the faces. The experimentation has been done using three publicly available databases, namely, Bhosphorus, Texas and CASIA 3D face databases. The experimental results are shown that the proposed algorithm is efficient in terms of accuracy and detection time, in comparison with other methods based on PCA only and RT+PCA. It is observed that 40 Eigen faces of PCA and 5 LDA components lead to an average recognition rate of 99.20% using SVM classifier.

  1. Regional White Matter Decreases in Alzheimer's Disease Using Optimized Voxel-Based Morphometry

    Background: Most studies that attempt to clarify structural abnormalities related to functional disconnection in patients with Alzheimer's disease (AD) have focused on exploring pathological changes in cortical gray matter. However, white matter fibers connecting these cerebral areas may also be abnormal. Purpose: To investigate the regional changes of white matter volume in patients with AD compared to healthy subjects. Material and Methods: White matter volume changes in whole-brain magnetic resonance images acquired from 19 patients with AD and 20 healthy subjects (control group) were observed using the optimized voxel-based morphometry (VBM) method. In addition, the corpus callosum (CC) of AD patients and the control group was investigated further by outlining manually the boundary of the CC on a midsagittal slice. Each area of the CC was then corrected by dividing each subject's intracranial area in the midsagittal plane. Results: Compared with the control group, AD patients showed significantly reduced white matter volumes in the posterior part of the CC and the temporal lobe in the left and right hemispheres. Moreover, the voxel showing peak statistical difference in the posterior of the CC was left sided. The five subdivisions of the CC were also significantly smaller among the AD patients relative to the control group. Conclusion: Our findings suggest that these abnormalities in white matter regions may contribute to the functional disconnections in AD

  2. Regional White Matter Decreases in Alzheimer's Disease Using Optimized Voxel-Based Morphometry

    Shuyu Li; Fang Pu; Feng Shi; Sheng Xie; Yinhua Wang; Tianzi Jiang (Dept. of Bioengineering, Beijing Univ. of Aeronautics and Astronautics, Beijing (China))

    2008-02-15

    Background: Most studies that attempt to clarify structural abnormalities related to functional disconnection in patients with Alzheimer's disease (AD) have focused on exploring pathological changes in cortical gray matter. However, white matter fibers connecting these cerebral areas may also be abnormal. Purpose: To investigate the regional changes of white matter volume in patients with AD compared to healthy subjects. Material and Methods: White matter volume changes in whole-brain magnetic resonance images acquired from 19 patients with AD and 20 healthy subjects (control group) were observed using the optimized voxel-based morphometry (VBM) method. In addition, the corpus callosum (CC) of AD patients and the control group was investigated further by outlining manually the boundary of the CC on a midsagittal slice. Each area of the CC was then corrected by dividing each subject's intracranial area in the midsagittal plane. Results: Compared with the control group, AD patients showed significantly reduced white matter volumes in the posterior part of the CC and the temporal lobe in the left and right hemispheres. Moreover, the voxel showing peak statistical difference in the posterior of the CC was left sided. The five subdivisions of the CC were also significantly smaller among the AD patients relative to the control group. Conclusion: Our findings suggest that these abnormalities in white matter regions may contribute to the functional disconnections in AD

  3. Regional White Matter Decreases in Alzheimer's Disease Using Optimized Voxel-Based Morphometry

    Shuyu Li; Fang Pu; Feng Shi; Sheng Xie; Yinhua Wang; Tianzi Jiang [Dept. of Bioengineering, Beijing Univ. of Aeronautics and Astronautics, Beijing (China)

    2008-02-15

    Background: Most studies that attempt to clarify structural abnormalities related to functional disconnection in patients with Alzheimer's disease (AD) have focused on exploring pathological changes in cortical gray matter. However, white matter fibers connecting these cerebral areas may also be abnormal. Purpose: To investigate the regional changes of white matter volume in patients with AD compared to healthy subjects. Material and Methods: White matter volume changes in whole-brain magnetic resonance images acquired from 19 patients with AD and 20 healthy subjects (control group) were observed using the optimized voxel-based morphometry (VBM) method. In addition, the corpus callosum (CC) of AD patients and the control group was investigated further by outlining manually the boundary of the CC on a midsagittal slice. Each area of the CC was then corrected by dividing each subject's intracranial area in the midsagittal plane. Results: Compared with the control group, AD patients showed significantly reduced white matter volumes in the posterior part of the CC and the temporal lobe in the left and right hemispheres. Moreover, the voxel showing peak statistical difference in the posterior of the CC was left sided. The five subdivisions of the CC were also significantly smaller among the AD patients relative to the control group. Conclusion: Our findings suggest that these abnormalities in white matter regions may contribute to the functional disconnections in AD.

  4. Voxel-Based Morphometry ALE meta-analysis of Bipolar Disorder

    Magana, Omar; Laird, Robert

    2012-03-01

    A meta-analysis was performed independently to view the changes in gray matter (GM) on patients with Bipolar disorder (BP). The meta-analysis was conducted on a Talairach Space using GingerALE to determine the voxels and their permutation. In order to achieve the data acquisition, published experiments and similar research studies were uploaded onto the online Voxel-Based Morphometry database (VBM). By doing so, coordinates of activation locations were extracted from Bipolar disorder related journals utilizing Sleuth. Once the coordinates of given experiments were selected and imported to GingerALE, a Gaussian was performed on all foci points to create the concentration points of GM on BP patients. The results included volume reductions and variations of GM between Normal Healthy controls and Patients with Bipolar disorder. A significant amount of GM clusters were obtained in Normal Healthy controls over BP patients on the right precentral gyrus, right anterior cingulate, and the left inferior frontal gyrus. In future research, more published journals could be uploaded onto the database and another VBM meta-analysis could be performed including more activation coordinates or a variation of age groups.

  5. An Efficient Multimodal 2D + 3D Feature-based Approach to Automatic Facial Expression Recognition

    Li, Huibin

    2015-07-29

    We present a fully automatic multimodal 2D + 3D feature-based facial expression recognition approach and demonstrate its performance on the BU-3DFE database. Our approach combines multi-order gradient-based local texture and shape descriptors in order to achieve efficiency and robustness. First, a large set of fiducial facial landmarks of 2D face images along with their 3D face scans are localized using a novel algorithm namely incremental Parallel Cascade of Linear Regression (iPar-CLR). Then, a novel Histogram of Second Order Gradients (HSOG) based local image descriptor in conjunction with the widely used first-order gradient based SIFT descriptor are used to describe the local texture around each 2D landmark. Similarly, the local geometry around each 3D landmark is described by two novel local shape descriptors constructed using the first-order and the second-order surface differential geometry quantities, i.e., Histogram of mesh Gradients (meshHOG) and Histogram of mesh Shape index (curvature quantization, meshHOS). Finally, the Support Vector Machine (SVM) based recognition results of all 2D and 3D descriptors are fused at both feature-level and score-level to further improve the accuracy. Comprehensive experimental results demonstrate that there exist impressive complementary characteristics between the 2D and 3D descriptors. We use the BU-3DFE benchmark to compare our approach to the state-of-the-art ones. Our multimodal feature-based approach outperforms the others by achieving an average recognition accuracy of 86.32%. Moreover, a good generalization ability is shown on the Bosphorus database.

  6. Age and gender effects on normal regional cerebral blood flow studied using two different voxel-based statistical analyses; Effets de l'age et du genre sur la perfusion cerebrale regionale etudiee par deux methodes d'analyse statistique voxel-par-voxel

    Pirson, A.S.; George, J.; Krug, B.; Vander Borght, T. [Universite Catholique de Louvain, Service de Medecine Nucleaire, Cliniques Universitaires de Mont-Godinne, Yvoir (Belgium); Van Laere, K. [Leuven Univ. Hospital, Nuclear Medicine Div. (Belgium); Jamart, J. [Universite Catholique de Louvain, Dept. de Biostatistiques, Cliniques Universitaires de Mont-Godinne, Yvoir (Belgium); D' Asseler, Y. [Ghent Univ., Medical Signal and Image Processing Dept. (MEDISIP), Faculty of applied sciences (Belgium); Minoshima, S. [Washington Univ., Dept. of Radiology, Seattle (United States)

    2009-10-15

    Fully automated analysis programs have been applied more and more to aid for the reading of regional cerebral blood flow SPECT study. They are increasingly based on the comparison of the patient study with a normal database. In this study, we evaluate the ability of Three-Dimensional Stereotactic Surface Projection (3 D-S.S.P.) to isolate effects of age and gender in a previously studied normal population. The results were also compared with those obtained using Statistical Parametric Mapping (S.P.M.99). Methods Eighty-nine {sup 99m}Tc-E.C.D.-SPECT studies performed in carefully screened healthy volunteers (46 females, 43 males; age 20 - 81 years) were analysed using 3 D-S.S.P.. A multivariate analysis based on the general linear model was performed with regions as intra-subject factor, gender as inter-subject factor and age as co-variate. Results Both age and gender had a significant interaction effect with regional tracer uptake. An age-related decline (p < 0.001) was found in the anterior cingulate gyrus, left frontal association cortex and left insula. Bilateral occipital association and left primary visual cortical uptake showed a significant relative increase with age (p < 0.001). Concerning the gender effect, women showed higher uptake (p < 0.01) in the parietal and right sensorimotor cortices. An age by gender interaction (p < 0.01) was only found in the left medial frontal cortex. The results were consistent with those obtained with S.P.M.99. Conclusion 3 D-S.S.P. analysis of normal r.C.B.F. variability is consistent with the literature and other automated voxel-based techniques, which highlight the effects of both age and gender. (authors)

  7. Voxel based morphometry in optical coherence tomography: validation and core findings

    Antony, Bhavna J.; Chen, Min; Carass, Aaron; Jedynak, Bruno M.; Al-Louzi, Omar; Solomon, Sharon D.; Saidha, Shiv; Calabresi, Peter A.; Prince, Jerry L.

    2016-03-01

    Optical coherence tomography (OCT) of the human retina is now becoming established as an important modality for the detection and tracking of various ocular diseases. Voxel based morphometry (VBM) is a long standing neuroimaging analysis technique that allows for the exploration of the regional differences in the brain. There has been limited work done in developing registration based methods for OCT, which has hampered the advancement of VBM analyses in OCT based population studies. Following on from our recent development of an OCT registration method, we explore the potential benefits of VBM analysis in cohorts of healthy controls (HCs) and multiple sclerosis (MS) patients. Specifically, we validate the stability of VBM analysis in two pools of HCs showing no significant difference between the two populations. Additionally, we also present a retrospective study of age and sex matched HCs and relapsing remitting MS patients, demonstrating results consistent with the reported literature while providing insight into the retinal changes associated with this MS subtype.

  8. Inertial Sensor-Based Touch and Shake Metaphor for Expressive Control of 3D Virtual Avatars.

    Patil, Shashidhar; Chintalapalli, Harinadha Reddy; Kim, Dubeom; Chai, Youngho

    2015-01-01

    In this paper, we present an inertial sensor-based touch and shake metaphor for expressive control of a 3D virtual avatar in a virtual environment. An intuitive six degrees-of-freedom wireless inertial motion sensor is used as a gesture and motion control input device with a sensor fusion algorithm. The algorithm enables user hand motions to be tracked in 3D space via magnetic, angular rate, and gravity sensors. A quaternion-based complementary filter is implemented to reduce noise and drift. An algorithm based on dynamic time-warping is developed for efficient recognition of dynamic hand gestures with real-time automatic hand gesture segmentation. Our approach enables the recognition of gestures and estimates gesture variations for continuous interaction. We demonstrate the gesture expressivity using an interactive flexible gesture mapping interface for authoring and controlling a 3D virtual avatar and its motion by tracking user dynamic hand gestures. This synthesizes stylistic variations in a 3D virtual avatar, producing motions that are not present in the motion database using hand gesture sequences from a single inertial motion sensor. PMID:26094629

  9. Inertial Sensor-Based Touch and Shake Metaphor for Expressive Control of 3D Virtual Avatars

    Shashidhar Patil

    2015-06-01

    Full Text Available In this paper, we present an inertial sensor-based touch and shake metaphor for expressive control of a 3D virtual avatar in a virtual environment. An intuitive six degrees-of-freedom wireless inertial motion sensor is used as a gesture and motion control input device with a sensor fusion algorithm. The algorithm enables user hand motions to be tracked in 3D space via magnetic, angular rate, and gravity sensors. A quaternion-based complementary filter is implemented to reduce noise and drift. An algorithm based on dynamic time-warping is developed for efficient recognition of dynamic hand gestures with real-time automatic hand gesture segmentation. Our approach enables the recognition of gestures and estimates gesture variations for continuous interaction. We demonstrate the gesture expressivity using an interactive flexible gesture mapping interface for authoring and controlling a 3D virtual avatar and its motion by tracking user dynamic hand gestures. This synthesizes stylistic variations in a 3D virtual avatar, producing motions that are not present in the motion database using hand gesture sequences from a single inertial motion sensor.

  10. Obstacle classification and 3D measurement in unstructured environments based on ToF cameras.

    Yu, Hongshan; Zhu, Jiang; Wang, Yaonan; Jia, Wenyan; Sun, Mingui; Tang, Yandong

    2014-01-01

    Inspired by the human 3D visual perception system, we present an obstacle detection and classification method based on the use of Time-of-Flight (ToF) cameras for robotic navigation in unstructured environments. The ToF camera provides 3D sensing by capturing an image along with per-pixel 3D space information. Based on this valuable feature and human knowledge of navigation, the proposed method first removes irrelevant regions which do not affect robot's movement from the scene. In the second step, regions of interest are detected and clustered as possible obstacles using both 3D information and intensity image obtained by the ToF camera. Consequently, a multiple relevance vector machine (RVM) classifier is designed to classify obstacles into four possible classes based on the terrain traversability and geometrical features of the obstacles. Finally, experimental results in various unstructured environments are presented to verify the robustness and performance of the proposed approach. We have found that, compared with the existing obstacle recognition methods, the new approach is more accurate and efficient. PMID:24945679

  11. Obstacle Classification and 3D Measurement in Unstructured Environments Based on ToF Cameras

    Hongshan Yu

    2014-06-01

    Full Text Available Inspired by the human 3D visual perception system, we present an obstacle detection and classification method based on the use of Time-of-Flight (ToF cameras for robotic navigation in unstructured environments. The ToF camera provides 3D sensing by capturing an image along with per-pixel 3D space information. Based on this valuable feature and human knowledge of navigation, the proposed method first removes irrelevant regions which do not affect robot’s movement from the scene. In the second step, regions of interest are detected and clustered as possible obstacles using both 3D information and intensity image obtained by the ToF camera. Consequently, a multiple relevance vector machine (RVM classifier is designed to classify obstacles into four possible classes based on the terrain traversability and geometrical features of the obstacles. Finally, experimental results in various unstructured environments are presented to verify the robustness and performance of the proposed approach. We have found that, compared with the existing obstacle recognition methods, the new approach is more accurate and efficient.

  12. Model-based risk assessment for motion effects in 3D radiotherapy of lung tumors

    Werner, René; Ehrhardt, Jan; Schmidt-Richberg, Alexander; Handels, Heinz

    2012-02-01

    Although 4D CT imaging becomes available in an increasing number of radiotherapy facilities, 3D imaging and planning is still standard in current clinical practice. In particular for lung tumors, respiratory motion is a known source of uncertainty and should be accounted for during radiotherapy planning - which is difficult by using only a 3D planning CT. In this contribution, we propose applying a statistical lung motion model to predict patients' motion patterns and to estimate dosimetric motion effects in lung tumor radiotherapy if only 3D images are available. Being generated based on 4D CT images of patients with unimpaired lung motion, the model tends to overestimate lung tumor motion. It therefore promises conservative risk assessment regarding tumor dose coverage. This is exemplarily evaluated using treatment plans of lung tumor patients with different tumor motion patterns and for two treatment modalities (conventional 3D conformal radiotherapy and step-&- shoot intensity modulated radiotherapy). For the test cases, 4D CT images are available. Thus, also a standard registration-based 4D dose calculation is performed, which serves as reference to judge plausibility of the modelbased 4D dose calculation. It will be shown that, if combined with an additional simple patient-specific breathing surrogate measurement (here: spirometry), the model-based dose calculation provides reasonable risk assessment of respiratory motion effects.

  13. Low-cost structured-light based 3D capture system design

    Dong, Jing; Bengtson, Kurt R.; Robinson, Barrett F.; Allebach, Jan P.

    2014-03-01

    Most of the 3D capture products currently in the market are high-end and pricey. They are not targeted for consumers, but rather for research, medical, or industrial usage. Very few aim to provide a solution for home and small business applications. Our goal is to fill in this gap by only using low-cost components to build a 3D capture system that can satisfy the needs of this market segment. In this paper, we present a low-cost 3D capture system based on the structured-light method. The system is built around the HP TopShot LaserJet Pro M275. For our capture device, we use the 8.0 Mpixel camera that is part of the M275. We augment this hardware with two 3M MPro 150 VGA (640 × 480) pocket projectors. We also describe an analytical approach to predicting the achievable resolution of the reconstructed 3D object based on differentials and small signal theory, and an experimental procedure for validating that the system under test meets the specifications for reconstructed object resolution that are predicted by our analytical model. By comparing our experimental measurements from the camera-projector system with the simulation results based on the model for this system, we conclude that our prototype system has been correctly configured and calibrated. We also conclude that with the analytical models, we have an effective means for specifying system parameters to achieve a given target resolution for the reconstructed object.

  14. Sensitivity study of voxel-based PET image comparison to image registration algorithms

    Yip, Stephen, E-mail: syip@lroc.harvard.edu; Chen, Aileen B.; Berbeco, Ross [Department of Radiation Oncology, Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115 (United States); Aerts, Hugo J. W. L. [Department of Radiation Oncology, Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115 and Department of Radiology, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts 02115 (United States)

    2014-11-01

    Purpose: Accurate deformable registration is essential for voxel-based comparison of sequential positron emission tomography (PET) images for proper adaptation of treatment plan and treatment response assessment. The comparison may be sensitive to the method of deformable registration as the optimal algorithm is unknown. This study investigated the impact of registration algorithm choice on therapy response evaluation. Methods: Sixteen patients with 20 lung tumors underwent a pre- and post-treatment computed tomography (CT) and 4D FDG-PET scans before and after chemoradiotherapy. All CT images were coregistered using a rigid and ten deformable registration algorithms. The resulting transformations were then applied to the respective PET images. Moreover, the tumor region defined by a physician on the registered PET images was classified into progressor, stable-disease, and responder subvolumes. Particularly, voxels with standardized uptake value (SUV) decreases >30% were classified as responder, while voxels with SUV increases >30% were progressor. All other voxels were considered stable-disease. The agreement of the subvolumes resulting from difference registration algorithms was assessed by Dice similarity index (DSI). Coefficient of variation (CV) was computed to assess variability of DSI between individual tumors. Root mean square difference (RMS{sub rigid}) of the rigidly registered CT images was used to measure the degree of tumor deformation. RMS{sub rigid} and DSI were correlated by Spearman correlation coefficient (R) to investigate the effect of tumor deformation on DSI. Results: Median DSI{sub rigid} was found to be 72%, 66%, and 80%, for progressor, stable-disease, and responder, respectively. Median DSI{sub deformable} was 63%–84%, 65%–81%, and 82%–89%. Variability of DSI was substantial and similar for both rigid and deformable algorithms with CV > 10% for all subvolumes. Tumor deformation had moderate to significant impact on DSI for progressor

  15. Determination of Magnet Specification of 13 MeV Proton Cyclotron Based on Opera 3D

    Taufik

    2014-08-01

    Full Text Available The magnet is one of the main components of a cyclotron, used to form a circular particle beam trajectories and to provide focusing of the beam. To support the mastery of 13-MeV proton cyclotron technologies, cyclotron magnet design must be done to satisfy cyclotron magnet requirements. This research was conducted by studying important parameters in designing the cyclotron magnet which is then used to determine the design requirements. The magnet design was based on the results of a 3D simulation using Opera 3D software. Opera 3D is a software developed by Cobham plc to solve physical problems in 3D such as magnetostatic using finite element methods. The simulation started by drawing a 3D model of the magnet using a modeler, followed by magnetic field calculations by Tosca module in the Opera 3D software. Simulation results were analyzed with the Genspeo software to determine whether the parameters of the cyclotron magnet have met design requirements. The results indicate that the magnet design satisfied the cyclotron magnet design requirement, that B in the median plane of the magnetic pole approached the isochronous curve, providing axial and radial focusing beam, crossing the resonance line at vr = 1 when the particle energy is low and the particle energy is more than 13 MeV, and lead to small enough phase shift of about 13°. The dimension of the cyclotron magnet is 1.96 m × 1.30 m × 1.21 m; its weight is 17.3 ton; its coil current is 88,024 ampere-turn; its center magnetic field is 1.27479 T; its maximum magnetic field is 1.942116 T; its minimum magnetic field is 0.7689 T; its valley gap is 120 mm; its hill gaps are 40 to 50.78 mm; and its hill angles are 35° to 44°.to 44°

  16. Antiproliferative Activity and Cellular Uptake of Evodiamine and Rutaecarpine Based on 3D Tumor Models

    Hui Guo

    2016-07-01

    Full Text Available Evodiamine (EVO and rutaecarpine (RUT are promising anti-tumor drug candidates. The evaluation of the anti-proliferative activity and cellular uptake of EVO and RUT in 3D multicellular spheroids of cancer cells would better recapitulate the native situation and thus better reflect an in vivo response to the treatment. Herein, we employed the 3D culture of MCF-7 and SMMC-7721 cells based on hanging drop method and evaluated the anti-proliferative activity and cellular uptake of EVO and RUT in 3D multicellular spheroids, and compared the results with those obtained from 2D monolayers. The drugs’ IC50 values were significantly increased from the range of 6.4–44.1 μM in 2D monolayers to 21.8–138.0 μM in 3D multicellular spheroids, which may be due to enhanced mass barrier and reduced drug penetration in 3D models. The fluorescence of EVO and RUT was measured via fluorescence spectroscopy and the cellular uptake of both drugs was characterized in 2D tumor models. The results showed that the cellular uptake concentrations of RUT increased with increasing drug concentrations. However, the EVO concentrations uptaken by the cells showed only a small change with increasing drug concentrations, which may be due to the different solubility of EVO and Rut in solvents. Overall, this study provided a new vision of the anti-tumor activity of EVO and RUT via 3D multicellular spheroids and cellular uptake through the fluorescence of compounds.

  17. Determination of Magnet Specification of 13 MeV Proton Cyclotron Based on Opera 3D

    The magnet is one of the main components of a cyclotron, used to form a circular particle beam trajectories and to provide focusing of the beam. To support the mastery of 13-MeV proton cyclotron technologies, cyclotron magnet design must be done to satisfy cyclotron magnet requirements. This research was conducted by studying important parameters in designing the cyclotron magnet which is then used to determine the design requirements. The magnet design was based on the results of a 3D simulation using Opera 3D software. Opera 3D is a software developed by Cobham plc to solve physical problems in 3D such as magnetostatic using finite element methods. The simulation started by drawing a 3D model of the magnet using a modeler, followed by magnetic field calculations by Tosca module in the Opera 3D software. Simulation results were analyzed with the Genspeo software to determine whether the parameters of the cyclotron magnet have met design requirements. The results indicate that the magnet design satisfied the cyclotron magnet design requirement, that B in the median plane of the magnetic pole approached the isochronous curve, providing axial and radial focusing beam, crossing the resonance line at vr = 1 when the particle energy is low and the particle energy is more than 13 MeV, and lead to small enough phase shift of about 13°. The dimension of the cyclotron magnet is 1.96 m × 1.30 m × 1.21 m; its weight is 17.3 ton; its coil current is 88,024 ampere-turn; its center magnetic field is 1.27479 T; its maximum magnetic field is 1.942116 T; its minimum magnetic field is 0.7689 T; its valley gap is 120 mm; its hill gaps are 40 to 50.78 mm; and its hill angles are 35° to 44°. (author)

  18. FUSION OF AIRBORNE AND TERRESTRIAL IMAGE-BASED 3D MODELLING FOR ROAD INFRASTRUCTURE MANAGEMENT – VISION AND FIRST EXPERIMENTS

    S. Nebiker; S. Cavegn; Eugster, H.; Laemmer, K.; J. Markram; Wagner, R.

    2012-01-01

    In this paper we present the vision and proof of concept of a seamless image-based 3d modelling approach fusing airborne and mobile terrestrial imagery. The proposed fusion relies on dense stereo matching for extracting 3d point clouds which – in combination with the original airborne and terrestrial stereo imagery – create a rich 3d geoinformation and 3d measuring space. For the seamless exploitation of this space we propose using a new virtual globe technology integrating the ai...

  19. Image-Based Airborne LiDAR Point Cloud Encoding for 3d Building Model Retrieval

    Chen, Yi-Chen; Lin, Chao-Hung

    2016-06-01

    With the development of Web 2.0 and cyber city modeling, an increasing number of 3D models have been available on web-based model-sharing platforms with many applications such as navigation, urban planning, and virtual reality. Based on the concept of data reuse, a 3D model retrieval system is proposed to retrieve building models similar to a user-specified query. The basic idea behind this system is to reuse these existing 3D building models instead of reconstruction from point clouds. To efficiently retrieve models, the models in databases are compactly encoded by using a shape descriptor generally. However, most of the geometric descriptors in related works are applied to polygonal models. In this study, the input query of the model retrieval system is a point cloud acquired by Light Detection and Ranging (LiDAR) systems because of the efficient scene scanning and spatial information collection. Using Point clouds with sparse, noisy, and incomplete sampling as input queries is more difficult than that by using 3D models. Because that the building roof is more informative than other parts in the airborne LiDAR point cloud, an image-based approach is proposed to encode both point clouds from input queries and 3D models in databases. The main goal of data encoding is that the models in the database and input point clouds can be consistently encoded. Firstly, top-view depth images of buildings are generated to represent the geometry surface of a building roof. Secondly, geometric features are extracted from depth images based on height, edge and plane of building. Finally, descriptors can be extracted by spatial histograms and used in 3D model retrieval system. For data retrieval, the models are retrieved by matching the encoding coefficients of point clouds and building models. In experiments, a database including about 900,000 3D models collected from the Internet is used for evaluation of data retrieval. The results of the proposed method show a clear superiority

  20. Organic MEMS/NEMS-based high-efficiency 3D ITO-less flexible photovoltaic cells

    A novel approach based on three-dimensional (3D) architecture for polymeric photovoltaic cells made up of an array of sub-micron and nano-pillars which not only increase the area of the light absorbing surface, but also improve the carrier collection efficiency of bulk-heterojunction organic solar cells is presented. The approach also introduces coating of 3D anodes with a new solution-processable highly conductive transparent polymer (Orgacon™) that replaces expensive vacuum-deposited ITO (indium tin oxide) as well as the additional hole-collecting layer of conventional PEDOT:PSS (poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate)). In addition, the described procedure is well suited to roll-to-roll high-throughput manufacturing. The high aspect-ratio 3D pillars which form the basis for this new architecture are patterned through micro-electromechanical-system- and nano-electromechanical-system-based processes. For the particular case of P3HT (poly(3-hexylthiophene)) and PCBM (phenyl-C61-butyric acid methyl ester) active material, efficiencies in excess of 6% have been achieved for these photovoltaic cells of 3D architecture using ITO-less flexible PET (polyethylene terephthalate) substrates. This increase in efficiency turns out to be more than twice higher than those achieved for their 2D counterparts. (paper)

  1. A 3D Model Based Imdoor Navigation System for Hubei Provincial Museum

    Xu, W.; Kruminaite, M.; Onrust, B.; Liu, H.; Xiong, Q.; Zlatanova, S.

    2013-11-01

    3D models are more powerful than 2D maps for indoor navigation in a complicate space like Hubei Provincial Museum because they can provide accurate descriptions of locations of indoor objects (e.g., doors, windows, tables) and context information of these objects. In addition, the 3D model is the preferred navigation environment by the user according to the survey. Therefore a 3D model based indoor navigation system is developed for Hubei Provincial Museum to guide the visitors of museum. The system consists of three layers: application, web service and navigation, which is built to support localization, navigation and visualization functions of the system. There are three main strengths of this system: it stores all data needed in one database and processes most calculations on the webserver which make the mobile client very lightweight, the network used for navigation is extracted semi-automatically and renewable, the graphic user interface (GUI), which is based on a game engine, has high performance of visualizing 3D model on a mobile display.

  2. Four-view stereoscopic imaging and display system for web-based 3D image communication

    Kim, Seung-Cheol; Park, Young-Gyoo; Kim, Eun-Soo

    2004-10-01

    In this paper, a new software-oriented autostereoscopic 4-view imaging & display system for web-based 3D image communication is implemented by using 4 digital cameras, Intel Xeon server computer system, graphic card having four outputs, projection-type 4-view 3D display system and Microsoft' DirectShow programming library. And its performance is also analyzed in terms of image-grabbing frame rates, displayed image resolution, possible color depth and number of views. From some experimental results, it is found that the proposed system can display 4-view VGA images with a full color of 16bits and a frame rate of 15fps in real-time. But the image resolution, color depth, frame rate and number of views are mutually interrelated and can be easily controlled in the proposed system by using the developed software program so that, a lot of flexibility in design and implementation of the proposed multiview 3D imaging and display system are expected in the practical application of web-based 3D image communication.

  3. Improving Low-dose Cardiac CT Images based on 3D Sparse Representation

    Shi, Luyao; Hu, Yining; Chen, Yang; Yin, Xindao; Shu, Huazhong; Luo, Limin; Coatrieux, Jean-Louis

    2016-03-01

    Cardiac computed tomography (CCT) is a reliable and accurate tool for diagnosis of coronary artery diseases and is also frequently used in surgery guidance. Low-dose scans should be considered in order to alleviate the harm to patients caused by X-ray radiation. However, low dose CT (LDCT) images tend to be degraded by quantum noise and streak artifacts. In order to improve the cardiac LDCT image quality, a 3D sparse representation-based processing (3D SR) is proposed by exploiting the sparsity and regularity of 3D anatomical features in CCT. The proposed method was evaluated by a clinical study of 14 patients. The performance of the proposed method was compared to the 2D spares representation-based processing (2D SR) and the state-of-the-art noise reduction algorithm BM4D. The visual assessment, quantitative assessment and qualitative assessment results show that the proposed approach can lead to effective noise/artifact suppression and detail preservation. Compared to the other two tested methods, 3D SR method can obtain results with image quality most close to the reference standard dose CT (SDCT) images.

  4. Multi-dimensional Seismic Response Analysis of Base-Isolated Frame Structure with 3D Isolator

    Xiong Shishu; Huang Liting; Chen Jinfeng; Su Jingsu

    2005-01-01

    The three-dimensional lead-rubber dish-spring bearing (3DB) is proposed in this paper. The 3DB is composed of lead rubber bearing (LRB) and dish-spring bearing (DSB) with damper in series. The 3DB put forward in this paper is effective in the resolution of difficulties in strong vertical capacity and vertical damping of three-dimensional isolation bearings. It effectively suppresses rocking motions as well. The analytical model and motion equations of multi-dimensional seismic responses of 3D base-isolated frame structures are established. Taking a five-storey frame structure as an example, an extensive simulation analysis is carried out. The results show that the 3D base-isolated structure with the proposed 3DB is effective in 3D isolation; it can reduce seismic responses by 50 % compared to a non-isolated structure. Therefore, the 3D isolation problem in building can be solved easily and effectively with the 3DB proposed in this paper.

  5. 3D Inversion of Magnetic Data through Wavelet based Regularization Method

    Maysam Abedi

    2015-06-01

    Full Text Available This study deals with the 3D recovering of magnetic susceptibility model by incorporating the sparsity-based constraints in the inversion algorithm. For this purpose, the area under prospect was divided into a large number of rectangular prisms in a mesh with unknown susceptibilities. Tikhonov cost functions with two sparsity functions were used to recover the smooth parts as well as the sharp boundaries of model parameters. A pre-selected basis namely wavelet can recover the region of smooth behaviour of susceptibility distribution while Haar or finite-difference (FD domains yield a solution with rough boundaries. Therefore, a regularizer function which can benefit from the advantages of both wavelets and Haar/FD operators in representation of the 3D magnetic susceptibility distributionwas chosen as a candidate for modeling magnetic anomalies. The optimum wavelet and parameter β which controls the weight of the two sparsifying operators were also considered. The algorithm assumed that there was no remanent magnetization and observed that magnetometry data represent only induced magnetization effect. The proposed approach is applied to a noise-corrupted synthetic data in order to demonstrate its suitability for 3D inversion of magnetic data. On obtaining satisfactory results, a case study pertaining to the ground based measurement of magnetic anomaly over a porphyry-Cu deposit located in Kerman providence of Iran. Now Chun deposit was presented to be 3D inverted. The low susceptibility in the constructed model coincides with the known location of copper ore mineralization.

  6. Brain structure in diving players on MR imaging studied with voxel-based morphometry

    Gaoxia Wei; Jing Luo; Youfa Li

    2009-01-01

    We adopted professional diving players as a typical subject pool to explore whether structural brain differences relative to motor skill acquisition exist between highly skilled athletes and non-athletes. Based on the voxel-based morphometric (VBM) technique, structural MRIs of the brains of 12 elite diving players with professional training were analyzed and compared with those of control subjects with-out any professional physical training. Diving players showed significantly increased gray matter density in the thalamus and left pre-central gyrus than control subjects. However, future researches are needed to prove the contribution of preposition and practice. It also suggests that athletes as the subject pool could form a new subject pool to explore plastic change induced by motor skill acquisition.

  7. Voxel-based classification of FDG PET in dementia using inter-scanner normalization.

    Thiele, Frank; Young, Stewart; Buchert, Ralph; Wenzel, Fabian

    2013-08-15

    Statistical mapping of FDG PET brain images has become a common tool in differential diagnosis of patients with dementia. We present a voxel-based classification system of neurodegenerative dementias based on partial least squares (PLS). Such a classifier relies on image databases of normal controls and dementia cases as training data. Variations in PET image characteristics can be expected between databases, for example due to differences in instrumentation, patient preparation, and image reconstruction. This study evaluates (i) the impact of databases from different scanners on classification accuracy and (ii) a method to improve inter-scanner classification. Brain FDG PET databases from three scanners (A, B, C) at two clinical sites were evaluated. Diagnostic categories included normal controls (NC, nA=26, nB=20, nC=24 for each scanner respectively), Alzheimer's disease (AD, nA=44, nB=11, nC=16), and frontotemporal dementia (FTD, nA=13, nB=13, nC=5). Spatially normalized images were classified as NC, AD, or FTD using partial least squares. Supervised learning was employed to determine classifier parameters, whereby available data is sub-divided into training and test sets. Four different database setups were evaluated: (i) "in-scanner": training and test data from the same scanner, (ii) "x-scanner": training and test data from different scanners, (iii) "train other": train on both x-scanners, and (iv) "train all": train on all scanners. In order to moderate the impact of inter-scanner variations on image evaluation, voxel-by-voxel scaling was applied based on "ratio images". Good classification accuracy of on average 94% was achieved for the in-scanner setups. Accuracy deteriorated for setups with mismatched scanners (79-91%). Ratio-image normalization improved all results with mismatched scanners (85-92%). In conclusion, automatic classification of individual FDG PET in differential diagnosis of dementia is feasible. Accuracy can vary with respect to scanner or

  8. Nodule Detection in a Lung Region that's Segmented with Using Genetic Cellular Neural Networks and 3D Template Matching with Fuzzy Rule Based Thresholding

    The purpose of this study was to develop a new method for automated lung nodule detection in serial section CT images with using the characteristics of the 3D appearance of the nodules that distinguish themselves from the vessels. Lung nodules were detected in four steps. First, to reduce the number of region of interests (ROIs) and the computation time, the lung regions of the CTs were segmented using Genetic Cellular Neural Networks (G-CNN). Then, for each lung region, ROIs were specified with using the 8 directional search; +1 or -1 values were assigned to each voxel. The 3D ROI image was obtained by combining all the 2-Dimensional (2D) ROI images. A 3D template was created to find the nodule-like structures on the 3D ROI image. Convolution of the 3D ROI image with the proposed template strengthens the shapes that are similar to those of the template and it weakens the other ones. Finally, fuzzy rule based thresholding was applied and the ROI's were found. To test the system's efficiency, we used 16 cases with a total of 425 slices, which were taken from the Lung Image Database Consortium (LIDC) dataset. The computer aided diagnosis (CAD) system achieved 100% sensitivity with 13.375 FPs per case when the nodule thickness was greater than or equal to 5.625 mm. Our results indicate that the detection performance of our algorithm is satisfactory, and this may well improve the performance of computer aided detection of lung nodules

  9. 4DCBCT-based motion modeling and 3D fluoroscopic image generation for lung cancer radiotherapy

    Dhou, Salam; Hurwitz, Martina; Mishra, Pankaj; Berbeco, Ross; Lewis, John

    2015-03-01

    A method is developed to build patient-specific motion models based on 4DCBCT images taken at treatment time and use them to generate 3D time-varying images (referred to as 3D fluoroscopic images). Motion models are built by applying Principal Component Analysis (PCA) on the displacement vector fields (DVFs) estimated by performing deformable image registration on each phase of 4DCBCT relative to a reference phase. The resulting PCA coefficients are optimized iteratively by comparing 2D projections captured at treatment time with projections estimated using the motion model. The optimized coefficients are used to generate 3D fluoroscopic images. The method is evaluated using anthropomorphic physical and digital phantoms reproducing real patient trajectories. For physical phantom datasets, the average tumor localization error (TLE) and (95th percentile) in two datasets were 0.95 (2.2) mm. For digital phantoms assuming superior image quality of 4DCT and no anatomic or positioning disparities between 4DCT and treatment time, the average TLE and the image intensity error (IIE) in six datasets were smaller using 4DCT-based motion models. When simulating positioning disparities and tumor baseline shifts at treatment time compared to planning 4DCT, the average TLE (95th percentile) and IIE were 4.2 (5.4) mm and 0.15 using 4DCT-based models, while they were 1.2 (2.2) mm and 0.10 using 4DCBCT-based ones, respectively. 4DCBCT-based models were shown to perform better when there are positioning and tumor baseline shift uncertainties at treatment time. Thus, generating 3D fluoroscopic images based on 4DCBCT-based motion models can capture both inter- and intra- fraction anatomical changes during treatment.

  10. Research on 3-D base isolation system applied to new power reactor 3-D seismic isolation device with rolling seal type air spring: Pt.2

    A three dimensional seismic base isolation device was developed for heavy structures and buildings such as nuclear power reactor buildings. The device realizes 3-D isolation by combining a LRB (laminated rubber bearing) for horizontal isolation with an air spring for vertical isolation in series. In this study, scale models of the 3-D base isolation device were made and were tested to examine the dynamic properties and ultimate strengths of the device. The performance of the device under earthquake excitation was examined through shaking table tests of 1/7 scale models. As the results, it was confirmed that the device worked smoothly under the horizontal and vertical excitations, and that the theoretical formulae of the orifice damping could explain the test results. The high-pressure air springs of trial production were forced to burst to find out which factor influenced ultimate strength. It was confirmed from results of the burst test that the strength of the air spring depended upon the diameter of rolling part of the bellows and the number of layers of the reinforcing fibers. Judging from the results of the shaking table test and the burst test, the developed 3-D base isolation device was applicable to a nuclear power plant building. (authors)

  11. 3D Maize Plant Reconstruction Based on Georeferenced Overlapping LiDAR Point Clouds

    Miguel Garrido

    2015-12-01

    Full Text Available 3D crop reconstruction with a high temporal resolution and by the use of non-destructive measuring technologies can support the automation of plant phenotyping processes. Thereby, the availability of such 3D data can give valuable information about the plant development and the interaction of the plant genotype with the environment. This article presents a new methodology for georeferenced 3D reconstruction of maize plant structure. For this purpose a total station, an IMU, and several 2D LiDARs with different orientations were mounted on an autonomous vehicle. By the multistep methodology presented, based on the application of the ICP algorithm for point cloud fusion, it was possible to perform the georeferenced point clouds overlapping. The overlapping point cloud algorithm showed that the aerial points (corresponding mainly to plant parts were reduced to 1.5%–9% of the total registered data. The remaining were redundant or ground points. Through the inclusion of different LiDAR point of views of the scene, a more realistic representation of the surrounding is obtained by the incorporation of new useful information but also of noise. The use of georeferenced 3D maize plant reconstruction at different growth stages, combined with the total station accuracy could be highly useful when performing precision agriculture at the crop plant level.

  12. 3D animation of facial plastic surgery based on computer graphics

    Zhang, Zonghua; Zhao, Yan

    2013-12-01

    More and more people, especial women, are getting desired to be more beautiful than ever. To some extent, it becomes true because the plastic surgery of face was capable in the early 20th and even earlier as doctors just dealing with war injures of face. However, the effect of post-operation is not always satisfying since no animation could be seen by the patients beforehand. In this paper, by combining plastic surgery of face and computer graphics, a novel method of simulated appearance of post-operation will be given to demonstrate the modified face from different viewpoints. The 3D human face data are obtained by using 3D fringe pattern imaging systems and CT imaging systems and then converted into STL (STereo Lithography) file format. STL file is made up of small 3D triangular primitives. The triangular mesh can be reconstructed by using hash function. Top triangular meshes in depth out of numbers of triangles must be picked up by ray-casting technique. Mesh deformation is based on the front triangular mesh in the process of simulation, which deforms interest area instead of control points. Experiments on face model show that the proposed 3D animation facial plastic surgery can effectively demonstrate the simulated appearance of post-operation.

  13. PCA-based 3D Shape Reconstruction of Human Foot Using Multiple Viewpoint Cameras

    Edmée Amstutz; Tomoaki Teshima; Makoto Kimura; Masaaki Mochimaru; Hideo Saito

    2008-01-01

    This paper describes a multiple camera-based method to reconstruct the 3D shape of a human foot. From a foot database,an initial 3D model of the foot represented by a cloud of points is built. The shape parameters, which can characterize more than 92% of a foot, are defined by using the principal component analysis method. Then, using "active shape models", the initial 3D model is adapted to the real foot captured in multiple images by applying some constraints (edge points' distance and color variance). We insist here on the experiment part where we demonstrate the efficiency of the proposed method on a plastic foot model, and also on real human feet with various shapes. We propose and compare different ways of texturing the foot which is needed for reconstruction. We present an experiment performed on the plastic foot model and on human feet and propose two different ways to improve the final 3D shape's accuracy according to the previous experiments' results. The first improvement proposed is the densification of the cloud of points used to represent the initial model and the foot database. The second improvement concerns the projected patterns used to texture the foot. We conclude by showing the obtained results for a human foot with the average computed shape error being only 1.06mm.

  14. Grammar-based Automatic 3D Model Reconstruction from Terrestrial Laser Scanning Data

    Yu, Q.; Helmholz, P.; Belton, D.; West, G.

    2014-04-01

    The automatic reconstruction of 3D buildings has been an important research topic during the last years. In this paper, a novel method is proposed to automatically reconstruct the 3D building models from segmented data based on pre-defined formal grammar and rules. Such segmented data can be extracted e.g. from terrestrial or mobile laser scanning devices. Two steps are considered in detail. The first step is to transform the segmented data into 3D shapes, for instance using the DXF (Drawing Exchange Format) format which is a CAD data file format used for data interchange between AutoCAD and other program. Second, we develop a formal grammar to describe the building model structure and integrate the pre-defined grammars into the reconstruction process. Depending on the different segmented data, the selected grammar and rules are applied to drive the reconstruction process in an automatic manner. Compared with other existing approaches, our proposed method allows the model reconstruction directly from 3D shapes and takes the whole building into account.

  15. Vision-Based Long-Range 3D Tracking, applied to Underground Surveying Tasks

    Mossel, Annette; Gerstweiler, Georg; Vonach, Emanuel; Kaufmann, Hannes; Chmelina, Klaus

    2014-04-01

    To address the need of highly automated positioning systems in underground construction, we present a long-range 3D tracking system based on infrared optical markers. It provides continuous 3D position estimation of static or kinematic targets with low latency over a tracking volume of 12 m x 8 m x 70 m (width x height x depth). Over the entire volume, relative 3D point accuracy with a maximal deviation ≤ 22 mm is ensured with possible target rotations of yaw, pitch = 0 - 45° and roll = 0 - 360°. No preliminary sighting of target(s) is necessary since the system automatically locks onto a target without user intervention and autonomously starts tracking as soon as a target is within the view of the system. The proposed system needs a minimal hardware setup, consisting of two machine vision cameras and a standard workstation for data processing. This allows for quick installation with minimal disturbance of construction work. The data processing pipeline ensures camera calibration and tracking during on-going underground activities. Tests in real underground scenarios prove the system's capabilities to act as 3D position measurement platform for multiple underground tasks that require long range, low latency and high accuracy. Those tasks include simultaneously tracking of personnel, machines or robots.

  16. Standardization based on human factors for 3D display: performance characteristics and measurement methods

    Uehara, Shin-ichi; Ujike, Hiroyasu; Hamagishi, Goro; Taira, Kazuki; Koike, Takafumi; Kato, Chiaki; Nomura, Toshio; Horikoshi, Tsutomu; Mashitani, Ken; Yuuki, Akimasa; Izumi, Kuniaki; Hisatake, Yuzo; Watanabe, Naoko; Umezu, Naoaki; Nakano, Yoshihiko

    2010-02-01

    We are engaged in international standardization activities for 3D displays. We consider that for a sound development of 3D displays' market, the standards should be based on not only mechanism of 3D displays, but also human factors for stereopsis. However, we think that there is no common understanding on what the 3D display should be and that the situation makes developing the standards difficult. In this paper, to understand the mechanism and human factors, we focus on a double image, which occurs in some conditions on an autostereoscopic display. Although the double image is generally considered as an unwanted effect, we consider that whether the double image is unwanted or not depends on the situation and that there are some allowable double images. We tried to classify the double images into the unwanted and the allowable in terms of the display mechanism and visual ergonomics for stereopsis. The issues associated with the double image are closely related to performance characteristics for the autostereoscopic display. We also propose performance characteristics, measurement and analysis methods to represent interocular crosstalk and motion parallax.

  17. A Phytic Acid Induced Super-Amphiphilic Multifunctional 3D Graphene-Based Foam.

    Song, Xinhong; Chen, Yiying; Rong, Mingcong; Xie, Zhaoxiong; Zhao, Tingting; Wang, Yiru; Chen, Xi; Wolfbeis, Otto S

    2016-03-14

    Surfaces with super-amphiphilicity have attracted tremendous interest for fundamental and applied research owing to their special affinity to both oil and water. It is generally believed that 3D graphenes are monoliths with strongly hydrophobic surfaces. Herein, we demonstrate the preparation of a 3D super-amphiphilic (that is, highly hydrophilic and oleophilic) graphene-based assembly in a single-step using phytic acid acting as both a gelator and as a dopant. The product shows both hydrophilic and oleophilic intelligence, and this overcomes the drawbacks of presently known hydrophobic 3D graphene assemblies. It can absorb water and oils alike. The utility of the new material was demonstrated by designing a heterogeneous catalytic system through incorporation of a zeolite into its amphiphilic 3D scaffold. The resulting bulk network was shown to enable efficient epoxidation of alkenes without prior addition of a co-solvent or stirring. This catalyst also can be recovered and re-used, thereby providing a clean catalytic process with simplified work-up. PMID:26890034

  18. Topology Optimization Design of 3D Continuum Structure with Reserved Hole Based on Variable Density Method

    Bai Shiye

    2016-05-01

    Full Text Available An objective function defined by minimum compliance of topology optimization for 3D continuum structure was established to search optimal material distribution constrained by the predetermined volume restriction. Based on the improved SIMP (solid isotropic microstructures with penalization model and the new sensitivity filtering technique, basic iteration equations of 3D finite element analysis were deduced and solved by optimization criterion method. All the above procedures were written in MATLAB programming language, and the topology optimization design examples of 3D continuum structure with reserved hole were examined repeatedly by observing various indexes, including compliance, maximum displacement, and density index. The influence of mesh, penalty factors, and filter radius on the topology results was analyzed. Computational results showed that the finer or coarser the mesh number was, the larger the compliance, maximum displacement, and density index would be. When the filtering radius was larger than 1.0, the topology shape no longer appeared as a chessboard problem, thus suggesting that the presented sensitivity filtering method was valid. The penalty factor should be an integer because iteration steps increased greatly when it is a noninteger. The above modified variable density method could provide technical routes for topology optimization design of more complex 3D continuum structures in the future.

  19. GPU-Based Block-Wise Nonlocal Means Denoising for 3D Ultrasound Images

    Liu Li

    2013-01-01

    Full Text Available Speckle suppression plays an important role in improving ultrasound (US image quality. While lots of algorithms have been proposed for 2D US image denoising with remarkable filtering quality, there is relatively less work done on 3D ultrasound speckle suppression, where the whole volume data rather than just one frame needs to be considered. Then, the most crucial problem with 3D US denoising is that the computational complexity increases tremendously. The nonlocal means (NLM provides an effective method for speckle suppression in US images. In this paper, a programmable graphic-processor-unit- (GPU- based fast NLM filter is proposed for 3D ultrasound speckle reduction. A Gamma distribution noise model, which is able to reliably capture image statistics for Log-compressed ultrasound images, was used for the 3D block-wise NLM filter on basis of Bayesian framework. The most significant aspect of our method was the adopting of powerful data-parallel computing capability of GPU to improve the overall efficiency. Experimental results demonstrate that the proposed method can enormously accelerate the algorithm.

  20. 3D Elastic Registration of Ultrasound Images Based on Skeleton Feature

    LI Dan-dan; LIU Zhi-Yan; SHEN Yi

    2005-01-01

    In order to eliminate displacement and elastic deformation between images of adjacent frames in course of 3D ultrasonic image reconstruction, elastic registration based on skeleton feature was adopt in this paper. A new automatically skeleton tracking extract algorithm is presented, which can extract connected skeleton to express figure feature. Feature points of connected skeleton are extracted automatically by accounting topical curvature extreme points several times. Initial registration is processed according to barycenter of skeleton. Whereafter, elastic registration based on radial basis function are processed according to feature points of skeleton. Result of example demonstrate that according to traditional rigid registration, elastic registration based on skeleton feature retain natural difference in shape for organ's different part, and eliminate slight elastic deformation between frames caused by image obtained process simultaneously. This algorithm has a high practical value for image registration in course of 3D ultrasound image reconstruction.

  1. Interaction Design of National Dance Based on Realistic 3D Character

    Guoxin Tan

    2013-08-01

    Full Text Available Great improvement has been achieved in the protection of national dance through multimedia technology. An interactive design approach for national dance based on realistic 3D character is proposed in this paper. This approach comes with three sub steps: Firstly, the realistic face was reconstructed based on a front photo, in this step, the facial feature points of photo are selected interactively; and then, the realistic face was built through texture mapping and fusion based on the standardized face model database. Secondly, the construction of realistic body is realized through introducing the stretching model and the vector differential adjuster. Finally, the interactive display of national dance is realized by virtual reality engine. The experimental results show that this approach is user-friendly, and can generate a high-quality realistic 3D character in real time while protects the worthy cultural heritage effectively at the same time.

  2. 3D Modelling of CMMs Probing Accuracy and Settings using Fuzzy Knowledge Bases

    Achiche, Sofiane; Wozniack, Adam

    2011-01-01

    probes are proposed. The fuzzy models are automatically generated using a dedicated genetic algorithm developed by the authors. The algorithm uses hybrid coding, binary for the rule base and real for the data base. This hybrid coding, used with a set of specialized operators of reproduction, proved......One of the fundamental elements that determines the precision of Coordinate Measuring Machines (CMMs) is the probe, which locates measuring points within measurement volume. In this paper genetically generated fuzzy knowledge based models of 3D probing accuracy for one and two stage touch trigger...... to be an effective learning environment in this case. Data collection of the measured objects’ coordinates was carried out using a special set-up for probe testing. The authors used a novel method that applies a low-force high-resolution displacement transducer for probe error examination in 3D space outside the CMM...

  3. Towards a 3d Based Platform for Cultural Heritage Site Survey and Virtual Exploration

    Seinturier, J.; Riedinger, C.; Mahiddine, A.; Peloso, D.; Boï, J.-M.; Merad, D.; Drap, P.

    2013-07-01

    This paper present a 3D platform that enables to make both cultural heritage site survey and its virtual exploration. It provides a single and easy way to use framework for merging multi scaled 3D measurements based on photogrammetry, documentation produced by experts and the knowledge of involved domains leaving the experts able to extract and choose the relevant information to produce the final survey. Taking into account the interpretation of the real world during the process of archaeological surveys is in fact the main goal of a survey. New advances in photogrammetry and the capability to produce dense 3D point clouds do not solve the problem of surveys. New opportunities for 3D representation are now available and we must to use them and find new ways to link geometry and knowledge. The new platform is able to efficiently manage and process large 3D data (points set, meshes) thanks to the implementation of space partition methods coming from the state of the art such as octrees and kd-trees and thus can interact with dense point clouds (thousands to millions of points) in real time. The semantisation of raw 3D data relies on geometric algorithms such as geodetic path computation, surface extraction from dense points cloud and geometrical primitive optimization. The platform provide an interface that enables expert to describe geometric representations of interesting objects like ashlar blocs, stratigraphic units or generic items (contour, lines, … ) directly onto the 3D representation of the site and without explicit links to underlying algorithms. The platform provide two ways for describing geometric representation. If oriented photographs are available, the expert can draw geometry on a photograph and the system computes its 3D representation by projection on the underlying mesh or the points cloud. If photographs are not available or if the expert wants to only use the 3D representation then he can simply draw objects shape on it. When 3D

  4. A landmark-based method for the geometrical 3D calibration of scanning microscopes

    Ritter, M.

    2007-04-27

    This thesis presents a new strategy and a spatial method for the geometric calibration of 3D measurement devices at the micro-range, based on spatial reference structures with nanometersized landmarks (nanomarkers). The new method was successfully applied for the 3D calibration of scanning probe microscopes (SPM) and confocal laser scanning microscopes (CLSM). Moreover, the spatial method was also used for the photogrammetric self-calibration of scanning electron microscopes (SEM). In order to implement the calibration strategy to all scanning microscopes used, the landmark-based principle of reference points often applied at land survey or at close-range applications has been transferred to the nano- and micro-range in the form of nanomarker. In order to function as a support to the nanomarkers, slope-shaped step pyramids have been developed and fabricated by focused ion beam (FIB) induced metal deposition. These FIB produced 3D microstructures have been sized to embrace most of the measurement volume of the scanning microscopes. Additionally, their special design allows the homogenous distribution of the nanomarkers. The nanomarkers were applied onto the support and the plateaus of the slope-step pyramids by FIB etching (milling) as landmarks with as little as several hundreds of nanometers in diameter. The nanomarkers are either of point-, or ring-shaped design. They are optimized so that they can be spatially measured by SPM and CLSM, and, imaged and photogrammetrically analyzed on the basis of SEM data. The centre of the each nanomarker serves as reference point in the measurement data or images. By applying image processing routines, the image (2D) or object (3D) coordinates of each nanomarker has been determined with subpixel accuracy. The correlative analysis of the SPM, CLSM and photogrammetric SEM measurement data after 3D calibration resulted in mean residues in the measured coordinates of as little as 13 nm. Without the coupling factors the mean

  5. Avalanche for shape and feature-based virtual screening with 3D alignment.

    Diller, David J; Connell, Nancy D; Welsh, William J

    2015-11-01

    This report introduces a new ligand-based virtual screening tool called Avalanche that incorporates both shape- and feature-based comparison with three-dimensional (3D) alignment between the query molecule and test compounds residing in a chemical database. Avalanche proceeds in two steps. The first step is an extremely rapid shape/feature based comparison which is used to narrow the focus from potentially millions or billions of candidate molecules and conformations to a more manageable number that are then passed to the second step. The second step is a detailed yet still rapid 3D alignment of the remaining candidate conformations to the query conformation. Using the 3D alignment, these remaining candidate conformations are scored, re-ranked and presented to the user as the top hits for further visualization and evaluation. To provide further insight into the method, the results from two prospective virtual screens are presented which show the ability of Avalanche to identify hits from chemical databases that would likely be missed by common substructure-based or fingerprint-based search methods. The Avalanche method is extended to enable patent landscaping, i.e., structural refinements to improve the patentability of hits for deployment in drug discovery campaigns. PMID:26458937

  6. Quantitative analysis of the central-chest lymph nodes based on 3D MDCT image data

    Lu, Kongkuo; Bascom, Rebecca; Mahraj, Rickhesvar P. M.; Higgins, William E.

    2009-02-01

    Lung cancer is the leading cause of cancer death in the United States. In lung-cancer staging, central-chest lymph nodes and associated nodal stations, as observed in three-dimensional (3D) multidetector CT (MDCT) scans, play a vital role. However, little work has been done in relation to lymph nodes, based on MDCT data, due to the complicated phenomena that give rise to them. Using our custom computer-based system for 3D MDCT-based pulmonary lymph-node analysis, we conduct a detailed study of lymph nodes as depicted in 3D MDCT scans. In this work, the Mountain lymph-node stations are automatically defined by the system. These defined stations, in conjunction with our system's image processing and visualization tools, facilitate lymph-node detection, classification, and segmentation. An expert pulmonologist, chest radiologist, and trained technician verified the accuracy of the automatically defined stations and indicated observable lymph nodes. Next, using semi-automatic tools in our system, we defined all indicated nodes. Finally, we performed a global quantitative analysis of the characteristics of the observed nodes and stations. This study drew upon a database of 32 human MDCT chest scans. 320 Mountain-based stations (10 per scan) and 852 pulmonary lymph nodes were defined overall from this database. Based on the numerical results, over 90% of the automatically defined stations were deemed accurate. This paper also presents a detailed summary of central-chest lymph-node characteristics for the first time.

  7. A voxel-based finite element model for the prediction of bladder deformation

    Purpose: A finite element (FE) bladder model was previously developed to predict bladder deformation caused by bladder filling change. However, two factors prevent a wide application of FE models: (1) the labor required to construct a FE model with high quality mesh and (2) long computation time needed to construct the FE model and solve the FE equations. In this work, we address these issues by constructing a low-resolution voxel-based FE bladder model directly from the binary segmentation images and compare the accuracy and computational efficiency of the voxel-based model used to simulate bladder deformation with those of a classical FE model with a tetrahedral mesh. Methods: For ten healthy volunteers, a series of MRI scans of the pelvic region was recorded at regular intervals of 10 min over 1 h. For this series of scans, the bladder volume gradually increased while rectal volume remained constant. All pelvic structures were defined from a reference image for each volunteer, including bladder wall, small bowel, prostate (male), uterus (female), rectum, pelvic bone, spine, and the rest of the body. Four separate FE models were constructed from these structures: one with a tetrahedral mesh (used in previous study), one with a uniform hexahedral mesh, one with a nonuniform hexahedral mesh, and one with a low-resolution nonuniform hexahedral mesh. Appropriate material properties were assigned to all structures and uniform pressure was applied to the inner bladder wall to simulate bladder deformation from urine inflow. Performance of the hexahedral meshes was evaluated against the performance of the standard tetrahedral mesh by comparing the accuracy of bladder shape prediction and computational efficiency. Results: FE model with a hexahedral mesh can be quickly and automatically constructed. No substantial differences were observed between the simulation results of the tetrahedral mesh and hexahedral meshes (<1% difference in mean dice similarity coefficient to

  8. Voxel-Based Dose Prediction with Multi-Patient Atlas Selection for Automated Radiotherapy Treatment Planning

    McIntosh, Chris

    2016-01-01

    Automating the radiotherapy treatment planning process is a technically challenging problem. The majority of automated approaches have focused on customizing and inferring dose volume objectives to used in plan optimization. In this work we outline a multi-patient atlas-based dose prediction approach that learns to predict the dose-per-voxel for a novel patient directly from the computed tomography (CT) planning scan without the requirement of specifying any objectives. Our method learns to automatically select the most effective atlases for a novel patient, and then map the dose from those atlases onto the novel patient. We extend our previous work to include a conditional random field for the optimization of a joint distribution prior that matches the complementary goals of an accurately spatially distributed dose distribution while still adhering to the desired dose volume histograms. The resulting distribution can then be used for inverse-planning with a new spatial dose objective, or to create typical do...

  9. Gray matter abnormalities in Internet addiction: A voxel-based morphometry study

    Background: This study aims to investigate brain gray matter density (GMD) changes in adolescents with Internet addiction (IA) using voxel-based morphometry (VBM) analysis on high-resolution T1-weighted structural magnetic resonance images. Methods: Eighteen IA adolescents and 15 age- and gender-matched healthy controls took part in this study. High-resolution T1-weighted magnetic resonance imaging scans were performed on the two groups. VBM analysis was used to compare the GMD between the two groups. Results: Compared with healthy controls, IA adolescents had lower GMD in the left anterior cingulate cortex, left posterior cingulate cortex, left insula, and left lingual gyrus. Conclusions: Our findings suggested that brain structural changes were present in IA adolescents, and this finding may provide a new insight into the pathogenesis of IA.

  10. Gray matter abnormalities in Internet addiction: A voxel-based morphometry study

    Zhou Yan, E-mail: clare1475@hotmail.com [Department of Radiology, RenJi Hospital, Jiao Tong University Medical School, Shanghai 200127 (China); Lin Fuchun, E-mail: fclin@wipm.ac.cn [State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China); Du Yasong, E-mail: yasongdu@yahoo.com.cn [Department of Child and Adolescent Psychiatry Shanghai Mental Health Center, Shanghai Jiao Tong University, Shanghai 200030 (China); Qin Lingdi, E-mail: flyingfool838@hotmail.com [Department of Radiology, RenJi Hospital, Jiao Tong University Medical School, Shanghai 200127 (China); Zhao Zhimin, E-mail: zmzsky@163.com [Department of Child and Adolescent Psychiatry Shanghai Mental Health Center, Shanghai Jiao Tong University, Shanghai 200030 (China); Xu Jianrong, E-mail: xujianr@hotmail.com [Department of Radiology, RenJi Hospital, Jiao Tong University Medical School, Shanghai 200127 (China); Lei Hao, E-mail: leihao@wipm.ac.cn [State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China)

    2011-07-15

    Background: This study aims to investigate brain gray matter density (GMD) changes in adolescents with Internet addiction (IA) using voxel-based morphometry (VBM) analysis on high-resolution T1-weighted structural magnetic resonance images. Methods: Eighteen IA adolescents and 15 age- and gender-matched healthy controls took part in this study. High-resolution T1-weighted magnetic resonance imaging scans were performed on the two groups. VBM analysis was used to compare the GMD between the two groups. Results: Compared with healthy controls, IA adolescents had lower GMD in the left anterior cingulate cortex, left posterior cingulate cortex, left insula, and left lingual gyrus. Conclusions: Our findings suggested that brain structural changes were present in IA adolescents, and this finding may provide a new insight into the pathogenesis of IA.

  11. The relationship between trait positive empathy and brain structure: a voxel-based morphometry study.

    Yue, Tong; Pan, Weigang; Huang, Xiting

    2016-04-13

    Although studies relating to positive empathy have received increased attention in recent years, no studies have been carried out to explore the neural basis of positive empathy. Using a voxel-based morphometry analysis, this study investigates the relationship between trait positive empathy (as measured by the Positive Empathy Scale) and its association with brain structure in 86 healthy college students. The results indicate that an individual's ability to show positive empathy is positively correlated with the volume of gray matter in the right insula, left anterior cingulate cortex, dorsolateral prefrontal cortex, and medial prefrontal cortex. It may be suggested that the differences between the abilities of emotion processing and regulating play important roles in shaping an individual's positive empathy traits from the perspective of brain morphometry. PMID:26963166

  12. Clinical evaluation of 3D/3D MRI-CBCT automatching on brain tumors for online patient setup verification - A step towards MRI-based treatment planning

    Buhl, Sune K.; Duun-Christensen, Anne Katrine; Kristensen, Brian H.;

    2010-01-01

    undergoing postoperative radiotherapy for malignant brain tumors received a weekly CBCT. In total 18 scans was matched with both CT and MRI as reference. The CBCT scans were acquired using a Clinac iX 2300 linear accelerator (Varian Medical Systems) with an On-Board Imager (OBI). Results. For the phantom......Background. Magnetic Resonance Imaging (MRI) is often used in modern day radiotherapy (RT) due to superior soft tissue contrast. However, treatment planning based solely on MRI is restricted due to e. g. the limitations of conducting online patient setup verification using MRI as reference. In this...... study 3D/3D MRI-Cone Beam CT (CBCT) automatching for online patient setup verification was investigated. Material and methods. Initially, a multi-modality phantom was constructed and used for a quantitative comparison of CT-CBCT and MRI-CBCT automatching. Following the phantom experiment three patients...

  13. Voxel-based lesion-symptom mapping of stroke lesions underlying somatosensory deficits

    Sarah Meyer

    2016-01-01

    Full Text Available The aim of this study was to investigate the relationship between stroke lesion location and the resulting somatosensory deficit. We studied exteroceptive and proprioceptive somatosensory symptoms and stroke lesions in 38 patients with first-ever acute stroke. The Erasmus modified Nottingham Sensory Assessment was used to clinically evaluate somatosensory functioning in the arm and hand within the first week after stroke onset. Additionally, more objective measures such as the perceptual threshold of touch and somatosensory evoked potentials were recorded. Non-parametric voxel-based lesion-symptom mapping was performed to investigate lesion contribution to different somatosensory deficits in the upper limb. Additionally, structural connectivity of brain areas that demonstrated the strongest association with somatosensory symptoms was determined, using probabilistic fiber tracking based on diffusion tensor imaging data from a healthy age-matched sample. Voxels with a significant association to somatosensory deficits were clustered in two core brain regions: the central parietal white matter, also referred to as the sensory component of the superior thalamic radiation, and the parietal operculum close to the insular cortex, representing the secondary somatosensory cortex. Our objective recordings confirmed findings from clinical assessments. Probabilistic tracking connected the first region to thalamus, internal capsule, brain stem, postcentral gyrus, cerebellum, and frontal pathways, while the second region demonstrated structural connections to thalamus, insular and primary somatosensory cortex. This study reveals that stroke lesions in the sensory fibers of the superior thalamocortical radiation and the parietal operculum are significantly associated with multiple exteroceptive and proprioceptive deficits in the arm and hand.

  14. Voxel-based lesion-symptom mapping of stroke lesions underlying somatosensory deficits.

    Meyer, Sarah; Kessner, Simon S; Cheng, Bastian; Bönstrup, Marlene; Schulz, Robert; Hummel, Friedhelm C; De Bruyn, Nele; Peeters, Andre; Van Pesch, Vincent; Duprez, Thierry; Sunaert, Stefan; Schrooten, Maarten; Feys, Hilde; Gerloff, Christian; Thomalla, Götz; Thijs, Vincent; Verheyden, Geert

    2016-01-01

    The aim of this study was to investigate the relationship between stroke lesion location and the resulting somatosensory deficit. We studied exteroceptive and proprioceptive somatosensory symptoms and stroke lesions in 38 patients with first-ever acute stroke. The Erasmus modified Nottingham Sensory Assessment was used to clinically evaluate somatosensory functioning in the arm and hand within the first week after stroke onset. Additionally, more objective measures such as the perceptual threshold of touch and somatosensory evoked potentials were recorded. Non-parametric voxel-based lesion-symptom mapping was performed to investigate lesion contribution to different somatosensory deficits in the upper limb. Additionally, structural connectivity of brain areas that demonstrated the strongest association with somatosensory symptoms was determined, using probabilistic fiber tracking based on diffusion tensor imaging data from a healthy age-matched sample. Voxels with a significant association to somatosensory deficits were clustered in two core brain regions: the central parietal white matter, also referred to as the sensory component of the superior thalamic radiation, and the parietal operculum close to the insular cortex, representing the secondary somatosensory cortex. Our objective recordings confirmed findings from clinical assessments. Probabilistic tracking connected the first region to thalamus, internal capsule, brain stem, postcentral gyrus, cerebellum, and frontal pathways, while the second region demonstrated structural connections to thalamus, insular and primary somatosensory cortex. This study reveals that stroke lesions in the sensory fibers of the superior thalamocortical radiation and the parietal operculum are significantly associated with multiple exteroceptive and proprioceptive deficits in the arm and hand. PMID:26900565

  15. A voxel-based mouse for internal dose calculations using Monte Carlo simulations (MCNP)

    Murine models are useful for targeted radiotherapy pre-clinical experiments. These models can help to assess the potential interest of new radiopharmaceuticals. In this study, we developed a voxel-based mouse for dosimetric estimates. A female nude mouse (30 g) was frozen and cut into slices. High-resolution digital photographs were taken directly on the frozen block after each section. Images were segmented manually. Monoenergetic photon or electron sources were simulated using the MCNP4c2 Monte Carlo code for each source organ, in order to give tables of S-factors (in Gy Bq sup - sup 1 s sup - sup 1) for all target organs. Results obtained from monoenergetic particles were then used to generate S-factors for several radionuclides of potential interest in targeted radiotherapy. Thirteen source and 25 target regions were considered in this study. For each source region, 16 photon and 16 electron energies were simulated. Absorbed fractions, specific absorbed fractions and S-factors were calculated for 16 radionuclides of interest for targeted radiotherapy. The results obtained generally agree well with data published previously. For electron energies ranging from 0.1 to 2.5 MeV, the self-absorbed fraction varies from 0.98 to 0.376 for the liver, and from 0.89 to 0.04 for the thyroid. Electrons cannot be considered as 'non-penetrating' radiation for energies above 0.5 MeV for mouse organs. This observation can be generalized to radionuclides: for example, the beta self-absorbed fraction for the thyroid was 0.616 for I-131; absorbed fractions for Y-90 for left kidney-to-left kidney and for left kidney-to-spleen were 0.486 and 0.058, respectively. Our voxel-based mouse allowed us to generate a dosimetric database for use in preclinical targeted radiotherapy experiments. (author)

  16. Dynamic WIFI-Based Indoor Positioning in 3D Virtual World

    Chan, S.; Sohn, G.; Wang, L.; Lee, W.

    2013-11-01

    A web-based system based on the 3DTown project was proposed using Google Earth plug-in that brings information from indoor positioning devices and real-time sensors into an integrated 3D indoor and outdoor virtual world to visualize the dynamics of urban life within the 3D context of a city. We addressed limitation of the 3DTown project with particular emphasis on video surveillance camera used for indoor tracking purposes. The proposed solution was to utilize wireless local area network (WLAN) WiFi as a replacement technology for localizing objects of interest due to the wide spread availability and large coverage area of WiFi in indoor building spaces. Indoor positioning was performed using WiFi without modifying existing building infrastructure or introducing additional access points (AP)s. A hybrid probabilistic approach was used for indoor positioning based on previously recorded WiFi fingerprint database in the Petrie Science and Engineering building at York University. In addition, we have developed a 3D building modeling module that allows for efficient reconstruction of outdoor building models to be integrated with indoor building models; a sensor module for receiving, distributing, and visualizing real-time sensor data; and a web-based visualization module for users to explore the dynamic urban life in a virtual world. In order to solve the problems in the implementation of the proposed system, we introduce approaches for integration of indoor building models with indoor positioning data, as well as real-time sensor information and visualization on the web-based system. In this paper we report the preliminary results of our prototype system, demonstrating the system's capability for implementing a dynamic 3D indoor and outdoor virtual world that is composed of discrete modules connected through pre-determined communication protocols.

  17. Digital 3D Modeling of Whole Garment Based on Structure Illumination

    TAO Jun

    2006-01-01

    With the coming of information age and the development of computer science, digitalization of whole garment is becoming more and more important. The surface of whole garment is sequent and glossy so that it is lack of the texture characteristic which is the key of digital 3D modeling.According to this reason, the structure illumination is steered into a method of this paper. The paper proposes the method by which 3D model of whole garment is created from 2D image sequences directly but not by the common techniques using general CAD model. In the paper the structure illumination is generated by the slide projector and the modeling of whole garment is based on the strict theory of the digital photogrammetry, computer vision and image processing pattern recognition. Because whole garment is lack of the applicable texture for matching, the characteristic texture generated by the structure illumination is added onto the surface of whole garment. After the characteristic texture is extracted from images and is matched well, 3D coordinates of the characteristic texture can be calculated out by the space forward intersection.Then the whole garment model is acquired by connecting all neighbour space points in the TIN and rendering the real texture of whole garment automatically. The 3D modeling method is untouched so that it is nondestructive which is just suitable for the messaline and the clothing. The method of whole garment 3D modeling proposed in the paper is flexible, effective and practical, which is confirmed by the results of the reconstructing experiments.

  18. Depth-based coding of MVD data for 3D video extension of H.264/AVC

    Rusanovskyy, Dmytro; Hannuksela, Miska M.; Su, Wenyi

    2013-06-01

    This paper describes a novel approach of using depth information for advanced coding of associated video data in Multiview Video plus Depth (MVD)-based 3D video systems. As a possible implementation of this conception, we describe two coding tools that have been developed for H.264/AVC based 3D Video Codec as response to Moving Picture Experts Group (MPEG) Call for Proposals (CfP). These tools are Depth-based Motion Vector Prediction (DMVP) and Backward View Synthesis Prediction (BVSP). Simulation results conducted under JCT-3V/MPEG 3DV Common Test Conditions show, that proposed in this paper tools reduce bit rate of coded video data by 15% of average delta bit rate reduction, which results in 13% of bit rate savings on total for the MVD data over the state-of-the-art MVC+D coding. Moreover, presented in this paper conception of depth-based coding of video has been further developed by MPEG 3DV and JCT-3V and this work resulted in even higher compression efficiency, bringing about 20% of delta bit rate reduction on total for coded MVD data over the reference MVC+D coding. Considering significant gains, proposed in this paper coding approach can be beneficial for development of new 3D video coding standards. [Figure not available: see fulltext.

  19. 3D model-based detection and tracking for space autonomous and uncooperative rendezvous

    Shang, Yang; Zhang, Yueqiang; Liu, Haibo

    2015-10-01

    In order to fully navigate using a vision sensor, a 3D edge model based detection and tracking technique was developed. Firstly, we proposed a target detection strategy over a sequence of several images from the 3D model to initialize the tracking. The overall purpose of such approach is to robustly match each image with the model views of the target. Thus we designed a line segment detection and matching method based on the multi-scale space technology. Experiments on real images showed that our method is highly robust under various image changes. Secondly, we proposed a method based on 3D particle filter (PF) coupled with M-estimation to track and estimate the pose of the target efficiently. In the proposed approach, a similarity observation model was designed according to a new distance function of line segments. Then, based on the tracking results of PF, the pose was optimized using M-estimation. Experiments indicated that the proposed method can effectively track and accurately estimate the pose of freely moving target in unconstrained environment.

  20. A web-based solution for 3D medical image visualization

    Hou, Xiaoshuai; Sun, Jianyong; Zhang, Jianguo

    2015-03-01

    In this presentation, we present a web-based 3D medical image visualization solution which enables interactive large medical image data processing and visualization over the web platform. To improve the efficiency of our solution, we adopt GPU accelerated techniques to process images on the server side while rapidly transferring images to the HTML5 supported web browser on the client side. Compared to traditional local visualization solution, our solution doesn't require the users to install extra software or download the whole volume dataset from PACS server. By designing this web-based solution, it is feasible for users to access the 3D medical image visualization service wherever the internet is available.

  1. Towards 3D ultrasound image based soft tissue tracking: a transrectal ultrasound prostate image alignment system

    Baumann, Michael; Daanen, Vincent; Troccaz, Jocelyne

    2007-01-01

    The emergence of real-time 3D ultrasound (US) makes it possible to consider image-based tracking of subcutaneous soft tissue targets for computer guided diagnosis and therapy. We propose a 3D transrectal US based tracking system for precise prostate biopsy sample localisation. The aim is to improve sample distribution, to enable targeting of unsampled regions for repeated biopsies, and to make post-interventional quality controls possible. Since the patient is not immobilized, since the prostate is mobile and due to the fact that probe movements are only constrained by the rectum during biopsy acquisition, the tracking system must be able to estimate rigid transformations that are beyond the capture range of common image similarity measures. We propose a fast and robust multi-resolution attribute-vector registration approach that combines global and local optimization methods to solve this problem. Global optimization is performed on a probe movement model that reduces the dimensionality of the search space a...

  2. Self-similarity Based Editing of 3D Surface Textures Using Height and Albedo Maps

    DONG Junyu; REN Jing; CHEN Guojiang

    2007-01-01

    This paper presents an inexpensive method for self-similarity based editing of real-world 3D surface textures by using height and albedo maps. Unlike self-similarity based 2D texture editing approaches which only make changes to pixel color or intensity values, this technique also allows surface geometry and reflectance of the captured 3D surface textures to be edited and relit using illumination conditions and viewing angles that differ from those of the original. A single editing operation at a given location affects all similar areas and produces changes on all images of the sample rendered under different conditions. Since surface height and albedo maps can be used to describe seabed topography and geologic features, which play important roles in many oceanic processes, the proposed method can be effectively employed in applications regarding visualization and simulation of oceanic phenomena.

  3. Computation of Edge-Edge-Edge Events Based on Conicoid Theory for 3-D Object Recognition

    WU Chenye; MA Huimin

    2009-01-01

    The availability of a good viewpoint space partition is crucial in three dimensional (3-D) object rec-ognition on the approach of aspect graph. There are two important events depicted by the aspect graph ap-proach, edge-edge-edge (EEE) events and edge-vertex (EV) events. This paper presents an algorithm to compute EEE events by characteristic analysis based on conicoid theory, in contrast to current algorithms that focus too much on EV events and often overlook the importance of EEE events. Also, the paper provides a standard flowchart for the viewpoint space partitioning based on aspect graph theory that makes it suitable for perspective models. The partitioning result best demonstrates the algorithm's efficiency with more valu-able viewpoints found with the help of EEE events, which can definitely help to achieve high recognition rate for 3-D object recognition.

  4. WE-G-18A-04: 3D Dictionary Learning Based Statistical Iterative Reconstruction for Low-Dose Cone Beam CT Imaging

    Purpose: To develop a 3D dictionary learning based statistical reconstruction algorithm on graphic processing units (GPU), to improve the quality of low-dose cone beam CT (CBCT) imaging with high efficiency. Methods: A 3D dictionary containing 256 small volumes (atoms) of 3x3x3 voxels was trained from a high quality volume image. During reconstruction, we utilized a Cholesky decomposition based orthogonal matching pursuit algorithm to find a sparse representation on this dictionary basis of each patch in the reconstructed image, in order to regularize the image quality. To accelerate the time-consuming sparse coding in the 3D case, we implemented our algorithm in a parallel fashion by taking advantage of the tremendous computational power of GPU. Evaluations are performed based on a head-neck patient case. FDK reconstruction with full dataset of 364 projections is used as the reference. We compared the proposed 3D dictionary learning based method with a tight frame (TF) based one using a subset data of 121 projections. The image qualities under different resolutions in z-direction, with or without statistical weighting are also studied. Results: Compared to the TF-based CBCT reconstruction, our experiments indicated that 3D dictionary learning based CBCT reconstruction is able to recover finer structures, to remove more streaking artifacts, and is less susceptible to blocky artifacts. It is also observed that statistical reconstruction approach is sensitive to inconsistency between the forward and backward projection operations in parallel computing. Using high a spatial resolution along z direction helps improving the algorithm robustness. Conclusion: 3D dictionary learning based CBCT reconstruction algorithm is able to sense the structural information while suppressing noise, and hence to achieve high quality reconstruction. The GPU realization of the whole algorithm offers a significant efficiency enhancement, making this algorithm more feasible for potential

  5. Validation of SPAMM Tagged MRI Based Measurement of 3D Soft Tissue Deformation

    Kevin M. Moerman; Sprengers, Andre M. J.; Ciaran K. Simms; Lamerichs, Rolf M.; Stoker, Jaap; Aart J. Nederveen

    2016-01-01

    This study presents and validates a novel (non-ECG-triggered) MRI sequence based on SPAtial Modulation of the Magnetization (SPAMM) to non-invasively measure 3D (quasi-static) soft tissue deformations using only six acquisitions (three static and three indentations). In current SPAMM tagged MRI approaches data is typically constructed from many repeated motion cycles. This has so far restricted its application to the measurement of highly repeatable and periodic movements (e.g. cardiac deform...

  6. A first 3D parallel diffusion solver based on a mixed dual finite element approximation

    This paper presents a new extension of the mixed dual finite element approximation of the diffusion equation in rectangular geometry. The mixed dual formulation has been extended in order to take into account discontinuity conditions. The iterative method is based on an alternating direction method which uses the current as unknown. This method is parallelizable and have very fast convergence properties. Some results for a 3D calculation on the CRAY computer are presented. (orig.)

  7. Web-Based Data Visualization with 3D Portrayals for Communications Applications

    Sharakhov, Nikita Igorevich

    2014-01-01

    The modern web has evolved into a highly capable software platform, which enables near-native performance, while offering installation-free cross-platform applications with a uniform user base and rapid update deployment. SVG, WebGL, and HTML5 Canvas, along with various higher-level JavaScript frameworks allow web applications to drive both 2D and 3D visualization. These technologies allow developing novel visualization applications, which can be applied in the communication domain to geosp...

  8. Edge-based electric field formulation in 3D CSEM simulations: A parallel approach

    Castillo-Reyes, Octavio; de la Puente, Josep; Puzyrev, Vladimir; Cela, José M.

    2015-01-01

    This paper presents a parallel computing scheme for the data computation that arise when applying one of the most popular electromagnetic methods in exploration geophysics, namely, controlled-source electromagnetic (CSEM). The computational approach is based on linear edge finite element method in 3D isotropic domains. The total electromagnetic field is decomposed into primary and secondary electromagnetic field. The primary field is calculated analytically using an horizontal layered-e...

  9. Highly Omnidirectional and Frequency Controllable Carbon/Polyaniline-based 2D and 3D Monopole Antenna

    Keun-Young Shin; Minkyu Kim; James S. Lee; Jyongsik Jang

    2015-01-01

    Highly omnidirectional and frequency controllable carbon/polyaniline (C/PANI)-based, two- (2D) and three-dimensional (3D) monopole antennas were fabricated using screen-printing and a one-step, dimensionally confined hydrothermal strategy, respectively. Solvated C/PANI was synthesized by low-temperature interfacial polymerization, during which strong π–π interactions between graphene and the quinoid rings of PANI resulted in an expanded PANI conformation with enhanced crystallinity and improv...

  10. Practice based 3D Biomimetry Design Research: Sea Star Lamp Concept

    Taylor, Andrew; Unver, Ertu

    2012-01-01

    The research explores biomimetic for surface, textiles and product design. The Sea Star lamp is one of a series of practice based collaborations; nature design experiments, product development and exhibition installations created between textile surface design researchers and 3D digital design practitioners. The strategic search for role models in nature is what discerns biomimetic from the ever existing inspiration from nature. While bio-inspiration may be limited to a morphological a...

  11. Pitfalls of voxel-based amyloid PET analyses for diagnosis of Alzheimer's disease. Artifacts due to non-specific uptake in the white matter and the skull

    Two methods are commonly used in brain image voxel-based analyses widely used for dementia work-ups: 3-dimensional stereotactic surface projections (3D-SSP) and statistical parametric mapping (SPM). The methods calculate the Z-scores of the cortical voxels that represent the significance of differences compared to a database of brain images with normal findings, and visualize them as surface brain maps. The methods are considered useful in amyloid positron emission tomography (PET) analyses to detect small amounts of amyloid-β deposits in early-stage Alzheimer's disease (AD), but are not fully validated. We analyzed the 11C-labeled 2-(2-[2-dimethylaminothiazol-5-yl]ethenyl)-6-(2-[fluoro]ethoxy)benzoxazole (BF-227) amyloid PET imaging of 56 subjects (20 individuals with mild cognitive impairment [MCl], 19 AD patients, and 17 non-demented [ND] volunteers) with 3D-SSP and the easy Z-score imaging system (eZIS) that is an SPM-based method. To clarify these methods' limitations, we visually compared Z-score maps output from the two methods and investigated the causes of discrepancies between them. Discrepancies were found in 27 subjects (9 MCl, 13 AD, and 5 ND). Relatively high white matter uptake was considered to cause higher Z-scores on 3D-SSP in 4 subjects (1 MCl and 3 ND). Meanwhile, in 17 subjects (6 MCl, 9 AD, and 2 ND), Z-score overestimation on eZIS corresponded with high skull uptake and disappeared after removing the skull uptake ('scalping'). Our results suggest that non-specific uptakes in the white matter and skull account for errors in voxel-based amyloid PET analyses. Thus, diagnoses based on 3D-SSP data require checking white matter uptake, and 'scalping' is recommended before eZIS analysis. (author)

  12. Synchrotron radiation-based characterization of interconnections in microelectronics: recent 3D results

    Bleuet, P.; Audoit, G.; Bertheau, J.; Charbonnier, J.; Cloetens, P.; Djomeni Weleguela, M. L.; Ferreira Sanchez, D.; Hodaj, F.; Gergaud, P.; Lorut, F.; Micha, J.-S.; Thuaire, A.; Ulrich, O.

    2014-09-01

    In microelectronics, more and more attention is paid to the physical characterization of interconnections, to get a better understanding of reliability issues like voiding, cracking and performance degradation. Those interconnections have a 3D architecture with features in the deep sub-micrometer range, requiring a probe with high spatial resolution and high penetration depth. Third generation synchrotron sources are the ideal candidate for that, and we show hereafter the potential of synchrotron-based hard x-ray nanotomography to investigate the morphology of through silicon vias (TSVs) and copper pillars, using projection (holotomography) and scanning (fluorescence) 3D imaging, based on a series of experiments performed at the ESRF. In particular, we highlight the benefits of the method to characterize voids, but also the distribution of intermetallics in copper pillars, which play a critical role for the device reliability. Beyond morphological imaging, an original acquisition scheme based on scanning Laue tomography is introduced. It consists in performing a raster scan (z,θ) of a sample illuminated by a synchrotron polychromatic beam while recording diffraction data. After processing and image reconstruction, it allows for 3D reconstruction of grain orientation, strain and stress in copper TSV and also in the surrounding Si matrix.

  13. 3-D-CT reconstructions in fractures of the skull base and facial skeleton

    3-D reconstructions of the skull base, temporal bone, and skull fractures were compared to 2-D CT to evaluate the diagnostic value in traumatized patients. 38 patients with 22 fractures of the facial skeleton (orbita, zygomatic, Le Fort), 12 temporal bone, and 4 skull fractures were investigated. Subjective grading was perfomed by two physicians (ENT/RAD) in respect of quality diagnostic validity and estimated clinical impact. The average image validity and quality were graded good. In the temporal bone the average information supplied by 3-D was of inferior value; here, the lack of information regarding the inner ear structures was responsible for the lack of clinical impact. In fractures of the facial skeleton and the skull base of good to very good image quality was seen and clinical relevance was high. 3-D CT is capable of demonstrating fractures, which is of little value in the temporal bone, but of high value in the skull base and the facial skeleton, especially if surfaces are involved or fragments are displaced. (orig.)

  14. Full-viewpoint 3D Space Object Recognition Based on Kernel Locality Preserving Projections

    Meng Gang; Jiang Zhiguo; Liu Zhengyi; Zhang Haopeng; Zhao Danpei

    2010-01-01

    Space object recognition plays an important role in spatial exploitation and surveillance,followed by two main problems:lacking of data and drastic changes in viewpoints.In this article,firstly,we build a three-dimensional (3D) satellites dataset named BUAA Satellite Image Dataset (BUAA-SID 1.0) to supply data for 3D space object research.Then,based on the dataset,we propose to recognize full-viewpoint 3D space objects based on kemel locality preserving projections (KLPP).To obtain more accurate and separable description of the objects,firstly,we build feature vectors employing moment invariants,Fourier descriptors,region covariance and histogram of oriented gradients.Then,we map the features into kernel space followed by dimensionality reduction using KLPP to obtain the submanifold of the features.At last,k-nearest neighbor (kNN) is used to accomplish the classification.Experimental results show that the proposed approach is more appropriate for space object recognition mainly considering changes of viewpoints.Encouraging recognition rate could be obtained based on images in BUAA-SID 1.0,and the highest recognition result could achieve 95.87%.

  15. S values for 131I based on the ICRP adult voxel phantoms

    To improve the estimates of organ doses from nuclear medicine procedures using 131I, the authors calculated a comprehensive set of 131I S values, defined as absorbed doses in target tissues per unit of nuclear transition in source regions, for different source and target combinations. The authors used the latest reference adult male and female voxel phantoms published by the International Commission on Radiological Protection (ICRP Publication 110) and the 131I photon and electron spectra from the ICRP Publication 107 to perform Monte Carlo radiation transport calculations using MCNPX2.7 to compute the S values. For each phantom, the authors simulated 55 source regions with an assumed uniform distribution of 131I. They computed the S values for 42 target tissues directly, without calculating specific absorbed fractions. From these calculations, the authors derived a comprehensive set of S values for 131I for 55 source regions and 42 target tissues in the ICRP male and female voxel phantoms. Compared with the stylised phantoms from Oak Ridge National Laboratory (ORNL) that consist of 22 source regions and 24 target regions, the new data set includes 1662 additional S values corresponding to additional combinations of source-target tissues that are not available in the stylised phantoms. In a comparison of S values derived from the ICRP and ORNL phantoms, the authors found that the S values to the radiosensitive tissues in the ICRP phantoms were 1.1 (median, female) and 1.3 (median, male) times greater than the values based on the ORNL phantoms. However, for several source-target pairs, the difference was up to 10-fold. The new set of S values can be applied prospectively or retrospectively to the calculation of radiation doses in adults internally exposed to 131I, including nuclear medicine patients treated for thyroid cancer or hyperthyroidism. (authors)

  16. Disulfide-Based Diblock Copolymer Worm Gels: A Wholly-Synthetic Thermoreversible 3D Matrix for Sheet-Based Cultures

    Simon, Karen Alambra; Warren, Nicholas J.; Mosadegh, Bobak; Mohammady, Marym R.; Whitesides, George McClelland; Armes, Steven P.

    2015-01-01

    It is well-known that 3D in vitro cell cultures provide a much better model than 2D cell cultures for understanding the in vivo microenvironment of cells. However, significant technical challenges in handling and analyzing 3D cell cultures remain, which currently limits their widespread application. Herein, we demonstrate the application of wholly synthetic thermoresponsive block copolymer worms in sheet-based 3D cell culture. These worms form a soft, free-standing gel reversibly at 20–37 °C,...

  17. An optimized voxel-based morphometry study of gray matter abnormalities in patients with obsessive-compulsive disorder

    Objective: To explore changes of gray matter volume in patients with obsessive- compulsive disorder (OCD) in Chinese Han population using optimized voxel-based morphometry (VBM), and investigate its relationship with clinical symptoms. Methods: Twenty patients with OCD and 20 age, sex and handedness matched healthy controls were scanned using 3D-T1 images on a 3.0 T MR system. The high resolution T1WI was preprocessed according to the optimized VBM protocol in Statistical Parametric Mapping (SPM5). Two-sample t test was performed to characterize the differences of the gray matter volume (GMV) between the OCD patients and healthy controls, and the correlations between the GMV and symptom severity and cumulative illness duration were examined using Pearson correlation in SPSS 16.0, respectively. Results: Compared to controls, OCD patients demonstrated increased GMV in left thalamus, right thalamus and left cerebellum after false discovery rate (FDR) correction. No areas of significantly decreased GMV was observed in OCD patients in relative to healthy controls. The mean eigenvalue ranged from 0.5782 to 0.889 representing the left thalamus volume of OCD patients was 0.6813±0.0718, and that ranged from 0.5546 to 0.9062 was 0.6869±0.0808 for right thalamus. The mean eigenvalues were positively correlated in bilateral thalamus (r=0.94, P<0.01). Conclusion: Using optimized VBM, the current research indicates that the pathophysiology of OCD is associated with GMV abnormalities not only in cortico-striato-thalamo-cortical (CSTC) circuit, but also in the cerebellum. (authors)

  18. Strategies for improving the Voxel-based statistical analysis for animal PET studies: assessment of cerebral glucose metabolism in cat deafness model

    In imaging studies of the human brain, voxel-based statistical analysis method was widely used, since these methods were originally developed for the analysis of the human brain data, they are not optimal for the animal brain data. The aim of this study is to optimize the procedures for the 3D voxel-based statistical analysis of cat FDG PET brain images. A microPET Focus 120 scanner was used. Eight cats underwent FDG PET scans twice before and after inducing the deafness. Only the brain and adjacent regions were extracted from each data set by manual masking. Individual PET image at normal and deaf state was realigned to each other to remove the confounding effects by the different spatial normalization parameters on the results of statistical analyses. Distance between the sampling points on the reference image and kernel size of Gaussian filter applied to the images before estimating the realignment parameters were adjusted to 0.5 mm and 2 mm. Both data was then spatial normalized onto study-specific cat brain template. Spatially normalized PET data were smoothed and voxel-based paired t-test was performed. Cerebral glucose metabolism decreased significantly after the loss of hearing capability in parietal lobes, postcentral gyri, STG, MTG, lTG, and IC at both hemisphere and left SC (FDR corrected P < 0.05, k=50). Cerebral glucose metabolism in deaf cats was found to be significantly higher than in controls in the right cingulate (FDR corrected P < 0.05, k=50). The ROI analysis also showed significant reduction of glucose metabolism in the same areas as in the SPM analysis, except for some regions (P < 0.05). Method for the voxel-based analysis of cat brain PET data was optimized for analysis of cat brain PET. This result was also confirmed by ROI analysis. The results obtained demonstrated the high localization accuracy and specificity of the developed method, and were found to be useful for examining cerebral glucose metabolism in a cat cortical deafness model

  19. Strategies for improving the Voxel-based statistical analysis for animal PET studies: assessment of cerebral glucose metabolism in cat deafness model

    Kim, Jin Su; Lee, Jae Sung; Park, Min Hyun; Kang, Hye Jin; Im, Ki Chun; Moon, Dae Hyuk; Lim, Sang Moo; Oh, Seung Ha; Lee, Dong Soo [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

    2007-07-01

    In imaging studies of the human brain, voxel-based statistical analysis method was widely used, since these methods were originally developed for the analysis of the human brain data, they are not optimal for the animal brain data. The aim of this study is to optimize the procedures for the 3D voxel-based statistical analysis of cat FDG PET brain images. A microPET Focus 120 scanner was used. Eight cats underwent FDG PET scans twice before and after inducing the deafness. Only the brain and adjacent regions were extracted from each data set by manual masking. Individual PET image at normal and deaf state was realigned to each other to remove the confounding effects by the different spatial normalization parameters on the results of statistical analyses. Distance between the sampling points on the reference image and kernel size of Gaussian filter applied to the images before estimating the realignment parameters were adjusted to 0.5 mm and 2 mm. Both data was then spatial normalized onto study-specific cat brain template. Spatially normalized PET data were smoothed and voxel-based paired t-test was performed. Cerebral glucose metabolism decreased significantly after the loss of hearing capability in parietal lobes, postcentral gyri, STG, MTG, lTG, and IC at both hemisphere and left SC (FDR corrected P < 0.05, k=50). Cerebral glucose metabolism in deaf cats was found to be significantly higher than in controls in the right cingulate (FDR corrected P < 0.05, k=50). The ROI analysis also showed significant reduction of glucose metabolism in the same areas as in the SPM analysis, except for some regions (P < 0.05). Method for the voxel-based analysis of cat brain PET data was optimized for analysis of cat brain PET. This result was also confirmed by ROI analysis. The results obtained demonstrated the high localization accuracy and specificity of the developed method, and were found to be useful for examining cerebral glucose metabolism in a cat cortical deafness model.

  20. Hand Gesture Spotting Based on 3D Dynamic Features Using Hidden Markov Models

    Elmezain, Mahmoud; Al-Hamadi, Ayoub; Michaelis, Bernd

    In this paper, we propose an automatic system that handles hand gesture spotting and recognition simultaneously in stereo color image sequences without any time delay based on Hidden Markov Models (HMMs). Color and 3D depth map are used to segment hand regions. The hand trajectory will determine in further step using Mean-shift algorithm and Kalman filter to generate 3D dynamic features. Furthermore, k-means clustering algorithm is employed for the HMMs codewords. To spot meaningful gestures accurately, a non-gesture model is proposed, which provides confidence limit for the calculated likelihood by other gesture models. The confidence measures are used as an adaptive threshold for spotting meaningful gestures. Experimental results show that the proposed system can successfully recognize isolated gestures with 98.33% and meaningful gestures with 94.35% reliability for numbers (0-9).

  1. A Simple Isolation Criterion based on 3D Redshift Space Mapping

    Spector, Oded

    2009-01-01

    We selected a sample of galaxies, extremely isolated in 3D redshift space, based on data from NED and the ongoing ALFALFA HI (21cm) survey. A simple selection criterion was employed: having no neighbors closer than 300 km/s in 3D redshift space. The environments of galaxies, selected using this criterion and NED data alone, were analyzed theoretically using a constrained simulation of the local Universe, and were found to be an order of magnitude less dense than environments around randomly selected galaxies. One third of the galaxies selected using NED data alone did not pass the criterion when tested with ALFALFA data, implying that the use of unbiased HI data significantly improves the quality of the sample.

  2. [Establishment of database with standard 3D tooth crowns based on 3DS MAX].

    Cheng, Xiaosheng; An, Tao; Liao, Wenhe; Dai, Ning; Yu, Qing; Lu, Peijun

    2009-08-01

    The database with standard 3D tooth crowns has laid the groundwork for dental CAD/CAM system. In this paper, we design the standard tooth crowns in 3DS MAX 9.0 and create a database with these models successfully. Firstly, some key lines are collected from standard tooth pictures. Then we use 3DS MAX 9.0 to design the digital tooth model based on these lines. During the design process, it is important to refer to the standard plaster tooth model. After some tests, the standard tooth models designed with this method are accurate and adaptable; furthermore, it is very easy to perform some operations on the models such as deforming and translating. This method provides a new idea to build the database with standard 3D tooth crowns and a basis for dental CAD/CAM system. PMID:19813628

  3. Numerical Simulation of Injection Molding Cooling Process Based on 3D Surface Model

    CUIShu-biao; ZHOUHua-min; LIDe-qun

    2004-01-01

    The design of the coohng system of injection molds directly affects both productivity and the quality of the final part. Using the cooling process CAE system to instruct the mold design, the efficiency and quality of design can be improved greatly. At the same time, it is helpful to confirm the cooling system structure and optimize the process conditions. In this paper, the 3D surface model of mold cavity is used to replace the middle-plane model in the simulation by Boundary Element Method, which break the bottleneck of the application of the injection molding simulation softwares base on the middle-plane model. With the improvements of this paper, a practical and commercial simulation software of injection molding cooling process named as HsCAE3D6.0 is developed.

  4. Excitation of anti-symmetric coupled spoof SPPs in 3D SIS waveguides based on coupling

    Li-li, Tian; Yang, Chen; Jian-long, Liu; Kai, Guo; Ke-ya, Zhou; Yang, Gao; Shu-tian, Liu

    2016-07-01

    According to the electromagnetic field distributions, there exist two kinds of coupled spoof surface plasmon polaritons (SSPPs), the symmetric and anti-symmetric modes, in the three-dimensional (3D) subwavelength spoof–insulator–spoof (SIS) waveguide. We study the dispersion and excitation of the two kinds of coupled SSPPs supported by the 3D SIS waveguide. The evolution of the dispersion with the thickness and gap width of the waveguide is numerically investigated, and we give a theoretical analysis according to the coupling mechanism. Specially, based on the coupling mechanism, we design a zipper structure, through which the excitation and propagation of the anti-symmetric coupled modes can be realized effectively. Project supported by the National Basic Research Program of China (Grant No. 2013CBA01702) and the National Natural Science Foundation of China (Grant Nos. 61377016, 61575055, 10974039, 61307072, 61308017, and 61405056).

  5. Tunable fluorescence enhancement based on bandgap-adjustable 3D Fe3O4 nanoparticles

    Hu, Fei; Gao, Suning; Zhu, Lili; Liao, Fan; Yang, Lulu; Shao, Mingwang

    2016-06-01

    Great progress has been made in fluorescence-based detection utilizing solid state enhanced substrates in recent years. However, it is still difficult to achieve reliable substrates with tunable enhancement factors. The present work shows liquid fluorescence enhanced substrates consisting of suspensions of Fe3O4 nanoparticles (NPs), which can assemble 3D photonic crystal under the external magnetic field. The photonic bandgap induced by the equilibrium of attractive magnetic force and repulsive electrostatic force between adjacent Fe3O4 NPs is utilized to enhance fluorescence intensity of dye molecules (including R6G, RB, Cy5, DMTPS-DCV) in a reversible and controllable manner. The results show that a maximum of 12.3-fold fluorescence enhancement is realized in the 3D Fe3O4 NP substrates without the utilization of metal particles for PCs/DMTPS-DCV (1.0 × 10‑7 M, water fraction (f w) = 90%).

  6. Multi-view indoor human behavior recognition based on 3D skeleton

    Peng, Ling; Lu, Tongwei; Min, Feng

    2015-12-01

    For the problems caused by viewpoint changes in activity recognition, a multi-view interior human behavior recognition method based on 3D framework is presented. First, Microsoft's Kinect device is used to obtain body motion video in the positive perspective, the oblique angle and the side perspective. Second, it extracts bone joints and get global human features and the local features of arms and legs at the same time to form 3D skeletal features set. Third, online dictionary learning on feature set is used to reduce the dimension of feature. Finally, linear support vector machine (LSVM) is used to obtain the results of behavior recognition. The experimental results show that this method has better recognition rate.

  7. MUTUAL INFORMATION BASED 3D NON-RIGID REGISTRATION OF CT/MR ABDOMEN IMAGES

    2001-01-01

    A mutual information based 3D non-rigid registration approach was proposed for the registration of deformable CT/MR body abdomen images. The Parzen Windows Density Estimation (PWDE) method is adopted to calculate the mutual information between the two modals of CT and MRI abdomen images. By maximizing MI between the CT and MR volume images, the overlapping part of them reaches the biggest, which means that the two body images of CT and MR matches best to each other. Visible Human Project (VHP) Male abdomen CT and MRI Data are used as experimental data sets. The experimental results indicate that this approach of non-rigid 3D registration of CT/MR body abdominal images can be achieved effectively and automatically, without any prior processing procedures such as segmentation and feature extraction, but has a main drawback of very long computation time. Key words: medical image registration; multi-modality; mutual information; non-rigid; Parzen window density estimation

  8. A web-based 3D visualisation and assessment system for urban precinct scenario modelling

    Trubka, Roman; Glackin, Stephen; Lade, Oliver; Pettit, Chris

    2016-07-01

    Recent years have seen an increasing number of spatial tools and technologies for enabling better decision-making in the urban environment. They have largely arisen because of the need for cities to be more efficiently planned to accommodate growing populations while mitigating urban sprawl, and also because of innovations in rendering data in 3D being well suited for visualising the urban built environment. In this paper we review a number of systems that are better known and more commonly used in the field of urban planning. We then introduce Envision Scenario Planner (ESP), a web-based 3D precinct geodesign, visualisation and assessment tool, developed using Agile and Co-design methods. We provide a comprehensive account of the tool, beginning with a discussion of its design and development process and concluding with an example use case and a discussion of the lessons learned in its development.

  9. A PC-based technique for creating 3D plots from monochromatic TL glow curves

    Recording of thermoluminescence emission spectra of many minerals is beset with the problem of detecting low (TL) emission intensities at high temperatures where the thermal noise is competing. Although very expensive techniques have been described in literature to obtain elegantly isometric plots of temperature, wavelength and TL intensity of weakly emitting minerals, the present work describes a very simple method of creating 3D projections of TL emission from measurements of monochromatic TL glow curves and using a commercially available PC software. A microprocessor-based data acquisition system has been indigenously developed and interfaced to the conventional TL glow-curve recorder. The digitised data are directly fed into an IBM compatible PC-XT and the 3D plots are created using a commercially available software named 'SURFER'. The programme can also generate contour maps. Typical plots are presented for the case of minerals like Scapolite, Spodumene an Kunzite. (author). 4 refs., 6 figs

  10. A Novel Algorithm Based on 3D-MUSIC Algorithm for Localizing Near-Field Source

    SHAN Zhi-yong; ZHOU Xi-lang; PEN Gen-jiang

    2005-01-01

    A novel 3-D MUSIC algorithm based on the classical 3D-MUSIC algorithm for the location of near-field source was presented. Under the far-field assumption of actual near-field, two algebraic relations of the location parameters between the actual near-field sources and the far-field ones were derived. With Fourier transformation and polynomial-root methods, the elevation and the azimuth of the far-field were obtained, the tracking paths can be developed, and the location parameters of the near-field source can be determined, then the more accurate results can be estimated using an optimization method. The computer simulation results p rove that the algorithm for the location of the near-fields is more accurate, effective and suitable for real-time applications.

  11. Fast 3D EM scattering and radiation solvers based on MLFMA

    Hu Jun; Nie Zaiping; Lei Lin; Hu Jie; Gong Xiaodong; Zhao Huapeng

    2008-01-01

    As the fastest integral equation solver to date, the multilevel fast multipole algorithm (MLFMA)has been applied successfully to solve electromagnetic scattering and radiation from 3D electrically large objects.But for very large-scale problems, the storage and CPU time required in MLFMA are still expensive. Fast 3D electromagnetic scattering and radiation solvers are introduced based on MLFMA. A brief review of MLFMA is first given. Then, four fast methods including higher-order MLFMA (HO-MLFMA), fast far field approximation combined with adaptive ray propagation MLFMA (FAFFA-ARP-MLFMA), local MLFMA and parallel MLFMA are introduced. Some typical numerical results demonstrate the efficiency of these fast methods.

  12. 3D structural analysis of proteins using electrostatic surfaces based on image segmentation

    Vlachakis, Dimitrios; Champeris Tsaniras, Spyridon; Tsiliki, Georgia; Megalooikonomou, Vasileios; Kossida, Sophia

    2016-01-01

    Herein, we present a novel strategy to analyse and characterize proteins using protein molecular electro-static surfaces. Our approach starts by calculating a series of distinct molecular surfaces for each protein that are subsequently flattened out, thus reducing 3D information noise. RGB images are appropriately scaled by means of standard image processing techniques whilst retaining the weight information of each protein’s molecular electrostatic surface. Then homogeneous areas in the protein surface are estimated based on unsupervised clustering of the 3D images, while performing similarity searches. This is a computationally fast approach, which efficiently highlights interesting structural areas among a group of proteins. Multiple protein electrostatic surfaces can be combined together and in conjunction with their processed images, they can provide the starting material for protein structural similarity and molecular docking experiments.

  13. 3D measurement method based on combined temporal encoding structured light

    Yu, Xiaoyang; Wang, Yang; Yu, Shuang; Cheng, Hao; Sun, Xiaoming; Yu, Shuchun; Chen, Deyun

    2013-10-01

    Three-dimensional (3D) vision measurement technology based on encoding structured light plays an important role and has become the main development trend in the field of 3D non-contact measurement. However, how to synthetically improve measurement speed, accuracy and sampling density is still a difficult problem. Thus in the present work, a novel 3D measurement method based on temporal encoding structured light by combining trapezoidal phase-shifting pattern and cyclic code pattern is proposed. Due to trapezoidal phase-shifting has the advantages of high sampling density and high-speed, the proposed method can maintain these advantages by using cyclic code to expand the range of trapezoidal phase-shifting. In addition, the correction scheme is designed to solve the problem of cycle dislocation. Finally, simulation experimental platform is built with 3ds max and MATLAB. Experimental analyses and results show that, the maximal error is less than 3 mm in the range from 400 mm to 1100 mm, cycle dislocation correction has a good effect.

  14. Error Evaluation in a Stereovision-Based 3D Reconstruction System

    Kohler Sophie

    2010-01-01

    Full Text Available The work presented in this paper deals with the performance analysis of the whole 3D reconstruction process of imaged objects, specifically of the set of geometric primitives describing their outline and extracted from a pair of images knowing their associated camera models. The proposed analysis focuses on error estimation for the edge detection process, the starting step for the whole reconstruction procedure. The fitting parameters describing the geometric features composing the workpiece to be evaluated are used as quality measures to determine error bounds and finally to estimate the edge detection errors. These error estimates are then propagated up to the final 3D reconstruction step. The suggested error analysis procedure for stereovision-based reconstruction tasks further allows evaluating the quality of the 3D reconstruction. The resulting final error estimates enable lastly to state if the reconstruction results fulfill a priori defined criteria, for example, fulfill dimensional constraints including tolerance information, for vision-based quality control applications for example.

  15. Low-Cost Impact Detection and Location for Automated Inspections of 3D Metallic Based Structures

    Carlos Morón

    2015-05-01

    Full Text Available This paper describes a new low-cost means to detect and locate mechanical impacts (collisions on a 3D metal-based structure. We employ the simple and reasonably hypothesis that the use of a homogeneous material will allow certain details of the impact to be automatically determined by measuring the time delays of acoustic wave propagation throughout the 3D structure. The location of strategic piezoelectric sensors on the structure and an electronic-computerized system has allowed us to determine the instant and position at which the impact is produced. The proposed automatic system allows us to fully integrate impact point detection and the task of inspecting the point or zone at which this impact occurs. What is more, the proposed method can be easily integrated into a robot-based inspection system capable of moving over 3D metallic structures, thus avoiding (or minimizing the need for direct human intervention. Experimental results are provided to show the effectiveness of the proposed approach.

  16. AN IMAGE-BASED TECHNIQUE FOR 3D BUILDING RECONSTRUCTION USING MULTI-VIEW UAV IMAGES

    F. Alidoost

    2015-12-01

    Full Text Available Nowadays, with the development of the urban areas, the automatic reconstruction of the buildings, as an important objects of the city complex structures, became a challenging topic in computer vision and photogrammetric researches. In this paper, the capability of multi-view Unmanned Aerial Vehicles (UAVs images is examined to provide a 3D model of complex building façades using an efficient image-based modelling workflow. The main steps of this work include: pose estimation, point cloud generation, and 3D modelling. After improving the initial values of interior and exterior parameters at first step, an efficient image matching technique such as Semi Global Matching (SGM is applied on UAV images and a dense point cloud is generated. Then, a mesh model of points is calculated using Delaunay 2.5D triangulation and refined to obtain an accurate model of building. Finally, a texture is assigned to mesh in order to create a realistic 3D model. The resulting model has provided enough details of building based on visual assessment.

  17. 3D Road Scene Monitoring Based on Real-Time Panorama

    Yuezhou Wu

    2014-01-01

    Full Text Available Road monitoring helps to control the regional traffic situation so as to adjust the traffic flow. Real-time panorama is conducive to timely treat traffic accidents and to greatly improve traffic capacity. This paper designs a 3D road scene monitoring framework based on real-time panorama. The system is the combination of large scale panorama, satellite map textures, and 3D scene model, in which users can ramble freely. This paper has the following contributions. Firstly, land-points were extracted followed by motion detection, then comotion algorithm was applied to land-points from adjacent cameras, and homography matrix was constructed. Secondly, reference camera was chosen and transformed to overhead viewpoint; subsequently multiviews were morphed to the same viewpoint and stitched to panorama. Finally, the registration based on high-precision GPS information between 2D road panorama and 3D scene model was also proposed. The proposed framework has been successfully applied to a large road intersection monitoring. Experimental results are furnished at the end of the paper.

  18. Research on the Multi-view Point 3-D Clouds Splicing Algorithm based on Local Registration

    Daoming Feng

    2013-01-01

    Full Text Available The paper proposed a new 3-D measurement point cloud splicing algorithm. The algorithm utilizes registration ideal in model identification technology to realize unbound and accurate splicing of 3-D data. First, sample the overlapping areas in the two 3-D point clouds which need to be spliced. Carry out pre-processing over the sampled point cloud with principal analysis method based on the statistic theory. Through extracting the feature vector that could best indicate the point cloud information, it realizes the dimension reduction for data. Then, apply improved iterate corresponding point algorithm to the sampled point cloud data which has realized pre-registration to achieve accurate registration. In the process, the set of progressive decrease of iterate condition by different levels reduced the iterate times. The utilization of new comprehensive distance measurement function effectively increases the accuracy and robustness of overall iterated convergence. Finally, apply the transformation parameter based on local sampled point cloud calculation to the entire point cloud splicing and achieve the accurate registration of multiple sampled point cloud. In the end, the actual test proved that the algorithm boasts high splicing accuracy with high overall convergence robustness, few convergence iterate times and strong anti-noise capacity.

  19. 3D label-free prostate specific antigen (PSA) immunosensor based on graphene-gold composites.

    Jang, Hee Dong; Kim, Sun Kyung; Chang, Hankwon; Choi, Jeong-Woo

    2015-01-15

    Highly sensitive and label-free detection of the prostate specific antigen (PSA) remains a challenge in the diagnosis of prostate cancer. Here, a novel three-dimensional (3D) electrochemical immunosensor capable of sensitive and label-free detection of PSA is reported. This unique immunosensor is equipped with a highly conductive graphene (GR)-based gold (Au) composite modified electrode. The GR-based Au composite is prepared using aerosol spray pyrolysis and the morphology of the composite is the shape of a crumpled GR ball decorated with Au nanoparticles. Unlike the previous research, this novel 3D immunosensor functions very well over a broad linear range of 0-10 ng/mL with a low detection limit of 0.59 ng/mL; furthermore, it exhibits a significantly increased electron transfer and high sensitivity toward PSA. The highest rate of current change with respect to the PSA concentration is 5 μA/(ng/mL). Satisfactory selectivity, reproducibility, and stability of the 3D immunosensor are also exhibited. PMID:25150936

  20. 3D Metamaterial Based on a Regular Array of Resonant Dielectric Inclusions

    I. Vendik

    2009-06-01

    Full Text Available The 3D regular lattice of bi-spherical dielectric resonant inclusions arranged in a cubic lattice as two sets of spheres made from the same dielectric material having different radii and embedded in a host dielectric material with lower dielectric permittivity was carefully investigated. The magnetic resonance corresponding to the first Mie resonance in the spherical particles is followed by forming a regular array of effective magnetic dipoles, and the structure of the identical spherical dielectric resonators can be designed as an isotropic μ-negative 3D-metamaterial. For the electric resonance it was found experimentally and by the simulation that the resonant response of the electric dipole was weakly pronounced and the μ-negative behavior was remarkably suppressed. To enhance the electric dipole contribution we considered another kind of the symmetry of the bi-spherical arrangement of the particles corresponding to the body-centered cubic symmetry instead of the symmetry of NaCl analog considered previously. Electromagnetic properties of a volumetric structure based on a regular lattice of identical cubic dielectric particles is also considered and analyzed as μ-negative metamaterial. The cubic particle based 3D-metamaterial is preferable for practical realization as compared with the spherical inclusions.

  1. MO-C-18A-01: Advances in Model-Based 3D Image Reconstruction

    Chen, G [University of Wisconsin, Madison, WI (United States); Pan, X [University Chicago, Chicago, IL (United States); Stayman, J [Johns Hopkins University, Baltimore, MD (United States); Samei, E [Duke University Medical Center, Durham, NC (United States)

    2014-06-15

    Recent years have seen the emergence of CT image reconstruction techniques that exploit physical models of the imaging system, photon statistics, and even the patient to achieve improved 3D image quality and/or reduction of radiation dose. With numerous advantages in comparison to conventional 3D filtered backprojection, such techniques bring a variety of challenges as well, including: a demanding computational load associated with sophisticated forward models and iterative optimization methods; nonlinearity and nonstationarity in image quality characteristics; a complex dependency on multiple free parameters; and the need to understand how best to incorporate prior information (including patient-specific prior images) within the reconstruction process. The advantages, however, are even greater – for example: improved image quality; reduced dose; robustness to noise and artifacts; task-specific reconstruction protocols; suitability to novel CT imaging platforms and noncircular orbits; and incorporation of known characteristics of the imager and patient that are conventionally discarded. This symposium features experts in 3D image reconstruction, image quality assessment, and the translation of such methods to emerging clinical applications. Dr. Chen will address novel methods for the incorporation of prior information in 3D and 4D CT reconstruction techniques. Dr. Pan will show recent advances in optimization-based reconstruction that enable potential reduction of dose and sampling requirements. Dr. Stayman will describe a “task-based imaging” approach that leverages models of the imaging system and patient in combination with a specification of the imaging task to optimize both the acquisition and reconstruction process. Dr. Samei will describe the development of methods for image quality assessment in such nonlinear reconstruction techniques and the use of these methods to characterize and optimize image quality and dose in a spectrum of clinical

  2. In vivo bioluminescence tomography based on multi-view projection and 3D surface reconstruction

    Zhang, Shuang; Wang, Kun; Leng, Chengcai; Deng, Kexin; Hu, Yifang; Tian, Jie

    2015-03-01

    Bioluminescence tomography (BLT) is a powerful optical molecular imaging modality, which enables non-invasive realtime in vivo imaging as well as 3D quantitative analysis in preclinical studies. In order to solve the inverse problem and reconstruct inner light sources accurately, the prior structural information is commonly necessary and obtained from computed tomography or magnetic resonance imaging. This strategy requires expensive hybrid imaging system, complicated operation protocol and possible involvement of ionizing radiation. The overall robustness highly depends on the fusion accuracy between the optical and structural information. In this study we present a pure optical bioluminescence tomographic system (POBTS) and a novel BLT method based on multi-view projection acquisition and 3D surface reconstruction. The POBTS acquired a sparse set of white light surface images and bioluminescent images of a mouse. Then the white light images were applied to an approximate surface model to generate a high quality textured 3D surface reconstruction of the mouse. After that we integrated multi-view luminescent images based on the previous reconstruction, and applied an algorithm to calibrate and quantify the surface luminescent flux in 3D.Finally, the internal bioluminescence source reconstruction was achieved with this prior information. A BALB/C mouse with breast tumor of 4T1-fLuc cells mouse model were used to evaluate the performance of the new system and technique. Compared with the conventional hybrid optical-CT approach using the same inverse reconstruction method, the reconstruction accuracy of this technique was improved. The distance error between the actual and reconstructed internal source was decreased by 0.184 mm.

  3. Assessment of Eye Fatigue Caused by 3D Displays Based on Multimodal Measurements

    Jae Won Bang

    2014-09-01

    Full Text Available With the development of 3D displays, user’s eye fatigue has been an important issue when viewing these displays. There have been previous studies conducted on eye fatigue related to 3D display use, however, most of these have employed a limited number of modalities for measurements, such as electroencephalograms (EEGs, biomedical signals, and eye responses. In this paper, we propose a new assessment of eye fatigue related to 3D display use based on multimodal measurements. compared to previous works Our research is novel in the following four ways: first, to enhance the accuracy of assessment of eye fatigue, we measure EEG signals, eye blinking rate (BR, facial temperature (FT, and a subjective evaluation (SE score before and after a user watches a 3D display; second, in order to accurately measure BR in a manner that is convenient for the user, we implement a remote gaze-tracking system using a high speed (mega-pixel camera that measures eye blinks of both eyes; thirdly, changes in the FT are measured using a remote thermal camera, which can enhance the measurement of eye fatigue, and fourth, we perform various statistical analyses to evaluate the correlation between the EEG signal, eye BR, FT, and the SE score based on the T-test, correlation matrix, and effect size. Results show that the correlation of the SE with other data (FT, BR, and EEG is the highest, while those of the FT, BR, and EEG with other data are second, third, and fourth highest, respectively.

  4. Assessment of eye fatigue caused by 3D displays based on multimodal measurements.

    Bang, Jae Won; Heo, Hwan; Choi, Jong-Suk; Park, Kang Ryoung

    2014-01-01

    With the development of 3D displays, user's eye fatigue has been an important issue when viewing these displays. There have been previous studies conducted on eye fatigue related to 3D display use, however, most of these have employed a limited number of modalities for measurements, such as electroencephalograms (EEGs), biomedical signals, and eye responses. In this paper, we propose a new assessment of eye fatigue related to 3D display use based on multimodal measurements. compared to previous works Our research is novel in the following four ways: first, to enhance the accuracy of assessment of eye fatigue, we measure EEG signals, eye blinking rate (BR), facial temperature (FT), and a subjective evaluation (SE) score before and after a user watches a 3D display; second, in order to accurately measure BR in a manner that is convenient for the user, we implement a remote gaze-tracking system using a high speed (mega-pixel) camera that measures eye blinks of both eyes; thirdly, changes in the FT are measured using a remote thermal camera, which can enhance the measurement of eye fatigue, and fourth, we perform various statistical analyses to evaluate the correlation between the EEG signal, eye BR, FT, and the SE score based on the T-test, correlation matrix, and effect size. Results show that the correlation of the SE with other data (FT, BR, and EEG) is the highest, while those of the FT, BR, and EEG with other data are second, third, and fourth highest, respectively. PMID:25192315

  5. Image-driven, model-based 3D abdominal motion estimation for MR-guided radiotherapy

    Stemkens, Bjorn; Tijssen, Rob H. N.; de Senneville, Baudouin Denis; Lagendijk, Jan J. W.; van den Berg, Cornelis A. T.

    2016-07-01

    Respiratory motion introduces substantial uncertainties in abdominal radiotherapy for which traditionally large margins are used. The MR-Linac will open up the opportunity to acquire high resolution MR images just prior to radiation and during treatment. However, volumetric MRI time series are not able to characterize 3D tumor and organ-at-risk motion with sufficient temporal resolution. In this study we propose a method to estimate 3D deformation vector fields (DVFs) with high spatial and temporal resolution based on fast 2D imaging and a subject-specific motion model based on respiratory correlated MRI. In a pre-beam phase, a retrospectively sorted 4D-MRI is acquired, from which the motion is parameterized using a principal component analysis. This motion model is used in combination with fast 2D cine-MR images, which are acquired during radiation, to generate full field-of-view 3D DVFs with a temporal resolution of 476 ms. The geometrical accuracies of the input data (4D-MRI and 2D multi-slice acquisitions) and the fitting procedure were determined using an MR-compatible motion phantom and found to be 1.0–1.5 mm on average. The framework was tested on seven healthy volunteers for both the pancreas and the kidney. The calculated motion was independently validated using one of the 2D slices, with an average error of 1.45 mm. The calculated 3D DVFs can be used retrospectively for treatment simulations, plan evaluations, or to determine the accumulated dose for both the tumor and organs-at-risk on a subject-specific basis in MR-guided radiotherapy.

  6. The Relevance Voxel Machine (RVoxM): A Self-Tuning Bayesian Model for Informative Image-Based Prediction

    Sabuncu, Mert R.; Van Leemput, Koen

    2012-01-01

    This paper presents the relevance voxel machine (RVoxM), a dedicated Bayesian model for making predictions based on medical imaging data. In contrast to the generic machine learning algorithms that have often been used for this purpose, the method is designed to utilize a small number of spatially...

  7. The Neural Basis of Reversible Sentence Comprehension: Evidence from Voxel-Based Lesion Symptom Mapping in Aphasia

    Thothathiri, Malathi; Kimberg, Daniel Y.; Schwartz, Myrna F.

    2012-01-01

    We explored the neural basis of reversible sentence comprehension in a large group of aphasic patients (n = 79). Voxel-based lesion symptom mapping revealed a significant association between damage in temporo-parietal cortex and impaired sentence comprehension. This association remained after we controlled for phonological working memory. We…

  8. Dyslexia and Voxel-Based Morphometry: Correlations between Five Behavioural Measures of Dyslexia and Gray and White Matter Volumes

    Tamboer, Peter; Scholte, H. Steven; Vorst, Harrie C. M.

    2015-01-01

    In voxel-based morphometry studies of dyslexia, the relation between causal theories of dyslexia and gray matter (GM) and white matter (WM) volume alterations is still under debate. Some alterations are consistently reported, but others failed to reach significance. We investigated GM alterations in a large sample of Dutch students (37 dyslexics…

  9. Accelerated cerebral white matter development in preterm infants: a voxel-based morphometry study with diffusion tensor MR imaging

    Giménez, Mónica; Born, A Peter; Nagy, Zoltan;

    2008-01-01

    Twenty-seven preterm infants were compared to 10 full-term infants at term equivalent age using a voxel-based analysis of diffusion tensor imaging of the brain. Preterm infants exhibited higher fractional anisotropy values, which may suggest accelerated maturation, in the location of the sagittal...

  10. Dyslexia and voxel-based morphometry: correlations between five behavioural measures of dyslexia and gray and white matter volumes

    P. Tamboer; H.S. Scholte; H.C.M. Vorst

    2015-01-01

    In voxel-based morphometry studies of dyslexia, the relation between causal theories of dyslexia and gray matter (GM) and white matter (WM) volume alterations is still under debate. Some alterations are consistently reported, but others failed to reach significance. We investigated GM alterations in

  11. 3D Geological Modeling and Visualization of Rock Masses Based on Google Earth: A Case Study

    Mei, Gang; Xu, Nengxiong

    2013-01-01

    Google Earth (GE) has become a powerful tool for geological modeling and visualization. An interesting and useful feature of GE, Google Street View, can allow the GE users to view geological structure such as layers of rock masses at a field site. In this paper, we introduce a practical solution for building 3D geological models for rock masses based on the data acquired by use with GE. A real study case at Haut-Barr, France is presented to demonstrate our solution. We first locate the position of Haut-Barr in GE, and then determine the shape and scale of the rock masses in the study area, and thirdly acquire the layout of layers of rock masses in the Google Street View, and finally create the approximate 3D geological models by extruding and intersecting. The generated 3D geological models can simply reflect the basic structure of the rock masses at Haut-Barr, and can be used for visualizing the rock bodies interactively.

  12. Context-Aware AAL Services through a 3D Sensor-Based Platform

    Alessandro Leone

    2013-01-01

    Full Text Available The main goal of Ambient Assisted Living solutions is to provide assistive technologies and services in smart environments allowing elderly people to have high quality of life. Since 3D sensing technologies are increasingly investigated as monitoring solution able to outperform traditional approaches, in this work a noninvasive monitoring platform based on 3D sensors is presented providing a wide-range solution suitable in several assisted living scenarios. Detector nodes are managed by low-power embedded PCs in order to process 3D streams and extract postural features related to person’s activities. The feature level of details is tuned in accordance with the current context in order to save bandwidth and computational resources. The platform architecture is conceived as a modular system suitable to be integrated into third-party middleware to provide monitoring functionalities in several scenarios. The event detection capabilities were validated by using both synthetic and real datasets collected in controlled and real-home environments. Results show the soundness of the presented solution to adapt to different application requirements, by correctly detecting events related to four relevant AAL services.

  13. A new combined prior based reconstruction method for compressed sensing in 3D ultrasound imaging

    Uddin, Muhammad S.; Islam, Rafiqul; Tahtali, Murat; Lambert, Andrew J.; Pickering, Mark R.

    2015-03-01

    Ultrasound (US) imaging is one of the most popular medical imaging modalities, with 3D US imaging gaining popularity recently due to its considerable advantages over 2D US imaging. However, as it is limited by long acquisition times and the huge amount of data processing it requires, methods for reducing these factors have attracted considerable research interest. Compressed sensing (CS) is one of the best candidates for accelerating the acquisition rate and reducing the data processing time without degrading image quality. However, CS is prone to introduce noise-like artefacts due to random under-sampling. To address this issue, we propose a combined prior-based reconstruction method for 3D US imaging. A Laplacian mixture model (LMM) constraint in the wavelet domain is combined with a total variation (TV) constraint to create a new regularization regularization prior. An experimental evaluation conducted to validate our method using synthetic 3D US images shows that it performs better than other approaches in terms of both qualitative and quantitative measures.

  14. Sample based 3D face reconstruction from a single frontal image by adaptive locally linear embedding

    ZHANG Jian; ZHUANG Yue-ting

    2007-01-01

    In this paper, we propose a highly automatic approach for 3D photorealistic face reconstruction from a single frontal image. The key point of our work is the implementation of adaptive manifold learning approach. Beforehand, an active appearance model (AAM) is trained for automatic feature extraction and adaptive locally linear embedding (ALLE) algorithm is utilized to reduce the dimensionality of the 3D database. Then, given an input frontal face image, the corresponding weights between 3D samples and the image are synthesized adaptively according to the AAM selected facial features. Finally, geometry reconstruction is achieved by linear weighted combination of adaptively selected samples. Radial basis function (RBF) is adopted to map facial texture from the frontal image to the reconstructed face geometry. The texture of invisible regions between the face and the ears is interpolated by sampling from the frontal image. This approach has several advantages: (1) Only a single frontal face image is needed for highly automatic face reconstruction; (2) Compared with former works, our reconstruction approach provides higher accuracy; (3) Constraint based RBF texture mapping provides natural appearance for reconstructed face.

  15. 3D Fast Automatic Segmentation of Kidney Based on Modified AAM and Random Forest.

    Jin, Chao; Shi, Fei; Xiang, Dehui; Jiang, Xueqing; Zhang, Bin; Wang, Ximing; Zhu, Weifang; Gao, Enting; Chen, Xinjian

    2016-06-01

    In this paper, a fully automatic method is proposed to segment the kidney into multiple components: renal cortex, renal column, renal medulla and renal pelvis, in clinical 3D CT abdominal images. The proposed fast automatic segmentation method of kidney consists of two main parts: localization of renal cortex and segmentation of kidney components. In the localization of renal cortex phase, a method which fully combines 3D Generalized Hough Transform (GHT) and 3D Active Appearance Models (AAM) is applied to localize the renal cortex. In the segmentation of kidney components phase, a modified Random Forests (RF) method is proposed to segment the kidney into four components based on the result from localization phase. During the implementation, a multithreading technology is applied to speed up the segmentation process. The proposed method was evaluated on a clinical abdomen CT data set, including 37 contrast-enhanced volume data using leave-one-out strategy. The overall true-positive volume fraction and false-positive volume fraction were 93.15%, 0.37% for renal cortex segmentation; 83.09%, 0.97% for renal column segmentation; 81.92%, 0.55% for renal medulla segmentation; and 80.28%, 0.30% for renal pelvis segmentation, respectively. The average computational time of segmenting kidney into four components took 20 seconds. PMID:26742124

  16. A Skeleton-Based 3D Shape Reconstruction of Free-Form Objects with Stereo Vision

    Saini, Deepika; Kumar, Sanjeev

    2015-12-01

    In this paper, an efficient approach is proposed for recovering the 3D shape of a free-form object from its arbitrary pair of stereo images. In particular, the reconstruction problem is treated as the reconstruction of the skeleton and the external boundary of the object. The reconstructed skeleton is termed as the line-like representation or curve-skeleton of the 3D object. The proposed solution for object reconstruction is based on this evolved curve-skeleton. It is used as a seed for recovering shape of the 3D object, and the extracted boundary is used for terminating the growing process of the object. NURBS-skeleton is used to extract the skeleton of both views. Affine invariant property of the convex hulls is used to establish the correspondence between the skeletons and boundaries in the stereo images. In the growing process, a distance field is defined for each skeleton point as the smallest distance from that point to the boundary of the object. A sphere centered at a skeleton point of radius equal to the minimum distance to the boundary is tangential to the boundary. Filling in the spheres centered at each skeleton point reconstructs the object. Several results are presented in order to check the applicability and validity of the proposed algorithm.

  17. PACS-based interface for 3D anatomical structure visualization and surgical planning

    Koehl, Christophe; Soler, Luc; Marescaux, Jacques

    2002-05-01

    The interpretation of radiological image is routine but it remains a rather difficult task for physicians. It requires complex mental processes, that permit translation from 2D slices into 3D localization and volume determination of visible diseases. An easier and more extensive visualization and exploitation of medical images can be reached through the use of computer-based systems that provide real help from patient admission to post-operative followup. In this way, we have developed a 3D visualization interface linked to a PACS database that allows manipulation and interaction on virtual organs delineated from CT-scan or MRI. This software provides the 3D real-time surface rendering of anatomical structures, an accurate evaluation of volumes and distances and the improvement of radiological image analysis and exam annotation through a negatoscope tool. It also provides a tool for surgical planning allowing the positioning of an interactive laparoscopic instrument and the organ resection. The software system could revolutionize the field of computerized imaging technology. Indeed, it provides a handy and portable tool for pre-operative and intra-operative analysis of anatomy and pathology in various medical fields. This constitutes the first step of the future development of augmented reality and surgical simulation systems.

  18. A 3D transport-based core analysis code for research reactors with unstructured geometry

    Highlights: • A core analysis code package based on 3D neutron transport calculation in complex geometry is developed. • The fine considerations on flux mapping, control rod effects and isotope depletion are modeled. • The code is proved to be with high accuracy and capable of handling flexible operational cases for research reactors. - Abstract: As an effort to enhance the accuracy in simulating the operations of research reactors, a 3D transport core analysis code system named REFT was developed. HELIOS is employed due to the flexibility of describing complex geometry. A 3D triangular nodal SN method transport solver, DNTR, endows the package the capability of modeling cores with unstructured geometry assemblies. A series of dedicated methods were introduced to meet the requirements of research reactor simulations. Afterwards, to make it more user friendly, a graphical user interface was also developed for REFT. In order to validate the developed code system, the calculated results were compared with the experimental results. Both the numerical and experimental results are in close agreement with each other, with the relative errors of keff being less than 0.5%. Results for depletion calculations were also verified by comparing them with the experimental data and acceptable consistency was observed in results

  19. Microchip-based electrochemical detection using a 3-D printed wall-jet electrode device.

    Munshi, Akash S; Martin, R Scott

    2016-02-01

    Three dimensional (3-D) printing technology has evolved dramatically in the last few years, offering the capability of printing objects with a variety of materials. Printing microfluidic devices using this technology offers various advantages such as ease and uniformity of fabrication, file sharing between laboratories, and increased device-to-device reproducibility. One unique aspect of this technology, when used with electrochemical detection, is the ability to produce a microfluidic device as one unit while also allowing the reuse of the device and electrode for multiple analyses. Here we present an alternate electrode configuration for microfluidic devices, a wall-jet electrode (WJE) approach, created by 3-D printing. Using microchip-based flow injection analysis, we compared the WJE design with the conventionally used thin-layer electrode (TLE) design. It was found that the optimized WJE system enhances analytical performance (as compared to the TLE design), with improvements in sensitivity and the limit of detection. Experiments were conducted using two working electrodes - 500 μm platinum and 1 mm glassy carbon. Using the 500 μm platinum electrode the calibration sensitivity was 16 times higher for the WJE device (as compared to the TLE design). In addition, use of the 1 mm glassy carbon electrode led to limit of detection of 500 nM for catechol, as compared to 6 μM for the TLE device. Finally, to demonstrate the versatility and applicability of the 3-D printed WJE approach, the device was used as an inexpensive electrochemical detector for HPLC. The number of theoretical plates was comparable to the use of commercially available UV and MS detectors, with the WJE device being inexpensive to utilize. These results show that 3-D-printing can be a powerful tool to fabricate reusable and integrated microfluidic detectors in configurations that are not easily achieved with more traditional lithographic methods. PMID:26649363

  20. Ion track reconstruction in 3D using alumina-based fluorescent nuclear track detectors

    Niklas, M.; Bartz, J. A.; Akselrod, M. S.; Abollahi, A.; Jäkel, O.; Greilich, S.

    2013-09-01

    Fluorescent nuclear track detectors (FNTDs) based on Al2O3: C, Mg single crystal combined with confocal microscopy provide 3D information on ion tracks with a resolution only limited by light diffraction. FNTDs are also ideal substrates to be coated with cells to engineer cell-fluorescent ion track hybrid detectors (Cell-Fit-HD). This radiobiological tool enables a novel platform linking cell responses to physical dose deposition on a sub-cellular level in proton and heavy ion therapies. To achieve spatial correlation between single ion hits in the cell coating and its biological response the ion traversals have to be reconstructed in 3D using the depth information gained by the FNTD read-out. FNTDs were coated with a confluent human lung adenocarcinoma epithelial (A549) cell layer. Carbon ion irradiation of the hybrid detector was performed perpendicular and angular to the detector surface. In situ imaging of the fluorescently labeled cell layer and the FNTD was performed in a sequential read-out. Making use of the trajectory information provided by the FNTD the accuracy of 3D track reconstruction of single particles traversing the hybrid detector was studied. The accuracy is strongly influenced by the irradiation angle and therefore by complexity of the FNTD signal. Perpendicular irradiation results in highest accuracy with error of smaller than 0.10°. The ability of FNTD technology to provide accurate 3D ion track reconstruction makes it a powerful tool for radiobiological investigations in clinical ion beams, either being used as a substrate to be coated with living tissue or being implanted in vivo.

  1. Advantages and drawbacks of Thiol-ene based resins for 3D-printing

    Leonards, Holger; Engelhardt, Sascha; Hoffmann, Andreas; Pongratz, Ludwig; Schriever, Sascha; Bläsius, Jana; Wehner, Martin; Gillner, Arnold

    2015-03-01

    The technology of 3D printing is conquering the world and awakens the interest of many users in the most varying of applications. New formulation approaches for photo-sensitive thiol-ene resins in combination with various printing technologies, like stereolithography (SLA), projection based printing/digital light processing (DLP) or two-photon polymerization (TPP) are presented. Thiol-ene polymerizations are known for its fast and quantitative reaction and to form highly homogeneous polymer networks. As the resins are locally and temporally photo-curable the polymerization type is very promising for 3D-printing. By using suitable wavelengths, photoinitiator-free fabrication is feasible for single- and two photon induced polymerization. In this paper divinyl ethers of polyethylene glycols in combination with star-shaped tetrathiols were used to design a simple test-system for photo-curable thiol-ene resins. In order to control and improve curing depth and lateral resolution in 3D-polymerization processes, either additives in chemical formulation or process parameters can be changed. The achieved curing depth and resolution limits depend on the applied fabrication method. While two-/multiphoton induced lithography offers the possibility of micron- to sub-micron resolution it lacks in built-up speed. Hence single-photon polymerization is a fast alternative with optimization potential in sub-10-micron resolution. Absorber- and initiator free compositions were developed in order to avoid aging, yellowing and toxicity of resulting products. They can be cured with UV-laser radiation below 300 nm. The development at Fraunhofer ILT is focusing on new applications in the field of medical products and implants, technical products with respect to mechanical properties or optical properties of 3D-printed objects. Recent process results with model system (polyethylene glycol divinylether/ Pentaerithrytol tetrakis (3-mercaptopropionat), Raman measurements of polymer conversion

  2. Model based 3D segmentation and OCT image undistortion of percutaneous implants.

    Müller, Oliver; Donner, Sabine; Klinder, Tobias; Dragon, Ralf; Bartsch, Ivonne; Witte, Frank; Krüger, Alexander; Heisterkamp, Alexander; Rosenhahn, Bodo

    2011-01-01

    Optical Coherence Tomography (OCT) is a noninvasive imaging technique which is used here for in vivo biocompatibility studies of percutaneous implants. A prerequisite for a morphometric analysis of the OCT images is the correction of optical distortions caused by the index of refraction in the tissue. We propose a fully automatic approach for 3D segmentation of percutaneous implants using Markov random fields. Refraction correction is done by using the subcutaneous implant base as a prior for model based estimation of the refractive index using a generalized Hough transform. Experiments show the competitiveness of our algorithm towards manual segmentations done by experts. PMID:22003731

  3. Neural correlates of post-conventional moral reasoning: a voxel-based morphometry study.

    Kristin Prehn

    Full Text Available Going back to Kohlberg, moral development research affirms that people progress through different stages of moral reasoning as cognitive abilities mature. Individuals at a lower level of moral reasoning judge moral issues mainly based on self-interest (personal interests schema or based on adherence to laws and rules (maintaining norms schema, whereas individuals at the post-conventional level judge moral issues based on deeper principles and shared ideals. However, the extent to which moral development is reflected in structural brain architecture remains unknown. To investigate this question, we used voxel-based morphometry and examined the brain structure in a sample of 67 Master of Business Administration (MBA students. Subjects completed the Defining Issues Test (DIT-2 which measures moral development in terms of cognitive schema preference. Results demonstrate that subjects at the post-conventional level of moral reasoning were characterized by increased gray matter volume in the ventromedial prefrontal cortex and subgenual anterior cingulate cortex, compared with subjects at a lower level of moral reasoning. Our findings support an important role for both cognitive and emotional processes in moral reasoning and provide first evidence for individual differences in brain structure according to the stages of moral reasoning first proposed by Kohlberg decades ago.

  4. Neural correlates of post-conventional moral reasoning: a voxel-based morphometry study.

    Prehn, Kristin; Korczykowski, Marc; Rao, Hengyi; Fang, Zhuo; Detre, John A; Robertson, Diana C

    2015-01-01

    Going back to Kohlberg, moral development research affirms that people progress through different stages of moral reasoning as cognitive abilities mature. Individuals at a lower level of moral reasoning judge moral issues mainly based on self-interest (personal interests schema) or based on adherence to laws and rules (maintaining norms schema), whereas individuals at the post-conventional level judge moral issues based on deeper principles and shared ideals. However, the extent to which moral development is reflected in structural brain architecture remains unknown. To investigate this question, we used voxel-based morphometry and examined the brain structure in a sample of 67 Master of Business Administration (MBA) students. Subjects completed the Defining Issues Test (DIT-2) which measures moral development in terms of cognitive schema preference. Results demonstrate that subjects at the post-conventional level of moral reasoning were characterized by increased gray matter volume in the ventromedial prefrontal cortex and subgenual anterior cingulate cortex, compared with subjects at a lower level of moral reasoning. Our findings support an important role for both cognitive and emotional processes in moral reasoning and provide first evidence for individual differences in brain structure according to the stages of moral reasoning first proposed by Kohlberg decades ago. PMID:26039547

  5. Dimensionality Reduction Based Optimization Algorithm for Sparse 3-D Image Reconstruction in Diffuse Optical Tomography

    Bhowmik, Tanmoy; Liu, Hanli; Ye, Zhou; Oraintara, Soontorn

    2016-03-01

    Diffuse optical tomography (DOT) is a relatively low cost and portable imaging modality for reconstruction of optical properties in a highly scattering medium, such as human tissue. The inverse problem in DOT is highly ill-posed, making reconstruction of high-quality image a critical challenge. Because of the nature of sparsity in DOT, sparsity regularization has been utilized to achieve high-quality DOT reconstruction. However, conventional approaches using sparse optimization are computationally expensive and have no selection criteria to optimize the regularization parameter. In this paper, a novel algorithm, Dimensionality Reduction based Optimization for DOT (DRO-DOT), is proposed. It reduces the dimensionality of the inverse DOT problem by reducing the number of unknowns in two steps and thereby makes the overall process fast. First, it constructs a low resolution voxel basis based on the sensing-matrix properties to find an image support. Second, it reconstructs the sparse image inside this support. To compensate for the reduced sensitivity with increasing depth, depth compensation is incorporated in DRO-DOT. An efficient method to optimally select the regularization parameter is proposed for obtaining a high-quality DOT image. DRO-DOT is also able to reconstruct high-resolution images even with a limited number of optodes in a spatially limited imaging set-up.

  6. 3D delivered dose assessment using a 4DCT-based motion model

    Cai, Weixing; Hurwitz, Martina H.; Williams, Christopher L.; Dhou, Salam; Berbeco, Ross I.; Mishra, Pankaj, E-mail: wcai@lroc.harvard.edu, E-mail: jhlewis@lroc.harvard.edu; Lewis, John H., E-mail: wcai@lroc.harvard.edu, E-mail: jhlewis@lroc.harvard.edu [Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115 (United States); Seco, Joao [Francis H. Burr Proton Therapy Center, Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02115 (United States)

    2015-06-15

    Purpose: The purpose of this work is to develop a clinically feasible method of calculating actual delivered dose distributions for patients who have significant respiratory motion during the course of stereotactic body radiation therapy (SBRT). Methods: A novel approach was proposed to calculate the actual delivered dose distribution for SBRT lung treatment. This approach can be specified in three steps. (1) At the treatment planning stage, a patient-specific motion model is created from planning 4DCT data. This model assumes that the displacement vector field (DVF) of any respiratory motion deformation can be described as a linear combination of some basis DVFs. (2) During the treatment procedure, 2D time-varying projection images (either kV or MV projections) are acquired, from which time-varying “fluoroscopic” 3D images of the patient are reconstructed using the motion model. The DVF of each timepoint in the time-varying reconstruction is an optimized linear combination of basis DVFs such that the 2D projection of the 3D volume at this timepoint matches the projection image. (3) 3D dose distribution is computed for each timepoint in the set of 3D reconstructed fluoroscopic images, from which the total effective 3D delivered dose is calculated by accumulating deformed dose distributions. This approach was first validated using two modified digital extended cardio-torso (XCAT) phantoms with lung tumors and different respiratory motions. The estimated doses were compared to the dose that would be calculated for routine 4DCT-based planning and to the actual delivered dose that was calculated using “ground truth” XCAT phantoms at all timepoints. The approach was also tested using one set of patient data, which demonstrated the application of our method in a clinical scenario. Results: For the first XCAT phantom that has a mostly regular breathing pattern, the errors in 95% volume dose (D95) are 0.11% and 0.83%, respectively for 3D fluoroscopic images

  7. Precise Depth Image Based Real-Time 3D Difference Detection

    Kahn, Svenja

    2014-01-01

    3D difference detection is the task to verify whether the 3D geometry of a real object exactly corresponds to a 3D model of this object. This thesis introduces real-time 3D difference detection with a hand-held depth camera. In contrast to previous works, with the proposed approach, geometric differences can be detected in real time and from arbitrary viewpoints. Therefore, the scan position of the 3D difference detection be changed on the fly, during the 3D scan. Thus, the user can move the ...

  8. Method for 3D Image Representation with Reducing the Number of Frames based on Characteristics of Human Eyes

    Kohei Arai

    2016-10-01

    Full Text Available Method for 3D image representation with reducing the number of frames based on characteristics of human eyes is proposed together with representation of 3D depth by changing the pixel transparency. Through experiments, it is found that the proposed method allows reduction of the number of frames by the factor of 1/6. Also, it can represent the 3D depth through visual perceptions. Thus, real time volume rendering can be done with the proposed method.

  9. Highly Omnidirectional and Frequency Controllable Carbon/Polyaniline-based 2D and 3D Monopole Antenna

    Shin, Keun-Young; Kim, Minkyu; Lee, James S.; Jang, Jyongsik

    2015-09-01

    Highly omnidirectional and frequency controllable carbon/polyaniline (C/PANI)-based, two- (2D) and three-dimensional (3D) monopole antennas were fabricated using screen-printing and a one-step, dimensionally confined hydrothermal strategy, respectively. Solvated C/PANI was synthesized by low-temperature interfacial polymerization, during which strong π-π interactions between graphene and the quinoid rings of PANI resulted in an expanded PANI conformation with enhanced crystallinity and improved mechanical and electrical properties. Compared to antennas composed of pristine carbon or PANI-based 2D monopole structures, 2D monopole antennas composed of this enhanced hybrid material were highly efficient and amenable to high-frequency, omnidirectional electromagnetic waves. The mean frequency of C/PANI fiber-based 3D monopole antennas could be controlled by simply cutting and stretching the antenna. These antennas attained high peak gain (3.60 dBi), high directivity (3.91 dBi) and radiation efficiency (92.12%) relative to 2D monopole antenna. These improvements were attributed the high packing density and aspect ratios of C/PANI fibers and the removal of the flexible substrate. This approach offers a valuable and promising tool for producing highly omnidirectional and frequency-controllable, carbon-based monopole antennas for use in wireless networking communications on industrial, scientific, and medical (ISM) bands.

  10. Applying internet based 3D visualisation and priority games in public consultation

    Hansen, Henning Sten; Kristensen, Peter Nordskov

    2006-01-01

    The County of Northern Jutland had just finalised a public consultation concerning a new connection across Limfjorden, which separates the northernmost part of Jutland, called Vendsyssel, from the mainland of Jutland. The County administration was quite aware of the fact the decision concerning the...... involved in the decision-making process. The current paper demonstrates how web-based interactive tools can support the participation of the citizens. The use of 3D geo-visualisation / VR makes it easier to represent spatial information in a way that is more similar to how people observe and perceive them...

  11. Validation of SPAMM Tagged MRI Based Measurement of 3D Soft Tissue Deformation

    Moerman, Kevin M; Simms, Ciaran K; Lamerichs, Rolf M; Stoker, Jaap; Nederveen, Aart J

    2016-01-01

    This study presents and validates a novel (non-ECG-triggered) MRI sequence based on SPAtial Modulation of the Magnetization (SPAMM) to non-invasively measure 3D (quasi-static) soft tissue deformations using only six acquisitions (three static and three indentations). In current SPAMM tagged MRI approaches data is typically constructed from many repeated motion cycles. This has so far restricted its application to the measurement of highly repeatable and periodic movements (e.g. cardiac deformation). In biomechanical applications where soft tissue deformation is artificially induced, often by indentation, significant repeatability constraints exist and, for clinical applications, discomfort and health issues generally preclude a large number of repetitions.

  12. A 3d talking head for mobile devices based on unofficial ios webgl support

    Benin, Alberto; Cosi, Piero; Leone, Giuseppe Riccardo

    2012-01-01

    In this paper we present the implementation of a WebGL Talking Head for iOS mobile devices (Apple iPhone and iPad). It works on standard MPEG-4 Facial Animation Parameters (FAPs) and speaks with the Italian version of FESTIVAL TTS. It is totally based on true real human data. The 3D kinematics information are used to create lips articulatory model and to drive directly the talking face, generating human facial movements. In the last year we developed the WebGL version of the avatar. WebGL, wh...

  13. Model-Based Estimation of 3-D Stiffness Parameters in Photonic-Force Microscopy

    Thévenaz, P; Singh, A.S.G.; Bertseva, E.; Lekki, J.; Kulik, A. J.; Unser, M

    2010-01-01

    We propose a system to characterize the 3-D diffusion properties of the probing bead trapped by a photonic-force microscope. We follow a model-based approach, where the model of the dynamics of the bead is given by the Langevin equation. Our procedure combines software and analog hardware to measure the corresponding stiffness matrix. We are able to estimate all its elements in real time, including off-diagonal terms. To achieve our goal, we have built a simple analog computer that performs a...

  14. Efficient 3D movement-based kernel density estimator and application to wildlife ecology

    Tracey-PR, Jeff; Sheppard, James K.; Lockwood, Glenn K.; Chourasia, Amit; Tatineni, Mahidhar; Fisher, Robert N.; Sinkovits, Robert S.

    2014-01-01

    We describe an efficient implementation of a 3D movement-based kernel density estimator for determining animal space use from discrete GPS measurements. This new method provides more accurate results, particularly for species that make large excursions in the vertical dimension. The downside of this approach is that it is much more computationally expensive than simpler, lower-dimensional models. Through a combination of code restructuring, parallelization and performance optimization, we were able to reduce the time to solution by up to a factor of 1000x, thereby greatly improving the applicability of the method.

  15. 3D constitutive model of anisotropic damage for unidirectional ply based on physical failure mechanisms

    Qing, Hai; Mishnaevsky, Leon

    2010-01-01

    A 3D anisotropic continuum damage model is developed for the computational analysis of the elastic–brittle behaviour of fibre-reinforced composite. The damage model is based on a set of phenomenological failure criteria for fibre-reinforced composite, which can distinguish the matrix and fibre...... failure under tensile and compressive loading. The homogenized continuum theory is adopted for the anisotropic elastic damage constitutive model. The damage modes occurring in the longitudinal and transverse directions of a ply are represented by a damage vector. The elastic damage model is implemented in...

  16. Mapping the brain in type II diabetes: Voxel-based morphometry using DARTEL

    Purpose: To investigate the pattern of brain volume changes of the brain in patients with type II diabetes mellitus using voxel-based morphometry. Material and methods: Institutional ethics approval and informed consent were obtained. VBM based on the high resolution three-dimensional T1-weighted fast spoiled gradient recalled echo MRI images was obtained from 16 type II diabetes patients (mean age 61.2 years) and 16 normal controls (mean age 59.6 years). All images were spatially preprocessed using Diffeomorphic Anatomical Registration using Exponentiated Lie algebra (DARTEL) algorithm, and the DARTEL templates were made from 100 normal subjects. Statistical parametric mapping was generated using analysis of covariance (ANCOVA). Results: An atrophy pattern of gray matter was seen in type II diabetes patients compared with controls that involved the right superior, middle, and inferior temporal gyri, right precentral gyrus, and left rolandic operculum region. The loss of white matter volume in type II diabetes mellitus was observed in right temporal lobe and left inferior frontal triangle region. ROI analysis revealed that the gray and white matter volume of right temporal lobe were significant lower in type II diabetes mellitus than that in controls (P < 0.05). Conclusion: This work demonstrated that type II diabetes mellitus patients mainly exhibited gray and white matter atrophy in right temporal lobe, and this finding supported that type II diabetes mellitus could lead to subtle diabetic brain structural changes in patients without dementia or macrovascular complications.

  17. Mapping the brain in type II diabetes: Voxel-based morphometry using DARTEL

    Chen, Zhiye [Department of Radiology, PLA General Hospital, 28 Fuxing Road, Beijing 100853 (China); Li, Lin [Department of Geriatric Endocrinology, PLA General Hospital, Beijing 100853 (China); Sun, Jie [Department of Endocrinology, PLA General Hospital, Beijing 100853 (China); Ma, Lin, E-mail: cjr.malin@vip.163.com [Department of Radiology, PLA General Hospital, 28 Fuxing Road, Beijing 100853 (China)

    2012-08-15

    Purpose: To investigate the pattern of brain volume changes of the brain in patients with type II diabetes mellitus using voxel-based morphometry. Material and methods: Institutional ethics approval and informed consent were obtained. VBM based on the high resolution three-dimensional T1-weighted fast spoiled gradient recalled echo MRI images was obtained from 16 type II diabetes patients (mean age 61.2 years) and 16 normal controls (mean age 59.6 years). All images were spatially preprocessed using Diffeomorphic Anatomical Registration using Exponentiated Lie algebra (DARTEL) algorithm, and the DARTEL templates were made from 100 normal subjects. Statistical parametric mapping was generated using analysis of covariance (ANCOVA). Results: An atrophy pattern of gray matter was seen in type II diabetes patients compared with controls that involved the right superior, middle, and inferior temporal gyri, right precentral gyrus, and left rolandic operculum region. The loss of white matter volume in type II diabetes mellitus was observed in right temporal lobe and left inferior frontal triangle region. ROI analysis revealed that the gray and white matter volume of right temporal lobe were significant lower in type II diabetes mellitus than that in controls (P < 0.05). Conclusion: This work demonstrated that type II diabetes mellitus patients mainly exhibited gray and white matter atrophy in right temporal lobe, and this finding supported that type II diabetes mellitus could lead to subtle diabetic brain structural changes in patients without dementia or macrovascular complications.

  18. Focal retrograde amnesia: voxel-based morphometry findings in a case without MRI lesions.

    Sehm, Bernhard; Frisch, Stefan; Thöne-Otto, Angelika; Horstmann, Annette; Villringer, Arno; Obrig, Hellmuth

    2011-01-01

    Focal retrograde amnesia (FRA) is a rare neurocognitive disorder presenting with an isolated loss of retrograde memory. In the absence of detectable brain lesions, a differentiation of FRA from psychogenic causes is difficult. Here we report a case study of persisting FRA after an epileptic seizure. A thorough neuropsychological assessment confirmed severe retrograde memory deficits while anterograde memory abilities were completely normal. Neurological and psychiatric examination were unremarkable and high-resolution MRI showed no neuroradiologically apparent lesion. However, voxel-based morphometry (VBM)-comparing the MRI to an education-, age-and sex-matched control group (n = 20) disclosed distinct gray matter decreases in left temporopolar cortex and a region between right posterior parahippocampal and lingual cortex. Although the results of VBM-based comparisons between a single case and a healthy control group are generally susceptible to differences unrelated to the specific symptoms of the case, we believe that our data suggest a causal role of the cortical areas detected since the retrograde memory deficit is the preeminent neuropsychological difference between patient and controls. This was paralleled by grey matter differences in central nodes of the retrograde memory network. We therefore suggest that these subtle alterations represent structural correlates of the focal retrograde amnesia in our patient. Beyond the implications for the diagnosis and etiology of FRA, our results advocate the use of VBM in conditions that do not show abnormalities in clinical radiological assessment, but show distinct neuropsychological deficits. PMID:22028902

  19. The correlation between gray matter volume and perceived social support: a voxel-based morphometry study.

    Che, XianWei; Wei, DongTao; Li, WenFu; Li, HaiJiang; Qiao, Lei; Qiu, Jiang; Zhang, QingLin; Liu, YiJun

    2014-01-01

    Social support refers to interpersonal exchanges that include the combinations of aid, affirmation and affection. Perceived social support is a kind of subjective judgment of one's availability of social support. In spite of the importance of perceived social support to health, however, its neural substrate remains unknown. To address this question, voxel-based morphometry was employed to investigate the neural bases of individual differences in responses to the Perceived Social Support Scale (PSSS) in healthy volunteers (144 men and 203 women; mean age = 19.9; SD = 1.33, age range : 17-27). As a result, multiple regression analysis revealed that the PSSS scores were significantly and positively correlated with gray matter volume in a cluster that mainly included areas in posterior parts of posterior cingulate cortex, bilateral lingual cortex, left occipital lobe and cuneus. Highly-supported individuals had larger gray matter volume in these brain regions, implying a relatively high level of ability to engage in self-referential processes and social cognition. Our results provide a biological basis for exploring perceived social support particularly in relationship to various health parameters and outcomes. PMID:24397344

  20. Gray matter correlates of creative potential: a latent variable voxel-based morphometry study.

    Jauk, Emanuel; Neubauer, Aljoscha C; Dunst, Beate; Fink, Andreas; Benedek, Mathias

    2015-05-01

    There is increasing research interest in the structural and functional brain correlates underlying creative potential. Recent investigations found that interindividual differences in creative potential relate to volumetric differences in brain regions belonging to the default mode network, such as the precuneus. Yet, the complex interplay between creative potential, intelligence, and personality traits and their respective neural bases is still under debate. We investigated regional gray matter volume (rGMV) differences that can be associated with creative potential in a heterogeneous sample of N=135 individuals using voxel-based morphometry (VBM). By means of latent variable modeling and consideration of recent psychometric advancements in creativity research, we sought to disentangle the effects of ideational originality and fluency as two independent indicators of creative potential. Intelligence and openness to experience were considered as common covariates of creative potential. The results confirmed and extended previous research: rGMV in the precuneus was associated with ideational originality, but not with ideational fluency. In addition, we found ideational originality to be correlated with rGMV in the caudate nucleus. The results indicate that the ability to produce original ideas is tied to default-mode as well as dopaminergic structures. These structural brain correlates of ideational originality were apparent throughout the whole range of intellectual ability and thus not moderated by intelligence. In contrast, structural correlates of ideational fluency, a quantitative marker of creative potential, were observed only in lower intelligent individuals in the cuneus/lingual gyrus. PMID:25676914