Home  About us  Contact
 

Reconstruction Procedure (reconstruction + procedure)

Distribution by Scientific Domains
Medical Sciences66%

Selected Abstracts

Human motion reconstruction from monocular images using genetic algorithms

COMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 3-4 2004
Jianhui Zhao
Abstract This paper proposed an optimization approach for human motion recovery from the un-calibrated monocular images containing unlimited human movements. A 3D skeleton human model based on anatomy knowledge is employed with encoded biomechanical constraints for the joints. Energy Function is defined to represent the deviations between projection features and extracted image features. Reconstruction procedure is developed to adjust joints and segments of the human body into their proper positions. Genetic Algorithms are adopted to find the optimal solution effectively in the high dimensional parameter space by simultaneously considering all the parameters of the human model. The experimental results are analysed by Deviation Penalty. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Superresolution planar diffraction tomography through evanescent fields,

INTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY, Issue 1 2002
Sean K. Lehman
We consider the problem of noninvasively locating objects buried in a layered medium such as land mines in the ground or objects concealed in a wall. In such environments, the transmitter(s) and receiver(s) are frequently within the near-field region of the illuminating radiation. In these cases, the scattered evanescent field carries useful information on the scattering object. Conventional diffraction tomography techniques neglect, by their design, the evanescent field. Under near-field conditions, they treat it as noise as opposed to valid data. If correctly incorporated into a reconstruction algorithm, the evanescent field, which carries high spatial frequency information, can be used to achieve resolution beyond the classical limit of ,/2, or "superresolution." We build on the generalized holography theory presented by Langenberg to develop a planar diffraction tomography algorithm that incorporates evanescent field information to achieve superresolution. Our theory is based on a generalization of the Fourier transform, which allows for complex spatial frequencies in a manner similar to the Laplace transform. We specialize our model to the case of a two-dimensional multimonostatic, wideband imaging system, and derive an extended resolution reconstruction procedure. We implement and apply our reconstruction to two data sets collected using the Lawrence Livermore National Laboratory (LLNL) Micropower Impulse Radar (MIR). © 2002 John Wiley & Sons, Inc. Int J Imaging Syst Technol 12, 16,26, 2002 [source]

Distal ureteral atresia: Recovery of renal function after relief of obstruction at ten months old

INTERNATIONAL JOURNAL OF UROLOGY, Issue 6 2005
SATOSHI ASHIMINE
Abstract A large cystic mass that occupied more than half of the abdomen was identified by ultrasound in a 10-month-old boy. Intravenous pyelography failed to visualize the right kidney, so we created a loop ureterocutaneostomy followed by temporary nephrostomy to improve renal function. Exploratory surgery revealed complete atresia of the distal right ureter. A ureteral stricture developed after ureteroneocystostomy and undiversion of the loop, so a second reconstruction procedure was required (pelvi-ureteroplasty and reimplantation of the right ureter with a psoas hitch) to free the patient from dependence on catheters. Despite the occurrence of giant hydronephrosis secondary to complete ureteral obstruction at the age of 10 months, the function of the right kidney could be preserved. Accordingly, aggressive attempts to promote functional recovery may be justified even when patients have advanced hydronephrosis. [source]

Reconstruction of atomistic details from coarse-grained structures

JOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 6 2010
Andrzej J. Rzepiela
Abstract We present an algorithm to reconstruct atomistic structures from their corresponding coarse-grained (CG) representations and its implementation into the freely available molecular dynamics (MD) program package GROMACS. The central part of the algorithm is a simulated annealing MD simulation in which the CG and atomistic structures are coupled via restraints. A number of examples demonstrate the application of the reconstruction procedure to obtain low-energy atomistic structural ensembles from their CG counterparts. We reconstructed individual molecules in vacuo (NCQ tripeptide, dipalmitoylphosphatidylcholine, and cholesterol), bulk water, and a WALP transmembrane peptide embedded in a solvated lipid bilayer. The first examples serve to optimize the parameters for the reconstruction procedure, whereas the latter examples illustrate the applicability to condensed-phase biomolecular systems. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010 [source]

Compressed sensing MRI with multichannel data using multicore processors

MAGNETIC RESONANCE IN MEDICINE, Issue 4 2010
Ching-Hua Chang
Abstract Compressed sensing (CS) is a promising method to speed up MRI. Because most clinical MRI scanners are equipped with multichannel receive systems, integrating CS with multichannel systems may not only shorten the scan time but also provide improved image quality. However, significant computation time is required to perform CS reconstruction, whose complexity is scaled by the number of channels. In this article, we propose a reconstruction procedure that uses ubiquitously available multicore central processing unit to accelerate CS reconstruction from multiple channel data. The experimental results show that the reconstruction efficiency benefits significantly from parallelizing the CS reconstructions and pipelining multichannel data into multicore processors. In our experiments, an additional speedup factor of 1.6,2.0 was achieved using the proposed method on a quad-core central processing unit. The proposed method provides a straightforward way to accelerate CS reconstruction with multichannel data for parallel computation. Magn Reson Med, 2010. © 2010 Wiley-Liss, Inc. [source]

Efficacy of small reconstruction plates in vascularized bone graft mandibular reconstruction,

HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 7 2006
D. Gregory Farwell MD, FACS
Abstract Background: Utilization of vascularized bone grafts rigidly fixated with titanium reconstruction plates is the method of choice for reconstruction of segmental mandibular defects. We hypothesized that the use of the newer 2.0-mm locking reconstruction plate (LRP) is not associated with higher rates of complications when compared with larger, previously used plating systems. Methods: A retrospective case series of 184 patients undergoing 185 vascularized bone graft reconstruction procedures of the mandible was conducted. Results: There were 37 plate complications. There was no significant difference in complication rates for the 2 most used plate types (14.5% with the 2.0-mm LRP and 22.2% with the 2.4-mm LRP). Conclusions: Use of the smaller 2.0-mm LRP was not associated with an increase in the complications of plate fracture, exposure, infection, or nonunion. Because of its lower profile and ease of application, the 2.0-mm LRP is our plate of choice for mandibular reconstruction. © 2006 Wiley Periodicals, Inc. Head Neck, 2006 [source]