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One of the basic principles for internal fixation is the achievement of stable construct for proper bone healing. Locking compression plate (LCP) achieved it through locking screws that create a fixed-angle construct providing angular stability. The plate and screws combination to construct a stable fixation depends on factors such as the type of fracture and surgical preference. The optimum combination...
Instability is one of the symptoms associated with Rheumatoid Arthritis of the wrist joint. The instability which is caused by weakened ligaments as well as worn cartilages makes the carpal bones to move freely, causing a painful condition. Wrist arthroplasty is one of the treatments for severe cases of Rheumatoid Arthritis of the wrist joint. This project involved biomechanical analysis of wrist...
The multi-modal image registration is essential to integrate complementary image information from different modalities of the same organ. In order to find a reliable geometric transformation for registration, a proper choice of similarity measure is required. Even though normalized mutual information (NMI) is popular for multi-modal image registration, it limits the registration performance since...
The objective of this study is to develop a detailed three-dimensional geometrically and biomechanically accurate finite element model of the human lower cervical spine (C4-C6), and applied to determination of movement of the mobile type artificial disc replacement Prodisc-C made by Synthes. 3D (FE) model of the multi-level cervical spine was consists of three vertebrae and two intervertebral discs...
This paper dealt with the following topics: CT imaging; medical image processing; eye; neurophysiological disease; EEG; brain-computer interfaces; patient treatment; biomedical ultrasonics; respiratory motion; medical disorder; MRI; ultrasonic surgery; SVM; biomechanics; hidden Markov model; coronary angiography; and other related topics on medical image analysis.
Frontal-orbital advancement is the accepted surgical treatment for correcting the cranial deformity associated with premature fusion of one of the coronal cranial sutures. Removal and reshaping of the brow and lower forehead bone is performed to correct ipsilateral frontal flattening and parietal bulging, recession of the supraorbital rim, and contralateral forehead bossing. In addition to the functional...
In this paper we present a deformation registration technique that utilizes rigid registration for bony structures while allowing elastic transformation of soft tissue to more accurately register the entire image volume. The technique is applied to the registration of computed tomography images of the thoracic and abdominal regions. First, bony structures are segmented from the CT data. The landmarks...
Cardiovascular interventions in the region of the aortic isthmus such as stent-grafting and vessel transposition introduce substantial changes in the deformation properties of the affected vessels. The changes play a fundamental role in the long-term prognosis for any such treatment, but are only poorly understood to date. We explore a fully automated method to quantify the deformation patterns of...
This paper presents the first demonstration of real time 3D tracking of organ deformation based on one-sided, limited view needlescopic optical imaging and a single pre-operative MRI/CT scan. The reconstruction is based on the empirical observation that the spherical harmonic coefficients corresponding to distorted surfaces of any given organ lie in lower dimensional spaces that can be learned during...
We present the first results of a new technique to bin cone-beam projections without imposing any motion model. Such a technique is required for studying motion in regions of the body, such as the pelvis, where motion exists and is unpredictable. All motion information is obtained directly from the projections and the binning is performed through an exhaustive search of possible assignments. Simplifying...
Registration between 3-D volumes and 2-D fluoro images for Electrophysiology (EP) is a challenging task due to the lack of corresponding features between 2-D and 3-D data. This paper presents an automatic, accurate and workflow-friendly 2-D/3-D registration method specially designed for patient movement correction during EP procedures. Firstly, 2-D spines are enhanced by exploiting the temporal information...
This paper presents a new algorithm for real time tracking of the exterior and interior surfaces of organs using sparse sampling of the exterior surfaces. The tracking is based on identifying subspaces in which the coefficients of spherical harmonic representations of the surfaces live. It uses pre operative CT/MRI scans during training, and needlescopic images acquired during tracking. We study different...
Rupture of abdominal aortic aneurysm (AAA) ranks as the 13th leading cause of death in the US. Fluid Structure Interaction (FSI) analysis was conducted with the aim of strengthening the current diagnostic measures of the disease, in particular, to (i) predict the location of wall rupture, (ii) estimate the state of pathology from the calculated ruptured potential index (RPI) and (iii) predict the...
The goal of this study was to determine if mineral dissolution from cancellous bone specimens alters stereology parameters determined by Micro-Computed Tomography (Micro-CT). Sheep cancellous bone cores were excised from lumbar vertebrae and randomized for immediate storage in one of four ??bathing?? solutions - Phosphate Buffered Saline (PBS), PBS supersaturated with Hydroxyapatite (HA) (PBS+HA),...
The artificial prosthesises currently used are only different in the femoral head size, neck length and stem thickness, but there is not any individualized prosthesis. At present, prosthesis looseness is the main problem of artificial femoral replacement, and individual matching level of joints is the bottleneck of restricting prosthesis replacement surgery. If we can design and produce corresponding...
The acetabular cartilage is normally represented as a spherical shape in orthopedic clinic and related researches. The aim of the study was to present a new mathematic representation with better fit to the acetabular cartilage surface and to investigate the role of its shape on the hip joint contact stress. Combined with reverse engineering technique, surface-fitting algorithms and mathematical curve...
Fluid structure interaction (FSI) simulations of patient-specific fusiform non-ruptured and contained ruptured Abdominal Aortic Aneurysm (AAA) geometries were conducted. The goals were: (1) to test the ability of our FSI methodology to predict the location of rupture, by correlating the high wall stress regions with the rupture location, (2) estimate the state of the pathological condition by calculating...
Using an interactive, 3D, kinematic simulation of the human skeleton, the motion of the sacro-iliac (SI) joint is modeled based upon descriptions available in the literature. The major ligaments are added to the simulation data structure using deformable cubic B-spline curve paths. Ligament strains were generated and studied in response to the motion simulations. Results improve our understanding...
In order to check validity of the porcine ligamentum flavum as a substitute of human tissue for evaluating the epidural needles, the thickness and the Young's modulus were measured, and a finite element analysis was carried out. Twenty-four specimens were stained by the Elastica-van Gieson method. The average value of the thickness was 1.2 mm. The tensile tester was employed for measuring the Young's...
Growth rate of abdominal aortic aneurysm (AAA) is thought to be an important indicator of the potential risk of rupture. Wall stress is also thought to be a trigger for its rupture. However, stress change during the expansion of an AAA is unclear. Forty-four patients with AAAs were included in this longitudinal follow-up study. They were assessed by serial abdominal ultrasonography and computerized...
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