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Computed tomography has played a key role in bone structure imaging for over two decades. However, when a metal implant present in the sample, the reconstructions are seriously distorted by artefacts, and no method has successfully met the clinical demands. This paper presents a new method for partial reconstruction in computed tomography. The metal implant is reconstructed separately and the correspondence...
In order to optimize the position of oral implants and make the best possible use of the available bone volume in the oral implant therapy, a computer-aided oral implantology system including the framework, modeling, preoperative 3D planning, registration method, optical tracking systems and real-time navigation is introduced in this study. With the support of this system, the precision achieved in...
The anterior cruciate ligament (ACL) functions as a mechanical stabilizer in the tibiofemoral joint. Over 250,000 Americans each year suffer ACL ruptures and tears, making the ACL the most commonly injured knee ligament. Methods which permit the in situ monitoring of changes in ACL graft mechanical properties during healing are needed. A long term goal in ACL reconstruction is to regenerate the ACL-bone...
A robot-assisted orthopedic telesurgery system, named HIT-RAOTS, has been developed according to Chinese conventional operation method. Its main function includes obtaining images with information of position and orientation of fracture, providing fracture information for doctors, assisting the doctors to complete the reposition of fracture and locking operation of intramedullary nail. In this system,...
While focusing at accurate 3D joint kinematics, this paper explores the problem of how to perform a robust rigid registration for a sequence of object surfaces observed using standard 3D medical imaging techniques. Each object instance is assumed to give access to a polyhedral encoding of its boundary. We consider the case where object instances are noised with significant truncations and segmentation...
In order to study the biomechanical mechanism properties of intervertebral disc herniation, combining the CT and MRI data-based anatomical structure of spine. A three-dimensional geometric model of the lumber disk was constructed. Based on the geometric model, a three-dimensional finite element modeling (FEM) for biomechanical analysis has been created. The FEM will represents a promising tool in...
There is a novel method for creating a 2-d parameterized finite element model of the human femur with matching artificial hip joint based on X-ray image before the hip joint replacement surgery. It can help us to evaluate the selected appropriate hip joint prosthesis
Recent advances in tissue-engineered cartilage open the door to new clinical treatments of joint lesions. Common to all therapies with in-vitro engineered autografts is the need for optimal fit of the construct, to allow screwless implantation and optimal integration into the live joint. Computer assisted surgery techniques are prime candidates to ensure the required accuracy while at the same time...
The aim of this study was to optimize MRI conventional protocols for BMD measurements using MR-relaxometry in systems not facilitated with special multi echo protocols. Since, cortical and trabecular bone separation can not be performed in DEXA, so the results might lead to erroneous interpretation of BMD values. One method for bone quality determination is MR relaxometry that derives R2(=1/T2), R2*(=1/T2*)...
Scoliosis is a common and poorly understood spinal disorder that is clinically monitored with a series of full spinal X-rays. The purpose of this study was to predict scoliosis future progression at 6- and 12-month intervals with successive spinal indices and a hybrid learning technique (i.e., the combination of fuzzy c-means clustering and artificial neural network (ANN)). Ultimately this could decrease...
Anatomical structure morphing is the process of estimating the patient-specific 3D shape of a given anatomy from a few digitized surface points. This provides an appropriate intra-operative 3D visualization without pre or intra-operative imaging. Our method fits a statistical deformable model to the digitized landmarks and bone surface points which are usually sparse. The statistical deformable model...
The feasibility of assessing cancellous bone from the spectral maximum shift (SMS) of the backscattered ultrasonic signal is investigated. And the SMS of backscatter signals from bovine tibiae cancellous bone in vitro were measured and discussed. The spectral maximum of the backscattered signal downshift with increases of the apparent density of cancellous bone. When the bone suffered from osteoporosis,...
In this experiment, the bone marrow stroma cells (BMSCs) were harvested and then cultured in "neural stem cells (NSCs) medium" which was modulated by our lab with R R. of China patent number as ZL 02134314.4 in vitro. The proliferation of NSCs was confirmed by formation of cell's clones and scan electron microscopy test. The identifications of NSCs, neurons-like cells and glial-like cells...
Understanding how stretch sensitive reflexes contribute to the coordination of whole arm posture and movement is best understood in the context of multijoint perturbations. However, it is difficult to assess the mechanisms contributing to reflex activity during such unconstrained tasks due to the uncertainties associated with estimating the relative importance of biomechanical and neural coupling...
The spinal shock-absorbing disc needs to have the flexibility to enable the spine to bend and twist. At the same time under loading, its lateral and axial deformations have to be contained, so that it does not herniate and impinge on the spinal-chord. The disc is composed of a fluid-like nucleus pulposus (NP) contained within an annulus. Hence when the disc is loaded, the NP gets pressurized and stresses...
In order to eliminate displacement and elastic deformation between images of adjacent frames in course of 3D ultrasonic image reconstruction, elastic registration based on morphology skeleton was adopted in this paper. Feature points of connected skeleton are extracted automatically by accounting topical curvature extreme points several times. Initial registration is processed according to barycenter...
Automated identification, pose and size estimation, and contour extraction of diaphyseal bone fragments can greatly improve the usability of a computer-assisted fluoroscopy-based navigation system for long bone fracture reduction. In this paper, a two step solution is proposed. The pose and size of a diaphyseal fragment are estimated through 3D morphable object fitting using a parametric cylinder...
Bone mass loss caused by microgravity is considered as one of the worst influences to human body during long-term spaceflight. As one of the countermeasures to retain bone mass, muscle electrical stimulation is just started in spaceflight application and needs further research. This work is aimed to investigate the effects of muscle electrical stimulation based on the tail-suspended rat experiment...
An algorithm to determine the human brain (gray matter (GM) and white matter (WM)) from computed tomography (CT) head volumes with large slice thickness is proposed based on thresholding and brain mask propagation. Firstly, a 2D reference image is chosen to represent the intensity characteristics of the original 3D data set. Secondly, the region of interest of the reference image is determined as...
Our algorithm contains two major steps: the intervertebral disk localization step, and the vertebra detection and segmentation step. In the first step, we apply a model-based searching method to approximately locate all the intervertebral disk clues between adjacent vertebrae of the whole spine and the best slice selection. A new approach using an intensity profile on a polynomial function for fitting...
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