3D object reassembly using region-pair-relation and balanced cluster tree.

Background And Objective: Object reassembly is a key technology in scenarios such as surgical planning and broken object restoration. Based on previous research, this work intends to explore the general tasks of 3D object reassembly, including conventional object reconstruction and bone fracture reduction.

Methods: We introduce an efficient and robust region-pair-relation descriptor, which incorporates strong geometric constraints and remains invariant to rotation and translation.

Synchrotron Radiation-Based Three-Dimensional Visualization of Angioarchitectural Remodeling in Hippocampus of Epileptic Rats.

Characterizing the three-dimensional (3D) morphological alterations of microvessels under both normal and seizure conditions is crucial for a better understanding of epilepsy. However, conventional imaging techniques cannot detect microvessels on micron/sub-micron scales without angiography. In this study, synchrotron radiation (SR)-based X-ray in-line phase-contrast imaging (ILPCI) and quantitative 3D characterization were used to acquire high-resolution, high-contrast images of rat brain tissue under both normal and seizure conditions.

Automatic liver vessel segmentation using 3D region growing and hybrid active contour model.

This paper proposes a new automatic method for liver vessel segmentation by exploiting intensity and shape constraints of 3D vessels. The core of the proposed method is to apply two different strategies: 3D region growing facilitated by bi-Gaussian filter for thin vessel segmentation, and hybrid active contour model combined with K-means clustering for thick vessel segmentation. They are then integrated to generate final segmentation results.

Semi-automatic segmentation of femur based on harmonic barrier.

Background And Objective: Segmentation of the femur from the hip joint in computed tomography (CT) is an important preliminary step in hip surgery planning and simulation. However, this is a time-consuming and challenging task due to the weak boundary, the varying topology of the hip joint, and the extremely narrow or blurred space between the femoral head and the acetabulum. To address these problems, this study proposed a semi-automatic segmentation framework based on harmonic fields for accurate segmentation.

Biomechanics of the sclera and effects on intraocular pressure.

Accumulating evidence indicates that glaucoma is a multifactorial neurodegenerative disease characterized by the loss of retinal ganglion cells (RGC), resulting in gradual and progressive permanent loss of vision. Reducing intraocular pressure (IOP) remains the only proven method for preventing and delaying the progression of glaucomatous visual impairment. However, the specific role of IOP in optic nerve injury remains controversial, and little is known about the biomechanical mechanism by which elevated IOP leads to the loss of RGC.

Influence of Trabecular Bone on Peri-Implant Stress and Strain Based on Micro-CT Finite Element Modeling of Beagle Dog.

The objective of this investigation is to analyze the influence of trabecular microstructure modeling on the biomechanical distribution of the implant-bone interface. Two three-dimensional finite element mandible models, one with trabecular microstructure (a refined model) and one with macrostructure (a simplified model), were built. The values of equivalent stress at the implant-bone interface in the refined model increased compared with those of the simplified model and strain on the contrary.

Extended Occupational Therapy Reintegration Strategies for a Woman With Guillain-Barré Syndrome: Case Report.

This case report describes a unique long-term functional recovery process to promote successful community reintegration for a woman with Guillain-Barré syndrome (GBS), a rare autoimmune disease. Her main symptoms were very limited mobility and depressive symptoms due to the unknown cause of and cure for the illness. Holistic occupational strategies helped the client stabilize her emotional state, create a safe home environment, improve a communication method, increase physical activity, and promote social participation.

Biomechanical analysis of press-extension technique on degenerative lumbar with disc herniation and staggered facet joint.

This study investigates the effect of a new Chinese massage technique named "press-extension" on degenerative lumbar with disc herniation and facet joint dislocation, and provides a biomechanical explanation of this massage technique. Self-developed biomechanical software was used to establish a normal L1-S1 lumbar 3D FE model, which integrated the spine CT and MRI data-based anatomical structure. Then graphic technique is utilized to build a degenerative lumbar FE model with disc herniation and facet joint dislocation.

NiMoO4 nanofibres designed by electrospining technique for glucose electrocatalytic oxidation.

Electrochemical oxidation of glucose is the guarantee to realize nonenzymatic sensing of glucose, but greatly hindered by the slow kinetics of its oxidation process. Herein, various nanomaterials were designed as catalysts to accelerate glucose oxidation reaction. However, how to effectively build an excellent platform for promoting the glucose oxidation is still a great challenge.

Nanostring-cluster hierarchical structured Bi2O3: synthesis, evolution and application in biosensing.

In the present study, a simple strategy was developed to fabricate a new Bi2O3 nanostring-cluster hierarchical structure. Precursor microrods composed of Bi(C2O4)OH were initially grown under hydrothermal conditions. After calcination in air, Bi(C2O4)OH microrods were carved into unique string-cluster structures by the gas produced during the decomposition process.

Automatic Tooth Segmentation of Dental Mesh Based on Harmonic Fields.

An important preprocess in computer-aided orthodontics is to segment teeth from the dental models accurately, which should involve manual interactions as few as possible. But fully automatic partition of all teeth is not a trivial task, since teeth occur in different shapes and their arrangements vary substantially from one individual to another. The difficulty is exacerbated when severe teeth malocclusion and crowding problems occur, which is a common occurrence in clinical cases.

Influence of orthotropy on biomechanics of peri-implant bone in complete mandible model with full dentition.

Objective: The study was to investigate the impact of orthotropic material on the biomechanics of dental implant, based on a detailed mandible with high geometric and mechanical similarity.

Materials And Methods: Multiple data sources were used to elaborate detailed biological structures and implant CAD models. In addition, an extended orthotropic material assignment methodology based on harmonic fields was used to handle the alveolar ridge region to generate compatible orthotropic fields.

Interactive tooth partition of dental mesh base on tooth-target harmonic field.

The accurate tooth partition of dental mesh is a crucial step in computer-aided orthodontics. However, tooth boundary identification is not a trivial task for tooth partition, since different shapes and their arrangements vary substantially among common clinical cases. Though curvature field is traditionally used for identifying boundaries, it is normally not reliable enough.

[Finite element method analysis of anteflexion traction on various angles for the treatment of cervical spine].

Objective: To analyze the data of angle variation on traction based on a finite element model of complete cervical spine with straight physiological curvature, and try to give experimental reference and suggestion in treating cervical spondylosis.

Methods: A 43-year-old female patient with straight cervical spine was chosen and the CT scan data were collected. By using specially designed modeling system, a high quality finite element model of complete cervical spine with straight physiological curvature is generated,which included ligament and muscle according to anatomy.

Physical modeling with orthotropic material based on harmonic fields.

Although it is well known that human bone tissues have obvious orthotropic material properties, most works in the physical modeling field adopted oversimplified isotropic or approximated transversely isotropic elasticity due to the simplicity. This paper presents a convenient methodology based on harmonic fields, to construct volumetric finite element mesh integrated with complete orthotropic material. The basic idea is taking advantage of the fact that the longitudinal axis direction indicated by the shape configuration of most bone tissues is compatible with the trajectory of the maximum material stiffness.

Real time 3D simulation for nose surgery and automatic individual prosthesis design.

This paper presents an intuitive nose surgery planning and simulation system, using 3D laser scan image and lateral X-ray image, to provide high quality prediction of the postoperative appearance, and design the patient specific prosthesis model automatically. After initial registration, the internal surface of soft tissue at the nose region was generated by the statistical data for soft tissue thickness adapted by the individual thickness information from the X-ray image. Then, the sketch contour of the 3D scan data on the lateral X-ray image was modified manually or adjusted automatically according to some aesthetic statistical data, to drive the simulation in real time by the state-of-the-art Laplacian surface deformation method.

A newly designed big cup nitinol stent for gastric outlet obstruction.

Aim: To find out whether a newly designed big cup nitinol stent is suitable for treatment of patients with gastric outlet obstruction resulting from gastric cancer.

Methods: The new stent is composed of a proximal big cup segment (20 mm in length and 48-55 mm in diameter), a middle part (60 mm in length and 20 mm in diameter) covered by a polyethylene membrane and a distal sphericity (20 mm in length and 28 mm in diameter). Half of the proximal big cup segment is also covered by a polyethylene membrane, which is adjacent to the middle part of the stent.

[Three dimension finite element analysis of anisotropic mandible with dental implants effect on implant-bone interface].

Objective: To establish anisotropic mandible model with dental implants and to investigate the effect of anisotropy material on stress and strain distribution of implant-bone interface.

Methods: Three-dimensional finite element models of whole mandible with anisotropic and equivalent isotropic material were created by CT scanning and universal surgical integration system (USIS) software developed by the authors. Two ITI threaded implants were implanted in the posterior teeth area.

Implant-bone interface stress distribution in immediately loaded implants of different diameters: a three-dimensional finite element analysis.

Purpose: To establish a 3D finite element model of a mandible with dental implants for immediate loading and to analyze stress distribution in bone around implants of different diameters.

Materials And Methods: Three mandible models, embedded with thread implants (ITI, Straumann, Switzerland) with diameters of 3.3, 4.

An extension to 3D topological thinning method based on LUT for colon centerline extraction.

Topological thinning is a valid but time-consuming method to calculate the centerline of human colon or other hollow organs accurately. An optimized 3D topological thinning method based on Look-up Table (LUT), which was proposed by Sadlier, proves to be effective in improving the efficiency on many occasions. However, it is still inefficient when processing some complex datasets.

Effect of diameter and length on stress distribution of the alveolar crest around immediate loading implants.

Background: Many clinical observations have shown that immediate loading is indicated when the stabilization of the bone/implant is optimal and when the estimated loads are not excessively high. Nonetheless, more experimental studies are needed to consider the immediate loading protocol as a safe procedure. Mechanical analysis using the finite element (FE) method analysis has been employed by many authors to understand the biomechanical behavior around dental implants.

Anisotropic finite element modeling for patient-specific mandible.

This paper presents an ad hoc modular software tool to quasi-automatically generate patient-specific three-dimensional (3D) finite element (FE) model of the human mandible. The main task is taking into account the complex geometry of the individual mandible, as well as the inherent highly anisotropic material law. At first, by computed tomography data (CT), the individual geometry of the complete range of mandible was well reproduced, also the separation between cortical and cancellous bone.