Digital style design systems from concept to sophisticated shape

This paper reports four digital style design systems to construct a sophisticated shape from a concept or a rough sketch. First one is a system to automatically construct a 3D digital model form key words expressing the product concept. Second one is a system to automatically construct the 3D digital model from a rough sketch drown by a designer. Third one is a system to automatically sophisticate a 3D digital model according to the high light lines indicated by a designer. Fourth one is a system to sophisticate a 3D digital model by forming characteristic lines indicated by a designer.     

A Prototype manufacturing process for a health care IT appliance: a case study on an artery pulse monitoring system (APMOS)

This paper explores how a prototype of an IT appliance is manufactured through designing a housing of the appliance aesthetically, and designing the interface of its display. The aim of this study is to understand the role of prototype, and to clarify the problems and insufficient technology with which we should confront, and to investigate the efficient solutions to manufacture IT appliances well. The prototype manufacturing process presented here are to sketch the housings, to create clay models, to create 3D CAD models, to design interface of a display for an IT appliance, to manufacture functional mock-ups, and to examine the usability. An appliance to be developed is an artery pulse monitoring system named (APMOS). APMOS can measure blood pressure and the artery pulse, and let us know the condition for judging the possibility of arteriosclerosis. In this paper, we discuss in detail a manufacturing process from the concepts of the idea sketches to the usability test of the functional mock-up of APMOS.     

Computer assisted information resources navigation

In this paper, the design and development of Computer Assisted Information Resources Navigation (CAIRN) is discussed. CAIRN system is a medical information retrieval system that allows physicians and students to store full text medical information from any resource, organize and retrieve it. The most important feature of CAIRN is its capability to assist the user, physician, student etc. in selecting documents against a submitted query in Natural Language. The retrieved documents are presented in decreasing order according to their similarity to the submitted query. The nearest neighbour method is used. An alternative similarity measure based on a new calculation of the length of documents is proposed and some experimentation with it is discussed.     

Image-based models of cardiac structure with applications in arrhythmia and defibrillation studies

The objective of this article is to present a set of methods for constructing realistic computational models of cardiac structure from high-resolution structural and diffusion tensor magnetic resonance images and to demonstrate the applicability of the models in simulation studies. The structural image is segmented to identify various regions such as normal myocardium, ventricles, and infarct. A finite element mesh is generated from the processed structural data, and fiber orientations are assigned to the elements. The Purkinje system, when visible, is modeled using linear elements that interconnect a set of manually identified points. The methods were applied to construct 2 different models; and 2 simulation studies, which demonstrate the applicability of the models in the analysis of arrhythmia and defibrillation, were performed. The models represent cardiac structure with unprecedented detail for simulation studies.     

Analysis of Polygonal Computer Model Parameters and Influence on Fabric Drape Simulation

Contemporary CAD systems enable 3D clothing simulation for the purpose of predicting the appearance and behavior of conventional and intelligent clothing in real conditions. The physical and mechanical properties of the fabric and the simulation parameters play an important role in this issue. The paper presents an analysis of the parameters of the polygonal computer model that affect fabric drape simulation. Experimental research on physical and mechanical properties were performed for nine fabrics. For this purpose, the values of the parameters for the tensile, bending, shear, and compression properties were determined at low loads, while the complex deformations were analyzed using Cusick drape meter devices. The fabric drape simulations were performed using the 2D/3D CAD system for a computer clothing design on a disk model, corresponding to real testing on the drape tester in order to allow a correlation analysis between the values of drape parameters of the simulated fabrics and the realistically measured values for each fabric. Each fabric was simulated as a polygonal model with a variable related to the side length of the polygon to analyze the influence of the polygon size, i.e., mesh density, on the model behavior in the simulation. Based on the simulated fabric drape shape, the values of the areas within the curves necessary to calculate the drape coefficients of the simulated fabrics were determined in the program for 3D modelling. The results were statistically processed and correlations between the values of the drape coefficients and the optimal parameters for simulating certain physical and mechanical properties of the fabric were determined. The results showed that the mesh density of the polygonal model is an important parameter for the simulation results.     

Towards Customized Footwear with Improved Comfort

A methodology enabling the customization of shoes for comfort improvement is proposed and assessed. For this aim, 3D printed graded density inserts were placed in one of the critical plantar pressure zones of conventional insoles, the heel. A semi-automated routine was developed to design the 3D inserts ready for printing, which comprises three main stages: (i) the definition of the number of areas with different mesh density, (ii) the generation of 2D components with continuous graded mesh density, and (iii) the generation of a 3D component having the same 2D base mesh. The adequacy of the mesh densities used in the inserts was previously assessed through compression tests, using uniform mesh density samples. Slippers with different pairs of inserts embedded in their insoles were mechanically characterized, and their comfort was qualitatively assessed by a panel of users. All users found a particular pair, or a set, of prototype slippers more comfortable than the original ones, taken as reference, but their preferences were not consensual. This emphasizes the need for shoe customization, and the usefulness of the proposed methodology to achieve such a goal.     

Physical reproduction of cardiac sutures. A new field of investigation in cardiology

A new technique of physical reproduction of cardiac anatomy has been developed from volumetric data and its practical value assessed in cardiological practice. The acquisition of the volumetric data was by 3D echocardiography. Parallel and equidistant 2D views were selected from this information. The images were printed at a scale adjusted to the true dimensions of the structures of interest and then stuck on a support, the thickness of which was identical to the distance between the views, and the slices were superimposed while respecting the initial orientation. This technique has been adapted secondarily to modern industrial processes of rapid prototyping (3D printing and powdering) allowing automatic tooling of models. Several physical models have been made: whole heart in end diastole, mitral valve stenosis and prolapse, atrial septal defect with insertion of a percutaneous prosthetic device, great vessels at the base of the heart. There are many possible cardiological applications of physical models: investigation of complex cardiac disease, pre- and per-operative simulation of surgical procedures, elaboration of prosthetic material, physiopathological studies, teaching and training, patient information.     

基于CT精细扫描构建人体胸腰段脊柱三维有限元模型的方法及意义

目的探讨基于CT精细扫描构建人体胸腰段脊柱三维有限元模型的方法及临床意义。方法将以各向同性分辨率0．625mm薄层扫描所得的层厚0．65mm人体胸腰段连续断层210层Dicom格式CT图像,直接读入Mimics后界定骨组织阈值、提取各层面轮廓线、图像边缘分割、选择性编辑及补洞处理,去除冗余数据,三维化处理后获得胸腰段三维几何面网格模型,将其保存为后缀名．1is的Ansys文件,直接导入Ansys有限元分析软件进行体网格划分,再将体网格转入Mimics,根据CT值赋值,再次导入Ansys添加韧带、关节约束后生成三维有限元模型。结果快捷建立了外形逼真、计算精确的人体胸腰段脊柱三维有限元模型。结论应用精细CT扫描技术,图像Dicom标准,Mimics软件能直接与Ansys软件进行对接,并能根据CT值直接赋值使胸腰段脊柱三维有限元模型的建立更加快捷、精确。     

Scaling Scientific Cellular Automata Microstructure Evolution Model of Static Recrystallization toward Practical Industrial Calculations

An attempt to bridge the gap between capabilities offered by advanced full-field microstructure evolution models based on the cellular automata method and their practical applications to daily industrial technology design was the goal of the work. High-performance parallelization techniques applied to the cellular automata static recrystallization (CA-SRX) model were selected as a case study. Basic assumptions of the CA-SRX model and developed modifications allowing high-performance computing are presented within the paper. Particular attention is placed on the development of the parallel computation scheme allowing numerical simulations even for a large volume of material. The development of new approaches to handle communication within the distributed environment is also addressed in the paper as a means to obtain higher computational efficiency. Evaluation of model limits was based on the scalability analysis. The investigation was carried out for the 3D and 2D case studies. Therefore, the complex static recrystallization cellular automata simulation taking into account the influence of recovery, nucleation based on accumulated energy, and the progress of recrystallization as a function of stored energy and grain boundary mobility with high-performance computing capabilities is now possible. The research highlighted that parallelization is more effective with an increasing number of cellular automata cells processed during the entire simulation. It was also proven that the developed parallelization scheme and communication mechanism provides a possibility of obtaining scaled speedup over 700 times for 2D and over 800 times for 3D computational domains, which is crucial for future applications in industrial practice. Therefore, the presented approach’s main advantage is based on the possibility of running the calculation based on input data obtained directly from high-resolution 3D imaging of the microstructure. With that, the full immersion of the experimental results into the numerical model is possible. The second novelty aspect of this work is related to the identification of the quality of model predictions as a function of model size reductions.     

Feasibility and validation of registration of three-dimensional left atrial models derived from computed tomography with a noncontact cardiac mapping system.

OBJECTIVES: The purpose of this study was to determine the feasibility and assess the validity of registering three-dimensional (3D) models from computed tomographic (CT) images using a cardiac mapping system. BACKGROUND: Registration of 3D anatomic models with an interventional system could help identify and navigate mapping and ablation catheters over a complex structure such as the left atrium (LA). METHODS: ECG-gated, contrast-enhanced cardiac CT imaging was performed in 14 patients with atrial fibrillation. Segmentation was used to create 3D models of the LA. The 3D models were registered with the mapping system using a series of fiducial points. Registration was accomplished retrospectively in the first 10 patients, and catheter navigation was visualized from recorded data. In the final four patients, registration was accomplished in real time during electrophysiologic study. The mapping catheter position, as it was navigated inside the LA, was applied to the registered model in real time. For the validation study, temporary pacing leads were implanted in the LA of 10 dogs. Following this, CT scanning, segmentation, LA model importation, and registration was described previously. After registration, a mapping catheter was positioned at the site of each buried lead according to the registered model with no fluoroscopic guidance. A radiofrequency lesion was created at this location, and the dog was sacrificed, the heart removed and stained, and the distance between the buried lead and the lesion measured. RESULTS: During the feasibility study, the location of the catheter in the registered model correlated with fluoroscopy, angiography, and intracardiac electrograms. LA endocardial potentials during sinus rhythm and any premature atrial contractions also were successfully delineated over the registered models. In the validation study, the mean target registration error was 2.0 +/- 3.6 mm. CONCLUSIONS: Registration of CT-derived 3D models of the LA using a cardiac mapping system is feasible and accurate.     

The role of radixin in altered localization of canalicular conjugate export pump Mrp2 in cholestatic rat liver.

Aim: Cholestasis has been associated with the endocytic retrieval of multidrug resistance protein 2 (Mrp2), but its mechanism is still unclear. Recent studies have indicated that radixin, a cross-linker between the actin filaments and membrane proteins, may be activated by phosphorylation and may be required for the canalicular localization of Mrp2. Methods: We investigated the role of radixin in the altered localization of Mrp2 in rat models of intrahepatic (ethinyl estradiol treatment) and extrahepatic (bile duct ligation) cholestasis using immunofluorescence microscopy. The changes in localization and expression were analyzed using Scion Image for Windows. Results: In both models, Mrp2 was localized outside as well as inside the ZO-1 staining, indicating partial dislocation from the canalicular membrane. In contrast to the steep elevation of the immunostaining intensity curves for Mrp2 in the controls, the corresponding curves in both models were broadened and flattened, confirming endocytic retrieval into the hepatocytes. Mrp2 and radixin were colocalized at the canalicular domain in the controls, whereas in both cholestatic rats they were dissociated at some canaliculi, indicating the disturbed colocalization of Mrp2 and radixin in cholestasis. The fluorescence of phosphorylated radixin, an active form of radixin, markedly decreased in both cholestatic models, which was supported by the reduced peak fluorescence intensities. Conclusion: The disturbed colocalization of Mrp2 and radixin may contribute to the endocytic retrieval of Mrp2 in cholestasis due to the failure to anchor Mrp2 in the canalicular membrane, in which the phosphorylated radixin may play a major role.     

2D Ultrasound and 3D MR Image Registration of the Prostate for Brachytherapy Surgical Navigation

Two-dimensional (2D) ultrasound (US) images are widely used in minimally invasive prostate procedure for its noninvasive nature and convenience. However, the poor quality of US image makes it difficult to be used as guiding utility. To improve the limitation, we propose a multimodality image guided navigation module that registers 2D US images with magnetic resonance imaging (MRI) based on high quality preoperative models. A 2-step spatial registration method is used to complete the procedure which combines manual alignment and rapid mutual information (MI) optimize algorithm. In addition, a 3-dimensional (3D) reconstruction model of prostate with surrounding organs is employed to combine with the registered images to conduct the navigation. Registration accuracy is measured by calculating the target registration error (TRE). The results show that the error between the US and preoperative MR images of a polyvinyl alcohol hydrogel model phantom is 1.37 ± 0.14 mm, with a similar performance being observed in patient experiments.     

基于深度学习的超声内镜分站和胰腺分割识别系统

目的 尝试构建1个基于深度学习的内镜超声检查（endoscopic ultrasonography,EUS）质量控制系统,并验证其价值。 方法 从武汉大学人民医院消化内镜中心数据库中,回顾性收集2016年12月—2019年12月间的269个EUS检查资料,分为：（1）用于训练模型的训练数据集A,包含205个检查,其中16 305张图像用于分类训练,1 953张图像用于分割训练;（2）用于评估模型性能的测试数据集B,包含44个检查,其中1 606张图像用于分类验证,480张图像用于分割验证;（3）用于内镜医师与模型进行比较的数据集C,包含20个检查,共150张图像。EUS专家（具有10年以上的EUS操作经验）甲和乙通过讨论对训练集A和测试集B、C的所有图像进行分类和标注,其结果用作金标准。EUS专家丙和高年资EUS医师（具有5年以上的EUS操作经验）丁、戊对数据集C中的图像进行分类和标注,其结果用于与深度学习模型进行比较。主要观察指标包括分类的准确率、分割的Dice（F1指数）和一致性分析的Kappa系数。 结果 在测试数据集B中,模型分类的平均准确率为94.1%,胰腺分割的平均Dice为0.826,血管分割的平均Dice为0.841。在数据集C中,模型的分类准确率达到90.0％,专家丙、高年资医师丁和戊分别为89.3％、88.7％和87.3％;模型的胰腺和血管分割Dice系数分别为0.740和0.859,专家丙分别为0.708和0.778,高年资医师丁分别为0.747和0.875,高年资医师戊分别为0.774和0.789,模型与专家的水平相当。一致性分析结果显示,模型与内镜医师之间达成了较好的一致性（Kappa系数分别为：模型与专家丙间0.823、模型与高年资医师丁间0.840、模型与高年资医师戊间0.799）。 结论 基于深度学习的EUS分站和胰腺分割识别系统可以用于胰腺EUS的质量控制,具有与EUS专家相当的分类和分割识别水平。     

Intracoronary fracture and embolization of a coronary angioplasty balloon catheter: retrieval by a simple technique.

We report a technique for retrieval of a balloon along with a portion of its shaft from the coronary system using a simple technique that does not involve the use of snare or any other retrieval tool. An additional angioplasty wire and a balloon catheter were used to remove the balloon from the coronary system.     

Optimally sparse representation in general (nonorthogonal) dictionaries via l minimization

Given a dictionary D = {d(k)} of vectors d(k), we seek to represent a signal S as a linear combination S = summation operator(k) gamma(k)d(k), with scalar coefficients gamma(k). In particular, we aim for the sparsest representation possible. In general, this requires a combinatorial optimization process. Previous work considered the special case where D is an overcomplete system consisting of exactly two orthobases and has shown that, under a condition of mutual incoherence of the two bases, and assuming that S has a sufficiently sparse representation, this representation is unique and can be found by solving a convex optimization problem: specifically, minimizing the l(1) norm of the coefficients gamma. In this article, we obtain parallel results in a more general setting, where the dictionary D can arise from two or several bases, frames, or even less structured systems. We sketch three applications: separating linear features from planar ones in 3D data, noncooperative multiuser encoding, and identification of over-complete independent component models.     

Computerized data retrieval system for colon surgery

Good clinical practice is based on a continuous reevaluation of one's own work as compared with published standards. That which limits particularly the private practitioner from examining and publishing his data, is not the lack of desire, but the scarcity of opportunities and resources to do so. Computers as tools for data retrieval and analysis for research purposes and patient management have been available for some time. They have been of limited utility for most surgeons because of an inhibiting size and/or training period, and illogical design. The authors discuss the limitations of much of the available computer “tools,” and present a system, METABASE, specifically designed for colon and rectal surgeons to use in their private practices for data retrieval and analysis. Read at the joint meeting of the American Society of Colon and Rectal Surgeons, with the Section of Colo-Proctology, Royal Society of Medicine, and the Section of Colonic and Rectal Surgery, Royal Australasian College of Surgeons, New Orleans, Louisiana, May 6 to 11, 1984.     

Generative Design and Integrated 3D Printing Manufacture of Cross Joints

The integrated process of design and fabrication is invariably of particular interest and important to improve the quality and reduce the production cycle for structural joints, which are key components for connecting members and transferring loads in structural systems. In this work, using the generative design method, a pioneering idea was successfully realized to attain a reasonable configuration of the cross joints, which was then consecutively manufactured using 3D printing technology. Firstly, the initial model and generation conditions of a cross joint were constructed by the machine learning-based generative design algorithm, and hundreds of models were automatically generated. Then, based on the design objective and cost index of the cross joint, three representative joints were selected for further numerical analysis to verify the advantages of generative design. Finally, 3D printing was utilized to produce generative joints; the influences of printing parameters on the quality of 3D printing are further discussed in this paper. The results show that the cross joints from the generative design method have varied and innovative configurations and the best static behaviors. 3D printing technology can enhance the accuracy of cross joint fabrication. It is viable to utilize the integrated process of generative design and 3D printing to design and manufacture cross joints.     

A system for determination of 3D vessel tree centerlines from biplane images

With the increasing number and complexity of therapeutic coronary interventions, there is an increasing need for accurate quantitative measurements. These interventions and measurements may be facilitated by accurate and reproducible magnifications and orientations of the vessel structures, specifically by accurate 3D vascular tree centerlines. A number of methods have been proposed to calculate 3D vascular tree centerlines from biplane images. In general, the calculated magnifications and orientations are accurate to within approximately 1–3% and 2–5°, respectively. Here, we present a complete system for determination of the 3D vessel centerlines from biplane angiograms without the use of a calibration object. Subsequent to indication of the vessel centerlines, the imaging geometry and 3D centerlines are calculated automatically and within approximately 2 min. The system was evaluated in terms of the intra- and inter-user variations of the various calculated quantities. The reproducibilities obtained with this system are comparable to or better than the accuracies and reproducibilities quoted for other proposed methods. Based on these results and those reported in earlier studies, we believe that this system will provide accurate and reproducible vascular tree centerlines from biplane images while the patient is still on the table, and thereby will facilitate interventions and associated quantitative analyses of the vasculature.     

The process of designing a rotating platform artificial knee prosthesis with posterior stabilizers by finite element analysis

The purpose of this paper is to design a rotating platform knee prosthesis with posterior stabilizers. This design is based on reverse engineering and interactive acquisition and reconstruction of 3D models combined with the finite element method. A 3D geometric model of a healthy knee joint was created from an anatomical knee model by using an active acquisition system based on a 3D scanner. This healthy model comprises a portion of the long bones (femur, tibia and fibula), as well as the transverse ligament, medial collateral ligament, posterior cruciate ligament, anterior cruciate ligament, medial meniscus and cartilage. The digital model that was obtained was repaired and converted to an engineering drawing format by use of CATIA© software. Also, based on the foregoing format, a rotating platform knee prosthesis was designed and assembled by this software. Once the healthy and artificial models were repaired, the Mentat Marc© software was used to develop the healthy and artificial knee FE models. From the anthropometry of the human body, a combination of loads and positions were obtained by use of 3D Static Strength Prediction software. The normal stresses, Von Mises stresses and all relative displacements of the healthy and artificial knee FE model were determined. The Von Mises stresses on both the cortical and the trabecular bone of the artificial and healthy knee FE model were analyzed and compared. The prosthesis was designed for the knee of a male patient of height and body weight of 190 cm and 120 kg, respectively.     

Appearance preserving simplification of 3D CAD model with large-scale assembly structures

Currently commercial 3D CAD systems which had only been used in upper stage of design scenes become widely used in lower stages such as rough sales purposes, model exporting to external users or e-commerce on Web. Usually, in the design stage, solid models even of very fine parts or full-detailed shapes have been built in the CAD systems, and the assembly models tend to have a huge number of parts and very complex inner structures. Moreover, for achieving the light-weight and strengthened parts, the inner structures of the housing such as ribs or bosses have had very complex geometries. However, when they are used for browsing, styling review and sales purposes, there is hardly the occasion where is full-detailed assembly models are required, and the primary purpose of the systems is often to fast render external shapes rather than to render detailed inner structures. Appearance preserving simplification of large scale assembly model available to the commercial 3D CAD systems is strongly needed for these purposes. Therefore, this paper proposes several appearance preserving simplification methods of 3D CAD model with large-scale assembly structures. Three simplification methods are proposed in the paper; (1) only by removing invisible parts from the assembly, (2) by removing both invisible form features from the part surface and invisible parts themselves from the assembly, and (3) by removing both form features and parts which are invisible even when position and orientation of movable parts change in the assembly. Our methods are based on an algorithm which can directly detect invisible parts or features by pre-rendering the models from multiple view directions and reading the rendered results from the frame buffer. Our algorithm can be carried out regardless of CAD systems. Thanks to using the current GPU, invisible parts or features detection is robust and fast in the algorithm. If needed, geometric dependency among the features in the assembly can be kept even in the simplification. The performances of these simplification methods in model size reduction and the processing time are examined.