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Contact force play is a significant role in success of the cardiac ablation. However, it is still challenging to estimate contact force when a catheter is under large bending and multiple contacts. This paper develops a new multi-section static model of the tendon-driven catheters for both real-time intrinsic force sensing and interaction control. The model allows estimating the catheter shape by...
Different from traditional algorithms, the material modeling method utilizing luma Y in YUV color space has been developed in this paper. Our method, which interactively acquires material appearance from a single image, includes four main steps: removing highlight, recovering normal based on luma Y, estimating diffuse coefficient, setting glossiness and specular coefficient interactively. The experiment...
Accurate and precise control of catheters inside a vasculature is a difficult yet important task. Current manual approaches require significant surgical skill. Over the years, surgeons build up a sort of mental kinematic map telling them how to handle the catheter in order to steer the catheter tip safely through the vessel system. The input-output behaviour of the catheter is complex and depends...
Accurate Power Distribution Network (PDN) design is crucial for Signal/Power Integrity (SI/PI) and Electromagnetic Interference (EMI) compliance. Achieving target power-ground (PG) noise levels for low power complex PDNs requires several design and analysis cycles. Although several classes of analysis tools, 2.5D and 3D, are commercially available, the presence of design tools are limited e.g. parametric...
Many skin detection approaches have been proposed in the image analysis literature. Some are simple and static; the others are dynamic and rely on complex machine learning algorithms and training data. Generally the simple approaches are preferred. We hypothesize that the developers' choice for the simple approaches are due to the reasonable quality of results and ease of implementation, since the...
Crowd density estimation for counting persons, or for determining interactions among persons, groups of people, or crowds has been a challenging problem since persons can be occluded by other persons in (highly) crowded situations. The successful development of such techniques has diverse purposes, such as reassigning limited resources (e.g., public transportation) properly by counting floating population...
Cuneiform scripts constitute an immense source of information about ancient history, dating back almost four thousand years. Documents were written by imprinting wedge-shaped impressions into wet clay tablets, and current scholarly practice typically transcribes the resulting markings by hand with ink on paper. This work develops algorithmic methods for cuneiform script, combining feature extraction...
Lung nodule segmentation is the first and the most difficult step in every Computer Aided Diagnosis (CAD). Difficulty arises due to the boring and time-consuming nature of the manual lung segmentation process. In this paper, we propose a novel automatic lung segmentation method for accurate localization of the lung nodules in computer tomography (CT) images. We present a combination of the Graph Cut...
Specularities, which are often visible in images, may be problematic in computer vision since they depend on parameters which are difficult to estimate in practice. We present an empirical model called JOLIMAS: JOint LIght-MAterial Specularity, which allows specularity prediction. JOLIMAS is reconstructed from images of specular reflections observed on a planar surface and implicitly includes light...
In the era of modern computing based environment, the process of design is conceptualized, implemented and tested in a close loop integrating different modules of design, manufacturing and usages. In this regard, this paper presents a computing based design model for the design of a ‘Pneumatic Driven Variable Buoyancy System (PDVBS)’ for ‘Autonomous Underwater Vehicles (AUVs)’. The presented design...
Drilled shaft is an important substructure foundation in building construction. A drilled shaft needs to be placed precisely in high accuracy and satisfy the diameter precision requirement. In order to measure the verticality and the diameter of a shaft, the M-superimposed Gaussian Echoes Model (GEM) is used to estimate the time of flight (TOF) of ultrasound. Compared to the conventional threshold...
The paper deals with possibilities of geometry simplification for FE structural model calculating natural frequencies and mode shapes of rotor of small squirrel-cage induction motor. Proposed simplifications lead to the computing time savings while good result accuracy is preserved. All results are verified by experimental measurement.
This paper demonstrates how procedural modeling and computer graphics techniques can be combined for creating fast, accurate and realistic modeling of archaeological parts of buildings which can be used for games and virtual environments. As a case study the Ionic order of Greek and Roman temples is examined. In particular, the temple of Portunus in Rome, Italy was used as a case study. A set of geometric...
The article presents the use of 3-dimensional thinning algorithm in creation of skeletal structures describing the area of pelvis and its surrounding. The skeletal descriptors are created for the models of pelvis and femurs and further transformed from its voxel representation into the graph. The result of the skeletonization is compared with the Reeb graphs created for the same bone models. The usefulness...
With the emergence of a large number of 3D models, retrieving 3D models is becoming more and more important. It is well known that 3D shape features suffer from sparse sampling and view-based features have the ambiguity of different views for a 3D model. In this paper we present a method which combines 3D shape features with view-based features of 3D model to retrieve models. Moreover, according to...
Soft tissue deformation is an important part of virtual surgery simulation systems. Real-time and realistic simulation of soft tissue deformation in humans is crucial for virtual surgery simulation systems. Soft tissue deformation simulation mainly applies a linear and viscoelastic biomechanical model, however, this model loses numerous properties of soft tissue. As a consequence, a realistic representation...
We present in this paper an original method to estimate the pose of a monocular camera while simultaneously modeling and capturing the elastic deformation of the object to be augmented. Our method tackles a challenging problem where ambiguities between rigid motion and non-rigid deformation are present. This issue represents a major lock for the establishment of an efficient surgical augmented reality...
In this paper, we present a probabilistic approach to segmentation of malignant breast masses which have irregular shape, spiculated margins and which may be embedded in high density glandular tissue. First, we perform contrast enhancement of the image using a simple logarithmic transformation. Then, we derive a segmentation technique based on a specific class of Markov random fields (MRFs) known...
This paper proposes a novel and efficient shape-based approach for hand dorsal vein recognition. A coarse-to-fine segmentation method is first introduced to precisely detect the boundaries of the vein areas. A generalized graph model, namely Width Skeleton Model (WSM), is built then, which takes both the topology of the vein network and the width of the vessel into account, thereby achieving more...
Third generation full-waveform (FW) LIDAR systems collect time-resolved 1D signals generated by laser pulses reflecting off of intercepted objects. From these signals, scene depth profiles along each pulse path can be readily constructed. Using the conventional sampling process, however, massive amounts of data are typically required in order to achieve acceptable depth and spatial resolutions, and...
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