scholarly journals A Two-Stage Registration Method for Dental Volumetric Data and Mesh Data

2021 ◽  
Vol 16 (4) ◽  
pp. 1-15
Author(s):  
Shuai Yang ◽  
Wenjing Shi ◽  
Yongzhen Ke ◽  
Yongjiang Xue
Keyword(s):  
Computer Aided Design ◽  
Scale Transformation ◽  
Software Systems ◽  
Two Stage ◽  
Unit Quaternion ◽  
Registration Method ◽  
Registration Errors ◽  
Scan Data ◽  
Good Trade ◽  
Surface Scan

Dental computed tomography (CT) images and optical surface scan data are widely used in dental computer-aided design systems. Registration is essential if they are used in software systems. Existing automatic registration methods are either time-consuming or rough, and interactive registration methods are experience-dependent and tedious because of a great deal of purely manual interactions. For overcoming these disadvantages, a two-stage registration method is proposed. In the rough registration stage, the rough translation and rotation matrices are obtained by applying unit quaternion based method on the points interactively selected from the two types of data. In the precise registration stage, the stridden sampling is used to reduce computational complexity and the proposed registration algorithm with scale transformation is used for precise registration. The proposed method offers a good trade-off between precision and time cost. The experimental results demonstrate that the proposed method provides faster convergence and smaller registration errors than existing methods.

scholarly journals Digital Workflow to Fabricate Complete Dentures for Edentulous Patients Using a Reversing and Superimposing Technique

2021 ◽  
Vol 11 (13) ◽  
pp. 5786
Author(s):  
Hwa-Jung Lee ◽  
Jeongho Jeon ◽  
Hong Seok Moon ◽  
Kyung Chul Oh
Keyword(s):  
Additive Manufacturing ◽  
Computer Aided Design ◽  
Digital Data ◽  
Complete Dentures ◽  
Intraoral Scanner ◽  
Digital Workflow ◽  
Denture Base ◽  
Scan Data ◽  
Edentulous Patients ◽  
Aided Design

This technical procedure demonstrates a 4-step completely digital workflow for the fabrication of complete dentures in edentulous patients. The digital scan data of the edentulous arches were obtained using an intraoral scanner, followed by the fabrication of modeless trial denture bases using additive manufacturing. Using the trial denture base and a wax rim assembly, the interarch relationship was recorded. This record was digitized using an intraoral scanner and reversed for each maxillary and mandibular section individually. The digital scan data directly obtained using the intraoral scanner were superimposed over the reversed data, establishing a proper interarch relationship. The artificial teeth were arranged virtually and try-in dentures were additively manufactured. Subsequently, the gingival and tooth sections were additively manufactured individually and characterized. Thus, fabrication of digital complete dentures can be accomplished using digital data characteristics. The workflow includes data acquisition using an intraoral scanner, data processing using reverse engineering and computer-aided design software programs, and additive manufacturing.

scholarly journals DEVELOPMENT OF THE BASIC CAPACITIVE ACCELEROMETERS MODELS BASED ON THE VHDL-AMS LANGUAGE FOR THE CIRCUIT LEVEL OF COMPUTER-AIDED DESIGN

2020 ◽  
Vol 2 (1) ◽  
pp. 15-20
Author(s):  
V. M. Teslyuk ◽  
◽  
P. Yu. Denysyuk ◽  
T. V. Teslyuk ◽  
◽  
...  
Keyword(s):  
Differential Equations ◽  
Computer Aided Design ◽  
Structural Parameters ◽  
Software Systems ◽  
Mems Devices ◽  
Electric Circuits ◽  
Capacitive Accelerometer ◽  
Level Of Automation ◽  
Electric Parameters ◽  
Physical Principles

In the article, the basic VHDL-AMS models of MEMS-based capacitive accelerometers were developed. The models were designed for two basic types of capacitive accelerometers, namely lamellar and counter-pivotal. The developed models allow us to determine the source of electrical capacitive accelerometers depending on the incoming mechanical and structural parameters and were constructed for MEMS CAD at the circuit level. The circuit level of MEMS development requires an analysis of the total integrated device electric circuits. For this purpose, all the MEMS components should be written in the specific software systems, which would be understandable for the software system. Taking into account that MEMS devices operate on different physical principles, certain difficulties may arise during the electrical analysis, that is, the work of mechanical or other devices need to be described with the help of electric parameters. In the general case, the method for building the VHDL-AMS model of the MEMS-based capacitive accelerometer is needed construction of the simplified mechanical model, and then a simplified electrical model. On the basis of the simplified models, the VHDL-AMS model of electromechanical MEMS devices has been developed. In the article, the method of automated synthesis and mathematical models using the VHDL-AMS language, which is based on the method of electrical analogies were described. They use systems of ordinary differential equations and partial differential equations to determine the relationships between input and output parameters. The sequence and quantity of used differential equations are determined by the physical principles of operation of the MEMS element and the number of energy transformations, which allows increasing the level of automation of synthesis operations compared to existing methods. The results of the basic lamellar and counter-pivotal capacitive accelerometers are also shown. This enables to conduct research and analysis of its parameters and investigate the output electric parameters dependence on the input mechanical ones.

Digital Technologies in Architecture and Engineering

2018 ◽  
pp. 618-653
Author(s):  
Sara Eloy ◽  
Miguel Sales Dias ◽  
Pedro Faria Lopes ◽  
Elisângela Vilar
Keyword(s):  
Computer Aided Design ◽  
Teaching And Learning ◽  
Systems Design ◽  
Digital Technologies ◽  
3D Modelling ◽  
Shape Grammar ◽  
Software Systems ◽  
Science Curricula ◽  
Aided Design

This chapter focuses on the development and adoption of new Multimedia, Computer Aided Design, and other ICT technologies for both Architecture and Computer Science curricula and highlights the multidisciplinary work that can be accomplished when these two areas work together. The authors describe in detail the addressed educational skills and the related developed research and highlight the contributions towards the improvements of teaching and learning in those areas. This chapter discusses the role of digital technologies, such as Virtual Reality, Augmented Reality, Multimedia, 3D Modelling software systems, Design Processes and its evaluation tools, such as Shape Grammar and Space Syntax, within the Architecture curricula.

scholarly journals On-Site 4-in-1 Alignment: Visualization and Interactive CAD Model Retrofitting Using UAV, LiDAR’s Point Cloud Data, and Video

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3908 ◽  
Author(s):  
Pavan Kumar B. N. ◽  
Ashok Kumar Patil ◽  
Chethana B. ◽  
Young Ho Chai
Keyword(s):  
Computer Aided Design ◽  
Point Cloud ◽  
Laser Scanner ◽  
Video Frame ◽  
Cad Model ◽  
Point Cloud Data ◽  
Registration Method ◽  
Industrial Facilities ◽  
Cloud Data ◽  
Generic Framework

Acquisition of 3D point cloud data (PCD) using a laser scanner and aligning it with a video frame is a new approach that is efficient for retrofitting comprehensive objects in heavy pipeline industrial facilities. This work contributes a generic framework for interactive retrofitting in a virtual environment and an unmanned aerial vehicle (UAV)-based sensory setup design to acquire PCD. The framework adopts a 4-in-1 alignment using a point cloud registration algorithm for a pre-processed PCD alignment with the partial PCD, and frame-by-frame registration method for video alignment. This work also proposes a virtual interactive retrofitting framework that uses pre-defined 3D computer-aided design models (CAD) with a customized graphical user interface (GUI) and visualization of a 4-in-1 aligned video scene from a UAV camera in a desktop environment. Trials were carried out using the proposed framework in a real environment at a water treatment facility. A qualitative and quantitative study was conducted to evaluate the performance of the proposed generic framework from participants by adopting the appropriate questionnaire and retrofitting task-oriented experiment. Overall, it was found that the proposed framework could be a solution for interactive 3D CAD model retrofitting on a combination of UAV sensory setup-acquired PCD and real-time video from the camera in heavy industrial facilities.

S203 – The STAMP Registration for Image-guided Otologic Surgery

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P143-P144
Author(s):  
Nozomu Matsumoto ◽  
Jaesung Hong ◽  
Hashizume Makoto ◽  
Shizuo Komune
Keyword(s):  
Surgical Navigation ◽  
Phantom Study ◽  
Image Guided Surgery ◽  
Registration Method ◽  
Guided Surgery ◽  
Otologic Surgery ◽  
Image Guided ◽  
Registration Errors ◽  
Preoperative Procedures ◽  
New System

Objectives 1) Develop a less invasive but accurate enough registration strategy for otological surgical navigation. 2) Evaluate the new system in phantom study. 3) Evaluate the new system in cochlear implant surgeries. Methods A new registration method was developed for otologic surgery. Previously, the registration for accurate image-guided surgery often required invasive fiducial markers attached on patient's bone. We utilized the template of the bone surface to transfer the pre-made virtual bone-anchored markers to the patient's bone intraoperatively and eliminated the necessity for preoperative marker positioning or preoperative additional CT scan. Results We tested this Surface Template-Assisted Marker Positioning (STAMP) method using 5 temporal bone replicas, and in 5 ear surgeries (2 cochlear implants, 3 translabyrinthine acoustic neuroma surgeries) to investigate whether this method improves, or at least retains, the accuracy of image- guided surgery (IGS). The fiducial registration errors and target registration errors in the phantom study was ∼0.7 mm and ∼1.5 mm, respectively. The target registration errors in replicas were always less than 2 mm. In actual ear surgeries the fiducial registration errors were ∼0.6 mm and the target registration errors were less than 2 mm in 4 of 5 surgeries. All patients received successful cochlear implantation or tumor removal. Conclusions The new method reduced the preoperative procedures for patients but did not reduce the accuracy of the surgical navigation. Our method would be a useful IGS method in the field of otology where both accuracy and non-invasiveness are required.

Monte Carlo simulation and analysis of free-form surface registration

1997 ◽  
Vol 211 (8) ◽  
pp. 605-617 ◽  
Author(s):  
D Brujic ◽  
M Ristic
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Confidence Intervals ◽  
Computer Aided Design ◽  
Maximum Error ◽  
Surface Registration ◽  
Performance Criteria ◽  
Free Form ◽  
Registration Method ◽  
Free Form Surfaces

Accurate dimensional inspection and error analysis of free-form surfaces requires accurate registration of the component in hand. Registration of surfaces defined as non-uniform rational B-splines (NURBS) has been realized through an implementation of the iterative closest point method (ICP). The paper presents performance analysis of the ICP registration method using Monte Carlo simulation. A large number of simulations were performed on an example of a precision engineering component, an aero-engine turbine blade, which was judged to possess a useful combination of geometric characteristics such that the results of the analysis had generic significance. Data sets were obtained through CAD (computer aided design)-based inspection. Confidence intervals for estimated transformation parameters, maximum error between a measured point and the nominal surface (which is extremely important for inspection) mean error and several other performance criteria are presented. The influence of shape, number of measured points, measurement noise and some less obvious, but not less important, factors affecting confidence intervals are identified through statistical analysis.

Engineering Graphics Course Using Modern Software Systems for Students of Civil Engineering University

2015 ◽  
Vol 3 (1) ◽  
pp. 47-58 ◽  
Author(s):  
Петухова ◽  
Anna Petukhova
Keyword(s):  
Computer Aided Design ◽  
Civil Engineering ◽  
Integrated Approach ◽  
3D Models ◽  
Technical Condition ◽  
Railway Track ◽  
Software Systems ◽  
Gradual Transition ◽  
Engineering Graphics ◽  
Amount Of Knowledge

We should equip the graduates of technical universities with the most modern knowledge. It is one of the most impor - tant teaching aims. Civil engineer must be able to draw, read drawings, simulate parts, mechanisms, structures, buildings and sites on their computers. This is a great amount of knowledge and a huge range of skills, and their formation requires a gradual transition from drawings using pencil and ruler, through a standard drawing program (such Autodesk AutoCAD and Compass ASCON) to the more complex software systems (AutoCAD, Revit and AutoCAD Civil 3D). The article presents our experience in developing educational programs for undergraduate and specialties. The program is designed for "General construction", "Railway Construction", "Management of the technical condition of the railway track", "Bridges", "Tunnels and Subways", "Industrial and Civil Engineering", "Water supply and sanitation". The system of training is based on a modular principle. The first module "Descriptive Geometry" uses the classic teaching methods. Although it is supplemented by modern visualization tools (electronic posters, presentations, 3D models). The second module "Engineering Graphics" is built with a focus on computer way of doing drawings. At this stage, we form the basic skills of drawing and 3D-modeling. The main goal the next phase of training (course "Computer Graphics") is to form good skills in computer-aided design. In the last stage (course "Software"), we use the most modern software systems using BIM. An integrated approach can effectively reach both local and general educational purposes and creates a base for the formation of core professional competencies engineer.

Segmenting 3D surface scan data of the human body by 2D projection

2000 ◽  
Author(s):  
Peng Li ◽  
Brian D. Corner ◽  
Steven Paquette
Keyword(s):  
Human Body ◽  
3D Surface ◽  
Scan Data ◽  
Surface Scan
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