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Quantitative Computed Tomography (QCT) derived Bone Mineral Density (BMD) in finite element studies: a review of the literature

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Journal of Experimental Orthopaedics 2016年第1期3卷 1-16页

作者： Knowles, Nikolas K. Reeves, Jacob M. Ferreira, Louis M. Graduate Program in Biomedical Engineering The University of Western Ontario 1151 Richmond St London ON Canada Roth|McFarlane Hand and Upper Limb Centre Surgical Mechatronics Laboratory St. Josephs Health Care 268 Grosvenor St London ON Canada Collaborative Training Program in Musculoskeletal Health Research and Bone and Joint Institute The University of Western Ontario 1151 Richmond St London ON Canada Department of Mechanical and Materials Engineering The University of Western Ontario 1151 Richmond St London ON Canada

Background: Finite element modeling of human bone provides a powerful tool to evaluate a wide variety of outcomes in a highly repeatable and parametric manner. These models are most often derived from computed tomography data, with mechanical properties related to bone mineral density (BMD) from the x-ray energy attenuation provided from this data. To increase accuracy, many researchers report the use of quantitative computed tomography (QCT), in which a calibration phantom is used during image acquisition to improve the estimation of BMD. Since model accuracy is dependent on the methods used in the calculation of BMD and density-mechanical property relationships, it is important to use relationships developed for the same anatomical location and using the same scanner settings, as these may impact model accuracy. The purpose of this literature review is to report the relationships used in the conversion of QCT equivalent density measures to ash, apparent, and/or tissue densities in recent finite element (FE) studies used in common density-modulus relationships. For studies reporting experimental validation, the validation metrics and results are presented. Results: Of the studies reviewed, 29% reported the use of a dipotassium phosphate (K₂HPO₄) phantom, 47% a hydroxyapatite (HA) phantom, 13% did not report phantom type, 7% reported use of both K₂HPO₄ and HA phantoms, and 4% alternate phantom types. Scanner type and/or settings were omitted or partially reported in 31% of studies. The majority of studies used densitometric and/or density-modulus relationships derived from different anatomical locations scanned in different scanners with different scanner settings. The methods used to derive various densitometric relationships are reported and recommendations are provided toward the standardization of reporting metrics. Conclusions: This review assessed the current state of QCT-based FE modeling with use of clinical scanne

关键词： Bone density Finite element analysis Mechanical properties QCT

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Development of bionic invasion membrane for the study of multiple sclerosis

Development of bionic invasion membrane for the study of mul...

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IEEE International Conference on Nano/Micro Engineered and Molecular Systems (NEMS)

作者： Chia-Yi Lee Kin Fong Lei Cheng-Lung Ku Chia-Hao Huang Ph.D. Program in Biomedical Engineering Chang Gung University Taiwan Department of Mechanical Engineering Chang Gung University Taiwan Graduate Institute of Clinical Medical Science Chang Gung University Taiwan Graduate Institute of Medical Mechatronics Chang Gung University Taiwan

ISBN: (纸本)9781509019489

Multiple sclerosis (MS) is an autoimmune disease and leads to many inflammations. Cause of this disease is autoreactive T cells invade the blood-brain-barrier and attack the myelin sheath. Because MS infringes upon young human and has gradual loss of bodily functions, the disease has a burden on society and economy. Traditional treatment is to use immune-suppressant, but it has many side effects. Currently, the most effective treatment of MS is to use Natalizumab. Target molecule of this agent is α4-integrin of T cells. The mechanism is to prevent invasion of activated lymphocytes across the blood-brain-barrier. However, this agent affects the overall immune response and easily generates side effects of progressive multifocal leukoencephalopathy (PML). Transwall systems are often used to investigate cell invasion, but there is no specific protein immobilizing on the isolation membrane of these systems. In this work, we have successfully developed a bionic invasion membrane for the study of MS. Different chemokines were applied to the system for the demonstration of drug screening application. The bionic invasion membrane was a PP/PTEE membrane coated with VCAM-1 protein. Jurkat T cell was used to evaluate the feasibility of using the membrane for the study of MS. Results indicated that the invasion ability of T cells was reduced by VCAM-1 protein. The current work provides bionic invasion membrane for the study of MS in vitro.

关键词： Biomembranes Proteins Multiple sclerosis Immune system Microfluidics Color

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Hardware Architecture of the EKF Prediction Stage applied to mobile robot localization 6

Hardware Architecture of the EKF Prediction Stage applied to...

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6th IEEE Latin American Symposium on Circuits and Systems, LASCAS 2015

作者： Contreras, Luis Cruz, Sérgio Motta, J.M.S.T. Llanos, Carlos H. Graduate Program in Mechatronics Systems Department of Mechanical Engineering University of Brasilia Brasilia D.F.70910-900 Brazil

ISBN: (纸本)9781479983322

This work presents an FPGA-based Hardware Architecture to implement the Prediction Stage of the Extended Kalman Filter (EKF) applied to the localization problem in mobile robotics. The algorithm has been implemented and run on an Altera Cyclone IV FPGA with a Nios II processor, being adapted and applied to the mobile platform Pioneer 3AT (P3AT). The prediction stage was based on a dead-reckoning system model and its architecture was designed for floating-point representation. In this project the complete EKF was also implemented considering an estimation stage hardware architecture previously developed using a Laser Range Finder (LRF) sensor, producing an overall balanced implementation. Finally, it was evaluated the system performance and suitability, measuring FPGA resources consumption and comparing execution time with a software solution. © 2015 IEEE.

关键词： Extended Kalman filters

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Nonlinear reduced order observer design for elastic drive systems using invariant manifolds

Nonlinear reduced order observer design for elastic drive sy...

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International Conference on mechatronics (ICM)

作者： Irfan Ullah Khan Rached Dhaouadi Mechatronics Engineering Graduate Program College of Engineering American University of Sharjah Sharjah UAE

This paper presents the design of a nonlinear reduced order observer to estimate the load position and speed of an elastic drive system. The reduced order observer is designed using the notion of invariant manifold. First, a manifold is defined in terms of the error dynamics. Then, the mapping functions are selected in such a way that the error dynamics become asymptotically stable at the equilibrium point. Simulation and experimental results are shown to validate the proposed methodology for a two mass model system.

关键词： Observers Manifolds Load modeling Design methodology Mathematical model Asymptotic stability Torque

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Proposal for an image-based software system for dental implant positioning 15

Proposal for an image-based software system for dental impla...

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15th IEEE International Conference on Bioinformatics and Bioengineering, BIBE 2015

作者： Rizzatti, Cesar Luiz Rudek, Marcelo Szejka, Anderson Luis Canciglieri, Osiris Trajanovic, Miroslav Pontifical Catholic University of Parana-PUCPR Mechatronics Eng. Dept. Curitiba Brazil Graduate Program in Production Engineering and Systems - PPGEPS Curitiba Brazil Department for Production IT and Management University of Nis Faculty of Machanical Engineering Serbia

ISBN: (纸本)9781467379830

The technological development in healthcare experienced in actual days has relationship with the integration of many knowledge areas, fundamentally by searching new solutions in order to improve the quality of life of the society. Examples of this reality appears in medicine and engineering areas, where the computer-assisted techniques works together to solve many healthcare problems. In the surgical procedures context as well, as in dental implant planning, the surgeon still determine some parameters according to his personal experience, where only the visualization of the problems through Computed Tomography images are not enough to ensure the success of the procedure. Thus, this research aims to propose a computational model, as a decision support tool, in order to define a more appropriate positioning for dental implants. This is a fundamental part to determination of the necessary parameters for the process planning because the information is obtained automatically straight from image processing. The prototype presented in this work comprises a user-friendly interface, which allows dentists to observe the bone and dental structure in multi-perspective images. Also, it determines the implant location by an automatic procedure without intervention of dentist. The text shows a study case with the autonomous determination of an implant position. © 2015 IEEE.

关键词： Computerized tomography

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Using Finite Element Analysis and Experimental Analysis on Vibration of a Piezoelectric Micro Pump

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Journal of Applied Mathematics and Physics 2015年第8期3卷 1038-1043页

作者： Bo-Wun Huang Jung-Ge Tseng Chien-Hua Chang Chen-Yuan Li Graduate Institute of Mechatronics Engineering Cheng Shiu University Kaohsiung Taiwan Medical Mechatronics Engineering Program Cheng Shiu University Kaohsiung Taiwan Department of Mechanical Engineering Chinese Culture University Taipei Taiwan

Due to the rise of biological and MEMS technology in recent years, some micro flow system components have drawn attention and been developed by many investigators. The importance of micro-pumps manufactured is higher than the other part of micro flow system since it is the power source of the entire micro-flow system and responsible for driving working fluid in the microfluidic system. In actual operation, the instability and bad dynamic characteristics of the micro-pump will cause larger fluid flow mobility error, such as transport behavior and response procedures failure, etc., and even damage the microfluidic system. Therefore, to investigate the stability and dynamic characteristics of a micro pump is necessary. The Finite element analysis (FEA), ANSYS Workbench, is employed to analyze the dynamic characteristics of this micro pump, and experiment is also considered in this study.

关键词： Component Micro Pump Finite Element Analysis Piezoelectric

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Using Finite Element Analysis and Experimental Analysis on Vibration of a Piezoelectric Micro Pump

Using Finite Element Analysis and Experimental Analysis on V...

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2015 Workshop 8

作者： Bo-Wun Huang Jung-Ge Tseng Chien-Hua Chang Chen-Yuan Li Graduate Institute of Mechatronics Engineering Cheng Shiu University Medical Mechatronics Engineering Program Cheng Shiu University Department of Mechanical Engineering Chinese Culture University

Due to the rise of biological and MEMS technology in recent years, some micro flow system components have drawn attention and been developed by many investigators. The importance of micro-pumps manufactured is higher than the other part of micro flow system since it is the power source of the entire micro-flow system and responsible for driving working fluid in the microfluidic system. In actual operation, the instability and bad dynamic characteristics of the micro-pump will cause larger fluid flow mobility error, such as transport behavior and response procedures failure, etc., and even damage the microfluidic system. Therefore, to investigate the stability and dynamic characteristics of a micro pump is necessary. The Finite element analysis（FEA）, ANSYS Workbench, is employed to analyze the dynamic characteristics of this micro pump, and experiment is also considered in this study.

关键词： Component Micro Pump Finite Element Analysis Piezoelectric

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Robust H_2 Control of Active Suspension -Improvement of Ride Comfort and Driving Stability

Robust H_2 Control of Active Suspension -Improvement of Ride...

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Conference on Control Applications

作者： Kohei Suzuki Tatsuo Toda Gan Chen Isao Takami Department of System Design and Engineering Graduate Program of Mechatronics Nanzan University Aichi Japan Faculty of Science and Engineering Nanzan University Aichi Japan

ISBN: (纸本)9781479977970

This paper suggests a method of robust control for an active suspension to improve both of the ride comfort and the driving stability using half car model. The ride comfort is evaluated by the vertical acceleration and the pitch acceleration of the human body. The driving stability is evaluated by the vertical force of front and rear wheels. The purpose of this paper is to improve the ride comfort and the driving stability by using state feedback. On the other hand, the robust stability is also important factor to evaluate the performance of the car. In this study, the front and rear weights of car body are considered as uncertain parameters depending on the passengers and the loads. Their weights influence on the pitch motion of the car body. The robust H_2 controller is designed to guarantee the robust stability for the system with uncertain parameters with polytopic representation. These problems are solved by a finite set of Linear Matrix Inequality (LMI). The effectiveness of the proposed method is illustrated by simulations and experiments.

关键词： comfort driving stability experiments

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A Comparison of Adaptive Trajectory Tracking Controllers for Wheeled Mobile Robots

A Comparison of Adaptive Trajectory Tracking Controllers for...

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International Symposium on mechatronics and its Applications

作者： Ehab I. Al Khatib Wasim M. F. Al-Masri Shayok Mukhopadhyay Mohammad A. Jaradat Mamoun Abdel-Hafez Mechatronics Engineering Graduate Program American University of Sharjah Sharjah UAE Department of Electrical Engineering American University of Sharjah Sharjah UAE Department of Mechanical Engineering American University of Sharjah Sharjah UAE

ISBN: (纸本)9781467377980

Two adaptive trajectory tracking controllers for wheeled mobile robots are tested in this work. Adaptively tuned proportional control is one approach, where as the other controller uses a Universal Adaptive Stabilization (UAS) based technique. Using simulations, the robustness of the above controllers is quantified in the presence of measurement noise. The robustness is measured in terms of the Integral of absolute magnitude of the error (IAE), the Integral of square of the error (ISE), and the Integral of time multiplied by the absolute value of the error (ITAE) criteria. It is observed that the UAS based technique shows fast convergence in the absence of noise. To combat the effect of noise, the authors reset the adaptation gains after the adaptation gains reach a preset bound. With this technique it is found that the UAS based technique converges to the trajectory being tracked faster than the adaptively tuned proportional controller, and also faster than a traditional input-output state feedback linearization based controller.

关键词： UAS Comparison Adaptive Trajectory Tracking Controllers

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A Quantized Adaptive Approach To Three Phase Switched Rectifier Voltage Control

A Quantized Adaptive Approach To Three Phase Switched Rectif...

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International Symposium on mechatronics and its Applications

作者： Ali Alghamri Shayok Mukhopadhyay Ahmed Osman Mechatronics Engineering Graduate Program Department of Electrical Engineering American University of Sharjah PO Box 26666 Sharjah UAE

ISBN: (纸本)9781467377980

This paper presents a strategy for controlling the terminal voltage of a three phase switched rectifier. The novelty of the proposed method is that we use model reference adaptive control (MRAC) along with a custom designed switching mechanism. The switching mechanism is inspired by quantized control techniques. In this paper we do not focus on controlling the individual line currents but only on controlling the terminal voltage. The mathematical formulation of this problem is presented following the MRAC framework. Further we also validate the mathematical model by comparing its output with a Simulink based model which uses pre-existing blocks from the appropriate Simulink toolbox. Finally we also present simulation results of the proposed control scheme to show that using MRAC with the proposed quantization technique achieves desired *** work can be extended in future for extracting maximum power from wind generators in a microgrid system.

关键词： Quantized Adaptive Approach Three Phase Switched Rectifier Voltage Control MRAC

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