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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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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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State Estimation for a Small Scale Flybar-less Helicopter

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Procedia Technology 2014年 15卷 258-267页

作者： Mohammad Al-Sharman Mamoun Abdel-Hafez Muhannad Al-Omari Mechatronics graduate program American university of Sharjah Sharjah P.O. Box 26666UAE Department of mechatronical engineering American university of Sharjah Sharjah P.O. Box 26666UAE

Unmanned helicopters have been used extensively in the last few decades as a research platform for different applications. Flybarless, single-rotor helicopters are famous for their increased agility and high maneuverability, which makes them a suitable platform for many challenging applications. This paper is concerned with the problem of attitude and flapping angles estimation of a flybar-less small scale single rotor helicopter. A nonlinear model for the Maxi Joker 3 helicopter is used to simulate test data. A Kalman filter is designed and implemented to estimate both the attitude and the flapping angles of the helicopter. Results are shown at the end of the paper to validate the performance of the proposed approach.

关键词： UAV Small Scale Flybar-less Helicopter Attitude Estimation Kalman Filter Flapping Angles Estimation.

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Microfluidic device for refractive index measurement of fluid sample

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Procedia engineering 2010年 5卷 1340-1343页

作者： Sang Youl Yoon Sung Yang Graduate-program of Medical System Engineering GIST Gwangju Republic of Korea School of Information & Mechatronics GIST Gwangju Republic of Korea Department of Nanobio Materials and Electronics GIST Gwangju Republic of Korea

This paper represents a novel microfluidic device for simple refractive index (RI) measurement of fluid sample with sub microliter volume. The defocusing imaging technique using a three pinhole aperture plate is implemented for the refractive index measurement. For the self-calibration, the microfluidic device has a measurement region and a self-calibration region, and both regions are designed to be captured on single image frame. Thus, the refractive index of a sample fluid is automatically calculated with the self-calibration. For the demonstration of the proposed device, standard refractive index liquids with the refractive indices of 1.300, 1.400, 1.500, 1.600 and 1.700 are used. The measured refractive index has the maximum deviation of 0.0036 (0.24%) from the standard refractive index values.

关键词： Refractometer Microfluidic device Defocusing imaging Three pinhole Self-calibration Refractive index measurement

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Fuzzy Logic for Assessing the Health of a Corn Crop within Family Farming

Fuzzy Logic for Assessing the Health of a Corn Crop within F...

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Latin America Congress on Computational Intelligence (LA-CCI)

作者： Vanessa Mendonça Mikael Santos Daniel M. Muñoz Carlos Humberto Llanos Department of Computer Science Federal Institute of Brasilia Department of Mechanical Engineering Mechatronics Graduate Program Department of Agronomy Federal Institute of Brasilia Faculty of Gama Electronics Engineering Undergraduate Program University of Brasilia Brasilia DF Brazil

ISBN: (数字)9798350374575

ISBN: (纸本)9798350374582

Technological advancements are increasingly evident across various sectors, including automobiles, industry, and healthcare. In precision agriculture, significant progress has been made, with AgroTICs and Smart Agriculture gaining substantial traction in the market. However, a gap remains between cutting-edge technology and family farming, presenting a challenge from both social and applied research perspectives. However, there is still a gap between cutting-edge technology and family farming, which creates a challenge from a social and applied research point of view. In this context, this paper proposes a monitoring model based on Fuzzy Logic and sensor automation applied to estimate the health of a corn crop. The proposed Fuzzy inference system involves calculating an indicator of nutrients as well as the average color and area of corn plants. The nutrient indicator is automatically computed by an ESP32 microcontroller using sensor readings, while the average color and area inputs are manually entered via a mobile application. Additionally, the Fuzzy inference is integrated into the ESP32. The model underwent experimental validation on the health of the plantation, and the results were evaluated in four areas: one was designated for testing, and three were for validation. The model achieved an accuracy of 97.5% in Scenario 3, categorized as ’Very Favorable’, and an accuracy of 65% in Scenarios 2 and 4, categorized as ‘Unfavorable’. The implications of this research contribute to the advancement of AgroTICs among small producers, with the potential to enhance and automate the monitoring of their harvest production.

关键词： Fuzzy logic Accuracy Computational modeling Plantations Crops Production Color Nutrients Monitoring Fuzzy systems

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Optimal Maintenance Time under Imperfect Preventive Maintenance 2

Optimal Maintenance Time under Imperfect Preventive Maintena...

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2nd International Conference on Vulnerability and Risk Analysis and Management, ICVRAM 2014 and the 6th International Symposium on Uncertainty Modeling and Analysis, ISUMA 2014

作者： Coque, M.A. Souza, G.F.M. Mechanical Engineering Graduate Program University of São Paulo Cidade Universitária São Av Prof. Mello Moraes São Paulo SP2231 Brazil Mechatronics and Mechanical System Engineering Department University of São Paulo Cidade Universitária Av Prof Mello Moraes São Paulo SP2231 Brazil

ISBN: (纸本)9780784413609

The preventive maintenance (PM) is scheduled periodically to restore the system condition. However, PM activities cannot generally restore the system to as good as new condition but in an intermediate situation, which is called imperfect PM. The PM interval optimization is useful for improving system reliability. A popular approach to optimization interval is minimizing the maintenance costs. The goal of this work is to obtain optimal PM intervals that minimize expected cost considered PM imperfect, in other words we obtain the optimal PM intervals assuming that the PM action restores the system operating state to be somewhere between as good as new and as bad as old. The results are applied in a real data and the PM is maintained at a decreasing sequence of intervals, which is more practical since most systems need more frequent maintenance with increased usage and age. Furthermore consider a wrong PM perfect hypotheses increase the maintenance cost substantially. © 2014 American Society of Civil Engineers.

关键词： Preventive maintenance

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How Fast Can a Robotic Drummer Beat Using Dielectric Elastomer Actuators?

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IEEE Robotics and Automation Letters 2024年第3期9卷 2638-2645页

作者： Wakle, Sudhir Lin, Tse-Han Huang, Shu Basu, Sumit Lau, Gih-Keong National Yang Ming Chiao Tung University International College of Semiconductor Technology Hsinchu30010 Taiwan Indian Institute of Technology Kanpur Mechanical Engineering Department Kanpur208016 India National Yang Ming Chiao Tung University Department of Graduate Degree Program of Robotics Hsinchu30010 Taiwan Industrial Technology Research Institute Mechanical and Mechatronics System Research Labs Zhudong 31057 Taiwan National Yang Ming Chiao Tung University Department of Mechanical Engineering International College of Semiconductor Technology Hsinchu30010 Taiwan

Fast drumming presents a speed challenge to many robotic arms. To simultaneously meet the needs for speed, stroke, and force, we proposed and tested a new double-saddle dielectric elastomer actuator (DEA) as the artificial biceps for driving a lightweight robotic drummer. This work finds that fast force induction is instrumental to the fast drumming by a DEA-driven drumstick. While a pure-shear series of DEA under a large pre-stretch and lateral reinforcement can generate a large isotonic stroke, it is not fast in isometric force induction. Instead, this work found a double-saddle DEA, which is a degenerated two-segment pure-shear DEA with a middle laterally buckled beam, managed to induce a faster isometric force at a 0.5 s down time constant when its ultimate actuation tapered due to substantial strain stiffening effect. As such, this double-saddle DEA-driven drummer suffered less from the dynamic stroke decrement than the 8-segment DEA did. A 4.4 g DEA managed to swing freely a 7.8 g drumstick up to nearly 60° at 6 kV and a maximum tip speed of up to 0.45 m/s. The drumming frequency upon 5.5 kV activation was up to 2-2.5 Hz. In comparison, an 8-segment pure-shear DEA-driven drummer failed to reach the drum when pulsed at 2 Hz. Interestingly, a slower stroke excited multiple drumbeats due to secondary bounces. To achieve a faster drumming to match a human drummer, it is foreseen that a harder dielectric elastomer material will help drive a faster soft robot. © 2016 IEEE.

关键词： Dielectric materials

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Group Method of Data Handling for Modeling Magnetorheological Dampers

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Intelligent Control and Automation 2013年第1期4卷 70-79页

作者： Khaled Assaleh Tamer Shanableh Yasmin Abu Kheil Department of Computer Science and Engineering American University of Sharjah Sharjah United Arab Emirates Department of Electrical Engineering American University of Sharjah Sharjah United Arab Emirates Mechatronics Graduate Program American University of Sharjah Sharjah United Arab Emirates

This paper proposes the use of Group Method of Data Handling (GMDH) technique for modeling Magneto-Rheological (MR) dampers in the context of system identification. GMDH is a multilayer network of quadratic neurons that offers an effective solution to modeling non-linear systems. As such, we propose the use of GMDH to approximate the forward and inverse dynamic behaviors of MR dampers. We also introduce two enhanced GMDH-based solutions. Firstly, a two-tier architecture is proposed whereby an enhanced GMD model is generated by the aid of a feedback scheme. Secondly, stepwise regression is used as a feature selection method prior to GMDH modeling. The proposed enhancements to GMDH are found to offer improved prediction results in terms of reducing the root-mean-squared error by around 40%.

关键词： System Identification Magneto-Rheological Dampers Group Method of Data Handling Polynomial Classifier

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Characterization of Thermally Driven V -shaped MEMS Actuator Using an Alternate Nonlinear RC Model

Characterization of Thermally Driven V -shaped MEMS Actuator...

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International Conference on Electric Power and Energy Conversion Systems (EPECS)

作者： Nidal A. Sherif Rached Dhaouadi Maher Bakri-Kassem Mechatronics Graduate Program American University of Sharjah Sharjah UAE Department of Electrical Engineering American University of Sharjah Sharjah UAE Department of Systems Design Engineering University of Waterloo Waterloo Canada

ISBN: (数字)9798331516963

ISBN: (纸本)9798331516970

This paper presents a reduced and efficient alternate model to simulate the nonlinear dynamics of a thermally driven V-shaped MEMS actuator. The experimental observation of the dynamic voltage-displacement relationship shows an overdamped response with a variable rise-time and fall-time indicating the simultaneous presence of complex energy storage and energy dissipation mechanisms. To completely characterize these mechanisms and yet have a simple representation for control, we develop an alternate model consisting of a set of ordinary nonlinear differential equations representing the behavior of a nonlinear RC circuit with variable parameters that are a function of the applied voltage. The simulation results show good agreement with the measured data and confirm the accuracy of the proposed alternate model.

关键词： Micromechanical devices Actuators Transient response Thermal variables control Energy dissipation Thermal variables measurement Mathematical models Integrated circuit modeling Voltage control Energy storage

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Design and implementation of a human stress detection system: A biomechanics approach

Design and implementation of a human stress detection system...

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International Symposium on mechatronics and Its Applications, ISMA

作者： Mohammad S. Sharawi Murad Shibli Mohammad I. Sharawi Computer Engineering Department Philadelphia University Amman Jordan Mechanical Engineering Department and Mechatronics Graduate Program American University Sharjah UAE Electronics Engineering Department Princess Sumaya University for Technology Amman Jordan

This paper presents the design and mechatronics implementation of a human stress detection system (HSDS) using a biomechanics approach. A simple, compact and easy to use system is developed and built on a 2-layer PCB. It consists of two transducers, an LCD display and a micro-controller chip along with their respective interfacing circuits. After characterizing the two transducers, an algorithm was developed based on the measurements to classify the human stress condition. A simple classification rule that was adopted revealed that the system can detect 78% of the stressed examinees. The overall system success rate in identifying one of three states (relaxed, half stressed and stressed) was 60%. One major application for HSDS could be in the automotive industry were the driver condition is constantly monitored, and if a stress state is detected, the driver can be notified to stop the car and relax.

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