Speciknee: An Engineering Software Tool for Design of Simple Four-Bar Prosthesis Joints for Above-Knee Amputees

Author(s):  
Thomas J. Thompson ◽  
Erkai Watson

This paper presents the vector analysis used to develop an educational computer design tool which could enable prosthetists and mechanical designers to tailor the motion of low-cost, four-bar prosthetic knees to the sizes and needs of individual amputees. In designing a prosthetic knee joint, it is important to control the position of the lower leg in three angles of flexion and to control its center of rotation in the standing position. In 2010 [1] this problem was analyzed using vector methods, and an algorithm was written which produced curves displaying pivot locations which solve the problem exactly. Since then, a software tool called Speciknee has been developed by building on the core vector computational method and adding a user-friendly operator interface through which a designer could input individual patient needs, select pivot points along the set of curves where prosthetic joint pivots could be placed, and animate the mechanism.

2013 ◽  
Vol 846-847 ◽  
pp. 1676-1680
Author(s):  
Rui Sun ◽  
Yong Wang ◽  
Shao Peng Li

With the large-scale promotion and application of CAN bus in automotive electronics, a set software tool supporting the development, analysis and test of CAN bus network is required for the design of CAN network and single automotive electronic unit. Since the CAN bus development and analysis tool adopted by the buyer is quite expensive and it should be bonded to specific CAN card, it is not applicable for parallel development. The team of the author realized a low-cost CAN network development and analysis tool with Java and JNI by taking Eclipse as the development platform. The tool mainly includes two parts, namely the networking protocol design tool and bus monitoring tool. The former realizes the design of signal matrix, provides several views for the network signal, and generates XML signal matrix as the interface of bus monitoring tool; while the latter realizes the control and interface of ordinary CAN card, which will carry out the real-time monitor of bus data and provide several views of the data for further analysis through connecting CAN card to the CAN bus network.


2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Navaneetha Krishnan Rajan ◽  
Zeying Song ◽  
Kenneth R. Hoffmann ◽  
Marek Belohlavek ◽  
Eileen M. McMahon ◽  
...  

Two-dimensional echocardiography (echo) is the method of choice for noninvasive evaluation of the left ventricle (LV) function owing to its low cost, fast acquisition time, and high temporal resolution. However, it only provides the LV boundaries in discrete 2D planes, and the 3D LV geometry needs to be reconstructed from those planes to quantify LV wall motion, acceleration, and strain, or to carry out flow simulations. An automated method is developed for the reconstruction of the 3D LV endocardial surface using echo from a few standard cross sections, in contrast with the previous work that has used a series of 2D scans in a linear or rotational manner for 3D reconstruction. The concept is based on a generalized approach so that the number or type (long-axis (LA) or short-axis (SA)) of sectional data is not constrained. The location of the cross sections is optimized to minimize the difference between the reconstructed and measured cross sections, and the reconstructed LV surface is meshed in a standard format. Temporal smoothing is implemented to smooth the motion of the LV and the flow rate. This software tool can be used with existing clinical 2D echo systems to reconstruct the 3D LV geometry and motion to quantify the regional akinesis/dyskinesis, 3D strain, acceleration, and velocities, or to be used in ventricular flow simulations.


Author(s):  
A. Romei ◽  
R. Maffulli ◽  
C. Garcia Sanchez ◽  
S. Lavagnoli

The use of multi-stage centrifugal compressors carries out a leading role in oil and gas process applications. Green operation and market competitiveness require the use of low-cost reliable compression units with high efficiencies and wide operating range. A methodology is presented for the design optimization of multi-stage centrifugal compressors with prediction of the compressor map and estimation of the uncertainty limits. A one-dimensional (1D) design tool has been developed that automatically generates a multi-stage radial compressor satisfying the target machine requirements based on a few input parameters. The compressor performance map is then assessed using the method proposed by Casey-Robinson [1], and the approach developed by Al-Busaidi-Pilidis [2]. The off-design performance method relies on empirical correlations calibrated on the performance maps of many single-stage centrifugal compressors. An uncertainty quantification study on the predicted performance maps was conducted using Monte Carlo method (MCM) and generalized Polynomial Chaos Expansion (gPCE). Finally, the design procedure has been coupled to an in-house optimizer based on evolutionary algorithms. The complete design procedure has been applied to a multi-stage industrial compressor test case. A multi-objective optimization of a multi-stage industrial compressor has been performed targeting maximum compressor efficiency and flow range. The results of the optimization show the existence of optimum compressor architectures and how the Pareto fronts evolve depending on the number of stages and shafts.


Author(s):  
Seyyed Mahdi Nemati Mehr ◽  
Salman Sohrabi ◽  
Pedram Falsafi ◽  
Paniz Gorji

In this paper we developed a new mathematical model for the flow inside cascade impactors and via this simplified model, we determined the particle size distribution by a fast and low cost computational method. Using cascade impactors for determining the particle size distribution, one can use comprehensive CFD methods to fully simulate the particle traces. Although the results from those CFD analyses can be very accurate, usually that is not a time and cost efficient routine. In contrast, we showed that by using our proposed calculation we can estimate the particle size distribution very fast and yet with the slight error — comparing to the results from CFD method. Cascade impactors are being used to measure the range of substances moving through an opening and determine the particle size of distributed substances. Air flow containing aerosol entering in each stage, after colliding vertically with a plate will deviate 90 degrees from its original direction. Larger (massive) particles cannot follow the flow because of their larger linear momentum. Hence, they will deviate from the flow and deposit on the plate instead. The mass difference before and after the experiment represents the deposited mass in each stage. By integrating multiple uniquely designed stages into one impactor, we can determine size of particles in the flow. Typical cascade impactors consist of up to ten stages in which different size of aerosols are being separated. This paper presents a simple model for the flow in one single stage of a cascade impactor. Flow inside cascade impactor is approximated by stagnation point potential flow with the stream function of Psi = Axy, and particles are tracked by velocity verlet algorithm. Absorbed particles are associated with unit value; otherwise they are associated with zero. It is assumed that particles in entrance have random size distribution and location. Drag, Saffman and Brownian forces are taken into account in this model for different particle sizes. The results are discussed in detail and compared with data driven from different approaches in the literature.


2014 ◽  
Vol 10 (2) ◽  
pp. 76
Author(s):  
Philippe Mariage ◽  
M.M. Handeme Nguema ◽  
Laurent Clavier

The aim of this paper is to study the feasibility of getting information from a cargo van returning back on its storage area by using a low cost communication system. According to the low speed of the vehicle and to the involved short distances, a UHF RFID solution is considered. An experimental study shows that passive tags may be read successfully but not in the entire space of the van. A semi-empirical numerical method based on the Geometrical Optics is derived in order to build a fast computer aided-positioning tool that may help to optimize the location of the tags. The same software tool is used for carrying out a parametric study that informs on the best antenna system to use. It is find out that a solution using passive tags and two antennas limits the theoretical results to 90% successful reading percentage whereas using semi-passive tags ensures a 100% one in the whole space of the vehicle.


2020 ◽  
Author(s):  
Xiao Chen ◽  
Yi Xiong ◽  
Yinbo Liu ◽  
Yuqing Chen ◽  
Shoudong Bi ◽  
...  

Abstract Background: As one of the most common post-transcriptional modifications (PTCM) in RNA, 5-cytosine-methylation plays important roles in many biological functions such as RNA metabolism and cell fate decision. Through accurate identification of 5-methylcytosine (m5C) sites on RNA, researchers can better understand the exact role of 5-cytosine-methylation in these biological functions. In recent years, computational methods of predicting m5C sites have attracted lots of interests because of its efficiency and low-cost. However, both the accuracy and efficiency of these methods are not satisfactory yet and need further improvement. Results: In this work, we have developed a new computational method, m5CPred-SVM, to identify m5C sites in three species, H. sapiens, M. musculus and A. thaliana. To build this model, we first collected benchmark datasets following three recently published methods. Then, six types of sequence-based features were generated based on RNA segments and the sequential forward feature selection strategy was used to obtain the optimal feature subset. After that, the performance of models based on different learning algorithms were compared, and the model based on the support vector machine provided the highest prediction accuracy. Finally, our proposed method, m5CPred-SVM was compared with several existing methods, and the result showed that m5CPred-SVM offered substantially higher prediction accuracy than previously published methods. It is expected that our method, m5CPred-SVM, can become a useful tool for accurate identification of m5C sites.Conclusion: In this study, by introducing position-specific propensity related features, we built a new model, m5CPred-SVM, to predict RNA m5C sites of three different species. The result shows that our model outperformed the existing state-of-art models. Our model is available for users through a web server at http://zhulab.ahu.edu.cn/m5CPred-SVM.


2013 ◽  
Vol 4 (1) ◽  
pp. 86-96
Author(s):  
Pranav Shrestha

The design of any physical product involves prototyping. Building physical prototypes of the products can be expensive and time consuming. An alternate to physical prototyping is haptic virtual prototyping, which simulates the product using a computer and a haptic device. A haptic device is one that produces the forces similar to that of the product, giving the user a realistic feel of the product. Since the feel of a product plays a significant role in its commercial success, the importance of haptic virtual prototyping as a design tool is increasing. This paper discusses the haptic simulation of a push button on a low cost and commercially available haptic device called Novint Falcon.  Two different models were created – the first one was a simple push button, and the second was an on/off click button. The parameters of the two models were selected such that they have the most accurate tactile response or feel of the product. The two models successfully simulated the feel of the buttons, and it was found that haptic virtual prototyping of buttons is achievable using a low cost haptic interaction system.


2020 ◽  
Author(s):  
Jeffrey Sanders ◽  
Carla E. Estridge ◽  
Matthew B Jackson ◽  
Thomas JL Mustard ◽  
Samuel J. Tucker ◽  
...  

Thermoset polymers are an area of intense research due to their low cost, ease of processing, environmental resistance, and unique physical properties. The favorable properties of this class of polymers have many applications in aerospace, automotive, marine, and sports equipment industries. Molecular simulations of thermosets are frequently used to model formation of the polymer network, and to predict the thermomechanical properties. These simulations usually require custom algorithms that are not easily accessible to non-experts and not suited for high throughput screening. To address these issues, we have developed a robust cross-linking algorithm that can incorporate different types of chemistries and leverage GPU-enabled molecular dynamics simulations. Automated simulation analysis tools for cross-linking simulations are also presented. Using four well known epoxy/amine formulations as a foundational case study and benzoxazine as an example of how additional chemistries can be modeled, we demonstrate the power of the algorithm to accurately predict curing and thermophysical properties. These tools are able to streamline the thermoset simulation process, opening up avenues to in-silico high throughput screening for advanced material development.


Author(s):  
Paul G. Lee ◽  
Daeyong Lee ◽  
Gary A. Gabriele

Abstract The proper use of integral attachment features in mechanical assemblies has been more of an art than an engineering science. An organized set of design steps for generating conceptual integral attachment designs has recently been developed based on work begun by Bonenberger. These steps outline a formal design methodology for exploring the design space of possible alternative attachment concepts. This paper describes the development of a software tool that attempts to implement the integral attachment design methodology to assist a designer in developing attachment concepts. The tool is implemented using the Java programming language. A graphical interface is used to present the methodology as a series of options that approximate the design situation. This hides many of the details of the methodology in favor of ease of use. The end result is a set of suggestions for integral fasteners that are matched to the design situation. A discussion of how the hundreds of images are handled using Java is provided. A sample case study illustrates the approach of the program. The tool represents one of the few examples of a design tool aimed specifically at generating design concepts.


10.14311/754 ◽  
2005 ◽  
Vol 45 (4) ◽  
Author(s):  
P. Kaňovský ◽  
L. Smrcek ◽  
C. Goodchild

The study described in this paper deals with the issue of a design tool for the autopilot of an Unmanned Aerial Vehicle (UAV) and the selection of the airdata and inertial system sensors. This project was processed in cooperation with VTUL a PVO o.z. [1]. The feature that distinguishes the autopilot requirements of a UAV (Figs. 1, 7, 8) from the flight systems of conventional manned aircraft is the paradox of controlling a high bandwidth dynamical system using sensors that are in harmony with the low cost low weight objectives that UAV designs are often expected to achieve. The principal function of the autopilot is flight stability, which establishes the UAV as a stable airborne platform that can operate at a precisely defined height. The main sensor for providing this height information is a barometric altimeter. The solution to the UAV autopilot design was realised with simulations using the facilities of Matlab® and in particular Simulink®[2]. 


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