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1 – 10 of 43This study aims to solve the problems of low flow rate and low efficiency of micropumps in high-frequency applications. This micropump system was proposed to meet the requirements…
Abstract
Purpose
This study aims to solve the problems of low flow rate and low efficiency of micropumps in high-frequency applications. This micropump system was proposed to meet the requirements of 1–5 ml/min for microthrusters or drug delivery devices.
Design/methodology/approach
In this paper, a comprehensive analysis indicator and numerical procedure were disclosed and used to demonstrate the fluid dynamic characteristics and performance of a micropump. Accordingly, the reliability of the two-way coupling calculation was ensured through mutual verification of the real structure and the numerical system.
Findings
The research results indicate that the Polydimethylsiloxane (PDMS) microchannel can realize the contraction and expansion mechanism, allowing the fluid to generate different levels of pressure gradient during the working stroke and also enhancing the characteristics of energy consumption and storage of the flow field.
Originality/value
The pressure gradient between the fluid and PDMS microchannel can facilitate the improvement of the fluid backflow in a micropump. Therefore, in terms of performance improvement, the PDMS micropump increased the maximum backflow and optimum efficiency by approximately 50 and 90%, respectively.
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This bibliography is offered as a practical guide to published papers, conference proceedings papers and theses/dissertations on the finite element (FE) and boundary element (BE…
Abstract
This bibliography is offered as a practical guide to published papers, conference proceedings papers and theses/dissertations on the finite element (FE) and boundary element (BE) applications in different fields of biomechanics between 1976 and 1991. The aim of this paper is to help the users of FE and BE techniques to get better value from a large collection of papers on the subjects. Categories in biomechanics included in this survey are: orthopaedic mechanics, dental mechanics, cardiovascular mechanics, soft tissue mechanics, biological flow, impact injury, and other fields of applications. More than 900 references are listed.
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Teleoperated minimally invasive surgical robots can significantly enhance a surgeon's accuracy, dexterity and visualization. However, current commercially available systems do not…
Abstract
Teleoperated minimally invasive surgical robots can significantly enhance a surgeon's accuracy, dexterity and visualization. However, current commercially available systems do not include significant haptic (force and tactile) feedback to the operator. This paper describes experiments to characterize this problem, as well as several methods to provide haptic feedback in order to improve surgeon's performance. There exist a variety of sensing and control methods that enable haptic feedback, although a number of practical considerations, e.g. cost, complexity and biocompatibility, present significant challenges. The ability of teleoperated robot‐assisted surgical systems to measure and display haptic information leads to a number of additional exciting clinical and scientific opportunities, such as active operator assistance through “virtual fixtures” and the automatic acquisition of tissue properties.
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Asmaa F. Elelamy, Nasser S. Elgazery and R. Ellahi
This paper aims to investigate a mathematical model with numerical simulation for bacterial growth in the heart valve.
Abstract
Purpose
This paper aims to investigate a mathematical model with numerical simulation for bacterial growth in the heart valve.
Design/methodology/approach
For antibacterial activities and antibodies properties, nanoparticles have been used. As antibiotics are commonly thought to be homogeneously dispersed through the blood, therefore, non-Newtonian fluid of Casson micropolar blood flow in the heart valve for two dimensional with variable properties is used. The heat transfer with induced magnetic field translational attraction under the influence of slip is considered for the resemblance of the heart valve prosthesis. The numeral results have been obtained by using the Chebyshev pseudospectral method.
Findings
It is proven that vascular resistance decreases for increasing blood velocity. It is noted that when the magnetic field will be induced from the heart valve prosthesis then it may cause a decrease in vascular resistance. The unbounded molecules and antibiotic concentration that are able to penetrate the bacteria are increased by increasing values of vascular resistance. The bacterial growth density cultivates for upswing values of magnetic permeability and magnetic parameters.
Originality/value
To the best of the authors’ knowledge, this is the first study to investigate a mathematical model with numerical simulation for bacterial growth in the heart valve.
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Ivo A.M.J. Broeders and Jelle Ruurda
The introduction of laparoscopy in surgery offered clear advantages to patients. Surgeons, however, had to deal with various types of problems inherent to the essential…
Abstract
The introduction of laparoscopy in surgery offered clear advantages to patients. Surgeons, however, had to deal with various types of problems inherent to the essential differences in surgical approach. One of these problems, reduced dexterity, was solved at the end of the previous decade by the introduction of robotic surgery systems. Discusses the backgrounds for development of the Intuitive Surgical “Da Vinci” systems and gives an overview of current status and functionality.
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The results of five experiments on design of work stations are discussed. The first two experiments investigated the effects of work surface height on performance, the third…
Abstract
The results of five experiments on design of work stations are discussed. The first two experiments investigated the effects of work surface height on performance, the third investigated eye‐hand coordination at two heights and directions of movement, the fourth investigated both height and direction of movement, and the fifth studied the effect of angle and direction (in versus out) of movement. It was found that the optimum height is about one inch below the elbow. The effect of angle at a height is important: the best moves for a right‐hand movement are at 45 degrees.
The XTRA access system is aimed at making the interaction with expert systems much easier for inexperienced users. It communicates with the user in a natural language (German…
Abstract
The XTRA access system is aimed at making the interaction with expert systems much easier for inexperienced users. It communicates with the user in a natural language (German) extracting data relevant to the expert system from the natural language input. It answers users' queries concerning the terminology used and provides what the developers describe as “User‐accommodated natural‐language verbalisations of results and explanations provided by the expert system”. This development is described by J. Allgayer, K. Harbusch, A. Kobsa, C. Reddig, N. Reithinger and D. Schmauks in the International Journal of Man‐Machine Studies, Vol. 31, Part 2, August 1989, pp. 161–95. The developers of this system have introduced a number of novel artificial intelligence techniques. These have included the combination of natural language user input and user gestures on the terminal screen. Four different knowledge sources aid referent identification and simultaneous communication of the access system with the user and the expert system have been incorporated.
SELECTED by the European Council of the International Committee for Scientific Management (C.I.O.S.) to organise the first European Conference devoted entirely to management…
Abstract
SELECTED by the European Council of the International Committee for Scientific Management (C.I.O.S.) to organise the first European Conference devoted entirely to management problems, the British Institure of Management has risen nobly to the occasion with a three‐day programme full of interest and variety within the main framework of the conference theme. It is hoped that representatives from no less than fourteen European countries will attend.
Paul W. Cleary, Raymond C.Z. Cohen, Simon M. Harrison, Matthew D. Sinnott, Mahesh Prakash and Stuart Mead
The purpose of this paper is to show how simulation of the flow of particulates and fluids using discrete element modelling (DEM) and smoothed particle dynamics (SPH) particle…
Abstract
Purpose
The purpose of this paper is to show how simulation of the flow of particulates and fluids using discrete element modelling (DEM) and smoothed particle dynamics (SPH) particle methods, offer opportunities for better understanding the dynamics of flow processes.
Design/methodology/approach
DEM and SPH methods are demonstrated in a broad range of computationally‐demanding applications including comminution, biomedical, geophysical extreme flow events (risk/disaster modelling), eating of food by humans and elite water‐based sports.
Findings
DEM is ideally suited to predicting industrial and geophysical applications where collisions between particles are the dominant physics. SPH is highly suited to multi‐physics fluid flow applications in industrial, biophysical and geophysical applications. The advantages and disadvantages of these particle methods are discussed.
Research limitations/implications
Research results are limited by the numerical resolution that can currently be afforded.
Practical implications
The paper demonstrates the use of particle‐based computational methods in a series of high value applications. Enterprises that share interests in these applications will benefit in their product and service development by adopting these methods.
Social implications
The ability to model disasters provides governments and companies with the opportunity and obligation to use these to render knowable disasters which were previously considered unknowable. The ability to predict the breakdown of food during eating opens up opportunities for the design of superior performing foods with lower salt, sugar and fat that can directly contribute to improved health outcomes and can influence government food regulatory policy.
Originality/value
The paper extends the scale and range of modelling of particle methods for demanding leading‐edge problems, of practical interest in engineering and applied sciences.
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Ray O. Prather, Alain Kassab, Marcus William Ni, Eduardo Divo, Ricardo Argueta-Morales and William M. DeCampli
Predictive models implemented in medical procedures can potentially bring great benefit to patients and represent a step forward in targeted treatments based on a patient’s…
Abstract
Purpose
Predictive models implemented in medical procedures can potentially bring great benefit to patients and represent a step forward in targeted treatments based on a patient’s physiological condition. It is the purpose of this paper to outline such a model.
Design/methodology/approach
A multi-scale 0D-3D model based on patient specific geometry combines a 0-dimensional lumped parameter model (LPM) with a 3D computational fluid dynamics (CFD) analysis coupled in time, to obtain physiologically viable flow parameters.
Findings
A comparison of physiological data gathered from literature with flow-field measurements in this model shows the viability of this method in relation to potential predictions of pathological flows repercussions and candidate treatments.
Research limitations/implications
A limitation of the model is the absence of compliance in the walls in the CFD fluid domain; however, compliance of the peripheral vasculature is accounted for by the LPM. Currently, an attempt is in progress to extend this multi-scale model to account for the fluid-structure interaction of the ventricular assist device vasculature and hemodynamics.
Originality/value
This work reports on a predictive pulsatile flow model that can be used to investigate surgical alternatives to reduce strokes in LVADs.
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