bluuebunny/crossref_metadata_2025 huggingface dataset:
Inverse dynamics and feedforward controllers for high precision position/force tracking of flexible joint robots
Authors: Jankowski Krzysztof P. , Elmaraghy Hoda A.
Published: March 2009

A nonlinear feedback control based on inverse dynamics is proposed for robots with flexible joints during constrained motion task execution. Based on constrained system formalism, the presented control scheme achieves simultaneous, independent control of both position and contact force at the robot end-effector. The method can be directly applied to robot control, or it can be used as the basis for developing other advanced control strategies. In this paper, a. feedforward controller is considered. Issues related to the practical application of the full inverse dynamics and feedforward control algorithms, such as evaluation of feedback variables, the use of predictors to eliminate the time delay of digital control, and the design of robust controllers, are discussed. The results of extensive numerical simulation are used to show the effectiveness of the proposed controllers and to compare their performances. It is shown that it is possible to achieve high precision tracking if the appropriate predictors are used to eliminate the effect of computational delay of the digital controller. Applying a straightforward approach for robustness of the proposed controllers has additionally improved the trajectory tracking accuracy.
Characteristics and signal processing of a proximity sensor
Authors: Li Y.F.
Published: March 2009

This paper presents a fibre optic proximity sensor suitable for robotic applications. The sensor characteristics are first identified through experiments. Then the signal processing problem is studied for general applications where no prior knowledge of the sensor environment is assumed. The nonlinear filtering is carried out by applying a Kalman Filter. Particular attention is paid to the target nature dependence of the sensor output. Experimental results are reported by using the sensors on a real robot system.
On flexible link manipulators: modeling and analysis using the algebra of rotations
Authors: Xi F. , Fenton R.G.
Published: March 2009

In this paper, a complete model of the elasto-kinematics is formulated in terms of a new kinematic notation, called the algebra of rotations. Based on this formulation, the elegant and concise expressions are derived for the displacement equation and especially the Jacobians governing the motion mapping between the manipulator tip and joint variables as well as link deflections. Introduction of the elasto-kinematics into the elasto-dynamics can directly take into consideration the nonlinear coupling between joint variables and link deflections, and thus improve the result of the elasto-dynamics.
Fundamental problems of robot control: Part I, Innovations in the realm of robot servo-loops
Authors: Arimoto Suguru
Published: March 2009

After the enthusiasm for creating “intelligent robots” in the early 1980's, progress of robotics research in the past decade has not fulfilled our expectations but revealed various difficulties in understanding motor control by man and implementing intelligent functions in robotic machines. To regain the initiative in the development of intelligent machines, this paper first presents a critical review of the state of the art of robot control and points out the necessity for improving robot servo-loops in order to facilitate skilled and dexterious motions in robotic manipulators and mechanical hands. It is then shown that the introduction of a quasi-natural potential in Lagrange's formulation of robot dynamics gives rise to the design of hyperstable PID servo-loops, which establish global asymptotic stability of set-point control. The hyperstability theoretical framework is then applied to the design of control commands in various control problems, such as hybrid (position/force) control, impedance control, model-based adaptive control, and learning control. In all cases, the passivity concept of residual robot dynamics plays a vital role in conjunction with the concept of feedback connections of two hyperstable nonlinear or linear blocks.
A three dimensional localiser for autonomous robot vehicles
Authors: Kleeman Lindsay
Published: March 2009

A novel design of a three dimensional localiser intended for autonomous robot vehicles is presented. A prototype is implemented in air using ultrasonic beacons at known positions, and can be adapted to underwater environments where it has important applications, such as deep sea maintenance, data collection and reconnaissance tasks. The paper presents the hardware design, algorithms for position and orientation determination (six degrees of freedom), and performance results of a laboratory prototype. Two approaches are discussed for position and orientation determination – (i) fast single measurement set techniques and (ii) computationally slower Kalman filter based techniques. The Kalman filter approach allows the incorporation of robot motion information, more accurate beacon modelling and the capability of processing data from more than four beacons, the minimum number required for localisation.
From identification to motion optimization of a planar manipulator
Authors: Gaudin H. , Bessonnet G.
Published: March 2009

Identification of inertia constants and joint frictions of a robot manipulator is achievedin situ, without dismantling operations, by means of specific test motions. The necessary estimation of actuating torques is carried out by measuring, with Hall effect transducers, the current absorbed by the motors which power the system. This identification is accomplished by using a precise methodological order adapted to a planar SCARA type manipulator with two degrees of freedom. The identification of friction laws underscores a hysteresis phenomenon of the dissipative torques. This indicates that friction doesn't result from a simple superposition of a dry friction law and a viscous damping law. The identification results were applied with success to implementation of optimized trajectories computed on the basis of a dynamic criterion. The effective minimization of the performance criterion along the optimized trajectories, according to the corresponding standard trajectories, was verified experimentally by evaluating the motor work and actuator torques.
Collision-avoidance control for redundant articulated robots
Authors: Rahmanian-Shahri N. , Troch I.
Published: March 2009

A new mathematical formulation of robot and obstacles is presented such that for on-line collision recognition only robot joint positions in the workspace are required. This reduces calculation time essentially because joint positions in workspace can be computed every time from the joint variables through robot geometry. It is assumed that the obstacles in the workspace of the manipulator are represented by convex polygons. For every link of the redundant robot and every obstacle a boundary ellipse is defined in workspace such that there is no collision if the robot joints are outside this ellipsis.

In addition to this, a collision avoidance method is presented which allows the use of redundant degrees of freedom such that a manipulator can avoid obstacles while tracking the desired end-effector trajectory. The method is based on the generalized inverse with boundary ellipse functions as optimization criteria. The method permits the tip of the hand to approach any arbitrary point in the free space while the kinematic control algorithm maximizes the boundary ellipse function of the critical link. The effectiveness of the proposed methods is discussed by theoretical considerations and illustrated by simulations of the motion of three- and four-link planar manipulators between obstacles.
A virtual sensor implementation for a flexible assembly machine
Authors: Rowland J. J. , Nicholls H. R.
Published: March 2009

We describe a sensor integration system which we have designed and implemented for a large fully-integrated flexible assembly machine. The machine was developed by a consortium to explore the design and implementation issues involved. The sensor integration system was designed for execution on a multiple transputer architecture, and co-ordinates all the sensory information in the machine. It uses the concept of virtual sensing to provide sensory data at an appropriate level of abstraction to the machine supervisor, which controls execution of the assembly tasks.
Kinematics, kinematic constraints and path planning for wheeled mobile robots
Authors: Wang Yongji , Linnett J.A. , Roberts J.
Published: March 2009

The problem associated with planning a collision-free path for a wheeled mobile robot (WMR) moving among obstacles in the workspace is investigated in this paper. A kinematic model, including the general nonholonomic constraint equation, is developed first, followed by the analysis of some general maneuvering characteristics of the WMR. The analytic solutions to the typical path curves, such as circle and straight line, which are important in the path planning problem, are also derived. From the analysis of the established kinematic model, some factors which affect the path planning problem for a WMR and therefore must be taken into account are revealed and the general description of the path planning problem for a WMR is formuated. In conclusion, a possible architecture of the algorithm for a practical WMR is presented.
Bang bang motion control of a Cartesian crane
Authors: DeSantis R. M. , Krau S.
Published: March 2009

A motion controller for an overhead Cartesian crane in three-dimensional Euclidean (3-D) space is designed under the constraint that the control action belong to a discrete set of assigned values. The design approach rests upon a two-step procedure: first, a constraintfree motion controller is determined that satisfies the required dynamic specifications; second, this controller is replaced with an equivalent controller satisfying the discrete action constraint. The first step is implemented by means of a heuristic 3-D extension of a well-proven 2-D controller, the second step by applying recent sliding mode results. Numerical simulations illustrate the properties of the resulting feedback system under both nominal and perturbed operating conditions.
Robotic arm self-taught path planning using transportation model heuristics
Authors: Fant Earnest W. , Tran Sylvia L.
Published: March 2009

The objective of this experimental research was to determine whether or not an integrated vision and robotic arm system, using grey level detection and a transportation model heuristic, could plan and execute its own point-to-point navigation. The heuristic is the shortest-route algorithm which deals with finding the smallest possible distance to visit multiple locations only once. The only point taught by a human operator was a starting position and all other points within the workspace, to be visited by the robotic arm to perform tasks such as screw-fastening, adhesive application and detailed inspection of assemblies, were learned by the system.
Terrain Exploration of a Sensor-Based Robot Moving Among Unknown Obstacles of Polygonal Shape
Authors: Chen Zen , Huang Chih-Ming
Published: March 2009

The problem of incremental terrain acquisition is addressed in this paper. Through a systematic planning of movements in an unknown terrain filled with polygonal obstacles, a sensor-based robot is shown to be able to incrementally build the entire terrain model; the model will be described in terms of visibility graph and visibility window. The terrain model is built area by area without any overlapping between explored areas. As a consequence, the terrain is obtained as a tessellation of disjoint star polygons. And the adjacency relations between star polygons are represented by a star polygon adjacency graph (SPAG graph). The incremental exploration process consists of two basic tasks: local exploration and exploration merging. Useful lemmas are derived for these two tasks and, then, the algorithms for the tasks are given. Examples are used to illustrate the algorithms. Two strategies for planning robot movements in the unknown terrain environment are suggested and compared. They are the depth-first search and the breadth-first search applied to the SPAG graph. Finally, the performance evaluation of the method and comparison with some existing methods are presented.
Towards a virtual reality-assisted movement diagnostics - an outline
Authors: Medved Vladimir
Published: March 2009

The paper proposes a concept of a movement diagnostics system of enhanced performances. The existing system, using electromyographic (EMG) and ground reaction force signals as inputs, has been applied primarily to sports locomotion evaluation and testing, providing suitable quantitative criteria. The proposed enhancement relies on movement simulation facility, incorporating subject-specific anatomical and functional data on the neuro-musculo-skeletal system of extremities. Reflecting the principles of anthropomorphic robotics, the computer graphics simulation is conceptualized to generate artificial (synthesized) movement patterns in virtual reality.

By comparing synthesized and measured signals the suitable feedback information is provided that may be used to enhance the overall system's performance. Using the power of computer technology and computer graphics, a user-friendly system of high ergonomic potentials is thus devised, in order to enhance the quality and efficacy of diagnostic procedure. The bioengineering principles used and the merging of measurement with simulation in the process of operation define a powerful instrument applicable to both healthy and pathological movement assessment.
Air jets imaging tactile sensing device for automation applications
Authors: Benhadj R. , Dawson B.
Published: March 2009

This paper details the design principles of operation of a pneumatic proximity-to-tactile sensing device for part handling and recognition in a flexible manufacturing environment. The sensing device utilises a densely packed line array of piezoresistive pressure sensors, providing continuous variable outputs. The sensing plane of the device incorporates a corresponding line array of air jets which develop an air cushion when striking a target of interest. The back pressure levels from these air jets form the basis for the task of target detection and recognition.
Development of digital stroke sensing cylinder and its performance evaluation
Authors: Yang S.Y. , Lee M.C. , Lee M.H. , Arimoto S.
Published: March 2009

Automation of heavy construction machinery needs sensors that can detect each position under severe construction fields. Motivated by this need a hydraulic cylinder equipped with Hall sensors of Ga-As type has been developed. However, this sensor device has some problems associated with incorrect detection of positions owing to the existence of some magnetic slope and electric noises. To solve these problems, this paper proposes a digital stroke sensing cylinder enhanced by digital signal processing. An apparatus of two hydraulic systems coupled with each other is installed in an experimental setup to evaluate the performance of the developed digital stroke sensing cylinder. In order to control the position of a cylinder rod, a PWM method is used. Evaluation of the performance is carried out under artificial disturbances such as an impulse, addition of some magnetic slope, and additional noises.
On avoiding singularities in redundant robot kinematics
Authors: Tchoń Krzysztof , Matuszok Aleksander
Published: March 2009

For redundant robot kinematics with a degree of redundancy 1 a self-motion vector field is examined whose equilibrium points lie at singular configurations of the kinematics, and whose orbits determine the self-motion manifolds. It is proved that the self-motion vector field is divergence-free. Locally, around singular configurations of corank 1, the self-motion vector field defines a 2-dimensional Hamiltonian dynamical system. An analysis of the phase portrait of this system in a neighbourhood of a singular configuration solves completely the question of avoidability or unavoidability of this configuration. Complementarily, sufficient conditions for avoidability and unavoidability are proposed in an analytic form involving the self-motion Hamilton function. The approach is illustrated with examples. A connection with normal forms of kinematics is established.
Control of grasp stiffness using a multifingered robot hand with redundant joints
Authors: Choi H. R. , Chung W. K. , Youm Y.
Published: March 2009

This paper addresses a method of satisfactorily controlling the grasp of objects. Emphasis is placed on achieving the desired stiffness of a grasped object as accurately as possible, especially when the fingers have redundant joints. A model describing the relation between stiffness and force is derived. Based upon this model, a hierarchical control scheme of the grasp stiffness, called decentralized object stiffness control (DOSC) is proposed. DOSC is composed of a fingertip stiffness synthesis (FSS) algorithm and orthogonal stiffness decomposition control (OSDC). Employing the proposed FSS always achieves the desired grasp stiffness by solving the constrained least square problem. The computed fingertip stiffness is achieved by OSDC. It offers a feasible way of controlling the fingertip stiffness as well as maintaining the stability of the finger configuration by modulating the joint stiffness. The developed control method is implemented on a two-fingered planar robot hand one finger of which has a redundant joint. The effectiveness of the control method is confirmed experimentally.
Modeling and path-tracking control of a mobile wheeled robot with a differential drive
Authors: DeSantis R. M.
Published: March 2009

Topics relevant to modeling and control of mobile wheeled robots with a differential drive are discussed by assuming a motion that is planar and free from lateral and longitudinal slippages, and by taking into account dynamic and kinematic properties of the vehicle. Based on the concept of geometric path-tracking, a controller is designed that is a memoryless function of the lateral, heading, and velocity path-tracking offsets. If these offsets are kept small and the assigned tracking velocity is constant, then this controller may be given a linear, time-invariant and decoupled PID (Proportional + integral + derivative) structure.
A novel differential shape memory alloy actuator for position control
Authors: Gorbet Robert B. , Russell R. Andrew
Published: March 2009

This paper discusses a novel design for a rotary differential NiTi shape memory alloy actuator, which incorporates a mobile heat sink. The new mechanism is described in detail, and its performance in a position control system is compared with that of the same actuator without heat sink. Experimental results are presented which show an improvement in actuator response time, as well as closed-loop bandwidth. The design of the mechanism gives enhanced performance, without the increased power consumption associated with fixed heat sinks.
Force control for walking on soft terrains
Authors: Lehtinen Hannu
Published: March 2009

Force control of walking machines is essential in a natural soft and uneven terrain. A load adaptive PI force control method for the hydraulic actuation system of MECANT I has been developed. The I term of the controller is changed according to the desired load. Force control satisfies the support requirement also when a leg penetrates the terrain. A method to distribute support forces in an optimal manner has been developed. A rule based altitude controller and a dead-zone and saturation based attitude controller calculates the desired body forces. Walking tests on uneven wet sand fields show the useful applicability of the method.
Trajectory planning of multiple coordinating robots using genetic algorithms
Authors: Sun Shudong , Morris A.S. , Zalzala A.M.S.
Published: March 2009

The paper focuses on the problem of trajectory planning of multiple coordinating robots. When multiple robots collaborate to manipulate one object, a redundant system is formed. There are a number of trajectories that the system can follow. These can be described in Cartesian coordinate space by an nth order polynomial. This paper presents an optimisation method based on the Genetic Algorithms (GAs) which chooses the parameters of the polynomial, such that the execution time and the drive torques for the robot joints are minimized. With the robot's dynamic constraints taken into account, the pitimised trajectories are realisable. A case study with two planar-moving robots, each having three degrees of freedom, shows that the method is effective.
Improving the accuracy of a vibratory sensor using Kalman filtering
Authors: Pham D.T. , Hafeez K.
Published: March 2009

This paper presents a Kalman filtering technique for reducing errors in locating 3-D objects using a sensor system. The location information is employed to control the motion of an industrial robot to pick up the objects. The sensor consists of a rigid platform mounted on a flexible column. Each object to be located is placed on the sensor. The static deflections and natural frequencies of vibrations of the sensor are measured and processed to determine the position and orientation of the object. In practice, the sensor signals obtained are corrupted with noise leading to errors in location determination. A Kalman filter is used to reduce the noise present in the sensor system.
Simplification of manipulator dynamic formulations utilizing a dimensionless method
Authors: Lin Yueh-Jaw , Zhang Hai-Yan
Published: March 2009

This paper presents a new approach for simplifying dynamic equations of motion of robot manipulators by using a nondimensionalization scheme. With this approach the dynamic analysis is done in a nondimensional space. That is, it is required to establish a dimensionless coordinate system in which the dynamic equations of motion of manipulators are formulated. The characteristic parameters of the manipulators are then defined by choosing proper physical quantities as basic units for nondimensionalization. Within the nondimensional space the Lagrange method is applied to the manipulator to obtain a set of general dimensionless equations of motion. This dimensionless dynamic formulation of manipulators leads to an easier way to simplify the dynamic formulation by neglecting insignificant terms using the order of magnitude comparison. The dimensionless dynamic model and its simplified version of PUMA 560 robot are implemented using the proposed approach. It is found that the simplified dynamic model greatly reduces the computation burden of the inverse dynamics. Simulation results also show that the simplified model is extremely accurate. This implies that the proposed nondimensional simplification emethod is reliable.
Robotics for health care: a review of the literature
Authors: Kassler Michael
Published: March 2009

This paper surveys the scientific literature on present and future applications of robotics to health care. The term ‘health care’ refers to different forms of assistance rendered to people who are unable without such assistance to perform physical tasks that ‘healthy’ people accomplish unaided. Research efforts and accomplishments to date are concentrated in four main application areas: rehabilitation; patient transfer; assistance to surgery; and ‘microrobots’ suitable for use inside people. Some initial work has been done in other areas including robotic diagnosis and therapy.
Mechanical concept of the neurosurgical robot ‘Minerva’
Authors: Glauser D. , Flury P. , Burckhardt C. W.
Published: March 2009

We describe a robot capable of performing all procedures necessary to carry out a complete stereotactic neurosurgical operation under the control and supervision of a surgeon. The operation consists of the introduction of a small probe with diameter 2–3 mm through a hole without trepanation. The robot has been built and is now being tested and evaluated. The accompanying control software as well as various medical probes are either in development or partially tested. The installation will be able to carry out a complete intervention under the surveillance of a computed tomography scanner. In this article we emphasize the design choices required to eliminate gearing backlash in a crucial degree of freedom.
Measurement of robustness for biped locomotion using a linearized Poincaré map
Authors: Cheng M. -Y. , Lin C. -S.
Published: March 2009

Many studies on control of dynamic biped walking have been done in the past two decades. While the biped dynamics is highly nonlinear, the stability analysis, if done, is usually based on a linearized model. The validity of the linearized model may become questionable if the walking involves states that are too far away from the operating point. In this paper, an approach for evaluating the robustness based on the linearized Poincare map is suggested and examined. The Poincare map is a useful tool to investigate the periodic motion of a dynamic system. Using the Poincare“ map, one can study an associated discrete time map instead of studying the continuous time system directly. Investigation of stability of a periodic motion can be reduced to the study of the stability of a fixed point of the Poincaré map. The computational method that results in a measurement for evaluating the robustness of biped locomotion is developed. Our simulation study has verified that the suggested measurement is a good indicator.
Manipulating robots along helical trajectories
Authors: Selig J. M. , Ovseevitch A. I.
Published: March 2009

Current industrial robots are highly non-linear systems. However, the control strategies in most commercially available robots largely ignore the non-linearity. The resulting linear approximations are only valid at low speeds. Any improvement would allow robots to move faster and hence be more productive. There has been much academic research into robot control, but this has almost always separated the control and the trajectory planning. In this work we seek to combine these tasks and hence simplify the computations required. We investigate how to control a general robot in such a way that it's gripper follows straight line, circular or helical paths. These simple paths are both one parameter subgroups for the group of proper rigid motions and geodesies for certain metrics on the group. This suggests a non-linear feedback control law which turns the closed loop dynamics of the robot into the equations for geodesies. Although these equations are not completely stable we are able to modify the control law so that the resulting closed loop dynamics are stable. Hence, the end-effector of the robot will follow straight line, helical or circular trajectories.
A method for controlling robotic contact tasks
Authors: Payandeh Shahram
Published: March 2009

In robotic tasks where the manipulator has to make transition from free space motion to constrained one, there always exists a inevitable impact phase (contact transition phase). Examples can be the autonomous exploratory motion of the end-effector in a cluttered environment, or grasping and manipulation of objects using dexterous mechanical end-effector. A number of controllers have been proposed in the literature with various discussions on their practical implications. In this paper a simple and efficient controller is proposed for the robotic contact tasks. The controller is based on the notion of switching control law where the structure of the controller remains unchanged during the phase transition and only the magnitudes of its gains are changed. The proposed control law maintans the stable performance during the impact phase of the manipulator when making contact with general environment. In addition, the controller exhibits stable and robust performance during the post-contact phase with the desired contact force regulation. The stability of the proposed controller is shown using the Lyapunov method which guarantees the exponential rate of convergence of the state during the contact transition to post-contact phase. Experimental results are presented to demonstrate the practicality of the proposed controller.
Static and dynamic modelling of a two-flexible-link robot manipulator
Authors: Morris A.S. , Madani A.
Published: March 2009

This paper is addressed at the difficulty of accurately modelling a two-flexible-link manipulator system, which is a necessary pre-requisite for future work developing a high-performance controller for such manipulators. Recent work concerned with the development of an accurate single-flexible-link model is first reviewed and then the expansion of a single-link model into a two-flexible-link system in a way which properly takes into account the coupling and interactions between the two links is discussed. The method of approach taken is to calculate the elastic and rigid motions of the links separately and then to combine these according to the principle of superposition. The application of the model developed is demonstrated in a simulated two-flexiblelink system.
Causal inverse dynamics of a flexible hub-arm system through Liapunov's second method
Authors: Ata Atef , Elkhoga Salwa , Shalaby Mohamed , Asfour Shihab
Published: March 2009

The main objective of this work is to study the performance of a flexible single hub-arm system. The equations of motion are derived using the extended Hamilton principle. The Liapunov functional is used as a condition for the stability analysis. The Liapunov functional is considered as the sum of the internal energy of the flexible beam. The required drive torque was obtained directly through the solution of the inverse dynamic problem. Although the flexible link is nonminimum phase in nature, the use of Liapunov and the PD controller guarantee the causality for the stable case. The effects of tip mass as well as its inertia in the case of stable and asymptotic stable systems were investigated to ensure the validity of this procedure.
Kinematic calibration using the product of exponentials formula
Authors: Okamura Koichiro , Park F.C.
Published: March 2009

We present a method for kinematic calibration of open chain mechanisms based on the product of exponentials (POE) formula. The POE formula represents the forward kinematics of an open chain as a product of matrix exponentials, and is based on a modern geometric interpretation of classical screw theory. Unlike the kinematic representations based on the Denavit- Hartenberg (D-H) parameters, the kinematic parameters in the POE formula vary smoothly with changes in the joint axes, ad hoc methods designed to address the inherent singularities in the D-H parameters are therefore unnecessary. Another important advantage is that simple closed-form expressions can be obtained for the derivatives of the forward kinematic equations with respect to the kinematic parameters. After introducing the POE formula, we derive a least-squares kinematic calibration algorithm for general open chain mechanisms. Simulation results with a 6-axis open chain are presented.
Secondary school specialization in robotics and FMS: A practical experience (a viewpoint)
Authors: Miljakovic-Jevtic I. , Potkonjak Veljko
Published: March 2009

This paper deals with the problems of the education of the staff in robotics and flexible automation at the secondary school level. It deals with an experiment which aims at training technicians for robotics and flexible manufacturing systems. The experiment began in 1989. and now the second generation of students that studies according to the curricula of this experiment has completed the education. Previous experience, especially from the standpoint of the result of the students and problems that arise during the realization of the experiment, are analyzed in this text.
R & D Profile: Robotics Laboratory of the Mihailo Pupin Institute, Beograd, Yugoslavia
Authors: Vukobratovich Miomir
Published: March 2009

The Mihailo Pupin Institute is among the largest and most eminent research organizations in technical sciences in Yugoslavia. Founded in 1946 as the Telecommunications Institute of the Serbian Academy of Sciences and Arts, it was given its present name 13 years later. In the Institute's early days the personnel, about one hundred employees, just a few of them researchers, has grown to more than 850 employees, 300 of them researchers, working in a 15,000 sq. meters modern research center.
Mobile microrobots
Authors: Shimoyama Isao , Yasuda Takashi , Miura Hirofumi , Kubo Fujisawa Yayoi , Ezura Yuichi
Published: March 2009

This paper discusses suitable mechanisms and functions of a mobile microrobot from the point of view ofscale effects. Several assumptions are made using animalscaling. A large scale model is shown to demonstrate these mechanisms. Moreover, microsized models have been built on silicon wafers by using polysilicon as rigidplates and polyimide as elastic joints. The results showthat suitable mechanisms and functions may be different from those of a conventional robot.
A discrete-event systems approach to modeling dextrous manipulation
Authors: Ricker S.L. , Sarkar N. , Rudiet K.
Published: March 2009

To perform dextrous manipulation efficiently, it is necessary to coordinate the interactions of many component processes. This paper investigates one approach to coordination: discrete-event systems. The applicability of discrete-event systems to the modeling of dextrous manipulation tasks is studied. Discrete-event control theory offers formal methods for determining whether a coordinator of the components can be generated. A representative dextrous manipulation task, the planar Grasp-Lift-Replace task of Howe and Cutkosky, is presented as a discrete-event process. The task is extended to include two-fingered exploratory procedures. The effectiveness of the discrete-event system approach is illustrated through simulations of several test cases.
Simultaneous velocity, impact and force control
Authors: Zotovic Stanisic Ranko , Valera Fernández Ángel
Published: March 2009

In this paper, we propose a control method to achieve three objectives simultaneously: velocity regulation during free motion, impact damping and finally force reference tracking. During impact, the parameters are switched in order to dissipate the energy of the system as fast as possible and the optimal switching criteria are deduced. The possibility of sliding regimes is analysed and the theoretical results are verified in simulations.
The Changing Environment of Health Care
Authors: Blanpain Jan E.
Published: March 2009

It has been repeated ad nauseam in recent years that health care is changing rapidly. Today even the pattern of change itself is in flux: modifications seem to be accelerating and shifts are of a more profound nature. Moreover, the prevailing changes are highly interactive and send ripples through a health care arena which presents all the symptoms of turmoil.
The Consensus Development Program of the National Institutes of Health
Authors: Jacoby Itzhak
Published: March 2009

This paper recounts the origins of consensus development as a means of technology assessment and traces the evolution of the process from its rather amorphous and variable beginnings to the codified and consistent model of today. Where appropriate, evaluative findings and anecdotal observations will be recounted.
Trends in the Diffusion of Selected Medical Technology in the Federal Republic of Germany
Authors: Schicke R. K.
Published: March 2009

This article contends that the German social and economic situation is conducive to the rapid diffusion of innovative medical technology. While there is public control over hospital facilities, the pluralistic health care system and decentralized government responsibilities contribute to an essentially laissez faire regulatory environment. There is perfunctory planning and regulation for major medical expenditures, but the essential constraints are financial. This is no comprehensive program for the assessment of diagnostic technologies and the effective imposition of guidelines depends on the cooperative effort of various financing organizations, professional interests, and public pressure groups.
Economic Forces and Hospital Technology
Authors: Goddeeris John H.
Published: March 2009

This paper considers economic forces on the organization and use of technology in hospitals from a U.S. perspective. U.S. hospitals are moving from a period of very loose financial constraints to one in which the demand side of the market is likely to exert much greater discipline. Theory and limited evidence suggest some important effects on the adoption and use of technology, leading in general to more emphasis on cost reduction and less emphasis on costly quality improvements. Also discussed are economic influences on the movement of technology out of the hospital and on the development of new technologies. Finally, some peculiarities of very high cost technologies are noted.
Integrating Ancient and Modern Medicine in Chinese Hospitals
Authors: Chen Hao-Hui
Published: March 2009

Modern industrial society and its industrial processes can sometimes discourage the practice of traditional medicine. The existence and use of traditional Chinese medicine for several thousands of years indicates that it has sound elements. As has been true with features of other ancient, highly developed civilizations, the discipline of traditional Chinese medicine offers a valuable resource in the treatment and prevention of disease. Its scientific aspects and valuable experiences must continue to be developed according to Western scientific methodology. China has initiated a program to utilize modern industrialized technology in the integration of the traditional Chinese and modern Western medical systems. The policy and process aimed at integrating traditional Chinese medicine with Western medicine are presented in this paper.These measures have resulted in considerable utilization and development of the traditional Chinese medicine system, and have had a major impact on the development of public health care, as well as medical technology and science. The positive interactions between these fields of study and existing problems are discussed, and some comments on future expectations are presented.
Reflections on Medical Technology as a Special Type of Capital
Authors: Field Mark G.
Published: March 2009

The classical equation for the production of goods and services, that is, the combination of labor, capital, and knowledge, constrained by the time dimension, may also be used to examine the production of medical and hospital services. However, this is qualified by the special nature of the “capital” used in health care, particularly medical technology. Because of the particular nature of health services, the adoption and the use of technology follows rules that are different from those in the industrial sphere. These differences are examined in some detail as are the implications for the health field in general, and for the hospitals where most of the new (and often costly) technology is located.
American College of Physicians Begins Planning for Physicians Network
Authors: Radany Margaret Higgins
Published: March 2009

In September 1986, the American College of Physicians initiated the planning phase of its Physicians Network, an effort aimed at tapping the resources of the College's membership to collect information on physician practice patterns and their relationship to the outcomes of care. Funding for the planning has been approved by the Henry J. Kaiser Family Foundation, Menlo Park, California, and will support the 15 month project.
Ernest Amory Codman, M.D., and End Results of Medical Care
Authors: Neuhauser Duncan
Published: March 2009

Ernest Amory Codman, M.D., was one of the most important figures in the history of outcomes research in medicine. While his contemporaries scorned his efforts to create systematic procedures to evaluate the end results of medical care, his work foreshadowed many of today's most pressing issues in technology assessment. This arti traces Codman's career as an innovator and political gadfly at the Massachusetts General Hospital during the first three decades of this century, and examines the development and demise of his end-result system.
Present and Future Value of Dental Composite Materials and Sealants
Authors: Dogon I. Leon
Published: March 2009

This article reviews the development, composition, chemistry, recent technological advances, and extent of use of composite resin restorative materials, adhesives, and pit and fissure sealants. The problems related to the clinical behavior of these materials in the oral environment are dealt with, and methods of minimizing their present deficiencies are suggested. Future directions that might be taken to improve these materials and solve some of the inadequacies that these materials exhibit are also discussed.
Analysis of The National Institutes of Health Medicare Coverage Assessment
Authors: Dubinsky Michael , Ferguson John H.
Published: March 2009

The National Institutes of Health (NIH) is periodically asked to conduct assessments of new medical technologies to assist in coverage decisions made at the Office of Health Technology Assessment (OHTA) for the Health Care Financing Administration coverage policy. Analysis of NIH assessments indicates that even though most NIH assessments rely only on expert opinion, OHTA agreed with NIH recommendaations in over 90%.
Diagnostic Imaging in Small Hospitals
Authors: Racoveanu N. T. , Fresle D. A.
Published: March 2009

Diagnostic imaging in small hospitals is discussed. Four key questions are answered: (1) Are diagnostic imaging technologies necessary at this level? (2) Which technologies should be chosen and why? (3) How can they be most rationally and cost effectively used? (4) How can their total impact on health care be assessed? The paper concludes that small hospitals should have diagnostic imaging facilities and that the modalities of choice are diagnostic radiology and ultrasonography. A detailed description is given of the WHO Basic Radiological System and General Purpose Ultrasonographic equipment together with WHO recommendations for the rational use of diagnostic imaging.
The Ethics and Feasibility of Randomized Trials of Diagnostic Technology: A Reply
Authors: Guyatt Gordon H. , Drummond Michael F.
Published: March 2009

Drs. Weinstein and Wulff (in issue 1:3) have raised legitimate and important concerns about the ethical acceptability and feasibility of randomized control trials (RCTs) of diagnostic technologies. Their criticisms are all the more compelling in light of their strong advocacy of rigorous evaluation, and their insights into the advantages of RCTs and potential problems with alternative approaches as outlined with great clarity in Dr. Weinstein's paper. We shall not attempt a point by point rebuttal (partly because we are in full or partial agreement with most of their comments) but instead will highlight several issues which we believe merit further discussion.
Policies Regarding Treatment of End-Stage Renal Disease in the United States and United Kingdom
Authors: Marine Susan Klein , Simmons Roberta G.
Published: March 2009

The treatment of End-Stage Renal Disease (ESRD) represents a victory for medical technology. Dialysis and kidney transplantation, developed in the early 1960s, offer alternative treatments to patients whose own kidneys no longer function; before, these patients faced a terminal diagnosis. Dialysis is a mechanical treatment in which the patient is connected to a machine that cleanses the blood of impurities and returns it to the body. Although recent innovations (e.g., continuous ambulatory peritoneal dialysis—CAPD) facilitate patient independence from a machine, replacement of the diseased kidneys is the most desirable and least expensive treatment for many patients (33;39). Kidney transplantation remains the most effective and common type of transplantation, and a new kidney (from a living-related or cadaver donor) often dramatically improves the recipient's health and general well-being (20;39). Now, in the mid-1980s, these technologies are no longer new and innovative. Further analysis of these established but costly technologies provides a perspective on the long-range implications of innovations in patient care: while some new issues have emerged, many problems originally associated with these treatments seem to have intensified. Access to treatment remains a central issue, closely linked to the dilemma of equity versus cost. The contrast in the access provided by the United States and Great Britain is dramatic (40); in 1982, the rate of ESRD treatment within the U.S. was twice that of the U.K. (353 versus 160 patients per million) (37). The U.S. policy is basically one of unlimited access, whereas the U.K. has restricted access.
The Biological Revolution and Its Cultural Context
Authors: Kaye Howard L.
Published: March 2009

In a recent article in Commentary, American medical sociologist Florence Ruderman observes that the evolution of medical practice and medical attitudes in the United States has been guided largely by the autonomous development of biomedical science and technology. “Science”, she asserts:

… is a profoundly unsettling force … it causes endless dislocations and conflicts. Most basically, science is a source of independent values, motives, norms of conduct, and criteria of judgment. It sets its own course, defines its own goals. As for technology, its impact on medicine is even more obvious and direct; again, not just in producing tools or power but in transmitting values and in shaping the field from within. One need only think of the artificial-heart cases now in the news to realize that the physicians involved … are impelled by a technological drive that has its own logic and values, its own momentum—and its own dangers (24,45).
Evolution and Current Status of the Orphan Drug Act
Authors: Asbury Carolyn H.
Published: March 2009

The 1983 Orphan Drug Act was designed in response to market and regulatory disincentives that limited industrial interest in developing drugs needed by people in the United States with rare diseases and conditions. These disincentives evolved from changes in the pharmaceutical industry and in regulatory testing requirements. In the eight years since the Act and subsequent amendments have been in effect, the law has been associated with the new development and approval of 40 marketed drugs and 12 biologicals to treat rare (orphan) diseases. An additional 281 drugs and 141 biologicals have been entered into development and designated as orphans. Finally, the law has mandated exploration of whether the incentives of the Act are necessary and appropriate for stimulating industrial development of orphan medical drugs and devices. Despite this progress, controversies have arisen over three profitable orphan products that have benefited from the law's provisions. This has created the need for continued assessment of the Act's benefits and costs.
Clinical Pet Scanning: A “Short-lived” Orphan
Authors: Coleman R. Edward , Briner William H. , Siegel Barry A.
Published: March 2009

Positron emission tomography (PET) is a method of nuclear medicine imaging that uses short-lived radiopharmaceuticals to detect and quantify the metabolic abnormalities of disease processes. PET initially was developed in a research environment as a research tool; data from these research studies resulted in the gradual recognition that PET studies would be useful for various routine clinical applications. The diffusion of PET into clinical practice has been slow in comparison with other new imaging methods (e.g., magnetic resonance imaging). This slow diffusion is attributable to several factors, including the complexity and high cost of PET, the uncertain role of the U.S. Food and Drug Administration in regulating the radiopharmaceuticals that are produced and used on-site for PET studies, and the apparent slow pace at which the Health Care Financing Administration and other third-party payers are developing policies for reimbursing for PET.