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Sample records for robust randomised controlled

  1. Robust Adaptive Control

    NASA Technical Reports Server (NTRS)

    Narendra, K. S.; Annaswamy, A. M.

    1985-01-01

    Several concepts and results in robust adaptive control are are discussed and is organized in three parts. The first part surveys existing algorithms. Different formulations of the problem and theoretical solutions that have been suggested are reviewed here. The second part contains new results related to the role of persistent excitation in robust adaptive systems and the use of hybrid control to improve robustness. In the third part promising new areas for future research are suggested which combine different approaches currently known.

  2. Robust control of accelerators

    SciTech Connect

    Johnson, W.J.D. ); Abdallah, C.T. )

    1990-01-01

    The problem of controlling the variations in the rf power system can be effectively cast as an application of modern control theory. Two components of this theory are obtaining a model and a feedback structure. The model inaccuracies influence the choice of a particular controller structure. Because of the modeling uncertainty, one has to design either a variable, adaptive controller or a fixed, robust controller to achieve the desired objective. The adaptive control scheme usually results in very complex hardware; and, therefore, shall not be pursued in this research. In contrast, the robust control methods leads to simpler hardware. However, robust control requires a more accurate mathematical model of the physical process than is required by adaptive control. Our research at the Los Alamos National Laboratory (LANL) and the University of New Mexico (UNM) has led to the development and implementation of a new robust rf power feedback system. In this paper, we report on our research progress. In section one, the robust control problem for the rf power system and the philosophy adopted for the beginning phase of our research is presented. In section two, the results of our proof-of-principle experiments are presented. In section three, we describe the actual controller configuration that is used in LANL FEL physics experiments. The novelty of our approach is that the control hardware is implemented directly in rf without demodulating, compensating, and then remodulating.

  3. Robust control of accelerators

    NASA Astrophysics Data System (ADS)

    Joel, W.; Johnson, D.; Chaouki, Abdallah T.

    1991-07-01

    The problem of controlling the variations in the rf power system can be effectively cast as an application of modern control theory. Two components of this theory are obtaining a model and a feedback structure. The model inaccuracies influence the choice of a particular controller structure. Because of the modelling uncertainty, one has to design either a variable, adaptive controller or a fixed, robust controller to achieve the desired objective. The adaptive control scheme usually results in very complex hardware; and, therefore, shall not be pursued in this research. In contrast, the robust control method leads to simpler hardware. However, robust control requires a more accurate mathematical model of the physical process than is required by adaptive control. Our research at the Los Alamos National Laboratory (LANL) and the University of New Mexico (UNM) has led to the development and implementation of a new robust rf power feedback system. In this article, we report on our research progress. In section 1, the robust control problem for the rf power system and the philosophy adopted for the beginning phase of our research is presented. In section 2, the results of our proof-of-principle experiments are presented. In section 3, we describe the actual controller configuration that is used in LANL FEL physics experiments. The novelty of our approach is that the control hardware is implemented directly in rf. without demodulating, compensating, and then remodulating.

  4. Supported employment: randomised controlled trial*

    PubMed Central

    Howard, Louise M.; Heslin, Margaret; Leese, Morven; McCrone, Paul; Rice, Christopher; Jarrett, Manuela; Spokes, Terry; Huxley, Peter; Thornicroft, Graham

    2010-01-01

    Background There is evidence from North American trials that supported employment using the individual placement and support (IPS) model is effective in helping individuals with severe mental illness gain competitive employment. There have been few trials in other parts of the world. Aims To investigate the effectiveness and cost-effectiveness of IPS in the UK. Method Individuals with severe mental illness in South London were randomised to IPS or local traditional vocational services (treatment as usual) (ISRCTN96677673). Results Two hundred and nineteen participants were randomised, and 90% assessed 1 year later. There were no significant differences between the treatment as usual and intervention groups in obtaining competitive employment (13% in the intervention group and 7% in controls; risk ratio 1.35, 95% CI 0.95–1.93, P = 0.15), nor in secondary outcomes. Conclusions There was no evidence that IPS was of significant benefit in achieving competitive employment for individuals in South London at 1-year follow-up, which may reflect suboptimal implementation. Implementation of IPS can be challenging in the UK context where IPS is not structurally integrated with mental health services, and economic disincentives may lead to lower levels of motivation in individuals with severe mental illness and psychiatric professionals. PMID:20435968

  5. Robust control for uncertain structures

    NASA Technical Reports Server (NTRS)

    Douglas, Joel; Athans, Michael

    1991-01-01

    Viewgraphs on robust control for uncertain structures are presented. Topics covered include: robust linear quadratic regulator (RLQR) formulas; mismatched LQR design; RLQR design; interpretations of RLQR design; disturbance rejection; and performance comparisons: RLQR vs. mismatched LQR.

  6. Robust controls with structured perturbations

    NASA Technical Reports Server (NTRS)

    Keel, Leehyun

    1993-01-01

    This final report summarizes the recent results obtained by the principal investigator and his coworkers on the robust stability and control of systems containing parametric uncertainty. The starting point is a generalization of Kharitonov's theorem obtained in 1989, and its generalization to the multilinear case, the singling out of extremal stability subsets, and other ramifications now constitutes an extensive and coherent theory of robust parametric stability that is summarized in the results contained here.

  7. The Internet and randomised controlled trials.

    PubMed

    Kelly, M A; Oldham, J

    1997-11-01

    Several factors constrain the implementation of Randomised Controlled Trials (RCTs). To obtain large sample sizes a multicentred multinational trial may be necessary or a long sampling period. The larger the trial the larger is the unit cost. To allow larger sample sizes, shorter sampling periods and lower unit costs, new methods are needed. The Internet and in particular the WWW provides such an opportunity. The WWW can provide global access, fast interaction and automation. A prototype Internet Trials Service (ITS) is currently being tested with a real international clinical trial (the Growth Restriction Intervention Trial--GRIT). The ITS is hosted on a Web server. It provides a series of HTML documents that describe the GRIT protocol. Registered centres may enter patients into the GRIT trial via ITS. Java applets are used to collect trial data before returning the study number and randomisation. ITS assumes all trial data will be intercepted by a sniffer. Therefore no information is sent that could specifically identify a patient, this must be sent later by more secure means. ITS assumes that trial centres can be spoofed. To authenticate the patients entered into the trial and the trial data sent, a regular audit report is sent to each centre by secure means for confirmation. By using Java, a full functional data entry system can be developed that runs locally within any Java enabled browser. It can perform data validation locally and also provide a sophisticated user interface. PMID:9506401

  8. Robust flight control of rotorcraft

    NASA Astrophysics Data System (ADS)

    Pechner, Adam Daniel

    With recent design improvement in fixed wing aircraft, there has been a considerable interest in the design of robust flight control systems to compensate for the inherent instability necessary to achieve desired performance. Such systems are designed for maximum available retention of stability and performance in the presence of significant vehicle damage or system failure. The rotorcraft industry has shown similar interest in adopting these reconfigurable flight control schemes specifically because of their ability to reject disturbance inputs and provide a significant amount of robustness for all but the most catastrophic of situations. The research summarized herein focuses on the extension of the pseudo-sliding mode control design procedure interpreted in the frequency domain. Application of the technique is employed and simulated on two well known helicopters, a simplified model of a hovering Sikorsky S-61 and the military's Black Hawk UH-60A also produced by Sikorsky. The Sikorsky helicopter model details are readily available and was chosen because it can be limited to pitch and roll motion reducing the number of degrees of freedom and yet contains two degrees of freedom, which is the minimum requirement in proving the validity of the pseudo-sliding control technique. The full order model of a hovering Black Hawk system was included both as a comparison to the S-61 helicopter design system and as a means to demonstrate the scaleability and effectiveness of the control technique on sophisticated systems where design robustness is of critical concern.

  9. Randomised Controlled Trials in Education Research: A Case Study of an Individually Randomised Pragmatic Trial

    ERIC Educational Resources Information Center

    Torgerson, Carole J.

    2009-01-01

    The randomised controlled trial (RCT) is an evaluative method used by social scientists in order to establish whether or not an intervention is effective. This contribution discusses the fundamental aspects of good RCT design. These are illustrated through the use of a recently completed RCT which evaluated an information and communication…

  10. Robust control with structured perturbations

    NASA Technical Reports Server (NTRS)

    Keel, Leehyun

    1988-01-01

    Two important problems in the area of control systems design and analysis are discussed. The first is the robust stability using characteristic polynomial, which is treated first in characteristic polynomial coefficient space with respect to perturbations in the coefficients of the characteristic polynomial, and then for a control system containing perturbed parameters in the transfer function description of the plant. In coefficient space, a simple expression is first given for the l(sup 2) stability margin for both monic and non-monic cases. Following this, a method is extended to reveal much larger stability region. This result has been extended to the parameter space so that one can determine the stability margin, in terms of ranges of parameter variations, of the closed loop system when the nominal stabilizing controller is given. The stability margin can be enlarged by a choice of better stabilizing controller. The second problem describes the lower order stabilization problem, the motivation of the problem is as follows. Even though the wide range of stabilizing controller design methodologies is available in both the state space and transfer function domains, all of these methods produce unnecessarily high order controllers. In practice, the stabilization is only one of many requirements to be satisfied. Therefore, if the order of a stabilizing controller is excessively high, one can normally expect to have a even higher order controller on the completion of design such as inclusion of dynamic response requirements, etc. Therefore, it is reasonable to have a lowest possible order stabilizing controller first and then adjust the controller to meet additional requirements. The algorithm for designing a lower order stabilizing controller is given. The algorithm does not necessarily produce the minimum order controller; however, the algorithm is theoretically logical and some simulation results show that the algorithm works in general.

  11. Robust Fixed-Structure Controller Synthesis

    NASA Technical Reports Server (NTRS)

    Corrado, Joseph R.; Haddad, Wassim M.; Gupta, Kajal (Technical Monitor)

    2000-01-01

    The ability to develop an integrated control system design methodology for robust high performance controllers satisfying multiple design criteria and real world hardware constraints constitutes a challenging task. The increasingly stringent performance specifications required for controlling such systems necessitates a trade-off between controller complexity and robustness. The principle challenge of the minimal complexity robust control design is to arrive at a tractable control design formulation in spite of the extreme complexity of such systems. Hence, design of minimal complexitY robust controllers for systems in the face of modeling errors has been a major preoccupation of system and control theorists and practitioners for the past several decades.

  12. Randomised controlled trial of mesalazine in IBS

    PubMed Central

    Barbara, Giovanni; Cremon, Cesare; Annese, Vito; Basilisco, Guido; Bazzoli, Franco; Bellini, Massimo; Benedetti, Antonio; Benini, Luigi; Bossa, Fabrizio; Buldrini, Paola; Cicala, Michele; Cuomo, Rosario; Germanà, Bastianello; Molteni, Paola; Neri, Matteo; Rodi, Marcello; Saggioro, Alfredo; Scribano, Maria Lia; Vecchi, Maurizio; Zoli, Giorgio; Corinaldesi, Roberto; Stanghellini, Vincenzo

    2016-01-01

    Objective Low-grade intestinal inflammation plays a role in the pathophysiology of IBS. In this trial, we aimed at evaluating the efficacy and safety of mesalazine in patients with IBS. Design We conducted a phase 3, multicentre, tertiary setting, randomised, double-blind, placebo-controlled trial in patients with Rome III confirmed IBS. Patients were randomly assigned to either mesalazine, 800 mg, or placebo, three times daily for 12 weeks, and were followed for additional 12 weeks. The primary efficacy endpoint was satisfactory relief of abdominal pain/discomfort for at least half of the weeks of the treatment period. The key secondary endpoint was satisfactory relief of overall IBS symptoms. Supportive analyses were also performed classifying as responders patients with a percentage of affirmative answers of at least 75% or >75% of time. Results A total of 185 patients with IBS were enrolled from 21 centres. For the primary endpoint, the responder patients were 68.6% in the mesalazine group versus 67.4% in the placebo group (p=0.870; 95% CI −12.8 to 15.1). In explorative analyses, with the 75% rule or >75% rule, the percentage of responders was greater in the mesalazine group with a difference over placebo of 11.6% (p=0.115; 95% CI −2.7% to 26.0%) and 5.9% (p=0.404; 95% CI −7.8% to 19.4%), respectively, although these differences were not significant. For the key secondary endpoint, overall symptoms improved in the mesalazine group and reached a significant difference of 15.1% versus placebo (p=0.032; 95% CI 1.5% to 28.7%) with the >75% rule. Conclusions Mesalazine treatment was not superior than placebo on the study primary endpoint. However, a subgroup of patients with IBS showed a sustained therapy response and benefits from a mesalazine therapy. Trial registration number ClincialTrials.gov number, NCT00626288. PMID:25533646

  13. Outcomes in a Randomised Controlled Trial of Mathematics Tutoring

    ERIC Educational Resources Information Center

    Topping, K. J.; Miller, D.; Murray, P.; Henderson, S.; Fortuna, C.; Conlin, N.

    2011-01-01

    Background: Large-scale randomised controlled trials (RCT) are relatively rare in education. The present study was an attempt to scale up previous small peer tutoring projects, while investing only modestly in continuing professional development for teachers. Purpose: A two-year RCT of peer tutoring in mathematics was undertaken in one local…

  14. The future of randomised controlled trials in urology.

    PubMed

    Dahm, Philipp; N'Dow, James; Holmberg, Lars; Hamdy, Freddie

    2014-07-01

    Randomised controlled trials in urology are challenging yet essential for generating high-quality, practice-changing evidence. Future trials should focus on high-priority questions, be conducted by multidisciplinary investigative teams with patient and public stakeholder involvement, and be grounded in successful feasibility studies. PMID:24495465

  15. Robustness analysis applied to substructure controller synthesis

    NASA Technical Reports Server (NTRS)

    Gonzalez-Oberdoerffer, Marcelo F.; Craig, Roy R., Jr.

    1993-01-01

    The stability and robustness of the controlled system obtained via the substructure control synthesis (SCS) method of Su et al. (1990) were examined using a six-bay truss model, and employing an LQG control design method to obtain controllers for two separate structures. It is found that the assembled controller provides a stability in this instance. A qualitative assessment of the stability robustness of the system with controller designed with the SCS method is provided by obtaining a controller using the complete truss model and comparing the robustness of the corresponding closed-loop systems.

  16. Sources of Bias in Outcome Assessment in Randomised Controlled Trials: A Case Study

    ERIC Educational Resources Information Center

    Ainsworth, Hannah; Hewitt, Catherine E.; Higgins, Steve; Wiggins, Andy; Torgerson, David J.; Torgerson, Carole J.

    2015-01-01

    Randomised controlled trials (RCTs) can be at risk of bias. Using data from a RCT, we considered the impact of post-randomisation bias. We compared the trial primary outcome, which was administered blindly, with the secondary outcome, which was not administered blindly. From 44 schools, 522 children were randomised to receive a one-to-one maths…

  17. Robust Decentralized Controller Design: Subsystem Approach

    NASA Astrophysics Data System (ADS)

    Rosinová, Danica; Thuan, Nguyen Quang; Veselý, Vojtech; Marko, L'ubomír

    2012-01-01

    The paper addresses the problem of the robust output feedback PI controller design for complex large-scale stable systems with a state decentralized control structure. A decentralized control design procedure is proposed for static output feedback control which is based on solving robust control design problems of subsystems' size. The presented approach is based on the Generalized Gershgorin Theorem and uses the so-called equivalent subsystems approach to consider the interactions in the local robust controller design. The resulting decentralized control scheme has been successfully tested on two examples: a linearized model of three interconnected boiler-turbine subsystems and a linear model of four cooperating DC motors where the problem is to design four local PI controllers for a large scale system which will guarantee robust stability and performance of the closed-loop uncertain system.

  18. Robust Multiobjective Controllability of Complex Neuronal Networks.

    PubMed

    Tang, Yang; Gao, Huijun; Du, Wei; Lu, Jianquan; Vasilakos, Athanasios V; Kurths, Jurgen

    2016-01-01

    This paper addresses robust multiobjective identification of driver nodes in the neuronal network of a cat's brain, in which uncertainties in determination of driver nodes and control gains are considered. A framework for robust multiobjective controllability is proposed by introducing interval uncertainties and optimization algorithms. By appropriate definitions of robust multiobjective controllability, a robust nondominated sorting adaptive differential evolution (NSJaDE) is presented by means of the nondominated sorting mechanism and the adaptive differential evolution (JaDE). The simulation experimental results illustrate the satisfactory performance of NSJaDE for robust multiobjective controllability, in comparison with six statistical methods and two multiobjective evolutionary algorithms (MOEAs): nondominated sorting genetic algorithms II (NSGA-II) and nondominated sorting composite differential evolution. It is revealed that the existence of uncertainties in choosing driver nodes and designing control gains heavily affects the controllability of neuronal networks. We also unveil that driver nodes play a more drastic role than control gains in robust controllability. The developed NSJaDE and obtained results will shed light on the understanding of robustness in controlling realistic complex networks such as transportation networks, power grid networks, biological networks, etc. PMID:26441452

  19. Robust nonlinear control of vectored thrust aircraft

    NASA Technical Reports Server (NTRS)

    Doyle, John C.; Murray, Richard; Morris, John

    1993-01-01

    An interdisciplinary program in robust control for nonlinear systems with applications to a variety of engineering problems is outlined. Major emphasis will be placed on flight control, with both experimental and analytical studies. This program builds on recent new results in control theory for stability, stabilization, robust stability, robust performance, synthesis, and model reduction in a unified framework using Linear Fractional Transformations (LFT's), Linear Matrix Inequalities (LMI's), and the structured singular value micron. Most of these new advances have been accomplished by the Caltech controls group independently or in collaboration with researchers in other institutions. These recent results offer a new and remarkably unified framework for all aspects of robust control, but what is particularly important for this program is that they also have important implications for system identification and control of nonlinear systems. This combines well with Caltech's expertise in nonlinear control theory, both in geometric methods and methods for systems with constraints and saturations.

  20. Research in robust control for hypersonic aircraft

    NASA Technical Reports Server (NTRS)

    Calise, A. J.

    1993-01-01

    The research during the second reporting period has focused on robust control design for hypersonic vehicles. An already existing design for the Hypersonic Winged-Cone Configuration has been enhanced. Uncertainty models for the effects of propulsion system perturbations due to angle of attack variations, structural vibrations, and uncertainty in control effectiveness were developed. Using H(sub infinity) and mu-synthesis techniques, various control designs were performed in order to investigate the impact of these effects on achievable robust performance.

  1. A probabilistic solution of robust H∞ control problem with scaled matrices

    NASA Astrophysics Data System (ADS)

    Xie, R.; Gong, J. Y.

    2016-07-01

    This paper addresses the robust H∞ control problem with scaled matrices. It is difficult to find a global optimal solution for this non-convex optimisation problem. A probabilistic solution, which can achieve globally optimal robust performance within any pre-specified tolerance, is obtained by using the proposed method based on randomised algorithm. In the proposed method, the scaled H∞ control problem is divided into two parts: (1) assume the scaled matrices be random variables, the scaled H∞ control problem is converted to a convex optimisation problem for the fixed sample of the scaled matrix and a optimal solution corresponding to the fixed sample is obtained; (2) a probabilistic optimal solution is obtained by using the randomised algorithm based on a finite number N optimal solutions, which are obtained in part (1). The analysis shows that the worst case complexity of proposed method is a polynomial.

  2. Experimental Robust Control of Structural Acoustic Radiation

    NASA Technical Reports Server (NTRS)

    Cox, David E.; Gibbs, Gary P.; Clark, Robert L.; Vipperman, Jeffrey S.

    1998-01-01

    This work addresses the design and application of robust controllers for structural acoustic control. Both simulation and experimental results are presented. H(infinity) and mu-synthesis design methods were used to design feedback controllers which minimize power radiated from a panel while avoiding instability due to unmodeled dynamics. Specifically, high order structural modes which couple strongly to the actuator-sensor path were poorly modeled. This model error was analytically bounded with an uncertainty model, which allowed controllers to be designed without artificial limits on control effort. It is found that robust control methods provide the control designer with physically meaningful parameters with which to tune control designs and can be very useful in determining limits of performance. Experimental results also showed, however, poor robustness properties for control designs with ad-hoc uncertainty models. The importance of quantifying and bounding model errors is discussed.

  3. Applications of robust control theory - Educational implications

    NASA Technical Reports Server (NTRS)

    Dorato, P.; Yedavalli, R. K.

    1992-01-01

    A survey is made of applications of robust control theory to problems of flight control, control of flexible space structures, and engine control which have appeared in recent conferences and journals. An analysis is made of which theoretical techniques are most commonly used and what implications this has for graduate and undergraduate education in aerospace engineering.

  4. Robust Fuzzy Controllers Using FPGAs

    NASA Technical Reports Server (NTRS)

    Monroe, Author Gene S., Jr.

    2007-01-01

    Electro-mechanical device controllers typically come in one of three forms, proportional (P), Proportional Derivative (PD), and Proportional Integral Derivative (PID). Two methods of control are discussed in this paper; they are (1) the classical technique that requires an in-depth mathematical use of poles and zeros, and (2) the fuzzy logic (FL) technique that is similar to the way humans think and make decisions. FL controllers are used in multiple industries; examples include control engineering, computer vision, pattern recognition, statistics, and data analysis. Presented is a study on the development of a PD motor controller written in very high speed hardware description language (VHDL), and implemented in FL. Four distinct abstractions compose the FL controller, they are the fuzzifier, the rule-base, the fuzzy inference system (FIS), and the defuzzifier. FL is similar to, but different from, Boolean logic; where the output value may be equal to 0 or 1, but it could also be equal to any decimal value between them. This controller is unique because of its VHDL implementation, which uses integer mathematics. To compensate for VHDL's inability to synthesis floating point numbers, a scale factor equal to 10(sup (N/4) is utilized; where N is equal to data word size. The scaling factor shifts the decimal digits to the left of the decimal point for increased precision. PD controllers are ideal for use with servo motors, where position control is effective. This paper discusses control methods for motion-base platforms where a constant velocity equivalent to a spectral resolution of 0.25 cm(exp -1) is required; however, the control capability of this controller extends to various other platforms.

  5. A robust line search for learning control

    SciTech Connect

    Driessen, B.J.; Kwok, K.S.; Sadegh, N.

    1998-11-01

    In this paper a new line search for a Newton Rhapson learning control algorithm is presented. Theorems and rigorous proofs of its increased robustness over existing line searches are provided, and numerical examples are used to further validate the theorems. Also, the previously posed open question of whether robust optimal trajectory learning is possible is also addressed. It is shown that the answer is generally no, at least for gradient-based learning control algorithms.

  6. Robust Control Design for Large Space Structures

    NASA Technical Reports Server (NTRS)

    Eastman, W. L.; Bossi, J. A.

    1985-01-01

    The control design problem for the class of future spacecraft referred to as large space structures (LSS) is by now well known. The issue is the reduced order control of a very high order, lightly damped system with uncertain system parameters, particularly in the high frequency modes. A design methodology which incorporates robustness considerations as part of the design process is presented. Combining pertinent results from multivariable systems theory and optimal control and estimation, LQG eigenstructure assignment and LQG frequency shaping, were used to improve singular value robustness measures in the presence of control and observation spillover.

  7. Robust fuzzy logic control of mechanical systems

    NASA Astrophysics Data System (ADS)

    Kohn-Rich, Sylvia

    An approach for the design of robust fuzzy control laws for a large class of mechanical systems was developed. The approach applies Lyapunov's Stability Theory to ensure closed loop stability in the presence of plant perturbations and bounded disturbances. It uses inherent properties of an important class of mechanical and aerospace systems, such as robotic manipulators and large spacecraft, to derive closed-loop stability conditions. Based on these conditions, a methodology for the design of robust fuzzy control systems with guaranteed closed-loop stability was developed. Two classes of control laws for mechanical systems were considered. First, a methodology for point-to-point control was formulated. It combines an energy-type approach with Lyapunov's Stability Theory and its extensions, to obtain robust stability conditions for the closed-loop system. A procedure for control system development based on the above conditions is presented. Finally, a procedure for the implementation of the fuzzy control system with guaranteed performance and closed-loop stability characteristics is formulated. In the second part of the dissertation, the problem of robust tracking for mechanical systems was considered. Based on Lyapunov's Stability Theory and its extensions due to Leitmann and Corless, conditions were developed to prove robust stability and performance in the presence of plant uncertainties, bounded disturbances and control saturation. These conditions involve a large number of parameters and functional dependencies that can be chosen by the designer, therefore are well suited for Fuzzy Logic Control implementation. Three different fuzzy implementation methods for the proposed controls system were analyzed and their relative advantages were discussed. An extensive simulation study of the proposed approach was conducted. It demonstrated the excellent performance of the proposed control systems. The proposed method showed superior performance compared to other robust

  8. Synthesis Methods for Robust Passification and Control

    NASA Technical Reports Server (NTRS)

    Kelkar, Atul G.; Joshi, Suresh M. (Technical Monitor)

    2000-01-01

    The research effort under this cooperative agreement has been essentially the continuation of the work from previous grants. The ongoing work has primarily focused on developing passivity-based control techniques for Linear Time-Invariant (LTI) systems. During this period, there has been a significant progress made in the area of passivity-based control of LTI systems and some preliminary results have also been obtained for nonlinear systems, as well. The prior work has addressed optimal control design for inherently passive as well as non- passive linear systems. For exploiting the robustness characteristics of passivity-based controllers the passification methodology was developed for LTI systems that are not inherently passive. Various methods of passification were first proposed in and further developed. The robustness of passification was addressed for multi-input multi-output (MIMO) systems for certain classes of uncertainties using frequency-domain methods. For MIMO systems, a state-space approach using Linear Matrix Inequality (LMI)-based formulation was presented, for passification of non-passive LTI systems. An LMI-based robust passification technique was presented for systems with redundant actuators and sensors. The redundancy in actuators and sensors was used effectively for robust passification using the LMI formulation. The passification was designed to be robust to an interval-type uncertainties in system parameters. The passification techniques were used to design a robust controller for Benchmark Active Control Technology wing under parametric uncertainties. The results on passive nonlinear systems, however, are very limited to date. Our recent work in this area was presented, wherein some stability results were obtained for passive nonlinear systems that are affine in control.

  9. Structurally robust control of complex networks

    NASA Astrophysics Data System (ADS)

    Nacher, Jose C.; Akutsu, Tatsuya

    2015-01-01

    Robust control theory has been successfully applied to numerous real-world problems using a small set of devices called controllers. However, the real systems represented by networks contain unreliable components and modern robust control engineering has not addressed the problem of structural changes on complex networks including scale-free topologies. Here, we introduce the concept of structurally robust control of complex networks and provide a concrete example using an algorithmic framework that is widely applied in engineering. The developed analytical tools, computer simulations, and real network analyses lead herein to the discovery that robust control can be achieved in scale-free networks with exactly the same order of controllers required in a standard nonrobust configuration by adjusting only the minimum degree. The presented methodology also addresses the probabilistic failure of links in real systems, such as neural synaptic unreliability in Caenorhabditis elegans, and suggests a new direction to pursue in studies of complex networks in which control theory has a role.

  10. Structurally robust control of complex networks.

    PubMed

    Nacher, Jose C; Akutsu, Tatsuya

    2015-01-01

    Robust control theory has been successfully applied to numerous real-world problems using a small set of devices called controllers. However, the real systems represented by networks contain unreliable components and modern robust control engineering has not addressed the problem of structural changes on complex networks including scale-free topologies. Here, we introduce the concept of structurally robust control of complex networks and provide a concrete example using an algorithmic framework that is widely applied in engineering. The developed analytical tools, computer simulations, and real network analyses lead herein to the discovery that robust control can be achieved in scale-free networks with exactly the same order of controllers required in a standard nonrobust configuration by adjusting only the minimum degree. The presented methodology also addresses the probabilistic failure of links in real systems, such as neural synaptic unreliability in Caenorhabditis elegans, and suggests a new direction to pursue in studies of complex networks in which control theory has a role. PMID:25679675

  11. Average-cost based robust structural control

    NASA Technical Reports Server (NTRS)

    Hagood, Nesbitt W.

    1993-01-01

    A method is presented for the synthesis of robust controllers for linear time invariant structural systems with parameterized uncertainty. The method involves minimizing quantities related to the quadratic cost (H2-norm) averaged over a set of systems described by real parameters such as natural frequencies and modal residues. Bounded average cost is shown to imply stability over the set of systems. Approximations for the exact average are derived and proposed as cost functionals. The properties of these approximate average cost functionals are established. The exact average and approximate average cost functionals are used to derive dynamic controllers which can provide stability robustness. The robustness properties of these controllers are demonstrated in illustrative numerical examples and tested in a simple SISO experiment on the MIT multi-point alignment testbed.

  12. The Middeck Active Control Experiment (MACE): Identification for robust control

    NASA Astrophysics Data System (ADS)

    Karlov, Valery I.

    Viewgraphs on identification for robust control for the Middeck Active Control Experiment (MACE) are presented. Topics covered include: identification for robust control; three levels of identification; basic elements of the approach; advantages of 'post-ID' model of uncertainty; advantages of optimization; and practical realization.

  13. The Middeck Active Control Experiment (MACE): Identification for robust control

    NASA Technical Reports Server (NTRS)

    Karlov, Valery I.

    1992-01-01

    Viewgraphs on identification for robust control for the Middeck Active Control Experiment (MACE) are presented. Topics covered include: identification for robust control; three levels of identification; basic elements of the approach; advantages of 'post-ID' model of uncertainty; advantages of optimization; and practical realization.

  14. Matlab as a robust control design tool

    NASA Technical Reports Server (NTRS)

    Gregory, Irene M.

    1994-01-01

    This presentation introduces Matlab as a tool used in flight control research. The example used to illustrate some of the capabilities of this software is a robust controller designed for a single stage to orbit air breathing vehicles's ascent to orbit. The global requirements of the controller are to stabilize the vehicle and follow a trajectory in the presence of atmospheric disturbances and strong dynamic coupling between airframe and propulsion.

  15. Robust multivariable controller design for flexible spacecraft

    NASA Technical Reports Server (NTRS)

    Joshi, Suresh M.; Armstrong, Ernest S.

    1986-01-01

    Large, flexible spacecraft are typically characterized by a large number of significant elastic modes with very small inherent damping, low, closely spaced natural frequencies, and the lack of accurate knowledge of the structural parameters. Summarized here is some recent research on the design of robust controllers for such spacecraft, which will maintain stability, and possible performance, despite these problems. Two types of controllers are considered, the first being the linear-quadratic-Gaussian-(LQG)-type. The second type utilizes output feedback using collocated sensors and actuators. The problem of designing robust LQG-type controllers using the frequency domain loop transfer recovery (LTR) method is considered, and the method is applied to a large antenna model. Analytical results regarding the regions of stability for LQG-type controllers in the presence of actuator nonlinearities are also presented. The results obtained for the large antenna indicate that the LQG/LTR method is a promising approach for control system design for flexible spacecraft. For the second type of controllers (collocated controllers), it is proved that the stability is maintained in the presence of certain commonly encountered nonlinearities and first-order actuator dynamics. These results indicate that collocated controllers are good candidates for robust control in situations where model errors are large.

  16. Research in robust control for hypersonic aircraft

    NASA Technical Reports Server (NTRS)

    Calise, A. J.

    1994-01-01

    The research during the third reporting period focused on fixed order robust control design for hypersonic vehicles. A new technique was developed to synthesize fixed order H(sub infinity) controllers. A controller canonical form is imposed on the compensator structure and a homotopy algorithm is employed to perform the controller design. Various reduced order controllers are designed for a simplified version of the hypersonic vehicle model used in our previous studies to demonstrate the capabilities of the code. However, further work is needed to investigate the issue of numerical ill-conditioning for large order systems and to make the numerical approach more reliable.

  17. Befriending carers of people with dementia: randomised controlled trial

    PubMed Central

    2008-01-01

    Objective To evaluate the effectiveness of a voluntary sector based befriending scheme in improving psychological wellbeing and quality of life for family carers of people with dementia. Design Single blind randomised controlled trial. Setting Community settings in East Anglia and London. Participants 236 family carers of people with primary progressive dementia. Intervention Contact with a befriender facilitator and offer of match with a trained lay volunteer befriender compared with no befriender facilitator contact; all participants continued to receive “usual care.” Main outcome measures Carers’ mood (hospital anxiety and depression scale—depression) and health related quality of life (EuroQoL) at 15 months post-randomisation. Results The intention to treat analysis showed no benefit for the intervention “access to a befriender facilitator” on the primary outcome measure or on any of the secondary outcome measures. Conclusions In common with many carers’ services, befriending schemes are not taken up by all carers, and providing access to a befriending scheme is not effective in improving wellbeing. Trial registration Current Controlled Trials ISRCTN08130075. PMID:18505757

  18. Robust Stabilization Control for an Electric Bicycle

    NASA Astrophysics Data System (ADS)

    Kawamura, Takuro; Murakami, Toshiyuki

    Recently, bicycles have gained immense popularity because they have high mobility and are an environment-friendly means of transport. However, many people tend to avoid riding a bicycle because it is unstable. In order to solve this problem, stabilization control for a bicycle has been researched. The aim of this study is improvement of the robustness in stabilization control. To achieve this goal, control systems that use a camber angle disturbance observer (CADO) are proposed. Two kinds of CADOs are proposed in this paper, and the performances of these two observers are compared. The proposed control systems provide higher robustness than does the conventional method. The validity of the proposed methods is confirmed by the experimental results.

  19. Robust adaptive control of HVDC systems

    SciTech Connect

    Reeve, J.; Sultan, M. )

    1994-07-01

    The transient performance of an HVDC power system is highly dependent on the parameters of the current/voltage regulators of the converter controls. In order to better accommodate changes in system structure or dc operating conditions, this paper introduces a new adaptive control strategy. The advantages of automatic tuning for continuous fine tuning are combined with predetermined gain scheduling in order to achieve robustness for large disturbances. Examples are provided for a digitally simulated back-to-back dc system.

  20. What proportion of primary psychiatric interventions are based on evidence from randomised controlled trials?

    PubMed Central

    Geddes, J R; Game, D; Jenkins, N E; Peterson, L A; Pottinger, G R; Sackett, D L

    1996-01-01

    OBJECTIVES: To estimate the proportion of psychiatric inpatients receiving primary interventions based on randomised controlled trials or systematic reviews of randomised controlled trials. DESIGN: Retrospective survey. SETTING: Acute adult general psychiatric ward. SUBJECTS: All patients admitted to the ward during a 28 day period. MAIN OUTCOME MEASURES: Primary interventions were classified according to whether or not they were supported by evidence from randomised controlled trials or systematic reviews. RESULTS: The primary interventions received by 26/40 (65%; 95% confidence interval (95% CI) 51% to 79%) of patients admitted during the period were based on randomised trials or systematic reviews. CONCLUSIONS: When patients were used as the denominator, most primary interventions given in acute general psychiatry were based on experimental evidence. The evidence was difficult to locate; there is an urgent need for systematic reviews of randomised controlled trials in this area. PMID:10164145

  1. Low bandwidth robust controllers for flight

    NASA Technical Reports Server (NTRS)

    Biezad, Daniel J.; Chou, Hwei-Lan

    1993-01-01

    Through throttle manipulations, engine thrust can be used for emergency flight control for multi-engine aircraft. Previous study by NASA Dryden has shown the use of throttles for emergency flight control to be very difficult. In general, manual fly-by-throttle is extremely difficult - with landing almost impossible, but control augmentation makes runway landings feasible. Flight path control using throttles-only to achieve safe emergency landing for a large jet transport airplane, Boeing 720, was investigated using Quantitative Feedback Theory (QFT). Results were compared to an augmented control developed in a previous simulation study. The control augmentation corrected the unsatisfactory open-loop characteristics by increasing system bandwidth and damping, but increasing the control bandwidth substantially proved very difficult. The augmented pitch control is robust under no or moderate turbulence. The augmented roll control is sensitive to configuration changes.

  2. Low Bandwidth Robust Controllers for Flight

    NASA Technical Reports Server (NTRS)

    Biezad, Daniel J.; Chou, Hwei-Lan

    1993-01-01

    Through throttle manipulations, engine thrust can be used for emergency flight control for multi-engine aircraft. Previous study by NASA Dryden has shown the use of throttles for emergency flight control to be very difficult. In general, manual fly-by-throttle is extremely difficult - with landing almost impossible, but control augmentation makes runway landings feasible. Flight path control using throttles-only to achieve safe emergency landing for a large jet transport airplane, Boeing 720, was investigated using Quantitative Feedback Theory (QFT). Results were compared to an augmented control developed in a previous simulation study. The control augmentation corrected the unsatisfactory open-loop characteristics by increasing system bandwidth and damping, but increasing the control bandwidth substantially proved very difficult. The augmented pitch control is robust under no or moderate turbulence. The augmented roll control is sensitive to configuration changes.

  3. Robust and efficient in situ quantum control

    NASA Astrophysics Data System (ADS)

    Ferrie, Christopher; Moussa, Osama

    2015-05-01

    Precision control of quantum systems is the driving force for both quantum technology and the probing of physics at the quantum and nanoscale levels. We propose an implementation-independent method for in situ quantum control that leverages recent advances in the direct estimation of quantum gate fidelity. Our algorithm takes account of the stochasticity of the problem, is suitable for closed-loop control, and requires only a constant number of fidelity-estimating experiments per iteration independent of the dimension of the control space. It is efficient and robust to both statistical and technical noise.

  4. Robust control technique for nuclear power plants

    SciTech Connect

    Murphy, G.V.; Bailey, J.M.

    1989-03-01

    This report summarizes the linear quadratic Guassian (LQG) design technique with loop transfer recovery (LQG/LTR) for design of control systems. The concepts of return ratio, return difference, inverse return difference, and singular values are summarized. The LQG/LTR design technique allows the synthesis of a robust control system. To illustrate the LQG/LTR technique, a linearized model of a simple process has been chosen. The process has three state variables, one input, and one output. Three control system design methods are compared: LQG, LQG/LTR, and a proportional plus integral controller (PI). 7 refs., 20 figs., 6 tabs.

  5. Web-based randomised controlled trials in orthodontics.

    PubMed

    Cioffi, Iacopo; Martina, Roberto; Michelotti, Ambrosina; Chiodini, Paolo; Tagliaferri, Renato; Farella, Mauro

    2008-01-01

    Randomised controlled trials (RCT) are considered the best source of scientific evidence--the gold standard--when evaluating the efficacy of orthodontic treatments. Frequently, RCT are planned as multicentre trials, with the intention of increasing statistical power and raising the precision of outcome estimates. The management of large-scale RCT, however, requires even more thorough organisation than conventional RCT. Indeed, the need for high accuracy and standardisation in data collection, research aids, secretarial skills, staff and patient training, and organisational meetings, make these studies time-consuming, expensive and, in general, relatively complex to carry out well. A website was developed to support a large scale-orthodontic RCT which aimed to evaluate the efficacy of a functional appliance(www.ortodonzia.unina.it). Websites such as this can increase the quality of data collection, simplify the randomisation process, speed up data collection, and improve trial monitoring. Web-based RCT have the potential to help globalise orthodontic research and also increase our rate of acquisition of evidence in orthodontics. PMID:19151687

  6. Is an Intervention Using Computer Software Effective in Literacy Learning? A Randomised Controlled Trial

    ERIC Educational Resources Information Center

    Brooks, G.; Miles, J. N. V.; Torgerson, C. J.; Torgerson, D. J.

    2006-01-01

    Background: Computer software is widely used to support literacy learning. There are few randomised trials to support its effectiveness. Therefore, there is an urgent need to rigorously evaluate computer software that supports literacy learning. Methods: We undertook a pragmatic randomised controlled trial among pupils aged 11-12 within a single…

  7. Deprescribing in Frail Older People: A Randomised Controlled Trial

    PubMed Central

    Potter, Kathleen; Flicker, Leon; Page, Amy; Etherton-Beer, Christopher

    2016-01-01

    Objectives Deprescribing has been proposed as a way to reduce polypharmacy in frail older people. We aimed to reduce the number of medicines consumed by people living in residential aged care facilities (RACF). Secondary objectives were to explore the effect of deprescribing on survival, falls, fractures, hospital admissions, cognitive, physical, and bowel function, quality of life, and sleep. Methods Ninety-five people aged over 65 years living in four RACF in rural mid-west Western Australia were randomised in an open study. The intervention group (n = 47) received a deprescribing intervention, the planned cessation of non-beneficial medicines. The control group (n = 48) received usual care. Participants were monitored for twelve months from randomisation. Primary outcome was change in the mean number of unique regular medicines. All outcomes were assessed at baseline, six, and twelve months. Results Study participants had a mean age of 84.3±6.9 years and 52% were female. Intervention group participants consumed 9.6±5.0 and control group participants consumed 9.5±3.6 unique regular medicines at baseline. Of the 348 medicines targeted for deprescribing (7.4±3.8 per person, 78% of regular medicines), 207 medicines (4.4±3.4 per person, 59% of targeted medicines) were successfully discontinued. The mean change in number of regular medicines at 12 months was -1.9±4.1 in intervention group participants and +0.1±3.5 in control group participants (estimated difference 2.0±0.9, 95%CI 0.08, 3.8, p = 0.04). Twelve intervention participants and 19 control participants died within 12 months of randomisation (26% versus 40% mortality, p = 0.16, HR 0.60, 95%CI 0.30 to 1.22) There were no significant differences between groups in other secondary outcomes. The main limitations of this study were the open design and small participant numbers. Conclusions Deprescribing reduced the number of regular medicines consumed by frail older people living in residential care with no

  8. Optimal and robust control of transition

    NASA Technical Reports Server (NTRS)

    Bewley, T. R.; Agarwal, R.

    1996-01-01

    Optimal and robust control theories are used to determine feedback control rules that effectively stabilize a linearly unstable flow in a plane channel. Wall transpiration (unsteady blowing/suction) with zero net mass flux is used as the control. Control algorithms are considered that depend both on full flowfield information and on estimates of that flowfield based on wall skin-friction measurements only. The development of these control algorithms accounts for modeling errors and measurement noise in a rigorous fashion; these disturbances are considered in both a structured (Gaussian) and unstructured ('worst case') sense. The performance of these algorithms is analyzed in terms of the eigenmodes of the resulting controlled systems, and the sensitivity of individual eigenmodes to both control and observation is quantified.

  9. Surrogate endpoints for overall survival in metastatic melanoma: a meta-analysis of randomised controlled trials

    PubMed Central

    Flaherty, Keith T; Hennig, Michael; Lee, Sandra J; Ascierto, Paolo A; Dummer, Reinhard; Eggermont, Alexander M M; Hauschild, Axel; Kefford, Richard; Kirkwood, John M; Long, Georgina V; Lorigan, Paul; Mackensen, Andreas; McArthur, Grant; O'Day, Steven; Patel, Poulam M; Robert, Caroline; Schadendorf, Dirk

    2015-01-01

    Summary Background Recent phase 3 trials have shown an overall survival benefit in metastatic melanoma. We aimed to assess whether progression-free survival (PFS) could be regarded as a reliable surrogate for overall survival through a meta-analysis of randomised trials. Methods We systematically reviewed randomised trials comparing treatment regimens in metastatic melanoma that included dacarbazine as the control arm, and which reported both PFS and overall survival with a standard hazard ratio (HR). We correlated HRs for overall survival and PFS, weighted by sample size or by precision of the HR estimate, assuming fixed and random effects. We did sensitivity analyses according to presence of crossover, trial size, and dacarbazine dose. Findings After screening 1649 reports and meeting abstracts published before Sept 8, 2013, we identified 12 eligible randomised trials that enrolled 4416 patients with metastatic melanoma. Irrespective of weighting strategy, we noted a strong correlation between the treatment effects for PFS and overall survival, which seemed independent of treatment type. Pearson correlation coefficients were 0.71 (95% CI 0.29–0.90) with a random-effects assumption, 0.85 (0.59–0.95) with a fixed-effects assumption, and 0.89 (0.68–0.97) with sample-size weighting. For nine trials without crossover, the correlation coefficient was 0.96 (0.81–0.99), which decreased to 0.93 (0.74–0.98) when two additional trials with less than 50% crossover were included. Inclusion of mature follow-up data after at least 50% crossover (in vemurafenib and dabrafenib phase 3 trials) weakened the PFS to overall survival correlation (0.55, 0.03–0.84). Inclusion of trials with no or little crossover with the random-effects assumption yielded a conservative statement of the PFS to overall survival correlation of 0.85 (0.51–0.96). Interpretation PFS can be regarded as a robust surrogate for overall survival in dacarbazine-controlled randomised trials of

  10. Robustness

    NASA Technical Reports Server (NTRS)

    Ryan, R.

    1993-01-01

    Robustness is a buzz word common to all newly proposed space systems design as well as many new commercial products. The image that one conjures up when the word appears is a 'Paul Bunyon' (lumberjack design), strong and hearty; healthy with margins in all aspects of the design. In actuality, robustness is much broader in scope than margins, including such factors as simplicity, redundancy, desensitization to parameter variations, control of parameter variations (environments flucation), and operational approaches. These must be traded with concepts, materials, and fabrication approaches against the criteria of performance, cost, and reliability. This includes manufacturing, assembly, processing, checkout, and operations. The design engineer or project chief is faced with finding ways and means to inculcate robustness into an operational design. First, however, be sure he understands the definition and goals of robustness. This paper will deal with these issues as well as the need for the requirement for robustness.

  11. Adaptive control: Stability, convergence, and robustness

    NASA Technical Reports Server (NTRS)

    Sastry, Shankar; Bodson, Marc

    1989-01-01

    The deterministic theory of adaptive control (AC) is presented in an introduction for graduate students and practicing engineers. Chapters are devoted to basic AC approaches, notation and fundamental theorems, the identification problem, model-reference AC, parameter convergence using averaging techniques, and AC robustness. Consideration is given to the use of prior information, the global stability of indirect AC schemes, multivariable AC, linearizing AC for a class of nonlinear systems, AC of linearizable minimum-phase systems, and MIMO systems decouplable by static state feedback.

  12. System identification for robust control design

    SciTech Connect

    Dohner, J.L.

    1995-04-01

    System identification for the purpose of robust control design involves estimating a nominal model of a physical system and the uncertainty bounds of that nominal model via the use of experimentally measured input/output data. Although many algorithms have been developed to identify nominal models, little effort has been directed towards identifying uncertainty bounds. Therefore, in this document, a discussion of both nominal model identification and bounded output multiplicative uncertainty identification will be presented. This document is divided into several sections. Background information relevant to system identification and control design will be presented. A derivation of eigensystem realization type algorithms will be presented. An algorithm will be developed for calculating the maximum singular value of output multiplicative uncertainty from measured data. An application will be given involving the identification of a complex system with aliased dynamics, feedback control, and exogenous noise disturbances. And, finally, a short discussion of results will be presented.

  13. A multi-centre randomised controlled trial of rehabilitation aimed at improving outdoor mobility for people after stroke: Study protocol for a randomised controlled trial

    PubMed Central

    2012-01-01

    . Discussion This study protocol describes a pragmatic randomised controlled trial that will hopefully provide robust evidence of the benefit of outdoor mobility interventions after stroke for clinicians working in the community. The results will be available towards the end of 2012. Trial registration ISRCTN58683841 PMID:22721452

  14. Community involvement in dengue vector control: cluster randomised trial

    PubMed Central

    Toledo, M E; Rodríguez, M; Gomez, D; Baly, A; Benitez, J R; Van der Stuyft, P

    2009-01-01

    Objective To assess the effectiveness of an integrated community based environmental management strategy to control Aedes aegypti, the vector of dengue, compared with a routine strategy. Design Cluster randomised trial. Setting Guantanamo, Cuba. Participants 32 circumscriptions (around 2000 inhabitants each). Interventions The circumscriptions were randomly allocated to control clusters (n=16) comprising routine Aedes control programme (entomological surveillance, source reduction, selective adulticiding, and health education) and to intervention clusters (n=16) comprising the routine Aedes control programme combined with a community based environmental management approach. Main outcome measures The primary outcome was levels of Aedes infestation: house index (number of houses positive for at least one container with immature stages of Ae aegypti per 100 inspected houses), Breteau index (number of containers positive for immature stages of Ae aegypti per 100 inspected houses), and the pupae per inhabitant statistic (number of Ae aegypti pupae per inhabitant). Results All clusters were subjected to the intended intervention; all completed the study protocol up to February 2006 and all were included in the analysis. At baseline the Aedes infestation levels were comparable between intervention and control clusters: house index 0.25% v 0.20%, pupae per inhabitant 0.44×10−3 v 0.29×10−3. At the end of the intervention these indices were significantly lower in the intervention clusters: rate ratio for house indices 0.49 (95% confidence interval 0.27 to 0.88) and rate ratio for pupae per inhabitant 0.27 (0.09 to 0.76). Conclusion A community based environmental management embedded in a routine control programme was effective at reducing levels of Aedes infestation. Trial registration Current Controlled Trials ISRCTN88405796. PMID:19509031

  15. Robust, Practical Adaptive Control for Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Orr, Jeb. S.; VanZwieten, Tannen S.

    2012-01-01

    A modern mechanization of a classical adaptive control concept is presented with an application to launch vehicle attitude control systems. Due to a rigorous flight certification environment, many adaptive control concepts are infeasible when applied to high-risk aerospace systems; methods of stability analysis are either intractable for high complexity models or cannot be reconciled in light of classical requirements. Furthermore, many adaptive techniques appearing in the literature are not suitable for application to conditionally stable systems with complex flexible-body dynamics, as is often the case with launch vehicles. The present technique is a multiplicative forward loop gain adaptive law similar to that used for the NASA X-15 flight research vehicle. In digital implementation with several novel features, it is well-suited to application on aerodynamically unstable launch vehicles with thrust vector control via augmentation of the baseline attitude/attitude-rate feedback control scheme. The approach is compatible with standard design features of autopilots for launch vehicles, including phase stabilization of lateral bending and slosh via linear filters. In addition, the method of assessing flight control stability via classical gain and phase margins is not affected under reasonable assumptions. The algorithm s ability to recover from certain unstable operating regimes can in fact be understood in terms of frequency-domain criteria. Finally, simulation results are presented that confirm the ability of the algorithm to improve performance and robustness in realistic failure scenarios.

  16. Treatment of irritable bowel syndrome: a review of randomised controlled trials

    PubMed Central

    AKEHURST, R; KALTENTHALER, E

    2001-01-01

    Irritable bowel syndrome (IBS) is a common chronic disorder that is associated with significant disability and health care costs. The purpose of this paper is to review and assess published randomised controlled trials examining the clinical effectiveness of interventions for IBS for 1987-1998. A literature search was conducted to identify randomised controlled trials of IBS treatments: 45 studies were identified that described randomised controlled trials and of these, six fulfilled all three criteria used to assess the quality of randomised controlled trials, as described by Jadad and colleagues.1 These criteria are: adequate description of randomisation, double blinding, and description of withdrawals and dropouts. It is concluded that there are few studies which offer convincing evidence of effectiveness in treating the IBS symptom complex. This review strongly suggests that future work should include well designed trials that: describe the randomisation method; use internationally approved diagnostic criteria; and are double blinded and placebo controlled. Clear well defined outcome measures are necessary. Inclusion of quality of life measures allows comparison between trials in different therapeutic areas. Conducting such studies will help to overcome some of the difficulties identified in this review.

 PMID:11156653

  17. Multi-application controls: Robust nonlinear multivariable aerospace controls applications

    NASA Technical Reports Server (NTRS)

    Enns, Dale F.; Bugajski, Daniel J.; Carter, John; Antoniewicz, Bob

    1994-01-01

    This viewgraph presentation describes the general methodology used to apply Honywell's Multi-Application Control (MACH) and the specific application to the F-18 High Angle-of-Attack Research Vehicle (HARV) including piloted simulation handling qualities evaluation. The general steps include insertion of modeling data for geometry and mass properties, aerodynamics, propulsion data and assumptions, requirements and specifications, e.g. definition of control variables, handling qualities, stability margins and statements for bandwidth, control power, priorities, position and rate limits. The specific steps include choice of independent variables for least squares fits to aerodynamic and propulsion data, modifications to the management of the controls with regard to integrator windup and actuation limiting and priorities, e.g. pitch priority over roll, and command limiting to prevent departures and/or undesirable inertial coupling or inability to recover to a stable trim condition. The HARV control problem is characterized by significant nonlinearities and multivariable interactions in the low speed, high angle-of-attack, high angular rate flight regime. Systematic approaches to the control of vehicle motions modeled with coupled nonlinear equations of motion have been developed. This paper will discuss the dynamic inversion approach which explicity accounts for nonlinearities in the control design. Multiple control effectors (including aerodynamic control surfaces and thrust vectoring control) and sensors are used to control the motions of the vehicles in several degrees-of-freedom. Several maneuvers will be used to illustrate performance of MACH in the high angle-of-attack flight regime. Analytical methods for assessing the robust performance of the multivariable control system in the presence of math modeling uncertainty, disturbances, and commands have reached a high level of maturity. The structured singular value (mu) frequency response methodology is presented

  18. Can "realist" randomised controlled trials be genuinely realist?

    PubMed

    Van Belle, Sara; Wong, Geoff; Westhorp, Gill; Pearson, Mark; Emmel, Nick; Manzano, Ana; Marchal, Bruno

    2016-01-01

    In this paper, we respond to a paper by Jamal and colleagues published in Trials in October 2015 and take an opportunity to continue the much-needed debate about what applied scientific realism is. The paper by Jamal et al. is useful because it exposes the challenges of combining a realist evaluation approach (as developed by Pawson and Tilley) with the randomised controlled trial (RCT) design.We identified three fundamental differences that are related to paradigmatic differences in the treatment of causation between post-positivist and realist logic: (1) the construct of mechanism, (2) the relation between mediators and moderators on one hand and mechanisms and contexts on the other hand, and (3) the variable-oriented approach to analysis of causation versus the configurational approach.We show how Jamal et al. consider mechanisms as observable, external treatments and how their approach reduces complex causal processes to variables. We argue that their proposed RCT design cannot provide a truly realist understanding. Not only does the proposed realist RCT design not deal with the RCT's inherent inability to "unpack" complex interventions, it also does not enable the identification of the dynamic interplay among the intervention, actors, context, mechanisms and outcomes, which is at the core of realist research. As a result, the proposed realist RCT design is not, as we understand it, genuinely realist in nature. PMID:27387202

  19. Should desperate volunteers be included in randomised controlled trials?

    PubMed

    Allmark, P; Mason, S

    2006-09-01

    Randomised controlled trials (RCTs) sometimes recruit participants who are desperate to receive the experimental treatment. This paper defends the practice against three arguments that suggest it is unethical first, desperate volunteers are not in equipoise. Second clinicians, entering patients onto trials are disavowing their therapeutic obligation to deliver the best treatment; they are following trial protocols rather than delivering individualised care. Research is not treatment; its ethical justification is different. Consent is crucial. Third, desperate volunteers do not give proper consent: effectively, they are coerced. This paper responds by advocating a notion of equipoise based on expert knowledge and widely shared values. Where such collective, expert equipoise exists there is a prima facie case for an RCT. Next the paper argues that trial entry does not involve clinicians disavowing their therapeutic obligation; individualised care based on insufficient evidence is not in patients best interest. Finally, it argues that where equipoise exists it is acceptable to limit access to experimental agents; desperate volunteers are not coerced because their desperation does not translate into a right to receive what they desire. PMID:16943339

  20. Neonatal ECMO Study of Temperature (NEST) - a randomised controlled trial

    PubMed Central

    2010-01-01

    Background Existing evidence indicates that once mature neonates with severe cardio-respiratory failure become eligible for Extra Corporeal Membrane Oxygenation (ECMO) their chances of intact survival are doubled if they actually receive ECMO. However, significant numbers survive with disability. NEST is a multi-centre randomised controlled trial designed to test whether, in neonates requiring ECMO, cooling to 34°C for the first 48 to 72 hours of their ECMO course leads to improved later health status. Infants allocated to the control group will receive ECMO at 37°C throughout their course, which is currently standard practice around the world. Health status of both groups will be assessed formally at 2 years corrected age. Methods/Design All infants recruited to the study will be cared for in one of the four United Kingdom (UK) ECMO centres. Babies who are thought to be eligible will be assessed by the treating clinician who will confirm eligibility, ensure that consent has been obtained and then randomise the baby using a web based system, based at the National Perinatal Epidemiology Unit (NPEU) Clinical Trials Unit. Trial registration. Babies allocated ECMO without cooling will receive ECMO at 37°C ± 0.2°C. Babies allocated ECMO with cooling will be managed at 34°C ± 0.2°C for up to 72 hours from the start of their ECMO run. The minimum duration of cooling will be 48 hours. Rewarming (to 37°C) will occur at a rate of no more than 0.5°C per hour. All other aspects of ECMO management will be identical. Primary outcome: Cognitive score from the Bayley Scales of Infant and Toddler Development, 3rd edition (Bayley-III) at age of 2 years (24 - 27 months). Discussion For the primary analysis, children will be analysed in the groups to which they are assigned, comparing the outcome of all babies allocated to "ECMO with cooling" with all those allocated to "ECMO" alone, regardless of deviation from the protocol or treatment received. For the primary outcome the

  1. Robust adaptive control for Unmanned Aerial Vehicles

    NASA Astrophysics Data System (ADS)

    Kahveci, Nazli E.

    anti-windup compensation. Our analysis on the indirect adaptive scheme reveals that the perturbation terms due to parameter errors do not cause any unbounded signals in the closed-loop. The stability of the adaptive system is established, and the properties of the proposed control scheme are demonstrated through simulations on a UAV model with input magnitude saturation constraints. The robust adaptive control design is further developed to extend our results to rate-saturated systems.

  2. Famciclovir for ophthalmic zoster: a randomised aciclovir controlled study

    PubMed Central

    Tyring, S.; Engst, R.; Corriveau, C.; Robillard, N.; Trottier, S.; Van Slycken, S.; Crann, R.; Locke, L.; Saltzman, R.; Palestine, A.

    2001-01-01

    AIMS—To compare the efficacy and safety of famciclovir with aciclovir for the treatment of ophthalmic zoster.
METHODS—Randomised, double masked, aciclovir controlled, parallel group in 87 centres worldwide including 454 patients with ophthalmic zoster of trigeminal nerve (V1) comprised the intent to treat population. Oral famciclovir 500 mg three times daily or oral aciclovir 800 mg five times daily for 7 days. Assessments included day 0 (screening), days 3 and 7 (during treatment), days 10, 14, 21, 28 and monthly thereafter, up to 6 months (follow up). Proportion of patients who experienced ocular manifestations, severe manifestations and non-severe manifestations; loss of visual acuity was the main outcome measure.
RESULTS—The percentage of patients who experienced one or more ocular manifestations was similar for famciclovir (142/245, 58.0%) and aciclovir (114/196, 58.2%) recipients, with no significant difference between groups (OR 0.99; 95% CI 0.68, 1.45). The percentage of patients who experienced severe and non-severe manifestations was similar between groups, with no significant difference. The prevalence of individual ocular manifestations was comparable between groups. There was no significant difference between groups for visual acuity loss.
CONCLUSION—Famciclovir 500 mg three times daily was well tolerated and demonstrated efficacy similar to aciclovir 800 mg five times daily.

 PMID:11316720

  3. Thermoregulatory effects of swaddling in Mongolia: a randomised controlled study

    PubMed Central

    Tsogt, Bazarragchaa; Manaseki-Holland, Semira; Pollock, Jon; Blair, Peter S; Fleming, Peter

    2016-01-01

    Objective To investigate thermal balance of infants in a Mongolian winter, and compare the effects of traditional swaddling with an infant sleeping-bag in apartments or traditional tents (Gers). Design A substudy within a randomised controlled trial. Setting Community in Ulaanbaatar, Mongolia. Subjects A stratified randomly selected sample of 40 swaddled and 40 non-swaddled infants recruited within 48 h of birth. Intervention Sleeping-bags and baby outfits of total thermal resistance equivalent to that of swaddled babies. Outcome measure Digital recordings of infants’ core, peripheral, environmental and microenvironmental temperatures at 30-s intervals over 24 h at ages 1 month and 3 months. Results In Gers, indoor temperatures varied greatly (<0–>25°C), but remained between 20°C and 22°C, in apartments. Despite this, heavy wrapping, bed sharing and partial head covering, infant core and peripheral temperatures were similar and no infants showed evidence of significant heat or cold stress whether they were swaddled or in sleeping-bags. At 3 months, infants in sleeping-bags showed the ‘mature’ diurnal pattern of a fall in core temperature after sleep onset, accompanied by a rise in peripheral temperature, with a reverse pattern later in the night, just before awakening. This pattern was not related to room temperature, and was absent in the swaddled infants, suggesting that the mature diurnal pattern may develop later in them. Conclusions No evidence of cold stress was found. Swaddling had no identifiable thermal advantages over sleeping-bags during the coldest times, and in centrally heated apartments could contribute to the risk of overheating during the daytime. Trial registration number ISRTN01992617. PMID:26515228

  4. Randomised controlled trial of vitamin D supplementation in sarcoidosis

    PubMed Central

    Bolland, Mark J; Wilsher, Margaret L; Grey, Andrew; Horne, Anne M; Fenwick, Sheryl; Gamble, Greg D; Reid, Ian R

    2013-01-01

    Objectives The role vitamin D intake/production plays in sarcoidosis-associated hypercalcaemia is uncertain. However, authoritative reviews have recommended avoiding sunlight exposure and vitamin D supplements, which might lead to adverse skeletal outcomes from vitamin D insufficiency. We investigated the effects of vitamin D supplementation on surrogate measures of skeletal health in patients with sarcoidosis and vitamin D insufficiency. Design Randomised, placebo-controlled trial. Setting Clinical research centre. Participants 27 normocalcaemic patients with sarcoidosis and 25-hydroxyvitamin D (25OHD) <50 nmol/L. Intervention 50 000 IU weekly cholecalciferol for 4 weeks, then 50 000 IU monthly for 11 months or placebo. Primary and secondary outcome measures The primary endpoint was the change in serum calcium over 12 months, and secondary endpoints included measurements of calcitropic hormones, bone turnover markers and bone mineral density (BMD). Results The mean age of participants was 57 years and 70% were women. The mean (SD) screening 25OHD was 35 (12) and 38 (9) nmol/L in the treatment and control groups, respectively. Vitamin D supplementation increased 25OHD to 94 nmol/L after 4 weeks, 84 nmol/L at 6 months and 78 nmol/L at 12 months, while levels remained stable in the control group. 1,25-Dihydroxy vitamin D levels were significantly different between the groups at 4 weeks, but not at 6 or 12 months. There were no between-groups differences in albumin-adjusted serum calcium, 24 h urine calcium, markers of bone turnover, parathyroid hormone or BMD over the trial. One participant developed significant hypercalcaemia after 6 weeks (total cholecalciferol dose 250 000 IU). Conclusions In patients with sarcoidosis and 25OHD <50 nmol/L, vitamin D supplements did not alter average serum calcium or urine calcium, but had no benefit on surrogate markers of skeletal health and caused one case of significant hypercalcaemia

  5. Testing the activitystat hypothesis: a randomised controlled trial protocol

    PubMed Central

    2012-01-01

    Background The activitystat hypothesis proposes that when physical activity or energy expenditure is increased or decreased in one domain, there will be a compensatory change in another domain to maintain an overall, stable level of physical activity or energy expenditure. To date, there has been no experimental study primarily designed to test the activitystat hypothesis in adults. The aim of this trial is to determine the effect of two different imposed exercise loads on total daily energy expenditure and physical activity levels. Methods This study will be a randomised, multi-arm, parallel controlled trial. Insufficiently active adults (as determined by the Active Australia survey) aged 18–60 years old will be recruited for this study (n=146). Participants must also satisfy the Sports Medicine Australia Pre-Exercise Screening System and must weigh less than 150 kg. Participants will be randomly assigned to one of three groups using a computer-generated allocation sequence. Participants in the Moderate exercise group will receive an additional 150 minutes of moderate to vigorous physical activity per week for six weeks, and those in the Extensive exercise group will receive an additional 300 minutes of moderate to vigorous physical activity per week for six weeks. Exercise targets will be accumulated through both group and individual exercise sessions monitored by heart rate telemetry. Control participants will not be given any instructions regarding lifestyle. The primary outcome measures are activity energy expenditure (doubly labeled water) and physical activity (accelerometry). Secondary measures will include resting metabolic rate via indirect calorimetry, use of time, maximal oxygen consumption and several anthropometric and physiological measures. Outcome measures will be conducted at baseline (zero weeks), mid- and end-intervention (three and six weeks) with three (12 weeks) and six month (24 week) follow-up. All assessors will be blinded to group

  6. Mobile phone SMS messages can enhance healthy behaviour: a meta-analysis of randomised controlled trials.

    PubMed

    Orr, Jayne A; King, Robert J

    2015-01-01

    Healthy behaviour, such as smoking cessation and adherence to prescribed medications, mitigates illness risk factors but health behaviour change can be challenging. Mobile phone short-message service (SMS) messages are increasingly used to deliver interventions designed to enhance healthy behaviour. This meta-analysis used a random-effects model to synthesise 38 randomised controlled trials that investigated the efficacy of SMS messages to enhance healthy behaviour. Participants (N = 19,641) lived in developed and developing countries and were diverse with respect to age, ethnicity, socioeconomic background and health behaviours targeted for change. SMS messages had a small, positive, significant effect (g = 0.291) on a broad range of healthy behaviour. This effect was maximised when multiple SMS messages per day were used (g = 0.395) compared to using lower frequencies (daily, multiple per week and once-off) (g = 0.244). The low heterogeneity in this meta-analysis (I (2) = 38.619) supports reporting a summary effect size and implies that the effect of SMS messaging is robust, regardless of population characteristics or healthy behaviour targeted. SMS messaging is a simple, cost-effective intervention that can be automated and can reach any mobile phone owner. While the effect size is small, potential health benefits are well worth achieving. PMID:25739668

  7. Robust tracking control of a magnetically suspended rigid body

    NASA Technical Reports Server (NTRS)

    Lim, Kyong B.; Cox, David E.

    1994-01-01

    This study is an application of H-infinity and micro-synthesis for designing robust tracking controllers for the Large Angle Magnetic Suspension Test Facility. The modeling, design, analysis, simulation, and testing of a control law that guarantees tracking performance under external disturbances and model uncertainties is investigated. The type of uncertainties considered and the tracking performance metric used is discussed. This study demonstrates the tradeoff between tracking performance at low frequencies and robustness at high frequencies. Two sets of controllers were designed and tested. The first set emphasized performance over robustness, while the second set traded off performance for robustness. Comparisons of simulation and test results are also included. Current simulation and experimental results indicate that reasonably good robust tracking performance can be attained for this system using multivariable robust control approach.

  8. Robust tracking control of a magnetically suspended rigid body

    NASA Technical Reports Server (NTRS)

    Lim, Kyong B.; Cox, David E.

    1993-01-01

    This study is an application of H-infinity and microsynthesis for designing robust tracking controllers for the Large Angle Magnetic Suspension Test Facility. The modeling, design, analysis, simulation, and testing of a control law that guarantees tracking performance under external disturbances and model uncertainties is investigated. The type of uncertainties considered and the tracking performance metric used is discussed. This study demonstrates the tradeoff between tracking performance at low frequencies and robustness at high frequencies. Two sets of controllers were designed and tested. The first set emphasized performance over robustness, while the second set traded off performance for robustness. Comparisons of simulation and test results are also included. Current simulation and experimental results indicate that reasonably good robust tracking performance can be attained for this system, using multivariable robust control approach.

  9. Experimental Robust Control Studies on an Unstable Magnetic Suspension System

    NASA Technical Reports Server (NTRS)

    Lim, Kyong B.; Cox, David E.

    1993-01-01

    This study is an experimental investigation of the robustness of various controllers designed for the Large Angle Magnetic Suspension Test Fixture (LAMSTF). Both analytical and identified nominal models are used for designing controllers along with two different types of uncertainty models. Robustness refers to maintain- ing tracking performance under analytical model errors and dynamically induced eddy currents, while external disturbances are not considered. Results show that incorporating robustness into analytical models gives significantly better results. However, incorporating incorrect uncertainty models may lead to poorer performance than not designing for robustness at all. Designing controllers based on accurate identified models gave the best performance. In fact, incorporating a significant level of robustness into an accurate nominal model resulted in reduced performance. This paper discusses an assortment of experimental results in a consistent manner using robust control theory.

  10. SWIM (sickle with ibuprofen and morphine) randomised controlled trial fails to recruit: lessons learnt

    PubMed Central

    Cho, Gavin; Anie, Kofi A; Buckton, Jacky; Kiilu, Patricia; Layton, Mark; Alexander, Lydia; Hemmaway, Claire; Sutton, Dorothy; Amos, Claire; Doré, Caroline J; Kahan, Brennan; Meredith, Sarah

    2016-01-01

    Objectives Sickle With Ibuprofen and Morphine (SWIM) trial was designed to assess whether co-administration of ibuprofen (a non-steroidal anti-inflammatory drug) resulted in a reduction of opioid consumption delivered by patient-controlled analgesia (PCA) for acute pain in sickle cell disease. Design A randomised, placebo-controlled, double-blind trial. Setting UK multicentre trial in acute hospital setting. Participants Adults with sickle cell disease of any gender and phenotype aged 16 years and over. Interventions Oral ibuprofen at a dose of 800 mg three times daily or placebo in addition to opioids (morphine or diamorphine) administered via PCA pump for up to 4 days. Main outcome measures The primary outcome measure was opioid consumption over 4 days following randomisation. Results The SWIM trial closed early because it failed to randomise to its target of 316 patients within a reasonable time. Conclusions The key issues identified include the unanticipated length of time between informed consent and randomisation, difficulties in randomisation of patients in busy emergency departments, availability of trained staff at weekends and out of hours, fewer centres than expected using PCA routinely for sickle cell pain treatment, lack of research staff and support for participation, and the trial design. There are implications for future UK trials in sickle cell disease. Trial registration number ISRCTN97241637, NCT00880373; Pre-results. PMID:27288381

  11. Integrated identification and robust control tuning for large space structures

    NASA Technical Reports Server (NTRS)

    Yam, Y.; Bayard, D. S.; Scheid, R. E.

    1990-01-01

    System identification is studied for the explicit purpose of supporting modern H-infinity robust control design objectives. In the analysis, the true plant is not assumed to be in the identification model set. An integrated identification/robust control problem is posed in which the optimal solution guarantees the best robust performance relative to the system information contained in a given experimental data set. A numerical example demonstrating an approximate solution to the problem indicates the usefulness of the approach.

  12. A criterion for joint optimization of identification and robust control

    NASA Technical Reports Server (NTRS)

    Bayard, D. S.; Yam, Y.; Mettler, E.

    1992-01-01

    A criterion for system identification is developed that is consistent with the intended used of the fitted model for modern robust control synthesis. Specifically, a joint optimization problem is posed which simultaneously solves the plant model estimate and control design, so as to optimize robust performance over the set of plants consistent with a specified experimental data set.

  13. Robust adaptive vibration control of a flexible structure.

    PubMed

    Khoshnood, A M; Moradi, H M

    2014-07-01

    Different types of L1 adaptive control systems show that using robust theories with adaptive control approaches has produced high performance controllers. In this study, a model reference adaptive control scheme considering robust theories is used to propose a practical control system for vibration suppression of a flexible launch vehicle (FLV). In this method, control input of the system is shaped from the dynamic model of the vehicle and components of the control input are adaptively constructed by estimating the undesirable vibration frequencies. Robust stability of the adaptive vibration control system is guaranteed by using the L1 small gain theorem. Simulation results of the robust adaptive vibration control strategy confirm that the effects of vibration on the vehicle performance considerably decrease without the loss of the phase margin of the system. PMID:24703188

  14. Identification and robust control of an experimental servo motor.

    PubMed

    Adam, E J; Guestrin, E D

    2002-04-01

    In this work, the design of a robust controller for an experimental laboratory-scale position control system based on a dc motor drive as well as the corresponding identification and robust stability analysis are presented. In order to carry out the robust design procedure, first, a classic closed-loop identification technique is applied and then, the parametrization by internal model control is used. The model uncertainty is evaluated under both parametric and global representation. For the latter case, an interesting discussion about the conservativeness of this description is presented by means of a comparison between the uncertainty disk and the critical perturbation radius approaches. Finally, conclusions about the performance of the experimental system with the robust controller are discussed using comparative graphics of the controlled variable and the Nyquist stability margin as a robustness measurement. PMID:12071255

  15. Robustness Analysis and Optimally Robust Control Design via Sum-of-Squares

    NASA Technical Reports Server (NTRS)

    Dorobantu, Andrei; Crespo, Luis G.; Seiler, Peter J.

    2012-01-01

    A control analysis and design framework is proposed for systems subject to parametric uncertainty. The underlying strategies are based on sum-of-squares (SOS) polynomial analysis and nonlinear optimization to design an optimally robust controller. The approach determines a maximum uncertainty range for which the closed-loop system satisfies a set of stability and performance requirements. These requirements, de ned as inequality constraints on several metrics, are restricted to polynomial functions of the uncertainty. To quantify robustness, SOS analysis is used to prove that the closed-loop system complies with the requirements for a given uncertainty range. The maximum uncertainty range, calculated by assessing a sequence of increasingly larger ranges, serves as a robustness metric for the closed-loop system. To optimize the control design, nonlinear optimization is used to enlarge the maximum uncertainty range by tuning the controller gains. Hence, the resulting controller is optimally robust to parametric uncertainty. This approach balances the robustness margins corresponding to each requirement in order to maximize the aggregate system robustness. The proposed framework is applied to a simple linear short-period aircraft model with uncertain aerodynamic coefficients.

  16. Stochastic robustness of linear control systems

    NASA Technical Reports Server (NTRS)

    Stengel, Robert F.; Ryan, Laura E.

    1990-01-01

    A simple numerical procedure for estimating the stochastic robustness of a linear, time-invariant system is described. Monte Carlo evaluation of the system's eigenvalues allows the probability of instability and the related stochastic root locus to be estimated. This definition of robustness is an alternative to existing deterministic definitions that address both structured and unstructured parameter variations directly. This analysis approach treats not only Gaussian parameter uncertainties but non-Gaussian cases, including uncertain-but-bounded variations. Trivial extensions of the procedure admit alternate discriminants to be considered. Thus, the probabilities that stipulated degrees of instability will be exceeded or that closed-loop roots will leave desirable regions also can be estimated. Results are particularly amenable to graphical presentation.

  17. Robust controller design for a skid to turn missile

    NASA Astrophysics Data System (ADS)

    Sreenatha, A. G.; Rajhans, Vivek; Bhardwaj, Neeraj

    1999-11-01

    The design and analysis of Robust Autopilot for skid-to-turn missile is presented. Two of the popular Robust Controller design approaches, The Loop Shaping Design Procedure (LSDP) and The Robust Eigenstructure Assignment are considered. The missile model considered in the present work is having lightly damped modes and non-minimum phase zeros, with stringent performance requirements. Numerical results are presented to evaluate the Robustness of stability and performance of the controller. Merits and demerits of the above said methodologies are brought out clearly as applied to this specific plant.

  18. Cost averaging techniques for robust control of flexible structural systems

    NASA Technical Reports Server (NTRS)

    Hagood, Nesbitt W.; Crawley, Edward F.

    1991-01-01

    Viewgraphs on cost averaging techniques for robust control of flexible structural systems are presented. Topics covered include: modeling of parameterized systems; average cost analysis; reduction of parameterized systems; and static and dynamic controller synthesis.

  19. Adaptive robust control of the EBR-II reactor

    SciTech Connect

    Power, M.A.; Edwards, R.M.

    1996-05-01

    Simulation results are presented for an adaptive H{sub {infinity}} controller, a fixed H{sub {infinity}} controller, and a classical controller. The controllers are applied to a simulation of the Experimental Breeder Reactor II primary system. The controllers are tested for the best robustness and performance by step-changing the demanded reactor power and by varying the combined uncertainty in initial reactor power and control rod worth. The adaptive H{sub {infinity}} controller shows the fastest settling time, fastest rise time and smallest peak overshoot when compared to the fixed H{sub {infinity}} and classical controllers. This makes for a superior and more robust controller.

  20. Review of Randomised Controlled Trials of Internet Interventions for Mental Disorders and Related Conditions

    ERIC Educational Resources Information Center

    Griffiths, Kathleen M.; Christensen, Helen

    2006-01-01

    Self-help Internet interventions have the potential to enable consumers to play a central role in managing their own health. This paper contains a systematic review of 15 randomised controlled trials of the effectiveness of self-help Internet interventions for mental disorders and related conditions. Conditions addressed by the interventions…

  1. Reading and Language Intervention for Children at Risk of Dyslexia: A Randomised Controlled Trial

    ERIC Educational Resources Information Center

    Duff, Fiona J.; Hulme, Charles; Grainger, Katy; Hardwick, Samantha J.; Miles, Jeremy N. V.; Snowling, Margaret J.

    2014-01-01

    Background: Intervention studies for children at risk of dyslexia have typically been delivered preschool, and show short-term effects on letter knowledge and phoneme awareness, with little transfer to literacy. Methods: This randomised controlled trial evaluated the effectiveness of a reading and language intervention for 6-year-old children…

  2. Skills Training to Avoid Inadvertent Plagiarism: Results from a Randomised Control Study

    ERIC Educational Resources Information Center

    Newton, Fiona J.; Wright, Jill D.; Newton, Joshua D.

    2014-01-01

    Plagiarism continues to be a concern within academic institutions. The current study utilised a randomised control trial of 137 new entry tertiary students to assess the efficacy of a scalable short training session on paraphrasing, patch writing and plagiarism. The results indicate that the training significantly enhanced students' overall…

  3. Stress in Fathers of Moderately and Late Preterm Infants: A Randomised Controlled Trial

    ERIC Educational Resources Information Center

    Ravn, Ingrid Helen; Lindemann, Rolf; Smeby, Nina Aarhus; Bunch, Eli Haugen; Sandvik, Leiv; Smith, Lars

    2012-01-01

    The atypical behaviour of preterm infants can elicit stress in fathers and influence their ability to perceive and interpret infants' cues. This study investigated whether fathers of moderately and late preterm infants were more stressed than fathers of term infants. In a randomised controlled trial, we also studied the effect of the Mother-Infant…

  4. Intelligence and Persisting with Medication for Two Years: Analysis in a Randomised Controlled Trial

    ERIC Educational Resources Information Center

    Deary, Ian J.; Gale, Catharine R.; Stewart, Marlene C. W.; Fowkes, F. Gerald R.; Murray, Gordon D.; Batty, G. David; Price, Jacqueline F.

    2009-01-01

    The study examined whether verbal intelligence is associated with persisting to take medication for up to two years. The design is a prospective follow-up of compliance with taking medication in high-risk individuals participating in a randomised, placebo-controlled trial set in Central Scotland. Participants were 1993 people aged between 50 and…

  5. Representation of People with Intellectual Disabilities in Randomised Controlled Trials on Antipsychotic Treatment for Behavioural Problems

    ERIC Educational Resources Information Center

    Scheifes, A.; Stolker, J. J.; Egberts, A. C. G.; Nijman, H. L. I.; Heerdink, E. R.

    2011-01-01

    Background: Behavioural problems are common in people with intellectual disability (ID) and are often treated with antipsychotics. Aim: To establish the frequency and characteristics of people with ID included in randomised controlled trials (RCTs) on antipsychotic treatment for behavioural problems, and to investigate the quality of these RCTs.…

  6. Gabapentin for the Management of Chronic Pelvic Pain in Women (GaPP1): A Pilot Randomised Controlled Trial

    PubMed Central

    Lewis, Steff C.; Bhattacharya, Siladitya; Wu, Olivia; Vincent, Katy; Jack, Stuart A.; Critchley, Hilary O. D.; Porter, Maureen A.; Cranley, Denise; Wilson, John A.; Horne, Andrew W.

    2016-01-01

    Chronic pelvic pain (CPP) affects 2.1–24% of women. Frequently, no underlying pathology is identified, and the pain is difficult to manage. Gabapentin is prescribed for CPP despite no robust evidence of efficacy. We performed a pilot trial in two UK centres to inform the planning of a future multicentre RCT to evaluate gabapentin in CPP management. Our primary objective was to determine levels of participant recruitment and retention. Secondary objectives included estimating potential effectiveness, acceptability to participants of trial methodology, and cost-effectiveness of gabapentin. Women with CPP and no obvious pelvic pathology were assigned to an increasing regimen of gabapentin (300-2700mg daily) or placebo. We calculated the proportion of eligible women randomised, and of randomised participants who were followed up to six months. The analyses by treatment group were by intention-to-treat. Interviews were conducted to evaluate women’s experiences of the trial. A probabilistic decision analytical model was used to estimate cost-effectiveness. Between September 2012–2013, 47 women (34% of those eligible) were randomised (22 to gabapentin, 25 to placebo), and 25 (53%) completed six-month follow-up. Participants on gabapentin had less pain (BPI difference 1.72 points, 95% CI:0.07–3.36), and an improvement in mood (HADS difference 4.35 points, 95% CI:1.97–6.73) at six months than those allocated placebo. The majority of participants described their trial experience favorably. At the UK threshold for willingness-to-pay, the probabilities of gabapentin or no treatment being cost-effective are similar. A pilot trial assessing gabapentin for CPP was feasible, but uncertainty remains, highlighting the need for a large definitive trial. Trial registration Controlled-Trials.com ISRCTN45178534 PMID:27070434

  7. Robust Control Design for Systems With Probabilistic Uncertainty

    NASA Technical Reports Server (NTRS)

    Crespo, Luis G.; Kenny, Sean P.

    2005-01-01

    This paper presents a reliability- and robustness-based formulation for robust control synthesis for systems with probabilistic uncertainty. In a reliability-based formulation, the probability of violating design requirements prescribed by inequality constraints is minimized. In a robustness-based formulation, a metric which measures the tendency of a random variable/process to cluster close to a target scalar/function is minimized. A multi-objective optimization procedure, which combines stability and performance requirements in time and frequency domains, is used to search for robustly optimal compensators. Some of the fundamental differences between the proposed strategy and conventional robust control methods are: (i) unnecessary conservatism is eliminated since there is not need for convex supports, (ii) the most likely plants are favored during synthesis allowing for probabilistic robust optimality, (iii) the tradeoff between robust stability and robust performance can be explored numerically, (iv) the uncertainty set is closely related to parameters with clear physical meaning, and (v) compensators with improved robust characteristics for a given control structure can be synthesized.

  8. Generalized internal model robust control for active front steering intervention

    NASA Astrophysics Data System (ADS)

    Wu, Jian; Zhao, Youqun; Ji, Xuewu; Liu, Yahui; Zhang, Lipeng

    2015-03-01

    Because of the tire nonlinearity and vehicle's parameters' uncertainties, robust control methods based on the worst cases, such as H ∞, µ synthesis, have been widely used in active front steering control, however, in order to guarantee the stability of active front steering system (AFS) controller, the robust control is at the cost of performance so that the robust controller is a little conservative and has low performance for AFS control. In this paper, a generalized internal model robust control (GIMC) that can overcome the contradiction between performance and stability is used in the AFS control. In GIMC, the Youla parameterization is used in an improved way. And GIMC controller includes two sections: a high performance controller designed for the nominal vehicle model and a robust controller compensating the vehicle parameters' uncertainties and some external disturbances. Simulations of double lane change (DLC) maneuver and that of braking on split- µ road are conducted to compare the performance and stability of the GIMC control, the nominal performance PID controller and the H ∞ controller. Simulation results show that the high nominal performance PID controller will be unstable under some extreme situations because of large vehicle's parameters variations, H ∞ controller is conservative so that the performance is a little low, and only the GIMC controller overcomes the contradiction between performance and robustness, which can both ensure the stability of the AFS controller and guarantee the high performance of the AFS controller. Therefore, the GIMC method proposed for AFS can overcome some disadvantages of control methods used by current AFS system, that is, can solve the instability of PID or LQP control methods and the low performance of the standard H ∞ controller.

  9. Robust control design verification using the modular modeling system

    SciTech Connect

    Edwards, R.M.; Ben-Abdennour, A.; Lee, K.Y.

    1991-01-01

    The Modular Modeling System (B W MMS) is being used as a design tool to verify robust controller designs for improving power plant performance while also providing fault-accommodating capabilities. These controllers are designed based on optimal control theory and are thus model based controllers which are targeted for implementation in a computer based digital control environment. The MMS is being successfully used to verify that the controllers are tolerant of uncertainties between the plant model employed in the controller and the actual plant; i.e., that they are robust. The two areas in which the MMS is being used for this purpose is in the design of (1) a reactor power controller with improved reactor temperature response, and (2) the design of a multiple input multiple output (MIMO) robust fault-accommodating controller for a deaerator level and pressure control problem.

  10. Design of flight control systems via robust decoupled servomechanism theory

    NASA Technical Reports Server (NTRS)

    Wang, S.-H.; Davison, E. J.

    1979-01-01

    Decoupling theory and robust servomechanism theory are applied to the design of linear multivariable systems with large parameter variations. In addition to being approximately decoupled in the transient period, the over-all system achieves tracking and disturbance rejection robustly in the steady state. An example in flight control system is given.

  11. Robust on-off pulse control of flexible space vehicles

    NASA Technical Reports Server (NTRS)

    Wie, Bong; Sinha, Ravi

    1993-01-01

    The on-off reaction jet control system is often used for attitude and orbital maneuvering of various spacecraft. Future space vehicles such as the orbital transfer vehicles, orbital maneuvering vehicles, and space station will extensively use reaction jets for orbital maneuvering and attitude stabilization. The proposed robust fuel- and time-optimal control algorithm is used for a three-mass spacing model of flexible spacecraft. A fuel-efficient on-off control logic is developed for robust rest-to-rest maneuver of a flexible vehicle with minimum excitation of structural modes. The first part of this report is concerned with the problem of selecting a proper pair of jets for practical trade-offs among the maneuvering time, fuel consumption, structural mode excitation, and performance robustness. A time-optimal control problem subject to parameter robustness constraints is formulated and solved. The second part of this report deals with obtaining parameter insensitive fuel- and time- optimal control inputs by solving a constrained optimization problem subject to robustness constraints. It is shown that sensitivity to modeling errors can be significantly reduced by the proposed, robustified open-loop control approach. The final part of this report deals with sliding mode control design for uncertain flexible structures. The benchmark problem of a flexible structure is used as an example for the feedback sliding mode controller design with bounded control inputs and robustness to parameter variations is investigated.

  12. Robust tuning of robot control systems

    NASA Technical Reports Server (NTRS)

    Minis, I.; Uebel, M.

    1992-01-01

    The computed torque control problem is examined for a robot arm with flexible, geared, joint drive systems which are typical in many industrial robots. The standard computed torque algorithm is not directly applicable to this class of manipulators because of the dynamics introduced by the joint drive system. The proposed approach to computed torque control combines a computed torque algorithm with torque controller at each joint. Three such control schemes are proposed. The first scheme uses the joint torque control system currently implemented on the robot arm and a novel form of the computed torque algorithm. The other two use the standard computed torque algorithm and a novel model following torque control system based on model following techniques. Standard tasks and performance indices are used to evaluate the performance of the controllers. Both numerical simulations and experiments are used in evaluation. The study shows that all three proposed systems lead to improved tracking performance over a conventional PD controller.

  13. High-performance quantitative robust switching control for optical telescopes

    NASA Astrophysics Data System (ADS)

    Lounsbury, William P.; Garcia-Sanz, Mario

    2014-07-01

    This paper introduces an innovative robust and nonlinear control design methodology for high-performance servosystems in optical telescopes. The dynamics of optical telescopes typically vary according to azimuth and altitude angles, temperature, friction, speed and acceleration, leading to nonlinearities and plant parameter uncertainty. The methodology proposed in this paper combines robust Quantitative Feedback Theory (QFT) techniques with nonlinear switching strategies that achieve simultaneously the best characteristics of a set of very active (fast) robust QFT controllers and very stable (slow) robust QFT controllers. A general dynamic model and a variety of specifications from several different commercially available amateur Newtonian telescopes are used for the controller design as well as the simulation and validation. It is also proven that the nonlinear/switching controller is stable for any switching strategy and switching velocity, according to described frequency conditions based on common quadratic Lyapunov functions (CQLF) and the circle criterion.

  14. Robustness of solutions to a benchmark control problem

    NASA Technical Reports Server (NTRS)

    Stengel, Robert F.; Marrison, Christopher I.

    1992-01-01

    The robustness of 10 solutions to a benchmark control design problem presented at the 1990 American Control Conference has been evaluated. The 10 controllers have second-to-eighth-order transfer functions and have been designed using several different methods, including H-infinity optimization, loop-transfer recovery, imaginary-axis shifting, constrained optimization, structured covariance, game theory, and the internal model principle. Stochastic robustness analysis quantifies the controllers' stability and performance robustness with structured uncertainties in up to six system parameters. The analysis provides insights into system response that are not readily derived from other robustness criteria and provides a common ground for judging controllers produced by alternative methods. One important conclusion is that gain and phase margins are not reliable indicators of the probability of instability. Furthermore, parameter variations actually may improve the likelihood of achieving selected performance metrics, as demonstrated by results for the probability of settling-time exceedance.

  15. A Robustly Stabilizing Model Predictive Control Algorithm

    NASA Technical Reports Server (NTRS)

    Ackmece, A. Behcet; Carson, John M., III

    2007-01-01

    A model predictive control (MPC) algorithm that differs from prior MPC algorithms has been developed for controlling an uncertain nonlinear system. This algorithm guarantees the resolvability of an associated finite-horizon optimal-control problem in a receding-horizon implementation.

  16. Conductive Education as a Method of Stroke Rehabilitation: A Single Blinded Randomised Controlled Feasibility Study

    PubMed Central

    Jutley-Neilson, Jagjeet; Russell, Nicholas C. C.; Sackley, Catherine M.

    2016-01-01

    Background. Conductive Education for stroke survivors has shown promise but randomised evidence is unavailable. This study assessed the feasibility of a definitive randomised controlled trial to evaluate efficacy. Methods. Adult stroke survivors were recruited through local community notices. Those completing the baseline assessment were randomised using an online program and group allocation was independent. Intervention group participants received 10 weekly 1.5-hour sessions of Conductive Education at the National Institute of Conductive Education in Birmingham, UK. The control group participants attended two group meetings. The study evaluated the feasibility of recruitment procedures, delivery of the intervention, retention of participants, and appropriateness of outcome measures and data collection methods. Independent assessments included the Barthel Index, the Stroke Impact Scale, the Timed Up and Go test, and the Hospital Anxiety and Depression Scale. Results. Eighty-two patients were enrolled; 77 completed the baseline assessment (46 men, mean age 62.1 yrs.) and were randomised. 70 commenced the intervention (n = 37) or an equivalent waiting period (n = 33). 32/37 completed the 10-week training and 32/33 the waiting period. There were no missing items from completed questionnaires and no adverse events. Discussion. Recruitment, intervention, and assessment methods worked well. Transport issues for intervention and assessment appointments require review. Conclusion. A definitive trial is feasible. This trial is registered with ISRCTN84064492. PMID:27418997

  17. Modern CACSD using the Robust-Control Toolbox

    NASA Technical Reports Server (NTRS)

    Chiang, Richard Y.; Safonov, Michael G.

    1989-01-01

    The Robust-Control Toolbox is a collection of 40 M-files which extend the capability of PC/PRO-MATLAB to do modern multivariable robust control system design. Included are robust analysis tools like singular values and structured singular values, robust synthesis tools like continuous/discrete H(exp 2)/H infinity synthesis and Linear Quadratic Gaussian Loop Transfer Recovery methods and a variety of robust model reduction tools such as Hankel approximation, balanced truncation and balanced stochastic truncation, etc. The capabilities of the toolbox are described and illustated with examples to show how easily they can be used in practice. Examples include structured singular value analysis, H infinity loop-shaping and large space structure model reduction.

  18. Vehicle active steering control research based on two-DOF robust internal model control

    NASA Astrophysics Data System (ADS)

    Wu, Jian; Liu, Yahui; Wang, Fengbo; Bao, Chunjiang; Sun, Qun; Zhao, Youqun

    2016-03-01

    Because of vehicle's external disturbances and model uncertainties, robust control algorithms have obtained popularity in vehicle stability control. The robust control usually gives up performance in order to guarantee the robustness of the control algorithm, therefore an improved robust internal model control(IMC) algorithm blending model tracking and internal model control is put forward for active steering system in order to reach high performance of yaw rate tracking with certain robustness. The proposed algorithm inherits the good model tracking ability of the IMC control and guarantees robustness to model uncertainties. In order to separate the design process of model tracking from the robustness design process, the improved 2 degree of freedom(DOF) robust internal model controller structure is given from the standard Youla parameterization. Simulations of double lane change maneuver and those of crosswind disturbances are conducted for evaluating the robust control algorithm, on the basis of a nonlinear vehicle simulation model with a magic tyre model. Results show that the established 2-DOF robust IMC method has better model tracking ability and a guaranteed level of robustness and robust performance, which can enhance the vehicle stability and handling, regardless of variations of the vehicle model parameters and the external crosswind interferences. Contradiction between performance and robustness of active steering control algorithm is solved and higher control performance with certain robustness to model uncertainties is obtained.

  19. Computation of robustly stabilizing PID controllers for interval systems.

    PubMed

    Matušů, Radek; Prokop, Roman

    2016-01-01

    The paper is focused on the computation of all possible robustly stabilizing Proportional-Integral-Derivative (PID) controllers for plants with interval uncertainty. The main idea of the proposed method is based on Tan's (et al.) technique for calculation of (nominally) stabilizing PI and PID controllers or robustly stabilizing PI controllers by means of plotting the stability boundary locus in either P-I plane or P-I-D space. Refinement of the existing method by consideration of 16 segment plants instead of 16 Kharitonov plants provides an elegant and efficient tool for finding all robustly stabilizing PID controllers for an interval system. The validity and relatively effortless application of presented theoretical concepts are demonstrated through a computation and simulation example in which the uncertain mathematical model of an experimental oblique wing aircraft is robustly stabilized. PMID:27350931

  20. Panaceas, uncertainty, and the robust control framework in sustainability science

    PubMed Central

    Anderies, John M.; Rodriguez, Armando A.; Janssen, Marco A.; Cifdaloz, Oguzhan

    2007-01-01

    A critical challenge faced by sustainability science is to develop strategies to cope with highly uncertain social and ecological dynamics. This article explores the use of the robust control framework toward this end. After briefly outlining the robust control framework, we apply it to the traditional Gordon–Schaefer fishery model to explore fundamental performance–robustness and robustness–vulnerability trade-offs in natural resource management. We find that the classic optimal control policy can be very sensitive to parametric uncertainty. By exploring a large class of alternative strategies, we show that there are no panaceas: even mild robustness properties are difficult to achieve, and increasing robustness to some parameters (e.g., biological parameters) results in decreased robustness with respect to others (e.g., economic parameters). On the basis of this example, we extract some broader themes for better management of resources under uncertainty and for sustainability science in general. Specifically, we focus attention on the importance of a continual learning process and the use of robust control to inform this process. PMID:17881574

  1. A robust fuzzy logic controller for robot manipulators with uncertainties.

    PubMed

    Yi, S Y; Chung, M J

    1997-01-01

    Owing to load variation and unmodeled dynamics, a robot manipulator can be classified as a nonlinear dynamic system with structured and unstructured uncertainties. In this paper, the stability and robustness of a class of the fuzzy logic control (FLC) is investigated and a robust FLC is proposed for a robot manipulator with uncertainties. In order to show the performance of the proposed control algorithm, computer simulations are carried out on a simple two-link robot manipulator. PMID:18255910

  2. Robust Design of Motor PWM Control using Modeling and Simulation

    NASA Astrophysics Data System (ADS)

    Zhan, Wei

    A robust design method is developed for Pulse Width Modulation (PWM) motor speed control. A first principle model for DC permanent magnetic motor is used to build a Simulink model for simulation and analysis. Based on the simulation result, the main factors that contributed to the average speed variation are identified using Design of Experiment (DOE). A robust solution is derived to reduce the aver age speed control variation using Response Surface Method (RSM). The robustness of the new design is verified using the simulation model.

  3. Robust nonlinear attitude control of flexible spacecraft

    NASA Technical Reports Server (NTRS)

    Singh, Sahjendra N.

    1987-01-01

    This paper presents an approach to large-angle rotational maneuvers of a spacecraft-beam-tip body configuration based on nonlinear invertibility and linear feedback stabilization. A control law u sub d is derived for the decoupled control of attitude angles, lateral elastic deflections, slopes due to bending and angular deflection due to torsion at the tip of the beam using torquers and force actuators. For the stabilization of the elastic modes, a linear feedback control law u sub s is obtained based on a linearized model augmented with a servocompensator. Simulation results are presented to show that large slewing and elastic mode stabilization can be accomplished.

  4. Advanced robust tracking control of a powered wheelchair system.

    PubMed

    Nguyen, Nghia T; Nguyen, Hung T; Su, Steven

    2007-01-01

    In this paper, the dynamic multivariable model of the wheelchair system is obtained including the presence of transportation lags. The triangular diagonal dominance (TDD) decoupling technique is applied to reduce this multivariable control problem into two independent scalar control problems. An advanced robust control technique for the wheelchair has been developed based on the combination of a TDD decoupling strategy and neural network controller design. The results obtained from the real-time implementation confirm that robust performance for this multivariable wheelchair control system can indeed be achieved. PMID:18003071

  5. Robust H∞ Control for Spacecraft Rendezvous with a Noncooperative Target

    PubMed Central

    Wu, Shu-Nan; Zhou, Wen-Ya; Tan, Shu-Jun; Wu, Guo-Qiang

    2013-01-01

    The robust H∞ control for spacecraft rendezvous with a noncooperative target is addressed in this paper. The relative motion of chaser and noncooperative target is firstly modeled as the uncertain system, which contains uncertain orbit parameter and mass. Then the H∞ performance and finite time performance are proposed, and a robust H∞ controller is developed to drive the chaser to rendezvous with the non-cooperative target in the presence of control input saturation, measurement error, and thrust error. The linear matrix inequality technology is used to derive the sufficient condition of the proposed controller. An illustrative example is finally provided to demonstrate the effectiveness of the controller. PMID:24027446

  6. Design of robust level control system of nuclear steam generator

    NASA Astrophysics Data System (ADS)

    Lee, Y. J.; Na, M. G.

    2007-12-01

    The nuclear steam generator feedwater control system is designed by the robust control methods. The design is divided into two steps. First, the feedwater controller in the feedwater station is designed by H ∞ and MWS methods. Then the controller located on the feedback loop is designed both by classical PID and by robust technique. It is found that the feedback controller of simple PID whose coefficients vary with the power is proper for the system performance. The simulations show that the hybrid system of H ∞ and PID has a good performance with proper stability margins.

  7. Robust Adaptive Control In Hilbert Space

    NASA Technical Reports Server (NTRS)

    Wen, John Ting-Yung; Balas, Mark J.

    1990-01-01

    Paper discusses generalization of scheme for adaptive control of finite-dimensional system to infinite-dimensional Hilbert space. Approach involves generalization of command-generator tracker (CGT) theory. Does not require reference model to be same order as that of plant, and knowledge of order of plant not needed. Suitable for application to high-order systems, main emphasis on adjustment of low-order feedback-gain matrix. Analysis particularly relevant to control of large, flexible structures.

  8. Controlled quantum dialogue robust against conspiring users

    NASA Astrophysics Data System (ADS)

    Kao, Shih-Hung; Hwang, Tzonelih

    2016-07-01

    This paper explores a new security problem in controlled quantum dialogue (CQD) protocols, where the communicants may try to conspire to communicate without the controller's permission. According to our survey, all the previous CQD protocols suffer from this attack. In order to resolve this problem, we also present an improvement protocol. The security analyses show that the improved scheme is secure under this and other well-known attacks.

  9. Robust predictive cruise control for commercial vehicles

    NASA Astrophysics Data System (ADS)

    Junell, Jaime; Tumer, Kagan

    2013-10-01

    In this paper we explore learning-based predictive cruise control and the impact of this technology on increasing fuel efficiency for commercial trucks. Traditional cruise control is wasteful when maintaining a constant velocity over rolling hills. Predictive cruise control (PCC) is able to look ahead at future road conditions and solve for a cost-effective course of action. Model- based controllers have been implemented in this field but cannot accommodate many complexities of a dynamic environment which includes changing road and vehicle conditions. In this work, we focus on incorporating a learner into an already successful model- based predictive cruise controller in order to improve its performance. We explore back propagating neural networks to predict future errors then take actions to prevent said errors from occurring. The results show that this approach improves the model based PCC by up to 60% under certain conditions. In addition, we explore the benefits of classifier ensembles to further improve the gains due to intelligent cruise control.

  10. Design and tuning of robust PID controller for HVAC systems

    SciTech Connect

    Kasahara, Masato; Matsuba, Tadahiko; Kuzuu, Yoshiaki; Yamazaki, Takanori; Hashimoto, Yukihiro; Kamimura, Kazuyuki; Kurosu, Shigeru

    1999-07-01

    This paper concerns the development of a new design and tuning method for use with robust proportional-plus-integral-plus-derivative (PID) controllers that are commonly used in the heating, ventilating, and air-conditioning (HVAC) fields. The robust PID controller is designed for temperature control of a single-zone environmental space. Although the dynamics of environmental space are described by higher-order transfer functions, most HVAC plants are approximated by first-order lag plus deadtime systems. Its control performance is examined for this commonly approximated controlled plant. Since most HVAC plants are complex with nonlinearity, distributed parameters, and multivariables, a single set of PID gains does not necessarily yield a satisfactory control performance. For this reason, the PID controller must be designed as a robust control system considering model uncertainty caused by changes in characteristics of the plant. The PID gains obtained by solving a two-disk type of mixed sensitivity problem can be modified by contrast to those tuned by the traditional Ziegler-Nichols rule. The results, which are surprisingly simple, are given as linear functions of ratio of deadtime to time constant for robustness. The numerical simulation and the experiments on a commercial-size test plant for air conditioning suggest that the robust PID controller proposed in this paper is effective enough for practical applications.

  11. Motor control or graded activity exercises for chronic low back pain? A randomised controlled trial

    PubMed Central

    Macedo, Luciana G; Latimer, Jane; Maher, Chris G; Hodges, Paul W; Nicholas, Michael; Tonkin, Lois; McAuley, James H; Stafford, Ryan

    2008-01-01

    Background Chronic low back pain remains a major health problem in Australia and around the world. Unfortunately the majority of treatments for this condition produce small effects because not all patients respond to each treatment. It appears that only 25–50% of patients respond to exercise. The two most popular types of exercise for low back pain are graded activity and motor control exercises. At present however, there are no guidelines to help clinicians select the best treatment for a patient. As a result, time and money are wasted on treatments which ultimately fail to help the patient. Methods This paper describes the protocol of a randomised clinical trial comparing the effects of motor control exercises with a graded activity program in the treatment of chronic non specific low back pain. Further analysis will identify clinical features that may predict a patient's response to each treatment. One hundred and seventy two participants will be randomly allocated to receive either a program of motor control exercises or graded activity. Measures of outcome will be obtained at 2, 6 and 12 months after randomisation. The primary outcomes are: pain (average pain intensity over the last week) and function (patient-specific functional scale) at 2 and 6 months. Potential treatment effect modifiers will be measured at baseline. Discussion This trial will not only evaluate which exercise approach is more effective in general for patients will chronic low back pain, but will also determine which exercise approach is best for an individual patient. Trial registration number ACTRN12607000432415 PMID:18454877

  12. A novel robust speed controller scheme for PMBLDC motor.

    PubMed

    Thirusakthimurugan, P; Dananjayan, P

    2007-10-01

    The design of speed and position controllers for permanent magnet brushless DC motor (PMBLDC) drive remains as an open problem in the field of motor drives. A precise speed control of PMBLDC motor is complex due to nonlinear coupling between winding currents and rotor speed. In addition, the nonlinearity present in the developed torque due to magnetic saturation of the rotor further complicates this issue. This paper presents a novel control scheme to the conventional PMBLDC motor drive, which aims at improving the robustness by complete decoupling of the design besides minimizing the mutual influence among the speed and current control loops. The interesting feature of this robust control scheme is its suitability for both static and dynamic aspects. The effectiveness of the proposed robust speed control scheme is verified through simulations. PMID:17544426

  13. Robust Control for the Mercury Laser Altimeter

    NASA Technical Reports Server (NTRS)

    Rosenberg, Jacob S.

    2006-01-01

    Mercury Laser Altimeter Science Algorithms is a software system for controlling the laser altimeter aboard the Messenger spacecraft, which is to enter into orbit about Mercury in 2011. The software will control the altimeter by dynamically modifying hardware inputs for gain, threshold, channel-disable flags, range-window start location, and range-window width, by using ranging information provided by the spacecraft and noise counts from instrument hardware. In addition, because of severe bandwidth restrictions, the software also selects returns for downlink.

  14. Robust tuning of two-loop automatic control systems

    NASA Astrophysics Data System (ADS)

    Smirnov, N. I.; Sabanin, V. R.; Repin, A. I.

    2007-07-01

    We propose a solution to the problem of finding trade-off robust tuning parameters for two-loop automatic control systems by means of a numerical simulation method using the authors’ version of the Optim-MGA evolutionary optimization algorithm. Results from calculating and analyzing a two-loop superheated steam temperature control system employing a PI controller and a differentiator are presented.

  15. A stochastic approach to robust broadband structural control

    NASA Technical Reports Server (NTRS)

    Macmartin, Douglas G.; Hall, Steven R.

    1992-01-01

    Viewgraphs on a stochastic approach to robust broadband structural control are presented. Topics covered include: travelling wave model; dereverberated mobility model; computation of dereverberated mobility; power flow; impedance matching; stochastic systems; control problem; control of stochastic systems; using cost functional; Bernoulli-Euler beam example; compensator design; 'power' dual variables; dereverberation of complex structure; and dereverberated transfer function.

  16. A Robust Control Design Framework for Substructure Models

    NASA Technical Reports Server (NTRS)

    Lim, Kyong B.

    1994-01-01

    A framework for designing control systems directly from substructure models and uncertainties is proposed. The technique is based on combining a set of substructure robust control problems by an interface stiffness matrix which appears as a constant gain feedback. Variations of uncertainties in the interface stiffness are treated as a parametric uncertainty. It is shown that multivariable robust control can be applied to generate centralized or decentralized controllers that guarantee performance with respect to uncertainties in the interface stiffness, reduced component modes and external disturbances. The technique is particularly suited for large, complex, and weakly coupled flexible structures.

  17. Variable neural adaptive robust control: a switched system approach.

    PubMed

    Lian, Jianming; Hu, Jianghai; Żak, Stanislaw H

    2015-05-01

    Variable neural adaptive robust control strategies are proposed for the output tracking control of a class of multiinput multioutput uncertain systems. The controllers incorporate a novel variable-structure radial basis function (RBF) network as the self-organizing approximator for unknown system dynamics. It can determine the network structure online dynamically by adding or removing RBFs according to the tracking performance. The structure variation is systematically considered in the stability analysis of the closed-loop system using a switched system approach with the piecewise quadratic Lyapunov function. The performance of the proposed variable neural adaptive robust controllers is illustrated with simulations. PMID:25881366

  18. Specificity and robustness in transcription control networks.

    PubMed

    Sengupta, Anirvan M; Djordjevic, Marko; Shraiman, Boris I

    2002-02-19

    Recognition by transcription factors of the regulatory DNA elements upstream of genes is the fundamental step in controlling gene expression. How does the necessity to provide stability with respect to mutation constrain the organization of transcription control networks? We examine the mutation load of a transcription factor interacting with a set of n regulatory response elements as a function of the factor/DNA binding specificity and conclude on theoretical grounds that the optimal specificity decreases with n. The predicted correlation between variability of binding sites (for a given transcription factor) and their number is supported by the genomic data for Escherichia coli. The analysis of E. coli genomic data was carried out using an algorithm suggested by the biophysical model of transcription factor/DNA binding. Complete results of the search for candidate transcription factor binding sites are available at http://www.physics.rockefeller.edu/~boris/public/search_ecoli. PMID:11854503

  19. Low bandwidth robust controllers for flight

    NASA Technical Reports Server (NTRS)

    Biezad, Daniel J.; Chou, Hwei-Lan

    1992-01-01

    During the final reporting period (Jun. - Dec. 1992), analyses of the longitudinal and lateral flying qualities were made for propulsive-only flight control (POFC) of a Boeing 720 aircraft model. Performance resulting from compensators developed using Quantitative Feedback Theory (QFT) is documented and analyzed. This report is a first draft of a thesis to be presented by graduate student Hwei-Lan Chou. The final thesis will be presented to NASA when it is completed later this year. The latest landing metrics related to bandwidth criteria and based on the Neal-Smith approach to flying qualities prediction were used in developing performance criteria for the controllers. The compensator designs were tested on the NASA simulator and exhibited adequate performance for piloted flight. There was no significant impact of QFT on performance of the propulsive-only flight controllers in either the longitudinal or lateral modes of flight. This was attributed to the physical limits of thrust available and the engine rate of response, both of whiih severely limited the available bandwidth of the closed-loop system.

  20. A Computational Framework to Control Verification and Robustness Analysis

    NASA Technical Reports Server (NTRS)

    Crespo, Luis G.; Kenny, Sean P.; Giesy, Daniel P.

    2010-01-01

    This paper presents a methodology for evaluating the robustness of a controller based on its ability to satisfy the design requirements. The framework proposed is generic since it allows for high-fidelity models, arbitrary control structures and arbitrary functional dependencies between the requirements and the uncertain parameters. The cornerstone of this contribution is the ability to bound the region of the uncertain parameter space where the degradation in closed-loop performance remains acceptable. The size of this bounding set, whose geometry can be prescribed according to deterministic or probabilistic uncertainty models, is a measure of robustness. The robustness metrics proposed herein are the parametric safety margin, the reliability index, the failure probability and upper bounds to this probability. The performance observed at the control verification setting, where the assumptions and approximations used for control design may no longer hold, will fully determine the proposed control assessment.

  1. Group mindfulness-based intervention for distressing voices: A pragmatic randomised controlled trial.

    PubMed

    Chadwick, Paul; Strauss, Clara; Jones, Anna-Marie; Kingdon, David; Ellett, Lyn; Dannahy, Laura; Hayward, Mark

    2016-08-01

    Group Person-Based Cognitive Therapy (PBCT) integrates cognitive therapy and mindfulness to target distinct sources of distress in psychosis. The present study presents data from the first randomised controlled trial investigating group PBCT in people distressed by hearing voices. One-hundred and eight participants were randomised to receive either group PBCT and Treatment As Usual (TAU) or TAU only. While there was no significant effect on the primary outcome, a measure of general psychological distress, results showed significant between-group post-intervention benefits in voice-related distress, perceived controllability of voices and recovery. Participants in the PBCT group reported significantly lower post-treatment levels of depression, with this effect maintained at six-month follow-up. Findings suggest PBCT delivered over 12weeks effectively impacts key dimensions of the voice hearing experience, supports meaningful behaviour change, and has lasting effects on mood. PMID:27146475

  2. A complex intervention to improve pregnancy outcome in obese women; the UPBEAT randomised controlled trial

    PubMed Central

    2014-01-01

    Background Despite the widespread recognition that obesity in pregnant women is associated with adverse outcomes for mother and child, there is no intervention proven to reduce the risk of these complications. The primary aim of this randomised controlled trial is to assess in obese pregnant women, whether a complex behavioural intervention, based on changing diet (to foods with a lower glycemic index) and physical activity, will reduce the risk of gestational diabetes (GDM) and delivery of a large for gestational age (LGA) infant. A secondary aim is to determine whether the intervention lowers the long term risk of obesity in the offspring. Methods/Design Multicentre randomised controlled trial comparing a behavioural intervention designed to improve glycemic control with standard antenatal care in obese pregnant women. Inclusion criteria; women with a BMI ≥30 kg/m2 and a singleton pregnancy between 15+0 weeks and 18+6 weeks’ gestation. Exclusion criteria; pre-defined, pre-existing diseases and multiple pregnancy. Randomisation is on-line by a computer generated programme and is minimised by BMI category, maternal age, ethnicity, parity and centre. Intervention; this is delivered by a health trainer over 8 sessions. Based on control theory, with elements of social cognitive theory, the intervention is designed to improve maternal glycemic control. Women randomised to the control arm receive standard antenatal care until delivery according to local guidelines. All women have a 75 g oral glucose tolerance test at 27+0- 28+6 weeks’ gestation. Primary outcome; Maternal: diagnosis of GDM, according to the International Association of Diabetes in Pregnancy Study Group (IADPSG) criteria. Neonatal; infant LGA defined as >90th customised birth weight centile. Sample size; 1546 women to provide 80% power to detect a 25% reduction in the incidence of GDM and a 30% reduction in infants large for gestational age. Discussion All aspects of this protocol have been

  3. Robust time and frequency domain estimation methods in adaptive control

    NASA Technical Reports Server (NTRS)

    Lamaire, Richard Orville

    1987-01-01

    A robust identification method was developed for use in an adaptive control system. The type of estimator is called the robust estimator, since it is robust to the effects of both unmodeled dynamics and an unmeasurable disturbance. The development of the robust estimator was motivated by a need to provide guarantees in the identification part of an adaptive controller. To enable the design of a robust control system, a nominal model as well as a frequency-domain bounding function on the modeling uncertainty associated with this nominal model must be provided. Two estimation methods are presented for finding parameter estimates, and, hence, a nominal model. One of these methods is based on the well developed field of time-domain parameter estimation. In a second method of finding parameter estimates, a type of weighted least-squares fitting to a frequency-domain estimated model is used. The frequency-domain estimator is shown to perform better, in general, than the time-domain parameter estimator. In addition, a methodology for finding a frequency-domain bounding function on the disturbance is used to compute a frequency-domain bounding function on the additive modeling error due to the effects of the disturbance and the use of finite-length data. The performance of the robust estimator in both open-loop and closed-loop situations is examined through the use of simulations.

  4. Randomised controlled trial of topical kanuka honey for the treatment of acne

    PubMed Central

    Semprini, Alex; Corin, Andrew; Sheahan, Davitt; Tofield, Christopher; Helm, Colin; Montgomery, Barney; Fingleton, James; Weatherall, Mark; Beasley, Richard

    2016-01-01

    Objective To investigate the efficacy of Honevo, a topical 90% medical-grade kanuka honey, and 10% glycerine (honey product) as a treatment for facial acne. Design Randomised controlled trial with single blind assessment of primary outcome variable. Setting Outpatient primary care from 3 New Zealand localities. Participants Of 136 participants aged between 16 and 40 years with a diagnosis of acne and baseline Investigator's Global Assessment (IGA) for acne score of ≥2.68, participants were randomised to each treatment arm. Interventions All participants applied Protex, a triclocarban-based antibacterial soap twice daily for 12 weeks. Participants randomised to the honey product treatment arm applied this directly after washing off the antibacterial soap, twice daily for 12 weeks. Outcome measures The primary outcome was ≥2 point decrease in IGA score from baseline at 12 weeks. Secondary outcomes included mean lesion counts and changes in subject-rated acne improvement and severity at weeks 4 and 12, and withdrawals for worsening acne. Results 4/53 (7.6%) participants in the honey product group and 1/53 (1.9%) of participants in the control group had a ≥ 2 improvement in IGA score at week 12, compared with baseline, OR (95% CI) for improvement 4.2 (0.5 to 39.3), p=0.17. There were 15 and 14 participants who withdrew from the honey product group and control group, respectively. Conclusions This randomised controlled trial did not find evidence that addition of medical-grade kanuka honey in combination with 10% glycerine to standard antibacterial soap treatment is more effective than the use of antibacterial soap alone in the treatment of acne. Trial registration number ACTRN12614000003673; Results. PMID:26832428

  5. Calculating the probability of random sampling for continuous variables in submitted or published randomised controlled trials.

    PubMed

    Carlisle, J B; Dexter, F; Pandit, J J; Shafer, S L; Yentis, S M

    2015-07-01

    In a previous paper, one of the authors (JBC) used a chi-squared method to analyse the means (SD) of baseline variables, such as height or weight, from randomised controlled trials by Fujii et al., concluding that the probabilities that the reported distributions arose by chance were infinitesimally small. Subsequent testing of that chi-squared method, using simulation, suggested that the method was incorrect. This paper corrects the chi-squared method and tests its performance and the performance of Monte Carlo simulations and ANOVA to analyse the probability of random sampling. The corrected chi-squared method and ANOVA method became inaccurate when applied to means that were reported imprecisely. Monte Carlo simulations confirmed that baseline data from 158 randomised controlled trials by Fujii et al. were different to those from 329 trials published by other authors and that the distribution of Fujii et al.'s data were different to the expected distribution, both p < 10(-16) . The number of Fujii randomised controlled trials with unlikely distributions was less with Monte Carlo simulation than with the 2012 chi-squared method: 102 vs 117 trials with p < 0.05; 60 vs 86 for p < 0.01; 30 vs 56 for p < 0.001; and 12 vs 24 for p < 0.00001, respectively. The Monte Carlo analysis nevertheless confirmed the original conclusion that the distribution of the data presented by Fujii et al. was extremely unlikely to have arisen from observed data. The Monte Carlo analysis may be an appropriate screening tool to check for non-random (i.e. unreliable) data in randomised controlled trials submitted to journals. PMID:26032950

  6. Robust adaptive tracking control for nonholonomic mobile manipulator with uncertainties.

    PubMed

    Peng, Jinzhu; Yu, Jie; Wang, Jie

    2014-07-01

    In this paper, mobile manipulator is divided into two subsystems, that is, nonholonomic mobile platform subsystem and holonomic manipulator subsystem. First, the kinematic controller of the mobile platform is derived to obtain a desired velocity. Second, regarding the coupling between the two subsystems as disturbances, Lyapunov functions of the two subsystems are designed respectively. Third, a robust adaptive tracking controller is proposed to deal with the unknown upper bounds of parameter uncertainties and disturbances. According to the Lyapunov stability theory, the derived robust adaptive controller guarantees global stability of the closed-loop system, and the tracking errors and adaptive coefficient errors are all bounded. Finally, simulation results show that the proposed robust adaptive tracking controller for nonholonomic mobile manipulator is effective and has good tracking capacity. PMID:24917071

  7. Optimization of robustness of network controllability against malicious attacks

    NASA Astrophysics Data System (ADS)

    Xiao, Yan-Dong; Lao, Song-Yang; Hou, Lv-Lin; Bai, Liang

    2014-11-01

    As the controllability of complex networks has attracted much attention recently, how to design and optimize the robustness of network controllability has become a common and urgent problem in the engineering field. In this work, we propose a method that modifies any given network with strict structural perturbation to effectively enhance its robustness against malicious attacks, called dynamic optimization of controllability. Unlike other structural perturbations, the strict perturbation only swaps the links and keeps the in- and out-degree unchanged. A series of extensive experiments show that the robustness of controllability and connectivity can be improved dramatically. Furthermore, the effectiveness of our method is explained from the views of underlying structure. The analysis results indicate that the optimization algorithm makes networks more homogenous and assortative.

  8. Robust levitation control for maglev systems with guaranteed bounded airgap.

    PubMed

    Xu, Jinquan; Chen, Ye-Hwa; Guo, Hong

    2015-11-01

    The robust control design problem for the levitation control of a nonlinear uncertain maglev system is considered. The uncertainty is (possibly) fast time-varying. The system has magnitude limitation on the airgap between the suspended chassis and the guideway in order to prevent undesirable contact. Furthermore, the (global) matching condition is not satisfied. After a three-step state transformation, a robust control scheme for the maglev vehicle is proposed, which is able to guarantee the uniform boundedness and uniform ultimate boundedness of the system, regardless of the uncertainty. The magnitude limitation of the airgap is guaranteed, regardless of the uncertainty. PMID:26524957

  9. Robust vibration control of flexible linkage mechanisms using piezoelectric films

    NASA Astrophysics Data System (ADS)

    Liao, Wen-Hwei; Chou, Jyh-Horng; Horng, Ing-Rong

    1997-08-01

    Based on the state space model of the flexible linkage mechanism equipped with piezoelectric films, a robust control methodology for suppressing elastodynamic responses of the high-speed flexible linkage mechanism with linear time-varying parameter perturbations by employing an observer-based feedback controller is presented. The instability caused by the linear time-varying parameter perturbations and the instability caused by the combined effect of control and observation spillover are investigated and carefully prevented by two robust stability criteria proposed in this paper. Numerical simulation of a slider - crank mechanism example is performed to evaluate the improvement of the elastodynamic responses.

  10. Chinese Obstetrics & Gynecology journal club: a randomised controlled trial

    PubMed Central

    Tsui, Ilene K; Dodson, William C; Kunselman, Allen R; Kuang, Hongying; Han, Feng-Juan; Legro, Richard S; Wu, Xiao-Ke

    2016-01-01

    Objectives To assess whether a journal club model could improve comprehension and written and spoken medical English in a population of Chinese medical professionals. Setting and participants The study population consisted of 52 medical professionals who were residents or postgraduate master or PhD students in the Department of Obstetrics and Gynecology, Heilongjiang University of Chinese Medicine, China. Intervention After a three-part baseline examination to assess medical English comprehension, participants were randomised to either (1) an intensive journal club treatment arm or (2) a self-study group. At the conclusion of the 8-week intervention participants (n=52) were re-tested with new questions. Outcome measures The primary outcome was the change in score on a multiple choice examination. Secondary outcomes included change in scores on written and oral examinations which were modelled on the Test of English as a Foreign Language (TOEFL). Results Both groups had improved scores on the multiple choice examination without a statistically significant difference between them (90% power). However, there was a statistically significant difference between the groups in mean improvement in scores for both written (95% CI 1.1 to 5.0; p=0.003) and spoken English (95% CI 0.06 to 3.7; p=0.04) favouring the journal club intervention. Conclusions Interacting with colleagues and an English-speaking facilitator in a journal club improved both written and spoken medical English in Chinese medical professionals. Journal clubs may be suitable for use as a self-sustainable teaching model to improve fluency in medical English in foreign medical professionals. Trial registration number NCT01844609. PMID:26823180

  11. Simulator training for endobronchial ultrasound: a randomised controlled trial.

    PubMed

    Konge, Lars; Clementsen, Paul Frost; Ringsted, Charlotte; Minddal, Valentina; Larsen, Klaus Richter; Annema, Jouke T

    2015-10-01

    Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is very operator dependent and has a long learning curve. Simulation-based training might shorten the learning curve, and an assessment tool with solid validity evidence could ensure basic competency before unsupervised performance.A total of 16 respiratory physicians, without EBUS experience, were randomised to either virtual-reality simulator training or traditional apprenticeship training on patients, and then each physician performed EBUS-TBNA procedures on three patients. Three blinded, independent assessor assessed the video recordings of the procedures using a newly developed EBUS assessment tool (EBUSAT).The internal consistency was high (Cronbach's α=0.95); the generalisability coefficient was good (0.86), and the tool had discriminatory ability (p<0.001). Procedures performed by simulator-trained novices were rated higher than procedures performed by apprenticeship-trained novices: mean±sd are 24.2±7.9 points and 20.2±9.4 points, respectively; p=0.006. A pass/fail standard of 28.9 points was established using the contrasting groups method, resulting in 16 (67%) and 20 (83%) procedures performed by simulator-trained novices and apprenticeship-trained novices failing the test, respectively; p<0.001.The endobronchial ultrasound assessment tool could be used to provide reliable and valid assessment of competence in EBUS-TBNA, and act as an aid in certification. Virtual-reality simulator training was shown to be more effective than traditional apprenticeship training. PMID:26160875

  12. Metacognitive training for schizophrenia: a multicentre randomised controlled trial.

    PubMed

    Briki, Malick; Monnin, Julie; Haffen, Emmanuel; Sechter, Daniel; Favrod, Jérôme; Netillard, Christian; Cheraitia, Elisabeth; Marin, Karine; Govyadovskaya, Svetlana; Tio, Grégory; Bonin, Bernard; Chauvet-Gelinier, Jean-Christophe; Leclerc, Stéphanie; Hodé, Yann; Vidailhet, Pierre; Berna, Fabrice; Bertschy, Anna Zinetti; Vandel, Pierre

    2014-08-01

    A psychotherapeutic approach for schizophrenia is now recommended as an adjuvant for psychopharmacology, since antipsychotic medications only have a partial impact especially as regards positive symptoms and insight. In addition, cognitive distortions and the lack of metacognitive skills might increase positive symptoms leading to poor social functioning. This underlines the need for specific approaches which target cognitive processes relevant for insight, and abilities in metacognition. Metacognitive training (MCT) is a structured group intervention, which enhances a patient's reflection on cognitive biases and improves problem-solving. The aim of our study was to assess MCTs' short term impact on insight, symptoms and quality of life. Fifty patients with schizophrenia or schizoaffective disorders and persistent positive symptoms (delusions or hallucinations) were enrolled in the study. After baseline assessment participants were randomised either to supportive therapy or MCT. Both groups used the same design (1h-session twice a week during 8weeks) although the basic knowledge given to participants was different between interventions. Participants were assessed at eight weeks based on the Scale to Assess Unawareness of Mental Disorder, Positive and Negative Syndrome Scale (PANSS), Psychotic Symptom Rating Scales, the Calgary Depression Scale for Schizophrenia and the Quality of Life Scale. Between-group differences were significant in favour of MCT on the PANSS positive scale. Between-group differences in post- and pre-test values showed a trend in favour of MCT for insight on hallucinations. Results of our study indicate that the MCT has an effect on reducing positive symptomatology, and a trend impact on insight and social functioning. PMID:24972754

  13. Robust high-performance control for robotic manipulators

    NASA Technical Reports Server (NTRS)

    Seraji, H.

    1989-01-01

    A robust control scheme to accomplish accurate trajectory tracking for an integrated system of manipulator-plus-actuators is proposed. The control scheme comprises a feedforward and a feedback controller. The feedforward controller contains any known part of the manipulator dynamics that can be used for online control. The feedback controller consists of adaptive position and velocity feedback gains and an auxiliary signal which is simply generated by a fixed-gain proportional/integral/derivative controller. The feedback controller is updated by very simple adaptation laws which contain both proportional and integral adaptation terms. By introduction of a simple sigma modification to the adaptation laws, robustness is guaranteed in the presence of unmodeled dynamics and disturbances.

  14. Social Stories in mainstream schools for children with autism spectrum disorder: a feasibility randomised controlled trial

    PubMed Central

    Marshall, David; Wright, Barry; Allgar, Victoria; Adamson, Joy; Williams, Christine; Ainsworth, Hannah; Cook, Liz; Varley, Danielle; Hackney, Lisa; Dempster, Paul; Ali, Shehzad; Trepel, Dominic; Collingridge Moore, Danielle; Littlewood, Elizabeth; McMillan, Dean

    2016-01-01

    Objectives To assess the feasibility of recruitment, retention, outcome measures and intervention training/delivery among teachers, parents and children. To calculate a sample size estimation for full trial. Design A single-centre, unblinded, cluster feasibility randomised controlled trial examining Social Stories delivered within a school environment compared with an attentional control. Setting 37 primary schools in York, UK. Participants 50 participants were recruited and a cluster randomisation approach by school was examined. Participants were randomised into the treatment group (n=23) or a waiting list control group (n=27). Outcome measures Acceptability and feasibility of the trial, intervention and of measurements required to assess outcomes in a definitive trial. Results An assessment of the questionnaire completion rates indicated teachers would be most appropriate to complete the primary outcome measure. 2 outcome measures: the Social Responsiveness Scale (SRS)-2 and a goal-based measure showed both the highest levels of completion rates (above 80%) at the primary follow-up point (6 weeks postintervention) and captured relevant social and behaviour outcomes. Power calculations were based on these 2 outcome measures leading to a total proposed sample size of 180 participant groups. Conclusions Results suggest that a future trial would be feasible to conduct and could inform the policy and practice of using Social Stories in mainstream schools. Trial registration number ISRCTN96286707; Results. PMID:27515756

  15. Robust Control Design for Uncertain Nonlinear Dynamic Systems

    NASA Technical Reports Server (NTRS)

    Kenny, Sean P.; Crespo, Luis G.; Andrews, Lindsey; Giesy, Daniel P.

    2012-01-01

    Robustness to parametric uncertainty is fundamental to successful control system design and as such it has been at the core of many design methods developed over the decades. Despite its prominence, most of the work on robust control design has focused on linear models and uncertainties that are non-probabilistic in nature. Recently, researchers have acknowledged this disparity and have been developing theory to address a broader class of uncertainties. This paper presents an experimental application of robust control design for a hybrid class of probabilistic and non-probabilistic parametric uncertainties. The experimental apparatus is based upon the classic inverted pendulum on a cart. The physical uncertainty is realized by a known additional lumped mass at an unknown location on the pendulum. This unknown location has the effect of substantially altering the nominal frequency and controllability of the nonlinear system, and in the limit has the capability to make the system neutrally stable and uncontrollable. Another uncertainty to be considered is a direct current motor parameter. The control design objective is to design a controller that satisfies stability, tracking error, control power, and transient behavior requirements for the largest range of parametric uncertainties. This paper presents an overview of the theory behind the robust control design methodology and the experimental results.

  16. Case management vocational rehabilitation for women with breast cancer after surgery: a feasibility study incorporating a pilot randomised controlled trial

    PubMed Central

    2013-01-01

    Background There is a paucity of methodologically robust vocational rehabilitation (VR) intervention trials. This study assessed the feasibility and acceptability of a VR trial of women with breast cancer to inform the development of a larger interventional study. Methods Women were recruited in Scotland and randomised to either a case management VR service or to usual care. Data were collected on eligibility, recruitment and attrition rates to assess trial feasibility, and interviews conducted to determine trial acceptability. Sick leave days (primary outcome) were self-reported via postal questionnaire every 4 weeks during the first 6 months post-surgery and at 12 months. Secondary outcome measures were change in employment pattern, quality of life and fatigue. Results Of the 1,114 women assessed for eligibility, 163 (15%) were eligible. The main reason for ineligibility was age (>65 years, n = 637, 67%). Of those eligible, 111 (68%) received study information, of which 23 (21%) consented to participate in the study. Data for 18 (78%) women were analysed (intervention: n = 7; control: n = 11). Participants in the intervention group reported, on average, 53 fewer days of sick leave over the first 6 months post-surgery than those in the control group; however, this difference was not statistically significant (p = 0.122; 95% confidence interval −15.8, 122.0). No statistically significant differences were found for secondary outcomes. Interviews with trial participants indicated that trial procedures, including recruitment, randomisation and research instruments, were acceptable. Conclusions Conducting a pragmatic trial of effectiveness of a VR intervention among cancer survivors is both feasible and acceptable, but more research about the exact components of a VR intervention and choice of outcomes to measure effectiveness is required. VR to assist breast cancer patients in the return to work process is an important component of cancer survivorship plans. Trial

  17. Gut-directed hypnotherapy for irritable bowel syndrome: piloting a primary care-based randomised controlled trial

    PubMed Central

    Roberts, Lesley; Wilson, Sue; Singh, Sukhdev; Roalfe, Andrea; Greenfield, Sheila

    2006-01-01

    Background In western populations irritable bowel syndrome (IBS) affects between 10% and 30% of the population and has a significant effect on quality of life. It generates a substantial workload in both primary and secondary care and has significant cost implications. Gut-directed hypnotherapy has been demonstrated to alleviate symptoms and improve quality of life but has not been assessed outside of secondary and tertiary referral centres. Aim To assess the effectiveness of gut-directed hypnotherapy as a complementary therapy in the management of IBS. Design of study Randomised controlled trial. Setting Primary care patients aged 18–65 years inclusive, with a diagnosis of IBS of greater than 6 weeks' duration and having failed conventional management, located in South Staffordshire and North Birmingham, UK. Method Intervention patients received five sessions of hypnotherapy in addition to their usual management. Control patients received usual management alone. Data regarding symptoms and quality of life were collected at baseline and again 3, 6, and 12 months post-randomisation. Results Both groups demonstrated a significant improvement in all symptom dimensions and quality of life over 12 months. At 3 months the intervention group had significantly greater improvements in pain, diarrhoea and overall symptom scores (P<0.05). No significant differences between groups in quality of life were identified. No differences were maintained over time. Intervention patients, however, were significantly less likely to require medication, and the majority described an improvement in their condition. Conclusions Gut-directed hypnotherapy benefits patients via symptom reduction and reduced medication usage, although the lack of significant difference between groups beyond 3 months prohibits its general introduction without additional evidence. A large trial incorporating robust economic analysis is, therefore, urgently recommended. PMID:16464325

  18. Optimal Robust Motion Controller Design Using Multiobjective Genetic Algorithm

    PubMed Central

    Svečko, Rajko

    2014-01-01

    This paper describes the use of a multiobjective genetic algorithm for robust motion controller design. Motion controller structure is based on a disturbance observer in an RIC framework. The RIC approach is presented in the form with internal and external feedback loops, in which an internal disturbance rejection controller and an external performance controller must be synthesised. This paper involves novel objectives for robustness and performance assessments for such an approach. Objective functions for the robustness property of RIC are based on simple even polynomials with nonnegativity conditions. Regional pole placement method is presented with the aims of controllers' structures simplification and their additional arbitrary selection. Regional pole placement involves arbitrary selection of central polynomials for both loops, with additional admissible region of the optimized pole location. Polynomial deviation between selected and optimized polynomials is measured with derived performance objective functions. A multiobjective function is composed of different unrelated criteria such as robust stability, controllers' stability, and time-performance indexes of closed loops. The design of controllers and multiobjective optimization procedure involve a set of the objectives, which are optimized simultaneously with a genetic algorithm—differential evolution. PMID:24987749

  19. Social Dancing and Incidence of Falls in Older Adults: A Cluster Randomised Controlled Trial

    PubMed Central

    Merom, Dafna; Mathieu, Erin; Cerin, Ester; Morton, Rachael L.; Simpson, Judy M.; Anstey, Kaarin J.; Sherrington, Catherine; Lord, Stephen R.; Cumming, Robert G.

    2016-01-01

    Background The prevention of falls among older people is a major public health challenge. Exercises that challenge balance are recognized as an efficacious fall prevention strategy. Given that small-scale trials have indicated that diverse dance styles can improve balance and gait of older adults, two of the strongest risk factors for falls in older people, this study aimed to determine whether social dance is effective in i) reducing the number of falls and ii) improving physical and cognitive fall-related risk factors. Methods and Findings A parallel two-arm cluster randomized controlled trial was undertaken in 23 self-care retirement villages (clusters) around Sydney, Australia. Eligible villages had to have an appropriate hall for dancing, house at least 60 residents, and not be currently offering dance as a village activity. Retirement villages were randomised using a computer generated randomisation method, constrained using minimisation. Eligible participants had to be a resident of the village, be able to walk at least 50 m, and agree to undergo physical and cognitive testing without cognitive impairment. Residents of intervention villages (12 clusters) were offered twice weekly one-hour social dancing classes (folk or ballroom dancing) over 12 mo (80 h in total). Programs were standardized across villages and were delivered by eight dance teachers. Participants in the control villages (11 clusters) were advised to continue with their regular activities. Main outcomes: falls during the 12 mo trial and Trail Making Tests. Secondary outcomes: The Physiological Performance Assessment (i.e., postural sway, proprioception, reaction time, leg strength) and the Short Physical Performance Battery; health-related physical and mental quality of life from the Short-Form 12 (SF-12) Survey. Data on falls were obtained from 522 of 530 (98%) randomised participants (mean age 78 y, 85% women) and 424 (80%) attended the 12-mo reassessment, which was lower among folk dance

  20. Robust controllers for the Middeck Active Control Experiment using Popov controller synthesis

    NASA Technical Reports Server (NTRS)

    How, Jonathan P.; Hall, Steven R.

    1993-01-01

    Recent work in robust control with real parameter uncertainties has focused on absolute stability and its connections to real mu theory. In particular, the research has investigated the Popov stability criterion and its associated Lur'e-Postnikov Liapunov functions. State space representations of this Popov stability analysis tests are included in an H2 design formulation to provide a powerful technique for robust controller synthesis. This synthesis approach uses a state space optimization procedure to design controllers that minimize an overbound of an H2 cost functional and satisfy stability analysis tests based on the Popov multiplier. The controller and stability multiplier coefficients are optimized simultaneously, which avoids the iteration and curve-fitting procedures required by the D-K algorithm of mu synthesis. While previous work has demonstrated this synthesis approach on benchmark control problems, the purpose of this paper is to use Popov controller synthesis to design robust compensators for the Middeck Active Control Experiment (MACE).

  1. Inositol for the prevention of neural tube defects: a pilot randomised controlled trial.

    PubMed

    Greene, Nicholas D E; Leung, Kit-Yi; Gay, Victoria; Burren, Katie; Mills, Kevin; Chitty, Lyn S; Copp, Andrew J

    2016-03-01

    Although peri-conceptional folic acid (FA) supplementation can prevent a proportion of neural tube defects (NTD), there is increasing evidence that many NTD are FA non-responsive. The vitamin-like molecule inositol may offer a novel approach to preventing FA-non-responsive NTD. Inositol prevented NTD in a genetic mouse model, and was well tolerated by women in a small study of NTD recurrence. In the present study, we report the Prevention of Neural Tube Defects by Inositol (PONTI) pilot study designed to gain further experience of inositol usage in human pregnancy as a preliminary trial to a future large-scale controlled trial to evaluate efficacy of inositol in NTD prevention. Study subjects were UK women with a previous NTD pregnancy who planned to become pregnant again. Of 117 women who made contact, ninety-nine proved eligible and forty-seven agreed to be randomised (double-blind) to peri-conceptional supplementation with inositol plus FA or placebo plus FA. In total, thirty-three randomised pregnancies produced one NTD recurrence in the placebo plus FA group (n 19) and no recurrences in the inositol plus FA group (n 14). Of fifty-two women who declined randomisation, the peri-conceptional supplementation regimen and outcomes of twenty-two further pregnancies were documented. Two NTD recurred, both in women who took only FA in their next pregnancy. No adverse pregnancy events were associated with inositol supplementation. The findings of the PONTI pilot study encourage a large-scale controlled trial of inositol for NTD prevention, but indicate the need for a careful study design in view of the unwillingness of many high-risk women to be randomised. PMID:26847388

  2. Total or Partial Knee Arthroplasty Trial - TOPKAT: study protocol for a randomised controlled trial

    PubMed Central

    2013-01-01

    Background In the majority of patients with osteoarthritis of the knee the disease originates in the medial compartment. There are two fundamentally different approaches to knee replacement for patients with unicompartmental disease: some surgeons feel that it is always best to replace both the knee compartments with a total knee replacement (TKR); whereas others feel it is best to replace just the damaged component of the knee using a partial or unicompartment replacement (UKR). Both interventions are established and well-documented procedures. Little evidence exists to prove the clinical and cost-effectiveness of either management option. This provides an explanation for the high variation in treatment of choice by individual surgeons for the same knee pathology. The aim of the TOPKAT study will be to assess the clinical and cost effectiveness of TKRs compared to UKRs in patients with medial compartment osteoarthritis. Methods/Design The design of the study is a single layer multicentre superiority type randomised controlled trial of unilateral knee replacement patients. Blinding will not be possible as the surgical scars for each procedure differ. We aim to recruit 500 patients from approximately 28 secondary care orthopaedic units from across the UK including district general and teaching hospitals. Participants will be randomised to either UKR or TKR. Randomisation will occur using a web-based randomisation system. The study is pragmatic in terms of implant selection for the knee replacement operation. Participants will be followed up for 5 years. The primary outcome is the Oxford Knee Score, which will be collected via questionnaires at 2 months, 1 year and then annually to 5 years. Secondary outcomes will include cost-effectiveness, patient satisfaction and complications data. Trial registration Current Controlled Trials ISRCTN03013488; ClinicalTrials.gov Identifier: NCT01352247 PMID:24028414

  3. Corticosteroids in acute traumatic brain injury: systematic review of randomised controlled trials.

    PubMed Central

    Alderson, P.; Roberts, I.

    1997-01-01

    OBJECTIVE: To quantify the effectiveness and safety of corticosteroids in the treatment of acute traumatic brain injury. DESIGN: Systematic review of randomised controlled trials of corticosteroids in acute traumatic brain injury. Summary odds ratios were estimated as an inverse variance weighted average of the odds ratios for each study. SETTING: Randomised trials available by March 1996. SUBJECTS: The included trials with outcome data comprised 2073 randomised participants. RESULTS: The effect of corticosteroids on the risk of death was reported in 13 included trials. The pooled odds ratio for the 13 trials was 0.91 (95% confidence interval 0.74 to 1.12). Pooled absolute risk reduction was 1.8% (-2.5% to 5.7%). For the 10 trials that reported death or disability the pooled odds ratio was 0.90 (0.72 to 1.11). For infections of any type the pooled odds ratio was 0.92 (0.69 to 1.23) and for the seven trials reporting gastrointestinal bleeding it was 1.05 (0.44 to 2.52). With only those trials with the best quality of concealment of allocation, the pooled odds ratio estimates for death and death or disability became closer to unity. CONCLUSIONS: This systematic review of randomised controlled trials of corticosteroids in acute traumatic brain injury shows that there remains considerable uncertainty over their effects. Neither moderate benefits nor moderate harmful effects can be excluded. The widely practicable nature of the drugs and the importance of the health problem suggest that large simple trials are feasible and worth while to establish whether there are any benefits from use of corticosteroids in this setting. PMID:9224126

  4. Robust attitude control for Cassini spacecraft flying by Titan

    NASA Technical Reports Server (NTRS)

    Chiang, R.; Lisman, S.; Wong, E.; Enright, P.; Breckenridge, W.; Jahanshahi, M.

    1993-01-01

    This paper summarizes a few years attitude control design work on Cassini spacecraft with emphasis on the mission of Titan flyby. The study consists of modeling of the spacecraft dynamics, fuel sloshing, aerodynamic disturbance, controller design, nonlinear simulation, and establishing geometric command profiles. Both classical bang-bang control and modern robust H-infinity control have been designed and evaluated in nonlinear simulation to access the system tracking performance. Design procedures as well as their critical design issues are discussed in detail. Full model nonlinear simulations indicate that a simple 12-state H-infinity controller achieves better radar tracking performance than the classical bang-bang controller with less fuel throughout the flyby mission. Detailed robustness analysis of both designs will be published elsewhere.

  5. Robust Control of Non-Passive Systems via Passification

    NASA Technical Reports Server (NTRS)

    Kelkar, A. G.; Joshi, S. M.

    1997-01-01

    This paper presents methods which enable the use of passivity-based control design techniques to control non-passive systems. For inherently non-passive finite- dimensional linear time-invaraint systems, passification methods are presented to render such systems passive by suitable compensation. The passified system can then be controlled by a class of passive linear controllers. The idea is to exploit the robust stability properties of passivity-based control laws for uncertain systems. The proposed passification methods are demonstrated by application to the ACC benchmark problem and to pitch-axis control of an F-18 High Alpha Research Vehicle (HARV) model.

  6. Robust control systems design by H-infinity optimization theory

    NASA Technical Reports Server (NTRS)

    Chang, B. C.; Li, X. P.; Banda, S. S.; Yeh, H. H.

    1991-01-01

    In this paper, step-by-step procedures of applying the H-infinity theory to robust control systems design are given. The objective of the paper is to eliminate the possible difficulties a control engineer may encounter in applying H-infinity control theory and to clear up some misconceptions about H-infinity theory like high-gain controller and numerical obstacles, etc. An efficient algorithm is used to compute the optimal H-infinity norm. The Glover and Doyle (1988) controller formulas are slightly modified and used to construct an optimal controller without any numerical difficulties.

  7. Robust Optimal Adaptive Control Method with Large Adaptive Gain

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan T.

    2009-01-01

    In the presence of large uncertainties, a control system needs to be able to adapt rapidly to regain performance. Fast adaptation is referred to the implementation of adaptive control with a large adaptive gain to reduce the tracking error rapidly. However, a large adaptive gain can lead to high-frequency oscillations which can adversely affect robustness of an adaptive control law. A new adaptive control modification is presented that can achieve robust adaptation with a large adaptive gain without incurring high-frequency oscillations as with the standard model-reference adaptive control. The modification is based on the minimization of the Y2 norm of the tracking error, which is formulated as an optimal control problem. The optimality condition is used to derive the modification using the gradient method. The optimal control modification results in a stable adaptation and allows a large adaptive gain to be used for better tracking while providing sufficient stability robustness. Simulations were conducted for a damaged generic transport aircraft with both standard adaptive control and the adaptive optimal control modification technique. The results demonstrate the effectiveness of the proposed modification in tracking a reference model while maintaining a sufficient time delay margin.

  8. A new robust control for minirotorcraft unmanned aerial vehicles.

    PubMed

    Mokhtari, M Rida; Cherki, Brahim

    2015-05-01

    This paper presents a new robust control based on finite-time Lyapunov stability controller and proved with backstepping method for the position and the attitude of a small rotorcraft unmanned aerial vehicle subjected to bounded uncertainties and disturbances. The dynamical motion equations are obtained by the Newton-Euler formalism. The proposed controller combines the advantage of the backstepping approach with finite-time convergence techniques to generate a control laws to guarantee the faster convergence of the state variables to their desired values in short time and compensate for the bounded disturbances. A formal proof of the closed-loop stability and finite-time convergence of tracking errors is derived using the Lyapunov function technique. Simulation results are presented to corroborate the effectiveness and the robustness of the proposed control method. PMID:25677710

  9. A self-management programme for COPD: a randomised controlled trial.

    PubMed

    Mitchell, Katy E; Johnson-Warrington, Vicki; Apps, Lindsay D; Bankart, John; Sewell, Louise; Williams, Johanna E; Rees, Karen; Jolly, Kate; Steiner, Michael; Morgan, Mike; Singh, Sally J

    2014-12-01

    Studies of programmes of self-management support for chronic obstructive pulmonary disease (COPD) have been inconclusive. The Self-Management Programme of Activity, Coping and Education (SPACE) FOR COPD is a 6-week self-management intervention for COPD, and this study aimed to evaluate the effectiveness of this intervention in primary care. A single-blind randomised controlled trial recruited people with COPD from primary care and randomised participants to receive usual care or SPACE FOR COPD. Outcome measures were performed at baseline, 6 weeks and 6 months. The primary outcome was symptom burden, measured by the self-reported Chronic Respiratory Questionnaire (CRQ-SR) dyspnoea domain. Secondary outcomes included other domains of the CRQ-SR, shuttle walking tests, disease knowledge, anxiety, depression, self-efficacy, smoking status and healthcare utilisation. 184 people with COPD were recruited and randomised. At 6 weeks, there were significant differences between groups in CRQ-SR dyspnoea, fatigue and emotion scores, exercise performance, anxiety, and disease knowledge. At 6 months, there was no between-group difference in change in CRQ-SR dyspnoea. Exercise performance, anxiety and smoking status were significantly different between groups at 6 months, in favour of the intervention. This brief self-management intervention did not improve dyspnoea over and above usual care at 6 months; however, there were gains in anxiety, exercise performance, and disease knowledge. PMID:25186259

  10. Robust Neural Sliding Mode Control of Robot Manipulators

    SciTech Connect

    Nguyen Tran Hiep; Pham Thuong Cat

    2009-03-05

    This paper proposes a robust neural sliding mode control method for robot tracking problem to overcome the noises and large uncertainties in robot dynamics. The Lyapunov direct method has been used to prove the stability of the overall system. Simulation results are given to illustrate the applicability of the proposed method.

  11. Inherent robustness of discrete-time adaptive control systems

    NASA Technical Reports Server (NTRS)

    Ma, C. C. H.

    1986-01-01

    Global stability robustness with respect to unmodeled dynamics, arbitrary bounded internal noise, as well as external disturbance is shown to exist for a class of discrete-time adaptive control systems when the regressor vectors of these systems are persistently exciting. Although fast adaptation is definitely undesirable, so far as attaining the greatest amount of global stability robustness is concerned, slow adaptation is shown to be not necessarily beneficial. The entire analysis in this paper holds for systems with slowly varying return difference matrices; the plants in these systems need not be slowly varying.

  12. Robust model-based controller synthesis for the SCOLE configuration

    NASA Technical Reports Server (NTRS)

    Armstrong, E. S.; Joshi, S. M.; Stewart, E. J.

    1988-01-01

    The design of a robust compensator is considered for the SCOLE configuration using a frequency-response shaping technique based on the LQG/LTR algorithm. Results indicate that a tenth-order compensator can be used to meet stability-performance-robustness conditions for a 26th-order SCOLE model without destabilizing spillover effects. Since the SCOLE configuration is representative of many proposed spaceflight experiments, the results and design techniques employed potentially should be applicable to a wide range of large space structure control problems.

  13. Variable Neural Adaptive Robust Control: A Switched System Approach

    SciTech Connect

    Lian, Jianming; Hu, Jianghai; Zak, Stanislaw H.

    2015-05-01

    Variable neural adaptive robust control strategies are proposed for the output tracking control of a class of multi-input multi-output uncertain systems. The controllers incorporate a variable-structure radial basis function (RBF) network as the self-organizing approximator for unknown system dynamics. The variable-structure RBF network solves the problem of structure determination associated with fixed-structure RBF networks. It can determine the network structure on-line dynamically by adding or removing radial basis functions according to the tracking performance. The structure variation is taken into account in the stability analysis of the closed-loop system using a switched system approach with the aid of the piecewise quadratic Lyapunov function. The performance of the proposed variable neural adaptive robust controllers is illustrated with simulations.

  14. Mitigation of Remedial Action Schemes by Decentralized Robust Governor Control

    SciTech Connect

    Elizondo, Marcelo A.; Marinovici, Laurentiu D.; Lian, Jianming; Kalsi, Karanjit; Du, Pengwei

    2014-04-15

    This paper presents transient stability improvement by a new distributed hierarchical control architecture (DHC). The integration of remedial action schemes (RAS) to the distributed hierarchical control architecture is studied. RAS in power systems are designed to maintain stability and avoid undesired system conditions by rapidly switching equipment and/or changing operating points according to predetermined rules. The acceleration trend relay currently in use in the US western interconnection is an example of RAS that trips generators to maintain transient stability. The link between RAS and DHC is through fast acting robust turbine/governor control that can also improve transient stability. In this paper, the influence of the decentralized robust turbine/governor control on the design of RAS is studied. Benefits of combining these two schemes are increasing power transfer capability and mitigation of RAS generator tripping actions; the later benefit is shown through simulations.

  15. Computational methods of robust controller design for aerodynamic flutter suppression

    NASA Technical Reports Server (NTRS)

    Anderson, L. R.

    1981-01-01

    The development of Riccati iteration, a tool for the design and analysis of linear control systems is examined. First, Riccati iteration is applied to the problem of pole placement and order reduction in two-time scale control systems. Order reduction, yielding a good approximation to the original system, is demonstrated using a 16th order linear model of a turbofan engine. Next, a numerical method for solving the Riccati equation is presented and demonstrated for a set of eighth order random examples. A literature review of robust controller design methods follows which includes a number of methods for reducing the trajectory and performance index sensitivity in linear regulators. Lastly, robust controller design for large parameter variations is discussed.

  16. Robust control design techniques for active flutter suppression

    NASA Technical Reports Server (NTRS)

    Ozbay, Hitay; Bachmann, Glen R.

    1994-01-01

    In this paper, an active flutter suppression problem is studied for a thin airfoil in unsteady aerodynamics. The mathematical model of this system is infinite dimensional because of Theodorsen's function which is irrational. Several second order approximations of Theodorsen's function are compared. A finite dimensional model is obtained from such an approximation. We use H infinity control techniques to find a robustly stabilizing controller for active flutter suppression.

  17. Sahaja yoga in the management of moderate to severe asthma: a randomised controlled trial

    PubMed Central

    Manocha, R; Marks, G; Kenchington, P; Peters, D; Salome, C

    2002-01-01

    Background: Sahaja Yoga is a traditional system of meditation based on yogic principles which may be used for therapeutic purposes. A study was undertaken to assess the effectiveness of this therapy as an adjunctive tool in the management of asthma in adult patients who remained symptomatic on moderate to high doses of inhaled steroids. Methods: A parallel group, double blind, randomised controlled trial was conducted. Subjects were randomly allocated to Sahaja yoga and control intervention groups. Both the yoga and the control interventions required the subjects to attend a 2 hour session once a week for 4 months. Asthma related quality of life (AQLQ, range 0–4), Profile of Mood States (POMS), level of airway hyperresponsiveness to methacholine (AHR), and a diary card based combined asthma score (CAS, range 0–12) reflecting symptoms, bronchodilator usage, and peak expiratory flow rates were measured at the end of the treatment period and again 2 months later. Results: Twenty one of 30 subjects randomised to the yoga intervention and 26 of 29 subjects randomised to the control group were available for assessment at the end of treatment. The improvement in AHR at the end of treatment was 1.5 doubling doses (95% confidence interval (CI) 0.0 to 2.9, p=0.047) greater in the yoga intervention group than in the control group. Differences in AQLQ score (0.41, 95% CI –0.04 to 0.86) and CAS (0.9, 95% CI –0.9 to 2.7) were not significant (p>0.05). The AQLQ mood subscale did improve more in the yoga group than in the control group (difference 0.63, 95% CI 0.06 to 1.20), as did the summary POMS score (difference 18.4, 95% CI 0.2 to 36.5, p=0.05). There were no significant differences between the two groups at the 2 month follow up assessment. Conclusions: This randomised controlled trial has shown that the practice of Sahaja yoga does have limited beneficial effects on some objective and subjective measures of the impact of asthma. Further work is required to

  18. Farm practices to control E. coli O157 in young cattle--a randomised controlled trial.

    PubMed

    Ellis-Iversen, Johanne; Smith, Richard P; Van Winden, Steven; Paiba, Giles A; Watson, Eamon; Snow, Lucy C; Cook, Alasdair J C

    2008-01-01

    A randomised controlled trial was used to investigate the effect of three complex management intervention packages to reduce the burden of E. coli O157 in groups of young-stock on cattle farms in England and Wales. All intervention farms were assigned measures to avoid buying in new animals and having direct contact or sharing water sources with other cattle. Furthermore, package A (7 farms) aimed to keep a clean environment and closed groups of young-stock; package B (14 farms) aimed for improved water and feed hygiene, whilst package C was assigned both A and B. The control farms (26 farms) were asked not to alter their practices. Farms, which were assigned intervention package A, exhibited a 48% reduction in E. coli O157 burden over the 4.5 months (average) of observation, compared to 18% on the control farms. The effect of package A compared to the control farms in a crude intention-to-treat model was RR = 0.26 (p=0.122). When the risk ratio was adjusted for actual application of the different measures, the effect of intervention package A became stronger and statistically significant (RR = 0.14 p=0.032). Statistical evidence (p< 0.05) showed that dry bedding and maintaining animals in the same groups were the most important measures within the package and weak evidence (p< 0.1) showed that a closed herd policy and no contact with other cattle may also be of importance. Compliance with the other measures in package A had no influence on the effect of the package. No evidence of effect of the other two intervention packages was found. PMID:18073090

  19. A Robust Cooperated Control Method with Reinforcement Learning and Adaptive H∞ Control

    NASA Astrophysics Data System (ADS)

    Obayashi, Masanao; Uchiyama, Shogo; Kuremoto, Takashi; Kobayashi, Kunikazu

    This study proposes a robust cooperated control method combining reinforcement learning with robust control to control the system. A remarkable characteristic of the reinforcement learning is that it doesn't require model formula, however, it doesn't guarantee the stability of the system. On the other hand, robust control system guarantees stability and robustness, however, it requires model formula. We employ both the actor-critic method which is a kind of reinforcement learning with minimal amount of computation to control continuous valued actions and the traditional robust control, that is, H∞ control. The proposed system was compared method with the conventional control method, that is, the actor-critic only used, through the computer simulation of controlling the angle and the position of a crane system, and the simulation result showed the effectiveness of the proposed method.

  20. A randomised controlled trial evaluating family mediated exercise (FAME) therapy following stroke

    PubMed Central

    Galvin, Rose; Cusack, Tara; Stokes, Emma

    2008-01-01

    Background Stroke is a leading cause of disability among adults worldwide. Evidence suggests that increased duration of exercise therapy following stroke has a positive impact on functional outcome following stroke. The main objective of this randomised controlled trial is to evaluate the impact of additional family assisted exercise therapy in people with acute stroke. Methods/Design A prospective multi-centre single blind randomised controlled trial will be conducted. Forty patients with acute stroke will be randomised into either an experimental or control group. The experimental group will receive routine therapy and additional lower limb exercise therapy in the form of family assisted exercises. The control group will receive routine therapy with no additional formal input from their family members. Participants will be assessed at baseline, post intervention and followed up at three months using a series of standardised outcome measures. A secondary aim of the project is to evaluate the impact of the family mediated exercise programme on the person with stroke and the individual(s) assisting in the delivery of exercises using a qualitative methodology. The study has gained ethical approval from the Research Ethics Committees of each of the clinical sites involved in the study. Discussion This study will evaluate a structured programme of exercises that can be delivered to people with stroke by their 'family members/friends'. Given that the progressive increase in the population of older people is likely to lead to an increased prevalence of stroke in the future, it is important to reduce the burden of this illness on the individual, the family and society. Family mediated exercises can maximise the carry over outside formal physiotherapy sessions, giving patients the opportunity for informal practice. Trial Registration The protocol for this study is registered with the US NIH Clinical trials registry (NCT00666744) PMID:18570643

  1. Physical activity for cancer survivors: meta-analysis of randomised controlled trials

    PubMed Central

    Fong, Daniel Y T; Hui, Bryant P H; Lee, Antoinette M; Macfarlane, Duncan J; Leung, Sharron S K; Cerin, Ester; Chan, Wynnie Y Y; Leung, Ivy P F; Taylor, Aliki J; Cheng, Kar-keung

    2012-01-01

    Objective To systematically evaluate the effects of physical activity in adult patients after completion of main treatment related to cancer. Design Meta-analysis of randomised controlled trials with data extraction and quality assessment performed independently by two researchers. Data sources Pubmed, CINAHL, and Google Scholar from the earliest possible year to September 2011. References from meta-analyses and reviews. Study selection Randomised controlled trials that assessed the effects of physical activity in adults who had completed their main cancer treatment, except hormonal treatment. Results There were 34 randomised controlled trials, of which 22 (65%) focused on patients with breast cancer, and 48 outcomes in our meta-analysis. Twenty two studies assessed aerobic exercise, and four also included resistance or strength training. The median duration of physical activity was 13 weeks (range 3-60 weeks). Most control groups were considered sedentary or were assigned no exercise. Based on studies on patients with breast cancer, physical activity was associated with improvements in insulin-like growth factor-I, bench press, leg press, fatigue, depression, and quality of life. When we combined studies on different types of cancer, we found significant improvements in body mass index (BMI), body weight, peak oxygen consumption, peak power output, distance walked in six minutes, right handgrip strength, and quality of life. Sources of study heterogeneity included age, study quality, study size, and type and duration of physical activity. Publication bias did not alter our conclusions. Conclusions Physical activity has positive effects on physiology, body composition, physical functions, psychological outcomes, and quality of life in patients after treatment for breast cancer. When patients with cancer other than breast cancer were also included, physical activity was associated with reduced BMI and body weight, increased peak oxygen consumption and peak power

  2. Ultrasound in management of rheumatoid arthritis: ARCTIC randomised controlled strategy trial

    PubMed Central

    Aga, Anna-Birgitte; Olsen, Inge Christoffer; Lillegraven, Siri; Hammer, Hilde B; Uhlig, Till; Fremstad, Hallvard; Madland, Tor Magne; Lexberg, Åse Stavland; Haukeland, Hilde; Rødevand, Erik; Høili, Christian; Stray, Hilde; Noraas, Anne; Hansen, Inger Johanne Widding; Bakland, Gunnstein; Nordberg, Lena Bugge; van der Heijde, Désirée; Kvien, Tore K

    2016-01-01

    Objective To determine whether a treatment strategy based on structured ultrasound assessment would lead to improved outcomes in rheumatoid arthritis, compared with a conventional strategy. Design Multicentre, open label, two arm, parallel group, randomised controlled strategy trial. Setting Ten rheumatology departments and one specialist centre in Norway, from September 2010 to September 2015. Participants 238 patients were recruited between September 2010 and April 2013, of which 230 (141 (61%) female) received the allocated intervention and were analysed for the primary outcome. The main inclusion criteria were age 18-75 years, fulfilment of the 2010 American College of Rheumatology/European League Against Rheumatism classification criteria for rheumatoid arthritis, disease modifying anti-rheumatic drug naivety with indication for disease modifying drug therapy, and time from first patient reported swollen joint less than two years. Patients with abnormal kidney or liver function or major comorbidities were excluded. Interventions 122 patients were randomised to an ultrasound tight control strategy targeting clinical and imaging remission, and 116 patients were randomised to a conventional tight control strategy targeting clinical remission. Patients in both arms were treated according to the same disease modifying anti-rheumatic drug escalation strategy, with 13 visits over two years. Main outcome measures The primary endpoint was the proportion of patients with a combination between 16 and 24 months of clinical remission, no swollen joints, and non-progression of radiographic joint damage. Secondary outcomes included measures of disease activity, radiographic progression, functioning, quality of life, and adverse events. All participants who attended at least one follow-up visit were included in the full analysis set. Results 26 (22%) of the 118 analysed patients in the ultrasound tight control arm and 21 (19%) of the 112 analysed patients in the

  3. Management of type 2 diabetes in China: the Happy Life Club, a pragmatic cluster randomised controlled trial using health coaches

    PubMed Central

    Browning, Colette; Chapman, Anna; Yang, Hui; Liu, Shuo; Zhang, Tuohong; Enticott, Joanne C; Thomas, Shane A

    2016-01-01

    Objective To assess the effectiveness of a coach-led motivational interviewing (MI) intervention in improving glycaemic control, as well as clinical, psychosocial and self-care outcomes of individuals with type 2 diabetes mellitus (T2DM) compared with usual care. Design Pragmatic cluster randomised controlled trial (RCT). Setting Community Health Stations (CHSs) in Fengtai district, Beijing, China. Participants Of the 41 randomised CHSs (21 intervention and 20 control), 21 intervention CHSs (372 participants) and 18 control CHSs (296 participants) started participation. Intervention Intervention participants received telephone and face-to-face MI health coaching in addition to usual care from their CHS. Control participants received usual care only. Medical fees were waived for both groups. Outcome measures Outcomes were assessed at baseline, 6 and 12 months. Primary outcome measure was glycated haemoglobin (HbA1c). Secondary outcomes included a suite of anthropometric, blood pressure (BP), fasting blood, psychosocial and self-care measures. Results At 12 months, no differential treatment effect was found for HbA1c (adjusted difference 0.02, 95% CI −0.40 to 0.44, p=0.929), with both treatment and control groups showing significant improvements. However, two secondary outcomes: psychological distress (adjusted difference −2.38, 95% CI −4.64 to −0.12, p=0.039) and systolic BP (adjusted difference −3.57, 95% CI −6.08 to −1.05, p=0.005) were robust outcomes consistent with significant differential treatment effects, as supported in sensitivity analyses. Interestingly, in addition to HbA1c, both groups displayed significant improvements in triglycerides, LDL cholesterol and HDL cholesterol. Conclusions In line with the current Chinese primary healthcare reform, this study is the first large-scale cluster RCT to be implemented within real-world CHSs in China, specifically addressing T2DM. Although a differential treatment effect was not observed for Hb

  4. Robust power system controller design based on measured models

    SciTech Connect

    Fatehi, F.; Smith, J.R.; Pierre, D.A.

    1996-05-01

    This paper presents combined system identification and controller design methods to dampen low-frequency oscillations in multimachine power systems. An iterative closed-loop identification method is used to find a linear model for the power system. Linear quadratic Gaussian controller design with loop transfer recovery (LQG/LTR), based on a generalized technique for the nonminimum phase (NMP) power system model, is used to design controllers. Simulation results are presented to demonstrate the robustness of controllers based on closed-loop identified plant models and the amount of loop transfer recovery that is possible for NMP plant models.

  5. Analysis and design of robust decentralized controllers for nonlinear systems

    SciTech Connect

    Schoenwald, D.A.

    1993-07-01

    Decentralized control strategies for nonlinear systems are achieved via feedback linearization techniques. New results on optimization and parameter robustness of non-linear systems are also developed. In addition, parametric uncertainty in large-scale systems is handled by sensitivity analysis and optimal control methods in a completely decentralized framework. This idea is applied to alleviate uncertainty in friction parameters for the gimbal joints on Space Station Freedom. As an example of decentralized nonlinear control, singular perturbation methods and distributed vibration damping are merged into a control strategy for a two-link flexible manipulator.

  6. A Comprehensive Robust Adaptive Controller for Gust Load Alleviation

    PubMed Central

    Quagliotti, Fulvia

    2014-01-01

    The objective of this paper is the implementation and validation of an adaptive controller for aircraft gust load alleviation. The contribution of this paper is the design of a robust controller that guarantees the reduction of the gust loads, even when the nominal conditions change. Some preliminary results are presented, considering the symmetric aileron deflection as control device. The proposed approach is validated on subsonic transport aircraft for different mass and flight conditions. Moreover, if the controller parameters are tuned for a specific gust model, even if the gust frequency changes, no parameter retuning is required. PMID:24688411

  7. Study protocol for a randomised controlled trial of electronic cigarettes versus nicotine patch for smoking cessation

    PubMed Central

    2013-01-01

    Background Electronic cigarettes (e-cigarettes or electronic nicotine delivery systems [ENDS]) are electrically powered devices generally similar in appearance to a cigarette that deliver a propylene glycol and/or glycerol mist to the airway of users when drawing on the mouthpiece. Nicotine and other substances such as flavourings may be included in the fluid vaporised by the device. People report using e-cigarettes to help quit smoking and studies of their effects on tobacco withdrawal and craving suggest good potential as smoking cessation aids. However, to date there have been no adequately powered randomised trials investigating their cessation efficacy or safety. This paper outlines the protocol for this study. Methods/design Design: Parallel group, 3-arm, randomised controlled trial. Participants: People aged ≥18 years resident in Auckland, New Zealand (NZ) who want to quit smoking. Intervention: Stratified blocked randomisation to allocate participants to either Elusion™ e-cigarettes with nicotine cartridges (16 mg) or with placebo cartridges (i.e. no nicotine), or to nicotine patch (21 mg) alone. Participants randomised to the e-cigarette groups will be told to use them ad libitum for one week before and 12 weeks after quit day, while participants randomised to patches will be told to use them daily for the same period. All participants will be offered behavioural support to quit from the NZ Quitline. Primary outcome: Biochemically verified (exhaled carbon monoxide) continuous abstinence at six months after quit day. Sample size: 657 people (292 in both the nicotine e-cigarette and nicotine patch groups and 73 in the placebo e-cigarettes group) will provide 80% power at p = 0.05 to detect an absolute difference of 10% in abstinence between the nicotine e-cigarette and nicotine patch groups, and 15% between the nicotine and placebo e-cigarette groups. Discussion This trial will inform international debate and policy on the regulation and

  8. Comprehensive warm-up programme to prevent injuries in young female footballers: cluster randomised controlled trial

    PubMed Central

    Myklebust, Grethe; Steffen, Kathrin; Holme, Ingar; Silvers, Holly; Bizzini, Mario; Junge, Astrid; Dvorak, Jiri; Bahr, Roald; Andersen, Thor Einar

    2008-01-01

    Objective To examine the effect of a comprehensive warm-up programme designed to reduce the risk of injuries in female youth football. Design Cluster randomised controlled trial with clubs as the unit of randomisation. Setting 125 football clubs from the south, east, and middle of Norway (65 clusters in the intervention group; 60 in the control group) followed for one league season (eight months). Participants 1892 female players aged 13-17 (1055 players in the intervention group; 837 players in the control group). Intervention A comprehensive warm-up programme to improve strength, awareness, and neuromuscular control during static and dynamic movements. Main outcome measure Injuries to the lower extremity (foot, ankle, lower leg, knee, thigh, groin, and hip). Results During one season, 264 players had relevant injuries: 121 players in the intervention group and 143 in the control group (rate ratio 0.71, 95% confidence interval 0.49 to 1.03). In the intervention group there was a significantly lower risk of injuries overall (0.68, 0.48 to 0.98), overuse injuries (0.47, 0.26 to 0.85), and severe injuries (0.55, 0.36 to 0.83). Conclusion Though the primary outcome of reduction in lower extremity injury did not reach significance, the risk of severe injuries, overuse injuries, and injuries overall was reduced. This indicates that a structured warm-up programme can prevent injuries in young female football players. Trial registration ISRCTN10306290. PMID:19066253

  9. Greening vacant lots to reduce violent crime: a randomised controlled trial

    PubMed Central

    Garvin, Eugenia C; Cannuscio, Carolyn C; Branas, Charles C

    2014-01-01

    Background Vacant lots are often overgrown with unwanted vegetation and filled with trash, making them attractive places to hide illegal guns, conduct illegal activities such as drug sales and prostitution, and engage in violent crime. There is some evidence that greening vacant lots is associated with reductions in violent crime. Methods We performed a randomised controlled trial of vacant lot greening to test the impact of this intervention on police reported crime and residents’ perceptions of safety and disorder. Greening consisted of cleaning the lots, planting grass and trees, and building a wooden fence around the perimeter. We randomly allocated two vacant lot clusters to the greening intervention or to the control status (no intervention). Administrative data were used to determine crime rates, and local resident interviews at baseline (n=29) and at follow-up (n=21) were used to assess perceptions of safety and disorder. Results Unadjusted difference-in-differences estimates showed a non-significant decrease in the number of total crimes and gun assaults around greened vacant lots compared with control. People around the intervention vacant lots reported feeling significantly safer after greening compared with those living around control vacant lots (p<0.01). Conclusions In this study, greening was associated with reductions in certain gun crimes and improvements in residents’ perceptions of safety. A larger randomised controlled trial is needed to further investigate the link between vacant lot greening and violence reduction. PMID:22871378

  10. Robust, Decoupled, Flight Control Design with Rate Saturating Actuators

    NASA Technical Reports Server (NTRS)

    Snell, S. A.; Hess, R. A.

    1997-01-01

    Techniques for the design of control systems for manually controlled, high-performance aircraft must provide the following: (1) multi-input, multi-output (MIMO) solutions, (2) acceptable handling qualities including no tendencies for pilot-induced oscillations, (3) a tractable approach for compensator design, (4) performance and stability robustness in the presence of significant plant uncertainty, and (5) performance and stability robustness in the presence actuator saturation (particularly rate saturation). A design technique built upon Quantitative Feedback Theory is offered as a candidate methodology which can provide flight control systems meeting these requirements, and do so over a considerable part of the flight envelope. An example utilizing a simplified model of a supermaneuverable fighter aircraft demonstrates the proposed design methodology.

  11. Decentralized adaptive control of robot manipulators with robust stabilization design

    NASA Technical Reports Server (NTRS)

    Yuan, Bau-San; Book, Wayne J.

    1988-01-01

    Due to geometric nonlinearities and complex dynamics, a decentralized technique for adaptive control for multilink robot arms is attractive. Lyapunov-function theory for stability analysis provides an approach to robust stabilization. Each joint of the arm is treated as a component subsystem. The adaptive controller is made locally stable with servo signals including proportional and integral gains. This results in the bound on the dynamical interactions with other subsystems. A nonlinear controller which stabilizes the system with uniform boundedness is used to improve the robustness properties of the overall system. As a result, the robot tracks the reference trajectories with convergence. This strategy makes computation simple and therefore facilitates real-time implementation.

  12. Robust control of hypersonic vehicles considering propulsive and aeroelastic effects

    NASA Technical Reports Server (NTRS)

    Buschek, Harald; Calise, Anthony J.

    1993-01-01

    The influence of propulsion system variations and elastic fuselage behavior on the flight control system of an airbreathing hypersonic vehicle is investigated. Thrust vector magnitude and direction changes due to angle of attack variations affect the pitching moment. Low structural vibration frequencies may occur close to the rigid body modes influencing the angle of attack and lead to possible cross coupling. These effects are modeled as uncertainties in the context of a robust control study of a hypersonic vehicle model accelerating through Mach 8 using H-infinity and mu synthesis techniques. Various levels of uncertainty are introduced into the system. Both individual and simultaneous appearance of uncertainty are considered. The results indicate that the chosen design technique is suitable for this kind of problem provided that a fairly good knowledge of the effects mentioned above is available. The order of the designed controller is reduced but robust performance is lost which shows the need for fixed order design techniques.

  13. Robust and fast learning for fuzzy cerebellar model articulation controllers.

    PubMed

    Su, Shun-Feng; Lee, Zne-Jung; Wang, Yan-Ping

    2006-02-01

    In this paper, the online learning capability and the robust property for the learning algorithms of cerebellar model articulation controllers (CMAC) are discussed. Both the traditional CMAC and fuzzy CMAC are considered. In the study, we find a way of embeding the idea of M-estimators into the CMAC learning algorithms to provide the robust property against outliers existing in training data. An annealing schedule is also adopted for the learning constant to fulfill robust learning. In the study, we also extend our previous work of adopting the credit assignment idea into CMAC learning to provide fast learning for fuzzy CMAC. From demonstrated examples, it is clearly evident that the proposed algorithm indeed has faster and more robust learning. In our study, we then employ the proposed CMAC for an online learning control scheme used in the literature. In the implementation, we also propose to use a tuning parameter instead of a fixed constant to achieve both online learning and fine-tuning effects. The simulation results indeed show the effectiveness of the proposed approaches. PMID:16468579

  14. Robust sliding mode continuous control of an IM drive

    SciTech Connect

    Jezernik, K.; Hren, A.; Drevensek, D.

    1995-12-31

    A control approach for robust trajectory tracking of IM servodrive based on the variable structure systems (VSS) is described. A new discrete-time control algorithm has been developed by combining VSS and Lyapunov design. It possesses all the good properties of the sliding mode and avoids the unnecessary discontinuity of the control input, thus eliminating chattering which has been considering as serious obstacles for applications of VSS. A unified control approach for current, torque and motion control based on the discrete-time sliding mode for application in indirect vector control of an IM drive is developed. The sliding mode approach can be applied to the control of an Im drive due to the replacement of the hysteresis controller with widely used PWM technique. All the theoretical issues are verified by experiment. The experimental system consists of a transputer and a microcontroller, thus allowing parallel processing.

  15. Modeling, Robust Control, and Experimental Validation of a Supercavitating Vehicle

    NASA Astrophysics Data System (ADS)

    Escobar Sanabria, David

    This dissertation considers the mathematical modeling, control under uncertainty, and experimental validation of an underwater supercavitating vehicle. By traveling inside a gas cavity, a supercavitating vehicle reduces hydrodynamic drag, increases speed, and minimizes power consumption. The attainable speed and power efficiency make these vehicles attractive for undersea exploration, high-speed transportation, and defense. However, the benefits of traveling inside a cavity come with difficulties in controlling the vehicle dynamics. The main challenge is the nonlinear force that arises when the back-end of the vehicle pierces the cavity. This force, referred to as planing, leads to oscillatory motion and instability. Control technologies that are robust to planing and suited for practical implementation need to be developed. To enable these technologies, a low-order vehicle model that accounts for inaccuracy in the characterization of planing is required. Additionally, an experimental method to evaluate possible pitfalls in the models and controllers is necessary before undersea testing. The major contribution of this dissertation is a unified framework for mathematical modeling, robust control synthesis, and experimental validation of a supercavitating vehicle. First, we introduce affordable experimental methods for mathematical modeling and controller testing under planing and realistic flow conditions. Then, using experimental observations and physical principles, we create a low-order nonlinear model of the longitudinal vehicle motion. This model quantifies the planing uncertainty and is suitable for robust controller synthesis. Next, based on the vehicle model, we develop automated tools for synthesizing controllers that deliver a certificate of performance in the face of nonlinear and uncertain planing forces. We demonstrate theoretically and experimentally that the proposed controllers ensure higher performance when the uncertain planing dynamics are

  16. Decentralized robust nonlinear model predictive controller for unmanned aerial systems

    NASA Astrophysics Data System (ADS)

    Garcia Garreton, Gonzalo A.

    The nonlinear and unsteady nature of aircraft aerodynamics together with limited practical range of controls and state variables make the use of the linear control theory inadequate especially in the presence of external disturbances, such as wind. In the classical approach, aircraft are controlled by multiple inner and outer loops, designed separately and sequentially. For unmanned aerial systems in particular, control technology must evolve to a point where autonomy is extended to the entire mission flight envelope. This requires advanced controllers that have sufficient robustness, track complex trajectories, and use all the vehicles control capabilities at higher levels of accuracy. In this work, a robust nonlinear model predictive controller is designed to command and control an unmanned aerial system to track complex tight trajectories in the presence of internal and external perturbance. The Flight System developed in this work achieves the above performance by using: 1. A nonlinear guidance algorithm that enables the vehicle to follow an arbitrary trajectory shaped by moving points; 2. A formulation that embeds the guidance logic and trajectory information in the aircraft model, avoiding cross coupling and control degradation; 3. An artificial neural network, designed to adaptively estimate and provide aerodynamic and propulsive forces in real-time; and 4. A mixed sensitivity approach that enhances the robustness for a nonlinear model predictive controller overcoming the effect of un-modeled dynamics, external disturbances such as wind, and measurement additive perturbations, such as noise and biases. These elements have been integrated and tested in simulation and with previously stored flight test data and shown to be feasible.

  17. Wraparound care for youth injured by violence: study protocol for a pilot randomised control trial

    PubMed Central

    Snider, Carolyn; Jiang, Depeng; Logsetty, Sarvesh; Strome, Trevor; Klassen, Terry

    2015-01-01

    Introduction Injury by violence is the fourth cause of death and the leading reason for a youth to visit an emergency department (ED) in Canada. In Winnipeg, 20% of youth who visit an ED with an injury due to violence have a second visit for a subsequent violent injury within 1 year. Youth injured by violence are in a reflective and receptive state of mind, rendering the ED setting appropriate for intervention. Methods and analysis This protocol describes a wraparound care model delivered by a support worker with lived experience with violence, supported by social workers and links to multiple community partners. Support workers will be on call 24 h a day, 7 days a week in order to start the intervention in the ED and take advantage of the ‘teachable moment’. The protocol is of a pilot randomised control trial to assess the feasibility of a randomised control trial designed to assess efficacy. For the pilot trial, we will assess recruitment, treatment fidelity, participant adherence and safety. The intervention arm will receive wraparound care initiated at the time of their visit for injury due to violence. The control arm will receive standard care. We will use an adapted preconsent randomisation methodology. This intervention has been developed using an integrated knowledge translation approach. Discussion Interventions delivered in the ED for youth injured by violence require an approach that is appropriate for the unique situation the youth are in. Ethics The University of Manitoba Health Research Ethics Board (HS 16445 (Cohort study) and HS 16444 (WrapAround Care study) granted ethical approval. Trial registration number NCT01895738. PMID:25991461

  18. Robust control of burst suppression for medical coma

    NASA Astrophysics Data System (ADS)

    Westover, M. Brandon; Kim, Seong-Eun; Ching, ShiNung; Purdon, Patrick L.; Brown, Emery N.

    2015-08-01

    Objective. Medical coma is an anesthetic-induced state of brain inactivation, manifest in the electroencephalogram by burst suppression. Feedback control can be used to regulate burst suppression, however, previous designs have not been robust. Robust control design is critical under real-world operating conditions, subject to substantial pharmacokinetic and pharmacodynamic parameter uncertainty and unpredictable external disturbances. We sought to develop a robust closed-loop anesthesia delivery (CLAD) system to control medical coma. Approach. We developed a robust CLAD system to control the burst suppression probability (BSP). We developed a novel BSP tracking algorithm based on realistic models of propofol pharmacokinetics and pharmacodynamics. We also developed a practical method for estimating patient-specific pharmacodynamics parameters. Finally, we synthesized a robust proportional integral controller. Using a factorial design spanning patient age, mass, height, and gender, we tested whether the system performed within clinically acceptable limits. Throughout all experiments we subjected the system to disturbances, simulating treatment of refractory status epilepticus in a real-world intensive care unit environment. Main results. In 5400 simulations, CLAD behavior remained within specifications. Transient behavior after a step in target BSP from 0.2 to 0.8 exhibited a rise time (the median (min, max)) of 1.4 [1.1, 1.9] min; settling time, 7.8 [4.2, 9.0] min; and percent overshoot of 9.6 [2.3, 10.8]%. Under steady state conditions the CLAD system exhibited a median error of 0.1 [-0.5, 0.9]%; inaccuracy of 1.8 [0.9, 3.4]%; oscillation index of 1.8 [0.9, 3.4]%; and maximum instantaneous propofol dose of 4.3 [2.1, 10.5] mg kg-1. The maximum hourly propofol dose was 4.3 [2.1, 10.3] mg kg-1 h-1. Performance fell within clinically acceptable limits for all measures. Significance. A CLAD system designed using robust control theory achieves clinically acceptable

  19. Robust control of burst suppression for medical coma

    PubMed Central

    Westover, M Brandon; Kim, Seong-Eun; Ching, ShiNung; Purdon, Patrick L; Brown, Emery N

    2015-01-01

    Objective Medical coma is an anesthetic-induced state of brain inactivation, manifest in the electroencephalogram by burst suppression. Feedback control can be used to regulate burst suppression, however, previous designs have not been robust. Robust control design is critical under real-world operating conditions, subject to substantial pharmacokinetic and pharmacodynamic parameter uncertainty and unpredictable external disturbances. We sought to develop a robust closed-loop anesthesia delivery (CLAD) system to control medical coma. Approach We developed a robust CLAD system to control the burst suppression probability (BSP). We developed a novel BSP tracking algorithm based on realistic models of propofol pharmacokinetics and pharmacodynamics. We also developed a practical method for estimating patient-specific pharmacodynamics parameters. Finally, we synthesized a robust proportional integral controller. Using a factorial design spanning patient age, mass, height, and gender, we tested whether the system performed within clinically acceptable limits. Throughout all experiments we subjected the system to disturbances, simulating treatment of refractory status epilepticus in a real-world intensive care unit environment. Main results In 5400 simulations, CLAD behavior remained within specifications. Transient behavior after a step in target BSP from 0.2 to 0.8 exhibited a rise time (the median (min, max)) of 1.4 [1.1, 1.9] min; settling time, 7.8 [4.2, 9.0] min; and percent overshoot of 9.6 [2.3, 10.8]%. Under steady state conditions the CLAD system exhibited a median error of 0.1 [−0.5, 0.9]%; inaccuracy of 1.8 [0.9, 3.4]%; oscillation index of 1.8 [0.9, 3.4]%; and maximum instantaneous propofol dose of 4.3 [2.1, 10.5] mg kg−1. The maximum hourly propofol dose was 4.3 [2.1, 10.3] mg kg−1 h−1. Performance fell within clinically acceptable limits for all measures. Significance A CLAD system designed using robust control theory achieves clinically acceptable

  20. Robust Feedback Control of Flow Induced Structural Radiation of Sound

    NASA Technical Reports Server (NTRS)

    Heatwole, Craig M.; Bernhard, Robert J.; Franchek, Matthew A.

    1997-01-01

    A significant component of the interior noise of aircraft and automobiles is a result of turbulent boundary layer excitation of the vehicular structure. In this work, active robust feedback control of the noise due to this non-predictable excitation is investigated. Both an analytical model and experimental investigations are used to determine the characteristics of the flow induced structural sound radiation problem. The problem is shown to be broadband in nature with large system uncertainties associated with the various operating conditions. Furthermore the delay associated with sound propagation is shown to restrict the use of microphone feedback. The state of the art control methodologies, IL synthesis and adaptive feedback control, are evaluated and shown to have limited success for solving this problem. A robust frequency domain controller design methodology is developed for the problem of sound radiated from turbulent flow driven plates. The control design methodology uses frequency domain sequential loop shaping techniques. System uncertainty, sound pressure level reduction performance, and actuator constraints are included in the design process. Using this design method, phase lag was added using non-minimum phase zeros such that the beneficial plant dynamics could be used. This general control approach has application to lightly damped vibration and sound radiation problems where there are high bandwidth control objectives requiring a low controller DC gain and controller order.

  1. ‘Putting Life in Years’ (PLINY) telephone friendship groups research study: pilot randomised controlled trial

    PubMed Central

    2014-01-01

    Background Loneliness in older people is associated with poor health-related quality of life (HRQoL). We undertook a parallel-group randomised controlled trial to evaluate the effectiveness and cost-effectiveness of telephone befriending for the maintenance of HRQoL in older people. An internal pilot tested the feasibility of the trial and intervention. Methods Participants aged >74 years, with good cognitive function, living independently in one UK city were recruited through general practices and other sources, then randomised to: (1) 6 weeks of short one-to-one telephone calls, followed by 12 weeks of group telephone calls with up to six participants, led by a trained volunteer facilitator; or (2) a control group. The main trial required the recruitment of 248 participants in a 1-year accrual window, of whom 124 were to receive telephone befriending. The pilot specified three success criteria which had to be met in order to progress the main trial to completion: recruitment of 68 participants in 95 days; retention of 80% participants at 6 months; successful delivery of telephone befriending by local franchise of national charity. The primary clinical outcome was the Short Form (36) Health Instrument (SF-36) Mental Health (MH) dimension score collected by telephone 6 months following randomisation. Results We informed 9,579 older people about the study. Seventy consenting participants were randomised to the pilot in 95 days, with 56 (80%) providing valid primary outcome data (26 intervention, 30 control). Twenty-four participants randomly allocated to the research arm actually received telephone befriending due to poor recruitment and retention of volunteer facilitators. The trial was closed early as a result. The mean 6-month SF-36 MH scores were 78 (SD 18) and 71 (SD 21) for the intervention and control groups, respectively (mean difference, 7; 95% CI, -3 to 16). Conclusions Recruitment and retention of participants to a definitive trial with a

  2. The WHO antenatal care randomised controlled trial: rationale and study design.

    PubMed

    Villar, J; Bakketeig, L; Donner, A; al-Mazrou, Y; Ba'aqeel, H; Belizán, J M; Carroli, G; Farnot, U; Lumbiganon, P; Piaggio, G; Berendes, H

    1998-10-01

    The World Health Organisation and collaborating institutions in developing countries are conducting a multicentre randomised controlled trial to evaluate a new antenatal care (ANC) programme, consisting of tests, clinical procedures and follow-up actions scientifically demonstrated to be effective in improving maternal and newborn outcomes. These activities are distributed, for practical reasons, over four visits during the course of pregnancy and are aimed at achieving predetermined goals. The study is taking place in four countries, Argentina, Cuba, Saudi Arabia and Thailand. Recruitment of study subjects started on 1 May 1996. All 53 ANC clinical units had been enrolled by December 1996. Clinics in each country were randomly allocated (cluster randomisation) to provide either the new programme or the traditional programme currently in use. Approximately 24,000 women presenting for ANC at these clinics over an average period of 18 months will have been recruited. As women attending the control clinics receive the 'best standard treatment' as currently offered in these clinics, individual informed consent is requested only from women attending the intervention clinics. Authorities of the corresponding health districts and all participating clinics have provided written institutional informed consent before randomisation. The primary outcome of the trial in relation to maternal conditions is the rate of a morbidity indicator index, defined as the presence of at least one of the following conditions for which ANC is relevant: (a) pre-eclampsia or eclampsia during pregnancy or within 24 h of delivery; (b) postpartum anaemia (haemoglobin < 90 g/L); or (c) severe urinary tract infection/pyelonephritis, defined as an episode requiring antibiotic treatment and/or hospitalisation. The primary fetal outcome is the rate of low birthweight (< 2500 g). Adverse maternal and fetal outcomes are expected for approximately 10% of the control group. Several maternal and perinatal

  3. Robust Concentration and Frequency Control in Oscillatory Homeostats

    PubMed Central

    Thorsen, Kristian; Agafonov, Oleg; Selstø, Christina H.; Jolma, Ingunn W.; Ni, Xiao Y.; Drengstig, Tormod; Ruoff, Peter

    2014-01-01

    Homeostatic and adaptive control mechanisms are essential for keeping organisms structurally and functionally stable. Integral feedback is a control theoretic concept which has long been known to keep a controlled variable robustly (i.e. perturbation-independent) at a given set-point by feeding the integrated error back into the process that generates . The classical concept of homeostasis as robust regulation within narrow limits is often considered as unsatisfactory and even incompatible with many biological systems which show sustained oscillations, such as circadian rhythms and oscillatory calcium signaling. Nevertheless, there are many similarities between the biological processes which participate in oscillatory mechanisms and classical homeostatic (non-oscillatory) mechanisms. We have investigated whether biological oscillators can show robust homeostatic and adaptive behaviors, and this paper is an attempt to extend the homeostatic concept to include oscillatory conditions. Based on our previously published kinetic conditions on how to generate biochemical models with robust homeostasis we found two properties, which appear to be of general interest concerning oscillatory and homeostatic controlled biological systems. The first one is the ability of these oscillators (“oscillatory homeostats”) to keep the average level of a controlled variable at a defined set-point by involving compensatory changes in frequency and/or amplitude. The second property is the ability to keep the period/frequency of the oscillator tuned within a certain well-defined range. In this paper we highlight mechanisms that lead to these two properties. The biological applications of these findings are discussed using three examples, the homeostatic aspects during oscillatory calcium and p53 signaling, and the involvement of circadian rhythms in homeostatic regulation. PMID:25238410

  4. Adaptive robust control of longitudinal and transverse electron beam profiles

    NASA Astrophysics Data System (ADS)

    Rezaeizadeh, Amin; Schilcher, Thomas; Smith, Roy S.

    2016-05-01

    Feedback control of the longitudinal and transverse electron beam profiles are considered to be critical for beam control in accelerators. In the feedback scheme, the longitudinal or transverse beam profile is measured and compared to a desired profile to give an error estimate. The error is then used to act on the appropriate actuators to correct the profile. The role of the transverse feedback is to steer the beam in a particular trajectory, known as the "orbit." The common approach for orbit correction is based on approximately inverting the response matrix, and in the best case, involves regulating or filtering the singular values. In the current contribution, a more systematic and structured way of handling orbit correction is introduced giving robustness against uncertainties in the response matrix. Moreover, the input bounds are treated to avoid violating the limits of the corrector currents. The concept of the robust orbit correction has been successfully tested at the SwissFEL injector test facility. In the SwissFEL machine, a photo-injector laser system extracts electrons from a cathode and a similar robust control method is developed for the longitudinal feedback control of the current profile of the electron bunch. The method manipulates the angles of the crystals in the laser system to produce a desired charge distribution over the electron bunch length. This approach paves the way towards automation of laser pulse stacking.

  5. Robust adaptive backstepping control for reentry reusable launch vehicles

    NASA Astrophysics Data System (ADS)

    Wang, Zhen; Wu, Zhong; Du, Yijiang

    2016-09-01

    During the reentry process of reusable launch vehicles (RLVs), the large range of flight envelope will not only result in high nonlinearities, strong coupling and fast time-varying characteristics of the attitude dynamics, but also result in great uncertainties in the atmospheric density, aerodynamic coefficients and environmental disturbances, etc. In order to attenuate the effects of these problems on the control performance of the reentry process, a robust adaptive backstepping control (RABC) strategy is proposed for RLV in this paper. This strategy consists of two-loop controllers designed via backstepping method. Both the outer and the inner loop adopt a robust adaptive controller, which can deal with the disturbances and uncertainties by the variable-structure term with the estimation of their bounds. The outer loop can track the desired attitude by the design of virtual control-the desired angular velocity, while the inner one can track the desired angular velocity by the design of control torque. Theoretical analysis indicates that the closed-loop system under the proposed control strategy is globally asymptotically stable. Even if the boundaries of the disturbances and uncertainties are unknown, the attitude can track the desired value accurately. Simulation results of a certain RLV demonstrate the effectiveness of the control strategy.

  6. Frequency domain identification for robust large space structure control design

    NASA Technical Reports Server (NTRS)

    Yam, Y.; Bayard, D. S.; Scheid, R. E.

    1991-01-01

    A methodology is demonstrated for frequency domain identification of large space structures which systematically transforms experimental raw data into a form required for synthesizing H(infinity) controllers using modern robust control design software (e.g., Matlab Toolboxes). A unique feature of this approach is that the additive uncertainty is characterized to a specified statistic confidence rather than with hard bounds. In this study, the difference in robust performance is minimal between the two levels of confidence. In general cases, the present methodology provides a tool for performance/confidence level tradeoff studies. For simplicity, the additive uncertainty on a frequency grid is considered and the interpolation error in between grid points is neglected.

  7. Parametric uncertainty modeling for application to robust control

    NASA Technical Reports Server (NTRS)

    Belcastro, Christine M.; Chang, B.-C.; Fischl, Robert

    1993-01-01

    Viewgraphs and a paper on parametric uncertainty modeling for application to robust control are included. Advanced robust control system analysis and design is based on the availability of an uncertainty description which separates the uncertain system elements from the nominal system. Although this modeling structure is relatively straightforward to obtain for multiple unstructured uncertainties modeled throughout the system, it is difficult to formulate for many problems involving real parameter variations. Furthermore, it is difficult to ensure that the uncertainty model is formulated such that the dimension of the resulting model is minimal. A procedure for obtaining an uncertainty model for real uncertain parameter problems in which the uncertain parameters can be represented in a multilinear form is presented. Furthermore, the procedure is formulated such that the resulting uncertainty model is minimal (or near minimal) relative to a given state space realization of the system. The approach is demonstrated for a multivariable third-order example problem having four uncertain parameters.

  8. Safety education of pedestrians for injury prevention: a systematic review of randomised controlled trials

    PubMed Central

    Duperrex, Olivier; Bunn, Frances; Roberts, Ian

    2002-01-01

    Objectives To quantify the effectiveness of safety education of pedestrians. Design Systematic review of randomised controlled trials of safety education programmes for pedestrians of all ages. Main outcome measures Effect of safety education on pedestrians' injuries, behaviour, attitude, and knowledge and on pedestrian-motor vehicle collisions. Quality of trials: methods of randomisation; and numbers lost to follow up Results We identified 15 randomised controlled trials of safety education programmes for pedestrians. Fourteen trials targeted children, and one targeted institutionalised adults. None assessed the effect of safety education on the occurrence of pedestrian injury, but six trials assessed its effect on behaviour. The effect of pedestrian education on behaviour varied considerably across studies and outcomes. Conclusions Pedestrian safety education can change observed road crossing behaviour, but whether this reduces the risk of pedestrian injury in road traffic crashes is unknown. There is a lack of good evidence of effectiveness of safety education for adult pedestrians, specially elderly people. None of the trials was conducted in low or middle income countries. What is already known on this topicRoad traffic crashes are a leading cause of death and disablement, and pedestrians are particularly vulnerable road usersSeveral organisations strongly recommend road safety educationAs resources are limited, a key question concerns the relative effectiveness of different prevention strategies, including road safety education of pedestriansWhat this study addsThis systematic review showed safety education for pedestrians could improve children's knowledge and change their observed road crossing behaviourHowever, effects on pedestrian injury were unknownThere is a lack of good evidence of effectiveness of safety education for adult pedestrians, especially elderly people, and in low and middle income countries PMID:12003885

  9. Reporting of radiographic methods in randomised controlled trials assessing structural outcomes in rheumatoid arthritis

    PubMed Central

    Baron, Gabriel; Boutron, Isabelle; Giraudeau, Bruno; Ravaud, Philippe

    2007-01-01

    Background Because an increasing number of clinical trials evaluating disease‐modifying antirheumatic drugs in rheumatoid arthritis (RA) emphasise radiographic outcomes as a primary outcome, using a reproducible radiographic measure should be placed at a premium. Aim To evaluate the reporting of radiographic methods in randomised trials assessing radiographic outcomes in RA. Methods Medline was searched for randomised controlled trials assessing radiographic outcomes published between January 1994 and December 2005 in general medical and specialty journals with a high impact factor. One reader extracted data (radiographic acquisition, assessment and reproducibility) using a standardised form. Results A total of 46 reports were included in the analysis. The mean (SD) methodological quality scores on the Jadad scale (range 0–5) and the Delphi list (0–9) were 2.9 (1.2) and 6.4 (1.3), respectively. Use of a standardised procedure for the acquisition of the radiographs was reported in 2 (4.3%) articles. 2 (4.3%) reports indicated that the quality of the radiographs was evaluated. In 65.2% of the reports, ⩾2 radiographic scores were used. Reporting of radiographic assessment was well detailed for number of readers (91.3%), information on readers (71.7%), blinding (91.4%) and how films were viewed (74.0%). The reproducibility of the reading was reported in 39.1% of the articles. Conclusion The reporting of results of randomised controlled trials of radiographic outcomes in RA shows great variability in radiographic scores used. Reporting of radiographic methods could be improved upon, especially the acquisition procedure and the reproducibility of the reading. PMID:17158823

  10. Physiotherapy Post Lumbar Discectomy: Prospective Feasibility and Pilot Randomised Controlled Trial

    PubMed Central

    Rushton, Alison; Goodwin, Peter C.

    2015-01-01

    Objectives To evaluate: acceptability and feasibility of trial procedures; distribution of scores on the Roland Morris Disability Questionnaire (RMDQ, planned primary outcome); and efficient working of trial components. Design and Setting A feasibility and external pilot randomised controlled trial (ISRCTN33808269, assigned 10/12/2012) was conducted across 2 UK secondary care outpatient physiotherapy departments associated with regional spinal surgery centres. Participants Consecutive consenting patients aged >18 years; post primary, single level, lumbar discectomy. Interventions Participants were randomised to either 1:1 physiotherapy outpatient management including patient leaflet, or patient leaflet alone. Main Outcome Measures Blinded assessments were made at 4 weeks post surgery (baseline) and 12 weeks post baseline (proposed primary end point). Secondary outcomes included: Global Perceived Effect, back/leg pain, straight leg raise, return to work/function, quality of life, fear avoidance, range of movement, medication, re-operation. Results At discharge, 110 (44%) eligible patients gave consent to be contacted. 59 (54%) patients were recruited. Loss to follow up was 39% at 12 weeks, with one site contributing 83% losses. Mean (SD) RMDQ was 10.07 (5.58) leaflet and 10.52 (5.94) physiotherapy/leaflet at baseline; and 5.37 (4.91) leaflet and 5.53 (4.49) physiotherapy/leaflet at 12 weeks. 5.1% zero scores at 12 weeks illustrated no floor effect. Sensitivity to change was assessed at 12 weeks with mean (SD) change -4.53 (6.41), 95%CI -7.61 to -1.44 for leaflet; and -6.18 (5.59), 95%CI -9.01 to -3.30 for physiotherapy/leaflet. RMDQ mean difference (95%CI) between change from baseline to twelve weeks was 1.65(-2.46 to 5.75). Mean difference (95%CI) between groups at 12 weeks was -0.16 (-3.36 to 3.04). Participant adherence with treatment was good. No adverse events were reported. Conclusions Both interventions were acceptable, and it is promising that they both

  11. Feasibility of surgical randomised controlled trials with a placebo arm: a systematic review

    PubMed Central

    Wartolowska, Karolina; Collins, Gary S; Hopewell, Sally; Judge, Andrew; Dean, Benjamin J F; Rombach, Ines; Beard, David J; Carr, Andrew J

    2016-01-01

    Objectives To find evidence, either corroborating or refuting, for many persisting beliefs regarding the feasibility of carrying out surgical randomised controlled trials with a placebo arm, with emphasis on the challenges related to recruitment, funding, anaesthesia or blinding. Design Systematic review. Data sources and study selection The analysis involved studies published between 1959 and 2014 that were identified during an earlier systematic review of benefits and harms of placebo-controlled surgical trials published in 2014. Results 63 trials were included in the review. The main problem reported in many trials was a very slow recruitment rate, mainly due to the difficulty in finding eligible patients. Existing placebo trials were funded equally often from commercial and non-commercial sources. General anaesthesia or sedation was used in 41% of studies. Among the reviewed trials, 81% were double-blinded, and 19% were single-blinded. Across the reviewed trials, 96% (range 50–100%) of randomised patients completed the study. The withdrawal rate during the study was similar in the surgical and in the placebo groups. Conclusions This review demonstrated that placebo-controlled surgical trials are feasible, at least for procedures with a lower level of invasiveness, but also that recruitment is difficult. Many of the presumed challenges to undertaking such trials, for example, funding, anaesthesia or blinding of patients and assessors, were not reported as obstacles to completion in any of the reviewed trials. PMID:27008687

  12. Tweeting links to Cochrane Schizophrenia Group reviews: a randomised controlled trial

    PubMed Central

    Adams, C E; Bodart, A Y M; Sampson, S; Zhao, S; Montgomery, A A

    2016-01-01

    Objective To assess the effects of using health social media on web activity. Design Individually randomised controlled parallel group superiority trial. Setting Twitter and Weibo. Participants 170 Cochrane Schizophrenia Group full reviews with an abstract and plain language summary web page. Interventions Three randomly ordered slightly different 140 character or less messages, each containing a short URL to the freely accessible summary page sent on specific times on one single day. This was compared with no messaging. Outcome The primary outcome was web page visits at 1 week. Secondary outcomes were other metrics of web activity at 1 week. Results 85 reviews were randomised to each of the intervention and control arms. Google Analytics allowed 100% follow-up within 1 week of completion. Intervention and control reviews received a total of 1162 and 449 visits, respectively (IRR 2.7, 95% CI 2.2 to 3.3). Fewer intervention reviews had single page only visits (16% vs 31%, OR 0.41, 0.19 to 0.88) and users spent more time viewing intervention reviews (geometric mean 76 vs 31 s, ratio 2.5, 1.3 to 4.6). Other secondary metrics of web activity all showed strong evidence in favour of the intervention. Conclusions Tweeting in this limited area of healthcare increases ‘product placement’ of evidence with the potential for that to influence care. Trial registration number ISRCTN84658943. PMID:26956164

  13. Out-of-hours antibiotic prescription after screening with C reactive protein: a randomised controlled study

    PubMed Central

    Rebnord, Ingrid Keilegavlen; Sandvik, Hogne; Batman Mjelle, Anders; Hunskaar, Steinar

    2016-01-01

    Objective To evaluate the effect of preconsultation C reactive protein (CRP) screening on antibiotic prescribing and referral to hospital in Norwegian primary care settings with low prevalence of serious infections. Design Randomised controlled observational study at out-of-hours services in Norway. Setting Primary care. Participants 401 children (0–6 years) with fever and/or respiratory symptoms were recruited from 5 different out-of-hours services (including 1 paediatric emergency clinic) in 2013–2015. Intervention Data were collected from questionnaires and clinical examination results. Every third child was randomised to a CRP test before the consultation; for the rest, the doctor ordered a CRP test if considered necessary. Outcome measures Main outcome variables were prescription of antibiotics and referral to hospital. Results In the group pretested with CRP, the antibiotic prescription rate was 26%, compared with 22% in the control group. In the group pretested with CRP, 5% were admitted to hospital, compared with 9% in the control group. These differences were not statistically significant. The main predictors for ordering a CRP test were parents' assessment of seriousness of the illness and the child's temperature. Paediatricians ordered CRP tests less frequently than did other doctors (9% vs 56%, p<0.001). Conclusions Preconsultation screening with CRP of children presenting to out-of-hours services with fever and/or respiratory symptoms does not significantly affect the prescription of antibiotics or referral to hospital. Trial registration number NCT02496559; Results. PMID:27173814

  14. An adaptive robust controller for time delay maglev transportation systems

    NASA Astrophysics Data System (ADS)

    Milani, Reza Hamidi; Zarabadipour, Hassan; Shahnazi, Reza

    2012-12-01

    For engineering systems, uncertainties and time delays are two important issues that must be considered in control design. Uncertainties are often encountered in various dynamical systems due to modeling errors, measurement noises, linearization and approximations. Time delays have always been among the most difficult problems encountered in process control. In practical applications of feedback control, time delay arises frequently and can severely degrade closed-loop system performance and in some cases, drives the system to instability. Therefore, stability analysis and controller synthesis for uncertain nonlinear time-delay systems are important both in theory and in practice and many analytical techniques have been developed using delay-dependent Lyapunov function. In the past decade the magnetic and levitation (maglev) transportation system as a new system with high functionality has been the focus of numerous studies. However, maglev transportation systems are highly nonlinear and thus designing controller for those are challenging. The main topic of this paper is to design an adaptive robust controller for maglev transportation systems with time-delay, parametric uncertainties and external disturbances. In this paper, an adaptive robust control (ARC) is designed for this purpose. It should be noted that the adaptive gain is derived from Lyapunov-Krasovskii synthesis method, therefore asymptotic stability is guaranteed.

  15. Robust Nonlinear Feedback Control of Aircraft Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Garrard, William L.; Balas, Gary J.; Litt, Jonathan (Technical Monitor)

    2001-01-01

    This is the final report on the research performed under NASA Glen grant NASA/NAG-3-1975 concerning feedback control of the Pratt & Whitney (PW) STF 952, a twin spool, mixed flow, after burning turbofan engine. The research focussed on the design of linear and gain-scheduled, multivariable inner-loop controllers for the PW turbofan engine using H-infinity and linear, parameter-varying (LPV) control techniques. The nonlinear turbofan engine simulation was provided by PW within the NASA Rocket Engine Transient Simulator (ROCETS) simulation software environment. ROCETS was used to generate linearized models of the turbofan engine for control design and analysis as well as the simulation environment to evaluate the performance and robustness of the controllers. Comparison between the H-infinity, and LPV controllers are made with the baseline multivariable controller and developed by Pratt & Whitney engineers included in the ROCETS simulation. Simulation results indicate that H-infinity and LPV techniques effectively achieve desired response characteristics with minimal cross coupling between commanded values and are very robust to unmodeled dynamics and sensor noise.

  16. Study protocol: a randomised controlled trial of the effects of a multi-modal exercise program on cognition and physical functioning in older women

    PubMed Central

    2012-01-01

    Background Intervention studies testing the efficacy of cardiorespiratory exercise have shown some promise in terms of improving cognitive function in later life. Recent developments suggest that a multi-modal exercise intervention that includes motor as well as physical training and requires sustained attention and concentration, may better elicit the actual potency of exercise to enhance cognitive performance. This study will test the effect of a multi-modal exercise program, for older women, on cognitive and physical functioning. Methods/design This randomised controlled trial involves community dwelling women, without cognitive impairment, aged 65–75 years. Participants are randomised to exercise intervention or non-exercise control groups, for 16 weeks. The intervention consists of twice weekly, 60 minute, exercise classes incorporating aerobic, strength, balance, flexibility, co-ordination and agility training. Primary outcomes are measures of cognitive function and secondary outcomes include physical functioning and a neurocognitive biomarker (brain derived neurotrophic factor). Measures are taken at baseline and 16 weeks later and qualitative data related to the experience and acceptability of the program are collected from a sub-sample of the intervention group. Discussion If this randomised controlled trial demonstrates that multimodal exercise (that includes motor fitness training) can improve cognitive performance in later life, the benefits will be two-fold. First, an inexpensive, effective strategy will have been developed that could ameliorate the increased prevalence of age-related cognitive impairment predicted to accompany population ageing. Second, more robust evidence will have been provided about the mechanisms that link exercise to cognitive improvement allowing future research to be better focused and potentially more productive. Trial registration Australian and New Zealand Clinical Trial Registration Number: ANZCTR12612000451808 PMID

  17. Computerised cognitive behaviour therapy for depression in adolescents: study protocol for a feasibility randomised controlled trial

    PubMed Central

    Wright, Barry; Tindall, Lucy; Littlewood, Elizabeth; Adamson, Joy; Allgar, Victoria; Bennett, Sophie; Gilbody, Simon; Verduyn, Chrissie; Alderson-Day, Ben; Dyson, Lisa; Trépel, Dominic; Ali, Shehzad

    2014-01-01

    Introduction The 1 year prevalence of depression in adolescents is about 2%. Treatment with antidepressant medication is not recommended for initial treatment in young people due to concerns over high side effects, poor efficacy and addictive potential. Evidence suggests that cognitive behaviour therapy (CBT) is an effective treatment for depression and is currently one of the main treatment options recommended in adolescents. Given the affinity young people have with information technology they may be treated effectively, more widely and earlier in their illness evolution using computer-administered CBT (CCBT). Currently little is known about the clinical and resource implications of implementing CCBT within the National Health Service for adolescents with low mood/depression. We aim to establish the feasibility of running a fully powered randomised controlled trial (RCT). Methods and analysis Adolescents aged 12–18 with low mood/depression, (scoring ≥20 on the Mood and Feelings Questionnaire (MFQ)), will be approached to participate. Consenting participants will be randomised to either a CCBT programme (Stressbusters) or accessing selected websites providing information about low mood/depression. The primary outcome measure will be the Beck Depression Inventory (BDI). Participants will also complete generic health measures (EQ5D-Y, HUI2) and resource use questionnaires to examine the feasibility of cost-effectiveness analysis. Questionnaires will be completed at baseline, 4 and 12-month follow-ups. Progress and risk will be monitored via the MFQ administered at each treatment session. The acceptability of a CCBT programme to adolescents; and the willingness of clinicians to recruit participants and of participants to be randomised, recruitment rates, attrition rates and questionnaire completion rates will be collected for feasibility analysis. We will estimate ‘numbers needed’ to plan a fully powered RCT of clinical and cost-effectiveness. Ethics and

  18. Temporary sympathectomy in chronic refractory angina: a randomised, double-blind, placebo-controlled trial

    PubMed Central

    Denby, Christine; Eleuteri, Antonio; Tsang, Hoo kee; Leach, Austin; Hammond, Clare; Bridson, John D; Fisher, Michael; Elt, Matthew; Laflin, Robert; Fisher, Anthony C

    2015-01-01

    Background: Temporary sympathectomy by injection of bupivacaine at the site of the left stellate ganglion is used in the management of refractory angina at several UK centres. Although patients frequently report significant reduction in symptoms, efficacy has not been established by double-blind, randomised placebo-controlled trial (RCT). Objective: To investigate the efficacy of the procedure for the first time by a double-blind RCT. Methods: Consecutive patients referred to the authors’ National Health Service (NHS) angina centre who were candidates for temporary sympathectomy were invited to participate in a trial. A total of 65 patients were randomised to receive either bupivacaine or saline injections. Identical syringes were prepared remotely, blinding patients and staff from randomisation. Cardiac autonomic function was measured 3 hours pre- and post-injection using new heart rate variability (HRV) analyses. Angina episodes were recorded contemporaneously by patients in study diaries in the 7-day periods pre- and post-injection. Results: In 51 patients suitable for analysis, no significant differences between the active and placebo groups were found in patient-recorded frequency or intensity of angina episodes pre- and post-injection. However, across both groups combined, a significant difference was found in the frequency of angina episodes pre- and post-injection. Conclusion: The reduction in frequency of angina episodes produced by this procedure may not be due to drug pharmacology. It may be a placebo response or due to the mechanical effects of the injection of fluid. There is a need for further work using a larger patient cohort considering both mechanical and psychological factors. PMID:26516570

  19. Pragmatic randomised controlled trial of group psychoeducation versus group support in the maintenance of bipolar disorder

    PubMed Central

    2011-01-01

    Background Non-didactically delivered curriculum based group psychoeducation has been shown to be more effective than both group support in a specialist mood disorder centre in Spain (with effects lasting up to five years), and treatment as usual in Australia. It is unclear whether the specific content and form of group psychoeducation is effective or the chance to meet and work collaboratively with other peers. The main objective of this trial is to determine whether curriculum based group psychoeducation is more clinically and cost effective than unstructured peer group support. Methods/design Single blind two centre cluster randomised controlled trial of 21 sessions group psychoeducation versus 21 sessions group peer support in adults with bipolar 1 or 2 disorder, not in current episode but relapsed in the previous two years. Individual randomisation is to either group at each site. The groups are carefully matched for the number and type of therapists, length and frequency of the interventions and overall aim of the groups but differ in content and style of delivery. The primary outcome is time to next bipolar episode with measures of the therapeutic process, barriers and drivers to the effective delivery of the interventions and economic analysis. Follow up is for 96 weeks after randomisation. Discussion The trial has features of both an efficacy and an effectiveness trial design. For generalisability in England it is set in routine public mental health practice with a high degree of expert patient involvement. Trial Registration ISRCTN62761948 Funding National Institute for Health Research, England. PMID:21777426

  20. Graduated compression stockings to treat acute leg pain associated with proximal DVT. A randomised controlled trial.

    PubMed

    Kahn, S R; Shapiro, S; Ducruet, T; Wells, P S; Rodger, M A; Kovacs, M J; Anderson, D; Tagalakis, V; Morrison, D R; Solymoss, S; Miron, M-J; Yeo, E; Smith, R; Schulman, S; Kassis, J; Kearon, C; Chagnon, I; Wong, T; Demers, C; Hanmiah, R; Kaatz, S; Selby, R; Rathbun, S; Desmarais, S; Opatrny, L; Ortel, T L; Galanaud, J-P; Ginsberg, J S

    2014-12-01

    Acute deep venous thrombosis (DVT) causes leg pain. Elastic compression stockings (ECS) have potential to relieve DVT-related leg pain by diminishing the diameter of distended veins and increasing venous blood flow. It was our objective to determine whether ECS reduce leg pain in patients with acute DVT. We performed a secondary analysis of the SOX Trial, a multicentre randomised placebo controlled trial of active ECS versus placebo ECS to prevent the post-thrombotic syndrome.The study was performed in 24 hospital centres in Canada and the U.S. and included 803 patients with a first episode of acute proximal DVT. Patients were randomised to receive active ECS (knee length, 30-40 mm Hg graduated pressure) or placebo ECS (manufactured to look identical to active ECS, but lacking therapeutic compression). Study outcome was leg pain severity assessed on an 11-point numerical pain rating scale (0, no pain; 10, worst possible pain) at baseline, 14, 30 and 60 days after randomisation. Mean age was 55 years and 60% were male. In active ECS patients (n=409), mean (SD) pain severity at baseline and at 60 days were 5.18 (3.29) and 1.39 (2.19), respectively, and in placebo ECS patients (n=394) were 5.38 (3.29) and 1.13 (1.86), respectively. There were no significant differences in pain scores between groups at any assessment point, and no evidence for subgroup interaction by age, sex or anatomical extent of DVT. Results were similar in an analysis restricted to patients who reported wearing stockings every day. In conclusion, ECS do not reduce leg pain in patients with acute proximal DVT. PMID:25183442

  1. Community-based randomised controlled trial evaluating falls and osteoporosis risk management strategies

    PubMed Central

    Ciaschini, PM; Straus, SE; Dolovich, LR; Goeree, RA; Leung, KM; Woods, CR; Zimmerman, GM; Majumdar, SR; Spadafora, S; Fera, LA; Lee, HN

    2008-01-01

    Background Osteoporosis-related fractures are a significant public health concern. Interventions that increase detection and treatment of osteoporosis, as well as prevention of fractures and falls, are substantially underutilized. This paper outlines the protocol for a pragmatic randomised trial of a multifaceted community-based care program aimed at optimizing the evidence-based management of falls and fractures in patients at risk. Design 6-month randomised controlled study. Methods This population-based study was completed in the Algoma District of Ontario, Canada a geographically vast area with Sault Ste Marie (population 78 000) as its main city. Eligible patients were allocated to an immediate intervention protocol (IP) group, or a delayed intervention protocol (DP) group. The DP group received usual care for 6 months and then was crossed over to receive the interventions. Components of the intervention were directed at the physicians and their patients and included patient-specific recommendations for osteoporosis therapy as outlined by the clinical practice guidelines developed by Osteoporosis Canada, and falls risk assessment and treatment. Two primary outcomes were measured including implementation of appropriate osteoporosis and falls risk management. Secondary outcomes included quality of life and the number of falls, fractures, and hospital admissions over a twelve-month period. The patient is the unit of allocation and analysis. Analyses will be performed on an intention to treat basis. Discussion This paper outlines the protocol for a pragmatic randomised trial of a multi-faceted, community-based intervention to optimize the implementation of evidence based management for patients at risk for falls and osteoporosis. Trial Registration This trial has been registered with clinicaltrials.gov (ID: NCT00465387) PMID:18983670

  2. Parametric robust control and system identification: Unified approach

    NASA Technical Reports Server (NTRS)

    Keel, Leehyun

    1994-01-01

    Despite significant advancement in the area of robust parametric control, the problem of synthesizing such a controller is still a wide open problem. Thus, we attempt to give a solution to this important problem. Our approach captures the parametric uncertainty as an H(sub infinity) unstructured uncertainty so that H(sub infinity) synthesis techniques are applicable. Although the techniques cannot cope with the exact parametric uncertainty, they give a reasonable guideline to model the unstructured uncertainty that contains the parametric uncertainty. An additional loop shaping technique is also introduced to relax its conservatism.

  3. Reducing postpartum weight retention and improving breastfeeding outcomes in overweight women: a pilot randomised controlled trial.

    PubMed

    Martin, Julia; MacDonald-Wicks, Lesley; Hure, Alexis; Smith, Roger; Collins, Clare E

    2015-03-01

    Overweight and obesity is prevalent among women of reproductive age (42% BMI > 25 kg/m2) and parity is associated with risk of weight gain. Weight gain greater than that recommended by the Institute of Medicine (IOM )is also associated with lower rates of breastfeeding initiation and duration in women. The aim of this pilot randomised controlled trial is to examine the feasibility of recruiting and maintaining a cohort of pregnant women with the view of reducing postpartum weight retention and improving breastfeeding outcomes. Women (BMI of 25-35 kg/m2 (n = 36)) were recruited from the John Hunter Hospital antenatal clinic in New South Wales, Australia. Participants were stratified by BMI and randomised to one of three groups with follow-up to six months postpartum. Women received a dietary intervention with or without breastfeeding support from a lactation consultant, or were assigned to a wait-list control group where the dietary intervention was issued at three months postpartum. Feasibility and acceptability was assessed by participation rates and questionnaire. Analysis of variance and covariance was conducted to determine any differences between groups. Sixty-nine per cent of the participants were still enrolled at six months postpartum. This pilot demonstrated some difficulties in recruiting women from antenatal clinics and retaining them in the trial. Although underpowered; the results on weight; biomarkers and breastfeeding outcomes indicated improved metabolic health. PMID:25723973

  4. Study protocol: A cluster randomised controlled trial of implementation intentions to reduce smoking initiation in adolescents

    PubMed Central

    2013-01-01

    Background The current literature suggests that forming implementation intentions (simple ‘if-then’ plans) about how to refuse the offer of a cigarette may be an effective intervention to reduce smoking initiation in adolescents. This study is a pragmatic trial to test the effectiveness and cost-effectiveness of such an intervention in reducing smoking initiation in a sample of UK adolescents. Methods/Design A cluster randomised controlled trial with at least 36 schools randomised to receive an implementation intention intervention targeting reducing smoking initiation (intervention group) or increasing homework (control group). Interventions will be conducted at the classroom level and be repeated every six months for four years (eight interventions). Objectively assessed (carbon monoxide monitor) and self-reported smoking plus smoking related cognitions (e.g., smoking intentions, attitudes, norms and self-efficacy) will be assessed at baseline and 12, 24, 36 and 48 months post baseline. Objectively assessed smoking at 48 months post baseline will be the primary outcome variable. Health economic analyses will assess life years gained. Discussion The results of the trial will provide information on the impact of a repeated implementation intention for refusing offers of cigarettes on rates of smoking initiation in adolescents. Trial registration ISRCTN27596806 PMID:23332020

  5. Physical Activity Counselling during Pulmonary Rehabilitation in Patients with COPD: A Randomised Controlled Trial

    PubMed Central

    Burtin, Chris; Langer, Daniel; van Remoortel, Hans; Demeyer, Heleen; Gosselink, Rik; Decramer, Marc; Dobbels, Fabienne; Janssens, Wim; Troosters, Thierry

    2015-01-01

    Background Pulmonary rehabilitation programs only modestly enhance daily physical activity levels in patients with chronic obstructive pulmonary disease (COPD). This randomised controlled trial investigates the additional effect of an individual activity counselling program during pulmonary rehabilitation on physical activity levels in patients with moderate to very severe COPD. Methods Eighty patients (66±7 years, 81% male, forced expiratory volume in 1 second 45±16% of predicted) referred for a six‐month multidisciplinary pulmonary rehabilitation program were randomised. The intervention group was offered an additional eight-session activity counselling program. The primary outcomes were daily walking time and time spent in at least moderate intense activities. Results Baseline daily walking time was similar in the intervention and control group (median 33 [interquartile range 16–47] vs 29 [17–44]) whereas daily time spent in at least moderate intensity was somewhat higher in the intervention group (17[4–50] vs 12[2–26] min). No significant intervention*time interaction effects were observed in daily physical activity levels. In the whole group, daily walking time and time spent in at least moderate intense activities did not significantly change over time. Conclusions The present study identified no additional effect of eight individual activity counselling sessions during pulmonary rehabilitation to enhance physical activity levels in patients with COPD. Trial Registration clinicaltrials.gov NCT00948623 PMID:26697853

  6. Adolescents’ use of purpose built shade in secondary schools: cluster randomised controlled trial

    PubMed Central

    White, Vanessa; Wakefield, Melanie A; Jamsen, Kris M; White, Victoria; Livingston, Patricia M; English, Dallas R; Simpson, Julie A

    2009-01-01

    Objective To examine whether students use or avoid newly shaded areas created by shade sails installed at schools. Design Cluster randomised controlled trial with secondary schools as the unit of randomisation. Setting 51 secondary schools with limited available shade, in Australia, assessed over two spring and summer terms. Participants Students outside at lunch times. Intervention Purpose built shade sails were installed in winter 2005 at full sun study sites to increase available shade for students in the school grounds. Main outcome measure Mean number of students using the primary study sites during weekly observations at lunch time. Results Over the study period the mean change in students using the primary study site from pre-test to post-test was 2.63 (95% confidence interval 0.87 to 4.39) students in intervention schools and −0.03 (−1.16 to 1.09) students in control schools. The difference in mean change between groups was 2.67 (0.65 to 4.68) students (P=0.011). Conclusions Students used rather than avoided newly shaded areas provided by purpose built shade sails at secondary schools in this trial, suggesting a practical means of reducing adolescents’ exposure to ultraviolet radiation. Trial registration Exempt. PMID:19223344

  7. Reducing conflict and containment rates on acute psychiatric wards: The Safewards cluster randomised controlled trial

    PubMed Central

    Bowers, Len; James, Karen; Quirk, Alan; Simpson, Alan; Stewart, Duncan; Hodsoll, John

    2015-01-01

    Background Acute psychiatric wards manage patients whose actions may threaten safety (conflict). Staff act to avert or minimise harm (containment). The Safewards model enabled the identification of ten interventions to reduce the frequency of both. Objective To test the efficacy of these interventions. Design A pragmatic cluster randomised controlled trial with psychiatric hospitals and wards as the units of randomisation. The main outcomes were rates of conflict and containment. Participants Staff and patients in 31 randomly chosen wards at 15 randomly chosen hospitals. Results For shifts with conflict or containment incidents, the experimental condition reduced the rate of conflict events by 15% (95% CI 5.6–23.7%) relative to the control intervention. The rate of containment events for the experimental intervention was reduced by 26.4% (95% CI 9.9–34.3%). Conclusions Simple interventions aiming to improve staff relationships with patients can reduce the frequency of conflict and containment. Trial registration IRSCTN38001825. PMID:26166187

  8. Visibility aids for pedestrians and cyclists: a systematic review of randomised controlled trials.

    PubMed

    Kwan, Irene; Mapstone, James

    2004-05-01

    This study aims to quantify the effect of visibility aids on the occurrence of pedestrian and cyclist-motor vehicle collisions and injuries, and drivers' responses in detection and recognition. Trial reports were systematically reviewed according to predefined eligibility criteria, including randomised controlled trials or controlled before-and-after trials comparing visibility aids and no visibility aids, and of different visibility aids on pedestrian and cyclist safety, and drivers' responses in detection and recognition. This included trials in which the order of interventions was randomised, or balanced using a Latin square design. Two reviewers independently assessed validity of trials and abstracted data. The main outcome measures were pedestrian and cyclist-motor vehicle collisions and injuries, and drivers'/observers' responses in the detection and recognition time, distance and frequency. No trials which assessed the effect of visibility aids on pedestrian and cyclist-motor vehicle collisions and injuries were identified. Twelve trials examined the effectiveness of daytime visibility aids and 25 trials on night time visibility aids, including 882 participants. Drivers' and observers' detection and recognition improved with visibility aids. For daytime, fluorescent materials in yellow, red and orange colours enhanced detection and recognition. "Biomotion" markings enhanced recognition. Substantial heterogeneity between the trials limits the possibility for meta-analysis. Visibility aids have the potential to improve detection and recognition and would merit further development to gain public acceptance. However, the impact of visibility aids on pedestrian and cyclist safety is unknown and needs to be determined. PMID:15003574

  9. Transitional care for the highest risk patients: findings of a randomised control study

    PubMed Central

    Low, Lian Leng; Allen, John; Barbier, Sylvaine; Ng, Lee Beng; Ng, Matthew Joo Ming; Tay, Wei Yi; Tan, Shu Yun

    2015-01-01

    Background Interventions to prevent readmissions of patients at highest risk have not been rigorously evaluated. We conducted a randomised controlled trial to determine if a post-discharge transitional care programme can reduce readmissions of such patients in Singapore. Methods We randomised 840 patients with two or more unscheduled readmissions in the prior 90 days and Length of stay, Acuity of admission, Comorbidity of patient, Emergency department utilisation score ≥10 to the intervention programme (n = 419) or control (n = 421). Patients allocated to the intervention group received post-discharge surveillance by a multidisciplinary integrated care team and early review in the clinic. The primary outcome was the proportion of patients with at least one unscheduled readmission within 30 days after discharge. Results We found no statistically significant reduction in readmissions or emergency department visits in patients on the intervention group compared to usual care. However, patients in the intervention group reported greater patient satisfaction (p < 0.001). Conclusion Any beneficial effect of interventions initiated after discharge is small for high-risk patients with multiple comorbidity and complex care needs. Future transitional care interventions should focus on providing the entire cycle of care for such patients starting from time of admission to final transition to the primary care setting. Trial Registration Clinicaltrials.gov, no NCT02325752 PMID:27118956

  10. Linear, multivariable robust control with a mu perspective

    NASA Technical Reports Server (NTRS)

    Packard, Andy; Doyle, John; Balas, Gary

    1993-01-01

    The structured singular value is a linear algebra tool developed to study a particular class of matrix perturbation problems arising in robust feedback control of multivariable systems. These perturbations are called linear fractional, and are a natural way to model many types of uncertainty in linear systems, including state-space parameter uncertainty, multiplicative and additive unmodeled dynamics uncertainty, and coprime factor and gap metric uncertainty. The structured singular value theory provides a natural extension of classical SISO robustness measures and concepts to MIMO systems. The structured singular value analysis, coupled with approximate synthesis methods, make it possible to study the tradeoff between performance and uncertainty that occurs in all feedback systems. In MIMO systems, the complexity of the spatial interactions in the loop gains make it difficult to heuristically quantify the tradeoffs that must occur. This paper examines the role played by the structured singular value (and its computable bounds) in answering these questions, as well as its role in the general robust, multivariable control analysis and design problem.

  11. Nonlinear Robust Control Synthesis Methods for Spacecraft Applications

    NASA Astrophysics Data System (ADS)

    LeBel, Stefan

    This thesis focuses on practical methods for constructing robust nonlinear control systems. In general, the development of such control systems is characterized by the solution to one or more Hamilton-Jacobi partial differential equations (HJE). However, no general analytical solution has yet been obtained to solve this optimization problem. Solutions have thus far only been obtained under certain conditions. Therefore, the first significant contribution of this thesis is a method for obtaining analytical expressions for approximate solutions to a common form of HJE (under certain assumptions regarding the class of nonlinear systems used). Additionally, modern state space controller synthesis techniques typically result in state estimators of equal or greater dimension than the plant model. However, it is often desirable, or even necessary, to approximate these controllers by models of lower state dimension. Presently, methods for developing nonlinear state balancing transformations are not very well understood. Therefore, the second significant contribution of this thesis is a proper algorithm for the application of state balancing techniques to nonlinear control systems and the subsequent reduction of the number of control states. The method to be developed for state balancing is based on the above framework for constructing analytical solutions to the HJE. In this thesis we will make use of three existing robust nonlinear control methods from the literature. These three methods have the advantage that they can all be constructed from solutions to a single form of HJE. Thus, by developing a method for obtaining analytical expressions for the solution to a single form of HJE, we are able to develop explicit polynomial solutions for each of these three control methods. Due to the difficulties associated with quantifying robustness and performance properties for nonlinear systems, the effectiveness of the three control methods considered shall be demonstrated via

  12. Improving outcomes of preschool language delay in the community: protocol for the Language for Learning randomised controlled trial

    PubMed Central

    2012-01-01

    Background Early language delay is a high-prevalence condition of concern to parents and professionals. It may result in lifelong deficits not only in language function, but also in social, emotional/behavioural, academic and economic well-being. Such delays can lead to considerable costs to the individual, the family and to society more widely. The Language for Learning trial tests a population-based intervention in 4 year olds with measured language delay, to determine (1) if it improves language and associated outcomes at ages 5 and 6 years and (2) its cost-effectiveness for families and the health care system. Methods/Design A large-scale randomised trial of a year-long intervention targeting preschoolers with language delay, nested within a well-documented, prospective, population-based cohort of 1464 children in Melbourne, Australia. All children received a 1.25-1.5 hour formal language assessment at their 4th birthday. The 200 children with expressive and/or receptive language scores more than 1.25 standard deviations below the mean were randomised into intervention or ‘usual care’ control arms. The 20-session intervention program comprises 18 one-hour home-based therapeutic sessions in three 6-week blocks, an outcome assessment, and a final feed-back/forward planning session. The therapy utilises a ‘step up-step down’ therapeutic approach depending on the child’s language profile, severity and progress, with standardised, manualised activities covering the four language development domains of: vocabulary and grammar; narrative skills; comprehension monitoring; and phonological awareness/pre-literacy skills. Blinded follow-up assessments at ages 5 and 6 years measure the primary outcome of receptive and expressive language, and secondary outcomes of vocabulary, narrative, and phonological skills. Discussion A key strength of this robust study is the implementation of a therapeutic framework that provides a standardised yet tailored approach for

  13. Anticipated regret to increase uptake of colorectal cancer screening (ARTICS): A randomised controlled trial.

    PubMed

    O'Carroll, Ronan E; Chambers, Julie A; Brownlee, Linda; Libby, Gillian; Steele, Robert J C

    2015-10-01

    Screening is important for early detection of colorectal cancer. Our aim was to determine whether a simple anticipated regret (AR) intervention could increase uptake of colorectal cancer screening. A randomised controlled trial of a simple, questionnaire-based AR intervention, delivered alongside existing pre-notification letters, was conducted. A total of 60,000 adults aged 50-74 years from the Scottish National Screening programme were randomised into the following groups: (1) no questionnaire (control), (2) Health Locus of Control questionnaire (HLOC) or (3) HLOC plus AR questionnaire. The primary outcome was return of the guaiac faecal occult blood test (FOBT). The secondary outcomes included intention to return test kit and perceived disgust (ICK). A total of 59,366 people were analysed as allocated (intention-to-treat (ITT)); no overall differences were seen between the treatment groups on FOBT uptake (control: 57.3%, HLOC: 56.9%, AR: 57.4%). In total, 13,645 (34.2%) individuals returned the questionnaires. Analysis of the secondary questionnaire measures showed that AR indirectly affected FOBT uptake via intention, whilst ICK directly affected FOBT uptake over and above intention. The effect of AR on FOBT uptake was also moderated by intention strength: for less-than-strong intenders only, uptake was 4.2% higher in the AR (84.6%) versus the HLOC group (80.4%) (95% CI for difference (2.0, 6.5)). The findings show that psychological concepts including AR and perceived disgust (ICK) are important factors in determining FOBT uptake. However, the AR intervention had no simple effect in the ITT analysis. It can be concluded that, in those with low intentions, exposure to AR may be required to increase FOBT uptake. The current controlled trials are presented at the website www.controlled-trials.com (number: ISRCTN74986452). PMID:26301484

  14. Anticipated regret to increase uptake of colorectal cancer screening (ARTICS): A randomised controlled trial

    PubMed Central

    O'Carroll, Ronan E.; Chambers, Julie A.; Brownlee, Linda; Libby, Gillian; Steele, Robert J.C.

    2015-01-01

    Screening is important for early detection of colorectal cancer. Our aim was to determine whether a simple anticipated regret (AR) intervention could increase uptake of colorectal cancer screening. A randomised controlled trial of a simple, questionnaire-based AR intervention, delivered alongside existing pre-notification letters, was conducted. A total of 60,000 adults aged 50–74 years from the Scottish National Screening programme were randomised into the following groups: (1) no questionnaire (control), (2) Health Locus of Control questionnaire (HLOC) or (3) HLOC plus AR questionnaire. The primary outcome was return of the guaiac faecal occult blood test (FOBT). The secondary outcomes included intention to return test kit and perceived disgust (ICK). A total of 59,366 people were analysed as allocated (intention-to-treat (ITT)); no overall differences were seen between the treatment groups on FOBT uptake (control: 57.3%, HLOC: 56.9%, AR: 57.4%). In total, 13,645 (34.2%) individuals returned the questionnaires. Analysis of the secondary questionnaire measures showed that AR indirectly affected FOBT uptake via intention, whilst ICK directly affected FOBT uptake over and above intention. The effect of AR on FOBT uptake was also moderated by intention strength: for less-than-strong intenders only, uptake was 4.2% higher in the AR (84.6%) versus the HLOC group (80.4%) (95% CI for difference (2.0, 6.5)). The findings show that psychological concepts including AR and perceived disgust (ICK) are important factors in determining FOBT uptake. However, the AR intervention had no simple effect in the ITT analysis. It can be concluded that, in those with low intentions, exposure to AR may be required to increase FOBT uptake. The current controlled trials are presented at the website www.controlled-trials.com (number: ISRCTN74986452). PMID:26301484

  15. School-based intervention for the prevention of HPV among adolescents: a cluster randomised controlled study

    PubMed Central

    Grandahl, Maria; Rosenblad, Andreas; Stenhammar, Christina; Tydén, Tanja; Westerling, Ragnar; Larsson, Margareta; Oscarsson, Marie; Andrae, Bengt; Dalianis, Tina; Nevéus, Tryggve

    2016-01-01

    Objective To improve primary prevention of human papillomavirus (HPV) infection by promoting vaccination and increased condom use among upper secondary school students. Design Cluster randomised controlled trial. Setting 18 upper secondary schools in Sweden. Participants Schools were first randomised to the intervention or the control group, after which individual classes were randomised so as to be included or not. Of the 832 students aged 16 years invited to participate during the regular individual health interview with the school nurse, 751 (90.2%) agreed to participate and 741 (89.1%) students completed the study. Interventions The intervention was based on the Health Belief Model (HBM). According to HBM, a person's health behaviour can be explained by individual beliefs regarding health actions. School nurses delivered 30 min face-to-face structured information about HPV, including cancer risks and HPV prevention, by propagating condom use and HPV vaccination. Students in the intervention and the control groups completed questionnaires at baseline and after 3 months. Main outcome measures Intention to use condom with a new partner and beliefs about primary prevention of HPV, and also specifically vaccination status and increased condom use. Results All statistical analyses were performed at the individual level. The intervention had a significant effect on the intention to use condom (p=0.004). There was also a significant effect on HBM total score (p=0.003), with a 2.559 points higher score for the intervention group compared to the controls. The influence on the HBM parameters susceptibility and severity was also significant (p<0.001 for both variables). The intervention also influenced behaviour: girls in the intervention group chose to have themselves vaccinated to a significantly higher degree than the controls (p=0.02). No harms were reported. Conclusions The school-based intervention had favourable effects on the beliefs about primary prevention

  16. Preventing Weight Gain in Women in Rural Communities: A Cluster Randomised Controlled Trial

    PubMed Central

    Lombard, Catherine; Harrison, Cheryce; Kozica, Samantha; Zoungas, Sophia; Ranasinha, Sanjeeva; Teede, Helena

    2016-01-01

    Background Obesity is reaching epidemic proportions in both developed and developing countries. Even modest weight gain increases the risk for chronic illness, yet evidence-based interventions to prevent weight gain are rare. This trial will determine if a simple low-intensity intervention can prevent weight gain in women compared to general health information. Methods and Findings We conducted a 1-yr pragmatic, cluster randomised controlled trial in 41 Australian towns (clusters) randomised using a computer-generated randomisation list for intervention (n = 21) or control (n = 20). Women aged 18 to 50 yr were recruited from the general population to receive a 1-yr self-management lifestyle intervention (HeLP-her) consisting of one group session, monthly SMS text messages, one phone coaching session, and a program manual, or to a control group receiving one general women’s health education session. From October 2012 to April 2014 we studied 649 women, mean age 39.6 yr (+/− SD 6.7) and BMI of 28.8 kg/m2 (+/− SD 6.9) with the primary outcome weight change between groups at 1 yr. The mean change in the control was +0.44 kg (95% CI −0.09 to 0.97) and in the intervention group −0.48kg (95% CI −0.99 to 0.03) with an unadjusted between group difference of −0.92 kg (95% CI −1.67 to −0.16) or −0.87 kg (95% CI −1.62 to −0.13) adjusted for baseline values and clustering. Secondary outcomes included improved diet quality and greater self-management behaviours. The intervention appeared to be equally efficacious across all age, BMI, income, and education subgroups. Loss to follow-up included 23.8% in the intervention group and 21.8% in the control group and was within the anticipated range. Limitations include lack of sensitive tools to measure the small changes to energy intake and physical activity. Those who gained weight may have been less inclined to return for 1 yr weight measures. Conclusions A low intensity lifestyle program can prevent the

  17. Live lecture versus video podcast in undergraduate medical education: A randomised controlled trial

    PubMed Central

    2010-01-01

    Background Information technology is finding an increasing role in the training of medical students. We compared information recall and student experience and preference after live lectures and video podcasts in undergraduate medical education. Methods We performed a crossover randomised controlled trial. 100 students were randomised to live lecture or video podcast for one clinical topic. Live lectures were given by the same instructor as the narrator of the video podcasts. The video podcasts comprised Powerpoint™ slides narrated using the same script as the lecture. They were then switched to the other group for a second clinical topic. Knowledge was assessed using multiple choice questions and qualitative information was collected using a questionnaire. Results No significant difference was found on multiple choice questioning immediately after the session. The subjects enjoyed the convenience of the video podcast and the ability to stop, review and repeat it, but found it less engaging as a teaching method. They expressed a clear preference for the live lecture format. Conclusions We suggest that video podcasts are not ready to replace traditional teaching methods, but may have an important role in reinforcing learning and aiding revision. PMID:20932302

  18. Effectiveness of group body psychotherapy for negative symptoms of schizophrenia: multicentre randomised controlled trial†

    PubMed Central

    Priebe, S.; Savill, M.; Wykes, T.; Bentall, R. P.; Reininghaus, U.; Lauber, C.; Bremner, S.; Eldridge, S.; Röhricht, F.

    2016-01-01

    Background Negative symptoms of schizophrenia have a severe impact on functional outcomes and treatment options are limited. Arts therapies are currently recommended but more evidence is required. Aims To assess body psychotherapy as a treatment for negative symptoms compared with an active control (trial registration: ISRCTN84216587). Method Schizophrenia out-patients were randomised into a 20-session body psychotherapy or Pilates group. The primary outcome was negative symptoms at end of treatment. Secondary outcomes included psychopathology, functional, social and treatment satisfaction outcomes at treatment end and 6-months later. Results In total, 275 participants were randomised. The adjusted difference in negative symptoms was 0.03 (95% CI −1.11 to 1.17), indicating no benefit from body psychotherapy. Small improvements in expressive deficits and movement disorder symptoms were detected in favour of body psychotherapy. No other outcomes were significantly different. Conclusions Body psychotherapy does not have a clinically relevant beneficial effect in the treatment of patients with negative symptoms of schizophrenia. PMID:27151073

  19. Metabolic manipulation in chronic heart failure: study protocol for a randomised controlled trial

    PubMed Central

    2011-01-01

    Background Heart failure is a major cause of morbidity and mortality in society. Current medical therapy centres on neurohormonal modulation with angiotensin converting enzyme inhibitors and β-blockers. There is growing evidence for the use of metabolic manipulating agents as adjunctive therapy in patients with heart failure. We aim to determine the effect of perhexiline on cardiac energetics and alterations in substrate utilisation in patients with non-ischaemic dilated cardiomyopathy. Methods A multi-centre, prospective, randomised double-blind, placebo-controlled trial of 50 subjects with non-ischaemic dilated cardiomyopathy recruited from University Hospital Birmingham NHS Foundation Trust and Cardiff and Vale NHS Trust. Baseline investigations include magnetic resonance spectroscopy to assess cardiac energetic status, echocardiography to assess left ventricular function and assessment of symptomatic status. Subjects are then randomised to receive 200 mg perhexiline maleate or placebo daily for 4 weeks with serum drug level monitoring. All baseline investigations will be repeated at the end of the treatment period. A subgroup of patients will undergo invasive investigations with right and left heart catheterisation to calculate respiratory quotient, and mechanical efficiency. The primary endpoint is an improvement in the phosphocreatine to adenosine triphosphate ratio at 4 weeks. Secondary end points are: i) respiratory quotient; ii) mechanical efficiency; iii) change in left ventricular (LV) function. Trial Registration ClinicalTrials.gov: NCT00841139 ISRCTN: ISRCTN2887836 PMID:21645332

  20. Study Protocol: Screening and Treatment of Alcohol-Related Trauma (START) – a randomised controlled trial

    PubMed Central

    2012-01-01

    Background The incidence of mandibular fractures in the Northern Territory of Australia is very high, especially among Indigenous people. Alcohol intoxication is implicated in the majority of facial injuries, and substance use is therefore an important target for secondary prevention. The current study tests the efficacy of a brief therapy, Motivational Care Planning, in improving wellbeing and substance misuse in youth and adults hospitalised with alcohol-related facial trauma. Methods and design The study is a randomised controlled trial with 6 months of follow-up, to examine the effectiveness of a brief and culturally adapted intervention in improving outcomes for trauma patients with at-risk drinking admitted to the Royal Darwin Hospital maxillofacial surgery unit. Potential participants are identified using AUDIT-C questionnaire. Eligible participants are randomised to either Motivational Care Planning (MCP) or Treatment as Usual (TAU). The outcome measures will include quantity and frequency of alcohol and other substance use by Timeline Followback. The recruitment target is 154 participants, which with 20% dropout, is hoped to provide 124 people receiving treatment and follow-up. Discussion This project introduces screening and brief interventions for high-risk drinkers admitted to the hospital with facial trauma. It introduces a practical approach to integrating brief interventions in the hospital setting, and has potential to demonstrate significant benefits for at-risk drinkers with facial trauma. Trial Registration The trial has been registered in Australian New Zealand Clinical Trials Registry (ANZCTR) and Trial Registration: ACTRN12611000135910. PMID:23106916

  1. Preovulatory uterine flushing with saline as a treatment for unexplained infertility: a randomised controlled trial protocol

    PubMed Central

    Dodin, Sylvie; Moore, Lynne; Bujold, Emmanuel; Lefebvre, Jessica; Bergeron, Marie-Ève

    2016-01-01

    Introduction In vitro fertilisation (IVF) is the treatment of choice for unexplained infertility. Preovulatory uterine flushing could reduce intrauterine debris and inflammatory factors preventing pregnancy and constitute an alternative to IVF. Our objective is to assess the efficacy of preovulatory uterine flushing with physiological saline for the treatment of unexplained infertility. Methods and analysis We will perform a randomised controlled trial based on consecutive women aged between 18 and 37 years consulting for unexplained infertility for at least 1 year. On the day of their luteinising hormone surge, 192 participants will be randomised in two equal groups to either receive 20 mL of physiological saline by an intrauterine catheter or 10 mL of saline intravaginally. We will assess relative risk of live birth (primary outcome), as well as pregnancy (secondary outcome) over one cycle of treatment. We will report the side effects, complications and acceptability of the intervention. Ethics and dissemination This project was approved by the Ethics committee of the Centre Hospitatlier Universitaire de Quebec (no 2015–1146). Uterine flushing is usually well tolerated by women and would constitute a simple, affordable and minimally invasive treatment for unexplained infertility. We plan to communicate the results of the review by presenting research abstracts at conferences and by publishing the results in a peer-reviewed journal. Trial registration number NCT02539290; Pre-results. PMID:26739737

  2. Prolonged-release fampridine and walking and balance in MS: randomised controlled MOBILE trial

    PubMed Central

    Hupperts, Raymond; Lycke, Jan; Short, Christine; Gasperini, Claudio; McNeill, Manjit; Medori, Rossella; Tofil-Kaluza, Agata; Hovenden, Maria; Mehta, Lahar R; Elkins, Jacob

    2016-01-01

    Background: Mobility impairment is a common disability in MS and negatively impacts patients’ lives. Objective: Evaluate the effect of prolonged-release (PR) fampridine (extended-release dalfampridine in the United States) on self-assessed walking disability, dynamic/static balance and safety in patients with MS. Methods: MOBILE was a randomised, double-blind, exploratory, placebo-controlled trial. Patients with progressive/relapsing-remitting MS and Expanded Disability Status Scale score of 4.0–7.0 were treated with PR-fampridine or placebo twice daily for 24 weeks. Efficacy endpoints included change from baseline in the 12-item MS Walking Scale (MSWS-12), Timed Up and Go (TUG) test and Berg Balance Scale (BBS). Results: 132 patients were randomised at 24 sites in six countries. PR-fampridine therapy resulted in greater median improvements from baseline in MSWS-12 score, TUG speed and BBS total score versus placebo over 24 weeks. A higher proportion of patients receiving PR-fampridine versus placebo experienced significant improvements at MSWS-12 improvement thresholds ⩾7 (p = 0.0275), ⩾8 (p = 0.0153) and ⩾9 points (p = 0.0088) and TUG speed thresholds ⩾10% (p = 0.0021) and ⩾15% (p = 0.0262). PR-fampridine was well tolerated. Conclusions: PR-fampridine therapy resulted in early and sustained improvements in broad measures of walking and balance over six months. PMID:25921050

  3. Replicability of sight word training and phonics training in poor readers: a randomised controlled trial

    PubMed Central

    Kohnen, S; Jones, K; Eve, P; Banales, E; Larsen, L; Castles, A

    2015-01-01

    Given the importance of effective treatments for children with reading impairment, paired with growing concern about the lack of scientific replication in psychological science, the aim of this study was to replicate a quasi-randomised trial of sight word and phonics training using a randomised controlled trial (RCT) design. One group of poor readers (N = 41) did 8 weeks of phonics training (i.e., phonological decoding) and then 8 weeks of sight word training (i.e., whole-word recognition). A second group did the reverse order of training. Sight word and phonics training each had a large and significant valid treatment effect on trained irregular words and word reading fluency. In addition, combined sight word and phonics training had a moderate and significant valid treatment effect on nonword reading accuracy and fluency. These findings demonstrate the reliability of both phonics and sight word training in treating poor readers in an era where the importance of scientific reliability is under close scrutiny. PMID:26019992

  4. Supervised exercises for adults with acute lateral ankle sprain: a randomised controlled trial

    PubMed Central

    van Rijn, Rogier M; van Os, Anton G; Kleinrensink, Gert-Jan; Bernsen, Roos MD; Verhaar, Jan AN; Koes, Bart W; Bierma-Zeinstra, Sita MA

    2007-01-01

    Background During the recovery period after acute ankle sprain, it is unclear whether conventional treatment should be supported by supervised exercise. Aim To evaluate the short- and long-term effectiveness of conventional treatment combined with supervised exercises compared with conventional treatment alone in patients with an acute ankle sprain. Design Randomised controlled clinical trial. Setting A total of 32 Dutch general practices and the hospital emergency department. Method Adults with an acute lateral ankle sprain consulting general practices or the hospital emergency department were allocated to either conventional treatment combined with supervised exercises or conventional treatment alone. Primary outcomes were subjective recovery (0–10 point scale) and the occurrence of a re-sprain. Measurements were carried out at intake, 4 weeks, 8 weeks, 3 months, and 1 year after injury. Data were analysed using intention-to-treat analyses. Results A total of 102 patients were enrolled and randomised to either conventional treatment alone or conventional treatment combined with supervised exercise. There was no significant difference between treatment groups concerning subjective recovery or occurrence of re-sprains after 3 months and 1-year of follow-up. Conclusion Conventional treatment combined with supervised exercises compared to conventional treatment alone during the first year after an acute lateral ankle sprain does not lead to differences in the occurrence of re-sprains or in subjective recovery. PMID:17925136

  5. Cognitive therapy for internalised stigma in people experiencing psychosis: A pilot randomised controlled trial.

    PubMed

    Morrison, Anthony P; Burke, Eilish; Murphy, Elizabeth; Pyle, Melissa; Bowe, Samantha; Varese, Filippo; Dunn, Graham; Chapman, Nicola; Hutton, Paul; Welford, Mary; Wood, Lisa J

    2016-06-30

    We aimed to evaluate the feasibility of Cognitive Therapy (CT) as an intervention for internalised stigma in people with psychosis. We conducted a single-blind randomised controlled pilot trial comparing CT plus treatment as usual (TAU) with TAU only. Participants were assessed at end of treatment (4 months) and follow-up (7 months). Twenty-nine participants with schizophrenia spectrum disorders were randomised. CT incorporated up to 12 sessions over 4 months (mean sessions=9.3). Primary outcome was the Internalised Stigma of Mental Illness Scale - Revised (ISMI-R) total score, which provides a continuous measure of internalised stigma associated with mental health problems. Secondary outcomes included self-rated recovery, internalised shame, emotional problems, hopelessness and self-esteem. Recruitment rates and retention for this trial were good. Changes in outcomes were analysed following the intention-to-treat principle, using ANCOVAs adjusted for baseline symptoms. There was no effect on our primary outcome, with a sizable reduction observed in both groups, but several secondary outcomes were significantly improved in the group assigned to CT, in comparison with TAU, including internalised shame, hopelessness and self-rated recovery. Stigma-focused CT appears feasible and acceptable in people with psychosis who have high levels of internalised stigma. A larger, definitive trial is required. PMID:27092862

  6. Patient-controlled oral analgesia versus nurse-controlled parenteral analgesia after caesarean section: a randomised controlled trial.

    PubMed

    Bonnal, A; Dehon, A; Nagot, N; Macioce, V; Nogue, E; Morau, E

    2016-05-01

    We assessed the effectiveness of early patient-controlled oral analgesia compared with parenteral analgesia in a randomised controlled non-inferiority trial of women undergoing elective caesarean section under regional anaesthesia. Seventy-seven women received multimodal paracetamol, ketoprofen and morphine analgesia. The woman having patient-controlled oral analgesia were administered four pillboxes on the postnatal ward containing tablets and instructions for self-medication, the first at 7 h after the spinal injection and then three more at 12-hourly intervals. Pain at rest and on movement was evaluated using an 11-point verbal rating scale at 2 h and then at 6-hourly intervals for 48 h. The pre-defined non-inferiority limit for the difference in mean pain scores (patient-controlled oral analgesia minus parenteral) was one. The one-sided 95% CI of the difference in mean pain scores was significantly lower than one at all time-points at rest and on movement, demonstrating non-inferiority of patient-controlled oral analgesia. More women used morphine in the patient-controlled oral analgesia group (22 (58%)) than in the parenteral group (9 (23%); p = 0.002). The median (IQR [range]) number of morphine doses in the patient-controlled oral analgesia group was 2 (1-3 [1-7]) compared with 1 (1-1 [1-2]); p = 0.006) in the parenteral group. Minor drug errors or omissions were identified in five (13%) women receiving patient-controlled oral analgesia. Pruritus was more frequent in the patient-controlled oral analgesia group (14 (37%) vs 6 (15%) respectively; p = 0.03), but no differences were noted for other adverse events and maternal satisfaction. After elective caesarean section, early patient-controlled oral analgesia is non-inferior to standard parenteral analgesia for pain management, and can be one of the steps of an enhanced recovery process. PMID:26931110

  7. Robust observer-based adaptive fuzzy sliding mode controller

    NASA Astrophysics Data System (ADS)

    Oveisi, Atta; Nestorović, Tamara

    2016-08-01

    In this paper, a new observer-based adaptive fuzzy integral sliding mode controller is proposed based on the Lyapunov stability theorem. The plant is subjected to a square-integrable disturbance and is assumed to have mismatch uncertainties both in state- and input-matrices. Based on the classical sliding mode controller, the equivalent control effort is obtained to satisfy the sufficient requirement of sliding mode controller and then the control law is modified to guarantee the reachability of the system trajectory to the sliding manifold. In order to relax the norm-bounded constrains on the control law and solve the chattering problem of sliding mode controller, a fuzzy logic inference mechanism is combined with the controller. An adaptive law is then introduced to tune the parameters of the fuzzy system on-line. Finally, for evaluating the controller and the robust performance of the closed-loop system, the proposed regulator is implemented on a real-time mechanical vibrating system.

  8. Robust Inversion and Data Compression in Control Allocation

    NASA Technical Reports Server (NTRS)

    Hodel, A. Scottedward

    2000-01-01

    We present an off-line computational method for control allocation design. The control allocation function delta = F(z)tau = delta (sub 0) (z) mapping commanded body-frame torques to actuator commands is implicitly specified by trim condition delta (sub 0) (z) and by a robust pseudo-inverse problem double vertical line I - G(z) F(z) double vertical line less than epsilon (z) where G(z) is a system Jacobian evaluated at operating point z, z circumflex is an estimate of z, and epsilon (z) less than 1 is a specified error tolerance. The allocation function F(z) = sigma (sub i) psi (z) F (sub i) is computed using a heuristic technique for selecting wavelet basis functions psi and a constrained least-squares criterion for selecting the allocation matrices F (sub i). The method is applied to entry trajectory control allocation for a reusable launch vehicle (X-33).

  9. "Every Child Counts": Testing Policy Effectiveness Using a Randomised Controlled Trial, Designed, Conducted and Reported to CONSORT Standards

    ERIC Educational Resources Information Center

    Torgerson, Carole; Wiggins, Andy; Torgerson, David; Ainsworth, Hannah; Hewitt, Catherine

    2013-01-01

    We report a randomised controlled trial evaluation of an intensive one-to-one numeracy programme--"Numbers Count"--which formed part of the previous government's numeracy policy intervention--"Every Child Counts." We rigorously designed and conducted the trial to CONSORT guidelines. We used a pragmatic waiting list design to…

  10. A Randomised Controlled Trial to Determine the Effectiveness of an Early Psychological Intervention with Children Involved in Road Traffic Accidents

    ERIC Educational Resources Information Center

    Stallard, Paul; Velleman, Richard; Salter, Emma; Howse, Imogen; Yule, William; Taylor, Gordon

    2006-01-01

    Objective: To determine whether an early intervention using a psychological debriefing format is effective in preventing psychological distress in child road traffic accident survivors. Design: Randomised controlled trial. Setting: Accident and Emergency Department, Royal United Hospital, Bath. Subjects: 158 children aged 7-18. Follow-up…

  11. A Randomised Controlled Trial Using Mobile Advertising to Promote Safer Sex and Sun Safety to Young People

    ERIC Educational Resources Information Center

    Gold, J.; Aitken, C. K.; Dixon, H. G.; Lim, M. S. C.; Gouillou, M.; Spelman, T.; Wakefield, M.; Hellard, M. E.

    2011-01-01

    Mobile phone text messages (SMS) are a promising method of health promotion, but a simple and low cost way to obtain phone numbers is required to reach a wide population. We conducted a randomised controlled trial with simultaneous brief interventions to (i) evaluate effectiveness of messages related to safer sex and sun safety and (ii) pilot the…

  12. Are Prenatal Ultrasound Scans Associated with the Autism Phenotype? Follow-Up of a Randomised Controlled Trial

    ERIC Educational Resources Information Center

    Stoch, Yonit K.; Williams, Cori J.; Granich, Joanna; Hunt, Anna M.; Landau, Lou I.; Newnham, John P.; Whitehouse, Andrew J. O.

    2012-01-01

    An existing randomised controlled trial was used to investigate whether multiple ultrasound scans may be associated with the autism phenotype. From 2,834 single pregnancies, 1,415 were selected at random to receive ultrasound imaging and continuous wave Doppler flow studies at five points throughout pregnancy (Intensive) and 1,419 to receive a…

  13. A Randomised Controlled Trial of the Use of a Piece of Commercial Software for the Acquisition of Reading Skills

    ERIC Educational Resources Information Center

    Khan, Muhammad Ahmad; Gorard, Stephen

    2012-01-01

    We report here the overall results of a cluster randomised controlled trial of the use of computer-aided instruction with 672 Year 7 pupils in 23 secondary school classes in the north of England. A new piece of commercial software, claimed on the basis of publisher testing to be effective in improving reading after just six weeks of use in the…

  14. All-Wales licensed premises intervention (AWLPI): a randomised controlled trial to reduce alcohol-related violence

    PubMed Central

    2014-01-01

    Background Alcohol-related violence in and in the vicinity of licensed premises continues to place a considerable burden on the United Kingdom’s (UK) health services. Robust interventions targeted at licensed premises are therefore required to reduce the costs of alcohol-related harm. Previous evaluations of interventions in licensed premises have a number of methodological limitations and none have been conducted in the UK. The aim of the trial was to determine the effectiveness of the Safety Management in Licensed Environments intervention designed to reduce alcohol-related violence in licensed premises, delivered by Environmental Health Officers, under their statutory authority to intervene in cases of violence in the workplace. Methods/Design A national randomised controlled trial, with licensed premises as the unit of allocation. Premises were identified from all 22 Local Authorities in Wales. Eligible premises were those with identifiable violent incidents on premises, using police recorded violence data. Premises were allocated to intervention or control by optimally balancing by Environmental Health Officer capacity in each Local Authority, number of violent incidents in the 12 months leading up to the start of the project and opening hours. The primary outcome measure is the difference in frequency of violence between intervention and control premises over a 12 month follow-up period, based on a recurrent event model. The trial incorporates an embedded process evaluation to assess intervention implementation, fidelity, reach and reception, and to interpret outcome effects, as well as investigate its economic impact. Discussion The results of the trial will be applicable to all statutory authorities directly involved with managing violence in the night time economy and will provide the first formal test of Health and Safety policy in this environment. If successful, opportunities for replication and generalisation will be considered. Trial registration

  15. Outcomes of a randomised controlled trial of a complex genetic counselling intervention to improve family communication.

    PubMed

    Hodgson, Jan; Metcalfe, Sylvia; Gaff, Clara; Donath, Susan; Delatycki, Martin B; Winship, Ingrid; Skene, Loane; Aitken, MaryAnne; Halliday, Jane

    2016-03-01

    When an inherited genetic condition is diagnosed in an individual it has implications for other family members. Privacy legislation and ethical considerations can restrict health professionals from communicating directly with other family members, and so it is frequently the responsibility of the first person in a family to receive the diagnosis (the proband) to share this news. Communication of genetic information is challenging and many at-risk family members remain unaware of important information that may be relevant to their or their children's health. We conducted a randomised controlled trial in six public hospitals to assess whether a specifically designed telephone counselling intervention improved family communication about a new genetic diagnosis. Ninety-five probands/parents of probands were recruited from genetics clinics and randomised to the intervention or control group. The primary outcome measure was the difference between the proportion of at-risk relatives who contacted genetics services for information and/or genetic testing. Audit of the family genetic file after 18 months revealed that 25.6% of intervention group relatives compared with 20.9% of control group relatives made contact with genetic services (adjusted odds ratio (OR) 1.30, 95% confidence interval 0.70-2.42, P=0.40). Although no major difference was detected overall between the intervention and control groups, there was more contact in the intervention group where the genetic condition conferred a high risk to offspring (adjusted OR 24.0, 95% confidence interval 3.4-168.5, P=0.001). The increasing sophistication and scope of genetic testing makes it imperative for health professionals to consider additional ways of supporting families in communicating genetic information. PMID:26130486

  16. Prenatal Vitamin D Supplementation and Child Respiratory Health: A Randomised Controlled Trial

    PubMed Central

    Goldring, Stephen T.; Griffiths, Chris J.; Martineau, Adrian R.; Robinson, Stephen; Yu, Christina; Poulton, Sheree; Kirkby, Jane C.; Stocks, Janet; Hooper, Richard; Shaheen, Seif O.; Warner, John O.; Boyle, Robert J.

    2013-01-01

    Background Observational studies suggest high prenatal vitamin D intake may be associated with reduced childhood wheezing. We examined the effect of prenatal vitamin D on childhood wheezing in an interventional study. Methods We randomised 180 pregnant women at 27 weeks gestation to either no vitamin D, 800 IU ergocalciferol daily until delivery or single oral bolus of 200,000 IU cholecalciferol, in an ethnically stratified, randomised controlled trial. Supplementation improved but did not optimise vitamin D status. Researchers blind to allocation assessed offspring at 3 years. Primary outcome was any history of wheeze assessed by validated questionnaire. Secondary outcomes included atopy, respiratory infection, impulse oscillometry and exhaled nitric oxide. Primary analyses used logistic and linear regression. Results We evaluated 158 of 180 (88%) offspring at age 3 years for the primary outcome. Atopy was assessed by skin test for 95 children (53%), serum IgE for 86 (48%), exhaled nitric oxide for 62 (34%) and impulse oscillometry of acceptable quality for 51 (28%). We found no difference between supplemented and control groups in risk of wheeze [no vitamin D: 14/50 (28%); any vitamin D: 26/108 (24%) (risk ratio 0.86; 95% confidence interval 0.49, 1.50; P = 0.69)]. There was no significant difference in atopy, eczema risk, lung function or exhaled nitric oxide between supplemented groups and controls. Conclusion Prenatal vitamin D supplementation in late pregnancy that had a modest effect on cord blood vitamin D level, was not associated with decreased wheezing in offspring at age three years. Trial Registration Controlled-Trials.com ISRCTN68645785 PMID:23826104

  17. Prevention of acute knee injuries in adolescent female football players: cluster randomised controlled trial

    PubMed Central

    Atroshi, Isam; Magnusson, Henrik; Wagner, Philippe; Hägglund, Martin

    2012-01-01

    Objective To evaluate the effectiveness of neuromuscular training in reducing the rate of acute knee injury in adolescent female football players. Design Stratified cluster randomised controlled trial with clubs as the unit of randomisation. Setting 230 Swedish football clubs (121 in the intervention group, 109 in the control group) were followed for one season (2009, seven months). Participants 4564 players aged 12-17 years (2479 in the intervention group, 2085 in the control group) completed the study. Intervention 15 minute neuromuscular warm-up programme (targeting core stability, balance, and proper knee alignment) to be carried out twice a week throughout the season. Main outcome measures The primary outcome was rate of anterior cruciate ligament injury; secondary outcomes were rates of severe knee injury (>4 weeks’ absence) and any acute knee injury. Results Seven players (0.28%) in the intervention group, and 14 (0.67%) in the control group had an anterior cruciate ligament injury. By Cox regression analysis according to intention to treat, a 64% reduction in the rate of anterior cruciate ligament injury was seen in the intervention group (rate ratio 0.36, 95% confidence interval 0.15 to 0.85). The absolute rate difference was −0.07 (95% confidence interval −0.13 to 0.001) per 1000 playing hours in favour of the intervention group. No significant rate reductions were seen for secondary outcomes. Conclusions A neuromuscular warm-up programme significantly reduced the rate of anterior cruciate ligament injury in adolescent female football players. However, the absolute rate difference did not reach statistical significance, possibly owing to the small number of events. Trial registration Clinical trials NCT00894595. PMID:22556050

  18. Passivity-based Robust Control of Aerospace Systems

    NASA Technical Reports Server (NTRS)

    Kelkar, Atul G.; Joshi, Suresh M. (Technical Monitor)

    2000-01-01

    This report provides a brief summary of the research work performed over the duration of the cooperative research agreement between NASA Langley Research Center and Kansas State University. The cooperative agreement which was originally for the duration the three years was extended by another year through no-cost extension in order to accomplish the goals of the project. The main objective of the research was to develop passivity-based robust control methodology for passive and non-passive aerospace systems. The focus of the first-year's research was limited to the investigation of passivity-based methods for the robust control of Linear Time-Invariant (LTI) single-input single-output (SISO), open-loop stable, minimum-phase non-passive systems. The second year's focus was mainly on extending the passivity-based methodology to a larger class of non-passive LTI systems which includes unstable and nonminimum phase SISO systems. For LTI non-passive systems, five different passification. methods were developed. The primary effort during the years three and four was on the development of passification methodology for MIMO systems, development of methods for checking robustness of passification, and developing synthesis techniques for passifying compensators. For passive LTI systems optimal synthesis procedure was also developed for the design of constant-gain positive real controllers. For nonlinear passive systems, numerical optimization-based technique was developed for the synthesis of constant as well as time-varying gain positive-real controllers. The passivity-based control design methodology developed during the duration of this project was demonstrated by its application to various benchmark examples. These example systems included longitudinal model of an F-18 High Alpha Research Vehicle (HARV) for pitch axis control, NASA's supersonic transport wind tunnel model, ACC benchmark model, 1-D acoustic duct model, piezo-actuated flexible link model, and NASA

  19. A randomised controlled trial of post-operative rehabilitation after surgical decompression of the lumbar spine

    PubMed Central

    Denzler, Raymond; Dvorak, Jiri; Müntener, Markus; Grob, Dieter

    2007-01-01

    Spinal decompression is the most common type of spinal surgery carried out in the older patient, and is being performed with increasing frequency. Physiotherapy (rehabilitation) is often prescribed after surgery, although its benefits compared with no formal rehabilitation have yet to be demonstrated in randomised control trials. The aim of this randomised controlled trial was to examine the effects on outcome up to 2 years after spinal decompression surgery of two types of postoperative physiotherapy compared with no postoperative therapy (self-management). Hundred and fifty-nine patients (100 men, 59 women; 65 ± 11 years) undergoing decompression surgery for spinal stenosis/herniated disc were randomised to one of the following programmes beginning 2 months post-op: recommended to “keep active” (CONTROL; n = 54); physiotherapy, spine stabilisation exercises (PT-StabEx; n = 56); physiotherapy, mixed techniques (PT-Mixed; n = 49). Both PT programmes involved 2 × 30 min sessions/week for up to 12 weeks, with home exercises. Pain intensity (0–10 graphic rating scale, for back and leg pain separately) and self-rated disability (Roland Morris) were assessed before surgery, before and after the rehabilitation phase (approx. 2 and 5 months post-op), and at 12 and 24 months after the operation. ‘Intention to treat’ analyses were used. At 24 months, 151 patients returned questionnaires (effective return rate, excluding 4 deaths, 97%). Significant reductions in leg and back pain and self-rated disability were recorded after surgery (P < 0.05). Pain showed no further changes in any group up to 24 months later, whereas disability declined further during the “rehabilitation” phase (P < 0.05) then stabilised, but with no significant group differences. 12 weeks of post-operative physiotherapy did not influence the course of change in pain or disability up to 24 months after decompression surgery. Advising patients to keep active by

  20. Discontinuation and non-publication of surgical randomised controlled trials: observational study

    PubMed Central

    Chapman, Stephen J; Shelton, Bryony; Mahmood, Humza; Fitzgerald, J Edward; Harrison, Ewen M

    2014-01-01

    Objective To determine the rate of early discontinuation and non-publication of randomised controlled trials involving patients undergoing surgery. Design Cross sectional observational study of registered and published trials. Setting Randomised controlled trials of interventions in patients undergoing a surgical procedure. Data sources The ClinicalTrials.gov database was searched for interventional trials registered between January 2008 and December 2009 using the keyword “surgery”. Recruitment status was extracted from the ClinicalTrials.gov database. A systematic search for studies published in peer reviewed journals was performed; if they were not found, results posted on the ClinicalTrials.gov results database were sought. Email queries were sent to trial investigators of discontinued and unpublished completed trials if no reason for the respective status was disclosed. Main outcome measures Trial discontinuation before completion and non-publication after completion. Logistic regression was used to determine the effect of funding source on publication status, with adjustment for intervention type and trial size. Results Of 818 registered trials found using the keyword “surgery”, 395 met the inclusion criteria. Of these, 21% (81/395) were discontinued early, most commonly owing to poor recruitment (44%, 36/81). The remaining 314 (79%) trials proceeded to completion, with a publication rate of 66% (208/314) at a median time of 4.9 (interquartile range 4.0-6.0) years from study completion to publication search. A further 6% (20/314) of studies presented results on ClinicalTrials.gov without a corresponding peer reviewed publication. Industry funding did not affect the rate of discontinuation (adjusted odds ratio 0.91, 95% confidence interval 0.54 to 1.55) but was associated with a lower odds of publication for completed trials (0.43, 0.26 to 0.72). Investigators’ email addresses for trials with an uncertain fate were identified for 71.4% (10/14) of

  1. Parent-focused treatment for adolescent anorexia nervosa: a study protocol of a randomised controlled trial

    PubMed Central

    2014-01-01

    Background Family-based treatment is an efficacious outpatient intervention for medically stable adolescents with anorexia nervosa. Previous research suggests family-based treatment may be more effective for some families when parents and adolescents attend separate therapy sessions compared to conjoint sessions. Our service developed a novel separated model of family-based treatment, parent-focused treatment, and is undertaking a randomised controlled trial to compare parent-focused treatment to conjoint family-based treatment. Methods/Design This randomised controlled trial will recruit 100 adolescents aged 12–18 years with DSM-IV anorexia nervosa or eating disorder not otherwise specified (anorexia nervosa type). The trial commenced in 2010 and is expected to be completed in 2015. Participants are recruited from the Royal Children’s Hospital Eating Disorders Program, Melbourne, Australia. Following a multidisciplinary intake assessment, eligible families who provide written informed consent are randomly allocated to either parent-focused treatment or conjoint family-based treatment. In parent-focused treatment, the adolescent sees a clinical nurse consultant and the parents see a trained mental health clinician. In conjoint family-based treatment, the whole family attends sessions with the mental health clinician. Both groups receive 18 treatment sessions over 6 months and regular medical monitoring by a paediatrician. The primary outcome is remission at end of treatment and 6 and 12 month follow up, with remission defined as being ≥ 95% expected body weight and having an eating disorder symptom score within one standard deviation of community norms. The secondary outcomes include partial remission and changes in eating pathology, depressive symptoms and self-esteem. Moderating and mediating factors will also be explored. Discussion This will be first randomised controlled trial of a parent-focused model of family-based treatment of adolescent

  2. Lay support for pregnant women with social risk: a randomised controlled trial

    PubMed Central

    Kenyon, Sara; Jolly, Kate; Hemming, Karla; Hope, Lucy; Blissett, Jackie; Dann, Sophie-Anna; Lilford, Richard; MacArthur, Christine

    2016-01-01

    Objectives We sought evidence of effectiveness of lay support to improve maternal and child outcomes in disadvantaged families. Design Prospective, pragmatic, individually randomised controlled trial. Setting 3 Maternity Trusts in West Midlands, UK. Participants Following routine midwife systematic assessment of social risk factors, 1324 nulliparous women were assigned, using telephone randomisation, to standard maternity care, or addition of referral to a Pregnancy Outreach Worker (POW) service. Those under 16 years and teenagers recruited to the Family Nurse Partnership trial were excluded. Interventions POWs were trained to provide individual support and case management for the women including home visiting from randomisation to 6 weeks after birth. Standard maternity care (control) included provision for referring women with social risk factors to specialist midwifery services, available to both arms. Main outcome measures Primary outcomes were antenatal visits attended and Edinburgh Postnatal Depression Scale (EPDS) 8–12 weeks postpartum. Prespecified, powered, subgroup comparison was among women with 2 or more social risks. Secondary outcomes included maternal and neonatal birth outcomes; maternal self-efficacy, and mother-to-infant bonding at 8–12 weeks; child development assessment at 6 weeks, breastfeeding at 6 weeks, and immunisation uptake at 4 months, all collected from routine child health systems. Results Antenatal attendances were high in the standard care control and did not increase further with addition of the POW intervention (10.1 vs 10.1 (mean difference; MD) −0.00, 95% CI (95% CI −0.37 to 0.37)). In the powered subgroup of women with 2 or more social risk factors, mean EPDS (MD −0.79 (95% CI −1.56 to −0.02) was significantly better, although for all women recruited, no significant differences were seen (MD −0.59 (95% CI −1.24 to 0.06). Mother-to-infant bonding was significantly better in the intervention group

  3. A randomised controlled trial of patient led training in medical education: protocol

    PubMed Central

    2010-01-01

    Background Estimates suggest that approximately 1 in 10 patients admitted to hospital experience an adverse event resulting in harm. Methods to improve patient safety have concentrated on developing safer systems of care and promoting changes in professional behaviour. There is a growing international interest in the development of interventions that promote the role of patients preventing error, but limited evidence of effectiveness of such interventions. The present study aims to undertake a randomised controlled trial of patient-led teaching of junior doctors about patient safety. Methods/Design A randomised cluster controlled trial will be conducted. The intervention will be incorporated into the mandatory training of junior doctors training programme on patient safety. The study will be conducted in the Yorkshire and Humber region in the North of England. Patients who have experienced a safety incident in the NHS will be recruited. Patients will be identified through National Patient Safety Champions and local Trust contacts. Patients will receive training and be supported to talk to small groups of trainees about their experiences. The primary aim of the patient-led teaching module is to increase the awareness of patient safety issues amongst doctors, allow reflection on their own attitudes towards safety and promote an optimal culture among the doctors to improve safety in practice. A mixture of qualitative and quantitative methods will be used to evaluate the impact of the intervention, using the Attitudes to Patient Safety Questionnaire (APSQ) as our primary quantitative outcome, as well as focus groups and semi-structured interviews. Discussion The research team face a number of challenges in developing the intervention, including integrating a new method of teaching into an existing curriculum, facilitating effective patient involvement and identifying suitable outcome measures. Trial Registration Current controlled Trials: ISRCTN94241579 PMID:21129179

  4. Effectiveness of ear syringing in general practice: a randomised controlled trial and patients' experiences.

    PubMed Central

    Memel, David; Langley, Carole; Watkins, Chris; Laue, Barbara; Birchall, Martin; Bachmann, Max

    2002-01-01

    BACKGROUND: Ear syringing is a common procedure performed for a variety of symptoms in primary care. Reports of its effectiveness vary considerably and no randomised controlled trials (RCTs) have been performed. AIM: To estimate the effect of ear syringing on hearing thresholds and on symptoms leading to ear syringing in general practice. DESIGN OF STUDY: Randomised single-blind controlled trial. Before-and-after self-assessments of symptoms. SETTING: Patients from three general practices in the Bristol area attending twice-weekly clinics dedicated to ear syringing over a 12-week period. METHOD: Patients were randomly assigned to have their hearing tested before and after ear syringing, or twice before ear syringing. Changes in hearing threshold were measured by pure tone audiometry (PTA). All patients completed sef-assessment forms of symptoms using Likert scales before, and one week after, ear syringing. RESULTS: Hearing threshold improved by 10 dB or more in 34% (95% confidence interval [CI] = 21% to 47%) of the intervention group and 1.6% of control group (number needed to treat = 3.1, 95% CI = 2.2 to 5.2, P<0.001). The levels of improvement in the intervention group ranged between 15 dB and 36 dB. The symptoms that most commonly improved included hearing on the phone, pain, a feeling of blocked ears, and hearing one-to-one. There was a strong relationship between the change thresholds, as measure using PTA, and self-reports of hearing improvement. Secondary analysis was unable to identify predictors of objectively measured improvement. CONCLUSION: Ear syringing improved hearing threshold in a substantial proportion of patients. An even larger proportion reported an improvement in symptoms. It was not possible to predict which patients would benefit. PMID:12434959

  5. Nebulised steroid in the treatment of croup: a systematic review of randomised controlled trials.

    PubMed Central

    Griffin, S; Ellis, S; Fitzgerald-Barron, A; Rose, J; Egger, M

    2000-01-01

    BACKGROUND: Croup is one of the commonest respiratory complaints among children. There is growing evidence that steroids may be an effective treatment. AIM: To assess the effectiveness of treatment with nebulised steroid for children with croup. METHOD: Systematic review of randomised controlled trials comparing administration of nebulised steroid with placebo. Trials were identified from searches of three bibliographic databases, the Cochrane Controlled Trials Register, correspondence with the manufacturers of nebulised steroid, and one round of manual citation searching. RESULTS: Eight randomised controlled trials were identified including 574 children with mild to severe croup. Overall, the mean age was 25.2 months and 72% of children were male. All trials were hospital-based and of good methodological quality, with adequate concealment of treatment allocation and blind outcome assessment. Children treated with nebulised steroid were significantly more likely to show an improvement in croup score by five hours (combined relative risk = 1.48, 95% confidence interval [CI] = 1.27 to 1.74) and significantly less likely to need hospital admission after attending the emergency department (combined relative risk = 0.56, 95% CI = 0.42 to 0.75) than the placebo group. The funnel plot indicated the presence of publication bias, with smaller studies showing the larger effects, but this could also be owing to less pronounced effects in studies of older children with milder croup. CONCLUSIONS: Nebulised steroids are effective in the treatment of children attending hospital departments with croup. A meta-analysis based on individual patient data could clarify to what extent the effect depends on age and severity of disease. New trials are needed to define the indications for, and effectiveness of, steroid treatment of croup in the community. PMID:10750214

  6. Recruitment issues when primary care population clusters are used in randomised controlled clinical trials: climbing mountains or pushing boulders uphill?

    PubMed

    Hoddinott, Pat; Britten, Jane; Harrild, Kirsten; Godden, David J

    2007-05-01

    Cluster randomised controlled trials for health promotion, education, public health or organisational change interventions are becoming increasingly common to inform evidence-based policy. However, there is little published methodological evidence on recruitment strategies for primary care population clusters. In this paper, we discuss how choosing which population cluster to randomise can impact on the practicalities of recruitment in primary care. We describe strategies developed through our experiences of recruiting primary care organisations to participate in a national randomised controlled trial of a policy to provide community breastfeeding groups for pregnant and breastfeeding mothers, the BIG (Breastfeeding in Groups) trial. We propose an iterative qualitative approach to recruitment; collecting data generated through the recruitment process, identifying themes and using the constant comparative method of analysis. This can assist in developing successful recruitment strategies and contrasts with the standardised approach commonly used when recruiting individuals to participate in randomised controlled trials. Recruiting primary care population clusters to participate in trials is currently an uphill battle in Britain. It is a complex process, which can benefit from applying qualitative methods to inform trial design and recruitment strategy. Recruitment could be facilitated if health service managers were committed to supporting peer reviewed, funded and ethics committee approved research at national level. PMID:16996320

  7. Genetic and Environmental Control of Neurodevelopmental Robustness in Drosophila

    PubMed Central

    Mellert, David J.; Williamson, W. Ryan; Shirangi, Troy R.; Card, Gwyneth M.; Truman, James W.

    2016-01-01

    Interindividual differences in neuronal wiring may contribute to behavioral individuality and affect susceptibility to neurological disorders. To investigate the causes and potential consequences of wiring variation in Drosophila melanogaster, we focused on a hemilineage of ventral nerve cord interneurons that exhibits morphological variability. We find that late-born subclasses of the 12A hemilineage are highly sensitive to genetic and environmental variation. Neurons in the second thoracic segment are particularly variable with regard to two developmental decisions, whereas its segmental homologs are more robust. This variability “hotspot” depends on Ultrabithorax expression in the 12A neurons, indicating variability is cell-intrinsic and under genetic control. 12A development is more variable and sensitive to temperature in long-established laboratory strains than in strains recently derived from the wild. Strains with a high frequency of one of the 12A variants also showed a high frequency of animals with delayed spontaneous flight initiation, whereas other wing-related behaviors did not show such a correlation and were thus not overtly affected by 12A variation. These results show that neurodevelopmental robustness is variable and under genetic control in Drosophila and suggest that the fly may serve as a model for identifying conserved gene pathways that stabilize wiring in stressful developmental environments. Moreover, some neuronal lineages are variation hotspots and thus may be more amenable to evolutionary change. PMID:27223118

  8. Robust isothermal electric control of exchange bias at room temperature

    NASA Astrophysics Data System (ADS)

    Binek, Christian

    2011-03-01

    Voltage-controlled spintronics is of particular importance to continue progress in information technology through reduced power consumption, enhanced processing speed, integration density, and functionality in comparison with present day CMOS electronics. Almost all existing and prototypical solid-state spintronic devices rely on tailored interface magnetism, enabling spin-selective transmission or scattering of electrons. Controlling magnetism at thin-film interfaces, preferably by purely electrical means, is a key challenge to better spintronics. Currently, most attempts to electrically control magnetism focus on potentially large magnetoelectric effects of multiferroics. We report on our interest in magnetoelectric Cr 2 O3 (chromia). Robust isothermal electric control of exchange bias is achieved at room temperature in perpendicular anisotropic Cr 2 O3 (0001)/CoPd exchange bias heterostructures. This discovery promises significant implications for potential spintronics. From the perspective of basic science, our finding serves as macroscopic evidence for roughness-insensitive and electrically controllable equilibrium boundary magnetization in magnetoelectric antiferromagnets. The latter evolves at chromia (0001) surfaces and interfaces when chromia is in one of its two degenerate antiferromagnetic single domain states selected via magnetoelectric annealing. Theoretical insight into the boundary magnetization and its role in electrically controlled exchange bias is gained from first-principles calculations and general symmetry arguments. Measurements of spin-resolved ultraviolet photoemission, magnetometry at Cr 2 O3 (0001) surfaces, and detailed investigations of the unique exchange bias properties of Cr 2 O3 (0001)/CoPd including its electric controllability provide macroscopically averaged information about the boundary magnetization of chromia. Laterally resolved X-ray PEEM and temperature dependent MFM reveal detailed microscopic information of the chromia

  9. Recruiting pregnant smokers for a placebo-randomised controlled trial of nicotine replacement therapy

    PubMed Central

    Coleman, Tim; Antoniak, Marilyn; Britton, John; Thornton, Jim; Lewis, Sarah; Watts, Kim

    2004-01-01

    Background Smoking in pregnancy is a public health problem and effective methods for reducing this are required. Although nicotine replacement therapy (NRT) is effective for smoking cessation in non-pregnant people, there is no direct evidence concerning its effectiveness in pregnancy. Despite this, clinical guidelines recommend the cautious use of NRT during pregnancy. Randomised controlled trials are needed to determine the safety and efficacy of NRT when used by pregnant women for smoking cessation, but the feasibility of recruiting women to such trials is unknown. Consequently, in this study we aimed to determine i) the feasibility of recruiting women to a RCT of NRT in pregnancy as they attend hospital antenatal ultrasound examinations, ii) the proportion of such women who are eligible for and interested in trial enrolment and iii) research staff perceptions of how one method of trial recruitment could be improved. Methods During a one month period, all women attending for antenatal ultrasound examination in an English teaching hospital were asked to complete a questionnaire which determined their eligibility to enrol in a proposed placebo controlled randomised trial investigating the effectiveness of NRT in pregnancy. Women who were eligible to participate were asked whether they would do so and those who accepted enrolment were offered an appointment with a smoking cessation advisor. Results Over 99% (851/858) of women agreed to complete a questionnaire about smoking habits whilst waiting for ultrasound examinations. 10.3% (88/851) of women attending for antenatal ultrasound fitted eligibility criteria for a proposed RCT of NRT in pregnancy, but only 3.6% [(31/851), 95% CI, 2.4 to 4.9%] indicated on the questionnaire that they would like to take part in a study involving randomisation to placebo or active patches. Researchers offered trial enrolment to 26 of these 31 women and 96% (25) accepted. Staff recruiting women believed that trial recruitment would be

  10. Telemonitoring based service redesign for the management of uncontrolled hypertension: multicentre randomised controlled trial

    PubMed Central

    Hanley, Janet; Wild, Sarah; Pagliari, Claudia; Paterson, Mary; Lewis, Steff; Sheikh, Aziz; Krishan, Ashma; Stoddart, Andrew; Padfield, Paul

    2013-01-01

    Objective To determine if an intervention consisting of telemonitoring and supervision by usual primary care clinicians of home self measured blood pressure and optional patient decision support leads to clinically important reductions in daytime systolic and diastolic ambulatory blood pressure in patients with uncontrolled blood pressure. Design Multicentre randomised controlled trial. Setting 20 primary care practices in south east Scotland. Participants 401 people aged 29-95 years with uncontrolled blood pressure (mean daytime ambulatory measurement ≥135/85 mm Hg but ≤210/135 mm Hg). Intervention Self measurement and transmission of blood pressure readings to a secure website for review by the attending nurse or doctor and participant, with optional automated patient decision support by text or email for six months. Main outcome measures Blinded assessment of mean daytime systolic ambulatory blood pressure six months after randomisation. Results 200 participants were randomised to the intervention and 201 to usual care; primary outcome data were available for 90% of participants (182 and 177, respectively). The mean difference in daytime systolic ambulatory blood pressure adjusted for baseline and minimisation factors between intervention and usual care was 4.3 mm Hg (95% confidence interval 2.0 to 6.5; P=0.0002) and for daytime diastolic ambulatory blood pressure was 2.3 mm Hg (0.9 to 3.6; P=0.001), with higher values in the usual care group. The intervention was associated with a mean increase of one general practitioner (95% confidence interval 0.5 to 1.6; P=0.0002) and 0.6 (0.1 to 1.0; P=0.01) practice nurse consultations during the course of the study. Conclusions Supported self monitoring by telemonitoring is an effective method for achieving clinically important reductions in blood pressure in patients with uncontrolled hypertension in primary care settings. However, it was associated with increase in use of National Health Service resources. Further

  11. Robust reliable control design for networked control system with sampling communication

    NASA Astrophysics Data System (ADS)

    Sakthivel, R.; Santra, Srimanta; Mathiyalagan, K.; Su, Hongye

    2015-12-01

    In this article, the problem of robust exponential stability and reliable stabilisation for a class of continuous-time networked control systems (NCSs) with a sample-data controller and unknown time-varying sampling rate is considered. The analysis is based on average dwell-time, Lyapunov-Krasovskii functional and linear matrix inequality (LMI) technique. The delay-dependent criteria are developed for ensuring the robust exponential stability of the considered NCSs. The obtained conditions are formulated in terms of LMIs that can easily be solved by using standard software packages. Furthermore, the result is extended to study the robust stabilisation for NCS with parameter uncertainties. A state feedback controller is constructed in terms of the solution to a set of LMIs, which guarantee the robust exponential stabilisation of NCS and the controller. Finally, numerical examples are presented to illustrate the effectiveness of the obtained results.

  12. Preliminary demonstration of a robust controller design method

    NASA Technical Reports Server (NTRS)

    Anderson, L. R.

    1980-01-01

    Alternative computational procedures for obtaining a feedback control law which yields a control signal based on measurable quantitites are evaluated. The three methods evaluated are: (1) the standard linear quadratic regulator design model; (2) minimization of the norm of the feedback matrix, k via nonlinear programming subject to the constraint that the closed loop eigenvalues be in a specified domain in the complex plane; and (3) maximize the angles between the closed loop eigenvectors in combination with minimizing the norm of K also via the constrained nonlinear programming. The third or robust design method was chosen to yield a closed loop system whose eigenvalues are insensitive to small changes in the A and B matrices. The relationship between orthogonality of closed loop eigenvectors and the sensitivity of closed loop eigenvalues is described. Computer programs are described.

  13. Free breakfasts in schools: design and conduct of a cluster randomised controlled trial of the Primary School Free Breakfast Initiative in Wales [ISRCTN18336527

    PubMed Central

    Moore, Laurence; Moore, Graham F; Tapper, Katy; Lynch, Rebecca; Desousa, Carol; Hale, Janine; Roberts, Chris; Murphy, Simon

    2007-01-01

    Background School-based breakfast provision is increasingly being seen as a means of improving educational performance and dietary behaviour amongst children. Furthermore, recognition is growing that breakfast provision offers potential as a means of addressing social inequalities in these outcomes. At present however, the evidence base on the effectiveness of breakfast provision in bringing about these improvements is limited. Methods/Design This paper describes the research design of a large scale evaluation of the effectiveness of the Welsh Assembly Government's Primary School Free Breakfast Initiative. A cluster randomised trial, with school as the unit of randomisation was used for the outcome evaluation, with a nested qualitative process evaluation. Quantitative outcome measures included dietary habits, attitudes, cognitive function, classroom behaviour, and school attendance. The study recruited 111 primary schools in Wales, of which 56 were randomly assigned to control condition and 55 to intervention. Participants were Year 5 and 6 students (aged 9–11 years) in these schools. Data were collected for all 111 schools at each of three time points: baseline, 4 month and 12 month follow-up. This was achieved through a repeated cross-sectional survey of approximately 4350 students on each of these occasions. Of those students in Year 5 at baseline, 1975 provided data at one or both of the follow-ups, forming a nested cohort. The evaluation also included a nested process evaluation, using questionnaires, semi-structured interviews and case studies with students, school staff, and local authority scheme coordinators as key informants. Discussion An overview of the methods used for the evaluation is presented, providing an example of the feasibility of conducting robust evaluations of policy initiatives using a randomised trial design with nested process evaluation. Details are provided of response rates and the flow of participants. Reflection is offered on

  14. Multicentre randomised controlled trials in obstetrics and gynaecology: an analysis of trends over three decades.

    PubMed

    Raza, A; Chien, P F W; Khan, K S

    2009-07-01

    To assess the trend in multicentre randomised controlled trials (RCTs), a database of 670 RCTs was assembled from four generic obstetric and gynaecological journals (Acta Obstetricia et Gynecologica Scandinavica, British Journal of Obstetrics & Gynaecology, Obstetrics & Gynecology and American Journal of Obstetrics & Gynecology) for 1975, 1980, 1985, 1990, 1995, 2000 and 2005. During this period, there was an inflationary trend with the proportion of published multicentre RCTs (from 12.9% in 1975 of all RCTs to 23.8% in 2005; P = 0.008). Multicentre RCTs had multiauthored publications (OR = 2.90; 95% CI 1.99-4.22) and more often received external funding (OR = 2.41; 95% CI 1.70-3.48) than single centre RCTs. The inflationary trend in multicentre RCTs requiring funding and collaboration represents the increasing complexity of medical research necessary to underpin evidence-based practice. PMID:19459867

  15. Prebiotics Do Not Influence the Severity of Atopic Dermatitis in Infants: A Randomised Controlled Trial

    PubMed Central

    Hill, Martin; Skýba, Tomáš

    2015-01-01

    The objective was to evaluate the effects of a hypoallergenic (HA) formula supplemented with prebiotic galacto-oligosaccharides on the severity of atopic manifestations. A randomised clinical trial was conducted. The control group was infants, fed with hypoallergenic formula and without supplementation. The duration of the study was six months. The primary outcome of the study was a difference in the severity of atopic dermatitis measured using SCORAD (Scoring Atopic Dermatitis) criteria. Secondary outcomes were anthropometry (length, weight, and head circumference), together with the tolerance and incidence of infections. Both groups showed a decrease of average SCORAD values, but no statistically significant difference between the evaluated groups was observed. There were no statistically significant differences in anthropometry, or the tolerance or incidence of infections. Although there is no evidence, that consumption of a hypoallergenic infant formula enriched with prebiotic galacto-oligosaccharides had any effect on SCORAD, it was safe and well tolerated. Trial Registration www.clinicaltrials.gov NCT 02077088 PMID:26571488

  16. Vouchers versus Lotteries: What works best in promoting Chlamydia screening? A cluster randomised controlled trial

    PubMed Central

    Niza, Claudia; Rudisill, Caroline; Dolan, Paul

    2014-01-01

    In this cluster randomised trial (N=1060), we tested the impact of financial incentives (£5 voucher vs. £200 lottery) framed as a gain or loss to promote Chlamydia screening in students aged 18–24 years, mimicking the standard outreach approach to student in halls of residence. Compared to the control group (1.5%), the lottery increased screening to 2.8% and the voucher increased screening to 22.8%. Incentives framed as gains were marginally more effective (10.5%) that loss-framed incentives (7.1%). This work fundamentally contributes to the literature by testing the predictive validity of Prospect Theory to change health behaviour in the field. PMID:25061507

  17. A randomised controlled trial of cognitive-behaviour therapy for clinical perfectionism: A preliminary study

    PubMed Central

    Riley, Caroline; Lee, Michelle; Cooper, Zafra; Fairburn, Christopher G.; Shafran, Roz

    2007-01-01

    Perfectionism can be a problem in its own right and it can impede the progress of treatment of Axis I disorders. This study reports on a preliminary randomised controlled trial of cognitive-behaviour therapy (CBT) for “clinical perfectionism”. Twenty participants were randomly assigned to either immediate treatment (IT) (n=10) or a waitlist (NL) (n=10). Treatment consisted of ten sessions of CBT over eight weeks. Two participants did not complete the follow-up assessments (10%). Fifteen of the original 20 participants (75%) were clinically significantly improved after treatment and the effect size was large (1.8). Treatment gains were maintained at 8-week and 16-week follow-up. PMID:17275781

  18. A comparison of three methods of wound closure following arthroplasty: a prospective, randomised, controlled trial.

    PubMed

    Khan, R J K; Fick, D; Yao, F; Tang, K; Hurworth, M; Nivbrant, B; Wood, D

    2006-02-01

    We carried out a blinded prospective randomised controlled trial comparing 2-octylcyanoacrylate (OCA), subcuticular suture (monocryl) and skin staples for skin closure following total hip and total knee arthroplasty. We included 102 hip replacements and 85 of the knee.OCA was associated with less wound discharge in the first 24 hours for both the hip and the knee. However, with total knee replacement there was a trend for a more prolonged wound discharge with OCA. With total hip replacement there was no significant difference between the groups for either early or late complications. Closure of the wound with skin staples was significantly faster than with OCA or suture. There was no significant difference in the length of stay in hospital, Hollander wound evaluation score (cosmesis) or patient satisfaction between the groups at six weeks for either hips or knees. We consider that skin staples are the skin closure of choice for both hip and knee replacements. PMID:16434531

  19. Cognitive behaviour therapy to improve mood in people with epilepsy: a randomised controlled trial.

    PubMed

    Gandy, Milena; Sharpe, Louise; Nicholson Perry, Kathryn; Thayer, Zoe; Miller, Laurie; Boserio, Janet; Mohamed, Armin

    2014-01-01

    This study compared a 9-week individualised Cognitive Behaviour Therapy (CBT) programme for people with epilepsy (PWE), with a wait-list control. Fifty-nine PWE were randomised and 45 (75%) completed post-treatment outcomes. People with lower quality of life (QoL), particularly for cognitive functioning, were more likely to drop out. Analyses based on treatment completers demonstrated significant improvements on the Neurological Depressive Disorders Inventory for Epilepsy (p = .045) and Hospital Anxiety Depression Scale-Depression subscale (p = .048). Importantly, CBT significantly reduced the likelihood of clinical depressive symptoms (p = .014) and suicidal ideation (p = .005). Improvements were not observed for anxiety, QoL or maintained overtime for depression. Results suggest that CBT was effective, however, and could be improved to increase patient retention and long-term outcomes. PMID:24635701

  20. Vouchers versus Lotteries: What works best in promoting Chlamydia screening? A cluster randomised controlled trial.

    PubMed

    Niza, Claudia; Rudisill, Caroline; Dolan, Paul

    2014-03-01

    In this cluster randomised trial (N=1060), we tested the impact of financial incentives (£5 voucher vs. £200 lottery) framed as a gain or loss to promote Chlamydia screening in students aged 18-24 years, mimicking the standard outreach approach to student in halls of residence. Compared to the control group (1.5%), the lottery increased screening to 2.8% and the voucher increased screening to 22.8%. Incentives framed as gains were marginally more effective (10.5%) that loss-framed incentives (7.1%). This work fundamentally contributes to the literature by testing the predictive validity of Prospect Theory to change health behaviour in the field. PMID:25061507

  1. Quality control analytical methods: strategies to ensure a robust quality-control microbiology program.

    PubMed

    Griffiths, Tricia; Connors, Anne

    2013-01-01

    As the regulatory environment for compounding pharmacies continues to evolve, facilities can take immediate steps to strengthen their quality-control microbiology and environmental monitoring programs. Robust programs that are timely, comprehensive, and effective will minimize risk and help support positive patient outcomes. This article provides a roadmap for putting in place a robust quality-control microbiology program in the face of United States Pharmacopeia Chapter 797 standards, and highlights several technologies for environmental monitoring that support a successful program. PMID:23696174

  2. A Robust H ∞ Controller for an UAV Flight Control System

    PubMed Central

    López, J.; Dormido, R.; Dormido, S.; Gómez, J. P.

    2015-01-01

    The objective of this paper is the implementation and validation of a robust H ∞ controller for an UAV to track all types of manoeuvres in the presence of noisy environment. A robust inner-outer loop strategy is implemented. To design the H ∞ robust controller in the inner loop, H ∞ control methodology is used. The two controllers that conform the outer loop are designed using the H ∞ Loop Shaping technique. The reference vector used in the control architecture formed by vertical velocity, true airspeed, and heading angle, suggests a nontraditional way to pilot the aircraft. The simulation results show that the proposed control scheme works well despite the presence of noise and uncertainties, so the control system satisfies the requirements. PMID:26221622

  3. A Robust H ∞ Controller for an UAV Flight Control System.

    PubMed

    López, J; Dormido, R; Dormido, S; Gómez, J P

    2015-01-01

    The objective of this paper is the implementation and validation of a robust H ∞ controller for an UAV to track all types of manoeuvres in the presence of noisy environment. A robust inner-outer loop strategy is implemented. To design the H ∞ robust controller in the inner loop, H ∞ control methodology is used. The two controllers that conform the outer loop are designed using the H ∞ Loop Shaping technique. The reference vector used in the control architecture formed by vertical velocity, true airspeed, and heading angle, suggests a nontraditional way to pilot the aircraft. The simulation results show that the proposed control scheme works well despite the presence of noise and uncertainties, so the control system satisfies the requirements. PMID:26221622

  4. Control of multiterminal HVDC systems embedded in AC networks. Volume 2. Robustness of multivariable control systems

    NASA Astrophysics Data System (ADS)

    Athans, M.; Lee, W. H.; Lehtomaki, N. A.; Levy, B. C.; Ng, P. T. P.

    1982-05-01

    The robustness of the stability of multivariable linear time-invariant feedback control systems with respect to model uncertainty is considered using frequency domain criteria. Available and new robustness tests are unified under a common framework based on the nature and structure of model errors. These results are derived using a multivariable version of Nyquist's stability theorem in which the minimum singular value of the return difference transfer matrix is shown to be the multivariable generalization of the distance to the critical point of a single-input, single-output (SISO) Nyquist diagram. Using the return difference transfer matrix a very general robustness theorem is presented from which all of the robustness tests dealing with specific model errors may be derived. The robustness of linear-quadratic-Gaussian control systems are analyzed via this robustness theory and multiloop stability margins are presented; in particular, a new type of margin, a cross-feed margin, is introduced. Other frequency domain analysis and design techniques are also briefly discussed and their relation to the present robustness analysis is examined. In addition a linear-quadratic based design procedure that quarantees a prescribed degree of stability is developed, with special emphasis upon its robustness properties.

  5. Auto-servoventilation in heart failure with sleep apnoea: a randomised controlled trial.

    PubMed

    Arzt, Michael; Schroll, Stephan; Series, Frederic; Lewis, Keir; Benjamin, Amit; Escourrou, Pierre; Luigart, Ruth; Kehl, Victoria; Pfeifer, Michael

    2013-11-01

    We tested the hypotheses that in patients with congestive heart failure (CHF) and sleep disordered breathing (SDB) auto-servoventilation (ASV) improves cardiac function and quality of life. Between March 2007 and September 2009, patients with stable CHF (left ventricular ejection fraction (LVEF) ≤ 40%) and SDB (apnoea/hypopnoea index ≥ 20 events · h(-1)) were randomised to receive either ASV (BiPAP ASV (Philips Respironics, Murrysville, PA, USA), n=37) and optimal medical management, or optimal medical management alone (n=35). Outcomes were assessed at baseline and 12 weeks. The apnoea/hypopnoea index assessed with polysomnography scored in one core laboratory was significantly more reduced in the ASV group (-39 ± 16 versus -1 ± 13 events · h(-1); p<0.001) with an average use of 4.5 ± 3.0 h · day(-1). Both groups showed similar improvements of the primary end-point LVEF (+3.4 ± 5 versus +3.5 ± 6%; p=0.915) assessed with echocardiography. In the ASV group, reduction of N-terminal pro-brain natriuretic peptide (NT-proBNP) was significantly greater (-360 ± 569 versus +135 ± 625 ng · mL(-1); p=0.010). No differences were observed between the groups in subjective quality of life. In patients with CHF and SDB, ASV reduced NT-proBNP levels, but improvement of LVEF or quality of life was not greater than in the control group. The data support that such patients can be randomised in large-scale, long-term trials of positive airway pressure therapy versus control to determine effects on cardiovascular outcome. PMID:23222879

  6. Food incentives to improve completion of tuberculosis treatment: randomised controlled trial in Dili, Timor-Leste

    PubMed Central

    Martins, Nelson; Morris, Peter

    2009-01-01

    Objective To determine the effectiveness of the provision of whole food to enhance completion of treatment for tuberculosis. Design Parallel group randomised controlled trial. Setting Three primary care clinics in Dili, Timor-Leste. Participants 270 adults aged ≥18 with previously untreated newly diagnosed pulmonary tuberculosis. Main outcome measures Completion of treatment (including cure). Secondary outcomes included adherence to treatment, weight gain, and clearance of sputum smears. Outcomes were assessed remotely, blinded to allocation status. Interventions Participants started standard tuberculosis treatment and were randomly assigned to intervention (nutritious, culturally appropriate daily meal (weeks 1-8) and food package (weeks 9-32) (n=137) or control (nutritional advice, n=133) groups. Randomisation sequence was computer generated with allocation concealment by sequentially numbered, opaque, sealed envelopes. Results Most patients with tuberculosis were poor, malnourished men living close to the clinics; 265/270 (98%) contributed to the analysis. The intervention had no significant beneficial or harmful impact on the outcome of treatment (76% v 78% completion, P=0.7) or adherence (93% for both groups, P=0.7) but did lead to improved weight gain at the end of treatment (10.1% v 7.5% improvement, P=0.04). Itch was more common in the intervention group (21% v 9%, P<0.01). In a subgroup analysis of patients with positive results on sputum smears, there were clinically important improvements in one month sputum clearance (85% v 67%, P=0.13) and completion of treatment (78% v 68%, P=0.3). Conclusion Provision of food did not improve outcomes with tuberculosis treatment in these patients in Timor-Leste. Further studies in different settings and measuring different outcomes are required. Trial registration Clinical Trials NCT0019256. PMID:19858174

  7. The use of glucosamine for chronic low back pain: a systematic review of randomised control trials

    PubMed Central

    Sodha, Reena; Sivanadarajah, Naveethan; Alam, Mahbub

    2013-01-01

    Objectives To ascertain whether the use of oral glucosamine influences symptoms or functional outcomes in patients with chronic low back pain (LBP) thought to be related to spinal osteoarthritis (OA). Design Systematic review of randomised control trials. Searches were performed up to March 2011 on Medline, AMED, CINHAL, Cochrane and EMBASE with subsequent reference screening of retrieved studies. In addition, the grey literature was searched via opensigle. Included studies were required to incorporate at least one of the Cochrane Back Pain Review Group's outcome measures as part of their design. Trials with participants over 18 years with a minimum of 12 weeks of back pain, in combination with radiographic changes of OA in the spine, were included. Studies were rated for risk-of-bias and graded for quality. Results 148 studies were identified after screening and meeting eligibility requirements, and three randomised controlled trials (n=309) were included in the quantitative synthesis. The review found that there was low quality but generally no evidence of an effect from glucosamine on function, with no change in the Roland-Morris Disability Questionnaire score in all studies. Conflicting evidence was demonstrated with pain scores with two studies showing no difference and one study with a high risk-of-bias showing both a statistically and clinically significant improvement from taking glucosamine. Conclusions On the basis of the current research, any clinical benefit of oral glucosamine for patients with chronic LBP and radiographic changes of spinal OA can neither be demonstrated nor excluded based on insufficient data and the low quality of existing studies. PMID:23794557

  8. Defining Feasibility and Pilot Studies in Preparation for Randomised Controlled Trials: Development of a Conceptual Framework

    PubMed Central

    Eldridge, Sandra M.; Lancaster, Gillian A.; Campbell, Michael J.; Thabane, Lehana; Hopewell, Sally; Coleman, Claire L.; Bond, Christine M.

    2016-01-01

    We describe a framework for defining pilot and feasibility studies focusing on studies conducted in preparation for a randomised controlled trial. To develop the framework, we undertook a Delphi survey; ran an open meeting at a trial methodology conference; conducted a review of definitions outside the health research context; consulted experts at an international consensus meeting; and reviewed 27 empirical pilot or feasibility studies. We initially adopted mutually exclusive definitions of pilot and feasibility studies. However, some Delphi survey respondents and the majority of open meeting attendees disagreed with the idea of mutually exclusive definitions. Their viewpoint was supported by definitions outside the health research context, the use of the terms ‘pilot’ and ‘feasibility’ in the literature, and participants at the international consensus meeting. In our framework, pilot studies are a subset of feasibility studies, rather than the two being mutually exclusive. A feasibility study asks whether something can be done, should we proceed with it, and if so, how. A pilot study asks the same questions but also has a specific design feature: in a pilot study a future study, or part of a future study, is conducted on a smaller scale. We suggest that to facilitate their identification, these studies should be clearly identified using the terms ‘feasibility’ or ‘pilot’ as appropriate. This should include feasibility studies that are largely qualitative; we found these difficult to identify in electronic searches because researchers rarely used the term ‘feasibility’ in the title or abstract of such studies. Investigators should also report appropriate objectives and methods related to feasibility; and give clear confirmation that their study is in preparation for a future randomised controlled trial designed to assess the effect of an intervention. PMID:26978655

  9. Systematic review of randomised controlled trials of strategies to promote adherence to tuberculosis treatment.

    PubMed Central

    Volmink, J.; Garner, P.

    1997-01-01

    OBJECTIVE: To determine the effectiveness of strategies to promote adherence to treatment for tuberculosis. IDENTIFICATION: Searches in Medline (1966 to August 1996), the Cochrane trials register (up to October 1996), and LILACS (Literatura Latinoamericana y del Caribe en Ciencias de la Salud) (1982 to September 1996); screening of references in articles on compliance and adherence; contact with experts in research on tuberculosis and adherence. INCLUSION CRITERIA: Randomised or pseudorandomised controlled trials of interventions to promote adherence with curative or preventive treatment for tuberculosis, with at least one measure of adherence. MAIN OUTCOME MEASURE: Relative risks and 95% confidence intervals for estimates of effect for categorical outcomes. RESULTS: Five trials met the inclusion criteria. The relative risk for tested reminder cards sent to patients who defaulted on treatment was 1.2 (95% confidence interval 1.1 to 1.4), for help given to patients by lay health workers 1.4 (1.1 to 1.8), for monetary incentives offered to patients 1.6 (1.3 to 2.0), for health education 1.2 (1.1 to 1.4), for a combination of a patient incentive and health education 2.4 (1.5 to 3.7) or 1.1 (1.0 to 1.2), and for intensive supervision of staff in tuberculosis clinics 1.2 (1.1 to 1.3). There were no completed trials of directly observed treatment. All of the interventions tested improved adherence. On current evidence it is unclear whether health education by itself leads to better adherence to treatment. CONCLUSIONS: Reliable evidence is available to show some specific strategies improve adherence to tuberculosis treatment, and these should be adopted in health systems, depending on their appropriateness to practice circumstances. Further innovations require testing to help find specific approaches that will be useful in low income countries. Randomised controlled trials evaluating the independent effects of directly observed treatment are awaited. PMID:9418086

  10. Multiple-dose activated charcoal in acute self-poisoning: a randomised controlled trial

    PubMed Central

    Eddleston, Michael; Juszczak, Edmund; Buckley, Nick A; Senarathna, Lalith; Mohamed, Fahim; Dissanayake, Wasantha; Hittarage, Ariyasena; Azher, Shifa; Jeganathan, K; Jayamanne, Shaluka; Sheriff, MH Rezvi; Warrell, David A

    2008-01-01

    Summary Background The case-fatality for intentional self-poisoning in the rural developing world is 10–50-fold higher than that in industrialised countries, mostly because of the use of highly toxic pesticides and plants. We therefore aimed to assess whether routine treatment with multiple-dose activated charcoal, to interrupt enterovascular or enterohepatic circulations, offers benefit compared with no charcoal in such an environment. Methods We did an open-label, parallel group, randomised, controlled trial of six 50 g doses of activated charcoal at 4-h intervals versus no charcoal versus one 50 g dose of activated charcoal in three Sri Lankan hospitals. 4632 patients were randomised to receive no charcoal (n=1554), one dose of charcoal (n=1545), or six doses of charcoal (n=1533); outcomes were available for 4629 patients. 2338 (51%) individuals had ingested pesticides, whereas 1647 (36%) had ingested yellow oleander (Thevetia peruviana) seeds. Mortality was the primary outcome measure. Analysis was by intention to treat. The trial is registered with controlled-trials.com as ISRCTN02920054. Findings Mortality did not differ between the groups. 97 (6·3%) of 1531 participants in the multiple-dose group died, compared with 105 (6·8%) of 1554 in the no charcoal group (adjusted odds ratio 0·96, 95% CI 0·70–1·33). No differences were noted for patients who took particular poisons, were severely ill on admission, or who presented early. Interpretation We cannot recommend the routine use of multiple-dose activated charcoal in rural Asia Pacific; although further studies of early charcoal administration might be useful, effective affordable treatments are urgently needed. PMID:18280328

  11. Cognitive Behavioural Suicide Prevention for Male Prisoners: A pilot randomised controlled trial

    PubMed Central

    Pratt, D.; Tarrier, N.; Dunn, G.; Awenat, Y.; Shaw, J.; Ulph, F.; Gooding, P.

    2015-01-01

    Background Prisoners have an exceptional risk of suicide. Cognitive behavioural therapy for suicidal behaviour has been shown to offer considerable potential, but has yet to be formally evaluated within prisons. This study investigated the feasibility of delivering and evaluating a novel, manualised cognitive behavioural suicide prevention (CBSP) therapy for suicidal male prisoners. Methods A pilot randomised controlled trial of CBSP in addition to treatment as usual (CBSP; n=31) compared to treatment as usual alone (TAU; n=31), was conducted in a male prison in England. The primary outcome was self-injurious behaviour occurring within the past six months. Secondary outcomes were dimensions of suicidal ideation, psychiatric symptomatology, personality dysfunction and psychological determinants of suicide, including depression and hopelessness. The trial was prospectively registered (number ISRCTN59909209). Results Relative to TAU, participants receiving CBSP therapy achieved a significantly greater reduction in suicidal behaviours with a moderate treatment effect (Cohen’s d=−0.72, 95%CI: −1.71 to 0.09; baseline mean [SD], TAU: 1.39[3.28] vs CBSP: 1.06[2.10], 6 months mean [SD], TAU: 1.48[3.23] vs CBSP: 0.58[1.52]). Significant improvements were achieved on measures of psychiatric symptomatology and personality dysfunction. Improvements on psychological determinants of suicide were non-significant. More than half of participants in the CBSP group achieved a clinically significant recovery by the end of therapy, compared to a quarter of the TAU group. Conclusions The delivery and evaluation of cognitive behavioural suicide prevention therapy within a prison is feasible. CBSP therapy offers significant promise in the prevention of prison suicide and an adequately powered randomised controlled trial is warranted. PMID:26165919

  12. Seminars may increase recruitment to randomised controlled trials: lessons learned from WISDOM

    PubMed Central

    Paine, Bronwen J; Stocks, Nigel P; MacLennan, Alastair H

    2008-01-01

    Background Recruiting patients to large randomised controlled trials (RCTs) in the primary care setting can be challenging. Research teams need to identify and utilise strategies that both maximise the efficiency of recruitment and minimise the burden on general practitioners. Purpose To describe our methods for identifying, approaching and recruiting female patients aged 50–69 years to a long-term double-blind RCT of hormone therapy (HT) – the Women's International Study of long Duration Oestrogen after Menopause (WISDOM). The effectiveness of conducting group seminars with patients prior to one-to-one screening is discussed. Methods Female patients aged between 50 and 69 years were sent letters from participating general practitioners in Adelaide inviting them to participate in WISDOM and attend an initial seminar providing information about HT and the trial prior to a screening interview with a trial nurse. Recruitment rates for those who did or did not attend group seminars were compared. Results Women who attended a group seminar conducted by the research team were twice as likely to attend an initial screening visit and enrol to participate in WISDOM than women who did not attend a seminar (p < 0.001). In addition, it was estimated that the time required to randomise a woman in the trial, and the number and duration of telephone calls to screen out uninterested women, was reduced for the seminar group. Conclusion Conducting group seminars with potential participants may be a useful strategy for maximising recruitment from general practice, by increasing patient information and reducing a research team's workload. Trial registration Current Controlled Trials ISRCTN63718836 PMID:18226264

  13. Randomised, double blind, placebo‐controlled trial of selenium supplementation in adult asthma

    PubMed Central

    Shaheen, Seif O; Newson, Roger B; Rayman, Margaret P; Wong, Angela P‐L; Tumilty, Michael K; Phillips, Joanna M; Potts, James F; Kelly, Frank J; White, Patrick T; Burney, Peter G J

    2007-01-01

    Background Epidemiological evidence from observational studies has suggested that blood levels and dietary intake of selenium of adults with asthma are lower than those of controls. The only previous trial of selenium supplementation in adults with asthma found no objective evidence of benefit but involved only 24 participants. Methods A randomised, double blind, placebo‐controlled trial of selenium supplementation was performed in adults with asthma in London, UK, the majority of whom (75%) reported inhaled steroid use at baseline. 197 participants were randomised to receive either a high‐selenium yeast preparation (100 µg daily, n = 99) or placebo (yeast only, n = 98) for 24 weeks. The primary outcome was asthma‐related quality of life (QoL) score. Secondary outcomes included lung function, asthma symptom scores, peak flow and bronchodilator usage. Linear regression was used to analyse the change in outcome between the two treatment arms by “intention to treat”. Results There was a 48% increase in plasma selenium between baseline and end of trial in the active treatment group but no change in the placebo group. While the QoL score improved more in the active treatment group than in the placebo group, the difference in change in score between the two groups was not significant (−0.05 (95% CI −0.19 to 0.09); p = 0.47). Selenium supplementation was not associated with any significant improvement in secondary outcomes compared with placebo. Conclusions Selenium supplementation had no clinical benefit in adults with asthma, the majority of whom were taking inhaled steroids. PMID:17234657

  14. A randomised controlled trial of acceptance and commitment therapy (ACT) for psychosis: study protocol

    PubMed Central

    2014-01-01

    Background Cognitive behavior therapy for psychosis has been a prominent intervention in the psychological treatment of psychosis. It is, however, a challenging therapy to deliver and, in the context of increasingly rigorous trials, recent reviews have tempered initial enthusiasm about its effectiveness in improving clinical outcomes. Acceptance and commitment therapy shows promise as a briefer, more easily implemented therapy but has not yet been rigorously evaluated in the context of psychosis. The purpose of this trial is to evaluate whether Acceptance and Commitment Therapy could reduce the distress and disability associated with psychotic symptoms in a sample of community-residing patients with chronic medication-resistant symptoms. Methods/Design This is a single (rater)-blind multi-centre randomised controlled trial comparing Acceptance and Commitment Therapy with an active comparison condition, Befriending. Eligible participants have current residual hallucinations or delusions with associated distress or disability which have been present continuously over the past six months despite therapeutic doses of antipsychotic medication. Following baseline assessment, participants are randomly allocated to treatment condition with blinded, post-treatment assessments conducted at the end of treatment and at 6 months follow-up. The primary outcome is overall mental state as measured using the Positive and Negative Syndrome Scale. Secondary outcomes include preoccupation, conviction, distress and disruption to life associated with symptoms as measured by the Psychotic Symptom Rating Scales, as well as social functioning and service utilisation. The main analyses will be by intention-to-treat using mixed-model repeated measures with non-parametric methods employed if required. The model of change underpinning ACT will be tested using mediation analyses. Discussion This protocol describes the first randomised controlled trial of Acceptance and commitment therapy in

  15. Recruiting older people to a randomised controlled dietary intervention trial - how hard can it be?

    PubMed Central

    2010-01-01

    Background The success of a human intervention trial depends upon the ability to recruit eligible volunteers. Many trials fail because of unrealistic recruitment targets and flawed recruitment strategies. In order to predict recruitment rates accurately, researchers need information on the relative success of various recruitment strategies. Few published trials include such information and the number of participants screened or approached is not always cited. Methods This paper will describe in detail the recruitment strategies employed to identify older adults for recruitment to a 6-month randomised controlled dietary intervention trial which aimed to explore the relationship between diet and immune function (The FIT study). The number of people approached and recruited, and the reasons for exclusion, will be discussed. Results Two hundred and seventeen participants were recruited to the trial. A total of 7,482 letters were sent to potential recruits using names and addresses that had been supplied by local Family (General) Practices. Eight hundred and forty three potential recruits replied to all methods of recruitment (528 from GP letters and 315 from other methods). The eligibility of those who replied was determined using a screening telephone interview, 217 of whom were found to be suitable and agreed to take part in the study. Conclusion The study demonstrates the application of multiple recruitment methods to successfully recruit older people to a randomised controlled trial. The most successful recruitment method was by contacting potential recruits by letter on NHS headed note paper using contacts provided from General Practices. Ninety percent of recruitment was achieved using this method. Adequate recruitment is fundamental to the success of a research project, and appropriate strategies must therefore be adopted in order to identify eligible individuals and achieve recruitment targets. Trial registration number ISRCTN45031464. PMID:20175903

  16. A randomised controlled comparison of injection, thermal, and mechanical endoscopic methods of haemostasis on mesenteric vessels

    PubMed Central

    Hepworth, C; Kadirkamanathan, S; Gong, F; Swain, C

    1998-01-01

    Background and aims—A randomised controlled comparison of haemostatic efficacy of mechanical, injection, and thermal methods of haemostasis was undertaken using canine mesenteric vessels to test the hypothesis that mechanical methods of haemostasis are more effective in controlling haemorrhage than injection or thermal methods. The diameter of arteries in human bleeding ulcers measures up to 3.45 mm; mesenteric vessels up to 5 mm were therefore studied. 
Methods—Mesenteric vessels were randomised to treatment with injection sclerotherapy (adrenaline and ethanolamine), bipolar diathermy, or mechanical methods (band, clips, sewing machine, endoloops). The vessels were severed and haemostasis recorded. 
Results—Injection sclerotherapy and clips failed to stop bleeding from vessels of 1 mm (n=20) and 2 mm (n=20). Bipolar diathermy was effective on 8/10 vessels of 2 mm but failed on 3 mm vessels (n=5). Unstretched elastic bands succeeded on 13/15 vessels of 2 mm but on only 3/10 vessels of 3 mm. The sewing machine achieved haemostasis on 8/10 vessels of 4 mm but failed on 5 mm vessels (n=5); endoloops were effective on all 5 mm vessels (n=5). 
Conclusions—Only mechanical methods were effective on vessels greater than 2 mm in diameter. Some mechanical methods (banding and clips) were less effective than expected and need modification. Thermal and (effective) mechanical methods were significantly (p<0.01) more effective than injection sclerotherapy. The most effective mechanical methods were significantly more effective (p<0.01) than thermal or injection on vessels greater than 2mm. 

 Keywords: endoscopic haemostasis; mesenteric vessels PMID:9616305

  17. Defining Feasibility and Pilot Studies in Preparation for Randomised Controlled Trials: Development of a Conceptual Framework.

    PubMed

    Eldridge, Sandra M; Lancaster, Gillian A; Campbell, Michael J; Thabane, Lehana; Hopewell, Sally; Coleman, Claire L; Bond, Christine M

    2016-01-01

    We describe a framework for defining pilot and feasibility studies focusing on studies conducted in preparation for a randomised controlled trial. To develop the framework, we undertook a Delphi survey; ran an open meeting at a trial methodology conference; conducted a review of definitions outside the health research context; consulted experts at an international consensus meeting; and reviewed 27 empirical pilot or feasibility studies. We initially adopted mutually exclusive definitions of pilot and feasibility studies. However, some Delphi survey respondents and the majority of open meeting attendees disagreed with the idea of mutually exclusive definitions. Their viewpoint was supported by definitions outside the health research context, the use of the terms 'pilot' and 'feasibility' in the literature, and participants at the international consensus meeting. In our framework, pilot studies are a subset of feasibility studies, rather than the two being mutually exclusive. A feasibility study asks whether something can be done, should we proceed with it, and if so, how. A pilot study asks the same questions but also has a specific design feature: in a pilot study a future study, or part of a future study, is conducted on a smaller scale. We suggest that to facilitate their identification, these studies should be clearly identified using the terms 'feasibility' or 'pilot' as appropriate. This should include feasibility studies that are largely qualitative; we found these difficult to identify in electronic searches because researchers rarely used the term 'feasibility' in the title or abstract of such studies. Investigators should also report appropriate objectives and methods related to feasibility; and give clear confirmation that their study is in preparation for a future randomised controlled trial designed to assess the effect of an intervention. PMID:26978655

  18. Improving health-related fitness in adolescents: the CrossFit Teens™ randomised controlled trial.

    PubMed

    Eather, Narelle; Morgan, Philip James; Lubans, David Revalds

    2016-01-01

    The aim of this study was to evaluate the preliminary efficacy and feasibility of the CrossFit Teens™ resistance training programme for improving health-related fitness and resistance training skill competency in adolescents. This assessor-blinded randomised controlled trial was conducted in one secondary school in the Hunter Region, Australia, from July to September 2013. Ninety-six (96) students (age = 15.4 (.5) years, 51.5% female) were randomised into intervention (n = 51) or control (n = 45) conditions for 8-weeks (60 min twice per week). Waist circumference, body mass index (BMI), BMI-Z score (primary outcomes), cardiorespiratory fitness (shuttle run test), muscular fitness (standing jump, push-up, handgrip, curl-up test), flexibility (sit and reach) and resistance training skill competency were measured at baseline and immediate post-intervention. Feasibility measures of recruitment, retention, adherence and satisfaction were assessed. Significant group-by-time intervention effects were found for waist circumference [-3.1 cm, P < 0.001], BMI [-1.38 kg · m(‒)(2), P < 0.001], BMI-Z [-0.5 z-scores, P < 0.001], sit and reach [+3.0 cm, P < 0.001], standing jump [+0.1 m, P = 0.021] and shuttle run [+10.3 laps, P = 0.019]. Retention rate was 82.3%. All programme sessions were delivered and participants' mean satisfaction scores ranged from 4.2 to 4.6 out of 5. The findings demonstrate that CrossFit Teens™ is a feasible and efficacious programme for improving health-related fitness in adolescents. PMID:25972203

  19. Smartphone-Supported versus Full Behavioural Activation for Depression: A Randomised Controlled Trial

    PubMed Central

    Ly, Kien Hoa; Topooco, Naira; Cederlund, Hanna; Wallin, Anna; Bergström, Jan; Molander, Olof; Carlbring, Per; Andersson, Gerhard

    2015-01-01

    Background There is need for more cost and time effective treatments for depression. This is the first randomised controlled trial in which a blended treatment - including four face-to-face sessions and a smartphone application - was compared against a full behavioural treatment. Hence, the aim of the current paper was to examine whether a blended smartphone treatment was non-inferior to a full behavioural activation treatment for depression. Methods This was a randomised controlled non-inferiority trial (NCT01819025) comparing a blended treatment (n=46) against a full ten-session treatment (n=47) for people suffering from major depression. Primary outcome measure was the BDI-II, that was administered at pre- and post-treatment, as well as six months after the treatment. Results Results showed significant improvements in both groups across time on the primary outcome measure (within-group Cohen’s d=1.35; CI [−0.82, 3.52] to d=1.47; CI [−0.41, 3.35]; between group d=−0.13 CI [−2.37, 2.09] and d=−0.10 CI [−2.53, 2.33]). At the same time, the blended treatment reduced the therapist time with an average of 47%. Conclusions We could not establish whether the blended treatment was non-inferior to a full BA treatment. Nevertheless, this study points to that the blended treatment approach could possibly treat nearly twice as many patients suffering from depression by using a smartphone applica¬tion as add-on. More studies are needed before we can suggest that the blended treatment method is a promising cost-effective alternative to regular face-to-face treatment for depression. Trial Registration Cognitive Behavioral Therapy Treatment of Depression With Smartphone Support NCT01819025 PMID:26010890

  20. Robust parameter design for automatically controlled systems and nanostructure synthesis

    NASA Astrophysics Data System (ADS)

    Dasgupta, Tirthankar

    2007-12-01

    This research focuses on developing comprehensive frameworks for developing robust parameter design methodology for dynamic systems with automatic control and for synthesis of nanostructures. In many automatically controlled dynamic processes, the optimal feedback control law depends on the parameter design solution and vice versa and therefore an integrated approach is necessary. A parameter design methodology in the presence of feedback control is developed for processes of long duration under the assumption that experimental noise factors are uncorrelated over time. Systems that follow a pure-gain dynamic model are considered and the best proportional-integral and minimum mean squared error control strategies are developed by using robust parameter design. The proposed method is illustrated using a simulated example and a case study in a urea packing plant. This idea is also extended to cases with on-line noise factors. The possibility of integrating feedforward control with a minimum mean squared error feedback control scheme is explored. To meet the needs of large scale synthesis of nanostructures, it is critical to systematically find experimental conditions under which the desired nanostructures are synthesized reproducibly, at large quantity and with controlled morphology. The first part of the research in this area focuses on modeling and optimization of existing experimental data. Through a rigorous statistical analysis of experimental data, models linking the probabilities of obtaining specific morphologies to the process variables are developed. A new iterative algorithm for fitting a Multinomial GLM is proposed and used. The optimum process conditions, which maximize the above probabilities and make the synthesis process less sensitive to variations of process variables around set values, are derived from the fitted models using Monte-Carlo simulations. The second part of the research deals with development of an experimental design methodology, tailor

  1. Effect of intermittent feedback control on robustness of human-like postural control system.

    PubMed

    Tanabe, Hiroko; Fujii, Keisuke; Suzuki, Yasuyuki; Kouzaki, Motoki

    2016-01-01

    Humans have to acquire postural robustness to maintain stability against internal and external perturbations. Human standing has been recently modelled using an intermittent feedback control. However, the causality inside of the closed-loop postural control system associated with the neural control strategy is still unknown. Here, we examined the effect of intermittent feedback control on postural robustness and of changes in active/passive components on joint coordinative structure. We implemented computer simulation of a quadruple inverted pendulum that is mechanically close to human tiptoe standing. We simulated three pairs of joint viscoelasticity and three choices of neural control strategies for each joint: intermittent, continuous, or passive control. We examined postural robustness for each parameter set by analysing the region of active feedback gain. We found intermittent control at the hip joint was necessary for model stabilisation and model parameters affected the robustness of the pendulum. Joint sways of the pendulum model were partially smaller than or similar to those of experimental data. In conclusion, intermittent feedback control was necessary for the stabilisation of the quadruple inverted pendulum. Also, postural robustness of human-like multi-link standing would be achieved by both passive joint viscoelasticity and neural joint control strategies. PMID:26931281

  2. Effect of intermittent feedback control on robustness of human-like postural control system

    NASA Astrophysics Data System (ADS)

    Tanabe, Hiroko; Fujii, Keisuke; Suzuki, Yasuyuki; Kouzaki, Motoki

    2016-03-01

    Humans have to acquire postural robustness to maintain stability against internal and external perturbations. Human standing has been recently modelled using an intermittent feedback control. However, the causality inside of the closed-loop postural control system associated with the neural control strategy is still unknown. Here, we examined the effect of intermittent feedback control on postural robustness and of changes in active/passive components on joint coordinative structure. We implemented computer simulation of a quadruple inverted pendulum that is mechanically close to human tiptoe standing. We simulated three pairs of joint viscoelasticity and three choices of neural control strategies for each joint: intermittent, continuous, or passive control. We examined postural robustness for each parameter set by analysing the region of active feedback gain. We found intermittent control at the hip joint was necessary for model stabilisation and model parameters affected the robustness of the pendulum. Joint sways of the pendulum model were partially smaller than or similar to those of experimental data. In conclusion, intermittent feedback control was necessary for the stabilisation of the quadruple inverted pendulum. Also, postural robustness of human-like multi-link standing would be achieved by both passive joint viscoelasticity and neural joint control strategies.

  3. Effect of intermittent feedback control on robustness of human-like postural control system

    PubMed Central

    Tanabe, Hiroko; Fujii, Keisuke; Suzuki, Yasuyuki; Kouzaki, Motoki

    2016-01-01

    Humans have to acquire postural robustness to maintain stability against internal and external perturbations. Human standing has been recently modelled using an intermittent feedback control. However, the causality inside of the closed-loop postural control system associated with the neural control strategy is still unknown. Here, we examined the effect of intermittent feedback control on postural robustness and of changes in active/passive components on joint coordinative structure. We implemented computer simulation of a quadruple inverted pendulum that is mechanically close to human tiptoe standing. We simulated three pairs of joint viscoelasticity and three choices of neural control strategies for each joint: intermittent, continuous, or passive control. We examined postural robustness for each parameter set by analysing the region of active feedback gain. We found intermittent control at the hip joint was necessary for model stabilisation and model parameters affected the robustness of the pendulum. Joint sways of the pendulum model were partially smaller than or similar to those of experimental data. In conclusion, intermittent feedback control was necessary for the stabilisation of the quadruple inverted pendulum. Also, postural robustness of human-like multi-link standing would be achieved by both passive joint viscoelasticity and neural joint control strategies. PMID:26931281

  4. Robust control of mitotic spindle orientation in the developing epidermis

    PubMed Central

    Poulson, Nicholas D.

    2010-01-01

    Progenitor cells must balance self-amplification and production of differentiated progeny during development and homeostasis. In the epidermis, progenitors divide symmetrically to increase surface area and asymmetrically to promote stratification. In this study, we show that individual epidermal cells can undergo both types of division, and therefore, the balance is provided by the sum of individual cells’ choices. In addition, we define two control points for determining a cell’s mode of division. First is the expression of the mouse Inscuteable gene, which is sufficient to drive asymmetric cell division (ACD). However, there is robust control of division orientation as excessive ACDs are prevented by a change in the localization of NuMA, an effector of spindle orientation. Finally, we show that p63, a transcriptional regulator of stratification, does not control either of these processes. These data have uncovered two important regulatory points controlling ACD in the epidermis and allow a framework for analysis of how external cues control this important choice. PMID:21098114

  5. Acupuncture for menopausal vasomotor symptoms: study protocol for a randomised controlled trial

    PubMed Central

    2014-01-01

    Background Hot flushes and night sweats (vasomotor symptoms) are common menopausal symptoms, often causing distress, sleep deprivation and reduced quality of life. Although hormone replacement therapy is an effective treatment, there are concerns about serious adverse events. Non-hormonal pharmacological therapies are less effective and can also cause adverse effects. Complementary therapies, including acupuncture, are commonly used for menopausal vasomotor symptoms. While the evidence for the effectiveness of acupuncture in treating vasomotor symptoms is inconclusive, acupuncture has a low risk of adverse effects, and two small studies suggest it may be more effective than non-insertive sham acupuncture. Our objective is to assess the efficacy of needle acupuncture in improving hot flush severity and frequency in menopausal women. Our current study design is informed by methods tested in a pilot study. Methods/design This is a stratified, parallel, randomised sham-controlled trial with equal allocation of participants to two trial groups. We are recruiting 360 menopausal women experiencing a minimum average of seven moderate hot flushes a day over a seven-day period and who meet diagnostic criteria for the Traditional Chinese Medicine diagnosis of Kidney Yin deficiency. Exclusion criteria include breast cancer, surgical menopause, and current hormone replacement therapy use. Eligible women are randomised to receive either true needle acupuncture or sham acupuncture with non-insertive (blunt) needles for ten treatments over eight weeks. Participants are blinded to treatment allocation. Interventions are provided by Chinese medicine acupuncturists who have received specific training on trial procedures. The primary outcome measure is hot flush score, assessed using the validated Hot Flush Diary. Secondary outcome measures include health-related quality of life, anxiety and depression symptoms, credibility of the sham treatment, expectancy and beliefs about

  6. Prophylactic antibiotic regimens in tumour surgery (PARITY): protocol for a multicentre randomised controlled study

    PubMed Central

    Ghert, Michelle; Deheshi, Benjamin; Holt, Ginger; Randall, R Lor; Ferguson, Peter; Wunder, Jay; Turcotte, Robert; Werier, Joel; Clarkson, Paul; Damron, Timothy; Benevenia, Joseph; Anderson, Megan; Gebhardt, Mark; Isler, Marc; Mottard, Sophie; Healey, John; Evaniew, Nathan; Racano, Antonella; Sprague, Sheila; Swinton, Marilyn; Bryant, Dianne; Thabane, Lehana; Guyatt, Gordon; Bhandari, Mohit

    2012-01-01

    Introduction Limb salvage with endoprosthetic reconstruction is the standard of care for the management of lower-extremity bone tumours in skeletally mature patients. The risk of deep postoperative infection in these procedures is high and the outcomes can be devastating. The most effective prophylactic antibiotic regimen remains unknown, and current clinical practice is highly varied. This trial will evaluate the effect of varying postoperative prophylactic antibiotic regimens on the incidence of deep infection following surgical excision and endoprosthetic reconstruction of lower-extremity bone tumours. Methods and analysis This is a multicentre, blinded, randomised controlled trial, using a parallel two-arm design. 920 patients 15 years of age or older from 12 tertiary care centres across Canada and the USA who are undergoing surgical excision and endoprosthetic reconstruction of a primary bone tumour will receive either short (24 h) or long (5 days) duration postoperative antibiotics. Exclusion criteria include prior surgery or infection within the planned operative field, known colonisation with methicillin-resistant Staphylococcus aureus or vancomycin-resistant Enterococcus at enrolment, or allergy to the study antibiotics. The primary outcome will be rates of deep postoperative infections in each arm. Secondary outcomes will include type and frequency of antibiotic-related adverse events, patient functional outcomes and quality-of-life scores, reoperation and mortality. Randomisation will be blocked, with block sizes known only to the methods centre responsible for randomisation, and stratified by location of tumour and study centre. Patients, care givers and a Central Adjudication Committee will be blinded to treatment allocation. The analysis to compare groups will be performed using Cox regression and log-rank tests to compare survival functions at α=0.05. Ethics and dissemination This study has ethics approval from the McMaster University

  7. Withdrawal of inhaled corticosteroids in people with COPD in primary care: a randomised controlled trial

    PubMed Central

    Choudhury, Aklak B; Dawson, Carolyn M; Kilvington, Hazel E; Eldridge, Sandra; James, Wai-Yee; Wedzicha, Jadwiga A; Feder, Gene S; Griffiths, Chris J

    2007-01-01

    Background Guidelines recommend inhaled corticosteroids (ICS) for patients with severe chronic obstructive pulmonary disease (COPD). Most COPD patients are managed in primary care and receive ICS long-term and irrespective of severity. The effect of withdrawing ICS from COPD patients in primary care is unknown. Methods In a pragmatic randomised, double-blind, placebo-controlled trial in 31 practices, 260 COPD patients stopped their usual ICS (median duration of use 8 years) and were allocated to 500 mcg fluticasone propionate twice daily (n = 128), or placebo (n = 132). Follow-up assessments took place at three monthly intervals for a year at the patients' practice. Our primary outcome was COPD exacerbation frequency. Secondary outcomes were time to first COPD exacerbation, reported symptoms, peak expiratory flow rate and reliever inhaler use, and lung function and health related quality of life. Results In patients randomised to placebo, COPD exacerbation risk over one year was RR: 1.11 (CI: 0.91–1.36). Patients taking placebo were more likely to return to their usual ICS following exacerbation, placebo: 61/128 (48%); fluticasone: 34/132 (26%), OR: 2.35 (CI: 1.38–4.05). Exacerbation risk whilst taking randomised treatment was significantly raised in the placebo group 1.48 (CI: 1.17–1.86). Patients taking placebo exacerbated earlier (median time to first exacerbation: placebo (days): 44 (CI: 29–59); fluticasone: 63 (CI: 53–74), log rank 3.81, P = 0.05) and reported increased wheeze. In a post-hoc analysis, patients with mild COPD taking placebo had increased exacerbation risk RR: 1.94 (CI: 1.20–3.14). Conclusion Withdrawal of long-term ICS in COPD patients in primary care increases risk of exacerbation shortens time to exacerbation and causes symptom deterioration. Patients with mild COPD may be at increased risk of exacerbation after withdrawal. Trial Registration ClinicalTrials.gov NCT00440687 PMID:18162137

  8. Robust Thermal Control of Propulsion Lines for Space Missions

    NASA Technical Reports Server (NTRS)

    Bhandari, Pradeep

    2011-01-01

    A document discusses an approach to insulating propulsion lines for spacecraft. In spacecraft that have propulsion lines that are located externally with open bus architecture, the lines are typically insulated by Multi Layer Insulation (MLI) blankets. MLI on propulsion lines tends to have large and somewhat random variances in its heat loss properties (effective emittance) from one location to the next, which makes it an un-robust approach to control propulsion line temperatures. The approach described here consists of a clamshell design in which the inner surface of the shell is coated with low-emissivity aluminized Kapton tape, and the outer surface is covered with black tape. This clamshell completely encloses the propulsion line. The line itself is covered with its heater, which in turn, is covered completely with black tape. This approach would be low in heater power needs because even though the outer surface of the prop line (and its heater) is covered with black tape as well as the outer surface of the clamshell, the inner surface of the clamshell is covered with low-emissivity aluminized Kapton tape. Hence, the heat loss from the line will be small and comparable to the MLI based one. In terms of contamination changing the radiative properties of surfaces, since the clamshell s inner surface is always protected during handling and is only installed after all the work on the prop line has been completed, the controlling surface, which is the clamshell s inner surface, is always in pristine condition. This proposed design allows for a much more deterministic and predictable design using a very simple and implementable approach for thermal control. It also uses low heater power and is robust to handling and contamination during and after implementation.

  9. Robust Diffeomorphic Mapping via Geodesically Controlled Active Shapes

    PubMed Central

    Tward, Daniel J.; Ma, Jun; Miller, Michael I.; Younes, Laurent

    2013-01-01

    This paper presents recent advances in the use of diffeomorphic active shapes which incorporate the conservation laws of large deformation diffeomorphic metric mapping. The equations of evolution satisfying the conservation law are geodesics under the diffeomorphism metric and therefore termed geodesically controlled diffeomorphic active shapes (GDAS). Our principal application in this paper is on robust diffeomorphic mapping methods based on parameterized surface representations of subcortical template structures. Our parametrization of the GDAS evolution is via the initial momentum representation in the tangent space of the template surface. The dimension of this representation is constrained using principal component analysis generated from training samples. In this work, we seek to use template surfaces to generate segmentations of the hippocampus with three data attachment terms: surface matching, landmark matching, and inside-outside modeling from grayscale T1 MR imaging data. This is formulated as an energy minimization problem, where energy describes shape variability and data attachment accuracy, and we derive a variational solution. A gradient descent strategy is employed in the numerical optimization. For the landmark matching case, we demonstrate the robustness of this algorithm as applied to the workflow of a large neuroanatomical study by comparing to an existing diffeomorphic landmark matching algorithm. PMID:23690757

  10. Development of Control Models and a Robust Multivariable Controller for Surface Shape Control

    SciTech Connect

    Winters, S

    2003-06-18

    Surface shape control techniques are applied to many diverse disciplines, such as adaptive optics, noise control, aircraft flutter control and satellites, with an objective to achieve a desirable shape for an elastic body by the application of distributed control forces. Achieving the desirable shape is influenced by many factors, such as, actuator locations, sensor locations, surface precision and controller performance. Building prototypes to complete design optimizations or controller development can be costly or impractical. This shortfall, puts significant value in developing accurate modeling and control simulation approaches. This thesis focuses on the field of adaptive optics, although these developments have the potential for application in many other fields. A static finite element model is developed and validated using a large aperture interferometer system. This model is then integrated into a control model using a linear least squares algorithm and Shack-Hartmann sensor. The model is successfully exercised showing functionality for various wavefront aberrations. Utilizing a verified model shows significant value in simulating static surface shape control problems with quantifiable uncertainties. A new dynamic model for a seven actuator deformable mirror is presented and its accuracy is proven through experiment. Bond graph techniques are used to generate the state space model of the multi-actuator deformable mirror including piezo-electric actuator dynamics. Using this verified model, a robust multi-input multi-output (MIMO) H{sub {infinity}} controller is designed and implemented. This controller proved superior performance as compared to a standard proportional-integral controller (PI) design.

  11. Neuromuscular training and the risk of leg injuries in female floorball players: cluster randomised controlled study

    PubMed Central

    2008-01-01

    Objective To investigate whether a neuromuscular training programme is effective in preventing non-contact leg injuries in female floorball players. Design Cluster randomised controlled study. Setting 28 top level female floorball teams in Finland. Participants 457 players (mean age 24 years)—256 (14 teams) in the intervention group and 201 (14 teams) in the control group—followedup for one league season (six months). Intervention A neuromuscular training programme to enhance players’ motor skills and body control, as well as to activate and prepare their neuromuscular system for sports specific manoeuvres. Main outcome measure Acute non-contact injuries of the legs. Results During the season, 72 acute non-contact leg injuries occurred, 20 in the intervention group and 52 in the control group. The injury incidence per 1000 hours playing and practise in the intervention group was 0.65 (95% confidence interval 0.37 to 1.13) and in the control group was 2.08 (1.58 to 2.72). The risk of non-contact leg injury was 66% lower (adjusted incidence rate ratio 0.34, 95% confidence interval 0.20 to 0.57) in the intervention group. Conclusion A neuromuscular training programme was effective in preventing acute non-contact injuries of the legs in female floorball players. Neuromuscular training can be recommended in the weekly training of these athletes. Trial registration Current Controlled Trials ISRCTN26550281. PMID:18595903

  12. A randomised controlled trial of an SMS-based mobile epilepsy education system.

    PubMed

    Lua, Pei Lin; Neni, Widiasmoro Selamat

    2013-01-01

    We evaluated an epilepsy education programme based on text messaging (SMS). Epilepsy outpatients from three hospitals in Malaysia were randomised into two groups: intervention and control. Patients in the control group were supplied with printed epilepsy educational material while those in the intervention group also received text messages from the Mobile Epilepsy Educational System (MEES). A total of 136 patients completed the study (mean age 31 years; 91% Malay; 51% with an illness duration of more than 5 years). A between-group analysis showed that the awareness, knowledge and attitudes (AKA) about epilepsy did not significantly differ between the groups at baseline (P > 0.05). The intervention patients reported better AKA levels during follow-up compared to the control patients (P < 0.05). A within-group analysis showed that in intervention patients, there were significant improvements in all AKA domains with larger effect sizes (P < 0.01) while control patients also exhibited significant improvement in most domains except for Awareness but with smaller effect sizes. After controlling for possible confounding variables (age, gender, educational qualification, monthly income and baseline mean for each domain), the intervention group still reported significantly higher AKA than the control group particularly in Awareness (P < 0.001) and Total AKA (P = 0.003). There was also significantly better medication adherence and clinic attendance in the intervention group (P < 0.05). The results suggest that the addition of the MEES to conventional epilepsy education is effective in improving AKA. PMID:23390210

  13. Mixing Nulliparous and Multiparous Women in Randomised Controlled Trials of Preeclampsia Prevention Is Debatable: Evidence from a Systematic Review

    PubMed Central

    Simon, Emmanuel; Caille, Agnès; Perrotin, Franck; Giraudeau, Bruno

    2013-01-01

    Background Nulliparity is a major risk factor of preeclampsia investigated in numerous trials of its prevention. Objective We aimed to assess whether these trials considered nulliparity in subject selection or analysis of results. Search Strategy 01 April 2013 search of MEDLINE via PubMed, EMBASE and the Cochrane Library. 01 April 2013 search of trials registered in Clinicaltrials.gov. Selection Criteria Randomised controlled trials and metaanalyses of preeclampsia prevention with no restriction to period of publication or language. Metaanalyses were selected to fully identify relevant trials. Data Collection and Analysis One reader appraised each selected article/registered protocol using a pretested, standardized data abstraction form developed in a pilot test. For each article, he recorded whether both nulliparous and multiparous were included and, in case of mixed populations, whether randomisation was stratified, and whether subgroup analyses had been reported. For registered protocols, he only assessed whether it was planned to include mixed populations. Main Results 88 randomised controlled trials were identified, representing 83,396 included women. In 58 of the 88 articles identified (65.9%), preeclampsia was the primary outcome. In 31 of these (53.4%), the investigation combined nulliparous and multiparous women; only two reports in 31 (6.5%) stated that randomisation was stratified on parity and only four (12.9%) described a subgroup analysis by parity. Of the 30 registered trials, 20 (66.6%) planned to include both nulliparous and multiparous women. Conclusion Parity is largely ignored in randomised controlled trials of preeclampsia prevention, which raises difficulties in interpreting the results. PMID:23826112

  14. Identification, Uncertainty Characterization and Robust Control Synthesis Applied to Large Flexible Structures Control

    NASA Technical Reports Server (NTRS)

    Bayard, David S.; Chiang, Richard Y.

    1996-01-01

    This paper demonstrates an approach to frequency domain identification for the explicit purpose of designing robust H(infinity) controllers. The approach transforms raw experimental data into a plant set estimate directly usable by modern robust control design software(e.g., Matlab Robust Control Toolboxes [11][2]). A key issue in control design from raw data is the question of whether the controller will work when applied to the true system. The main feature fo this approach is that the resulting controller in guaranteed to work as designed(when applied to the true system) to a prescribed statistical confidence. While the overall methodology addresses key theoretical issues, it has at the same time been specifically designed to support practical implementations. A simulation example is included to demonstrate the overall approach.

  15. Effect of dronabinol on progression in progressive multiple sclerosis (CUPID): a randomised, placebo-controlled trial

    PubMed Central

    Zajicek, John; Ball, Susan; Wright, David; Vickery, Jane; Nunn, Andrew; Miller, David; Cano, Mayam Gomez; McManus, David; Mallik, Sharukh; Hobart, Jeremy

    2013-01-01

    Summary Background Laboratory evidence has shown that cannabinoids might have a neuroprotective action. We investigated whether oral dronabinol (Δ9-tetrahydrocannabinol) might slow the course of progressive multiple sclerosis. Methods In this multicentre, parallel, randomised, double-blind, placebo-controlled study, we recruited patients aged 18–65 years with primary or secondary progressive multiple sclerosis from 27 UK neurology or rehabilitation departments. Patients were randomly assigned (2:1) to receive dronabinol or placebo for 36 months; randomisation was by stochastic minimisation, using a computer-generated randomisation sequence, balanced according to expanded disability status scale (EDSS) score, centre, and disease type. Maximum dose was 28 mg per day, titrated against bodyweight and adverse effects. Primary outcomes were EDSS score progression (masked assessor, time to progression of ≥1 point from a baseline score of 4·0–5·0 or ≥0·5 points from a baseline score of ≥5·5, confirmed after 6 months) and change from baseline in the physical impact subscale of the 29-item multiple sclerosis impact scale (MSIS-29-PHYS). All patients who received at least one dose of study drug were included in the intention-to-treat analyses. This trial is registered as an International Standard Randomised Controlled Trial (ISRCTN 62942668). Findings Of the 498 patients randomly assigned to a treatment group, 329 received at least one dose of dronabinol and 164 received at least one dose of placebo (five did not receive the allocated intervention). 145 patients in the dronabinol group had EDSS score progression (0·24 first progression events per patient-year; crude rate) compared with 73 in the placebo group (0·23 first progression events per patient-year; crude rate); HR for prespecified primary analysis was 0·92 (95% CI 0·68–1·23; p=0·57). Mean yearly change in MSIS-29-PHYS score was 0·62 points (SD 3·29) in the dronabinol group versus 1·03 points

  16. DiPALS: Diaphragm Pacing in patients with Amyotrophic Lateral Sclerosis - a randomised controlled trial.

    PubMed Central

    McDermott, Christopher J; Bradburn, Mike J; Maguire, Chin; Cooper, Cindy L; Baird, Wendy O; Baxter, Susan K; Cohen, Judith; Cantrill, Hannah; Dixon, Simon; Ackroyd, Roger; Baudouin, Simon; Bentley, Andrew; Berrisford, Richard; Bianchi, Stephen; Bourke, Stephen C; Darlison, Roy; Ealing, John; Elliott, Mark; Fitzgerald, Patrick; Galloway, Simon; Hamdalla, Hisham; Hanemann, C Oliver; Hughes, Philip; Imam, Ibrahim; Karat, Dayalan; Leek, Roger; Maynard, Nick; Orrell, Richard W; Sarela, Abeezar; Stradling, John; Talbot, Kevin; Taylor, Lyn; Turner, Martin; Simonds, Anita K; Williams, Tim; Wedzicha, Wisia; Young, Carolyn; Shaw, Pamela J

    2016-01-01

    BACKGROUND Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease resulting in death, usually from respiratory failure, within 2-3 years of symptom onset. Non-invasive ventilation (NIV) is a treatment that when given to patients in respiratory failure leads to improved survival and quality of life. Diaphragm pacing (DP), using the NeuRx/4(®) diaphragm pacing system (DPS)™ (Synapse Biomedical, Oberlin, OH, USA), is a new technique that may offer additional or alternative benefits to patients with ALS who are in respiratory failure. OBJECTIVE The Diaphragm Pacing in patients with Amyotrophic Lateral Sclerosis (DiPALS) trial evaluated the effect of DP on survival over the study duration in patients with ALS with respiratory failure. DESIGN The DiPALS trial was a multicentre, parallel-group, open-label, randomised controlled trial incorporating health economic analyses and a qualitative longitudinal substudy. PARTICIPANTS Eligible participants had a diagnosis of ALS (ALS laboratory-supported probable, clinically probable or clinically definite according to the World Federation of Neurology revised El Escorial criteria), had been stabilised on riluzole for 30 days, were aged ≥ 18 years and were in respiratory failure. We planned to recruit 108 patients from seven UK-based specialist ALS or respiratory centres. Allocation was performed using 1 : 1 non-deterministic minimisation. INTERVENTIONS Participants were randomised to either standard care (NIV alone) or standard care (NIV) plus DP using the NeuRX/4 DPS. MAIN OUTCOME MEASURES The primary outcome was overall survival, defined as the time from randomisation to death from any cause. Secondary outcomes were patient quality of life [assessed by European Quality of Life-5 Dimensions, three levels (EQ-5D-3L), Short Form questionnaire-36 items and Sleep Apnoea Quality of Life Index questionnaire]; carer quality of life (EQ-5D-3L and Caregiver Burden Inventory); cost-utility analysis and health

  17. Study protocol for the randomised controlled trial: combined multimarker screening and randomised patient treatment with ASpirin for evidence-based PREeclampsia prevention (ASPRE)

    PubMed Central

    O'Gorman, Neil; Wright, David; Rolnik, Daniel L; Nicolaides, Kypros H; Poon, Liona C

    2016-01-01

    Introduction Pre-eclampsia (PE) affects 2–3% of all pregnancies and is a major cause of maternal and perinatal morbidity and mortality. Prophylactic use of low-dose aspirin in women at risk for PE may substantially reduce the prevalence of the disease. Effective screening for PE requiring delivery before 37 weeks (preterm PE) can be provided by a combination of maternal factors, uterine artery Doppler, mean arterial pressure, maternal serum pregnancy-associated plasma protein A and placental growth factor at 11–13 weeks' gestation, with a detection rate of 75% at a false-positive rate of 10%. We present a protocol (V.6, date 25 January 2016) for the ASpirin for evidence-based PREeclampsia prevention (ASPRE) trial, which is a double-blinded, placebo-controlled, randomised controlled trial (RCT) that uses an effective PE screening programme to determine whether low-dose aspirin given to women from 11 to 13 weeks' gestation will reduce the incidence of preterm PE. Methods and analysis All eligible women attending for their first trimester scan will be invited to participate in the screening study for preterm PE. Those found to be at high risk of developing preterm PE will be invited to participate in the RCT. Further scans will be conducted for assessment of fetal growth and biomarkers. Pregnancy and neonatal outcomes will be collected and analysed. The first enrolment for the pilot study was in April 2014. As of April 2016, 26 670 women have been screened and 1760 recruited to the RCT. The study is registered on the International Standard Randomised Controlled Trial Number (ISRCTN) registry. Trial registration number ISRCTN13633058. PMID:27354081

  18. Auricular Acupuncture and Cognitive Behavioural Therapy for Insomnia: A Randomised Controlled Study

    PubMed Central

    Bergdahl, L.; Broman, J.-E.; Berman, A. H.; Haglund, K.; von Knorring, L.; Markström, A.

    2016-01-01

    Objective. The most effective nonpharmacological treatment for insomnia disorder is cognitive behavioural therapy-insomnia (CBT-i). However CBT-i may not suit everyone. Auricular acupuncture (AA) is a complementary treatment. Studies show that it may alleviate insomnia symptoms. The aim of this randomised controlled study was to compare treatment effects of AA with CBT-i and evaluate symptoms of insomnia severity, anxiety, and depression. Method. Fifty-nine participants, mean age 60.5 years (SD 9.4), with insomnia disorder were randomised to group treatment with AA or CBT-i. Self-report questionnaires, the Insomnia Severity Index (ISI), Dysfunctional Beliefs and Attitudes about Sleep scale (DBAS-16), Epworth Sleepiness Scale (ESS), and Hospital Anxiety and Depression scale (HAD), were collected at baseline, after treatment, and at 6-month follow-up. A series of linear mixed models were performed to examine treatment effect over time between and within the groups. Results. Significant between-group improvements were seen in favour of CBT-i in ISI after treatment and at the 6-month follow-up and in DBAS-16 after treatment. Both groups showed significant within-group postintervention improvements in ISI, and these changes were maintained six months later. The CBT-i group also showed a significant reduction in DBAS-16 after treatment and six months later. Conclusions. Compared to CBT-i, AA, as offered in this study, cannot be considered an effective stand-alone treatment for insomnia disorder. The trial is registered with ClinicalTrials.gov NCT01765959. PMID:27242930

  19. Evaluation of a stroke family care worker: results of a randomised controlled trial.

    PubMed Central

    Dennis, M.; O'Rourke, S.; Slattery, J.; Staniforth, T.; Warlow, C.

    1997-01-01

    OBJECTIVE: To examine the effect of contact with a stroke family care worker on the physical, social, and psychological status of stroke patients and their carers. DESIGN: Randomised controlled trial with broad entry criteria and blinded outcome assessment six months after randomisation. SETTING: A well organised stroke service in an Edinburgh teaching hospital. SUBJECTS: 417 patients with an acute stroke in the previous 30 days randomly allocated to be contacted by a stroke family care worker (210) or to receive standard care (207). The patients represented 67% of all stroke patients assessed at the hospital during the study period. MAIN OUTCOME MEASURES: Patient completed Barthel index, Frenchay activities index, general health questionnaire, hospital anxiety and depression scale, social adjustment scale, mental adjustment to stroke scale, and patient satisfaction questionnaire; carer completed Frenchay activities index, general health questionnaire, hospital anxiety and depression scale, social adjustment scale, caregiving bassles scale, and carer satisfaction questionnaire. RESULTS: The groups were balanced for all important baseline variables. There were no significant differences in physical outcomes in patients or carers, though patients in the treatment group were possibly more helpless less well adjusted socially, and more depressed, whereas carers in the treatment group were possibly less hassled and anxious. However, both patients and carers in the group contacted by the stroke family care worker expressed significantly greater satisfaction with certain aspects of their care, in particular those related to communication and support. CONCLUSIONS: The introduction of a stroke family care worker improved patients' and their carers' satisfaction with services and may have had some effect on psychological and social outcomes but did not improve measures of patients' physical wellbeing. PMID:9133884

  20. A Blinded, Randomised, Controlled Trial of Stapled Versus Tissue Glue Closure of Neck Surgery Incisions

    PubMed Central

    Ridgway, DM; Mahmood, F; Moore, L; Bramley, D; Moore, PJ

    2007-01-01

    INTRODUCTION Cosmetic acceptability of scar and neck mobility are important outcomes after collar line incision for neck surgery. This randomised, controlled trial compares these parameters in closures using tissue glue (Dermabond™, Ethicon, UK) and skin staples. PATIENTS AND METHODS Patients requiring a collar line incision were randomised to receiving tissue glue or staples for skin closure. Time for closure to be completed was recorded. Mobility of the neck was assessed using a visual analogue scale at 48 h and 1 week after surgery. At 6 weeks, cosmetic appearance was assessed using a linear 1–10 visual analogue scale by the patient, surgeon and an independent blinded assessor. Results were compared using appropriate statistical tests. RESULTS Glued (n = 14) and stapled (n = 15) closures were performed for hemithyroidectomy (n = 8 versus 6), sub-total thyroidectomy (n = 2 versus 4), total thyroidectomy (n = 1 versus 4) and parathyroidectomy (n = 3 versus 1). Closure with tissue glue took significantly longer than with staples (mean, 95 versus 28 s; P < 0.001). Neck mobility scores were comparable at 48 h and 1 week (mean, 4.8 versus 4.4; P = 0.552: and 2.7 versus 2.6; P = 0.886). Cosmetic appearance at 6 weeks was comparable when patient (mean, 1.7 versus 1.8; P = 0.898), surgeon (mean, 2.6 versus 2.3; P = 0.633) and independent assessment (mean, 1.4 versus 1.9; P = 0.365) was performed. CONCLUSIONS The use of glued skin closure may increase the duration of surgery but acceptable neck mobility and wound cosmesis can be achieved by the more rapid application of stapled skin closure in cervicotomy incisions. PMID:17394707

  1. The reporting quality of parallel randomised controlled trials in ophthalmic surgery in 2011: a systematic review

    PubMed Central

    Yao, A C; Khajuria, A; Camm, C F; Edison, E; Agha, R

    2014-01-01

    Purpose Randomised controlled trials (RCTs) represent a gold standard for evaluating therapeutic interventions. However, poor reporting clarity can prevent readers from assessing potential bias that can arise from a lack of methodological rigour. The Consolidated Standards of Reporting Trials statement for non-pharmacological interventions 2008 (CONSORT NPT) was developed to aid reporting. RCTs in ophthalmic surgery pose particular challenges in study design and implementation. We aim to provide the first assessment of the compliance of RCTs in ophthalmic surgery to the CONSORT NPT statement. Method In August 2012, the Medline database was searched for RCTs in ophthalmic surgery reported between 1 January 2011 and 31 December 2011. Results were searched by two authors and relevant papers selected. Papers were scored against the 23-item CONSORT NPT checklist and compared against surrogate markers of paper quality. The CONSORT score was also compared between different RCT designs. Results In all, 186 papers were retrieved. Sixty-five RCTs, involving 5803 patients, met the inclusion criteria. The mean CONSORT score was 8.9 out of 23 (39%, range 3.0–14.7, SD 2.49). The least reported items related to the title and abstract (1.6%), reporting intervention adherence (3.1%), and interpretation of results (4.7%). No significant correlation was found between CONSORT score and journal impact factor (R=0.14, P=0.29), number of authors (R=0.01, P=0.93), or whether the RCT used paired-eye, one-eye, or two-eye designs in their randomisation (P=0.97). Conclusions The reporting of RCTs in ophthalmic surgery is suboptimal. Further work is needed by trial groups, funding agencies, authors, and journals to improve reporting clarity. PMID:25214001

  2. Intelligence and persisting with medication for two years: Analysis in a randomised controlled trial

    PubMed Central

    Deary, Ian J.; Gale, Catharine R.; Stewart, Marlene C.W.; Fowkes, F. Gerald R.; Murray, Gordon D.; Batty, G. David; Price, Jacqueline F.

    2009-01-01

    The study examined whether verbal intelligence is associated with persisting to take medication for up to two years. The design is a prospective follow-up of compliance with taking medication in high-risk individuals participating in a randomised, placebo-controlled trial set in Central Scotland. Participants were 1993 people aged between 50 and 77 years with an ankle brachial index ≤ 0.95. The medication was 100 mg aspirin or placebo daily. The principal outcome measure was continuing with taking medication or stopping it due to having ‘changed one's mind’. Higher verbal intelligence was associated with a greater likelihood of continuing to take medication up to two years after randomisation. For a standard deviation increase in Mill Hill Vocabulary Scale score, risk of stopping medication in the first two years of the study was 0.75 (95% CI 0.64 to 0.87, p < 0.001). Comparing the highest and lowest quartiles of IQ, the lowest IQ group's relative rate of stopping medication was 2.51 (95% CI 1.52 to 4.22). The effect was not attenuated after adjustment for sex, smoking, or level of deprivation. Verbal intelligence is associated with continuing, medium-to-long term engagement with health self-care, even in the face of uncertainty about whether active treatment is being received, whether the treatment is known to be effective in general, and whether it will be helpful to the individual taking it. Such persisting with potentially helpful health behaviours in the face of uncertainty might partly explain why people with higher intelligence live longer and suffer less morbidity from chronic diseases. PMID:19907664

  3. Intelligence and persisting with medication for two years: Analysis in a randomised controlled trial.

    PubMed

    Deary, Ian J; Gale, Catharine R; Stewart, Marlene C W; Fowkes, F Gerald R; Murray, Gordon D; Batty, G David; Price, Jacqueline F

    2009-11-01

    The study examined whether verbal intelligence is associated with persisting to take medication for up to two years. The design is a prospective follow-up of compliance with taking medication in high-risk individuals participating in a randomised, placebo-controlled trial set in Central Scotland. Participants were 1993 people aged between 50 and 77 years with an ankle brachial index randomisation. For a standard deviation increase in Mill Hill Vocabulary Scale score, risk of stopping medication in the first two years of the study was 0.75 (95% CI 0.64 to 0.87, p < 0.001). Comparing the highest and lowest quartiles of IQ, the lowest IQ group's relative rate of stopping medication was 2.51 (95% CI 1.52 to 4.22). The effect was not attenuated after adjustment for sex, smoking, or level of deprivation. Verbal intelligence is associated with continuing, medium-to-long term engagement with health self-care, even in the face of uncertainty about whether active treatment is being received, whether the treatment is known to be effective in general, and whether it will be helpful to the individual taking it. Such persisting with potentially helpful health behaviours in the face of uncertainty might partly explain why people with higher intelligence live longer and suffer less morbidity from chronic diseases. PMID:19907664

  4. Auricular Acupuncture and Cognitive Behavioural Therapy for Insomnia: A Randomised Controlled Study.

    PubMed

    Bergdahl, L; Broman, J-E; Berman, A H; Haglund, K; von Knorring, L; Markström, A

    2016-01-01

    Objective. The most effective nonpharmacological treatment for insomnia disorder is cognitive behavioural therapy-insomnia (CBT-i). However CBT-i may not suit everyone. Auricular acupuncture (AA) is a complementary treatment. Studies show that it may alleviate insomnia symptoms. The aim of this randomised controlled study was to compare treatment effects of AA with CBT-i and evaluate symptoms of insomnia severity, anxiety, and depression. Method. Fifty-nine participants, mean age 60.5 years (SD 9.4), with insomnia disorder were randomised to group treatment with AA or CBT-i. Self-report questionnaires, the Insomnia Severity Index (ISI), Dysfunctional Beliefs and Attitudes about Sleep scale (DBAS-16), Epworth Sleepiness Scale (ESS), and Hospital Anxiety and Depression scale (HAD), were collected at baseline, after treatment, and at 6-month follow-up. A series of linear mixed models were performed to examine treatment effect over time between and within the groups. Results. Significant between-group improvements were seen in favour of CBT-i in ISI after treatment and at the 6-month follow-up and in DBAS-16 after treatment. Both groups showed significant within-group postintervention improvements in ISI, and these changes were maintained six months later. The CBT-i group also showed a significant reduction in DBAS-16 after treatment and six months later. Conclusions. Compared to CBT-i, AA, as offered in this study, cannot be considered an effective stand-alone treatment for insomnia disorder. The trial is registered with ClinicalTrials.gov NCT01765959. PMID:27242930

  5. Metformin in severe exacerbations of chronic obstructive pulmonary disease: a randomised controlled trial

    PubMed Central

    Hitchings, Andrew W; Lai, Dilys; Jones, Paul W; Baker, Emma H

    2016-01-01

    Background Severe exacerbations of COPD are commonly associated with hyperglycaemia, which predicts adverse outcomes. Metformin is a well-established anti-hyperglycaemic agent in diabetes mellitus, possibly augmented with anti-inflammatory effects, but its effects in COPD are unknown. We investigated accelerated metformin therapy in severe COPD exacerbations, primarily to confirm or refute an anti-hyperglycaemic effect, and secondarily to explore its effects on inflammation and clinical outcome. Methods This was a multicentre, randomised, double-blind, placebo-controlled trial testing accelerated metformin therapy in non-diabetic patients, aged ≥35 years, hospitalised for COPD exacerbations. Participants were assigned in a 2:1 ratio to 1 month of metformin therapy, escalated rapidly to 2 g/day, or matched placebo. The primary end point was mean in-hospital blood glucose concentration. Secondary end points included the concentrations of fructosamine and C reactive protein (CRP), and scores on the COPD Assessment Test and Exacerbations of Chronic Pulmonary Disease Tool. Results 52 participants (mean (±SD) age 67±9 years) were randomised (34 to metformin, 18 to placebo). All were included in the primary end point analysis. The mean blood glucose concentrations in the metformin and placebo groups were 7.1±0.9 and 8.0±3.3 mmol/L, respectively (difference −0.9 mmol/L, 95% CI −2.1 to +0.3; p=0.273). No significant between-group differences were observed on any of the secondary end points. Adverse reactions, particularly gastrointestinal effects, were more common in metformin-treated participants. Conclusion Metformin did not ameliorate elevations in blood glucose concentration among non-diabetic patients admitted to hospital for COPD exacerbations, and had no detectable effect on CRP or clinical outcomes. Trial registration number ISRCTN66148745 and NCT01247870. PMID:26917577

  6. Ciprofloxacin DPI: a randomised, placebo-controlled, phase IIb efficacy and safety study on cystic fibrosis

    PubMed Central

    Dorkin, Henry L; Staab, Doris; Operschall, Elisabeth; Alder, Jeff; Criollo, Margarita

    2015-01-01

    Background Treatment of infective bronchitis involving Pseudomonas aeruginosa is a cornerstone of care in patients with cystic fibrosis (CF). This phase IIb, randomised, double-blind, placebo-controlled study assessed the efficacy and safety of ciprofloxacin dry powder for inhalation (DPI) in this population. Methods Patients with CF, ≥12 years of age (N=286), were randomised to ciprofloxacin DPI (32.5 mg (n=93) or 48.75 mg (n=93)), or corresponding placebo (32.5 mg, n=65; 48.75 mg, n=35) twice daily for 28 days. The primary objective was the change in forced expiratory volume in 1 s (FEV1) from baseline (day 0) to end of treatment (day 29) in the intent-to-treat population for ciprofloxacin DPI compared with the corresponding placebo group. Results The primary effectiveness objective was not met; there were no significant differences in change in FEV1 between ciprofloxacin DPI and the corresponding placebo group for either dose (p=0.154). However, in pooled analyses, FEV1 decline from baseline to treatment end was significantly lower with ciprofloxacin DPI than with placebo (pooled data; p=0.02). Ciprofloxacin DPI showed positive effects on sputum bacterial load and quality of life, but these effects were not maintained at the 4-week follow-up. Ciprofloxacin DPI was well tolerated and there were no significant differences in type/incidence of treatment-emergent adverse events by treatment group (p=0.115). Conclusions Further investigations are needed to determine the full scope of the beneficial effects of ciprofloxacin DPI for patients with CF. Trial registration number Clinicaltrials.gov NCT00645788; EudraCT 2008-008314-40. PMID:26688732

  7. Enhancing relationship functioning during the transition to parenthood: a cluster-randomised controlled trial.

    PubMed

    Daley-McCoy, Cathyrn; Rogers, Maeve; Slade, Pauline

    2015-10-01

    This randomised controlled trial examined the feasibility of enhancing relationship functioning in couples during the transition to parenthood through the development and delivery of a low-intensity antenatal intervention. The 2-h psycho-educational programme marks the first of its kind to be trialled in the UK and was delivered as an adjunct to existing antenatal classes provided through the National Health Service. A cluster randomised design was used as antenatal classes rather than participants were randomly allocated to either treatment condition. Feasibility was assessed on the basis of pragmatic delivery and acceptability of the intervention. Data from 47 participants who received the intervention and 36 participants who did not was then compared to provide a preliminary indication of its effectiveness. Outcomes were assessed in terms of relationship satisfaction, couple communication and psychological distress. The intervention appeared feasible in terms of pragmatic delivery, rates of uptake and attendance at sessions. Participant evaluation forms also indicated that people were reasonably satisfied with the intervention and would recommend it to friends. Three significant phases × condition interactions were indicated using mixed-methods analyses of variance (ANOVAs); women in the intervention condition reported significantly less deterioration in relationship satisfaction (F(1, 44) = 3.11; p = 0.021; eta(2) = 0.07), while men in the intervention condition reported significantly less deterioration in couple communication (F(1, 35) = 2.59; p = 0.029; eta(2) = 0.08) and significant improvement in their experience of psychological distress (adjusted z = 1.99; p = 0.023; Cohen's d = 0.47). These positive preliminary indicators lend support to future large-scale investigation. PMID:25663309

  8. Acupuncture for post anaesthetic recovery and postoperative pain: study protocol for a randomised controlled trial

    PubMed Central

    2014-01-01

    Background We report on the design and implementation of a study protocol entitled Acupuncture randomised trial for post anaesthetic recovery and postoperative pain - a pilot study (ACUARP) designed to investigate the effectiveness of acupuncture therapy performed in the perioperative period on post anaesthetic recovery and postoperative pain. Methods/Design The study is designed as a randomised controlled pilot trial with three arms and partial double blinding. We will compare (a) press needle acupuncture, (b) no treatment and (c) press plaster acupressure in a standardised anaesthetic setting. Seventy-five patients scheduled for laparoscopic surgery to the uterus or ovaries will be allocated randomly to one of the three trial arms. The total observation period will begin one day before surgery and end on the second postoperative day. Twelve press needles and press plasters are to be administered preoperatively at seven acupuncture points. The primary outcome measure will be time from extubation to ‘ready for discharge’ from the post anaesthesia care unit (in minutes). The ‘ready for discharge’ end point will be assessed using three different scores: the Aldrete score, the Post Anaesthetic Discharge Scoring System and an In-House score. Secondary outcome measures will comprise pre-, intra- and postoperative variables (which are anxiety, pain, nausea and vomiting, concomitant medication). Discussion The results of this study will provide information on whether acupuncture may improve patient post anaesthetic recovery. Comparing acupuncture with acupressure will provide insight into potential therapeutic differences between invasive and non-invasive acupuncture techniques. Trial registration NCT01816386 (First received: 28 October 2012) PMID:25047046

  9. Robust quantum control using smooth pulses and topological winding

    PubMed Central

    Barnes, Edwin; Wang, Xin; Das Sarma, S.

    2015-01-01

    The greatest challenge in achieving the high level of control needed for future technologies based on coherent quantum systems is the decoherence induced by the environment. Here, we present an analytical approach that yields explicit constraints on the driving field which are necessary and sufficient to ensure that the leading-order noise-induced errors in a qubit’s evolution cancel exactly. We derive constraints for two of the most common types of noise that arise in qubits: slow fluctuations of the qubit energy splitting and fluctuations in the driving field itself. By theoretically recasting a phase in the qubit’s wavefunction as a topological winding number, we can satisfy the noise-cancelation conditions by adjusting driving field parameters without altering the target state or quantum evolution. We demonstrate our method by constructing robust quantum gates for two types of spin qubit: phosphorous donors in silicon and nitrogen-vacancy centers in diamond. PMID:26239195

  10. A Robust Reinforcement Learning Control Design Method for Nonlinear System with Partially Unknown Structure

    NASA Astrophysics Data System (ADS)

    Nakano, Kazuhiro; Obayashi, Masanao; Kuremoto, Takashi; Kobayashi, Kunikazu

    We propose a robust control system which has robustness for disturbance and can deal with a nonlinear system with partially unknown structure by fusing reinforcement learning and robust control theory. First, we solved an optimal control problem without using unknown part of functions of the system, using neural network and the repetition learning of reinforcement learning algorithm. Second, we built the robust reinforcement learning control system which permits uncertainty and has robustness for disturbance by fusing the idea of H infinity control theory with above system.

  11. Effects of American ginseng (Panax quinquefolius) on neurocognitive function: an acute, randomised, double-blind, placebo-controlled, crossover study

    PubMed Central

    Ossoukhova, Anastasia; Owen, Lauren; Ibarra, Alvin; Pipingas, Andrew; He, Kan; Roller, Marc; Stough, Con

    2010-01-01

    Rationale Over the last decade, Asian ginseng (Panax ginseng) has been shown to improve aspects of human cognitive function. American ginseng (Panax quinquefolius) has a distinct ginsenoside profile from P. ginseng, promising cognitive enhancing properties in preclinical studies and benefits processes linked to human cognition. Objectives The availability of a highly standardised extract of P. quinquefolius (Cereboost™) led us to evaluate its neurocognitive properties in humans for the first time. Methods This randomised, double-blind, placebo-controlled, crossover trial (N = 32, healthy young adults) assessed the acute mood, neurocognitive and glycaemic effects of three doses (100, 200 400 mg) of Cereboost™ (P. quinquefolius standardised to 10.65% ginsenosides). Participants' mood, cognitive function and blood glucose were measured 1, 3 and 6 h following administration. Results There was a significant improvement of working memory (WM) performance associated with P. quinquefolius. Corsi block performance was improved by all doses at all testing times. There were differential effects of all doses on other WM tasks which were maintained across the testing day. Choice reaction time accuracy and ‘calmness’ were significantly improved by 100 mg. There were no changes in blood glucose levels. Conclusions This preliminary study has identified robust working memory enhancement following administration of American ginseng. These effects are distinct from those of Asian ginseng and suggest that psychopharmacological properties depend critically on ginsenoside profiles. These results have ramifications for the psychopharmacology of herbal extracts and merit further study using different dosing regimens and in populations where cognition is fragile. PMID:20676609

  12. Effects of a training program after surgically treated ankle fracture: a prospective randomised controlled trial

    PubMed Central

    Nilsson, Gertrud M; Jonsson, Kjell; Ekdahl, Charlotte S; Eneroth, Magnus

    2009-01-01

    Background Despite conflicting results after surgically treated ankle fractures few studies have evaluated the effects of different types of training programs performed after plaster removal. The aim of this study was to evaluate the effects of a 12-week standardised but individually suited training program (training group) versus usual care (control group) after plaster removal in adults with surgically treated ankle fractures. Methods In total, 110 men and women, 18-64 years of age, with surgically treated ankle fracture were included and randomised to either a 12-week training program or to a control group. Six and twelve months after the injury the subjects were examined by the same physiotherapist who was blinded to the treatment group. The main outcome measure was the Olerud-Molander Ankle Score (OMAS) which rates symptoms and subjectively scored function. Secondary outcome measures were: quality of life (SF-36), timed walking tests, ankle mobility tests, muscle strength tests and radiological status. Results 52 patients were randomised to the training group and 58 to the control group. Five patients dropped out before the six-month follow-up resulting in 50 patients in the training group and 55 in the control group. Nine patients dropped out between the six- and twelve-month follow-up resulting in 48 patients in both groups. When analysing the results in a mixed model analysis on repeated measures including interaction between age-group and treatment effect the training group demonstrated significantly improved results compared to the control group in subjects younger than 40 years of age regarding OMAS (p = 0.028), muscle strength in the plantar flexors (p = 0.029) and dorsiflexors (p = 0.030). Conclusion The results of this study suggest that when adjusting for interaction between age-group and treatment effect the training model employed in this study was superior to usual care in patients under the age of 40. However, as only three out of nine outcome

  13. Physiotherapy for sleep disturbance in chronic low back pain: a feasibility randomised controlled trial

    PubMed Central

    2010-01-01

    Background Sleep disturbance is becoming increasingly recognised as a clinically important symptom in people with chronic low back pain (CLBP, low back pain >12 weeks), associated with physical inactivity and depression. Current research and international clinical guidelines recommend people with CLBP assume a physically active role in their recovery to prevent chronicity, but the high prevalence of sleep disturbance in this population may be unknowingly limiting their ability to participate in exercise-based rehabilitation programmes and contributing to poor outcomes. There is currently no knowledge concerning the effectiveness of physiotherapy on sleep disturbance in people with chronic low back pain and no evidence of the feasibility of conducting randomized controlled trials that comprehensively evaluate sleep as an outcome measure in this population. Methods/Design This study will evaluate the feasibility of a randomised controlled trial (RCT), exploring the effects of three forms of physiotherapy (supervised general exercise programme, individualized walking programme and usual physiotherapy, which will serve as the control group) on sleep quality in people with chronic low back pain. A presenting sample of 60 consenting patients will be recruited in the physiotherapy department of Beaumont Hospital, Dublin, Ireland, and randomly allocated to one of the three groups in a concealed manner. The main outcomes will be sleep quality (self-report and objective measurement), and self-reported functional disability, pain, quality of life, fear avoidance, anxiety and depression, physical activity, and patient satisfaction. Outcome will be evaluated at baseline, 3 months and 6 months. Qualitative telephone interviews will be embedded in the research design to obtain feedback from a sample of participants' about their experiences of sleep monitoring, trial participation and interventions, and to inform the design of a fully powered future RCT. Planned analysis will

  14. The effectiveness of brief alcohol interventions delivered by community pharmacists: randomised controlled trial

    PubMed Central

    Norman, Ian; Whittlesea, Cate; Murrells, Trevor; McCambridge, Jim

    2016-01-01

    Background & Aims To undertake the first randomised controlled trial to evaluate the effectiveness of a brief intervention delivered by community pharmacists to reduce hazardous or harmful drinking. Design This parallel group individually randomised trial, allocated participants to brief alcohol intervention (n=205) or a leaflet-only control condition (n=202), with follow-up study after 3 months. Setting 16 community pharmacies in one London borough, UK. Participants 407 pharmacy customers (aged 18 or over) with AUDIT scores 8-19 inclusive. Intervention A brief motivational discussion of approximately 10 minutes duration for which 17 pharmacists received a half-day of training. Measurements Hazardous or harmful drinking was assessed using the Alcohol Use Disorders Identification Test (AUDIT) administered by telephone by a researcher blind to allocation status. The two primary outcomes were: 1) change in AUDIT total scores and 2) the proportions no longer hazardous or harmful drinkers (scoring <8) at three months. The four secondary outcomes were: the three sub-scale scores of the AUDIT (for consumption, problems and dependence), and health status according to the EQ-5D (a standardised instrument for use as a measure of health outcome). Findings At 3 months 326 (80% overall; 82% intervention, 78% control) participants were followed up. The difference in reduction in total AUDIT score (intervention minus control) was −0.57 95% CI −1.59 to 0.45, p = 0.28. The odds ratio for AUDIT <8 (control as reference) was 0.87 95% CI 0.50 to 1.51, p = 0.61). For two of the four secondary outcomes (dependence score: −0.46 95% CI −0.82 to −0.09, p = 0.014; health status score: −0.09 95% CI −0.16 to −0.02, p = 0.013) the control group did better, and in the other two there were no differences (consumption score: −0.05 95% CI −0.54 to 0.44, p = 0.85; non-dependence problems score: −0.13 95% CI −0.66 to 0.41). Sensitivity analyses did not change these findings

  15. Nordic Walking improves daily physical activities in COPD: a randomised controlled trial

    PubMed Central

    2010-01-01

    Background In patients with COPD progressive dyspnoea leads to a sedentary lifestyle. To date, no studies exist investigating the effects of Nordic Walking in patients with COPD. Therefore, the aim was to determine the feasibility of Nordic Walking in COPD patients at different disease stages. Furthermore we aimed to determine the short- and long-term effects of Nordic Walking on COPD patients' daily physical activity pattern as well as on patients exercise capacity. Methods Sixty COPD patients were randomised to either Nordic Walking or to a control group. Patients of the Nordic Walking group (n = 30; age: 62 ± 9 years; FEV1: 48 ± 19% predicted) underwent a three-month outdoor Nordic Walking exercise program consisting of one hour walking at 75% of their initial maximum heart rate three times per week, whereas controls had no exercise intervention. Primary endpoint: daily physical activities (measured by a validated tri-axial accelerometer); secondary endpoint: functional exercise capacity (measured by the six-minute walking distance; 6MWD). Assessment time points in both groups: baseline, after three, six and nine months. Results After three month training period, in the Nordic Walking group time spent walking and standing as well as intensity of walking increased (Δ walking time: +14.9 ± 1.9 min/day; Δ standing time: +129 ± 26 min/day; Δ movement intensity: +0.40 ± 0.14 m/s2) while time spent sitting decreased (Δ sitting time: -128 ± 15 min/day) compared to baseline (all: p < 0.01) as well as compared to controls (all: p < 0.01). Furthermore, 6MWD significantly increased compared to baseline (Δ 6MWD: +79 ± 28 meters) as well as compared to controls (both: p < 0.01). These significant improvements were sustained six and nine months after baseline. In contrast, controls showed unchanged daily physical activities and 6MWD compared to baseline for all time points. Conclusions Nordic Walking is a feasible, simple and effective physical training modality

  16. Multifactorial intervention for children with asthma and overweight (Mikado): study design of a randomised controlled trial

    PubMed Central

    2013-01-01

    Background In children, the prevalence’s of both obesity and asthma are disconcertingly high. Asthmatic children with obesity are characterised by less asthma control and a high need for asthma medication. As the obese asthmatic child is becoming more common in the clinical setting and the disease burden of the asthma-obesity phenotype is high, there is an increasing need for effective treatment in these children. In adults, weight reduction resulted in improved lung function, better asthma control and less need for asthma medication. In children this is hardly studied. The Mikado study aims to evaluate the effectiveness of a long term multifactorial weight reduction intervention, on asthma characteristics in children with asthma and a high body weight. Methods/design The Mikado study is a two-armed, randomised controlled trial. In total, 104 participants will be recruited via online questionnaires, pulmonary paediatricians, the youth department of the Municipal Health Services and cohorts of existing studies. All participants will be aged 6–16 years, will have current asthma, a Body Mass Index in the overweight or obesity range, and no serious comorbidities (such as diabetes, heart diseases). Participants in the intervention arm will receive a multifactorial intervention of 18 months consisting of sessions concerning sports, parental involvement, individual counselling and lifestyle advices including dietary advices and cognitive behavioural therapy. The control group will receive usual care. The primary outcome variables will include Forced Expiratory Volume in one second and Body Mass Index - Standard Deviation Score. Secondary outcomes will include other lung function parameters (including dynamic and static lung function parameters), asthma control, asthma-specific quality of life, use of asthma medication and markers of systemic inflammation and airway inflammation. Discussion In this randomised controlled trial we will study the potential of a

  17. Randomised controlled trial of topical kanuka honey for the treatment of rosacea

    PubMed Central

    Braithwaite, Irene; Hunt, Anna; Riley, Judith; Fingleton, James; Kocks, Janwillem; Corin, Andrew; Helm, Colin; Sheahan, Davitt; Tofield, Christopher; Montgomery, Barney; Holliday, Mark; Weatherall, Mark; Beasley, Richard

    2015-01-01

    Objective To investigate the efficacy of topical 90% medical-grade kanuka honey and 10% glycerine (Honevo) as a treatment for rosacea. Design Randomised controlled trial with blinded assessment of primary outcome variable. Setting Outpatient primary healthcare population from 5 New Zealand sites. Participants 138 adults aged ≥16, with a diagnosis of rosacea, and a baseline blinded Investigator Global Assessment of Rosacea Severity Score (IGA-RSS) of ≥2. 69 participants were randomised to each treatment arm. 1 participant was excluded from the Honevo group, and 7 and 15 participants withdrew from the Honevo and control groups, respectively. Interventions Participants were randomly allocated 1:1 to Honevo or control cream (Cetomacrogol), applied twice daily for 8 weeks. Main outcome measures The primary outcome measure was the proportion of participants who had a ≥2 improvement in the 7-point IGA-RSS at week 8 compared to baseline. Secondary outcomes included change in IGA-RSS and subject-rated visual analogue score of change in severity (VAS-CS) on a 100 mm scale (0 mm ‘much worse’, 100 mm ‘much improved’) at weeks 2 and 8. Results 24/68 (34.3%) in the Honevo group and 12/69 (17.4%) in the control group had a ≥2 improvement in IGA-RSS at week 8 compared to baseline (relative risk 2.03; 95% CI 1.11 to 3.72, p=0.020). The change in IGA-RSS for Honevo compared to control at week 2 minus baseline was −1 (Hodges-Lehman estimate, 95% CI −1 to 0, p=0.03), and at week 8 minus baseline was −1 (Hodges-Lehman estimate, 95% CI −1 to 0, p=0.005). The VAS-CS at week 2 was 9.1 (95% CI 3.5 to 14.7), p=0.002, and at week 8 was 12.3 (95% CI 5.7 to 18.9)¸ p<0.001 for Honevo compared to control. Conclusions Honevo is an effective treatment for rosacea. Trial registration number This trial was registered in the Australian and New Zealand Clinical Trials Registry ACTRN12614000004662. PMID:26109117

  18. Single port/incision laparoscopic surgery compared with standard three-port laparoscopic surgery for appendicectomy - a randomised controlled trial

    PubMed Central

    2012-01-01

    Background Laparoscopic surgery has become the preferred approach for many procedures because of reduced post-operative pain, better recovery, shorter hospital stay and improved cosmesis. Single incision laparoscopic surgery is one of the many recent variants where either standard ports or a specially designed single multi-channel port is introduced through a single skin incision. While the cosmetic advantage of this is obvious, the evidence base for claims of reduced morbidity and better post-operative recovery is weak. This study aims to compare the effectiveness of single port/incision laparoscopic appendicectomy with standard three-port laparoscopic appendicectomy in adult patients at six weeks post-surgery. We also wish to assess the feasibility of a multicentre randomised controlled trial comparing single port/incision laparoscopic surgery with standard three-port laparoscopic surgery for other surgical techniques. Methods and design Patients diagnosed with suspected appendicitis and requiring surgical treatment will be randomised to receive either standard three-port or single incision laparoscopic surgery. Data will be collected from clinical notes, operation notes and patient reported questionnaires. The following outcomes will be considered: 1. Effectiveness of the surgical procedure in terms of: •patient reported outcomes •clinical outcomes •resource use 2. Feasibility of conducting a randomised controlled trial (RCT) in the emergency surgical setting by quantifying: •patient eligibility •randomisation acceptability •feasibility of blinding participants to the intervention received •completion rates of case report forms and patient reported questionnaires Trial registration ISRCTN66443895 (assigned 10 March 2011, first patient randomised 09 January 2011) PMID:23111090

  19. Self-Management education for adults with poorly controlled epILEpsy (SMILE (UK)): a randomised controlled trial protocol

    PubMed Central

    2014-01-01

    Background Teaching people with epilepsy to identify and manage seizure triggers, implement strategies to remember to take antiepileptic drugs, implement precautions to minimize risks during seizures, tell others what to do during a seizure and learn what to do during recovery may lead to better self-management. No teaching programme exists for adults with epilepsy in the United Kingdom although a number of surveys have shown patients want more information. Methods/Design This is a multicentre, pragmatic, parallel group randomised controlled trial to evaluate the effectiveness and cost-effectiveness of a two-day Self-Management education for epILEpsy (SMILE (UK)), which was originally developed in Germany (MOSES). Four hundred and twenty eight adult patients who attended specialist epilepsy outpatient clinics at 15 NHS participating sites in the previous 12 months, and who fulfil other eligibility criteria will be randomised to receive the intervention (SMILE (UK) course with treatment as usual- TAU) or to have TAU only (control). The primary outcome is the effect on patient reported quality of life (QoL). Secondary outcomes are seizure frequency and psychological distress (anxiety and depression), perceived impact of epilepsy, adherence to medication, management of adverse effects from medication, and improved self-efficacy in management (mastery/control) of epilepsy. Within the trial there will be a nested qualitative study to explore users’ views of the intervention, including barriers to participation and the perceived benefits of the intervention. The cost-effectiveness of the intervention will also be assessed. Discussion This study will provide quantitative and qualitative evidence of the impact of a structured self management programme on quality of life and other aspects of clinical and cost effectiveness in adults with poorly controlled epilepsy. Trial registration Current Controlled Trials: ISRCTN57937389. PMID:24694207

  20. Robust Dynamics and Control of a Partially Observed Markov Chain

    SciTech Connect

    Elliott, R. J. Malcolm, W. P. Moore, J. P.

    2007-12-15

    In a seminal paper, Martin Clark (Communications Systems and Random Process Theory, Darlington, 1977, pp. 721-734, 1978) showed how the filtered dynamics giving the optimal estimate of a Markov chain observed in Gaussian noise can be expressed using an ordinary differential equation. These results offer substantial benefits in filtering and in control, often simplifying the analysis and an in some settings providing numerical benefits, see, for example Malcolm et al. (J. Appl. Math. Stoch. Anal., 2007, to appear).Clark's method uses a gauge transformation and, in effect, solves the Wonham-Zakai equation using variation of constants. In this article, we consider the optimal control of a partially observed Markov chain. This problem is discussed in Elliott et al. (Hidden Markov Models Estimation and Control, Applications of Mathematics Series, vol. 29, 1995). The innovation in our results is that the robust dynamics of Clark are used to compute forward in time dynamics for a simplified adjoint process. A stochastic minimum principle is established.

  1. Robust, Flexible Motion Control for the Mars Explorer Rovers

    NASA Technical Reports Server (NTRS)

    Maimone, Mark; Biesiadecki, Jeffrey

    2007-01-01

    The Mobility Flight Software, running on computers aboard the Mars Explorer Rover (MER) robotic vehicles Spirit and Opportunity, affords the robustness and flexibility of control to enable safe and effective operation of these vehicles in traversing natural terrain. It can make the vehicles perform specific maneuvers commanded from Earth, and/or can autonomously administer multiple aspects of mobility, including choice of motion, measurement of actual motion, and even selection of targets to be approached. Motion of a vehicle can be commanded by use of multiple layers of control, ranging from motor control at a low level, direct drive operations (e.g., motion along a circular arc, motion along a straight line, or turn in place) at an intermediate level to goal-position driving (that is, driving to a specified location) at a high level. The software can also perform high-level assessment of terrain and selection of safe paths across the terrain: this involves processing of the digital equivalent of a local traversability map generated from images acquired by stereoscopic pairs of cameras aboard the vehicles. Other functions of the software include interacting with the rest of the MER flight software and performing safety checks.

  2. Comparison communities in a cluster randomised trial innovate in response to 'being controlled'.

    PubMed

    Hawe, Penelope; Riley, Therese; Gartrell, Alexandra; Turner, Karen; Canales, Claudia; Omstead, Darlene

    2015-05-01

    We conducted qualitative interviews among primary health care teams and community agencies in eight communities in Victoria, Australia which had (1) agreed to be part of a universal primary care and community development intervention to reduce post natal depression and promote maternal health; and (2) were randomised to the comparison arm. The purpose was to document their experience with and interpretation of the trial. Although 'control' in a controlled trial refers to the control of confounding of the trial result by factors other than allocation to the intervention, participants interpreted 'control' to mean restrictions on what they were allowed to do during the trial period. They had agreed not to use the Edinburgh Post Natal Depression Scale or the SF 36 in clinical practice and not to implement any of the elements of the intervention. We found that no elements of the intervention were implemented. However, the extension of the trial from three to five years made the trial agreement a strain. The imposition of trial conditions also encouraged a degree of lateral thinking and innovation in service delivery (quality improvement). This may have potentially contributed to the null trial results. The observations invite interrogation of intervention theory and consequent rethinking of the way contamination in a cluster trial is defined. PMID:25863725

  3. Patient-initiated appointments compared with standard outpatient care for rheumatoid arthritis: a randomised controlled trial

    PubMed Central

    Fredriksson, Cecilia; Ebbevi, David; Waldheim, Eva; Lindblad, Staffan; Ernestam, Sofia

    2016-01-01

    Objectives To test the hypothesis that implementing a patient-initiated system of care could improve clinical outcome in rheumatoid arthritis (RA) using disease activity guided management. Methods An 18-month controlled blinded end point two-centre study with 131 patients with RA randomised to intervention (n=64) or control (n=67). The intervention group participants were guaranteed appointments to a rheumatologist within 10 working days if they subjectively experienced a flare in disease activity. The control group participants were booked in advance according to guidelines. Independent assessments were performed in the two groups at 0, 3, 6, 12 and 18 months. Outcome measures included: Disease Activity Score 28 (DAS28), a Visual Analogue Scale (satisfaction with care, confidence in care), number of appointments with a rheumatologist. Results DAS28 decreased. Median satisfaction and confidence in care were >90 mm on Visual Analog Scale. Median number of appointments was 3. There were no significant differences between the groups among these outcomes. Visits in the intervention group more often resulted in change of treatment than in the control group (p<0.001). Conclusions Patient-initiated care was neither better nor inferior to traditional care in terms of outcomes analysed. Patient-initiated appointments can safely be used in everyday outpatient care of RA to empower the patient, if disease activity guided management is applied. Further research should investigate if this intervention can target a subgroup of patients and hence also result in released resources. PMID:27042334

  4. Topical tranexamic acid as a novel treatment for bleeding peptic ulcer: A randomised controlled trial

    PubMed Central

    Rafeey, Mandana; Shoaran, Maryam; Ghergherechi, Robabeh

    2016-01-01

    Background: Peptic ulcers are among the most common causes of upper gastrointestinal (GI) bleeding in children. The standard care for GI bleeding is endoscopy for diagnostic and therapeutic purposes. We aimed to assess the effect of topical tranexamic acid (TXA) via endoscopic procedures in children with GI bleeding caused by bleeding ulcers. Procedure: In this randomised controlled trial, 120 children were evaluated by diagnostic procedures for GI bleeding, of which 63 (30 girls, 33 boys) aged 1-month to 15 years were recruited. The patients were randomly divided into case and control groups. In the case group, TXA was administered directly under endoscopic therapy. In the control group, epinephrine (1/10,000) was submucosally injected to the four quadrants of ulcer margins as the routine endoscopic therapy. In both groups, the patients received supportive medical therapy with intravenous fluids and proton pump inhibitor drugs. Results: The mean ± standard deviation age of the children was 5 ± 2.03 years. Rebleeding occurred in 15 (11.4%) and 21 (9.8%) patients in the case and control groups, respectively (P = 0.50). The frequency of blood transfusion episodes (P = 0.06) and duration of hospital stay (P = 0.07) were not statistically different between the groups. Conclusion: Using topical TXA via endoscopic procedures may be effective in cases of GI bleedings caused by active bleeding ulcers. In order to establish this therapeutic effect, a large number of clinical studies are needed. PMID:27251517

  5. Identification and robust control of linear parameter-varying systems

    NASA Astrophysics Data System (ADS)

    Lee, Lawton Hubert

    This dissertation deals with linear parameter-varying (LPV) systems: linear dynamic systems that depend on time-varying parameters. These systems appear in gain scheduling problems, and much recent research has been devoted to their prospective usefulness for systematic gain scheduling. We primarily focus on robust control of uncertain LPV systems and identification of LPV systems that are modelable as linear-fractional transformations (LFTs). Using parameter-dependent quadratic Lyapunov functions, linear matrix inequalities (LMIs), and scaled small-gain arguments, we define notions of stability and induced-{cal L}sb2 performance for uncertain LPV systems whose parameters and rates of parameter variation satisfy given bounds. The performance criterion involves integral quadratic constraints and implies naturally parameter-dependent induced-{cal L}sb2 norm bounds. We formulate and solve an {cal H}sb{infty}-like control problem for an LPV plant with measurable parameters and an "Output/State Feedback" structure: the feedback outputs include some noiselessly measured states. Necessary and sufficient solvability conditions reduce to LMIs that can be solved approximately using finite-dimensional convex programming. Reduced-order LPV controllers are constructed from the LMI solutions. A D-K iteration-like procedure provides robustness to structured, time-varying, parametric uncertainty. The design method is applied to a motivating example: flight control for the F-16 VISTA throughout its subsonic flight envelope. Parameter-dependent weights and {cal H}sb{infty} design principles describe the performance objectives. Closed-loop responses exhibited by nonlinear simulations indicate satisfactory flying qualities. Identification of linear-fractional LPV systems is treated using maximum-likelihood parameter estimation. Computing the gradient and Hessian of a maximum-likelihood cost function reduces to simulating one LPV filter per identified parameter. We use nonlinear

  6. Telehealth for patients at high risk of cardiovascular disease: pragmatic randomised controlled trial

    PubMed Central

    O’Cathain, Alicia; Thomas, Clare; Edwards, Louisa; Gaunt, Daisy; Dixon, Padraig; Hollinghurst, Sandra; Nicholl, Jon; Large, Shirley; Yardley, Lucy; Fahey, Tom; Foster, Alexis; Garner, Katy; Horspool, Kimberley; Man, Mei-See; Rogers, Anne; Pope, Catherine; Montgomery, Alan A

    2016-01-01

    Objective To assess whether non-clinical staff can effectively manage people at high risk of cardiovascular disease using digital health technologies. Design Pragmatic, multicentre, randomised controlled trial. Setting 42 general practices in three areas of England. Participants Between 3 December 2012 and 23 July 2013 we recruited 641 adults aged 40 to 74 years with a 10 year cardiovascular disease risk of 20% or more, no previous cardiovascular event, at least one modifiable risk factor (systolic blood pressure ≥140 mm Hg, body mass index ≥30, current smoker), and access to a telephone, the internet, and email. Participants were individually allocated to intervention (n=325) or control (n=316) groups using automated randomisation stratified by site, minimised by practice and baseline risk score. Interventions Intervention was the Healthlines service (alongside usual care), comprising regular telephone calls from trained lay health advisors following scripts generated by interactive software. Advisors facilitated self management by supporting participants to use online resources to reduce risk factors, and sought to optimise drug use, improve treatment adherence, and encourage healthier lifestyles. The control group comprised usual care alone. Main outcome measures The primary outcome was the proportion of participants responding to treatment, defined as maintaining or reducing their cardiovascular risk after 12 months. Outcomes were collected six and 12 months after randomisation and analysed masked. Participants were not masked. Results 50% (148/295) of participants in the intervention group responded to treatment compared with 43% (124/291) in the control group (adjusted odds ratio 1.3, 95% confidence interval 1.0 to 1.9; number needed to treat=13); a difference possibly due to chance (P=0.08). The intervention was associated with reductions in blood pressure (difference in mean systolic −2.7 mm Hg (95% confidence interval −4.7 to −0.6 mm Hg

  7. Patient controlled analgesia with remifentanil versus epidural analgesia in labour: randomised multicentre equivalence trial

    PubMed Central

    Bloemenkamp, Kitty W; Franssen, Maureen T; Papatsonis, Dimitri N; Hajenius, Petra J; Hollmann, Markus W; Woiski, Mallory D; Porath, Martina; van den Berg, Hans J; van Beek, Erik; Borchert, Odette W H M; Schuitemaker, Nico; Sikkema, J Marko; Kuipers, A H M; Logtenberg, Sabine L M; van der Salm, Paulien C M; Oude Rengerink, Katrien; Lopriore, Enrico; van den Akker-van Marle, M Elske; le Cessie, Saskia; van Lith, Jan M; Struys, Michel M; Mol, Ben Willem J; Dahan, Albert; Middeldorp, Johanna M

    2015-01-01

    Objective To determine women’s satisfaction with pain relief using patient controlled analgesia with remifentanil compared with epidural analgesia during labour. Design Multicentre randomised controlled equivalence trial. Setting 15 hospitals in the Netherlands. Participants Women with an intermediate to high obstetric risk with an intention to deliver vaginally. To exclude a clinically relevant difference in satisfaction with pain relief of more than 10%, we needed to include 1136 women. Because of missing values for satisfaction this number was increased to 1400 before any analysis. We used multiple imputation to correct for missing data. Intervention Before the onset of active labour consenting women were randomised to a pain relief strategy with patient controlled remifentanil or epidural analgesia if they requested pain relief during labour. Main outcome measures Primary outcome was satisfaction with pain relief, measured hourly on a visual analogue scale and expressed as area under the curve (AUC), thus providing a time weighted measure of total satisfaction with pain relief. A higher AUC represents higher satisfaction with pain relief. Secondary outcomes were pain intensity scores, mode of delivery, and maternal and neonatal outcomes. Analysis was done by intention to treat. The study was defined as an equivalence study for the primary outcome. Results 1414 women were randomised, of whom 709 were allocated to patient controlled remifentanil and 705 to epidural analgesia. Baseline characteristics were comparable. Pain relief was ultimately used in 65% (447/687) in the remifentanil group and 52% (347/671) in the epidural analgesia group (relative risk 1.32, 95% confidence interval 1.18 to 1.48). Cross over occurred in 7% (45/687) and 8% (51/671) of women, respectively. Of women primarily treated with remifentanil, 13% (53/402) converted to epidural analgesia, while in women primarily treated with epidural analgesia 1% (3/296) converted to remifentanil. The

  8. Educational Intervention Improves Anticoagulation Control in Atrial Fibrillation Patients: The TREAT Randomised Trial

    PubMed Central

    Clarkesmith, Danielle E.; Pattison, Helen M.; Lip, Gregory Y. H.; Lane, Deirdre A.

    2013-01-01

    Background Stroke prevention in atrial fibrillation (AF), most commonly with warfarin, requires maintenance of a narrow therapeutic target (INR 2.0 to 3.0) and is often poorly controlled in practice. Poor patient-understanding surrounding AF and its treatment may contribute to the patient’s willingness to adhere to recommendations. Method A theory-driven intervention, developed using patient interviews and focus groups, consisting of a one-off group session (1–6 patients) utilising an “expert-patient” focussed DVD, educational booklet, self-monitoring diary and worksheet, was compared in a randomised controlled trial (ISRCTN93952605) against usual care, with patient postal follow-ups at 1, 2, 6, and 12-months. Ninety-seven warfarin-naïve AF patients were randomised to intervention (n=46, mean age (SD) 72.0 (8.2), 67.4% men), or usual care (n=51, mean age (SD) 73.7 (8.1), 62.7% men), stratified by age, sex, and recruitment centre. Primary endpoint was time within therapeutic range (TTR); secondary endpoints included knowledge, quality of life, anxiety/depression, beliefs about medication, and illness perceptions. Main Findings Intervention patients had significantly higher TTR than usual care at 6-months (76.2% vs. 71.3%; p=0.035); at 12-months these differences were not significant (76.0% vs. 70.0%; p=0.44). Knowledge increased significantly across time (F (3, 47) = 6.4; p<0.01), but there were no differences between groups (F (1, 47) = 3.3; p = 0.07). At 6-months, knowledge scores predicted TTR (r=0.245; p=0.04). Patients’ scores on subscales representing their perception of the general harm and overuse of medication, as well as the perceived necessity of their AF specific medications predicted TTR at 6- and 12-months. Conclusions A theory-driven educational intervention significantly improves TTR in AF patients initiating warfarin during the first 6-months. Adverse clinical outcomes may potentially be reduced by improving patients’ understanding of

  9. Multicomponent intervention to reduce daily sedentary time: a randomised controlled trial

    PubMed Central

    Carr, Lucas J; Karvinen, Kristina; Peavler, Mallory; Smith, Rebecca; Cangelosi, Kayla

    2013-01-01

    Objectives To test the efficacy of a multicomponent technology intervention for reducing daily sedentary time and improving cardiometabolic disease risk among sedentary, overweight university employees. Design Blinded, randomised controlled trial. Setting A large south-eastern university in the USA. Participants 49 middle-aged, primarily female, sedentary and overweight adults working in sedentary jobs enrolled in the study. A total of 40 participants completed the study. Interventions Participants were randomised to either: (1) an intervention group (N=23; 47.6+9.9 years; 94.1% female; 33.2+4.5 kg/m2); (2) or wait-list control group (N=17; 42.6+8.9 years; 86.9% female; 31.7+4.9 kg/m2). The intervention group received a theory-based, internet-delivered programme, a portable pedal machine at work and a pedometer for 12 weeks. The wait-list control group maintained their behaviours for 12 weeks. Outcome measures Primary (sedentary and physical activity behaviour measured objectively through StepWatch) and secondary (heart rate, blood pressure, height, weight, waist circumference, per cent body fat, cardiorespiratory fitness, fasting lipids) outcomes were measured at baseline and postintervention (12 weeks). Exploratory outcomes including intervention compliance and process evaluation measures were also assessed postintervention. Results Compared to controls, the intervention group reduced daily sedentary time (mean change (95%CI): −58.7 min/day (−118.4 to 0.99; p<0.01)) after adjusting for baseline values and monitor wear time. Intervention participants logged on to the website 71.3% of all intervention days, used the pedal machine 37.7% of all working intervention days and pedalled an average of 31.1 min/day. Conclusions These findings suggest that the intervention was engaging and resulted in reductions in daily sedentary time among full-time sedentary employees. These findings hold public health significance due to the growing number of

  10. A lifestyle intervention for primary care patients with depression and anxiety: A randomised controlled trial.

    PubMed

    Forsyth, Adrienne; Deane, Frank P; Williams, Peter

    2015-12-15

    This study aimed to evaluate the efficacy of a diet and exercise lifestyle intervention on mental health outcomes for patients currently being treated for depression and/or anxiety in primary care. Patients (n=119) referred by general practitioners to the 12-week randomised controlled trial were assigned to either an intervention of six visits to a dual qualified dietitian/exercise physiologist (DEP) where motivational interviewing and activity scheduling were used to engage patients in individually-tailored lifestyle change (focussed on diet and physical activity), or an attention control with scheduled telephone contact. Assessments conducted at baseline (n=94) and 12 weeks (n=60) were analysed with an intent-to-treat approach using linear mixed modelling. Significant improvement was found for both groups on Depression, Anxiety and Stress Scale (DASS) scores, measures of nutrient intake and total Australian modified Healthy Eating Index (Aust-HEI) scores. Significant differences between groups over time were found only for iron intake and body mass index. Patients participating in individual consultations with a dietitian were more likely to maintain or improve diet quality than those participating in an attention control. This study provides initial evidence to support the role of dietitians in the management of patients with depression and/or anxiety. PMID:26453120

  11. Sunflower therapy for children with specific learning difficulties (dyslexia): a randomised, controlled trial.

    PubMed

    Bull, Leona

    2007-02-01

    The aim of the study was to determine the clinical and perceived effectiveness of the Sunflower therapy in the treatment of childhood dyslexia. The Sunflower therapy includes applied kinesiology, physical manipulation, massage, homeopathy, herbal remedies and neuro-linguistic programming. A multi-centred, randomised controlled trial was undertaken with 70 dyslexic children aged 6-13 years. The research study aimed to test the research hypothesis that dyslexic children 'feel better' and 'perform better' as a result of treatment by the Sunflower therapy. Children in the treatment group and the control group were assessed using a battery of standardised cognitive, Literacy and self-esteem tests before and after the intervention. Parents of children in the treatment group gave feedback on their experience of the Sunflower therapy. Test scores were compared using the Mann Whitney, and Wilcoxon statistical tests. While both groups of children improved in some of their test scores over time, there were no statistically significant improvements in cognitive or Literacy test performance associated with the treatment. However, there were statistically significant improvements in academic self-esteem, and reading self-esteem, for the treatment group. The majority of parents (57.13%) felt that the Sunflower therapy was effective in the treatment of learning difficulties. Further research is required to verify these findings, and should include a control group receiving a dummy treatment to exclude placebo effects. PMID:17210507

  12. The effect of chlorhexidine in reducing oral colonisation in geriatric patients: a randomised controlled trial

    PubMed Central

    Sharif-Abdullah, Sharifah Shafinaz Binti; Chong, Mei Chan; Surindar-Kaur, Surat Singh; Kamaruzzaman, Shahrul Bahyah; Ng, Kwan Hoong

    2016-01-01

    INTRODUCTION Inadequate oral care has been implicated in the development of aspiration pneumonia in frail geriatric patients and is a major cause of mortality, due to the colonisation of microbes in vulnerable patients. This type of pneumonia has been associated with an increase in respiratory pathogens in the oral cavity. The aim of this study was to evaluate the effects of chlorhexidine compared to routine oral care in edentulous geriatric inpatients. METHODS A double-blind, parallel-group randomised controlled trial was carried out. The intervention group received oral care with chlorhexidine 0.2%, while the control group received routine oral care with thymol. Nurses provided oral care with assigned solutions of 20 mL once daily over seven days. Oral cavity assessment using the Brief Oral Health Status Examination form was performed before each oral care procedure. Data on medication received and the subsequent development of aspiration pneumonia was recorded. An oral swab was performed on Day 7 to obtain specimens to test for colonisation. RESULTS The final sample consisted of 35 (control) and 43 (intervention) patients. Chlorhexidine was effective in reducing oral colonisation compared to routine oral care with thymol (p < 0.001). The risk of oral bacterial colonisation was nearly three times higher in the thymol group compared to the chlorhexidine group. CONCLUSION The use of chlorhexidine 0.2% significantly reduced oral colonisation and is recommended as an easier and more cost-effective alternative for oral hygiene. PMID:27211885

  13. Robustness of DNA repair through collective rate control.

    PubMed

    Verbruggen, Paul; Heinemann, Tim; Manders, Erik; von Bornstaedt, Gesa; van Driel, Roel; Höfer, Thomas

    2014-01-01

    DNA repair and other chromatin-associated processes are carried out by enzymatic macromolecular complexes that assemble at specific sites on the chromatin fiber. How the rate of these molecular machineries is regulated by their constituent parts is poorly understood. Here we quantify nucleotide-excision DNA repair in mammalian cells and find that, despite the pathways' molecular complexity, repair effectively obeys slow first-order kinetics. Theoretical analysis and data-based modeling indicate that these kinetics are not due to a singular rate-limiting step. Rather, first-order kinetics emerge from the interplay of rapidly and reversibly assembling repair proteins, stochastically distributing DNA lesion repair over a broad time period. Based on this mechanism, the model predicts that the repair proteins collectively control the repair rate. Exploiting natural cell-to-cell variability, we corroborate this prediction for the lesion-recognition factor XPC and the downstream factor XPA. Our findings provide a rationale for the emergence of slow time scales in chromatin-associated processes from fast molecular steps and suggest that collective rate control might be a widespread mode of robust regulation in DNA repair and transcription. PMID:24499930

  14. A Cluster Randomised Controlled Effectiveness Trial Evaluating Perinatal Home Visiting among South African Mothers/Infants

    PubMed Central

    Rotheram-Borus, Mary Jane; Tomlinson, Mark; le Roux, Ingrid M.; Harwood, Jessica M.; Comulada, Scott; O'Connor, Mary J.; Weiss, Robert E.; Worthman, Carol M.

    2014-01-01

    Background Interventions are needed to reduce poor perinatal health. We trained community health workers (CHWs) as home visitors to address maternal/infant risks. Methods In a cluster randomised controlled trial in Cape Town townships, neighbourhoods were randomised within matched pairs to 1) the control, healthcare at clinics (n = 12 neighbourhoods; n = 594 women), or 2) a home visiting intervention by CBW trained in cognitive-behavioural strategies to address health risks (by the Philani Maternal, Child Health and Nutrition Programme), in addition to clinic care (n = 12 neighbourhoods; n = 644 women). Participants were assessed during pregnancy (2% refusal) and 92% were reassessed at two weeks post-birth, 88% at six months and 84% at 18 months later. We analysed 32 measures of maternal/infant well-being over the 18 month follow-up period using longitudinal random effects regressions. A binomial test for correlated outcomes evaluated overall effectiveness over time. The 18 month post-birth assessment outcomes also were examined alone and as a function of the number of home visits received. Results Benefits were found on 7 of 32 measures of outcomes, resulting in significant overall benefits for the intervention compared to the control when using the binomial test (p = 0.008); nevertheless, no effects were observed when only the 18 month outcomes were analyzed. Benefits on individual outcomes were related to the number of home visits received. Among women living with HIV, intervention mothers were more likely to implement the PMTCT regimens, use condoms during all sexual episodes (OR = 1.25; p = 0.014), have infants with healthy weight-for-age measurements (OR = 1.42; p = 0.045), height-for-age measurements (OR = 1.13, p<0.001), breastfeed exclusively for six months (OR = 3.59; p<0.001), and breastfeed longer (OR = 3.08; p<0.001). Number of visits was positively associated with infant birth weight ≥2500 grams (OR

  15. Physical fitness training in Subacute Stroke (PHYS-STROKE) - study protocol for a randomised controlled trial

    PubMed Central

    2014-01-01

    Background Given the rising number of strokes worldwide, and the large number of individuals left with disabilities after stroke, novel strategies to reduce disability, increase functions in the motor and the cognitive domains, and improve quality of life are of major importance. Physical activity is a promising intervention to address these challenges but, as yet, there is no study demonstrating definite outcomes. Our objective is to assess whether additional treatment in the form of physical fitness-based training for patients early after stroke will provide benefits in terms of functional outcomes, in particular gait speed and the Barthel Index (co-primary outcome measures) reflecting activities of daily living (ADL). We will gather secondary functional outcomes as well as mechanistic parameters in an exploratory approach. Methods/Design Our phase III randomised controlled trial will recruit 215 adults with moderate to severe limitations of walking and ADL 5 to 45 days after stroke onset. Participants will be stratified for the prognostic variables of “centre”, “age”, and “stroke severity”, and randomly assigned to one of two groups. The interventional group receives physical fitness training delivered as supported or unsupported treadmill training (cardiovascular active aerobic training; five times per week, over 4 weeks; each session 50 minutes; total of 20 additional physical fitness training sessions) in addition to standard rehabilitation treatment. The control intervention consists of relaxation sessions (non-cardiovascular active; five times per week week, over 4 weeks; each session 50 minutes) in addition to standard rehabilitation treatment. Co-primary efficacy endpoints will be gait speed (in m/s, 10 m walk) and the Barthel Index (100 points total) at 3 months post-stroke, compared to baseline measurements. Secondary outcomes include standard measures of quality of life, sleep and mood, cognition, arm function, maximal oxygen uptake

  16. Acupuncture point injection treatment of primary dysmenorrhoea: a randomised, double blind, controlled study

    PubMed Central

    Wade, C; Wang, L; Zhao, W J; Cardini, F; Kronenberg, F; Gui, S Q; Ying, Z; Zhao, N Q; Chao, M T; Yu, J

    2016-01-01

    Objective To determine if injection of vitamin K3 in an acupuncture point is optimal for the treatment of primary dysmenorrhoea, when compared with 2 other injection treatments. Setting A Menstrual Disorder Centre at a public hospital in Shanghai, China. Participants Chinese women aged 14–25 years with severe primary dysmenorrhoea for at least 6 months not relieved by any other treatment were recruited. Exclusion criteria were the use of oral contraceptives, intrauterine devices or anticoagulant drugs, pregnancy, history of abdominal surgery, participation in other therapies for pain and diagnosis of secondary dysmenorrhoea. Eighty patients with primary dysmenorrhoea, as defined on a 4-grade scale, completed the study. Two patients withdrew after randomisation. Interventions A double-blind, double-dummy, randomised controlled trial compared vitamin K3 acupuncture point injection to saline acupuncture point injection and vitamin K3 deep muscle injection. Patients in each group received 3 injections at a single treatment visit. Primary and secondary outcome measures The primary outcome was the difference in subjective perception of pain as measured by an 11 unit Numeric Rating Scale (NRS). Secondary measurements were Cox Pain Intensity and Duration scales and the consumption of analgesic tablets before and after treatment and during 6 following cycles. Results Patients in all 3 groups experienced pain relief from the injection treatments. Differences in NRS measured mean pain scores between the 2 active control groups were less than 1 unit (−0.71, CI −1.37 to −0.05) and not significant, but the differences in average scores between the treatment hypothesised to be optimal and both active control groups (1.11, CI 0.45 to 1.78) and (1.82, CI 1.45 to 2.49) were statistically significant in adjusted mixed-effects models. Menstrual distress and use of analgesics were diminished for 6 months post-treatment. Conclusions Acupuncture point injection of

  17. Case management for frequent users of the emergency department: study protocol of a randomised controlled trial

    PubMed Central

    2014-01-01

    Background We devised a randomised controlled trial to evaluate the effectiveness and efficiency of an intervention based on case management care for frequent emergency department users. The aim of the intervention is to reduce such patients’ emergency department use, to improve their quality of life, and to reduce costs consequent on frequent use. The intervention consists of a combination of comprehensive case management care and standard emergency care. It uses a clinical case management model that is patient-identified, patient-directed, and developed to provide high intensity services. It provides a continuum of hospital- and community-based patient services, which include clinical assessment, outreach referral, and coordination and communication with other service providers. Methods/Design We aim to recruit, during the first year of the study, 250 patients who visit the emergency department of the University Hospital of Lausanne, Switzerland. Eligible patients will have visited the emergency department 5 or more times during the previous 12 months. Randomisation of the participants to the intervention or control groups will be computer generated and concealed. The statistician and each patient will be blinded to the patient’s allocation. Participants in the intervention group (N = 125), additionally to standard emergency care, will receive case management from a team, 1 (ambulatory care) to 3 (hospitalization) times during their stay and after 1, 3, and 5 months, at their residence, in the hospital or in the ambulatory care setting. In between the consultations provided, the patients will have the opportunity to contact, at any moment, the case management team. Participants in the control group (N = 125) will receive standard emergency care only. Data will be collected at baseline and 2, 5.5, 9, and 12 months later, including: number of emergency department visits, quality of life (EuroQOL and WHOQOL), health services use, and relevant costs

  18. Evaluation of an online Diabetes Needs Assessment Tool (DNAT) for health professionals: a randomised controlled trial

    PubMed Central

    2009-01-01

    Background Continuous medical education is traditionally reliant to a large extent on self-directed learning based on individuals' perceived learning priorities. Evidence suggests that this ability to self-assess is limited, and more so in the least competent. Therefore, it may be of benefit to utilise some form of external assessment for this purpose. Many diabetes educational programmes have been introduced, but few have been assessed for their benefit in a systematic manner. As diabetes is an increasingly prevalent disease, methods for the dissemination and understanding of clinical guidelines need to be explored for their effectiveness. This paper describes the study design of a randomised controlled trial to evaluate the effectiveness of using an interactive online Diabetes Needs Assessment Tool (DNAT), that builds a learning curriculum based on identified knowledge gaps, compared with conventional self-directed learning. The study assesses the effect of these interventions on health professionals' knowledge of diabetes management, evaluates the acceptability of this process of learning and self-reported changes in clinical practice as a result of this novel educational process. Methods Following a baseline assessment, participants will be randomised to undergo a 4-month learning period where they will either be given access to the diabetes learning modules alone (control group) or a Diabetes Needs Assessment Tool (DNAT) plus the diabetes learning modules (intervention group). On completion of the DNAT, a personalised learning report will be created for each participant identifying needs alongside individualised recommendations of the most appropriate learning modules to meet those requirements. All participants will complete a Diabetes Knowledge Test before and immediately after the allocated learning and the primary outcome will be the state of knowledge at 4 months. Learners will also be surveyed immediately after the learning period to assess the

  19. Communication interventions to improve adherence to infection control precautions: a randomised crossover trial

    PubMed Central

    2013-01-01

    Background Ineffective communication of infection control requirements during transitions of care is a potential cause of non-compliance with infection control precautions by healthcare personnel. In this study, interventions to enhance communication during inpatient transfers between wards and radiology were implemented, in the attempt to improve adherence to precautions during transfers. Methods Two interventions were implemented, comprising (i) a pre-transfer checklist used by radiology porters to confirm a patient’s infectious status; (ii) a coloured cue to highlight written infectious status information in the transfer form. The effectiveness of the interventions in promoting adherence to standard precautions by radiology porters when transporting infectious patients was evaluated using a randomised crossover trial at a teaching hospital in Australia. Results 300 transfers were observed over a period of 4 months. Compliance with infection control precautions in the intervention groups was significantly improved relative to the control group (p < 0.01). Adherence rate in the control group was 38%. Applying the coloured cue resulted in a compliance rate of 73%. The pre-transfer checklist intervention achieved a comparable compliance rate of 71%. When both interventions were applied, a compliance rate of 74% was attained. Acceptability of the coloured cue was high, but adherence to the checklist was low (40%). Conclusions Simple measures to enhance communication through the provision of a checklist and the use a coloured cue brought about significant improvement in compliance with infection control precautions by transport personnel during inpatient transfers. The study underscores the importance of effective communication in ensuring compliance with infection control precautions during transitions of care. PMID:23388051

  20. Pain Levels after Local Anaesthetic with or without Hyaluronidase in Carpal Tunnel Release: A Randomised Controlled Trial

    PubMed Central

    Yeo, G.; Gupta, A.; Ding, G.; Skerman, H.; Khatun, M.; Melsom, D.

    2015-01-01

    Purpose. Hyaluronidase is an enzyme that temporarily liquefies the interstitial barrier, allowing easy dispersal of local anaesthetic through cleavage of tissue planes. This prospective, blinded, randomised controlled study investigates the utility of adding hyaluronidase to local anaesthetic in the setting of carpal tunnel release. Methods. 70 consecutive carpal tunnel release patients were recruited and randomised into a control group only receiving local anaesthetic and a hyaluronidase group receiving both hyaluronidase and local anaesthetic. Pain scores were rated using the visual analogue scale (VAS) by patients immediately after local anaesthetic injection and again immediately after the carpal tunnel release. Results. Preoperative VAS scores, taken after local anaesthetic injection, were greater than postoperative VAS scores. Postoperative VAS scores were significantly lower in the hyaluronidase group and tourniquet times were significantly shorter in the hyaluronidase group. Conclusion. Hyaluronidase addition to local anaesthetic in carpal tunnel release resulted in significant reductions in operative time and pain immediately after operation. PMID:26587288

  1. Robust attitude control design for spacecraft under assigned velocity and control constraints.

    PubMed

    Hu, Qinglei; Li, Bo; Zhang, Youmin

    2013-07-01

    A novel robust nonlinear control design under the constraints of assigned velocity and actuator torque is investigated for attitude stabilization of a rigid spacecraft. More specifically, a nonlinear feedback control is firstly developed by explicitly taking into account the constraints on individual angular velocity components as well as external disturbances. Considering further the actuator misalignments and magnitude deviation, a modified robust least-squares based control allocator is employed to deal with the problem of distributing the previously designed three-axis moments over the available actuators, in which the focus of this control allocation is to find the optimal control vector of actuators by minimizing the worst-case residual error using programming algorithms. The attitude control performance using the controller structure is evaluated through a numerical example. PMID:23618744

  2. Adjunctive rifampicin to reduce early mortality from Staphylococcus aureus bacteraemia (ARREST): study protocol for a randomised controlled trial

    PubMed Central

    2012-01-01

    Background Staphylococcus aureus bacteraemia is a common and serious infection, with an associated mortality of ~25%. Once in the blood, S. aureus can disseminate to infect almost any organ, but bones, joints and heart valves are most frequently affected. Despite the infection’s severity, the evidence guiding optimal antibiotic therapy is weak: fewer than 1,500 patients have been included in 16 randomised controlled trials investigating S. aureus bacteraemia treatment. It is uncertain which antibiotics are most effective, their route of administration and duration, and whether antibiotic combinations are better than single agents. We hypothesise that adjunctive rifampicin, given in combination with a standard first-line antibiotic, will enhance killing of S. aureus early in the treatment course, sterilise infected foci and blood faster, and thereby reduce the risk of dissemination, metastatic infection and death. Our aim is to determine whether adjunctive rifampicin reduces all-cause mortality within 14 days and bacteriological failure or death within 12 weeks from randomisation. Methods We will perform a parallel group, randomised (1:1), blinded, placebo-controlled trial in NHS hospitals across the UK. Adults (≥18 years) with S. aureus (meticillin-susceptible or resistant) grown from at least one blood culture who have received ≤96 h of active antibiotic therapy for the current infection and do not have contraindications to the use of rifampicin will be eligible for inclusion. Participants will be randomised to adjunctive rifampicin (600-900mg/day; orally or intravenously) or placebo for the first 14 days of therapy in combination with standard single-agent antibiotic therapy. The co-primary outcome measures will be all-cause mortality up to 14 days from randomisation and bacteriological failure/death (all-cause) up to 12 weeks from randomisation. 940 patients will be recruited, providing >80% power to detect 45% and 30% reductions in the two co

  3. Feasibility and effectiveness of a low cost campaign on antibiotic prescribing in Italy: community level, controlled, non-randomised trial

    PubMed Central

    Paltrinieri, Barbara; Marata, Anna Maria; Gagliotti, Carlo; Pan, Angelo; Moro, Maria Luisa; Capelli, Oreste; Magrini, Nicola

    2013-01-01

    Objectives To test the hypothesis that a multifaceted, local public campaign could be feasible and influence antibiotic prescribing for outpatients. Design Community level, controlled, non-randomised trial. Setting Provinces of Modena and Parma in Emilia-Romagna, northern Italy, November 2011 to February 2012. Population 1 150 000 residents of Modena and Parma (intervention group) and 3 250 000 residents in provinces in the same region but where no campaign had been implemented (control group). Interventions Campaign materials (mainly posters, brochures, and advertisements on local media, plus a newsletter on local antibiotic resistance targeted at doctors and pharmacists). General practitioners and paediatricians in the intervention area participated in designing the campaign messages. Main outcomes measures Primary outcome was the average change in prescribing rates of antibiotics for outpatient in five months, measured as defined daily doses per 1000 inhabitants/day, using health districts as the unit of analysis. Results Antibiotic prescribing was reduced in the intervention area compared with control area (−4.3%, 95% confidence interval −7.1% to −1.5%). This result was robust to “sensitivity analysis” modifying the baseline period from two months (main analysis) to one month. A higher decrease was observed for penicillins resistant to β lactamase and a lower decrease for penicillins susceptible to β lactamase, consistent with the content of the newsletter on antibiotic resistance directed at health professionals. The decrease in expenditure on antibiotics was not statistically significant in a district level analysis with a two month baseline period (main analysis), but was statistically significant in sensitivity analyses using either a one month baseline period or a more powered doctor level analysis. Knowledge and attitudes of the target population about the correct use of antibiotics did not differ between the intervention and control

  4. Can exercise improve self esteem in children and young people? A systematic review of randomised controlled trials.

    PubMed

    Ekeland, E; Heian, F; Hagen, K B

    2005-11-01

    A systematic review to determine if exercise alone or as part of a comprehensive intervention can improve self esteem in children and young people is described. Twenty three randomised controlled trials were analysed. A synthesis of several small, low quality trials indicates that exercise may have short term beneficial effects on self esteem in children and adolescents. However, high quality research on defined populations with adequate follow up is needed. PMID:16244186

  5. Validating a new non-penetrating sham acupuncture device: two randomised controlled trials.

    PubMed

    Park, Jongbae; White, Adrian; Stevinson, Clare; Ernst, Edzard; James, Martin

    2002-12-01

    For clinical trials of acupuncture, it would be desirable to have a sham procedure that is indistinguishable from the real treatment, yet inactive. A sham needle has been designed which telescopes instead of penetrating the skin. The Park Sham Device involves an improved method of supporting the sham needle and requires validation. The objective of these studies was to test whether the sham procedure using the new device was 1) indistinguishable from the same procedure using real needles in acupuncture naïve subjects, and 2) inactive, where the specific needle sensation (de qi) is taken as a surrogate measure of activity. The studies were designed as subject and assessor blind, randomised controlled trials. Study 1) included 58 patients enrolled in a clinical trial of acupuncture for acute stroke. Study 2) included 63 healthy, acupuncture naïve, adult volunteers. The interventions used were real or sham acupuncture using the Park Sham Device. Study 1) was set in a district general hospital, and study 2) in a university laboratory. The outcome measure in study 1) was the form of treatment that patients believed they had received. In study 2) the outcome measure was experience of de qi, as judged by three acupuncture experts. No patient in either group(study 1) believed he or she had been treated with the sham needle. In 40 volunteers (study 2) for whom experts achieved consensus, the relative risk of experiencing de qi with real acupuncture to that with sham acupuncture was 15.38 (95% CI 2.26 to 104.86). The inter-rater reliability of all 13 experts (study 2), calculated from their judgements on 10 subjects selected by randomisation, was 0.52 (95% CI 0.19 to 0.61). In conclusion, the results suggest that the procedure using the new device is indistinguishable from the same procedure using real needles in acupuncture naïve subjects, and is inactive, where the specific needle sensation (de qi) is taken as a surrogate measure of activity. It is therefore a valid

  6. Helmet therapy in infants with positional skull deformation: randomised controlled trial

    PubMed Central

    van Vlimmeren, Leo A; Groothuis-Oudshoorn, Catharina G M; Van der Ploeg, Catharina P B; IJzerman, Maarten J; Boere-Boonekamp, Magda M

    2014-01-01

    Objective To determine the effectiveness of helmet therapy for positional skull deformation compared with the natural course of the condition in infants aged 5-6 months. Design Pragmatic, single blinded, randomised controlled trial (HEADS, HElmet therapy Assessment in Deformed Skulls) nested in a prospective cohort study. Setting 29 paediatric physiotherapy practices; helmet therapy was administered at four specialised centres. Participants 84 infants aged 5 to 6 months with moderate to severe skull deformation, who were born after 36 weeks of gestation and had no muscular torticollis, craniosynostosis, or dysmorphic features. Participants were randomly assigned to helmet therapy (n=42) or to natural course of the condition (n=42) according to a randomisation plan with blocks of eight. Interventions Six months of helmet therapy compared with the natural course of skull deformation. In both trial arms parents were asked to avoid any (additional) treatment for the skull deformation. Main outcome measures The primary outcome was change in skull shape from baseline to 24 months of age assessed using plagiocephalometry (anthropometric measurement instrument). Change scores for plagiocephaly (oblique diameter difference index) and brachycephaly (cranioproportional index) were each included in an analysis of covariance, using baseline values as the covariate. Secondary outcomes were ear deviation, facial asymmetry, occipital lift, and motor development in the infant, quality of life (infant and parent measures), and parental satisfaction and anxiety. Baseline measurements were performed in infants aged between 5 and 6 months, with follow-up measurements at 8, 12, and 24 months. Primary outcome assessment at 24 months was blinded. Results The change score for both plagiocephaly and brachycephaly was equal between the helmet therapy and natural course groups, with a mean difference of −0.2 (95% confidence interval −1.6 to 1.2, P=0.80) and 0.2 (−1.7 to 2.2, P=0

  7. Feasibility study of an integrated stroke self-management programme: a cluster-randomised controlled trial

    PubMed Central

    Jones, Fiona; Gage, Heather; Drummond, Avril; Bhalla, Ajay; Grant, Robert; Lennon, Sheila; McKevitt, Christopher; Riazi, Afsane; Liston, Matthew

    2016-01-01

    Objectives To test the feasibility of conducting a controlled trial into the effectiveness of a self-management programme integrated into stroke rehabilitation. Design A feasibility cluster-randomised design was utilised with stroke rehabilitation teams as units of randomisation. Setting Community-based stroke rehabilitation teams in London. Participants 78 patients with a diagnosis of stroke requiring community based rehabilitation. Intervention The intervention consisted of an individualised approach to self-management based on self-efficacy. Clinicians were trained to integrate defined self-management principles into scheduled rehabilitation sessions, supported by a patient-held workbook. Main outcomes measures Patient measures of quality of life, mood, self-efficacy and functional capacity, and health and social care utilisation, were carried out by blinded assessors at baseline, 6 weeks and 12 weeks. Fidelity and acceptability of the delivery were evaluated by observation and interviews. Results 4 community stroke rehabilitation teams were recruited, and received a total of 317 stroke referrals over 14 months. Of these, 138 met trial eligibility criteria and 78 participants were finally recruited (56.5%). Demographic and baseline outcome measures were similar between intervention and control arms, with the exception of age. All outcome measures were feasible to use and clinical data at 12 weeks were completed for 66/78 participants (85%; 95% CI 75% to 92%). There was no significant difference in any of the outcomes between the arms of the trial, but measures of functional capacity and self-efficacy showed responsiveness to the intervention. Observation and interview data confirmed acceptability and fidelity of delivery according to predetermined criteria. Costs varied by site. Conclusions It was feasible to integrate a stroke self-management programme into community rehabilitation, using key principles. Some data were lost to follow-up, but overall

  8. Randomised controlled trial of local corticosteroid injections for de Quervain's tenosynovitis in general practice

    PubMed Central

    Peters-Veluthamaningal, Cyriac; Winters, Jan C; Groenier, Klaas H; Meyboom-deJong, Betty

    2009-01-01

    Background De Quervain's tenosynovitis is a stenosing tenosynovitis of the first dorsal compartment of the wrist and leads to wrist pain and to impaired function of the wrist and hand. It can be treated by splinting, local corticosteroid injection and operation. In this study effectiveness of local corticosteroid injections for de Quervain's tenosynovitis provided by general practitioners was assessed. Methods Participants with de Quervain's tenosynovitis were recruited by general practitioners. Short-term outcomes (one week after injections) were assessed in a randomised, placebo-controlled trial. Long-term effectiveness was evaluated in an open prospective cohort-study of steroid responders during a follow-up period of 12 months. Participants were randomised to one or two local injections of 1 ml of triamcinolonacetonide (TCA) or 1 ml of NaCl 0.9% (placebo). Non-responders to NaCl were treated with additional TCA injections. Main outcomes were immediate treatment response, severity of pain, improvement as perceived by participant and functional disability using sub items hand and finger function of the Dutch Arthritis Impact Measurement Scale (Dutch AIMS-2-HFF). Results 11 general practitioners included 21 wrists in 21 patients. The TCA-group had better results for short-term outcomes treatment response (78% vs. 25%; p = 0.015), perceived improvement (78% vs. 33%; p = 0.047) and severity of pain (4.27 vs. 1.33; p = 0.031) but not for the Dutch-AIMS-HFF (2.71 vs. 1.92; p = 0.112). Absolute risk reduction for the main outcome short-term treatment response was 0.55 (95% CI: 0.34, 0.76) with a number needed to treat of 2 (95% CI: 1, 3). In the cohort of steroid responders (n = 12) the beneficial effects of steroid injections were sustained during the follow-up of 12 months regarding severity of pain (p = 0.67) and scores of Dutch AIMS-2-HFF (p = 0.36), but not for patient perceived improvement (p = 0.02). No adverse events were observed during the 12 months of follow

  9. Recovery of chronically lame dairy cows following treatment for claw horn lesions: a randomised controlled trial

    PubMed Central

    Thomas, H. J.; Remnant, J. G.; Bollard, N. J.; Burrows, A.; Whay, H. R.; Bell, N. J.; Mason, C.; Huxley, J. N.

    2016-01-01

    A positively controlled, randomised controlled trial (RCT) was undertaken to test recovery of cows with claw horn lesions resulting in lameness of greater than two weeks duration. Cows on seven commercial farms were mobility scored fortnightly and selected by lameness severity and chronicity. Study cows all received a therapeutic trim then random allocation of: no further treatment (trim only (TRM)), plastic shoe (TS) or plastic shoe and NSAID (TSN). Recovery was assessed by mobility score at 42 (±4) days post treatment by an observer blind to treatment group. Multivariable analysis showed no significant effect of treatment with an almost identical, low response rate to treatment across all groups (Percentage non-lame at outcome: TRM – 15 per cent, TS – 15 per cent, TSN – 16 per cent). When compared with results of a similar RCT on acutely lame cows, where response rates to treatment were substantially higher, it can be concluded that any delay in treatment is likely to reduce the rate of recovery, suggesting early identification and treatment is key. Thirty-eight per cent of animals treated in this study were lame on the contralateral limb at outcome suggesting that both hindlimbs should be examined and a preventive or if necessary a therapeutic foot trim performed when lameness is identified particularly if the duration of lameness is unknown. PMID:26811441

  10. Recovery of chronically lame dairy cows following treatment for claw horn lesions: a randomised controlled trial.

    PubMed

    Thomas, H J; Remnant, J G; Bollard, N J; Burrows, A; Whay, H R; Bell, N J; Mason, C; Huxley, J N

    2016-01-30

    A positively controlled, randomised controlled trial (RCT) was undertaken to test recovery of cows with claw horn lesions resulting in lameness of greater than two weeks duration. Cows on seven commercial farms were mobility scored fortnightly and selected by lameness severity and chronicity. Study cows all received a therapeutic trim then random allocation of: no further treatment (trim only (TRM)), plastic shoe (TS) or plastic shoe and NSAID (TSN). Recovery was assessed by mobility score at 42 (±4) days post treatment by an observer blind to treatment group. Multivariable analysis showed no significant effect of treatment with an almost identical, low response rate to treatment across all groups (Percentage non-lame at outcome: TRM - 15 per cent, TS - 15 per cent, TSN - 16 per cent). When compared with results of a similar RCT on acutely lame cows, where response rates to treatment were substantially higher, it can be concluded that any delay in treatment is likely to reduce the rate of recovery, suggesting early identification and treatment is key. Thirty-eight per cent of animals treated in this study were lame on the contralateral limb at outcome suggesting that both hindlimbs should be examined and a preventive or if necessary a therapeutic foot trim performed when lameness is identified particularly if the duration of lameness is unknown. PMID:26811441

  11. Randomised controlled trial of graded exercise in patients with the chronic fatigue syndrome.

    PubMed Central

    Fulcher, K. Y.; White, P. D.

    1997-01-01

    OBJECTIVE: To test the efficacy of a graded aerobic exercise programme in the chronic fatigue syndrome. DESIGN: Randomised controlled trial with control treatment crossover after the first follow up examination. SETTING: Chronic fatigue clinic in a general hospital department of psychiatry. SUBJECTS: 66 patients with the chronic fatigue syndrome who had neither a psychiatric disorder nor appreciable sleep disturbance. INTERVENTIONS: Random allocation to 12 weeks of either graded aerobic exercise or flexibility exercises and relaxation therapy. Patients who completed the flexibility programme were invited to cross over to the exercise programme afterwards. MAIN OUTCOME MEASURE: The self rated clinical global impression change score, "very much better" or "much better" being considered as clinically important. RESULTS: Four patients receiving exercise and three receiving flexibility treatment dropped out before completion. 15 of 29 patients rated themselves as better after completing exercise treatment compared with eight of 30 patients who completed flexibility treatment. Analysis by intention to treat gave similar results (17/33 v 9/33 patients better). Fatigue, functional capacity, and fitness were significantly better after exercise than after flexibility treatment. 12 of 22 patients who crossed over to exercise after flexibility treatment rated themselves as better after completing exercise treatment 32 of 47 patients rated themselves as better three months after completing supervised exercise treatment 35 of 47 patients rated themselves as better one year after completing supervised exercise treatment. CONCLUSION: These findings support the use of appropriately prescribed graded aerobic exercise in the management of patients with the chronic fatigue syndrome. PMID:9180065

  12. Acupuncture for the Treatment of Oculomotor Paralysis: A Pilot Randomised Controlled Trial

    PubMed Central

    Bi, Jia-Qi; Li, Wei; Yang, Qi; Li, Bao-lin; Meng, Qing-Gang; Liu, Yu-fu

    2016-01-01

    This study consisted of a single centre randomised controlled trial with two parallel arms: an acupuncture group (n = 20) with 27 affected eyes and a sham group (n = 20) with 23 affected eyes. Participants in the acupuncture group received acupuncture treatment once daily, three times weekly for four weeks. Participants assigned to the control group received sham acupuncture, the same protocol as that used for the acupuncture group but without insertion of needles into the skin. The primary outcome measure was the cervical range of motion (CROM) score. Secondary outcome measures were the palpebral fissure size, response rate, and adverse events. All 40 participants completed the study. In the comparison of acupuncture and sham acupuncture, a significant difference was observed between acupuncture and sham acupuncture in CROM score (21.37 ± 15.16 and 32.21 ± 19.54, resp.) (P < 0.05) and palpebral fissure size (7.19 ± 2.94 and 5.41 ± 2.45, resp.) (P < 0.05). Response rate was also significantly different in the acupuncture group (P < 0.05). No adverse events were reported in both groups in this study. In summary, it was demonstrated that acupuncture had a feasibility positive effect on oculomotor paralysis. PMID:27313646

  13. Acupuncture for patients with functional dyspepsia: study protocol of a randomised controlled trial

    PubMed Central

    Zheng, Hui; Xu, Jing; Li, Juan; Li, Xiang; Zhao, Ling; Chang, Xiaorong; Liu, Mi; Gong, Biao; Li, Xuezhi; Liang, Fanrong

    2013-01-01

    Introduction Whether acupuncture is efficacious for patients with functional dyspepsia is still controversial. So we designed a randomised controlled trial to settle the problem. Methods and analysis We designed a multicentre, two-arm, sham-controlled clinical trial. 200 participants with functional dyspepsia will be randomly assigned to the true acupuncture (TA) group and sham acupuncture (SA) group in a 1:1 ratio. Participants in the TA group will receive acupuncture at points selected according to syndrome differentiation. Participants in the sham acupuncture group will receive penetrations at sham points. Participants in both groups will receive 20 sessions of electroacupuncture in 4 weeks, five times continuously with a 2 day rest in a week. The primary outcome is the proportion of patients reporting the absence of dyspeptic symptoms at 16 weeks after inclusion. The secondary outcome includes a Short-Form Leeds Dyspepsia Questionnaire, the Chinese version of the 36-Item Short Form Survey, the Chinese version of the Nepean dyspepsia index, etc. Ethics and dissemination The study protocol has been approved by the institutional review boards and ethics committees of the first affiliated hospital of Chengdu University of TCM, the first affiliated hospital of Hunan University of TCM and Chongqing Medical University, respectively (from April to August 2012). The results of this trial will be disseminated in a peer-reviewed journal and presented at international congresses. Trials registration ClinicalTrials.gov NCT01671670. PMID:23901030

  14. β-Blockers in sepsis: protocol for a systematic review and meta-analysis of randomised control trials

    PubMed Central

    Duan, Erick H; Oczkowski, Simon J W; Belley-Cote, Emilie; Whitlock, Richard; Lamontagne, Francois; Devereaux, Phillip J; Cook, Deborah J

    2016-01-01

    Introduction Sepsis is a common and deadly complication of infection. As part of the host response, sympathetic stimulation can result in septic myocardial depression, and metabolic, haematological and immunological dysfunction. Administration of β-blockers may attenuate this pathophysiological response to infection, but the effects on clinical outcomes are unknown. The objective of this systematic review is to determine the efficacy and safety of β-blockers in adults with sepsis using data from randomised control trials. Methods and analysis We will identify randomised control trials comparing treatment with β-blockers, versus placebo or standard care in adults with sepsis. Data sources will include MEDLINE, EMBASE, CENTRAL, clinical trial registries and conference proceedings. Two reviewers will independently determine trial eligibility. For each included trial, we will conduct duplicate independent data extraction, risk of bias assessment and evaluation of the quality of the evidence using the GRADE approach. Ethics and dissemination Our systematic review will evaluate the effects of β-blockers in adults with sepsis, comprehensively summarising and appraising the available evidence from randomised control trials. The results of this systematic review will help clinicians treating patients with sepsis to understand the potential role of β-blockade, and inform future research on this topic. Our findings will be disseminated through conference presentation and publication in a peer-reviewed journal. Trial registration number CRD42016036933. PMID:27338886

  15. Robust control of multi-jointed arm with a decentralized autonomous control mechanism

    NASA Technical Reports Server (NTRS)

    Kimura, Shinichi; Miyazaki, Ken; Suzuki, Yoshiaki

    1994-01-01

    A decentralized autonomous control mechanism applied to the control of three dimensional manipulators and its robustness to partial damage was assessed by computer simulation. Decentralized control structures are believed to be quite robust to time delay between the operator and the target system. A 10-jointed manipulator based on our control mechanism was able to continue its positioning task in three-dimensional space without revision of the control program, even after some of its joints were damaged. These results suggest that this control mechanism can be effectively applied to space telerobots, which are associated with serious time delay between the operator and the target system, and which cannot be easily repaired after being partially damaged.

  16. Theory of planned behaviour variables and objective walking behaviour do not show seasonal variation in a randomised controlled trial

    PubMed Central

    2014-01-01

    Background Longitudinal studies have shown that objectively measured walking behaviour is subject to seasonal variation, with people walking more in summer compared to winter. Seasonality therefore may have the potential to bias the results of randomised controlled trials if there are not adequate statistical or design controls. Despite this there are no studies that assess the impact of seasonality on walking behaviour in a randomised controlled trial, to quantify the extent of such bias. Further there have been no studies assessing how season impacts on the psychological predictors of walking behaviour to date. The aim of the present study was to assess seasonal differences in a) objective walking behaviour and b) Theory of Planned Behaviour (TPB) variables during a randomised controlled trial of an intervention to promote walking. Methods 315 patients were recruited to a two-arm cluster randomised controlled trial of an intervention to promote walking in primary care. A series of repeated measures ANCOVAs were conducted to examine the effect of season on pedometer measures of walking behaviour and TPB measures, assessed immediately post-intervention and six months later. Hierarchical regression analyses were conducted to assess whether season moderated the prediction of intention and behaviour by TPB measures. Results There were no significant differences in time spent walking in spring/summer compared to autumn/winter. There was no significant seasonal variation in most TPB variables, although the belief that there will be good weather was significantly higher in spring/summer (F = 19.46, p < .001). Season did not significantly predict intention or objective walking behaviour, or moderate the effects of TPB variables on intention or behaviour. Conclusion Seasonality does not influence objectively measured walking behaviour or psychological variables during a randomised controlled trial. Consequently physical activity behaviour outcomes in trials will

  17. Antidepressant Controlled Trial For Negative Symptoms In Schizophrenia (ACTIONS): a double-blind, placebo-controlled, randomised clinical trial.

    PubMed Central

    Barnes, Thomas Re; Leeson, Verity C; Paton, Carol; Costelloe, Céire; Simon, Judit; Kiss, Noemi; Osborn, David; Killaspy, Helen; Craig, Tom Kj; Lewis, Shôn; Keown, Patrick; Ismail, Shajahan; Crawford, Mike; Baldwin, David; Lewis, Glyn; Geddes, John; Kumar, Manoj; Pathak, Rudresh; Taylor, Simon

    2016-01-01

    BACKGROUND Negative symptoms of schizophrenia represent deficiencies in emotional responsiveness, motivation, socialisation, speech and movement. When persistent, they are held to account for much of the poor functional outcomes associated with schizophrenia. There are currently no approved pharmacological treatments. While the available evidence suggests that a combination of antipsychotic and antidepressant medication may be effective in treating negative symptoms, it is too limited to allow any firm conclusions. OBJECTIVE To establish the clinical effectiveness and cost-effectiveness of augmentation of antipsychotic medication with the antidepressant citalopram for the management of negative symptoms in schizophrenia. DESIGN A multicentre, double-blind, individually randomised, placebo-controlled trial with 12-month follow-up. SETTING Adult psychiatric services, treating people with schizophrenia. PARTICIPANTS Inpatients or outpatients with schizophrenia, on continuing, stable antipsychotic medication, with persistent negative symptoms at a criterion level of severity. INTERVENTIONS Eligible participants were randomised 1 : 1 to treatment with either placebo (one capsule) or 20 mg of citalopram per day for 48 weeks, with the clinical option at 4 weeks to increase the daily dosage to 40 mg of citalopram or two placebo capsules for the remainder of the study. MAIN OUTCOME MEASURES The primary outcomes were quality of life measured at 12 and 48 weeks assessed using the Heinrich's Quality of Life Scale, and negative symptoms at 12 weeks measured on the negative symptom subscale of the Positive and Negative Syndrome Scale. RESULTS No therapeutic benefit in terms of improvement in quality of life or negative symptoms was detected for citalopram over 12 weeks or at 48 weeks, but secondary analysis suggested modest improvement in the negative symptom domain, avolition/amotivation, at 12 weeks (mean difference -1.3, 95% confidence interval -2.5 to -0.09). There

  18. Comparative efficacy of selective serotonin reuptake inhibitors (SSRI) in treating major depressive disorder: a protocol for network meta-analysis of randomised controlled trials

    PubMed Central

    Jia, Yongliang; Zhu, Hongmei; Leung, Siu-wai

    2016-01-01

    Introduction There have been inconsistent findings from randomised controlled trials (RCTs) and systematic reviews on the efficacies of selective serotonin reuptake inhibitors (SSRIs) as the first-line treatment of major depressive disorder (MDD). Besides inconsistencies among randomised controlled trials (RCTs), their risks of bias and evidence grading have seldom been evaluated in meta-analysis. This study aims to compare the efficacy of SSRIs by conducting a Bayesian network meta-analysis, which will be the most comprehensive evaluation of evidence to resolve the inconsistency among previous studies. Methods and analyses SSRIs including citalopram, escitalopram, fluoxetine, fluvoxamine, paroxetine, sertraline and vilazodone have been selected. Systematic database searching and screening will be conducted for the RCTs on drug treatment of patients with MDD according to pre-specified search strategies and selection criteria. PubMed, the Cochrane Library, EMBASE, ScienceDirect, the US Food and Drug Administration Website, ClinicalTrial.gov and WHO Clinical Trials will be searched. Outcome data including Hamilton Depression Rating Scale (HDRS), Montgomery-Åsberg Depression Rating Scale (MADRS) and Clinical Global Impression (CGI) from eligible RCTs will be extracted. The outcomes will be analysed as ORs and mean differences under a random-effects model. A Bayesian network meta-analysis will be conducted with WinBUGS software, to compare the efficacies of SSRIs. Subgroup and sensitivity analysis will be performed to explain the study heterogeneity and evaluate the robustness of the results. Meta-regression analysis will be conducted to determine the possible factors affecting the efficacy outcomes. The Cochrane risk of bias assessment tool will be used to assess the RCT quality, and the Grading of Recommendation, Assessment, Development and Evaluation will be used to assess the strength of evidence from the meta-analysis. Ethics and dissemination No ethical approval

  19. A systematic review and meta-analysis of randomised controlled trials of treatments for clozapine-induced obesity and metabolic syndrome.

    PubMed

    Zimbron, Jorge; Khandaker, Golam M; Toschi, Chiara; Jones, Peter B; Fernandez-Egea, Emilio

    2016-09-01

    Metabolic complications are commonly found in people treated with clozapine. Reviews on the management of this problem have generally drawn conclusions by grouping different types of studies involving patients treated with various different antipsychotics. We carried out a systematic review and meta-analysis of pharmacological and non-pharmacological treatments for clozapine-induced obesity or metabolic syndrome. Two researchers independently searched PubMed and Embase for randomised controlled trials (RCTs) of treatments for clozapine-induced obesity or metabolic syndrome. All other types of studies were excluded. We only included RCTs where more than 50% of participants were taking clozapine. We identified 15 RCTs. Effective pharmacological treatments for clozapine-induced obesity and metabolic syndrome include metformin, aripiprazole, and Orlistat (in men only). Meta-analysis of three studies showed a robust effect of metformin in reducing body mass index and waist circumference but no effects on blood glucose, triglyceride levels, or HDL levels. In addition, there is limited evidence for combined calorie restriction and exercise as a non-pharmacological alternative for the treatment of clozapine-induced obesity, but only in an in-patient setting. Rosiglitazone, topiramate, sibutramine, phenylpropanolamine, modafinil, and atomoxetine have not shown to be beneficial, despite reports of efficacy in other populations treated with different antipsychotics. We conclude that randomised-controlled trial data support the use of metformin, aripiprazole, and Orlistat (in men only) for treating clozapine-induced obesity. Calorie restriction in combination with an exercise programme may be effective as a non-pharmacological alternative. Findings from trials in different populations should not be extrapolated to people being treated with clozapine. PMID:27496573

  20. A randomised control study of a fully automated internet based smoking cessation programme

    PubMed Central

    Swartz, L H G; Noell, J W; Schroeder, S W; Ary, D V

    2006-01-01

    Objective The objective of this project was to test the short term (90 days) efficacy of an automated behavioural intervention for smoking cessation, the “1‐2‐3 Smokefree” programme, delivered via an internet website. Design Randomised control trial. Subjects surveyed at baseline, immediately post‐intervention, and 90 days later. Settings The study and the intervention occurred entirely via the internet site. Subjects were recruited primarily via worksites, which referred potential subjects to the website. Subjects The 351 qualifying subjects were notified of the study via their worksite and required to have internet access. Additionally, subjects were required to be over 18 years of age, smoke cigarettes, and be interested in quitting smoking in the next 30 days. Eligible subjects were randomly assigned individually to treatment or control condition by computer algorithm. Intervention The intervention consisted of a video based internet site that presented current strategies for smoking cessation and motivational materials tailored to the user's race/ethnicity, sex, and age. Control subjects received nothing for 90 days and were then allowed access to the programme. Main outcome measures The primary outcome measure was abstinence from smoking at 90 day follow up. Results At follow up, the cessation rate at 90 days was 24.1% (n  =  21) for the treatment group and 8.2% (n  =  9) for the control group (p  =  0.002). Using an intent‐to‐treat model, 12.3% (n  =  21) of the treatment group were abstinent, compared to 5.0% (n  =  9) in the control group (p  =  0.015). Conclusions These evaluation results suggest that a smoking cessation programme, with at least short term efficacy, can be successfully delivered via the internet. PMID:16436397

  1. A novel school-based intervention to improve nutrition knowledge in children: cluster randomised controlled trial

    PubMed Central

    2010-01-01

    Background Improving nutrition knowledge among children may help them to make healthier food choices. The aim of this study was to assess the effectiveness and acceptability of a novel educational intervention to increase nutrition knowledge among primary school children. Methods We developed a card game 'Top Grub' and a 'healthy eating' curriculum for use in primary schools. Thirty-eight state primary schools comprising 2519 children in years 5 and 6 (aged 9-11 years) were recruited in a pragmatic cluster randomised controlled trial. The main outcome measures were change in nutrition knowledge scores, attitudes to healthy eating and acceptability of the intervention by children and teachers. Results Twelve intervention and 13 control schools (comprising 1133 children) completed the trial. The main reason for non-completion was time pressure of the school curriculum. Mean total nutrition knowledge score increased by 1.1 in intervention (baseline to follow-up: 28.3 to 29.2) and 0.3 in control schools (27.3 to 27.6). Total nutrition knowledge score at follow-up, adjusted for baseline score, deprivation, and school size, was higher in intervention than in control schools (mean difference = 1.1; 95% CI: 0.05 to 2.16; p = 0.042). At follow-up, more children in the intervention schools said they 'are currently eating a healthy diet' (39.6%) or 'would try to eat a healthy diet' (35.7%) than in control schools (34.4% and 31.7% respectively; chi-square test p < 0.001). Most children (75.5%) enjoyed playing the game and teachers considered it a useful resource. Conclusions The 'Top Grub' card game facilitated the enjoyable delivery of nutrition education in a sample of UK primary school age children. Further studies should determine whether improvements in nutrition knowledge are sustained and lead to changes in dietary behaviour. PMID:20219104

  2. Massage or music for pain relief in labour: a pilot randomised placebo controlled trial.

    PubMed

    Kimber, L; McNabb, M; Mc Court, C; Haines, A; Brocklehurst, P

    2008-11-01

    Research on massage therapy for maternal pain and anxiety in labour is currently limited to four small trials. Each used different massage techniques, at different frequencies and durations, and relaxation techniques were included in three trials. Given the need to investigate massage interventions that complement maternal neurophysiological adaptations to labour and birth pain(s), we designed a pilot randomised controlled trial (RCT) to test the effects of a massage programme practised during physiological changes in pain threshold, from late pregnancy to birth, on women's reported pain, measured by a visual analogue scale (VAS) at 90 min following birth. To control for the potential bias of the possible effects of support offered within preparation for the intervention group, the study included 3 arms--intervention (massage programme with relaxation techniques), placebo (music with relaxation techniques) and control (usual care). The placebo offered a non-pharmacological coping strategy, to ensure that use of massage was the only difference between intervention and placebo groups. There was a trend towards slightly lower mean pain scores in the intervention group but these differences were not statistically significant. No differences were found in use of pharmacological analgesia, need for augmentation or mode of delivery. There was a trend towards more positive views of labour preparedness and sense of control in the intervention and placebo groups, compared with the control group. These findings suggest that regular massage with relaxation techniques from late pregnancy to birth is an acceptable coping strategy that merits a large trial with sufficient power to detect differences in reported pain as a primary outcome measure. PMID:18304848

  3. Cognitive behavioural therapy for medically unexplained physical symptoms: a randomised controlled trial.

    PubMed Central

    Speckens, A. E.; van Hemert, A. M.; Spinhoven, P.; Hawton, K. E.; Bolk, J. H.; Rooijmans, H. G.

    1995-01-01

    OBJECTIVE--To examine the additional effect of cognitive behavioural therapy for patients with medically unexplained physical symptoms in comparison with optimised medical care. DESIGN--Randomised controlled trial with follow up assessments six and 12 months after the baseline evaluation. SETTING--General medical outpatient clinic in a university hospital. SUBJECTS--An intervention group of 39 patients and a control group of 40 patients. INTERVENTIONS--The intervention group received between six and 16 sessions of cognitive behavioural therapy. Therapeutic techniques used included identification and modification of dysfunctional automatic thoughts and behavioural experiments aimed at breaking the vicious cycles of the symptoms and their consequences. The control group received optimised medical care. MAIN OUTCOME MEASURES--The degree of change, frequency and intensity of the presenting symptoms, psychological distress, functional impairment, hypochondriacal beliefs and attitudes, and (at 12 months of follow up) number of visits to the general practitioner. RESULTS--At six months of follow up the intervention group reported a higher recovery rate (odds ratio 0.40; 95% confidence interval 0.16 to 1.00), a lower mean intensity of the physical symptoms (difference -1.2; -2.0 to -0.3), and less impairment of sleep (odds ratio 0.38; 0.15 to 0.94) than the controls. After adjustment for coincidental baseline differences the intervention and control groups also differed with regard to frequency of the symptoms (0.32; 0.13 to 0.77), limitations in social (0.35; 0.14 to 0.85) and leisure (0.36; 0.14 to 0.93) activities, and illness behaviour (difference -2.5; -4.6 to -0.5). At 12 months of follow up the differences between the groups were largely maintained. CONCLUSION--Cognitive behavioural therapy seems to be a feasible and effective treatment in general medical patients with unexplained physical symptoms. PMID:7496281

  4. Impact on learning of an e-learning module on leukaemia: a randomised controlled trial

    PubMed Central

    2012-01-01

    Background e-learning resources may be beneficial for complex or conceptually difficult topics. Leukaemia is one such topic, yet there are no reports on the efficacy of e-learning for leukaemia. This study compared the learning impact on senior medical students of a purpose-built e-learning module on leukaemia, compared with existing online resources. Methods A randomised controlled trial was performed utilising volunteer senior medical students. Participants were randomly allocated to Study and Control groups. Following a pre-test on leukaemia administered to both groups, the Study group was provided with access to the new e-learning module, while the Control group was directed to existing online resources. A post-test and an evaluation questionnaire were administered to both groups at the end of the trial period. Results Study and Control groups were equivalent in gender distribution, mean academic ability, pre-test performance and time studying leukaemia during the trial. The Study group performed significantly better than the Control group in the post-test, in which the group to which the students had been allocated was the only significant predictor of performance. The Study group’s evaluation of the module was overwhelmingly positive. Conclusions A targeted e-learning module on leukaemia had a significant effect on learning in this cohort, compared with existing online resources. We believe that the interactivity, dialogic feedback and integration with the curriculum offered by the e-learning module contributed to its impact. This has implications for e-learning design in medicine and other disciplines. PMID:22640463

  5. Specialist nurse support for patients with stroke in the community: a randomised controlled trial.

    PubMed Central

    Forster, A.; Young, J.

    1996-01-01

    OBJECTIVE--To evaluate whether specialist nurse visits enhance the social integration and perceived health of patients with stroke or alleviate stress in carers in longer term stroke care. DESIGN--Stratified randomised controlled trial; both groups assessed at time of recruitment and at 3, 6, and 12 months. SETTING--Patients with disability related to new stroke who lived in their own homes in the Bradford Metropolitan District. SUBJECTS--240 patients aged 60 years or over, randomly allocated to control group (n = 120) or intervention group (n = 120). Intervention--Visits by specialist outreach nurses over 12 months to provide information, advice, and support; minimum of six visits during the first six months. The control group received no visits. MAIN OUTCOME MEASURES--The Barthel index (functional ability), the Frenchay activities index (social activity), the Nottingham health profile (perceived health status). Stress among carers was indicated by the general health questionnaire-28 (28 items). The nurses recorded their interventions in trial diaries. RESULTS--There were no significant differences in perceived health, social activities, or stress among carers between the treatment and control groups at any of the assessments points. A subgroup of mildly disabled patients with stroke (Barthel index 15-19) had an improved social outcome at six months (Frenchay activities index, Median difference 3 (95% confidence interval 0 to 6; P = 0.03) and for the full 12 months of follow up (analysis of covariance P = 0.01) compared with the control group. CONCLUSIONS--The specialist nurse intervention resulted in a small improvement in social activities only for the mildly disabled patients. No proved strategy yet exists that can be recommended to address the psychosocial difficulties of patients with stroke and their families. PMID:8664717

  6. A pilot randomised controlled trial of negative pressure wound therapy to treat grade III/IV pressure ulcers [ISRCTN69032034

    PubMed Central

    2012-01-01

    Background Negative pressure wound therapy (NPWT) is widely promoted as a treatment for full thickness wounds; however, there is a lack of high-quality research evidence regarding its clinical and cost effectiveness. A trial of NPWT for the treatment of grade III/IV pressure ulcers would be worthwhile but premature without assessing whether such a trial is feasible. The aim of this pilot randomised controlled trial was to assess the feasibility of conducting a future full trial of NPWT for the treatment of grade III and IV pressure ulcers and to pilot all aspects of the trial. Methods This was a two-centre (acute and community), pilot randomised controlled trial. Eligible participants were randomised to receive either NPWT or standard care (SC) (spun hydrocolloid, alginate or foam dressings). Outcome measures were time to healing of the reference pressure ulcer, recruitment rates, frequency of treatment visits, resources used and duration of follow-up. Results Three hundred and twelve patients were screened for eligibility into this trial over a 12-month recruitment period and 12/312 participants (3.8%) were randomised: 6 to NPWT and 6 to SC. Only one reference pressure ulcer healed (NPWT group) during follow-up (time to healing 79 days). The mean number of treatment visits per week was 3.1 (NPWT) and 5.7 (SC); 6/6 NPWT and 1/6 SC participants withdrew from their allocated trial treatment. The mean duration of follow-up was 3.8 (NPWT) and 5.0 (SC) months. Conclusions This pilot trial yielded vital information for the planning of a future full study including projected recruitment rate, required duration of follow-up and extent of research nurse support required. Data were also used to inform the cost-effectiveness and value of information analyses, which were conducted alongside the pilot trial. Trial registration Current Controlled Trials ISRCTN69032034. PMID:22839453

  7. Robustness and Actuator Bandwidth of MRP-Based Sliding Mode Control for Spacecraft Attitude Control Problems

    NASA Astrophysics Data System (ADS)

    Keum, Jung-Hoon; Ra, Sung-Woong

    2009-12-01

    Nonlinear sliding surface design in variable structure systems for spacecraft attitude control problems is studied. A robustness analysis is performed for regular form of system, and calculation of actuator bandwidth is presented by reviewing sliding surface dynamics. To achieve non-singular attitude description and minimal parameterization, spacecraft attitude control problems are considered based on modified Rodrigues parameters (MRP). It is shown that the derived controller ensures the sliding motion in pre-determined region irrespective of unmodeled effects and disturbances.

  8. Control design for robust stability in linear regulators: Application to aerospace flight control

    NASA Technical Reports Server (NTRS)

    Yedavalli, R. K.

    1986-01-01

    Time domain stability robustness analysis and design for linear multivariable uncertain systems with bounded uncertainties is the central theme of the research. After reviewing the recently developed upper bounds on the linear elemental (structured), time varying perturbation of an asymptotically stable linear time invariant regulator, it is shown that it is possible to further improve these bounds by employing state transformations. Then introducing a quantitative measure called the stability robustness index, a state feedback conrol design algorithm is presented for a general linear regulator problem and then specialized to the case of modal systems as well as matched systems. The extension of the algorithm to stochastic systems with Kalman filter as the state estimator is presented. Finally an algorithm for robust dynamic compensator design is presented using Parameter Optimization (PO) procedure. Applications in a aircraft control and flexible structure control are presented along with a comparison with other existing methods.

  9. Do parents recall and understand children's weight status information after BMI screening? A randomised controlled trial

    PubMed Central

    Dawson, Anna M; Taylor, Rachael W; Williams, Sheila M; Taylor, Barry J; Brown, Deirdre A

    2014-01-01

    Objectives As parents of young children are often unaware their child is overweight, screening provides the opportunity to inform parents and provide the impetus for behaviour change. We aimed to determine if parents could recall and understand the information they received about their overweight child after weight screening. Design Randomised controlled trial of different methods of feedback. Setting Participants were recruited through primary and secondary care but appointments took place at a University research clinic. Participants and intervention 1093 children aged 4–8 years were screened. Only overweight children (n=271, 24.7%) are included in this study. Parents of overweight children were randomised to receive feedback regarding their child's weight using best practice care (BPC) or motivational interviewing (MI) at face-to-face interviews typically lasting 20–40 min. 244 (90%) parents participated in a follow-up interview 2 weeks later to assess recall and understanding of information from the feedback session. Primary and secondary outcome measures Interviews were audio-taped and transcribed verbatim before coding for amount and accuracy of recall. Scores were calculated for total recall and sub-categories of interest. Results Overall, 39% of the information was recalled (mean score 6.3 from possible score of 16). Parents given feedback via BPC recalled more than those in the MI group (difference in total score 0.48; 95% CI 0.05 to 0.92). Although 94% of parents were able to correctly recall their child's weight status, fewer than 10 parents could accurately describe what the measurements meant. Maternal education (0.81; 0.25 to 1.37) and parental ratings of how useful they found the information (0.19; 0.04 to 0.35) were significant predictors of recall score in multivariate analyses. Conclusions While parents remember that their child's body mass index is higher than recommended, they are unable to remember much of the information and advice

  10. The Cool Little Kids randomised controlled trial: Population-level early prevention for anxiety disorders

    PubMed Central

    2011-01-01

    Background The World Health Organization predicts that by 2030 internalising problems (e.g. depression and anxiety) will be second only to HIV/AIDS in international burden of disease. Internalising problems affect 1 in 7 school aged children, impacting on peer relations, school engagement, and later mental health, relationships and employment. The development of early childhood prevention for internalising problems is in its infancy. The current study follows two successful 'efficacy' trials of a parenting group intervention to reduce internalising disorders in temperamentally inhibited preschool children. Cool Little Kids is a population-level randomised trial to determine the impacts of systematically screening preschoolers for inhibition then offering a parenting group intervention, on child internalising problems and economic costs at school entry. Methods/Design This randomised trial will be conducted within the preschool service system, attended by more than 95% of Australian children in the year before starting school. In early 2011, preschool services in four local government areas in Melbourne, Australia, will distribute the screening tool. The ≈16% (n≈500) with temperamental inhibition will enter the trial. Intervention parents will be offered Cool Little Kids, a 6-session group program in the local community, focusing on ways to develop their child's bravery skills by reducing overprotective parenting interactions. Outcomes one and two years post-baseline will comprise child internalising diagnoses and symptoms, parenting interactions, and parent wellbeing. An economic evaluation (cost-consequences framework) will compare incremental differences in costs of the intervention versus control children to incremental differences in outcomes, from a societal perspective. Analyses will use the intention-to-treat principle, using logistic and linear regression models (binary and continuous outcomes respectively) to compare outcomes between the trial arms

  11. Evaluation of Lay Support in Pregnant women with Social risk (ELSIPS): a randomised controlled trial

    PubMed Central

    2012-01-01

    Background Maternal, neonatal and child health outcomes are worse in families from black and ethnic minority groups and disadvantaged backgrounds. There is little evidence on whether lay support improves maternal and infant outcomes among women with complex social needs within a disadvantaged multi-ethnic population in the United Kingdom (UK). Method/Design The aim of this study is to evaluate a lay Pregnancy Outreach Worker (POW) service for nulliparous women identified as having social risk within a maternity service that is systematically assessing social risks alongside the usual obstetric and medical risks. The study design is a randomised controlled trial (RCT) in nulliparous women assessed as having social risk comparing standard maternity care with the addition of referral to the POW support service. The POWs work alongside community midwifery teams and offer individualised support to women to encourage engagement with services (health and social care) from randomisation (before 28 weeks gestation) until 6 weeks after birth. The primary outcomes have been chosen on the basis that they are linked to maternal and infant health. The two primary outcomes are engagement with antenatal care, assessed by the number of antenatal visits; and maternal depression, assessed using the Edinburgh Postnatal Depression Scale at 8-12 weeks after birth. Secondary outcomes include maternal and neonatal morbidity and mortality, routine child health assessments, including immunisation uptake and breastfeeding at 6 weeks. Other psychological outcomes (self efficacy) and mother-to-infant bonding will also be collected using validated tools. A sample size of 1316 will provide 90% power (at the 5% significance level) to detect increased engagement with antenatal services of 1.5 visits and a reduction of 1.5 in the average EPDS score for women with two or more social risk factors, with power in excess of this for women with any social risk factor. Analysis will be by intention to

  12. Early intervention for adolescents with Patellofemoral Pain Syndrome - a pragmatic cluster randomised controlled trial

    PubMed Central

    2012-01-01

    Background Self-reported knee pain is highly prevalent among adolescents. As much as 50% of the non-specific knee pain may be attributed to Patellofemoral Pain Syndrome (PFPS). In the short term, exercise therapy appears to have a better effect than patient education consisting of written information and general advice on exercise or compared with placebo treatment. But the long-term effect of exercise therapy compared with patient education is conflicting. The purpose of this study is to examine the short- and long-term effectiveness of patient education compared with patient education and multimodal physiotherapy applied at a very early stage of the condition among adolescents. Methods/Design This study is a single blind pragmatic cluster randomised controlled trial. Four upper secondary schools have been invited to participate in the study (approximately 2500 students, aged 15-19 years). Students are asked to answer an online questionnaire regarding musculoskeletal pain. The students who report knee pain are contacted by telephone and offered a clinical examination by a rheumatologist. Subjects who fit the inclusion criteria and are diagnosed with PFPS are invited to participate in the study. A minimum of 102 students with PFPS are then cluster-randomised into two intervention groups based on which school they attend. Both intervention groups receive written information and education. In addition to patient education, one group receives multimodal physiotherapy consisting primarily of neuromuscular training of the muscles around the foot, knee and hip and home exercises. The students with PFPS fill out self-reported questionnaires at baseline, 3, 6, 12 and 24 months after inclusion in the study. The primary outcome measure is perception of recovery measured on a 7-point Likert scale ranging from "completely recovered" to "worse than ever" at 12 months. Discussion This study is designed to investigate the effectiveness of patient education compared with patient

  13. Tactile acuity training for patients with chronic low back pain: a pilot randomised controlled trial

    PubMed Central

    2014-01-01

    Background Chronic pain can disrupt the cortical representation of a painful body part. This disruption may play a role in maintaining the individual’s pain. Tactile acuity training has been used to normalise cortical representation and reduce pain in certain pain conditions. However, there is little evidence for the effectiveness of this intervention for chronic low back pain (CLBP). The primary aim of this study was to inform the development of a fully powered randomised controlled trial (RCT) by providing preliminary data on the effect of tactile acuity training on pain and function in individuals with CLBP. The secondary aim was to obtain qualitative feedback about the intervention. Methods In this mixed-methods pilot RCT 15 individuals were randomised to either an intervention (tactile acuity training) or a placebo group (sham tactile acuity training). All participants received 3 sessions of acuity training (intervention or sham) from a physiotherapist and were requested to undertake daily acuity home training facilitated by an informal carer (friend/relative). All participants also received usual care physiotherapy. The primary outcome measures were pain (0-100visual analogue scale (VAS)) and function (Roland Morris Disability Questionnaire (RMDQ)). Participants and their informal carers were invited to a focus group to provide feedback on the intervention. Results The placebo group improved by the greatest magnitude for both outcome measures, but there was no statistically significant difference (Mean difference (95%CI), p-value) between groups for change in pain (25.6 (-0.7 to 51.9), p = 0.056) or function (2.2 (-1.6 to 6.0), p = 0.237). Comparing the number of individuals achieving a minimally clinically significant improvement, the placebo group had better outcomes for pain with all participants achieving ≥30% improvement compared to only a third of the intervention group (6/6 vs. 3/9, p = 0.036). Qualitatively, participants reported that

  14. Effect of peer led programme for asthma education in adolescents: cluster randomised controlled trial

    PubMed Central

    Shah, Smita; Peat, Jennifer K; Mazurski, Evalynn J; Wang, Han; Sindhusake, Doungkamol; Bruce, Colleen; Henry, Richard L; Gibson, Peter G

    2001-01-01

    Objective To determine the effect of a peer led programme for asthma education on quality of life and related morbidity in adolescents with asthma. Design Cluster randomised controlled trial. Setting Six high schools in rural Australia. Participants 272 students with recent wheeze, recruited from a cohort of 1515 students from two school years (mean age 12.5 and 15.5 years); 251 (92.3%) completed the study. Intervention A structured education programme for peers comprising three steps (the “Triple A Program”). Main outcome measures Quality of life, school absenteeism, asthma attacks, and lung function. Results When adjusted for year and sex, mean total quality of life scores showed significant improvement in the intervention than control group. Clinically important improvement in quality of life (>0.5 units) occurred in 25% of students with asthma in the intervention group compared with 12% in the control group (P=0.01). The number needed to treat was 8 (95% confidence interval 4.5 to 35.7). The effect of the intervention was greatest in students in year 10 and in females. Significant improvements occurred in the activities domain (41% v 28%) and in the emotions domain (39% v 19%) in males in the intervention group. School absenteeism significantly decreased in the intervention group only. Asthma attacks at school increased in the control group only. Conclusion The triple A programme leads to a clinically relevant improvement in quality of life and related morbidity in students with asthma. Wider dissemination of this programme in schools could play an important part in reducing the burden of asthma in adolescents. PMID:11238152

  15. Design of a randomised acupuncture trial on functional neck/shoulder stiffness with two placebo controls

    PubMed Central

    2014-01-01

    Background Functional neck/shoulder stiffness is one of the most well-known indications for acupuncture treatment in Japan. There is little evidence for the effectiveness of acupuncture treatment for functional neck/shoulder stiffness. Research using two different placebos may allow an efficient method to tease apart the components of real acupuncture from various kinds of ‘non-specific’ effects such as ritual with touch or ritual alone. Herein, we describe a protocol of an ongoing, single-centre, randomised, placebo-controlled trial which aims to assess whether, in functional neck/shoulder stiffness, acupuncture treatment with skin piercing has a specific effect over two types of placebo: skin-touching plus ritual or ritual alone. Methods Six acupuncturists and 400 patients with functional neck/shoulder stiffness are randomly assigned to four treatment groups: genuine acupuncture penetrating the skin, skin-touch placebo or no-touch placebo needles in a double-blind manner (practitioner-patient blinding) or no-treatment control group. Each acupuncturist applies a needle to each of four acupoints (Bladder10, Small Intestine14, Gallbladder21 and Bladder42) in the neck/shoulder to 50 patients. Before, immediately after and 24 hours after the treatment, patients are asked about the intensity of their neck/shoulder stiffness. After the treatment, practitioners and patients are asked to guess whether the treatment is “penetrating”, “skin-touch” or “no-touch” or to record “cannot identify the treatment”. Discussion In addition to intention-to-treat analysis, we will conduct subgroup analysis based on practitioners’ or patients’ guesses to discuss the efficacy and effectiveness of treatments with skin piercing and various placebo controls. The results of practitioner and patient blinding will be discussed. We believe this study will further distinguish the role of different components of acupuncture. Trial registration Current Controlled Trial

  16. Successful GP intervention with frequent attenders in primary care: randomised controlled trial

    PubMed Central

    Bellón, Juan Ángel; Rodríguez-Bayón, Antonina; de Dios Luna, Juan; Torres-González, Francisco

    2008-01-01

    Background Frequent attenders to GP clinics can place an unnecessary burden on primary care. Interventions to reduce frequent attendance have had mixed results. Aim To assess the effectiveness of a GP intervention to reduce frequent-attender consultations. Design of study Randomised controlled trial with frequent attenders divided into an intervention group and two control groups (one control group was seen by GPs also providing care to patients undergoing the intervention). Setting A health centre in southern Spain. Method Six GPs and 209 randomly-selected frequent attenders participated. Three GPs were randomly allocated to perform the new intervention: of the 137 frequent attenders registered with these three GPs, 66 were randomly allocated to receive the intervention (IG) and 71 to a usual care control group (CG2). The other three GPs offered usual care to the other 72 frequent attenders (CG1). The main outcome measure was the total number of consultations 1 year post-intervention. Baseline measurements were recorded of sociodemographic characteristics, provider–user interface, chronic illnesses, and psychosocial variables. GPs allocated to the new intervention received 15 hours' training which incorporated biopsychosocial, organisational, and relational approaches. After 1 year of follow-up frequent attenders were contacted. An intention-to-treat analysis was used. Results A multilevel model was built with three factors: time, patient, and doctor. After adjusting for covariates, the mean number of visits at 1 year in IG was 13.10 (95% confidence interval [CI] = 11.39 to 14.94); in the CG1 group was 19.37 (95% CI = 17.31 to 21.55); and in the CG2 group this was 16.72 (95% CI =14.84 to 18.72). Conclusion The new intervention with GPs resulted in a significant and relevant reduction in frequent-attender consultations. Although further trials are needed, this intervention is recommended to GPs interested in reducing consultations by their frequent attenders

  17. Efficacy and safety of the Chaihuguizhiganjiang-suanzaoren granule on primary insomnia: study protocol for a randomised controlled trial

    PubMed Central

    Liu, Qing-Quan; Zhang, Jie; Guo, Rong-Juan; Xie, Ying-Zhen; Fu, Qing-Nan; He, Tian; Zhu, Xue-Qi; Du, Jie; Yang, Jing; Wang, Jia-Lin; Wei, Min-Min; Li, Qian-Qian; Shi, Guang-Xia; Liu, Cun-Zhi

    2016-01-01

    Introduction Insomnia is a highly prevalent, often debilitating and economically burdensome sleep disorder with limited effective therapies. Few data are available to understand which of the therapeutic alternatives is the most effective for patients with insomnia, especially for Traditional Chinese Medicine (TCM). Chinese herbal medicine, as a typical TCM, is one of the most popular complementary and alternative therapies for insomnia. We aim to evaluate the efficacy and safety of the Chaihuguizhiganjiang-suanzaoren granule (CSG), a Chinese herbal medicine treatment, in patients with primary insomnia. Methods and analysis This is a multicentre, placebo-controlled, double-blinded, randomised controlled clinical trial. A total of 258 participants are randomly allocated to two groups: the intervention group or the placebo group. The intervention group receives CSG and the placebo group receives a placebo granule. The patients receive either CSG or placebo two times daily for 8 weeks. The primary outcome is the Pittsburgh sleep quality index (PSQI). Secondary outcomes include the Insomnia Severity Index (ISI), Total Sleep Time (TST) and the Short-Form Health Survey (SF-36). The assessment is performed at baseline (before randomisation), 4, 8 and 12 weeks after randomisation. Ethics and dissemination The protocol has been approved by the Research Ethical Committee of Beijing Hospital of Traditional Chinese Medicine Affiliated to Capital Medical University (reference: 2014BL-003-01). The trial will be helpful in identifying the efficacy and safety of CSG in patients with primary insomnia. Trial registration number ISRCTN22001145; Pre-results. PMID:26839010

  18. A multifaceted workplace intervention for low back pain in nurses' aides: a pragmatic stepped wedge cluster randomised controlled trial.

    PubMed

    Rasmussen, Charlotte Diana Nørregaard; Holtermann, Andreas; Bay, Hans; Søgaard, Karen; Birk Jørgensen, Marie

    2015-09-01

    This study established the effectiveness of a workplace multifaceted intervention consisting of participatory ergonomics, physical training, and cognitive-behavioural training (CBT) for low back pain (LBP). Between November 2012 and May 2014, we conducted a pragmatic stepped wedge cluster randomised controlled trial with 594 workers from eldercare workplaces (nursing homes and home care) randomised to 4 successive time periods, 3 months apart. The intervention lasted 12 weeks and consisted of 19 sessions in total (physical training [12 sessions], CBT [2 sessions], and participatory ergonomics [5 sessions]). Low back pain was the outcome and was measured as days, intensity (worst pain on a 0-10 numeric rank scale), and bothersomeness (days) by monthly text messages. Linear mixed models were used to estimate the intervention effect. Analyses were performed according to intention to treat, including all eligible randomised participants, and were adjusted for baseline values of the outcome. The linear mixed models yielded significant effects on LBP days of -0.8 (95% confidence interval [CI], -1.19 to -0.38), LBP intensity of -0.4 (95% CI, -0.60 to -0.26), and bothersomeness days of -0.5 (95% CI, -0.85 to -0.13) after the intervention compared with the control group. This study shows that a multifaceted intervention consisting of participatory ergonomics, physical training, and CBT can reduce LBP among workers in eldercare. Thus, multifaceted interventions may be relevant for improving LBP in a working population. PMID:25993549

  19. Robust Control of Uncertain Systems via Dissipative LQG-Type Controllers

    NASA Technical Reports Server (NTRS)

    Joshi, Suresh M.

    2000-01-01

    Optimal controller design is addressed for a class of linear, time-invariant systems which are dissipative with respect to a quadratic power function. The system matrices are assumed to be affine functions of uncertain parameters confined to a convex polytopic region in the parameter space. For such systems, a method is developed for designing a controller which is dissipative with respect to a given power function, and is simultaneously optimal in the linear-quadratic-Gaussian (LQG) sense. The resulting controller provides robust stability as well as optimal performance. Three important special cases, namely, passive, norm-bounded, and sector-bounded controllers, which are also LQG-optimal, are presented. The results give new methods for robust controller design in the presence of parametric uncertainties.

  20. Antioxidant supplementation for the prevention of kwashiorkor in Malawian children: randomised, double blind, placebo controlled trial

    PubMed Central

    Ciliberto, Heather; Ciliberto, Michael; Briend, Andreé; Ashorn, Per; Bier, Dennis; Manary, Mark

    2005-01-01

    Objective To evaluate the efficacy of antioxidant supplementation in preventing kwashiorkor in a population of Malawian children at high risk of developing kwashiorkor. Design Prospective, double blind, placebo controlled trial randomised by household. Setting 8 villages in rural southern Malawi. Participants 2372 children in 2156 households aged 1-4 years were enrolled; 2332 completed the trial. Intervention Daily supplementation with an antioxidant powder containing riboflavin, vitamin E, selenium, and N-acetylcysteine in a dose that provided about three times the recommended dietary allowance of each nutrient or placebo for 20 weeks. Main outcome measures The primary outcome was the incidence of oedema. Secondary outcomes were the rates of change for weight and length and the number of days of infectious symptoms. Results 62 children developed kwashiorkor (defined by the presence of oedema); 39/1184 (3.3%) were in the antioxidant group and 23/1188 (1.9%) were in the placebo group (relative risk 1.70, 95% confidence interval 0.98 to 2.42). The two groups did not differ in rates of weight or height gain. Children who received antioxidant supplementation did not experience less fever, cough, or diarrhoea. Conclusions Antioxidant supplementation at the dose provided did not prevent the onset of kwashiorkor. This finding does not support the hypothesis that depletion of vitamin E, selenium, cysteine, or riboflavin has a role in the development of kwashiorkor. PMID:15851401

  1. Efficacy of metacognitive therapy for prolonged grief disorder: protocol for a randomised controlled trial

    PubMed Central

    Wenn, Jenine; O'Connor, Moira; Breen, Lauren J; Kane, Robert T; Rees, Clare S

    2015-01-01

    Introduction Studies of effective psychotherapy for individuals suffering from the effects of prolonged grief disorder (PGD) are scarce. This paper describes the protocol for an evaluation of a metacognitive therapy programme designed specifically for PGD, to reduce the psychological distress and loss of functioning resulting from bereavement. Methods and analysis The proposed trial comprises three phases. Phase 1 consists of a review of the literature and semistructured interviews with key members of the target population to inform the development of a metacognitive therapy programme for Prolonged Grief. Phase 2 involves a randomised controlled trial to implement and evaluate the programme. Male and female adults (N=34) will be randomly assigned to either a wait list or an intervention group. Measures of PGD, anxiety, depression, rumination, metacognitions and quality of life will be taken pretreatment and posttreatment and at the 3-month and 6-month follow-up. The generalised linear mixed model will be used to assess treatment efficacy. Phase 3 will test the social validity of the programme. Discussion This study is the first empirical investigation of the efficacy of a targeted metacognitive treatment programme for PGD. A focus on identifying and changing the metacognitive mechanisms underpinning the development and maintenance of prolonged grief is likely to be beneficial to theory and practice. Ethics Ethics approval was obtained from Curtin University Human Research Ethics Committee (Approval number HR 41/2013.) Trial registration number ACTRN12613001270707. PMID:26646828

  2. Proton pump inhibition prevents gastrointestinal bleeding in ultramarathon runners: a randomised, double blinded, placebo controlled study

    PubMed Central

    Thalmann, M; Sodeck, G H; Kavouras, S; Matalas, A; Skenderi, K; Yannikouris, N; Domanovits, H

    2006-01-01

    Background Ultra‐endurance running is emerging as a popular sport in Western industrialised countries. Gastrointestinal bleeding has been reported to be an adverse effect in these runners. Objective To see if the oral administration of a proton pump inhibitor would reduce the incidence of gastrointestinal bleeding in an ultramarathon. Methods In a randomised, double blinded, placebo controlled study, a prophylactic regimen of three days of an oral proton pump inhibitor (pantoprazole 20 mg) was tested in healthy athletes participating in the Spartathlon ultramarathon. The incidence of gastrointestinal bleeding was assessed by a stool guaiac test. Results Results were obtained for 70 healthy volunteers. The data for 20 of 35 runners in the intervention group and 17 of 35 runners in the placebo group were entered into the final analysis. At the end of the ultramarathon, two subjects in the intervention group and 12 in the placebo group had positive stool guaiac tests (risk difference 0.86; 95% confidence interval 0.45 to 0.96; p  =  0.001). Conclusion A short prophylactic regimen of oral proton pump inhibition can successfully decrease the incidence of gastrointestinal bleeding in participants in an ultramarathon. PMID:16556794

  3. Randomised controlled trial of eutectic mixture of local anaesthetics cream for venepuncture in healthy preterm infants

    PubMed Central

    Acharya, A; Bustani, P; Phillips, J; Taub, N; Beattie, R

    1998-01-01

    AIM—To assess the safety and efficacy of EMLA cream (eutectic mixture of local anaesthetics) used to induce surface anaesthesia for venepuncture in healthy preterm infants.
METHODS—Nineteen infants, median gestational age 31 weeks (range 26-33 weeks) were assessed in a randomised, double blind, placebo controlled, cross-over trial. Changes in physiological variables (heart rate, blood pressure, oxygen saturation) and behavioural responses (neonatal facial coding system score, crying time) before and after venepuncture with EMLA cream were compared with those obtained with a placebo cream to assess efficacy. Toxicity was assessed by comparing methaemoglobin concentrations at 1 hour and 8 hours after application.
RESULTS—There was no significant difference in efficacy between EMLA and placebo creams in physiological and behavioural responses. There was no significant difference in methaemoglobin concentrations one hour after the cream had been applied. At eight hours, however, concentrations were significantly higher after EMLA than placebo (p=0.016). There was no evidence of clinical toxicity.
CONCLUSION—This study does not support the routine use of EMLA for venepuncture in healthy preterm infants.

 PMID:9577286

  4. Randomised, Double Blind, Placebo-Controlled Trial of Echinacea Supplementation in Air Travellers

    PubMed Central

    Tiralongo, E.; Lea, R. A.; Wee, S. S.; Hanna, M. M.; Griffiths, L. R.

    2012-01-01

    Objective. To identify whether a standardised Echinacea formulation is effective in the prevention of respiratory and other symptoms associated with long-haul flights. Methods. 175 adults participated in a randomised, double-blind placebo-controlled trial travelling back from Australia to America, Europe, or Africa for a period of 1–5 weeks on commercial flights via economy class. Participants took Echinacea (root extract, standardised to 4.4 mg alkylamides) or placebo tablets. Participants were surveyed before, immediately after travel, and at 4 weeks after travel regarding upper respiratory symptoms and travel-related quality of life. Results. Respiratory symptoms for both groups increased significantly during travel (P < 0.0005). However, the Echinacea group had borderline significantly lower respiratory symptom scores compared to placebo (P = 0.05) during travel. Conclusions. Supplementation with standardised Echinacea tablets, if taken before and during travel, may have preventive effects against the development of respiratory symptoms during travel involving long-haul flights. PMID:22229040

  5. Haemodynamic effects of parenteral vs. enteral paracetamol in critically ill patients: a randomised controlled trial.

    PubMed

    Kelly, S J; Moran, J L; Williams, P J; Burns, K; Rowland, A; Miners, J O; Peake, S L

    2016-10-01

    Paracetamol is a commonly used drug in the intensive care unit. There have been reports in the literature of an association with significant hypotension, a potentially important interaction for labile critically ill patients. Route of administration may influence the incidence of hypotension. This single-centre, prospective, open-label, randomised, parallel-arm, active-control trial was designed to determine the incidence of hypotension following the administration of paracetamol to critically ill patients. Fifty adult patients receiving paracetamol for analgesia or pyrexia were randomly assigned to receive either the parenteral or enteral formulation of the drug. Paracetamol concentrations were measured at baseline and at multiple time points over 24 h. The maximal plasma paracetamol concentration was significantly different between routes; 156 vs. 73 micromol.l(-1) [p = 0.0005] following the first dose of parenteral or enteral paracetamol, respectively. Sixteen hypotensive events occurred in 12 patients: parenteral n = 12; enteral n = 4. The incident rate ratio for parenteral vs. enteral paracetamol was 2.94 (95% CI 0.97-8.92; p = 0.06). The incidence of hypotension associated with paracetamol administration is higher than previously reported and tends to be more frequent with parenteral paracetamol. PMID:27611038

  6. A guide to performing a peer review of randomised controlled trials.

    PubMed

    Del Mar, Chris; Hoffmann, Tammy C

    2015-01-01

    Peer review of journal articles is an important step in the research process. Editors rely on the expertise of peer reviewers to properly assess submissions. Yet, peer review quality varies widely and few receive training or guidance in how to approach the task. This paper describes some of the main steps that peer reviewers in general and, in particular, those performing reviewes of randomised controlled trials (RCT), can use when carrying out a review. It can be helpful to begin with a brief read to acquaint yourself with the study, followed by a detailed read and a careful check for flaws. These can be divided into 'major' (problems that must be resolved before publication can be considered) and 'minor' (suggested improvements that are discretionary) flaws. Being aware of the appropriate reporting checklist for the study being reviewed (such as CONSORT and its extensions for RCTs) can also be valuable. Competing interests or prejudices might corrode the review, so ensuring transparency about them is important. Finally, ensuring that the paper's strengths are acknowledged along with a dissection of the weaknesses provides balance and perspective to both authors and editors. Helpful reviews are constructive and improve the quality of the paper. The proper conduct of a peer review is the responsibility of all who accept the role. PMID:26521647

  7. Effects of Green Tea on Streptococcus mutans Counts- A Randomised Control Trail

    PubMed Central

    R, Srinivas; B, Vikram Simha; Y, Sandhya Sree; T, Chandra Shekar; P, Siva Kumar

    2014-01-01

    Context: Mouth rinses have been in use from time immemorial as a supplement for routine oral hygiene. There are many number of mouth rinses currently available in the market in which many of them possess certain drawback, which has necessitated the search for alternate mouth rinses. Aim: The aim of the present study was to assess the effect of rinsing with green tea in comparison with chlorhexidine and plain water on Streptococcus mutans count. Setting and Design: A short term, single blinded, cross over randomised control clinical trial. Materials and Methods: Study includes a total of 30 subjects aged 20 to 25 years divided into three groups that is green tea group, chlorhexidine group, and plain water group. A baseline plaque samples were collected and under supervision of examiner all the subjects rinsed with 10 ml of respective solutions for one minute. Plaque samples were collected at five minutes after rinsing. All the 30 subjects were exposed to all the three rinses with a wash out period of seven days between the interventions. All the samples were sent to microbial analysis. Results: Wilcoxon matched pair test and Mann-Whitney U test showed that both chlorhexidine and green tea significantly reduced Streptococcus mutans colony counts compared to plain water. Conclusion: The results of present study indicate that green tea mouth rinse proved to be equally effective compared to chlorhexidine which is considered as gold standard. This may also be a valuable public health intervention as it is economical and has multiple health benefits. PMID:25584303

  8. Injury prevention in male veteran football players - a randomised controlled trial using "FIFA 11+".

    PubMed

    Hammes, Daniel; Aus der Fünten, Karen; Kaiser, Stephanie; Frisen, Eugen; Bizzini, Mario; Meyer, Tim

    2015-01-01

    The warm-up programme "FIFA 11+" has been shown to reduce football injuries in different populations, but so far veteran players have not been investigated. Due to differences in age, skill level and gender, a simple transfer of these results to veteran football is not recommended. The purpose of this study was to investigate the preventive effects of the "FIFA 11+" in veteran football players. Twenty veteran football teams were recruited for a prospective 9-month (1 season) cluster-randomised trial. The intervention group (INT, n = 146; 45 ± 8 years) performed the "FIFA 11+" at the beginning of each training session, while the control group (CON, n = 119; 43 ± 6 years) followed its regular training routine. Player exposure hours and injuries were recorded according to an international consensus statement. No significant difference was found between INT and CON in overall injury incidence (incidence rate ratio [IRR]: 0.91 [0.64-1.48]; P = 0.89). Only severe injuries reached statistical significance with higher incidence in CON (IRR: 0.46 [0.21-0.97], P = 0.04). Regular conduction (i.e. once a week) of the "FIFA 11+" did not prevent injuries in veteran footballers under real training and competition circumstances. The lack of preventive effects is likely due to the too low overall frequency of training sessions. PMID:25370591

  9. Typhoid fever vaccines: systematic review and meta-analysis of randomised controlled trials.

    PubMed

    Fraser, Abigail; Paul, Mical; Goldberg, Elad; Acosta, Camilo J; Leibovici, Leonard

    2007-11-01

    We undertook a systematic review and meta-analysis of randomised controlled trials comparing a typhoid fever vaccine with any alternative typhoid fever vaccine or inactive agent. Trials evaluating killed whole-cell vaccines were excluded. The cumulative efficacy at 3 years for the Ty21a and the polysaccharide Vi vaccine were similar: 51% (95%CI 36%, 62%), and 55% (95%CI 30%, 70%), respectively. The cumulative efficacy of the Vi-rEPA vaccine at 3.8 years was higher, 89% (95%CI 76%, 97%), but this vaccine has not yet been licensed for use and was evaluated in only one trial. Adverse events were mild in nature and for most, not significantly more frequent in any of the vaccine groups when compared with placebo. Both the currently licensed Ty21a and Vi vaccine, are safe and efficacious for preventing typhoid fever. Neither vaccine is currently registered for administration to children below 2 years of age. Given the recent finding that typhoid fever also affects infants, development of a conjugate vaccine is warranted. PMID:17928109

  10. Effect of β radiation on success of glaucoma drainage surgery in South Africa: randomised controlled trial

    PubMed Central

    Kirwan, James F; Cousens, Simon; Venter, Lynette; Cook, Colin; Stulting, Andries; Roux, Paul; Murdoch, Ian

    2006-01-01

    Objective To evaluate whether β radiation may offer a practical method of improving surgical success for glaucoma drainage surgery in South Africa. Design Double blind, randomised controlled trial. Setting Three public hospitals in South Africa. Participants 450 black Africans with primary glaucoma. Interventions Trabeculectomy with 1000 cGy β radiation or standard trabeculectomy without β radiation (placebo). Main outcome measures Primary outcome measure was surgical failure within 12 months (intraocular pressure > 21 mm Hg while receiving no treatment for ocular hypotension). Secondary outcomes were visual acuity, surgical reintervention for cataract, and intraoperative and postoperative complications. Results 320 people were recruited. β radiation was given to 164; 20 (6%) were not seen again after surgery. One year after surgery the estimated risk of surgical failure was 30% (95% confidence interval 22% to 38%) in the placebo arm compared with 5% (2% to 10%) in the radiation arm. The radiation group experienced a higher incidence of operable cataract (18 participants) than the placebo group (five participants; P = 0.01). At two years the estimated risks with placebo and β radiation were, respectively, 2.8% (0.9% to 8.3%) and 16.7% (10.0% to 27.3%). Conclusion β radiation substantially reduced the risk of surgical failure after glaucoma surgery. Some evidence was, however, found of an increased risk for cataract surgery (a known complication of trabeculectomy) in the β radiation arm during the two years after surgery. Trial registration ISRCTN62430622. PMID:17023435

  11. Individualised homeopathy as an adjunct in the treatment of childhood asthma: a randomised placebo controlled trial

    PubMed Central

    White, A; Slade, P; Hunt, C; Hart, A; Ernst, E

    2003-01-01

    Background: Homeopathy is frequently used to treat asthma in children. In the common classical form of homeopathy, prescriptions are individualised for each patient. There has been no rigorous investigation into this form of treatment for asthma. Methods: In a randomised, double blind, placebo controlled trial the effects of individualised homeopathic remedies were compared with placebo medication in 96 children with mild to moderate asthma as an adjunct to conventional treatment. The main outcome measure was the active quality of living subscale of the Childhood Asthma Questionnaire administered at baseline and follow up at 12 months. Other outcome measures included other subscales of the same questionnaire, peak flow rates, use of medication, symptom scores, days off school, asthma events, global assessment of change, and adverse reactions. Results: There were no clinically relevant or statistically significant changes in the active quality of life score. Other subscales, notably those measuring severity, indicated relative improvements but the sizes of the effects were small. There were no differences between the groups for other measures. Conclusions: This study provides no evidence that adjunctive homeopathic remedies, as prescribed by experienced homeopathic practitioners, are superior to placebo in improving the quality of life of children with mild to moderate asthma in addition to conventional treatment in primary care. PMID:12668794

  12. Advance care planning: A systematic review of randomised controlled trials conducted with older adults.

    PubMed

    Weathers, Elizabeth; O'Caoimh, Rónán; Cornally, Nicola; Fitzgerald, Carol; Kearns, Tara; Coffey, Alice; Daly, Edel; O'Sullivan, Ronan; McGlade, Ciara; Molloy, D William

    2016-09-01

    Advance care planning (ACP), involving discussions between patients, families and healthcare professionals on future healthcare decisions, in advance of anticipated impairment in decision-making capacity, improves satisfaction and end-of-life care while respecting patient autonomy. It usually results in the creation of a written advanced care directive (ACD). This systematic review examines the impact of ACP on several outcomes (including symptom management, quality of care and healthcare utilisation) in older adults (>65years) across all healthcare settings. Nine randomised controlled trials (RCTs) were identified by searches of the CINAHL, PubMed and Cochrane databases. A total of 3646 older adults were included (range 72-88 years). Seven studies were conducted with community dwellers and the other two RCTs were conducted in nursing homes. Most studies did not implement a standardised ACD, or measure the impact on quality of end-of-life care or on the death and dying experience. All studies had some risk of bias, with most scoring poorly on the Oxford Quality Scale. While ACP interventions are well received by older adults and generally have positive effects on outcomes, this review highlights the need for well-designed RCTs that examine the economic impact of ACP and its effect on quality of care in nursing homes and other sectors. PMID:27451328

  13. Assessment of an electronic voting system within the tutorial setting: A randomised controlled trial [ISRCTN54535861

    PubMed Central

    Palmer, Edward J; Devitt, Peter G; De Young, Neville J; Morris, David

    2005-01-01

    Background Electronic voting systems have been used in various educational settings with little measurement of the educational impact on students. The goal of this study was to measure the effects of the inclusion of an electronic voting system within a small group tutorial. Method A prospective randomised controlled trial was run at the Royal Adelaide Hospital, a teaching hospital in Adelaide, Australia. 102 students in their first clinical year of medical school participated in the study where an electronic voting system was introduced as a teaching aid into a standard tutorial. Long-term retention of knowledge and understanding of the topics discussed in the tutorials was measured and student response to the introduction of the electronic voting system was assessed. Results Students using the electronic voting system had improved long-term retention of understanding of material taught in the tutorial. Students had a positive response to the use of this teaching aid. Conclusion Electronic voting systems can provide a stimulating learning environment for students and in a small group tutorial may improve educational outcomes. PMID:16000178

  14. Nebulised amiloride in respiratory exacerbations of cystic fibrosis: a randomised controlled trial.

    PubMed Central

    Bowler, I M; Kelman, B; Worthington, D; Littlewood, J M; Watson, A; Conway, S P; Smye, S W; James, S L; Sheldon, T A

    1995-01-01

    OBJECTIVE--To assess the benefit of nebulised amiloride added to the standard inpatient treatment of a respiratory exacerbation in cystic fibrosis. DESIGN--Prospective, randomised, double blind, placebo controlled trial. SUBJECTS--27 cystic fibrosis patients (mean age 12.8 years). SETTING--Two hospitals in Leeds, UK. RESULTS--Both forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) showed improvements over the course of treatment, although there was no difference in respiratory function between the two groups at any of three time periods during the study. The time to reach peak FVC was significantly reduced in the amiloride group (4.2 v 7.6 days; 95% CI 0.4 to 6.4 days), but not in the time to reach peak FEV1 (5.7 v 7.9 days; 95% CI -1.2 to 5.6 days). CONCLUSIONS--Amiloride did not result in a greater overall improvement in respiratory function. There was a suggestion that it may have an effect on the rate of improvement, and thus may possibly influence the duration of treatment. This hypothesis deserves further evaluation. Images p428-a PMID:8554360

  15. Developing the evidence-base for Safe Communities: a multi-level, partly randomised, controlled trial.

    PubMed

    Seedat, M; McClure, R; Suffla, S; van Niekerk, A

    2012-01-01

    Safe Communities, representing a global activation of the public health logic, may be strengthened through theoretical, methodological and empirical support. In the spirit of this Special Issue that aims to analyse the achievements and challenges inherent to Safe Communities, we offer our contribution in the form of a methodology of a multi-country child safety, peace and health promotion study. The study, situated within an African-centred initiative called Ukuphepha - an isiZulu word meaning demonstrating African safety - is underpinned by four theoretical claims that frame injury and violence prevention as a multi-disciplinary issue to be addressed through a suite of interventions to family and extended social systems. The interventions, sensitive to the priorities of each participating country, have been informed by the literature on effective interventions and the authors' joint experiences of community development. The study is designed as a population-based, multi-level, multi-intervention partly randomised controlled trial, and there are potentially 24 participant communities representing South Africa, Mozambique, Egypt, Zambia, Uganda, Bangladesh, Malaysia and Australia - over three commencement phases. Whereas process evaluation will focus on community engagement, impact evaluation will consider risk and protective factors, and outcome evaluation will examine the overall effectiveness of the interventions. Notwithstanding the many challenges, the study will provide insights into the methodology and mechanisms of ecologically-oriented interventions that locate injury and violence prevention as an activity arising from safety, peace and health promotion. PMID:22873717

  16. Robust Multivariable Flutter Suppression for the Benchmark Active Control Technology (BACT) Wind-Tunnel Model

    NASA Technical Reports Server (NTRS)

    Waszak, Martin R.

    1997-01-01

    The Benchmark Active Controls Technology (BACT) project is part of NASA Langley Research Center s Benchmark Models Program for studying transonic aeroelastic phenomena. In January of 1996 the BACT wind-tunnel model was used to successfully demonstrate the application of robust multivariable control design methods (H and -synthesis) to flutter suppression. This paper addresses the design and experimental evaluation of robust multivariable flutter suppression control laws with particular attention paid to the degree to which stability and performance robustness was achieved.

  17. Robust PD Sway Control of a Lifted Load for a Crane Using a Genetic Algorithm

    NASA Astrophysics Data System (ADS)

    Kawada, Kazuo; Sogo, Hiroyuki; Yamamoto, Toru; Mada, Yasuhiro

    PID control schemes still continue to be widely used for most industrial control systems. This is mainly because PID controllers have simple control structures, and are simple to maintain and tune. However, it is difficult to find a set of suitable control parameters in the case of time-varying and/or nonlinear systems. For such a problem, the robust controller has been proposed.Although it is important to choose the suitable nominal model in designing the robust controller, it is not usually easy.In this paper, a new robust PD controller design scheme is proposed, which utilizes a genetic algorithm.

  18. Nutritional route in oesophageal resection trial II (NUTRIENT II): study protocol for a multicentre open-label randomised controlled trial

    PubMed Central

    Berkelmans, Gijs H K; Wilts, Bas J W; Kouwenhoven, Ewout A; Kumagai, Koshi; Nilsson, Magnus; Weijs, Teus J; Nieuwenhuijzen, Grard A P; van Det, Marc J; Luyer, Misha D P

    2016-01-01

    Introduction Early start of an oral diet is safe and beneficial in most types of gastrointestinal surgery and is a crucial part of fast track or enhanced recovery protocols. However, the feasibility and safety of oral intake directly following oesophagectomy remain unclear. The aim of this study is to investigate the effects of early versus delayed start of oral intake on postoperative recovery following oesophagectomy. Methods and analysis This is an open-label multicentre randomised controlled trial. Patients undergoing elective minimally invasive or hybrid oesophagectomy for cancer are eligible. Further inclusion criteria are intrathoracic anastomosis, written informed consent and age 18 years or older. Inability for oral intake, inability to place a feeding jejunostomy, inability to provide written consent, swallowing disorder, achalasia, Karnofsky Performance Status <80 and malnutrition are exclusion criteria. Patients will be randomised using online randomisation software. The intervention group (direct oral feeding) will receive a liquid oral diet for 2 weeks with gradually expanding daily maximums. The control group (delayed oral feeding) will receive enteral feeding via a jejunostomy during 5 days and then start the same liquid oral diet. The primary outcome measure is functional recovery. Secondary outcome measures are 30-day surgical complications; nutritional status; need for artificial nutrition; need for additional interventions; health-related quality of life. We aim to recruit 148 patients. Statistical analysis will be performed according to an intention to treat principle. Results are presented as risk ratios with corresponding 95% CIs. A two-tailed p<0.05 is considered statistically significant. Ethics and dissemination Our study protocol has received ethical approval from the Medical research Ethics Committees United (MEC-U). This study is conducted according to the principles of Good Clinical Practice. Verbal and written informed consent is

  19. A modular robust control framework for control of movement elicited by multi-electrode intraspinal microstimulation

    NASA Astrophysics Data System (ADS)

    Roshani, Amir; Erfanian, Abbas

    2016-08-01

    Objective. An important issue in restoring motor function through intraspinal microstimulation (ISMS) is the motor control. To provide a physiologically plausible motor control using ISMS, it should be able to control the individual motor unit which is the lowest functional unit of motor control. By focal stimulation only a small group of motor neurons (MNs) within a motor pool can be activated. Different groups of MNs within a motor pool can potentially be activated without involving adjacent motor pools by local stimulation of different parts of a motor pool via microelectrode array implanted into a motor pool. However, since the system has multiple inputs with single output during multi-electrode ISMS, it poses a challenge to movement control. In this paper, we proposed a modular robust control strategy for movement control, whereas multi-electrode array is implanted into each motor activation pool of a muscle. Approach. The controller was based on the combination of proportional-integral-derivative and adaptive fuzzy sliding mode control. The global stability of the controller was guaranteed. Main results. The results of the experiments on rat models showed that the multi-electrode control can provide a more robust control and accurate tracking performance than a single-electrode control. The control output can be pulse amplitude (pulse amplitude modulation, PAM) or pulse width (pulse width modulation, PWM) of the stimulation signal. The results demonstrated that the controller with PAM provided faster convergence rate and better tracking performance than the controller with PWM. Significance. This work represents a promising control approach to the restoring motor functions using ISMS. The proposed controller requires no prior knowledge about the dynamics of the system to be controlled and no offline learning phase. The proposed control design is modular in the sense that each motor pool has an independent controller and each controller is able to control ISMS

  20. Effect of Oral Lactoferrin on Cataract Surgery Induced Dry Eye: A Randomised Controlled Trial

    PubMed Central

    Singh, Sneha

    2015-01-01

    Context Cataract surgery is one of the most frequently performed intra-ocular surgeries, of these manual Small Incision Cataract Surgery (SICS) is a time tested technique of cataract removal. Any corneal incisional surgery, including cataract surgery, can induce dry eye postoperatively. Various factors have been implicated, of which oneis the inflammation induced by the surgery. Lactoferrin, a glycoprotein present in tears is said to have anti-inflammatory effects, and promotes cell growth. It has been used orally in patients of immune mediated dry eye to alleviate symptoms. Aim This study was aimed to evaluate the dry eyes induced by manual Small Incision Cataract Surgery, and the effect if any, of oral lactoferrin on the dry eyes. Settings and Trial Design A single centre, prospective randomised controlled trial with a concurrent parallel design. The study was carried out on patients presenting in the OPD of Rohilkhand Medical College hospital for cataract surgery. Materials and Methods Sixty four patients of cataract surgery were included in the study. Patients with pre-existing dry eyes, ocular disease or systemic disease predisposing to dry eyes were excluded from the study. The selected patients were assigned into two groups by simple randomisation-Control Group A-32 patients that did not receive oral lactoferrin postoperatively. Group B-32 patients that received oral lactoferrin 350 gm postoperatively from day 1 after SICS. All patients were operated for cataract and their pre and postoperative (on days 7, 14, 30 and 60) dry eye status was assessed using the mean tear film break-up time (tBUT) and Schirmer test 1 (ST 1) as the evaluating parameters. Subjective evaluation of dry eye was done using Ocular Surface Disease Index (OSDI) scoring. Data was analysed for 58 patients, as 6 did not complete the follow up. Statistical Analysis Unpaired t-test was used to calculate the p-values. Result There was a statistically significant difference between the t

  1. Effectiveness of out-of-home day care for disadvantaged families: randomised controlled trial

    PubMed Central

    Toroyan, Tami; Roberts, Ian; Oakley, Ann; Laing, Gabrielle; Mugford, Miranda; Frost, Chris

    2003-01-01

    Objective To assess the effects of providing daycare facilities for young children on the health and welfare of disadvantaged families. Design Randomised controlled trial. Eligible children from the application list to a daycare facility were randomly allocated to receive a daycare place or not. Setting Early Years daycare centre in Borough of Hackney, London. Participants 120 mothers and 143 eligible children (aged between 6 months and 3.5 years). Intervention A place at the centre, which provided high quality day care. Control families used other child care that they secured for themselves. Main outcome measures Maternal paid employment, household income, child health and development. Results At 18 months' follow up, 67% of intervention group mothers and 60% of control group mothers were in paid employment (adjusted risk ratio 1.23 (95% confidence interval 0.99 to 1.52)), but were no more likely to have a weekly household income of above £200 (risk ratio 0.88 (0.70 to 1.09)). Intervention group children had more otitis media with effusion (risk ratio 1.74 (1.02 to 2.96)) and used more health services (1.58 (1.05 to 2.38)), but both estimates were imprecise. Conclusion The provision of child day care may have increased maternal employment, but it did not seem to increase household income. The results suggest that providing day care may be insufficient as a strategy to reduce poverty. The study shows how random allocation can be used to ration and evaluate interventions where demand exceeds supply. PMID:14563749

  2. Postnatal support for mothers living in disadvantaged inner city areas: a randomised controlled trial

    PubMed Central

    Wiggins, M; Oakley, A; Roberts, I; Turner, H; Rajan, L; Austerberry, H; Mujica, R; Mugford, M; Barker, M

    2005-01-01

    Study objective: To evaluate the effect of two forms of postnatal social support for disadvantaged inner city mothers on maternal and child health outcomes. Design: Randomised controlled trial with economic and process evaluations and follow up at 12 and 18 months. The two intervention groups received either the offer of a year of monthly supportive listening home visits by a support health visitor (SHV), or a year of support from community groups providing drop in sessions, home visiting and/or telephone support (CGS). Each was compared with a control group that received standard health visitor services. Setting: Two disadvantaged boroughs of London, United Kingdom. Participants: 731 women from culturally diverse backgrounds with infants. Main results: At 12 and 18 months, there was little impact for either intervention on the main outcomes: child injury (SHV: relative risk 0.99; 95% confidence intervals 0.68 to 1.45, CGS: 0.91; 0.61 to1.36), maternal smoking (SHV: 0.86; 0.62 to 1.19, CGS: 0.97; 0.72 to 1.33) or maternal depression (SHV: 0.86; 0.62 to1.19, CGS: 0.93; 0.69 to 1.27). SHV women had different patterns of health service use (with fewer taking their children to the GP) and had less anxious experiences of motherhood than control women. User satisfaction with the SHV intervention was high. Uptake of the CGS intervention was low: 19%, compared with 94% for the SHV intervention. Conclusions: There was no evidence of impact on the primary outcomes of either intervention among this culturally diverse population. The SHV intervention was associated with improvement in some of the secondary outcomes. PMID:15767382

  3. Optimal robust control of drug delivery in cancer chemotherapy: a comparison between three control approaches.

    PubMed

    Moradi, Hamed; Vossoughi, Gholamreza; Salarieh, Hassan

    2013-10-01

    During the drug delivery process in chemotherapy, both of the cancer cells and normal healthy cells may be killed. In this paper, three mathematical cell-kill models including log-kill hypothesis, Norton-Simon hypothesis and Emax hypothesis are considered. Three control approaches including optimal linear regulation, nonlinear optimal control based on variation of extremals and H∞-robust control based on μ-synthesis are developed. An appropriate cost function is defined such that the amount of required drug is minimized while the tumor volume is reduced. For the first time, performance of the system is investigated and compared for three control strategies; applied on three nonlinear models of the process. In additions, their efficiency is compared in the presence of model parametric uncertainties. It is observed that in the presence of model uncertainties, controller designed based on variation of extremals is more efficient than the linear regulation controller. However, H∞-robust control is more efficient in improving robust performance of the uncertain models with faster tumor reduction and minimum drug usage. PMID:23891423

  4. Robust control of integrated motor-transmission powertrain system over controller area network for automotive applications

    NASA Astrophysics Data System (ADS)

    Zhu, Xiaoyuan; Zhang, Hui; Cao, Dongpu; Fang, Zongde

    2015-06-01

    Integrated motor-transmission (IMT) powertrain system with directly coupled motor and gearbox is a good choice for electric commercial vehicles (e.g., pure electric buses) due to its potential in motor size reduction and energy efficiency improvement. However, the controller design for powertrain oscillation damping becomes challenging due to the elimination of damping components. On the other hand, as controller area network (CAN) is commonly adopted in modern vehicle system, the network-induced time-varying delays that caused by bandwidth limitation will further lead to powertrain vibration or even destabilize the powertrain control system. Therefore, in this paper, a robust energy-to-peak controller is proposed for the IMT powertrain system to address the oscillation damping problem and also attenuate the external disturbance. The control law adopted here is based on a multivariable PI control, which ensures the applicability and performance of the proposed controller in engineering practice. With the linearized delay uncertainties characterized by polytopic inclusions, a delay-free closed-loop augmented system is established for the IMT powertrain system under discrete-time framework. The proposed controller design problem is then converted to a static output feedback (SOF) controller design problem where the feedback control gains are obtained by solving a set of linear matrix inequalities (LMIs). The effectiveness as well as robustness of the proposed controller is demonstrated by comparing its performance against that of a conventional PI controller.

  5. A multi-centre randomised controlled trial of Transfusion Indication Threshold Reduction on transfusion rates, morbidity and healthcare resource use following cardiac surgery: Study protocol

    PubMed Central

    Brierley, Rachel C.M.; Pike, Katie; Miles, Alice; Wordsworth, Sarah; Stokes, Elizabeth A.; Mumford, Andrew D.; Cohen, Alan; Angelini, Gianni D.; Murphy, Gavin J.; Rogers, Chris A.; Reeves, Barnaby C.

    2014-01-01

    Thresholds for red blood cell transfusion following cardiac surgery vary by hospital and surgeon. The TITRe2 multi-centre randomised controlled trial aims to randomise 2000 patients from 17 United Kingdom centres, and tests the hypothesis that a restrictive transfusion threshold will reduce postoperative morbidity and health service costs compared to a liberal threshold. Patients consent to take part in the study pre-operatively but are only randomised if their haemoglobin falls below 9 g/dL during their post-operative hospital stay. The primary outcome is a binary composite outcome of any serious infectious or ischaemic event in the first three months after randomisation. Many challenges have been encountered in the set-up and running of the study. PMID:24675014

  6. Protocol to evaluate the impact of yoga supplementation on cognitive function in schizophrenia: a randomised controlled trial

    PubMed Central

    Bhatia, Triptish; Mazumdar, Sati; Mishra, Nagendra Narayan; Gur, Raquel E.; Gur, Ruben C.; Nimgaonkar, Vishwajit Laxmikant; Deshpande, Smita Neelkanth

    2015-01-01

    Background Schizophrenia (SZ) is a chronic illness that is treated symptomatically. Cognitive dysfunction is a core feature of SZ that is relatively intractable to pharmacotherapy. Yoga can improve cognitive function among healthy individuals. A recent open trial indicated significant benefits of yoga training (YT) in conjunction with conventional pharmacotherapy among patients with SZ. Aims To describe the protocol for an ongoing randomised controlled trial designed to test whether the reported beneficial effects of YT on cognitive function among SZ patients can be replicated. Secondarily, the effects of YT on daily functioning living skills are evaluated. Methods Consenting patients with SZ receive routine clinical treatment and are randomised to adjunctive YT, adjunctive physical exercise (PE) or treatment as usual (proposed N = 234 total, N = 78 in each group). The trial involves YT or PE 5 days a week and lasts 3 weeks. Participants are evaluated thrice over 6 months. Cognitive functions measured by Trail Making Test, University of Pennsylvania Neurocognitive Computerised Battery were primary outcome measures while clinical severity and daily functioning measured by Independent Living Skills Survey were secondary outcome measures. Results A total of 309 participants have been randomised as of 31 August 2013, which exceeded beyond 294 proposed after attrition. Once participants begin YT or PE they generally complete the protocol. No injuries have been reported. Conclusions Short term YT is feasible and acceptable to Indian SZ patients. If beneficial effects of YT are detected, it will provide a novel adjunctive cognitive remediation strategy for SZ patients. PMID:25241756

  7. Managed Activity Graded Exercise iN Teenagers and pre-Adolescents (MAGENTA) feasibility randomised controlled trial: study protocol

    PubMed Central

    Brigden, Amberly; Beasant, Lucy; Hollingworth, William; Metcalfe, Chris; Gaunt, Daisy; Mills, Nicola; Jago, Russell; Crawley, Esther

    2016-01-01

    Introduction Paediatric chronic fatigue syndrome or myalgic encephalomyelitis (CFS/ME) is a relatively common and disabling condition, yet there is a limited evidence base for treatment. There is good evidence that graded exercise therapy is moderately effective in adults with CFS/ME, but there is little evidence for the effectiveness, cost-effectiveness, acceptability or best method of delivery for paediatric CFS/ME. This study aims to investigate the acceptability and feasibility of carrying out a multicentre randomised controlled trial investigating the effectiveness of graded exercise therapy compared with activity management for children/teenagers who are mildly or moderately affected with CFS/ME. Methods and analysis 100 paediatric patients (8–17 years) with CFS/ME will be recruited from 3 specialist UK National Health Service (NHS) CFS/ME services (Bath, Cambridge and Newcastle). Patients will be randomised (1:1) to receive either graded exercise therapy or activity management. Feasibility analysis will include the number of young people eligible, approached and consented to the trial; attrition rate and treatment adherence; questionnaire and accelerometer completion rates. Integrated qualitative methods will ascertain perceptions of feasibility and acceptability of recruitment, randomisation and the interventions. All adverse events will be monitored to assess the safety of the trial. Ethics and dissemination The trial has received ethical approval from the National Research Ethics Service (South West—Frenchay 15/SW/0124). Trial registration number ISRCTN23962803; Pre-results. PMID:27377634

  8. Pressure and pain In Systemic sclerosis/Scleroderma - an evaluation of a simple intervention (PISCES): randomised controlled trial protocol

    PubMed Central

    2012-01-01

    Background Foot problems associated with Systemic Sclerosis (SSc)/Scleroderma have been reported to be both common and disabling. There are only limited data describing specifically, the mechanical changes occurring in the foot in SSc. A pilot project conducted in preparation for this trial confirmed the previous reports of foot related impairment and reduced foot function in people with SSc and demonstrated a link to mechanical etiologies. To-date there have been no formal studies of interventions directed at the foot problems experienced by people with Systemic Sclerosis. The primary aim of this trial is to evaluate whether foot pain and foot-related health status in people with Systemic Sclerosis can be improved through the provision of a simple pressure-relieving insole. Methods The proposed trial is a pragmatic, multicenter, randomised controlled clinical trial following a completed pilot study. In four participating centres, 140 consenting patients with SSc and plantar foot pain will be randomised to receive either a commercially available pressure relieving and thermally insulating insole, or a sham insole with no cushioning or thermal properties. The primary end point is a reduction in pain measured using the Foot Function Index Pain subscale, 12 weeks after the start of intervention. Participants will complete the primary outcome measure (Foot Function Index pain sub-scale) prior to randomisation and at 12 weeks post randomisation. Secondary outcomes include participant reported pain and disability as derived from the Manchester Foot Pain and Disability Questionnaire and plantar pressures with and without the insoles in situ. Discussion This trial protocol proposes a rigorous and potentially significant evaluation of a simple and readily provided therapeutic approach which, if effective, could be of a great benefit for this group of patients. Trial registration number ISRCTN: ISRCTN02824122 PMID:22309847

  9. Multicentre randomised control trial comparing real time teledermatology with conventional outpatient dermatological care: societal cost-benefit analysis

    PubMed Central

    Wootton, R; Bloomer, S E; Corbett, R; Eedy, D J; Hicks, N; Lotery, H E; Mathews, C; Paisley, J; Steele, K; Loane, M A

    2000-01-01

    Objectives Comparison of real time teledermatology with outpatient dermatology in terms of clinical outcomes, cost-benefits, and patient reattendance. Design Randomised controlled trial with a minimum follow up of three months. Setting Four health centres (two urban, two rural) and two regional hospitals. Subjects 204 general practice patients requiring referral to dermatology services; 102 were randomised to teledermatology consultation and 102 to traditional outpatient consultation. Main outcome measures Reported clinical outcome of initial consultation, primary care and outpatient reattendance data, and cost-benefit analysis of both methods of delivering care. Results No major differences were found in the reported clinical outcomes of teledermatology and conventional dermatology. Of patients randomised to teledermatology, 55 (54%) were managed within primary care and 47 (46%) required at least one hospital appointment. Of patients randomised to the conventional hospital outpatient consultation, 46 (45%) required at least one further hospital appointment, 15 (15%) required general practice review, and 40 (39%) no follow up visits. Clinical records showed that 42 (41%) patients seen by teledermatology attended subsequent hospital appointments compared with 41 (40%) patients seen conventionally. The net societal cost of the initial consultation was £132.10 per patient for teledermatology and £48.73 for conventional consultation. Sensitivity analysis revealed that if each health centre had allocated one morning session a week to teledermatology and the average round trip to hospital had been 78 km instead of 26 km, the costs of the two methods of care would have been equal. Conclusions Real time teledermatology was clinically feasible but not cost effective compared with conventional dermatological outpatient care. However, if the equipment were purchased at current prices and the travelling distances greater, teledermatology would be a cost effective alternative

  10. Levonorgestrel-Releasing Intrauterine System vs. Usual Medical Treatment for Menorrhagia: An Economic Evaluation Alongside a Randomised Controlled Trial

    PubMed Central

    Sanghera, Sabina; Roberts, Tracy Elizabeth; Barton, Pelham; Frew, Emma; Daniels, Jane; Middleton, Lee; Gennard, Laura; Kai, Joe; Gupta, Janesh Kumar

    2014-01-01

    Objective To undertake an economic evaluation alongside the largest randomised controlled trial comparing Levonorgestrel-releasing intrauterine device (‘LNG-IUS’) and usual medical treatment for women with menorrhagia in primary care; and compare the cost-effectiveness findings using two alternative measures of quality of life. Methods 571 women with menorrhagia from 63 UK centres were randomised between February 2005 and July 2009. Women were randomised to having a LNG-IUS fitted, or usual medical treatment, after discussing with their general practitioner their contraceptive needs or desire to avoid hormonal treatment. The treatment was specified prior to randomisation. For the economic evaluation we developed a state transition (Markov) model with a 24 month follow-up. The model structure was informed by the trial women's pathway and clinical experts. The economic evaluation adopted a UK National Health Service perspective and was based on an outcome of incremental cost per Quality Adjusted Life Year (QALY) estimated using both EQ-5D and SF-6D. Results Using EQ-5D, LNG-IUS was the most cost-effective treatment for menorrhagia. LNG-IUS costs £100 more than usual medical treatment but generated 0.07 more QALYs. The incremental cost-effectiveness ratio for LNG-IUS compared to usual medical treatment was £1600 per additional QALY. Using SF-6D, usual medical treatment was the most cost-effective treatment. Usual medical treatment was both less costly (£100) and generated 0.002 more QALYs. Conclusion Impact on quality of life is the primary indicator of treatment success in menorrhagia. However, the most cost-effective treatment differs depending on the quality of life measure used to estimate the QALY. Under UK guidelines LNG-IUS would be the recommended treatment for menorrhagia. This study demonstrates that the appropriate valuation of outcomes in menorrhagia is crucial. PMID:24638071

  11. Design and Validation of Optimized Feedforward with Robust Feedback Control of a Nuclear Reactor

    SciTech Connect

    Shaffer, Roman; He Weidong; Edwards, Robert M.

    2004-08-15

    Design applications for robust feedback and optimized feedforward control, with confirming results from experiments conducted on the Pennsylvania State University TRIGA reactor, are presented. The combination of feedforward and feedback control techniques complement each other in that robust control offers guaranteed closed-loop stability in the presence of uncertainties, and optimized feedforward offers an approach to achieving performance that is sometimes limited by overly conservative robust feedback control. The design approach taken in this work combines these techniques by first designing robust feedback control. Alternative methods for specifying a low-order linear model and uncertainty specifications, while seeking as much performance as possible, are discussed and evaluated. To achieve desired performance characteristics, the optimized feedforward control is then computed by using the nominal nonlinear plant model that incorporates the robust feedback control.

  12. Sliding-Mode Control Applied for Robust Control of a Highly Unstable Aircraft

    NASA Technical Reports Server (NTRS)

    Vetter, Travis Kenneth

    2002-01-01

    An investigation into the application of an observer based sliding mode controller for robust control of a highly unstable aircraft and methods of compensating for actuator dynamics is performed. After a brief overview of some reconfigurable controllers, sliding mode control (SMC) is selected because of its invariance properties and lack of need for parameter identification. SMC is reviewed and issues with parasitic dynamics, which cause system instability, are addressed. Utilizing sliding manifold boundary layers, the nonlinear control is converted to a linear control and sliding manifold design is performed in the frequency domain. An additional feedback form of model reference hedging is employed which is similar to a prefilter and has large benefits to system performance. The effects of inclusion of actuator dynamics into the designed plant is heavily investigated. Multiple Simulink models of the full longitudinal dynamics and wing deflection modes of the forward swept aero elastic vehicle (FSAV) are constructed. Additionally a linear state space models to analyze effects from various system parameters. The FSAV has a pole at +7 rad/sec and is non-minimum phase. The use of 'model actuators' in the feedback path, and varying there design, is heavily investigated for the resulting effects on plant robustness and tolerance to actuator failure. The use of redundant actuators is also explored and improved robustness is shown. All models are simulated with severe failure and excellent tracking, and task dependent handling qualities, and low pilot induced oscillation tendency is shown.

  13. Randomised controlled trial of behavioural infant sleep intervention to improve infant sleep and maternal mood

    PubMed Central

    Hiscock, H; Wake, M

    2002-01-01

    Objective To compare the effect of a behavioural sleep intervention with written information about normal sleep on infant sleep problems and maternal depression. Design Randomised controlled trial. Setting Well child clinics, Melbourne, Australia Participants 156 mothers of infants aged 6-12 months with severe sleep problems according to the parents. Main outcome measures Maternal report of infant sleep problem; scores on Edinburgh postnatal depression scale at two and four months. Intervention Discussion on behavioural infant sleep intervention (controlled crying) delivered over three consultations. Results At two months more sleep problems had resolved in the intervention group than in the control group (53/76 v 36/76, P=0.005). Overall depression scores fell further in the intervention group than in the control group (mean change −3.7, 95% confidence interval −4.7 to −2.7, v −2.5, −1.7 to −3.4, P=0.06). For the subgroup of mothers with depression scores of 10 and over more sleep problems had resolved in the intervention group than in the control group (26/33 v 13/33, P=0.001). In this subgroup depression scores also fell further for intervention mothers than control mothers at two months (−6.0, −7.5 to −4.0, v −3.7, −4.9 to −2.6, P=0.01) and at four months (−6.5, −7.9 to 5.1 v –4.2, –5.9 to −2.5, P=0.04). By four months, changes in sleep problems and depression scores were similar. Conclusions Behavioural intervention significantly reduces infant sleep problems at two but not four months. Maternal report of symptoms of depression decreased significantly at two months, and this was sustained at four months for mothers with high depression scores. What is already known on this topicInfant sleep problems and postnatal depression are both common potentially serious problemsWomen whose infants have sleep problems are more likely to report symptoms of depressionUncontrolled studies in clinical populations suggest that reducing infant

  14. A randomised placebo controlled 12 week trial of budesonide and prednisolone in rheumatoid arthritis

    PubMed Central

    Kirwan, J; Hallgren, R; Mielants, H; Wollheim, F; Bjorck, E; Persson, T; Book, C; Bowman, S; Byron, M; Cox, N; Field, M; Kanerud, L; Leirisalo-Repo, M; Malaise, M; Mohammad, A; Palmer, R; Petersson, I; Ringertz, B; Sheldon, P; Simonsson, M; Snowden, N; Van den Bosch, F

    2004-01-01

    Objectives: To compare budesonide, a locally acting glucocorticoid with minimal systemic exposure, with conventional glucocorticoid treatment and placebo in rheumatoid arthritis. Methods: A double blind, randomised, controlled trial over 12 weeks in 143 patients with active rheumatoid arthritis, comparing budesonide 3 mg daily, budesonide 9 mg daily, prednisolone 7.5 mg daily, and placebo. Particular attention was paid to the pattern of clinical response and to changes in the four week period following discontinuation of treatment. Results: There were improvements in tender joint count and swollen joint count on budesonide 9 mg compared with placebo (28% for tender and 34% for swollen joint counts, p<0.05). Prednisolone 7.5 mg gave similar results, while budesonide 3 mg was less effective. ACR20 response criteria were met by 25% of patients on placebo, 22% on budesonide 3 mg, 42% on budesonide 9 mg, and 56% on prednisolone 7.5 mg. A rapid and significant reduction in symptoms and signs in response to budesonide 9 mg and prednisolone 7.5 mg was evident by two weeks and maximal at eight weeks. There was no evidence that budesonide provided a different pattern of symptom control from prednisolone, or that symptoms became worse than placebo treatment levels after discontinuation of glucocorticoid treatment. Adverse effects attributable to glucocorticoids were equally common in all groups. Conclusions: The symptomatic benefits of budesonide 9 mg and prednisolone 7.5 mg are achieved within a short time of initiating treatment, are maintained for three months, and are not associated with any rebound in symptoms after stopping treatment. PMID:15140776

  15. A randomised controlled trial of small particle inhaled steroids in refractory eosinophilic asthma (SPIRA)

    PubMed Central

    Hodgson, David; Anderson, John; Reynolds, Catherine; Meakin, Garry; Bailey, Helen; Pavord, Ian; Shaw, Dominick; Harrison, Tim

    2015-01-01

    Background Some patients with refractory asthma have evidence of uncontrolled eosinophilic inflammation in the distal airways. While traditional formulations of inhaled steroids settle predominantly in the large airways, newer formulations with an extra-fine particle size have a more peripheral pattern of deposition. Specifically treating distal airway inflammation may improve asthma control. Methods 30 patients with refractory asthma despite high dose inhaled corticosteroids were identified as having persistent airway eosinophilia. Following 2 weeks of prednisolone 30 mg, patients demonstrating an improvement in asthma control were randomised to receive either ciclesonide 320 µg twice daily or placebo in addition to usual maintenance therapy for 8 weeks. The primary outcome measure was sputum eosinophil count at week 8. Alveolar nitric oxide was measured as a marker of distal airway inflammation. Results There was continued suppression of differential sputum eosinophil counts with ciclesonide (median 2.3%) but not placebo (median 4.5%) though the between-group difference was not significant. When patients who had changed their maintenance prednisolone dose during the trial were excluded the difference between groups was significant (1.4% vs 4.5%, p=0.028). Though alveolar nitric oxide decreased with ciclesonide the value did not reach statistical significance. Conclusions These data demonstrate that patients with ongoing eosinophilic inflammation are not truly refractory, and that suppression of airway eosinophilia may be maintained with additional inhaled corticosteroid. Further work is needed with a focus on patient-orientated outcome measures such as exacerbation rate, with additional tests of small airway function. Trial registration number NCT01171365. Protocol available at http://www.clinicaltrials.gov. PMID:25858909

  16. Methods of hysterectomy: systematic review and meta-analysis of randomised controlled trials

    PubMed Central

    Johnson, Neil; Barlow, David; Lethaby, Anne; Tavender, Emma; Curr, Liz; Garry, Ray

    2005-01-01

    Objective To evaluate the most appropriate surgical method of hysterectomy (abdominal, vaginal, or laparoscopic) for women with benign disease. Design Systematic review and meta-analysis. Data sources Cochrane Menstrual Disorders and Subfertility Group Trials Register, Cochrane Central Register of Controlled Trials, Medline, Embase, and Biological Abstracts. Selection of studies Only randomised controlled trials were selected; participants had to have benign gynaecological disease; interventions had to comprise at least one hysterectomy method compared with another; and trials had to report primary outcomes (time taken to return to normal activities, intraoperative visceral injury, and major long term complications) or secondary outcomes (operating time, other immediate complications of surgery, short term complications, and duration of hospital stay). Results 27 trials (total of 3643 participants) were included. Return to normal activities was quicker after vaginal than after abdominal hysterectomy (weighted mean difference 9.5 (95% confidence interval 6.4 to 12.6) days) and after laparoscopic than after abdominal hysterectomy (difference 13.6 (11.8 to 15.4) days), but was not significantly different for laparoscopic versus vaginal hysterectomy (difference -1.1 (-4.2 to 2.1) days). There were more urinary tract injuries with laparoscopic than with abdominal hysterectomy (odds ratio 2.61 (95% confidence interval 1.22 to 5.60)), but no other intraoperative visceral injuries showed a significant difference between surgical approaches. Data were notably absent for many important long term patient outcome measures, where the analyses were underpowered to detect important differences, or they were simply not reported in trials. Conclusions Significantly speedier return to normal activities and other improved secondary outcomes (shorter duration of hospital stay and fewer unspecified infections or febrile episodes) suggest that vaginal hysterectomy is preferable to

  17. Children Learning About Secondhand Smoke (CLASS II): protocol of a pilot cluster randomised controlled trial

    PubMed Central

    Siddiqi, Kamran; Huque, Rumana; Jackson, Cath; Parrott, Steve; Dogar, Omara; Shah, Sarwat; Thomson, Heather; Sheikh, Aziz

    2015-01-01

    Introduction Exposure to secondhand smoke (SHS) increases children’s risk of acquiring chest and ear infections, tuberculosis, meningitis and asthma. Smoking bans in public places (where implemented) have significantly reduced adults’ exposure to SHS. However, for children, homes remain the most likely place for them to be exposed to SHS. Additional measures are therefore required to protect children from SHS. In a feasibility study in Dhaka, Bangladesh, we have shown that a school-based smoke-free intervention (SFI) was successful in encouraging children to negotiate and implement smoking restrictions in homes. We will now conduct a pilot trial to inform plans to undertake a cluster randomised controlled trial (RCT) investigating the effectiveness and cost-effectiveness of SFI in reducing children’s exposure to SHS. Methods and analysis We plan to recruit 12 primary schools in Dhaka, Bangladesh. From these schools, we will recruit approximately 360 schoolchildren in year 5 (10–12 years old), that is, 30 per school. SFI consists of six interactive educational activities aimed at increasing pupils’ knowledge about SHS and related harms, motivating them to act, providing skills to negotiate with adults to persuade them not to smoke inside homes and helping families to ‘sign-up’ to a voluntary contract to make their homes smoke-free. Children in the control arm will receive the usual education. We will estimate: recruitment and attrition rates, acceptability, fidelity to SFI, effect size, intracluster correlation coefficient, cost of intervention and adverse events. Our primary outcome will consist of SHS exposure in children measured by salivary cotinine. Secondary outcomes will include respiratory symptoms, lung function tests, healthcare contacts, school attendance, smoking uptake, quality of life and academic performance. Ethics and dissemination The trial has received ethics approval from the Research Governance Committee at the University of York

  18. Group hypnosis vs. relaxation for smoking cessation in adults: a cluster-randomised controlled trial

    PubMed Central

    2013-01-01

    Background Despite the popularity of hypnotherapy for smoking cessation, the efficacy of this method is unclear. We aimed to investigate the efficacy of a single-session of group hypnotherapy for smoking cessation compared to relaxation in Swiss adult smokers. Methods This was a cluster-randomised, parallel-group, controlled trial. A single session of hypnosis or relaxation for smoking cessation was delivered to groups of smokers (median size = 11). Participants were 223 smokers consuming ≥ 5 cigarettes per day, willing to quit and not using cessation aids (47.1% females, M = 37.5 years [SD = 11.8], 86.1% Swiss). Nicotine withdrawal, smoking abstinence self-efficacy, and adverse reactions were assessed at a 2-week follow-up. The main outcome, self-reported 30-day point prevalence of smoking abstinence, was assessed at a 6-month follow up. Abstinence was validated through salivary analysis. Secondary outcomes included number of cigarettes smoked per day, smoking abstinence self-efficacy, and nicotine withdrawal. Results At the 6-month follow up, 14.7% in the hypnosis group and 17.8% in the relaxation group were abstinent. The intervention had no effect on smoking status (p = .73) or on the number of cigarettes smoked per day (p = .56). Smoking abstinence self-efficacy did not differ between the interventions (p = .14) at the 2-week follow-up, but non-smokers in the hypnosis group experienced reduced withdrawal (p = .02). Both interventions produced few adverse reactions (p = .81). Conclusions A single session of group hypnotherapy does not appear to be more effective for smoking cessation than a group relaxation session. Trial registration Current Controlled Trials ISRCTN72839675. PMID:24365274

  19. Robust Control for the Segway with Unknown Control Coefficient and Model Uncertainties

    PubMed Central

    Kim, Byung Woo; Park, Bong Seok

    2016-01-01

    The Segway, which is a popular vehicle nowadays, is an uncertain nonlinear system and has an unknown time-varying control coefficient. Thus, we should consider the unknown time-varying control coefficient and model uncertainties to design the controller. Motivated by this observation, we propose a robust control for the Segway with unknown control coefficient and model uncertainties. To deal with the time-varying unknown control coefficient, we employ the Nussbaum gain technique. We introduce an auxiliary variable to solve the underactuated problem. Due to the prescribed performance control technique, the proposed controller does not require the adaptive technique, neural network, and fuzzy logic to compensate the uncertainties. Therefore, it can be simple. From the Lyapunov stability theory, we prove that all signals in the closed-loop system are bounded. Finally, we provide the simulation results to demonstrate the effectiveness of the proposed control scheme. PMID:27367696

  20. Robust Control for the Segway with Unknown Control Coefficient and Model Uncertainties.

    PubMed

    Kim, Byung Woo; Park, Bong Seok

    2016-01-01

    The Segway, which is a popular vehicle nowadays, is an uncertain nonlinear system and has an unknown time-varying control coefficient. Thus, we should consider the unknown time-varying control coefficient and model uncertainties to design the controller. Motivated by this observation, we propose a robust control for the Segway with unknown control coefficient and model uncertainties. To deal with the time-varying unknown control coefficient, we employ the Nussbaum gain technique. We introduce an auxiliary variable to solve the underactuated problem. Due to the prescribed performance control technique, the proposed controller does not require the adaptive technique, neural network, and fuzzy logic to compensate the uncertainties. Therefore, it can be simple. From the Lyapunov stability theory, we prove that all signals in the closed-loop system are bounded. Finally, we provide the simulation results to demonstrate the effectiveness of the proposed control scheme. PMID:27367696

  1. Practical robustness measures in multivariable control system analysis. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Lehtomaki, N. A.

    1981-01-01

    The robustness of the stability of multivariable linear time invariant feedback control systems with respect to model uncertainty is considered using frequency domain criteria. Available robustness tests are unified under a common framework based on the nature and structure of model errors. These results are derived using a multivariable version of Nyquist's stability theorem in which the minimum singular value of the return difference transfer matrix is shown to be the multivariable generalization of the distance to the critical point on a single input, single output Nyquist diagram. Using the return difference transfer matrix, a very general robustness theorem is presented from which all of the robustness tests dealing with specific model errors may be derived. The robustness tests that explicitly utilized model error structure are able to guarantee feedback system stability in the face of model errors of larger magnitude than those robustness tests that do not. The robustness of linear quadratic Gaussian control systems are analyzed.

  2. Optimal H∞ robust output feedback control for satellite formation in arbitrary elliptical reference orbits

    NASA Astrophysics Data System (ADS)

    Wei, Changzhu; Park, Sang-Young; Park, Chandeok

    2014-09-01

    A two degree-of-freedom signal-based optimal H∞ robust output feedback controller is designed for satellite formation in an arbitrary elliptical reference orbit. Based on high-fidelity linearized dynamics of relative motion, uncertainties introduced by non-zero eccentricity and gravitational J2 perturbation are separated to construct a robust control model. Furthermore, a distributed robust control model is derived by modifying the perturbed robust control model of each satellite with the eigenvalues of the Laplacian matrix of the communication graph, which represent uncertainty in the communication topology. A signal-based optimal H∞ robust controller is then designed primarily. Considering that the uncertainties involved in the distributed robust control model have a completely diagonal structure, the corresponding analyses are made through structured singular value theory to reduce the conservativeness. Based on simulation results, further designs including increasing the degrees of freedom of the controller, modifying the performance and control weighted functions, adding a post high-pass filter according to the dynamic characteristics, and reducing the control model are made to improve the control performance. Nonlinear simulations demonstrate that the resultant optimal H∞ robust output feedback controller satisfies the robust performance requirements under uncertainties caused by non-zero eccentricity, J2 perturbation, and varying communication topology, and that 5 m accuracy in terms of stable desired formation configuration can be achieved by the presented optimal H∞ robust controller. In addition to considering the widely discussed uncertainties caused by the orbit of each satellite in a formation, the optimal H∞ robust output feedback control model presented in the current work considers the uncertainties caused by varying communication topology in the satellite formation that works in a cooperative way. Other new improvements include adopting a

  3. Experimental study of robustness in adaptive control for large flexible structures

    NASA Technical Reports Server (NTRS)

    Ih, Che-Hang Charles; Bayard, David S.; Ahmed, Asif; Wang, Shyh Jong

    1990-01-01

    An experimental study is performed to investigate the robustness of model reference adaptive control for the large flexible structures control application. The main nonidealities of concern are unmodeled dynamics, input saturation, and time delay effects (here, actuator and sensor dynamics are lumped into the last item for convenience). This study focuses on the robustness with respect to input saturation and time delay effects, since robustness to unmodeled dynamics is inherent to the basic algorithm and has been demonstrated experimentally elsewhere.

  4. The application of cost averaging techniques to robust control of the benchmark problem

    NASA Technical Reports Server (NTRS)

    Hagood, Nesbitt W.; Crawley, Edward F.

    1991-01-01

    A method is presented for the synthesis of robust controllers for linear time invariant systems with parameterized uncertainty structures. The method involves minimizing the average quadratic (H2) cost over the parameterized system. Bonded average cost implies stability over the set of systems. The average cost functional is minimized to derive robust fixed-order dynamic compensators. The robustness properties of these controllers are demonstrated on the sample problem.

  5. Patient-reported Outcomes in Randomised Controlled Trials of Prostate Cancer: Methodological Quality and Impact on Clinical Decision Making

    PubMed Central

    Efficace, Fabio; Feuerstein, Michael; Fayers, Peter; Cafaro, Valentina; Eastham, James; Pusic, Andrea; Blazeby, Jane

    2014-01-01

    Context Patient-reported outcomes (PRO) data from randomised controlled trials (RCTs) are increasingly used to inform patient-centred care as well as clinical and health policy decisions. Objective The main objective of this study was to investigate the methodological quality of PRO assessment in RCTs of prostate cancer (PCa) and to estimate the likely impact of these studies on clinical decision making. Evidence acquisition A systematic literature search of studies was undertaken on main electronic databases to retrieve articles published between January 2004 and March 2012. RCTs were evaluated on a predetermined extraction form, including (1) basic trial demographics and clinical and PRO characteristics; (2) level of PRO reporting based on the recently published recommendations by the International Society for Quality of Life Research; and (3) bias, assessed using the Cochrane Risk of Bias tool. Studies were systematically analysed to evaluate their relevance for supporting clinical decision making. Evidence synthesis Sixty-five RCTs enrolling a total of 22 071 patients were evaluated, with 31 (48%) in patients with nonmetastatic disease. When a PRO difference between treatments was found, it related in most cases to symptoms only (n = 29, 58%). Although the extent of missing data was generally documented (72% of RCTs), few reported details on statistical handling of this data (18%) and reasons for dropout (35%). Improvements in key methodological aspects over time were found. Thirteen (20%) RCTs were judged as likely to be robust in informing clinical decision making. Higher-quality PRO studies were generally associated with those RCTs that had higher internal validity. Conclusions Including PRO in RCTs of PCa patients is critical for better evaluating the treatment effectiveness of new therapeutic approaches. Marked improvements in PRO quality reporting over time were found, and it is estimated that at least one-fifth of PRO RCTs have provided sufficient

  6. Robustness of a distributed neural network controller for locomotion in a hexapod robot

    NASA Technical Reports Server (NTRS)

    Chiel, Hillel J.; Beer, Randall D.; Quinn, Roger D.; Espenschied, Kenneth S.

    1992-01-01

    A distributed neural-network controller for locomotion, based on insect neurobiology, has been used to control a hexapod robot. How robust is this controller? Disabling any single sensor, effector, or central component did not prevent the robot from walking. Furthermore, statically stable gaits could be established using either sensor input or central connections. Thus, a complex interplay between central neural elements and sensor inputs is responsible for the robustness of the controller and its ability to generate a continuous range of gaits. These results suggest that biologically inspired neural-network controllers may be a robust method for robotic control.

  7. TREC-SAVE: a randomised trial comparing mechanical restraints with use of seclusion for aggressive or violent seriously mentally ill people: study protocol for a randomised controlled trial

    PubMed Central

    2011-01-01

    Background Thousands of people whose aggression is thought due to serious mental illness are secluded or restrained every day. Without fair testing these techniques will continue to be used outside of a rigorous evidence base. With such coercive treatment this leaves all concerned vulnerable to abuse and criticism. This paper presents the protocol for a randomised trial comparing seclusion with restraints for people with serious mental illnesses. Methods/Design Setting-General psychiatric wards of a large psychiatric hospital in Rio de Janeiro, Brazil. Participants-Anyone aggressive or violent suspected or known to have serious mental illness for whom restriction is felt to be indicated by nursing and medical staff, but also for whom they are unsure whether seclusion or restraint would be indicated. Interventions-The standard care of either strong cotton banding to edge of bed with medications as indicated and close observation or the other standard care of use of a minimally furnished seclusion room but with open but barred windows onto the nursing station. Outcomes-time to restrictions lifted, early change of treatment, additional episodes, adverse effects/events, satisfaction with care during episode. Duration-2 weeks. Identifier: ISRCTN 49454276 http://www.controlled-trials.com/ISRCTN49454276 PMID:21774823

  8. Injury risk in runners using standard or motion control shoes: a randomised controlled trial with participant and assessor blinding

    PubMed Central

    Malisoux, Laurent; Chambon, Nicolas; Delattre, Nicolas; Gueguen, Nils; Urhausen, Axel; Theisen, Daniel

    2016-01-01

    Background/aim This randomised controlled trial investigated if the usage of running shoes with a motion control system modifies injury risk in regular leisure-time runners compared to standard shoes, and if this influence depends on foot morphology. Methods Recreational runners (n=372) were given either the motion control or the standard version of a regular running shoe model and were followed up for 6 months regarding running activity and injury. Foot morphology was analysed using the Foot Posture Index method. Cox regression analyses were used to compare injury risk between the two groups, based on HRs and their 95% CIs, controlling for potential confounders. Stratified analyses were conducted to evaluate the effect of motion control system in runners with supinated, neutral and pronated feet. Results The overall injury risk was lower among the participants who had received motion control shoes (HR=0.55; 95% CI 0.36 to 0.85) compared to those receiving standard shoes. This positive effect was only observed in the stratum of runners with pronated feet (n=94; HR=0.34; 95% CI 0.13 to 0.84); there was no difference in runners with neutral (n=218; HR=0.78; 95% CI 0.44 to 1.37) or supinated feet (n=60; HR=0.59; 95% CI 0.20 to 1.73). Runners with pronated feet using standard shoes had a higher injury risk compared to those with neutral feet (HR=1.80; 95% CI 1.01 to 3.22). Conclusions The overall injury risk was lower in participants who had received motion control shoes. Based on secondary analysis, those with pronated feet may benefit most from this shoe type. PMID:26746907

  9. Non-invasive vagus nerve stimulation for PREVention and Acute treatment of chronic cluster headache (PREVA): A randomised controlled study

    PubMed Central

    Diener, Hans-Christoph; Silver, Nicholas; Magis, Delphine; Reuter, Uwe; Andersson, Annelie; Liebler, Eric J; Straube, Andreas

    2015-01-01

    Background Chronic cluster headache (CH) is a debilitating disorder for which few well-controlled studies demonstrate effectiveness of available therapies. Non-invasive vagus nerve stimulation (nVNS) was examined as adjunctive prophylactic treatment of chronic CH. Methods PREVA was a prospective, open-label, randomised study that compared adjunctive prophylactic nVNS (n = 48) with standard of care (SoC) alone (control (n = 49)). A two-week baseline phase was followed by a four-week randomised phase (SoC plus nVNS vs control) and a four-week extension phase (SoC plus nVNS). The primary end point was the reduction in the mean number of CH attacks per week. Response rate, abortive medication use and safety/tolerability were also assessed. Results During the randomised phase, individuals in the intent-to-treat population treated with SoC plus nVNS (n = 45) had a significantly greater reduction in the number of attacks per week vs controls (n = 48) (−5.9 vs −2.1, respectively) for a mean therapeutic gain of 3.9 fewer attacks per week (95% CI: 0.5, 7.2; p = 0.02). Higher ≥50% response rates were also observed with SoC plus nVNS (40% (18/45)) vs controls (8.3% (4/48); p < 0.001). No serious treatment-related adverse events occurred. Conclusion Adjunctive prophylactic nVNS is a well-tolerated novel treatment for chronic CH, offering clinical benefits beyond those with SoC. PMID:26391457

  10. Exercise and manual physiotherapy arthritis research trial (EMPART): a multicentre randomised controlled trial

    PubMed Central

    French, Helen P; Cusack, Tara; Brennan, Aisling; White, Breon; Gilsenan, Clare; Fitzpatrick, Martina; O'Connell, Paul; Kane, David; FitzGerald, Oliver; McCarthy, Geraldine M

    2009-01-01

    Background Osteoarthritis (OA) of the hip is a major cause of functional disability and reduced quality of life. Management options aim to reduce pain and improve or maintain physical functioning. Current evidence indicates that therapeutic exercise has a beneficial but short-term effect on pain and disability, with poor long-term benefit. The optimal content, duration and type of exercise are yet to be ascertained. There has been little scientific investigation into the effectiveness of manual therapy in hip OA. Only one randomized controlled trial (RCT) found greater improvements in patient-perceived improvement and physical function with manual therapy, compared to exercise therapy. Methods and design An assessor-blind multicentre RCT will be undertaken to compare the effect of a combination of manual therapy and exercise therapy, exercise therapy only, and a waiting-list control on physical function in hip OA. One hundred and fifty people with a diagnosis of hip OA will be recruited and randomly allocated to one of 3 groups: exercise therapy, exercise therapy with manual therapy and a waiting-list control. Subjects in the intervention groups will attend physiotherapy for 6–8 sessions over 8 weeks. Those in the control group will remain on the waiting list until after this time and will then be re-randomised to one of the two intervention groups. Outcome measures will include physical function (WOMAC), pain severity (numerical rating scale), patient perceived change (7-point Likert scale), quality of life (SF-36), mood (hospital anxiety and depression scale), patient satisfaction, physical activity (IPAQ) and physical measures of range of motion, 50-foot walk and repeated sit-to stand tests. Discussion This RCT will compare the effectiveness of the addition of manual therapy to exercise therapy to exercise therapy only and a waiting-list control in hip OA. A high quality methodology will be used in keeping with CONSORT guidelines. The results will contribute

  11. Robust fault-tolerant tracking control design for spacecraft under control input saturation.

    PubMed

    Bustan, Danyal; Pariz, Naser; Sani, Seyyed Kamal Hosseini

    2014-07-01

    In this paper, a continuous globally stable tracking control algorithm is proposed for a spacecraft in the presence of unknown actuator failure, control input saturation, uncertainty in inertial matrix and external disturbances. The design method is based on variable structure control and has the following properties: (1) fast and accurate response in the presence of bounded disturbances; (2) robust to the partial loss of actuator effectiveness; (3) explicit consideration of control input saturation; and (4) robust to uncertainty in inertial matrix. In contrast to traditional fault-tolerant control methods, the proposed controller does not require knowledge of the actuator faults and is implemented without explicit fault detection and isolation processes. In the proposed controller a single parameter is adjusted dynamically in such a way that it is possible to prove that both attitude and angular velocity errors will tend to zero asymptotically. The stability proof is based on a Lyapunov analysis and the properties of the singularity free quaternion representation of spacecraft dynamics. Results of numerical simulations state that the proposed controller is successful in achieving high attitude performance in the presence of external disturbances, actuator failures, and control input saturation. PMID:24751476

  12. Reporting trends of randomised controlled trials in heart failure with preserved ejection fraction: a systematic review

    PubMed Central

    Zheng, Sean L; Chan, Fiona T; Maclean, Edd; Jayakumar, Shruti; Nabeebaccus, Adam A

    2016-01-01

    Background Heart failure with preserved ejection fraction (HFpEF) causes significant cardiovascular morbidity and mortality. Current consensus guidelines reflect the neutral results from randomised controlled trials (RCTs). Adequate trial reporting is a fundamental requirement before concluding on RCT intervention efficacy and is necessary for accurate meta-analysis and to provide insight into future trial design. The Consolidated Standards of Reporting Trials (CONSORT) 2010 statement provides a framework for complete trial reporting. Reporting quality of HFpEF RCTs has not been previously assessed, and this represents an important validation of reporting qualities to date. Objectives The aim was to systematically identify RCTs investigating the efficacy of pharmacological therapies in HFpEF and to assess the quality of reporting using the CONSORT 2010 statement. Methods MEDLINE, EMBASE and CENTRAL databases were searched from January 1996 to November 2015, with RCTs assessing pharmacological therapies on clinical outcomes in HFpEF patients included. The quality of reporting was assessed against the CONSORT 2010 checklist. Results A total of 33 RCTs were included. The mean CONSORT score was 55.4% (SD 17.2%). The CONSORT score was strongly correlated with journal impact factor (r=0.53, p=0.003) and publication year (r=0.50, p=0.003). Articles published after the introduction of CONSORT 2010 statement had a significantly higher mean score compared with those published before (64% vs 50%, p=0.02). Conclusions Although the CONSORT score has increased with time, a significant proportion of HFpEF RCTs showed inadequate reporting standards. The level of adherence to CONSORT criteria could have an impact on the validity of trials and hence the interpretation of intervention efficacy. We recommend improving compliance with the CONSORT statement for future RCTs. PMID:27547434

  13. Discrepancies between registration and publication of randomised controlled trials: an observational study

    PubMed Central

    Stevenson, Graham; Thornton, James G

    2014-01-01

    Summary Objectives To determine the consistency between information contained in the registration and publication of randomised controlled trials (RCTs). Design An observational study of RCTs published between May 2011 and May 2012 in the British Medical Journal (BMJ) and the Journal of the American Medical Association (JAMA) comparing registry data with publication data. Participants and Settings Data extracted from published RCTs in BMJ and JAMA. Main outcome measures Timing of trial registration in relation to completion of trial data collection and publication. Registered versus published primary and secondary outcomes, sample size. Results We identified 40 RCTs in BMJ and 36 in JAMA. All 36 JAMA trials and 39 (98%) BMJ trials were registered. All registered trials were registered prior to publication. Thirty-two (82%) BMJ trials recorded the date of data completion; of these, in two trials the date of trial registration postdated the registered date of data completion. There were discrepancies between primary outcomes declared in the trial registry information and in the published paper in 18 (47%) BMJ papers and seven (19%) JAMA papers. The original sample size stated in the trial registration was achieved in 24 (60%) BMJ papers and 21 (58%) JAMA papers. Conclusions Compulsory registration of RCTs is meaningless if the content of registry information is not complete or if discrepancies between registration and publication are not reported. This study demonstrates that discrepancies in primary and secondary outcomes and sample size between trial registration and publication remain commonplace, giving further strength to the World Health Organisation’s argument for mandatory completion of a minimum number of compulsory fields. PMID:25057391

  14. Doubly blind: a systematic review of gender in randomised controlled trials

    PubMed Central

    Phillips, Susan P; Hamberg, Katarina

    2016-01-01

    Background Although observational data show social characteristics such as gender or socio-economic status to be strong predictors of health, their impact is seldom investigated in randomised controlled studies (RCTs). Objective & design Using a random sample of recent RCTs from high-impact journals, we examined how the most often recorded social characteristic, sex/gender, is considered in design, analysis, and interpretation. Of 712 RCTs published from September 2008 to 31 December 2013 in the Annals of Internal Medicine, British Medical Journal, Lancet, Canadian Medical Association Journal, or New England Journal of Medicine, we randomly selected 57 to analyse funding, methods, number of centres, documentation of social circumstances, inclusion/exclusion criteria, proportions of women/men, and reporting about sex/gender in analyses and discussion. Results Participants’ sex was recorded in most studies (52/57). Thirty-nine percent included men and women approximately equally. Overrepresentation of men in 43% of studies without explicit exclusions for women suggested interference in selection processes. The minority of studies that did analyse sex/gender differences (22%) did not discuss or reflect upon these, or dismissed significant findings. Two studies reinforced traditional beliefs about women's roles, finding no impact of breastfeeding on infant health but nevertheless reporting possible benefits. Questionable methods such as changing protocols mid-study, having undefined exclusion criteria, allowing local researchers to remove participants from studies, and suggesting possible benefit where none was found were evident, particularly in industry-funded research. Conclusions Social characteristics like sex/gender remain hidden from analyses and interpretation in RCTs, with loss of information and embedding of error all along the path from design to interpretation, and therefore, to uptake in clinical practice. Our results suggest that to broaden external

  15. Comparison of propranolol and pregabalin for prophylaxis of childhood migraine: a randomised controlled trial.

    PubMed

    Bakhshandeh Bali, MohammadKazem; Rahbarimanesh, Ali Akbar; Sadeghi, Manelie; Sedighi, Mostafa; Karimzadeh, Parvaneh; Ghofrani, Mohammad

    2015-01-01

    Migraine involves 5-10% of children and adolescents. Thirty percent of children with severe migraine attacks have school absence and reduced quality of life that need preventive therapy. The purpose of this randomised control trial study is to compare the effectiveness, safety and the tolerability of pregabalin toward Propranolol in migraine prophylaxis of children. From May 2011 to October 2012, 99 children 3-15 years referred to the neurology clinic of Mofid Children's Hospital with a diagnosis of migraine enrolled the study. Patients randomly divided into two groups (A&B). We treated children of group A with capsule of pregabalin as children of group B with tablet of propranolol for at least 8 weeks. In this study, 99 patients were examined that 91 children reached the last stage. The group A consistsed of 46 patients, 12(26.1%) girls, 34 (73.9%) boys and the group B consisted of 45 patients, 14(31.1%) girls, 31 (68.9%) boys. Basis of age, gender, headache onset, headache frequency, migraine type, triggering and relieving factors there was no significant difference among these groups (P>0.05). After 4 and 8 weeks of Pregabalin usage monthly headache frequency decreased to 2.2±4.5 and 1.76±6.2 respectively. Propranolol reduced monthly headache frequency up to 3.73±6.11 and 3.34±5.95 later 4 and 8 weeks respectively. There was a significant difference between these two groups according to headache frequency reduction (P=0.04). Pregabalin efficacy in reducing the frequency and duration of pediatric migraine headache is considerable in comparison with propranolol. PMID:26024701

  16. Telephone-delivered nutrition and exercise counselling after auto-SCT: a pilot, randomised controlled trial.

    PubMed

    Hung, Y-C; Bauer, J D; Horsely, P; Coll, J; Bashford, J; Isenring, E A

    2014-06-01

    Adverse changes in nutrition-related outcomes including quality of life (QoL) occur after PBSC transplantation. This randomised controlled trial aims to evaluate the impact of nutrition and exercise counselling provided at hospital discharge on nutritional status, body composition and QoL post transplantation. Usual care (UC) (n=19) received no intervention after discharge; extended care (EC) (n=18) received fortnightly telephone counselling from a dietitian and exercise physiologist up to 100 days post transplantation. Nutritional status (patient-generated subjective global assessment, and diet history), QoL (EORTC QLQ-C30 version 3) and body composition (air displacement plethysmography) were assessed at pre-admission, discharge and 100 days post transplantation. Intervention groups were compared using two-sample t-tests of changes in the outcomes; results were adjusted using analysis of covariance. EC exhibited clinically important but not statistically significant increases in protein intake (14.7 g; confidence interval (CI) 95% -6.5, 35.9, P=0.165), cognitive functioning (7.2; CI 95% -7.9, 22.2, P=0.337) and social functioning (16.5; CI 95% -7.3, 40.3, P=0.165) compared with UC. Relative to pre-admission, EC experienced less weight loss than UC (-3.3 kg; CI 95% -6.7, 0.2, P=0.062). Physical activity was not significantly different between the groups. Ongoing nutrition and exercise counselling may prevent further weight loss and improve dietary intake and certain QoL components in autologous PBSC transplantation patients following hospitalisation. PMID:24710562

  17. New vertebral fractures after vertebroplasty: 2 year results from a randomised controlled trial

    PubMed Central

    Staples, MP; Howe, BM; Ringler, MD; Mitchell, P; Wriedt, CHR; Wark, JD; Ebeling, PR; Osborne, RH; Kallmes, DF; Buchbinder, R

    2015-01-01

    Purpose To assess the effect of vertebroplasty (VP) on the risk of further radiologically apparent vertebral fracture within two years of the procedure. Methods We conducted a randomised placebo-controlled trial of VP in people with acute osteoporotic vertebral fracture. Eligible participants were randomly assigned to VP (n=38) or placebo (n=40). Cement volume and leakage were recorded for the VP group. Plain thoracolumbar radiographs were taken at baseline, 12 and 24 months. Two independent radiologists assessed these for new and progressed fractures at the same, adjacent and non-adjacent levels. Results At 12 and 24 months, radiographs were available for 45 (58%) and 47 (60%) participants respectively. There were no between-group differences for new or progressed fractures: 32 and 40 in the VP group after 12 and 24 months compared with 21 and 33 in the placebo group (hazard ratio (HR) 1.80, 95% confidence interval (CI) 0.82 to 3.94). Similar results were seen when considering only adjacent (HR (95% CI): 2.30 (0.57 to 9.29)), and non-adjacent (HR (95% CI): 1.45 (0.55 to 3.81) levels. In all comparisons there was a consistent trend towards higher risk of any type of fracture in the group undergoing VP. Within the VP group, fracture risk was unrelated to total (HR (95% CI): 0.91 (0.71 to 1.17)) or relative (HR (95% CI): 1.31 (0.15 to 11.48)) cement volume, or cement leakage (HR (95% CI): 1.20 (0.63 to 2.31)). Conclusion For patients undergoing VP our study did not demonstrate significant increases in subsequent fracture risk beyond that experienced by those with vertebral fractures who did not undergo the procedure. However, because of the non-significant numerical increases observed, studies with adequate power are needed to draw definite conclusions about fracture risk. PMID:26272712

  18. Melatonin premedication versus placebo in wisdom teeth extraction: a randomised controlled trial

    PubMed Central

    Seet, Edwin; Liaw, Chen Mei; Tay, Sylvia; Su, Chang

    2015-01-01

    INTRODUCTION Pain after wisdom teeth surgery can be moderate in severity and is compounded by preoperative anxiety in young patients. We studied the effect of melatonin premedication on postoperative pain and preoperative anxiety in patients undergoing wisdom teeth extractions. METHODS This randomised controlled trial recruited 76 patients at Khoo Teck Puat Hospital who were American Society of Anesthesiologists physical status I and II, aged 21 to 65 and scheduled to undergo elective extraction of all four wisdom teeth under general anaesthesia. Patients with a history of long-term use or allergy to melatonin were excluded. The patients received either 6 mg melatonin or a placebo 90 minutes before surgery. Visual analogue scale (VAS) scores at multiple time intervals for postoperative pain and preoperative anxiety, patient satisfaction and first-night sleep quality scores were obtained. Mixed-effects regression models were used for longitudinal analysis of VAS pain, anxiety and satisfaction scores. RESULTS Maximum VAS scores for pain and anxiety were 18.6 ± 19.1 mm at 60 minutes postoperatively and 26.2 ± 23.4 mm at 90 minutes preoperatively, respectively. After adjusting for gender, female patients who received melatonin had a faster rate of reduction of VAS pain (p = 0.020) and anxiety scores (p = 0.003) over time compared to the placebo group. No such effect was demonstrated in male patients. There was no significant difference in sleep quality or satisfaction scores. CONCLUSION Melatonin use did not consistently contribute to pain and anxiety amelioration in all patients. Our study demonstrated a positive effect in female patients, suggestive of sexual dimorphism. PMID:26702161

  19. Herbal medicines for treating tic disorders: a systematic review of randomised controlled trials

    PubMed Central

    2014-01-01

    Background It was reported that 64% of tic disorder patients used complementary and alternative medicine. This review aims to evaluate the efficacy of herbal medicines in treating tic disorders. Methods We searched eight databases including MEDLINE and CINAHL from their respective inceptions up to September 2013. The search terms were related to the concept of “herbal medicine” AND “tic disorder OR Tourette’s syndrome”. We included randomised controlled trials (RCTs) of any type of herbal medicines. We assessed the methodological quality of the trials according to the Cochrane risk of bias criteria. Results Sixty one studies were identified, and four RCTs met the inclusion criteria. Two types of herbal medicines, Qufeng Zhidong Recipe (QZR) decoction and Ningdong (ND) granules, were used in the included RCTs. All four RCTs had a high risk of bias. Two RCTs tested the effects of QZR on the Yale Global Tic Severity Scale (YGTSS) score and response rate compared with conventional medicine. The meta-analysis showed significant effects of QZR on the YGTSS score with high statistical heterogeneity (n = 142; weighted mean difference: −18.34; 95% confidence interval (CI): −23.07 to −13.60; I2 = 97%) and the response rate (n = 142; risk ratio: 1.69; 95% CI: 1.39 to 2.06; I2 = 0%). One RCT compared ND granules with placebo and showed significant effects on the YGTSS score and response rate. The other RCT show significant effects of ND granules plus conventional medicine on the response rate compared with conventional medicine only. Conclusion This systematic review provided first piece of limited meta-analytic evidence for the effectiveness of herbal medicines in improving the symptoms of tic disorders. PMID:24507013

  20. Effectiveness of the Baby Friendly Community Initiative in Italy: a non-randomised controlled study

    PubMed Central

    Cattaneo, Adriano; Bettinelli, Maria Enrica; Chapin, Elise; Macaluso, Anna; Córdova do Espírito Santo, Lílian; Murante, Anna Maria; Montico, Marcella

    2016-01-01

    Objective To assess the effectiveness of the Baby Friendly Community Initiative (BFCI) on exclusive breast feeding at 6 months. Design Controlled, non-randomised trial. Setting 18 Local Health Authorities in 9 regions of Italy. Participants 5094 mother/infant dyads in 3 cohorts were followed up to 12 months after birth in 3 rounds of data collection: at baseline, after implementation of the intervention in the early intervention group and after implementation in the late intervention group. 689 (14%) dyads did not complete the study. Intervention Implementation of the 7 steps of the BFCI. Main outcome measures The rate of exclusive breast feeding at 6 months was the primary outcome; breast feeding at discharge, 3 and 12 months was also measured. Results The crude rates of exclusive breast feeding at discharge, 3 and 6 months, and of any breast feeding at 6 and 12 months increased at each round of data collection after baseline in the early and late intervention groups. At the end of the project, 10% of infants were exclusively breast fed at 6 months and 38% were continuing to breast feed at 12 months. However, the comparison by adjusted rates and logistic regression failed to show statistically significant differences between groups and rounds of data collection in the intention-to-treat analysis, as well as when compliance with the intervention and training coverage was taken into account. Conclusions The study failed to demonstrate an effect of the BFCI on the rates of breast feeding. This may be due, among other factors, to the time needed to observe an effect on breast feeding following this complex intervention. PMID:27154476

  1. Integrative medicine for subacute stroke rehabilitation: a study protocol for a multicentre, randomised, controlled trial

    PubMed Central

    Fang, Jianqiao; Chen, Lifang; Chen, Luni; Wang, Chao; Keeler, Crystal Lynn; Ma, Ruijie; Xu, Shouyu; Shen, Laihua; Bao, Yehua; Ji, Conghua

    2014-01-01

    Introduction Many patients with stroke receive integrative medicine in China, which includes the basic treatment of Western medicine and routine rehabilitation, in conjunction with acupuncture and Chinese medicine. The question of whether integrative medicine is efficacious for stroke rehabilitation is still controversial and very little research currently exists on the integrated approach for this condition. Consequently, we will conduct a multicentre, randomised, controlled, assessor-blinded clinical trial to assess the effectiveness of integrative medicine on stroke rehabilitation. Methods and analysis 360 participants recruited from three large Chinese medical hospitals in Zhejiang Province will be randomly divided into the integrative medicine rehabilitation (IMR) group and the conventional rehabilitation (CR) group in a 1:1 ratio. Participants in the IMR group will receive acupuncture and Chinese herbs in addition to basic Western medicine and rehabilitation treatment. The CR group will not receive acupuncture and Chinese herbal medicine. The assessment data will be collected at baseline, 4 and 8 weeks postrandomisation, and then at 12 weeks’ follow-up. The primary outcome is measured by the Modified Barthel Index. The secondary outcomes are the National Institutes of Health Stroke Scale (NIHSS), Fugl-Meyer Assessment, the mini-mental state examination and Montreal Cognitive, Hamilton's Depression Scale and Self-Rating Depression Scale, and the incidence of adverse events. Ethics and dissemination Ethical approval was obtained from ethics committees of three hospitals. The results will be disseminated in a peer-reviewed journal and presented at international congresses. The results will also be disseminated to patients by telephone, during follow-up calls inquiring on patient's post-study health status. Trial registration number Chinese Clinical Trial Register: ChiCTR-TRC-12001972, http://www.chictr.org/en/proj/show.aspx?proj=2561 PMID:25475247

  2. Home screening for sexually transmitted diseases in high‐risk young women: randomised controlled trial

    PubMed Central

    Cook, Robert L; Østergaard, Lars; Hillier, Sharon L; Murray, Pamela J; Chang, Chung‐Chou H; Comer, Diane M; Ness, Roberta B

    2007-01-01

    Objective Home screening tests could eliminate several barriers to testing sexually transmitted diseases (STDs). Aim To determine whether offering repeated home screening tests would increase the rate of testing for chlamydia and gonorrhoea in a high‐risk sample of young women. Methods In this randomised controlled trial, 403 young women (mean age 18.9 years, 70% black) with a recent STD or with STD‐related risk factors were enrolled. Participants were recruited from clinics and high‐prevalence neighbourhoods and then randomly assigned to receive either a home testing kit or an invitation to attend a medical clinic for testing at 6, 12 and 18 months after enrollment. Over 80% of women were followed for 2 years. The trial is registered with ClinicalTrials.gov, number NCT 00177437. Results Of 197 women in the intervention group, 140 (71%) returned at least one home test and 25 of 249 (10%) home tests were positive. Women who received home screening tests completed significantly more STD tests overall (1.94 vs 1.41 tests per woman‐year, p<0.001) and more STD tests in the absence of symptoms (1.18 vs 0.75 tests per woman‐year, p<0.001). More women in the intervention group completed at least one test when asymptomatic (162 (82.2%) vs 117 (61.3%), p<0.001). The intervention was most effective among women recruited outside medical clinics. There was no significant difference in the overall rate of STDs detected. Conclusions Home screening significantly increased the utilisation of chlamydia and gonorrhoea testing in this sample of high‐risk young women, and thus represents a feasible strategy to facilitate STD testing in young women. PMID:17301105

  3. Outpatient versus inpatient uterine polyp treatment for abnormal uterine bleeding: randomised controlled non-inferiority study

    PubMed Central

    Cooper, Natalie A M; Middleton, Lee; Diwakar, Lavanya; Smith, Paul; Denny, Elaine; Roberts, Tracy; Stobert, Lynda; Jowett, Susan; Daniels, Jane

    2015-01-01

    Objective To compare the effectiveness and acceptability of outpatient polypectomy with inpatient polypectomy. Design Pragmatic multicentre randomised controlled non-inferiority study. Setting Outpatient hysteroscopy clinics in 31 UK National Health Service hospitals. Participants 507 women who attended as outpatients for diagnostic hysteroscopy because of abnormal uterine bleeding and were found to have uterine polyps. Interventions Participants were randomly assigned to either outpatient uterine polypectomy under local anaesthetic or inpatient uterine polypectomy under general anaesthesia. Data were collected on women’s self reported bleeding symptoms at baseline and at 6, 12, and 24 months. Data were also collected on pain and acceptability of the procedure at the time of polypectomy. Main outcome measures The primary outcome was successful treatment, determined by the women’s assessment of bleeding at six months, with a prespecified non-inferiority margin of 25%. Secondary outcomes included generic (EQ-5D) and disease specific (menorrhagia multi-attribute scale) quality of life, and feasibility and acceptability of the procedure. Results 73% (166/228) of women in the outpatient group and 80% (168/211) in the inpatient group reported successful treatment at six months (intention to treat relative risk 0.91, 95% confidence interval 0.82 to 1.02; per protocol relative risk 0.92, 0.82 to 1.02). Failure to remove polyps was higher (19% v 7%; relative risk 2.5, 1.5 to 4.1) and acceptability of the procedure was lower (83% v 92%; 0.90, 0.84 to 0.97) in the outpatient group Quality of life did not differ significantly between the groups. Four uterine perforations, one of which necessitated bowel resection, all occurred in the inpatient group. Conclusions Outpatient polypectomy was non-inferior to inpatient polypectomy. Failure to remove a uterine polyp was, however, more likely with outpatient polypectomy and acceptability of the procedure was slightly lower. Trial

  4. Effect of lactobacillus in preventing post-antibiotic vulvovaginal candidiasis: a randomised controlled trial

    PubMed Central

    Pirotta, Marie; Gunn, Jane; Chondros, Patty; Grover, Sonia; O'Malley, Paula; Hurley, Susan; Garland, Suzanne

    2004-01-01

    Objective To test whether oral or vaginal lactobacillus can prevent vulvovaginitis after antibiotic treatment. Design Randomised, placebo controlled, double blind, factorial 2×2 trial. Setting Fifty general practices and 16 pharmacies in Melbourne, Australia. Participants Non-pregnant women aged 18-50 years who required a short course of oral antibiotics for a non-gynaecological infection: 278 were enrolled in the study, and results were available for 235. Interventions Lactobacillus preparations taken orally or vaginally, or both, from enrolment until four days after completion of their antibiotic course. Main outcome measures Participants' reports of symptoms of post-antibiotic vulvovaginitis, with microbiological evidence of candidiasis provided by a self obtained vaginal swab. Results Overall, 55/235 (23% (95% confidence interval 18% to 29%)) women developed post-antibiotic vulvovaginitis. Compared with placebo, the odds ratio for developing post-antibiotic vulvovaginitis with oral lactobacillus was 1.06 (95% confidence interval 0.58 to 1.94) and with vaginal lactobacillus 1.38 (0.75 to 2.54). Compliance with antibiotics and interventions was high. The trial was terminated after the second interim analysis because of lack of effect of the interventions. Given the data at this time, the chances of detecting a significant reduction in vulvovaginitis with oral or vaginal lactobacillus treatment were less than 0.032 and 0.0006 respectively if the trial proceeded to full enrolment. Conclusions The use of oral or vaginal forms of lactobacillus to prevent post-antibiotic vulvovaginitis is not supported by these results. Further research on this subject is unlikely to be fruitful, unless new understandings about the pathogenesis of post-antibiotic vulvovaginitis indicate a possible role for lactobacillus. PMID:15333452

  5. Double blind randomised controlled trial of two different breathing techniques in the management of asthma

    PubMed Central

    Slader, C A; Reddel, H K; Spencer, L M; Belousova, E G; Armour, C L; Bosnic‐Anticevich, S Z; Thien, F C K; Jenkins, C R

    2006-01-01

    Background Previous studies have shown that breathing techniques reduce short acting β2 agonist use and improve quality of life (QoL) in asthma. The primary aim of this double blind study was to compare the effects of breathing exercises focusing on shallow nasal breathing with those of non‐specific upper body exercises on asthma symptoms, QoL, other measures of disease control, and inhaled corticosteroid (ICS) dose. This study also assessed the effect of peak flow monitoring on outcomes in patients using breathing techniques. Methods After a 2 week run in period, 57 subjects were randomised to one of two breathing techniques learned from instructional videos. During the following 30 weeks subjects practised their exercises twice daily and as needed for relief of symptoms. After week 16, two successive ICS downtitration steps were attempted. The primary outcome variables were QoL score and daily symptom score at week 12. Results Overall there were no clinically important differences between the groups in primary or secondary outcomes at weeks 12 or 28. The QoL score remained unchanged (0.7 at baseline v 0.5 at week 28, p = 0.11 both groups combined), as did lung function and airway responsiveness. However, across both groups, reliever use decreased by 86% (p<0.0001) and ICS dose was reduced by 50% (p<0.0001; p>0.10 between groups). Peak flow monitoring did not have a detrimental effect on asthma outcomes. Conclusion Breathing techniques may be useful in the management of patients with mild asthma symptoms who use a reliever frequently, but there is no evidence to favour shallow nasal breathing over non‐specific upper body exercises. PMID:16517572

  6. Comparison of methadone and buprenorphine for opiate detoxification (LEEDS trial): a randomised controlled trial

    PubMed Central

    Wright, Nat MJ; Sheard, Laura; Adams, Clive E; Rushforth, Bruno J; Harrison, Wendy; Bound, Nicole; Hart, Roger; Tompkins, Charlotte NE

    2011-01-01

    Background Many opiate users require prescribed medication to help them achieve abstinence, commonly taking the form of a detoxification regime. In UK prisons, drug users are nearly universally treated for their opiate use by primary care clinicians, and once released access GP services where 40% of practices now treat drug users. There is a paucity of evidence evaluating methadone and buprenorphine (the two most commonly prescribed agents in the UK) for opiate detoxification. Aim To evaluate whether buprenorphine or methadone help to achieve drug abstinence at completion of a reducing regimen for heroin users presenting to UK prison health care for detoxification. Design Open-label, pragmatic, randomised controlled trial in three prison primary healthcare departments in the north of England. Method Prisoners (n = 306) using illicit opiates were recruited and given daily sublingual buprenorphine or oral methadone, in the context of routine care, over a standard reduced regimen of not more than 20 days. The primary outcome measure was abstinence from illicit opiates at 8 days post detoxification, as indicated by urine test (self-report/clinical notes where urine sample was not feasible). Secondary outcomes were also recorded. Results Abstinence was ascertained for 73.7% at 8 days post detoxification (urine sample = 52.6%, self report = 15.2%, clinical notes = 5.9%). There was no statistically significant difference in the odds of achieving abstinence between methadone and buprenorphine (odds ratio [OR] = 1.69; 95% confidence interval [CI] = 0.81 to 3.51; P = 0.163). Abstinence was associated solely with whether or not the participant was still in prison at that time (15.22 times the odds; 95% CI = 4.19 to 55.28). The strongest association for lasting abstinence was abstinence at an earlier time point. Conclusion There is equal clinical effectiveness between methadone and buprenorphine in achieving abstinence from opiates at 8 days post detoxification within prison

  7. Pedometers to enhance physical activity in COPD: a randomised controlled trial

    PubMed Central

    Horta, Paula; Espinoza, José; Aguilera, Miguel; Balmaceda, Nicolás; Castro, Ariel; Ruiz, Mauricio; Díaz, Orlando; Hopkinson, Nicholas S.

    2015-01-01

    Physical inactivity is a cardinal feature of chronic obstructive pulmonary disease (COPD), and is associated with increased morbidity and mortality. Pedometers, which have been used in healthy populations, might also increase physical activity in patients with COPD. COPD patients taking part in a 3-month individualised programme to promote an increase in their daily physical activity were randomised to either a standard programme of physical activity encouragement alone, or a pedometer-based programme. Assessments were performed by investigators blinded to treatment allocation. Change in average 1-week daily step count, 6-min walking distance (6MWD), modified Medical Research Council scale, St George’s respiratory questionnaire (SGRQ) and COPD assessment test (CAT) were compared between groups. 102 patients were recruited, of whom 97 completed the programme (pedometer group: n=50; control group: n=47); 60.8% were male with a mean±sd age of 68.7±8.5 years, and forced expiratory volume in 1 s (FEV1) 66.1±19.4% and FEV1/forced vital capacity 55.2±9.5%. Both groups had comparable characteristics at baseline. The pedometer group had significantly greater improvements in: physical activity 3080±3254 steps·day−1 versus 138.3±1950 steps·day−1 (p<0.001); SGRQ −8.8±12.2 versus −3.8±10.9 (p=0.01); CAT score −3.5±5.5 versus −0.6±6.6 (p=0.001); and 6MWD 12.4±34.6 versus −0.7±24.4 m (p=0.02) than patients receiving activity encouragement only. A simple physical activity enhancement programme using pedometers can effectively improve physical activity level and quality of life in COPD patients. PMID:25261324

  8. Treatment of herpes simplex gingivostomatitis with aciclovir in children: a randomised double blind placebo controlled study.

    PubMed Central

    Amir, J.; Harel, L.; Smetana, Z.; Varsano, I.

    1997-01-01

    OBJECTIVES: To examine the efficacy of aciclovir suspension for treating herpetic gingivostomatitis in young children. DESIGN: Randomised double blind placebo controlled study. SETTING: Day care unit of a tertiary paediatric hospital. SUBJECTS: 72 children aged 1-6 years with clinical manifestations of gingivostomatitis lasting less than 72 hours; 61 children with cultures positive for herpes simplex virus finished the study. MAIN OUTCOME MEASURES: Duration of oral lesions, fever, eating and drinking difficulties, and viral shedding. INTERVENTION: Aciclovir suspension 15 mg/kg five times a day for seven days, or placebo. RESULTS: Children receiving aciclovir had oral lesions for a shorter period than children receiving placebo (median 4 v 10 days (difference 6 days, 95% confidence interval 4.0 to 8.0)) and earlier disappearance of the following signs and symptoms: fever (1 v 3 days (2 days, 0.8 to 3.2)); extraoral lesions (lesions around the mouth but outside the oral cavity) (0 v 5.5 days (5.5 days, 1.3 to 4.7)); eating difficulties (4 v 7 days (3 days, 1.31 to 4.69)); and drinking difficulties (3 v 6 days (3 days, 1.1 to 4.9)). Viral shedding was significantly shorter in the group treated with aciclovir (1 v 5 days (4 days, 2.9 to 5.1)). CONCLUSIONS: Oral aciclovir treatment for herpetic gingivostomatitis, started within the first three days of onset, shortens the duration of all clinical manifestations and the infectivity of affected children. Further studies are needed to evaluate the ideal dose and length of treatment. PMID:9224082

  9. Challenges associated with recruiting multigenerational, multicultural families into a randomised controlled trial: Balancing feasibility with validity.

    PubMed

    Hughes, Donna; Hutchinson, Amanda; Prichard, Ivanka; Chapman, Janine; Wilson, Carlene

    2015-07-01

    Recruitment of participants into research studies has become an increasingly difficult task with justifiable criticisms of representativeness of samples. The difficulties of recruitment are exacerbated when the study is longitudinal, requires multiple members from one family and incorporates people from non-dominant ethnic backgrounds. This paper describes a complex trial's recruitment process. Family groups were required for a longitudinal randomised controlled trial investigating links between health and dietary behaviours with an aim to improve primary prevention health messages and initiatives. To be representative of the multi-ethnic composition of the South Australian population, families from three of South Australia's largest ethnic backgrounds were invited to participate. Of these, only families with participating members spanning three generations were enrolled, so that links between health and lifestyle behaviours with possible generational ties could be investigated. Immense difficulties were faced during recruitment and significant modifications to the initial recruitment plan were necessary to enable the enrolment of 96 families. Challenges faced included lack of response to recruitment materials displaying complex eligibility criteria and different response outcomes from different communities. Solutions implemented included simplifying materials and tailoring recruitment activities to specific communities' needs. This trial's recruitment journey will be used as a case study to highlight the practicalities of recruiting for complex trials. Recommendations will be provided for future researchers seeking to recruit multigenerational, multi-ethnic families into the same study, along with issues to consider regarding the implications of the recruitment journey on the integrity of a complex trial and the potential threats to internal validity. PMID:26051796

  10. Randomised, double-blind controlled trial by dose reduction of implanted intrathecal morphine delivery in chronic non-cancer pain

    PubMed Central

    Raphael, Jon H; Duarte, Rui V; Southall, Jane L; Nightingale, Peter; Kitas, George D

    2013-01-01

    Objective This study aimed to investigate the efficacy of intrathecal morphine in the long term by hypothesising that a reduction of the intrathecal opioid dose following long-term administration would increase the level of pain intensity. Design Randomised, double-blind, controlled, parallel group trial. Setting Department of Pain Management, Russells Hall Hospital, Dudley, UK. Participants 24 patients with non-cancer pain implanted with morphine reservoirs were assessed for eligibility. Interventions Participants were randomly allocated to one of two parallel groups in which one of the groups had no change in morphine dose and the other group had a small reduction (20%) in dosage every week during a 10-week follow-up. Outcome Primary outcomes were visual analogue scale (VAS) pain score change and withdrawal from the study due to lack of efficacy. Results 9 of the patients assessed for eligibility declined to participate in the study. 15 patients were randomised to control (n=5) or intervention (n=10) and included in an intention-to-treat analysis. Owing to worsening of pain, seven patients withdrew from the study prematurely. None knew prior to withdrawal which arm of the study they were in, but all turned out to be in the dose-reduction arm. The calculation of dropout rates between groups indicated a significant statistical difference (p=0.026) and recruitment was ceased. The VAS change between baseline and the last observation was smaller in the control group (median, Mdn=11) than in the intervention group (Mdn=30.5), although not statistically significant, Z=−1.839, p=0.070; r=−0.47. Within groups, VAS was significantly lower at baseline (Mdn=49.5) than at the last observation (Mdn=77.5) for the reduction group, Z=−2.805, p=0.002; r=−0.627 but not for the control group (p=0.188). Conclusions This double-blind randomised controlled trial of chronic intrathecal morphine administration suggests the effectiveness of this therapy for the management of

  11. Robust Control for Microgravity Vibration Isolation using Fixed Order, Mixed H2/Mu Design

    NASA Technical Reports Server (NTRS)

    Whorton, Mark

    2003-01-01

    Many space-science experiments need an active isolation system to provide a sufficiently quiescent microgravity environment. Modern control methods provide the potential for both high-performance and robust stability in the presence of parametric uncertainties that are characteristic of microgravity vibration isolation systems. While H2 and H(infinity) methods are well established, neither provides the levels of attenuation performance and robust stability in a compensator with low order. Mixed H2/H(infinity), controllers provide a means for maximizing robust stability for a given level of mean-square nominal performance while directly optimizing for controller order constraints. This paper demonstrates the benefit of mixed norm design from the perspective of robustness to parametric uncertainties and controller order for microgravity vibration isolation. A nominal performance metric analogous to the mu measure, for robust stability assessment is also introduced in order to define an acceptable trade space from which different control methodologies can be compared.

  12. 6-PACK programme to decrease fall injuries in acute hospitals: cluster randomised controlled trial

    PubMed Central

    Morello, Renata T; Wolfe, Rory; Brand, Caroline A; Haines, Terry P; Hill, Keith D; Brauer, Sandra G; Botti, Mari; Cumming, Robert G; Livingston, Patricia M; Sherrington, Catherine; Zavarsek, Silva; Lindley, Richard I; Kamar, Jeannette

    2016-01-01

    Objective To evaluate the effect of the 6-PACK programme on falls and fall injuries in acute wards. Design Cluster randomised controlled trial. Setting Six Australian hospitals. Participants All patients admitted to 24 acute wards during the trial period. Interventions Participating wards were randomly assigned to receive either the nurse led 6-PACK programme or usual care over 12 months. The 6-PACK programme included a fall risk tool and individualised use of one or more of six interventions: “falls alert” sign, supervision of patients in the bathroom, ensuring patients’ walking aids are within reach, a toileting regimen, use of a low-low bed, and use of a bed/chair alarm. Main outcome measures The co-primary outcomes were falls and fall injuries per 1000 occupied bed days. Results During the trial, 46 245 admissions to 16 medical and eight surgical wards occurred. As many people were admitted more than once, this represented 31 411 individual patients. Patients’ characteristics and length of stay were similar for intervention and control wards. Use of 6-PACK programme components was higher on intervention wards than on control wards (incidence rate ratio 3.05, 95% confidence interval 2.14 to 4.34; P<0.001). In all, 1831 falls and 613 fall injuries occurred, and the rates of falls (incidence rate ratio 1.04, 0.78 to 1.37; P=0.796) and fall injuries (0.96, 0.72 to 1.27; P=0.766) were similar in intervention and control wards. Conclusions Positive changes in falls prevention practice occurred following the introduction of the 6-PACK programme. However, no difference was seen in falls or fall injuries between groups. High quality evidence showing the effectiveness of falls prevention interventions in acute wards remains absent. Novel solutions to the problem of in-hospital falls are urgently needed. Trial registration Australian New Zealand Clinical Trials Registry ACTRN12611000332921. PMID:26813674

  13. Efficacy of the heater probe in peptic ulcer with a non-bleeding visible vessel. A controlled, randomised study.

    PubMed Central

    Jaramillo, J L; Carmona, C; Gálvez, C; de la Mata, M; Miño, G

    1993-01-01

    A controlled, randomised study was performed to evaluate the efficacy of treatment with heater probe in the prevention of rebleeding from peptic ulcer with a non-bleeding visible vessel. One hundred and one patients were randomised into two groups: patients to be treated by heater probe (n = 51) and controls without active treatment (n = 50). In the heater probe group rebleeding occurred in five patients (10%) v 13 (26%) in the control group (p = 0.03), with a comparative risk of 0.38 in favour of the heater probe group. The difference in proportions of successful treatment for each group was 16.2% in favour of the heater probe (95% CI = 2 to 31%). Haemorrhage directly related to heater probe treatment occurred in four patients. In three of them bleeding was easily controlled by further heater probe pulses. There were no other complications and no death in the heater probe group. One patient in the control group died of pulmonary embolism. No significant differences in the length of stay in hospital, blood transfusions, surgical rates, or death were found; the design of the study, however, precluded an adequate assessment of these variables, because the heater probe was an optional rescue treatment when high surgical risk patients rebled. These results suggest that the heater probe is an effective and safe procedure in the prevention of recurrent haemorrhage in peptic ulcer with a non-bleeding visible vessel. PMID:8244132

  14. Can text messages increase safer sex behaviours in young people? Intervention development and pilot randomised controlled trial.

    PubMed Central

    Free, Caroline; McCarthy, Ona; French, Rebecca S; Wellings, Kaye; Michie, Susan; Roberts, Ian; Devries, Karen; Rathod, Sujit; Bailey, Julia; Syred, Jonathan; Edwards, Phil; Hart, Graham; Palmer, Melissa; Baraitser, Paula

    2016-01-01

    BACKGROUND Younger people bear the heaviest burden of sexually transmitted infections (STIs). Partner notification, condom use and STI testing can reduce infection but many young people lack the knowledge, skills and confidence needed to carry out these behaviours. Text messages can provide effective behavioural support. The acceptability and feasibility of a randomised controlled trial of safer sex support delivered by text message are not known. OBJECTIVES To assess the acceptability and feasibility of a randomised controlled trial of a safer sex intervention delivered by text message for young people aged 16-24 years. DESIGN (1) Intervention development; (2) follow-up procedure development; (3) a pilot, parallel-arm randomised controlled trial with allocation via remote automated randomisation (ratio of 1 : 1) (participants were unmasked, whereas researchers analysing samples and data were masked); and (4) qualitative interviews. SETTING Participants were recruited from sexual health services in the UK. PARTICIPANTS Young people aged 16-24 years diagnosed with chlamydia or reporting unprotected sex with more than one partner in the last year. INTERVENTIONS A theory- and evidence-based safer sex intervention designed, with young people's input, to reduce the incidence of STIs by increasing the correct treatment of STIs, partner notification, condom use and STI testing before unprotected sex with a new partner. The intervention was delivered via automated mobile phone messaging over 12 months. The comparator was a monthly text message checking contact details. MAIN OUTCOME MEASURES (1) Development of the intervention based on theory, evidence and expert and user views; (2) follow-up procedures; (3) pilot trial primary outcomes: full recruitment within 3 months and follow-up rate for the proposed primary outcomes for the main trial; and (4) participants' views and experiences regarding the acceptability of the intervention. RESULTS In total, 200 participants

  15. Nicotine patches in pregnant smokers: randomised, placebo controlled, multicentre trial of efficacy

    PubMed Central

    Grangé, Gilles; Jacob, Nelly; Tanguy, Marie-Laure

    2014-01-01

    Objective To determine the efficacy of 16 hour nicotine patches among pregnant smokers, with the dose individually adjusted according to saliva cotinine levels (potential range 10-30 mg/day). Design Randomised, double blind, placebo controlled, parallel group, multicentre trial (Study of Nicotine Patch in Pregnancy, SNIPP) between October 2007 and January 2013. Setting 23 maternity wards in France. Participants 476 pregnant smokers aged more than 18 years and between 12 and 20 weeks’ gestation, who smoked at least five cigarettes a day. After exclusions, 402 women were randomised: 203 to nicotine patches and 199 to placebo patches. Data were available on 192 live births in each group. Interventions Nicotine and identical placebo patches were administered from quit day up to the time of delivery. Doses were adjusted to saliva cotinine levels when smoking to yield a substitution rate of 100%. Participants were assessed monthly and received behavioural smoking cessation support. Main outcome measures The primary outcomes were complete abstinence (self report confirmed by carbon monoxide level in expired air ≤8 ppm) from quit date to delivery, and birth weight. The secondary outcomes were point prevalence of abstinence, time to lapse (a few puffs) or relapse, and delivery and birth characteristics. All data were analysed on an intention to treat basis. Results Complete abstinence was achieved by 5.5% (n=11) of women in the nicotine patch group and 5.1% (n=10) in the placebo patch group (odds ratio 1.08, 95% confidence interval 0.45 to 2.60). The median time to the first cigarette smoked after target quit day was 15 days in both groups (interquartile range 13-18 in the nicotine patch group, 13-20 in the placebo patch group). The point prevalence abstinence ranged from 8% to 12.5% in the nicotine patch group and 8% to 9.5% in the placebo patch group without statistically significant differences. The nicotine substitution rate did not differ from 100%, and the self

  16. Patient perceptions regarding benefits of single visit scale and polish: a randomised controlled trial

    PubMed Central

    2013-01-01

    Background Single visit scale and polish is frequently carried out in dental practices however there is little evidence to support (or refute) its clinical effectiveness. The purpose of this research was to compare patient-reported outcomes between groups receiving a scale and polish at 6-, 12-, and 24-month intervals. Outcomes recorded included participants’ subjective assessment of their oral cleanliness; the perceived importance of scale and polish for oral health and aesthetics; and frequency at which this treatment is required. Methods A practice-based randomised control trial was undertaken, with a 24-month follow-up period. Participants were healthy adults with no significant periodontal disease (BPE codes <3) randomly allocated to three groups to receive scale and polish at 6-, 12-, or 24-month intervals. Patient-reported outcomes were recorded at baseline and follow-up. Oral cleanliness was reported using a 5-point scale and recorded by examiners blinded to trial group allocation. A self-completed questionnaire enabled participants to report perceived importance of scale and polish (5-point scale), and required frequency of treatment (6-point scale). The main hypothesis was that participants receiving 6-monthly scale and polish would report higher levels of oral cleanliness compared to participants receiving scale and polish at 12- and 24-month intervals. Results 369 participants were randomised: 125 to the 6-month group; 122 to the 12-month group; and 122 to the 24-month group. Complete data set analysis was carried out to include 107 (6-month group), 100 (12-month group) and 100 (24-month group) participants. Multiple imputation analyses were conducted where follow-up data was missing. The difference in the proportions of participants reporting a 'high’ level of oral cleanliness at follow-up was significant (Chi-squared P = 0.003): 52.3% (6-month group), 47.0% (12-month group) and 30.0% (24-month group). Scale and polish was thought to be