G. Kember

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The classical Grodins model of chemical respiratory control is analysed. Scaling and asymptotic analysis are used to reduce the model drastically to a much simplified form. In essence, the model consists of two separate controllers due to oxygen and carbon dioxide. The authors focus on the carbon dioxide controller, and show that it can be considered as two(More)
Vagal nerve stimulation in cardiac therapy involves delivering electrical current to the vagal sympathetic complex in patients experiencing heart failure. The therapy has shown promise but the mechanisms by which any benefit accrues is not understood. In this paper we model the response to increased levels of stimulation of individual components of the(More)
We present a method based on dynamical systems theory which can be used to filter time series in a way which is superior to classical Fourier decomposition. This method is applied to three data-sets, taken from respiratory measurements of two children in quiet and REM sleep. Our purpose is to filter the several different oscillatory mechanisms which(More)
We show how the use of " smart " embeddings of time series can indicate the presence of (large) delay in a system, and how they can be used to enhance predictions based on nonlinear dynamics methods. 1. Delay equations are of wide relevance to natural x=f(x 1) [7], but the rapid oscillations make any dynamical systems, particularly in medicine and such easy(More)
Model-based predictive control is an advanced control strategy that uses a move suppression factor or constrained optimization methods for achieving satisfactory closed-loop dynamic responses of complex systems. While these approaches are suitable for many processes, they are formulated on the selection of certain parameters that are ambiguous and also(More)
The recent application of methods from nonlinear systems theory to the analysis of time series can be used to provide a novel technique for filtering such series, when they represent the coupled output of several distinct oscillators. The method is a nonlinear analogue of Fourier spectral analysis, but is potentially more powerful, in that it allows for(More)
The performances of two MPC (model predictive control) techniques, move-suppressed and shifted, are studied under normally distributed random communication delays to test the potential of MPC as a control method over the Internet. A conventional PID is also implemented under the same delay conditions. All controls are run in a time-scheduling scheme. The(More)