Franz Kappel

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Based on the four compartment model by Grodins we develop a model for the response of the cardiovascular system to a short term submaximal workload. Basic mechanisms included in the model are Starling's law of the heart, the Bowditch effect and autoregulation in the peripheral regions. A fundamental assumption is that the action of the feedback control is(More)
Typical optimal design methods for inverse or parameter estimation problems are designed to choose optimal sampling distributions through minimization of a specific cost function related to the resulting error in parameter estimates. It is hoped that the inverse problem will produce parameter estimates with increased accuracy using data collected according(More)
We consider the problem of estimating a modeling parameter μ using a weighted least squares criterion Jd(y, μ) = ∑n i=1 1 3⁄4(ti) ( y(ti) − f(ti, μ) )2 for given data y by introducing an abstract framework involving generalized measurement procedures characterized by probability measures. We take an optimal design perspective, the general premise(More)
This paper considers a model developed to study the cardiovascular control system response to orthostatic stress as induced by two variations of lower body negative pressure (LBNP) experiments. This modeling approach has been previously applied to study control responses to transition from rest to aerobic exercise, to transition to non-REM sleep and to(More)
This article examines the functional and clinical impact of time delays that arise in human physiological systems, especially control systems. An overview of the mathematical and physiological contexts for considering time delays will be illustrated, from the system level to cell level, by examining models that incorporate time delays. This examination will(More)