3rd April 2014, 6:00pm
Mathematical models of human balance, Dr Piotr Kowalczyk (Manchester Metropolitan University)
Abstract
Many engineering and biological systems are characterised by the presence of abrupt transitions. For instance, brain activity, measured by means of Electroencephalography (EEG), is characterised by spiking and bursting behaviour, with the dynamics evolving over time scales ranging from milliseconds to minutes. Feedback control mechanisms used, for instance, in power engineering contain switching elements which, on the macroscopic scale, may be considered as acting instantaneously. The introduction of idealised instantaneous action in mathematical models leads to, so-called, hybrid formalism.
In recent years, much of research effort has been spent on understanding the character of control strategy which ensures human balance control during quiet standing. Human balance control during quiet standing is often modelled using linear, continuous time systems. These models exclude thresholds, instantaneous switchings and time variant processes such as open loops.
However, impulsive like muscle movements have been detected during quiet standing, and so it should come as no surprise that among the biomechanics community switched and intermittent control models have been used to account for sway dynamics during quiet standing. There is currently a controversy whether human quiet standing can be better captured by a linear time invariant process, or whether it is an intermittent or switched control that can better capture the balance control mechanism.
In the talk, I will present switched mathematical model of human balance control during quiet standing and discuss the dynamics that can be observed in our hybrid model system. The effect of noise on system dynamics as well as a method for the detection of discontinuities in the time series data of our model system will be discussed. Relevance of our findings to human balance control will be also discussed.
Venue: Room E32, John Dalton Building, Oxford Road, Manchester Metropolitan University
No charge is made to attend meetings and non-members are welcome.
