Re: Lyapunov exponent in hemodynamical time series
http://www.cnd.mcgill.ca/
http://www.cnd.mcgill.ca/bios/glass/cardiac(new).htm
Roger Bagula wrote:
Karl Loy wrote:
Hi,
I'm an anesthesiologist doing some research in nonlinear timeseries
analysis of hemodynamical measurements. More precisely, I'm trying to
calculate the largest Lyapunov exponent and correlation dimension of
some hemodynamic parameters like invasive blood pressure. Still I have
some kind of trouble finding the adequate embedding parameters.
Is there anybody having experience with this kind of analysis?
Thanks a lot for every answer,
M. Stephan, MD
Here are some links that might help:
http://www.physionet.org/physiotools/lyapunov/l1d2/
http://www.vscht.cz/mat/Pavel.Pokorny/easynum/
Downloadable code here:
http://personalpages.umist.ac.uk/staff/H.Zhang-3/
Sensitive dependence on initial conditions along with behaviour of the
Lyapunov exponent has been useful for characterizing the dynamic measure
of the cardiac system (Hagerman et al., 1996)
http://www.math.toronto.edu/courses/335/projects/francois/report.html
> UPO analysis of standard dynamical systems:
>
> We analyzed the dynamics of human cardiac system from the electrical
> activity of the heart namely Electrocardiogram (ECG) through the
> Unstable Periodic Orbits (UPOs) which is a topological property. UPOs
> represent the skeleton for the strange attractor of dynamical systems,
> and there by many quantities that characterize chaos such as fractal
> dimension, average Lyapunov exponent and entropy can be determined by
> knowing the properties of UPO. The UPOs are extracted from the
> attractor reconstructed by time-delay method proposed by Takens,
> followed by the method of close returns proposed by Kostelich et al
> with some modifications.
>
http://www.public.asu.edu/~nkrish2/doctoral.html
<http://www.public.asu.edu/%7Enkrish2/doctoral.html>
.
