@article{ref1,
title="Postural instability via a loss of intermittent control in elderly and patients with  Parkinson's disease: a model-based and data-driven approach",
journal="Chaos, solitons and fractals",
year="2020",
author="Suzuki, Yasuyuki and Nakamura, Akihiro and Milosevic, Matija and Nomura, Kunihiko and Tanahashi, Takao and Endo, Takuyuki and Sakoda, Saburo and Morasso, Pietro and Nomura, Taishin",
volume="30",
number="11",
pages="e113140-e113140",
abstract="Postural instability is one of the major symptoms of Parkinson's disease. Here, we  assimilated a model of intermittent delay feedback control during quiet standing  into postural sway data from healthy young and elderly individuals as well as  patients with Parkinson's disease to elucidate the possible mechanisms of  instability. Specifically, we estimated the joint probability distribution of a set  of parameters in the model using the Bayesian parameter inference such that the  model with the inferred parameters can best-fit sway data for each individual. It  was expected that the parameter values for three populations would distribute  differently in the parameter space depending on their balance capability. Because  the intermittent control model is parameterized by a parameter associated with the  degree of intermittency in the control, it can represent not only the intermittent  model but also the traditional continuous control model with no intermittency. We  showed that the inferred parameter values for the three groups of individuals are  classified into two major groups in the parameter space: one represents the  intermittent control mostly for healthy people and patients with mild postural  symptoms and the other the continuous control mostly for some elderly and patients  with severe postural symptoms. The results of this study may be interpreted by  postulating that increased postural instability in most Parkinson's patients and  some elderly persons might be characterized as a dynamical disease.<p /> <p>Language: en</p>",
language="en",
issn="0960-0779",
doi="10.1063/5.0022319",
url="http://dx.doi.org/10.1063/5.0022319"
}