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Biometry of eyes in type 1 diabetesAdnan, X., Suheimat, M., Efron, N., Edwards, K., Pritchard, N., Mathur, A., Mallen, Edward A.H., Atchison, D.A. January 2015 (has links)
No / This is a comprehensive study of a large range of biometric and optical parameters in people with type 1 diabetes. The parameters of 74 people with type 1 diabetes and an age matched control group were assessed. Most of the people with diabetes had low levels of neuropathy, retinopathy and nephropathy. Marginal or no significant differences were found between groups for corneal shape, corneal thickness, pupil size, and pupil decentrations. Relative to the control group, the diabetes group demonstrated smaller anterior chamber depths, more curved lenses, greater lens thickness and lower lens equivalent refractive index. While the optics of diabetic eyes make them appear as older eyes than those of people of the same age without diabetes, the differences did not increase significantly with age. Age-related changes in the optics of the eyes of people with diabetes need not be accelerated if the diabetes is well controlled.
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Are the Physiological and Digital Systems Converging? : Exploring the relation between humans and mobile technologies.Zetterholm, My January 2016 (has links)
This thesis has its starting point in the digitalization of society focusing on the rapid development of mobile technologies and the increasing interplay between humans and machines. The use of information and communication technologies (ICT) is extending at a fast pace, affecting all parts of society, and the everyday life of most individuals. The fast progressing development of mobile technologies (smartphones and their accessories/ wearable’s) is creating new trends such as health tracking and quantified self. These mobile technologies can register an increasing number of physiological features, implying that the interconnection between the physiological and digital systems is increasing. This creates a range of new possibilities within health and medical research but it also creates new challenges and the need for new knowledge in how we relate these devices to our bodies. In the psychological perspective, smartphone use is increasing and previous studies imply that these devices are affecting our behaviour, our mental health as well as our cognitive functions. This implies for a need to understand the relation we have to these devices also in a psychological perspective, focusing on emotions and cognition. This study set out to explore the relation between humans and technologies from a systems perspective. The research question involved: How are users and smartphones related in physical and psychological perspectives? The methods used were questionnaires and interviews. The respondents were students in two European universities, who described their experiences of smartphone use, and three doctors (in medicine and biomedicine) that provided interesting aspects in how mobile technologies can be related to the human body from a system perspective In a physical perspective the users as well as their physical environments could be described as converging with the digital systems. The need of being connected and have access to all life-spheres at once seemed to be an important driving force, implying that users are dependent on information and a converged life-style. In a psychological perspective, the emotional bond seemed stronger then the actual physical need. The perceptions of smartphones differed, but a common denominator described by both Swedish and Albanian users, was the perception of the smartphone as something with human-like features, comparable to a friend. The last part of the study concerned if smartphones can be seen as a new entity of our own system, comparable to an organ. The result suggests that this depends on the individual use, if the technologies is used to sustain health, the value it provides, and it is also a matter of the users ontological believes. The concept of physio-digital convergence is proposed as a new concept to analyse the development of increasing use of mobile technologies further.
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Nonlinear Impulsive and Hybrid Dynamical SystemsNersesov, Sergey G 23 June 2005 (has links)
Modern complex dynamical systems typically possess a
multiechelon hierarchical hybrid structure characterized by
continuous-time dynamics at the lower-level units and logical
decision-making units at the higher-level of hierarchy. Hybrid
dynamical systems involve an interacting countable collection of
dynamical systems defined on subregions of the partitioned state
space. Thus, in addition to traditional control systems, hybrid
control systems involve supervising controllers which serve to
coordinate the (sometimes competing) actions of the lower-level
controllers. A subclass of hybrid dynamical systems are impulsive
dynamical systems which consist of three elements, namely, a
continuous-time differential equation, a difference equation, and
a criterion for determining when the states of the system are to
be reset. One of the main topics of this dissertation is the
development of stability analysis and control design for impulsive
dynamical systems. Specifically, we generalize Poincare's
theorem to dynamical systems possessing left-continuous flows to
address the stability of limit cycles and periodic orbits of
left-continuous, hybrid, and impulsive dynamical systems. For
nonlinear impulsive dynamical systems, we present partial
stability results, that is, stability with respect to part of the
system's state. Furthermore, we develop adaptive control framework
for general class of impulsive systems as well as energy-based
control framework for hybrid port-controlled Hamiltonian systems.
Extensions of stability theory for impulsive dynamical systems
with respect to the nonnegative orthant of the state space are
also addressed in this dissertation. Furthermore, we design
optimal output feedback controllers for set-point regulation of
linear nonnegative dynamical systems. Another main topic that has
been addressed in this research is the stability analysis of
large-scale dynamical systems. Specifically, we extend the theory
of vector Lyapunov functions by constructing a generalized
comparison system whose vector field can be a function of the
comparison system states as well as the nonlinear dynamical system
states. Furthermore, we present a generalized convergence result
which, in the case of a scalar comparison system, specializes to
the classical Krasovskii-LaSalle invariant set theorem. Moreover,
we develop vector dissipativity theory for large-scale dynamical
systems based on vector storage functions and vector supply rates.
Finally, using a large-scale dynamical systems perspective, we
develop a system-theoretic foundation for thermodynamics.
Specifically, using compartmental dynamical system energy flow
models, we place the universal energy conservation, energy
equipartition, temperature equipartition, and entropy
nonconservation laws of thermodynamics on a system-theoretic
basis.
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