Sleep apnea in children with refractory monosymptomatic nocturnal enuresis.

Background: Children with nocturnal enuresis (NE) are believed to have deep sleep with high arousal threshold. Studies suggest that obstructive sleep apnea-hypopnea syndrome (OSAHS) and NE are common problems during childhood. We sought to assess the prevalence of OSAHS in children with refractory NE and whether its severity is associated with the frequency of bedwetting.

Screening for minimal hepatic encephalopathy in asymptomatic drivers with liver cirrhosis.

Background And Study Aims: Minimal hepatic encephalopathy (MHE) represents a part of the spectrum of hepatic encephalopathy (HE). It can have a far-reaching impact on quality and ability to function in daily life and may progress to overt HE. This study was designed to screen for MHE in drivers with liver cirrhosis in Mansoura, a city in the Nile delta in Egypt.

Outcome of medical and surgical management in intractable idiopathic trigeminal neuralgia.

Background: The neurovascular conflict in trigeminal neuralgia is an intractable condition; medical treatment is usually of long duration and can be annoying for both patients and clinicians.

Aim: This prospective study was designed to assess the outcome of microvascular decompression (MVD) in patients with more than 3 years' history of intractable idiopathic trigeminal neuralgia (TN) and poor response to drugs.

Materials And Methods: Twenty-one patients (8 females and 13 males) with intractable idiopathic TN (group 1) underwent MVD and were followed up for 2 years.

Design of fast state observers using a backstepping-like approach with application to synchronization of chaotic systems.

A simple technique is introduced to build fast state observers for chaotic systems when only a scalar time series of the output is available. This technique relies on using a backstepping-like approach via introducing new virtual states that can be observed using the drive-response synchronization mechanism. The proposed dynamic structure of the virtual states allows for employing control parameters that can adjust the convergence rate of the observed states.

Parameter identification technique for uncertain chaotic systems using state feedback and steady-state analysis.

A technique is introduced for identifying uncertain and/or unknown parameters of chaotic dynamical systems via using simple state feedback. The proposed technique is based on bringing the system into a stable steady state and then solving for the unknown parameters using a simple algebraic method that requires access to the complete or partial states of the system depending on the dynamical model of the chaotic system. The choice of the state feedback is optimized in terms of practicality and causality via employing a single feedback signal and tuning the feedback gain to ensure both stability and identifiability.

A nonlinear controller design for permanent magnet motors using a synchronization-based technique inspired from the Lorenz system.

The dynamic behavior of a permanent magnet synchronous machine (PMSM) is analyzed. Nominal and special operating conditions are explored to show that the PMSM can experience chaos. A nonlinear controller is introduced to control these unwanted chaotic oscillations and to bring the PMSM to a stable steady state.

Design of model-based controllers for a class of nonlinear chaotic systems using a single output feedback and state observers.

A model-based control methodology for suppressing chaos for nonlinear systems is introduced. The proposed methodology generates new periodic orbits or steady states, which are not the solutions of the free system, using output feedback and state observers. The design uses the certainty equivalence principle to construct a linear closed loop system that can follow desired outputs with zero steady state offsets via using a pole-placement-like approach.