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Background Rhinitis and obstructive sleep apnea (OSA) often coexist during childhood. To delineate this clinical association, we examined OSA severity and polysomnogram (PSG) features in children with rhinitis and OSA. Given that rapid-eye-movement (REM) sleep is characterized by nasal congestion, we hypothesized that children with rhinitis have more REM-related breathing abnormalities. Methods We conducted a retrospective cross-sectional analysis of 145 children with PSG-diagnosed A. Outcomes included PSG parameters and obstructive apnea–hypopnea index (OAHI) during REM and non-REM. Linear multivariable models examined the joint effect of rhinitis and OSA parameters with control for potential confounders. Results Rhinitis was present in 43% of children with OSA (n = 63) but overall OAHI severity was unaffected by the presence of rhinitis. In contrast, OAHI during REM sleep in children with moderate-severe OSA was significantly increased subjects with rhinitis and OSA (44.1/hr; SE = 6.4) compared with those with OSA alone (28.2/hr; SE = 3.8). Conclusion Rhinitis is highly prevalent in children with OSA. Although OSA is not more severe in children with rhinitis, they do have a distinct OSA phenotype characterized by more REM-related OSA. Further research is needed to delineate the link between REM-sleep and the physiology of the nose during health and disease.

In this document, an adaptive algorithm is proposed to identify anomalies in moving objects, such as pedestrians, cars, motorcyclists and cyclists. The anomalies detected by this algorithm are: occlusions, an object partially entering or exiting a frame, alterations in the object velocities or collisions between two or more objects in the frame. The classification between frames with anomaly and no anomaly is achieved by finding an adaptive threshold that depends on the video sequences.

In this paper we introduce a Modular Snakelike Robot designed to satisfy a variety of visual perception tasks. We first explain the novel modular design of the robotic platform to cover the necessary perception strategies proposed to capture the visual information of the scene. The visual model proposed is based on the plenoptic Light Field (LF) captured with the platform. We provide examples for depth estimation and computational photography techniques using the modular robot. The perception and computational photography applications of the proposed platform include Synthetic Aperture, Synthetic Refocusing, Image Stitching and Depth Estimation.

Background Asthma and obstructive sleep apnea (OSA) often coexists during childhood. To delineate this clinical association, we investigated the phenotypical features of OSA in asthmatic children. Specifically, we hypothesized that asthmatic children have a distinct OSA phenotype that involves a higher prevalence of Rapid-Eye-Movement (REM)-related breathing abnormalities relative to children with OSA alone. Methods We conducted a retrospective cross-sectional analysis of 141 children aged 2–12 years with OSA diagnosed by polysomnography (PSG) in our sleep center. Outcomes included PSG parameters, maximal %SaO2 REM desaturations and prevalence of REM-related OSA. Multivariate linear regression model or logistic regression model was built to study the joint effect of asthma and OSA parameters with control for potential confounders (significance level P

This article describes a Wave Field Synthesis (WFS) MATLAB toolbox designed by the authors. The toolbox provides the user with the possibility to create several WFS settings and simulate the resulting wavefront including an optimization algorithm that uses the created parameters to minimize the mean squared error (MSE) in a particular region of the simulation space. The outcome of the optimization provides new driving functions to generate a modified wavefront that meets minimum MSE characteristics.

In this paper we present an image rectification method for a multi-view image set captured by a mobile and articulated camera arrangement. The cameras are located in individual modules, each module consist in a camera, a single actuator and a proprioceptive angle sensor (servomotor encoder). Each module is connected to other modules in a linear chain configuration, with the restriction that the optical axis of all cameras are coplanar. The rectification proposed is based on an initial calibration-rectification with a known pattern. Then, a continuous self-rectification is proposed by using the Kalman filtered measures of the chain actuators. The rectification technique proposed is tested with real measurements from an articulated arrangement, results shown a fast and reliable sub pixel accuracy in the rectification.

In this document an algorithm is proposed to identify the state (available/occupied) of the parking spaces in outdoor areas. The algorithm was developed based on two features: the average local entropy, and the standard deviation of the average entropies of subregions of each parking space. The algorithm delivers a binary map, which contains the number of each parking space with its attributes such as area, position and label. The dispersion of the histogram (entropy) is an important factor to extract the information from the frames, since this allows to know if there is uniformity in gray values when there are or there are not any parked vehicles in the parking spaces. With the entropy, it is possible to calculate the two main features posited in this project. A Support Vector Machine (SVM) is proposed by using a linear kernel in order to ensure detection of vehicles.

This article describes a prototype FPGA implementation, of a delay-and-sum beamformer in the audio frequency range. This prototype is essentially a real-time acoustic camera, which is used to estimate a sound field intensity. Data acquisition is performed by means of a 4-microphone square array and the delay- and-sum beamforming algorithm is implemented on a Xilinx Spartan 3AN FPGA. The computed acoustic intensity images are visualized in a TFT display of a resolution of 320×240 pixels, at 26 frames-per-second.

The light field or LF is a function that describes the amount of light traveling in every direction (angular) through every point (spatial) in a scene, this LF can be captured in several ways, using arrays of cameras, or more recently using a single camera with an special lens, that allows the capture of angular and spatial information of light rays of a scene (LF). This recent camera implementation gives a different approach to find the dept of a scene using only a single camera. In order to estimate the depth, we describe a taxonomy, similar to the one used in stereo Depth-map algorithms. That consist in the creation of a cost tensor to represent the matching cost between different disparities, then, using a support weight window, aggregate the cost tensor, finally, using a winner-takes-all optimization algorithm, search for the best disparities. This paper explains in detail the several changes made to an stereo-like taxonomy, to be applied in a light field, and evaluate this algorithm using a recent database that for the first time, provides several ground-truth light fields, with a respective ground-truth depth map.

Few topics in image processing have been as extensively studied as stereo correspondence, these algorithms can be divided into two categories, local and global, depending on how the processing is done in the image. A stereo correspondence algorithm is called local if operate on sections of the images and global this treatment is performed on the entire images. In local algorithms specifically, this aggregation window is used for smoothing volume pairing cost, so that a better match is performed in presence of fronto-parallel regions. This article presents a comparison between Mean, Gaussian and Savitzky-Golay aggregation windows in local algorithms, analyzing the noise in test images and how the selection of the aggregation window affects the performance of the stereo matching algorithm.

The diagnosis of obstructive sleep apnea (OSA) relies on polysomnography (PSG), a multidimensional biosignal recording that is conducted in sleep laboratories. Standard PSG montage involves the use of nasal-oral airflow sensors to visualize cyclic episodes of upper airflow interruption, which are considered diagnostic of sleep apnea. Given the high-cost and discomfort associated with in-laboratory PSG, there is an emergent need for novel technology that simplifies OSA screening and diagnosis with less expensive methods. The main goal of this project was to identify novel OSA signatures based on the spectral analysis of thoraco-abdominal motion channels. Our main hypothesis was that proper spectral analysis can detect OSA cycles in adults using simultaneous recording of oxygen saturation (SaO2) and either, chest or abdominal motion. A sample study on 35 individuals was conducted with statistically significant results that suggest a strong relationship between airflow-independent signals and oxygen saturation. The impact of this new approach is that it may allow the design of more comfortable and reliable portable devices for screening, diagnosis and monitoring of OSA, functioning only with oximetry and airflow-independent (abdominal or chest) breathing sensors.

Rationale. The sleep-related factors that modulate the nocturnal worsening of asthma in children are poorly understood. This study addressed the hypothesis that asthmatic children have a REM sleep-related vulnerability trait that is independent of OSA.Methods. We conducted a retrospective cross-sectional analysis of pulse-oximetry signals obtained during REM and NREM sleep in control and asthmatic children (n=134). Asthma classification was based on preestablished clinical criteria. Multivariate linear regression model was built to control for potential confounders (significance levelP≤0.05).Results. Our data demonstrated that (1) baseline nocturnal respiratory parameters were not significantly different in asthmatic versus control children, (2) the maximal % of SaO2desaturation during REM, but not during NREM, was significantly higher in asthmatic children, and (3) multivariate analysis revealed that the association between asthma and REM-related maximal % SaO2desaturation was independent of demographic variables.Conclusion. These results demonstrate that children with asthma have a REM-related vulnerability trait that impacts oxygenation independently of OSA. Further research is needed to delineate the REM sleep neurobiological mechanisms that modulate the phenotypical expression of nocturnal asthma in children.

Background. Obese adolescents with Obstructive Sleep Apnea (OSA) have a unique pathophysiology that combines adenotonsillar hypertrophy and increased visceral fat distribution. We hypothesized that in this population waist circumference (WC), as a clinical marker of abdominal fat distribution, correlates with the likelihood of response to AT. Methods. We conducted a retrospective cohort study of obese adolescents (BMI ≥ 97th percentile) that underwent AT for therapy of severe OSA (n = 21). We contrasted WC and covariates in a group of subjects that had complete resolution of severe OSA after AT (n = 7) with those obtained in subjects with residual OSA after AT (n = 14). Multivariate linear and logistic models were built to control possible confounders. Results. WC correlated negatively with a positive AT response in young adolescents and the percentage of improvement in obstructive apnea-hypopnea index (OAHI) after AT (P ≤ 0.01). Extended multivariate analysis demonstrated that the link between WC and AT response was independent of demographic variables, OSA severity, clinical upper airway assessment, obesity severity (BMI), and neck circumference (NC). Conclusion. The results suggest that in obese adolescents, abdominal fat distribution determined by WC may be a useful clinical predictor for residual OSA after AT.

A new screen construction technique, which is described by means of a Maximum likelihood function as constraint of an iterative optimization procedure is introduced. Such stochastic screen function is spatially based, and is defined using the density function of a Markov point process. Further, a new high-capacity data embedding technique that focuses on exploiting the theory available for digital halftoning design, is also introduced. Such halftoning and watermarking scheme can be used in authentication and integrity verification applications as well as for general data embedding, where, digital signatures could be embedded into halftoned photos in a variety of identification documents. Being image independent, this new technique allows for imperceptible embedding such that no a priori knowledge is needed for recovery of inserted data.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.