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In this study, a functional clustering approach is proposed and tested for the identification of brain functional networks emerging during sleep-related seizures. Stereo-EEG signals recorded in patients with Type II Focal Cortical Dysplasia (FCD type II), were analyzed. This novel approach is able to identify the network configuration changes in pre-ictal and early ictal periods, by grouping Stereo-EEG...
Personalization is one of the drivers to deal with the sustainability of the health care systems in Eastern or Western countries. This position paper presents a set of challenges in personalized systems for Personal Health Care, especially in the field of cardiovascular diseases. Authors present the LINK initiative to push for this paradigm change, moving from personal to personalized health care,...
The aim of this study is the evaluation of the autonomic regulations during depressive stages in bipolar patients in order to test new quantitative and objective measures to detect such events. A sensorized T-shirt was used to record ECG signal and body movements during the night, from which HRV data and sleep macrostructure were estimated and analyzed. 9 out of 20 features extracted resulted to be...
This work aims to investigate sleep microstructure as expressed by Cyclic Alternating Pattern (CAP), and its possible alterations in pathological sleep. Three groups, of 10 subjects each, are considered: a) normal sleep, b) psychophysiological insomnia, and c) sleep misperception. One night sleep PSG and sleep macro- micro structure annotations were available per subject. The statistical properties...
This study analyzes the nonlinear properties of the EEG at transition points of the sequences that build the Cyclic Alternating Pattern (CAP). CAP is a sleep phenomenon built up by consecutive sequences of activations and non-activations observed during the sleep time. The sleep condition can be evaluated from the patterns formed by these sequences. Eleven recordings from healthy and good sleepers...
This study proposes a novel method to assist the detection of the components that build up the Cyclic Alternating Pattern (CAP). CAP is a sleep phenomenon formed by consecutive sequences of activations (A1, A2, A3) and non-activations during nonREM sleep. The main importance of CAP evaluation is the possibility of defining the sleep process more accurately. Ten recordings from healthy and good sleepers...
This study proposes an automatic method for the sleep-wake staging in normal and pathologic sleep based only on respiratory effort acquired from a Pressure Bed Sensor (PBS). Motion and respiratory movements were obtained through a PBS and sleep-wake staging was evaluated from those time series. 20 all night polysomnographies, with annotations, used as gold standard and the time series coming from...
An algorithm to evaluate the sleep macrostructure based on heart rate fluctuations from ECG signal is presented. This algorithm is an attempt to evaluate the sleep quality out of sleep centers. The algorithm is made up by a) a time-variant autoregressive model used as feature extractor and b) a hidden Markov model used as classifier. Characteristics coming from the joint probability of HRV features...
This study analyses the spectral components of the heart rate fluctuations of a new contact-less technology for sleep evaluation. Both heart beat interval (HBI) and movement activity were extracted from the multichannel ballistocardiographic (BCG) measurements, based on Emfit sensor foils placed into bed mattress. Powers spectral densities (PSD) of HBI have been compared with the ones obtained from...
In this work we applied the direct directed transfer function (dDTF) to fMRI simultaneously recorded with EEG. The objective of the current study is to explore the functional brain network formed by the regions involved in blood oxygen level dependent (BOLD) response related to interictal spikes in temporal lobe epilepsy (TLE). Since fMRI response have been often observed in extratemporal regions,...
In this work, bispectral and cross-bispectral analysis was applied to LFP and electromyographic (EMG) signals recorded in a patient with essential tremor, implanted in the subthalamic nucleus (STN) with DBS electrodes. Because the cross-bispectrum has sometimes a not plain interpretation, simulations were conducted to better understand the reliability of the estimation and to obtain a more detailed...
Peripheral Quantitative Computerized Tomography (pQCT) allows the acquisition of bone specimens with a spatial resolution adequate to visualize the 3D structure of the bone cortex and the trabecular network. At present, pQCT scanners are equipped with image processing software that limits the bone analysis in two dimensions and requires strong user interaction. In this work, a method is proposed to...
This study proposes three different methods to evaluate Obstructive Sleep Apnea (OSA) during sleep time solely based on the ECG signal. OSA is a common sleep disorder produced by repetitive occlusions of the upper airways, which produces a characteristic pattern on the ECG. Extraction of ECG characteristics as the heart rate variability and the QRS peak area offer alternative measures for cheap, non-invasive...
In this paper, we present a home device for the continuous monitoring of sleep and investigate its reliability regarding sleep evaluation. The system has been particularly designed for healthy people and for preventive purposes. It is not obtrusive and therefore can be used every night without impeding sleep in itself and without interfering with the normal way of life. The signal used for sleep evaluation...
In clinical routine, the evaluation of sustained attention is often performed analyzing behavioral data collected during specific tests. It is not common to match such analyses with a detailed examination of the subject's simultaneous electroencephalographic (EEG) activity, and particularly its frequency content. In this study, 9 healthy volunteers underwent a modified Conners' CPT test, while their...
We studied the blood oxygen level dependent (BOLD) response to interictal epileptic spikes in a group of patients with focal epilepsy by simultaneous recording of electroencephalography (EEG) and functional magnetic resonance imaging (fMRI). The detection of activated areas was performed by using an approach based on the theory of the general linear models (GLM). Since little is know about the haemodynamic...
Heart rate variability (HRV) during decreases in the amplitude fluctuations of pulse photopletysmography signal events (DAP) is studied. The DAP duration and the time span of the polysomnography (PSG) recording under study are also considered for identification of obstructive sleep apnea events in children. Oxygen desaturation is used as reference. The study involves recordings of 21 children. Periods...
This study proposes an alternative evaluation of obstructive sleep apnea (OSA) based on ECG signal during sleep time. OSA is a common sleep disorder produced by repetitive occlusions in the upper airways. This respiratory disturbance produces a specific pattern on ECG. Extraction of ECG characteristics, as heart rate variability (HRV) and peak R area, offers alternative measures for a sleep apnea...
This work proposes a mathematical approach for combining event-related potentials (ERPs) and functional magnetic resonance images (fMRI). Data were separately recorded during the same event-related experimental design, consisting of visually presented single letters and non-alphabetic symbols, that had to be either simply observed (passive condition) or read aloud (active condition). This protocol...
In this paper we discuss the possibility of performing a sleep evaluation form the heart rate variability (HRV) and respiratory signals. This is particularly useful for wearable devices. The HRV and the respiration were analyzed in the frequency domain and the statistics on the spectral and cross-spectral parameters put into evidence the possibility of a sleep evaluation on their basis. Additional...
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