Examinando por Autor "Ramele, Rodrigo"
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Artículo de Publicación Periódica A control strategy for a tethered follower robot for pulmonary rehabilitation(2020-12-03) Bianchi, Luciano Gustavo; Buniak, Esteban Alejandro; Ramele, Rodrigo; Santos, Juan Miguel"Patients that suffer Chronic Obstructive Pulmonary Disease (COPD) undergo a procedure called Pulmonary Rehabilitation that helps them to improve disease prognosis. Pulmonary Rehabilitation consists of different physical exercises and walking activities conducted at medical facilities under supervision of a physical therapist. In order to perform these procedures, patients require oxygen assistance, but the oxygen tank cannot be carried by the patient due to the musculoskeletal atrophy that characterize this pathology and external assistance is required. The assistance to transport the bulky oxygen tank can be provided by a robotic device that follows the patient while performing the physical activities. This work provides an initial study on the controlling mechanism of a differential tethered robot that implements a leader-follower configuration to carry the oxygen tank for these procedures. Two alternative control strategies are proposed. Results on a simulated and on a real prototype confirms the feasibility of the proposed solution."Artículo de Publicación Periódica EEG waveform analysis of P300 ERP with applications to brain computer interfaces(2018-11) Ramele, Rodrigo; Villar, Ana Julia; Santos, Juan Miguel"The Electroencephalography (EEG) is not just a mere clinical tool anymore. It has become the de-facto mobile, portable, non-invasive brain imaging sensor to harness brain information in real time. It is now being used to translate or decode brain signals, to diagnose diseases or to implement Brain Computer Interface (BCI) devices. The automatic decoding is mainly implemented by using quantitative algorithms to detect the cloaked information buried in the signal. However, clinical EEG is based intensively on waveforms and the structure of signal plots. Hence, the purpose of this work is to establish a bridge to fill this gap by reviewing and describing the procedures that have been used to detect patterns in the electroencephalographic waveforms, benchmarking them on a controlled pseudo-real dataset of a P300-Based BCI Speller and verifying their performance on a public dataset of a BCI Competition."Artículo de Publicación Periódica EPOC Emotiv EEG Basics(2022-10) Ramele, Rodrigo; Villar, Ana Julia; Santos, Juan MiguelThis document provides some basic guidance to start working with the EPOC Emotiv neuroheadset device and describes how to use it to perform basic Brain-Computer Interface (BCI) research. A brief tutorial on how to set up the device, from its electrophysiological point of view, as well as a description and practical code to perform some basic analysis, is explained. A basic experiment is introduced to detect one of the oldest and, indeed, quite still valuable electrophysiological correlate, visual occipital alpha waves, or Berger Rhythm. An additional experiment is expounded where the power spectrum of alpha waves is reduced when a subject is affected by background cognitive disturbances. This document also briefs about the extraction of information by using the EPOC Emotiv library and also with python Emokit package. This report presents a basic guide on how to use EEGLAB + MATLAB, as well as python stack to perform the neurophysiological analysis. Finally, a basic analysis on different feature extraction and classification methods is provided.Ponencia en Congreso Equilivest: A robotic vest to aid in post-stroke dynamic balance rehabilitation(2023-01) Paviotti, Franco; Buniak, Esteban; Ramele, Rodrigo; Freixes, Orestes; Santos, Juan MiguelBrain stroke is a devastating medical condition, that affects world population and is the main cause of disabilities worldwide. Disabilities related to stroke can affect motor pathways, and may lead to several motor function disorders. One important aspect of motor function is balance which is the ability to control the body’s center of mass inside the base support provided by the lower limb. Stroke can affect dynamic balance as well, which is manifested while walking, impairing autonomy and independence, important factors in Activities of Daily Living (ADL) particularly for young patients.Tesis de doctorado Histogram of gradient orientations of EEG signal plots for brain computer interfaces(2018) Ramele, Rodrigo; Santos, Juan Miguel; Villar, Ana Julia"Brain Computer Interface (BCI) or Brain Machine Interfaces (BMI), has proved the feasibility of a distinct non-biological communication channel to transmit information from the Central Nervous System (CNS) to a computer device. Promising success has been achieved with invasive BCI, though biocompatibilities issues and the complexity and risks of surgical procedures are the main drive to enhance current non-invasive technologies. Electroencephalography (EEG) is the most widespread method to gather information from the CNS in a non-invasive way. Clinical EEG has traditionally focused on temporal waveforms, but signal analysis methods which follow this path have been neglected in BCI research. This Thesis proposes a method and framework to analyze the waveform, the shape of the EEG signal, using the histogram of gradient orientations, a fruitful technique from Computer Vision which is used to characterize image local features. Inspiration comes from what traditionally electroencephalographers have been doing for almost a century: visually inspecting raw EEG signal plots."Artículo de Publicación Periódica Histogram of gradient orientations of signal plots applied to P300 detection(2019-07) Ramele, Rodrigo; Villar, Ana Julia; Santos, Juan Miguel"The analysis of Electroencephalographic (EEG) signals is of ulterior importance to aid in the diagnosis of mental disease and to increase our understanding of the brain. Traditionally, clinical EEG has been analyzed in terms of temporal waveforms, looking at rhythms in spontaneous activity, subjectively identifying troughs and peaks in Event-Related Potentials (ERP), or by studying graphoelements in pathological sleep stages. Additionally, the discipline of Brain Computer Interfaces (BCI) requires new methods to decode patterns from non-invasive EEG signals. This field is developing alternative communication pathways to transmit volitional information from the Central Nervous System. The technology could potentially enhance the quality of life of patients affected by neurodegenerative disorders and other mental illness. This work mimics what electroencephalographers have been doing clinically, visually inspecting, and categorizing phenomena within the EEG by the extraction of features from images of signal plots. These features are constructed based on the calculation of histograms of oriented gradients from pixels around the signal plot. It aims to provide a new objective framework to analyze, characterize and classify EEG signal waveforms. The feasibility of the method is outlined by detecting the P300, an ERP elicited by the oddball paradigm of rare events, and implementing an offline P300-based BCI Speller. The validity of the proposal is shown by offline processing a public dataset of Amyotrophic Lateral Sclerosis (ALS) patients and an own dataset of healthy subjects."Póster K-Complex detection algorithm in non-REM sleep(2020) Vázquez Chenlo, Aylin; Carosi, Julia; Carbonari, Giulia; Forcato, Cecilia; Ramele, Rodrigo"In order to evaluate the relation between KC and memory processes our main goal was to create a method with Machine Learning techniques to characterize and identify KCs."Póster K-complex localization and classification algorithm(2021) Vázquez Chenlo, Aylin; Carbonari, Giulia; Carosi, Julia; Forcato, Cecilia; Ramele, Rodrigo"K-Complexes (KCs) are events present in non-rapid eye movement (non-REM) sleep, which have cellular dynamics similar to slow waves and have 3 distinguishing components: an initial P200, a posterior N500 and a final P900. Sleep plays a fundamental role in memory consolidation, favoring the transfer of new information from the hippocampus to the neocortex and its cortico-cortical redistribution. There are currently no studies that directly link KCs with memory processes, so they are not being considered as a possible facilitating event of this hippocampal-cortical dialogue. "Artículo de Publicación Periódica Lucid dreams and out-of-body experiences reports : differences in emotional content, dream awareness, and dream control(2023) Gallo, Francisco T.; Herrero, Nerea L.; Tommasel, Antonela; Godoy, Daniela; Spiousas, Ignacio; Gasca-Rolin, Miguel; Ramele, Rodrigo; Gleiser, Pablo M.; Forcato, CeciliaLucid dreams (LDs) and out-of-body experiences (OBEs) are phenomena characterized by the return of higher cognitive abilities during sleep, including reflective self-awareness and abstract thought. Given the similarities in reflective self-awareness between LDs and OBEs, some authors consider them variations of the same phenomenon. This study aimed to compare the differences in content between non-LDs, LDs, and OBEs obtained from 60 participants over a two-month period, with 916 dream reports collected. The dream reports were analyzed using automatic methods based on Lexicons such as NRC Emotion Lexicon and Empath, and were scored based on Hall and Van de Castle's dream content scoring system with variations and additional measures. Results showed that OBE dreams were characterized by higher occurrences of negative emotions compared to both lucid and non-lucid dreams as measured by automatic and manual scoring systems. Also, more OBE dream reports contained words related to agency and insight, higher manual scoring of dream control-related expressions, and more total sensations, dream activities, reference to prospective memory evocations, spatial and body references, and more difficulties with movement within the dream environment, than lucid dreams. The findings support the idea that OBEs represent unique experiences distinguished from lucid dreams.Artículo de Publicación Periódica Object detection and statistical analysis of microscopy image sequences(2022) Hurovitz, Sasha Ivan; Chan, Debora; Ramele, Rodrigo; Gambini, Juliana"Confocal microscope images are wide useful in medical diagnosis and research. The automatic interpretation of this type of images is very important but it is a challenging endeavor in image processing area, since these images are heavily contaminated with noise, have low contrast and low resolution. This work deals with the problem of analyzing the penetration velocity of a chemotherapy drug in an ocular tumor called retinoblastoma. The primary retinoblastoma cells cultures are exposed to topotecan drug and the penetration evolution is documented by producing sequences of microscopy images. It is possible to quantify the penetration rate of topotecan drug because it produces fluorescence emission by laser excitation which is captured by the camera. In order to estimate the topotecan penetration time in the whole retinoblastoma cell culture, a procedure based on an active contour detection algorithm, a neural network classifier and a statistical model and its validation, is proposed. This new inference model allows to estimate the penetration time. Results show that the penetration mean time strongly depends on tumorsphere size and on chemotherapeutic treatment that the patient has previously received."Póster The role of 20-min naps on declarative memory persistence(2021) Vázquez Chenlo, Aylin; Carosi, Julia; Ramele, Rodrigo; Forcato, Cecilia"K-Complexes (KC) are events present in non-rapid eye movement (non-REM) sleep, which have cellular dynamics similar to slow waves and have 3 distinguishing components: an initial P200, a posterior N500 and a final P900. Sleep plays a fundamental role in memory consolidation, favoring the transfer of new information from the hippocampus to the neocortex and its cortico-cortical redistribution. KCs have been postulated as mediators of the hippocampal-cortical dialogue since they recruit distant neuronal populations that do not depend on cortical connections."Póster Role of dream content in memory processing during sleep: Preliminary setup(2021) Pretel, Matías; Herrero, Nerea; Fernández Sande, Joaquín; Brusco, Luis Ignacio; Ramele, Rodrigo; Kaczer, Laura; Forcato, Cecilia"After acquisition memories are in a labile state followed by a period of stabilization known as consolidation. This process is particularly favored by sleep, where the new information is spontaneously reactivated in the hippocampus, transferred and redistributed in neocortical networks facilitating long term consolidation. Also, during sleep, specifically during REM sleep, new memories are integrated into the stored information. From a neuroscientific perspective, dream content is proposed to be a consequence of the memory processes that occur during sleep. Thus, the incorporation of elements about the learned tasks during wakefulness in the content of a dream, can predict the performance of the task after sleep. Here, we developed a new paradigm to study whether dream content related to a new word learning task correlates with consolidation of new words and integration into the pre-existed semantic networks."Póster Slow wave detection algorithm in non-REM sleep(2020) Carbonari, Giulia; Carosi, Julia; Vázquez Chenlo, Aylin; Moris, Eugenia; Forcato, Cecilia; Ramele, Rodrigo; Larrabide, Ignacio"Online detection of slow waves."Ponencia en Congreso Time estimation of topotecan penetration in retinoblastoma cells through image sequence analysis(2020) Chan, Debora; Winter, Úrsula; Schaiquevich, Paula; Ramele, Rodrigo; Gambini, Juliana"Retinoblastoma is the most common intraocular tumor in childhood. Topotecan has been widely used as an antineoplastic agent for retinoblastoma treatment. Topotecan penetration into living tumorspheres is quantified using confocal microscopy. This fluorescent drug dyes the living tissue and it can be recorded in a sequence of images over a period of time. The effective penetration of the drug depends on culture characteristics and requires a very specific timing. This penetration time is calculated empirically by an expert. The purpose of this work is to offer a statistical model to automatically estimate the penetration time of topotecan in the cell, based on the information obtained from a sequence of tumorsphere images."Ponencia en Congreso Topotecan penetration assessment in retinoblastoma cells using Shannon entropy and coefficient of variation(2019-09) Howlin, Marcelo; Chan, Debora; Ramele, Rodrigo; Gambini, Juliana"Retinoblastoma is a common intraocular tumor of childhood. One of the medications used as an antineoplastic agent for retinoblastoma treatment is topotecan. Its penetration into living tumorspheres is quantified using confocal microscopy. Topotecan is a fluorescent drug and it dyes the living tissue. Then, it is recorded in a sequence of images over a period of time. The effective penetration of the drug depends on culture characteristics and requires a very specific timing which is calculated empirically by an expert. The purpose of this work is to offer a model to automatically estimate and evaluate the penetration time of topotecan in a cell, based on the information obtained from a sequence of tumorsphere images and using Shannon entropy and coefficient of variation."Artículo de Publicación Periódica Training a gaming agent on brainwaves(2020-12-07) Bartolomé, Francisco; Moreno, Juan; Navas, Natalia; Vitali, José; Ramele, Rodrigo; Santos, Juan Miguel"Error-related potential (ErrP) are a particular type of Event-Related Potential (ERP) elicited by a person attending a recognizable error. These Electroencephalographic (EEG) signals can be used to train a gaming agent by a Reinforcement Learning (RL) algorithm to learn an optimal policy. The experimental process consists of an observational human critic (OHC) observing a simple game scenario while their brain signals are captured. The game consists of a grid, where a blue spot has to reach a desired target in the fewest amount of steps. Results show that there is an effective transfer of information and that the agent successfully learns to solve the game efficiently, from the initial 97 steps on average required to reach the target to the optimal number of 8 steps. Our results are expressed in threefold: (i) the mechanics of a simple grid-based game that can elicit the ErrP signal component, (ii) the verification that the reward function only penalizes wrong steps, which means that type II error (not properly identifying a wrong movement) does not affect significantly the agent learning process; (iii) collaborative rewards from multiple observational human critics can be used to train the algorithm effectively and can compensate low classification accuracies and a limited scope of transfer learning schemes."