Avid Roman-Gonzalez

Dr. Avid Roman-Gonzalez


Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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30 November 2017 in PLOS ONE
Verified
Journal Article
Open access
PDF file
NVNatalia I. Vargas-Cuentas
Natalia I. Vargas-Cuentas
ARAvid Roman-Gonzalez
Avid Roman-Gonzalez
RGRobert H. Gilman
Robert H. Gilman
FBFranklin Barrientos
Franklin Barrientos
JTJames Ting
James Ting
MZMirko Zimic
Mirko Zimic
Autism spectrum disorder (ASD) currently affects nearly 1 in 160 children worldwide. In over two-thirds of evaluations, no validated diagnostics are used and gold standard diagnostic tools are used in less than 5% of evaluations. Currently, the diagnosis of ASD requires lengthy and expensive tests, in addition to clinical confirmation. Therefore, fast, cheap, portable, and easy-to-administer screening instruments for ASD are required. Several studies have shown that children with ASD have a lower preference for social scenes compared with children without ASD. Based on this, eye-tracking and measurement of gaze preference for social scenes has been used as a screening tool for ASD. Currently available eye-tracking software requires intensive calibration, training, or holding of the head to prevent interference with gaze recognition limiting its use in children with ASD. In this study, we designed a simple eye-tracking algorithm that does not require calibration or head holding, as a platform for future validation of a cost-effective ASD potential screening instrument. This system operates on a portable and inexpensive tablet to measure gaze preference of children for social compared to abstract scenes. A child watches a one-minute stimulus video composed of a social scene projected on the left side and an abstract scene projected on the right side of the tablet’s screen. We designed five stimulus videos by changing the social/abstract scenes. Every child observed all the five videos in random order. We developed an eye-tracking algorithm that calculates the child’s gaze preference for the social and abstract scenes, estimated as the percentage of the accumulated time that the child observes the left or right side of the screen, respectively. Twenty-three children without a prior history of ASD and 8 children with a clinical diagnosis of ASD were evaluated. The recorded video of the child´s eye movement was analyzed both manually by an observer and automatically by our algorithm. This study demonstrates that the algorithm correctly differentiates visual preference for either the left or right side of the screen (social or abstract scenes), identifies distractions, and maintains high accuracy compared to the manual classification. The error of the algorithm was 1.52%, when compared to the gold standard of manual observation. This tablet-based gaze preference/eye-tracking algorithm can estimate gaze preference in both children with ASD and without ASD to a high degree of accuracy, without the need for calibration, training, or restraint of the children. This system can be utilized in low-resource settings as a portable and cost-effective potential screening tool for ASD.

1 January 2012
Verified
Book Chapter
Closed access
PDF file
ARAvid Roman-Gonzalez
Avid Roman-Gonzalez

1 November 2016
Verified
Conference Paper
Closed access
RBRonald Barrientos
Ronald Barrientos
ARAvid Roman-Gonzalez
Avid Roman-Gonzalez
FBFranklin Barrientos
Franklin Barrientos
LSLeonardo Solis
Leonardo Solis
MCMalena Correa
Malena Correa
MZMirko Zimic
Mirko Zimic
Pneumonia is one of the major causes of child mortality. Unfortunately, in developing countries there is a lack of infrastructure and medical experts in rural areas to provide the required diagnostics opportunely. Lung ultrasound echography has proved to be an important tool to detect lung consolidates as evidence of pneumonia. This paper presents a method for automatic diagnostics of pneumonia using ultrasound imaging of the lungs. The approach presented here is based on the analysis of patterns present in rectangular segments from the ultrasound digital images. Specific features from the characteristic vectors were obtained and classified with standard neural networks. A training and testing set of positive and negative vectors were compiled. Vectors obtained from a single patient were included only in the testing or in the training set, but never in both. Our approach was able to correctly classify vectors with evidence of pneumonia, with 91.5% sensitivity and 100% specificity.

1 October 2016
Verified
Conference Paper
Closed access
NVNatalia I. Vargas-Cuentas
Natalia I. Vargas-Cuentas
DHDaniela Hidalgo
Daniela Hidalgo
ARAvid Roman-Gonzalez
Avid Roman-Gonzalez
MPMichael Power
Michael Power
RGRobert H. Gilman
Robert H. Gilman
MZMirko Zimic
Mirko Zimic
Autism Spectrum Disorders (ASD) are characterized by a deficit in social integration, language development, and restricted interests. ASD is defined as a prevalence development life disability. However, children who are early diagnosed and intervention improve long-term prognosis. This project proposes to detect autism in children at a first level (preclinical stage) using a tool "eye tracking" highly cost-effective and embedded in a tablet. The results obtained with this system have been compared with the outcomes of the Modified Autism in Children M-CHAT questionnaire.

1 May 2010
Verified
Conference Paper
Closed access
ARAvid Roman-Gonzalez
Avid Roman-Gonzalez
The present work is oriented to offer a communication system to people who undergo a severe loss of motor function as a result of various accidents and/or diseases so that they can control and interact better with the environment, for which a brain-computer interface has been implemented through the acquisition of EEG signals by electrodes and implementation of algorithms to extract characteristics and execute a method of classification that would interpret these signals and execute corresponding actions The first objective is to design and construct a system of communication and control based on the thought, able to catch and measure EEG signals. The second objective is to implement the system of data acquisition including a digital filter in real time that allows us to eliminate the noise. The third objective is to analyze the variation of the EEG signals in front of the different tasks under study and of implementing an algorithm of extraction of characteristics. The fourth objective is to work on the basis of the characteristics of the EEG signals, to implement a classification system that can discriminate between the two tasks under study on the basis of the corresponding battles.

5 February 2021 in IEEE Aerospace and Electronic Systems Magazine
Verified
Journal Article
Closed access
NVNatalia Indira Vargas-Cuentas
Natalia Indira Vargas-Cuentas
ARAvid Roman-Gonzalez
Avid Roman-Gonzalez
In the penultimate quarter of 2019, Bolivia suffered multiple forest fires in the Chiquitania and the Amazon region. According to experts and authorities, a category six wildfire, consumed at a rate of 4000 hectares per hour. Given this event, this article aims to use Landsat 8 satellite imagery to calculate the Normalized Burn Ratio (NBR), the Normalized Burn Ratio-Thermal (NBR-T), the Normalized Difference Vegetation Index (NDVI), and the Soil Adjusted Vegetation Index (SAVI) to categorize the environmental impact of the wildfires. These four indices were extracted from 22 postfire images, and it was found that the total burned area, in Beni department, that belongs to the Amazon region is 1183 134 hectares and the total burned area, in the municipalities that are inside or cross the Chiquitania is 3 825 359 hectares.