Xose A. Vila

Xose A. Vila
University of Vigo | UVIGO · Department of Computer Sciences

Ph. D.

About

95
Publications
37,154
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
1,668
Citations
Introduction
Xose A. Vila currently works at the Department of Computer Sciences, University of Vigo. Xose does research in Biomedical Engineering, specially in heart rate variability analysis. Their current project is 'HRV index on psychiatry: dependence disorders and depression'. He is the guest editor of the special issue on "Heart rate varibility: algorithms and software tools" of the Mathematical and Computational applications journal. (Visit: http://mdpi.com/si/28301)
Additional affiliations
September 2006 - present
University of Vigo
Position
  • Professor (Associate)
January 1998 - February 1998
September 1997 - February 1998
St. George Hospital, London
Position
  • Researcher
Education
October 1991 - May 1997
Santiago de Compostela
Field of study
October 1985 - June 1991
Santiago de Compostela
Field of study

Publications

Publications (95)
Article
Background and objective nowadays, numerous mobile applications capable of measuring the Heart Rate (HR) are continuously being launched. However, these tools do not allow to record and label the acquired HR signals while users are doing activities such as practising sports or viewing images. They do not allow to perform simultaneous HR acquisition...
Article
Full-text available
Heart rate variability (HRV) analysis is a powerful instrument that provides information about the heart conditions. However, there exist some limitations in the use of HRV in the clinical practice. Examples are the lack of reference values for healthy populations, different HR (Heart Rate) acquisition systems, and varying software packages. Other...
Article
Full-text available
Object indoor location is a field that receives much research effort but that is lacking enough maturity for its integration in popular devices like mobile phones. This paper describes the results of an experiment carried out to compare different pattern recognition algorithms in order to process the information from a set of Bluetooth transmitters...
Article
Full-text available
Background: Nowadays, the assessment of psychopathy relies on semistructured interviews plus file reviews. In order to improve the predictive validity of psychopathy at the individual level, tools that are not based on the rating of signs and symptoms are in great need. Sampling and methods: The present study was conducted in a representative sa...
Chapter
This chapter presents an example of a complete HRV analysis of several long-duration ECG records employing the RHRV software package, including frequency, nonlinear, andtime analysis. First, 3-h intervals of each ECG were extracted, corresponding to morning, afternoon, and night periods. Next, HRV analyses in both time and frequency domains were pe...
Chapter
Intervals of physiological interest within the heartbeat time series (such as apnea and ischemia) may be marked making use of tags in so-called episodes. Episodic information can be incorporated into RHRV from external files or can be added using functions included in the package. This information can be useful to compare sections of HRV records bo...
Chapter
Searching on Google Scholar the string “heart rate variability” (HRV) provides about half a million references, which gives us an idea of the research activity around this concept. This chapter describes the historical development of this research field, from the pioneering work of the eighteenth and nineteenth centuries to the boom of the final de...
Chapter
Heart rate variability can be analyzed by several methods, being time-domain methods the simplest measures that can be obtained from RR intervals series. Numerical indices summarizing the variability of the series are calculated from the RR intervals series. These measures are easily implemented and have low computational cost. They are usually cal...
Chapter
There are many complex systems in nature that can be explained by nonlinear interactions of its main components. The heart rate regulation is one of the most complex systems in the human body. Heart rhythm is innervated by both theparasympathetic and sympathetic branches of the ANS. At the same time, the autonomic nervous system is influenced by hu...
Chapter
The sympathetic and parasympathetic branches of the ANS strongly influence heart rate. Afferent sympathetic activity increases heart rate, while afferent parasympathetic activity decreases heart rate. The speed with which changes in these systems are reflected in changes in heart rate is different. The sympathetic system is slow in its effects (a f...
Chapter
The initial steps to work with RHRV functions are presented in this chapter. The process starts with the loading of records containing beat positions that should be preprocessed prior to frequency, time, ornonlinear analysis. Data can be stored in various types of files, and RHRV routines can deal with different data formats. Next, heart rate must...
Article
Full-text available
This paper proposes a beat detection algorithm specially tailored to be used with 12 channel ECG records. The algorithm first obtains beat positions on each channel, and then combines this information to get an improved estimate. The detection process involves two stages: 1) single-channel detection: implemented by improving one of the most popular...
Article
Full-text available
This paper proposes a computerized heartbeat detection method in single-channel electrocardiograms (ECGs). First, the well-known Pan-Tompkins technique was implemented, and next, a channel-dependent version was developed, by adjusting threshold values and reducing false QRS detections. The algorithms were tested with the MIT-BIH Arrhythmia Database...
Article
Full-text available
Several works studied the elicitation of emotions through the exposure of individuals to relevant stimuli, using spectral analysis of Heart Rate Variability (HRV) when people are subject to emotional elicitation. If correlation exists between HRV and emotional responses, spectral analysis can be used to study emotion regulation under external stimu...
Book
This book introduces readers to the basic concepts of Heart Rate Variability (HRV) and its most important analysis algorithms using a hands-on approach based on the open-source RHRV software. HRV refers to the variation over time of the intervals between consecutive heartbeats. Despite its apparent simplicity, HRV is one of the most important marke...
Conference Paper
Full-text available
This paper analyzes the impact of hearing of different language versions of the National Anthem of Ecuador among 60 university students of diverse ethnic and geographical origin, through measuring Heart Rate Variability (HRV). Research shows a perspective of neuroscience applied to social sciences, through the use of common tools of health sciences...
Chapter
This work analyzes the impact derived from viewing different political ads (with positive and negative emotional content), belonging to the campaigns of the main candidates to presidential elections of the Republic of Ecuador, celebrated on February 13rd, 2013. To perform this task, a sample of 20 Ecuadorian University students was considered, and...
Article
Full-text available
Background: Premature ventricular contractions (PVCs) are cardiac abnormalities that may occur in subjects with/without cardiovascular disorder. Detection is usually performed from electrocardiograms (ECGs); heart activity for a long period of time must be recorded at hospital or with ambulatory electrocardiography. An alternative with a common mo...
Article
Full-text available
Chronic obstructive pulmonary disease (COPD) patients present functional and structural changes of the respiratory system that have a profound influence on cardiac autonomic dysfunction. To analyse heart rate variability in COPD patients under stable condition and during acute exacerbation episodes (AECOPD). Twenty three severe COPD male patients,...
Article
Full-text available
We have compared three of the best QRS detection algorithms, regarding their results, to check the performance and to elucidate which get better accuracy. In the literature these algorithms were published in a theoretical way, without offering their code, so it is difficult to check its real behaviour over different collections of ECG records. This...
Article
One of the most promising non-invasive markers of the activity of the autonomic nervous system is heart rate variability (HRV). HRV analysis toolkits often provide spectral analysis techniques using the Fourier transform, which assumes that the heart rate series is stationary. To overcome this issue, the Short Time Fourier Transform (STFT) is often...
Conference Paper
Full-text available
This paper presents an extension to the RHRV package that enables nonlinear Heart Rate Variability (HRV) analysis. RHRV is an open source package for the R environment for statistical computing which already has sup-port for a wide variety of time and frequency HRV analysis methods. Now RHRV also provides a phase space reconstruction algorithm that...
Conference Paper
Full-text available
Heart Rate Variability (HRV) is an emerging research field in the study of diverse pathologies, as long as it allows considering another measurement for detecting possible aggravations. The aim of this work is to study the applicability of the analysis of HRV in order to establish if a person is at risk of suffering from suicidal ideation. This wor...
Conference Paper
Full-text available
In this work, a software package, called gHRV, and dedicated to the automatic analysis and study of the heart rate variability is presented. The software is provided with a graphical user interface, is both free and open source, and allows to perform both spectral and nonlinear analysis of several parameters related to the cardiac rhythm. To show t...
Conference Paper
Full-text available
This paper describes a free software tool (VARVI) developed in our research group to facilitate the analysis of heart rate variability (HRV) in response to different visual stimuli. This tool was developed after the realization that this type of studies are becoming to be used in fields such as psychiatry, psychology and marketing and that there ar...
Chapter
Full-text available
In outdoor localization, global positioning systems (GPS) has been widely used. Indoor applications require a precise estimation that GPS can not achieve. Several technologies have been tried out as WI-FI, RFID, Bluetooth, Zigbee and others. This paper describes an experiment conducted in a medium- sized room in which six zones have been identified...
Article
Automatic recognition of anomalous human activities and falls in an indoor setting from video sequences could be an enabling technology for low-cost, home-based health care systems. Detection systems based upon intelligent computer vision software can greatly reduce the costs and inconveniences associated with sensor based systems. In this paper, w...
Conference Paper
Full-text available
Heart rate variability (HRV) power spectrum analysis is a well-known technique used to study the activity of the autonomic nervous system. It is performed by calculating the spectral power of certain bands of the RR time series. There are several tools that perform this type of analysis: Kubios HRV, PhysioNet's HRV toolkit for MatLab and aHRV, amon...
Conference Paper
Full-text available
Chronic Obstructive Pulmonary Disease (COPD) is usually related to cardiovascular risk and sudden death. An effective tool for the diagnosis of exacerbations in COPD patients is the heart rate variability (HRV) analysis of polysomnograms, corresponding to patients which must be monitored in a clinical center. As an alternative, we present an ambula...
Conference Paper
Full-text available
This paper introduces a software application designed for Heart Rate Variability (HRV) analysis. The application, named gHRV, was implemented using Python programming language, and it is partially based on RHRV, an R package developed by the authors. gHRV is now in an early development stage, and it is focused on being used by researchers or clinic...
Article
Full-text available
Nowadays, sleep apnea is a disease with a high prevalence. Its diagnosis requires to admit the patient in a hospital sleep unit and to conduct a polysomnography during the night. For this reason, many efforts have been devoted to alternative techniques to diagnose apnea from other signals, such as ECG or oxygen saturation, easier to obtain outside...
Article
Full-text available
The location of objects and people by the use of Global Positioning System (GPS) or Global System for Mobile Communications (GSM) network is increasingly used to provide location-based services. These technologies work well outdoors and when the required accuracy is not very high, up to 10 meters. This paper describes an algorithm for monitoring el...
Article
Full-text available
The recognition of human actions is a very active research field in computer vision, where efforts are presently focused on the detection of human behavior in real-time video. In this paper, we present a novel spatio-temporal algorithm, called the Motion Vector Flow Instance (MVFI), for classification of actions in videos. We show the results of ap...
Article
Full-text available
Obstructive sleep apnea (OSA) is a serious disorder caused by intermittent airway obstruction which may have dangerous impact on daily living activities. Heart rate variability (HRV) analysis could be used for diagnosing OSA, since this disease affects HRV during sleep. In order to validate different algorithms developed for detecting OSA employing...
Article
Full-text available
In this paper we describe a software package for developing heart rate variability analysis. This package, called RHRV, is a third party extension for the open source statistical environment R, and can be freely downloaded from the R-CRAN repository. We review the state of the art of software related to the analysis of heart rate variability (HRV)....
Article
Full-text available
In this paper we describe a software package for developing heart rate variability analysis. This package, called RHRV, is a third party extension for the open source statistical environment R, and can be freely downloaded from the R-CRAN repository. We review the state of the art of software related to the analysis of heart rate variability (HRV)....
Conference Paper
Full-text available
Behavior determination and multiple object tracking for video surveillance are two of the most active fields of computer vision. The reason for this activity is largely due to the fact that there are many application areas. This paper describes work in developing software algorithms for the tele-assistance for the elderly, which could be used as ea...
Conference Paper
Full-text available
Indoor location or positioning is not a mature technology but with the spread of wireless communication technologies applications are nowadays more feasible. In the telecare field, indoor location could be used for tracking people position at home, in order to know their daily routine and automatically detect abnormalities. This paper describes a B...
Conference Paper
Full-text available
We describe a real-time computer vision application that creates sound from virtual musical instruments by tracking hand and finger movements with a color-based Sequential Monte Carlo algorithm. We show how the combination of real-time hand tracking, virtual MIDI SoundFont technology, and computer graphics, can be used for producing powerful yet in...
Article
Full-text available
Gesture and action recognition for video surveillance is an active field of computer vision. Nowadays, there are several techniques that attempt to address this problem by 3D mapping with a high computational cost. This paper describes software algorithms that can detect the persons in the scene and analyze different actions and gestures in real ti...
Conference Paper
Full-text available
Behavior determination and multiple object tracking for video surveillance are two of the most active fields of machine vision. We describe our system, which we are developing for applications in tele-assistance for the elderly, as an early warning monitor for anomalous events. Our system is based upon the computer vision library OpenCV. In this ar...
Conference Paper
Full-text available
This paper presents a new algorithm for the detection of Obstructive Sleep Apnea (OSA) from a single electrocardiogram lead. It is based on the alterations that OSA patients present in the LF and HF bands of the heart rate variability power spectrum. The algorithm calculates the power of the spectrum in two bands that roughly corresponding with the...
Article
Full-text available
Resumen En este artículo se presenta un estudio de caso, di-señado para ser utilizado en la materia Seguridad Informática o similar. Este tipo de actividad, tam-bién denominada método de caso, es un tipo de e– actividad que se caracteriza por utilizar una situa-ción real sobre la que los alumnos trabajan y discu-ten para llegar a conclusiones. En e...
Article
Full-text available
Heart rate variability (HRV) is an easily measurable physiological indicator with relevant clinical applicability. One important problem for HRV researchers is the lack of common data collections that could be used for testing their own algorithms. Moreover, free software tools for analyzing ECG records are scarce or they do not exist. Inspired by...
Article
Full-text available
We describe a novel software package, RHRV, which we have developed for studying heart rate variability (HRV) as an indicator for the state of the cardiovascular control system and as a discriminator for chronic sleep disorders. The RHRV package is written in the open source statistical environment R, and has recently been made available as a third...
Article
Full-text available
Currently, teachers who opt to use multimedia teaching resources in the classroom have to create them from scratch, or reuse others that they may find on the internet. Learning Object Repositories (LOR) have recently started to be created to facilitate the search and reuse of teaching materials. In this work we describe the final results of a proje...
Conference Paper
Full-text available
The heart rate variability (HRV) analysis has been proven to be an effective tool for the diagnosis of several diseases, such as heart failure or diabetes. To measure the HRV, various algorithms have been developed employing different programming languages. In this paper, we present a new package for R, a free software environment for statistical c...
Article
Neste artigo preséntase unha colección de ferramentas gratuítas para a elaboración de materiais docentes e adxúntanse referencias sobre outras alternativas.
Article
The present paper explores the challenges, issues and solutions to satisfy the security requirements of a Multi-Agent System (MAS) based on the JADE framework. By means of a prototype system used for Learning Management, an adequate security concept for MAS in general is presented. Hereby several security features are considered, ranging, among oth...
Article
Full-text available
In this work we propose the modelling of learning designs using an ontology that describes semantically the concepts defined in the IMS Learning Design specification (IMS LD). To demonstrate its possibilities, we present a comparison between the implementation of a learning design with Reload and Coppercore, the most cited applications for the desi...
Chapter
The use of time frequency distributions (TFDs) with adaptive kernels for the spectral estimation of non stationary signals has been shown to be an extremely useful tool in many applications. Nevertheless, their high computational cost, due to the necessity to calculate a new kernel in each time instance, poses an important problem in real time appl...
Article
Full-text available
In this paper, we present an ontology to represent the semantics of the IMS Learning Design (IMS LD) specification, a meta-language used to describe the main elements of the learning design process. The motivation of this work relies on the expressiveness limitations found on the current XML-Schema implementation of the IMS LD conceptual model. To...
Article
Full-text available
Se presenta un proyecto desarrollado en conjunto por el Grupo Stellae; el Centro de Estudios para el Aprendizaje (CETA); y el Grupo Liter 21 de la Universidad de Santiago, financiado Secretaría de Estado de Universidades e Investigación del Ministerio de Educación y Ciencia ( Programa de Estudio y Análisis de la convocatoria 2005 - Resolución 23/3/...
Article
Full-text available
In this paper we present a learning design ontology that is based on the IMS Learning Design (IMS LD) specification. The IMS LD is a metadata standard that de- scribes the elements of the design of any teaching-learning process on the basis of a well-founded conceptual model. However, this specification has been modelled and rep- resented using the...
Conference Paper
We present a multi-agent system (MAS) communication protocol for an intelligent learning management system that provides, among others, collaborative services. The motivation behind this study stems from the need to enhance the possibilities of the current software architecture of the EUME project. Our aim is to improve intelligent resource managem...
Conference Paper
We present a teacher interface for a computer supported educational system that we are developing. This interface was developed over a PDA with wireless network connectivity to be carried by the teacher into the classroom. The first prototype implemented an interface with a virtual keyboard and mouse in order to remotely manage the classroom server...
Conference Paper
Full-text available
In this paper the problem of educational resource management in a cooperative learning environment is discussed. A task model was elaborated to determine both functional and level-of-service requirements. Among the former we salient: (1) the remote control of classroom hardware devices, and (2) the accessibility to course materials. Among the later...
Article
Full-text available
In this paper, we present EUME Onto, an educational ontology that describe terms of learning design, contents and resources. This ontology is intended to (1) organize the available information; and (2) provide the grounds of the knowledge based for an Intelligent Learning Management System. EUME Onto is based on metadata standards such as IMS-EML,...
Article
Full-text available
Analysis of heart rate variability (HRV) is a valuable, non-invasive method for quantifying autonomic cardiac control in humans. Frequency-domain analysis of HRV involving myocardial ischaemic episodes should take into account its non-stationary behaviour. The wavelet transform is an alternative tool for the analysis of non-stationary signals. Four...
Article
Full-text available
Multiple sclerosis (MS) can cause alterations in autonomic cardiovascular functioning. Some authors attribute these anomalies detected in MS patients to brain stem lesions, due to the fact that important autonomic nuclei are located in this region of the brain. Other studies, however, have been unable to prove such a relation. AIMS. The purpose of...
Article
Full-text available
The monitoring of vital signs is a basic task that has been carried out on patients that are admitted into specialized units, such as coronary care units, intensive care units and operating rooms. There is now a good deal of interest in the ever-increasing possibility of such monitoring being extended further, outside the hospital setting (e.g. to...
Article
Full-text available
The resource accessibility problem in a cooperative learning environment can be stated as how both teachers and students can gain access to resources (informa-tion and hardware devices) not only from remote locations, but also from the classroom. In this paper we present a task model (TMo) that describes the services for a Resource Management Syste...