52 research outputs found
Procesamiento y caracterización de bioseñales para su uso en interfaces de control y afectividad
Las interfaces HCI y PC basadas en bioseñales constan de 3 fases: la captación de los datos, procesamiento y actuación sobre el sistema. El trabajo de esta tesis está centrado en el bloque de procesamiento de la información registrada por los electrodos. La naturaleza heterogénea de las bioseñales implica diferentes técnicas de captación y procesamiento para destacar y detectar aquellos elementos que son útiles para el objetivo que se busca. Para interfaces HCI, las señales deben se susceptibles de ser modificadas según la voluntad del individuo, destacando los transitorios asociados a estas acciones y minimizando aquellos elementos que puedan interferir negativamente, mientras que para PC los datos deben de contener información relativa al estado emocional del sujeto. El procesamiento de los datos es un elemento esencial para obtener unos resultados satisfactorios. A lo largo de la presente tesis se han expuesto dos técnicas de procesamiento basadas en la aplicación de envolventes inferiores, para eliminar o destacar transitorios en forma de campanas cóncavas/convexas de las señales EOG y ECG, y se han analizado las variaciones de las mismas junto a los datos de EEG ante situaciones de estrés y control de un teclado virtual
A new multisensor software architecture for movement detection: Preliminary study with people with cerebral palsy
A five-layered software architecture translating movements into mouse clicks has been developed and tested on an
Arduino platform with two different sensors: accelerometer and flex sensor. The archi-tecture comprises low-pass
and derivative filters, an unsupervised classifier that adapts continuously to the strength of the user's movements and
a finite state machine which sets up a timer to prevent in-voluntary movements from triggering false positives.
Four people without disabilities and four people with cerebral palsy (CP) took part in the experi-ments. People
without disabilities obtained an average of 100% and 99.3% in precision and true positive rate (TPR) respectively and
there were no statistically significant differences among type of sensors and placement. In the same experiment,
people with disabilities obtained 97.9% and 100% in precision and TPR respectively. However, these results worsened
when subjects used the system to access a commu-nication board, 89.6% and 94.8% respectively. With their usual
method of access-an adapted switch- they obtained a precision and TPR of 86.7% and 97.8% respectively. For 3-outof-
4 participants with disabilities our system detected the movement faster than the switch.
For subjects with CP, the accelerometer was the easiest to use because it is more sensitive to gross motor motion
than the flex sensor which requires more complex movements. A final survey showed that 3-out-of-4 participants
with disabilities would prefer to use this new technology instead of their tra-ditional method of access
Envelope filter sequence to delete blinks and overshoots
Background: Eye movements have been used in control interfaces and as indicators
of somnolence, workload and concentration. Different techniques can be used to
detect them: we focus on the electrooculogram (EOG) in which two kinds of interference
occur: blinks and overshoots. While they both draw bell-shaped waveforms, blinks
are caused by the eyelid, whereas overshoots occur due to target localization error and
are placed on saccade. They need to be extracted from the EOG to increase processing
effectiveness.
Methods: This paper describes off- and online processing implementations based
on lower envelope for removing bell-shaped noise; they are compared with a 300-msmedian
filter. Techniques were analyzed using two kinds of EOG data: those modeled
from our own design, and real signals. Using a model signal allowed to compare
filtered outputs with ideal data, so that it was possible to quantify processing precision
to remove noise caused by blinks, overshoots, and general interferences. We analyzed
the ability to delete blinks and overshoots, and waveform preservation.
Results: Our technique had a high capacity for reducing interference amplitudes
(>97%), even exceeding median filter (MF) results. However, the MF obtained better
waveform preservation, with a smaller dependence on fixation width.
Conclusions: The proposed technique is better at deleting blinks and overshoots than
the MF in model and real EOG signals
Stress and heart rate: significant parameters and their variations
The aim of this paper is to identify heart rate
parameters with higher significant values when a set of
people are performing a task under stress condition. In order
to accomplish this, one computer application with arithmetic
and memory activities which lets drive the subjects to
different stages of activity and stress has been designed.
Tests are formed by initial and final rest periods and three
task phases with incremental stressful level.
Electrocardiogram is measured in each state and parameters
are extracted from it. A statistical study using analysis of
variance (ANOVA) is done to see which ones are the most
significant. It is concluded that the median of RR segments is
the parameter to best determine the state of stress.Regional Government of Andalusia (p08-TIC-3631
EEG Feature Variations under Stress Situations
The goal of this study is to identify EEG parameters
and electrode positions with the highest significant values to
differentiate between tasks and relax periods. Different signals
were recorded as 12 subjects are doing arithmetic and memory
tasks under stress condition. The test consisted of an initial and
final 5-minute relax periods and three 4-minute performance
phases with increased stress level. q and a bands concentrated
mainly features whose variation were significant, and F3 and
P4 were the best positions to distinguish between performed
tasks and arousal level
Emotions Detection based on a Single-electrode EEG Device
The study of emotions using multiple channels of EEG represents a widespread practice in the field of research
related to brain computer interfaces (Brain Computer Interfaces). To date, few studies have been reported in
the literature with a reduced number of channels, which when used in the detection of emotions present results
that are less accurate than the rest. To detect emotions using an EEG channel and the data obtained is useful
for classifying emotions with an accuracy comparable to studies in which there is a high number of channels,
is of particular interest in this research framework. This article uses the Neurosky Maindwave device; which
has a single electrode to acquire the EEG signal, Matlab software and IBM SPSS Modeler; which process
and classify the signals respectively. The accuracy obtained in the detection of emotions in relation to the
economic resources of the hardware dedicated to the acquisition of EEG signal is remarkable
Customizable Software Interface for Monitoring Applications
In this paper we propose an application based on virtual keyboard and
automatic scanning to communicate with a PC and the others people. The aim
users are the people with disabilities. A high degree of customization is possible
in the software. So the user can selected the color of buttons, position of system
on screen, the kind of scanning, timer, the interface of communication, etc. Five
people without disabilities tested our system. The results of the tests show the
application reduce the fatigue of user and increased the text entry rate.Junta de Andalucía p08-TIC-363
A Flexible, Open, Multimodal System of Computer Control Based on Infrared Light
This In this paper, a system architecture that can be adapted to an individual’s motor capacity and preferences, to control a computer is presented. The system uses two different transducers based on the emission and the reflection of infrared light. These let to detect of voluntary blinks, winks, saccadic or head movements and/or sequences of them. Transducer selection and operational mode can be configured. The signal provided by the transducer is adapted, processed and sent to a computer by external hardware. The computer runs a row-column scanned switch-controlled Virtual Keyboard (VK). This sends commands to the operating system to control the computer, making possible to run any application such as a web browser, etc. The main system characteristics are flexibility and relatively low-cost hardware.Junta de Andalucía p08-TIC-363
Fingerprint indoor position system based on OpenMAC
This paper presents a work in progress for the developing of a fingerprint indoor position system based on
OpenMAC, an IEEE 802.15.4 embedded software implementation from Atmel to be used in different
scenarios like e_health, ambient living or smart building. The system is thought to work as another one that
we have yet developed but using the BitCloud Stack, a full-featured, second generation embedded software
stack from the same supplier, but improving it. The first steps followed up in the system development are
shown in this paper.Junta de Andalucía p08-TIC-363
The IEC-60870-5 standard for a personal server applied to telemedicine
This paper presents a proposal of a flexible telemedicine
system for remote patient monitoring. It can be used in
different kind of environments where there is only available low
speed transmission links like Radio Frequency. This proposal
includes the use of a previous work where the IEC-60870-S
standard was applied to the development of an open and flexible
RTU (Remote Terminal Unit) based in open hardware, a SoCtype
design using a FPGA programmed with the open core LEON
and open source, so both the hardware and the ISO are open
source.Junta de Andalucía p08-TIC-363
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