Search results for " Biomedical"
showing 10 items of 480 documents
Remote heart rate variability for emotional state monitoring
2018
International audience; Several researches have been conducted to recognize emotions using various modalities such as facial expressions , gestures, speech or physiological signals. Among all these modalities, physiological signals are especially interesting because they are mainly controlled by the autonomic nervous system. It has been shown for example that there is an undeniable relationship between emotional state and Heart Rate Variability (HRV). In this paper, we present a methodology to monitor emotional state from physiological signals acquired remotely. The method is based on a remote photoplethysmography (rPPG) algorithm that estimates remote Heart Rate Variability (rHRV) using a …
Facial Expressions to Evaluate Advertising: A Laboratory versus Living Room Study
2017
In recent years researchers have shown growing interest in the impact of emotions in television commercials and in advertising in general (Park and Thorson, 1990). Emotions also influence the attitude towards the brand and to the ad (Batney and Ray, 1986; Edell and Burke, 1987; Derbaix, 1995), increase the attention of the advertisement (Olney, Hobrook and Bartra, 1991), and brand recall (Stayman and Batra, 1991).
Classification of Heart Sounds Using Convolutional Neural Network
2020
Heart sounds play an important role in the diagnosis of cardiac conditions. Due to the low signal-to-noise ratio (SNR), it is problematic and time-consuming for experts to discriminate different kinds of heart sounds. Thus, objective classification of heart sounds is essential. In this study, we combined a conventional feature engineering method with deep learning algorithms to automatically classify normal and abnormal heart sounds. First, 497 features were extracted from eight domains. Then, we fed these features into the designed convolutional neural network (CNN), in which the fully connected layers that are usually used before the classification layer were replaced with a global averag…
Virtual simulation of an osseointegrated trans-humeral prosthesis: A falling scenario
2018
Abstract Introduction Traditional prosthetic solutions expose the amputee to numerous problems that limit his ability to safely perform the normal activities of daily life. In order to eliminate the problems related to the use of the traditional prosthesis with socket, a new technique was developed for fixing the prosthesis to the amputees based on the principle of osseointegration. The aim of this paper is to study and analyze the stress distribution on the interface between a trans-humeral osseointegrated prosthetic implant and the residual bone, identifying the most stressed areas and thus foreseeing possible failure phenomena of the entire prosthetic system and, after, to compare the st…
Influence of noise sources on FitzHugh-Nagumo model in suprathreshold regime
2005
We study the response time of a neuron in the transient regime of FitzHugh-Nagumo model, in the presence of a suprathreshold signal and noise sources. In the deterministic regime we find that the activation time of the neuron has a minimum as a function of the signal driving frequency. In the stochastic regime we consider two cases: (a) the fast variable of the model is noisy, and (b) the slow variable, that is the recovery variable, is subjected to fluctuations. In both cases we find two noise-induced effects, namely the resonant activation-like and the noise enhanced stability phenomena. The role of these noise-induced effects is analyzed. The first one produces suppression of noises, whi…
The importance of correct implants positioning and masticatory load direction on a fixed prosthesis
2018
Background Through the biomechanical study of dental implants, it is possible to understand the dissipation effects of masticatory loads in different situations and prevent the longevity of osseointegration. Aims: To evaluate the microstrains generated around external hexagon implants, using axial and non-axial loads in a fixed four-element prosthesis with straight implants and implants inclined at 17°. Material and Methods Three implants were modeled using CAD software following the manufacturer's measurements. Then, implants were duplicated and divided into two groups: one with straight implants and respective abutments, and the other with angled implants at 17° and respective abutments. …
Analysis of Upper Limbs Target-Reaching Movement and Muscle Co-Activation in Patients with First Time Stroke for Rehabilitation Progress Monitoring
2022
In this paper, the authors analysed changes occurring during the rehabilitation processes in patients after early stroke based on analysis of their upper limbs’ target-reaching movement and muscle co-activation. Ischemic stroke often results in reduced mobility of the upper extremities and frequently is a cause for long-term disability. The ever-developing technology of 3D movement analysis and miniaturisation of equipment for testing the bioelectrical activity of muscles can help to assess the progress of rehabilitation. The aim of this study was to examine the use of analysis of target-reaching movement indicators and muscle co-activation for diagnosing the rehabilitation process in post-…
Assessment of a mattress with phase change materials using a thermal and perception test
2017
Abstract Mattresses composed by phase change materials (PCMs) may improve the thermoregulation of the human body. The aim of the study was to analyse the thermoregulatory efficiency of a PCMs and a conventional mattresses via the evaluation of the skin temperature, thermal comfort and thermal perception. Twenty participants lay on a PCMs and a conventional mattress for 20 min in each mattress on the same day. Skin temperature of the back of the participants and temperature of the sheet of the mattresses were measured before and immediately after lying on each mattress. Thermal comfort and thermal perception were also reported during the last minute of the lying test. The PCMs mattress resul…
A new Frequency Domain Measure of Causality based on Partial Spectral Decomposition of Autoregressive Processes and its Application to Cardiovascular…
2019
We present a new method to quantify in the frequency domain the strength of directed interactions between linear stochastic processes. This issue is traditionally addressed by the directed coherence (DC), a popular causality measure derived from the spectral representation of vector autoregressive (AR) processes. Here, to overcome intrinsic limitations of the DC when it needs to be objectively quantified within specific frequency bands, we propose an approach based on spectral decomposition, which allows to isolate oscillatory components related to the pole representation of the vector AR process in the Z-domain. Relating the causal and non-causal power content of these components we obtain…
A study on the effect of contact pressure during physical activity on photoplethysmographic heart rate measurements
2020
Heart rate (HR) as an important physiological indicator could properly describe global subject&rsquo