Search results for " Biomedical"
showing 10 items of 480 documents
Forward acceleration of the centre of mass during ski skating calculated from force and motion capture data
2016
The purpose of this paper was to present and evaluate a methodology to determine the contribution of bilateral leg and pole thrusts to forward acceleration of the centre of mass (COM) of cross-country skiers from multi-dimensional ground reaction forces and motion capture data. Nine highly skilled cross-country (XC) skiers performed leg skating and V2-alternate skating (V2A) under constant environmental conditions on snow, while ground reaction forces measured from ski bindings and poles and 3D motion with high-speed cameras were captured. COM acceleration determined from 3D motion analyses served as a reference and was compared to the results of the proposed methodology. The obtained value…
Database to Ontology Mapping Patterns in RDB2OWL Lite
2016
We describe the RDB2OWL Lite language for relational database to RDF/OWL mapping specification and discuss the architectural and content specification patterns arising in mapping definition. RDB2OWL Lite is a simplification of original RDB2OWL with aggregation possibilities and order-based filters removed, while providing in-mapping SQL view definition possibilities. The mapping constructs and their usage patterns are illustrated on mapping examples from medical domain: medicine registries and hospital information system. The RDB2OWL Lite mapping implementation is offered both via translation into D2RQ and into standard R2RML mapping notations.
Biopolyester-based systems containing naturally occurring compounds with enhanced thermooxidative stability
2016
Background This work presents a sustainable approach for the stabilization of polylactic acid (PLA) against thermo-oxidative aging. Methods Naturally occurring phenolic and polyphenolic compounds, such as ferulic acid (FerAc), vanillic acid (VanAc), quercetin (Querc) and vitamin E (VitE), were introduced into PLA. Results The preliminary characterization of the systems formulated containing different amounts of natural stabilizers showed that all compounds used acted as plasticizers, leading to a decrease in rheological functions with respect to neat PLA, without significantly modifying the crystallinity of the raw material. The study of the thermo-oxidative behavior of neat PLA and PLA/nat…
Computer-Assisted Approaches for Uterine Fibroid Segmentation in MRgFUS Treatments: Quantitative Evaluation and Clinical Feasibility Analysis
2019
Nowadays, uterine fibroids can be treated using Magnetic Resonance guided Focused Ultrasound Surgery (MRgFUS), which is a non-invasive therapy exploiting thermal ablation. In order to measure the Non-Perfused Volume (NPV) for treatment response assessment, the ablated fibroid areas (i.e., Region of Treatment, ROT) are manually contoured by a radiologist. The current operator-dependent methodology could affect the subsequent follow-up phases, due to the lack of result repeatability. In addition, this fully manual procedure is time-consuming, considerably increasing execution times. These critical issues can be addressed only by means of accurate and efficient automated Pattern Recognition ap…
Causal brain-heart information transfer during visual emotional elicitation in healthy subjects: Preliminary evaluations and future perspectives
2017
Complex heartbeat dynamics is known to reflect subject's emotional state, thanks to numerous links to brain cortical and subcortical regions. Likewise, specific brain regions are deeply involved in vagally-mediated emotional processing and regulation. Nevertheless, although the brain-heart interplay has been studied during visual emotion elicitation, directional interactions have not been investigated so far. To fill this gap, in this study we investigate brain-heart dynamics during emotional elicitation in healthy subjects through measures of Granger causality (GC) between the two physiological systems. Data were gathered from 22 healthy volunteers who underwent pleasant/ unpleasant affect…
Information Transfer Between Respiration and Heart Rate During Sleep Apnea
2016
It is well-known that sleep apnea affects the respiration and the heart rate (HR), and studies have shown that the cardiorespiratory coupling is also compromised during obstructive sleep apnea (OSA). Furthermore, the classification of hypopneas is challenging, in particular when only ECG-derived features are used. In this context, this study investigates how different ECG-derived respiratory (EDR) signals resemble the respiratory effort during different types of apneas, and how the amount of information transferred from respiration to HR varies according to the respiratory signal used, real or ECG-derived. ECG and respiratory signals of 10 patients suffering from sleep apnea were analysed, …
A Framework to Assess the Information Dynamics of Source EEG Activity and Its Application to Epileptic Brain Networks
2020
This study introduces a framework for the information-theoretic analysis of brain functional connectivity performed at the level of electroencephalogram (EEG) sources. The framework combines the use of common spatial patterns to select the EEG components which maximize the variance between two experimental conditions, simultaneous implementation of vector autoregressive modeling (VAR) with independent component analysis to describe the joint source dynamics and their projection to the scalp, and computation of information dynamics measures (information storage, information transfer, statistically significant network links) from the source VAR parameters. The proposed framework was tested on…
An Electrooculography based Human Machine Interface for wheelchair control
2019
International audience; This paper presents a novel single channel Electrooculography (EOG) based efficient Human–Machine Interface (HMI) for helping the individuals suffering from severe paralysis or motor degenerative diseases to regain mobility. In this study, we propose a robust system that generates control command using only one type of asynchronous eye activity (voluntary eye blink) to navigate the wheelchair without a need of graphical user interface. This work demonstrates a simple but robust and effective multi-level threshold strategy to generate control commands from multiple features associated with the single, double and triple voluntary eye blinks to control predefined action…
The human-computer connection: An overview of brain-computer interfaces
2018
This article introduces the field of brain-computer interfaces (BCI), which allows the control of devices without the generation of any active motor output but directly from the decoding of the user’s brain signals. Here we review the current state of the art in the BCI field, discussing the main components of such an interface and illustrating ongoing research questions and prototypes for controlling a large variety of devices, from virtual keyboards for communication to robotics systems to replace lost motor functions and even clinical interventions for motor rehabilitation after a stroke. The article concludes with some insights into the future of BCI.
Influence of cortical bone and implant design in the primary stability of dental implants measured by two different devices of resonance frequency an…
2020
Background This study aimed to evaluate the effect of the implant design and the presence of cortical bone in the primary stability, as well as analyze the differences between the stability measurements obtained by two different resonance frequency analysis (RFA) devices. Material and methods A total of 80 Klockner implants of two different models [40 Essential Cone implants (group A) and 40 Vega implants (group B)] were used. The implants were placed in two polyurethane blocks that simulated the mechanical properties of the maxillary bone. One block featured a layer of cortical bone that was absent from the other block. The primary stability of all implants was measured by insertion torque…