The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Atrial fibrillation (AF) is the most common arrhythmia in the western countries and accounts for hundred thousand strokes per year. Electrocardiographic characteristics of AF have been demonstrated to help identify patients at risk of developing AF. Prolonged and highly fragmented P-waves have been observed in patients prone to AF, and time-domain. Morphological characteristics of the P-wave from...
Image-guided interventions have revolutionized the development of minimally invasive surgical procedures, leading to reduced patient trauma, fewer risks and shorter recovery times. However, one of the most frequently posed question with regards to an image guidance system is how accurate it is. In this work we provide a brief overview on accuracy considerations from our perspective on cardiac image-guided...
We have developed a novel adaptive multi-infusion advisory system for circulatory management of critically ill patients which co-ordinates infusion adjustments to ensure safe trajectories. This system should reduce patient hospital stay and improve patient outcome by enhancing the quality of patient circulatory control; alleviating the clinical cognitive load, giving staff more time for direct patient...
There is no doubt that the contribution of the Health Care Technologies to the tremendous evolution on Medicine since mid XX century has been one of its most important pillars. At the same time the innovation has been sometimes accused of been the root of the increase in the Health Care expenditure to support the Health of the society. Actually, when the Health Care Systems are focusing not only on...
In this study we propose the correntropy function as a discriminative measure for detecting nonlinearities in the respiratory pattern of chronic heart failure (CHF) patients with periodic or nonperiodic breathing pattern (PB or nPB, respectively). The complexity seems to be reduced in CHF patients with higher risk level. Correntropy reflects information on both, statistical distribution and temporal...
Sample Entropy (SampEn) is a nonlinear regularity index that requires the a priori selection of three parameters: the length of the sequences to be compared, m, the patterns similarity tolerance, r, and the number of samples under analysis, N. Appropriate values for m, r and N have been recommended in some cases, such as heart rate, hormonal data, etc., but no guidelines exist for the selection of...
Cardiovascular diseases, specifically myocardial infarction and end-stage heart failure represent some of the major pathologies that threaten human life. Here we present a novel approach for a bioactive cardiac patch based on a combination of biomedical and textile manufacturing techniques in concert with nano-biotechnology based tissue-engineering stratagems. The technological goal is to create BioNanoTextiles™...
The aim of this study was to investigate sex and age related differences in drug induced QT prolongation by dofetilide under reduced repolarization reserve in simulated ventricular cells. Left ventricular endocardial action potentials were simulated using a modified Luo Rudy model. Sex, age and regional differences in currents ICaL, IKr, IKs, and Ito were incorporated into the model by modifying the...
Systolic time intervals (STI) have shown significant diagnostic and prognostic value to assess the global cardiac function. Their value has been largely established in hospital settings. Currently, STI are considered a promising tool for long-term patient follow-up with chronic cardiovascular diseases. Several technologies exist that enable beat-by-beat assessment of STI in personal health application...
Closed loop systems, in which stimulation parameters are adjusted according to recorded signals would reduce the occurrence of side effects of stimulation and broaden current therapeutic options. As a step towards a closed-loop clinical system, we developed a single electrode stimulation / recording system for an in vitro microelectrode array. The system was used in vitro to simultaneously stimulate...
Left ventricular hypertrophy (LVH) is a complex cardiac condition mainly identified by the thickening of the myocardial wall. Although most of the contemporary cardiac imaging modalities provide high resolution 3D images, the wall thickness (WT) is still measured within the acquired planes. This way of measurement may introduce an error as cardiac wall is not necessarily orthogonal to the plane. In...
The wave speed (c) and the arrival time of reflected wave (Trw) in the common left carotid artery and common left femoral artery have been evaluated in 70 healthy subjects, aged 35-55 years with a non-invasive method. Wave speed and the arrival time of reflected waves were determined with InDU-loop and non-invasive wave intensity analysis (ndl) techniques, respectively. Diameter (D) was measured with...
We investigated the potential of adding cardiac and respiratory activity information to actigraphy for sleep-wake staging. A dataset of 35 recordings with full polysomnography and actigraphy was used to assess the performance of an automated sleep/wake Bayesian classifier using electrocardiogram, inductance plethysmogram estimate of respiratory effort and actigraphy. The best performance was achieved...
This paper provides a first description of a multiscale systems modeling approach applied to the congenital birth defect known as the tetralogy of Fallot. The multiscale approach adopted owes a lot to the effort of the world-wide physiome consortium and the work of research groups within the European Union on the Virtual Physiological Human. Both a spatial scale and time scale are used to establish...
Heart Rate variability (HRV) is important in characterizing heart functions. However, artifacts and trends are regularly observed to contaminate the HRV sequences. This study proposes a simple and effective preprocessor for the removal of artifacts and trend in the HRV sequences. A thresholding filter is applied to remove artifacts to maintain the HRV sequences in a reasonable range. A wavelet filter...
An evaluation of a newly CE approved bedside monitoring device used in a general hospital ward is presented. This evaluation has shown that it is feasible to use the system within this environment to provide medical staff with supplementary information on patient health, at more frequent intervals than traditional monitoring methods. The physiological data recorded by the body worn device is wirelessly...
Intradyalitic exercise programas are important to improve patient's hemodynamic stability. Blood pressure and metabolic changes are correlated when heat accumulation is due to increment of the body core temperature (+1.0°C). However, increase in temperature could be controlled by lowering dialysate's temperature using two main modalities techniques (isothermic and thermoneural) with different patient's...
We propose a new band-phase-randomized surrogate data method to evaluate the chaotic dynamics in the high (HF) and low frequency (LF) bands of heart rate variability (HRV) in healthy subjects. The chaotic strength of normal HRV as assessed by a noise titration assay completely vanished when its power spectrum was phase-randomized over the entire frequency band or the HF band alone, but not the LF...
The modeling of the electrical activity of the heart is of great medical and scientific interest, as it provides a way to get a better understanding of the related biophysical phenomena, allows the development of new techniques for diagnoses and serves as a platform for drug tests. However, due to the multi-scale nature of the underlying processes, the simulations of the cardiac bioelectric activity...
A novel fully integrated preamplifier stage for cardiac activity sensing is presented. The proposed design takes advantage of the High Voltage CMOS (HV) technology properties to comply with the safety requirements of implantable devices without the addition of external decoupling capacitors. The power consumption is minimum; while the input referred noise is kept well below the minimum signal to be...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.