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In recent years, there has been a rapid growth in patient monitoring and medical data analysis using decision support systems, smart alarm monitoring, expert systems and many other computer aided protocols. The main goal of this study was to enhance the developed diagnostic alarm system for detecting critical events during anaesthesia. The proposed diagnostic alarm system is called Fuzzy logic monitoring...
The carotid sinus baroreflex is one of the most important negative feedback systems to stabilize arterial pressure. Although static characteristics of the carotid sinus baroreflex can be assessed by using a stepwise input protocol under baroreflex open-loop conditions, the step duration has been determined empirically. In the present study, we examined the effects of different time windows (5–10,...
A model-based approach that integrates known portion of the cardiovascular system and unknown portion through a parameter estimation to predict evolution of the mean arterial pressure is considered. The unknown portion corresponds to the neural portion that acts like a controller that takes corrective actions to regulate the arterial blood pressure at a constant level. The input to the neural part...
Functional near-infrared spectroscopy (fNIRS) is a non-invasive optical neuroimaging method used to investigate functional activity of the cerebral cortex evoked by cognitive, visual, auditory and motor tasks, detecting regional changes of oxy- and deoxy-hemoglobin concentration. Accurate estimation of the stimulus-evoked hemodynamic response (HR) from fNIRS signals in order to quantitatively investigate...
HeartCycle is an integrated project aiming to provide a disease management solution for cardiovascular disease patients, by developing technologies, algorithms to interpret data and services to facilitate the remote management of patients at home. In this paper an overview of part of the algorithmic work package, oriented at motivating the patients to be compliant to treatment regimes and to adopt...
In this paper we present an autonomic cardiovascular model of a preterm infant of 28 weeks of gestation with a birth weight of 1000 g and a closed ductus arteriosus by the end of the first week, that is capable of describing the complex interactions between heart rate, blood pressure and respiration. The hemodynamic model consists of a pulsatile heart and several vascular compartments, and is regulated...
The excitation specificity of QT dynamic parameters was tested on three groups of subjects: healthy subjects; non-medicated hypertensive subjects with metabolic syndrome; and subjects with essential hypertension. Four different excitations of RR were used: bicycling exercise; tilt with breathing 0.1 and 0.33 Hz; and deep breathing. Linear dynamic feedback model of QT/RR coupling was supposed at the...
Cardiovascular diseases are the most popular cause of death in the world recently. For postoperatives, cardiac rehabilitation is still asked to maintain at home (phase II) to improve cardiac function. However, only one third of outpatients do the exercise regularly, reflecting the difficulty for home-based healthcare: lacking of monitoring and motivation. Hence, a cardio-pulmonary rehabilitation system...
The paper proposes a robust online adaptive neural network control scheme for an automated treadmill system. The proposed control scheme is based on Feedback-Error Learning Approach (FELA), by using which the plant Jacobian calculation problem is avoided. Modification of the learning algorithm is proposed to solve the overtraining issue, guaranteeing to system stability and system convergence. As...
Anaerobic endurance training (AET) can improve sympathomimetic hyperactivity, and anaerobic interval training (AIT) is recommended for patients who cannot exercise due to exertional breathlessness and leg fatigue. However, the difference in sympathetic nerve activation (SNA) and parasympathetic nerve activation (PNA) during AIT and AET is unclear. The aim of this study is to investigate the differences...
This paper proposes an adaptive neuro-fuzzy model to study the pathophysiology of essential hypertension. Using diverse inputs such as risk factors, physical relations and medical interventions, and states that include both transient and resting states for key physiological variables (blood pressure, total peripheral resistance), it can roughly predict both real-time and long-term blood pressure change...
The present paper has proposed two methods for obtaining the linear correlation of the baroreflex system without measurement of blood pressure. One is based on the pulse wave transit time which needs both the electrocardiogram and the photoplethysmogram. The other is based on the photoplethysmogram only. The results from the experiments showed that the effect of habitual exercise and the Valsalva...
An algorithm for rapid trend detection of physiological parameter is introduced for ambulatory monitoring applications. Kalman prediction error of monitored parameter is used to estimate the physiological status and detect rapid change. With this algorithm, rapid trend during ambulatory monitoring can be found to predict disease exacerbation; and it is also applied to identify outliers of measurement...
This paper intends to define an optimal range for the pump speed of Rotary Left Ventricular Assist Devices (LVADs) that are used in bridge-to-recovery treatments. If the pump is operating within that optimal range, the aortic valve will be working properly (i.e. opening and closing) in each cardiac cycle. The proper operation of the aortic valve is a very important factor in helping the heart muscle...
The aim of this paper was to study interactions between R-R intervals and respiratory phases in healthy children during night-time sleep using a novel technique based on joint symbolic dynamics. We investigated overnight polysomnography data of 40 healthy children. The R-R time series were extracted from electrocardiograms (ECG) and respiratory phases were obtained from abdominal sensors using the...
Calculating entropy rate in physiologic signals has proven very useful in many settings. Common entropy estimates for this purpose are sample entropy (SampEn) and its less robust elder cousin, approximate entropy (ApEn). Both approaches count matches within a tolerance r for templates of length m consecutive observations. When physiologic data records are long and well-behaved, both approaches work...
Sleep is a physiological process with an internal program of a number of well defined sleep stages and intermediate wakefulness periods. The sleep stages do modulate the autonomous nervous system and thereby the sleep stages are accompanied by different regulation regimes for the cardiovascular and respiratory system. The differences in regulation can be distinguished by new analysis techniques on...
This paper describes the design and development of a system for cardio rehabilitation of patients that suffered a myocardial infarction. The proposed solution focuses on exercise prescriptions and the encouragement of healthy behaviors. The innovative strategy of the design takes into account health promotion models to provide safe, assistive exercise training sessions, personalized feedbacks, and...
Exercise constitutes an important intervention aiming to improve health and quality of life for several categories of patients. Personalized exercise prescription is a rather complicated issue, requiring several aspects to be taken into account, e.g. patient's medical history and response to exercise, medication treatment, personal preferences, etc. The present work proposes an ontology-based framework...
Medical electronic systems are generating ever larger data sets from a variety of sensors and devices. Such systems are also being packaged in wearable designs for easy and broad use. The large volume of data and the constraints of low-power, extended-duration, and wireless monitoring impose the need for on-chip processing to distill clinically relevant information from the raw data. The higher-level...
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