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Thus far, attention has been paid to phenomena wherein the cardiovascular system and respiratory movement system have worked in coordination with one another, which has been studied. On the other hands, the earlier studies have hinted at the importance of considering mental and physical health from a holistic perspective, while taking into consideration the principles that prescribe the chaotic behavior...
Abdominal aortic aneurysm (AAA) is a cardiovascular disease which mostly appears in elderly people. Due to the weakening of aortic wall, a rupture occurs in the most inner layer of aorta and a thrombus is generated. If the diameter exceeds greater than 5.5 cm, a treatment strategy is required. As a result, CT imaging is utilized to screen and evaluate thrombus parameters for treatment. Exploitation...
Chest-worn accelerometers have been shown to detect acoustic and mechanical signals corresponding to cardiovascular activity. This paper aims at investigating and characterizing two different components of chest acceleration (seismocardiogram) along two orthogonal axes: firstly, the sub-10 Hz ballistic signal components dominant in the vertical axis and secondly, the 10-50 Hz acoustic signal components...
In this study we attempt to quantify the correlations between time asymmetric index (TAI) and physiological/ pathological measurements in order to predict the status of cardiac autonomic neuropathy (CAN) in patients with end-stage renal disease. The TAI can explore non-equilibrium dynamics that conventional time and frequency domain indices fail to consider. For comparing the effectiveness and applicability,...
Empirical mode decomposition (EMD) allows decomposing an observed multicomponent signal into a set of monocomponent signals called Intrinsic Mode Functions (IMFs). EMD provides a large number of IMFs and it is important to select the fundamental IMFs and eliminate the redundant ones. This paper proposes a new criterion, based simultaneously on the Minkowski distance and the Jensen Rényi divergence...
Electrocardiogram is previously verified as a new biometric for human identification. However, it is uncertain if changes of cardiovascular conditions may cause any difference. The research investigates if cardiovascular conditions may impact ECG biometrics. A longitudinal and cross-section investigation is applied on peritoneal dialysis patients. Our results show that ECG is still able to identify...
The study aimed to determine the potential of pulse wave velocity measurements to reflect changes in compliant cerebral arteries/arterioles in head injured patients. The approach utilizes the electrocardiogram and intracranial pressure signals to measure the wave transit time between heart and cranial cavity. Thirty five clinical records of nineteen head injured patients, with different levels of...
The Pulse Transit Time (PTT) is generally assumed to be a good surrogate measure to comfortably track blood pressure (BP) and blood pressure changes. This paper investigates PTT variations for healthy young subjects during a sequence of short-term physical exercises. PTT was measured by two different methodologies having different measurement accuracies as well as underlying assumptions: the total...
Monitoring cardiac output (CO) is important for the management of patient circulation in an operation room (OR) or intensive care unit (ICU). We assumed that the change in pulse wave transit time (PWTT) obtained from an electrocardiogram (ECG) and a pulse oximeter wave is correlated with the change in stroke volume (SV), from which CO is derived. The present study reports the verification of this...
The Dominant T-wave (DTW) offers an overall view of the venticular repolarization as it reflects the first-order derivative of the transmembrane potential of the myocytes during repolarization (TMPR). DTW can be estimated from the analysis of surface T-waves, which are modeled as a linear combination of DTW and its derivatives. Usually, the contribute of the DTW dominates but, when dispersion of the...
An analysis of the Long Term ST Database (LTSTDB) was conducted to quantify the spatio-temporal dynamics of ischemic and non-ischemic episodes. For all 86 recordings the ischemic episode length is described by a lognormal distribution and the non-ischemic episode length by a generalized extreme value distribution. For the 15 recordings that possess orthogonal (EASI) leads sets we derived the 12 standard...
The present study proposes a novel method of modelling the response of the renal blood flow (RBF) of rabbit kidneys to sympathetic nerve activity using polynomial nonlinear autoregressive with exogenous input (NARMAX) model. The nonlinear models were mapped into frequency domain using harmonic probing technique to get linear and nonlinear frequency response functions which are invariant descriptor...
In recent years, volumetric (3D) cardiac ultrasound imaging has become more readily available in daily clinical practice due to the introduction of matrix array transducer technology. To date, quantitative analysis of these data sets typically requires a significant amount of user interaction. Recently, our teams introduced methods that could help in automating this process. On the one hand, an edge...
The article emphasizes clinical significance of exercise electrocardiograph (ECG) test with nonlinear analysis applied on patients with coronary heart disease (CHD). The synchronous 12-lead ECG signals of sixty old patients with CHD have been studied by the methods of correlation dimension. The patients with CHD had lower correlation dimension in each exercise test program. The results also showed...
PET/CT units with high temporal resolution (particularly with 64-slice CT capability) are increasingly used as in clinical diagnosis and prognosis of cardiovascular disease. Since the CT sub-system in the combined PET/CT unit is used to perform attenuation correction of acquired PET data, misalignments between patient positioning for both scans can cause artifacts in the myocardial PET images potentially...
In this work, the effect of the electromagnetic radiation generated by mobile phone, on the heart rate variability (HRV) has been investigated using correlation dimension calculation which is a nonlinear analysis method. The 17 volunteer subjects participated to our work and the experiment is designed as three periods and each period have 7 minutes. The electrocardiogram (ECG) signals were recorded...
Cardiovascular stents are frequently used in the treatment of atherosclerosis. These stents are commonly comprised of metal and are naturally surrounded by an oxide layer. When multiple stents are placed in the body the electrochemical phenomenon of fretting corrosion may occur through the continuous pulsing of the artery. The goal of this study will be to determine if a correlation exists between...
Our aims were to use a chirp-type breathing maneuver to obtain a continuous relation between the high frequency component of HRV (HFRR) and respiratory frequency (RF), and to assess if it indicates the vagal withdrawal induced by a postural change. ECG and lung volume were registered from 30 subjects who performed, in sitting and standing, a 70-s continuous linear RF increase from 0.05 to 0.8 Hz at...
In recent decades many research effort has been expended in the field of noninvasive, continuous blood pressure (BP) estimation by cardiovascular surrogate parameters, mainly the pulse transit time (PTT). Due to differences in the measurement setup and in the consideration of important physiological aspects, however, there is a multitude of inconsistent statements about the BP tracking capabilities...
Color flow mapping has become an important clinical tool, for diagnosing a wide range of vascular diseases. Only the velocity component along the ultrasonic beam is estimated, so to find the actual blood velocity, the beam to flow angle has to be known. Because of the unpredictable nature of vascular hemodynamics, the flow angle cannot easily be found as the angle is temporally and spatially variant...
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