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We have developed a hydrodynamically levitated centrifugal blood pump for extracorporeal circulatory support. In the blood pump, a spiral groove bearing was adopted for a thrust bearing. In the spiral groove bearing, separation of erythrocytes and plasma by plasma skimming has been postulated to occur. However, it is not clarified that plasma skimming occurs in a spiral groove bearing. The purpose...
Cardiac recovery has been observed in end-stage heart failure patients with mechanical circulatory support. An intra-aortic ventricular assist device (IntraVAD) is a novel rotary blood pump designed to operate in the ascending aorta behind the aortic valve, working in series with the compromised left ventricle (LV). Such a device requires optimal motion control in order to enhance the myocardial perfusion...
Pulmonary conduit valves are used as one of the surgical treatment methods of congenital heart diseases. We have been designing a sophisticated pulmonary conduit valve for the right ventricular outflow tract reconstruction in pediatric patients. In this study, two types of polyester grafts with or without bulging structures for the conduit valves were used and evaluated from the hemodynamic point...
Calcific aortic valve disease (CAVD) is a cardiovascular condition that causes the progressive narrowing of the aortic valve (AV) opening, due to the growth of bone-like deposits all over the aortic root (AR). Transcatheter aortic valve replacement (TAVR), a minimally invasive procedure, has recently become the only lifesaving solution for patients that cannot tolerate the standard surgical valve...
Coarse graining of physiological time series such as the cardiac interbeat interval series by means of a symbolic transformation retains information about dynamical properties of the underlying system and complements standard measures of heart rate variability. The transformations of the original time series to the coarse grained symbolic series usually lead to a non-uniform occurrence of the different...
The fractal characteristics of heart rate variability are usually assessed by estimating short- and long-term scale coefficients, α1and α2, by detrended fluctuation analysis. Recently we extended this approach introducing a temporal spectrum of scale coefficients, α(τ), that describes the deviations of self-similarity from the bi-fractal model at each scale τ. Until now relatively short recordings...
This study was designed to characterize in time, frequency and information domains heart period (HP) and QT interval variabilities in asymptomatic (ASYMP) long QT syndrome type 2 (LQT2) subjects. HP, approximated as the temporal distance between two consecutive R-wave peaks, and QT, approximated as the temporal distance between the R-wave peak and the T-wave offset, were automatically derived from...
This study reports on the development of a gender-specific classification system able to discern between two levels of velocity of a caress-like stimulus, through information gathered from Autonomic Nervous System (ANS) linear and nonlinear dynamics. Specifically, caress-like stimuli were administered to 32 healthy volunteers (16 males) while monitoring electrocardiogram signal to extract Heart Rate...
The paper presents results of a sleep study on 60 newborn infants and 22 one-month infants, in quiet and active sleep and in prone and supine position. During the study, HRV and respiration were acquired and then analyzed with a multi-parametric approach. Time, Frequency Domain and Non-Linear parameters were calculated, also encompassing indices from the adult and fetal field. The novelty of this...
Cardiovascular diseases are the first cause of death in developed countries. Using electrocardiographic (ECG), blood pressure (BP) and respiratory flow signals, we obtained parameters for classifying cardiomyophaty patients. 42 patients with ischemic (ICM) and dilated (DCM) cardiomyophaties were studied. The left ventricular ejection fraction (LVEF) was used to stratify patients with low risk (LR:...
Recent studies have been performed on feature selection for diagnostics between non-ventricular rhythms and ventricular arrhythmias, or between non-ventricular fibrillation and ventricular fibrillation. However they did not assess classification directly between non-ventricular rhythms, ventricular tachycardia and ventricular fibrillation, which is important in both a clinical setting and preclinical...
Most sudden cardiac problems require rapid treatment to preserve life. In this regard, electrocardiograms (ECG) shown on vital parameter monitoring systems help medical staff to detect problems. In some situations, such monitoring systems may display information in a less than convenient way for medical staff. For example, vital parameters are displayed on large screens outside the field of view of...
This study was carried out to (i) track the motion of six atrioventricular junction (AVJ) sites from the two-, three-, and four-chamber cardiovascular magnetic resonance (CMR) views in 27 healthy subjects, (ii) extract four clinically most useful AVJ velocities (i.e., myocardial systolic velocities Sm1 and Sm2, early diastolic velocity Em, and late diastolic velocity Am) for each AVJ site, and (iii)...
The TASER® conducted electrical weapon (CEW) delivers electrical pulses that can temporarily incapacitate subjects. We analyzed the cardiac fibrillation risk with TASER CEWs. Our risk model accounted for realistic body mass index distributions, used a new model of effects of partial or oblique dart penetration and used recent epidemiological CEW statics.
Electrocardiographic (ECG) recording using adhesive patch-type ECG monitors (PEMs) has several advantages over conventional ECG recorders. However, due to the unconventional electrode locations used in PEM systems, the morphology of the acquired ECG signals may differ from conventional ECG leads used in the clinic impeding clinical interpretation. In this study, recordings from an ePatch® lead system...
Non-invasive ultrasound imaging of carotid plaques can provide information on the characteristics of the arterial wall including the size, morphology and texture of the atherosclerotic plaques. Several studies were carried out that demonstrated the usefulness of these feature sets for differentiating between asymptomatic and symptomatic plaques and their corresponding cerebrovascular risk stratification...
The need for a blood-brain barrier (BBB) model that accurately mimics the physiological characteristics of the in-vivo situation is well-recognized by researchers in academia and industry. However, there is currently no in-vitro model allowing studies of neuronal growth and/or function influenced by factors from the blood that cross through the BBB. Therefore, we established a 3D triple co-culture...
Extracellular microenvironmental signals modulate the coupling between cytoskeleton to nuclear links to regulate gene expression profiles. However the influence of actomyosin assembly on the morphology of the nucleus is not well understood. In this paper, we quantitatively demonstrate the role of cell geometry and specific actomyosin molecular components in their control of nuclear morphology.
In this paper we demonstrate a novel culturing system for brain slices and neuronal cells, which can control the concentration of nutrients and the waste removal from the culture by adjusting the fluid flow within the device. The entire system can be placed in an incubator. The system has been tested successfully with brain slices and PC12 cells. The culture substrate can be modified using metal electrodes...
Construction of stable capillary networks is required to provide sufficient oxygen and nutrients to the deep region of thick tissues, which is important in the context of 3D tissue engineering. Although conventional in vitro culture models have been used to investigate the mechanism of capillary formation, recent advances in microfluidics technologies allowed us to control biophysical and biochemical...
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