21 research outputs found
8E12 Parametric estimation of modeling of an ePTFE paediatric pulmonary valve function using transvalvular hemodynamic data
No full textMechanical Characterization of Individual Needles in Microneedle Arrays: Factors Affecting Compression Test Results
No full textBackground: This study aims to investigate the impact of test conditions on the results of the compression testing of microneedle arrays (MNAs). Methods: Uniaxial compression tests were conducted on polyglycolic acid-fabricated biodegradable MNAs. Load–displacement curves were obtained for varying conditions, including the number of microneedles (MNs) compressed simultaneously, compression speeds, and compression angles. Subsequently, the buckling load and stiffness were calculated, and the MN deformation during compression was observed. Results: The buckling load and stiffness per MN decreased significantly with a simultaneous increase in compressed MNs. The mean buckling load and stiffness of 52 MNs in single-needle compression tests were 0.211 ± 0.008 N and 13.9 ± 1.3 N/mm, respectively, with no variation among the three MNAs. However, a significant difference in buckling load and stiffness was observed among the MNs within the MNAs. Additionally, buckling loads and stiffnesses were significantly lower in certain MNs at the same location in different MNAs. Buckling load and stiffness decreased significantly during inclined compression compared to during vertical compression. While the tests evaluate the mechanical properties of MNAs, test results may vary depending on test conditions. Conclusions: Compression testing of the individual MNs comprising an MNA helps evaluate the mechanical properties of MNs and ensure the quality of MNAs
Sophisticated Hydrodynamic Simulation of Pulmonary Circulation for the Preclinical Examination of Right Heart Circulatory Assist Device
No full textEffect of valsalva in the pulmonary prosthetic conduit valve on hemodynamic function in a mock circulatory system
No full textNocturnal Blood Pressure Pattern Affects Left Ventricular Remodeling and Late Gadolinium Enhancement in Patients with Hypertension and Left Ventricular Hypertrophy.
No full textBACKGROUND:Left ventricular hypertrophy (LVH) is an independent predictor of cardiac mortality, regardless of its etiology. Previous studies have shown that high nocturnal blood pressure (BP) affects LV geometry in hypertensive patients. It has been suggested that continuous pressure overload affects the development of LVH, but it is unknown whether persistent pressure influences myocardial fibrosis or whether the etiology of LVH is associated with myocardial fibrosis. Comprehensive cardiac magnetic resonance (CMR) including the late gadolinium enhancement (LGE) technique can evaluate both the severity of changes in LV geometry and myocardial fibrosis. We tested the hypothesis that the nocturnal non-dipper BP pattern causes LV remodeling and fibrosis in patients with hypertension and LVH. METHODS:Forty-seven hypertensive patients with LVH evaluated by echocardiography (29 men, age 73.0±10.4 years) were examined by comprehensive CMR and 24-h ambulatory blood pressure monitoring (ABPM). RESULTS AND CONCLUSIONS:Among the 47 patients, twenty-four had nocturnal non-dipper BP patterns. Patients with nocturnal non-dipper BP patterns had larger LV masses and scar volumes independent of etiologies than those in patients with dipper BP patterns (p = 0.035 and p = 0.015, respectively). There was no significant difference in mean 24-h systolic BP between patients with and without nocturnal dipper BP patterns (p = 0.367). Among hypertensive patients with LVH, the nocturnal non-dipper blood pressure pattern is associated with both LV remodeling and myocardial fibrosis independent of LVH etiology
Hemodynamic effects of pressure-volume relation in the atrial contraction model on the total artificial heart using centrifugal blood pumps
No full textEngineering based assessment for a shape design of a pediatric ePTFE pulmonary conduit valve
No full textLVMI in patients with and without LGE.
No full text<p>In 47% of patients (n = 22), LGE (late gadolinium enhancement) could be detected. In all patients and those with nocturnal dipper BP (blood pressure) patterns, LGE positive groups had larger LVMI (left ventricular mass index) than the LGE negative group (p = 0.0007 and p = 0.0002).</p
Impact of age on left ventricular geometry and diastolic function in elderly patients with treated hypertension
No full textCognitive Function in Patients with Heart Failure is Related to Distribution of Body Water and Cardiac Diastolic Function
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