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BACKGROUND The anatomic opening area (AOA) is usually reported as the primary index of mechanical heart valve function. Because flow contracts immediately distal to an orifice as a result of the vena contracta effect, AOA may not be a good measure of true effective flow area. METHODS AND RESULTS Laser flow imaging was used to visualize the contraction in(More)
Purpose: In radiation therapy, gold nanoparticles (GNPs) are regarded as a promising radiosensitizer candidate. Several studies have revealed a dose enhancement by GNPs in X-ray and even proton irradiation. However, these studies have been limited to the depth direction. The dose distribution in both depth and lateral directions is crucial to evaluate the(More)
The purpose of our study was to investigate the utility of real-time 3-dimensional volumetric ultrasound coupled with echo contrast imaging to visualize and quantify effective flow areas for stenotic valves in vitro. Real-time 3-dimensional ultrasound imaging has recently emerged as a promising method for increasing the quantitative accuracy of(More)
We examined the utility of three-dimensional (3D) reconstruction of two-dimensional color Doppler images of the proximal jet to quantify the effective area of an orifice in an in vitro model. Steady and pulsatile flows were directed through various orifices; orifice vena contracta areas were quantified with laser flow visualization, thus providing gold(More)
Although velocity profiles downstream of mechanical valves have been measured in-vitro using Laser Doppler Anemometry (LDA), these studies have not measured velocities in the immediate proximity of the leaflets since the LDA technique prevents velocities from being measured in the immediate vicinity of any structure. Laser based Digital Particle Image(More)
UNLABELLED Accurate detection of the fetal heart signal (FEKG) early during pregnancy enhances the physician's ability to diagnose possible congenital cardiac defects. However, FEKG acquisition is hampered by excessive noise contamination from the maternal ekg (MEKG) and uterine muscular contraction. METHODS A new computerized system was developed to(More)
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