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We have applied the graphics processing unit (GPU) to computer generated holograms (CGH) to overcome the high computational cost of CGH and have compared the speed of a GPU implementation to a standard CPU implementation. The calculation speed of a GPU (GeForce 6600, nVIDIA) was found to be about 47 times faster than that of a personal computer with a Pentium 4 processor. Our system can realize real-time reconstruction of a 64-point 3-D object at video rate using a liquid-crystal display of resolution 800x600.

Clinical profiles were analysed of 18 children with congenital ventricular aneurysm (CVA) and diverticulum (CVD) (nine with CVA and nine with CVD). Of 18 children, only six had any symptoms, consisting of chest discomfort, palpitation, or convulsion. Heart murmurs were heard in nine of the 18 children, and a nonspecific systolic ejection murmur in one. A systolic click was heard in only four children. Dyskinesia of an abnormal protrusion of the cardiac silhouette on the chest x-ray film was detected in only three. The ECG revealed abnormal findings in all children. In those with CVA, signs of myocardial damage or left axis deviation (LAD) and left bundle branch block (LBBB) were the main findings. Among those with CVD, multiple premature ventricular contractions (PVCs) were present in four; some signs of myocardial damage were present in three. None of those with CVD had LAD or LBBB. Among the four children with right ventricular diverticulum, multiple PVCs were present in three. The lesions were detected by two-dimensional echocardiography (2DE) before angiography in 13 (72%) of 18 children. The wall kinetics of the lesions, as seen on 2DE, were in agreement with the subsequent angiographic findings.

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The purpose of this study was to examine the hemodynamic characteristics of expanded polytetrafluoroethylene (ePTFE) pulmonary valves with bulging sinuses quantitatively in a pediatric pulmonary mechanical circulatory system designed by us, in order to propose the optimal design for clinical applications. In this study, we developed a pediatric pulmonary mock circulation system, which consisted of a pneumatic right ventricular model, a pulmonary heart valve chamber, and a pulmonary elastic compliance tubing with resistive units. The hemodynamic characteristics of four different types of ePTFE valves and a monoleaflet mechanical heart valve were examined. Relationships between the leaflet movements and fluid characteristics were evaluated based on engineering analyses using echocardiography and a high-speed video camera under the pediatric circulatory conditions of the mock system. We successfully performed hemodynamic simulations in our pediatric pulmonary circulatory system that could be useful for quantitatively evaluating the pediatric heart valves. In the simulation study, the ePTFE valve with bulging sinuses exhibited a large eddy in the vicinity of the leaflets, whereas the straight tubing exhibited turbulent flow. The Reynolds number obtained in the valve with bulging sinuses was calculated to be 1667, which was smaller than that in the straight tubing (R (e) = 2454).The hemodynamic characteristics of ePTFE pediatric pulmonary heart valves were examined in our mock circulatory system. The presence of the bulging sinuses in the pulmonary heart valve decreased the hydrodynamic energy loss and increased the systolic opening area. Based on an in vitro experiment, we were able to propose an optimal selection of pulmonary valve design parameters that could yield a more sophisticated pediatric ePTFE valve shape.