Biomedical subjects

Atsushi Fujii

Publications and source records attributed to Atsushi Fujii.

3 recordsLinked to original sources

PubMed2006

Parallel three-step phase-shifting digital holography.

We propose parallel three-step phase-shifting digital holography as a technique capable of noiseless instantaneous measurement of three-dimensional objects based on phase-shifting interferometry. The proposed digital holography carries out three-step phase shifting at the same time by using a phase-shifting array device located in the reference beam. The array device has a periodic three-step phase distribution, and its configuration is simplified compared with that required for conventional parallel phase-shifting digital holography. Therefore the optical system of the proposed parallel phase-shifting digital holography is more suitable for the realization of the proposed holography. We conduct both a numerical simulation and a preliminary experiment. The results of the simulation and experiment agree well with those of the conventional phase-shifting method and are superior to the results obtained by conventional digital holography by using the Fresnel transform alone. Thus the effectiveness of the proposed technique is verified.

Journal Article↗

PubMed2006

Scheme to improve the reconstructed image in parallel quasi-phase-shifting digital holography.

We propose a scheme to improve the reconstructed image in parallel quasi-phase-shifting digital holography. Parallel quasi-phase-shifting digital holography is a technique capable of noiseless instantaneous measurement of three-dimensional objects, and it implements four kinds of phase shifting at a time with an array of 2 x 2 phase-shifting devices located in the reference wave. In the phase-shifting calculation in the reconstruction process of the technique, the scheme assigns the 2 x 2 cell configuration for each pixel in the vertical direction and for each 1-pixel interval in the horizontal direction of the hologram recorded by the image sensor. We conduct both a numerical simulation and a preliminary experiment. The results show that the proposed scheme can improve the quality of the reconstructed image calculated by the conventional scheme of parallel quasi-phase-shifting digital holography we previously proposed, and then the effectiveness of the proposed scheme is verified.

Journal Article↗

PubMed2004

Sutureless patch repair for small blowout rupture of the left ventricle after myocardial infarction.

Rupture of the left ventricular free wall is one of the most serious complications of myocardial infarction. A 73-year-old man with severe chest pain visited our hospital. Coronary angiography revealed acute myocardial infarction in the territory of the diagonal branch. About six hours after successful percutaneous coronary intervention, the patient fell into cardiogenic shock with chest pain. Echocardiography showed moderate pericardial effusion with a subepicardial hematoma, and percardioentesis led to the diagnosis of free wall rupture. Emergency surgery was performed with the use of intra-aortic balloon pumping. The rupture was a blowout type in a small tear at the anterolateral wall of the left ventricle. We repaired the tear with an off-pump sutureless patch using collagen fleece with fibrinogen-based impregnation (TachoComb) and equinous pericardium with fibrin spray. The patient was free of both re-rupture and pseudoaneurysm postoperatively, and was discharged 20 days after the operation. Considering previously reported various procedures for surgical repair, this technique may be useful if the tear is small.

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