Modification of the surgical strategy based on intraoperative echographic findings of atherosclerotic ascending aorta

To prevent the atheroembolic complications such as brain infarction due to the manipulation of atherosclerotic ascending aorta during cardiac surgery, the ascending aorta of 55 patients including 6 emergencies (mean age: 67.7 +/- 6.9 years, valvular disease: n = 12, ischemic heart disease only or combined with valvular disease: n = 43) were evaluated with intraoperative echography as a routine, to enable a proper placement of the cannulae, clamp etc. Irregular elevated lesions into the aortic lumen from the intima were identified in 7 patients (13%, mean age: 71.0 +/- 6.9 years) of ischemic heart disease, which included 2 emergent cases. Arch cannulation was employed in 3 patients with wide-spread lesions on the posterior wall and femoral cannulation was done in 1 patient with wide-spread lesions on the anterior wall. Two of these patients received CABG with in situ arterial conduits under ventricular fibrillation, and the other 2 patients received CABG with aortic cross clamping at the lesion-free site during proximal anastomosis of vein grafts (single clamp technique). Two patients with localized lesion were done CABG with partial aortic clamping and one of them had cerebral infarction during the operation. We recognized that manipulation of the ascending aorta has to be done with a meticulous care and well away from the diseased site. In another patient with localized lesion, the arch cannulation and the single clamp technique were used 2 cm away from that lesion. The brain infarcted patient completely recovered without any sequelae and the others also had no atheroembolic complications. Although calcified lesions on CT were correlated with atheromatous lesions on echogram (p = 0.004), these atheromatous plaques were not detected by enhanced CT, except in only one patient. For screening of the atherosclerosis of ascending aorta, the CT examination was not so effective and the intraoperative echography was the most sensitive and could be easily accomplished. In conclusion, in order to prevent the atheroembolism that might occur due to the improper manipulation of the diseased ascending aorta during usual procedures, surgical strategies have to be modified according to the position, extent and quality of the atherosclerotic lesions, diagnosed by intraoperative echoscanning of the aorta.     

Effect of heat treatments on apatite-forming ability of NaOH- and HCl-treated titanium metal

Titanium (Ti) metal was soaked in HCl solution after NaOH treatment and then subjected to heat treatments at different temperatures. Their apatite-forming abilities in a simulated body fluid (SBF) were discussed in terms of their surface structures and properties. The nanometer scale roughness formed on Ti metal after NaOH treatment remained after the HCl treatment and a subsequent heat treatment below 700°C. Hydrogen titanate was formed on Ti metal from an HCl treatment after NaOH treatment, and this was converted into titanium oxide of anatase and rutile phases by a subsequent heat treatment above 500°C. The scratch resistance of the surface layer increased with the formation of the titanium oxide after a heat treatment up to 700°C, and then decreased with increasing temperature. The Ti metal with a titanium oxide layer formed on its surface showed a high apatite-forming ability in SBF when the heat treatment temperature was in the range 500–700°C. The high apatite-forming ability was attributed to the positive surface charge in an SBF. These positive surface charges were ascribed to the presence of chloride ions, which were adsorbed on the surfaces and dissociated in the SBF to give an acid environment.     

Observation of Si pattern sidewall using inclination atomic force microscope for evaluation of line edge roughness

Inclination atomic force microscope (AFM) imaging has been studied on the possibility to observe a pattern sidewall in contact mode or digital probing (step-in) mode for a line edge roughness (LER) or line width roughness (LWR). Analysis of the AFM tip bending and slipping indicates that it is serious problem to measure and control very fine patterns within an error of less than 1 nm in contact of the tip on the steep slop of the pattern, and it is very important directly to observe the sidewall at inclination angle. In experiments using pyramidal tip and steep Si pattern with about 90 degrees slop, it has demonstrated that the inclination angle is 35-40 degrees for faithful observation of the sidewall. We have observed the etched strip lines on the sidewall with a width of about 100 nm and a depth of about 6.4 nm. We have demonstrated that the inclination AFM is very useful for evaluation of the LER or LWR.     

Generation of Smooth Surfaces by Controlling Curvature Variation

To satisfy a designer's intention for constructing aesthetic shapes such as automotive bodies, we propose a surface generation method. In the surface design process, designers determine shapes according to their great concern for the reflected images of vehicle surroundings, shade lines and highlight lines. Since reflection and shading are affected by changes of surface normal, the curvature variation of the surface, which represents the change of the surface normal, should be smooth and distributed as designers want. The proposed method controls curvature distribution directly by determining a surface shape from an evolute, which is a locus of the curvature center of the generatrix and moves along directrices to form the surface. It first generates evolutes of boundary curves to be generatrices as rational Bezier curves, then interpolates their shapes with the Bezier polygons, and locates the interpolated shape to the corresponding position of the directrices. By applying this method, we have confirmed that a smooth shape is generated from four boundary curves.     

Polarization-maintaining optical fibers used for a laser diode redundancy system in a submarine optical repeater

Polarization-maintaining optical fibers are developed for installation in a submarine optical repeater. These fibers preserve the polarization of light emitted from laser diodes (LD's) to a single-mode fiber through a light-switching coupler. Crosstalk of less than -30 dB in a 1-m length of these optical fibers, called PANDA optical fibers, is achieved with a bending radius greater than 10 mm, twists of less than 60 turns, and tension of less than 3 kg, and ambient temperatures of-20-80degC. The mechanical strength of these fibers is the same as that of single-mode fibers.     

Properties of variable-thickness NbN microbridges

Variable-thickness NbN microbridges have been fabricated by ion etching, using photoresist mask and obliquely evaporated Al films. A tungsten needle ≈3 µm in diameter is placed across the slit produced in the photoresist to define the bridge width. The NbN microbridges show many well-defined constant-voltage steps under microwave irradiation.     

Development of a wrist-worn calorie monitoring system using bluetooth

Methods and tools for monitoring real-time human body information in daily life are required for advanced healthcare. In this study, a method for estimating energy expenditure during health exercises was evaluated and a wrist-worn sensing system based on the method was developed. Pulse monitoring was used to calculate energy expenditure by estimating oxygen uptake from a correlation between heart rate and oxygen uptake. Bluetooth technology was utilized for sending data by wireless communication. By the newly developed system, energy expenditure during exercise can be estimated considering individual difference and distinguishing changes in grade or load. Our goal is to construct a miniaturized wearable system that monitors vital signs and has many applications for healthcare. The study suggests that a wearable pulse sensing system proposed could provide useful information for healthcare.     

Low-loss single polarisation fibres with asymmetrical strain birefringence

Low-loss and highly birefringent single polarisation fibres have been fabricated. The minimum transmission loss and the modal birefringence of the fibre with refractive-index difference ?=0.61% was 0.62 dB/km at ?=1.52 ?m and 8.5×10?5 at ?=1.15 ?m, respectively. The state of linear polarisation was stable against the handling conditions such as bending, twists, concentrated force, and temperature variations.