Construction of the muscle fatigue evaluation model based on accuracy of power

We have developed a rehabilitation support system that assists exercise training in order to reduce the physical load of therapists. Here, we propose a muscle fatigue evaluation method to decide the appropriate momentum for each patient. Many studies on muscle fatigue by electromyography (EMG) have been reported. However, muscle fatigue evaluation by EMG has the disadvantage of complexity of preparation and it can also give patients mental stress. To solve this problem, we propose muscle fatigue evaluation using an accuracy of muscle power. We verified the proposed method on the abduction/adduction of shoulders. We investigated how the accuracy of muscle power changes repeatedly under abduction/adduction while maintaining a constant power in the tangential direction. From the experimental results, we confirm a correlation between the increase in the amplitude of the EMG and an increase in power in the normal direction by a shift in the direction of power from the tangential direction, i.e., the target direction as the muscle fatigue increases.     

Development of a dual-shaft propeller thruster equipped with rotational speed sensor for UVMS control

Majority of underwater robots utilize single propeller thrusters for navigation. A disadvantage of using a single-shaft propeller thruster is that the thrust force generated from a single propeller for reverse and forward thrust is asymmetric due to the disturbed flow caused by the thruster’s body which may reduce thruster efficiency. Moreover, measurement procedures to precisely calculate propeller’s rotation speed were also not available. To address these problems, this paper proposes a dual-shaft magnetic coupling-driven propeller thruster for underwater robot, equipped with sensors for measuring propeller’s rotational speed. Numerical studies and experimental results on the position and orientation control of the proposed thruster are presented. Detail comparison of the rotational speed, thrust force and duty ratio between numerical calculation and actual experimental measurement results show the effectiveness of the proposed thruster. This paper also demonstrated that by using the proposed thruster, the control performance of an underwater robot can be improved significantly compared to commercially available thruster. The ability to determine propeller rotation directions is also a major advantage of this work.     

Global Illumination using Photon Ray Splatting

We present a novel framework for efficiently computing the indirect illumination in diffuse and moderately glossy scenes using density estimation techniques. Many existing global illumination approaches either quickly compute an overly approximate solution or perform an orders of magnitude slower computation to obtain high-quality results for the indirect illumination. The proposed method improves photon density estimation and leads to significantly better visual quality in particular for complex geometry, while only slightly increasing the computation time. We perform direct splatting of photon rays, which allows us to use simpler search data structures. Since our density estimation is carried out in ray space rather than on surfaces, as in the commonly used photon mapping algorithm, the results are more robust against geometrically incurred sources of bias. This holds also in combination with final gathering where photon mapping often overestimates the illumination near concave geometric features. In addition, we show that our photon splatting technique can be extended to handle moderately glossy surfaces and can be combined with traditional irradiance caching for sparse sampling and filtering in image space.     

Preparation of a Fine Powder of a Bi-Based High-Tc Ceramic Superconductor by Wet Ball-Milling: Effect of Fluids on Grinding Performance

A Bi-based high-Tc ceramic superconductor (Bi_1.6Pb_0.4Sr₂Ca₂Cu₃O _x ) was milled in various fluids and the effect of fluids on the crystal structure and morphology of the milled powder was studied. It was found that methyl acetate is an excellent fluid for wet grinding without decomposition of the 110 K phase. Dehydrated pure ethanol acts as a reagent to make cracks on the specific surface of Bi-based high-Tc superconducting oxide crystals during the operation, and this yields plate-like particles with many 002 faces.     

Gas sensitivity of metal oxide mixed tin oxide films prepared by spray pyrolysis

Various kinds of SnO₂ films, modified with the addition of iron, antimony, copper, titanium, manganese, nickel, cobalt or calcium oxides, were fabricated by using the spray pyrolysis technique and their gas-sensing characteristics were studied. From electrical measurements in air, the relative sensitivity towards inflammable gas of these SnO₂-based film sensors was compared. It was observed that SnO₂-based films of higher electrical resistance had a tendency to have higher sensitivity towards ethanol than the SnO₂-based films of lower resistance. The addition of p-type metal oxides, such as NiO and MnO, to the SnO₂ matrix was found to be effective in increasing the sensitivity towards inflammable gas.     

Self-separated PZT thick films with bulk-like piezoelectric and electromechanical properties

Self-separated Pb(Zr(0.52)Ti(0.48))O(3) (PZT) films were processed by a hydrothermal deposition and a rapid thermal separation method, followed by a sol-gel filling and sintering process. The films possess excellent piezoelectric and electromechanical properties close to those of bulk material. The maximum remnant polarization is over 30 μC/cm(2) and the electromechanical coupling factor (k(t)) reaches as high as 0.52. The unique microstructure characteristics of the PZT films, such as their highly dense structure, columnar grains, well-connected grain boundaries, and well-dispersed nanopores, could all contribute to the enhanced piezoelectric and electromechanical properties.     

Effects of curdlan and gellan gum on the surface structure of intestinal mucosa in rats

The effects of curdlan and gellan gum on the gastrointestinal function were studied, and the morphological structure of the intestinal mucosal surface was observed by scanning electron microscopy of rats fed curdlan and gellan gum diets for four weeks. The rats fed the curdlan diet showed a significant increase in the weight of the cecum and its contents and a decrease in fecal weight as compared to the rats fed a cellulose diet. On the other hand, the rats fed the gellan gum diet showed a weight loss in cecal contents and weight gain in colonic contents. The transit time of the gastrointestinal tract was extended by curdlan supplementation whereas it was shortened by gellan gum supplementation. The surface structures of the ileal and cecal mucosa were markedly abnormal in the rats fed the curdlan diet: the microvilli were tightly packed and had fallen out at places. In the gellan gum-fed rats, the tops of the ileal and cecal microvilli adhered to one another and were covered with their contents. There was no difference in the surface structure of colonic mucosa among the cellulose, curdlan and gellan gum diet groups.     

Small-bowel obstruction during enzymatic treatment of gastric bezoar

A 66-year-old woman had a sudden onset of small-bowel obstruction during enzymatic treatment for gastric persimmon bezoar. Oral enzymatic therapy is the most effective method of treatment for large phytobezoars when endoscopic extraction is not possible. However, this report suggests that a further endoscopic intervention may be necessary in case the dissolved bezoars cause small-bowel obstruction during this form of therapy.     

Two cases of encephalo-myelo-radiculoneuropathy, triggered by herpes simplex virus type-1 infection

We report two cases of encephalo-myelo-radiculoneuropathy, triggered by herpes simplex virus type-1 (HSV-1) infection. Patient 1 (a 25-year-old man) and patient 2 (a 52-year-old man) were admitted to the hospital because of fever, headache, abnormal behavior, and loss of consciousness. In each case, cerebrospinal fluid (CSF) showed lymphocytic pleocytosis with protein elevation, and serum and CSF IgG antibody titers to HSV-1 were elevated markedly. Although patient 1 was treated with aciclovir in the early phase of encephalitis, he developed severe quadriparesis as a sequela. Patient 2 was treated with a combination of aciclovir and corticosteroids, and he recovered completely about 4 months after the onset of the disease. There have been only a few reports of encephalo-myelo-radiculoneuropathy triggered by HSV-1 infection. Early corticosteroid therapy was effective in our patients with post-HSV-1 infectious encephalo-myelo-radiculoneuropathy. These two patients were studied with flow cytometry for peripheral blood lymphocyte subsets during the disease course. In the active stage of the disease, the helper-inducer (CD4 + CD29+), activated T cell (CD4 + CD25+), and cytotoxic/NK (CD8 Dull + CD11b Bright+) subsets were increased compared with subsets in controls. An interesting finding was mismatched responses with an increased suppressor-inducer (CD4 + Leu8+) subset and a decreased suppressor-effecter (CD8 Bright+ CD11b Dull+) subset, indicating a possible autoimmune character of encephalo-myelo-radiculoneuropathy triggered by viral infection.     

Involvement of L-type-like amino acid transporters in S-nitrosocysteine-stimulated noradrenaline release in the rat hippocampus

Nitrogen oxides, such as nitric oxide, have been shown to regulate neuronal functions, including neurotransmitter release. We investigated the effect of S-nitroso-L-cysteine (SNC) on noradrenaline (NA) release in the rat hippocampus in vivo and in vitro. SNC stimulated [3H]NA release from prelabeled hippocampal slices in a dose-dependent manner. SNC stimulated endogenous NA release within 30 min to almost five times the basal level in vivo (microdialysis in freely moving rats). In a Na+-containing Tyrode's buffer, SNC-stimulated [3H]NA release was inhibited 30% by the coaddition of L-leucine. In the Na+-free, choline-containing buffer, SNC-stimulated [3H]NA release, which was similar to that in the Na+-containing buffer, was inhibited markedly by L-leucine, L-alanine, L-methionine, L-phenylalanine, and L-tyrosine. The effects of the other amino acids examined were smaller or very limited. The effect of L-leucine was stronger than that of D-leucine. A specific inhibitor of the L-type amino acid transporter, 2-aminobicyclo[2.2.1]-heptane-2-carboxylate (BCH), inhibited the effects of SNC on [3H]NA release in the Na+-free buffer. Uptake of L-[3H]leucine into the slices in the Na+-free buffer was inhibited by SNC, BCH, and L-phenylalanine, but not by L-lysine. The effect of SNC on cyclic GMP accumulation was not inhibited by L-leucine, although SNC stimulated cyclic GMP accumulation at concentrations up to 25 microM, much less than the concentration that stimulates NA release. These findings suggest that SNC is incorporated into rat hippocampus via the L-type-like amino acid transporter, at least in Na+-free conditions, and that SNC stimulates NA release in vivo and in vitro in a cyclic GMP-independent manner.