A lot of previous studies have developed various exercise methods and devices in order to provide exercise effective for maintaining good health. In particular, it is recently well-known that underwater gait-training is a useful fitness movement especially for elderly person. In addition, our previous study, it has been reported to develop a device to induce locomotor-like stepping movements by injecting jet-water to foot sole of a person sitting in a bath. And we demonstrated that the new device can induce locomotor-like stepping movement by effectively flexing hip, knee and ankle joints. In this study, we focused on optimization of this device. Here, we investigated relations of the cyclic (slow, fast) injecting jet-water and the locomotor-like stepping movement. The result shows that coefficient of variation (C.V.) of knee and hip joint was significantly larger in the slow cyclic injecting jet-water compared with that of fast cyclic. We suggested that different cyclic injecting jet-water modulate locomotor-like stepping movement.

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The rates at which endothelial and smooth muscle cells in vessel walls should consume oxygen during blood transport along the length of a microvascular network are highly controversial. We examined the arteriovenous distribution of oxygen consumption by a microvessel wall exposed to circumferential wall stress and fluid shear stress. A model of retinal microcirculation in which a network that branched dichotomously at every bifurcation depended on both a flow conservation law and a modified Murray's law with a diameter exponent of 2.85 was used. Oxygen consumption was calculated from the integration of the number of branches multiplied by the consumption rates of the endothelial and smooth muscle cells per branch unit. The oxygen consumption by all of the microvessel walls was only about 1.9% of the total oxygen consumption throughout the microvascular network, including the surrounding tissues. This result suggests that the oxygen that had diffused across the microvessel walls was mainly consumed by the surrounding tissues. Also, based on the circumferential and shear stresses, the microvascular flow and pressure control system is presumably designed to optimize the vessel tone of the arteriolar network so that the microcirculation can accommodate material exchange.

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Motor racing athletes in the closed-cockpit category are always facing life-threatening situations caused by heat stroke, especially in hot weather. We report here the development of a novel infrared-radiation-type eardrum thermometer, with a built-in earphone, which can be used for continuous measurement in GT car racing. We examined the accuracy of the system for core body temperature monitoring in 10 healthy volunteers (21.8 ± 1.0 (S.D.) yrs) using a temperature controlled water bath. In addition, we assessed the usefulness of the system under real racing conditions with 2 professional drivers in the practice session of 2010 SUPER GT International Series Round 4 MALAYSIA being held at the Sepang International Circuit. To examine accuracy two thermistor probes, one inserted into the ear canal and the other beneath the tongue, were used for measurements of eardrum and sublingual temperatures respectively. An infrared eardrum thermometer was inserted into the contra-lateral ear canal. The measured temperatures were recorded at 30-s intervals. The results showed good correlation between the infrared eardrum temperature and both the direct eardrumtem temperature (r = 0.994, n = 1119, p < 0.001) and the sublingual temperature (r = 0.972, n = 1119, p < 0.001). The mean difference between these temperatures was + 0.09 °C, - 0.08 °C, and 1.96 S.D. was 0.21 °C, 0.44 °C, respectively. As for the field test, the system functioned satisfactorily during real racing conditions performed on the racing circuit. These results suggest that our new system can be used in a race setting as a reliable core temperature monitor and could help to improve safety of motor sports.

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