The objective of this study is to clarify the reason why the total metabolism of paraplegics ambulation increases for the FES application to their lower limbs rather than the no-FES although they are able to walk faster and longer distance with less fatigue at lower heart rate for the FES than the no-FES. Six thoracic paraplegics were measured the O₂-consumption of the lower limbs caused by the FES during a FES-therapy (sitting on a bicycle-like seat of a hydraulic lift and received stimulation to their thigh muscles, producing reciprocal gait), The O₂-consumption in terms of upper-body alone during ambulation was calculated by subtracting the above-mentioned consumption of the lower limbs and compared with that for the no-FES. The results reveald the energy expenditure of the upper body for no-FES was significantly higher than that for the FES, and it was concluded the feeling stress should be related not to the total metabolism but to the relative metabolism rate of the working muscle mass. Five orthosis systems were evaluated by the criterion proposed in this sudy and O₂-consumption could be guaranteed to be an useful veriable for a gait analysis.

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For evaluation of reproducibility of ventricular premature beat (VPB) by ambulatory electrocardiogram recording (AEG), we analysed individual property of VPB frequency using both the distribution and statistical standard deviation to explain long-term and short-term variance on AEG. In 22 outpatients with VPBs we compared the difference of VPB frequency on two succesive days' AEG (experiment I) with that on two days' AEG separated by 2 weeks (experiment II). The frequency distribution was classified into two types by plotting pattern of cumulative number of VPBs on the vertical axis with the number of VPBs per minute on the horizontal axis. An ‘unimodal’ type was defined that the distribution was almost normal and ‘multimodal’ type was the other. The ratio of changeless type was significantly higher in experiment I (95.4%) than that in experiment II (59.1%) (p<0.05). Each correlation coefficient in experiment I was significantly higher than that in experiment II (p<0.05) as to various standard deviations defined as follows: a average of 24 standard deviations per hour (SD_a), standard deviation of mean VPB frequency per minute as a short term variance (SD) and of mean VPB frequency per hour as a long term variance (SD_b)·√SD_a²+SD_b²/SD as an index of variability of VPB frequency was significantly small in experiment I than that in experiment II (p<0.05). As reproducibility of VPB frequency on AEG was better in experiment I, an estimation formula of individual ranges of the number of VPB on the following day might be possible. The difference between numbers of VPBs in experiment I was below some value obtained by √SD²+SD_b². We calculated statstically new reduction rate of upper confidence limit with each patient by the approximate formula. We concluded that we may get more accurate individual VPB estimation on the following day but that the estimation after more days is more difficult.

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In order to evaluate the conductor models, i. e. outer sphere (best fitting the cranium surface), cranium (surface itself) and inner sphere (best fitting the inner cranial surface) models, used in the neuromagnetic source localization, we measured magnetic fields using a cranium phantom filled with the saline. Current dipole sources in the phantom were localized with these three models. The three dimensional positions of the sources which were calculated with the cranium and inner sphere models showed good agreement with the actual source locations. Especially, cranium model is useful because of the easiness to obtain the data of the cranium surface. Using the cranium model, neuromagnetic sources evoked by monosyllable speech sounds (/ba/, /pa/, /ma/) were localized on the MRI tomograms and were compared with anatomical structure. On the horizontal plane of the MRI tomograms all the sources of different speech sounds were located in the transverse gyri of Heschl that is the primary auditory area. On the coronal plane they were located near the lower area of the Sylvian fissure, at which the transverse gyri of Heschl is located.

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Laser Doppler velocimeter can measure flow velocity with high resolution without disturbing flow itself and has been applied to the measurement of the blood flow velocity in microcirculation. However, the scattered light from the vessel wall is interfered with the scattered light from the red blood cells and it provokes low frequency noise so called spurious signal. The spectrum of the spurious signal lies closer to the Doppler spectrum and the reduction in SNR becomes serious when the blood velocity is reduced. The microscopic laser Doppler velocimeter used in this study was highly improved with respect to the accuracy of low velocity measurement because it could eliminate the influence of the spurious signal by the optimal optical arrangement and made recognizable separate Doppler spectrum. The proposed system could detect small velocity fluctuation in capillary even at the average velocity of only 0.76mm/s. The Fourier transform analysis revealed that the only significant fluctuation of the blood velocity in capillary was that related to the cardiac action as well as that in arteriole. The microscopic laser Doppler velocimeter was applied for analysis of the velocity of pulse wave in microcirculation. The velocity of the pulse wave was deduced from the phase delay of the blood velocity wave form at several positions along a sigle vessel in microcirculation.

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