In information transmission via vibrotactile sensation, undesirable fluctuations of sensation are sometimes observed according to the change of conditions of the skin and the vibrator.
In order to make the factors of these instabilities clear, studies were undertaken on 1) variations of mechanical parameters in vibration, mechanical resistance, mass and stiffness of skin due to activity change of muscles beneath the skin, 2) the effect of contact force of a vibrator with the skin on the parameters and 3) ambient temperature characteristics of a small loud speaker which is sometimes remodeled as the vibrator.
Mechanical parameters of the skin were calculated from mechanical dynamic impedance loci of a vibrometer which was positioned on the middle of extensor muscles of forearm with a strip of double-face adhesive tape. The contacting area was 0.50 cm². The loci were drawn on a X-Y recorder by plotting in-phase and quadrature components of output signal from the vibrometer for drive current, a vector analyzer having been used to divide the signal into two components. Activities of muscles were measured by EMG.
The results show that mechanical resistance, mass and stiffness of the skin increase according to the increment of contact force. Activity change of muscles from 0 to 420, μV-mean induces the increment of stiffness of skin from 80 to 350 N/m. The stiffness of a small loud speaker is sensitive to ambient temperature and the speaker which has been casually remodeled as a vibrator for information transmission is not suitable for a stable information transmitter.

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For measurements of blood velocity with a thermoelectric blood flowmeter, various sources of errors, which result in the zero drift of the flow level. These include difficulty of correcting the measured results mainly attributable to the nonlinear relationships between the blood velocity and the measured output such as originated from thermal shift of the hot junction and/or of the heater current, some degradations of the sensor during use, and noise and thermal drift in the amplifier system. Since the majority of these errors resulted in the unstable drift of the zero velocity level during measurements, it is important to facilitate detection of the zero velocity level during measurements without stopping the blood movement around the sensor by mechanical compression, which sometimes can not be done successfully. In order to eliminate this zero level setting during experiments, a new technique is proposed in this paper, i.e., that of setting the isothermal atmosphere around the hot junction located in the outer guide sleeve as a heat sink. This new method of setting zero velocity level has been developed by pulling back temporarily the thermal sensor into the guide sleeve, where thermal diffusion is maintained constant by a specially designed thermal compensation layer placed inside the guide tube. While the sensor is kept within this compensation layer, the thermal diffusion around the sensor may be simulated as the zero velocity atmosphere. Theoretical analysis related to this new technique has been considered from the standpoint of the thermal diffusion theory, and the theoretically computed results indicated fairly good agreement with the results obtained by the in vitro experiments.

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The purpose of this study is to determine objectively and intuitively to what degree the artificial arm supplied to a user excutes as a proxy for his inherent arm.
A normal person was used as a subject and tasks were performed using the artificial arm and his inherent arm. When the two abilities according to these two kinds of experiments were measured and compared, the personal parameters and environmental conditions included in the abilities test cancelled out and also the ratio of two abilities for a normal person could be assumed to be the ratio of the ability of the artificial arm handled by an amputee to the ability of the inherent arm which is assumed to exist at present, although it has been lost.
The authors have defined and studied the index number of the controlability, ab. ICA, as the ratio of two abilities mentioned above.
Data from tests on a subject taken after an interval of one year in controlling the conventional terminal device with and without sensory feedback device, and from a few subjects who had different degrees of skillfulness in controlling the powered elbow by means of a myo-electric potential, in general, confirm the reproducibility of theICAindex.

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The prognosis of the patient with rheumatic valvular disease was estimated by the statistical method called quantification using a digital computer.
This method gives a patient the scores which are summations of the weight of each category (clinical finding), and estimates the prognosis by the distribution of the scores.Each part of different prognoses has already been difined by the scores of patients whose prognoses were known, and these weights have been calculated with the clinical data thereof. As these weights are values in which the variance of the scores between groups of prognoses becomes maximum, estimations of other cases seem to come true in most probability.
The clinical findings of 101 cases were used for the calculation of weights. As these cases were observed during medication for an average of 5 years in our hospital, their prognoses were known. 10 clinical findings were selected on the basis of chest X-ray, electrocardiogram, phonocardiogram, cardiac catheterization, age, treatment, and symptoms. The scores of these patients were distributed in three parts of two dimensions.The fatal cases were found mostly in the third quadrant, the aggravated cases, in the first, and the unchanged cases, in the fourth. The estimations of the prognoses of 13 other patients with rheumatic valvular disease showed good agreement with actual conditions after 5 years in 11 cases (85 %).
This method applies easily to clinical data and seems to be a useful means by which prognosis can be estimated objectively, simply and as a whole picture of a patient.

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A thin-wall No. 6-7 French cardiac catheter is filled with optical fibers. The center fibers are gathered in one branch to carry the input light, and the surrounding fibers are gathered into a second branch. A thin (20-30μ) metalized glass diaphragm is mounted approximately 200 au from the tip of the fiber bundle. The diaphragm deflects in response to pressure, and varies the intensity of reflected light into the second branch of the catheter. The fiber bundle tip-to-diaphragm distance is critical, and must be adjusted to provide linear reflectance over the physiological ranges of pressure expected. The system is stabilized by providing a constant current source for the illuminating lamp, and a compensating bridge circuit. The lamp intensity is monitored by a second photodetector, and used in the bridge circuit to compensate for light fluctuations.
The time response of the pressure transducer to a step input is shown in Fig. 8.The upper trace shows the response from a conventional Statham pressure transducer, and the lower trace shows the response from the optical pressure transducer. The response from the optical transducer is observed sooner with a shorter rise time, indicating superior frequency and phase-shift response. Linearity is 1.5 %, from 0 to 300 mmHg, with a sensitivity of 200 millivolts per 300 mmHg. The excellent frequency response inherent in the glass membrane indicates that intracardiac sounds can also be obtained simultaneously with pressure measurements.

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