Calcium ions in KCl solution change the surface structure of Millipore DOPH model membrane and reduce the hydrophilic area. The stereoscopic microscope mounted with a photomultiplier on the eyepiece could detect quantitatively the conformational changes as the intensity of reflected light. The degree of the conformational change depended on kinds of salt solutions (KCl, NaCl, LiCl) and pH in these solutions. A higher Ca²⁺ ion concentration was needed to obtain change of the same degree in LiCl solution. From these results it has been concluded that the conformational change were caused by replacement of K⁺ ions with Ca²⁺ ions in the hydrophilic base of DOPH molecules.
The Millipore DOPH membrane increases the resistance, if the conformation changes with Ca²⁺ ions, and the resistance oscillates while a current and a pressure stimuli are applied. These stimuli create partially the concentration gradient of K⁺ ions in the membrane, and Ca²⁺ ions are dissociated from the hydrophilic base of DOPH molecules. The dissociation decreases the resistance, and it also drops the potential difference across the membrane which the constant current produces. As this drop decreases the gradient of K⁺ ion concentration in the membrane, Ca²⁺ ions again combine with the hydrophilic base and the membrane resistance also recovers. The repetition of this process is oscillation mechanism of the membrane resistance.

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The characteristics of proteins in in vivo human lenses have been investigated by analyzing the autocorrelation function, which is measured by the laser light scattering spectroscopic method. It has been found, in the usual analyzing method of a single component analysis, that the proteins in the lens contain two or more kinds. In this work, the simple method of two-component analysis has been proposed so as to be adopted to clinical studies.
Consequently, it has been found that the protein size in the human lens increases abruptly with age, and the protein distribution situation is expressed in three age-levels.

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An algorithm has been constructed for estimating an electrical dipole location and its moment in the brain from the scalp potentials measured with 16 electrodes. In this case, the precise head shape is taken into account and a homogeneous conductivity is assumed. The validity of the algorithm has been investigated by animal experiments. For this purpose a pair of thin wires was inserted into the cerebrum of a cat and an impulse current was applied across them to generate a current dipole in it. Dipole locations in the brain were estimated from the scalp potentials with the aid of the boundary element method.
The estimated dipole locations deviate from the real ones and the deviations are not random but rather systematic. They are displaced towards the center of the cerebrum, and the deviations are probably caused by the lack of uniformity in conductivity. The mean deviation of dipole locations in the cortex is 3mm.

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The platelet aggregability can be numerically evaluated, when one can determine the minimum dose of ADP necessary for developing the secondary aggregation of platelet-rich plasma. In this report, we propose the procedure of determining the critical ADP level by means of comparing the aggregation patterns with a set of standard patterns stored in a computer. The estimated ADP threshold level is then converted into an aggregation index PAT (platelet aggregability index), which enables us to grasp the increased platelet aggregability in a patient, as a risk factor of the cerebral ischemia.

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An electrical circuit model of the cerebral circulation is proposed. Changes of pulse waves of the cerebral blood volume have been simulated for the effect of increased intracranial pressure (ICP) on the cerebral blood flow using this model. The obtained results are considered useful in the application of rheoencephalogram to ICP monitoring under the electrical impedance method.

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This paper describes a new type of transducer designed for measuring the contact compliance of a soft body. It is very different from conventional electrodynamic vibrometer which consists of a moving coil and a loudspeaker magnet. The transducer is designed to operate with a piezoelectric disk which is employed as a driver unit. Therefore, the piezoelectric transducer proposed here is small, light, and consumes very little electricity. By using the piezoelectric transducer, experimental investigations have been conducted to deduce the characteristics of the contact compliance of a soft body. It was thus found that the instrument was helpful in drawing conclusions about the properties of soft bodies.

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