Marine Medicine is a part of Environmental Medicine as well as Space Medicine, and is indispensable for advancing diving technique. Main subjects in the study of Marine Medicine include effects of high pressure and of water temperature on man, comparative physiology of respiratory mechanisms, decompression sickness, effects of helium atmosphere on man and life-sustaining problems under the sea.
It is a well known fact that ME plays an important role in the above-mentioned studies. Undersea environment is, however, hostile not only to man but also to ME instruments. Therefore, several problems on ME, such as pressure-proof construction and rust-proof processing, safety, stability and high accuracy, should be solved.

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As a fundamental research on the rotating disc blood oxygenator, a theoretical and experimental investigation on oxygen transfer from a gas phase into a still venous blood layer is performed. Based on a physical model in which it is assumed that, at the surface of the blood layer, the oxygen concentration reaches equilibrium with the partial pressure of the oxygen in the atmosphere and dissolved oxygen diffuses into the blood, the amount of oxygen absorbed into blood layer W is theoretically derived as :
W=2B√Dt/π
where, D diffusion coefficient of oxygen into blood
t : time
B : constant which depends upon partial pressure of oxygen in the atmosphere
An experiment by using an actual human blood was performed and the experimental results agreed fairly well with the results calculated from the above equation.

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The epidermal stratum corneum behaves as a very important element for the skin impedance, and therefore adequate study of the electrical properties of the stratum corneum is required.
The essential points of this paper are written with detailed consideration given to the following items :
(1) The distribution function of relaxation times on vector impedance loci of the stratum corneum is induced, and it is found that this function of thin layer does not satisfy the Cole-Cole circular arc law.
(2) The average dielectric constant and the average resistivity of the stratum corneum and the inner organization underlying granular cell layer are shown respectively, and the various dielectric dispersions in every part of the skin layer are made clear.
(3) The resistivity distribution of the stratum corneum is given by a mathematical equation as follows :
ρ=ρ₀e^-αχ
where χ is the distance from the skin surface, and where values of attenuation coefficient α and resistivity ρ₀ on the skin surface are show. The stratum corneum forming a large resistance layer can become a current barrier, compared with the inner organization underlying granular cell layer having considerably lower resistance.

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Phonocardiographic microphones are more sensitive to room noise as compared with the contact type phonocardiographic transducers. However, the leakage path of room noise to the sensitive element of the microphone is unknown as yet, and it has been supposed that the room noise reached the microphone element by penetrating through small gaps between microphone attachment and chest wall surface.
In this paper, the leakage path of room noise is discussed in detail. As the results of many investigations, following facts have been confirmed : The noise does not penetrate through the gaps between microphone attachment and chest wall surface but it vibrates the chest wall surface, introduces the sound pressure in the air cavity of the microphone and produces an open-circuit voltage across the microphone terminals. Furthermore, the chest wall surface covered by the microphone attachment is vibrated by the room noise in relatively high amplitude in the range of 50 to 500 Hz owing to the resonance of the system consisting of the chest wall surface, air cavity and microphone itself. To diminish these effects, it is necessary to minimize the volume of the cavity as far as possible (less than 1 cm³). Because this is very difficult, the experiments were made by using a microphone with an equivalent volume of 3. 5 cm³. As a result, the effect of room noise could be decreased by about 10 dB at frequencies under 200 Hz.

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System analysis of Automated Multiphasic Health Testing Center and 'a procedure of optimum system design (minimum waiting time, minimum overall service time, and maximum utility ratio)' ae studied.
The service time distribution observed at Toshiba Multiphasic Health Screening Center in 1971, has the type of Peason III or normal distribution. This system may be assumed as a tandem queue model. The analysis is performed with the method of computer simulation specially developed.
The results of simulation study are as follows ; 1) traffic density for each station must be between 0.7 to 0.9 by adjusting start interval, number of equipment, and number of persons a day, 2) a critical station (the station of largest traffic density that mainly affects the system) inevitably exists on this system even if the equipment are installed effectively, therefore, in order to realize the optimum system, the traffic density at the critical station must be adjusted at the optimum value of about 0.88, 3) An error of about 6 percent is found between simulated and theoretically calculated values of overall service time of the optimum system, supposing the mean service time to be constant.
A design procedure of the optimum system is given based on these results.

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