A clinical entity of a slow pulse combined with epileptiform seizures has been known for many years and referred to as Adams-Stokes disease. Electricity has sporadically been applied to a stopped heart since nineteenth century. However, the modern era of cardiac pacing to Adams-Stokes disease began with the successful treatment of a patient by using transcutaneous electrodes by Zoll.
Initially, fixed asynchronous pacing was the only mode of cardiac pacing. Meanwhile, atrial synchronous, demand, bifocal demand and other pacing modes were introduced. As a result of the advent of various pacing modes and catheter electrodes, indications of cardiac pacing have been extended not only to heart block but to complicated tachyarrhythmias.
Currently, the mercury-zinc cell is the standard energy source, which limits a pacemaker life to about two years. Recently, new power sources such as lithium cells, rechargeable cells and nuclear energy cells have been developed, which would extend the pacemaker longevity more than ten years. Refinement of generator-electrode systems as well as of follow-up systems of patients would guarantee the patient safety.

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The software system called AISCR-V 2 (Automatic Interpretation System of Chest Roentgenograms-Version 2) was developed for automatic measurement and screening of chest photofluorograms. In this paper, the experimental results of detection of abnormal shadows in lung by this system are presented in detail. First, the outline of the pattern recognition procedure is stated. Then, some examples of 70 mm chest x-ray films and corresponding results given by the system are shown, which include lung cancer, pleurisy, sarcoidosis and bronchiectasis. Thirdly, results of classification of 15 films taken in mass screening are shown. All of 11 cases with abnormal shadows were correctly decided as abnormal, and one false alarm occurred in 4 normal cases. The system is composed of about 90 subroutines written in FORTRAN and the experiment was performed by FACOM 230/60 system at the Computation Center of Nagoya University. It took more than 20 minutes to process one film, including the output time of various intermediate results.

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A possible model is proposed which may explain the property of the evoked potential. The model is composed of a pacemaker and a number of micro oscillation systems. It is assumed that these minor systems oscillate in the different frequencies and are coupled to and entrain the other oscillators into their frequencies. The activity of the system under a stimulation and the evoked activity in terms of the stimulation are discussed and analyzed by simulation on the digital computer.

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Recently, accurate blood pressure measurements have been required for many purposes. For example, if the blood pressure can be measured accurately at various points of an aorta, a great deal of information about the cardiovascular system can be obtained. The most reliable method measuring the blood pressure is the direct method by catheter insertion. This method has been applied for long time as the most reliable method, despite involvement of considerable error. There are many causes for the errors, such as (1) wave distortion due to the resonance phenomenon of measurement system, (2) changes in physiological state of the subject due to the insertion of a catheter into the arterial system, (3) pressure wave reflection at the tip of the catheter. The second cause is too complicated to discuss, and the third cause has already been reported1). The first cause is the most serious one, and is discussed in this paper.
The resonance phenomenon occurs in the usual blood pressure measurements due to the inertia of saline in the catheter and the compliance of the electrical manometer. Many researchers have been trying to reduce the error due to the resonance phenomenon, but no method which is effective for clinical and experimental application has yet been made available.
In this paper, a simple damper device is proposed for the reduction of the resonance phenomenon. This damper device is inserted between the catheter and the electrical manometer. This blood pressure measurement system is discussed theoretically and experimentally and it has been verified that this system can measure the blood pressure waveform accurately enough for clinical and experimental application. This system is quite useful for the measurement of dp/dt because of the high measurement accuracy of the rising edge of blood pressure waveform. The behavior of this system is compared with that of of other error reduction methods.
It is shown that this system is the best one and is as good as catheter tip manometers.

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[in Japanese]

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