A cassette-tape long-term (up to 24 hours) ECG recorder and high-speed analyzer for the tape has been designed and developed experimentally. By using modern electronics technology, such as integrated circuits, shift register and phase shiftless filter, the developed system has proved to have characteristics which are more or less satisfactory. The high-lights of the system : i) the heart-rate is given by each beat-to-beat interval rather than by an averaging of a certain period, ii) -recording and analysis are carried out by two channels rather than one, iii) phase shiftless filter is utilized, and iv) ST deviation is detected and recorded on time scale. By using the system, 78 recording and analysis sessions were held with clinical cases and with healthy subjects as well, and the usefulness of the system was proven in detecting and counting episodes including extrasystoles, atrioventricular block and ST segments deviation. Problems encountered and possible means for their solution, too, are described.

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It is very important for clinical diagnosis to detect and estimate the regional cardiac wall motion abnormalities. In particular, direct detection and recording of such motion offer valuable data for recognizing the occurrence of myocardial ischemia at its early stage.
Up to now, many non-invasive techniques for this purpose have been presented but these methods do not satisfactorily meet our clinical needs in accuracy, precision, convenience and so forth.
The authors modified the Cardiokymograph proposed by Vas R., which had the basic defect of instability, and succeeded in developing a stable, easily operable and small-size device by our own hands. A special feature of this device is the use of a frequency-variable crystal-controlled oscillator, which contains the coil as the probe.
We tested many electrical characteristics and assured the effectiveness of our device. Our device was able to detect the cardiac wall motion from all the areas of the precordial chest wall of a patient. In order to operate our device, only one time adjustment of the gain controller was necessary so that the time required for recording one point was very short.
Cardiokymograms in healthy persons and those in myocardial infarction cases were comparod and distinctive paradoxical waveforms could be clearly recognized.

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A computer-aided instruction system of antimicrobial therapy has been developed to assist the physician in memorizing huge amount of drug information and in selecting an appropriate regimen of the therapy. The features of the system can be summarized as follows. 1. The computer lists up all of the recommendable regimens of antimicrobials from which the physician can choose one according to his own clinical experience. This implies that the physician still holds the position of making the final decision in the therapy. 2. The system covers necessary information of the drugs usable for infectious diseases which can easily be up-dated. 3. The physician can get what he really wants to know in less than 5 minutes. This feature would be important for the busy physician working in the outpatient clinic. 4. Since the system is compact, it can be implemented on a micro-computer.

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A mathematical model of the body fluid control system is constructed and simulation results on this model are presented. The model accurately depicts the physiological functions and anatomical structures of the body fluid system. It can easily follow various sets of physiological experiments and pathological disorders.
This paper initially describes the procedure of the modeling in detail. The procedure is specifically based on the transfer function technique, which is used in the area of control engineering. It then demonstrates the results of a water-loading experiment on normal subjects. Finally, the experimental and simulated results are compared and the quantitative validity of the model is confirmed.

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The ISCHEM (Information System for Coronary Heart Evaluation and Management) is an information system capable of gathering, storing, retrieving, and analyzing medical record of patients with ischemic heart disease (IHD). The medical record database system has been one of the most expectative and yet most difficult problems in the computerized medicine, and there have been few successful systems of the kind. Our five-year analysis and experiments on this subject has made it possible to design and implement ISCHEM at our clinic.
IHD is one of the major causes of death in Japan and the long term observation, evaluation and management of patients are key features for both practice of medicine and clinical study. In addition to basic functions, ISCHEM is especially aimed at (1) follow-up help for the patients, (2) visualization of the stored image data on a graphic display terminal, thus enabling doctors to grasp the problems of each patient at a glance, and (3) analysis of the stored data by statistical methods.
The ISCHEM was implemented on the general purpose computer system (ACOS 77/600) installed in our hospital. In order to realize the above functions, ISCHEM (1) has user-interface for both skilled and unskilled users which promotes effective interaction with the computer, (2) adopts bit-string technique for efficient storage and retrieval, and (3) has graphic display routines for presenting data on the coronary angiogram, left ventriculogram, and myocardial scintigram converted into illustrations simulating the original images.
Data are recorded by physicians on a _specially designed form and are used as input by clerical personnel, and utilized by medical staff members through CRT displays installed at several places in the hospital.
The ISCHEM has given a positive impact on our clinic and has been found to be effective for both patient care and the study of IHD and is expected to grow into a common database of IHD among our affiliated hospitals.

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Regions of interest (ROI) are used for obtaining washout curves of the blood circulatory system from RI angiocardiography.
This paper describes an automatic ROI setting method.
Assuming the central circulation as the four-compartment system, which is composed of an injection part of the right heart, the right heart, lungs and the left heart, assignment of pixels to the four compartments is made using the histogram of peak times which are detected from each pixel's time activity curve, and the labelling technique of the regions.
The left ventricle area is also detected from the left heart compartment's region by applying the spectral analysis, of the time activity curves.
A few examples are shown to clarify the practical applicability.

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This paper presents an approach to the computerized quantitative diagnosis of arrhythmia from the point of view of mathematical statistics.
We propose a method in which serial scatter diagrams of RR-interval in electrocardiogram are used. We have found that the use of the diagrams for classification of arrhythmias was effective. Therefore, we devised the method of automated diagnosis in which arrhythmia was recognized from the patterns in the diagrams.
The usefulness of the method was proved by comparing the results of diagnosis processed by this computer method on the controlled and arrhythmia subject with those performed by decision of medical doctors (cardiologists). These results are quite satisfactory, and this method may be made available for clinical examinations.

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