A simulation study, which analyses the relationship between the actual blood flow into the aorta, transthoracic impedance variation and the value of stroke volume measured by Kubicek's equation, was proposed on a simple vascular tube model by means of a digital computer. The effect of varying the value of such parameters as total transthoracic impedance (Z₀), elasticity of the aorta (E), peripheral resistance of the vascular beds (R_s) and velocity of the pressure pulse in the aorta on SV_z was also investigated. By the numerical computation of the differential equations introduced on this model, the following evidences were obtained :
(1) The amplitude (maximum flow velocity, Q_max), duration (ejection time, T_s) and rising and falling time (t_r and t_f) of the inflow were the most significant factors determining the SV, value.
(2) The SV_z value is equal to the actual inflow (SV), only when t_r=t_f=0 and the flow velocity is constant during the ejection time, i. e., the inflow is a square wave.
(3) The value of SV_z increases with increasing t_r, whereas it takes a constant value which is proportional to the product of Ts and dZ|dt| _max at any length of t_f. Thus the SV_z value increases with increasing t_f, if T_s is constant.
(4) Z₀ is a factor determining the sensitivity of this method.
(5) Evidences expressed in (1) - (4) were confirmed through experiments on the dogs.
(6) The value of SV_z shows little change with the change in the value of such parameters as E, Rs and velocity of the pressure pulse.

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The purposes of the medical record processing system are to provide data, (1) for improvement of medical care (2) for more efficient hospital management and (3) for medical research.
It is the purpose of this paper to analyse some problems of the medical record processing system and to propose a new evaluation method. The aspects examined in this paper are;
(1) items of medical record,
(2) information processing.
These analytical results enable us to determine the minimum necessary functions of the medical record processing system. A method for determining the optimum items under given conditions is also mentioned.

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Software techniques for solving two problems in monitoring the electrocardiograms of critically ill patients are described in this Paper.
(1) Logical filter for detection of a QRS complex : High frequency components are centered around the peak-points of a QRS complex and the waveform is roughly symmetrical with respect to a vertical line through.the peak-point. These characteristics of the QRS complex are utilized in designing the filter. This filter distinguishes the QRS complex well from other parts of electrocardiograms and various noises.
(2) Pattern recognition of a QRS complex with correlation coefficient : One typical QRS complex is selected and designated as “templet”. Subsequent QRS complexes are compared with this “templet” one by one. The degree of similarity to the “templet” is evaluated by a correlation coefficient. Without accurate detection of a QRS duration, 10 points before and after the peak of R-wave respectively (totalling 20 points) are regarded as one QRS complex (sampling rate : 250 points/second). Our method makes it possible to recognize ectopic beats automatically even if noises exist to some extent.

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[in Japanese]

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