The dynamic property of glucose-induced insulin secretion was simulated with the aid of control theory, and the relationship between the stepwise input of glucose concentration and the biphasic response of insulin as an output was expressed in the transfer function of proportional plus derivative action to glucose concentration.
By utilizing such a model, the following computer algorithm for the artificial beta cell was made-Rate of insulin infusion=K_pBG+K_dΔBG+K_c, where BG was the abbreviation for glucose concentration, ΔBG was the rate of change in BG, K_p, K_d were the coefficient for the proportional and derivative action, respectively, and K_c was the constant for basal insulin secretion.
Microcomputer, insulin infusion pump and digital printer were packed in a small case, which was connected with glucose analyzer.
Experiments were carried out in the depancreatized dogs to validate the insulin infusion program and the whole system. Against various kinds of glucose challenges, such as oral administration, iv impulsive or constant infusion, the blood glucose responses were controlled in physiological ranges when the derivative action was added to the proportional action properly in the insulin infusion regulatory system. The treatments of ketoacidosis were also performed and the results were satisfactory.
The characteristics of this system recognized in clinical applications to the diabetic patients were : 1) The rate of insulin infusion was small enough to keep the plasma concentration of insulin physiological, then insulin requirements were reduced to around a half of those given subcutaneously, 2) Glucose or glucagon infusion to restore hypoglycemia was not necessarily needed.

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A self-contained electronic device is described for controlling the limb load exerted by a patient in partial-weight-bearing walking exercise. The device measures the limb load with two removable load transducers attached to the sole of the patient's shoe, compares the load with two presettable thresholds, and emits audible biofeedback tones. A low-frequency tone is emitted when the load falls in the desired range, and a high-frequency tone is activated when the load exceeds the maximum load allowable for the patient. The device has accuracy of ±10% in all stages of the stance phase. Experimental results which demonstrate the effectiveness of the device in controlling the limb load are also presented.

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Radiocardiography has been widely used as a method of quantification of cardiac output, by applying the principle of dye dilution method. Kuwahara and Hirakawa, with their co-worker, have reported successive studies of the analysis of radiocardiogram by analog computer simulation and its clinical applications. To analyze radiocardiogram by simulation is to estimate parameters of a model by curve fitting approach, and the analog computer acts as an effective tool in this parameter estimation. However, as the curve fitting technique requires a skilled operator of the analog computer, an automatic analyzing system of radiocardiogram using a minicomputer is expected to be developed especially for clinical use.
In this paper, we show a differential-difference equation model of transport process of radioisotope appearing in radiocardiogram, and discuss about an algorithm for a minicomputer to estimate the parameter values of the model in a reasonably short time. After Fourier transformation of two modified radiocardiograms, actual and modeled, a least square estimation is adopted in the frequency domain. Since the criterion function in this estimation does not change its basic expression form before and after Fourier transformation and the data to be compared are effectively compressed into the narrow frequency range, the computation time can be reduced fairly well. Parameter sensitivity analysis is applied to clarify the effects of parameters on the model and to shorten the computation time.
Some clinical results of radiocardiograms analyzed by thealgorithm are shown and it is verified that the algorithm developed here is sufficiently useful and efficient for clinical use.

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The model consists of 400 Golgi compartments arranged in a bee-hive-like array and endlessly connected together by parallel fibers. Each compartment consists of one Golgi cell and the surrounding group of granule cells inhibited thereby.
The theory of linear systems was applied to variations from the uniform equilibrium state with the result that any input- or excitation-pattern may be expressed as a superposition of the characteristic patterns, each of which, according to the corresponding characteristic value, has itsown time constant and amplification degree.
The maximum characteristic value λ_M is positive and is accompanied with striped patterns due to lateral inhibition. The minimum characteristic value is negative and is accompanied with uni-form patterns. Since every characteristic value is proportional to the “inter-layer loop gain” γ, spacial difference in inhibition level as well as AGC-effect for average excitation is intensified as γ increases. The more smoothly the connection weight diminishes with distance, the smaller is λ_M, and the less dominant is the striping trend.
Results of computer simulation were on the above trends except the conditional occurence of synchronous Golgi firing. This synchronism brought about the oscillating uniform pattern and save way to rather stable and uneven excitation patterns like stripes or mosaics when random noise was independently added to Golgi cells.
Since physiological data seem to negate oscillations, the actual cerebellar cortex is likely to operate in the lateral inhibition mode and the resultant uneven inhibition may decide the contribu-tion of each Golgi compartment to the mossy fiber-parallel fiber pattern transformation. Under such situations, climbingfibersmighttakepart in the information processing of mossy fiber input more or less modifying the inhibition pattern.

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Comparison of more than two chest x-ray images and detection of changes among them are very significant in diagnosis and therapy of lung and heart diseases. In this paper, results of fundamental studies on automated comparison of chest x-ray images and detection of changes among them are presented. First, characteristics of variation in the shape of images of organs, and of variation in density values are estimated from a set of several films of the same patient taken at different times. A few methods for correcting variation in the shape of rib images and_ in density values are given together with comparative study of their performance and limitations. Second, effectiveness of a local correlation coefficient as a measure of change is investigated. Experiments are performed on the detection of abnormal shadows using the correlation coefficient between two subpictures cut out from the corresponding locations in right and left lung of the same film. A seventy-five percent detection rate is achieved for eighty pairs of subpictures obtained from chest photofluorograms. From the result achieved the method used here is considered promising.

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A new computerized system has been developed for the quantitative analysis of the ST-T pattern of the exercise electrocardiogram in patients with coronary heart disease. In our system, pertinent parameters which represent the configuration of the initial portion of the ST-T segment : were obtained by computer using the second order function fitting; f (t) = at²+bt+c. Before this procedure, smoothing by the moving average method and computer average of the electrocardiogram were also performed to minimize the influences of the unavoidable noises and beat-to-beat variations of the ST-T waveforms. Coefficients a and c of the fitted function, which reflect theconfiguration of the ST-T segment and ST junction's depression, respectively, are used for the, evaluation of the exercise electrocardiogram. In the clinical application, this system has been, proved to be useful for the diagnosis of coronary heart disease. The combination of coefficient a and c could discriminate patients with effort angina pectoris from healthy adults more clearly than. using coefficient c only, the extent of the ST junction's depression used commonly as criterion for the exercise electrocardiogram.

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Coordinate relationship exists between pupillary near reflex, lens accommodation and eye movement in response to a target moving back and forth. An attempt has been made to clarify this coordinate relationship through the analysis of pupillary near reflex.
Static characteristics of pupillary near reflex were measured under various intensities of background illumination. When background illumination was dark and pupil size was large, changes in pupil size to accommodative stimulus were small. These results appear to, be in accordance with “range non-linearity” that was advocated by Stark et al.
It was also observed that a remarkable difference existed between dynamic characteristics of pupillary light reflex and those of pupillary near reflex. Pupil noise was suppressed during near reflex. Results of the measurements of static and dynamic characteristics in response to light and accommodative stimuli given simultaneously indicate that these two stimuli give an additive effect on pupil size.
A measurement system by which pupil diameter, lens power and eye movement were simultaneously and dynamically recorded was developed. The pupil and vergence responses are recorded by infrared-sensitive TV cameras. Changes in lens power are recorded by Campbell type optometer. The step and frequency responses to accommodative stimulus revealed that the speed of eye movement was the highest and that of pupil response was the lowest.

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An excised and supported canine left ventricular preparation was used for the analysis of the ventricular performance.
In this preparation, the left ventricular volume and pressure were monitored and controlled with the newly developed pressure servo system. With this system, the ventricle contracted isobarically throughout the ejecting phase. Therefore, the effect of changes in pre-load and afterload on the stroke volume was studied at the constant heart rate and coronary perfusion pressure.

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The application of constant-temperature hot-film anemometry to blood flow velocity measurements, is discussed. There are several difficulties in calibration and use of this apparatus in liquids, which are, not encountered in its use in gases. The calibration of the hot-film probes for several homogeneous liquids and the bovine, blood with various hematocrit values was performed by a modified Seed's and Wood's method. The stability of calibration seems to depend upon the stability of rotation of the tank. The disturbances induced by the hot-film probe into liquids also have some extent of influence on the stability of the calibration. Preliminary animal experiments were designed to study the characteristics of intracardiac and intravascular blood flows. Flow velocity patterns in the left ventricle and the ascending aorta are demonstrated, showing almost similar character to those of other authors. Although the constant-temperature hot-film anemometry has not been used widely in physiological research, this method will be very useful in this area, for example, for identifying the complex nature of flows in cardiovascular chambers and canals because of, its excellent frequency response and position resolution.

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