The integration function of multi-sensory information in the central nervous system is discussed by analyzing the human operator's control characteristics in the two-dimensional manual tracking system. The tracking error, the nonlinearity index and the anisotropy index are used to analyze the operator's control characteristics. In the case of normal subjects, large tracking error was observed together with large anisotropy. The comparison between young and old normal subjects revealed that the depression of the central nervous system due to aging promoted the anisotropy of the control characteristics. The patients with hemiparesis, who were pointed out the lesions in the basal ganglia or the thalamus on computed tomography, had a large amount of tracking error through they had small degree of anisotropy. To account for the results mentioned above, a model of the integration function of multi-sensory information is proposed for the central hemispheric disorders. This model is used to ascertain the adequacy of the hypothesis that the anisotropy is derived from the bilaterality which is a basic structure for the connection of the neuronal network in the brain.

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This paper demonstrates that the human operator's control characteristics in the two dimensional manual tracking system have an anisotropy with respect to vertical and horizontal directions when the polarity of the control input is reversed by the controlled object. Several kinds of the experimental conditions have been used to ascertain that the anisotropy is related to the visual space transformation, which is assumed to be one of the integration functions of multi-sensory information in the central nervous system. It has been suggested that the processing time in the central nervous system for reinterpreting the visual space constructed by the reversed coordinates varies with the kind of the controlled object. A hypothesis that the time difference between the horizontal reversal and the vertical reversal causes the anisotropy is proposed. This implies that the anisotropy is derived from the bilaterality in the brain.

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A method for estimating mechanochemical constants of the skeletal muscle, such as elastic coefficient of the series elastic component (E_s), heat constant (a) and rate constant of energy liberation (b), was developed. These constants were determined by comparing model responses with measured force caused by stretching or shortening of the thumb. Validity and usefulness of the method were assessed by applying it to the thumb flexor muscles in five healthy subjects.
A special attention was paid to the nonlinear mechanical properties of the muscle varying with the intensity of the active state; that is, dynamic relations between force and length change over the interval when the constant contractile force was maintained were used for the estimation. The interval was from the onset of length perturbation to 50ms after that onset. Force response of the model closely agreed with the measured in human thumb. The parameter, E_s, can be estimated accurately. While individual values of a and b could not be estimated uniquely, its combination k=(a+c)/b(c: constant) could be determined accurately, where the parameter k is coefficient of velocity-dependent force-loss of the contractile machinery.

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A totally implantable motor-driven asisst heart system(TIAH) has been developed, characterized in vitro, and evaluated invivo for utilization in patients with end-stage cardiac failure refractory to conventional therapeutic techniques.
The TIAH system consists of two subsystems; motor-driven asisst heart, and transcutaneous energy transmission system (TET). The motor-driven asisst heart utilizes a ball-screw to convert high-speed rotary motion into low-speed rectilinear motion. The ball-screw is rotated by a three-phase DC-brushless motor. Magnetic coupling is utilized between actuator and blood pump to fill blood pump with blood from atrium by magnetic attracive force. The TET provides electrical energy to the implanted assist heart without passing wires through the skin. A pair of concave and convex ferrite core typetransformer is specially designed to prevent dislocation of the primary core in relation to the secondary core. Secondary voltage of the TET is regulated by controlling a duty cycle ratio of the square pluse supplied to the primary coil. Information on secondary voltage is transmitted through the skin by infrared pluses.
The TIAH system was undergone in vitro characterization and in vivo evaluation in a dog. The power required by the blood pump and drive system was measured in vitro. The in vitro test showed that the pump outflow of 5-61/min was obtain-ed against afterload of 70-100mmHg, under preload of 0-15mmH with the overall system efficiency of 4%. In vivo experimentusing a dog weighing 17.5k demonstrated counterpulsing operation of the motor-driven assist heart.
From the excellent system performance in terms of mechanical operation, electronics reliability and hemodynamic effecti-veness, it is concluded that the developed system is a promising totally implantable assist heart or total artificial heart system.

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We have designed and constructed a simple apparatus for continuous recording of sweating rate utilizing a hygrometer of electrostatic capacity type.
The present device consists of the following 3 parts: a plastic skin capsule equipped with a hygrometer and a multivibrator, a F/V converter circuit and a pen-recorder. The distinct feature of the new apparatus is summarized as follows.
(1) The capsule is small in size and easy to put use.
(2) Dry air was passed through the lumen of the capsule via an air inlet tube at a fixed flow rate in order to remove the vapor generated by in sensible perspirations.
(3) A linear relationship between the amount of evaporated water in the capsule and output voltage (1mV/1mg/5min) was obtained.
A few results of the preliminary application of this apparatus to human beings are presented.

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Neuromagnetic fields evoked by the auditory stimuli of pure tones and speech sounds were measured, and equivalent current dipoles were calculated based on a least squares method. In the N1_m component of the magnetic responses which occurred at about 100ms after the stimulus onset, the location of the current dipole elicited by high frequency tone was deeper and more anterior than that of the dipole elicited by low frquency tone in right and left hemispheres. This result indicates a ‘tonotopic organization’ in the human auditory cortex. In the left hemisphere, the location of the current dipole elicited by the speech sound of a vowel/a/was deeper and more anterior than that of the dipole elicited by a consonant-vowel/ka/. It is suggested that the magnetic responses reflect the activity of the neurons responding to acoustic, and also possibly phonetic, characteristics of the auditory stimuli. These differences of the dipole locations for different stimuli were analyzed by computer simulations evaluating the error range of the dipole location.

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A new catheter-device system which applies thermal energy to endocardium was developed. The heater was made of platinum wire (50μm OD) mounted on the catheter tip. The temperature of the heater was kept at a fixed level automatically by the device through monitoring the change of heater resistance.
When the heater was applied on agar surface, the temperature of the catheter tip reached a stable level in the first 10 seconds and the temperature did not rise beyond 55°C by the power of 20 watts and at its duration of 30 seconds.
When it was applied on fresh canine endocardium, a visible injured region expanded depending on the energy, but if did not exceed 3 milimeters in depth.
The developed catheter-device system provides a method to make a superficial injured region on the endocardium which can be enough to ablate the substrate inducing ventricular tachycardia.

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We present a method to simulate skin incision process at cerebral surgery planning system by X ray CT 3D-images. The cerebral surgery planning system consists of several parts. The first one of them must be skin incision, because operation begins with incising skin of head. Several years before our group have developed some methods to simulate opening skull and reaching tumor or other expected parts within head. The skin incision simulation can give information to doctor whether the incised skin disturb operation and if the incised skin will recover well after operation. But the simulation of shape change of soft tissue such as skin or brain and etc. have not been done yet. In this paper we simulate the skin incision process by using coordinate transformation and some other modification.

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