The microcomputer-based, multi-purpose biofeedback (BF) sytem was developed for several clinical applications. The main components of system were as follows : the microcomputer, (Apple II), a color CRT display, a synthesizer, an anlog-to-digital converter with 12 channel analog multiplexer. To fascilitate data processing, a Z80 CPU card with the disk operating system (CP/M) was also installed. First, 2-channel EMG BF training was introduced to motor disturbance caused by cervical spinal cord injury. Two EMG activities obtained from an upper limb of a subject were sampled by the system, then fedback as graphic patterns on a CRT or as auditory stimuli via a synthesizer. This multiple BF procedure with integrated feedback information was effective for reducing the muscle co-contraction in such a subject and the appropriate motor pattern tended to be established easily. Second, potentiometers were attached one each to two weight scales to which subject's weight was allocated. Analog outputs from the potentiometers were fed to the BF system. It was shown that reliable data to evaluate the voluntary control of standing posture in cerebral palsied children, could be obtained with the simple measuring devices and the system. It was discussed that, as shown in the second example described above, the quantitative data acquisition could be realized only with the addition of simple sensors or transducers. Furthermore, thtypical BF training process in clinical applications was summarized in terms of softwares of this system. The process consist of planning, execution, and evaluation of BF training, all of which are controlled and optimized at the software level. It was exemplified well in the multiple EMG BF training in the present report. It was suggested that further quantitative data analysis with this BF system is necessary to reveal the critical role of feedback information for more effective application of BF procedures to clinical situation.

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The theoretical interpretation of tremor mechanism and classification has given rise to considerable amount of controversy. Especially, a number of controversies has existed concerning the cause of physiological tremor, which was defined as vibrational movement of body part by involuntary or voluntary muscular contraction, accompanying with EMG. They may be summarized as follows : 1. Spinal reflex 2. Auto-nervous system 3. Mechanical oscillation 4. Heart beat, Ballistocardiogram (BCG) But none of these theories can explain all the experimental evidence. In fact, every one is considered to contribute to the physiological tremor to greater or lesser degree. Mcirovibration, defined as invisible and involuntary vibration on skin, is considered as a kind of tremor. It's mechanism remains not to be determined, as well as Physiological tremor. Thus far, there is a number of theoretical and empirical studies on physiological tremor and Microvibration mechanism, as well as remedial works such as Parkinson's disease. But very little work within the framework of biofeedback has been carried out on the control of tremor in spite of the potential importance of feedback training for the application to the treatment of disorders. Therefore, the fundamental study appears to be necessary for future application. In this experiment, it was investigated to determine whether normal subjects could learn to control their microvibration with biofeedback technique. Ten normal college male students were randomly assigned to two groups. All subjects were instructed to sit on the chair and put their right forearm on elbow rest and then Microvibration sensor (MT-3T, Nihon Koden Corp.) were attached on their M. Biceps Brachii. The protocol of experimental treatment was (1) the rest condition for four minutes, (2) the movement condition, holding 60% maximum voluntary contraction(MVC) for one minute, and (3) the experimental condition for ten minutes with or without auditory feedback signal of microvibration amplitude. The data was analyzed (1) integrated amplitude of Microvibration and (2) the first peak frequency of power spectrum. Microvibration amplitude in the rest condition was the same in two groups and periodically observed the ballistocardiogram elements in microvibration wave. But in experimental condition following the 60% MVC, the experimental group (EG) with auditory feedback signal of Microvibration amplitude significantly reduced microvibration amplitude, but the control group (CG) without auditory feedback signal did not reduce. The similar results were obtained in the first peak frequency for EG was significantly lower than that for CG in experimental condition. Our findings suggest that biofeedback technique is effective for controling microvibration amplitude.

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The arterial wall is distended outward due to the intraarterial pressure (I. e., blood pressure ; BP). Therefore, pushing back the arterial wall by using an appropriate counterpressure, the counter-pressure will balance with BP at the moment when the arterial distension is completely relieved (I. e., the vascular unloaded state). The vascular unloaded state is detectable from the occurrence of the maximum volume pulsation in an artery during the application of the counterpressure. When the transmural pressure reaches zero (I. e., unloaded), the highest compliance of the vascular wall results in the maximum amplitude of volume pulsations. Based on this principle, Yamakoshi et al. (1980) developed a new method for measuring instantaneous BP. A transmittance photoelectric plethysmograph is attached to the medial or root portion of a finger to detect the vascular volume change. The finger is inserted into an occluding cuff which is installed in a compression chamber filled with water. The chamber is connected with a diaphragm actuator which is further linked to a shaker. The finger can, therefore, be compressed or decompressed by the hydraulic pressure in the chamber (I. e., cuff pressure). First, a reference value for the servocontrol which corresponds to the vascular volume in the unloaded state is detected. This is obtained by performing an open-loop operation for the servo-control system. The cuff pressure is raised gradually using an external signal, and a mean level of the photoelectric plethysmogram is detected at the moment when the maximum amplitude of the pulsating signal is attained. After the reference value is determined, the closed-loop operation is made to measure the continuous BP. The plethysmographic signal is fed to a differential amplifier and subtracted from the reference value. The servocontrol error thus obtained is fed to a power amplifier. Consequently the output signal of the power amplifier drives the shaker which sets the diaphragm actuator going to control the cuff pressure. In this way, any variation in vascular volume due to the cbange in BP is instantaneously compensated for by the servocontrol system. The vascular volume is fixed at the reference value, and the cuff pres- sure follows instantaneously the BP. In this method, beat-to-beat systolic and diastolic BP as well as the BP waveform can be measured. Comparisons with direct measurement have been carried out successfully in many normotensive and hypertensive subjects. Unlike the Riva-Rocci method, the present one does not occlude the arteries of the finger but hold them under the vascular unloaded state. Venous return occurs little by little as the venous pressure in the dista is balanced against the cuff pressure. Therefore, the continuous measurement of BP can be carried out without much discomfort for long periods of time. Bodily movements and/or changes in posture seldomly produce the artifacts of BP recordings because the finger segment is compressed moderately in the cuff, and the frequency response of the whole system [is unform up to more than 60 Hz. In conclusion, the present method seems to be superior to other indirect methods. BP biofeedback experiments should be carried out more easily by use of this method.

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The current study examined the relationship between the field-dependence/independence and Skin Temperature(ST). Biofeedback trainings. 39 undergraduate students participated in 2 months biofeedback training sessions voluntarily. Before the biofeedback training periods, they were tested about their field-dependency with the portable type Rod-and-Frame Test (RFT) instrument, and they were tested with the same RFT instrument after the 2 months training periods again. Within the same period, 7 undergraduate students were tested with the same RFT instrument without biofeedback trainings, as a control group. The results showed that the more field-independent they were in the 1st RFTs, the more proficient they were in the ST biofeedback training, and that the scores of the RFTs tended to be more field-independent after the ST biofeedback trainings.

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Skin potential level (SPL) on the palmar surface reduces its electro-negativity with the decrement of arousal level. This phenomenon was applied to assessment of the level of arousal in motor driving. In the first experiment, SPL, electroencephalogram (EEC), electrooculogram (EOG) and electrocardiogram (ECG) were measured for each driver when he drove a car in a vehicle proving ground. Dangerous driving behavior which was caused by the decrement of arousal level was observed in the experiment. Results of the experiment show that changes in SPL and EOG were correlated with those in arousal level. However, no relation was found between the level of arousal and EEG or ECG. Then, in the second experiment, we tested a possibility to control the level of arousal by using SPL as its index. The driver was stimulated by an experimenter's voice when his SPL reached a certain threshold level. SPL increased each time the stimulation was given. The results show that SPL was kept above the threshold level and that no behavioral error was observed in driving. The feedback technique will be applicable to a doze alarm system for motor drivers, airplane pilots, etc.

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The effects of motivation and biofeedback upon learned heart rate (HR) speeding were examined. Undergraduate volunteers were randomly assigned to one of the following three groups : Feedback & Motivation (F&M) group, Motivation (M) group, and Feedback (F) group. The F&M-group was presented with feedback stimuli and was informed of the nature of response and the meaning |of| feedback. This group was also under the motivational condition ; the subjects were asked to increase HR and were promised a reward proportionately to the success of their performance. The M-group was under the same motivational condition but without feedback. The F-group, that was assisted by feedback, was given the information in the same way as the F&M-group, but was not under the motivational condition. The results indicated that the HR of the F-group decreased. The HR of the F&M-group and the M-group increased, but the difference between the two groups was not clear. Therefore, it was concluded that motivation played an important role in HR increasing and that feedback alone did not have a clear effect on the control of HR increase.

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