We have established and applied a basic principle for the regulation to an extracorporeal circulation (ECC) system. A fuzzy inference was also applied to the system in order to compensate a deficit of the conventional static regulation. Parameters were classified into surveillance and regulation parameter in order to describe regulation rules in IF-THEN formula. A hemodynamic condition of the experimental animal was also classified into the four conditions from I to IV by BP and PAD, where condition I is BP=high (H) and PAD=low (L), condition II is BP=L and PAD=L, condition III is BP=H and PAD=H, and condition IV is BP=L and PAD=H. A principle for regulation is always intended to shift into or stay in the condition I. This principle was described as several simplified rules. On the other hand, the comparative study between in the clinical cases (Wt. 13.3±5.99kg) and in the canine experiments (Wt. 11.6±2.25 kg) showed no statistical defference in hemodynamic stability during ECC. This result may suggest that the hemodynamic change during FCC with the autoregulation system was almost equivalent to the mannual circulation by specialists and also suggest the effectivity and the possibility for utilization of this system in the future.

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It is the well known fact that the dose distribution of radiotheraphy is greatly influenced by the patient's movements during irradiation. But even now, it must be monitored mainly by the operater, because we have no adequate monitoring device and system. Therefor, in the present study, we tried to detect the body movement accurately by utiliting the gravitational-center-detecting-image-processing system, named “patient movement monitor, ” which was developed by partially modificating industrial-shape-identifing device and tested our device in order to determine whether this device can be used as the various calibration systems for our purpose. We first examined the accuracy of detectability on the coordinate axes of two dimentional radiation field. Our data revealed that the speed of the monitoring was 15 data per second, the limit of resolution was less than 1mm, (SD=±1mm). We then measured the degree and patterns of the body movement during radiotherapy. The age distribution of tested cases ranged from childhood to senile, and measured body regions were head, chest and abdomen We were able to follow and measure the body movements satisfactorily in all the examined cases. The movements of patients were classified into two different patterns. The first, most frequent type showed a regular rhythmic pattern with low amplitude, which was considered to be physiological organ movements. The second type was an irregular pattern with various and relatively high amplitude. In conclusion, this monitoring system is available to monitor the patient's movements during external radiotherapy sufficiently at present, although this device still needs to be improved in future.

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A method for detecting respiratory sinus arrhythmia (RSA) by using an adaptive filter is proposed. RSA is a correlative component to breath which is comprised in a heart rate fluctuation. Since the spectrum of the breath changes with respiratory rate, methods that assume statistical stationarity, e. g. FFT, cannot detect RSA precisely under free breath. So we have adopted an adaptive filter which has two inputs. One is a primary input to which an interval between successive R-wave in ECG is applied. The other is a reference input to which a respiratory signal, such as chest movement or respiratory flow rate, is applied. This filter extracts correlated component to the reference signal in the primary input. A remarkable merit of an adaptive filter is a tracking capability, such as the characteristics are followed to input signal, even if power spectrum of the signal changes slowly with time. In this paper, a least mean square algorithm is used to control the filter because of its simplicity. There are two parameters to be decided for the adaptive filter. One is dimension n, and the other is convergent parameter μ. These parameters must be optimized, because they affect to tracking speed and error. A small μ causes slow tracking characteristics with small error. A large μ brings fast tracking speed with large error. As a result of simulation, we can conclude that the optimal μ is obtained by 1/(‘power of reference input’ ×70×n). To test the filter characteristics, change of RSA during exercise of bicycle ergometer and that with posture characteristics were measured under free breath. The results of experiments have shown that the proposed method is effective for the estimation of RSA.

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To clarify the mechanisms of transcapillary exchange of macromolecules, we tried to establish a new method for measurement of the local capillary permeability which can be obtained the diffusion (D) and convection (V) components separately. The anesthetized rabbit tenuissimus muscle was used to observe the micro-circulation and to measure the capillary permeability. After the injection of the fluorescent tracer (FITC-Albumin: FA67; M. W.=67, 000, FITC-Dextran: FD150; M. W.=150, 000 and FD500; M. W.=500, 000) via the jugular vein, temporal changes in the tracer concentration within the muscle tissue space were recorded as the fluorescent intensity changes by vital microscopic-TV system. D and V values were calculated by best-fitting the experimental concentration curve with the simulation curve based on the “Pore theory” in which macromolecules are assumed to pass across the capillary wall through the “Large pore” by diffusive and convective forces. Capillary permeability of diffusion component (P_dif) was calculated from D value as P_dif=D/X_w, where X_w is the diffusion distance (length of pore). All animal experiments were carried out to keep the muscle under vasodilation topically. Obtained P_dif and V values of FA 67, FD 150 and FD 500 were P_dif=26.6±15.6, V=76.6±5.0, P_dif=3.3±0.8, V=45.0±5.0 and P_dif=2.1±1.1, V=47.0±9.0 (×10^-9cm/s), respectively, which were largely consistent with the values reported by whole organ measurements. It was concluded that present method is useful to measure the local capillary permeability of macromolecules separated between diffusion and convection components.

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Tinnitus in 55 ears was treated with a custom made tinnitus suppressor which was designed to apply an alternative current to the cochlea of patients and the current level was in the range of 200-300μA. A well charge balanced stimulus waveforms, whose stimulus current density around the electrode is 1.25μC·cm^-2·geom/phase, was used and it was shown from our treatment that no problem in patients was observed. Averaged loudness level (difference between tinnitus level and hearing level) of tinnitus before treatment was 15.7dB, while 8.4dB after treatment. More than 5dB of tinnitus level was improved in 30 of 55 ears treated with the device and in 5 ears tinnitus disappeared.

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The reconstruction of three dimensional structure of cerebral arteries from two dimensional cineangiograms is useful to extract three dimensional information in the angiograms. In this paper, we consider the extraction of vessel center lines from the cineangiograms, which is a basic and important process for the three dimensional reconstruction. As the structure of cerebral arteries is extremely complicated and the vessel regions on the cineangiograms cross and overlap with each other, it is difficult to extract vessel center lines. A framewise extraction method is developed in this study, which repeats the vessel extraction upon each of a series of cineangiograms. On each frame, the system selects a proper image processing algorithm and parameters for the vessels under processing. The extraction method combines both the edge detection and the segmentation to improve the accuracy of vessel extraction from a single frame of cineangiograms. A vessel examining process is also proposed, which evaluates the possibility of extracted center lines being real cerebral arteries. The knowledge about cerebral arteries as well as that of cineangiograms is utilized in the processes for vessel extraction and vessel examination to improve the accuracy of the extraction results.

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In recent years magnetic stimulation has emerged as an useful method for stimulating nerves compared with the general electric stimulation using electrodes on the skin, and because magnetic stimulation is noninvasive and less painful than electric stimulation. In magnetic stimulation, it is important to estimate eddy currents induced in a volume conductor. It is, however, difficult to predict distributions of eddy currents in an inhomogeneous medium like as the human vertebra column. In this paper, we measured spatial distributions of eddy currents induced in the vicinity of an assumed human vertebra column in a tanks filled with saline solution, when the tank was exposed to pulsed magnetic fields. The eddy currents were measured with a current probe which is made of ultra-mini coaxial cable. In the tank with vertebra column, the distribution of the current is also compressed near the vertebra and the current flows along the surface of vertebra. The value of current density on processus transversus vertebrum with vertebra column is about 1.5 times bigger than without it. On the contrary, the current density near intervertebral foramen decreases about 70% rather than without vertebra column.

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To simulate blood pressure measurement done by medical doctors, a new type stethoscope, which is a commercialy available stethoscope equipped with an eddy-current displacement sensor and a microphone, is developed. Using this stethoscope and impedance plethysmograph, pulse wave-forms and sounds distal to the cuff and volume change of the artery under the cuff were measured in various experiments. In some experiments, common blood pressure measuring process is adopted and, in other experiments, cuff-pressure is kept constant. From the experimental results, the following facts are known. 1) Blood flow rate coming from upstream in the collapsed artery under the cuff is not affected by arterial pressure distal to the cuff. 2) Always the same sounds are produced when experimental conditions are kept constant. 3) When sounds are heard there exist always steep wave fronts. From these facts, the true mechanism of Korotkoff sound generation is known to be hydrolic-jump formation at the wave front during pressure wave propagation through collapsed artery segment under the cuff.

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An ablation of eschar (necrotic burnt skin) by various excimer irradiations are described in this paper. The eschar may cause infections in burnt patients. It is necessary to completely remove the eschar as soon as possible to perform skin graft, which is a sole treatment to save the patient. Escharectomy debridement is performed by scalpel or hand-dermatome with huge skillfulness. In order to improve debridement, it is necessary to develop more efficient (faster and easier) treatment. Since eschar may be high protein concentration with less water content comparing to a normal skin tissue, the use of the uv excimer laser may induce an efficient ablation. As a fundamental investigation for the uv excimer laser ablation, the ablation rates of the rabbit eschar by ArF, KrF, XeF and XeCl excimer laser irradiations were measured. And extracted skin samples were examined histologically. KrF laser irradiations indicate the efficient ablation rate with a sufficient selectivity from a normal skin. Following this ablation rate and using KrF laser with 80W average power, 30cm³ (for example; 10cm squares with 3mm depth) of the eschar could be ablated within 460s. This speed of the debridement is supposed to be faster than the current debridement.

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Thermal blankets which are mats with warm water circulation are often used to prevent body temperatures of anesthetized patients from decreasing in the operating room. Although the water temperature is controlled within an appropriate temperature range, burn injuries are sometimes found on the patient parts contacting the mat. The purpose of this study is to give some experimental evidence to clarify the mechanism of burn injuries found at pressurized parts under a normal temperature environment. The effects of the local pressure on temperature distribution and physiological activities in an anesthetized pig's haunch on a warm water mat were experimentally investigated. The local pressure on the haunch was found to cause (1) a decrease of blood perfusion rate, (2) a decrease of cooling rate due to blood flow, (3) an increase of local temperatures, (4) a decrease of tissue pH, and (5) a decrease of tissue oxygen saturation. These results agree with the phenomena induced by the decrease of blood flow rate. In addition, the ratio of the metabolic heat production rate under pressure to that without pressure was compared with the ratio of the blood flow rate under pressure to that without pressure. Experimental data were used for this analysis by a simplified heat transfer model. The former ratio was found to range three to four times the latter ratio for the conditions in this report. This means that the pressurized parts reach higher equilibrium temperatures than those without pressure. Finally, the effect of pressure on burn injuries at normal temperatures is discussed.

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In order to improve the emergency care in an ambulance, a paramedic system has been legislated. However, the paramedic can perform significant emergency care, only when the concrete instructions from a medical doctor are available. To operate this system effectively, a telemetry system was developed which transmits audio and medical signals from an ambulance to a medical doctor in a hospital. It also transmits the vocal instruction of the doctor from the hospital to the ambulance. A frequency-division multiplexing technique was applied to the simultaneous transmission of the audio and medical data using a single radio channel. The high-frequency portion of the audio signal is suppressed to be 0.3-1.1kHz, and the medical data is inserted in the portion, i. e. 2.0-2.8kHz. An experimental system was developed and the transmission experiments from moving automobile were conducted using a mobile telephone and emergency radio. Even with the lack of high-frequency component, the quality of vocal communication was satisfactory for emergency practice. The wavef orms of ECG signals were also satisfactory for emergency diagnosis and monitoring, even when the condition of radio transmission was degraded in normal condition. When the audio and medical data were transmitted simultaneously, there was no interference observed. This technique will allows us effective emergency diagnosis and treatment before hospital arrival with the currently used communication link without adding another channel.

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A fluorescence profile of a chromosome is a one-dimensional pattern indicating a distribution of fluorescence intensities along the chromosome in lengthwise. A method to measure fluorescence profiles of chromosomes flowing by a slit-scan flow cytometer and to search the profiles having plural dip-points, locations of centromeres, is a powerful method for detecting abnormal chromosomes. This method can inspect more than 10, 000 chromosomes per minute and fits for a new inspection technique using chromosome specific DNA probes. An outline of the method and examples of measured profiles of human abnormal chromosomes are described in this paper. Lengths of the chromosomes and locations of centromeres calculated from the profiles are also shown.

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