This paper discusses whether an application of the AR model to an acceleration data of a tremor is useful for a differential diagnosis between Parkinson's disease and other diseases with tremors, such as the essential tremor. The degree of the AR model was chosen as 7 according to Akaike's FPE criterion. The examinees were 19 Parkinson's disease patients, 21 essential tremor patients —a disease that mainly appears in the elderly and in Parkinson's disease patients— and 13 healthy elderly as the control. This study on the acceleration data showed that the first prediction coefficient, the same as the main tremor frequency, is the parameter that classifies the Parkinson's disease group and the essential tremor group. The 7th prediction coefficient is the parameter that classifies the pathological tremors observed in Parkinson's disease and essential tremor disease patients and the physiological tremors observed in healthy subjects. Although the effects of another prediction coefficients on the differential diagnosis between Parkinson's disease and other diseases with tremors are not clarified during this stage, adding the AR model parameters to diagnostics by the main tremor frequency can increase reliability of the diagnostics. This paper showed the usefulness of the AR model for the acceleration data of the tremor to classify Parkinson's disease and other diseases with tremors.

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The volume-compensation and Penaz methods are useful and helpful means for the measurement of blood pressure on a beat-by-beat basis. These methods are applied mainly for finger artery blood pressure measurement. When finger arterial blood pressure was continuously measured by the use these methods, a cuff attached circumferentially around the finger caused a blood flow impediment and venous congestion under the cuff and the distal portion of the cuff attachment site. To reduce the congestion, we designed a new cuff unit for a finger arterial pressure monitoring system based on the volume-compensation method. It consists of a disk-type cuff for local pressurization to the finger artery, a cuff-holding clip to ensure a firm attachment of the cuff with some local supporting points, and a photo-plethysmographic sensor. The cuff unit enables a successful blood pressure measurement the relieves venous congestion. Blood volume at the distal portion of the measurement site was measured by using a photo-plethysmograph to assess the venous congestion. The volume during measurement when the cuff unit used was reduced to less than a fourth of that when a conventional band-type cuff was used. To evaluate accuracy of the blood pressure measurement, the blood pressure values obtained by the cuff unit attached to the index finger were compared with those by the band-type cuff attached to the middle finger. Consequently, the correlation coefficients were 0.95-0.99 (p<0.0001), and the mean difference and the standard deviation ranged from -1.45-+1.81mmHg and 1.54-3.48mmHg through 12 healthy subjects. The present cuff unit seems useful and helpful in long-term and ambulatory finger arterial pressure monitoring based on the volume-compensation method.

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We designed the metal coating hollow fiber membrane coated with metal on the outer surface of the capillary membrane. We found that bacteria on the membrane were sterilized by a direct electric current passed through the metal on the membrane surface. The sterilization mechanism was created as follows: The leakage of intracellular contents was confirmed when bacteria were sterilized by the electric current. This leakage proved indirectly that the cell membrane was partially broken. In this paper, the leakage phenomenon and the mechanism on the sterilization were focused, and the possibility of whether the metal coating hollow fiber membrane became a new gene extraction device was examined. After the direct current to the membrane-surface-trapped Escherichia coli O157 was passed, the gene was examined. As a result, the vero toxin type 1 gene could be detected. The detection sensitivity on the gene extraction mainly depended on the concentration of sodium dodecyl sulfate (SDS), which was an anion surfactant, and on the value of the direct electric current. The highest sensitivity in the extraction was obtained under 5% SDS and 300mA. Under these conditions, the vero toxin type 1 genes were obtained when the bacterial number in a physiological salt solution was more than 10⁵CFU/ml. This system needed time to extract the gene in only 10 minutes. The system used also simpler equipment because it consisted of the perista pump and the power supply in addition to the membrane. Therefore the gene extraction method that used the metal coating hollow fiber membrane has the advantages of (a) requiring less time than a chemical extraction, which needs about an hour; (b) low contamination because of a simpler extraction process; and (c) the possibility of automation of the simple system.

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We analyzed the absolute sensitivity characteristics of air-coupled microphones and accelerometers in lung-sound measurements. Studies have revealed that the air-coupled microphone shows low-pass frequency responses because of its air-chamber compliance, but how the coupler affects the microphone's response in the pass band has not been examined. In the pass band, since the mechanical impedance of the air chamber is much higher than that of the chest wall, the vibration of the measured area on the chest-wall surface is stopped by the air chamber and the coupler rim in contact with the chest wall. We analyzed the normal stress distribution on the stopped surface and then assessed the effect of the coupler rim on the microphone response by calculating the ratio of the sound pressure exerted on the air chamber to the stop-surface pressure, i. e., the sound pressure averaged over the stopped surface. The stress concentrates on the outer edge of the rim, and its distribution changes with frequency. The measured sound pressure is therefore lower than the stop-surface pressure, and the measured pressure decreases as the frequency decreases. Although the response of the accelerometer greatly depends on the accelerometer's mass and contact area, it is generally difficult to measure unloaded chest-wall surface acceleration. We considered the accelerometer's response to sound pressure and showed it, using the stop-surface pressure as reference. We also showed that the response to sound pressure can be improved easily by increasing the seismic mass of the accelerometer and that the accelerometer may be used as a pressure sensor. The results of model experiments well agreed with theoretical predictions based on the mechanical properties of the medium used in the experiments. We evaluated the absolute sensitivity of the air-coupled microphone and the accelerometer by using stop-surface pressure as a common reference. This allows, regardless of the type of transducer, measured lung sounds to be treated consistently with the unit of sound pressure.

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