Publications (3)0 Total impact
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ABSTRACT: As the increase of intraoral acidity by ingesting sweet foods and acidic beverages usually results in dental caries and erosion, the measurement of intraoral pH is the basic part in the study of oral environment regarding dental caries and erosion. The purpose of the study was to develop an indwelling intraoral pH telemetry lasting longer than 24 hours in the mouth to overcome the limits of conventional wire electrode method previously used for salivary and plaque pH measurement, and to assess its effectiveness.
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ABSTRACT: The aged are faced with increasing risk for falls. The aged have the easily fragile bones than others. When falls have occurred, it is important to detect this emergency state because such events often lead to more serious illness or even death. A implementation of PDA system, for detection of emergency situation, was developed using 3-axis accelerometer in this paper as follows. The signals were acquired from the 3-axis accelerometer, and then transmitted to the PDA through Bluetooth module. This system can classify the human activity, and also detect the emergency state like falls. When the fall occurs, the system generates the alarm on the PDA. If a subject does not respond to the alarm, the system determines whether the current situation is an emergency state or not, and then sends some information to the emergency center in the case of urgent situation. Three different studies were conducted on 12 experimental subjects, with results indicating a good accuracy. The first study was performed to detect the posture change of human daily activity. The second study was performed to detect the correct direction of fall. The third study was conducted to check the classification of the daily physical activity. Each test was lasted at least 1 min. in third study. The output of acceleration signal was compared and evaluated by changing a various posture after attaching a 3-axis accelerometer module on the chest. The newly developed system has some important features such as portability, convenience and low cost. One of the main advantages of this system is that it is available at home healthcare environment. Another important feature lies in low cost to manufacture device. The implemented system can detect the fall accurately, so will be widely used in emergency situation.his paper, the PDA system was developed using the 3-axis accelerometer. First, the signals were acquired from the 3-axis accelerometer, and then transmitted to the PDA through Bluetooth module, Acode-300- - (Chipsen, Co. Korea). This system can classify the human activity, and also detect the emergency state like falls. When the fall is detected, the system generates the alarm on the PDA. If a subject does not respond to the alarm, the system determines that the current situation is an emergency state, and then sends some information to the emergency center.
Conference Paper: Estimation of the Blood Pressure using Arterial Pressure-Volume Model[Show abstract] [Hide abstract]
ABSTRACT: An analysis of the conventional blood pressure estimation method of the oscillometric sphygmomanometer was performed through a computer simulation using an arterial pressure-volume(APV) model. A more accurate blood pressure estimation method was proposed from the analysis. Traditionally, the maximum amplitude algorithm was applied on the oscillation waveforms of the APV model to get the mean arterial pressure and the characteristic ratio. In doing so, the shape of pressure waveforms and the cutoff frequency of high-pass filter circuitry strongly affected the estimation of mean arterial pressure and characteristic ratio. This resulted in errors when estimating blood pressure. To find an algorithm independent from the influence of waveform shapes and filter parameters, the volume oscillation of the APV model and the phase shift of the oscillation with FFT were identified by increasing the cuff pressure from 1 mmHg to 200 mmHg (1 mmHg per second). The phase shift between the ranges of volume oscillation was then only observed between the systolic and diastolic blood pressures. The same results were obtained from simulations performed on two different arterial blood pressure waveforms and one hyperthermia waveform.