Due to the possible occurrence of periodontal disease at an early age, it is important to have proper toothbrushing habits as early as possible. With this aim, the feasibility and concept of a smart toothbrush (ST) capable of tracing toothbrushing motion and orientation information was suggested. In this study, we proposed the advanced ST system and brushing region classification algorithm. In order to trace the brushing region and the orientation of a toothbrush in the mouth, we required the absolute coordinate information of ST. By using tilt-compensated azimuth (heading) algorithm, we found the inclination and orientation information of the toothbrush, and the orientation information while brushing inner tooth surfaces showed specific heading features that could be reliably discriminated from other brushing patterns. In order to evaluate the feasibility of clinical usage of the proposed ST, 16 brushing regions were investigated by 15 individual healthy subjects. The proposed ST system demonstrated 97.1%(±0.91) of the region detection accuracy and 15 brushing regions could be classified. This study also showed that the proposed ST system may be helpful for dental care personnel in patient education and instruction for oral hygiene regarding brushing habits.

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-Color is discerned due to the reflectance of object and its hue is determined by the Ratio of RGB spectrum. The aim of this study is to evaluate the Color information using by the optical system in terms of convenience and simplicity. Firstly, the differential Ratio of RGB is evaluated by photodiode Sensor which achieves a high efficiency with quick tranducer output. To extract the information of RGB Ratio, light emitting diode is built in Color sensing system with photodiode. Our proposed method is very economical, simple, and convenient. Our results can be applied to confirm the accurate information of Color in the research environments and commercial purposes. Thus RGB information can be determined subjectively and thus, the inherent characteristic of Color will be revealed precisely and its related features can be resolved in a real time mode.

-In this study, a new blood pressure measuring system was proposed and implemented. An additional small-cuff was placed on the center of a inner cuff to measure morphological signals and new oscillometric ratio. The proposed BP-measuring system is composed of an external cuff, an inner cuff and a small-cuff. Oscillation signal from small-cuff is interpolated with 7th-order fitting polynomials and SBP, DBP ratio were 22.2% and 87.7%. Experimental data were gathered from 20 volunteers (25±4 years) and arterial blood pressure values were compared with auscultation, sphygmomanometers, small-cuff and inner-cuff. As a result, the difference in systolic BP between auscultation and the small-cuff was 1.93(±1.28) mmHg, and the inner-cuff was 4.53(±4.39) mmHg, and sphygmomanometer was 6.68(±3.99) mmHg, and the corresponding difference in diastolic BP was 2.50(±2.04) mmHg, 3.50(±3.19) mmHg, 7.35(±5.62), respectively.