PVDF 필름 기반 센서를 이용한 무구속적인 누운 자세 추정

Abstract

Abstract: As body postures on bed affects various sleep related diseases, it is considered as important informationwhen monitoring sleeping in daily life. Though there have already been a few approaches to monitor body postureson bed conventionally, the development for simple and unconstrained methods is still needed to realize the long-termdaily monitoring. Focusing on the fact that ballistocardiogram changes depending on the body postures on bed, wedeveloped a novel method to estimate body posturesusing extremely simple, film-type ballistocardiogram sensorwhich is based on polyvinylidene fluoride(PVDF) film. With 10 subjects, we performed two experiments. One wasfor an estimation test to show that body postures on bed can be estimated by ballistocardiogram, and the other wasfor a reproducibility test to present the feasibility of ballistocardiogram based body postures monitoring. To estimatebody postures on bed, we made an individual template set of body postures by designating one ballistocardiogram(BCG) sample as a template in each postures. Then, we calculated Pearson’s correlation coefficients between a sam-ple and each templates and estimated the body posture of the sample by choosing a posture which corresponds tothe most significant correlation coefficients. As a result, we estimated body postures on bed with 99.2% accuracyin average and found that the estimation using ballistocardiogram is reproducible. Key words: Ballistocardiogram, sleeping position, PVDF film sensor