Youngsun Kong

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Two parameters that a breathing status monitor should provide include tidal volume (<inline-formula> <tex-math notation="LaTeX">$V_{T}$</tex-math></inline-formula>) and respiration rate (RR). Recently, we implemented an optical monitoring approach that tracks chest wall movements directly on a smartphone. In this paper, we explore the use of such noncontact(More)
Some smartphones have the capability to process video streams from both the front- and rear-facing cameras simultaneously. This paper proposes a new monitoring method for simultaneous estimation of heart and breathing rates using dual cameras of a smartphone. The proposed approach estimates heart rates using a rear-facing camera, while at the same time(More)
This paper proposes an indoor positioning system for walking people using Bluetooth RSSI with an accelerometer and a barometer on a smartphone. Basically, the step detection method is utilized with direction data for indoor location analysis. To estimate the moving distance of a pedestrian, signals are acquired from an accelerometer and a magnetic sensor on(More)
A smartphone-based tidal volume (V(T)) estimator was recently introduced by our research group, where an Android application provides a chest movement signal whose peak-to-peak amplitude is highly correlated with reference V(T) measured by a spirometer. We found a Normalized Root Mean Squared Error (NRMSE) of 14.998% ± 5.171% (mean ± SD) when the smartphone(More)
Correct labeling of breath phases is useful in the automatic analysis of respiratory sounds, where airflow or volume signals are commonly used as temporal reference. However, such signals are not always available. The development of a smartphone-based respiratory sound analysis system has received increased attention. In this study, we propose an optical(More)
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