Lung Movement Detection Method using Sound Waves for Continuous Breathing Monitoring

In health care, the continuous breathing monitoring device has not been popular yet, albeit personal daily breathing monitoring is expected to be used for the diagnosis of sleep apnea syndrome, stress management, and depression prevention. With the aim to realize personal and continuous breathing monitoring, this paper proposes a lung movement detection method that uses sound waves. This method has advantages of low cost, use of a small-scale and simple device, and easiness in wearing. The proposed method can sense lung movement only by a vibration speaker and a contact microphone placed on user’s chest and use the measured parameters in the sound signal processing. In this paper, the waveform comparison of the lung movement measured by the proposed method and the displacement of the thoracic diaphragm in breathing was conducted, and it was confirmed that the proposed method could capture lung movement in breathing with a high correlation.