A Continuous Respiratory Monitoring System Using Ultrasound Piezo Transducer

Prolonged monitoring of breathing under different physical conditions is important in many applications for personal health tracking or in hospitals. Ultrasound technology has been used widely for imaging and diagnosis of the human body. In this work, we introduce the use of ultrasound for human respiratory monitoring. The proposed system measures the respiration rate by capturing ultrasound reflections from heart and surrounding organ motions due to the breathing. This system is based on ultrasound B-mode to measure the Time Of Flight (TOF), amplitude and phase of reflected ultrasound signals generated by piezo sensors working at 1 MHz. Experimental results show that the system can obtain respiratory signal with an accuracy of 89% as compared to a SPR-BTA spirometer. A prototype is designed with low complexity hardware, delivering 89% accuracy of the obtained respiratory signal in comparison to a SPR-BTA spirometer.