A Wearable Ultrathin Flexible Sensor Inserted Into Nasal Cavity for Precise Sleep Respiratory Monitoring

A wearable flexible sensor fabricated on an ultrathin substrate is proposed for sleep respiratory monitoring in nasal cavity. The sensitive unit is composed of aurum multiturn microcoil fabricated on the surface of a polyimide catheter by the rotated lithography system, and the signal measurement is based on the principle of thermal resistance. The signal simulation and performance tests of the respiration sensor have been conducted, which demonstrate that the sensor has great performance in anti-interference, response speed, sensitivity, durability, and stability in long-time usage. The practical human tests in various simulated respiratory disease situations, mainly including apnea and hypopnea, display clear differences between normal and abnormal breathing signals measured by the sensor. The respiratory signals measured by this sensor can be utilized to analyze the various respiratory disease conditions. The presented wearable ultrathin flexible respiratory sensor has shown great potential for preliminary diagnosis of sleep respiratory diseases and sleep health monitoring.