基于聚偏氟乙烯薄膜的穿戴式呼吸检测系统

Development of a wearable respiration detection system based on polyvinylidene fluoride film

针对人体呼吸信号的特点设计一种基于聚偏氟乙烯(PVDF)压电薄膜材料的可穿戴式呼吸检测系统。人体呼吸时PVDF薄膜受力产生的感应电荷较少,经信号调理电路将电荷量转换成电压量。单片机通过模数转换器获得呼吸信号数据,通过蓝牙发送给上位机。上位机从获得的数据中提取呼吸波形,并进行平滑滤波、自适应双阈值来计算呼吸率。试验结果表明,本系统可以实时准确地检测出人体的呼吸波形,呼吸次数识别的准确率在90%以上,可以满足人体呼吸监护的需求。

In view of the characteristics of human respiratory signals,a wearable respiration detection system based on polyvinylidene fluoride(PVDF)piezoelectric film is proposed.The induced charge collected from human respiration by a PVDF thin film is relatively weak,and converts to the voltage by signal conditioning circuit.The microcontroller obtains the respiratory signal data through analog-to-digital converter,and sent to the host computer via Bluetooth.The host computer extracts the respiratory waveform from the obtained data and calculates respiratory rate via smooth filtering and adaptive dual-threshold technique.The experimental results showed that the system can accurately detect the respiratory waveform of the human body,and that the accuracy rate of the recognition of the number of breaths is above 90%,which meets the needs of human respiration monitoring.