呼吸信号检测用PVDF压电薄膜传感器设计

Design of Respiratory Signal Detection System with PVDF Piezoelectric Film Sensor

针对呼吸信号对人体的重要性,研究设计了一种基于PVDF压电薄膜的呼吸传感器,阐述了该呼吸传感器的设计与制作过程。根据呼吸信号特点,设计了相应的信号调理电路,通过检测人体呼吸过程中口鼻之间的气流对PVDF压电薄膜的弯曲变形,获得了稳定的呼吸信号。采用小波软阈值对原始信号去噪,通过设置波峰电压阈值与相邻两波峰间的时间间隔来准确确定波峰,统计了受试者的呼吸次数。实验结果表明基于该PVDF压电薄膜传感器组成的检测系统能够测得稳定的呼吸信号。

This ppaer makes a study of the respiratory sensor with PVDF piezoelectric film,describes its importance for human beings and its procedures of design and fabrication.And designs its corresponding conditioning circuits according to the characteristics of the respiratory signals.The respiratory signal is achieved by detecting the bending deformation derived from the airflow between the nose and mouth during expiration and inspiration.Soft threshold algorithm based on wavelet transformation is adopted in cancelling the noise.Then the peaks were exactly determined by setting voltage threshold of peaks and the interval of two adjacent peaks.In this way,the number of breaths is obtained.Experimental results reveal that the detection system with PVDF piezoelectric film sensor can be used to measure stable respiratory signals.