基于胸阻抗法的穿戴式呼吸检测方法研究

Research on Detection Method with Wearable Respiration Device Based on the Theory of Bio-impedance

针对人体呼吸信号检测的重要性,基于Cole-Cole生物阻抗模型,研制了一种可穿戴的呼吸信号检测装置。以Cole-Cole生物阻抗理论为基础,分析了人体在不同频率电信号下的阻抗特性。基于比例测量法设计了高信噪比的呼吸信号采集与调理电路。利用离散傅立叶变换(DFT)和动态差分阈值峰值检测技术从获得的数据中提取呼吸波形与呼吸率数值。通过实验验证了系统的有效性。测试结果表明,本系统可以准确检测呼吸波形,呼吸波形峰值点检测准确率在98%以上,可以满足实际呼吸检测需要。

Considering the importance of the human respiratory signal detection and based on the Cole-Cole bio-impedance model, we developed a wearable device for detecting human respiratory signal. The device can be used to analyze the impedance characteristics of human body at different frequencies based on the bio-impedance theory. The device is also based on the method of proportion measurement to design a high signal to noise ratio （SNR） circuit to get human respiratory signal. In order to obtain the waveform of the respiratory signal and the value of the respiration rate, we used the techniques of discrete Fourier transform （DFT） and dynamic difference threshold peak detection. Experiments showed that this system was valid, and we could see that it could accurately detect the waveform of respiration and the detection accuracy rate of respiratory wave peak point detection results was over 98%. So it can meet the needs of the actual breath test.