可穿戴式非接触心率监测传感器及心率异常分析研究

Cardiac disease have the characteristics of chanciness and paroxysmal，so the long time detection and analysis of ECG signals are indispensable. Heart Rate Variability (HRV) analysis based on RR interval of ECG signal is of paramount importance in study and predicts heart disease. Heart rate detection and Heart Rate Variability Analysis is an easy and valuable measure to study and predict heart disease. Currently, the ambulant heart rate sensor based on ECG signals are detected with wet electrodes of Ag/AgCl, which has the disadvantage of long preparation time, discomfort and accuracy decrease with the drying of the electrolyte. A new kind of non-contact heart rate sensor and real time HRV analysis system were proposed in this project, the sensor has integrated active electrodes and the ECG signal is detected through the capacitive coupling between the skin and active electrodes. This new ECG heart rate sensor has the advantage of short preparation time, long time reliable detection, repeating use and eliminating of the wet electrolyte etc. A new kind of sensing dry electrodes will be studied in detail; the static noise engendered by the friction will decrease dramatically with a new cushion layer on the sensing electrodes, which can control the local humidity around the electrodes. A new kind of input capacitance counterbalance circuit structure was adopted to decrease the front amplifier gain variation caused by electrodes displacement，thus minimize the motion drift effect caused by body movement. The false heart rate alarm will be decreased dramatically through on line reliability index computation based on collected ECG wave and 3D accelerometer data. The influence of slight displacement between the skin and electrodes on detection accuracy will decrease dramatically through the optimization of the sensor wearing structure. This new kind of non-contact wireless heart rate sensor and real time HRV analysis system corresponds to the low cost medical treatment trend, has great potential to be easily popularized among community and family.

心脏病的发病有很大的偶然性和突发性，基于心电RR间期的实时逐拍心率监测与心率异常分析是研究和预测心脏病的重要手段。当前用于动态心率监测的心电电极都是Ag/AgCl 湿电极，具有准备时间长，长时间监测时存在皮肤敏感不适，电极干燥影响监测精度等问题。本课题提出一种新型的具有集成有源敏感干电极的非接触式实时逐迫心率监测方案，并在线实时进行心率异常分析，探索为心脏猝死等心血管疾病的监测与预警提供有效手段。心率监测传感器电极与皮肤之间通过电容耦合，具有准备时间短、可重复使用、可长期可靠监测、舒适度高等优点。本课题研究的非接触式实时心率监测传感器，通过在敏感电极的表面增加缓冲层控制局部湿度环境的方法，大大降低由于摩擦引起的静电干扰对心率监测的影响；通过输入电容抵消结构，减小由于电极位移引起的系统增益变化造成的基线漂移和伪迹干扰；通过结合运动状态在线计算心率采集的可靠因子，降低心率超限报警的误警率。

心脏病的发病有很大的偶然性和突发性，基于心电RR间期的实时逐拍心率监测与心率异常分析是研究和预测心脏病的重要手段。当前用于动态心率监测的心电电极都是Ag/AgCl 湿电极，具有准备时间长，长时间监测时存在皮肤敏感不适，电极干燥影响监测精度等问题。本课题提出并实现了一种新型的具有集成有源敏感干电极的非接触式实时逐迫心率监测传感器，并可以在线实时进行心率异常分析，为心脏猝死等心血管疾病的监测与预警提供了有效手段。心率监测传感器电极与皮肤之间通过电容耦合，具有准备时间短、可重复使用、可长期可靠监测、舒适度高等优点。通过建立等效电路模型，对非接触式心率监测传感器的敏感结构和输入电阻、输入电容等关键参数进行了优化设计。研制的非接触式实时心率监测传感器，通过在敏感电极的表面增加缓冲层控制局部湿度环境的方法，大大降低了由于摩擦引起的静电干扰对心率监测精度的影响；通过输入电容抵消结构，减小了由于电极位移引起的系统增益变化造成的基线漂移和伪迹干扰，并通过五点滑动平均滤波、梳状滤波和小波去噪等方法进一步降低了环境噪声和基线漂移对心率监测精度的影响；通过结合运动状态和心电波形的信号质量在线计算心率采集的可靠因子，降低了心率超限报警的误警率。针对不同的应用场景分别开发了个人计算机版的和安卓智能终端版的实时心率异常分析程序。这种新型的非接触式的心率监护系统与当前国家大力倡导的低成本医疗十分契合，特别适合向社区和家庭等非专业人群推广。