基于光纤传感的生理参数监测系统研究

Research of Physiological Monitoring System Based on Optical Fiber Sensor

常规生理参数监测系统由于测量时接触皮肤,因此舒适感差、个体依从性差。为解决上述问题,该文基于生理的微弱运动可致光纤微弯曲变形进而致光强度发生变化的原理,研制了新型的基于光纤传感的生理参数监测系统。该系统通过光探测器自适应地检测细小的光强变化获得心冲击图(BCG)信号,利用信号处理算法获取心率、呼吸率和体动等信息;把光纤嵌入床垫或坐垫设计为三明治结构,既保护了光纤又增强了系统的可靠性和稳定性;采用蛇形返折走线将光纤均匀地分布在垫子中间,使系统具有高灵敏度。通过多家医院临床标准方法对比测试可得在95%的置信区间(±1.96SD)内该系统心率均值误差为–0.26±2.80次/min,与标准值之间的相关性为0.9984;呼吸率均值误差为0.41±1.49次/min,与标准值之间的相关性为0.9971。实验表明,研制的系统可在零负荷的状态下无感进行生理参数测量,在健康医疗领域具有广泛的应用前景。

Conventionally, the physiological monitoring system obtains singnal by electrode or bandage which is connected with skins and has disadvantages such as： uncomfortable and bad compliance to users. In order to overcome those problems, a new physiological monitoring system, which is based on the principle that micro bend of optical-fiber induced by weak movement of physiology can change the light intensity to get BallistoCardioGram （BCG） signal, is developed. In such system, the respiration rate, heart rate and body movement are obtained by self-adaption detecting the tiny variation of light intensity. In order to protect fiber and enhance the stability and reliability of system, the fiber is embedded into mattress or cushion with a sandwich structure. Simultaneously, it makes the system have high sensitivity that the fiber is uniformly routed with serpentine-curve shape in the middle of mattress or cushion. It is illustrated by the measurement in several hospitals that the mean error of heart rate is 0.26±2.80 times/min within 95% the confidence interval （±1.96SD） with a correlation 0.9984 to the standard values. It is exhibited as well that the mean error respiration rate is 0.41±1.49 times/rain within 95% the confidence interval （±1.96SD） with a correlation 0.9971 to the standard values. It is suggested that the developed system can be senselessly used under zero load and is promised in future.