摘要
用红外发光二极管和光电二极管组成的光耦合指套,放置在人身体的指尖部位,通过检测人体末梢组织在动脉舒张和收缩时对红外光的吸收度变化率,来检测人体动脉血压信号的异常.红外发射二极管的驱动采用PWM信号调制的恒流驱动,光电二极管接收穿透人体后的红外光并转换成微弱的电信号,再经过前置放大、倒相、压控二阶低通滤波、陷波电路、A/D转换等处理后,MCU从采集的数据中提取有关动脉血压信号的特征值,实现血压信号异常的无损连续监测.
An optical coupling finger stall, composed of IR LED and photo-diode, is placed at fingertip, when the IR transmission light intensity across a finger changes with the diastole and systole of arterial blood pressure, the inverter current of photo-diode varies. Therefore, the arterial blood pressure anomalies can be detected according to the changes. The drive current of IR LED, controlled by PWM is constant in the process of detection. The voltage signal converted by photo-diode is very week, so that it can easily be disturbed. The signal must be processed by the pre-amplification circuit, second order filter circuit, and wave trap. Finally, the data from A/D converter is collected and processed by MCU.
出处
《深圳职业技术学院学报》
CAS
2015年第1期23-26,共4页
Journal of Shenzhen Polytechnic
基金
中国科学院深圳先进技术研究院合作项目(6014.26K201164991)
