反射式红外光电肌肉收缩传感器设计

Design of IR optoelectronic muscle contraction sensor in reflection mode

利用光体积描记法(PPG)的优点,设计了反射式光电肌肉收缩传感器电路。用可编程恒流源驱动红外LED发出红外光照射到肌肉组织中,光在肌肉中经过"香蕉状"的传输路径最终散射出来,出射光强与肌肉的收缩程度相关。光电探测电路将微弱的出射光信号转换为电信号。经过后继滤波和放大电路处理后,由单片机进行AD采样。经测试,电路的各参数符合预期。运用设计的电路检测肱二头肌的等长收缩,经过两种手臂姿态的测试和分析,电路的输出信号可以反映出肌肉的收缩程度。

Use the advantage of photoplethysmogram(PPG),an IR optolelctronic muscle contraction sensor circuit in reflection mode is designed.An IR LED driven by a programmable current source emits into muscle tissue.The IR light transmits in a“banana shape”path and finally scatters out of the skin.The output light intensity is relevant to the contraction degree of the muscle.The optolelctronic detection circuit transform the tiny outgoing light signal into electrical signal,after subsequent filtering and amplification processing,AD sampling is carried out by microcontroller unit(MCU).The result shows that each parameter of the circuit is as expected.The circuit is used to detect isometric contraction of biceps brachii.By measurement and analysis on two arm postures,the output signal can reflect the contraction degree of the muscle.