Fiber optic sensor for heart rate detection

The principle of operation, design aspects, experimentation and performance of an extrinsic fiber optic sensor using fiber optic displacement sensor for the measurement of amplitude and frequency of heart rate signal is presented and investigated. The displacement sensor consists of fiber optic transmitter, fiber optic bundled probe and photodiode detector and an artificial electrocardiogram (ECG) signal is used in the testing. The sensitivity of the sensor is found to be 0.002 mV/μm and thus it is capable of measuring heart rate from 50 bpm to 300 bpm with linearity more than 99%. The simplicity of the design, high degree of sensitivity, dynamic range and the low cost of the fabrication make it suitable for real field applications. Moreover, accuracy and reliability are the excellent pay-offs of this fiber optic sensor.