Photoplethysmography sensor can be used to measure heart rate

oxygen saturation

respiration rate

and so on.Because of the limitation of the detecting location and the sensibility to the movement interference

it is developed for clinical application as usual

but not as home-appliance medical device.Thus

the sensor structure including LED and PD is redesigned to enhance the signal intensity

the detecting location on ear is selected by the comparison experiment

and also the 3-axis acceleration sensor is implemented to acquire the noise source for the adaptive filter which can weaken the movement interference in wallking and running state

and the heart rate can be calculated.After a sequence of activities experiment on human body

using ECG device as reference

the accuracy rate of the heart rate calculation is verified.