Problems with the ECG - Psoc 4

[RoFr_4201436]

Hello there,

I'm trying to create an electrocardiogram on psoc 4, using a TCRT5000 Reflective Optical Sensor. But when I analyze the data in a graph, a strange thing appears, because I think that when I put my finger on the sensor, the signals should go up and when I take them out, the signals should decrease, but the opposite happens, as in the image:

Someone can help me?

My circuit:

[EvPa_264126 · Accepted solution]

Perhaps this inclusion requires a more careful selection of the resistor(4.7 k), for example, to increase to 8-20K.
The voltage on the transistor collector should be in the region of 2-3V with and without a finger.
Usually, such an inclusion has poor thermal stability.
It makes sense to use a scheme with a common emitter: datasheet page 11 figure 11.
And, I hope you know that you will have a heart rate sensor and not an ECG.