Can not measure heart rate using AFE4400 because of noises

Hi everyone,

I want to do a small project related to measuring HR using AFE4400.

But the problem is that my received signal contain a lot of noise. I can't filter out HR pattern using these signal.

Below is my configuration for AFE4400:

Reg addr: 0x20,   Value: 0x000000          //default value

Reg addr: 0x21,   Value: 0x000005        //Ambient DAC 0uA, stage 2 amplify disable, stage 2 gain 0 dB, Cf= 5 pF, Rf=  10k

Reg addr: 0x22,   Value: 0x018888       ///turn on LED current on LED1 and LED2, value = 26mA

Reg addr: 0x23,   Value: 0x020100      //config: LED H-bridge,

My sampling rate is 100Hz.  LED is LP120-2 and photo-diode: LP8894

Can you guy give me any suggestion to improve my result.

Thanks so much