PPG Body Electrical noise and metal contact

Atul Priyadarshi

Other Parts Discussed in Thread: AFE4403

Hello all, Just curious that what are the effects of 50Hz electrical ambient noise from human body on PPG sensors (these cause effect on ECG sensor)? Are these noise captured along with PPG by AFE? Also, enclosing AFE and PPG setup in a metal containment(metal watch) can cause some effects on the signal from ppg sensors? Thanks Atul

over 9 years ago

0 Praveen Aroul over 9 years ago

TI__Mastermind 49766 points

Hello Atul,

Yes the 50 Hz power line interference can easily couple into the PPG signal.
If the coupling is from the contact with the human body or from the RF radiation within the metal containment, then that might affect the PPG signal as well. Common mode chokes might alleviate some of the RF interference.

0 Atul Priyadarshi over 9 years ago in reply to Praveen Aroul

Intellectual 845 points

Hello Praveen,

Is grounding the back metal plate, which is in contact with the body a way to reduce to this coupling noise?
About the common mode choke, Can you give me some reference design to use this common mode choke to reduce the noise?

Thanks

0 Amy Schnoor over 9 years ago in reply to Atul Priyadarshi

TI__Mastermind 18285 points

Atul,

The AFE4403 EVM has a choke that we used. It is L1.

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PPG Body Electrical noise and metal contact