We are using the AFE4300 chip to perform bioimpedance measurements on the human body. However, during testing in a hospital environment, we consistently observe abnormally high impedance readings. After thorough investigation, we suspect the issue is caused by electromagnetic interference (EMI) from nearby large-scale medical equipment (e.g., MRI, CT, etc.).
This interference appears to affect the analog front end, causing a shift in measured impedance values, particularly an increase in resistance. The same setup in a non-hospital environment performs as expected, which further supports our EMI hypothesis.
We would like to ask:
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Has TI observed similar EMI-related issues in AFE4300 applications?
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Are there recommended PCB layout strategies, shielding, or filtering techniques to mitigate such interference?
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Would adjusting the PGA gain or sampling frequency help reduce sensitivity to this kind of EMI?
Any guidance or suggestions from the TI team would be greatly appreciated.
