Electrical isolation and safety for EOG project using AD8232 and LPC845-BRK

[Benc-X99]

Hello Everyone, I'm in an EOG signal processing project with the LPC845-BRK and the AD8232 for acquiring the EOG signal (yes i know it is originally intended for ECG signals but i think it still works for EOG), I was wondering about the electrical safety, it's my first project with electrodes so I'm not sure what safety precautions i have to take, the AI recommended the ADUM4160 but I'm not sure that would work for me, help is appreciated thanks.
PD:(my house has no ground connection) :'(.

[jonpaul]

Isolation for patienmt connected electronics requires special transformer insulation or medical rated mains PSU.

Danger is from leakage current esecially for patients with pacemakers.

DUE TO RISK OF LIABILITY ANF LEAGAL ACTION CONSULT YOUR COUNTRIES LAWS AND REGUOATIONS AND A COMPLIANCE SPECIALIAST

Do not depend on a forum for safety related issues.

Jon

[Benc-X99]

Hi Jonpaul, thanks for your reply. The project I'm working on is for educational purposes only; no patients will be involved.

[Gyro]

The only relatively acceptable approach would be to power it from a battery and house the whole thing in a plastic enclosure. Captive leads would also be desirable (and preventing accidental disconnection of one or more leads, while the others are still connected). Anything else would need to be properly medically certified equipment (even this would need a to be in a an environment with a proper mains ground). I don't know how practical this would be, for you? A built-in screen? Logging to an SD card? Maybe Bluetooth?  You would also need to completely prevent any contact with mains powered equipment (eg. Physically blocking connection of a USB charger for an internal Lithium battery when it's in use).

As as upside, battery power would free you from a lot of mains leakage current noise pickup.


EDIT: Looking at the Analog devices article on ECG circuitry, it recommends 220k series safety resistors for the electrodes for the battery powered circuit... https://www.analog.com/en/resources/analog-dialogue/articles/ecg-front-end-design-simplified.html

P.S. I can't have any direct control of what you implement, or your skill level, so this shouldn't be regarded as safe advice.