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Pulse Ox sleep readings are NOT accurate

SHINEW
over 4 years ago

MightySat Overnight Pulse Ox

Recently upgraded to the Fenix 6x Sapphire. Loved everything about it but the overnight Pulse Ox reading showed that I was frequently in the low 80s, and I'm at sea level! So that made me worry a bit... I searched online to see if anyone has done an actual comparison with an accurate SpO2 meter during sleep but couldn't find any result.

Good thing that I have a hospital-grade SpO2 fingertip sensor to compare to, so I did a few nights of recording for comparison and this is what they look like when compared side by side, the hospital-grade SpO2 showed one short event of lowest oxygen saturation at 91%, my Fenix 6x Sapphire showed several occurrences of low 80s throughout the night.

Bottom line, the PulseOx feature should still be valuable for altitude adaptation, but don't freak out if you see your Garmin watches showing your oxygen saturation in the 80s, it's most likely inaccurate. it certainly is not for me :)

  • 0 over 2 years ago

    Can anyone share the hospital-grade SpO2 fingertip sensor their using? The pulse ox levels during sleep on my Garmin are scary!

  • 0 over 2 years ago

    Thank you so very much for this! Pray 

    I have been monitoring mine lately with only my Fenix 6 (no other sensors), and have had an almost identical experience with it - drops into the low 80s at night, and never has it been above 96%... the one cross reference I do have is a brief stay in the hospital for a kidney infection, I was of course on the hospital's monitor and was ~ 99-100% the whole time. 

  • 0 over 1 year ago in reply to jillcashworth

    I use the Fenix 6 Pro, I find the blood oxygen to be very erratic, I can do spot reading that that are -5 +5 of each other within minutes. Sleep OX is random, nearly always low 80's at times. Medical grade monitor I have is much more consistent, One other thing to note is skin colour, not sure how Garmin came to their conclusions but quite often different skin colour is not always considered, this can make a difference to accurate readings as it uses light to take the measurement.