Good discussion. Thanks guys. Just for fun I read an article in the March 30 Lancet that contains a definition of "critical" with respect to viral pneumonia such as COVID-19:

"The case definition adopted in China and elsewhere includes further
stratification of cases as severe (defined as tachypnoea [≥30 breaths per min], oxygen saturation ≤93% at rest, or PaO2/FiO2 ratio <300 mm Hg)."

I'm not a doctor, just a dumb pilot. But I do like to read! :)

O2 meter
 

My condolences to Allan, it?s a hard road. I was on a trip to Sheridan, Wy. With my wife, 63 years old, non, smoker. We checked her O2 level because she didn?t feel well and she had lived in Wyoming most of her life. Her O-2 was 85. One month later, back in Texas she was diagnosed with lung cancer and died 93 days later. The O-2 level was the first indication of a problem. She was in good physical shape.

Know what your normal is at home elevation. As you may have heard, one of our RV formation leads (Yobo) tracked his 02 from a normal of 98 down to 90 and was admitted when it dropped into the 80s. Was placed on ventilator within 24 hours. Has been unconscious on vent. for 6 of the typical 10-14 days if things go right.
Pulse oxymeter is another great tool just like a thermometer. Prayers for Yobo appreciated.

That's it, first the water and toilet paper, now the oxygen sensors. You guys gotta quit hoarding this stuff!

Pssst, Hey Allan, I want one too!

-Marc

I bought one over the summer for $20. Can't find one on amazon now for less than $60. So much for amazon's pledge to prevent their partners from gouging.

Larry

Ok. I've got an S 7 edge. But darn if I can find what you're talking about. Looked everywhere. Can you help? maybe with a private email?

You can download the app from the playstore. It resides in the Samsung App folder. I don't know how accurate it is but it does seem to work. It's the "stress test".

Apple too
 

For those that drink from the Apple, there is an app, Pulse Oximeter, that
uses the camera and flash. $4.99 at the app store.

O2 meter & Samsung Galaxy S7
 

Checked my Samsung Galaxy S7 with Samsung Health app.

Elevation: 600 ft - close to DFW airport
O2 reading: 99%
Heart Rate: 47 bpm

Need to hoard another device to verify readings :).

After measuring I jumped to my running shoes and went running for little over 11 miles.

I saw once at Aldi selling O2 / Heart Rate finger readers for $18.

Stay safe!

A quick google search reveals the bulk of the medical community agrees with you. I found none that recommended their use and a few that recommended against using them as a home Covid-19 diagnostic tool, for a variety of reasons.