I have been a reader and member of this website for a few years now. I have gained a huge amount of knowledge as a result. Thank you for putting together this regular newsround brief in a factual manner. The whole website is invaluable. Once again, thank you.
Pulse oximeters traditionally have worked by passing a spectrum of light through the skin, typically a finger or ear lobe, or the foot on a newborn. The light is shone through and picked up on the opposite side. The amount of light absorbed is calculated and a reading of oxygen is determined. Unless the technology has changed I would find it hard to see how a smart phone could measure oxygen saturation. But I am not an expert on Samsung phones. edit Having looked quickly at a video demonstrating the feature it may well be a development. It will not be a hospital grade reading, but regular readings and tracking when healthy would give you a trend. Remember, poor circulation, dirty sensors, ink stains on skin can cause questionable readings.
The Prepared has been on my favourites browser for about three years. I am so relieved that I took some simple steps about being prepared to shelter in place a few years ago. Water, generator, food and soap! Hand sanitizer added at the beginning of the year. About ten days ago I ordered a pulse oximeter (former RN, so I know the value of them). These are worrying times…but I am so grateful for the actions I took a while ago as a result of the advice I read on this website. Thank you to all the contributors. Stay safe and healthy.