Dear Customer,
It is widely known that despite being in the same hand, different fingers can show different SPO2 readings. The middle finger tends to show the highest readings of all the fingers in the same hand.On top of this, the dominant hand of a person is another factor. The readings tend to be higher in the dominant hand. The middle finger in the dominant hand is generally regarded as the one with highest and most accurate readings.
I believe you are aware that the readings in different fingers in the same hand can be different despite being in the same hand. But, going by your logic all fingers in one hand should have the same reading especially when they are so close to each other. However, this is not true, the readings can vary between finger to finger, be it in the same hand or the other hand! If the readings between the fingers in the same hand can vary despite being so close to each other then surely the readings in the same finger but in the other hand can also vary.
The logic here is somewhat similar to body temperature readings being different to each other depending on from where the reading have been taken. Also, other factors like – trembling of the finger, body movement, finger not inserted deep enough, unclear finger nail, low perfusion, cold finger, low haemoglobin, putting it on a limb with blood pressure cuff or an I.V catheter etc will also cause or add to the disparity.
The disparity between the readings is known to be there and in fact the product is doing it’s job by showing the results as expected. The product is completely ok.
With regards
Four Square Healthcare Ltd