After some advice, my son has had ongoing issues with dropping sats levels as low as 74/75 but normally self resolves. He often suffers with chest infections and we think he is aspirating. He was in hospital for monitoring and his sats would drop to 91/92 and heart rate ok even at 85 oxygen level but when sats were good I would notice heart rate to 140+ is this normal for a 13 month old? Also does anyone know of any good mobile sat monitors that are reliable?