Pulsoximeter with perfusion index or not?

[linusbert]

i'd like to acquire a pulsoximeter for better precision because my apple watch o2 monitor isnt that accurate. it sometimes shows 91% ... then a few sec later 100%...
therefore i want to get something precise.

but there are some devices which show perfusion index. and i wonder, do i need to get the PI or doesnt it have any worth for us?

i am looking at
bistos Pulsoximeter BT-710 (with PI)
and Nellcor PM10N (without PI?)
and masimo set (with PI and more)
or any suggestions?

i also want to monitor while sleeping. and it must be precise at that.

there is this thread
https://forums.phoenixrising.me/thr...vel-indicator-for-cardiovascular-death.83717/
and
https://forums.phoenixrising.me/thr...ry-in-nervous-system-and-muscle-tissue.80693/
suggesting usefulness for PI.

maybe this can be even a indicator if things are improving? better PI = improvement? also the other way around.