how to calculate the ratio between the maximum and minimum peaks of the two waves using two while loops?

[rai154]

hello everyone,

i'm rai from indonesia

I have a final project about pulse oximetriy, I have some problems,

how to calculate the ratio between the maximum and minimum peaks of the two waves using two while loops to calculate SpO2 ?
My program image can be seen below predicament ? 

[altenbach]

Duplicate. Please keep it all in one place.