Without advanced imaging equipment RV cannot be measured in a human in vivo. It's often *estimated* from forced vital capacity, which can be measured using a spirometer. There are (less expensive) stand-alone spirometers that simply report lung volumes, or the pneumotach (or other flow meter equivalent) on an indirect calorimeter ("metabolic cart") can be used. Also common is the *estimation* of RV using the patient's anthropomorphic data. These equations, as well as the FVC spirometry protocols, are all easily accessible via a simple google search.
Would you so kindly reply to the other questions asked? There really wasn't any calculations shown on figuring out what her bmi was, just how much she weighs. Thank you. I understand this video is over 10yrs old and so are the questions but you replied to one here that was only 3yrs ago. Is there another video we should follow up with that answers other's questions and how to calculate the BMI?
I have a hard time believing that she weighs 12.6 kg underwater either---aren't most people pretty close to neutral buoyancy? Is that the weight of the chair? Also, there is no difference between her mass in air and her mass underwater and her mass in outer space. Mass is not weight and is not buoyancy and is not force, but independent of those things! I think you may want to say "weight".