# Homework Help: Help with Respiratory Physiology calculations

1. Nov 28, 2015

Hi,
I have recently conducted a Respiratory physiology practical, where i measured the lung v0olumes and capacities, using the technique of spirometry. I therefore recorded the FEV1, FVC, FER AND PEF values from the spirometry.
However, i also had to collect and analyze the expired air; using a douglas bag and using the paramagnetic analyser, where i measured the oxygen concentration of the expired air collected in the bag for 3 minutes and also the volume of air remaining in the bag,and the number of breaths in one minute.

Anyway, i have jotted these recordings down. These are seen in the table rows 1-3, on the attached worksheet. However, i need help with the calculations of the variables in rows 4-6, these are: the exhaled minute volume , tidal volume, and oxygen exhaled rate.
I have attempted to work these out; the answers are shown in the 'rest' and 'exercise' columns.

Here are my workings out:

Exhaled minute volume:
I did: the total volume of expired air/ 3 minutes = rest (29.97) exercise (63)
(NOT SURE IF I WAS MEANT TO USE MINUTES OR CONVERT TO SECONDS?)

Tidal volume ATPS (L)
i did: Exhaled minute volume/no. of breathes in one minute
So: rest= 29.97/51=0.59
exercise= 63/59=1.07

Oxygen exhalation rate ATPS (ml min^-1)
Rest: 89.9/100 x 19.9 = 17.8901 x1000 /3 =5963.37
Exercise: 189/100 x 18.6 = 35.154 x 1000/3 =11,718

I tried to follow the instructions for working out the calculations as seen in (a), but i'm really not sure i've worked these out right?! As i am getting confused with all the different ways to calculate, for example the tidal volume.

I would like if you could look at these and help me out, letting me know if ive done these correctly!

Also, at the bottom of the worksheet it says about converting ATPS not sure if i was meant to do this or not..

Thanks a lot! And apologies for my messy handwriting in the worksheet!

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2. Dec 3, 2015