7.3 - Measuring the Process

Question 1

What is a peak flow meter?

Answer 1

Simple device that measures the rate at which air can be expelled from the lungs

Question 2

What are vitalographs?

Answer 2

Patient being tested breathes out as quickly as they can through a mouthpiece and the instrument produces a graph of the amount of air they can breathe out and how quickly its breathed out

Question 3

What is a spirometer?

Answer 3

Used to measure different aspects of the lung volume or to investigate breathing patterns

Question 4

Define vital capacity

Answer 4

The maximum volume of air that can be taken in or expelled from the lungs in one breath

Question 5

Define tidal volume

Answer 5

The volume of air we breathe in and out during each breath at rest

Question 6

Define breathing rate

Answer 6

The number of breaths we take per minute

Question 7

Define residual volume

Answer 7

The volume of air that is left in your lungs when you have exhaled as hard as possible

Question 8

Define total lung capacity

Answer 8

Sum of the vital capacity and the residual volume

Question 9

Explain how a spirometer works

Answer 9

• there is a oxygen filled chamber with a movable lid
• person breathes through a tube connected to the oxygen chamber
• as the person breathes in and out the lid of the chamber moves up and down
• this writes on a rotating drum creating a spirometer trace
• the spirometer can be hooked up to a motion sensor - will use the movement to produce electronic signals which are picked up by the data logger
• the soda line in the tube the subject breathes into absorbs the carbon dioxide
• the total volume of gas in the chamber decreases over time this is because the air that’s breathed out is a mixture of oxygen and carbon dioxide
• the carbon dioxide is absorbed by the soda lime so there’s only oxygen in the chamber which the subject inhale from
• as this oxygen gets used up by respiration the total volume decreases