Measuring Ventilation

What is a spirometer

Instrument that measures lung volumes using a chamber of known gas volume and a mouthpiece

What is a spirometer trace

Graph showing changes in lung volume over time during breathing

What is breathing rate

Number of breaths taken per minute measured by counting peaks on a spirometer trace

What is tidal volume

Volume of air inhaled or exhaled in a normal breath at rest

What is vital capacity

Maximum volume of air that can be inhaled or exhaled in one breath

What is inspiratory reserve volume

Maximum extra volume of air that can be inhaled after a normal inhalation

What is expiratory reserve volume

Maximum extra volume of air that can be exhaled after a normal exhalation

What is residual volume

Volume of air remaining in the lungs after the most forceful exhalation

What is total lung capacity

Vital capacity plus residual volume

What is oxygen consumption

Volume of oxygen used per minute measured from the slope of a spirometer trace

How is oxygen consumption calculated

Change in gas volume divided by time taken

What is ventilation rate

Volume of air inhaled per minute

How do you calculate ventilation rate

Tidal volume multiplied by breathing rate