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Sideline Spirometry Lab

BIO 171 · Pulmonary Ventilation Lab

Sideline Spirometry

Mike walked off the pitch 15 minutes ago, wheezing and working his neck muscles on every breath. His coach thinks it’s a fitness problem. Your group is the athletic training team. You have a spirometer, a stopwatch, and a decision to make before the second half.

Patient AMike, 20
PositionMidfield
Resp. rate22 /min
SpO₂95%
Accessory musclesIn use

Part A: Run the Spirometer

You are the tech. Coach each patient through quiet breathing, one huge breath in, and a full-force blast out.

Choose a patient

Hover over the trace, or focus the graph and use the arrow keys, to read volumes.

Lung volume (L) over time (s). Arrow keys move the cursor 0.1 s; hold Shift to move 1 s.

Spirometry trace.

Lung volume now2.40 L
Ready
Tech

Press Start test, then coach your patient.

The blast, zoomed in: FVC and FEV₁

Every patient you test lands on this graph so you can compare curve shapes. Pick a mark, then click the right spot on the curve (or use the arrow keys and Enter).

Forced expiration curves.

FEV₁/FVC scoreboard

Mark FVC and FEV₁ for a patient to put them on the scoreboard.

Equation builder: IRV

IRV can’t be read straight off one point. Build it from values you can get.

IRV = − −

Part B: The Straw Challenge

Feel what Mike feels. Time how long it takes each of you to empty your lungs through a narrower and narrower airway.

  1. Take the biggest breath you can.
  2. Press and hold the orange pad (or hold the Space bar) the moment you start blowing out.
  3. Let go when you are completely empty. Then try it through a drinking straw, then a coffee stirrer or a straw pinched halfway shut.

Times under 0.3 s are ignored. You can also type times into the table.

Your group’s data

    Exhale time in seconds for each group member and airway

    Why a narrow tube hurts so much

    Airflow resistance depends on the radius to the fourth power (R ∝ 1/r⁴). Squeeze Mike’s bronchiole and watch the resistance climb.

    Cross-section of a bronchiole; the smooth-muscle ring thickens as the open airway shrinks.

    ×1.0 resistance  ·  100% of normal airflow for the same push

    Drag the slider left to bronchoconstrict.

    Part C: The Sideline Call

    Twenty minutes after two puffs of albuterol, Mike is breathing comfortably, his neck muscles have relaxed, and his SpO₂ reads 98%. The coach wants him back in.

    Use your post-albuterol FEV₁ and FEV₁/FVC from Part A. Your group makes the call, and everyone has to agree.

    What do you tell the coach?

    A teaching simulation built on textbook-typical values. Not for clinical use.