Interactive Ventilator

An anesthesia workstation simulator for medical students learning ventilator and anesthetic physiology. This is a work-in-progress. We are constantly improving the model, fine-tuning dynamics, and pursuing clinical reality.

Core logic is based on Manual of Clinical Anesthesiology by Chu, Traynor, and Kurup.

GE Datex-Ohmeda · Patient Monitor
II
ABP
SpO₂
CO₂
NIBP
118/72
(88)
mmHg
TEMP
36.8
°C
GAS / AGENT
MAC0.95
EtO₂52%
Sevo2.1%
Aspect Medical · BIS Monitor
46
BIS
SR 0% · EMG 42dB
EEG
δ 1–4 Hzθ 4–8 Hzα 8–13 Hzβ 13–30 Hz
Dräger Zeus · Ventilator
Paw
cmH₂O
Flow
L/min
Vol
mL
TVset
480
mL
TVexp
478
mL
RR
12
br/min
MV
5.8
L/min
PIP
22
cmH₂O
Pplat
18
cmH₂O
PEEP
5
cmH₂O
Pmean
10
cmH₂O
FiO₂
50%
EtCO₂
36
mmHg
autoPEEP
0
cmH₂O
τ exp
0.25
s
P-VLoop
▸ Insp ◂ Exp
VC-CMV TV 480 mL · RR 12 · PEEP 5 · FiO₂ 50%
Ventilator Settings
480
12
5
50
1.0
Patient Physiology
50
5
200
0
Active Alarms
No active alarms
Train-of-Four 4/4
No Block ↗ Open tutorial
NMT Monitor · Train-of-Four Peripheral Nerve Stimulator — Educational Tutorial
TOF Count
4/4
TOF Ratio
1.00
Block Depth
No Block
No meaningful neuromuscular blockade. Normal response.
Block State
Drug Demonstration
What is Train-of-Four?
Four supramaximal stimuli at 2 Hz are applied to a peripheral nerve (usually the ulnar nerve at the wrist). The resulting muscle twitches are measured. Fade — where later twitches are progressively weaker — is the hallmark of nondepolarizing blockade. The TOF ratio (T4 ÷ T1) below 0.9 indicates residual paralysis even when all four twitches are visible.

Monitor Tutorial

5-Lead ECG Monitoring in the OR

HR72bpm
ST II0.0mm
ST V50.0mm
Regular rate and rhythm. Clear P wave before every QRS. Rate 60–100 bpm. Normal intraoperative finding.

Key Teaching Points

  • HR is derived from the RR interval — the distance between two consecutive R peaks
  • Lead II is the primary intraoperative lead for rhythm detection; P waves are largest here
  • V5 is the most sensitive single lead for detecting myocardial ischemia
  • ST changes >1 mm (elevation or depression) suggest ischemia — inform your attending
  • Always confirm a monitor rhythm with a pulse check before treating

Monitor Tutorial

Arterial Line Waveform Interpretation

SBP118mmHg
DBP72mmHg
MAP88mmHg
Normal arterial waveform. Brisk upstroke, clear dicrotic notch, normal pulse pressure (~46 mmHg). Waveform is reliable.

Key Teaching Points

  • Waveform shape reflects stroke volume + vascular resistance in real time
  • MAP is most clinically relevant — goal ≥65 mmHg to ensure organ perfusion
  • The dicrotic notch marks aortic valve closure and separates systole from diastole
  • Pulse pressure (SBP–DBP) reflects stroke volume; wide = hyperdynamic, narrow = low SV
  • A dampened waveform may be a line problem — flush and check before treating the patient

Monitor Tutorial

Pulse Oximetry and Pleth Waveform

SpO₂99%
PI2.4%
Normal pleth. Good amplitude, regular peaks, strong perfusion index. SpO₂ 99% is accurate and reliable.

Key Teaching Points

  • SpO₂ reflects oxygen saturation — it does NOT reflect ventilation (use EtCO₂ for that)
  • Pleth amplitude is your perfusion indicator — a flat wave is a red flag regardless of the number
  • "Good number ≠ good perfusion" — vasoconstricted patients can read 99% while hypoperfused
  • SpO₂ lags actual arterial saturation by 30–60 seconds — act early if the trend is downward
  • A noisy or absent waveform means the reading is unreliable — reposition the probe first

Monitor Tutorial

Capnography & Gas Monitoring

EtCO₂36mmHg
RR12/min
I — Dead space II — Upstroke III — Plateau ↓ Inspiration

The Capnogram

  • Phase I — Inspiratory baseline: dead space ventilation, CO₂ ≈ 0 mmHg
  • Phase II — Expiratory upstroke: mixing of dead space and alveolar gas, CO₂ rises sharply
  • Phase III — Alveolar plateau: CO₂-rich gas; EtCO₂ is measured at the very end of this phase
  • Downstroke — Inspiration begins; fresh gas washes CO₂ back to zero immediately
  • Normal EtCO₂: 35–45 mmHg. Reflects both ventilation and perfusion