The Apply Logic — Why Nothing Updates Until You Press It

This is the single most important behavior in TMA. New users trip on it constantly, so it gets its own article.

The Two Columns

Every vital in TMA exists in two states inside a session:

• Displayed value — what is currently on the Display Monitor right now
• New value — what the Controller has staged but not yet sent

When you adjust a slider, click an arrow, or type a number on the Controller, you change the New value. The Displayed value — and therefore the Display Monitor — does not move.

The Apply Button

Clicking Apply New Vitals tells the system: "Take everything in the New column and push it to the Display Monitor."

Once applied:

• The New value becomes the Displayed value
• Every connected Display Monitor and Viewer device updates instantly
• The Vital Values table on the Controller updates so both columns match

Why It Works This Way

Three reasons this is intentional:

1. Clean reveals. You can stage a dramatic change — HR 60 to 180, BP 120/80 to 70/40, SpO2 98% to 78% — all at once and reveal it on a single click. Without Apply, students would see vitals drift one at a time as you fiddle.
2. Mistake-proofing. You can change your mind before committing. Bumped a slider by accident? Reset it before Apply and nothing leaves the Controller.
3. Trending support. Apply is also the trigger that starts a trend. Without an explicit "go" signal, trending wouldn't have a defined start point.

What Does NOT Need Apply

A short list of things that update immediately without Apply:

• Rhythm changes (discrete state, not numeric)
• Capnography waveform changes
• Pleth morphology changes
• Display Controls toggles (Display Monitor on/off, AED Trainer, Rhythm Identification)
• Alarm threshold changes
• Battery and INOP toggles

Everything numeric goes through the Apply gate. Everything else is live.

The #1 Support Issue

If a student is staring at the monitor and nothing is happening: you haven't hit Apply.

If you've changed multiple vitals and want to reset them all before applying: use Reset to Default Vitals to reload the rhythm's defaults, then Apply.