The Alarms & Battery System

How TMA's hospital-grade alarm model works: warning vs. crisis thresholds, patient population presets, battery states, INOP sensor disconnects, and audio controls.

Written By LJ Merchant

Last updated 1 day ago

The Alarms & Battery System

The Alarms & Battery modal on the Controller has four tabs, all session-scoped. Changes apply to this session only.

Alarm Severities

TMA uses a two-tier alarm model:

  • Warning (yellow) β€” fires after 10 seconds out of range. Yellow border and value on the affected vital.
  • Crisis (red) β€” fires after 5 seconds out of range. Red border, red value, and red outline on the affected vital.

The delay is intentional. A vital that dips for two seconds doesn't trigger anything β€” only sustained out-of-range readings fire, just like a real monitor.

Tab 1 β€” Thresholds

Set the boundaries at which alarms fire for each vital (HR, SBP, DBP, MAP, SpO2, RR, Temp, EtCO2).

Each vital has four thresholds: Crisis Low, Warn Low, Warn High, Crisis High.

Patient population presets auto-fill clinically appropriate thresholds for each age band:

  • Adult (13 years and older)
  • Pediatric Infant (1–12 months)
  • Pediatric Child (1–7 years)
  • Pediatric Adolescent (8–12 years)
  • Neonatal (0–28 days)
  • Custom

You can select a preset and then manually adjust individual thresholds. The Reset to current preset defaults button restores the active preset's values.

Note: SpO2 upper thresholds are intentionally blank for all presets except Neonatal. High SpO2 is not a clinically actionable acute event for older patients. Neonates are the exception because of retinopathy of prematurity risk.

Tab 2 β€” Battery

Simulates a depleting or charging battery on the patient monitor.

  • Set percentage (0–100%) β€” type any value, or use the +10% and Set to 100% shortcuts
  • Drain mode β€” battery drops 1% per minute when on
  • Charge mode β€” battery rises 5% per minute when on
  • Both off β€” battery stays static

Battery alarm behavior:

  • At 20%: warning alarm fires (yellow)
  • At 10%: critical alarm fires (red)
  • At 0%: the Display Monitor shuts off entirely β€” DEVICE OFF state. Must be charged via this tab to restore.

Tab 3 β€” INOP (Sensor Disconnect)

Each toggle simulates a hardware fault or sensor disconnection. The affected vital displays as dashes (---) and an INOP alarm fires.

  • Lead off β€” ECG electrode disconnect. ECG trace shows a flat or noise artifact. This is not asystole β€” a trained student should recognize the difference.
  • SpO2 sensor disconnect β€” pulse ox probe off finger. SpO2 shows as ---.
  • NIBP cuff failure β€” cuff disconnect or overpressure. BP display errors out.
  • EtCO2 sensor disconnect β€” capnography line off. EtCO2 and waveform stop.

Toggle back off to restore the vital.

Tab 4 β€” Audio

  • Mute all alarm audio β€” silences audio alarms for all users in this session for its duration. Visual alarms still display. Use this for classrooms where audio is disruptive or when streaming to multiple TVs.
  • QRS beep β€” plays a heartbeat tone after each QRS complex. Off by default.

Silence Button vs. Mute Toggle

These are two different things:

  • Mute all alarm audio (Controller, Audio tab) β€” persistent session-wide silence. All future alarms are silent until unmuted.
  • Silence button (Display Monitor, top-left) β€” temporary. Silences the current alarm only. The next new alarm will still sound.