On this page
Asset Type
Manufacturer
Model
What This Guide Helps With
This guide assists Clinical Engineering in troubleshooting humidifier or tubing connection issues on a ResMed Lumis ventilator. Symptoms may include alarms indicating “humidifier not detected,” “circuit disconnected,” or “high leak,” unexpected ventilator shutdowns, or inconsistent delivery of pressure/volume due to accessory misconnection. Focus is on external, verifiable causes before assuming internal failure.
Step-by-Step Troubleshooting
Ensure Safe Patient Environment
- Move the patient to a backup ventilator if needed.
- Never disconnect tubing or humidifier while patient support is compromised.
Verify Device Power and Status
- Check that the Lumis ventilator powers on normally.
- Confirm battery/AC power status; low power can cause accessory errors.
Inspect Humidifier Placement and Connection
- Confirm the humidifier is seated correctly in the base unit.
- Check for proper alignment of pins, connectors, or magnetic locks.
- Ensure humidifier water chamber is filled to the recommended level; empty or low water may trigger errors.
Examine Tubing and Circuit Connections
- Ensure all tubing connections (inspiratory, expiratory, mask interface) are fully seated.
- Look for kinks, bends, or obstructions in tubing that may interfere with flow detection.
- Verify that the correct tubing type is used (manufacturer-specified).
Check for Humidifier or Tubing Damage
- Inspect for cracks, leaks, or worn seals.
- Replace any damaged parts with manufacturer-approved components.
Clean Contact Points
- Check connectors for moisture, debris, or condensation.
- Wipe contacts with a lint-free cloth if needed.
Power Cycle the Ventilator
- After connections are verified, restart the ventilator to reset accessory detection.
- Observe whether the device now recognizes the humidifier and tubing.
Verify Alarm Behavior
- Confirm that any previously triggered humidifier/circuit alarms are cleared.
- Document any recurring alarms for further evaluation.
If the Problem Persists
External checks have ruled out common causes.
- Removed from service
- Labeled Out of Service
- Sent for repair or bench evaluation
Knowing when to stop prevents patient risk and potential device damage.
Clinical Use Tip
- Never troubleshoot humidifier or tubing connections while the patient is actively dependent on the device.
- Ensure backup ventilation is ready before disconnecting any components.
- Regular inspection of tubing and humidifier during routine rounds can prevent these errors.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
Ventilator alarm indicates “humidifier not detected” or circuit disconnected.
Cause
What was observed during troubleshooting.
Example:
Humidifier seated incorrectly, tubing loose, or contact points obstructed.
Resolution
What action was taken.
Example:
Verified proper humidifier placement, reconnected tubing, cleaned contacts, restarted device; alarms cleared.
Helpful Details to Include
- Confirm AC power and battery status
- Humidifier water level checked
- Tubing type and connections verified
- No kinks or obstructions
- Connector cleanliness
- Alarm cleared after restart
Final Thought
Proper patient safety, stepwise troubleshooting, and careful documentation ensure issues are resolved efficiently while avoiding unnecessary internal repair or patient risk. Always escalate when external checks fail.
That is successful troubleshooting.