Following the procedure, the unit was tested and an error code related to Module/Sensor defective appeared.
As per additional information AI-027472, Gas blender displayed the error code: E15 (Fault in AD transformer, An AD transformer fault has occurred).
This kind of malfunction can be caused by:
- improper hospital gas supply (a minimum pressure of 2 bar per connection should be observed. Indeed, input pressure too low can cause a discrepancy in the target and actual values, leading to the reported issue);
- a missed gas blender warm-up phase (user error);
- defective gas blender's component (A/D-converter);
- a defective DC/DC board.
The unit was manufactured in 2013 and no other similar events were complained.
The affected device was returned back to the manufacturer's site for repair. The device was opened, checked, and cleaned. The reported issue could not be reproduced and the device was found to be working within specifications. Subsequent functional verification testing was completed without further issues and the unit was returned to service.
During the tests performed after the first occurrence, no hardware malfunctions were detected, the unit was found working as expected and within specification.
During repair visit, front panel was replaced (reported in complaint 2023-01551).
Based on the above, it cannot be ruled out that a missed warm-up phase / an improper hospital gas supply have led to the reported issue.
No specific action was currently deemed necessary, LivaNova maintains and document periodic customer events monitoring process in order to evaluate actions for products improvement.
The importance of N+1 is demonstrated in the response to the EGB failure and the ability to change out the defective equipment with a suitable back up. the incident further demonstrates the requirement for the availability of replacement equipment and the necessity of emergency drills and protocols.