|
The investigation was based on the log file of the affected device.Based on the log file analysis the reported device shutdown and stop of ventilation could not be confirmed.The analysis of the log file identified a failure of the blacklight of the display.The hardware analysis of previous complaints revealed that the activation of the inrush current limitation of the fuse on the printed circuit board of the lc display led to a dark backlight of the lc display.The activation of this fuse was traced back to adverse tolerances of the assembled electronic components on the adapter board of the display unit of the device (ecd).In case the backlight of the display unit fails during use, the user is no longer able to operate the device.The running ventilation is not affected and will be continued as set.Safety relevant parameters as fio2, minute volume, or airway pressure are displayed in the supplemental yellow/green oled-display wherein the user can see the on-going ventilation.The inrush current limitation of the fuse has already been increased in order to remedy this issue.The symptom can be resolved by switching off and on the device via the main switch.In the event of recurrence, replacement of the pcb "ecd adapter" is recommended.The number of similar cases, related to the same root cause, is within the expected range of the respective risk assessment and thus accepted.
|