A dräger field service engineer has examined the device in follow-up of the event and could confirm the reported aspect of ventilator shut-down.It could be traced back to a malfunction of the light barrier in the motor position detection system.The motor drives the ventilator piston via a threaded spindle; the number of rotations is proportional to the hub of the piston and thus, to the volume the ventilator applies.If the motor position cannot be determined anymore this may result in potentially hazardous output.Consequently, the system is designed to force a shut-down of automatic ventilation when motor position detection fails.The device posts a corresponding alarm to alert the user and, manual ventilation with the built-in breathing bag remains possible.The replacement of the light barrier has put back the device into fully operable conditions.Dräger finally concludes that the system responded as intended upon the malfunction of a single component.The failure of an electronic component after 16 years of operation can be considered acceptable.
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