A dräger service engineer examined the device on-site and determined that the diaphragm of the so-called fresh gas decoupling valve was stuck open.After the diaphragm was re-seated the device passed all tests and could be returned to use.This finding explains the observation reported by the customer: if the fresh gas decoupling valve remains open during the inspiration phase breathing gas will flow through it towards the absorber instead of through the inspiratory valve to the patient.This leads to reduced automatic ventilation while manual ventilation is not impaired by this issue.It is confirmed for the particular case that the device posted the appropriate alarms to alert the user about the restrictions.The particular valve was manufactured in 2006.Typically, moisture in the breathing system or improper cleaning is a contributing factor for the sticking.The number of similar cases, related to the same root cause, is within the expected range of the respective risk assessment and thus accepted.
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