Patent ID: 6553990
Filing Date: 2003-04-29
Classification: A61M

Abstract:
A process for changing the concentration in an anesthesia apparatus with a breathing circuit, the process comprising the steps of:providing a breathing circuit with an inspiration branch and an expiration branch, with a fresh gas metering unit connected to the breathing circuit and a pressure sensor in the breathing circuit, with a volume displacement device in the inspiration branch and a Positive End Expiratory Pressure (PEEP)/maximum pressure (PMAX) valve in the expiration branch; connecting an evaluating and control unit to the fresh gas metering unit, the pressure sensor, the volume displacement device and the PEEP/PMAX valve; completely returning the volume displacement device to a start position and substantially at the same time increasing the fresh gas supply from the fresh gas metering unit via the evaluating and control unit such that the volume displacement device is completely filled with the fresh gas fed in; and moving the volume displacement device forward completely while not exceeding a set pressure preset on the PEEP/PMAX valve in the breathing circuit.