Patent ID: 7959443

Claim:
A system for delivering CO 2 in a respiration closed-loop control system to a respiratory simulator, the system comprising: a piston/cylinder arrangement having: a first inlet for receiving a volume of air during an inhalation phase; a second inlet for receiving CO 2 ; and an outlet for releasing the air and CO 2 therethrough during an exhalation phase; a CO 2 supply connected to the piston/cylinder arrangement via a fluid path; a valve situated along the fluid path between the CO 2 supply and the piston/cylinder arrangement; a diffusing surface situated within the piston/cylinder arrangement for distributing the CO 2 within the cylinder; and a controller configured to: actuate the valve after the inhalation phases to allow a predefined amount of CO 2 to flow into the piston/cylinder arrangement to mix with the volume of air forming a volume containing the air and the added CO 2 to be released from the system in the exhalation phase thereof, wherein the predefined amount of CO 2 in combination with the air received during the inhalation phase emulates the amount of CO 2 released in an exhalation phase of a patient; and receive a first control signal representative of the predefined amount of CO 2 , wherein only CO 2 is added to the air in the piston/cylinder arrangement prior to the exhalation phase.