Patent ID: 8652064

Claim:
An apparatus for measuring an analyte in exhaled air, the apparatus comprising: an inlet through which the exhaled air is received; a tube coupled to the inlet, the tube having a plurality of paths and a non-linear portion, the non-linear portion being configured to temporarily store at least a portion of the exhaled air; a pump configured to circulate the exhaled air through the tube; a converter configured to partially convert the analyte from a first state to a second state; and an analyte sensor for measuring the analyte; wherein the at least a portion of the exhaled air is temporarily stored in the tube while it is determined whether the at least a portion of the exhaled air will be passed to the converter or the analyte sensor, and wherein the tube is configured to re-circulate the exhaled air through the converter until a percentage of the analyte converted to the second state exceeds a pre-determined threshold.