Sampling circuit for measuring analytes

摘要

This disclosure describes an apparatus and method for measuring analytes in exhaled air. The device contains an inlet through which exhaled air is received. A tube, having a number of different paths running throughout the device, is coupled to the inlet which enables the exhaled air to be re-circulated through the device. At least one portion of the tube is configured in a non-linear fashion. This particular portion of the tube may be used to temporarily store a sample of the exhaled air. The device also contains a converter configured to partially convert an analyte in the exhaled breath from a first state to a second state as the exhaled air is being re-circulated. An analyte sensor is also included to measure the levels of the converted analyte in the exhaled breath.