Patent ID: 8753286

Claim:
A spirometer for measuring pulmonary respiration of a test subject, comprising: a sensor unit, the sensor unit comprising a flow tube, a mass flow sensor disposed within the flow tube, the mass flow sensor being adapted to sense a mass flow of air flowing through the flow tube, and a sensor identification code; and a body, adapted to removably attach the sensor unit thereto, the body comprising a plurality of ambient air sensors adapted to sense a plurality of ambient air characteristics, the ambient air sensors being operatively connected to an analysis unit, wherein the mass flow sensor becomes operatively connected to the analysis unit when the sensor unit is attached to the body, and wherein the mass flow sensor comprises a first temperature element that is exposed to the mass flow of air flowing through the flow tube, and wherein during operation of the spirometer the first temperature element is heated to a target temperature, and wherein the mass flow of air flowing through the flow tube is derived from an amount of power that is required to maintain the target temperature of the first temperature element while being exposed to the mass flow of air flowing through the flow tube, and wherein the sensor unit is identified by reading the sensor identification code through a data connection between the sensor unit and the body when the sensor unit is attached to the body, and wherein the pulmonary respiration of the test subject is determined in the analysis unit by evaluating the mass flow of air flowing through the flow tube sensed by the mass flow sensor and the plurality of ambient air characteristics sensed by the plurality of ambient air sensors.