Abstract: The invention relates to a method for verifying a calibration of an ultrasonic spirometer, the method comprising determining an actual value of a distance between a first ultrasonic transducer and a second ultrasonic transducer of a spirometer, determining a difference between the actual value of the distance and a nominal value of the distance that is assigned to the spirometer, and accepting an actual calibration of the spirometer if an absolute value of the difference is smaller than or equal to a first threshold value, or refusing the actual calibration of the spirometer if the absolute value of the difference is bigger than the first threshold value, wherein the first threshold value is 5% of the nominal value of the distance. The invention further relates to a spirometer that is adapted to carry out this method as well as to a method for calibrating a spirometer.

Abstract: A holding device for a breathing tube for use in lung function diagnostics is disclosed. This holding device consists of a material that is transparent for light having a wavelength in a first wavelength range but nontransparent for light having a wavelength in a second wavelength range. In other aspects, a lung function diagnostics device comprising such a holding device and a method for reading out a coding on a surface of a breathing tube for use in lung function diagnostics are disclosed.

Abstract: A method for conditioning a breathing tube for use in lung function diagnostics and a breathing tube made by such a method. This method is characterized by heating at least a section of a fully assembled breathing tube by a heating source to a temperature of at least 40° C., wherein heating is performed during a first time period, the first time period lasting between 0.1 seconds and 5 seconds wherein the section includes at least one window covered by a mesh.

Abstract: This invention relates to a breathing tube for use in ultrasonic flow measurement systems for determining the volume flow and/or the molar mass of the respiration of humans and animals. According to the invention, the breathing tube at least partly has a polygonal cross-section. Furthermore at least one indicator is formed on the breathing tube, which can be read out via an external optical device.

Abstract: The invention describes a method that is used to determine the linearization curve of a sensor for specific gas components by combining this sensor with an ultrasonic molar mass sensor. The described method uses the fact that the molar mass sensor exhibits a completely linear response when two gas compositions of differing molar mass values are mixed. Using this feature a non linear-response of a sensor for specific gas components can be determined and a linearization curve can be computed.

Abstract: The invention describes a method that is used to determine the linearization curve of a sensor for specific gas components by combining this sensor with an ultrasonic molar mass sensor. The described method uses the fact that the molar mass sensor exhibits a completely linear response when two gas compositions of differing molar mass values are mixed. Using this feature a non linear-response of a sensor for specific gas components can be determined and a linearization curve can be computed.

Abstract: A method and device are provided for measuring state of lung function of a patient using ultrasonic flow and molar mass measurement. Flow and molar mass signals are recorded during tidal breathing without requiring patient cooperation. Statistical analysis of the recorded data in combination with anthropometirc data and/or data form a questionnaire can be used to diagnose various pulmonary ailments or diseases.