Digital Spirometer with LabView Interface

In the present document, the design and the construction of a low cost digital spirometer is presented like a basic tool for evaluate of the respiratory capacity. A Spirometer is the ideal instrument to measure the mechanics ventilatoria in respiratory studies that allow the analysis, determination and monitoring of diverse human respiratory diseases like asthma, pulmonary embolism, respiratory bronchitis and others deficiencies. The spirometer developed is an instrument portable, of easy handling and computerized that fulfills with the American norms given by the American Thorax Society (ATS) and the requirements of the Mexican population. By means of digital electronics and a pneumotachometer, the virtual instrument acquires and the respiratory flow using a NI USB interface. The volume-time and flow-volume graphs are displayed means a virtual instrument developed in Labview. The spirometrics test includes parameters of the mechanics ventilatoria like the FEV1 (Forced Expiratory Volume in the first second), FVC (Forced Vital Capacity), and MEF (Maximum Expiratory Flow).