Spirometers' technological evolution spurs increased confidence in results. Four generations of advances enable more useful diagnoses for asthma, emphysema or tuberculosis.

A century and a half of spirometry testing has seen the most common lung disease change from tuberculosis which reduces lung volumes to emphysema and asthma which reduce flow rates. Spirometers have evolved to highly accurate, relatively inexpensive hand-held instruments. These new spirometers use disposable flow sensors which eliminate the chance of cross-contamination and have microprocessors with programs which monitor and report the quality of the maneuvers as they are performed. Such improvements enable this highly useful diagnostic tool to be used more widely and with greater confidence.