Push-button activation of equipment for spirometric measurement is not uncommon. In a busy clinical service or a demanding research study, there may be need to evaluate subjects at a rate of up to about 60 per hour each hour during a 10-hour day for six days. Since our pulmonary-function instrument demands that seven pushbutt:ns be depressed sequentially twice, the number of digital depressions would be over 50 000. Such potential untimely destruction of the pulp under the nail of the finger might well dissatisfy any technician, especially distaff. By using a gas-driven intermediary, in lieu of these repeated digitally applied mechanical forces, pulmonary function variables may be obtained with ‘a flick of the wrist’.