Descriptive ventilatory mechanics from noninvasive analog display of ribcage and abdominal flow.

A rapidly responding analog display of ventilatory flow at the mouth, ribcage and abdomen allows interpretation of the relative activity of the diaphragm, accessory inspiratory muscles and abdominal expiratory muscles. These relative movements are exaggerated by having volunteers perform the ventilatory maneuvers of sniff, rapid exhalation and cough. Activity and regional lung flow can change in time periods in the tens of milliseconds. These rapid (within an inspiratory or expiratory time) relational changes in respiratory muscle activity and regional lung flow have not previously been demonstrated with a simple noninvasive measurement.