The patient quickly inhales a deep breath of test gas, holds his or her breath for 10 seconds, and then exhales quickly. The Jones method measures breathhold time (BHT) starting at 30 percent of inspiratory time (tI) and extending to half of sampling time.
RV: residual volume; TLC: total lung capacity.
Adapted from Am J Respir Crit Care Med 1995; 152:2185.
