Figure 1:

Schedule of study events. Healthy volunteers during the technical run-in phase received four 1-L doses of hyperpolarized (HP) ¹²⁹Xe, while age-matched control subjects and subjects with COPD during the efficacy phase received three doses. Age-matched control subjects and subjects with COPD underwent pulmonary function testing, whereas healthy volunteers did not. The specific monitoring schedule for each dose is broken out at the bottom of the figure. DL_CO-SB = single-breath diffusing capacity of lung for carbon monoxide, ECG = electrocardiography, Resp = respiratory rate recording, Spo₂ = oxygen saturation as measured by pulse oximetry.