Figure 2.

Positive-pressure gas loading manifold (nominal pressure is 2.7 atm for a 0.5 L OP-cell), which consists of Teflon pneumatic valves and tubing, one-way check valves, in-line O₂ and Rb getters/filters, vacuum and pressure sensors, and two exit paths: “in vivo” (i.e., for clinical use) and “in vitro” (i.e., for experiments not involving living organisms). Implementation of the Rb filter does not appear to measurably impact ¹²⁹Xe hyperpolarization (ref (20)).