Fig 1. Graph showing P_tO₂ data from one subject to illustrate the experimental protocol.

First, following an equilibration period of 30mins after probe insertion (not shown), six P_tO₂ measurements were obtained in the non-ischemic (right) hemisphere (3 control, 3 under hyperoxia), then MCAo and PO₂ probe insertion were carried out on the ischemic (left) hemisphere and P_tO₂ was measured every 10mins (again following a 30-min equilibration period after probe insertion) across three 30min control-hyperoxia cycles (18 measurements in total). Note the rapid equilibration in P_tO₂ after each change of oxygen condition, i.e., within the 10mins between measurements.