Figure 1. Encompass open-faced thermoplastic shell.

An example of the open-faced thermoplastic shell used with the Encompass system to facilitate optical surface imaging with Identify using stereoscopic imaging of the blue speckled light pattern. The open region used for motion monitoring goes from just above the eyebrows to just below the nose. There is also a biteblock incorporated into the region of the mask covering the mouth to improve inter- and intra-fraction positioning reproducibility.