Multiple sensory coordinate frames in a vestibular prosthetic. The approximate semi-circular canal (CANAL) coordinate frame has blue axes and labels based on canal names (LARP: left anterior - right posterior, RALP: right anterior - left posterior, H: horizontal). The prosthetic sensor (HMMS) axes are green with grey axes labels. HMMS rotations are also labeled (green), e.g. pitch is a rotation about the <Y> axis. The HEAD coordinate system is based on REID coordinates and uses the same axes labels (grey) as the HMMS. However, HEAD axes are not shown here to avoid clutter. The HEAD frame is aligned with the HMMS but coincident with CANAL.