Post-auricular Versus Frontal Bispectral Index

"Frontal sensors will be applied with lead 1 at the center of the forehead; lead 2, 2.8 cm lateral to lead 1; and lead 3 at the temporal area between the lateral canthus and the hairline.~Post auriclar sensors will be applied to the same side of the face, with lead 1 approximately 2.5 cm medial to the mastoid area, post-auricularly next to the hairline. Lead 2 will be attached at the mastoid area and lead 3 will be attached on the same side at the temporal area between the lateral canthus and the hairline."