1. From the Departments of Anesthesiology (A.S.K., M.C., T.F.F.), Surgery (T.V.B.), and Neurological Surgery (R.M.G.), Stony Brook University Medical Center, Stony Brook, New York; Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York (A.S.K., T.F.F.); Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania (R.C.M., S.S.S., A.G.Y.); a