title: Simultaneous full-field 3-D vibrometry of the human eardrum using spatial-bandwidth multiplexed holography.
abstract: Holographic interferometric methods typically require the use of three sensitivity vectors in order to obtain three-dimensional (3-D) information. Methods based on multiple directions of illumination have limited applications when studying biological tissues that have temporally varying responses such as the tympanic membrane (TM). Therefore, to measure 3-D displacements in such applications, the measurements along all the sensitivity vectors have to be done simultaneously. We propose a multiple-illumination directions approach to measure 3-D displacements from a single-shot hologram that contains displacement information from three sensitivity vectors. The hologram of an object of interest is simultaneously recorded with three incoherently superimposed pairs of reference and object beams. The incident off-axis angles of the reference beams are adjusted such that the frequency components of the multiplexed hologram are completely separate. Because of the differences in the directions and wavelengths of the reference beams, the positions of each reconstructed image corresponding to each sensitivity vector are different. We implemented a registration algorithm to accurately translate individual components of the hologram into a single global coordinate system to calculate 3-D displacements. The results include magnitudes and phases of 3-D sound-induced motions of a human cadaveric TM at several excitation frequencies showing modal and traveling wave motions on its surface.
authors.affiliation: Worcester Polytechnic Institute, Center for Holographic Studies and Laser micro-mechaTronics (CHSLT), Mechanical Engineering Department, Worcester, Massachusetts 01609, United States.
authors.forename: Morteza
authors.initials: M
authors.lastname: Khaleghi
authors.affiliation: Massachusetts Eye and Ear Infirmary, Eaton-Peabody Laboratory, Boston, Massachusetts 02114, United StatescHarvard Medical School, Department of Otology and Laryngology, Boston, Massachusetts 02114, United States.
authors.forename: Jérémie
authors.initials: J
authors.lastname: Guignard
authors.affiliation: Worcester Polytechnic Institute, Center for Holographic Studies and Laser micro-mechaTronics (CHSLT), Mechanical Engineering Department, Worcester, Massachusetts 01609, United StatesbMassachusetts Eye and Ear Infirmary, Eaton-Peabody Laboratory, Boston, M.
authors.forename: Cosme
authors.initials: C
authors.lastname: Furlong
authors.affiliation: Massachusetts Eye and Ear Infirmary, Eaton-Peabody Laboratory, Boston, Massachusetts 02114, United StatescHarvard Medical School, Department of Otology and Laryngology, Boston, Massachusetts 02114, United States.
authors.forename: John J
authors.initials: JJ
authors.lastname: Rosowski
mesh_terms: D000465:Algorithms; D005260:Female; D006696:Holography / Q000379:methods*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008875:Middle Aged; D014432:Tympanic Membrane / Q000033:anatomy & histology* / Q000502:physiology*