title: Hemodynamic Measurements of the Human Adult Head in Transmittance Mode by Near-Infrared Time-Resolved Spectroscopy.
abstract: Using a near-infrared time-resolved spectroscopy (TRS) system, we measured the human head in transmittance mode to obtain the optical properties and the hemodynamic changes of deep brain tissues in seven healthy adult volunteers during hyperventilation. For six out of seven volunteers, we obtained the optical signals with sufficient intensity within 10 sec. of sampling. We confirmed that it is possible to non-invasively measure the hemodynamic changes of the human head during hyperventilation, even in the transmittance measurements by the developed TRS system. These results showed that the level of deoxygenated hemoglobin was significantly increased, and the level of oxygenated and total hemoglobin and tissue oxygen saturation were also significantly decreased during hyperventilation. We expect that this TRS technique will be applied to clinical applications for measuring deep brain tissues and deep biological organs.
authors.affiliation: Central Research Laboratory, Hamamatsu Photonics K.K., Hamamatsu, Japan. hiro-su@crl.hpk.co.jp.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Suzuki
authors.affiliation: Central Research Laboratory, Hamamatsu Photonics K.K., Hamamatsu, Japan.
authors.forename: Motoki
authors.initials: M
authors.lastname: Oda
authors.affiliation: Central Research Laboratory, Hamamatsu Photonics K.K., Hamamatsu, Japan.
authors.forename: Etsuko
authors.initials: E
authors.lastname: Ohmae
authors.affiliation: Central Research Laboratory, Hamamatsu Photonics K.K., Hamamatsu, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Central Research Laboratory, Hamamatsu Photonics K.K., Hamamatsu, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Yamashita
authors.affiliation: Central Research Laboratory, Hamamatsu Photonics K.K., Hamamatsu, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Yoshimoto
authors.affiliation: Central Research Laboratory, Hamamatsu Photonics K.K., Hamamatsu, Japan.
authors.forename: Shu
authors.initials: S
authors.lastname: Homma
authors.affiliation: Central Research Laboratory, Hamamatsu Photonics K.K., Hamamatsu, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Yamashita
mesh_terms: D000328:Adult; D006439:Hemodynamics; D006801:Humans; D010100:Oxygen / Q000032:analysis; D019265:Spectroscopy, Near-Infrared / Q000379:methods*
chemical_list: D010100:Oxygen
keywords: Deep brain tissues; Hemodynamics; Near-infrared spectroscopy; Time-resolved spectroscopy; Tissue oxygen saturation