title: A Clinical Tissue Oximeter Using NIR Time-Resolved Spectroscopy.
abstract: The tNIRS-1, a new clinical tissue oximeter using NIR time-resolved spectroscopy (TRS), has been developed. The tNIRS-1 measures oxygenated, deoxygenated and total hemoglobin and oxygen saturation in living tissues. Two-channel TRS measurements are obtained using pulsed laser diodes (LD) at three wavelengths, multi-pixel photon counters (MPPC) for light detection, and time-to-digital converters (TDC) for time-of-flight photon measurements. Incorporating advanced semiconductor devices helped to make the design of this small-size, low-cost and low-power TRS instrument possible. In order to evaluate the correctness and reproducibility of measurement data obtained with the tNIRS-1, a study using blood phantoms and healthy volunteers was conducted to compare data obtained from a conventional SRS device and data from an earlier TRS system designed for research purposes. The results of the study confirmed the correctness and reproducibility of measurement data obtained with the tNIRS-1. Clinical evaluations conducted in several hospitals demonstrated a high level of usability in clinical situations and confirmed the efficacy of measurement data obtained with the tNIRS-1.
authors.affiliation: Systems Division, Hamamatsu Photonics K.K., Hamamatsu, Japan. fujisaka@sys.hpk.co.jp.
authors.forename: Shin-Ichi
authors.initials: SI
authors.lastname: Fujisaka
authors.affiliation: Systems Division, Hamamatsu Photonics K.K., Hamamatsu, Japan.
authors.forename: Takeo
authors.initials: T
authors.lastname: Ozaki
authors.affiliation: Systems Division, Hamamatsu Photonics K.K., Hamamatsu, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Systems Division, Hamamatsu Photonics K.K., Hamamatsu, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Kamada
authors.affiliation: Systems Division, Hamamatsu Photonics K.K., Hamamatsu, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Kitazawa
authors.affiliation: Systems Division, Hamamatsu Photonics K.K., Hamamatsu, Japan.
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Nishizawa
authors.affiliation: Systems Division, Hamamatsu Photonics K.K., Hamamatsu, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Takahashi
authors.affiliation: Systems Division, Hamamatsu Photonics K.K., Hamamatsu, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Suzuki
mesh_terms: D006801:Humans; D010092:Oximetry / Q000379:methods*; D019265:Spectroscopy, Near-Infrared / Q000295:instrumentation / Q000379:methods*
keywords: Medical device; Multi-pixel photon counter; NIRS; Time-resolved spectroscopy; Tissue oximeter