We present an in vivo broadband spectroscopic characterization of the human forehead. Absorption and scattering properties are measured on five healthy volunteers at five different interfiber distances, using time-resolved diffuse spectroscopy and interpreting data with a model of the diffusion equation for a homogeneous semi-infinite medium. A wavelength-tunable mode-locked laser and time-correlated singlephoton counting detection are employed, enabling fully spectroscopic measurements in the range of 700–1000 nm. The results show a large variation in the absorption and scattering properties of the head depending on the subject, whereas intrasubject variations, assessed at different interfiber distances, appear less relevant, particularly for what concerns the absorption coefficient. The high intersubject variability observed indicates that a unique set of optical properties for modeling the human head cannot be used correctly. To better interpret the results of the analysis of in vivo measurements, we performed a set of four-layer model Monte Carlo simulations based on different data sets for the optical properties of the human head, partially derived from the literature. The analysis indicated that, when simulated time-resolved curves are fitted with a homogeneous model for the photon migration, the retrieved absorption and reduced scattering coefficients are much closer to superficial layer values (i.e., scalp and skull) than to deeper layer ones (white and gray matter). In particular, for the shorter interfiber distances, the recovered values can be assumed as a good estimate of the optical properties of the first layer.

In vivo time-resolved reflectance spectroscopy of the human forehead / D. Comelli; A. Bassi; A. Pifferi; P. Taroni; A. Torricelli; R. Cubeddu; F. Martelli; G. Zaccanti. - In: APPLIED OPTICS. - ISSN 2155-3165. - ELETTRONICO. - 46:(2007), pp. 1717-1725. [10.1364/AO.46.001717]

In vivo time-resolved reflectance spectroscopy of the human forehead

MARTELLI, FABRIZIO
Membro del Collaboration Group
;
ZACCANTI, GIOVANNI
2007

Abstract

We present an in vivo broadband spectroscopic characterization of the human forehead. Absorption and scattering properties are measured on five healthy volunteers at five different interfiber distances, using time-resolved diffuse spectroscopy and interpreting data with a model of the diffusion equation for a homogeneous semi-infinite medium. A wavelength-tunable mode-locked laser and time-correlated singlephoton counting detection are employed, enabling fully spectroscopic measurements in the range of 700–1000 nm. The results show a large variation in the absorption and scattering properties of the head depending on the subject, whereas intrasubject variations, assessed at different interfiber distances, appear less relevant, particularly for what concerns the absorption coefficient. The high intersubject variability observed indicates that a unique set of optical properties for modeling the human head cannot be used correctly. To better interpret the results of the analysis of in vivo measurements, we performed a set of four-layer model Monte Carlo simulations based on different data sets for the optical properties of the human head, partially derived from the literature. The analysis indicated that, when simulated time-resolved curves are fitted with a homogeneous model for the photon migration, the retrieved absorption and reduced scattering coefficients are much closer to superficial layer values (i.e., scalp and skull) than to deeper layer ones (white and gray matter). In particular, for the shorter interfiber distances, the recovered values can be assumed as a good estimate of the optical properties of the first layer.
2007
46
1717
1725
Goal 3: Good health and well-being for people
D. Comelli; A. Bassi; A. Pifferi; P. Taroni; A. Torricelli; R. Cubeddu; F. Martelli; G. Zaccanti
File in questo prodotto:
File Dimensione Formato  
comelli_et_al_AO_brain_2007.pdf

Accesso chiuso

Tipologia: Versione finale referata (Postprint, Accepted manuscript)
Licenza: Tutti i diritti riservati
Dimensione 713.87 kB
Formato Adobe PDF
713.87 kB Adobe PDF   Richiedi una copia

I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificatore per citare o creare un link a questa risorsa: https://hdl.handle.net/2158/400045
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 53
  • ???jsp.display-item.citation.isi??? 43
social impact