Performance assessment of time-domain optical brain imagers, part 1: basic instrumental performance protocol

Heidrun Wabnitz; Dieter R. Taubert; Mikhail Mazurenka; Oliver Steinkellner; Alexander Jelzow; Rainer Macdonald; Daniel Milej; Piotr Sawosz; Michał Kacprzak; Adam Liebert; Robert Cooper; Jeremy Hebden; Antonio Pifferi; Andrea Farina; Ilaria Bargigia; Davide Contini; Matteo Caffini; Lucia Zucchelli; Lorenzo Spinelli; Rinaldo Cubeddu; Alessandro Torricelli

doi:10.1117/1.JBO.19.8.086010

14 August 2014 Performance assessment of time-domain optical brain imagers, part 1: basic instrumental performance protocol

Heidrun Wabnitz, Dieter R. Taubert, Mikhail Mazurenka, Oliver Steinkellner, Alexander Jelzow, Rainer Macdonald, Daniel Milej, Piotr Sawosz, Michał Kacprzak, Adam Liebert, Robert Cooper, Jeremy Hebden, Antonio Pifferi, Andrea Farina, Ilaria Bargigia, Davide Contini, Matteo Caffini, Lucia Zucchelli, Lorenzo Spinelli, Rinaldo Cubeddu, Alessandro Torricelli

Author Affiliations +

Journal of Biomedical Optics, Vol. 19, Issue 8, 086010 (August 2014). https://doi.org/10.1117/1.JBO.19.8.086010

Abstract

Performance assessment of instruments devised for clinical applications is of key importance for validation and quality assurance. Two new protocols were developed and applied to facilitate the design and optimization of instruments for time-domain optical brain imaging within the European project nEUROPt. Here, we present the “Basic Instrumental Performance” protocol for direct measurement of relevant characteristics. Two tests are discussed in detail. First, the responsivity of the detection system is a measure of the overall efficiency to detect light emerging from tissue. For the related test, dedicated solid slab phantoms were developed and quantitatively spectrally characterized to provide sources of known radiance with nearly Lambertian angular characteristics. The responsivity of four time-domain optical brain imagers was found to be of the order of 0.1 m₂ sr. The relevance of the responsivity measure is demonstrated by simulations of diffuse reflectance as a function of source-detector separation and optical properties. Second, the temporal instrument response function (IRF) is a critically important factor in determining the performance of time-domain systems. Measurements of the IRF for various instruments were combined with simulations to illustrate the impact of the width and shape of the IRF on contrast for a deep absorption change mimicking brain activation.

CC BY: © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

Citation Download Citation

Heidrun Wabnitz, Dieter R. Taubert, Mikhail Mazurenka, Oliver Steinkellner, Alexander Jelzow, Rainer Macdonald, Daniel Milej, Piotr Sawosz, Michał Kacprzak, Adam Liebert, Robert Cooper, Jeremy Hebden, Antonio Pifferi, Andrea Farina, Ilaria Bargigia, Davide Contini, Matteo Caffini, Lucia Zucchelli, Lorenzo Spinelli, Rinaldo Cubeddu, and Alessandro Torricelli "Performance assessment of time-domain optical brain imagers, part 1: basic instrumental performance protocol," Journal of Biomedical Optics 19(8), 086010 (14 August 2014). https://doi.org/10.1117/1.JBO.19.8.086010

Published: 14 August 2014

ACCESS THE FULL ARTICLE

JOURNAL ARTICLE
12 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY