Signal-to-noise and acquisition duration improvements for a hybrid-PMT and photodiode-based multiwavelength diffuse optical tomography system

Abstract

A new optical parallel detection system of both frequency and continuous wave domains was developed to improve the data quality and accuracy in recovery of all breast optical properties. This new system combines frequency domain (FD) measurements using photomultiplier tubes and continuous wavelengths (CW) measurements using photodiode detectors in order to incorporate addition NIR wavelengths up to 948nm. The FD measurements use 6 wavelengths (660, 735, 785, 808, 826, and 849 nm) while the CW use three wavelengths (903, 912, and 948nm). The frequency domain part of the system is described in detail and steps taken to improve signal to noise ratio are discussed. Furthermore, different acquisition procedures were tested in order to reduce the duration of a complete 9 wavelength acquisition.