Time-Domain Diffuse Correlation Spectroscopy

Diffuse Correlation Spectroscopy (DCS) is a novel technique based on the detection of temporal decorrelation of laser speckles through highly scattering media (e.g. biological tissues). It permits to detect movement of scatterers withing highly diffusive materials at depts of a few cm. One of the key applications is the non-invasive measurement of blood flow within biological tissues, for instance to detect non-invasively brain activation caused by increased blood flow in the human brain cortex.
This laboratory exploits a novel approach to DCS based on time-domain detection of photon migration through the scattering material. The information on the photon travelling time permits to map the photon depth distribution, leading – for instance – to a better localization and quantitation of brain activation. The laboratory is equipped with a unique laser source exploiting both high temporal coherence and relatively short pulse duration tuneable in the 700-1100 nm range, combined with a time-resolved single-photon detection stage.
The thesis activity can be focalised on some of the following aspects: 1) system development with emphasis on laser source optimisation and design of novel detection schemes; 2) design of reconstruction algorithms for spatial localisation of moving scatterers; 3) in vivo applications on healthy volunteers on simple protocols; 4) high-performance parallel processing for real-time visualization of blood flow.
Joint Laboratory in collaboration with Turgut Durduran, ICFO, Barcellona.