Regular paper

Enhancements on multi-exposure LASCA to reveal information of speed distribution

¹ Department of Medical Physics and Informatics, University of Szeged, Korányi fasor 9., H-6720 Szeged, Hungary
² Department of Optics and Quantum Electronics, University of Szeged, Dóm tér 9., H-6720 Szeged, Hungary
³ MTA-SZTE Research Group on Photoacoustic Spectroscopy, University of Szeged, Dóm tér 9., H-6720 Szeged, Hungary
⁴ Department of Physiology, University of Szeged, Dóm tér 10., H-6720 Szeged, Hungary
⁵ Department of Dermatology and Allergology Albert Szent-Györgyi Medical Center, University of Szeged, Korányi fasor 6., H-6720 Szeged, Hungary

^* zolei-szenasi.daniel@med.u-szeged.hu

Received: 3 December 2014
Revised: 28 May 2015

Abstract

Laser Speckle Contrast Analysis (LASCA) has been proven to be a highly useful tool for the full-field determination of the blood perfusion of a variety of tissues. Some of the major advantages of this technique are its relatively high spatial and temporal resolution as well as its good or excellent accordance to Doppler systems. However, traditionally it is only able to report a single characteristic speed regarding to the actual range of interest. This might be misleading if multiple characteristic speeds are present (e. g. tremor and perfusion in skin) or if several kinds of tissues are mixed (e. g. parenchyma and vessels in brain). Here we present two relatively simple extensions of LASCA for these problems. The application of multiple autocorrelation functions (combined with the usage of multiple exposure times) can help in the separation of multiple characteristic speeds. We also present a useful method for the separation of information those originate from a mixture of different tissues. The latter method can be also implemented to single-exposure systems.