Analysis of changes in blood flow oscillations under different probe pressure using laser Doppler spectrum decomposition

Abstract

Presently, in the modern laser Doppler flowmetry (LDF) the distribution of blood perfusion and its changes along the Doppler shift frequencies are simply ignored and/or not properly addressed. Utilizing the registered power spectrum of photocurrent, we introduce an LDF signal processing approach suitable for expanding of diagnostic capabilities of the technique. In particular, we demonstrate that it is possible to determine how the oscillations of blood flow (cardiac, breathe, myogenic, etc.) are distributed along the Doppler shift frequency. Wavelet analysis is utilized to extract the oscillations corresponded to the particular frequency sub-bands of blood perfusion. The main purpose of this study is to identify influence of local pressure by fiber optic probe on cardiac oscillations and their distribution along frequency of Doppler shift.