Time-frequency analysis and laser Doppler spectrum decomposition to reveal new feature space for diagnosis of diabetes mellitus vascular complications

Early diagnostics of microcirculation complications is an important area for biomedical photonics application. The blood perfusion measurements are capable of identification of particular markers for diagnostics of many pathological conditions of blood microcirculation in the skin. In this work, we apply the laser Doppler flowmetry method with the ability to record and process the power spectra of registered photocurrent. This approach provides the estimation of signal amplitude distribution along with the frequencies of Doppler-broadened laser radiation and blood perfusion distribution. In this work, we investigate the blood flow in the skin by the time-frequency analysis of the recorded laser Doppler spectra. The conducted studies allowed us to propose new diagnostic criteria for the diagnosis of diabetes mellitus type 2 complications. The diagnostic parameters have been tested together with binary classifiers based on the linear discriminant analysis and demonstrated to be able to successfully distinguish the groups of volunteers of different age and patients with microvascular complications.