Affiliations: University of Greifswald, Department of Dermatology, Fleischmannstr. 42‐44, 17487 Greifswald, Germany E‐mail: [email protected], juenger@uni‐greifswald.de
Abstract: A basic tool in microcirculation research is laser Doppler fluxmetry (LDF). The chaotic behaviour of the measured LDF‐time series acquires mathematical tools like, for instance, Wavelets. The notion of contrast is known as useful tool to measure differences between two LDF‐time series [K. Bräuer, Chaos, Attraktoren und Fraktale, Logos, Berlin, 2002]. The one time series arises from the blood flow in healthy skin and the other from a pigmented symmetric contra lateral skin lesion. Our approach is based on taking the contrast from all shorter non‐overlapping time intervals of approximate length 5 or 10 seconds. This gives a sample or more precisely, a time series of contrast values. Our goal is an expert system to decide between malign and beligne lesions by estimating the probability for a maligne lesion. As a data base we again use the same data set as [H.‐M. Häfner, K. Bräuer, M. Eichner, A. Steins, M. Möhrle, A. Blum and M. Jünger, Wavelet analysis of cutaneous blood flow in melanocytic skin lesions, J. Vasc. Res., submitted]. The statistical tool is logistic regression. We can show that 93% of data are correctly classified. If we check the expert system against the independent data base of the Greifswald dermatology department we get 78% correctly classified cases. Further work must be done to find a well distributed data base for an expert release system.
