Advanced sensor device for shape analysis of the tissue-reflected mean single period photoplethysmography (PPG) signals have been designed and clinically tested. The PPG signal shape reveals individual features of the patient's cardiovascular state. Clinical studies of several patient groups (e.g. diabetes mellitus, atherosclerosis obliterans, Reynaud’s syndrome) made it possible to specify components of the PPG signal that are sensitive to the corresponding organic or functional pathologies. Comparison of the right and left arm finger PPG signal shapes, for instance, appears to be an efficient tool for early screening of unilateral atherosclerosis obliterans.