The disclosure relates to the field a method of and apparatus for processing a photoplethysmograph signal to support the analysis of photoplethysmograph signals in clinical scenarios. A derivative of a photoplethysmograph signal acquired over a time period is calculated. The derivative of the acquired photoplethysmograph signal with respect to time is analyzed and displayed in an x-y diagram as a function of the acquired photoplethysmograph signal or vice versa.
