Abstract: The system includes an assortment (10) of sensors (10a, 10b, 10c), the working electrode (14a) of each sensor being covered with a specific reagent of a given proteolytic enzyme, including a substrate capable of releasing leaving groups (LG) via the action of said enzyme, a measuring apparatus (20) having an electronic circuit imposing a current, whose intensity or voltage may or may not be variable, between the electrodes, and for receiving in return a signal representative of the release of the LG, and an electronic apparatus (30) for processing the transmitted signal and displaying, on a display screen (32), an indication representative of the release of the LG as a function of time. Application to determination, in a plasma or whole blood sample, of the factors responsible for a coagulation anomaly.