A method and a system for detecting a crank angle of an engine includes detecting a non-toothed portion of a crank pulse rotor during a inlet valve open period for preventing falsely recognizing compression top dead center as a position of the non-toothed portion. An output of the variable attenuation circuit is detected by a detecting circuit. preferably a blood sample, where the biomarker is differentially expressed in osteoarthritis. In step III, each procedure is allocated stacked register usage based on the quota assignments of step II.