Patent ID: 6165131
Filing Date: 2000-12-26
Classification: A61B,G16H,Y10S

Abstract:
A method for indirectly measuring, by application of fuzzy logic rules, a physical signal to be monitored which would be difficult to directly measure and which has at least first and second significant values, the significant values splitting the physical signal to be monitored over time into a first operational zone corresponding to values below the first significant value, a second operational zone corresponding to values between the first and second significant values, and a third operational zone corresponding to values above the second significant value, only the second operational zone being involved by the presence of a periodic index signal related to the physical signal to be monitored, the method comprising the steps of:obtaining a derived physical signal from the physical signal to be monitored, the derived physical signal having a similar behavior as the physical signal to be monitored, but relatively small influence thereon, and being related to the periodic index signal;measuring a value of the derived physical signal and its variations over time at selected check points;determining a presence or absence of the periodic index signal using a first set of fuzzy logic rules; andmeasuring the second and first significant values of the physical signal to be monitored as start and end values, respectively, of the second operational zone, the start and end values correspond to a start and an end of the detection of the presence of the periodic index signal.