Schemes for obtaining estimation of physiological feature of specific user, establishing profile of physiological feature of specific user, and for establishing/managing/grading profiles of different users

A method for obtaining an estimation of a physiological feature of a specific user includes: using a physiological sensor device under a normal sensing mode to sense the physiological feature of the specific user to generate a physiological signal of the normal sensing mode; determining a matched physiological signal from a plurality of test physiological signals by comparing the plurality of test physiological signals with the physiological signal of the normal sensing mode; and calculating a resultant estimation of the physiological feature of the specific user according to the matched physiological signal and the profile of the physiological feature of the specific user.