US Patent 7877226 Apparatus and method for counting exercise repetitions

An apparatus and method for counting exercise repetitions are provided for counting exercise repetition even when an exerciser attaches the apparatus in different places and along different orientations of his or her body. The apparatus and method utilizes acceleration data along at least three axes and determines that a valid step is taken by the exerciser if at least one of acceleration profiles falls within at least one of pre-defined thresholds. Moreover, a method of identifying an optimal axis for exercise repetition measurement is disclosed by comparing the acceleration profiles of previous steps with amplitude, cycle and rhythm thresholds.