Patent ID: 7233872
Filing Date: 2007-06-19
Classification: A61B,G01C

Abstract:
1. A difference correcting method for a posture determining instrument equipped with at least an acceleration sensor to determine a posture and/or a position in a predetermined coordinate system, the method comprising: determining a direction of gravity in an initial still state by the acceleration sensor; moving the initial direction of gravity associatively with a motion of the posture determining instrument in the coordinate system to calculate a direction of gravity after the motion; setting the acceleration sensor in a still state to measure a direction of gravity after a passage of optional time; comparing the measured direction of gravity of the still state with the direction of gravity after the motion in the coordinate system, and regarding a difference therebetween as an error; correcting a measured value of the posture and/or the position in the coordinate system based on the error; and outputting the corrected measured value.