Patent ID: 9592013
Date: 2017-03-14
CPC Classifications: A61B,G01C,G06K

Claim:
1. Method for determining an instant velocity of a user using a sensing device destined to be worn on an arm of the user and comprising a motion sensor for measuring and delivering a motion signal representative of the user's movements when the sensing device is worn; the method comprising: measuring the motion signal; identifying when the user is performing a rhythmical activity and estimating a fundamental movement frequency of the user from the measured motion signal; identifying when the user is walking or running by calculating an activity level of the user using the measured motion signal and the fundamental movement frequency; when the user is walking or running, providing a relationship between the measured motion signal and corresponding features of the user's motion which are indicative of a propulsive impulsion of a user's step, by using a bio-mechanical model of human locomotion comprising an active damper model wherein the user's arms act as an active damper of torque produced by a propulsive phase of the user's legs; estimating a frequency of the user's step and estimating a user-relative step length of the user's step using the motion features; determining a user-relative instant velocity by combining the estimated user's step frequency and the estimated user-relative step length; and determining the instant velocity from the user-relative instant velocity using a calibration factor.