System and method for determining the posture of a person

Patent metadata

Field	Value
Publication number	US-9445752-B2
Application number	US-201013264965-A
Country	US
Kind code	B2
Filing date	Apr 26, 2010
Priority date	Apr 24, 2009
Publication date	Sep 20, 2016
Grant date	Sep 20, 2016

Abstract

A system for determining the posture of a person has a motion sensor (CM) with at least one axis of measurement, which is provided with fixing means (MF) for rigidly connecting said motion sensor (CM) to a user. Analysis means (AN) are also included for determining a posture of the user. The analysis means (AN) utilize: (A) joint densities of probabilities of a low-frequency component and a high-frequency component, these densities of probabilities being defined for each posture; and (B) probabilities of transition between two successive postures.

First claim

The invention claimed is:

1. A system for determining a posture of a person, comprising:
at least one motion sensor configured to be affixed to the person, the at least one motion sensor configured to measure k measurement axes, k being greater than or equal to two;
at least one filter coupled to the at least one motion sensor and configured to generate output signals that include first signals with frequencies higher than a first threshold selected for each axis of measurement, and second signals with frequencies below a second threshold lower than or equal to said first threshold;
a calculation module configured to calculate a density of probability of a first variable representing said first signals, said first variable modeled by a Chi-2 law with a degree of freedom equal to k, and to calculate a density of probability of a second variable representing said second signals, said second variable being a one-dimensional variable representative of the second signals along the k axes of measurement and being modeled by a Gaussian law; and
an analysis module configured to determine a posture of the person out of a plurality of postures by combining:
joint densities of probabilities of said first and second variables, the joint densities of probabilities being defined for each posture of the plurality of postures; and
probabilities of transition between two successive postures of the plurality of postures.

2. The system of claim 1 , wherein the calculation module is further configured to calculate the joint densities of probabilities (P(x(n),y(n))) defined at values of the second variable and the first variable by computing the product of a density of probability P x,i of obtaining a value (x(n)) for the second variable and a density of probability P y,i of obtaining a value (y(n)) for the first variable, the density of probability P x,i of obtaining the value (x(n)) and the density of probability P y,i of obtaining the value (y(n)) being defined for each state i by the following expressions:

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Assignees

• Jallon Pierre
• Commissariat Energie Atomique
• Movea

Inventors

• Jallon Pierre

Classifications

• G06F2218/00

  Aspects of pattern recognition specially adapted for signal processing · CPC title

• A61B5/1118

  Determining activity level · CPC title

• A61B5/1123

  Discriminating type of movement, e.g. walking or running (A61B5/1116, A61B5/112 take precedence) · CPC title

• A61B5/1116 Primary

  Determining posture transitions · CPC title

• G06K9/00335

  Physics · mapped topic