Method and system for postural stability assessment

Patent metadata

Field	Value
Publication number	US-11596328-B2
Application number	US-201815914286-A
Country	US
Kind code	B2
Filing date	Mar 7, 2018
Priority date	Jul 7, 2017
Publication date	Mar 7, 2023
Grant date	Mar 7, 2023

Abstract

This disclosure relates generally to health monitoring and assessment systems, and more particularly to perform postural stability assessment of a user and quantify the assessed postural stability. In an embodiment, the system, by monitoring specific actions (which are part of certain tests done for the postural stability assessment) being performed by a user, collects inputs which are then processed to determine SLS duration, the body joint vibration, and the body sway area of the user, while performing the tests. By processing the SLS duration, the body joint vibration, and the body sway area together, a postural stability index score for the user is determined, and based on this score, postural stability assessment for the user is performed.

First claim

What is claimed is:

1. A processor-implemented method for postural stability assessment of a user, said method comprising:
collecting spatio-temporal information of joints of a user through an input/output module via one or more hardware processors of a postural stability assessment system connected to a real-time motion sensor, the spatio-temporal information pertaining to a Single Limb Stance (SLS) duration, body joint vibration, and body sway area, wherein the spatio-temporal information of joints is associated with one or more actions performed by the user being monitored for postural stability assessment, wherein the real-time motion sensor monitors the one or more actions performed by the user and collect one or more real-time inputs,
wherein the spatio-temporal information of joints is collected by processing the real-time inputs of 3-D world co-ordinates (x, y, z) of the joints obtained from the real-time motion sensor, where ‘x’ represents left or right variation, ‘y’ represents up or down variation with respect to a ground and ‘z’ represents to or from variation of the user,
wherein the SLS duration is determined by monitoring a change in lifted leg's ankle y-coordinates in the real-time inputs to get precise timing on when the user lifts one-leg above the ground and also track movement of another leg of the user, and
wherein the body joint vibration is determined by monitoring an acceleration of hip joint center in x, y, z direction in the real-time inputs;

assessing, via the one or more hardware processors, a sway of Center of Mass (CoM) from the spatio-temporal information of joints of the user using a Statistically Equivalent Serial Chain (SESC) that locates the CoM of any linkage by means of serial chain and links in the serial chain are defined by their geometric configuration and mass distribution, wherein a shoulder center and a hip center are considered as a start point and an end point of the serial chain, respectively, wherein a midpoint of the serial chain is estimated to be the CoM, and a projection of the estimated CoM is equivalent to a body sway, and wherein the body sway area is calculated using a convex hull algorithm over the sway of CoM;
determining, via the one or more hardware processors, membership functions by classification of each of the SLS duration, the body joint vibration, and the body sway of all users into categories of good, bad, average, excellent, wherein each of the categories is defined in terms of a range of values, wherein the ranges of the membership functions are determined based on one or more diseases all the users have by:
collecting values for parameters having impact on the users' health; and
determining the ranges for the membership functions of the SLS duration, the body joint vibration, and the body sway area, that match the collected values of the parameters;

determining the SLS duration, the body joint vibration, and the body sway area, of said user as falling under at least one of the categories, via the one or more hardware processors, by comparing values of the SLS duration, the body joint vibration, and the body sway area of said user with the ranges of the membership functions based on one or more diseases the user is suffering from;
dynamically generating a postural stability index score for said user, based on said determined categories of the SLS duration, the body joint vibration, the body sway area, and one or more rules, via the one or more hardware processors, wherein the postural stability index score is generated by combining the range of membership functions of the SLS duration, the body joint vibration, and the body sway area using Fuzzy logic technique based on the one or more rules, wherein the rule comprises determining if the SLS duration is excellent, and the vibration index is good, and the sway area is good, then the postural stability index score is 75 to 100; and
automatically assessing, via the one or more hardware processors, postural stability of said user, by interpreting the postural stability index score, and providing recommendation of medical check up as output to the user, wherein the postural stability index score represents a level of postural stability of the user and indicate potential health risks.

2. A postural stability assessment system, said system comprising:
a processor; and
a memory module comprising a plurality of instructions, said plurality of instructions configured to cause the processor to:
monitor spatio-temporal information of joints of a user, associated with one or more actions being performed by the user and collecting the spatio-temporal information of joints of the user, by an Input/Output (I/O) module via one or more hardware processors of the postural stability assessment system connected to a real-time motion sensor that monitors the one or more actions performed by the user and collect one or more real-time inputs;
determine a value corresponding to Single Limb Stance (SLS) duration of the user, based on the spatio-temporal information, by a SLS duration measurement module of the postural stability assessment system;
determine a value corresponding to body joint vibration of the user, based on the spatio-temporal information, by a body joint vibration determination module of the postural stability assessment system;
determine a value corresponding to body sway area of the user, based on the spatio-temporal information, by a sway area determination module of the postural stability assessment system;
wherein the spatio-temporal information of joints is collected by processing real-time inputs of 3-D world co-ordinates (x, y, z) of the joints obtained from the real-time motion sensor, where ‘x’ represents left/right variation, ‘y’ represents up/down variation with respect to a ground and ‘z’ represents to/from variation of subject,
wherein the SLS duration is determined by monitoring a change in lifted leg's ankle y-coordinates in the real-time inputs to get precise timing on when the user lifts one-leg above the ground and also track movement of another leg of the user, and
wherein the body joint vibration is determined by monitoring an acceleration of hip joint center in x, y, z direction in the real-time inputs,

assess a sway of Center of Mass (CoM) from the spatio-temporal information of joints of the user using a Statistically Equivalent Serial Chain (SESC) that locates the CoM of any linkage by means of serial chain and links in the serial chain are defined by their geometric configuration and mass distribution, wherein a shoulder center and a hip center are considered as a start point and an end point of the serial chain, respectively, wherein a midpoint of the serial chain is estimated to be the CoM, and a projection of the estimated CoM is equivalent to a body sway, and wherein the body sway area is calculated using a convex hull algorithm over the sway of CoM;
determine membership functions by classification of each of the SLS duration, the body joint vibration, and the body sway of all users into categories of good, bad, average, excellent, wherein each of the categories is defined in terms of a range of values, wherein the ranges of the membership functions are determined based on one or more diseases all the users have by:
collecting values for parameters having impact on the users' health; and
determining the ranges for the membership functions of the SLS duration, the body joint vibration, and the body sway area, that match the collected values of the parameters;

determine the SLS duration, the body joint vibration, and the body sway area, of said user as falling under at least one of the categories, by comparing values of the SLS duration, the body joint vibration, and the body sway area of said user with the ranges of the membership function based on one or more diseases the user is suffering from;
dynamically generate a post

Assignees

• Tata Consultancy Services Ltd

Inventors

• Mazumder Oishee
• Chakravarty Kingshuk
• Chatterjee Debatri
• Sinha Aniruddha
• Das Abhijit

Classifications

• A61B5/1122

  of movement trajectories · CPC title

• G16H50/20

  for computer-aided diagnosis, e.g. based on medical expert systems · CPC title

• A61B5/7264 Primary

  Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems · CPC title

• A61B2503/08

  Elderly · CPC title

• A61B5/1128

  using image analysis (A61B5/1127 takes precedence) · CPC title