Adaptive model-based system to automatically quantify fall risk

Abstract

A method of conducting a structured test with a user. The structured test includes presenting an instruction to the user to perform at least one action for a test duration to test a current state of the user. Sensor data is received from one or more sensors worn by the user or placed near the user that indicate at least a motion or a posture of the user. The motion or the posture of the user during the structured test is measured with the sensor data. At least one of a timing of providing an instruction to perform at least one action and a test duration of a subsequent structured test is adjusted based on the measured motion or posture of the user, and the subsequent structured test is conducted with the user based on the adjusted at least one of the timing and the test duration.

What is claimed is: 
     
         1 . A computer-implemented method comprising:
 conducting a structured test with a user, the structured test including presenting an instruction to the user to perform at least one action for a test duration to test a current state of the user;   receiving, from one or more sensors worn by the user or placed near the user, sensor data that indicates at least a motion of the user or a posture of the user;   measuring, with the sensor data, the motion of the user or the posture of the user during the structured test;   adjusting at least one of a timing of providing an instruction to the user to perform at least one action for a subsequent structured test and a test duration of the subsequent structured test based on the measured motion of the user or the measured posture of the user; and   conducting the subsequent structured test with the user based on the adjusted at least one of the timing and the test duration.   
     
     
         2 . The computer-implemented method of  claim 1 , wherein the structured test comprises a test for measuring a mean radius of trace of the user while standing. 
     
     
         3 . The computer-implemented method of  claim 2 , wherein presenting the instruction to the user to perform the at least one action to test the current state of the user includes providing an instruction to the user to stand up. 
     
     
         4 . The computer-implemented method of  claim 3 , wherein the measuring the motion of the user or the posture of the user during the structured test includes measuring, with the sensor data, a starting position of the user and the mean radius of trace of the user while the user is standing, wherein the mean radius of trace represents an average distance that the user deviated from the starting position over the test duration. 
     
     
         5 . The computer-implemented method of  claim 3 , wherein measuring the motion of the user or the posture of the user during the structured test includes measuring, with the sensor data, at least one of a pitch, a roll, and a yaw angle of the user during the structured test. 
     
     
         6 . The computer-implemented method of  claim 1 , further comprising providing features based on the sensor data to a classifier trained on data about a plurality of users to generate a score indicating a likelihood of whether an input window is within a fall horizon, wherein the fall horizon is a predetermined period of time that immediately precedes a fall event. 
     
     
         7 . The computer-implemented method of  claim 6 , further comprising, in response to determining that the score is greater than a predetermined threshold, notifying a client device with information about a prediction of a fall risk of the user. 
     
     
         8 . The computer-implemented method of  claim 6 , wherein the features based on the sensor data include a measured mean radius of trace of the user while standing. 
     
     
         9 . The computer-implemented method of  claim 1 , wherein the structured test comprises detecting a center of gravity of the user while standing. 
     
     
         10 . A system, comprising:
 one or more sensors; and   a computing device having logic stored thereon that, in response to execution by the computing device, causes the computing device to perform actions comprising:
 presenting an instruction to a user to perform at least one action of a structured test for a test duration to test a current state of the user; 
 receiving, from the one or more sensors, sensor data that indicates at least a motion of the user or a posture of the user during the structured test; 
 measuring, using the sensor data, the motion of the user or the posture of the user during the structured test; 
 adjusting at least one of a timing of presenting an instruction to the user to perform at least one action for a subsequent structured test and a test duration of the subsequent structured test based on the measured motion of the user or the measured posture of the user; and 
 presenting the instruction to the user to perform at least one action of the subsequent structured test based on the adjusted at least one of the timing and the test duration. 
   
     
     
         11 . The system of  claim 10 , wherein the one or more sensors include at least one sensor worn by the user or placed near the user. 
     
     
         12 . The system of  claim 11 , wherein the computing device is worn by the user, and at least one sensor of the one or more sensors is incorporated into the computing device. 
     
     
         13 . The system of  claim 10 , wherein the structured test comprises a test for measuring a mean radius of trace of the user while standing. 
     
     
         14 . The system of  claim 13 , wherein presenting the instruction to the user to perform the at least one action to test the current state of the user includes providing an instruction to the user to stand up. 
     
     
         15 . The system of  claim 14 , wherein the measuring the motion of the user or the posture of the user during the structured test includes measuring, with the sensor data, a starting position of the user and the mean radius of trace of the user while the user is standing, wherein the mean radius of trace represents an average distance that the user deviated from the starting position over the test duration. 
     
     
         16 . The system of  claim 14 , wherein measuring the motion of the user or the posture of the user during the structured test includes measuring, with the sensor data, at least one of a pitch, a roll, and a yaw angle of the user during the structured test. 
     
     
         17 . The system of  claim 10 , wherein the actions further comprise providing features based on the sensor data to a classifier trained on data about a plurality of users to generate a score indicating a likelihood of whether an input window is within a fall horizon, wherein the fall horizon is a predetermined period of time that immediately precedes a fall event. 
     
     
         18 . The system of  claim 17 , wherein the actions further comprise, in response to determining that the score is greater than a predetermined threshold, notifying a client device with information about a prediction of a fall risk of the user. 
     
     
         19 . The system of  claim 17 , wherein the features based on the sensor data include a measured mean radius of trace of the user while standing. 
     
     
         20 . The system of  claim 10 , wherein the structured test comprises detecting a center of gravity of the user while standing.