title: Quantitative analysis of 180 degree turns for fall risk assessment using video sensors.
abstract: In this paper, we present a method for quantitatively and objectively assessing 180 degree turns using low cost video sensors. A three-dimensional voxel reconstruction, which is built using silhouettes captured from two calibrated web camera views, is used to represent the human body. Experiments were conducted in which participants performed the standard Timed Up and Go tests where 180 degree turns are evaluated. Our two calibrated cameras captured the images during the test. Two key parameters including turn time and turn steps are extracted using the voxel data. Good agreement for the turn time was found for our system compared to the expert rating. The extracted numbers of turn steps are one step less than the expert rating in many test runs. The difference comes mainly from the nature of the pivot turns, and the turn time difference between the expert rating and the algorithm, namely the determination of the time duration from the beginning to the end of the turn. The development of this technology provides potential for assessing 180 degree turns in the home setting as part of a balance, stability and fall risk assessment tool.
authors.affiliation: Electrical andComputer Engineering Dept, University of Missouri, Columbia, MO65211, USA. fwnf5@mail.mizzou.edu
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.forename: Marjorie
authors.initials: M
authors.lastname: Skubic
authors.forename: Carmen
authors.initials: C
authors.lastname: Abbott
authors.forename: James M
authors.initials: JM
authors.lastname: Keller
mesh_terms: D000058:Accidental Falls / Q000517:prevention & control*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D008875:Middle Aged; D015203:Reproducibility of Results; D018570:Risk Assessment; D013997:Time Factors; D014743:Videotape Recording / Q000295:instrumentation*; D016138:Walking