title: Gait measurement system for the multi-target stepping task using a laser range sensor.
abstract: For the prevention of falling in the elderly, gait training has been proposed using tasks such as the multi-target stepping task (MTST), in which participants step on assigned colored targets. This study presents a gait measurement system using a laser range sensor for the MTST to evaluate the risk of falling. The system tracks both legs and measures general walking parameters such as stride length and walking speed. Additionally, it judges whether the participant steps on the assigned colored targets and detects cross steps to evaluate cognitive function. However, situations in which one leg is hidden from the sensor or the legs are close occur and are likely to lead to losing track of the legs or false tracking. To solve these problems, we propose a novel leg detection method with five observed leg patterns and global nearest neighbor-based data association with a variable validation region based on the state of each leg. In addition, methods to judge target steps and detect cross steps based on leg trajectory are proposed. From the experimental results with the elderly, it is confirmed that the proposed system can improve leg-tracking performance, judge target steps and detect cross steps with high accuracy.
authors.affiliation: School of Science for Open and Environmental Systems, Graduate School of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan. ayanoriyorozu@a5.keio.jp.
authors.forename: Ayanori
authors.initials: A
authors.lastname: Yorozu
authors.affiliation: Department of Physical Therapy, Human Health Sciences, Graduate School of Medicine, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan. nishiguchi.shu.82s@st.kyoto-u.ac.jp.
authors.forename: Shu
authors.initials: S
authors.lastname: Nishiguchi
authors.affiliation: Graduate School of Comprehensive Human Sciences, University of Tsukuba, 3-29-1 Otsuka, Bunkyo-ku, Tokyo 112-0012, Japan. m-yamada@human.tsukuba.ac.jp.
authors.forename: Minoru
authors.initials: M
authors.lastname: Yamada
authors.affiliation: Department of Physical Therapy, Human Health Sciences, Graduate School of Medicine, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan. blue@hs.med.kyoto-u.ac.jp.
authors.forename: Tomoki
authors.initials: T
authors.lastname: Aoyama
authors.affiliation: Research & Development Division, Murata Machinery, Ltd., 136 Takeda-Mukaishiro-cho, Fushimi-ku, Kyoto 612-8686, Japan. toshiki.moriguchi@drw.muratec.co.jp.
authors.forename: Toshiki
authors.initials: T
authors.lastname: Moriguchi
authors.affiliation: Department of System Design Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan. takahashi@sd.keio.ac.jp.
authors.forename: Masaki
authors.initials: M
authors.lastname: Takahashi
mesh_terms: D000058:Accidental Falls / Q000517:prevention & control*; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001696:Biomechanical Phenomena / Q000502:physiology*; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D007866:Leg / Q000502:physiology; D008297:Male; D018670:Monitoring, Ambulatory / Q000295:instrumentation* / Q000379:methods*; D016138:Walking / Q000502:physiology
keywords: Kalman filter; data association; gait measurement; laser range sensor