title: Autonomous Quality Control of Joint Orientation Measured with Inertial Sensors.
abstract: Clinical mobility assessment is traditionally performed in laboratories using complex and expensive equipment. The low accessibility to such equipment, combined with the emerging trend to assess mobility in a free-living environment, creates a need for body-worn sensors (e.g., inertial measurement units-IMUs) that are capable of measuring the complexity in motor performance using meaningful measurements, such as joint orientation. However, accuracy of joint orientation estimates using IMUs may be affected by environment, the joint tracked, type of motion performed and velocity. This study investigates a quality control (QC) process to assess the quality of orientation data based on features extracted from the raw inertial sensors' signals. Joint orientation (trunk, hip, knee, ankle) of twenty participants was acquired by an optical motion capture system and IMUs during a variety of tasks (sit, sit-to-stand transition, walking, turning) performed under varying conditions (speed, environment). An artificial neural network was used to classify good and bad sequences of joint orientation with a sensitivity and a specificity above 83%. This study confirms the possibility to perform QC on IMU joint orientation data based on raw signal features. This innovative QC approach may be of particular interest in a big data context, such as for remote-monitoring of patients' mobility.
authors.affiliation: Faculty of Medicine and Health Sciences, Orthopedic service, department of surgery, Universit&#233; de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada. Karina.Lebel@usherbrooke.ca.|Research Center on Aging, Sherbrooke, QC J1H 4C4, Canada. Karina.Lebel@usherbrooke.ca.|Interdisciplinary Institute for Technological Innovation (3IT), Universit&#233; de Sherbrooke, Sherbrooke, QC J1K 0A5, Canada. Karina.Lebel@usherbrooke.ca.
authors.forename: Karina
authors.initials: K
authors.lastname: Lebel
authors.affiliation: Faculty of Medicine and Health Sciences, Orthopedic service, department of surgery, Universit&#233; de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada. patrick.boissy@usherbrooke.ca.|Research Center on Aging, Sherbrooke, QC J1H 4C4, Canada. patrick.boissy@usherbrooke.ca.|Interdisciplinary Institute for Technological Innovation (3IT), Universit&#233; de Sherbrooke, Sherbrooke, QC J1K 0A5, Canada. patrick.boissy@usherbrooke.ca.
authors.forename: Patrick
authors.initials: P
authors.lastname: Boissy
authors.affiliation: D&#233;partement des Sciences de l'activit&#233; Physique, Universit&#233; du Qu&#233;bec &#224; Montr&#233;al, Montreal, QC H2X 1Y4, Canada. hpnguyen@utexas.edu.|Centre de Recherche Institut Universitaire de G&#233;riatrie de Montr&#233;al, Montreal, QC H3W 1W4, Canada. hpnguyen@utexas.edu.
authors.forename: Hung
authors.initials: H
authors.lastname: Nguyen
authors.affiliation: D&#233;partement des Sciences de l'activit&#233; Physique, Universit&#233; du Qu&#233;bec &#224; Montr&#233;al, Montreal, QC H2X 1Y4, Canada. duval.christian@uqam.ca.|Centre de Recherche Institut Universitaire de G&#233;riatrie de Montr&#233;al, Montreal, QC H3W 1W4, Canada. duval.christian@uqam.ca.
authors.forename: Christian
authors.initials: C
authors.lastname: Duval
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D006801:Humans; D007596:Joints / Q000502:physiology*; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000295:instrumentation* / Q000592:standards*; D016571:Neural Networks, Computer; D011786:Quality Control; D055815:Young Adult
keywords: 3D orientation tracking; AHRS; IMU; MARG; MIMU; artificial neural network; attitude and heading reference system; inertial motion capture; inertial sensors; joint orientation; quality control