title: Inclination measurement of human movement using a 3-D accelerometer with autocalibration.
abstract: In the medical field, accelerometers are often used for measuring inclination of body segments and activity of daily living (ADL) because they are small and require little power. A drawback of using accelerometers is the poor quality of inclination estimate for movements with large accelerations. This paper describes the design and performance of a Kalman filter to estimate inclination from the signals of a triaxial accelerometer. This design is based on assumptions concerning the frequency content of the acceleration of the movement that is measured, the knowledge that the magnitude of the gravity is 1 g and taking into account a fluctuating sensor offset. It is shown that for measuring trunk and pelvis inclination during the functional three-dimensional activity of stacking crates, the inclination error that is made is approximately 20 root-mean square. This is nearly twice as accurate as compared to current methods based on low-pass filtering of accelerometer signals.
authors.affiliation: Institute of Biomedical Technology, Biomedical Signals and Systems, Department of Electrical Engineering, University of Twente, Enschede 7500 AE, the Netherlands. luinge@inertia.nl
authors.forename: Henk J
authors.initials: HJ
authors.lastname: Luinge
authors.forename: Peter H
authors.initials: PH
authors.lastname: Veltink
mesh_terms: D000054:Acceleration; D000465:Algorithms; D002138:Calibration; D006112:Gravitation; D006801:Humans; D017770:Lifting; D018670:Monitoring, Ambulatory / Q000295:instrumentation* / Q000379:methods*; D009068:Movement / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D013131:Spine / Q000502:physiology; D013647:Task Performance and Analysis; D013909:Thorax / Q000502:physiology; D014159:Transducers