Ambulatory Assessment of Instantaneous Velocity during Walking Using Inertial Sensor MeasurementsReportar como inadecuado


Ambulatory Assessment of Instantaneous Velocity during Walking Using Inertial Sensor Measurements


Ambulatory Assessment of Instantaneous Velocity during Walking Using Inertial Sensor Measurements - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

The BioRobotics Institute, Scuola Superiore Sant’Anna, 56127 Pisa, Italy





*

Author to whom correspondence should be addressed.



Academic Editor: Vittorio M. N. Passaro

Abstract A novel approach for estimating the instantaneous velocity of the pelvis during walking was developed based on Inertial Measurement Units IMUs. The instantaneous velocity was modeled by the sum of a cyclical component, decomposed in the Medio-Lateral ML, VerTical VT and Antero-Posterior AP directions, and the Average Progression Velocity APV over each gait cycle. The proposed method required the availability of two IMUs, attached to the pelvis and one shank. Gait cycles were identified from the shank angular velocity; for each cycle, the Fourier series coefficients of the pelvis and shank acceleration signals were computed. The cyclical component was estimated by Fourier-based time-integration of the pelvis acceleration. A Bayesian Linear Regression BLR with Automatic Relevance Determination ARD predicted the APV from the stride time, the stance duration, and the Fourier series coefficients of the shank acceleration. Healthy subjects performed tasks of Treadmill Walking TW and Overground Walking OW, and an optical motion capture system OMCS was used as reference for algorithm performance assessment. The widths of the limits of agreements ±1.96 standard deviation were computed between the proposed method and the reference OMCS, yielding, for the cyclical component in the different directions: ML: ±0.07 m-s ±0.10 m-s; VT: ±0.03 m-s ±0.05 m-s; AP: ±0.06 m-s ±0.10 m-s, in TW OW conditions. The ARD-BLR achieved an APV root mean square error of 0.06 m-s 0.07 m-s in the same conditions. View Full-Text

Keywords: body center of mass; walking speed; inertial measurement unit; Fourier harmonic analysis; Bayesian methods; regression body center of mass; walking speed; inertial measurement unit; Fourier harmonic analysis; Bayesian methods; regression





Autor: Angelo Maria Sabatini * and Andrea Mannini

Fuente: http://mdpi.com/



DESCARGAR PDF




Documentos relacionados