Whole Body Center of Mass Estimation with Portable Sensors: Using the Statically Equivalent Serial Chain and a Kinect

Sensors

Alejandro González¹  Mitsuhiro Hayashibe¹  Vincent Bonnet² 

[1] INRIA (Institut National de Recherche en Informatique et en Automatique), DEMAR Team, Montpellier 34095, France; E-Mails:;Movement to Health (M2H) Laboratory, EuroMov, University of Montpellier 1, Montpellier 34090, France; E-Mail:

关键词: statically equivalent serial chain (SESC);    identification;    center of mass (CoM);    subject-specificity;    Kinect;   

DOI  :  10.3390/s140916955

来源: mdpi

【 摘 要 】

The trajectory of the whole body center of mass (CoM) is useful as a reliable metric of postural stability. If the evaluation of a subject-specific CoM were available outside of the laboratory environment, it would improve the assessment of the effects of physical rehabilitation. This paper develops a method that enables tracking CoM position using low-cost sensors that can be moved around by a therapist or easily installed inside a patient's home. Here, we compare the accuracy of a personalized CoM estimation using the statically equivalent serial chain (SESC) method and measurements obtained with the Kinect to the case of a SESC obtained with high-end equipment (Vicon). We also compare these estimates to literature-based ones for both sensors. The method was validated with seven able-bodied volunteers for whom the SESC was identified using 40 static postures. The literature-based estimation with Vicon measurements had a average error 24.9 ± 3.7 mm; this error was reduced to 12.8 ± 9.1 mm with the SESC identification. When using Kinect measurements, the literature-based estimate had an error of 118.4 ± 50.0 mm, while the SESC error was 26.6 ± 6.0 mm. The subject-specific SESC estimate using low-cost sensors has an equivalent performance as the literature-based one with high-end sensors. The SESC method can improve CoM estimation of elderly and neurologically impaired subjects by considering variations in their mass distribution.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.