Format

Send to

Choose Destination
Sensors (Basel). 2016 Dec 10;16(12). pii: E2090.

An IMU-to-Body Alignment Method Applied to Human Gait Analysis.

Author information

1
Postgraduate Program in Electrical Engineering, Federal University of Espirito Santo (UFES), 29075-910 Vitória-ES, Brazil. laura.valencia@aluno.ufes.br.
2
Postgraduate Program in Biotechnology, Federal University of Espirito Santo (UFES), 29040-090 Vitória-ES, Brazil. arlindo.elias@aluno.ufes.br.
3
Postgraduate Program in Electrical Engineering, Federal University of Espirito Santo (UFES), 29075-910 Vitória-ES, Brazil. e.rocon@csic.es.
4
Neural and Cognitive Engineering Group, Centro de Automática y Robótica, CSIC-UPM, 28500 Madrid, Spain. e.rocon@csic.es.
5
Postgraduate Program in Electrical Engineering, Federal University of Espirito Santo (UFES), 29075-910 Vitória-ES, Brazil. teodiano.bastos@ufes.br.
6
Postgraduate Program in Electrical Engineering, Federal University of Espirito Santo (UFES), 29075-910 Vitória-ES, Brazil. frizera@ieee.org.

Abstract

This paper presents a novel calibration procedure as a simple, yet powerful, method to place and align inertial sensors with body segments. The calibration can be easily replicated without the need of any additional tools. The proposed method is validated in three different applications: a computer mathematical simulation; a simplified joint composed of two semi-spheres interconnected by a universal goniometer; and a real gait test with five able-bodied subjects. Simulation results demonstrate that, after the calibration method is applied, the joint angles are correctly measured independently of previous sensor placement on the joint, thus validating the proposed procedure. In the cases of a simplified joint and a real gait test with human volunteers, the method also performs correctly, although secondary plane errors appear when compared with the simulation results. We believe that such errors are caused by limitations of the current inertial measurement unit (IMU) technology and fusion algorithms. In conclusion, the presented calibration procedure is an interesting option to solve the alignment problem when using IMUs for gait analysis.

KEYWORDS:

anatomical calibration; human motion analysis; inertial sensor; joint angular kinematics; technical frames

PMID:
27973406
PMCID:
PMC5191070
DOI:
10.3390/s16122090
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Multidisciplinary Digital Publishing Institute (MDPI) Icon for PubMed Central
Loading ...
Support Center