Published in

BioMed Central, BioMedical Engineering OnLine, 1(9), 2010

DOI: 10.1186/1475-925x-9-37

Links

Tools

Export citation

Search in Google Scholar

Extraction of user's navigation commands from upper body force interaction in walker assisted gait

This paper is made freely available by the publisher.
This paper is made freely available by the publisher.

Full text: Download

Green circle
Preprint: archiving allowed
Green circle
Postprint: archiving allowed
Green circle
Published version: archiving allowed
Data provided by SHERPA/RoMEO

Abstract

[Background]: The advances in technology make possible the incorporation of sensors and actuators in rollators, building safer robots and extending the use of walkers to a more diverse population. This paper presents a new method for the extraction of navigation related components from upper-body force interaction data in walker assisted gait. A filtering architecture is designed to cancel: (i) the high-frequency noise caused by vibrations on the walker's structure due to irregularities on the terrain or walker's wheels and (ii) the cadence related force components caused by user's trunk oscillations during gait. As a result, a third component related to user's navigation commands is distinguished. [Results]: For the cancelation of high-frequency noise, a Benedict-Bordner g-h filter was designed presenting very low values for Kinematic Tracking Error ((2.035 ± 0.358)·10-2 kgf) and delay ((1.897 ± 0.3697)·101ms). A Fourier Linear Combiner filtering architecture was implemented for the adaptive attenuation of about 80% of the cadence related components' energy from force data. This was done without compromising the information contained in the frequencies close to such notch filters. [Conclusions]: The presented methodology offers an effective cancelation of the undesired components from force data, allowing the system to extract in real-time voluntary user's navigation commands. Based on this real-time identification of voluntary user's commands, a classical approach to the control architecture of the robotic walker is being developed, in order to obtain stable and safe user assisted locomotion. ; 16 páginas, 11 figuras, 2 tablas. ; The authors would like to thank the Spanish National Program of R&D - DPI that supports the Simbiosis Project (DPI2005-07417). Written consent for publication was obtained from the patient or their relative. The SIMBIOSIS Project is placed in the framework of the Spanish National Program of R&D and it is approved, along with the experimental and validation procedures, by Spanish Ministry of Science and Innovation (MICINN).