Soft Wearable Motion Sensing Suit for Lower Limb Biomechanics Measurements - Robotics Institute Carnegie Mellon University

Soft Wearable Motion Sensing Suit for Lower Limb Biomechanics Measurements

Yigit Menguc, Yong-Lae Park, Ernesto Martinez-Villalpando, Patrick Aubin, Miriam Zisook, Leia Stirling, Robert J. Wood, and Conor J. Walsh
Conference Paper, Proceedings of (ICRA) International Conference on Robotics and Automation, pp. 5289 - 5296, May, 2013

Abstract

Motion sensing has played an important role in the study of human biomechanics as well as the entertainment industry. Although existing technologies, such as optical or inertial based motion capture systems, have relatively high accuracy in detecting body motions, they still have inherent limitations with regards to mobility and wearability. In this paper, we present a soft motion sensing suit for measuring lower extremity joint motion. The sensing suit prototype includes a pair of elastic tights and three hyperelastic strain sensors. The strain sensors are made of silicone elastomer with embedded microchannels filled with conductive liquid. To form a sensing suit, these sensors are attached at the hip, knee, and ankle areas to measure the joint angles in the sagittal plane. The prototype motion sensing suit has significant potential as an autonomous system that can be worn by individuals during many activities outside the laboratory, from running to rock climbing. In this study we characterize the hyperelastic sensors in isolation to determine their mechanical and electrical responses to strain, and then demonstrate the sensing capability of the integrated suit in comparison with a ground truth optical motion capture system. Using simple calibration techniques, we can accurately track joint angles and gait phase. Our efforts result in a calculated trade off: with a maximum error less than 8%, the sensing suit does not track joints as accurately as optical motion capture, but its wearability means that it is not constrained to use only in a lab.

BibTeX

@conference{Menguc-2013-7712,
author = {Yigit Menguc and Yong-Lae Park and Ernesto Martinez-Villalpando and Patrick Aubin and Miriam Zisook and Leia Stirling and Robert J. Wood and Conor J. Walsh},
title = {Soft Wearable Motion Sensing Suit for Lower Limb Biomechanics Measurements},
booktitle = {Proceedings of (ICRA) International Conference on Robotics and Automation},
year = {2013},
month = {May},
pages = {5289 - 5296},
}