A Portable, Inexpensive Point-Tracking System for Validation of Wearable Biomechanics Sensors

G. P. Bailey, R. K. Harle

Abstract

In-field validation of the accuracy of wearable sensors is desirable since algorithms that perform well in a laboratory setting may not perform as well in real-world use. However, the use cases can be challenging. For example, a foot worn wearable designed to measure foot trajectory should expect to be used in a variety of scenarios ranging from straightforward (running track) to challenging (a woodland area with many undulations). Typically the more challenging the scenario the more difficult it is to get ground truth with conventional systems. We describe a low-cost, highly-portable, point tracking system that can be used where space and infrastructure is limited. The system is built around a pair of commodity video cameras in a stereo setup. We demonstrate how to configure the cameras, a novel technique to approximate shutter synchronisation to sub-frame interval, and we benchmark the system indoors against gold-standard motion capture systems. For a runner 3 m from the cameras were able to recover their foot trajectory with a mean spatial deviation of 1.7±1.1 cm.

References

  1. Bailey, G. P. and Harle, R. (2014a). Assessment of foot kinematics during steady state running using a footmounted IMU. In Procedia Engineering, volume 72, pages 32-37.
  2. Bailey, G. P. and Harle, R. K. (2014b). Investigation of Sensor Parameters for Kinematic Assessment of Steady State Running Using Foot Mounted IMUs. In Proceedings of the 2nd International Congress on Sports Sciences Research and Technology Support, pages 154-161. SCITEPRESS - Science and and Technology Publications.
  3. Bailey, G. P. and Harle, R. K. (2015). Measuring Temporal Parameters of Gait with Foot Mounted IMUs in Steady State Running. In Proceedings of the 3rd International Congress on Sport Sciences Research and Technology Support, number icSPORTS, pages 24- 33. SCITEPRESS - Science and and Technology Publications.
  4. Bichler, S., Ogris, G., Kremser, V., Schwab, F., Knott, S., and Baca, A. (2012). Towards high-precision IMU/GPS-based stride-parameter determination in an outdoor runners' scenario. In Procedia Engineering, volume 34, pages 592-597.
  5. Foxlin, E. (2005). Pedestrian tracking with shoe-mounted inertial sensors. IEEE Computer Graphics and Applications, 25(6):38-46.
  6. Hartley, R. I. and Zisserman, A. (2004). Multiple View Geometry in Computer Vision. Cambridge University Press, ISBN: 0521540518, second edition.
  7. Heikkilä, J. and Silvén, O. (1997). A Four-step Camera Calibration Procedure with Implicit Image Correction. Cvpr, pages 1106-1112.
  8. Mariani, B., Hoskovec, C., Rochat, S., Büla, C., Penders, J., and Aminian, K. (2010). 3D gait assessment in young and elderly subjects using foot-worn inertial sensors. Journal of Biomechanics, 43:2999-3006.
  9. Sabatini, A. M., Martelloni, C., Scapellato, S., and Cavallo, F. (2005). Assessment of walking features from foot inertial sensing. IEEE Transactions on Biomedical Engineering, 52:486-494.
  10. Zhang, Z. (2002). A Flexible New Technique for Camera Calibration (Technical Report). IEEE Transactions on Pattern Analysis and Machine Intelligence, 22(11):1330-1334.
Download


Paper Citation


in Harvard Style

P. Bailey G. and K. Harle R. (2016). A Portable, Inexpensive Point-Tracking System for Validation of Wearable Biomechanics Sensors . In Proceedings of the 4th International Congress on Sport Sciences Research and Technology Support - Volume 1: icSPORTS, ISBN 978-989-758-205-9, pages 115-123. DOI: 10.5220/0006082601150123


in Bibtex Style

@conference{icsports16,
author={G. P. Bailey and R. K. Harle},
title={A Portable, Inexpensive Point-Tracking System for Validation of Wearable Biomechanics Sensors},
booktitle={Proceedings of the 4th International Congress on Sport Sciences Research and Technology Support - Volume 1: icSPORTS,},
year={2016},
pages={115-123},
publisher={SciTePress},
organization={INSTICC},
doi={10.5220/0006082601150123},
isbn={978-989-758-205-9},
}


in EndNote Style

TY - CONF
JO - Proceedings of the 4th International Congress on Sport Sciences Research and Technology Support - Volume 1: icSPORTS,
TI - A Portable, Inexpensive Point-Tracking System for Validation of Wearable Biomechanics Sensors
SN - 978-989-758-205-9
AU - P. Bailey G.
AU - K. Harle R.
PY - 2016
SP - 115
EP - 123
DO - 10.5220/0006082601150123