A Method of Speed Control during Over-Ground Walking: Using a Digital Light-Emitting Diode Light Strip

Abstract:

The purpose of this report was to introduce the design of a portable, inexpensive and programmable digital light-emitting diode (LED) system to control overground walking speed. The system includes a custom-made 10 meters digital LED strip and a digital microcontroller. By controlling the duration time of the power supply to each LED unit, a visible running lights signal can provide a visual cue for speed control. To evaluate this design, five subjects were asked to walk overground while following the LED visual cue at five different target speeds. The actual walking speeds were determined using Vicon motion capture system. The results of this evaluation showed a good match between the actual and desired speeds. The average percent difference was 2.51%, measured over 250 walking trials by the subjects. 98% of trials had an percent difference smaller than 6.5%, which is the maximum tolerated error within the literature. The inter-trial reliability for the LED speed control system ranged from 0.85 to 0.88 for faster speeds (1.6 m/s, 1.4 m/s), and slightly lower ranging from 0.74 to 0.79 at slower speeds (1.2 m/s, 1.0 m/s, 0.8 m/s).

• Periodical: Advanced Materials Research (Volumes 718-720)
• Pages: 1371-1376
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.718-720.1371
• Online since: July 2013
• Authors: Liang Huang, Jie Zhuang, Yan Xin Zhang
• Keywords: Gait Analysis, LED, Light Strip, Microchip, Overground Walking, PWM

References

[1] J. Leitch, et al., "Identifying gait events without a force plate during running: a comparison of methods," Gait Posture, vol. 33, pp.130-2, Jan 2011.

DOI: 10.1016/j.gaitpost.2010.06.009

[2] S. J. Lee and J. Hidler, "Biomechanics of overground vs. treadmill walking in healthy individuals," J Appl Physiol, vol. 104, pp.747-55, Mar 2008.

DOI: 10.1152/japplphysiol.01380.2006

[3] S. Vallabhajosula, et al., "Do lower-extremity joint dynamics change when stair negotiation is initiated with a self-selected comfortable gait speed ?" Gait & Posture, 2011.

DOI: 10.1016/j.gaitpost.2011.09.007

[4] P. Van de Walle, et al., "Age-related changes in mechanical and metabolic energy during typical gait," Gait Posture, vol. 31, pp.495-501, Apr 2010.

DOI: 10.1016/j.gaitpost.2010.02.008

[5] B. C. Bennett, et al., "Angular momentum of walking at different speeds," Hum Mov Sci, vol. 29, pp.114-24, Feb 2010.

[6] M. Q. Liu, et al., "Muscle contributions to support and progression over a range of walking speeds," Journal of biomechanics, vol. 41, pp.3243-3252, 2008.

DOI: 10.1016/j.jbiomech.2008.07.031

[7] D. D. Espy, et al., "Control of center of mass motion state through cuing and decoupling of spontaneous gait parameters in level walking," J Biomech, vol. 43, pp.2548-53, Sep 17 2010.

DOI: 10.1016/j.jbiomech.2010.05.015

[8] R. D. Dupuis and M. R. Krames, "History, development, and applications of high-brightness visible light-emitting diodes," Journal of Lightwave Technology, vol. 26, pp.1154-1171, 2008.

DOI: 10.1109/jlt.2008.923628

[9] A. M. Trzynadlowski, Introduction to modern power electronics: Wiley, 2010.

[1] J. van der Geer, J.A.J. Hanraads, R.A. Lupton, The art of writing a scientific article, J. Sci. Commun. 163 (2000) 51-59.