Quantifying sway through surface deflection patterns: A novel approach using distributive tactile sensing

Abstract This paper describes an experiment that extends the distributive sensing approach to identify the three-dimensional location of an object in constant motion. Distributive sensing has previously been successful in the identification of size and location of statically placed objects. Here, a novel system is developed to measure balance or sway in patients. The experimental set-up consisted of a pendulum structure positioned on a supported steel plate. Three low-cost deflection sensors were positioned under the plate with the resulting signals used as inputs to a neural network implemented on a field-programmable gate array. The results show that the embedded system can accurately track the pendulum position in real time with a mean tracking error of around 6 per cent in all three dimensions. This evidence indicates that the technique is sufficiently sensitive and could be implemented in a pragmatic configuration for discriminating between balance and sway.

[1]  Keith J. Blow,et al.  Fast and accurate tactile sense feedback estimation for innovative flexible digit for clinical applications , 2006 .

[2]  P N Brett,et al.  A flexible digit with tactile feedback for invasive clinical applications , 2004, Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine.

[3]  Judith L. Miller Parkinson's disease primer. , 2002, Geriatric nursing.

[4]  R. Paillex,et al.  Changes in the standing posture of stroke patients during rehabilitation. , 2005, Gait & posture.

[5]  P N Brett,et al.  A smart sensing platform for the classification of ambulatory patterns , 2009, Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine.

[6]  R. Moe-Nilssen,et al.  Trunk accelerometry as a measure of balance control during quiet standing. , 2002, Gait & posture.

[7]  Zahra Moussavi,et al.  Center of mass approximation and prediction as a function of body acceleration , 2006, IEEE Transactions on Biomedical Engineering.

[8]  Peter N. Brett,et al.  Implementation of Hardwired Distributive Tactile Sensing for Innovative Flexible Digit , 2008, 2008 International Conference on BioMedical Engineering and Informatics.

[9]  J. Allum,et al.  Trunk sway measurements during stance and gait tasks in Parkinson's disease. , 2005, Gait & posture.

[10]  Pn Brett,et al.  A Sensing Technique for the Measurement of Tactile Forces in the Gripping of Dough-Like Materials , 1996 .

[11]  T.E. Prieto,et al.  Measures of postural steadiness: differences between healthy young and elderly adults , 1996, IEEE Transactions on Biomedical Engineering.

[12]  J. Collins,et al.  Open-loop and closed-loop control of posture: A random-walk analysis of center-of-pressure trajectories , 2004, Experimental Brain Research.

[13]  D. J. Webb,et al.  Distributive tactile sensing using fibre Bragg grating sensors , 2007, European Workshop on Optical Fibre Sensors.

[14]  Hermie Hermens,et al.  Standing balance evaluation using a triaxial accelerometer. , 2002, Gait & posture.

[15]  Xianghong Ma,et al.  Tracking the position of an unknown moving load along a plate using the distributive sensing method , 2007 .

[16]  Susan J. Lederman,et al.  A tactile sensor based on thin-plate deformation , 1994, Robotica.

[17]  Peter Brett,et al.  An approach to optimise the critical sensor locations in one-dimensional novel distributive tactile surface to maximise performance , 2003 .

[18]  P N Brett,et al.  A tactile sensing surface for artificial neural network based automatic recognition of the contact force position , 2000 .

[19]  Marcos Duarte,et al.  Age-related changes in human postural control of prolonged standing. , 2005, Gait & posture.

[20]  Susan M. Drake A Novel Approach. , 1996 .