D J Weber et al 2007 J. Neural Eng. 4 S168 doi:10.1088/1741-2560/4/3/S04
D J Weber1, R B Stein2, D G Everaert2 and A Prochazka2
Show affiliationsFunctional electrical stimulation (FES) holds great potential for restoring motor functions after brain and spinal cord injury. Currently, most FES systems are under simple finite state control, using external sensors which tend to be bulky, uncomfortable and prone to failure. Sensory nerve signals offer an interesting alternative, with the possibility of continuous feedback control. To test feasibility, we recorded from ensembles of sensory neurons with microelectrode arrays implanted in the dorsal root ganglion (DRG) of walking cats. Limb position and velocity variables were estimated accurately (average R2 values >0.5) over a range of walking speeds (0.1–0.5 m s−1) using a linear combination of firing rates from 10 or more neurons. We tested the feasibility of sensory control of intraspinal FES by recording from DRG neurons during hindlimb movements evoked by intraspinal microstimulation of the lumbar spinal cord in an anesthetized cat. Although electrical stimulation generated artifacts, this problem was overcome by detecting and eliminating events that occurred synchronously across the array of microelectrodes. The sensory responses to limb movement could then be measured and decoded to generate an accurate estimate of the limb state. Multichannel afferent recordings may thus provide FES systems with the feedback needed for adaptive control and perturbation compensation, though long-term stability remains a challenge.
87.80.-y Biophysical techniques (research methods)
87.19.lt Sensory systems: visual, auditory, tactile, taste, and olfaction
87.19.R- Mechanical and electrical properties of tissues and organs
Issue 3 (September 2007)
Received 30 January 2007, accepted for publication 13 July 2007
Published 22 August 2007
D J Weber et al 2007 J. Neural Eng. 4 S168
Peter Horak et al 1996 Quantum Semiclass. Opt. 8 583
Niklas Beisert and Radu Roiban JHEP11(2005)037
The HERMES collaboration JHEP11(2009)083
N V Lavrik et al 1996 Nanotechnology 7 315
A Fuliński et al 2005 New J. Phys. 7 132
Felipe Menanteau and John P. Hughes 2009 ApJ 694 L136
Yu M Aliev et al 1996 Plasma Sources Sci. Technol. 5 514
K Minami et al 1993 J. Micromech. Microeng. 3 81
G Brida et al 2000 Metrologia 37 629