@article {1645,
	title = {Two-photon calcium imaging from head-fixed Drosophila during optomotor walking behavior.},
	journal = {Nature Methods},
	volume = {7},
	year = {2010},
	month = {2010 Jul},
	pages = {535-40},
	abstract = {<p>Drosophila melanogaster is a model organism rich in genetic tools to manipulate and identify neural circuits involved in specific behaviors. Here we present a technique for two-photon calcium imaging in the central brain of head-fixed Drosophila walking on an air-supported ball. The ball{\textquoteright}s motion is tracked at high resolution and can be treated as a proxy for the fly{\textquoteright}s own movements. We used the genetically encoded calcium sensor, GCaMP3.0, to record from important elements of the motion-processing pathway, the horizontal-system lobula plate tangential cells (LPTCs) in the fly optic lobe. We presented motion stimuli to the tethered fly and found that calcium transients in horizontal-system neurons correlated with robust optomotor behavior during walking. Our technique allows both behavior and physiology in identified neurons to be monitored in a genetic model organism with an extensive repertoire of walking behaviors.</p>
},
	keywords = {Animals, Brain, Calcium, Computer-Assisted, Drosophila melanogaster, Fluorescence, Green Fluorescent Proteins, Image Processing, Motion, Motor Activity, Neurons, Signal Transduction, Walking},
	issn = {1548-7105},
	doi = {10.1038/nmeth.1468},
	author = {Seelig, Johannes D and Chiappe, M Eugenia and Lott, Gus K and Dutta, Anirban and Osborne, Jason E and Reiser, Michael B and Jayaraman, Vivek}
}
@article {6499,
	title = {Development of an implanted intramuscular EMG-triggered FES system for ambulation after incomplete spinal cord injury.},
	journal = {Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society.},
	volume = {2009},
	year = {2009},
	month = {2009},
	pages = {6793-7},
	abstract = {<p>Ambulation after spinal cord injury is possible with the aid of neuroprosthesis employing functional electrical stimulation (FES). Individuals with incomplete spinal cord injury (iSCI) retain partial volitional control of muscles below the level of injury, necessitating careful integration of FES with intact voluntary motor function for efficient walking. In this study, the intramuscular electromyogram (iEMG) was used to detect the intent to step and trigger FES-assisted walking in a volunteer with iSCI via an implanted neuroprosthesis consisting of two channels of bipolar iEMG signal acquisition and 12 independent channels of stimulation. The detection was performed with two types of classifiers- a threshold-based classifier that compared the running mean of the iEMG with a discrimination threshold to generate the trigger and a pattern recognition classifier that compared the time-history of the iEMG with a specified template of activity to generate the trigger whenever the cross-correlation coefficient exceeded a discrimination threshold. The pattern recognition classifier generally outperformed the threshold-based classifier, particularly with respect to minimizing False Positive triggers. The overall True Positive rates for the threshold-based classifier were 61.6\% and 87.2\% for the right and left steps with overall False Positive rates of 38.4\% and 33.3\%. The overall True Positive rates for the left and right step with the pattern recognition classifier were 57.2\% and 93.3\% and the overall False Positive rates were 11.9\% and 24.4\%. The subject showed no preference for either the threshold or pattern recognition-based classifier as determined by the Usability Rating Scale (URS) score collected after each trial and both the classifiers were perceived as moderately easy to use.</p>
},
	keywords = {Automated, Electric Stimulation, Electrodes, Electromyography, Humans, Implanted, Male, Muscles, Pattern Recognition, Recovery of Function, Spinal Cord Injuries, Walking},
	issn = {1557-170X},
	doi = {10.1109/IEMBS.2009.5333980},
	author = {Dutta, Anirban and Kobetic, Rudi and Triolo, Ronald}
}
