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TitleOptimization of electrode placement in electromyographic control of dielectric elastomers
Publication TypeConference Paper
Year of Publication2009
AuthorsWalbran, S.H., Calius E.P., Dunlop G.R., and Anderson I.A.
Conference NameProceedings of SPIE - The International Society for Optical Engineering
Date Published2009
KeywordsActuators, Amplification, Biopotentials, Classification accuracy, Conducting polymers, Control technologies, Data filtering, Dielectric elastomer, Dielectric elastomer actuators, Dielectric elastomers, Electrode placement, Electrode sites, Electrodes, Electromyographic, Electromyography, Electrophysiology, Human forearms, Human intention recognition, Human intentions, Key parts, Multiple degrees of freedom, Multiple electrodes, Optimal electrodes, Optimization, Plastics, Prosthetics, Rubber, Signal processing, Smart materials, Spatial gradients
AbstractHuman intention recognition is becoming a key part of powered prosthetics research. With the advent of smart materials, the usefulness of powered prosthetics has increased. Correspondingly, there is a greater need for control technology. Electromyography (EMG) has previously been used to control myoelectric hands; however the approach to electrode placement has been speculative at best. Carpi, Raspopovic and De Rossi have shown that dielectric elastomer actuators (DEAs) can be controlled by a variety of human electrophysiological signals, including EMG. To control a DEA device with multiple degrees of freedom using EMG, multiple electrode sites are required. This paper presents an approach to control an array of DEAs using a series of electrodes and an optimized electrode data filtering scheme to maximize classification accuracy when differentiating between hand grasps. A silicon mould of a human forearm was created with an array of electrodes embedded within it. Data from each electrode site was recorded using the Universal Electrophysiological Mapping (UnEmap) system developed at the University of Auckland Bioengineering Institute for the amplification and filtering of multiple biopotential signals. The recorded data was then processed off-line, in order to calculate spatial gradients; this would determine which electrode sites would give the best bipolar readings. The spatial gradients were then compared to each other in order to find the optimal electrode sites. Several points in the extensor compartment of the forearm were found to be useful in recognizing grasping, while several points in the flexor compartment of the forearm were found to be useful in differentiating between grasps. © 2009 SPIE.

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