Electrode Array to Determine Specific Axonal Firing in a Peripheral Nerve
Researchers and scientists at the APL have been trying to find better ways to communicate amputees' brains with the reflexive movements of their missing parts - ways that are reliable, precisely coordinated and non-invasive. Under normal circumstances, our brain indicates actions that should take place. An electrochemical signal travels along complex communication channels in our body, called neurons, and eventually, in the case of movement, stimulates specific muscles to enact precise movements. There has been success using the electrical signals from an amputee's healthy muscles to allow them to use to move his or her prosthetic arm by simply thinking it. Integration of electrode devices into the human nervous system provides a channel through which new control signals may be accessed. However, there is a need to better map the relationship between specific axonal stimulation and coordination with other axons within the same and nearby nerve fibers and the explicit movement that results. By applying these control signals to prosthetic appendages, environmental controls and computer inputs, the abilities of the subject can be greatly enhanced.
This invention involves and array of electrodes implanted in a radial fashion around the sheath of a peripheral nerve. Depending on the size of the identified nerve, three or more electrodes would be in contact with the surface of the nerve. The axonal pulse generated by the wave of depolarization which travels down the axon would be recorded by each electrode. Through varied measurements including the time the pulse arrives at each electrode, the position of the firing axon could be determined and discriminated from the other axons within that same nerve. Re-creating these precise stimulations could be used to control prosthesis.
There are several advantages to this novel technique. Unlike depth electrodes, currently inserted within a nerve fiber and only capable of detecting a limited number of neurons within a nerve, this technique has the potential to detect and map all the neurons within a nerve. This electrode array does not penetrate the nerve and is therefore less likely to cause scarring or other irritations within the nerve. Finally, this arrangement is less likely to become dislodged or moved from its intended orientation with movement and is not likely to disconnect.CONTACT:
Ms. H. L. Curran
Phone: (443) 778-7262