Focused stimulation in a medical stimulation device

摘要

A medical stimulation device such as a cochlear implant configured to provide stimulation of one or more spatially-restricted contiguous portion(s) of the spiral array of auditory nerve fibers in the cochlear (“discrete stimulation regions”). Each discrete stimulation region is defined by the constructive and/or destructive interference of stimulating and limiting signals simultaneously applied to electrode channels of an implanted electrode array, the stimulating and limiting signals being determined based upon transimpedance measurements of intracochlear electrode channels of the implanted electrode array representing specific spread functions of an individual recipient. The stimulating signal is preferably applied through a targeted electrode channel; that is, one or more successive electrodes which is/are adjacent to the discrete stimulation region. The targeted electrode channel is selected to represent a sound based on the outputs of a sound processor to stimulate neural activity in the discrete stimulation region to thereby cause a percept of the represented sound. The size of the discrete stimulation region is defined by the limiting signal(s) applied to electrode channel(s) other than the targeted electrode channel, and which negate(s) current spread which would otherwise occur in response to the stimulating signal.

主权项

1. A cochlear implant having an electrode array including a plurality of electrodes forming electrode channels, the electrode array being configured to be implanted in a particular recipient's cochlea,
wherein said implant is configured to provide stimulation of one or more discrete stimulation regions of the particular recipient's cochlea via application of one or more stimulating signals and one or more limiting signals simultaneously applied via the electrode channels, such that the one or more stimulating signals and the one or more limiting signals interfere with one another, wherein the one or more limiting signals have an opposite polarity as the one or more stimulating signals, the interference defining said one or more discrete stimulation regions; and wherein the cochlear implant is configured such that said one or more stimulating signals and said one or more limiting signals are based upon transimpedance measurements among electrode channels of the cochlear implant as implanted in the particular recipient, said transimpedance measurements representing specific current spread functions of the particular recipient.