Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Representing the Fine Structure in a Cochlear Implant Using Simultaneous and Non-Simultaneous Stimulation

IP.com Disclosure Number: IPCOM000033905D
Publication Date: 2005-Jan-04
Document File: 7 page(s) / 99K

Publishing Venue

The IP.com Prior Art Database

Abstract

The present disclosure relates to a method of representing the fine structure in a cochlear implant system (CIS) using simultaneous and non-simultaneous current navigation. In a conventional CIS current navigation strategy, envelope is extracted in each channel, and the remaining information (known as the fine structure) is not used or thrown away. Given the number of channels present in a CIS current processor, information in the fine structure is important for understanding speech in modulated noise, and is essential for representing musical melodies.

This text was extracted from a Microsoft Word document.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 28% of the total text.

Representing the Fine Structure in a Cochlear Implant Using Simultaneous and Non-Simultaneous Stimulation

Background

                    The present disclosure relates to a method for representing the fine structure in a cochlear implant system using simultaneous and non-simultaneous current navigation. 

Use of implantable cochlear stimulating devices for restoration of hearing is now a well-accepted modality for treating profound deafness.  A cochlear implant system may be fully implantable or partially implantable.  In a partially implantable device, there can be two components, an external component containing the battery and an implantable component that contains additional circuitry for processing the stimulation protocol.  The implantable component usually consists of a stimulating cochlear lead with an array of multiple electrodes attached to the lead.  The stimulating lead with the electrode array is inserted into the cochlea, for instance, into the tympanic chamber (scala tympani).  After the electrode array is implanted into the cochlea, the electrodes may be stimulated one at time.  In multi-channel systems having independent programmability for each electrode, different stimulus pulse amplitudes and, in some cases, pulsewidths may be delivered at two different electrodes in the same time interval.

                    The electrode array has a set of electrodes that can be linearly spaced apart along the distal portion of a stimulating lead.  As implanted in the cochlea, the electrode array may be placed adjacent to a particular set of cochlear nerve fibers that line the length of the cochlea (modiolus).  The nerve fibers are located between the basal (opening) to the apical (tip) of the cochlea and are spatially coded such that certain sound frequencies preferentially stimulate nerve fibers located at the apical ends or the basal end of the cochlea.  Thus, by choosing to stimulate through a specific set of electrodes along the cochlea, specific nerve fibers that code for specific sound frequencies can be stimulated.  Loudness (intensity) of sound may be coded by recruiting increasing numbers of cochlear nerve fibers.  Thus, a just perceptible or threshold sound may occur with stimulation of as few as 3 to 10 ganglion nerve cells, whereas to increase the perceived intensity of the sound, hundreds or even thousands of ganglion nerve cells must be recruited simultaneously.                 

                    Multi-channel stimulators are used in cochlear devices for restoration of hearing in the profoundly deaf.  Details associated with the operation of a typical cochlear implant system may be found in one or more of the following U.S. Patent Nos. 6,157,861; 6,002,966; 5,824,022; 5,603,726; 5,344,387; and 4,532,930.

Description

Before describing the present invention, it will be helpful to review the operation of a typical cochlear stimulation system.  A representative cochlear stimulation system 10 is illus...