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Silhouette Inductor for Signal Input Into an Implantable Cochlear Stimulator to be Worn Behind the Ear Disclosure Number: IPCOM000005897D
Publication Date: 2001-Nov-14
Document File: 4 page(s) / 1K

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The Prior Art Database


A silhouette inductor is an ear level device employed in the hearing aid industry for the inductive coupling of signals from assistive listening devices (e.g., FM systems). Telecoils, also known as basic inductors, are common components in post-auricular hearing aids. The telecoils are employed within the casings of post-auricular hearing aids. The patients hearing aid must contain a telecoil circuit in order for the signal from a silhouette inductor to be induced into the hearing aid amplifier. This inductor has the length and width of a standard full size post-auricular hearing aid but is less than 1/4 the thickness. The primary advantage of a silhouette inductor is the stable position of the inductor adjacent the telecoil mounted in the post-auricular hearing aid, thus leading to a stable electromagnetic field. The present invention uniquely applies a silhouette-type device to the Behind the Ear processor of an Implantable Cochlear Stimulator.

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Silhouette Inductor for Signal Input Into an Implantable Cochlear Stimulator to be Worn Behind the Ear


Implantable medical devices, known as Implantable Cochlear Stimulators (ICS), are used to help the profoundly deaf (those whose middle and/or outer ear is dysfunctional, but whose auditory nerve remains intact) to hear.  The sensation of hearing is achieved by directly exciting the auditory nerves with controlled impulses of electrical current, which impulses are generated as a function of perceived audio sounds.  The audio sounds are picked up by a microphone carried externally (not implanted) by the deaf person and converted to electrical signals.  The electrical signals, in turn, are processed and conditioned by a Wearable Sound Processor (WP) in an appropriate manner, e.g., converted to a sequence of pulses of varying width and/or amplitude, and then transmitted to an implanted receiver circuit of the ICS system. The implanted receiver circuit generates electrical current as a function of the processed signal it receives from the WP (which in turn is based on the audio sounds picked up by the external microphone). The implanted receiver circuit is connected to an electrode array that has been implanted into the cochlea of the inner ear. The electrical current generated by the implanted receiver circuit is applied to individual electrode pairs of the electrode array. It is this electrical current which directly stimulates the auditory nerve and provides the user with the sensation of hearing.

Typical ICS systems include an external headpiece positioned on the side of the user’s head, and require an external cable running from the external headpiece to the WP. The WP is typically worn or carried by the user on a belt or in a pocket. While the WP is not large, still may represent an inconvenience for the user. The cable which connects the WP and the headpiece may also be a source of irritation for the user.

An external device positioned behind the ear, known as the BTE (Behind the Ear) processor, performs the functions of both the WP and the headpiece, and thus eliminates the need for lengthy external cables.  The BTE device is positioned behind the ear to minimize its visibility, and typically requires no cabling to additional components.

The use of the BTE sound processors offers implant users a number of advantages over their body-worn units.  Some of these benefits are improved clarity in noise and the advantage mentioned above:  the freedom from the long cables and body packages.

One aspect of BTE device performance that has continued to lag behind that obtained with the body-borne sound processor is telephone access.  Subjects were asked to rate the clarity of the BTE on the phone each day during the first week of device use and at each weekly interval.  The majority of comments related to phone use during the trial period related to lack of volume, clarity, and the awkwardness of placing the phone over their BTE.  A number of patients...