Ear Implant

Natural hearing

How natural hearing works

http://www.cochlearamericas.com/Products/13.asp

The cochlear implant

The cochlear implant, an intact nervous system is required.

A hearing aid is a device that amplifies sound. The amplified sound then travels down the ear canal, past the ear drum and middle ear bones, to the cochlea.

http://eurociu.implantecoclear.org/implante_en.php

See the following picture of a cochlear implant

Cochear Implant Schema

New hearing mechanism the tectorial membrane, a gelatinous structure inside the cochlea of the ear.

http://medgadget.com/archives/ent/

With the multi-channel cochlear implant, the electrodes are used to stimulate the cochlea by delivering electricity to it. There are 22 electrodes at different positions along the implant so that it is possible to stimulate at many different sites. When the implant is inserted into the cochlea, the 22 electrodes allow auditory nerve fibres at different sites from the base of the cochlea to its apex to be stimulated selectively, thus enhancing the ability of the patient to distinguish different frequencies of sound.

http://www.science.org.au/nova/029/029glo.htm

Cochlear implants – wiring for sound

http://www.science.org.au/nova/029/029print.htm#radio%20waves

The processor, which rests behind the ear, picks up sound and transmits it across the skin to the receiver. The receiver converts the signal into vibrations and transmits them to a tiny transducer in the middle ear.

By transmitting energy directly to the middle ear bones, problems like poor sound quality, feedback and general discomfort are eliminated.

Conventional hearing aids typically have a life of only three or four years, while the implanted hearing device is expected to last at least ten years.

http://www.wchstv.com/newsroom/healthyforlife/1776.shtml

Surgery procedure

Minimaly invasive….using the laser to make a bloodless opening in the eardrum.

http://earsinus-com.web16.winsvr.net/?tabid=97

Ear surgery

http://www2.vhi.ie/topic/earsurgery

HOW DOES NORMAL HEARING WORK?

http://www.cssd.us/body.cfm?id=838

Communication Blue tooth

A proprietary binaural high speed wireless technology enables a pair of Epoq hearing devices to communicate at data transfer speeds 100 faster than hearing instruments now on the market. This real-time connectivity with voices and other sounds in the immediate listening environment provides accurate, stereophonic auditory information that is in synch with a user's visual experience. The same wireless connectivity also enables easy, hands-free access to the world of electronically transmitted sounds from Bluetooth-enabled cell phones and other popular electronic devices such as MP3 players and computers.

Oticon's newly developed wireless digital platform, RISE. Using innovative EarStreamT broadband technology, the hearing instrument creates a wireless sphere around users.

Wireless Connectivity to Cell Phones and More
Epoq provides a new and previously unavailable hearing solution to the use of cell phones. Earlier options such as removing one hearing aid or using a T-coil and the distractions caused by background noise often made cell phone use impossible for people with hearing loss.

http://medgadget.com/archives/ent/

Battery life

Wirear utilises a micro fuel cell, a miniature version of fuel cell that uses hydrogen from any hydrocarbon fuel. This technology is yet to be commercialized however; it is a proven technology as the power source of the future. The mechanical flexibility of the micro fuel cell has allowed the design to be organic so that the form naturally flows with the shape of the ear. A 2 ãŽ of micro fuel cell has an estimated life of six years in this type of application proving a more sustainable energy source than the current zinc-air batteries that last approximately three weeks in this application.

http://medgadget.com/archives/ent/

Middle Ear implant

Traditionally, hearing aids have been placed outside the eardrum. They pick up sounds and amplify them so the eardrum can transmit them. Many new ones fit snugly and almost invisibly into the ear canal.

The Vibrant Soundbridge consists of two components, an external audio processor and an internally implanted receiver.

The process bypasses both the ear canal and the eardrum and feeds energy to the middle ear bones directly.

http://www.wchstv.com/newsroom/healthyforlife/1776.shtml

Implantable hearing aids

http://www.asha.org/about/publications/leader-online/b-line/bl030624.htm

middle-ear implants (MEI) in the middle-ear cavity (MEI). MEI is used most often for those with sensorineural hearing loss (Chasin, M. [2002].

http://www.asha.org/about/publications/leader-online/b-line/bl030624.htm

A middle ear implant (MEI) is basically a hearing aid, but one in which the receiver ("loudspeaker") or the entire hearing aid is surgically inserted into the middle ear. Access to the middle ear is accomplished by a post-aural approach, similar to that of cochlear implants. There are at least six such devices now being developed, though only one has received FDA approval (the Symphonix device).

two of the systems now being developed are totally implantable and invisible. One uses the eardrum as a microphone - which is rather a neat idea - while the other actually implants a small microphone in the wall of the ear canal.

The one MEI that has received preliminary FDA approval is the Vibrant Soundbridge developed by Symphonix Devices, Inc. The internal receiver is implanted in the temporal bone behind the ear, again much like a cochlear implant.

http://www.hearingresearch.org/Dr.Ross/Implantable_HAs.htm

Based on the most recent review, there are four electromagnetically based MEIs that have received some status in the FDA regulatory approval system. None have been approved completely. However, it is expected that at least one may receive final approval by the end of 2000. The four devices are:

(1) the Vibrant Soundbridge from Symphonix
(2) the Otologics LLC implant led by Dr. John Fredrikson of Washington University,
(3) the Soundtec system based on the work of Dr. Jack Hough in Oklahoma and,
(4) the device of Dr. Anthony Maniglia of Cleveland.

These electromagnetic devices are only partially implantable, in that only the receiver (i.e., the magnet and associated transducing coil) is implanted. the microphone, and amplifier are worn externally

http://www.audiologyonline.com/articles/article_detail.asp?article_id=231

http://www.audiologyonline.com/articles/pf_article_detail.asp?article_id=231

communication between the microphone module 30 and implant module 60 be via a wireless channel, typically radio frequency,

Inductively-Coupled Control Unit for Fully Implantable Middle Ear Hearing Devices

http://ieeexplore.ieee.org/Xplore/login.jsp?url=/iel5/10755/33900/01615521.pdf

Preliminary Assessment of Remote Photoelectric Excitation of an Actuator for a Hearing Implant

http://ieeexplore.ieee.org/Xplore/login.jsp?url=/iel5/10755/33900/01615920.pdf

Guidance for Industry and FDA Staff

Implantable Middle Ear

Hearing Device

Document issued on: August 1, 2003

http://www.fda.gov/cdrh/ode/guidance/1406.pdf

This paper describes the optical characterization of human temporal bones for optimum sensor placement and reports the results of attaching a commercial accelerometer on the umbo for sound detection.

http://filer.case.edu/djy/publications/INSS06.pdf

One example of a partial middle ear implantable (P-MEI) hearing aid system….

an external radio frequency (RF) transmitter for transdermal RF communication of an electrical signal. An implanted receiver detects and rectifies the transmitted signal, driving an implanted coil in constant current mode.

http://www.patentgenius.com/patent/6005955.html

Powering a hearing implant

The device is powered by a battery that is recharged when the user places a small radio transmitter against his or her head for 60 to 90 minutes. The transmitter is held to the skin by a magnet in the implant. An inductive coil in the implant converts the radio energy to electricity and recharges the battery with it. The battery can stay inside the body for at least five years, according to the company, before it needs to be replaced.

a microphone implanted underneath the skin behind the user’s ear.

http://callierlibrary.wordpress.com/category/hearing-aids/

Internal radio receiver with external radio transmitter

HEARING AID The present invention relates to a hearing aid system comprising a hearing implant and method of powering a hearing implant.

Broadly speaking the present invention is based on powering a middle or inner ear implant using a light signal.

http://www.wipo.int/pctdb/en/wo.jsp?wo=2003063542&IA=WO2003063542&DISPLAY=DESC

It is possible for powering using a photo electric receiver

photoreceiver of the ear implant and converted to an electrical signal for driving the hearing actuator.

http://www.wipo.int/pctdb/en/wo.jsp?wo=2003063542&IA=WO2003063542&DISPLAY=DESC

A major feature of Spindel's approach is that the device doesn't obstruct the normal hearing process. "Leaving the middle ear system intact and establishing a second independent input pathway to the inner ear opens the possibility for using the normal acoustic pathway and round window electromagnet simultaneously to establish constructive and destructive sound patterns in the inner ear,"

http://bluestream.wustl.edu/WhitakerArchives/news/hearing.html

See the following picture of a Spindel middle ear implant

Hearing Aid Is there a better ear?

By David Plotz

The Project
What if we use the implant technology on undamaged ears? People with normal hearing could wear implants—or in a much less intrusive procedure, removable amplifiers in the middle ear—that would receive signals from microphones outside the ear.

There's no limit to what microphones could feed into the ear. Wearing a directional microphone would enable you to eavesdrop on conversations across a room or behind you. There are also microphones that enhance the "cocktail party effect"—the phenomenon that allows you to tune out loud chatter in order to hear the person talking to you. Such a mike would amplify a conversation right next to you but wash out all the other ambient noise. Using a combination of mikes would permit you to eavesdrop at a distance and then focus in on up-close chatter, with the flick of a switch.

http://www.slate.com/id/2079181

Auditory nerve implant

Music to deaf ears: Auditory nerve implant can deliver wide range of sounds, early tests show

Shown here is the portion of a device that, when inserted in the auditory nerve, transmitted a wide range of sounds to the brain in a University of Michigan animal study. The 16 stimulating sites are spaced 1/10 of a millimeter apart.

The possible auditory nerve implants likely would be suitable for the same people who are candidates today for cochlear implants

http://www.med.umich.edu/opm/newspage/2007/hd.htm

Picture of an electronic muscle stimulation (EMS) and transcutaneous electrical nerve stimulation (TENS)

http://www.skidmore.edu/~hfoley/Perc9.htm

Brainstem implant

First brainstem implants aim to tackle deafness

http://environment.newscientist.com/data/images/ns/cms/dn4540/dn4540-1_839.jpg

See the following picture of a brain stem plug implant

Electronic Brain Implant Helps Patients Regain Hearing After Cranial Nerve

http://findarticles.com/p/articles/mi_m1370/is_1_35/ai_70696248

Bones of face

Semi cancals for auditory tube and tensor tympani

http://www.theodora.com/anatomy/the_temporal_bone.html

Normal transverse cross sectional anatomy of the temporal bone at consecutive levels from bottom to top.
http://www.medcyclopaedia.com/library/radiology/chapter10/10_2.aspx

MRI of ear

http://www.bcm.edu/oto/jsolab/tngallery/pages/middle%20ear%20and%20mastoid%20cholesteatoma%20-%20preoperative.htm

CT Scan of ear

http://www.ljm.org.ly/modules.php?name=News&file=print&sid=1148

Nervous system disease

http://www.britannica.com/oscar/print?articleId=110705&fullArticle=true&tocId=75725

Balance

researchers constructed a circuit that could measure and transmit 3-D balance information to the brain through multiple electrodes connected to the vestibular nerve.

Once processed, the information is used to tailor timing of brief, electronic pulses through the electrodes implanted near the three branches of the vestibular nerve that respond to changes in head rotation. These branches normally carry signals from the inner ear's three semicircular canals.

To balance, we rely on input from our vestibular system; a set of fluid-filled canals in the inner ear. When we move, tiny hairs pick up disturbances in the fluid, and nerves attached to the canals transmit signals to the brain, which passes the information on to muscles controlling our eyes and posture.

http://medgadget.com/archives/ent/

Index

R a n d a l l M o r t o n BBus BComp BPsych

Ear Implant

Natural hearing

The cochlear implant

Communication Blue tooth

Battery life

Middle Ear implant

Powering a hearing implant

Auditory nerve implant

Brainstem implant

Bones of face

MRI of ear

CT Scan of ear

Nervous system disease

Balance