Why were cochlear implants invented




















Only the first 2 periods are detailed here. The invention of the first electrical capacitor in , the Leyden jar, provided a great stimulus to the medical application of electricity. The first extra-auricular electrical stimulation dates to at least as early as , with a report made by the English portraitist and electricity researcher Benjamin Wilson, who described his experiment on a deafened woman as follows 3 p :. The covered vial being electrised by two turns of the wheel only, I applied the end of a thick wire, which was fastened to the covering of the vial, to the left temple, just above the ear; then I brought the end of that wire, which was in the vial, towards the opposite part of her head, and there ensued a small explosion.

She was much surprized, and perceived a small warmth in her head, but chiefly across it, from ear to ear. I repeated the experiment four times, and made the electrical shock stronger each trial.

Wilson repeated the experiment a few times during the next days, resulting in an improvement of the woman's hearing. He tried the experiment on 6 other deaf individuals, however, without any success. After him, similar attempts were made in France, Sweden, Italy, and England. My invention relates, among other things, to improvements in means for passing an electric current through the mastoid bones and through the natural ear-passages of the human head and also of means for transmitting phonetic excitement to such media by the use of an electric current.

By , Ernst Glen Wever and Charles Bray of Princeton observed that an amplified output from an electrode placed intracranially in the acoustic nerve of a cat produced a copy of the speech waveform in both frequency and amplitude. Because of the proximity of these electrodes to the inner ear and the resulting production of sounds, the idea that direct stimulation of the auditory nerve might result in hearing was again hypothesized.

This patient had previously undergone temporal bone resection for a cholesteatoma, which had damaged his facial nerve. On February 25, , they placed an electrode in contact with a segment of the vestibular nerve 12 p , 13 :. This procedure, undertaken by Dr Eyries revealed such dreadful damage that after a 5 cm graft of the facial nerve, we hesitated for a while to place the appliance.

What we did was really for understandable psychological reasons and because we saw that a small segment of the eighth cranial nerve, measuring a few millimeters, was accessible without any additional risk. It belonged to the vestibular nerve. The induction device was 2. It had two stainless steel wires suitably orientated.

One was insulated with polyethene just to its tip, and was placed in contact with a small segment of nerve. The other was bare and was connected to the temporalis muscle, in which was placed the micro-coil. Doctors Doyle and House surgically placed a single wire electrode in the scala tympani through an opening anterior to the round window. On February 1, , in the same patient, the single wire electrode was replaced by a four-channel probe.

William House 16 p5 described, in , the operation as follows Figure 1 :. A gold wire electrode was placed in the scala tympani through the opening anterior to the round window. William House 17 p later described how he became interested in the development of such a device:. Some years ago during the early part of [probably in as mentioned in another statement 18 ], a patient brought me a two or three paragraph news clipping about what I considered to be a remarkable thing.

It was a story about a patient in Paris who was totally deaf until a wire was placed into the region of his inner ear. Through this he was able to perceive a sensation of sound. This stimulated me a great deal, and I began to search the literature to find out what I could about this. The implanted wire mentioned in the news article was the result of work done by Djourno and Eyries. All this was the start of the cochlear implant. In December , Dr. John Doyle, a neurosurgeon, his brother Jim Doyle, an electronics engineer, and Doctor William House, our own well-known otologic surgeon, worked together testing the electrical activity of the surgically exposed eighth nerve.

In a report of the same operation, William House 16 p5 wrote,. On February 1, the single electrode implant was removed.

A five wire electrode induction coil system was inserted on March 4, The round window was exposed and the electrodes were placed in the scala tympani. The induction coils were seated in the bone in the postauricular area. On March 15, , the device was removed, with uneventful healing. These facts are corroborated in an oral history interview that Phillip Seitz conducted with John and Jim Doyle in Other experiments were also conducted during stapes surgery, with the electrode being placed into the perilymph through the opened oval window.

A second patient also underwent implantation on January 9, , as described by William House 16 p5 in The wire was led along the bone of the middle fossa and brought out through a skin incision. After two test periods, however, the amount of current necessary for stimulation increased. Because it was thought infection or edema might be occurring, the wire was removed [2 weeks later].

The partnership between the Doyle brothers and William House soon ended for at least 2 reasons, the first being that the Doyles shared the details of these experiments with the press. William House 22 p recalled,. We began to be deluged by calls from people who had heard about the implant and its possibilities. The engineer who had constructed the implant exercised bad judgment and encouraged newspaper articles about the research we were doing. The second reason was that the Doyle brothers refused to share the full reports on the electronics and material they had developed.

There was no written contract between us and as far as I am concerned, it's mine. Now I would need to start all over again. The Doyle brothers continued their research, performing implantation in another patient the next year on November 23, , the surgeon being this time the otolaryngologist Leland House of the White Memorial Hospital of Los Angeles, California, with another otolaryngologist, Frederick Myles Turnbull.

A preliminary report was made by John Doyle, and discussed by William House, at the 16th clinical meeting of the American Medical Association, held in Los Angeles on November 27, , 24 followed by another report a few months later to the Los Angeles Neurological Society 25 p :.

An induction coil which had been previously imbedded in a plastic case methyl methacrylate was inserted in a craniectomy defect in the squamous position of a temporal bone of a patient suffering from essentially total congenital perceptive hearing loss. The active electrode was passed through a tunnel of bone into the middle ear and through a fenestra in the promontory of the cochlea between the oval and round windows. The procedure was also reported to the American Academy of Ophthalmology and Otolaryngology on October 19, After William House and Jim Doyle introduced implantation at the cochlea, fundamental physiological research began, notably in Germany and in the United States.

On July 26, , the Stanford University team of otolaryngologist Blair Simmons and engineer Robert White perioperatively conducted stimulation tests through a posterior craniotomy, with an electrode placed on the acoustic nerve, and then displaced on the inferior colliculus with less success. It is noteworthy that the incus was removed, and the electrode was slid through the epitympanic recess; the stapes being also removed, the medial wall of the vestibule was exposed, upon which the anterior ridge of the saccular recess could be seen.

Using this landmark as a guide, a preliminary 2 mm hole was made in the promontory approximately 3 mm anterior and 1 mm inferior to the superior margin of the oval window. Next a 0. Nerve-like tissue could be seen through the modiolar hole.

A six-electrode array was then successfully passed through the promontory hole and into the modiolar hole to a depth of about mm. The electrode was percutaneously connected with the external device. The patient was then regularly observed and examined. This was the first implantation of a multichannel CI. This procedure was reported in Science in , 30 and the following year Simmons' team published the first extensive article on the different aspects of electrical stimulation of the auditory nerve in humans.

By , William House and Jack Urban, an electrical engineer, had worked out the details for a new approach to the CI. Instead of placing an induction coil beneath the skin, they developed a percutaneous button containing an induction coil.

In early , conditions were ripe to try new implantations on 3 patients. As reported in , William House performed implantation on a patient on September 24, , using a silver multiple hard wire electrode. In , House added 2 other patients. Unfortunately, after several weeks, the button loosened in the bone, resulting in the failure of the system.

The second patient received his implant in the right ear, on June 18, Two years later, this patient also underwent implantation at the left ear with a multielectrode CI Figure 3. The relationship between the CI innovators during this period was collaborative, as well as competitive. The physicians met regularly, also in private. In , William House and Urban published their first article about the long-term results of electrode implantation and electronic stimulation of the cochlea in 1 patient.

The article was presented and discussed at the meeting of the American Otological Society, April 6 to 7, William House 22 p concluded his study by stating,. We feel that the electronic cochlea is now ready for more widespread testing and development.

We present this evidence in the hope that teams. The main critique of these first, mostly single-channel CI prototypes was the difficulty with insulating the electrode. The next step in the development of the CI was its use in clinical practice on a cohort of patients. Merzenich conducted various studies at the turn of on cats 35 and was interested, contrary to Michelson, in the development of a multichannel CI.

After these animal experiments, the UCSF team selected 4 patients who were tested with an electrode placed temporarily in the lower scala under local anesthesia. Two of these patients finally received a totally implanted CI in A transcanal approach was used to place the single bipolar electrode 36 p :.

A shallow groove was cut in the posterior canal wall deep enough to receive the leads from the intracochlear electrode. The electrode was then inserted through the round window into the lower scala. The lead terminated in a tiny amplitude-modulated radio receiver placed beneath the skin.

A preliminary report was published in , followed by a more complete one that was presented a few months later during the American Otological Society Meeting in San Francisco, May 28 to 29, I seem to have a number of friends here today.

In June , the first international conference on electrical stimulation of the acoustic nerve as a treatment for profound sensorineural deafness in humans was organized in San Francisco. The reports of this first congress were published 1 year later and specially distributed to the participants.

Confronted with the low level of success in speech discrimination with a single electrode, other types of devices were developed with multiple electrodes. After 3 years of laboratory work with the physiologist Patrick MacLeod, Chouard 39 - 41 reported 6 implantations of a device with 7 electrodes on patients presenting total bilateral deafness in Each electrode was introduced into the cochlea through a separate fenestration of the scala tympani.

An electrically isolated compartment was made in the scala for each electrode by means of little pieces of silastic. My child has hearing loss Learn more about the different types of hearing loss, how each can affect your child and how they can be treated. About hearing and hearing loss If you or someone close to you is affected by hearing loss, it's important you fully understand it.

What is hearing loss? Learn more. Cochlear implants A cochlear implant is an established, effective and long-term solution for people with moderate to profound hearing loss. Quality for today and tomorrow Why Cochlear is the right choice for you. Community and Networks Cochlear can connect you with people and information that can help you or your child on their hearing journey. Find a clinic Find your nearest clinic. Find your nearest clinic Search. Rehabilitation resources Cochlear provides a wide range of information and activities designed to help recipients and the professionals they work with develop or re-learn listening and language skills.

Cochlear implant systems Information on the best way to care and use your cochlear implant system for optimal hearing performance. This area will help you get the most out of your Baha System. Cochlear True Wireless Get the most from your new Cochlear True Wireless device, with information, advice and troubleshooting help. Show All Close All. Featured Cochlear Foundation launches global partnership with Malala Fund to remove hearing loss as a barrier to education - 22 September, Read article See all news.

About hearing loss What is hearing loss? Miyamoto, MD, received a phone call from his former mentor, William F. House, MD. House was calling to ask his former trainee to join a new multi-center clinical trial of cochlear implants. Miyamoto immediately agreed to join the study and traveled with his first patient to House Ear Institute HEI to complete the surgery. Miyamoto said. They felt that success was unobtainable. The results of that trial, concluding that CIs were beneficial to patients, helped dispel some of the controversy sparked in the scientific community.

By , the U. Many, including Dr. Miyamoto and John W. House, MD, president of House Research Institute and clinical professor in the department of otolaryngology at the University of Southern California, credit the late William House as the father of neurotology and as instrumental in the development and acceptance of cochlear implants.

House died on December 7, , at the age of 89 at his home in Aurora, Ore. John House, who is also Dr. Since , cochlear implant technology has followed a fairly rapid trajectory, fed by advancements from investigators around the world. By , according to the FDA, more than , patients worldwide had received cochlear implants.

In the U. The roots of cochlear implant technology go back more than years, said Dr. John House. In the s, Alessandro Volta, who developed the electric battery, placed metal probes into his own ears and connected them to a volt circuit.

Upon switching on the flow of current, he experienced a jolt but, more importantly for auditory science, he also heard a noise, which he noted was akin to the sound of boiling soup. Others also experimented with stimulation of the cochlea. In , Duchenne de Boulogne reported a buzzing and ringing sensation, achieved by using alternating current.

Much later, in the s, Ernest Glen Wever, a Princeton University psychology professor, worked with Charles Bray during an otological research fellowship at Johns Hopkins Medical Center in Baltimore to record electrical potentials in the cochlea that paralleled sound stimulus waveform. This work suggested the possibility that replicating those potentials could restore hearing. An induction coil with a return electrode was placed into the temporalis muscle.

Post-operatively, the patient detected different sound intensities and small closed sets of spoken words. When the Los Angeles Times picked up the story, one of Dr. The reports stimulated Dr. House to begin work on an auditory prosthesis. In , he teamed with neurosurgeon John Doyle, MD, to place single-electrode gold implants in a few patients. These patients could identify words in small closed sets, but electrode rejection and fear of infection intervened.



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