-
Alessandro Volta - Electrical current used by Allesandro Volta to stimulate the inner ear.
Electrical current used by Allesandro Volta to stimulate the inner ear. -
Period: to
History of Cochlear implants
-
Duchenne stimulates the ear using an alternating current
Duchenne of boulogne uses an alternating current that he produced by inserting a vibrator into the circuit to stimulate the ear -
Brenner published more extensive investigation
In 1868, Brenner published a more in depth investigation of the effects of altering polarity, rate and intensity of the stimulation and the placement on the electrodes.
He discovered that hearing quality was better with a negative polarity in the electrical stimulus. -
The work of Wever and Bray
Wever and Bray demonstrated that the response to the electrodes form the surrounding area of the auditory nerve of a cat was similar in frequency and amptitude to which the ear had been exposed to. -
Russian investigators Gersuni and Volokhov examine effects of altering electrical stimulus
They found that hearing could persist after the removal of the tympanic membrane and ossicles, therefore giving an opening for the cochlea to be the site of stimulation. -
Stevens and Jones
Stevens and Jones though that electrical stimulus could be transduced into sound vibrations before it reached theinne ear. They were able to figure out whether a linear or non-linear transducer was used. -
Studies of Stevens and Jones(1939) and Jones (1940)
The research done by Stevens and Jones indicated that when the cochlea was stimulated using electricity, there were three mechanisms which produced hearing.
The middle ear - acted as a transducer
Electrical Energy - Could be converted into sound by direct effect on the basilar membrane.
Direct stimulation of the auditory nerve produced a basic hearing sensation. -
Lundberg performed one of the first recorded attempts to stimulate the auditory nerve
Using a sinusoidal current during a neurosurgical operation, Lundberg performed one of the first recorded attempts to stimulate the auditory nerve. -
First article published about direct electrical excitation
First article published about the direct electrical excitation on the auditory nerve by Djourno & Eyries. Dr. William house hear about this research from a patient for the first time. -
First short term trial
First short term implants are implanted in two American patients by Dr. House. -
Dr. Blair Simmons implants 6 electrode unit
A six electrode unit is implanted in a patient by Dr. Blair Simmons. -
Doyle reported inserting a collection of into the cochlea
Doyle reported inserting a collection of electrodes into a patient with total perspective deafness. -
Simmons provided a more extensive study
More extensive study where electrodes were placed through the promontory and vestibule directly into the modiolar part of the auditory nerve. Each nerve fibre representing different frequencies, could be stimulated. -
Grame Clark reviews available reasearch
Grame Clark, a PhD student at the university of Sydney, began to review the research to “investigate whether a single or ultiple-channel (electrode)cochlear implant would be possible for the management of a profound hearing loss.” -
Speech processor was deveoped
Speech processor was developed to work with Dr House's 3M single electride implant and was made commercially. 1,000 were implanted between 1972 and the mid 1800's. -
Clinical applications refined by House (1976 and Michelson (1971)
Dr. William House studied the effects on patients when small electric currents were used on the promontory during middle ear procedures. During the 60's Dr. House implated several devices in totally deaf volunteers. Even though these work for a short period of time, they were cast aside due to the lack of biocompatibility. -
Several hundred children had been implanted
Several hundred children had been inplanted with the House 3m single channel device. -
Nucleus Multi-channel Cochlear Implant introduced
In Australia devlopment of the multi-channel cochlear implant was underway, which towards the end of the 80's was gpoing to be world known under the name of the "Nucleus Multi-channel Cochlear Implant." This implant enhanced spectral perception and speech recognition. -
The FDA formly approved the 3M/House cochlear implant
FDA formly approved the 3M/house cochlear implant. By the late 80's basically all safety concerns and concerns about the long term success were mostly resolved. -
Enhancements added to the multi-channel cochlea implant
Enhancements such as introduced coding strategies in the speech processor, assosicated with higher performance. THe commerical successive let the implant become known as an asisstive device. More improvements were made to reduce risks. -
Current Day
Although the basic concept is the same, improvements in technology have allowed us to improve the hearing quality and various oother parts of the cochlear implants.