Sunday, August 10, 2014

Oh, patents! Cochlear implants

Copyright © Françoise Herrmann

Going back again to the 2014 European patent Awards in Berlin, and the inventors nominated for the lifetime achievement award...
Among the three contenders for this award  was an Austrian, husband and wife team: Irwin Hochmair and Ingeborg Hochmair. This team invented an improved cochlear implant, a small computerized device implanted subcutaneously with electrodes extending to the base of the spiral-shaped inner ear called the cochlea. This miniature computerized device, equipped with electrodes, stimulates the auditory nerve with an electric field in response to speech signals, thereby restoring the capacity to hear the full spectrum of speech patterns and thus the capacity to produce them in speech. To date this device has been implanted in more than 200,000 people, affording them the opportunity to hear sounds.
The Hochmair cochlear implant device has two parts: a single channel transmitter, including the sound signal processor, which is carried around by the patient and hooked to the outer ear; and a single channel receiver which is implanted subcutaneously, in front of the skull bone, including two electrodes, one active and one grounding  that extend to the base of the cochlea. An electrical field is thus created at the base of the cochlea sufficient for stimulation of the auditory nerve, and energized at a frequency bandwidth that is large enough to accommodate all speech patterns.
In contrast to other neural stimulation devices for hearing, such as those inserted in the mastoid bone, operating on the principle of bone conduction, or those inserted inside the cochlea or even inside the auditory nerve, the Hochmair device purports to simplify insertion, without placement of electrodes inside the cochlea.

The abstract for the European patent EP0076096 titled Single Channel Auditory Stimulation is included below with two patent drawings. Fig 1 is a sliced drawing of an ear showing the positions of the implant, and Fig 2 shows the two parts of the device:

Chronic auditory stimulation is achieved by establishing an electric field at the base of the cochlea whereby full speech patterns are imparted to a patient. Penetration of the cochlea is not required thereby reducing the risks in installing the implanted electrodes (26. 28). In a preferred embodiment the electrodes are disc shaped with the ground electrode (28) being larger than the active electrode (26). The active electrode is preferably placed in the round window (32) at the base of the cochlea or on the promontory. The ground electrode is placed 2-10 mm from the active electrode to thereby confine the electric field. The interconnections to the electrodes are tissue compatible insulation covered wires (24) thereby minimizing stimulation of cutaneous nerve fibers. Abstract EP0076096


In an era of wireless devices and communication, there appear more improvements warranted for this type of cochlear implant disclosed with a wired transmitter connection. And most importantly, the competition may be coming from a totally different and decentered perspective on hearing.
 Indeed, there are viable socio-cultural options arising from the ever growing visibility and strength of the Deaf community (with a capital “D”). A path taken where people choose to embrace sign language fluency, and the absence of hearing and speech, creating the Deaf way of being, that is, a rich culture of meaning and life (Padden & Humphries, 1988). Indeed, a culture so vibrant that in the year 2005, it is deploring the loss of some of its members to the hearing community via cochlear implants, (Padden & Humphries, 2005; Waltzman, 2005).  
By way of illustration, the largest Deaf university of the United States, inspired by the early 19th century Institut des sourds et muets in Paris (France), is Gallaudet University, located in Washington D.C, established by an Act of Congress in 1864, now celebrating 150 years of excellence!

Padden, C. & T. Humphries (1988). Deaf in America: Voices from a culture. Cambridge, MA: Harvard University Press..
Padden, C. & T. Humphries (2005). Inside Deaf culture. Cambridge, MA: Harvard University Press.
Waltzman, S. (2005) Inside Deaf culture. Review in The New England Journal of Medicine, July 28, 2005, 353:436.
DOI: 10.1056/NEJM200507283530431


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