History of Cochlear Implants

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• History of Cochlear Implants

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History of Cochlear Implants

• We have come a long way in the last 20 years -
  technology, understanding of implants and their
  requirements
• What will the next 20 bring...

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History of Cochlear Implants

• Research (1)Early research 1700s and 1800s
• 1790 Galvani, Italy stimulated a dead frogs
  leg (movement of leg)
• 1800 Volta, Italy stimulated own auditory
  system (bubbling, cracking sounds heard)
• 1850 Duchenne, France stimulated own auditory
  system (fluttering sound heard)

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History of Cochlear Implants

• Research (1) 1900
• 1930 Wever and Bray, USA stimulated a cats
  auditory system (electrical response
  properties)
• 1930 Russian researchers effect of alternating
  electrical current with normal and residual
  hearing humans (clear sensation of hearing and
  understanding of speech)
• 1950 Lundberg, Sweden stimulated auditory nerve
  in a man during surgery (patient aware of noise)

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History of Cochlear Implants

• Research (2)
• 1957 Djourno, Eyries and Vallancian, France
• i) human surgery embedded small
  transducer into temporalis muscle, a lead
  from the coil into auditory nerve and a ground
  lead into temporalis muscle. Coupled with
  external stimulator and coil
• Patient heard chirping sound, reported
  assistance with lip-reading and background
  noise awareness, pitch differences and simple
  word recognition
• ii) as above on a second human patient with
  similar results

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History of Cochlear Implants

• Research (2) contd
• Initial results promising BUT doubts about safety
  and long term feasibility.
• Djourno et al abandoned research because of these
  doubts

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History of Cochlear Implants

• Research (3)
• 1960 House, USA
• i) with Doyle an engineer, in several
  human subjects placed electrode on auditory
  nerve.
• Doyle constructed a unit to transmit pure
  tones and speech. Results encouraging
• ii) Two patients implanted with gold
  electrodes. Results encouraging but electrodes
  had to be removed due to infection

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History of Cochlear Implants

• Research (3) contd
• 1964 Simmons, Mongeon, Lewis and Hungington,
  USA
• implanted profoundly deaf human with 6
  electrodes (reports of recognition of a limited
  range of frequencies and simple tunes)
• Simmons et al abandoned this research as they
  thought the long term benefits were limited

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History of Cochlear Implants

• Research (4)
• Over years many advancements but limitations with
  mechanics and technology
• Concern over long term safety of electrical
  stimulation
• It was thought that there would the side effect
  of secondary degeneration of afferent nerve
  fibres

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History of Cochlear Implants

• Research (4) contd
• With developments of new materials in space
  industry and developments with pacemakers rate of
  progress increased
• Pacemakers allowed researchers to observe effects
  of chronic pulsatile stimulation in humans over
  years

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History of Cochlear Implants

• Research (5)
• 1968 Michelson and Pialaux, USA animal study
  data that intracochlear electrodes could be
  maintained safely and would function for long
  periods of time

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History of Cochlear Implants

• Research (5)
• 1960s Clark, Australia animal studies
• 1960s House, USA single subject implanted
  successfully and developed a stimulator
  package patient could use that did not
  impede activity
• This was the first breakthrough from experimental
  period to clinical application period

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History of Cochlear Implants

• Research (6)
• 1973 House group, USA developed preop test
  battery
• 1973 In San Francisco the first International
  Conference on Electrical Stimulation of the
  Acoustic Nerve as a Treatment for Profound
  Sensorineural Deafness in Man

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History of Cochlear Implants

• Research (6)
• 1970s 3M bought the single channel technology
  and developed the 3M House device.
• This device was the first commercially
  available cochlear implant and was FDA approved
• From this time many research groups formed in the
  US, Australia, Europe and China with rapid
  developments - single channel/multichannel,
  intracochlear/extracochlear

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History of Cochlear Implants

• Distinguishing features of Cochlear Implants
• Type of stimulation
• Type of transmission link
• Number of channels
• Placement of electrode array

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Type of Stimulation Stimulus Waveform
Analogue / Pulsatile Typical analog and
pulsatile stimulation waveforms
Analogue Pulsatile
Type most used
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Transmission Link

• Transcutaneous Link
• Percutaneous Link
• Type most used

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Single/Multichannel Implants

• Single channel - one electrode pair
• Multichannel - multiple electrodes from 4 - 24
• Type most used

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Intra-cochlear/Extracochlear Implants

• Intracochlear - electrodes placed inside the
  cochlea
• Extracochlear - electrodes placed outside the
  cochlea
• Type most used

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Implants available then...

• Nucleus device
• MXM
• Hortmann
• 3m House
• 3M Vienna
• China devices

• Symbion/Ineraid/Richards
• Laura
• UCH
• Storz/UCSF/Minimed
• Banfai
• Others.

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Implants available now...

• Nucleus 22 Nucleus 24 - most widely used
• MXM
• Med El - (was 3M Vienna)
• Clarion - (was Storz/UCSF/Minimed)
• ALLHear single channel - (was 3M House)
• Laura - (was Antwerp Bionic Systems, then Philips
• now Cochlear)

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History of Cochlear Implants

• Research (7) - Nucleus device
• 1967 Clark, Australia animal studies begun at
  University of Melbourne
• 1970 Clark published paper on neurophysiological
  assessment of surgical treatment of profound
  deafness
• 1974 University of Melbournes first prototype
  fully implantable mult-channel receiver
  stimulator

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History of Cochlear Implants

• Research (7) Nucleus device contd
• 1978 Clark developed a 10 channel prototype
  implant and completed preliminary safety
  studies
• First two profoundly deaf patients implanted
  with 10 channel University prototype.
• Results very encouraging
• 1978-79 Formant based speech coding strategy
  (F0/F2)
• 1981 Cochlear LTD established in Sydney to
  develop Clarks research

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• Our first implantee, 1978
• University of Melbourne

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History of Cochlear Implants

• Research (8) Nucleus device contd
• 1982 Cochlear developed the first commercially
  available multichannel implant (22 channels)
  for FDA clinical trail in adults

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History of Cochlear Implants

• Research (8) Nucleus device contd
• 1982 10 postlingually deafened adults implanted
  with Nucleus 22 CI at University of Melbourne
• Frequency and thus spectral information
  provided by this implant
• Patients could perceive complex environmental
  sounds and recognize words even without
  visual cues

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History of Cochlear Implants

• Research (8) Nucleus device contd
• The clinical studies period had closed and the
  practical application and clinical testing period
  had begun

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History of Cochlear Implants

• Clinical Testing and milestones (1) Nucleus
  device
• 1985 First children implanted with the Nucleus
  22 CI at University of Melbourne
• FDA approves Nucleus F0/F2 WSP II
  strategy and processor for adults
• 1986 FDA approves Nucleus F1/F2 WSPIII
  strategy and processor for postlingually
  deafened adults

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History of Cochlear Implants

• Clinical Testing and milestones (2) Nucleus
  device
• 1989 FDA approves the Nucleus Multipeak -MSP
  strategy and processor for postlingually
  deafened adults.
• 1990 FDA approval for the Nucleus F0/F1/F2
  WSPIII and Multipeak MSP strategies and
  processors profoundly deaf children from 2 y.o.

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History of Cochlear Implants

• Clinical Testing and milestones (3) Nucleus
  device
• 1994 FDA approves the Nucleus SPEAK Spectra
  strategy and processor for postlingually deaf
  adults and deaf children.
• 1996 FDA approves clinical trial of Nucleus 24
  system in adults.

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History of Cochlear Implants

• Clinical Testing and milestones (4) Nucleus
  device
• 1997 FDA approves the Nucleus 24 system for
  postlingually deaf adults and deaf children.
• FDA approval for severely deaf children
• 1998 ESPrit speech processor released
• The worlds first multichannel ear level
  speech processor

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History of Cochlear Implants

• Clinical Testing and milestones (5) Nucleus
  device
• 1999 Clinical trials begun on Nucleus 24
  Contour
• 2000 FDA approves the Nucleus 24 Contour,
  Nucleus 24k, and Nucleus 24 ABI system for
  postlingually deafened adults and deaf children
  from 12 months of age.
• 2000 Ear-level processor for Nucleus 22 system
  released - ESPrit22