Cochlear Implant


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  • Firstly, a definition. What is a cochlear implant? An implant is a device etc (read from overhead)……….. What an implant does is: for an adult or child who has heard before, an implant will restore a level of hearing sensation. for a child who has never heard before, an implant will give the potential for hearing. With a child, to maximize this potential for hearing that the implant gives,it is critical that the child undergo listening training to learn to listen with the implant. So an implant is not a miracle sure but it gives hearing potential. This potential the implant provides is significant eg many adults can learn to use the telephone when using the implant and for children, if children are implanted young enough, they can in most cases learn to listen and speak and go through mainstream school
  • This slide shows the same view of an ear as the previous slide but with a CI in situ Here you can see the implant with electrode array inserted into the cochlea and the electronics package here embedded into the bone behind the ear.. This is the speech processor and headset with microphone. The sound is picked up by the microphone, sent to the speech processor where the important parts of the speech signal are picked out and coded. This code plus power from an external battery is sent to the transmitting coil over the implant. The information is then transmitted across the skin to the implant and decoded. This information is then sent to the electrodes in the form of tiny electrical pulses which directly stimulate the hearing nerve, bypassing the damaged parts of the ear. The nerve then transmits the signal up to the brain where we hear the sound. USE DEMO PRODUCT HERE
  • This shows a close up of the electrode array in the cochlea. Each dark band is an electrode and you can see how the tiny electrical pulses will stimulate the nerve here
  • Multiple channel ci were first implanted in children in Melbourne in 1985- 10 year old. Since that time over 10,00 children have been implanted with Nucleus CI and the age of implantation has dropped rapidly As reseach,clinical results on children showed better results when they receive their implant at an early age (during the critical phase of language development) and given our knowledge of language development, physiological studies of the effects of sensory deprivation and the effects of age of hearing aid fitting on outcomes for hearing impaired children.
  • 5 This shows an xray of the electrode array in the cochlea. We have 22 active electrodes in the array which extend around one and a half turns of the cochlea as you can see here. As you probably know the cochlea is organized so that we hear different frequencies in different parts of the cochlea. We hear high sounds here and low sounds here. Because there are 22 electrodes in the electrode array the implant recipient can hear the different frequencies in speech because a high sound will stimulate an electrode in this region and a low sound will stimulate an electrode in this region
  • This shows the programming equipment and the specialized software used to Map the speech processor.
  • 2-3 weeks following surgery the recipient returns to the clinic for the first fitting of the external companents the term MAPping/programming the procedure required for fine tuning the device to suit each individual’s needs requires specialised software and programming interface systems Is the process of measuring and controlling the amount of electrical current delivered to the cochlea. To provide the patient with comfortable and useful hearing sensations . Theaudiologist sets the speech procesor to the appropriate levels of stimulation for each electrode. The average number of postoperative visits is higher in paediatric than in adult programmes. Device fitting requires at least 2 clinicians. Duration of habilitation is higher.
  • Listening training is critical Without this the potential of the implant will never be reached
  • These are the core CI Team members. Viktorija will go into more detail about each member’s role
  • Cochlear Implant

    1. 1. Cochlear Implants - An introduction R.Ranjith Audiologist Madras ENT Research Foundation Chennai
    2. 2. What is a cochlear implant ? <ul><li>A cochlear implant is a hearing prosthesis designed to restore or provide a level of auditory sensation to adults and children who have a severe to profound bilateral sensori-neural hearing impairment and who get limited benefit from hearing aids </li></ul>
    3. 3. Parts of CI <ul><li>External </li></ul><ul><li>Microphone </li></ul><ul><li>Speech Procressor </li></ul><ul><li>Transmitting coil </li></ul><ul><li>Internal </li></ul><ul><li>Receiver /Stimulator </li></ul><ul><li>Electrode array </li></ul>
    4. 4. The Cochlear Implant in situ
    5. 5. Electrode Array in the Cochlea
    6. 7. Sound is received by the microphone Microphone
    7. 8. Sound is sent from microphone to speech processor cable Speech processor
    8. 9. Speech processor analyzes and digitizes the sound into coded signals Speech Processor
    9. 10. Coded signals are sent to the transmitting coil Transmitting coil Cables
    10. 11. Transmitting coil sends the code across the skin to the receiver/ stimulator of internal implant Transmitting coil Receiver/ stimulator
    11. 12. Signals are sent to the electrodes to stimulate the remaining nerve fibres electrode
    12. 13. Signals are recognized as sounds by the brain producing a hearing sensation
    13. 16. <ul><li>1985: </li></ul><ul><li>First children implanted </li></ul><ul><li>with Nucleus multichannel </li></ul><ul><li>cochlear implant in </li></ul><ul><li>Melbourne. </li></ul><ul><li>Over 50,000 children have been implanted and the age of implantation has dropped significantly. </li></ul>
    14. 17. Selection criteria - Children <ul><li>Twelve months of age or older </li></ul><ul><li>Bilateral severe to profound sensori- neural hearing loss - congenital or acquired </li></ul><ul><li>No or less benefit with the most optimised hearing aid </li></ul><ul><li>Aided audiometric thresholds that fall outside speech range at 2kHz </li></ul><ul><li>No medical or radiological contraindications </li></ul><ul><li>Motivation and good family support. </li></ul>
    15. 18. Candidacy Guideline Audiograms
    16. 19. Selection Criteria - Adults <ul><li>18 years of age or older </li></ul><ul><li>Profound, severe-profound, bilateral sensorineural hearing loss </li></ul><ul><li>Post lingual onset of profound deafness </li></ul><ul><li>Little or no benefit from hearing aids </li></ul><ul><li>No medical or radiological contraindications for surgery </li></ul>
    17. 20. Factors that may exclude candidacy <ul><li>Absence of auditory nerve or l ack of auditory nerve integrity bilaterally </li></ul><ul><li>Neurological damage impeding auditory processing </li></ul><ul><li>Medical risks of surgery that exceed the expected benefits of the cochlear implant </li></ul>
    18. 21. Factors that may influence outcomes with an implant <ul><li>Length of profound deafness </li></ul><ul><li>Age at implant </li></ul><ul><li>- 0 to 5yrs optimal </li></ul><ul><li>- 5 to 7 yrs Results will vary </li></ul><ul><li>-7yrs and above provided good HA use and </li></ul><ul><li>re/habilitation </li></ul><ul><li>Aetiology </li></ul><ul><li>Use of hearing aids prior to implantation </li></ul><ul><li>Amount and quality of re/habilitation before and after implant </li></ul><ul><li>Family support and commitment </li></ul><ul><li>Educational methods and communication mode </li></ul>
    19. 22. The process of getting an implant <ul><li>Pre surgery : </li></ul><ul><li>Initial Referral </li></ul><ul><li>Full medical evaluation </li></ul><ul><li>Full audiological evaluation to assess level and type of hearing loss (PTA.Impedance,ABR,ASSR,OAE and Prom-Stim) </li></ul><ul><li>Optimal hearing aid fitting and evaluation </li></ul><ul><li>Hearing aid trial and auditory training </li></ul><ul><li>Post training evaluation </li></ul><ul><li>Counseling of parents and family members </li></ul><ul><li>Acceptance for implant and final counseling </li></ul>
    20. 23. The process of getting an implant The process of getting an implant <ul><li>Surgery: </li></ul><ul><li>3 to 5 hours </li></ul><ul><li>1 to 2 day hospital stay </li></ul><ul><li>3 to 4 weeks later – switch on </li></ul>
    21. 24. X-Ray of Cochlear Implant in Situ
    22. 25. Next Details Menu Back
    23. 26. Neural Response Telemetry System Next Details Menu Back Transmitter Receiver Decoder Current Source Transmitter Encoder Amplifier Receiver PCI IF5 Card
    24. 27. Stimulation and Recording Modes Details Next Menu Back Stimulation Recording
    25. 28. Post Surgery: Fitting the externals <ul><li>Switch on </li></ul><ul><li>About three weeks following surgery the implantee will return to the clinic to have the external parts of the device fitted </li></ul><ul><li>This first fitting is called the ‘switch on’ or ‘tune up’ of the device </li></ul>
    26. 29. Clinical Programming System CPS
    27. 30. What is involved in activating the system? <ul><li>the term referred to as MAPping/programming </li></ul><ul><li>the procedure required for fine tuning the device to suit each individual’s hearing needs </li></ul><ul><li>requires specialised software and programming interface systems to program the speech processor. </li></ul><ul><li>Is the process of measuring and controlling the amount of electrical current delivered to the cochlea. To provide the patient with comfortable and useful hearing sensations. </li></ul>
    28. 31. <ul><li>Listening training </li></ul><ul><ul><li>An individual program is worked out for each recipient </li></ul></ul><ul><ul><li>Focus is on listening </li></ul></ul><ul><ul><li>For children: Listening training follows normal child speech and language developmental milestones – hearing age vs chronological age </li></ul></ul><ul><ul><li>Family must be involved </li></ul></ul><ul><ul><li>With children the parent is trained to carry over listening to home – in a natural environment </li></ul></ul>Listening training pre and post implant (AVT)
    29. 32. The Cochlear Implant Team: Core members <ul><li>The Parents </li></ul><ul><ul><li>Need to be involved in all evaluation processes and decisions. Must have realistic expectations and fully understand all aspects of process. </li></ul></ul><ul><li>The Surgeon </li></ul><ul><ul><li>Full medical and surgical evaluation, counseling, surgery and post surgical care </li></ul></ul><ul><li>The Audiologist </li></ul><ul><ul><li>Full audiological evaluation, hearing aid fitting, counseling, mapping, adult rehabilitation and ongoing follow up </li></ul></ul><ul><li>The Teacher of the Deaf/ Habilitationist </li></ul><ul><ul><li>Pre and post surgery listening training, full habilitation program planning for individual and full home training program for parents </li></ul></ul>
    30. 33.  Audallion beam former  Brain Stem Implants  Espirit 3 G speech processor  Neural response telemetry - NRT Newer developments
    31. 34. <ul><li>Completely implantable Implants </li></ul><ul><li>Neuronal regeneration factors </li></ul><ul><li>Improved speech coding strategies </li></ul><ul><li>Automated Mapping based on NRT </li></ul>Future
    32. 37. Thank You