introduction to cochlear implants for ei service providers roxanne j. aaron, ma, ccc-a, faaa the...
TRANSCRIPT
Introduction to Cochlear Implants for EI Service Providers
Roxanne J. Aaron, MA, CCC-A, FAAAThe Moog Center for Deaf Education
March 2005
Introduction
Hearing Loss Identified at Birth
Hearing Aids Fitted by age 3 to 6 months
Infants with Profound Hearing Loss Can Receive Cochlear Implants by age 12 months
Increased Caseloads of Young Children with CI
What is a Cochlear Implant?
A surgically implanted medical device that bypasses the damaged part of the inner ear to electrically stimulate the remaining neural fibers of the auditory nerve
Electrical current stimulates the remaining auditory nerve fibers in the damaged inner ear to generate sensations of hearing
What are the potential benefits of CI?
Access to sound Environmental sounds Speech sounds High frequency sounds Soft sounds
Development of speech recognition and speech communication
Who Can Get a Cochlear Implant?
Adults and children with severe to profound sensorineural hearing loss
Est. >90,000 recipients worldwide
Pediatric Candidacy Criteria 12 months old or older
Profound Sensorineural Hearing Loss; (Severe to Profound Sensorineural Hearing Loss if > 2 years old for Cochlear device)
Limited benefit from hearing aids
Open-Set Speech Perception (e.g.. MLNT; LNT) <20% Advanced Bionics and MED-EL, <30% Cochlear
Pediatric Candidacy Criteria No medical contraindications
No active middle ear disease No cochlear nerve or auditory pathway lesions Cochlear anatomy allows implantation
Able to tolerate surgery
Enrolled in an educational program that supports listening and speaking for communication
Highly motivated with appropriate expectations (family and child)
A Team Decision
ENT Specialist CI Surgeon Audiologist Speech/Language
Pathologist Educator of the
Hearing Impaired Child Psychologist Social Worker Parents
The Process of Obtaining a Cochlear Implant1. Hearing loss identification/diagnosis
2. Hearing aid trial (3-6 months)
3. Audiologic candidacy evaluation
4. Medical candidacy evaluation
5. Other evaluations (speech-language, educational, psychological, etc.)
The Process of Obtaining a Cochlear Implant
6. Team meeting
7. Surgery
8. Initial stimulation (a few weeks after surgery)
9. Ongoing CI programming (1 week, 1 month, 2 months, etc.)
10.Verification of performance with CI
The Process of Obtaining a Cochlear Implant
CI Surgery A 2 to 4 hour procedure completed under
general anesthesia The internal device is placed under the skin
behind the ear into a well created in the mastoid bone
The electrode array is inserted into the cochlea
Cochlear Implant Components
Internal Device Surgically implanted under
the skin Electronics package
(receiver-stimulator) with magnet
Electrode array placed inside the cochlea
External Device Worn on the body or at ear
level Sound/speech processor Microphone Coil with magnet
Cochlear Implant Components
The external components of the CI system pick up sounds, analyze them, and convert them into an electrical signal that is sent to the internal device located under the skin
Internal and external components are held close
to each other by a pair of magnets and communicate via transcutaneous transmission of a radio-frequency signal
Cochlear Implant Components
The internal device decodes the signal and sends electrical current to each electrode
When the electrodes stimulate the nerve fibers of the auditory nerve, the signal is received by the brain and interpreted as sound
Cochlear Implant Components
Cochlear Implant Companies
Devices from 3 manufacturers are FDA approved for implantation in children
Each company has their own internal and external components that are only compatible with each other Advanced Bionics Cochlear MED-EL
Advanced Bionics (www.cochlearimplant.com)
Clarion and Bionic Ear HiRes 90K internal
Platinum Series Processor
Auria BTE Processor
Cochlear (www.cochlear.com)
Nucleus Contour and Contour
Advance internals
SPrint processor
ESPrit 3G BTE Processor
MED-EL (www.medel.com)
Combi 40+ internal
Tempo+ BTE processor with 5 modular options
CIS-PRO+ body processor
Common Features of CI Sound Processors
Power Switch On-Off
Battery Charge Meter
Display Lights
Program Control Selects Program or MAP loaded into the processor
Individual programs may have differing parameters such as speech encoder strategy, rate of stimulation, pulse width
Individual programs have different electrical dynamic ranges for each electrode which affect the perception of soft, average, and loud sounds
Common Features of CI Sound Processors
Volume Control Adjusts level of loud
sounds within a program
Sensitivity Control Determines if distant or
very soft sounds will be processed
Know the Child and the Device
Know which CI the child is using
Know which settings have been recommended for the external processor Observe current settings Change to the recommended settings if needed
Verify the system is working prior to therapy Are the appropriate lights or displays working? Does child look up or alert to sound? Does child localize to sound? Can the child participate in a Ling or word sound check? Use monitor earphones
Know the Child and the Device
Talk to the CI audiologist about child's status, the device, and the recommended settings
Talk to parents about the child and the device Does the child use the device during all waking hours? Are the parents comfortable with maintaining and
troubleshooting the device?
Request support materials from the CI company (Educator Guides, Teacher Guides, Troubleshooting Guides, Videos)
Advanced Bionics 1-800-678-2575 Cochlear (Customer Service) 1-877-883-3101 MED-EL 1-888-633-3524
CI Programming Basics Audiologists select the parameters
for each listening program Speech encoder strategy Stimulation rate Number of electrodes stimulated, etc.
Audiologists work with each child to set the program(s) within the CI sound processor
CI Programming Basics The child participates in tasks to help
set the minimum and maximum amount of electrical current required for each electrode Threshold assessment
Behavioral observation Conditioned response (VRA, CPA)
Loudness scaling/balancing Electrophysiological measures (NRT, NRI,
ESRT)
CI Programming Basics
The settings derived during the CI programming session form a listening program or MAP that is loaded into the sound processor
The listening program or MAP contains information about the amount of electrical current required by the child for hearing
CI programming is an ongoing process designed to satisfy the child’s need for electrical stimulation to optimize the perception of speech
EI Therapists and CI Programming
EI therapists can assist the audiologist in CI programming directly or indirectly Due to more frequent contact, the therapist
may know the child better What toys does the child like or dislike? What motivates the child? Under what conditions does the child work best? How does the child behave when tired or bored with
a task?
EI Therapists and CI Programming Offer to directly assist the audiologist in CI
programming May be billable as “consultation with others” if
preauthorized
Offer to work on tasks in therapy that will facilitate CI programming Auditory detection tasks Concepts such as “big” vs. “little” to assist with
loudness scaling
EI Therapists and CI Programming Give feedback to the audiologist about
how the child is responding to sound during therapy What sounds can child detect? Are any sounds uncomfortable?
Keep the audiologist informed about the child’s progress in learning to communicate
Acknowledgements
Special thanks to the cochlear implant manufacturers for the images and support materials used for this presentation
Advanced BionicsCochlearMED-EL
Thank You