Final Flashcards
Impact of hearing loss in adulthood (18+)
-hearing/speech perception
-psycho-social-emotional
-school achievement
-vocational/economic
Impact of hearing loss in late childhood (7-18)
-hearing/speech perception
-language
-experiential/world knowledge
-psycho-social-emotional
-literacy
-school achievement
Impact of hearing loss in early childhood (3-7)
-hearing/speech perception
-speech production
-language
-experiential/world knowledge-psycho-social-emotional
-literacy
-school achievement
Impact of hearing loss in late prelingual (1-3)
-hearing/speech perception
-speech production
-language
-motor skills
-experiential/world knowledge
-psycho-social-emotional
-literacy
-school achievement
Impact of hearing loss in congenital or early acquired (birth to 1 year)
-hearing/speech perception
-speech production
-language
-motor skills
-experiential/world knowledge
-psycho-social-emotional
-literacy
-school achievement
CI development in 1748
benjamin wilson electrically stimulated the temple of a deaf individual
CI development in 1800
Italian physicist Allesandro Volta was the first person to attempt to stimulate their own auditory system with electrical stimulation
CI development in 1930
Wever and Bray recorded electrical response recorded from the vicinity of the auditory nerve of a cat.found it was similar in frequency and amplitude to the sounds to which ear had been exposed
CI development in 1950
Dr. Lundberg, a Swedish neurosurgeon, applied a sinusoidal electrical current during a neurosurgical operation and the patient described it as noise
CI development in 1957
Djourno and Eyries published article describing effects of electrical stimulation of auditory nerve
CI development in 1961
Dr. William House created own implantable technology. With Dr. John Doyle, they partnered to create early iterations of CI technology that were implanted into deaf ears
CI development in late 1960s
Dr. House partnered with electric engineer Jack Urban to develop the first single channel cochlear implant
CI development in 1964-1966
F. Blair Simmons at Stanford University placed 6 electrodes into the modiolus of a deaf patient which demonstrated first direct evidence of the place-pitch theory
CI development in 1969
first single channel CI was implanted. had a percutaneous plug that protruded through the skin
CI development in 1972
House/3M single electrode device, 1 ground. also now had a wearable sound processor with transcutaneous connection
CI development in 1980s
Vienna/3M (Burian, Hochmair-Desoyer and Hochmair); had 4 electrodes, 1 stimulated
Ineraid/Synbion multi-channel devices
-1970s and 80s
-6 intracochlear electrodes
4 channels
percutaneous
UCSF multi-channel devices
-4 channel system
-16 electrodes- 8 pairs, 4 chosen for stimulation
-four external coils using RF transmission
-redesigned into the Clarion implant
Dr. Graeme Clark
-father of modern cochlear implant
-inspired by a blade of grass in a snail shell, he created the modern electrode array
CI development in early 1980s
-physicians at UCSF and RTI collaborated to create an 8 channel CI
-single channel system for children
-clinical trials with multi-channel systems in Australia and US
CI development in 1987
- FDA approval of multi-channel devices demonstrating safety and efficacy for adults
CI development in 1990
FDA approval for children 2+
CI development in 2000
FDA approval for children 12 months+
CI development in 2019
FDA approval for SSD 5+ years
CI development in 2020
FDA approval for 9+ months
Cochlear devices
-nucleus cochlear implant system
-mini speech processor
-spectra processor
-SPrint speech processor–ESPrit speech processor
-ESPrit 22 speech processor
-ESPrit 3G speech processor
-nucleus freedom
-nucleus 5 sound processor
-nucleus 6
AB devices
-Clarion 1
-Clarion 1.2
-S-Series
-Platinum sound processor
-platinum BTE
-CII BTE
-hiRes Auria
-harmony
Med-el devices
-comfort CI system
-CIS pro+ processor
-combi 40
-tempo BTE
-OPUS2 and duet
NAD 1990 position statement
-claim children receive better speech perception from hearing aids than CIs
-research being conducted has no regard for the childs quality of life as a deaf adult
NAD 2000 position statement
-recognizes the rights of parents to make informed choices and respects their choice to use cochlear implants and all other assistive devices
-strongly supports the development of the whole child and of language and literacy
-parents have the right to know about and understand the various options available, including all factors that might impact development
Reasons for the Deaf Community’s Reaction to CIs
-lack of success with pre-lingual Deaf adults
-misinformation
-memories of being forced to wear HAs with no success
-do not want todays Deaf children to go through same loss of dignity by not being accepted in the hearing world
What is a cochlear implant?
-tool which is designed to detect, convert, code and transmit the salient features of acoustic signals into electrical signals that are delivered to the cochlea, the end organ of hearing
How does a cochlear implant work?
-mic captures the sound
-processor converts that sound to a digital signal
-that signal is sent through the cable to the coil
-the signal is sent across the skin to the implant where it is converted to electrical energy
-the energy is sent to the electrode array within the cochlea where it stimulate the hearing nerve
How do Cis and HAs differ?
-HAs: acoustically amplify sound through outer and middle ear to stimulate traveling wave in the cochlea, outcomes rely on the responsiveness of surviving hair cells
-CIs: bypass damaged hair cells and electrically stimulate the nerve directly, convert the acoustic input signal into an electrical pattern that is transmitted by FM signal through skin to internal device and delivered to electrodes in scala tympani, relies on surviving neural elements to be stimulated by direct delivery of current pulses
Basics of CI design
-all CI systems have challenges with hardware design and perceptual effects
-CI differ in how they address these challenges
-status of nerve influences effectiveness
-cochlea is the peripheral end of the auditory system
Speech or sound processing strategy
-set of rules used to control the conversion of signals from acoustic features into electrical properties
How are speech or sound processing strategies coded?
-number of electrodes
-locations of electrodes
-type of stimulation
-rate of stimulation
-amplitude of stimulation
-strategy
Current AB technology
-internal: HiRes Ultra 3D (HiFocus Slim J and Mid-Scala)
-external: Naida CI M, Sky CI M, Chorus (C1 devices)
Current Cochlear technology
-internal: CI612, CI622, CI632, CI624 and L24
-external: N8 and Kanso 2
Current Med-el technology
-internal: synchorny 2 portfolio- standard, medium, compressed, flexsoft, flex28, flex24, flex20
-external: Sonnet 2 and Sonnet 2 EAS, Rondo 3
CI retention options
-headbands
-pilot caps
-shirt clips
-hair clips
-double-sided tape
Hearing Hour Percentage
-compared amount of time subject had access to sound to the amount of time a typically developing child with normal hearing would have access to sound
-(wear time/ mean awake time) x 100
Adult unaided testing
-pure tone AC and bone: 125-8000 Hz
-SRT
-WRS
-tymps
-reflexes
-OAEs and ABR
Adult aided testing
-HA verification
-SF thresholds: 125-8000
-speech perception in quiet, noise
What is the presentation level of speech in noise? in quiet?
60 in quiet, 65 in noise to account for the extra effort
HINT sentence test
-designed as an adaptive noise test
-utilize in clinic with fixed noise
-each lists consists of 10 sentences with no ready indicator
CNC word lists
-developed to provide lists of monosyllabic words with equal phonemic distribution across lists
-10 lists of 50 words each
-each list should have approximately the same phonemic distribution as the English language
AzBio sentence test
-4 talkers
-15 sentence lists
-each list consists of 20 sentences
Spanish AzBio
-4 talkers
-42 sentence lists
-each list consists of 20 sentences
BKB-SIN
-designed to assess speech understanding in noise in CI listeners and those with HL
-18 list pairs
-each list pair consists of 20 sentences
-spoken by a male in 4-talker babble
-prerecorded SNRs that decrease in 3 dB steps with each sentence
-results are reported as the SNR in dB at which the subject understands 50% of the key words in the sentence
MSTB 3rd edition
-CNC for candidacy
-best aided listening
-sentences in noise should be administered at 65
-post-op testing only at 3 and 12 months post-op
How to isolate the test ear for asymmetric/SSD CI testing
-plug and muff
-masking through insert
-masking with circumaural
-direct audio
Appointment flow for pediatrics for CI eval
-tymps
-OAE/ABR
-unaided thresholds
-aided speech
-counseling
Pediatric general mapping appointment
-equipment check
-tymps
-booth testing (CI thresholds, unaided thresholds, speech)
-mapping
Adult appointment flow CI eval
-case history
-tymps
-ARTs/OAE
-unaided
-aided speech
-cognitive screener
-counseling
Adult general mapping appointment flow
-case history
-equipment check and listening check
-booth testing (CI thresholds, unaided thresholds, speech perception)
-mapping: impedances, NRI/NRT/ART
Adult CI candidacy appointment flow
-referrals- how and why patients come in
-CI eval process: audiologic eval, medical eval and counseling
-risks and benefits
-outcomes
-expectation
-tools for counseling
-aural rehab
-borderline candidate
CIQOL
-35 profile: 35 items on 6 domains (communication, emotional, entertainment, environmental, listening effort and social)
-10: global (provides a global evaluation of CI user QoL
-monitor changes pre/post CI and CI over time
-provides new information beyond speech perception scores (found to have a weak correlation with post-operative speech recognition outcomes)
FDA indications vs candidacy
-FDA- vary by manufacturer and insurers such as Medicare, can have different indications for who can receive a CI. developed through a clinical trial and are part of the devices label
Traditional adult CI FDA indications for Med-El
-18+
-bilateral severe to profound SNHl (PTA of 70 or greater at 500, 1000 and 2000)
-limited benefit from amplification: 40% correct or less in best-aided listening condition on recorded tests of open-set sentence recognition (HINT, CNC)
Traditional adult CI FDA indications for cochlear
-18+
-pre, peri, or post-linguistic SNHL
-moderate to profound HL in the low frequencies and profound HL in the mid to high frequencies
-limited benefit from amplification: 50% or less correct on recorded test of open-set sentence recognition in the ear to be implanted and 60% or less in the best-aided condition
Traditional adult CI FDA indications for AB
-18+
-post-lingual onset of severe or profound HL
-bilateral severe to profound SNHL
-limited amplification: 50% or less on a test of open set sentence recognition
EAS Adult CI FDA indications Med-El
-normal hearing to moderate SNHL in low frequencies (thresholds no poorer than 65 dB HL up to and including 500 Hz) with severe to profound mid to high frequency HL (no better than 70 dB HL at 3000 Hz and above) in the ear to be implanted
-CNC word recognition score in quiet in the best-aided condition 60% or less, in the ear to be implanted AND in the contralateral ear
EAS Adult CI FDA indications Cochlear
-18+
-thresholds less than or equal to 60 dB HL through 500 Hz and greater than 70 dB HL for 2000 Hz and higher
-60% or less on CNC word recognition scores in the ear to be implanted with 80% or less in the contralateral ear
Medical Evaluation
-medical exam and history review
-imaging
-minimum work up includes EKG, chest x-ray, blood work
-pre-op assessment by anesthesiologist
-chronic health conditions like diabetes and heart disease rarely prohibit implantation but must be considered
Common postoperative complications
-pain at incision
-dizziness/vertigo
-constipation
-tinnitus
-loss of residual hearing in the implanted ear
Uncommon postoperative complications
-wound hematoma
-infection
-facial nerve paralysis
-perilymphatic fistula
-device migration
-device failure
Adult follow-up timeline
-activation (2-4 weeks post-op)
-1 month
-3 months
-12 months
Audiological candidacy requirements (4)
-is there residual hearing to substantiate staying with traditional amplification or to warrant a hearing aid trial
-does patient perceive benefit from amplification in identifying environmental sounds or understanding speech in conversation
-would the patient achieve greater, equal or lesser outcomes with an implant as compared to the hearing aid
-do the benefits outweigh the risks
Ear candidacy considerations
-does the patient have a poorer ear
-history of hearing loss of each ear
-history of traditional amplification in each ear
-are both ears anatomically viable for electrode insertion
-patient preference
Medical candidacy consideration
-no medical contraindications
-cochlear patency: ossification
-cochlear anatomy: Mondini, EVA
-genetic disorders: osteogenesis imperfecta
-CNS concerns
-temporal bone fractures
-revision
Social candidacy considerations
-motivation level
-support system
-realistic expectations
-emotional state
-desire to communicate and interact in a hearing world
Benefits of CI. Improved…
-speech understanding in quiet
-identification of sounds
-quality of life
Factors that may influence outcomes
-onset of HL
-duration of HL
-how long without sound or stimulation
-status of the cochlea
-mode of communication
-appropriate expectations
-motivation level
-support system from family and friends
Reasonable expectations for pre-lingual patients
-sound detection
-identification of sounds
-closed-set word identification
-some open-set sentences
Reasonable expectations post-lingual patients
-obtain all levels of sound detection and identification
-closed set words and phrases
-complete open-set recognition at both sentence and word levels with average scores of 72% sentences in quiet and 56% words
Average post-op performance for our average CI patients
-CNC words: 51%
-AzBio in quiet: 67%
-AzBio SNR +10: 52%
Average post-op performance for our clinical EAS patients
-CNC words: 43%
-AzBio in quiet: 74%
-AzBio SNR + 10: 57%
-AzBio SNR +5: 36%
Potential benefits of EAS
-speech perception in noise
-enhanced music perception
SSD Adult CI candidacy indications Med-El
-5+ with profound SNHL in one ear and normal to 4000 Hz to mild in the other ear
-limited benefit from amplification: 5% or less on CNC in quiet when tested in ear to be implanted alone
-one month experience with CROS hearing aid or relevant device without subjective benefit
SSD Adult CI candidacy indications Cochlear
-5+ with severe to profound SNHL in one ear and normal to near normal up to 4000 Hz (less than 30 dB HL) in the contralateral ear
-limited benefit from amplification: 5% or less on CNC words with unilateral HA
Asymmetric Adult CI candidacy Med-El
-5+ with profound SNHL in one ear and mild to moderately severe SNHL in the other ear, with a difference of at least 15 dB in pure tone averages (PTAs) between ears
-limited benefit from amplification: 5% or less on CNC words in quiet when tested in ear to be implanted alone
-1 month experience with CROS or hearing aid or relevant device without subjective benefit
Potential benefits of CI for patients with unilateral or asymmetric HL
-speech perception with CI alone
-speech perception in spatially separated noise
-localization
-quality of life
Radio Frequency (RF) link
Connection between external piece and internal
How does a CI work? (9)
-external mic captures sound and transduces it into an electrical signal
-electrical signal is processed (pre-amplified or shaped) to improve the signal to noise ratio and increase audibility is soft sounds
-signal is analyzed by a digital signal processor to classify the input according to intensity, frequency and time domains before it is converted into an electrical code
-the coded signal is then converted from a digital signal into an electrical signal that is sent by RF via an electromagnetic signal by induction, received by an antennae
-the RF signal is carried by the power from the battery. the battery is the power supply for converting, coding and sustaining power for the ongoing process
-the internal stimulator also contains a digital signal processor which converts the digital code into electric pulses
-how the electrical pulses are sent along is determined by the speech coding strategy, the number of electrode contacts and the character and capacity of the electrode contacts
-the electrical stimulation delivered to the intracochlear electrode contacts returns to an extracochlear electrode, which serves as the ground or reference electrode
-the strength of the electric signal is determined for each individual user depending on amount of current needed to overcome structural and neural damage and the demands of this transmission process
Resistance/impedance
-measurement of the opposition to the flow of current in an electrical circuit, described in ohms
Resistance/impedances with CIs
-integrity of the electrode lead, electrode contact and the return electrode
-composition of fluid in the cochlea (inflammation from infection, hormonal changes and autoimmune reactions
-fibrotic tissue surrounding electrode contacts
-ossification
-electrode failure or issues with hermetic insulation
Ohms law
V = IR
-V is voltage
-R is resistance
-I = resulting current
Why do we need a ground
-electrical grounds allow for the completion of an electrical circuit during stimulation
-extracochlear grounds can be housed on the body of the CI, as a ring located around the electrode leads, or at the tip of a separate lead
Stimulus charge
-define by the pulse width and current amplitude
-increasing current amplitude or widening the pulse width delivers more current = louder percept for patient
Monopolar
-active electrode intracochlear referent electrode is outside the cochlea
-may be more than one referent (MP1, MP2, MP1+2)
-wider spread of current
-most commonly used
Bipolar
-both active and referent electrode are intracochlear
-can be adjacent electrodes or far apart (BP, BP+1, BP+X)
-can include multiple electrodes
-the physical separation determines the spread of the current
Why do modern CI systems utilize monopolar as the default over bipolar
-less current to achieve same perceptual loudness
-less differences in levels from one electrode to the next, able to interpolate which saves time
-improved battery life
-in most cases, monopolar electrode coupling does not result in facial nerve stimulation
Current steering
-virtual channels can be created by steering the current between electrodes
-ability to steer current between physical electrode contacts in order to deliver added spectral information
-AB advertises that this helps with hearing in noise, music appreciation, hearing environmental sounds and understanding tonal languages
-channels are stimulated to produce the percept of sound with features of pitch and loudness
-loudness percept is determined by electrical charge
-current amplitude and pulse width control the amount of electrical charge
-the greater the electrical charge, the louder the percept of sound
Telemetry
-provides information about the status of the electrode array and how it responds when being stimulated
-also enables features such as device identification and feedback on device function that can trigger alarms and warnings
-allows for estimation of battery life and determines amount of power required for external sound processor to deliver satisfactory signal
Impedance telemetry
-measure of electrode function + stimulability + compliance
-high impedance means low conductivity (resistance is opposition to current flow)
-low impedance allows for good conductivity or high compliance
-tests the current flow the passes low level current through the array
High impedance
-initial activation
-periods of prolonged non-use
-against nonconductive tissue or bone
Excessively high impedances
-outside the cochlea
-open circuit
-broken wire or contact
Low impedance
-intra-operative
-partial short
Excessively low
-short circuit
-channel interaction
Persistent fluctuations may be attributed to
-changes within the cochlea
-change in integrity/properties of cochlear fluids and tissues
-fault in cochlear implant
Compliance telemetry
-measure of capacity of the electrode to conduct current
-reciprocal of impedance
-issues with this may limit loudness growth and may require adjustments in pulse width or stimulation mode to overcome
Perceptual correlates
-intensity is coded by amount of stimulus/amplitude. How much current is applied to that electrode
-frequency conveyed by site of stimulation. which channel is being stimulated
-time conveyed by rate and pattern of stimulation. what is the rate os stimulation (pps)
