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2/16/2012
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Adventures in Bionic Hearing
Adventures in Bionic Hearing
Robert V. Shannon, Ph.D.House Research InstituteLos Angeles, California
Robert V. Shannon, Ph.D.House Research InstituteLos Angeles, California
Eisen Otol&Neurotol 2003, “Djourno, Eyries, and the First Implanted Electrical Neural
Stimulator to Restore Hearing”
Eisen Otol&Neurotol 2003, “Djourno, Eyries, and the First Implanted Electrical Neural
Stimulator to Restore Hearing”
First cochlear implant: 1957, ParisFirst cochlear implant: 1957, Paris
Normal Cochlea has:Active mechanical spectral analysis3-4,000 mechano-transducers (IHC)
~30,000 Nerve Fibers
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ABIABI
ICIICI
PABI
AMIAMI
INCIINCI
CICI
Dormanet al.2008
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Noise-Band Processor(4 bands)
Noise-Band Processor(4 bands)
Bandpass Filters300, 713, 1509, 3043, 6000 Hz
Bandpass Filters300, 713, 1509, 3043, 6000 Hz
Envelope Extraction:Half-wave
Rectifier + LPF
Envelope Extraction:Half-wave
Rectifier + LPF
Amplitude Manipulation
Unit
Amplitude Manipulation
Unit
0 6000 Hz0 6000 Hz
1
2
4
3 +
Bandpass Filters
Bandpass Filters
NoiseNoise
NoiseNoise
NoiseNoise
NoiseNoise
Number of Channels DEMO
1 2 4 8 16 32 Orig1 2 4 8 16 32 Orig
Instrumental Music - No vocals
4 8 16 32 Original
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Summary of Cochlear Implants
Summary of Cochlear Implants
• High level of speech performance in postlingually deaf adults
• Poor music perception
• Poor speech understanding in noise
• Children able to achieve mostly normal language development
• New directions in Cochlear Implants• Bilateral implants• Implants to supplement LF hearing• CIs in Single Sided Deafness• More electrodes/photolithographic arrays• Penetrating intraneural VIIIn electrodes
• High level of speech performance in postlingually deaf adults
• Poor music perception
• Poor speech understanding in noise
• Children able to achieve mostly normal language development
• New directions in Cochlear Implants• Bilateral implants• Implants to supplement LF hearing• CIs in Single Sided Deafness• More electrodes/photolithographic arrays• Penetrating intraneural VIIIn electrodes
Electrode in Cochlea – Nerve Far Away
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Two Electrodes – Major Interference
Electrode in Nerve – Highly Local
Electrode in Nerve – Highly Local
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Middlebrooks & Snyder JARO 2007
ACOUSTIC
dBdB
Comparison of spread of activation from acoustic, CI and intraneural stimulation as measured in ICComparison of spread of activation from acoustic, CI and intraneural stimulation as measured in IC
Middlebrooks & Snyder JARO 2007
Middlebrooks & Snyder JARO 2007
CIACOUSTIC
dB
Comparison of spread of activation from acoustic, CIand intraneural stimulation as measured in ICComparison of spread of activation from acoustic, CIand intraneural stimulation as measured in IC
Middlebrooks & Snyder JARO 2007
Middlebrooks & Snyder JARO 2007
CIACOUSTIC Intraneural
dB
Comparison of spread of activation from acoustic, CI and intraneural stimulation as measured in ICComparison of spread of activation from acoustic, CI and intraneural stimulation as measured in IC
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Intraneural Electrodes
Intraneural Electrodes
32 Channel Microwire Array From UCI32 Channel Microwire Array From UCI
Rigid carrier for insertion
Minimize diameter to minimize injury
Dissolvable?
Develop surgical approach
Holder/inserter tool for surgeon
Rigid carrier for insertion
Minimize diameter to minimize injury
Dissolvable?
Develop surgical approach
Holder/inserter tool for surgeon UCI Microwire array comparedTo human hair
UCI Microwire array comparedTo human hair
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VIIIa VIIIvVIIIa VIIIv
Snyder UCSFSnyder UCSF
Micro-CT of Electrode Inserted in Human Temporal Bone
Micro-CT of Electrode Inserted in Human Temporal Bone
Device DevelopmentDevice Development
• Developing the next generation cochlear implant• Reducing electrode-neuron distance is key• Penetrating microelectrodes into the nerve is the best
way to decrease distance
• Steps necessary for human trials• Short and long term animal models to check safety of
insertion and stimulation (UCI & HRI: NIH contract)• Human surgical approach (HRI)
3D modeling of auditory, vestibular and facial nervesCharacterize the variation in anatomy across patientsInsertion tool development
• Integrate research with company to bring to market• Estimated timeline: 3-5 years
• Developing the next generation cochlear implant• Reducing electrode-neuron distance is key• Penetrating microelectrodes into the nerve is the best
way to decrease distance
• Steps necessary for human trials• Short and long term animal models to check safety of
insertion and stimulation (UCI & HRI: NIH contract)• Human surgical approach (HRI)
3D modeling of auditory, vestibular and facial nervesCharacterize the variation in anatomy across patientsInsertion tool development
• Integrate research with company to bring to market• Estimated timeline: 3-5 years
Beyond the CochleaBeyond the Cochlea
• If speech pattern recognition is so robust, can we achieve good speech recognition by stimulating higher up in the system?
• Surely there is a point of diminishing returns – the higher in the system we stimulate the more intrinsic processing we bypass
• If speech pattern recognition is so robust, can we achieve good speech recognition by stimulating higher up in the system?
• Surely there is a point of diminishing returns – the higher in the system we stimulate the more intrinsic processing we bypass
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ABIABI
ICIICI
PABI
AMIAMI
INCIINCI
CICI
NF2: Chr 22 Dominant MutationNF2: Chr 22 Dominant Mutation
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Nucleus 24 ABINucleus 24 ABI
CI24M receiver-stimulator
Monopolarreference electrodes
(ball & plate)
Microcoiled electrodewires
Electrode array(21 platinum disks0.7mm diameter)
T-shapedDacronmesh
Removeablemagnet
ABI 24M Electrode ArrayABI 24M Electrode Array
ABIElectrode
array In situ
ABIElectrode
array In situ
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PABI: Penetrating Auditory Brainstem Implant
PABI: Penetrating Auditory Brainstem Implant
Funded by NIDCD Contract
Midbrain Implants: Surgical Approach
Midbrain Implants: Surgical Approach
Inferior Colliculus Implant(ICI) uses a surface electrode placed on the IC (Colletti-MedEl). First patient implanted Oct 05
Inferior Colliculus Implant(ICI) uses a surface electrode placed on the IC (Colletti-MedEl). First patient implanted Oct 05
Auditory Midbrain Implant(AMI) uses a penetrating electrode placed into the IC (Lenarz-Cochlear)Five patients implanted as of Spring 08
Auditory Midbrain Implant(AMI) uses a penetrating electrode placed into the IC (Lenarz-Cochlear)Five patients implanted as of Spring 08
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Auditory Midbrain ImplantLenarz et al. Otol & Neurotol
(2006)
Auditory Midbrain ImplantLenarz et al. Otol & Neurotol
(2006)
stylet
Electrode arrraywith 20 contactsElectrode arrraywith 20 contacts
Dacron MeshDacron Mesh
Diameter: 0.4 mm Length: 6 mm Site Size: 0.126 mm²
6 mm6 mm
Figure courtesy Minoo LenarzFigure courtesy Minoo Lenarz
Summary – AMI & ICISummary – AMI & ICI
• Thresholds low and stable
• Full loudness growth on all electrodes
• Pitch differences between electrodes
• Some speech token discrimination, but no recognition
• Thresholds low and stable
• Full loudness growth on all electrodes
• Pitch differences between electrodes
• Some speech token discrimination, but no recognition
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Summary of Prostheses Up to 2003
Summary of Prostheses Up to 2003
• CI does well – open set recognition is common
• ABI and PABI benefit from implant but obtain little-no open set speech recognition
• Even when basic info is in correct place (matching pitch and loudness patterns) NF2 ABI patients are not able to use it for speech recognition – why not?
• Is ABI already too high in the system - past the point of diminishing returns?
• CI does well – open set recognition is common
• ABI and PABI benefit from implant but obtain little-no open set speech recognition
• Even when basic info is in correct place (matching pitch and loudness patterns) NF2 ABI patients are not able to use it for speech recognition – why not?
• Is ABI already too high in the system - past the point of diminishing returns?
VittorioCollettiVerona
Video of 3 year old with ABIVideo of 3 year old with ABI
• Mondini type I with VIIIn aplasia
• Diagnosed at 2yr 3mo
• Implanted with ABI at 2yr 7mo
• Video shows testing over one year of auditory development
• Not typical – best of 35 ABI children
• Mondini type I with VIIIn aplasia
• Diagnosed at 2yr 3mo
• Implanted with ABI at 2yr 7mo
• Video shows testing over one year of auditory development
• Not typical – best of 35 ABI children
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Video: Testing Over the First Year of ABI Use
Video: Testing Over the First Year of ABI Use
Eisenberg et al. O&NO 2008
Eisenberg et al. O&NO 2008
• Goldenhar Syndrome – absence of IAM
• ABI at 3y3m, evaluated at 6 and 12 months
• Goldenhar Syndrome – absence of IAM
• ABI at 3y3m, evaluated at 6 and 12 months
New Results in NF2 ABIsNew Results in NF2 ABIs
• Some NF2 ABIs are able to understand speech similar to the best CIs (Warsaw, Würtzburg)
• 100% open set sentences in quiet• Conversational use of telephone• 50% Speech recognition at +3dB
SNR
• So good speech recognition ispossible with NF2 and an ABI
• Some NF2 ABIs are able to understand speech similar to the best CIs (Warsaw, Würtzburg)
• 100% open set sentences in quiet• Conversational use of telephone• 50% Speech recognition at +3dB
SNR
• So good speech recognition ispossible with NF2 and an ABI
RobertBehr:Fulda
RobertBehr:Fulda
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ConclusionsConclusions
• Cochlear implants provide sufficient sensory information for people to recognize speech and for young children to learn speech and language
• Cochlear implants do not provide sufficient sensory detail to allow music perception, voice quality, or speech recognition in noise
• ABI allows good speech recognition in some patients and even good speech and language development in some children
• Such prosthetic devices restore significant hearing and advance our understanding of the way sensory systems and the brain work together
• Cochlear implants provide sufficient sensory information for people to recognize speech and for young children to learn speech and language
• Cochlear implants do not provide sufficient sensory detail to allow music perception, voice quality, or speech recognition in noise
• ABI allows good speech recognition in some patients and even good speech and language development in some children
• Such prosthetic devices restore significant hearing and advance our understanding of the way sensory systems and the brain work together
