Advances in Implantable Technologies. Huw Cooper BAA 2014

Transcription

1 Advances in Implantable Technologies Huw Cooper BAA 2014

2 Implantable technologies for hearing Aim: to provide access to sound when conventional amplification no longer useful For severe- profound sensorineural hearing loss: Cochlear Implants (direct electrical stimulation) Severe-profound SNHL with well preserved LF hearing: combined electro-acoustic hearing (EAS) Moderate sensorineural or mixed hearing loss: middleear implantable devices (e.g: Vibrant Soundbridge) Conductive hearing loss: BAHA or Bonebridge Absent cochlea/disrupted VIII nerve: Auditory Brainstem implant (ABI)

3 Early 1980 s: The UCH/RNID single-channel cochlear implant

4 The first (single channel) paediatric cochlear implant

5 A typical multi-channel cochlear implant in situ

6 Implant centres in the UK

7 Advances in cochlear implantation Evolution of electrode arrays; quest for atraumatic insertion with best possible selectivity of stimulation Constant development of speech processing/stimulation strategies Sound processors to deliver electrical and acoustic stimulation together (EAS) Introduction of current technology into external hardware; e.g.: Remote controls Directional microphones, adaptive directionality Datalogging Intelligent scene classification Connectivity

8 Integrated to enrich residual hearing Nucleus 6 hybrid capability Every Nucleus 6 sound processor is hybrid ready Easily configured in a few simple steps Instant fit disposable domes or customised earmoulds Integrated programming to optimise the acoustic output

9 MedEl; SYNCHRONY Electrode Arrays Designed for atraumatic implantation FLEX Series FORM Series CLASSIC Series NEW

10 2014: SYNCHRONY Cochlear Implant System SYNCHRONY SONNET RONDO

11 SONNET Audio Processor Automatic Sound Management 2.0 Microphone Directionality Wind Noise Reduction Automatic Volume Control Datalogging Processor usage Average usage per day Programme usage Overall days logged Volume range Sensitivity range

12 Typical processing in current cochlear implant system (Nucleus 6)

13 Simply smarter, automated hearing performance SmartSound iq Music Speech in Noise Quiet Speech Wind Noise A range of technologies working together to meet user needs in every hearing situation Automatically adjusts to the hearing situation Industry first scene classifier (SCAN) Background noise reduction (SNR-NR) Wind noise reduction (WNR)

14 How is the device being used? Time on Air Time on air Time in speech Coil off events Time on air trends Time in speech trends

15 What is the sound environment? Scenes Sound environment of patient Classified by scenes: Speech in Noise Speech Noise Quiet Music Wind Scene exposure trends

16 Truly wireless connectivity No dongles, no cables Three different 2.4GHz wireless audio accessories Free from cables and neck-worn devices Software upgrade under development

17 Good low frequency hearing: EAS: (Electro-Acoustic Stimulation) Acoustic stimulation Electrical stimulation

18 Expanding indications Residual hearing: no bar to implantation; criteria constantly under review Recognition of benefits of bimodal or combined electric and acoustic hearing Bilateral implants; now routine for children, and for visually impaired adults Implantation in unilateral hearing loss; gaining experience Congenital/pre-lingually deaf adults; expanding group Growing interest in perception of music

19 How good is hearing with a cochlear implant? Speech recognition performance with cochlear implants has improved significantly with advances in speech coding strategies; Despite this, speech recognition in implant listeners is generally badly impaired by background noise; evidence suggests that the number of perceptually distinct spectral channels available to implant listeners is the limiting factor BUT: all cochlear implant manufacturers have developed methods to try and improve hearing in noise AND: many adults achieve amazing speech recognition performance in quiet and noise; many children implanted at a young age have grown up with near-normal spoken language

20 At what point is someone deaf enough for a cochlear implant to be the right thing to do?

21 NICE Guidance January 2009 (TAG 166): reported that there are approximately 613,000 > 16 years with severe to profound deafness in England and Wales. Approval given for: Unilateral CI for all severe to profoundly deaf Simultaneous bilateral CIs for: All children Adults who are also blind Sequential bilateral CIs for: Existing patients who would qualify for bilateral implants under the new Guidance Approval not given for: Bilateral implants for adults Bilateral implants for adults post meningitis NICE reviewed evidence in February 2011 & have kept current guidance as static

22 Selection criteria: NICE Guidance January 2009 Severe to profound deafness is defined as hearing only sounds that are louder than 90 dbhl at frequencies of 2 and 4 khz without acoustic hearing aids Adequate benefit from binaural acoustic hearing aids is defined for this guidance as: for adults, a score of 50% or greater on Bamford Kowal Bench (BKB) sentence testing at a sound intensity of 70 db SPL for children, speech, language and listening skills appropriate to age, developmental stage and cognitive ability

23 Selection criteria Based on a 3:1 probability that a cochlear implant will provide improved hearing (speech recognition) compared to pre-operative best-aided performance Criteria should change as outcomes improve with enhancements to technology Can one set of criteria be sensibly applied to all potential candidates? (well know association between short duration of deafness and better outcomes) NICE guidance: now 5 years old; overdue for revision Are sentences an appropriate and sensible method of determining candidacy?

24 BKB Sentence test (in quiet): % correct Open-set speech recognition in quiet (BKB sentences) for a series of 125 adult cochlear implant users in Birmingham First quartile= near 50% Rank order

25 Dowell RC, Hollow R and Winton L: Changing selection criteria for cochlear implants, the Melbourne experience

26 Criteria elsewhere in world Australia: based on findings of Dowell at al : <70% speech recognition (sentences) Other countries: varied, but many more relaxed criteria than UK

27 BKB Sentence score (9 months) Open-set speech discrimination (% correct with BKB sentences) v Duration of profound deafness in the implanted ear, n= Duration of deafness in implanted ear

28 BKB Sentence score (9 months) Open-set speech discrimination (% correct with BKB sentences) v Duration of profound deafness in the implanted ear, n= Duration of deafness in implanted ear

29 BKB Sentence score (9 months) Open-set speech discrimination (% correct with BKB sentences) v Duration of profound deafness in the implanted ear, n= Duration of deafness in implanted ear

30 Rough guide to cochlear implant criteria

31 Typical fitting range for EAS (Electro-Acoustic Stimulation)

32 EAS: a typical candidate

33 EAS: a typical candidate

34 Hearing preservation following cochlear implant surgery Hearing preservation surgery: slow, careful insertion; round window insertion; use of steroids; atraumatic electrodes Hartley et al, 2013: systematic review: 76% of implanted patients showed < 20 db reduction in hearing thresholds post surgery

35 Conclusion: Hearing can be preserved with standard-length (30mm) electrodes

36 MUSIC?

37 McDermott H (2004): Music perception with cochlear implants: a review. Trends in Amplification, 8(2): a) On average, cochlear implant users perceive rhythm about as well as listeners with normal hearing; b) Even with sophisticated multiple-channel sound processors, recognition of melodies is poor, especially without rhythmic cues, with performance at little better than chance levels for many implant users; c) Perception of timbre, e.g. as used to identify musical instruments, is unsatisfactory;

38 McDermott H (2004): Music perception with cochlear implants: a review. Trends in Amplification, 8(2): d) Implant users tend to rate the quality of musical sounds as less pleasant than do normal-hearing listeners; e) Auditory training programmes aimed at listening to music may help to improve enjoyment of music; f) Perception of pitch may be improved by enhancements to speech processing strategies; g) Combined electrical and acoustic hearing may help to improve music perception.

39 Helping improve perception of music

40 See:

41 Richard Reed: Musician and cochlear implant user

42 Can adults with unilateral deafness benefit from a cochlear implant?

43 Case study: unilateral deafness following traumatic head injury (GSW) 31 year old soldier shot in head Total hearing loss in right ear; mild loss in left ear Troublesome right sided tinnitus Successful right cochlear implant + cranioplasty Jan 2013; Successful bimodal listening (Right CI+ Left open-fit Oticon h/aid) 98% correct sentence recognition via right CI (left ear blocked) Not aware of tinnitus in implanted ear while implant activated

44

45 Should there be an upper age limit for cochlear implantation?

46 Age of patients implanted April 2008 to March 2011 (N=126) Age at surgery Patients

47 Age of patients implanted April 2008 to March 2011 (N=126) OVER Age at surgery Patients

48 Our oldest cochlear implant user: Jack, age 100

49 Cochlear implants in the elderly population Lachowska et al (2013): age alone should not be a relevant or excluding factor when choosing candidates for cochlear implantation. Chen at el (2013): Our results indicate that the safety profile of cochlear implantation in an older population is comparable to that of younger adults and children. We suggest that concerns for increased postoperative complications in patients of advanced age do not need to be a primary consideration when determining CI candidacy Ramos et al (2013): Cochlear implantation improves QoL of patients over 60 by the mere fact of having been implanted, regardless of poorer audiological benefits.

50 BKB scores pre-op vs. post-op; by age group

51 Should congenitally or pre-lingually deaf adults have cochlear implants?

52 Congenital/prelingually deaf adults Historically; opposed to cochlear implants and not considered suitable Theoretically- should not benefit as no memory of sound; no healthy auditory pathway; auditory cortex probably taken over by other senses Historical reports of non-auditory sensations resulting from cochlear stimulation Main language= BSL not spoken language Expectations of benefit: must be different to post-lingual adult population; i.e. no expectation of open-set (sound alone) speech recognition

53 Factors in favour of cochlear implantation in congenitally deaf adults History of some usable hearing in childhood Evidence of consistent hearing aid use Some spoken language completely or partially intelligible Sensible expectations of possible outcome and limitations of implant

54 Susan Stone: The experiences of congenitally profoundly deaf candidates who receive CIs as adults (presented at BCIG 2012) Qualitative study based on semi structured interviews From 2006, 21% of referrals were for prelingually deaf adults Key factors: Motivations, early experiences, identity, emotional wellbeing, lip-reading ability All reported: Advantages to hearing Lip-reading enhancement Finding some sounds unpleasant Improved emotional well being

55 Case study: congenitally deaf implant success Born profoundly deaf- maternal rubella Main language: BSL Long term bilateral hearing aid user; existing patient of our service Education: school for the deaf Zero open-set speech recognition with hearing aids Advanced bionics implant at age 29 Aware of wide range of environmental sounds No open-set speech discrimination but now asking for second side implant!

56 Cochlear implants are no longer only for the profoundly deaf; we now know that they can help many people with usable hearing who struggle with hearing aids alone Although implants do not convey music well, many implant users can enjoy music and training can help- especially if combined with some auditory information in other ear

57 ..more conclusions There is growing evidence of the benefit of cochlear implants for people with unilateral deafness, and this will become more common; Many elderly patients can gain useful benefit from cochlear implants, if medically fit

58 conclusions Growing numbers of congenitally- or prelingually deaf adults are now seeking cochlear implants and can gain some benefit (with limited expectations) Bilateral implantation is now routinely offered and funded for children, while experience with adults remains limited (and is not currently funded)

59 Middle-ear implantable hearing aids Niche market for patients who are unable (or unwilling?) to use conventional hearing aids Similar surgery to cochlear implant Limited by range of output Require stable hearing loss Very careful patient selection is essential

60 Mild to severe SNHL or mixed loss: Vibrant Soundbridge (VSB)

61

62 Vibrating Ossicular Prosthesis (VORP) Magnet Demodulator Silicone encapsulation Receiver coil Floating Mass Transducer (FMT)

63

64 Fitting range: SNHL (air conduction thresholds)

65 Fitting range: conductive or mixed losses (bone conduction thresholds)

66 Positioning of the FMT: conventional approach

67 Amade speech processor Twin microphones (one front, one back) Program change button

68 Audio Processor in situ no occlusion (ear canal free) easily hidden (covered by hair) Held by magnetic attraction

69 Potential benefits of MEI For patients unable to use conventional aids Elimination of the occlusion effect Elimination of feedback Improved sound quality of own voice Improved wearability and comfort Increased naturalness of sound quality Cosmetically v good

70 Middle-Ear implantable devices: Key selection criteria Main criteria: patients who are unable to use and benefit from conventional aiding Fitting of conventional aids has been fully trialled AC thresholds within fitting range (SNHL) OR BC thresholds within fitting range (conductive/mixed losses) Normal middle ear function (for SNHL fitting) Stable hearing thresholds Good Speech discrimination Realistic expectations Absence of skin conditions preventing use of AP Successful DDS test

71 SUMMARY Implantable technology for hearing is in a constant process of evolution Implanted solutions are available for all degrees and types of hearing loss Performance can be predicted to continue to improve, although the challenge of hearing speech in noise remains huge Populations who might benefit from cochlear implantation have changed and expanded; many old barriers have now been broken All audiologists should be aware of the technology!

72 THANKYOU FOR LISTENING QUESTION TIME?