Middle Ear Infection Postimplantation: Response of the round Window Membrane to <i>Streptococcus Pyogenes</i>

Cranswick, Noel; Franz, Burkhard; Clark, Graeme M.; Shepherd, Robert K.; Bloom, D. M.

doi:10.1177/00034894870960s124

Cited by 13 publications

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References 4 publications

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“…Additional evidence for the importance of a sheath around the electrode was obtained from the study by Cranswick et al (1987). The entry point through the round window was not sealed with tissue, and it was found there were two types of histological response in the cochlea, one with loose connective tissue in the basal turn, and another with an extensive sheath around the electrode array.…”

Section: The Safe and Effective Intra-cochlear Multiple-channel Electmentioning

confidence: 96%

“…With the formation of a sheath, capillaries brought the phagocytic white cells to the tissue surrounding the electrode and the space between the electrode and sheath, to engulf the bacteria (second line of defence). The same mechanism allowed lymphocytes to penetrate the tissue and space next to the electrode, and provide antibodies against the invading organisms (third line of defence) (Cranswick et al 1987).…”

Section: The Safe and Effective Intra-cochlear Multiple-channel Electmentioning

confidence: 99%

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The multiple-channel cochlear implant: the interface between sound and the central nervous system for hearing, speech, and language in deaf people—a personal perspective

Clark

2006

Phil. Trans. R. Soc. B

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The multiple-channel cochlear implant is the first sensori-neural prosthesis to effectively and safely bring electronic technology into a direct physiological relation with the central nervous system and human consciousness, and to give speech perception to severely-profoundly deaf people and spoken language to children.Research showed that the place and temporal coding of sound frequencies could be partly replicated by multiple-channel stimulation of the auditory nerve. This required safety studies on how to prevent the effects to the cochlea of trauma, electrical stimuli, biomaterials and middle ear infection. The mechanical properties of an array and mode of stimulation for the place coding of speech frequencies were determined.A fully implantable receiver-stimulator was developed, as well as the procedures for the clinical assessment of deaf people, and the surgical placement of the device. The perception of electrically coded sounds was determined, and a speech processing strategy discovered that enabled latedeafened adults to comprehend running speech. The brain processing systems for patterns of electrical stimuli reproducing speech were elucidated. The research was developed industrially, and improvements in speech processing made through presenting additional speech frequencies by place coding. Finally, the importance of the multiple-channel cochlear implant for early deafened children was established.Keywords: multiple-channel cochlear implant; electrical stimulation of the auditory nerve; management of severe-profound hearing loss OVERVIEWThe multiple-channel cochlear implant restores useful hearing in severely-profoundly deaf people. It bypasses the malfunctioning inner ear (cochlea) and provides information to the auditory centres in the brain through electrical stimulation of the hearing (auditory) nerves (figure 1). It has enabled tens of thousands of severelyprofoundly deaf people in over 70 countries to communicate in a hearing world. Deaf people have significant limitations communicating at home and in work environments, and this substantially affects their quality of life. Children born deaf or deafened early in life have difficulty developing spoken language. This affects their education, and as a result it is harder to obtain employment. The child's deafness may also create stresses within the family. Hearing occurs normally when sound vibrations are transmitted via the external and middle ears to the sense organ of hearing (organ of Corti) in the cochlea (figure 2). The organ of Corti lies on the basilar membrane, which vibrates selectively to different sound frequencies, so that it acts as a sound filter. High frequencies produce maximal vibrations at the basal end, and low frequencies at the apical end. Inner hair cells in the organ of Corti (figure 2) convert sound vibrations into electrical impulses that provide temporal and spatial patterns of auditory nerve excitation in the higher brain centres. In most cases, when a person has a severe-profound hearing loss they will have lost most ...

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Section: The Safe and Effective Intra-cochlear Multiple-channel Electmentioning

confidence: 96%

Section: The Safe and Effective Intra-cochlear Multiple-channel Electmentioning

confidence: 99%

The multiple-channel cochlear implant: the interface between sound and the central nervous system for hearing, speech, and language in deaf people—a personal perspective

Clark

2006

Phil. Trans. R. Soc. B

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“…With the formation of a sheath, capillaries could bring phagocytic white cells to the tissue surrounding the electrode and the space between the electrode and sheath to engulf the bacteria (second line of defense). The sheath also allowed lymphocytes to penetrate the tissue and space next to the electrode and provide antibodies against the invading organisms (third line of defense) [69].…”

Section: Prevention Of Inner Ear Infectionmentioning

confidence: 99%

Personal reflections on the multichannel cochlear implant and a view of the future

Clark¹

2008

JRRD

120

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Abstract-The multichannel cochlear implant is the first neural prosthesis to effectively and safely bring electronic technology into a direct physiological relation with the central nervous system and human consciousness. It is also the first cochlear implant to give speech understanding to tens of thousands of persons with profound deafness and spoken language to children born deaf in more than 80 countries. In so doing, it is the first major advance in research and technology to help deaf children communicate since Sign Language of the Deaf was developed at the Paris deaf school (L'Institut National de Jeunes Sourds de Paris) >200 years ago. Furthermore, biomedical research has been fundamental for ensuring that the multielectrode implant is safe as well as effective. More recent research has also shown that bilateral implants confer the benefits of binaural hearing. Future research using nanotechnology should see high-fidelity sound received, which would help deaf persons communicate in noise and enjoy music. Research should also lead to implants in ears with useful hearing.Key words: audiology, auditory neurophysiology, auditory psychophysics, bioengineering, education of hearing impaired, multichannel cochlear implant, nanotechnology, neural prosthesis, rehabilitation, severe to profound deafness, speech science. PERSONAL REFLECTIONS Hearing from Electrical Stimulation of Auditory Nerve Preliminary Studies on Subjects with HearingInterest in electrical methods of inducing hearing started after Alessandro Volta, who discovered the electrolytic cell, stimulated his own auditory system by connecting a battery of 30 or 40 "couples" to two metal rods, which he inserted into his ears. The sensation was momentary and lacked tonal quality [1].Because sound is an alternating disturbance in an elastic medium, stimulating the auditory system with a direct current (DC) was later appreciated to not reproduce a satisfactory hearing sensation. Consequently, Duchene of Boulogne in 1855 [2], and later others, stimulated the ear with an alternating current. The result, however, was still not satisfactory, and only noise was produced.Renewed interest occurred with the introduction of the thermionic valve, which enabled the auditory system to be stimulated electrically with much greater precision. This work was supported by the findings that the voltages recorded from the auditory nerve of a cat were similar in frequency and amplitude to the sounds presented to the ear, but they were still heard as noise [3].Abbreviations: ABF = adaptive beamformer, ACE = Advanced Combination Encoder, ADRO = adaptive dynamic range optimization, AGC = automatic gain control, ARC = Australian Research Council, ASC = automatic sensitivity control, CIS = continuous interleaved sampling, CNC = consonant-nucleusconsonant, DC = direct current, DRSP = differential rate speech processor, F0 = fundamental (voicing) frequency, F1 = first formant frequency, F2 = second formant frequency, FDA = Food and Drug Administration, NIH = National Institutes of Hea...

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“…Continuous stimulation 24 hours a day for 2000 hours with charge-balanced biphasic pulses had no effect on the auditory ganglion cells in the inner ear (Shepherd et al 1983). Finally, before embarking upon clinical investigations, a number of studies on the experimental animal were undertaken to help ensure that middle ear infection would not extend around the electrode array into the inner ear and lead to meningitis (Clark, Pyman et al 1984;Clark, Shepherd et al 1984;Franz et al 1984;Cranswick et al 1987). This was a possibility because the inner ear communicates with the cerebrospinal fluid within the cranial cavity through a number of routes (Clark 2003a).…”

Section: Basic Biological Research For a Multiple-channel Cochlear Immentioning

confidence: 99%

Bionic Ears: Their Development and Future Advances Using Neurotrophins and Inherently Conducting Polymers

Clark

Wallace

2004

Applied Bionics and Biomechanics

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Abstract:The development of the multiple-channel bionic ear for hearing and speech understanding in profoundly deaf people is the result of integrating biological and physical sciences with engineering. It is the first clinically successful restoration of sensory and brain function, and brings electronic technology into a direct functional relationship with human consciousness. It presently transmits essential place and coarse temporal information for the coding of frequency, but the fine temporal and place excitation of groups of nerve fibres is inadequate for high-fidelity sound. This is required for adequate musical appreciation and hearing in noise. Research has demonstrated that nerve growth factors preserve the peripheral processes of the auditory nerves so that an electrode array placed close to these fibres could produce this fine temporal and spatial coding. The nerve growth factors can be incorporated into inherently conducting polymers that are part of the array so the peripheral processes can be preserved at the same time as they are electrically stimulated.

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Middle Ear Infection Postimplantation: Response of the round Window Membrane to Streptococcus Pyogenes

Cited by 13 publications

References 4 publications

The multiple-channel cochlear implant: the interface between sound and the central nervous system for hearing, speech, and language in deaf people—a personal perspective

The multiple-channel cochlear implant: the interface between sound and the central nervous system for hearing, speech, and language in deaf people—a personal perspective

Personal reflections on the multichannel cochlear implant and a view of the future

Bionic Ears: Their Development and Future Advances Using Neurotrophins and Inherently Conducting Polymers

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