Graeme Clark Collection

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    The biologic safety of the Cochlear Corporation multiple-electrode intracochlear implant
    Webb, Robert L. ; Clark, Graeme M. ; Shepherd, Robert K. ; Franz, Burkhard K-H. ; Pyman, Brian C. ( 1988)
    Studies have been undertaken to confirm the biologic safety of the Cochlear Corporation multi-electrode intracochlear implant. The materials used are biocompatible. The electrode array is flexible: it can be inserted with minimal or no trauma, providing the insertion is stopped when resistance is first felt. An atraumatic insertion is facilitated if a good view is obtained along the scala tympani of the basal turn of the cochlea by drilling through the crista fenestrae. The passage of the electrode around the cochlea can be facilitated if the electrode is rotated during insertion (clockwise for the left and anticlockwise for the right cochlea). The electrode can be explanted and another one reinserted with minimal or no trauma. A seal established around the electrode after an implantation period of 2 weeks can prevent infection extending from the middle to the inner ear. The electrical stimulus parameters produced by the Nucleus receiver-stimulator cause no loss of spiral ganglion cells or corrosion of the platinum band electrodes. Long-term stimulation has been carried out for up to 8 years in patients without affecting their clinical performance.
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    Surgery for the safe insertion and reinsertion of the banded electrode array
    Clark, Graeme M. ; Pyman, B. C. ; Webb, R. L. ; Franz, B. K-H. G. ; Redhead, T. J. ; Shepherd, R. K. ( 1987)
    Adhering to the surgical technique outlined in the protocol for the Nucleus implant has resulted in over 100 patients worldwide obtaining significant benefit from multichannel stimulation. A detailed analysis of the results in 40 patients shows that it improves their awareness of environmental sounds and their abilities in understanding running speech when combined with lipreading. In addition, one third to one half of the patients also understand significant amounts of running speech without lipreading and some can have interactive conversations over the telephone. It is clear that any insertion trauma is not significant, which is confirmed by the excellent clinical results.
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    Preliminary results for the Cochlear Corporation multielectrode intracochlear implant in six prelingually deaf patients
    Clark, Graeme M. ; Busby, Peter A. ; Roberts, Susan A. ; Dowell, Richard C. ; Blamey, Peter J. ; Mecklenburg, Dianne J. ; Webb, Robert L. ; Pyman, Brian C. ; Franz, Burkhard K. ( 1987)
    The preliminary results from this study indicate that some prelingually deaf patients may get worthwhile help from a multiple-electrode cochlear implant that uses a formant-based speech processing strategy. It is encouraging that these improvements can occur in young adults and teenagers. The results for two children are also encouraging. A 10-year-old child obtained significant improvement on some speech perception tests. It was easy to set thresholds and comfortable listening levels on a 5-year-old child, and he is now a regular user of the device. There are, however, considerable variations in performance among the prelingual patients, which may be related to the following factors: whether they have had some hearing after birth, the method of education used, the motivation of the patient, and age at implantation.
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    Surgery for an improved multiple-channel cochlear implant
    Clark, Graeme M. ; Pyman, Brian C. ; Webb, Robert L. ; Bailey, Quentin E. ; Shepherd, Robert K. ( 1984)
    An improved multiple-channel cochlear implant has been developed. The titanium container with enclosed electronics, the receiver coil and the connector are embedded in medical-grade Silastic. The upper half of the implant has a diameter of 35 mm and a height of 4.5 mm. and the lower half a diameter of 23 mm and a height of.5 mm. The electrode array has also been designed to reduce the possibility of breakage due to repeated movements over many years. The surgery involves drilling a bed in the mastoid bone for the receiver-stimulator, and fixing the proximal electrode under the mastoid cortex. Gentle insertion of the electrode array through the round window and along the seala tympani is achieved with a specially designed microclaw.
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    Surgery for multielectrode cochlear implants
    Lehnhardt, E. ; Laszig, R. ; Webb, H. ; Franz, B. ; Pyman, B. ; Clark, Graeme M. ( 1987)
    For the surgery of the NUCLEUS Cochlear Implant (CI) in general anaesthesia we use a skin cut beginning at the bottom of the entrance to the outer ear canal, following the posterior circumference to a point nearly 12 o'clock. From here the incision runs superiorly to the tragus until two or three centimetres above the pinna base and in a wide smooth circle in direction to the occiput. The wide circle is necessary to get a distance of about 2 cm away from the package and also to guarantee the blood supply by the occipital artery and by the postauricular artery as well.