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5 COCHLEAR IMPLANTATION: ESTABLISHING CLINICAL FEASIBILITY, 1957-1982
5 COCHLEAR IMPLANTATION: ESTABLISHING CLINICAL FEASIBILITY, 1957-1982
Pages 97-124
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From page 97... ...
In 1930, Wever and Bray, working in the Department of Experimental Psychology at Princeton University, discovered the so-called "cochlear microphonic potential." They showed that if electrical contact was made with the auditory nerve of a cat and the potentials developed in it were amplified and passed through telephone receivers, sounds delivered to the animal's ear could be recognized by a listener. The quality of the "cat microphone" was such that if words were spoken into the cat's ear, a remote listener could identify them through the receiver.
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From page 98... ...
Speech can easily be recognized as speech, but only occasional words can be understood. Clearly, electrical stimulation does not promise much as an alternative means of hearing so long as so much distortion is present (Stevens, 1937~.
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From page 99... ...
Djourno, who was working on electrical stimulation of the auditory nerve in animals. After some deliberation they decided to try to implant the patient with an electrode, similar to that used in the animal research, which would stimulate his (functioning)
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From page 100... ...
It was really an eye opener what they could hear from these electrical stimulations during surgery. This encouraged us then to pick out some patients who had total losses as volunteers, and take them to surgery and try some of these stimulations .
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From page 101... ...
In May 1964, Simmons and a Stanford colleague implanted a 6-electrode array into the modiolus of a 60-year-old volunteer subject who was totally deaf in the right ear and was losing his hearing in the left ear. Suffering from retinitis pigmentosa, the subject was also losing his sight.
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From page 102... ...
Blair Simmons then stopped working on human auditory stimulation, though continuing with related experimental work on cats. By the 1960s, many investigators had produced acoustic sensations by means of electrical stimulation of the inner ear, in the context of research into the nature of hearing.
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From page 103... ...
Analytically, we shall try to understand how these workers, collectively, sought to establish the clinical context within which cochlear implantation could eventually become an acceptable medical treatment for sensorineural deafness. As we look at these programs
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From page 104... ...
A review of work on the emerging technique published in 1978 draws attention to the range of problems which cochlear implantation still posed: Artificial stimulation of the auditory system therefore poses difficult problems for the surgeon, the engineer, the physiologist, the speech therapist, the audiolo gist and the pathologist. How to achieve adequate selectivity of neural activa tion with minimal surgical invasion; how to devise biocompatible and reliable
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From page 105... ...
Different strategies entailed the recruitment and coordination of different combinations of expertise. NEW BEGINNINGS: COCHLEAR IMPLANTATION IN THE 1970s Work by House, Simmons, and Michelson In 1968, William House fumed back to cochlear implants, working now with Jack Urban, the president of a small engineering firm with interests in medical electronics.
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From page 106... ...
While William House was moving towards a clinical procedure, Blair Simmons' approach was very different. When Stanford colleagues in electrical engineering became interested, in about 1970, the cochlear prosthesis program was reestablished.
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From page 107... ...
At the time of this visit, Blair Simmons continued to regard cochlear implantation as an experimental procedure, and took the view that widespread clinical prescription of single-channel devices was premature. "All implants have been multichannel, made directly into the body of the cochlear nerve through the modiolus, in the belief that, with direct contact between electrodes and nerve fibers, thresholds would be lower, excitation would be more discrete and there would be less chance in principle of electrodes encountering 'gaps' in the array of surviving fibers than in the cochlea" (Ballantyne et al., 1978~.
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From page 108... ...
, and the fact that work was being done in different but cognate areas.4 But any such change of 3The references subsequently made to the cat work include a ``cochlea reflex,' whereby stimulation of one ear was said to inhibit the sensitivity of the opposite ear for the same frequency (used as an indicator of hearing in a laboratory animal) ; destruction of the organ of corti after long-term implantation; and the possibility of producing pitch discrimination without a multiple electrode but with a uniform electrical field within the cochlea produced by a simple bipolar electrode.
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From page 109... ...
Kiang's view at this time was that providing speech recognition through electrical stimulation was in theory feasible, though never with a single-channel implant. However, for multichannel devices to yield more satisfactory results, the electrodes would have to be positioned with considerable accuracy (a problem for the surgeon)
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From page 110... ...
He devoted the years 19721973 principally to animal studies: partly investigations of the long-term effects of implantation and electrical stimulation on the cochlea, partly investigations aimed at understanding what kind of pattern of controlled stimulation might generate adequate speech representation. This work was to provide indications as to the design of a multichannel system.
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From page 111... ...
the auditory nerve is active. By the end of the year three people had been implanted, and a note on what had been done appeared in La Nouvelle Presse Medicale (a general medical journal)
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From page 112... ...
After about a month, although the intelligibility of word lists remained poor, nearly 50 percent of a usual conversation could be understood without lip reading" (italics added)
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From page 113... ...
Both the original impetus to try artificial stimulation and the institutional structure that emerged were, however, very different from what had taken place in Paris. The ENT surgeon Ellis Douek had recently been appointed to a senior post at London's Guys Hospital, where he had been working on evoked responses.
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From page 114... ...
The idea that he work on artificial stimulation came from outside. The British department of health, prompted by a deafened Member of Parliament active on behalf of the disabled (Jack Ashley, now Lord AshleyJ, suggested to him that his specialty was doing far too little on sensorineural deafness, and why didn't he do something in that area.
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From page 115... ...
Yet from the point of view of progress in this field few cases could be more useful, both to match sound perceived with electrical stimulation and to compare, say, the value of such stimulation with amplification in the other ear (Fourcin et al., 1979~. Second was Fourcin's important contribution: the idea that, at least at first, the implant should be used to supplement the information available from lip reading.
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From page 116... ...
Also in 1977, the British department of health invited a group of three experts (two ear surgeons and a neurophysiologist) to review current efforts in the area of electrical stimulation of the inner ear and to make recommendations as to what British commitment to the area should be.
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From page 117... ...
The answer has to be sought in House's contribution to the stabilization of a clinical context for work on electrical stimulation. It was House's work, more than that of Simmons or Michelson and Merzenich, that attracted the attention of European orologists.
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From page 118... ...
, which began to produce prostheses for his use in 1975, and was ultimately able to scale up production. It is reasonable to interpret these efforts at creating a stable clinical context in which work on implantation could be pursued in terms of notions of "mobilization" or"enrollment"-of colleague orologists and audiologists, willing to refer possible implant candidates; of industry viewing an interesting potential market; and of health authorities willing to bear the costs of providing prostheses to selected patients.
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From page 119... ...
The activities of Blair Simmons and of Ellis Douek diverge significantly from this picture. Both remained committed to implanting on a very small scale, and throughout the period with which this paper is concerned both continued to believe that the procedure had to be regarded as experimental.
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From page 120... ...
H Dobelle worked in the Institute for Biomedical Engineering at the University of Utah, and was himself involved in experimental studies of electrical stimulation at this time.
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From page 121... ...
But what we are doing is the research to give you the implant of tomorrow" (interview with Ellis Douek, London, May 19921. CONCLUSIONS 121 A theoretical starting point for this reconstruction of the early history of cochlear implantation was the idea, derived from earlier work, that the lack of preexisting structures of provision and of appropriate devices for the sensorineurally deaf would present innovators with special problems.
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From page 122... ...
Combinations of expertise differed and were typically more fluid, and the relative emphasis given to different problematizations reflected scientific backgrounds. Whereas the therapeutic groups typically sought at an early stage to have a suitable device fabricated for implant, these experimental groups typically entered hesitantly and slowly into licensing agreements.
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From page 123... ...
1979. External electrical stimulation of the cochlea: Clinical, psychophysical, speech-perceptual, and histological findings.
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From page 124... ...
1965. Auditory nerve: Electrical stimulation in man.
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