Electrical and Electronic Engineering - Theses
Permanent URI for this collection
Search Results
1 - 1 of 1
-
ItemThe bioengineering development of a multi-channel, implantable hearing prosthesis for the profoundly deaf( 1978)This thesis describes the bioengineering development of a sensory prosthesis system specifically dedicated to the multi-channel electrical stimulation of the terminations of the auditory nerve in the cochleae of profoundly deaf persons. By simulating the gross pattern of electrical activity that would exist in the auditory nerve of a person with normal hearing, it is hoped that the sensation of hearing may be restored, and in particular, speech comprehension and communication re-established. In order that the complications associated with a percutaneous connection to the intra-cochlear array may be avoided, a system has been devised which comprises an implantable stimulator controlled transcutaneously by an external transmitter. The implementation of this concept has established an interface between the electrode array and an external speech processor which is sufficiently transparent with respect to stimulus parameter control, to permit the investigation of coding schemes based on current auditory neurophysiological studies. In particular, control over both the amplitude and relative time of stimulation (or phase), as well as frequency of stimulation, of up to fifteen independent channels is possible. The phase control facility is considered a unique feature of the system for coding temporal data. Finally, the transcutaneous link has been realised using a novel, dual radio frequency coupling system to provide efficient transfer of both power and data to the implanted device. The realisation of this link has been based upon the results of basic studies concerning the properties of coupling networks, together with the development of a high efficiency switching mode power converter to effect transcutaneous power transfer.