William Vanbrooks Harrison

Implantable cochlear stimulator system incorporating combination electrode/transducer

A hearing aid system provides acoustic modulation of the fluid within the cochlea of the inner ear corresponding to a first frequency range of sensed acoustic signals, e.g., lower-to-middle frequencies of the audible range, and electrical stimulation of the cochlea corresponding to a second frequency range, e.g., high frequencies of the audible range. In a preferred implementation, a short electrode/transducer array is provided for use with the hearing system. Such array is adapted to be inserted into the basal region of the scala tympani of the cochlea. The electrode/transducer array includes a plurality of spaced-apart electrode contacts through which electrical stimulation is provided to stimulate ganglion cells located in the basal region of the cochlea, which cells are responsible for perceiving the higher frequencies of the acoustic energy. The electrode/transducer further includes an acoustic modulator as an integral part thereof, in fluid communication with an acoustic transducer, through which acoustic modulation may be coupled to the fluid within the cochlea, thereby allowing normal hearing processes to occur in the cochlea. In the preferred implementation, the lower frequencies of sensed acoustic energy are processed to provide modulation of the acoustic modulator. An implantable cochlear stimulator (ICS), including the acoustic transducer and coil, and implantable speech processor (ISP), including an implantable microphone, are used with the system. In an alternative embodiment, the acoustic modulator within the electrode/transducer array is used as a sensor, to sense fluid modulation within the cochlea resulting from a functioning middle ear, and the acoustic transducer converts such sensed fluid modulation to electrical signals, thereby providing the function of an microphone implanted in the cochlea.

Spatial decimation stimulation in an implantable neural stimulator, such as a cochlear implant

A cochlear implant system, or other neural stimulation system, has the capability to stimulate fast enough to induce stochastic neural firing so as to restore “spontaneous” neural activity. The stimulation rate applied to the more distally-located electrodes of an electrode array connected to the implant system is reduced from the stimulation rate applied to the more proximally-located electrodes. Thus, in the case of a cochlear implant system, the apically-located regions within the cochlea are stimulated at a reduced rate in order to conserve power. Pulse widths of the reduced-rate pulses may further be increased, and amplitudes reduced, to further conserve power. As needed, a low-level random conditioner stimulation signal may be applied to the apical regions of the cochlea in order to ensure the occurrence of random neural firings.

Fluid filled microphone balloon to be implanted in the middle ear

An implantable microphone system, usable with a cochlear implant system or other hearing aid prosthesis, detects sound pressure waves (acoustic waves) at a movable member within the middle ear, e.g., the tympanic membrane or the stapes, through a fluid communication channel (20) established between the middle ear movable member and a microphone capsule (10). The microphone capsule (10) includes two compartments (11, 12) separated by a flexible diaphragm (13). One compartment (12) is in fluid communication with a thin-walled balloon, filled with a suitable fluid (30), positioned in contact with the movable member within the middle ear. The other compartment (11) is mechanically coupled through a suitable mechanical linkage (16) to a microphone sensor (14). The microphone sensor, in turn, is electrically connected to the cochlear implant system or other hearing aid prosthesis.