Abstract: A fenestration piercing the otic capsule bone of the cochlea receives a therapeutic appliance, such as a microactuator, plug, micropump for drug or therapeutic agent delivery, electrode, and the like. Several different ways of achieving a ‘water tight’ seal between the otic capsule bone and the therapeutic appliance are provided. The therapeutic appliance may be implanted with or without a sheath or sleeve lining the wall of the fenestration formed using specialized surgical burrs. The burrs permit safely fenestrating the otic capsule bone adjacent to the scala tympani of the cochlea without damaging the basilar membrane or organ of corti. This approach may also be adopted for safely fenestrating other areas of the inner ear such as the scala vestibuli, bony labyrinth of semicircular canals, or walls of the vestibule, or the oval or round windows thereof.

Abstract: A cochlear fenestration burr includes a shaft oriented along a longitudinal axis of rotation of the burr, a cylindrical depth stop member oriented along the axis, the depth stop member having a thickness dimension, a diameter dimension and a contact surface, an extension member extended outward from the contact surface and coaxial with the axis, a cutting member having a cutting surface supported by the extension member, and a cutting tip at the end of the cutting member in the center of the cutting surface and coaxial with the axis. A maximum cutting depth is defined by a distance along the axis between an end of the cutting tip and the contact surface. A cutting grit is disposed on the cutting tip and cutting surface.

Abstract: A cochlear fenestration burr includes a shaft oriented along a longitudinal axis of rotation of the burr, a cylindrical depth stop member oriented along the axis, the depth stop member having a thickness dimension, a diameter dimension and a contact surface, an extension member extended outward from the contact surface and coaxial with the axis, a cutting member having a cutting surface supported by the extension member, and a cutting tip at the end of the cutting member in the center of the cutting surface and coaxial with the axis. A maximum cutting depth is defined by a distance along the axis between an end of the cutting tip and the contact surface. A cutting grit is disposed on the cutting tip and cutting surface.

Abstract: A fenestration piercing the otic capsule bone of the cochlea receives a therapeutic appliance, such as a microactuator, plug, micropump for drug or therapeutic agent delivery, electrode, and the like. Several different ways of achieving a ‘water tight’ seal between the otic capsule bone and the therapeutic appliance are provided. The therapeutic appliance may be implanted with or without a sheath or sleeve lining the wall of the fenestration formed using specialized surgical burrs. The burrs permit safely fenestrating the otic capsule bone adjacent to the scala tympani of the cochlea without damaging the basilar membrane or organ of corti. This approach may also be adopted for safely fenestrating other areas of the inner ear such as the scala vestibuli, bony labyrinth of semicircular canals, or walls of the vestibule, or the oval or round windows thereof.

Abstract: A set of fenestration burrs, for fenestrating otic capsule bone (34), includes an initial burr (150) and a sequence of fenestration polishing burrs (180). A polishing burr (152, 1521), of each of the burrs (150, 180), carries at least one spiraling flute (166, 166?). Fenestrations (36) piercing the bone (34) formed using the burrs (150, 180) exhibit uniform diameters while excluding bone dust from the inner ear. An implantable casing (72) includes a hollow collar (76) from which projects a hollow sleeve (74) receivable into the fenestration (36). The casing (72) is secured there by at least one prong (92, 102) jutting from the sleeve (74). A therapeutic appliance (134) is insertable into the casing (72). A flange (116) extending from one end of the sleeve (74) carries at least one L-shaped slot (122) open at one end and extending circumferentially around the flange (116).

Abstract: A fenestration (36) piercing the otic capsule bone of the cochlea (34) receives a therapeutic appliance, such as a microactuator (78), plug (92), micropump for drug or therapeutic agent delivery, electrode (102), etc. Disclosed are several different ways of achieving a “water tight” seal between the otic capsule bone and the therapeutic appliance. Also disclosed are specific ways of implanting the therapeutic appliance both with and without a sheath (72) lining the wall of the fenestration (36) formed using specialized surgical burrs (122, 124, 162, 164).

Abstract: A set of fenestration burrs, for fenestrating otic capsule bone (34), includes an initial burr (150) and a sequence of fenestration polishing burrs (180). A polishing burr (152, 1521), of each of the burrs (150, 180), carries at least one spiraling flute (166, 166?). Fenestrations (36) piercing the bone (34) formed using the burrs (150, 180) exhibit uniform diameters while excluding bone dust from the inner ear. An implantable casing (72) includes a hollow collar (76) from which projects a hollow sleeve (74) receivable into the fenestration (36). The casing (72) is secured there by at least one prong (92, 102) jutting from the sleeve (74). A therapeutic appliance (134) is insertable into the casing (72). A flange (116) extending from one end of the sleeve (74) carries at least one L-shaped slot (122) open at one end and extending circumferentially around the flange (116).

Abstract: An improved fully implantable hearing aid (10) in a first aspect includes at least two microphones (28) to provide improved noise cancellation, and, with an array (132) of microphones (28), improved directivity. In a second aspect, the hearing aid (10) includes an improved microactuator (32′) in which deflections of a pair of piezoelectric plates (68) are coupled by liquid (52′) to a flexible diaphragm (44′) for stimulating fluid (20a) within an inner ear (17) of a subject (12). In a third aspect, the improved hearing aid (10) includes a directional booster (200) that the subject (12), having an implanted hearing aid (10), may wear on their head (122) for increasing directivity of perceived sound. A fourth aspect of the present invention is an improved implantable microactuator (32″, 32″′) that generates a mechanical displacement of a diaphragm (82) or a face (96) in response to an applied electrical signal.

Abstract: A implantable sealed microphone (50) includes a diaphragm (52) having a thin central region (54) surrounded by a thicker rim (56). One side of sheet electret material (72) is bonded to the diaphragm (52) while the other side contacts a roughened plate (82). The rim (56) is bonded to a housing (112) thereby hermetically enclosing the electret (72) and the plate (82). The microphone (50) also includes an electrical connector (94) that couples both the plate (82) and the electret (72) to an input of an amplifier (30) included in an implantable hearing aid system (10). Preferably, the microphone (50) is incorporated into a sealed electronics module (100) together with the amplifier (30) and an energy storage device such as a battery that energizes operation of the implantable hearing aid system (10). In such a configuration, the microphone's diaphragm (52) forms a surface of the electronics module's housing (112).

Abstract: Auditory system components and system adapted for implantation into a human subject for reducing conductive and/or sensorineural hearing deficiency in the subject. An electrically excitable microactuator is implantable either into a fenestration formed through a promontory or a stapes footplate which respectively separate a middle ear from an inner ear of the human subject. The auditory system also includes an implantable processor for supplying an electrical signal to the microactuator, and an implantable microsensor for transmitting an electrical signal responsive to impingement of sound on the microsensor.

Abstract: A microactuator (32) of an implantable hearing aid system (10) is secured within a casing (50) implanted into a fenestration (52) that pierces the promontory (18) of the otic capsule bone (31). The casing (50) includes a hollow sleeve (62) that has an outer surface (64) and a first end (66) that is received into the fenestration (52). The sleeve (62) also includes an inner surface (68) adapted to receive a barrel (74) of the microactuator (32). The casing (62) also includes a flange (76) that is integral with the sleeve (62) and projects outward from the outer surface (64) of the sleeve (62) about a second end (78) of the sleeve (62). Various means secure the sleeve (62) within the fenestration (52) such as screwing into the promontory (18) or clamping to the promontory (18). The casing may fasten the microactuator (32) to the casing (50) by a threaded attachment, with screws, with button-and-socket snap fasteners, or with a slotted tongue-and-groove lock.

Abstract: A implantable sealed microphone (50) includes a diaphragm (52) having a thin central region (54) surrounded by a thicker rim (56). One side of sheet electret material (72) is bonded to the diaphragm (52) while the other side contacts a roughened plate (82). The rim (56) is bonded to a housing (112) thereby hermetically enclosing the electret (72) and the plate (82). The microphone (50) also includes an electrical connector (94) that couples both the plate (82) and the electret (72) to an input of an amplifier (30) included in an implantable hearing aid system (10). Preferably, the microphone (50) is incorporated into a sealed electronics module (100) together with the amplifier (30) and an energy storage device such as a battery that energizes operation of the implantable hearing aid system (10). In such a configuration, the microphone's diaphragm (52) forms a surface of the electronics module's housing (112).

Abstract: A hearing aid includes an implantable microphone, signal-processing amplifier, battery, and microactuator. An electrical signal from the microphone is amplified and processed by the amplifier before being applied to the microactuator. The microactuator is adapted for implantation in a subject at a location from which it may mechanically create vibrations in the perilymph fluid within a subject's inner ear. A transducer of the microactuator is preferably a thin circular disk, 2 to 8 mils thick, of stress-biased PLZT. Disks of this stress-biased PLZT material can be mounted as drumheads in various different ways, preferably in conjunction with a flexible diaphragm, to small threaded metal tubes, e.g. 1.4 mm in diameter and 2.0 mm long. These tubes may be implanted into a fenestration formed through the promontory adjacent to the oval window of a subject's inner ear.

Abstract: An implantable auditory system for a human subject includes a microsensor, a processor and a microactuator. The microsensor is implanted in the middle ear to transduce sound waves into electrical signals. The processor is implanted in a hole surgically sculpted in the skull and controls amplification and processing of the electrical signals. The microactuator is micromachined from a single crystal and acts as a parallel plate capacitor, with a diaphragm spaced from the rest of the crystal by an extremely small void therebetween. The microactuator is implanted in the middle ear, and it may extend into the inner ear through a surgically formed fenestration or be mounted to the ossicular chain. Electrical signals conveyed to the microactuator set up electric fields across the narrow void and the diaphragm to produce electrostatic forces that cause the diaphragm to vibrate, thereby directly or indirectly vibrating fluid in the inner ear.

Abstract: Prostheses for reconstruction of the ossicles of the middle ear, comprising an elongated lever member replacing the incus and providing a mechanical advantage at least as great as that of natural middle ear ossicles, means for attachment thereof to the stapes if intact, or a synthetic stapes when the natural stapes is absent. A prosthesis for replacement only of the stapes is also disclosed. A method of stabilizing reconstructive prostheses for short-term and long-term hearing restoration is provided, comprising laser welding of prostheses in selected positions and placing porous surfaces of prostheses in contact with host bone whereby to promote bone ingrowth.