Abstract: An electrode array has an elongate flexible carrier that, when viewed in cross-section, is much more flexible in a first direction than in a second direction orthogonal thereto. The elongate flexible carrier is formed with a bias force that causes the array to flex in the first direction so as to assume the general spiral or circular shape of the scala tympani duct within the cochlea. The less-flexible direction is the direction that makes it difficult for the array to twist as it is inserted within the scala tympani duct. The bias force is sufficiently strong to cause the array to assume its preformed spiral shape even after being straightened during initial insertion into the cochlea. Electrode contacts, embedded into the carrier so as to be exposed along an inner or concave surface of the spiral, thus wrap snugly around the modiolus, thereby positioning the electrode contacts against the modiolar wall in an optimum position for stimulation.

Abstract: An implantable electrode array, adapted for insertion into either a left or right cochlea, assumes a spiral shape so as to hug the modiolar wall of the cochlea after insertion into the cochlea. All of the electrode contacts are spaced apart along one edge or side of the array, termed the "medial side", which medial side resides on the inside of the spiral. The electrode contacts are thus positioned in close proximity to the modiolar wall, closest to the ganglion cells that are to be stimulated by the electrode array. A positioning stylet made from a suitable memory wire is inserted into a longitudinal channel of the array. The stylet is made from memory wire and has properties selected to return to a desired memory spiral shape at or near body temperature (e.g., approximately 37.degree. C. or 98.6.degree. F.). The positioning stylet is cooled and bent as needed to assume a relatively straight, or non-spiral shape.

Abstract: An electrode array (10, 10') for stimulation of the cochlea includes an elongated tapered carrier (15) on which a multiplicity of separately controlled electrode contacts (20) are carried. A set of flexible fins (100, 110, 120) or bumps (120') or other dielectric members extend from the carrier in particular axes so as to cause the outside dimension of the array plus the dielectric members to readily fit within the cavity wherein the array is to be inserted. The dielectric members are made from compliant, dielectric material. When formed as fins, the dielectric members can be folded against the body of the carrier as it is inserted into the cochlea so that they readily slide past obstructions and accommodate variations in the cross-sectional dimensions of the cavity, e.g., the scala tympani (5) with only modest insertion forces.

Abstract: A microsurgical tool (8), in the form of forceps, allows access and micro-manipulation into very small confined spaces, such as the cochlea. The microsurgical tool includes an activation body (10) and a working head (20). The activation body is made from a pair of leaf springs (11) joined permanently at one end to a sliding bracket (12) and joined at the other end to a central section (15) with removable screws (13). The central section (15) tapers to an extension (15A) that extends to the working head. A push arm (16) has a first end coupled to the sliding bracket (12) and a second end pivotally joined to the working head (20). The working head (20) is made from a first jaw part (21) attached to the extension (15A), and a second jaw part (22) pivotally connected to the second end of the push arm (16).

Abstract: A tapered, flexible positioner, typically molded in a curved or hooked shape from a silicone polymer, is adapted to be inserted into the scala tympani duct of a human cochlea so as to position or force an electrode array, also inserted into the scala tympani duct, against the modiolar wall of the cochlea. The positioner may be inserted into the scala tympani duct before, or preferably after, insertion of the electrode array. The flexible positioner thus fills space within the scala tympani duct so as to force the electrode array, also inserted into the scala tympani duct, against the modiolar wall of the cochlea, where the electrode contacts of the electrode array may be more effective. In a preferred embodiment, a channeling groove is formed along one side of the positioner for receiving the electrode array.

Abstract: An efficient RF telemetry transmitter system includes a first stage and a second stage. The transmitter system sends power and data to an implant device using pulse-width modulation of a high fixed frequency clock signal, e.g., a 49 MHz clock signal, within the first stage in order to provide efficient generation of an RF output signal in the second stage. Digital logic gates and related circuitry, e.g., implemented in an application specific integrated circuit (ASIC), are used in the first stage to provide pulse-width modulation of the fixed frequency clock signal in order to optimally set the drive level of the output signal of the first stage, or inter-stage signal. ON/OFF keying, or other modulation scheme, further modulates the clock signal with data in the first stage. The second stage includes a Class-E amplifier circuit implemented with a single RF transistor, biased with a temperature-compensated offset voltage set just below the cut-off voltage of the transistor.

Abstract: An electrode array has a flexible carrier that, when viewed in cross-section, is much more flexible in a first direction than in a second direction orthogonal thereto. The flexible direction is the direction that allows the array to readily flex so as to assume the general spiral or circular shape of the scala tympani duct within the cochlea. The less-flexible direction is the direction that makes it difficult for the array to twist as it is inserted within the scala tympani duct. By placing the electrode contacts of the array on or near that surface of the array which becomes the inner surface of the spiral shape once implantation has occurred, the electrode array may be inserted within the cochlea using minimal force, yet twisting of the array becomes unlikely during insertion or thereafter. Four separate embodiments of the electrode array are described.

Abstract: An implantable system, such as a neural stimulator or a cochlear implant system, includes a rechargeable battery configuration having improved recharging and lifetime characteristics. The battery is housed within the implant's case and has first and second electrode plates. Each electrode plate has a plurality of slits that extend across a substantial portion of the plate's surface area. The slits in the electrode plates reduce the magnitude of eddy currents induced in the plates by external ac magnetic fields allowing faster battery recharging times. Alternatively, the electrode plates are wrapped in a spiral configuration such that, in the plane of the spiral, the electrode plates have a small cross-sectional area and no closed current loops. Additionally, the implant device may be housed in a case formed of a high-resistivity material and a circuit included in the implant device is configured to avoid large current loops that would result in eddy current heating.

Abstract: A system and method for conditioning pelvic muscle tissue for the purpose of treating urinary incontinence uses one or more tiny implantable stimulators (20)--termed "microstimulators"--implanted in or near certain pelvic structures so as to contact target muscle tissue. The microstimulators (20) are small enough to allow their implantation using a hypodermic needle (104). Once implanted, the microstimulators (20) are controlled using a controller (105, 106) and an appropriate coupling coil (102) that couples modulated radio frequency (RF) power into the microstimulators. A fitting station (110) facilitates adjusting the stimulus pattern and amplitude to best meet the needs of a given patient. Once fitted, electrical stimulation is thus provided to the target tissue in accordance with a specified externally-controlled exercise or other regime.

Abstract: Improved implantable microstimulators covered with a biocompatible polymeric coating in order to provide increased strength to the capsule thereof and to capture fragments of the microstimulator should it become mechanically disrupted and to make the microstimulator safer and easier to handle are provided here. The coating may include one or more diffusible chemical agents that are released in a controlled manner into the surrounding tissue. The chemical agents, such as trophic factors, antibiotics, hormones, neurotransmitters and other pharmaceutical substances, are selected to produce desired physiological effects, to aid, support or to supplement the effects of the electrical stimulation. Further, provided herein are systems employing the improved microstimulators to prevent and/or treat various disorders associated with prolonged inactivity, confinement or immobilization of one or more muscles.

Abstract: A programming system and method for use with an implantable tissue stimulator allows a clinician or patient to quickly determine a desired electrode stimulation pattern, including which electrodes of a multiplicity of electrodes in an electrode array should receive a stimulation current, including the amplitude, width and pulse repetition rate of such current. Such system and method allows the clinician or user to readily select and visualize a particular group of electrodes of the electrode array by displaying a visual image of the array, and then allows selection of a group of electrodes in the array, as well as the ability to move the selected group or change the size of the selected group, while applying a stimulation pulse current having a selected amplitude, width and pulse repetition rate, to the group of electrodes. Movement of the selected group of electrodes is facilitated through the use of a directional pointing device, such as a joystick.

Abstract: An electrode system includes (1) an electrode array, made in a straight or curved shape, but made on a flexible carrier so that it can easily bend within a curved body cavity, such as the cochlea; and (2) a flexible positioner, typically molded in a curved shape from a silicone polymer so as to make it easy to slide into the body cavity. Some embodiments may further include an electrode guiding insert. Yet other embodiments include only a flexible positioner adapted to fill space within a human cochlea so as to force an electrode array against a modiolar wall of the cochlea. Insertion of the electrode array is performed using one of two methods.

Abstract: An implantable medical device is made from an electronic subassembly hermetically sealed in a ceramic case filled with a potting material. Use of the potting material enhances the capacity of the device to withstand mechanical shock without failure. The device includes a hollow ceramic or other case having an open end to which a metal ring is hermetically bonded. The inside surface of the ceramic case is treated (cleansed and activated) to assure the potting material adheres to it. The potting material, while in a non-cured fluid or quasi-fluid state, is inserted inside of the ceramic case. The electronic circuitry is next inserted into the open end of the ceramic case while the potting material is still in a non-cured, soft or fluid state. The electronic circuitry displaces some of the potting material and the potting material fills the voids between the electronic circuitry and the ceramic case.

Abstract: A method and system provides a wide range of temporospatial patterns of electrical stimulation waveforms to be readily specified for respective channels of a multichannel cochlear prosthesis. The cochlear prosthesis includes a speech processor system and a cochlear stimulator. The speech processor system typically includes an external headpiece, including a microphone, coupled to a speech processor. The speech processor includes electronic circuitry, typically including a microprocessor, that converts acoustical signals sensed through the microphone to electrical signals, and processes the electrical signals in accordance with a desired speech processing strategy. The definition of simple or complex stimulation waveforms to be used as part of the selected speech processing strategy is facilitated, in a preferred embodiment, through the use of a template table stored in the speech processor. The rows and columns of the template table define time intervals and stimulation channels (and hence stimulation sites).

Abstract: An implant stimulator device uses tantalum and tantalum pentoxide as a system for the conveyance of electrical stimulation pulses from stimulus-forming circuitry contained within an hermetic enclosure to the saline fluids of body tissue to be stimulated. Internal coupling capacitors are not used, yet the danger of having DC current flow to the saline fluids is eliminated. A preferred embodiment provides a multiplicity of electrode contacts made from sintered, anodized tantalum, connected via tantalum wire leads to tantalum feedthroughs into the hermetically sealed package containing the stimulus pulse-forming electronic circuitry. One or more counter electrode contacts (for monopolar or bipolar configurations, respectively) made of activated iridium, non-activated iridium, iridium in combination with a noble or non-noble metal, platinum, gold, or other metal which forms a low impedance contact with body fluids, is/are connected via platinum or other conductive metal leads to return feedthroughs.

Abstract: A transcutaneous transmission patch transfers power and/or data to an implantable device implanted under a user's skin. The transcutaneous transmission patch is made of a flexible material with a top surface and a bottom surface. Located on or formed within the top surface is a pouch or cavity that houses electronic circuitry. The electronic circuitry typically includes a substrate on which an integrated circuit (IC) chip and a transmission coil are mounted. Alternatively, the transmission coil may be molded within the flexible material from which the pouch is made. The electronic circuitry is capable of transcutaneously transmitting power and/or data to a receiving coil in the implanted device. The electronic circuitry is powered by a battery or other power source which is also housed within the pouch or cavity or otherwise carried by the patch. The bottom surface of the transcutaneous transmission patch includes an adhesive layer that detachably secures the patch to a skin surface of the user.

Abstract: A pump for transferring fragile and aggressive fluids such as human blood and comprising a pumping chamber along with a fluid inlet port disposed on the chamber, and one or more outlet ports arranged transversely and medially of the inlet ports. A shrouded rotor is positioned within the pumping chamber having a core of dual-conical configuration converging toward opposed polar end regions and with an axis of rotation extending between the polar regions. The shrouded rotor includes magnets which are arranged at radially spaced locations and with a magnetic drive positioned to deliver rotational driving energy to the rotor. The sole support for the rotor are the hydrodynamic forces acting upon the rotor during its operation, with the rotor body having a relative density of between 10% and 90% of the relative density of the fluid being pumped.

Abstract: A pump for transferring fragile and aggressive fluids such as human blood and comprising a pumping chamber along with a pair of fluid inlet ports arranged in oppositely disposed relationship on the chamber, and one or more outlet ports arranged transversely and medially of the inlet ports. A rotor is positioned within the pumping chamber having a dual-conical configuration converging toward opposed polar end regions and with an axis of rotation extending between the polar regions. The rotor includes a plurality of radial vanes mounted on the outer surface of the dual cones forming the dual-conical configuration, and with the radially outward tips of the vanes encapsulating permanent magnets, with the vanes and permanent magnets being arranged at equally radially spaced locations. A magnetic drive is positioned to deliver rotational driving energy to the magnets in the rotor.

Abstract: A power control loop is established between an external control device and an implantable device so that only the amount of power needed by the implant device to sustain its present operating conditions is transmitted across a transcutaneous transmission link, thereby reducing the amount of power expended by the external control device. In one embodiment, the power control loop is used with a cochlea stimulating system that includes an externally wearable signal receiver and processor (WP) and an implanted cochlear stimulator (ICS). The power control loop is provided between the ICS and the WP such that power delivered to the ICS is precisely controlled in a closed loop manner, with a variable amount of RF energy (power) being transmitted across the transcutaneous link between the WP and ICS. The transmitted RF energy is received by the ICS and is converted to a voltage that is used as a power source within the ICS for stimulating electrode contacts of the ICS.

Abstract: A cochlear stimulation system includes (1) an implantable cochlear stimulator (ICS); (2) a behind-the-ear (BTE) wearable speech processor, including: coils for inductively coupling with the ICS, a first microphone, an LED indicator, and an FM receiver; (3) a remote control unit (RCU), including an FM transmitter, mode/control switches, a second microphone, an input jack for interfacing with external audio equipment, and a status indicator; and (4) an external programmer, including one or more ports for coupling the external programmer with a personal computer. The external programmer is used to program the ICS through the BTE processor to operate in a desired manner, and to perform tests on the ICS. Once the ICS is initially programmed, the user controls the sounds he or she "hears" with the ICS through the RCU, which RCU (when turned ON) is electronically coupled to the BTE processor through an FM (or other wireless) link. Through the RCU, the user may control, e.g.