Abstract: A method of manufacturing an electrode array has an elongate flexible carrier that 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: A subcutaneous tunneling and carrying tool has a handle, a rod, and a carrier. The tool is used in connection with the implantation of electrical stimulators within the body, and more particularly facilitates the surgical procedure in the connection of an electrode lead extension to the implantable stimulator when the electrode and stimulator may not be co-located. In one embodiment, tunneling is accomplished by a tip that also serves to connect the tool to a disposable carrier in which the lead extension connector is packaged. In another embodiment the carrier comprises a carrier body and a removable cover, wherein the carrier cover covers a carrier cavity during tunneling and includes a tunneling end, and the carrier cover is removed after tunneling to expose the carrier cavity, into which carrier cavity the electrode lead extension is inserted to carry back through the tunnel.

Abstract: An external transmitter circuit drives an implantable neural stimulator having an implanted coil from a primary coil driven by a power amplifier. For efficient power consumption, the transmitter output circuit (which includes the primary coil driven by the power amplifier inductively coupled with the implanted coil) operates as a tuned resonant circuit. When operating as a tuned resonant circuit, it is difficult to modulate the carrier signal with data having sharp rise and fall times without using a high power modulation amplifier. Sharp rise and fall times are needed in order to ensure reliable data transmission. To overcome this difficulty, the present invention includes an output switch that selectively inserts a resistor in the transmitter output coil circuit in order to de-tune the resonant circuit only during those times when data modulation is needed. Such de-tuning allows sharp rise and fall times in the data modulation without the need for using a high power modulation amplifier.

Abstract: A medication infusion system includes an implantable device and an external control device. The implantable device includes a constant flow pump and a flow rate that may be altered by commands received from the external control device. Power to execute the commands is also provided to the passive pump from the external control device. The external control device sends a command only when a flow rate change is to be made, or when status information is required. In one embodiment, the flow rate provided by the passive pump is controlled by a flow regulator, where the flow rate is changed by changing the restriction of a passage between regulator chambers.

Abstract: A neural stimulation system allows the magnitude of electrical stimuli generated by the system to be programmed to a desired level greater than or equal to a minimum perceived threshold and less than or equal to a maximum tolerable perceived threshold. The electrical stimuli are applied through selected groupings of individual electrode contacts of a multi-electrode-contact electrode array attached to pulse generation circuitry as either cathodes or anodes. The electrode array is implanted so that the individual electrode contacts are in contact with the body tissue to be stimulated. Stimulating electrical current pulses, defined by a prescribed set of stimulus parameters are generated and applied to the selected electrode contacts so as to flow from the anode electrodes to the cathode electrodes. The perceived magnitude of the applied stimuli is equalized in order to enable quick, automated, and/or interactive programming of the values of the stimulation parameters.

Abstract: A tool is provided for facilitating determining a proper location for an implantable device or medication, and for then delivering the implant to the precise location determined with the tool. To determine the target location, the tool may include a component for testing target locations, such as a stimulating probe for simulating a miniature implantable stimulator. In one embodiment, the tool is used to test a miniature implantable stimulator prior to depositing the implant precisely at the target location. The components of the tool are configured to maintain the implant at the target location while the tool is withdrawn. In one embodiment, a push rod assembly of the tool keeps the implant in position while it retracts the implant holder from around the implant. The ergonomic and light-weight tool leads to reduced surgical time, number and size of incisions, risk of infection, and likelihood of error.

Abstract: An improved hair-clip rotatably secures a headpiece of a Implantable Cochlear Stimulation (ICS) system adjacent to an implantable device of the ICS system. The hair-clip includes three fingers to securely grasp the headpiece around the cylindrical edge of the headpiece, while allowing rotation of the headpiece relative to the hair-clip. Both power and control signals are transmitted transcutaneously from the head piece to the implantable device. Efficient transmission of these signals requires that the headpiece be securely held in close alignment to the implantable device. The improved hair-clip securely holds the headpiece in place, and allows the headpiece to be rotated to position the headpiece cable. The ability to position the cable allows a user to achieve a comfortable and inconspicuous cable routing. The hair-clip also provides: retention regardless of skin flap thickness, secure retention during physical activity, and permits magnet-less retention thus minimizing interference with MRI examination.

Abstract: An implantable medical device, such as an implantable pulse generator (IPG) used with a spinal cord stimulation (SCS) system, includes a rechargeable lithium-ion battery having an anode electrode with a substrate made substantially from titanium. Such battery construction allows the rechargeable battery to be discharged down to zero volts without damage to the battery. The implantable medical device includes battery charging and protection circuitry that controls the charging of the battery so as to assure its reliable and safe operation. A multi-rate charge algorithm is employed that minimizes charging time while ensuring the battery cell is safely charged. Fast charging occurs at safer lower battery voltages (e.g., battery voltage above about 2.5 V), and slower charging occurs when the battery nears full charge higher battery voltages (e.g., above about 4.0 V). When potentially less-than-safe very low voltages are encountered (e.g., less than 2.

Abstract: A cochlear electrode array is adapted for use with a hybrid hearing aid system. The cochlear electrode array has a carrier on which spaced-apart electrode contacts are carried, and in one embodiment is formed in the shape of a blade, being flat in one direction and thin in another direction. In another embodiment, side fins extend out from opposing sides of the carrier on which the electrode contacts are carried. The blade electrode array, or electrode array with side fins, is adapted for minimally-invasive insertion into the inner ear. More particularly, the blade or finned electrode is designed to be inserted through a soft cochleostomy so as to reside between the spiral ligament membrane and the cochlear bony tissue along a lateral side of the cochlea, near the basal end of the cochlea.

Abstract: A spiral shield for an implantable secondary coil confines the electrical field of the coil, and thus prevents capacitive coupling of the coil through surrounding dielectrics (such as human tissue.) Known implantable devices receive power inductively, through a secondary coil, from a primary coil in an external device. Efficient power reception requires that the coils be tuned to the same resonant frequency. Use of the spiral shield results in predictable electrical behavior of the secondary coil and permits the secondary coil to be accurately tuned to the same resonate frequency as the primary coil. To further improve performance, spacers made from SILBIONE®LSR 70 reside between turns of the coil to reduce turn to turn and turn to shield capacitances. Reducing the capacitances prevents excessive reduction of the self resonant frequency of the coil. The coil is imbedded in SILBIONE®LSR 70, allowing for a thin and flexible coil.

Abstract: A Functional Electro Stimulation (FES) system provides physiologically based adjustment of stimulation parameters to achieve a high update rate for nerve and muscle stimulation at a reduced data transmission rate. FES systems generate electrical signals to stimulate nerves and muscles to provide movement for paraplegics and quadriplegics. Known FES systems comprise a multiplicity of microstimulators that are controlled by a single master controller. Control signals are transmitted over an RF link. A complete set of stimulation parameters comprising pulse amplitude, pulse width, and pulse frequency is initially transmitted to set initial stimulation parameters. Subsequent functional control of muscles is achieved by transmitting an increment to a single stimulation parameter. In a preferred embodiment the physiological behavior of the human body is copied by incrementing the pulse rate.

Abstract: A paddle-type electrode or electrode array is implantable like a percutaneously inserted lead, i.e., without requiring major surgery, and once implanted, expands to provide a platform for many electrode configurations. The electrode array is provided on a flexible, foldable, subcarrier or substrate. Such subcarrier or substrate folds or compresses during implantation, thereby facilitating its insertion using percutaneous implantation techniques and tools. Once implanted, such subcarrier or substrate expands, thereby placing the electrodes in a desired spaced-apart positional relationship, and thus achieving a desired electrode array configuration. A steering stylet may be accommodated in a lumen provided in the subcarrier or substrate. Insertion tools useful with such electrode arrays include a needle with an oblong cross-section, which accommodates the dimensions of the folded array, and also accommodates other electrode arrays that are not necessarily folded.

Abstract: A spinal cord stimulation (SCS) system provides multiple stimulation channels, each capable of producing up to 10 mA of current into a 1 K&OHgr; load. The SCS system further includes a replenishable power source, e.g., a rechargeable battery, that requires only an occasional recharge, and offers a life of at least 10 years at typical settings. Each of the multiple stimulus channels of the system may be combined with other channels to deliver more than 10 mA of current. Additionally, the SCS system has the capability to stimulate simultaneously on all available channels. Each channel has at least two outputs (one positive and one negative) that can be mapped via a low impedance switching matrix to any electrode contact or the system case, thereby allowing a clinician to provide unique electrical stimulation fields for each current channel. Moreover, this feature, combined with multi-contact electrodes arranged in two or three dimensional arrays, allows “virtual electrodes” to be realized.

Abstract: A moisture-resistant, wideband microphone subassembly for a Behind-The-Ear (BTE) hearing device, provides a barrier to perspiration and rain, while maintaining a good frequency response. The microphone subassembly is contained in the case of the BTE hearing device and comprises a microphone, a boot, and a moisture-resistant membrane. The boot structurally supports the microphone, provides a moisture seal around the microphone case, and provides the microphone with isolation from vibrations in the case of the BTE hearing device. The membrane resists the passage of moisture, while providing an acoustic window permitting sound waves to reach the microphone. In one embodiment high compliance washers sandwich the membrane to improve frequency response. A preferred embodiment provides a substantially flat acoustic frequency response to beyond 10 KHz.

Abstract: An implantable electrode assembly includes a leading section attached to the distal end of an electrode array. The electrode array has electrodes spaced along its length. Cochleostomies are drilled at both the base and apex of the cochlea. The leading section is inserted through the basal cochleostomy and promoted to the apical cochleostomy. A forward end of the leading section is then pulled through the apical cochleostomy, which causes the electrode array to be pulled into the cochlea. A depth marker on the electrode array indicates complete insertion. The leading section is detached from the electrode array and the electrode array is placed in tension by gently pulling both ends, which tension causes the electrode array to hug the modiolar wall of the cochlea. Wedges may be inserted at both cochleostomies to maintain the electrode array in tension.

Abstract: An electrode system is provided for insertion into an ossified cochlea. The electrode system includes a first electrode array and a second electrode array, both of which are electrically connected to a suitable implantable cochlear stimulator (ICS). Each of the two electrode arrays has a plurality of spaced-apart electrode contacts along one side or surface thereof, e.g., eight to twelve electrode contacts on the first electrode array, and six to ten electrode contacts on the second electrode array. A tunnel is drilled through the ossified portion of the cochlea into which the first electrode array is snugly inserted. The second electrode array is inserted into the cochlea near the second turn thereof. Where the cochlea is fully ossified, a second tunnel is drilled through the ossified portion at the second turn. A positioner may be used with the second electrode array in order to position its electrode contacts against the modiolar wall of the cochlea.

Abstract: 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.

Abstract: An anchor is provided for securing an elongated cylindrical member, such as a lead cable, to surrounding tissue. The anchor has a simple design that allows the anchor to be held in place on, e.g., a lead cable, without the need for sutures. In addition, the anchor may be manipulated to allow the anchor to move along the cylindrical member. Manipulation of the anchor is straight-forward, simple, and does not require tools, yet the anchor is reliably held in place, requiring intentional manipulation to be released. The anchor includes two coaxial sleeves holding the ends of a coaxial spring. As one sleeve is rotated in relation to the other, the spring is twisted, causing the inner diameter of the spring to increase or decrease. Once the inner diameter of the spring is increased to the point that is becomes larger than the outer diameter of the cylindrical member it surrounds, the anchor can slide on the cylindrical member.

Abstract: A feed forward power control loop is provided for a tissue stimulation system. The tissue stimulating system includes an external device and an implantable device. Only the amount of power required by the implantable device is transmitted across a transcutaneous transmission link to the implantable device from the external device, thereby reducing power fluctuations within the implantable device, and reducing the amount of power expended by the external device. In one embodiment, the power control loop is used with a cochlear stimulating system that includes an externally wearable signal receiver and processor (WP) and an implanted cochlear stimulator (ICS). The feed forward power control loop predicts the power requirements of the ICS. The prediction is used to determine the level of RF power to be transmitted by the WP.

Abstract: A myogenic-based evoked response (termed the “MER” for purposes of this application), heretofore considered an undesirable artifact in response to an applied Cochlear stimulus, is deliberately sensed and measured with permanently implanted electrodes connected to a Cochlear implant device. The measured MER is then used to assist in the objective programming of the Cochlear implant. The MER may be measured between two intra-Cochlear electrodes, between one intra-Cochlear electrode and one extra-Cochlear reference electrode, or between two extra-Cochlear electrodes. Because the measured MER is believed to pre-empt the actual stapedius reflex, the electrodes need not be placed into or in close proximity to the stapedial tendon, the stapes, or the facial nerve.