Abstract: A system and method of controlling the charging of the battery of a medical device using a remote inductive charger, with the method utilizing both a relatively fast closed-loop charging control based on a proxy for a target power transmission value in conjunction, and a slower closed-loop control based on an actual measured transmission value to control a charging power level for charging the medical device.

Abstract: Disclosed is an improved external controller useable in an implantable medical device system. The communication coil in the external controller is formed in a printed circuit board (PCB), i.e., by using the various tracing layers and vias of the PCB. As illustrated, the PCB coil is formed at a plurality of trace layers in the PCB, and comprises a plurality of turns at some or all of the layers. The communication coil may wrap around the other circuitry used in the external controller, which circuitry may be mounted to the front and/or back of the PCB. The geometry of the coil is specially tailored to maximize its inductance, and hence maximize its ability to communicate in the sub-4 MHz range which is not significantly attenuated by the human body.

Abstract: By incorporating magnetic field sensing coils in an external charger, it is possible to determine the position of an implantable device by sensing the reflected magnetic field from the implant. In one embodiment, two or more field sensing coils are arranged to sense the reflected magnetic field. By comparing the relative reflected magnetic field strengths of the sensing coils, the position of the implant relative to the external charger can be determined. Audio and/or visual feedback can then be communicated to the patient to allow the patient to improve the alignment of the charger.

Abstract: An improved integrated external controller/charger system useable with an implantable medical device is disclosed. The system comprises two main components: an external controller and an external charging coil assembly that is coupleable thereto. When the external charging coil assembly is coupled to the external controller, the system can be used to both send and receive data telemetry to and from the implantable medical device, and to send power to the device. Specifically, the external controller controls data telemetry by energizing at least one coil within the external controller, and the external controller controls power transmission by energizing a charging coil in the external charging coil assembly, which is otherwise devoid of its own control, power, and user interface. The result is a cheaper, simpler, more compact, and more convenient data telemetry and charging solution for the patient having a medical implant.

Abstract: By incorporating magnetic field sensing coils in an external charger, it is possible to determine the position of an implantable device by sensing the reflected magnetic field from the implant. In one embodiment, two or more field sensing coils are arranged to sense the reflected magnetic field. By comparing the relative reflected magnetic field strengths of the sensing coils, the position of the implant relative to the external charger can be determined. Audio and/or visual feedback can then be communicated to the patient to allow the patient to improve the alignment of the charger.

Abstract: An animal litter mixture comprising pine wood and silica gel is provided. The pinewood is preferably a sawdust form, although the pinewood may be in the form of fine shavings or compressed pellets. The silica gel may have one porosity or a mixture of porosity. In one embodiment of the animal litter mixture, the silica gel may be an indicator gel that changes colors when the silica is saturated with water.

Abstract: An exemplary system includes 1) a headpiece module configured to be affixed to a head of a patient and comprising a primary sound processor configured to generate stimulation parameters used to direct an auditory prosthesis implanted within the patient to apply electrical stimulation representative of one or more audio signals to the patient and 2) a sound processor module separate from the headpiece module and configured to be selectively and communicatively coupled to the headpiece module. The sound processor module includes a secondary sound processor configured to detect a communicative coupling of the sound processor module to the headpiece module and contribute to the generation of one or more of the stimulation parameters while the sound processor module is communicatively coupled to the headpiece module. Corresponding systems and methods are also disclosed.

Abstract: A combination charging and telemetry circuit for use within an implantable device, such as a microstimulator, uses a single coil for both charging and telemetry. In accordance with one aspect of the invention, one or more capacitors are used to tune the single coil to different frequencies, wherein the coil is used for multiple purposes, e.g., for receiving power from an external source and also for the telemetry of information to and from an external source.

Abstract: A combination charging and telemetry circuit for use within an implantable device, such as a microstimulator, uses a single coil for both charging and telemetry. In accordance with one aspect of the invention, one or more capacitors are used to tune the single coil to different frequencies, wherein the coil is used for multiple purposes, e.g., for receiving power from an external source and also for the telemetry of information to and from an external source.

Abstract: Electrical energy is transcutaneously transmitted from an external charger to an implanted medical device, wherein the external charger includes a charger head that is positioned on the patient to align with the implanted medical device for efficient charging. To secure the charger head in alignment with the implanted medical device, a belt with a buckle is provided for securing the charger head. The belt is adjustable in length by sliding end portions of the belt through a buckle and joining respective fabrics on the belt. The position of the buckle can also be adjusted for ease of patient use. Additional features of the belt provide for heat management to improve patient comfort and an additional strap to further adjust the length of the belt.

Abstract: A base station for passively recharging a battery in an implant without patient involvement is disclosed. The base station can be hand held or may comprise equipment configured to be placed at a fixed location, such as under a bed, on or next to a wall, etc. The base station can generate electric and magnetic fields (E-field and B-field) that couple with an antenna and a receiving coil within the implant to generate a charging current for charging the implant's battery. No handling or manipulation on part of the patient is necessary; the implant battery is passively charged whenever the patient is within range of either the magnetic or electric charging fields generated by base station. Charging using the B-field occurs when the IPG is at a relatively short distance from the base station, while charging using the E-field occurs at longer distances.

Abstract: An implantable medical device and external base station system are disclosed. The external base station can provide a passive electric field to power the implant, or to charge its battery. The base station may also power or charge using magnetic fields under certain circumstances. The Implantable medical device may comprise an implantable neurostimulator having a number of electrode leads extending from its body. One or more of the electrode leads can comprise the antenna for receiving the electric field from the base station, and resonance in that antenna can be rectified to provide the power for recharging the battery. Although the E-field provided by the base station does not provide as much power for recharging as does other traditional charging techniques (such as those using magnetic fields), it can occur passively and over longer distances to allow the patent's implant to be recharged when in relative proximity to the base station.

Abstract: To recharge an implanted medical device, an external device, typically in the form of an inductive charger, is placed over the implant to provide for transcutaneous energy transfer. The external charging device can be powered by a rechargeable battery. Since the battery is in close proximity to the charge coil, the large magnetic field produced by the charge coil induces eddy currents that flow on the battery's metallic case, often resulting in undesirable heating of the battery and reduced efficiency of the charger. This disclosure provides a means of shielding the battery from the magnetic field to reduce eddy current heating, thereby increasing efficiency. In one embodiment, the magnetic shield consists of one or more thin ferrite plates. The use of a ferrite shield allows the battery to be placed directly over the charge coil as opposed to outside the extent of the charge coil.

Abstract: An animal litter mixture comprising pine wood and silica gel is provided. The pinewood is preferably a sawdust form, although the pinewood may be in the form of fine shavings or compressed pellets. The silica gel may have one porosity or a mixture of porosity. In one embodiment of the animal litter mixture, the silica gel may be an indicator gel that changes colors when the silica is saturated with water.

Abstract: An improved external charger for a battery in an implantable medical device (implant), and technique for charging batteries in multiple implants using such improved external charger, is disclosed. During charging, values for a parameter measured in the implants are reported from the implants to the external charger. The external charger infers from the magnitudes of the parameters which of the implants has the highest and lowest coupling to the external charger, and so designates those implants as “hot” and “cold.” The intensity of the magnetic charging field is optimized for the cold implant consistent with the simulation to ensure that that the cold implant is charged with a maximum (fastest) battery charging current. The duty cycle of the magnetic charging field is also optimized for the hot implant consistent with the simulation to ensure that the hot implant does not exceed the power dissipation limit.

Abstract: An animal litter mixture comprising pine wood and silica gel is provided. The pinewood is preferably a sawdust form, although the pinewood may be in the form of fine shavings or compressed pellets. The silica gel may have one porosity or a mixture of porosity. In one embodiment of the animal litter mixture, the silica gel may be an indicator gel that changes colors when the silica is saturated with water.

Abstract: An improved external charger for a battery in an implantable medical device (implant), and technique for charging the battery using such improved external charger, is disclosed. In one example, simulation data is used to model the power dissipation of the charging circuitry in the implant at varying levels of implant power. A power dissipation limit is chosen to constrain the charging circuitry from producing an inordinate amount of heat to the tissue surrounding the implant, and duty cycles are determined for the various levels of input intensities to ensure that the power limit is not exceeded. A maximum simulated average battery current determines the optimal (i.e., quickest) battery charging current, and at least an optimal value for a parameter indicative of that current, for example, the voltage across the battery charging circuitry, is determined and stored in the external charger.

Abstract: By incorporating magnetic field sensing coils in an external charger, it is possible to determine the position of an implantable device by sensing the reflected magnetic field from the implant. In one embodiment, two or more field sensing coils are arranged to sense the reflected magnetic field. By comparing the relative reflected magnetic field strengths of the sensing coils, the position of the implant relative to the external charger can be determined. Audio and/or visual feedback can then be communicated to the patient to allow the patient to improve the alignment of the charger.

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.

Abstract: Implantable pulse generators and spinal cord stimulation (SCS) systems are provided. The implantable pulse generator comprises telemetry circuitry configured for wirelessly receiving programming signals from an external programmer, and a plurality of bi-directional current sources configured for being respectively coupled to a plurality of electrodes. The implantable pulse generator further comprises control circuitry configured for directing the bi-directional current sources to output current pulses of a selected amplitude and polarity to the electrodes in accordance with the programming signals. The SCS system may comprise a plurality of electrodes, an external programmer configured for transmitting programming signals, and the afore-described implantable pulse generator as described above.