Abstract: A charging system for an Implantable Medical Device (IMD) is disclosed having a charging coil and one or more sense coils. The charging coil and one or more sense coils are preferably housed in a charging coil assembly coupled to an electronics module by a cable. The charging coil is preferably a wire winding, while the one or more sense coils are concentric with the charging coil and preferably formed in one or more traces of a circuit board. One or more voltages induced on the one or more sense coils can be used to determine the resonant frequency of the charging coil/IMD coupled system. The determined resonant frequency can then be used to determine the position of the charging coil relative to the IMD. The magnetic field produced from the charging coil may also be driven at the resonant frequency to optimize power transfer to the IMD.

Abstract: A charging system for an Implantable Medical Device (IMD) is disclosed having a charging coil and one or more sense coils. The charging coil and one or more sense coils are preferably housed in a charging coil assembly coupled to an electronics module by a cable. The charging coil is preferably a wire winding, while the one or more sense coils are concentric with the charging coil and preferably formed in one or more traces of a circuit board. One or more voltages induced on the one or more sense coils can be used to determine whether the charging coil is (i) centered, (ii) not centered but not misaligned, or (iii) misaligned, with respect to the IMD being charged, which three conditions sequentially comprise lower coupling between the charging coil and the IMD. A charging algorithm is also disclosed that control charging dependent on these conditions.

Abstract: A charging system for an Implantable Medical Device (IMD) is disclosed having a charging coil and one or more sense coils preferably housed in a charging coil assembly coupled to an electronics module by a cable. The charging coil is preferably a wire winding, while the sense coils are preferably formed in one or more traces of a circuit board. One or more voltages induced on the one or more sense coils can be used to determine a phase angle between the voltage and a driving signal for the charging coil. The determined phase angle can then be used to determine the position of the charging coil relative to the IMD. Additionally, more than one parameter (phase angle, magnitude, resonant frequency) may be determined using the voltage may be used to determine position, including the radial offset and depth of the charging coil relative to the IMD.

Abstract: A charging system for an Implantable Medical Device (IMD) is disclosed having a charging coil and one or more sense coils. The charging coil and one or more sense coils are preferably housed in a charging coil assembly coupled to an electronics module by a cable. The charging coil is preferably a wire winding, while the one or more sense coils are concentric with the charging coil and preferably formed in one or more traces of a circuit board. The magnitude of one or more voltages induced on the one or more sense coils can be measured to determine the position of the charging coil relative to the IMD, and in particular whether the charging coil is (i) centered, (ii) not centered but not misaligned, or (iii) misaligned, with respect to the IMD being charged, which three conditions sequentially comprise lower coupling between the charging coil and the IMD.

Abstract: A charging system for an Implantable Medical Device (IMD) is disclosed having a charging coil and one or more sense coils preferably housed in a charging coil assembly coupled to an electronics module by a cable. The charging coil is preferably a wire winding, while the sense coils are preferably formed in one or more traces of a circuit board. One or more voltages induced on the one or more sense coils can be used to determine one or more parameters (magnitude, phase angle, resonant frequency) indicative of the position between the charging coil and the IMD, which position may include the radial offset and possibly also the depth of the charging coil relative to the IMD. Knowing the position, the power of the magnetic field produced by the charging coil can be adjusted to compensate for the position.

Abstract: An external controller/charger system for an implantable medical device is disclosed, in which the external controller/charger system provides automatic switching between telemetry and charging without any manual intervention by the patient. The external controller/charger system includes an external controller which houses a telemetry coil and an external charging coil coupled to the external controller. Normally, a charging session is carried out using the external charging coil, and a telemetry session is carried out using the telemetry coil. However, when a patient requests to carry out telemetry during a charging session, the external charging coil is used instead of the internal telemetry coil.

Abstract: An improved external trial stimulator provides neurostimulation functionality for implanted medical electrodes prior to implantation of an implantable neurostimulator. The external trial stimulator is housed in a four-part housing that provides mechanical and electrostatic discharge protection for the electronics mounted in a central frame of the housing. Connectors attached to leads from the electrodes connect to contacts that are recessed in the housing through ports that are centered for easy access. Multiple indicators provide information to users of the external trial stimulator.

Abstract: Disclosed is a plug-in accessory for operating a mobile device as an external controller for an Implantable Medical Device (IMD). The accessory includes a connector insertable into a port on the mobile device. Accessory circuitry can be powered by a battery or by the mobile device. An application on the mobile device in conjunction with the accessory configures the mobile phone for immediate use as an IMD external controller. When the accessory is inserted into the port or a switch on the accessory pressed, the application operates to validate the accessory; to unlock the phone; to secure the mobile device; and to render a graphical user interface on the mobile device for communicating with the IMD. The accessory can additionally include telemetry circuitry and an antenna for communicating with the IMD, rather than using short-range communication means provided in the mobile device itself.

Abstract: A convertible implantable stimulator that provides electrical stimulation therapy during an extended trial stimulation period (or permanently, if desired) in a fully implanted solution is disclosed. The convertible implantable stimulator preferably does not include an internal power supply and is therefore continuously powered by an external charger, such as a powering patch, in a first mode of operation. If the convertible implantable stimulator is determined to be effective and a patient desires more traditional stimulation therapy, a separate power supply module can subsequently be implanted and connected to the convertible implantable stimulator to provide power to the stimulator in a second mode of operation.

Abstract: An improved circuit board for an implantable stimulator device is disclosed having components embedded within the device's circuit board, and in particular having embedded components in the electrodes current paths, such as various numbers and/or combinations of DC-blocking capacitors, EMI filtering capacitors, and EMI filtering inductors. By embedding at least some of these components, the improved circuit board can accommodate additional IPG circuitry, or can be made smaller, which is significant given the trend to increase the number of electrodes in such devices. In a preferred embodiment, at least the filtering capacitors are embedded in the circuit board, while the DC-blocking capacitors are traditionally surface mounted, without reducing the number of DC-blocking capacitors compared to the number of electrodes the IPG supports.

Abstract: Disclosed is a plug-in accessory for operating a mobile device as an external controller for an Implantable Medical Device (IMD). The accessory includes a connector insertable into a port on the mobile device. Accessory circuitry can be powered by a battery or by the mobile device. An application on the mobile device in conjunction with the accessory configures the mobile phone for immediate use as an IMD external controller. When the accessory is inserted into the port or a switch on the accessory pressed, the application operates to validate the accessory; to unlock the phone; to secure the mobile device; and to render a graphical user interface on the mobile device for communicating with the IMD. The accessory can additionally include telemetry circuitry and an antenna for communicating with the IMD, rather than using short-range communication means provided in the mobile device itself.

Abstract: An external charger for an implantable medical device is disclosed which can automatically detect an implant and generate a charging field. The technique uses circuitry typically present in an external charger, such as control circuitry, a Load Shift Keying (LSK) demodulator, and a coupling detector. An algorithm in the control circuitry periodically issues charging fields of short duration in a standby mode. If the coupling detector detects the presence of a conductive material, the algorithm issues a listening window during which a charging field is generated. If an LSK reply signal is received at the LSK demodulator, the external charger can charge the implant in a normal fashion. If a movement signature is detected at the LSK demodulator indicative of a predetermined user movement of the external charger, a charging field is issued for a set timing period, to at least partially charge the IPG battery to restore LSK communications.

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 external charger for an implantable medical device is disclosed which can automatically detect an implant and generate a charging field. The technique uses circuitry typically present in an external charger, such as control circuitry, a Load Shift Keying (LSK) demodulator, and a coupling detector. An algorithm in the control circuitry periodically issues charging fields of short duration in a standby mode. If the coupling detector detects the presence of a conductive material, the algorithm issues a listening window during which a charging field is generated. If an LSK reply signal is received at the LSK demodulator, the external charger can charge the implant in a normal fashion. If a movement signature is detected at the LSK demodulator indicative of a predetermined user movement of the external charger, a charging field is issued for a set timing period, to at least partially charge the IPG battery to restore LSK communications.

Abstract: Receiver and digital demodulation circuitry for an external controller for communicating with an implantable medical device (IMD) is disclosed. A Digital Signal Processor (DSP) is used to sample received analog data transmitted from the IMD at a lower rate than would otherwise be required for the frequency components in the transmitted data by the Nyquist sampling criteria. To allow for this reduced sampling rate, the incoming data is shifted to a lower intermediate frequency using a switching circuit. The switching circuit receives a clock signal, which is preferably but not necessarily the same clock signal used by the DSP to sample the data. The switching circuit multiplies the received data with the clock signal to produce lower intermediate frequencies, which can then be adequately sampled at the DSP at the reduced sampling rate per the Nyquist sampling criteria.

Abstract: The disclosed means of determining alignment between an external charger and an implantable medical device (IMD) involves the use of reflected impedance modulation, i.e., by measuring at the external charger reflections arising from modulating the impedance of the charging coil in the IMD. During charging, the charging coil in the IMD is pulsed to modulate its impedance. The difference in the coil voltage (?V) produced at the external charger as a result of these pulses is assessed and is used by the external charger to indicate coupling. If the magnitude of ?V is above a threshold, the external charger considers the coupling to the IMD to be adequate, and an alignment indicator in the external charger is controlled accordingly. The magnitude of Vcoil can be assessed in addition to ?V to determine alignment with the IMD with improved precision, and/or to further define a high quality alignment condition.

Abstract: Disclosed is a charging coil assembly for a mobile device able to wirelessly provide power to charge a battery in an Implantable Medical Device (IMD). The assembly includes a coaxial connector that can be inserted into a coaxial audio port on the mobile device to allow bi-directional communications between the assembly and the mobile device. One or more housings coupled to the connector by a cable can include control circuitry, a charging coil, and a battery. The charging coil can be driven by control circuitry in the assembly or by a charging audio signal at an audio frequency provided by the mobile device via the audio port and connector. A Charging Application on the mobile device can detect and authenticate the charging coil assembly, and render a charging graphical user interface on the mobile device to control and/or monitor charging of the IMD.

Abstract: An external charging system for charging or powering an implantable medical device is disclosed which is self-affixing to the patient without the need for a holding device. The charging system can comprise a charging coil attached to a flexible member. The flexible member is bendable, and when bent will firmly hold its position on the patient. The system can include an electronics module including a user interface and the necessary electronics for activating the charging coil to produce a magnetic charging field. Wires can couple the charging coil in the coil module to the electronics in the electronics modules. The entire assembly can be encased in a water proof sleeve having a high-friction surface, which protects the charging system and helps the charging system to adhere to the patient.

Abstract: Disclosed are an external charger including a solar cell array for charging or powering an implantable medical device (IMD), and a cradle including a solar cell array for charging or powering an external charger for charging or powering an implantable medical device. The disclosed improved external charger or improved cradle are particularly beneficial for charging a battery in an external charger used to charge or power an IMD when a power source is otherwise unavailable, such as a wall socket.

Abstract: The disclosed system for providing closed loop charging between an external charger and an implantable medical device such as an IPG involves the use of reflected impedance modulation, i.e., by measuring at the external charger reflections arising from modulating the impedance of the charging coil in the IPG. During charging, the charging coil in the IPG is periodically pulsed to modulate its impedance. The magnitude of the change in the coil voltage produced at the external charger ?V as a result of these pulses is assessed and is used by the controller circuitry in the external charger as indicative of the coupling between the external charger and the IPG. The external charger adjusts its output power (e.g., Icharge) in accordance with the magnitude of ?V, thus achieving closed loop charging without the need of telemetering coupling parameters from the IPG.