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.

Abstract: An improved external charger for an implantable medical device is disclosed in which charging is at least partially controlled based on a sensed pressure impingent on its case, which pressure is indicative of the pressure between the external charger and a patient's tissue. The improved external charger includes pressure detection circuitry coupled to one or more pressure sensors for controlling the external device in accordance with the sensed impingent pressure. The sensed pressure can be used to control charging, for example, by suspending charging, by adjusting a maximum set point temperature for the external charger based on the measured pressure, or by issuing an alert via a suitable user interface. By so controlling the external charger on the basis of the measured pressure, the external charger is less likely to create potentially problematic or uncomfortable conditions for the user.

Abstract: An improved embodiment of an external device for an implantable medical device system is described herein, where the external device has both circuitry for charging the implantable medical device and circuitry for telemetering data to and from the medical implant contained within a single housing. The external device in one embodiment includes orthogonal radiators in which both the radiators are used for data transfer, and in which at least one of the radiators is used for power transfer. Having charging and data telemetry circuitry fully integrated within a single external device conveniences both patient and clinician.

Abstract: An improved external charger for charging the battery within or providing power to an implantable medical device is disclosed. The improved external charger includes circuitry for detecting the temperature of the external charger and for controlling charging to prevent exceeding a maximum temperature. The external charger in some embodiments includes a user interface for allowing a patient to set the external charger's maximum temperature. The user interface can be used to select either constant maximum temperatures, or can allow the user to choose from a number of stored charging programs, which programs can control the maximum temperature to vary over time. Alternatively, a charging program in the external charger can vary the maximum temperature set point automatically. By controlling the maximum temperature of the external charger during charging in these manners, the time needed to charge can be minimized while still ensuring a temperature that is comfortable for that patient.

Abstract: A telemetry wand to facilitate communication between a programmer and a neurostimulator device. The telemetry wand comprises an antenna, telemetry circuitry configured for transmitting signals between the programmer and the neurostimulator device via the antenna coil, a threaded screw receptacle configured for receiving a bolt of a conventional camera tripod, and a housing carrying the antenna coil, the telemetry circuitry, and the threaded screw receptacle.

Abstract: By incorporating magnetic field-inducing position determination coils (PDCs) in an external charger, it is possible to determine the position of an implantable device by actively inducing magnetic fields using the PDCs and sensing the reflected magnetic field from the implant. In one embodiment, the PDCs are driven by an AC power source with a frequency equal to the charging coil. In another embodiment, the PDCs are driven by an AC power source at a frequency different from that of the charging coil. By comparing the relative reflected magnetic field strengths at each of the PDCs, 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: A connection monitoring system for an implantable medical lead system includes an implantable lead, a first trial system cable, an external trial system, and a sensor. The lead has a distal end and at least one proximal end. The lead includes a plurality of terminals disposed at each proximal end. The first trial system cable has a distal end and at least one proximal end. The distal end of the first trial system cable is configured and arranged to electrically couple with the lead. The external trial system is configured and arranged to electrically couple with the first trial system cable. The sensor is electrically coupled to the external trial system. The sensor is configured and arranged for detecting a loss of electrical connectivity between the external trial system and the lead when the lead becomes electrically decoupled from the external trial system.

Abstract: A communications bridge device communicates between a consumer electronics device, such as a smart telephone, and an implantable medical device. The bridge forwards instructions and data between the consumer electronics device and the implantable medical device. The bridge contains a first transceiver that operates according to a communication protocol operating in the consumer electronics device (such as Bluetooth®), and second transceiver that operates according to a communications technique operating in the implantable medical device (e.g., Frequency Shift Keying). A software application is installed on the consumer electronics device, which provides a user interface for controlling and reading the implantable medical device. The software application is downloadable using standard cellular means. The bridge is preferably small, and easily and discreetly carried by the implantable medical device patient.

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: 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: Embodiments of an improved implantable medical device system for orientation-independent telemetry to and from the device are disclosed. The system includes an external controller which produces an electromagnetic field to induce a current in a coil in the implantable medical device and vise versa. In a preferred embodiment, the external controller comprises three orthogonal coils, each of which is potentially activated to generate or receive the electromagnetic field. Algorithms are disclosed to allow for the choice of one or more of the coils best suited for telemetry based on the chosen coil's orientation with respect to the telemetry coil in the implantable medical device. Because all three of the orthogonal coils are potentially activated if necessary, the result is that at least one of the coils will be in a proper orientation with respect to the coil in the implantable medical device, thereby improving telemetry efficiency.

Abstract: An improved external controller useable with an implantable medical device is disclosed. The external controller comprises a front cover, a back cover, and a sub-assembly. The sub-assembly comprises an electronics chassis on which non-surface mount components, such as the telemetry coils and the battery, can be affixed. The sub-assembly also includes the printed circuit board for the external controller, which is integrated into the chassis and electrically coupled to the telemetry coils and the battery. Once completed, the sub-assembly can be bolted between a front cover and a back cover, such that edges of the sub-assembly comprise the edges of the external case of the external controller.

Abstract: An improved external controller with dual microcontrollers useable with an implantable medical device is disclosed. The external controller comprises a low speed (low frequency) microcontroller and a high speed (high frequency) microcontroller. The low speed microcontroller receives telemetry data from the medical device, converts data into graphical commands, and transmits commands to the high speed microcontroller. The high speed microcontroller interprets the graphical commands, retrieves images indicative of the commands from a storage device, and renders the images onto a display screen. The high speed microcontroller may also process more complicated data sent from the low speed microcontroller, and return the results to the low speed microcontroller to allow it to form the graphics command for the high speed microcontroller to execute.

Abstract: Methods for optimizing telemetry in an implantable medical device system are disclosed, with the goal of equating and maximizing the communication distances between devices in the system, such as the external controller and the Implantable Pulse Generator (IPG). The method involves computerized simulation of maximum communication distances in both directions between the two devices while varying at least two parameters of the telemetry circuitry, such as the number of turns in the telemetry coils in the two devices. This results in a simulation output comprising a matrix in which each element comprises the bidirectional distance values. An element is determined for which the distances are equal (or nearly equal) and maximized (or nearly maximized), and the optimal values for the parameters are then chosen on that basis, with the result that the communication distance in one direction equals the communication distance in the other direction, and is maximized.

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: Embodiments of an improved implantable medical device system for orientation-independent telemetry to and from the device are disclosed. The system includes an external controller which produces an electromagnetic field to induce a current in a coil in the implantable medical device and vise versa. In a preferred embodiment, the external controller comprises three orthogonal coils, each of which is potentially activated to generate or receive the electromagnetic field. Algorithms are disclosed to allow for the choice of one or more of the coils best suited for telemetry based on the chosen coil's orientation with respect to the telemetry coil in the implantable medical device. Because all three of the orthogonal coils are potentially activated if necessary, the result is that at least one of the coils will be in a proper orientation with respect to the coil in the implantable medical device, thereby improving telemetry efficiency.

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: Embodiments of an improved implantable medical device system for orientation-independent telemetry to and from the device are disclosed. The system includes an external controller which produces an electromagnetic field to induce a current in a coil in the implantable medical device and vise versa. In a preferred embodiment, the external controller comprises three orthogonal coils, each of which is potentially activated to generate or receive the electromagnetic field. Algorithms are disclosed to allow for the choice of one or more of the coils best suited for telemetry based on the chosen coil's orientation with respect to the telemetry coil in the implantable medical device. Because all three of the orthogonal coils are potentially activated if necessary, the result is that at least one of the coils will be in a proper orientation with respect to the coil in the implantable medical device, thereby improving telemetry efficiency.

Abstract: An improved external charger for an implantable medical device is disclosed in which charging is at least partially controlled based on a sensed pressure impingent on its case, which pressure is indicative of the pressure between the external charger and a patient's tissue. The improved external charger includes pressure detection circuitry coupled to one or more pressure sensors for controlling the external device in accordance with the sensed impingent pressure. The sensed pressure can be used to control charging, for example, by suspending charging, by adjusting a maximum set point temperature for the external charger based on the measured pressure, or by issuing an alert via a suitable user interface. By so controlling the external charger on the basis of the measured pressure, the external charger is less likely to create potentially problematic or uncomfortable conditions for the user.

Abstract: An improved external controller/charger system for an implantable medical device is described herein, 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. Specifically, in one embodiment, the external controller/charger system automatically decouples the external charging coil from the charging circuitry and couples it to the telemetry circuitry.