Abstract: An example of a system may include an arrangement of electrodes configured to be operationally positioned for use in modulating targeted neural tissue, a neural modulator, a communication module, and a controller. The neural modulator may be configured to use at least some electrodes within the arrangement of electrodes to generate a modulation field. The communication module may be configured to receive user-provided selections. The controller may be configured to use the communication module to receive a user-provided selection of a desired electrode list where the electrode list identifies electrodes within the arrangement of electrodes that are available for use in modulating the targeted neural tissue, control the neural stimulation modulator to generate the modulation field, and use the electrodes identified in the electrode list to modulate the targeted neural tissue.

Abstract: Disclosed is a new architecture for an IPG having a master and slave electrode driver integrated circuits. The electrode outputs on the integrated circuits are wired together. Each integrated circuit can be programmed to provide pulses with different frequencies. Active timing channels in each of the master and slave integrated circuits are programmed to provide the desired pulses, while shadow timing channels in the master and slave are programmed with the timing data from the active timing channels in the other integrated circuit so that each chip knows when the other is providing a pulse, so that each chip can disable its recovery circuitry so as not to defeat those pulses. In the event of pulse overlap at a given electrode, the currents provided by each chip will add at the affected electrode. Compliance voltage generation is dictated by an algorithm to find an optimal compliance voltage even during periods when pulses are overlapping.

Abstract: Electrode voltage monitoring circuitry for an implantable neurostimulator system having a plurality of electrode-driver integrated circuits (ICs) in provided. Electrodes from either or both ICs can be chosen to provide stimulation, and one of the IC acts as the master while the other acts as the slave. Electrodes voltages on the slave IC are routed to the master IC, and thus the master IC can monitor both electrode voltages on the slave as well as electrode voltages on the master. Such voltages can be monitored for a variety of purposes, and in particular use of such voltage is disclosed for determining the resistance between electrodes and to set a compliance voltage for stimulation.

Abstract: A therapeutic neuromodulation system configured for providing therapy to a patient. The therapeutic neuromodulation system comprises a plurality of electrical terminals configured for being respectively coupled to a plurality of electrodes implanted within tissue, analog output circuitry configured for delivering therapeutic electrical energy between the plurality of electrical terminals in accordance with a set of modulation parameters that includes a defined current value, a voltage regulator configured for supplying an adjustable compliance voltage to the analog output circuitry, and control/processing circuitry configured for automatically performing a compliance voltage calibration process at a compliance voltage adjustment interval by periodically computing an adjusted compliance voltage value as a function of a compliance voltage margin.

Abstract: An improved architecture for an implantable medical device using a primary battery is disclosed which reduces the circumstances in which the voltage of the primary battery is boosted, and hence reduces the power draw in the implant. The architecture includes a boost converter for selectively boosting the voltage of the primary battery and for supplying that boosted voltage to certain of the circuit blocks, including digital circuitry, analog circuitry, and memory. However, the boost converter is only used to boost the battery voltage when its magnitude is below a threshold; if above the threshold, the battery voltage is passed to the circuit blocks without boosting. Additionally, some circuitry capable of operation even at low battery voltages—including the telemetry tank circuitry and the compliance voltage generator—receives the battery voltage directly without boosting, and without regard to the current magnitude of the battery voltage.

Abstract: Systems of techniques for controlling charge flow during the electrical stimulation of tissue. In one aspect, a method includes receiving a charge setting describing an amount of charge that is to flow during a stimulation pulse that electrically stimulates a tissue, and generating and delivering the stimulation pulse in a manner such that an amount of charge delivered to the tissue during the stimulation pulse accords with the charge setting.

Abstract: A neurostimulation device capable of being placed between a stimulation state and an EMI protection state. The neurostimulation device comprises a plurality of electrical terminals configured for being respectively coupled to a plurality of stimulation electrodes, stimulation output circuitry configured for being selectively activated during the stimulation state to output a plurality of stimulation pulses to the plurality of electrical terminals, electromagnetic protection circuitry configured for being selectively activated during the EMI protection state to prevent at least a portion of the electrical current induced on at least one of the electrical terminals by an electromagnetic field entering the stimulation output circuitry, and a controller configured for automatically defaulting the neurostimulation device to the EMI protection state.

Abstract: Sample and hold circuitry for monitoring electrodes and other voltages in an implantable neurostimulator is disclosed. The sample and hold circuitry in one embodiment contains multiplexers to selected appropriate voltages and to pass them to two storage capacitors during two different measurement phases. The capacitors are in a later stage serially connected to add the two voltages stored on the capacitors, and voltages present at the top and bottom of the serial connection are then input to a differential amplifier to compute their difference. The sample and hold circuitry is particularly useful in calculating the resistance between two electrodes, and is further particularly useful when resistance is measured using a biphasic pulse. The sample and hold circuitry is flexible, and can be used to measure other voltages of interest during biphasic or monophasic pulsing.

Abstract: Timing channel circuitry for controlling stimulation circuitry in an implantable stimulator is disclosed. The timing channel circuitry comprises a addressable memory. Data for the various phases of a desired pulse are stored in the memory using different numbers of words, including a command indicative of the number of words in the phase, a next address for the next phase stored in the memory, and a pulse width or duration of the current phase, control data for the stimulation circuitry, pulse amplitude, and electrode data. The command data is used to address through the words in the current phase via the address bus, which words are sent to a control register for the stimulation circuitry. After the duration of the pulse width for the current phase has passed, the stored next address is used to access the data for the next phase stored in the memory.

Abstract: A method for configuring stimulation pulses in an implantable stimulator device having a plurality of electrodes is disclosed, which method is particularly useful in adjusting the electrodes by current steering during initialization of the device. In one aspect, a set of ideal pulses for patient therapy is determined, in which at least two of the ideal pulses are of the same polarity and are intended to be simultaneous applied to corresponding electrodes on the implantable stimulator device during an initial duration. These pulses are reconstructed into fractionalized pulses, each comprised of pulse portions. The fractionalized pulses are applied to the corresponding electrodes on the device during a final duration, but the pulse portions of the fractionalized pulses are not simultaneously applied during the final duration.

Abstract: An algorithm programmed into the control circuitry of a rechargeable-battery Implantable Medical Device (IMD) is disclosed that can quantitatively forecast and determine the timing of an early replacement indicator (tEOLi) and an IMD End of Life (tEOL). These forecasts and determinations of tEOLi and tEOL occur in accordance with one or more parameters having an effect on rechargeable battery capacity, such as number of charging cycles, charging current, discharge depth, load current, and battery calendar age. The algorithm consults such parameters as stored over the history of the operation of the IMD in a parameter log, and in conjunction with a battery capacity database reflective of the effect of these parameters on battery capacity, determines and forecasts tEOLi and tEOL. Such forecasted or determined values may also be used by a shutdown algorithm to suspend therapeutic operation of the IMD.

Abstract: Methods and circuitry for determining an implanted-neurostimulator patient's position, and adjusting a situation program delivered by the neurostimulator based on the determined position, is disclosed. Impedance measurements of the patient's tissue are taken at the neurostimulator's electrodes, which measurements can comprise complex impedance measurements (magnitude and phase) taken at different frequencies. Such impedance measurements, which can be taken interleaved with stimulation therapy, are used to determine an “impedance fingerprint.” This fingerprint can be compared to other known fingerprints stored in the IPG, which known fingerprints are associated with particular stimulation programs. When a measured fingerprint matches one stored in the IPG, the stimulation program associated with the stored fingerprint is automatically used for patient therapy.

Abstract: An implantable medical device system includes an implantable medical device for providing stimulation therapy and two external power sources. A first external power source is used to power the implantable medical device when the stimulation therapy is low energy therapy. For example, the first external power device may be utilized to periodically recharge a battery in the implantable medical device. The second external power device may be utilized to power the implantable medical device when the stimulation therapy is high energy therapy. The second external power device may be a disposable patch that is affixed to a patient's skin to provide continuous power to the implantable medical device. The implantable medical device may communicate data to such a power device to cause it to adjust a strength of the charging field that it generates.

Abstract: A neuromodulation system configured for providing sub-threshold neuromodulation therapy to a patient. The neuromodulation system comprises a neuromodulation lead having at least one electrode configured for being implanted along a spinal cord of a patient, a plurality of electrical terminals configured for being respectively coupled to the at least one electrode, modulation output circuitry configured for delivering sub-threshold modulation energy to active ones of the at least one electrode, and control/processing circuitry configured for selecting a percentage from a plurality of percentages based on a known longitudinal location of the neuromodulation lead relative to the spinal cord, computing an amplitude value as a function of the selected percentage, and controlling the modulation output circuitry to deliver sub-threshold modulation energy to the patient at the computed amplitude value.

Abstract: A method and system of providing therapy to a patient implanted with an array of electrodes is provided. A train of electrical stimulation pulses is conveyed within a stimulation timing channel between a group of the electrodes to stimulate neural tissue, thereby providing continuous therapy to the patient. Electrical parameter is sensed within a sensing timing channel using at least one of the electrodes, wherein the first stimulation timing channel and sensing timing channel are coordinated, such that the electrical parameter is sensed during the conveyance of the pulse train within time slots that do not temporally overlap any active phase of the stimulation pulses.

Abstract: Timing channel circuitry for controlling stimulation circuitry in an implantable stimulator is disclosed. The timing channel circuitry comprises a addressable memory. Data for the various phases of a desired pulse are stored in the memory using different numbers of words, including a command indicative of the number of words in the phase, a next address for the next phase stored in the memory, and a pulse width or duration of the current phase, control data for the stimulation circuitry, pulse amplitude, and electrode data. The command data is used to address through the words in the current phase via the address bus, which words are sent to a control register for the stimulation circuitry. After the duration of the pulse width for the current phase has passed, the stored next address is used to access the data for the next phase stored in the memory.

Abstract: Battery management circuitry for an implantable medical device such as an implantable neurostimulator is described. The circuitry has a T-shape with respect to the battery terminal, with charging circuitry coupled between rectifier circuitry and the battery terminal on one side of the T, and load isolation circuitry coupled between the load and the battery terminal on the other side. The load isolation circuitry can comprise two switches wired in parallel. An undervoltage fault condition opens both switches to isolate the battery terminal from the load to prevent further dissipation of the battery. Other fault conditions will open only one the switches leaving the other closed to allow for reduced power to the load to continue implant operations albeit at safer low-power levels. The battery management circuitry can be fixed in a particular location on an integrated circuit which also includes for example the stimulation circuitry for the electrodes.

Abstract: An external charger for a battery in an implantable medical device and charging techniques are disclosed. 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 constrains the charging circuitry from producing an inordinate amount of heat to the tissue surrounding the implant, and duty cycles of a charging field are determined so as not to exceed that limit. 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 is determined and stored in the external charger. During charging, the actual value for that parameter is determined, and the intensity and/or duty cycle of the charging field are adjusted to ensure that charging is as fast as possible, while still not exceeding the power dissipation limit.

Abstract: The disclosed techniques allow for externalizing errors from an implantable medical device using the device's charging coil, for receipt at an external charger or other external device. Transmission of errors in this manner is particularly useful when telemetry of error codes through a traditional telemetry coil in the implant is not possible, for example, because the error experienced is so fundamental as to preclude use of such traditional means. By externalizing the error via the charging coil, and though the use of robust error modulation circuitry in the implant designed to be generally insensitive to fundamental errors, the external charger can be consulted to understand the failure mode involved, and to take appropriate action.

Abstract: An improved architecture for an implantable medical device using a primary battery is disclosed which reduces the circumstances in which the voltage of the primary battery is boosted, and hence reduces the power draw in the implant. The architecture includes a boost converter for selectively boosting the voltage of the primary battery and for supplying that boosted voltage to certain of the circuit blocks, including digital circuitry, analog circuitry, and memory. However, the boost converter is only used to boost the battery voltage when its magnitude is below a threshold; if above the threshold, the battery voltage is passed to the circuit blocks without boosting. Additionally, some circuitry capable of operation even at low battery voltages—including the telemetry tank circuitry and the compliance voltage generator—receives the battery voltage directly without boosting, and without regard to the current magnitude of the battery voltage.