Abstract: An example of a system may include electrodes on at least one lead configured to be operationally positioned for use in modulating a volume of neural tissue, where the neural tissue has an activation function. The system may further include a neural modulation generator configured to deliver energy using at least some electrodes to generate a modulation field within the volume of neural tissue. The neural modulation generator may be configured to use a programmed modulation parameter set to generate the modulation field. The programmed modulation parameter set having values selected to control energy delivery using the at least some electrodes to achieve an objective function specific to the activation function of the volume of neural tissue to promote uniformity of a response to the modulation field in the volume of neural tissue along a span of the at least one lead.

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: The problem of a potentially high amount of supra-threshold charge passing through the patient's tissue at the end of an Implantable Pulse Generator (IPG) program is addressed by circuitry that periodically dissipates only small amount of the charge stored on capacitances (e.g., DC-blocking capacitors) during a pulsed post-program recovery period. This occurs by periodically activating control signals to turn on passive recovery switches to form a series of discharge pulses each dissipating a sub-threshold amount of charge. Such periodic pulsed dissipation may extend the duration of post-program recovery, but is not likely to be noticeable by the patient when the programming in the IPG changes from a first to a second program. Periodic pulsed dissipation of charge may also be used during a program, such as between stimulation pulses.

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: A neuromodulation system and method of providing sub-threshold modulation therapy. Electrical modulation energy is delivered to a target tissue site of the patient at a programmed intensity value, thereby providing therapy to a patient without perception of stimulation. In response to an event, electrical modulation energy is delivered at incrementally increasing intensity values. At least one evoked compound action potential (eCAP) is sensed in a population of neurons at the target tissue site of the patient in response to the delivery of the electrical modulation energy at the incrementally increasing intensity values. One of the incrementally increased intensity values is selected based on the sensed eCAP(s). A decreased intensity value is automatically computed as a function of the selected intensity value. Electrical modulation energy is delivered to the target tissue site of the patient at the computed intensity value, thereby providing sub-threshold therapy to the patient.

Abstract: This document discusses, among other things, systems and methods to provide a paresthesia therapy to a patient using an implantable neuromodulation system, wherein providing the paresthesia therapy may include delivering to the patient an electrical waveform having a duration and a distribution of frequencies in the range of 0.001 kHz to 20 kHz, wherein the distribution of frequencies includes a first frequency group of one or more frequencies and a second frequency group of one or more frequencies, and wherein the patient continuously experiences paresthesia throughout the duration of the electrical waveform.

Abstract: The problem of a potentially high amount of supra-threshold charge passing through the patient's tissue at the end of an Implantable Pulse Generator (IPG) program is addressed by circuitry that periodically dissipates only small amount of the charge stored on capacitances (e.g., DC-blocking capacitors) during a pulsed post-program recovery period. This occurs by periodically activating control signals to turn on passive recovery switches to form a series of discharge pulses each dissipating a sub-threshold amount of charge. Such periodic pulsed dissipation may extend the duration of post-program recovery, but is not likely to be noticeable by the patient when the programming in the IPG changes from a first to a second program. Periodic pulsed dissipation of charge may also be used during a program, such as between stimulation pulses.

Abstract: A neuromodulation system and method of providing sub-threshold modulation therapy. Electrical modulation energy is delivered to a target tissue site of the patient at a programmed intensity value, thereby providing therapy to a patient without perception of stimulation. In response to an event, electrical modulation energy is delivered at incrementally increasing intensity values. At least one evoked compound action potential (eCAP) is sensed in a population of neurons at the target tissue site of the patient in response to the delivery of the electrical modulation energy at the incrementally increasing intensity values. One of the incrementally increased intensity values is selected based on the sensed eCAP(s). A decreased intensity value is automatically computed as a function of the selected intensity value. Electrical modulation energy is delivered to the target tissue site of the patient at the computed intensity value, thereby providing sub-threshold therapy to the patient.

Abstract: A current generation architecture for an implantable stimulator device such as an Implantable Pulse Generator (IPG) is disclosed. Current source and sink circuitry are both divided into coarse and fine portions, which respectively can provide coarse and fine current resolutions to a specified electrode on the IPG. The coarse portion is distributed across all of the electrodes and so can source or sink current to any of the electrodes. The coarse portion is divided into a plurality of stages, each of which is capable via an associated switch bank of sourcing or sinking a coarse amount of current to or from any one of the electrodes on the device. The fine portion of the current generation circuit preferably includes source and sink circuitry dedicated to each of the electrode on the device, which can comprise digital-to-analog current converters (DACs).

Abstract: Recovery circuitry for passively recovering charge from capacitances at electrodes in an Implantable Pulse Generator (IPG) is disclosed. The passive recovery circuitry includes passive recovery switches intervening between each electrode node and a common reference voltage, and each switch is in series with a variable resistance that may be selected based on differing use models of the IPG. The passive recovery switches may also be controlled in different modes. For example, in a first mode, the only recovery switches closed after a stimulation pulse are those associated with electrodes used to provide stimulation. In a second mode, all recovery switches are closed after a stimulation pulse, regardless of the electrodes used to provide stimulation. In a third mode, all recovery switches are closed continuously, which can provide protection when the IPG is in certain environments (e.g., MRI), and which can also be used during stimulation therapy itself.

Abstract: An external control device and method for programming an implantable neuromodulator coupled to an electrode array implanted adjacent tissue of a patient having a medical condition. Electrical modulation energy is conveyed to tissue of the patient in accordance with a series of modulation parameter sets. The patient perceives paresthesia in response to the conveyance of the electrical modulation energy to the tissue in accordance with at least one of the modulation parameter sets. One of the modulation parameter set(s) is identified based on the perceived paresthesia. Another modulation parameter set is derived from the identified modulation parameter set. Electrical modulation energy is conveyed to the tissue of the patient in accordance with the other modulation parameter set without causing the patient to perceive paresthesia. An external control device, neuromodulation system, and method of providing therapy to a patient.

Abstract: Recovery circuitry for passively recovering charge from capacitances at electrodes in an Implantable Pulse Generator (IPG) is disclosed. The passive recovery circuitry includes passive recovery switches intervening between each electrode node and a common reference voltage, and each switch is in series with a variable resistance that may be selected based on differing use models of the IPG. The passive recovery switches may also be controlled in different modes. For example, in a first mode, the only recovery switches closed after a stimulation pulse are those associated with electrodes used to provide stimulation. In a second mode, all recovery switches are closed after a stimulation pulse, regardless of the electrodes used to provide stimulation. In a third mode, all recovery switches are closed continuously, which can provide protection when the IPG is in certain environments (e.g., MRI), and which can also be used during stimulation therapy itself.

Abstract: Disclosed herein are circuits and methods for a multi-electrode implantable stimulator device incorporating one decoupling capacitor in the current path established via at least one cathode electrode and at least one anode electrode. In one embodiment, the decoupling capacitor may be hard-wired to a dedicated anode on the device. The cathodes are selectively activatable via stimulation switches. In another embodiment, any of the electrodes on the devices can be selectively activatable as an anode or cathode. In this embodiment, the decoupling capacitor is placed into the current path via selectable anode and cathode stimulation switches. Regardless of the implementation, the techniques allow for the benefits of capacitive decoupling without the need to associate decoupling capacitors with every electrode on the multi-electrode device, which saves space in the body of the device.

Abstract: An external control device, neuromodulation system, and method of providing therapy to a patient using an implantable neuromodulator implanted within the patient. Electrical modulation energy is delivered from the neuromodulator to the patient in accordance with the pre-existing modulation program when in one of the super-threshold delivery mode and the sub-threshold delivery mode. Operation of the neuromodulator is switched to the other of the super-threshold delivery mode and the sub-threshold delivery mode. A new modulation program may be derived from a pre-existing modulation program, and the neuromodulator may deliver the electrical modulation energy to the patient in accordance with the pre-existing modulation program during the other of the super-threshold delivery mode and the sub-threshold delivery mode.

Abstract: A new architecture is disclosed for an IPG having a master and slave electrode driver integrated circuits (ICs). The electrode outputs on the ICs are wired together. Each IC can be programmed to provide pulses with different frequencies. Active timing channels in master and slave ICs 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 IC 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: 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: A new architecture is disclosed for an IPG having a master and slave electrode driver integrated circuits (ICs). The electrode outputs on the ICs are wired together. Each IC can be programmed to provide pulses with different frequencies. Active timing channels in master and slave ICs 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 IC 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: An algorithm programmed into the control circuitry of a rechargeable-battery Implantable Medical Device (IMD) is disclosed that can adjust the charging current (Ibat) provided to the rechargeable battery over time (e.g., the life of the IMD) in accordance with one or more of the 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, estimates a change in the capacity of the battery, and adjust the charging current in one or both of trickle and active charging paths to slow the loss of battery capacity and extend the life of the IMD.

Abstract: An Implantable Pulse Generator (IPG) or External Trial Stimulator (ETS) system is disclosed that is capable of sensing an Evoked Compound Action Potential (ECAP), and (perhaps in conjunction with an external device) is capable of adjusting a stimulation program while keeping a location of a Central Point of Stimulation (CPS) constant. Specifically, one or more features of measured ECAP(s) indicative of its shape and size are determined, and compared to thresholds or ranges to modify the electrode configuration of the stimulation program.

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.