Rechargeable spinal cord stimulator system

A spinal cord stimulation system comprising:

• a multi-channel implantable pulse generator (IPG) having a replenishable power source, the IPG having a housing which contains IPG processing circuitry;
• an implantable electrode array detachably connected to the IPG, the electrode array having a multiplicity of n electrodes (En) thereon;
• and
• a multiplicity of m stimulation channels provided by the IPG, wherein each stimulation channel is independently programmable with different stimulation parameters,
• wherein m is equal to or less than n, and m is 2 or greater;
• wherein the IPG includes an independent, bi-directional current source, connected to each of the n electrodes;
• wherein each of the bi-directional current sources is electrically connected through a coupling capacitor to one of the n electrodes;
• and
• wherein each of the bi-directional current sources may be separately controlled to actively direct a current pulse of a selected amplitude and polarity to its respectively-connected electrode.

A spinal cord stimulation system comprising:

• a multi-channel implantable pulse generator (IPG) having a replenishable power source, the IPG having a housing which contains IPG processing circuitry;
• an implantable electrode array detachably connected to the IPG, the electrode array having a multiplicity of n electrodes (En) thereon;
• a multiplicity of m stimulation channels provided by the IPG, wherein each stimulation channel is independently programmable with different stimulation parameters,
• wherein m is equal to or less than n, and m is 2 or greater;
• an indifferent electrode,
• wherein the n electrodes and the indifferent electrode may be selectively grouped into at least m sets of electrodes, each set representing an independently controllable stimulation channel, each set having at least two electrodes,
• thereby providing m stimulation channels that may be either monopolar or bipolar electrode configurations;
• wherein a current pulse is generated for a first channel by actively directing a pulse of a respective amplitude and polarity for a time period equal to a selected pulse width to a first group of anodic electrodes within the first channel, while actively directing a current pulse of a respective amplitude and opposite polarity for the selected pulse width to a second group of cathodic electrodes within the first channel, the sum of all the anodic amplitude currents in the first channel being equal to the sum of all the cathodic amplitude currents, whereby charge balance is maintained in the first channel;
• and
• wherein a current pulse is generated for a second channel by actively directing a second current pulse of a respective amplitude and polarity form time period equal to a selected second pulse width to a selected group of anodic electrodes within the second channel, while actively directing a second current pulse of a respective amplitude and opposite polarity for the selected second pulse width to a selected group of cathodic electrodes within the second channel, the sum of all the anodic amplitude currents in the second channel being equal to the sum of all the cathodic amplitude currents, whereby charge balance is maintained in the second channel;
• and wherein a current pulse is similarly generated for each of the m channels, whereby charge balance is maintained in each of the m channels.

A spinal cord stimulation system comprising:

• a multi-channel implantable pulse generator (IPG) having a replenishable power source, the IPG having a housing which contains IPG processing circuitry;
• an implantable electrode array detachably connected to the IPG, the electrode array having a multiplicity of n electrodes (En) thereon;
• a multiplicity of m stimulation channels provided by the IPG, wherein each stimulation channel is independently programmable with different stimulation parameters,
• wherein m is equal to or less than n, and m is 2 or greater;
• an indifferent electrode,
• wherein the n electrodes and the indifferent electrode may be selectively grouped into at least m sets of electrodes, each set representing an independently controllable stimulation channel, each set having at least two electrodes,
• thereby providing m stimulation channels that may be either monopolar or bipolar electrode configurations;
• and
• an arbitration means for selectively preventing overlap of current pulses amongst the m channels.

A spinal cord stimulation system comprising:

• a multi-channel implantable pulse generator (IPG) having a replenishable power source, the IPG having a housing which contains IPG processing circuitry;
• an implantable electrode array detachably connected to the IPG, the electrode array having a multiplicity of n electrodes (En) thereon;
• a multiplicity of m stimulation channels provided by the IPG, wherein each stimulation channel is independently programmable with different stimulation parameters,
• wherein m is equal to or less than n, and m is 2 or greater;
• an indifferent electrode,
• wherein the n electrodes and the indifferent electrode may be selectively grouped into at least m sets of electrodes, each set representing an independently controllable stimulation channel, each set having at least two electrodes,
• thereby providing m stimulation channels that may be either monopolar or bipolar electrode configurations;
• and
• a low impedance switching matrix within the IPG, the switching matrix having a multiplicity of input ports selectively connected to a multiplicity of output nodes, each output node coupled to one of the n electrodes and the indifferent electrode, whereby connections to any subset of the n number of electrodes and the indifferent electrode is permitted.

A spinal cord stimulation system comprising:

• a multi-channel implantable pulse generator (IPG) having a replenishable power source, the IPG having a housing which contains IPG processing circuitry;
• an implantable electrode array detachably connected to the IPG, the electrode array having a multiplicity of n electrodes (En) thereon;
• a multiplicity of m stimulation channels provided by the IPG, wherein each stimulation channel is independently programmable with different stimulation parameters,
• wherein m is equal to or less than n, and m is 2 or greater;
• an indifferent electrode,
• wherein the n electrodes and the indifferent electrode may be selectively grouped into at least m sets of electrodes, each set representing an independently controllable stimulation channel, each set having at least two electrodes,
• thereby providing m stimulation channels that may be either monopolar or bipolar electrode configurations;
• and
• programmable output current digital to analog converters connected to each electrode node,
• wherein any electrode node, when enabled, can be grouped with any other electrode node that is enabled at the same time to form the m sets of electrodes, each set representing a channel.

A spinal cord stimulation system comprising:

• a multi-channel implantable pulse generator (IPG) having a replenishable power source, the IPG having a housing which contains IPG processing circuitry;
• an implantable electrode array detachably connected to the IPG, the electrode array having a multiplicity of n electrodes (En) thereon;
• a multiplicity of m stimulation channels provided by the IPG, wherein each stimulation channel is independently programmable with different stimulation parameters,
• wherein m is equal to or less than n, and m is 2 or greater;
• external components including a handhold programmer that may be selectively placed in telecommunicative contact with the IPG;
• a clinician programmer that is selectively coupled with the handheld programmer (HHP);
• and
• a portable charger that may be inductively coupled with the IPG in order to recharge the IPG power source.

A spinal cord stimulation system comprising:

• a multi-channel implantable pulse generator (IPG) having a replenishable power source, the IPG having a housing which contains IPG processing circuitry;
• an implantable electrode array detachably connected to the IPG, the electrode array having a multiplicity of n electrodes (En) thereon;
• a multiplicity of m stimulation channels provided by the IPG, wherein each stimulation channel is independently programmable with different stimulation parameters,
• wherein m is equal to or less than n, and m is 2 or greater;
• an external trial stimulator (ETS);
• and
• a percutaneous extension which temporarily couples the ETS with the implantable electrode array.

A spinal cord stimulation system comprising:

• a multi-channel implantable pulse generator (IPG) having a replenishable power source, the IPG having a housing which contains IPG processing circuitry;
• an implantable electrode array detachably connected to the IPG, the electrode array having a multiplicity of n electrodes (En) thereon;
• and
• a multiplicity of m stimulation channels provided by the IPG, wherein each stimulation channel is independently programmable with different stimulation parameters,
• wherein m is equal to or less than n, and m is 2 or greater;
• wherein the replenishable power source in the IPG comprises a rechargeable battery, and
• wherein the rechargeable battery is a lithium-ion battery having at least 720 mWhr capacity.

A spinal cord stimulation system comprising:

• a multi-channel implantable pulse generator (IPG) having a replenishable power source, the IPG having a housing which contains IPG processing circuitry;
• an implantable electrode array detachably connected to the IPG, the electrode array having a multiplicity of n electrodes (En) thereon;
• a multiplicity of m stimulation channels provided by the IPG, wherein each stimulation channel is independently programmable with different stimulation parameters,
• wherein m is equal to or less than n, and m is 2 or greater;
• and
• wherein the IPG contains independent, bi-directional output current sources connected to each of the n electrodes, thereby providing independently programmable, current-controlled, stimulation channels.

A spinal cord stimulation system comprising:

• a multi-channel implantable pulse generator (IPG) having a replenishable power source, the IPG having a housing which contains IPG processing circuitry;
• an implantable electrode array detachably connected to the IPG, the electrode array having a multiplicity of n electrodes (En) thereon;
• a multiplicity of m stimulation channels provided by the IPG, wherein each stimulation channel is independently programmable with different stimulation parameters,
• wherein m is equal to or less than n, and m is 2 or greater;
• and
• an arbitration circuit means for permitting the multiplicity of m stimulation channels to operate concurrently without interference between stimulation channels.

A spinal cord stimulation system comprising:

• a multi-channel implantable pulse generator (IPG) having a replenishable power source, the IPG having a housing which contains IPG processing circuitry;
• an implantable electrode array detachably connected to the IPG, the electrode array having a multiplicity of n electrodes (En) thereon;
• a multiplicity of m stimulation channels provided by the IPG, wherein each stimulation channel is independently programmable with different stimulation parameters,
• wherein m is equal to or less than n, and m is 2 or greater;
• and
• an indifferent electrode,
• wherein the IPG further comprises:
• an impedance measuring circuit to measure the impedance between any two of the n electrodes and the indifferent electrode.

A spinal cord stimulation system comprising:

• a multi-channel implantable pulse generator (IPG) having a replenishable power source, the IPG having a housing which contains IPG processing circuitry;
• an implantable electrode array detachably connected to the IPG, the electrode array having a multiplicity of n electrodes (En) thereon;
• and
• a multiplicity of m stimulation channels provided by the IPG, wherein each stimulation channel is independently programmable with different stimulation parameters,
• wherein m is equal to or less than n, and m is 2 or greater;
• and
• wherein the IPG contains a soft ramping circuit that ramps up the stimulation pulse magnitude at the beginning of a burst of stimulation pulses in at least one channel.

A spinal cord stimulation system comprising:

• implantable components including a multi-channel implantable pulse generator (IPG) having a replenishable power;
• an electrode array detachably connected to the IPG, the electrode array having a multiplicity of n electrodes (En) thereon;
• a real-time clock contained in the IPG to permit an auto-run schedule for operation of the IPG at certain times of the day;
• m independently controllable channels,
• wherein each stimulation channel is independently programmable with different stimulation parameters,
• wherein m is equal to or less than n, and m is 2 or greater;
• and
• an arbitration means for selectively preventing overlap of current pulses amongst the m stimulation channel.

A spinal cord stimulation system comprising:

• implantable components including a multi-channel implantable pulse generator (IPG) having a replenishable power source;
• an electrode array detachably connected to the IPG, the electrode array having a multiplicity of n electrodes (En) thereon;
• a real-time clock contained in the IPG to permit an auto-run schedule for operation of the IPG at certain times of the day;
• and
• an indifferent electrode,
• wherein the n electrodes and the indifferent electrode may be selectively grouped into at least m sets of electrodes, each set representing an independently controllable stimulation channel, each set having at least two electrodes,
• thereby providing m stimulation channels that may be set to either monopolar or bipolar electrode configurations.

A spinal cord stimulation system comprising:

• an implantable, multi-channel implantable pulse generator (IPG) having a replenishable power source;
• an implantable electrode array detachably connected to the IPG, the electrode array having a multiplicity of n electrodes (En) thereon;
• a secondary, implanted coil coupled electrically to the replenishable power source;
• an external battery charger including:
• a primary coil;
• a rechargeable battery contained in the charger, electrically coupled to the primary coil;
• and
• a power amplifier for applying alternating current derived from the rechargeable battery in the charger to the primary coil,
• whereby the alternating current in the primary coil is transcutaneously transferred to the secondary implanted coil to the replenishable power source contained in the IPG;
• and
• a means for using household AC power to charge up the rehargeable battery in the battery charger.

A spinal cord stimulation system comprising:

• an implantable, multi-channel implantable pulse generator (IPG) having a replenishable power source;
• an implantable electrode array detachably connected to the IPG, the electrode array having a multiplicity of n electrodes (En) thereon;
• a secondary, implanted coil coupled electrically to the replenishable power source;
• an external battery charger including:
• a primary coil;
• a rechargeable battery contained in the charger, electrically coupled to the primary coil;
• and
• a power amplifier for applying alternating current derived from the rechargeable battery in the charger to the primary coil,
• whereby the alternating current in the primary coil is transcutaneously transferred to the secondary implanted coil to the replenishable power source contained in the IPG;
• and
• alignment circuitry for detecting alignment between the primary and secondary coils, the alignment circuitry including a back telemetry receiver for monitoring the magnitude of the ac voltage at the primary coil as applied by the power amplifier,
• wherein reflected impedance associated with energy magnetically coupled through the primary coil is monitored.

A spinal cord stimulation system comprising:

• an implantable, multi-channel implantable pulse generator (IPG) having a replenishable power source;
• an implantable electrode array detachably connected to the IPG, the electrode array having a multiplicity of n electrodes (En) thereon;
• a secondary, implanted coil coupled electrically to the replenishable power source;
• an external battery charger including:
• a primary coil;
• a rechargeable battery contained in the charger, electrically coupled to the primary coil;
• and
• a power amplifier for applying alternating current derived from the rechargeable battery in the charger to the primary coil,
• whereby the alternating current in the primary coil is transcutaneously transferred to the secondary implanted coil to the replenishable power source contained in the IPG;
• and
• a charge complete and protection circuitry that detects when the replenishable power source is fully charged, and wherein said replenishable power source comprises a rechargeable battery, said charge complete and protection circuitry comprising:
• monitoring circuitry that monitors the voltage of the rechargeable battery and the charging current flowing to the rechargeable battery;
• and
• a rectifier circuit in the IPG,
• wherein the monitoring circuitry generates a flag signal when the rechargeable battery voltage and charging current reach prescribed levels, which prescribed levels indicate the battery is fully charged;
• wherein the rectifier circuit is switchable between a full-wave rectifier circuit and a half-wave rectifier circuit;
• wherein the rectifier circuit is switched to operate as the full-wave rectifier circuit during charging of the battery, and wherein the flag signal causes the rectifier circuit to switch to a half-wave rectifier circuit when the battery is fully charged, whereby modulation of the rectifier circuit between a full-wave rectifier circuit and a half-wave rectifier circuit is used to indicate whether the battery is fully charged;
• and
• wherein the charge complete detection circuitry detects the switching of the rectifier circuit from a full-wave rectifier circuit to a half-wave rectifier circuit by the change in reflected impedance sensed at the primary coil.

A method for implanting a spinal cord stimulator system into a patient for stimulation therapy, the method comprising:

• (a) implanting a nerve stimulation lead with a distally located, multi-electrode array placed near target tissue, said lead having a lead connector on the proximal end;
• (b) connecting the lead connector to a percutaneous extension;
• (c) externalizing the percutaneous extension through the skin;
• (d) connecting an external trial stimulator (ETS) to the externalized lead extension;
• (e) programming the stimulation parameters at first optimal values;
• (f) waiting a specified period of time and re-programming the stimulation parameters to second optimal values;
• (g) disconnecting the percutaneous extension from the lead connector;
• (h) connecting a multi-channel, implantable pulse generator to the lead connector;
• (i) implanting the implantable pulse generator, while programmed to the second, optimal stimulation parameters.

A method of charging a rechargeable battery contained within an implantable pulse generator (IPG), which IPG is connected to an implanted, secondary coil antenna, the method employing an external battery charger, which charger contains a rechargeable battery electrically connected to an external, primary antenna coil, the method comprising:

• (a) charging the rechargeable battery in the external battery charger using an external power source;
• (b) aligning the primary antenna coil with the implanted secondary coil;
• (c) broadcasting electromagnetic energy through the primary antenna coil;
• (d) receiving the broadcast electromagnetic energy through the secondary antenna coil, whereby an alternating current is produced in the secondary coil;
• (e) rectifying the induced, alternating current received by the secondary coil;
• (f) charging the rechargeable battery carried within the IPG, while monitoring the charging current or voltage across the battery as the battery is being charged to prevent overcharging;
• and
• (g) stopping the charging at the battery charger when the current or voltage at the battery in the IPG reaches a prescribed level.