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: An exemplary system for communicating with an implantable stimulator includes a coil configured to transmit a signal modulated with either on-off keying (OOK) modulation or Frequency Shift Keying (FSK) modulation. The system further includes a first telemetry receiver in the implantable stimulator configured to receive the signal in accordance with the OOK modulation and a second telemetry receiver in the implantable stimulator configured to receive the signal in accordance with the FSK modulation.

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: 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 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 implantable microstimulator configured for implantation beneath a patient's skin for tissue stimulation to prevent and/or treat various disorders, uses a self-contained power source. Periodic or occasional replenishment of the power source is accomplished, for example, by inductive coupling with an external device. A bidirectional telemetry link allows the microstimulator to provide information regarding the system's status, including the power source's charge level, and stimulation parameter states. Processing circuitry automatically controls the applied stimulation pulses to match a set of programmed stimulation parameters established for a particular patient. The microstimulator preferably has a cylindrical hermetically sealed case having a length no greater than about 27 mm and a diameter no greater than about 3.3 mm. A reference electrode is located on one end of the case and an active electrode is located on the other end.

Abstract: One embodiment is an implantable control module for coupling to one or more implantable stimulation leads. The control module includes a sealed housing, an electronic subassembly disposed in the housing, a header arrangement coupled to the housing, and a number of feedthrough elements. The header arrangement includes at least one receiving lumen and a number of contacts disposed within the at least one lumen. Each receiving lumen has two opposing openings which can receive an implantable stimulation lead through the opening and within the receiving lumen. The contacts are arranged within the at least one receiving lumen to make contact with (or otherwise be in electrical communication with) terminals at or on the stimulation lead received in the receiving lumen. The feedthrough elements extend from the header arrangement into the sealed housing, and electrically couple the contacts of the header arrangement with the electronic subassembly.

Abstract: An implantable microstimulator configured for implantation beneath a patient's skin for tissue stimulation to prevent and/or treat various disorders, uses a self-contained power source. Periodic or occasional replenishment of the power source is accomplished, for example, by inductive coupling with an external device. A bidirectional telemetry link allows the microstimulator to provide information regarding the system's status, including the power source's charge level, and stimulation parameter states. Processing circuitry automatically controls the applied stimulation pulses to match a set of programmed stimulation parameters established for a particular patient. The microstimulator preferably has a cylindrical hermetically sealed case having a length no greater than about 27 mm and a diameter no greater than about 3.3 mm. A reference electrode is located on one end of the case and an active electrode is located on the other end.

Abstract: A programmable linear voltage regulator and system for programming the regulator that improves the speed, power usage, and stability over conventional linear voltage regulators is disclosed. A controller that has knowledge of the current or expected activation of various loads sends bias control signals to a programmable biasing circuit of an error amplifier in the voltage regulator to adjust the bias current in accordance with the load current the regulator produces or is expected to produce. A look up table associated with the controller can be used to correlate the bias control signals with current or expected load conditions. Programming of the programmable biasing circuit may precede the enablement of a new load condition to ready the voltage regulator to handle the upcoming change in load current.

Abstract: Timer circuitry completely formable in an integrated circuit (IC) for generating a clock signal in an implantable medical device is disclosed. The timer circuitry can be formed on the same Application Specific Integrated Circuit typically used in the implant, and requires no external components. The timer circuitry comprises modification to a traditional astable timer circuit. A resistance in the disclosed timer circuit can be trimmed to adjust the frequency of the clock signal produced, thus allowing that frequency to be set to a precise value during manufacturing. Precision components are not needed in the RC circuit, which instead are used to set the rough value of the frequency of the clock signal. A regulator produces a power supply for the timer circuitry from a main power supply (Vcc), producing a clock signal with a frequency that is generally independent of temperature and Vcc fluctuations.

Abstract: A closed loop system is disclosed for monitoring patient movements, such as tremors, and for automatically controlling an implantable stimulator device on the basis of the detected movements. The system includes a motion sensor such as a wearable item that contains an accelerometer to monitor a patient's movements, such as a ring locatable proximate to a patient's hand tremor. The motion sensor periodically transmits a feedback signal to the implantable stimulator device instructing it to change the stimulation parameters, such as current amplitude, in an attempt to reduce the tremor. The motion sensor can additionally communicate with other system components such as an external controller. In a preferred embodiment, the motion sensor and the implantable stimulator device communicate using short range electromagnetic radio waves.

Abstract: An implantable microstimulator configured to be implanted beneath a patient's skin for tissue stimulation employs a bi-directional RF telemetry link for allowing data-containing signals to be sent to and from the implantable microstimulator from at least two external devices. Further, a separate electromagnetic inductive telemetry link allows data containing signals to be sent to the implantable microstimulator from at least one of the two external devices. The RF bidirectional telemetry link allows the microstimulator to inform the patient or clinician regarding the status of the microstimulator device, including the charge level of a power source, and stimulation parameter states. The microstimulator has a cylindrical hermetically sealed case having a length no greater than about 27 mm and a diameter no greater than about 3.3 mm. A reference electrode is located on one end of the case and an active electrode is located on the other end of the case.

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 exemplary system for communicating with an implantable stimulator includes a coil configured to transmit a signal modulated with either on-off keying (OOK) modulation or Frequency Shift Keying (FSK) modulation. The system further includes a first telemetry receiver in the implantable stimulator configured to receive the signal in accordance with the OOK modulation and a second telemetry receiver in the implantable stimulator configured to receive the signal in accordance with the FSK modulation.

Abstract: An exemplary system for communicating with an implantable stimulator includes a coil configured to transmit a signal modulated with either on-off keying (OOK) modulation or Frequency Shift Keying (FSK) modulation. The system further includes a first telemetry receiver in the implantable stimulator configured to receive the signal in accordance with the OOK modulation and a second telemetry receiver in the implantable stimulator configured to receive the signal in accordance with the FSK modulation.

Abstract: An implantable microstimulator configured for implantation beneath a patient's skin for tissue stimulation to prevent and/or treat various disorders, uses a self-contained power source. Periodic or occasional replenishment of the power source is accomplished, for example, by inductive coupling with an external device. A bidirectional telemetry link allows the microstimulator to provide information regarding the system's status, including the power source's charge level, and stimulation parameter states. Processing circuitry automatically controls the applied stimulation pulses to match a set of programmed stimulation parameters established for a particular patient. The microstimulator preferably has a cylindrical hermetically sealed case having a length no greater than about 27 mm and a diameter no greater than about 3.3 mm. A reference electrode is located on one end of the case and an active electrode is located on the other end.

Abstract: An implantable microstimulator configured to be implanted beneath a patient's skin for tissue stimulation employs a bi-directional RF telemetry link for allowing data-containing signals to be sent to and from the implantable microstimulator from at least two external devices. Further, a separate electromagnetic inductive telemetry link allows data containing signals to be sent to the implantable microstimulator from at least one of the two external devices. The RF bidirectional telemetry link allows the microstimulator to inform the patient or clinician regarding the status of the microstimulator device, including the charge level of a power source, and stimulation parameter states. The microstimulator has a cylindrical hermetically sealed case having a length no greater than about 27 mm and a diameter no greater than about 3.3 mm. A reference electrode is located on one end of the case and an active electrode is located on the other end of the case.

Abstract: An improved architecture for an implantable medical device such as an implantable pulse generator (IPG) is disclosed. In one embodiment, the various functional blocks for the IPG are incorporated into a signal integrated circuit (IC). Each of the functional blocks communicate with each other, and with other off-chip devices if necessary, via a centralized bus governed by a communication protocol. To communicate with the bus and to adhere to the protocol, each circuit block includes bus interface circuitry adherent with that protocol. Because each block complies with the protocol, any given block can easily be modified or upgraded without affecting the design of the other blocks, facilitating debugging and upgrading of the IPG circuitry. Moreover, because the centralized bus can be taken off the integrated circuit, extra circuitry can easily be added off chip to modify or add functionality to the IPG without the need for a major redesign of the main IPG IC.

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: Circuitry for generating a compliance voltage (V+) for the current sources and/or sinks in an implantable stimulator device is disclosed. The improved compliance voltage generation circuitry adjusts V+ to an optimal value in real time, even during the provision of a stimulation current. The circuitry uses amplifiers to measure the voltage drop across an active PDACs (current sources) and/or NDAC (current sinks) The measured voltages are input to a V+ regulator, which compares the measured voltage drops across the DACs to optimal values, and which feeds an optimized value for V+ back to the DACs in real time to keep the voltage drop(s) at those optimal levels during the stimulation current for efficient DAC operation.