Abstract: An implantable medical device capable of being placed between a first operational mode and a second operational mode. The medical device comprises a magnetic field sensing device configured for outputting a signal in response to sensing a magnetic field. The medical device further comprises a logic circuit configured for continuously asserting the signal during a time period when the neurostimulation device is in the first operational mode, and intermittently asserting the signal during at least one time period when the neurostimulation device is in the second operational mode. The medical device further comprises a delay circuit configured for introducing a time delay into the asserted signal, the time delay being less than the time period, but greater than each of the at least one time period. The medical device further comprises control circuitry configured for performing a function in response to receiving the delayed signal at a first input terminal.

Abstract: An improved implantable pulse generator (IPG) containing improved telemetry circuitry is disclosed. The IPG includes charging and telemetry coils within the IPG case, which increases their mutual inductance and potential to interfere with each other; particularly problematic is interference to the telemetry coil caused by the charging coil. To combat this, improved telemetry circuitry includes decoupling circuitry for decoupling the charging coil during periods of telemetry between the IPG and an external controller. Such decoupling circuitry can comprise use of pre-existing LSK circuitry during telemetry, or new discrete circuitry dedicated to decoupling. The decoupling circuitry is designed to prevent or at least reduce induced current flowing through the charging coil during data telemetry.

Abstract: A neurostimulation device capable of being placed between an active stimulation state and an inactive stimulation state and method of using same. The neurostimulation device comprises a plurality of electrical terminals configured for being respectively coupled to a plurality of stimulation electrodes, a first solid-state switching device coupled to a first one of the electrical terminals, a variable power source coupled to the first switching device, and a controller configured for, when the neurostimulation device is in the inactive stimulation state, prompting the variable power source to selectively output a relatively low voltage to place the first switching device into a first open state and a relatively high voltage to place the first switching device into a second open state.

Abstract: Combination charging and telemetry circuit for use within an implantable medical device uses a single coil for both charging and telemetry that is controlled via the use of an opto-switch. One or more capacitors are used to tune the coil to different frequencies for receiving power from an external device and for the telemetry of information to and from an external device. The opto-switch is coupled to the resonant circuit, but because its input is electrically decoupled from its output, it easy to control.

Abstract: Communication and charging circuitry for an implantable medical device is described having a single coil for receiving charging energy and for data telemetry. The circuitry removes from the AC side of the circuit a tuning capacitor and switch traditionally used to tune the tank circuitry to different frequencies for telemetry and charging. As such, the tank circuitry is simplified and contains no switchable components. A switch is serially connected to the storage capacitor on the DC side of the circuit. During telemetry, the switch is opened, thus disconnecting the storage capacitor from the tank circuit, and alleviating concerns that this capacitor will couple to the tank circuit and interfere with telemetry operations. During charging, the switch is closed, which allows the storage capacitor to couple to the tank circuitry through the rectifier during some portions of the tank circuitry's resonance.

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: 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: A stimulator includes an implantable pulse generator comprising circuit elements, a first power source, such as an ultracapacitor, that provides operating power for the circuit elements of the pulse generator. The pulse generator can also have a memory associated therewith, such as a volatile memory for storing programming data. A second power source that has higher voltage retention than the first power source can also be included. The second power source can be dedicated to the volatile memory and can provide operating power for the volatile memory.

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: Architectures 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. A parallel bus operating in accordance with a communication protocol couples the ICs, and certain functional blocks not needed in the slave are disabled. Stimulation parameters are loaded via the bus into each IC, and a stimulation enable command is issued on the bus to ensure simultaneous stimulation from the electrodes on both ICs. Clocking strategies are also disclosed to allow clocking of the master and slave ICs to be independently controlled, and to ensure that relevant internal and bus clocks used in the system are synchronized.

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: 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 improved implantable pulse generator (IPG) containing improved telemetry circuitry is disclosed. The IPG includes charging and telemetry coils within the IPG case, which increases their mutual inductance and potential to interfere with each other; particularly problematic is interference to the telemetry coil caused by the charging coil. To combat this, improved telemetry circuitry includes decoupling circuitry for decoupling the charging coil during periods of telemetry between the IPG and an external controller. Such decoupling circuitry can comprise use of pre-existing LSK circuitry during telemetry, or new discrete circuitry dedicated to decoupling. The decoupling circuitry is designed to prevent or at least reduce induced current flowing through the charging coil during data telemetry.

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 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: 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: 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: 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: A stimulator includes an implantable pulse generator comprising circuit elements, a first power source, such as an ultracapacitor, that provides operating power for the circuit elements of the pulse generator. The pulse generator can also have a memory associated therewith, such as a volatile memory for storing programming data. A second power source that has higher voltage retention than the first power source can also be included. The second power source can be dedicated to the volatile memory and can provide operating power for the volatile memory.