Abstract: Architectures for implantable stimulators having N electrodes are disclosed. The architectures contains X current sources, or DACs. In a single anode/multiple cathode design, one of the electrodes is designated as the anode, and up to X of the electrodes can be designated as cathodes and independently controlled by one of the X DACs, allowing complex patient therapy and current steering between electrodes. The design uses at least X decoupling capacitors: X capacitors in the X cathode paths, or one in the anode path and X?1 in the X cathode paths. In a multiple anode/multiple cathode design having X DACs, a total of X?1 decoupling capacitors are needed. Because the number of DACs X can typically be much less than the total number of electrodes (N), these architectures minimize the number of decoupling capacitors which saves space, and ensures no DC current injection even during current steering.

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 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: 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: Improved compliance voltage generation circuitry for a medical device is disclosed. The improved circuitry in one embodiment comprises a boost converter and a charge pump, either of which is capable of generating an appropriate compliance voltage from the voltage of the battery in the device. A telemetry enable signal indicating whether the implant's transmitter, receiver, or both, have been enabled is received. A “boost” signal from compliance voltage monitor-and-adjust logic circuitry is processed with the telemetry enable signal and its inverse to selectively enable either the charge pump or the boost converter: if the telemetry enable signal is not active, the boost converter is used to generate the compliance voltage; if the telemetry enable signal is active, the charge pump is used. Because the charge pump circuitry does not produce a magnetic field, the charge pump will not interfere with magnetically-coupled telemetry between the implant and an external controller.

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: Disclosed are implantable electronic devices and systems including a pair of microstimulators. The microstimulators include coils that are energized to generate magnetic fields aligned along a common axis.

Abstract: A method and system of providing therapy to a patient implanted with an array of electrodes is provided. Electrical stimulation current is conveyed from at least two of the electrodes to at least one of the electrodes along at least two electrical paths through tissue of the patient, and the electrical stimulation current is shifted between the electrical paths by actively adjusting one or more finite resistances respectively associated with one or more of the electrical paths.

Abstract: Disclosed are methods for synchronizing the time basis of logged data between an implantable medical device such as an IPG and an external device. The IPG logs various operational parameters as data and associates the same with a possibly-inaccurate IPG time stamp and a sequence number. Periodically, the external device sends accurate true time data to the IPG, which, like the operational parameter data, is logged with an IPG time stamp and a next sequence number. The IPG then orders the data sequences and timing sequences by time stamp in a combined data log, and divides that data log into regions in accordance with reset conditions apparent in the time stamp data. Slopes indicative of the relation between true time and time stamps are calculated for various regions on an intra-region or inter-region basis, which then allows for true time estimates to be calculated for the data sequences, thus providing an accurate time basis for the logged data.

Abstract: An implantable pulse generator or external trial stimulator for coupling to a lead with a distal end and a proximal end, the lead comprising at least one terminal disposed at the proximal end. The implantable pulse generator comprises a connector for receiving the proximal end of the lead, the connector having at least one contact, and a sensor configured and arranged for detecting electrical connectivity between the implantable pulse generator or external trial stimulator and the lead, the sensor comprising at least one sensor contact, the sensor contact being configured and arranged for electrically coupling to a terminal of the lead and at least one of the contacts of the connector when the lead is fully inserted in the connector and thereby detecting electrical connectivity between the implantable pulse generator or external trial stimulator and the lead.

Abstract: A connection monitoring system for an implantable medical lead system includes an implantable lead, a first trial system cable, an external trial system, and a sensor. The lead has a distal end and at least one proximal end. The lead includes a plurality of terminals disposed at each proximal end. The first trial system cable has a distal end and at least one proximal end. The distal end of the first trial system cable is configured and arranged to electrically couple with the lead. The external trial system is configured and arranged to electrically couple with the first trial system cable. The sensor is electrically coupled to the external trial system. The sensor is configured and arranged for detecting a loss of electrical connectivity between the external trial system and the lead when the lead becomes electrically decoupled from the external trial system.

Abstract: A combination charging and telemetry circuit for use within an implantable device, such as a microstimulator, uses a single coil for both charging and telemetry. In accordance with one aspect of the invention, one or more capacitors are used to tune the single coil to different frequencies, wherein the coil is used for multiple purposes, e.g., for receiving power from an external source and also for the telemetry of information to and from an external source.

Abstract: Compact electronic modules, which may be used with implantable microstimulators and other medical and non-medical devices, and manufacture/assembly of such modules are described. Component and circuitry designs utilize unique redistribution techniques and attachment methods. A number of component designs and packaging configurations maximize the volume efficiency of electronic modules. Also included are improved processes and systems enabling the manufacture and assembly of such compact packages.

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 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 improved transceiver circuit particularly useful in an inductively coupled wireless communication system such as an implantable medical device system is disclosed. The improved transceiver circuit is switchable to assume a serial L-C configuration in the transmit mode and a parallel L-C configuration in the receive mode, but does not require high voltage switches. A low-drive transmitter and a high-input-impedance receiver are used, which reduces power consumption in receive mode, while still maintaining good transmitter performance.

Abstract: A method for controlling an implantable medical device is disclosed. In one embodiment, a voltage of a power source within the implantable medical device is monitored. If this voltage is above a first threshold, the implantable medical device enables the following functions: it listens for a first type of telemetry from a first external component; it listens for a second type of telemetry from an external charging component; and it provides stimulation to device electrodes using the power source. By contrast, if the power source voltage falls below the first threshold, the implant discontinues listening for the first type of telemetry from the first external component and discontinues providing stimulation to device electrodes using the power source, but continues to listen for the second type of telemetry.

Abstract: In one embodiment, the present invention provides an implantable stimulation device that includes output current sources and/or sinks configured to provide an output current for a load (i.e., tissue). The output path of the output current source or sink comprises a transistor which operates in a linear mode instead of a saturation mode. Because operation in a linear mode results in smaller drain-to-source voltage drops, power consumption in the output current source or sink (and hence in the implantable stimulator) is reduced, reducing battery or other power source requirements. Operation in the linear mode is facilitated in useful embodiments by a load in an input path (into which a reference current is sent) and a load in the output path (which bears the output current). The loads can be active transistors or passive resistors. A feedback circuit (e.g.

Abstract: In one embodiment, the present invention provides an implantable stimulation device that includes output current sources and/or sinks configured to provide an output current for a load (i.e., tissue). The output path of the output current source or sink comprises a transistor which operates in a linear mode instead of a saturation mode. Because operation in a linear mode results in smaller drain-to-source voltage drops, power consumption in the output current source or sink (and hence in the implantable stimulator) is reduced, reducing battery or other power source requirements. Operation in the linear mode is facilitated in useful embodiments by a load in an input path (into which a reference current is sent) and a load in the output path (which bears the output current). The loads can be active transistors or passive resistors. A feedback circuit (e.g.

Abstract: An improved arbitration scheme for allowing concurrent stimulation and telemetry listening in a microstimulator is disclosed. A listening window for telemetry is permitted to proceed, and access to the microstimulator's coil granted, during at least a portion of the inter-pulse period that follows the issuance of a stimulation pulse. This is permissible because access to the coil is not needed during the entirety of the inter-pulse period. For example, the listening window can issue during that portion of the inter-pulse period when the decoupling capacitor is discharged, but cannot issue during that portion of the inter-pulse period when the compliance voltage is being generated for the next stimulation pulse. However, because compliance voltage generation occupies only a small portion of the inter-pulse period, the technique is not substantially limited.