Abstract: Apparatus and methods for generating an induction waveform for performing threshold testing in an implantable medical device are disclosed. Such tests may be performed during the implant procedure, or during a device checkup procedure, or routinely during the lifetime of the device. The threshold test may include induction of an arrhythmia (such as ventricular fibrillation) followed by delivery of therapy at various progressively-increasing stimulation parameters to terminate the arrhythmia. As such, the capability to induce fibrillation within the device is desired. Induction of the arrhythmias may be accomplished via delivery of a relatively low energy shock or through delivery of an induction stimulation pulse to the cardiac tissue timed concurrently with the vulnerable period of the cardiac cycle.

Abstract: An implantable medical device includes a low-power circuit and a multi-cell power source. The cells of the power source are coupled in a parallel configuration. The implantable medical device includes both a low power circuit that is selectively coupled between the first and second cells and a high power output circuit that is directly coupled to the first and second cells in a parallel configuration. An isolation circuit is coupled to the first cell, the second cell and the low power circuit to maintain a current isolation between the first cell and the second cell at least during delivery of current having a large magnitude to the high power output circuit.

Abstract: An implantable medical device includes a low-power circuit, a high-power circuit, and a dual-cell power source. The power source is coupled to a dual-transformer such that each cell is connected to only one of the transformers. Each transformer includes multiple windings and each of the windings is coupled to a capacitor, and the capacitors are all connected in a series configuration. The low power circuit is coupled to the power source and issues a control signal to control the delivery of charge from the power source to the plurality of capacitors through the first and second transformers.

Abstract: An implantable cardioverter defibrillator (ICD) configured to transmit a tissue conduction communication (TCC) signal includes a TCC transmitter module configured to generate the TCC signal and transmit the TCC signal via a plurality of electrodes. The TCC signal comprises a biphasic signal having an amplitude and a frequency, wherein at least one of the amplitude and the frequency are configured to avoid stimulation of tissue of the patient. The TCC transmitter module comprises protection circuitry coupled between a current source and the plurality of electrodes, wherein the protection circuitry is configured to protect the signal generator from an external anti-tachyarrhythmia shock delivered to the patient.

Abstract: An implantable medical device includes a low-power circuit and a multi-cell power source. The cells of the power source are coupled in a parallel configuration. The implantable medical device includes both a low power circuit that is selectively coupled between the first and second cells and a high power output circuit that is directly coupled to the first and second cells in a parallel configuration. An isolation circuit is coupled to the first cell, the second cell and the low power circuit to maintain a current isolation between the first cell and the second cell at least during delivery currents having a large magnitude that are delivered to the high power output circuit.

Abstract: An implantable medical device includes a low-power circuit, a high-power circuit, and a multi-cell power source. The implantable medical device delivers stimulation therapy to cardiac tissue. The cardioversion energy is delivered across through electrodes that are coupled to terminals of the high-power circuit. A protection circuit for protecting the low-voltage circuit components from high voltage pulses includes a first segment coupled to a first of the electrodes and a second segment coupled to a second of the electrodes, the components of the low-voltage circuit being coupled to the transthoracic protection circuit portion, and a reference potential corresponding to a ground potential, wherein the first and second segments of the transthoracic protection circuit portion are coupled to the reference potential in a parallel configuration.

Abstract: An implantable cardioverter defibrillator (ICD) configured to transmit a tissue conduction communication (TCC) signal includes a TCC transmitter module configured to generate the TCC signal and transmit the TCC signal via a plurality of electrodes. The TCC signal comprises a biphasic signal having an amplitude and a frequency, wherein at least one of the amplitude and the frequency are configured to avoid stimulation of tissue of the patient. The TCC transmitter module comprises protection circuitry coupled between a current source and the plurality of electrodes, wherein the protection circuitry is configured to protect the signal generator from an external anti-tachyarrhythmia shock delivered to the patient.

Abstract: An implantable medical device includes a low-power circuit, a high-power circuit, and a multi-cell power source. The implantable medical device delivers stimulation therapy to cardiac tissue. The cardioversion energy is delivered across through electrodes that are coupled to terminals of the high-power circuit. A protection circuit for protecting the low-voltage circuit components from high voltage pulses includes a first segment coupled to a first of the electrodes and a second segment coupled to a second of the electrodes, the components of the low-voltage circuit being coupled to the transthoracic protection circuit portion, and a reference potential corresponding to a ground potential, wherein the first and second segments of the transthoracic protection circuit portion are coupled to the reference potential in a parallel configuration.

Abstract: An implantable medical device includes a low-power circuit and a multi-cell power source. The cells of the power source are coupled in a parallel configuration. The implantable medical device includes both a low power circuit that is selectively coupled between the first and second cells and a high power output circuit that is directly coupled to the first and second cells in a parallel configuration. An isolation circuit is coupled to the first cell, the second cell and the low power circuit to maintain a current isolation between the first cell and the second cell at least during delivery currents having a large magnitude that are delivered to the high power output circuit.

Abstract: An implantable medical device includes a low-power circuit and a multi-cell power source. The cells of the power source are coupled in a parallel configuration. The implantable medical device includes both a low power circuit that is selectively coupled between the first and second cells and a high power output circuit that is directly coupled to the first and second cells in a parallel configuration. An isolation circuit is coupled to the first cell, the second cell and the low power circuit to maintain a current isolation between the first cell and the second cell at least during delivery of current having a large magnitude to the high power output circuit.

Abstract: An implantable medical device includes a low-power circuit, a high-power circuit, and a dual-cell power source. The power source is coupled to a dual-transformer such that each cell is connected to only one of the transformers. Each transformer includes multiple windings and each of the windings is coupled to a capacitor, and the capacitors are all connected in a series configuration. The low power circuit is coupled to the power source and issues a control signal to control the delivery of charge from the power source to the plurality of capacitors through the first and second transformers.

Abstract: The present invention provides an implantable medical device having at least two electrodes coupled to the device housing. The electrodes may be configured for sensing physiological signals such as cardiac signals and alternatively for providing an electrical stimulation therapy such as a pacing or defibrillation therapy. In accordance with aspects of the disclosure, the device housing provides a hermetic enclosure that includes a battery case hermetically coupled to a circuit assembly case. At least one of the at least two electrodes is coupled to an exterior surface of the battery case. The battery case is electrically insulated from the cathode and anode of the battery.

Abstract: Apparatus and methods for generating an induction waveform for performing threshold testing in an implantable medical device are disclosed. Such tests may be performed during the implant procedure, or during a device checkup procedure, or routinely during the lifetime of the device. The threshold test may include induction of an arrhythmia (such as ventricular fibrillation) followed by delivery of therapy at various progressively-increasing stimulation parameters to terminate the arrhythmia. As such, the capability to induce fibrillation within the device is desired. Induction of the arrhythmias may be accomplished via delivery of a relatively low energy shock or through delivery of an induction stimulation pulse to the cardiac tissue timed concurrently with the vulnerable period of the cardiac cycle.

Abstract: The present invention provides an implantable medical device having at least two electrodes coupled to the device housing. The electrodes may be configured for sensing physiological signals such as cardiac signals and alternatively for providing an electrical stimulation therapy such as a pacing or defibrillation therapy. In accordance with aspects of the disclosure, the device housing provides a hermetic enclosure that includes a first housing section that is hermetically coupled to a second housing section. At least one of the at least two electrodes is coupled to an exterior surface of the first housing section that encloses the battery components of the device. The first housing section is electrically insulated from the cathode and anode of the battery.

Abstract: The present invention provides an implantable medical device having at least two electrodes coupled to the device housing. The electrodes may be configured for sensing physiological signals such as cardiac signals and alternatively for providing an electrical stimulation therapy such as a pacing or defibrillation therapy. In accordance with aspects of the disclosure, the device housing provides a hermetic enclosure that includes a battery case hermetically coupled to a circuit assembly case. At least one of the at least two electrodes is coupled to an exterior surface of the battery case. The battery case is electrically insulated from the cathode and anode of the battery.

Abstract: The present invention provides an implantable medical device having at least two electrodes coupled to the device housing. The electrodes may be configured for sensing physiological signals such as cardiac signals and alternatively for providing an electrical stimulation therapy such as a pacing or defibrillation therapy. In accordance with aspects of the disclosure, the device housing provides a hermetic enclosure that includes a first housing section that is hermetically coupled to a second housing section. At least one of the at least two electrodes is coupled to an exterior surface of the first housing section that encloses the battery components of the device. The first housing section is electrically insulated from the cathode and anode of the battery.

Abstract: An implantable medical device (IMD) provides quadripolar transthoracic impedance measurement capability by forming at least one of the two electrodes associated with the canister of the device on a lead proximate the canister.

Abstract: An implantable medical device (IMD) provides quadripolar transthoracic impedance measurement capability by forming at least one of the two electrodes associated with the canister of the device on a lead proximate the canister.

Abstract: An implantable medical device (IMD) provides quadripolar transthoracic impedance measurement capability by forming at least one of the two electrodes associated with the canister of the device on a lead proximate the canister.

Abstract: An improved, long range, telemetry system for uplink and downlink telemetry transmission between an implantable medical device (IMD) and an external medical device (EMD), e.g. a programmer or monitor, specifically operable in accordance with a method for ensuring that the telemetry link is between an intended, rather than an un-intended, implantable medical device and the external medical device. Verification is effective if the operator of the EMD observes an implant event signal that is transmitted by uplink telemetry to the EMD from the IMD contemporaneously with a response-provoking action performed in the vicinity of the implant site of the intended patient. The operator directly observes the response-provoking event, when the patient is in sight, or assists the patient in timing the response-provoking event when the patient is not in sight but is at least in voice communication.