System, methods and devices are provided for identifying a failure state of a charge storage device. The system includes a charge storage device within an implantable medical device. An energy supply is configured to charge the charge storage device during a charging operation. A monitoring circuit is coupled to the charge storage device and is configured to collect voltage level measurements across the charge storage device at multiple points in time during the charging operation. Responsive to execution of program instructions, a processor collects the voltage level measurements across the charge storage device. The charge storage device exhibits a charge profile in which a voltage level across the charge storage device changes over the charging operation. The processor analyzes the voltage level measurements to identify a failure signature in the charge profile and generates an output indicative of a failure state for the charge storage device based on the analysis.

Improved devices, circuits and methods of operation in implantable stimulus systems. An implantable defibrillator may comprise a charging circuit using a transformer to store and build up energy on an HV capacitor or capacitor stack, with the HV capacitor in turn coupled to an H-bridge output circuit having low and high sides for issuing therapy. In the output current path, a current controlling circuitry is placed between the H-bridge and ground, allowing the greater flexibility in the selection of switching devices, and drivers for such devices, in the H-bridge circuit and/or enabling circuits between the H-bridge and the HV capacitor or other therapy circuit.

A medical device includes: a case at least a portion of which functions as a first electrode; a second electrode disposed in a header coupled to the case; a core assembly, the core assembly including operational circuitry enclosed within a core assembly housing, wherein the case includes the core assembly housing; and a battery assembly, the battery assembly including a battery enclosed within a battery housing, where the case further comprises the battery housing; where the operational circuitry is configured to drive a regulated voltage onto the case.

An illustrative method may include 1) generating, by an implantable stimulator, stimulation sessions, wherein the implantable stimulator comprises a central electrode of a first polarity centrally located on a first surface of a housing of the implantable stimulator and an annular electrode of a second polarity and that is spaced apart from the central electrode; and 2) applying, by the implantable stimulator, the stimulation sessions by way of the central electrode and the annular electrode to a location within a patient.

A method comprises generating, by an implantable stimulator, stimulation sessions at a duty cycle that is less than 0.05 and applying, by the implantable stimulator, the stimulation sessions to a patient. The duty cycle is a ratio of T3 to T4. Each stimulation session included in the stimulation sessions has a duration of T3 minutes and occurs at a rate of once every T4 minutes. The implantable stimulator is powered by a primary battery having an internal impedance greater than 5 ohms.

A method of treating hypertension includes an implantable stimulator generating stimulation sessions at a duty cycle that is less than 0.05 and applying the stimulation sessions by way of the central electrode and the annular electrode to a location associated with the hypertension and within a patient.

A medical device includes: a case at least a portion of which functions as a first electrode; a second electrode disposed in a header coupled to the case; a core assembly, the core assembly including operational circuitry enclosed within a core assembly housing, wherein the case includes the core assembly housing; and a battery assembly, the battery assembly including a battery enclosed within a battery housing, where the case further comprises the battery housing; where the operational circuitry is configured to drive a regulated voltage onto the case.

A method of treating hypertension in a patient includes generating, by an implantable stimulator configured to be implanted beneath a skin surface of the patient, stimulation sessions at a duty cycle that is less than 0.05 and applying, by the implantable stimulator in accordance with the duty cycle, the stimulation sessions to a tissue location associated with the hypertension. The duty cycle is a ratio of T3 to T4. Each stimulation session included in the stimulation sessions has a duration of T3 minutes and occurs at a rate of once every T4 minutes. The implantable stimulator is powered by a primary battery located within the implantable stimulator and having an internal impedance greater than 5 ohms.

An implantable medical device (IMD) includes multiple stimulation engines for independently stimulating respective electrode sets of a lead system while avoiding collisions and/or channel contention during stimulation delivery. A first voltage multiplier is configured to generate an adjustable target voltage having sufficient headroom at an output node that is commonly coupled to anodic nodes of respective stimulation engines. Each stimulation engine includes a secondary voltage multiplier to drive the respective anode and a current regulator powered by a floating voltage supply, wherein the current regulator is coupled to a cathodic node and configured to control how much stimulation current is pulled from the patient tissue.

Improved devices, circuits and methods of operation in implantable stimulus systems. An implantable defibrillator may comprise a charging circuit using a transformer to store and build up energy on an HV capacitor or capacitor stack, with the HV capacitor in turn coupled to an H-bridge output circuit having low and high sides for issuing therapy. A current monitoring circuitry is provided on the low side of the H-Bridge and used to form a feedback loop to control current into a transformer that converts battery voltage to a signal that charges the HV capacitor to control current through the H-bridge.