Apparatuses and methods are disclosed for efficient wireless powering of an electrical load with precise external control over pulsed voltage waveform and metering of charge delivered. The system interfaces to an inductive coil for RF power delivery from an external duty-cycled RF power transmitter, and the electrical load. The electrical load may be a photosensitive array of electrodes for an optically addressed, electrically activated retinal prosthesis. The voltage waveform to activate the load is controlled by the transmitted RF amplitude, including switching between cathodic and anodic phases of electrical stimulation. Charge delivered to the load is quantified as discharge events through a series capacitor, transmitted by backtelemetry to the receiver for continuous monitoring throughout the stimulation phases. The subject disclosure further provides for calibration of voltage amplitude and charge metering, to compensate for variable wireless link and load conditions, through additional stimulation phases with a supplementary load with known and stable characteristics.

The invention features methods and devices useful for stimulating brain tissue in a subject via electrodes within cranial bone. These methods and devices may be utilized for the detection, prevention, and/or treatment of neurological disorders via electric stimulation. Additionally, the methods and devices disclosed herein may be useful for the treatment, inhibition, and/or arrestment of the growth of tumors.

Embodiments presented herein are generally directed to techniques for separately transferring power and data from an external device to an implantable component of a partially or fully implantable medical device. The separated power and data transfer techniques use a single external coil and a single implantable coil. The external coil is part of an external resonant circuit, while the implantable coil is part of an implantable resonant circuit. The external coil is configured to transcutaneously transfer power and data to the implantable coil using separate (different) power and data time slots. At least one of the external or internal resonant circuit is substantially more damped during the data time slot than during the power time slot.

A system and method for altering bone growth on and within an orthopedic implant that includes an implant body; a plurality of electrodes, wherein each electrode is at least partially embedded in the implant body, and comprises: a set of primary electrodes comprising at least one electrode, wherein a non-embedded segment of each primary electrode is proximal to a bone growth region, a set of secondary electrodes comprising at least one electrode, wherein a non-embedded segment of each secondary electrode is distal to the bone growth region, and wherein the plurality of electrodes are configured to function in a stimulation operating mode, such that a subset of primary electrodes function as cathodes and a subset of secondary electrodes function as anodes; a control system comprising a processor, and circuitry that connects to the plurality of electrodes; and a power system.

Techniques are described for providing a therapeutic pseudo-constant DC current in an implantable stimulator using pulses whose positive and negative phases are not charge balanced. Such charge imbalanced pulses act to charge any capacitance in the current path between selected electrode nodes, such as the DC-blocking capacitors and/or any inherent capacitance such as those present at the electrode/tissue interface. These charged capacitances act during quiet periods between the pulses to induce a pseudo-constant DC current. Beneficially, these DC currents can be small enough to stay within charge density limits and hence not corrode the electrode or cause tissue damage, and further can be controlled to stay within such limits or for other reasons. Graphical user interface (GUI) aspects for generating the charge imbalanced pulses and for determining and/or controlling the pseudo-constant DC current are also provided.

An active implantable stimulating device (10) includes: (a) a tissue coupling unit (40) for being implanted directly onto a vagus nerve (Vn) of a patient, (b) an EEG-unit (70) for measuring an electroencephalogram of the patient, (c) an encapsulation unit (50) configured for being subcutaneously implanted, (d) an energy transfer lead (30) for transferring pulses of electrical and/or optical energy, (e) a signal transfer lead (60) for transferring signals between the EEG unit and the encapsulation unit. EEG electrodes (70a-70d) monitor the electric activity of the brain of a patient. The EEG signal is conveyed to the electronic circuit (53) in the form of EEG conditioned data. The electronic circuit analyses the EEG conditioned data to yield analysis results. The electronic circuit takes a decision to trigger energy pulses to stimulate the vagus nerve (VN).

An implantable device containing a plurality of batteries, the plurality of batteries including at least one first non-rechargeable battery, and at least one second rechargeable battery. A method for providing power for a Cardiac Contractility Modulation Implantable Cardioverter Defibrillator (ICD) device, the method including providing power for cardioversion or defibrillation operation by a first, non-rechargeable battery, and providing power for Cardiac Contractility Modulation operation by a second, rechargeable battery. A method for controlling power for an implantable device having a rechargeable battery, a non-rechargeable battery and a Cardioverter Defibrillator module, the method including measuring electric power level of the rechargeable battery, comparing the rechargeable battery level to a threshold, if the electric power level of the rechargeable battery is less than the threshold, then providing power for the device from the non-rechargeable battery. Related apparatus and methods are also described.

Disclosed is a system for recharging a selected power source wirelessly, such as through a power transmission. The power source may be positioned within a subject and be charged wirelessly through the subject, such as tissue of the subject. A thermal transfer system is provided to transfer or transport thermal energy from a first position to a second position, such as away from the subject.

A wireless power transfer system in which the driver and control circuitry are located within the electromagnetic field of the power transmission antenna, e.g., a charging coil. The power transfer system may be contained in a flexible housing, which change shape using one or more hinges, be formed of a conformable material and so on. Changes in the relative location of the antenna and the circuitry may cause interference in the circuitry and loading of the antenna, which in turn may impact the electromagnetic field output by the antenna. The wireless power system may include sensors that provide an indication of an amount of deformation of the system. The driver circuitry of this disclosure may receive an indication of the relative location of the circuitry to the antenna and compensate for changes in the output electromagnetic field caused by changes in the relative location.

A stent for intravascular stimulation comprises a scaffold comprising first and second scaffold structures, each scaffold structure comprising at least one substantially annular portion. The stent further comprises one or more anodal electrodes formed from or electrically coupled to at least a substantially annular portion of the first scaffold structure and one or more cathodal electrodes electrically formed from or coupled to at least a substantially annular portion of the second scaffold structure. The stent further comprises an anodal lead electrically coupled to the first scaffold structure to form a conductive path from the one or more anodal electrodes to a generator and a cathodal lead electrically coupled to the second scaffold structure to form a conductive path from the one or more cathodal electrodes to the generator. The stent further comprises a sleeve of insulating material, wherein the scaffold structures are attached to or formed on the sleeve of insulating material and are separated from each other by a distance such that the first and second scaffold structures are electrically insulated from each other.