Abstract: An implantable medical system includes an implantable medical device and a external charger. The implantable medical device includes a rechargeable power source, electronic components coupled to the rechargeable power source to deliver a therapy to or monitor a parameter of a patient, and a recharge system operably coupled to the rechargeable power source including a secondary coil to receive power via an inductive power transfer. The external charger includes a housing forming an internal compartment, recharger electronic components disposed on a printed circuit board assembly in the internal compartment, and a recharge coil assembly disposed within the internal compartment, the recharge coil assembly including a recharge coil to provide power to the secondary coil via the inductive power transfer and a flux guide having a ferrite sheet disposed between the recharge coil and the printed circuit board assembly.

Abstract: A method for controlling charging a power source of an implantable medical device (IMD) in a patient including determining a power being delivered to a primary coil of an external charging device for recharging, determining an estimated power delivered to the IMD power source an estimated heat generated by the primary coil based on a resistance of the primary coil determined as function of at least one of a recharge frequency, a temperature of the primary coil, and a current supplied to the primary coil, calculating an estimated heat generated by the IMD by subtracting the estimated heat generated by the primary coil and the estimated power delivered stored by the rechargeable power source from the power being delivered to a primary coil; and controlling based on the heat generated by the IMD, the power being delivered by the primary coil of the external charging device.

Abstract: Systems and methods for improved wireless recharging efficiency and decreased processing requirements are described. A plurality of duty cycle/input voltage pairs are stored in a recharger, corresponding to three subsets: a first subset corresponding to a constant minimum input voltage and an increasing duty cycle; a second subset corresponding to a constant duty cycle and an increasing input voltage; and a third subset corresponding to a maximum input voltage and an increasing duty cycle.

Abstract: The instant application relates to inductive charging of devices subject to migration. Embodiments described herein provide charging to devices at variable depths and locations to accommodate both net displacement of an implantable device as well as angular rotation of the implantable device by selecting appropriate sets or subsets of available field generation coils.