THERAPY DELIVERY METHOD AND SYSTEM FOR IMPLANTABLE MEDICAL DEVICES

摘要

Recent advancements in power electronics technology have provided opportunities for enhancements to circuits of implantable medical devices. The enhancements have contributed to increasing circuit miniaturization and an increased efficiency in the operation of the implantable medical devices. The therapy delivery circuits and techniques of the disclosure facilitate generation of a therapy stimulation waveform that may be shaped based on the patient's physiological response to the stimulation waveform. The generated therapy stimulation waveforms include a stepped leading-edge that may be shaped having a varying slope and varying amplitudes associated with each of the segments of the slope. Unlike the truncated exponential waveform delivered by the conventional therapy delivery circuit which is based on the behavior of the output capacitors (i.e., i=C(dV/dt)), the stimulation waveform of the present disclosure may be dynamically shaped as a function of an individual patient's response. The dynamically shaped therapy stimulation waveforms facilitate achieving lower capture thresholds which reduces the device's supply consumption thereby increasing longevity of the device and facilitate a reduction of tissue damage.

主权项

1. An implantable medical system having electronic circuitry and an electrode coupled to the electronic circuitry, the electronic circuitry comprising:
a microprocessor programmed to detect a predetermined event in response to signals received from the electrode; a controller coupled to the microprocessor, wherein the controller is programmed to generate a control signal in response to detection of the predetermined event; a delivery circuit coupled between the controller and the electrode, the delivery circuit including:
a plurality of capacitors; anda coupling circuit connected to the plurality of capacitors and operable to dynamically stack the plurality of capacitors in a first configuration during a first period that is coincident with the ascending part of the T-wave to induce ventricular fibrillation, recharging the plurality of capacitors in the first configuration, and subsequent to recharging the plurality of capacitors, reconfiguring the stacking of the plurality of capacitors into a second configuration that is different from the first configuration during a second period to deliver stimulation therapy in response to an onset of the induced ventricular fibrillation, wherein the reconfiguration comprises stacking the plurality of capacitors from the first configuration to a second configuration.