A wirelessly powered implantable stimulator device includes one or more antenna configured to receive an input signal non-inductively from an external antenna, the input signal containing (i) electrical energy to operate the implantable stimulator device and (ii) configuration data according to which a pulse-density modulation (PDM) encoded stimulus waveform signal is retrieved to synthesize a desired stimulation waveform; a circuit coupled to the one or more antenna; and one or more electrodes coupled to the circuit and configured to apply the desired stimulation waveform to neural tissue, wherein the circuit is configured to: rectify the input signal received at the one or more antennas non-inductively; extract the electrical energy and the configuration data from the input signal; and in accordance with the extracted configuration data, retrieve the pulse-density modulation (PDM) signal to synthesize the desired stimulation waveform therefrom.

Systems and methods for detecting cardiac arrhythmias such as atrial tachyarrhythmia (AT) are discussed. An exemplary system includes an arrhythmia detector circuit that can receive physiologic information sensed from a patient over time, detect an arrhythmia onset when the physiologic information during a first time period satisfies an onset condition, and in response to the detected arrhythmia onset, detect an arrhythmia termination when the physiologic information during a second time period, subsequent to and longer than the first time period, satisfies an exit condition. An arrhythmia episode can be detected based on an arrhythmia duration between the detected onset and termination. The detected sustained arrhythmia episode can be provided to a user or a processor for further processing.

A medical device is configured to detect an atrial tachyarrhythmia episode. The device senses a cardiac signal, identifies R-waves in the cardiac signal attendant ventricular depolarizations and determines classification factors from the R-waves identified over a predetermined time period. The device classifies the predetermined time period as one of unclassified, atrial tachyarrhythmia and non-atrial tachyarrhythmia by comparing the determined classification factors to classification criteria. A classification criterion is adjusted from a first classification criterion to a second classification criterion after at least one time period being classified as atrial tachyarrhythmia. An atrial tachyarrhythmia episode is detected by the device in response to at least one subsequent time period being classified as atrial tachyarrhythmia based on the adjusted classification criterion.

An implantable medical device for generating electrical stimulations, wherein the medical device is embodied to generate and emit, during a first stimulation phase, at least one first stimulation that has a first amplitude by means of energy from an energy storage element, and wherein the medical device is embodied, during a second stimulation phase following the first stimulation phase, to generate and emit at least one second stimulation that has a second amplitude by means of energy from the energy storage element, wherein the energy storage element is charged at least prior to the generation of the at least one first stimulation and after the generation of the at least one first stimulation, and wherein the medical device is embodied not to completely discharge the energy storage element by generating the at least one first stimulation. The invention furthermore relates to a method for controlling such a device.

A system for treating cardiac arrhythmias comprising a generator including: a sensing circuitry configured to evaluate one or more identified signals representative of electrical activity of the heart and detect an arrhythmia, a control circuitry that is configured to control delivery of a therapy in response to the detected arrhythmia, the therapy including a first stage of electrical pulses delivered via at least a first electrode, wherein the first set of electrical pulses is configured to destabilize and/or terminate a reentry associated with the arrhythmia, and a first lead coupled to the generator, wherein the first lead includes the first electrode.

Methods and apparatus for a three-stage atrial cardioversion therapy that treats atrial arrhythmias within pain tolerance thresholds of a patient. An implantable therapy generator adapted to generate and selectively deliver a three-stage atrial cardioversion therapy and at least two leads, each having at least one electrode adapted to be positioned proximate the atrium of the patient. The device is programmed for delivering a three-stage atrial cardioversion therapy via both a far-field configuration and a near-field configuration of the electrodes upon detection of an atrial arrhythmia. The three-stage atrial cardioversion therapy includes a first stage for unpinning of one or more singularities associated with an atrial arrhythmia, a second stage for anti-repinning of the one or more singularities, both of which are delivered via the far-field configuration of the electrodes, and a third stage for extinguishing of the one or more singularities delivered via the near-field configuration of the electrodes.

Systems and methods for treating atrial tachyarrhythmias such as atrial fibrillation (AF) are disclosed. By monitoring a patient's hemodynamic sensor response to a candidate AF therapy, the present systems and methods can be used to determine an individualized AF therapy leading to a desirable hemodynamic outcome. A medical system can include one or more programmable therapy circuits and a hemodynamic sensor circuit. The system includes a therapy selection circuit that automatically programs and sequentially delivers at least a first candidate therapy and a different second candidate therapy. By comparing the values of a hemodynamic parameter in response to or during the first candidate therapy to that in response to or during the second candidate therapy, a desired AF therapy can be determined as the candidate therapy that leads to faster or more significant hemodynamic recovery.

Embodiments of the invention provide methods for the detection and treatment of atrial fibrillation (AF) and related conditions. One embodiment provides a method comprising measuring electrical activity of the heart using electrodes arranged on the heart surface to define an area for detecting aberrant electrical activity (AEA) and then using the measured electrical activity (MEA) to detect foci of AEA causing AF. A pacing signal may then be sent to the foci to prevent AF onset. Atrial wall motion characteristics (WMC) may be sensed using an accelerometer placed on the heart and used with MEA to detect AF. The WMC may be used to monitor effectiveness of the pacing signal in preventing AF and/or returning the heart to normal sinus rhythm (NSR). Also, upon AF detection, a cardioversion signal may be sent to the atria using the electrodes to depolorize an atrial area causing AF and return the heart to NSR.

An example of a system may include a sensing circuit and an atrial fibrillation (AF) detection circuit. The sensing circuit may be configured to sense a cardiac signal indicative of atrial and ventricular depolarizations. The AF detection circuit may be configured to detect AF using the cardiac signal and may include a detector and a detection enhancer. The detector may be configured to detect the ventricular depolarizations using the cardiac signal, to measure ventricular intervals each between two successively detected ventricular depolarizations, and to detect the AF using the ventricular intervals. The detection enhancer may include a respiratory sinus arrhythmia (RSA) detector configured to detect RSA using the cardiac signal and may be configured to verify each detection of the AF based on whether the RSA is detected.

Devices and methods are described for occluding the left atrial appendage (LAA). The device excludes the LAA from blood flow to prevent blood from clotting within the LAA and subsequently embolizing, particularly in patients with atrial fibrillation. The implantable device is delivered via transcatheter delivery into the LAA and secured within the LAA. The implant comprises an expandable and compliant frame and an expandable and conformable tubular foam body carried by the frame. The device may have a thromboresistant cover at a proximal end and a thromboresistant coating on the foam body. The frame may have recapture struts inclining radially outwardly in the distal direction from a central hub. The frame may have axially extending side wall struts, with adjacent pairs of side wall struts joined at one or more apexes. Anchors extend from the frame to engage tissue. The anchors can also be reversible to allow retraction of the anchors and repositioning or retrieval of the device.