Described herein are methods, devices, and systems that monitor heart rate and/or for arrhythmic episodes based on sensed intervals that can include true R-R intervals as well as over-sensed R-R intervals. True R-R intervals are initially identified from an ordered list of the sensed intervals by comparing individual sensed intervals to a sum of an immediately preceding two intervals, and/or an immediately following two intervals. True R-R intervals are also identified by comparing sensed intervals to a mean or median of durations of sensed intervals already identified as true R-R intervals. Individual intervals in a remaining ordered list of sensed intervals (from which true R-R intervals have been removed) are classified as either a short interval or a long interval, and over-sensed R-R intervals are identified based on the results thereof. Such embodiments can be used, e.g., to reduce the reporting of and/or inappropriate responses to false positive tachycardia detections.

A medical device is configured to deliver therapeutic electrical stimulation pulses by generating frequency modulated electrical stimulation pulse signals. The medical device includes a pulse signal source and a modulator. The pulse signal source generates an electrical stimulation pulse signal having a pulse width. The modulator may include a high frequency modulator configured to modulate a frequency of the pulse signal from a starting frequency down to a minimum frequency during the pulse width. The modulator may include a low frequency bias generator to modulate the offset of the pulse signal between a minimum offset and a maximum offset in other examples.

Techniques and systems for monitoring cardiac arrhythmias and delivering electrical stimulation therapy using a subcutaneous implantable cardioverter defibrillator (SICD) and a leadless pacing device (LPD) are described. For example, the SICD may detect a tachyarrhythmia within a first electrical signal from a heart and determine, based on the tachyarrhythmia, to deliver anti-tachyarrhythmia shock therapy to the patient to treat the detected arrhythmia. The LPD may receive communication from the SICD requesting the LPD deliver anti-tachycardia pacing to the heart and determine, based on a second electrical signal from the heart sensed by the LPD, whether to deliver anti-tachycardia pacing (ATP) to the heart. In this manner, the SICD and LPD may communicate to coordinate ATP and/or cardioversion/defibrillation therapy. In another example, the LPD may be configured to deliver post-shock pacing after detecting delivery of anti-tachyarrhythmia shock therapy.

An implantable cardioverter defibrillator (ICD) receives a cardiac electrical signal by a sensing circuit while operating in a sensing without pacing mode and detects asystole based on the cardiac electrical signal. The ICD determines, in response to detecting the asystole, if asystole backup pacing is enabled, and automatically switches to a temporary pacing mode in response to the asystole backup pacing being enabled. Other examples of detecting asystole and providing a response to detecting asystole by the ICD are described herein.

An implantable medical device is configured to determine a first atrial arrhythmia score from ventricular events sensed by a sensing circuit of an implantable medical device and determine a second atrial arrhythmia score from an intraventricular signal comprising atrial mechanical event signals attendant to atrial systole and produced by a sensor of the implantable medical device. An atrial arrhythmia is detected based on the first atrial arrhythmia score and the second atrial arrhythmia score.

A medical device is configured to detect an alternating pattern of signal features determined from consecutive segments of a cardiac electrical signal and determine a gross morphology metric from at least one segment of the cardiac electrical signal. The device is configured to detect cardiac event oversensing in response to detecting the alternating pattern and the gross morphology metric not meeting tachyarrhythmia morphology criteria. The medical device may withhold detecting an arrhythmia in response to detecting the cardiac event oversensing.

A cardiac net with at least one electrode enhances the pacing effect on a ventricle. The cardiac net with at least one electrode includes non-conductive portions formed by weaving non-conductive or conductive thread, defibrillation electrodes, and pacing electrodes, which are connected to one another. The defibrillation electrodes are configured to cover the circumference of the heart substantially horizontally, and are placed on an upper side and a lower side of the heart. The pacing electrodes are placed between the defibrillation electrodes and used for sensing the motions of the heart and pacing the ventricle. The pacing electrodes are configured to cover the circumference of the heart substantially horizontally so as to overlay the center of a spiral wave reentry. This configuration allows excitatory stimulus to be applied to the heart from the circumference thereof, thereby enabling the pacing electrodes to perform effective pacing.

A method for assessment, optimization and logging of the effects of a therapy for a medical condition, including (a) receiving into a signal processor input signals indicative of the subject's brain activity; (b) characterizing the spatio-temporal behavior of the brain activity using the signals; (c) delivering a therapy to a target tissue of the subject; (d) characterizing the spatio-temporal effect of the therapy on the brain activity; (e) in response to the characterizing, optimizing at least one parameter of the therapy if the brain activity has not been satisfactorily modified and/or has been adversely modified by the therapy; (f) characterizing the spatio-temporal effect of the at least one optimized parameter; and (g) logging to memory the at least one optimized parameter. A computer readable program storage unit encoded with instructions that, when executed by a computer, performs the method.

Semi-autonomous vehicle apparatus which is controlled by a plurality of control sources includes a vehicle which may function autonomously and apparatus for control of the vehicle by either an onboard driver or a driver not situated onboard. The vehicle may also be controlled by an off-vehicle computational device. Hierarchy setting apparatus determines which one or combination of the possible control entities take priority. Persons using the apparatus are identified by either a password or, preferably by providing identification based on a biologic feature. Management of impaired vehicle operators is provided for.

Systems and methods for treating cardiac arrhythmias are disclosed. In one embodiment, an SICD comprises two or more electrodes, a charge storage device, and a controller operatively coupled to two or more of the electrodes and the charge storage device. In some embodiments, the controller is configured to monitor cardiac activity of the heart of the patient, detect an occurrence of a cardiac arrhythmia based on the cardiac activity, and determine a type of the detected cardiac arrhythmia from two or more types of cardiac arrhythmias. If the determined type of cardiac arrhythmia is one of a first set of cardiac arrhythmia types, the controller sends an instruction for reception by an LCP to initiate the application of ATP therapy by the LCP. If the determined type of cardiac arrhythmia is not one of the first set cardiac arrhythmia types, the controller does not send the instruction.