An active implantable medical device includes a VNS pulse bursts generator for stimulation of the vagus nerve according to several selectable configurations. The device may further include a sensor of the current activity level of the patient. The generator is controlled on the activity signal via a classifier determining the class of the current level of activity among a plurality of classes of activity. A controller selects a configuration of VNS therapy depending on the class of activity thus determined. Limits of the activity classes are dynamically changeable by a calibration module that conducts a historical analysis of the successive current activity levels over a predetermined analysis period. The calibration module can prepare a histogram of the historical analysis, and can define the limits of the activity classes depending on the outcome of the historical analysis and the histogram.

Systems and methods for managing cardiac arrhythmias are discussed. A data management system receives a first detection algorithm including a detection criterion for detecting a cardiac arrhythmia. An arrhythmia detector detects arrhythmia episodes from a physiologic signal using a second detection algorithm that is different from and has a higher sensitivity for detecting the cardiac arrhythmia than the first detection algorithm. The arrhythmia detector assigns a detection indicator to each of the detected arrhythmia episodes. The detection indicator indicates a likelihood that the detected arrhythmia episode satisfies the detection criterion of the first detection algorithm. The system prioritizes the detected arrhythmia episodes according to the assigned detection indicators, and outputs the arrhythmia episodes to a user or a process according to the episode prioritization.

Embodiments describe herein generally pertain to implantable medical device (IMDs), and methods for use therewith, that can be used to automatically switch an IMD from its normal operational mode to an MRI safe mode, and vice versa, within increased specificity. In certain embodiments, a controller of the IMD uses a magnetic field sensor to determine whether a first magnetic field condition is detected, and uses an accelerometer to determine whether a positional condition is detected. In response to the first magnetic field condition being detected, and the positional condition being detected, the controller can use the magnetic field sensor to determine whether a second magnetic field condition is detected, which differs from the first magnetic field condition. The controller can then cause the IMD to enter the MRI safe mode based at least in part on the first and second magnetic field conditions and the positional condition being detected.

A medical device senses cardiac electrical signals including T-waves attendant to ventricular myocardial repolarizations and detects a T-wave template condition associated with non-pathological changes in T-wave morphology. The device generates a T-wave template from T-waves sensed by the sensing circuit during the T-wave template condition. After generating the T-wave template, the device acquires a T-wave signal from the cardiac electrical signal and compares the acquired T-wave signal to the T-wave template. The device detects a pathological event in response to the acquired T-wave signal not matching the T-wave template.

The present disclosure relates to a medical system, comprising at least an implantable medical device, and a multi-axis accelerometer comprised by the implantable medical device for measuring an acceleration of the implantable medical device along a plurality of vectors, wherein the multi-axis accelerometer is configured to provide for each vector a signal indicative of the acceleration of the implantable medical device in the direction of the respective vector. The medical system is configured to assess said signals to automatically select or propose a vector of said plurality of vectors that comprises the best alignment with a pre-defined vector.

Systems and methods for monitoring and treating patients with heart failure are discussed. The system can store in a memory stimulation parameters, including stimulation timing parameters for a plurality of heart rate ranges. The system includes a plurality of timers with respective durations for the plurality of heart rate ranges. A stimulation control circuit can identify a target heart range in which a detected heart rate falls, and measure an atrioventricular (AV) conduction characteristic value in response to the timer for the target heart range being expired at the detected heart rate. The stimulation control circuit can update a stimulation parameter corresponding to the target heart rate range using the measured AV conduction characteristic. The updated stimulation parameter can be used in cardiac stimulation.

This document discusses, among other things, systems and methods to receive physiologic information from a patient during different first and second pacing periods having respective, different first and second atrioventricular (AV) delays, determine first and second physiologic parameters using respective received physiologic information from the first and second pacing periods, and adjust the first AV delay using the determined first and second physiologic parameters, wherein the second AV delay is longer than the first AV delay.

A medical device is configured to generate fluid status signal data of a patient by determining impedance metrics from an impedance signal, determining cardiac electrical signal amplitudes from a cardiac electrical signal and determining a calibration relationship between the impedance metrics and cardiac electrical signal amplitudes. The medical device generates a fluid status signal data by adjusting cardiac electrical signal amplitudes according to the determined calibration relationship. The fluid status signal data may be displayed or monitored for detecting a change in the patient's fluid status.

A wearable defibrillator for use in monitoring patient movement and cardiac activity and treating a patient includes a garment configured to be worn by the patient, treatment electrodes configured to apply an electric current to the patient, and an alarm module configured to provide audio, visual, and haptic notifications. The notifications are configured to indicate that an electric current will be administered imminently and prompt the patient to provide a response input. The wearable defibrillator includes a motion sensor configured to detect motion and body position of a patient, and a controller in electrical communication with the alarm module and the motion sensor. The controller is configured to monitor for the response input after the prompt, determine, based on the detected motion and body position, whether the patient is sleeping, and cause a change in one or more characteristics of the prompt on determining that the patient is sleeping.

A pacemaker control system includes a pacemaker; a plurality of sensors which are internal to the pacemaker, a plurality of sensors which are external to the pacemaker, a circuit for entering patient reports; and a circuit for using artificial intelligence to process outputs from the plurality sensors internal and external to the pacemaker and from the circuit for entering patient reports, which are collectively identified as a labeled dataset, to reiteratsvely learn a function which determines the labeled dataset most likely to provide optimal pacemaker function for the patient. The means for using artificial intelligence comprises a database of archive outputs from the plurality sensors internal and external to the pacemaker and from the means for entering patient reports for the patient used for optimization of rate modulation to intelligently, continuously and physiologically control the pacemaker.