Circuits, devices and methods are provided to manage modifications to protected registers within an implantable medical device (IMD). The circuit comprises a bus controller that includes an address register, an unlock register and a protected register (PR) enable unit. The PR enable unit sets a protect enable signal to an access state based on content loaded into the unlock register. A peripheral block includes a protected register that retains content for operating the IMD. The peripheral block includes a register access input to receive the protected enable signal. A PR write control unit is provided to enable an attempted write of the content from a data interface to the protected register when the protected enable signal has an access state.

Systems and methods for pacing cardiac conductive tissue are described. An embodiment of a medical system includes an electrostimulation circuit to generate His-bundle pacing (HBP) pulses to stimulate a His bundle, and a cardiac event detector to detect a His-bundle activity within a time window following an atrial activity. The cardiac event detector may use a cross-chamber blanking, or an adjustable His-bundle sensing threshold, to avoid or reduce over-sensing of far-field atrial activity and inappropriate inhibition of HBP therapy. The electrostimulation circuit may deliver HBP in the presence of the His-bundle activity. The system may further recognize the detected His-bundle activity as either a FFPW or a valid inhibitory event, and deliver or withhold HBP therapy based on the recognition of the His-bundle activity.

The invention is a device and a method for detecting a medically active implant capable of electrical stimulation implanted within a person. Moreover, the invention also relates to the use of the device for determining the operational status of the medically active implant. The device is characterized by components: a) at least two electrodes that are in, or can be brought into, contact with the person, b) an electrical voltage measuring unit which is electrically connected to the at least two electrodes and which is capable of generating electrical voltage timing signals and c) an evaluation unit which is connected to the electrical voltage measuring unit.

Described herein are methods for use with an implantable system including at least an atrial leadless pacemaker (aLP). Also described herein are specific implementations of an aLP, as well as implantable systems including an aLP. In certain embodiments, the aLP senses a signal from which cardiac activity associated with a ventricular chamber can be detected by the aLP itself based on feature(s) of the sensed signal. The aLP monitors the sensed signal for an intrinsic or paced ventricular activation within a ventricular event monitor window. In response to the aLP detecting an intrinsic or paced ventricular activation itself from the sensed signal within the ventricular event monitor window, the aLP resets an atrial escape interval timer that is used by the aLP to time delivery of an atrial pacing pulse if an intrinsic atrial activation is not detected within an atrial escape interval.

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.

An implantable medical device configured to provide for an intracardiac function comprises a body, a sensor arrangement arranged on the body and configured to receive cardiac sense signals, and a processing circuitry operatively connected to the sensor arrangement. The processing circuitry is configured to process cardiac sense signals received using the sensor arrangement to detect atrial events caused by atrial activity based on a comparison of the cardiac sense signals to a sense threshold for a number of cardiac cycles, to evaluate whether a reduction criterion is fulfilled, wherein the reduction criterion is fulfilled if in X1 out of Y1 cardiac cycles no atrial events have been detected, X1 being a natural number equal to or larger than 1 and Y1 being a natural number equal to or larger than X1, and to reduce the sense threshold if said reduction criterion is fulfilled.

A system including a medical device is provided. The medical device includes at least one sensor configured to acquire first data descriptive of a patient, first memory storing a plurality of templates, and at least one processor coupled to the at least one sensor and the first memory. The at least one processor is configured to identify a first template of the plurality of templates that is similar to the first data, to determine first difference data based on the first template and the first data, and to store the first difference data in association with the first template. The system may further include the programmable device.

Computer implemented methods, devices and systems for monitoring a trend in heart failure (HF) progression are provided. The method comprises sensing left ventricular (LV) activation events at multiple LV sensing sites along a multi-electrode LV lead. The activation events are generated in response to an intrinsic or paced ventricular event. The method implements program instructions on one or more processors for automatically determining a conduction pattern (CP) across the LV sensing sites based on the LV activation events, identifying morphologies (MP) for cardiac signals associated with the LV activation events and repeating the sensing, determining and identifying operations, at select intervals, to build a CP collection and an MP collection. The method calculates an HF trend based on the CP collection and MP collection and classifies a patient condition based on the HF trend to form an HF assessment.

A wearable cardiac device for providing feedback during device assembly includes a garment configured to be continuously worn and an electrode belt including a plurality of assemblable elements. Each of the assemblable elements is configured for assembly into the garment prior to use of the wearable cardiac device. The plurality of assemblable elements includes electrodes configured to facilitate sensing electrical signals associated with cardiac activity of and/or deliver one or more therapeutic pulses to a patient. At least one of the plurality of assemblable elements includes respective local assembly feedback circuitry. Each respective local assembly feedback circuitry includes an assembly verification sensor configured to sense whether the respective assemblable element is correctly assembled into the garment and local assembly feedback indicator(s) locally disposed on the respective assemblable element and configured to provide a human-discernable feedback alert indicating whether the respective assemblable element is correctly assembled into the garment.

A leadless cardiac pacemaker (LCP) configured to sense cardiac activity and to pace a patient's heart. The LCP may include a housing, a first electrode secured relative to the housing, a second electrode secured relative to the housing, and a pressure sensor secured relative to the housing and coupled to the environment outside of the housing. The LCP may further include circuitry in the housing in communication with the first electrode, the second electrode, and the pressure sensor. The circuitry may be configured to determine and store a plurality of impedance-pressure data pairs, from which a representation of a pressure-volume loop may be determined.