Abstract:
Techniques for minimizing rate of depletion of a non-rechargeable power source, to extend the operational lifetime of an implantable medical device that includes the non-rechargeable power source, by enforcing operational-mode-specific communication protocols whereby inter-device communication between the implantable medical device and another implantable medical device is such that level of power draw from the non-rechargeable power source by the implantable medical device is less than level of power draw from the rechargeable power source by the another implantable medical device for the implantable medical devices to engage in communication with each other.
Abstract:
Implantable medical systems enter an exposure mode of operation, either manually via a down linked programming instruction or by automatic detection by the implantable system of exposure to a magnetic disturbance. A controller then determines the appropriate exposure mode by considering various pieces of information including the device type including whether the device has defibrillation capability, pre-exposure mode of therapy including which chambers have been paced, and pre-exposure cardiac activity that is either intrinsic or paced rates. Additional considerations may include determining whether a sensed rate during the exposure mode is physiologic or artificially produced by the magnetic disturbance. When the sensed rate is physiologic, then the controller uses the sensed rate to trigger pacing and otherwise uses asynchronous pacing at a fixed rate.
Abstract:
An implantable medical device includes a housing having a proximal end and a distal end, a control module enclosed by the housing, and a pressure sensor electrically coupled to the control module. A fixation member is coupled to the housing distal end for anchoring the housing distal end at a fixation site within a cardiovascular system of a patient, and the pressure sensor is spaced apart proximally from the fixation member.
Abstract:
An implantable medical device having a housing that encloses a pulse generator and a sensing module includes a housing-based cathode electrode electrically coupled to the pulse generator and to the sensing module. A sensing extension extending from the housing proximal end includes an anode electrode electrically coupled to the sensing module for sensing cardiac electrical signals. The sensing extension includes a flotation member that causes the sensing extension to extend away from the housing along a direction of flowing blood when the implantable medical device is deployed within a cardiovascular system of a patient.
Abstract:
A leadless pacing device (LPD) includes a motion sensor configured to generate a motion signal as a function of heart movement. The LPD is configured to analyze the motion signal within an atrial contraction detection window that begins an atrial contraction detection delay period after activation of the ventricle, and detect a contraction of an atrium of the heart based on the analysis of the motion signal within the atrial contraction detection window. If the LPD does not detect a ventricular depolarization subsequent to the atrial contraction, e.g., with an atrio-ventricular (AV) interval beginning when the atrial contraction was detected, the LPD delivers a ventricular pacing pulse.
Abstract:
An implantable medical device system includes a pacemaker and an implantable cardioverter defibrillator (ICD). The pacemaker is configured to confirm a hemodynamically unstable rhythm based on an activity metric determined from an activity sensor signal after detecting a ventricular tachyarrhythmia and withhold anti-tachycardia pacing (ATP) pulses in response to confirming the hemodynamically unstable rhythm. The pacemaker may deliver ATP when a hemodynamically unstable rhythm is not confirmed based on the activity metric. The ICD is configured to detect the ATP and withhold a shock therapy in response to detecting the ATP in some examples.
Abstract:
An intracardiac pacemaker is configured to receive a cardiac electrical signal developed across a pair of electrodes coupled to the pacemaker and detect a crossing of a first sensing threshold of the cardiac electrical signal. A pacing escape interval timer is set to a first pacing escape interval in response to the cardiac electrical signal crossing the first sensing threshold. The pacing escape interval timer is adjusted if the cardiac electrical signal crosses a second sensing threshold during a time limit.
Abstract:
A medical device and associated method record signals from each real axis of a multi-axis sensor. An optimal axis for monitoring a physiological signal of the patient is identified from the real axes of the multi-axis sensor and multiple virtual axes. Coordinates defining the optimal axis are stored as respective weighting factors of the signals from each real axis of the multi-axis sensor. A metric of the physiological signal is determined using the multi-axis sensor signals and the weighting factors.
Abstract:
Cardiac resynchronization therapy (CRT) delivered to a heart of a patient may be adjusted based on detection of a surrogate indication of the intrinsic atrioventricular conduction of the heart. In some examples, the surrogate indication is determined to be a sense event of the first depolarizing ventricle of the heart within a predetermined period of time following the delivery of a fusion pacing stimulus to the later depolarizing ventricle. In some examples, the CRT is switched from a fusion pacing configuration to a biventricular pacing configuration if the surrogate indication is not detected, and the CRT is maintained in a fusion pacing configuration if the surrogate indication is detected.
Abstract:
A device includes a signal generator module, a processing module, and a housing. The signal generator module is configured to deliver pacing pulses to an atrium. The processing module is configured to detect a ventricular activation event and determine a length of an interval between the ventricular activation event and a previous atrial event that preceded the ventricular activation event. The processing module is further configured to schedule a time at which to deliver a pacing pulse to the atrium based on the length of the interval and control the signal generator module to deliver the pacing pulse at the scheduled time. The housing is configured for implantation within the atrium. The housing encloses the stimulation generator and the processing module.