Abstract: Computer implemented methods and systems for detecting noise in cardiac activity are provided. The method and system obtain a far field cardiac activity (CA) data set that includes far field CA signals for a series of beats, overlay a segment of the CA signals with a noise search window, and identify turns in the segment of the CA signals. The method and system determine whether the turns exhibit a turn characteristic that exceed a turn characteristic threshold, declare the segment of the CA signals as a noise segment based on the determining operation, shift the noise search window to a next segment of the CA signal and repeat the identifying, determining and declaring operations; and modify the CA signals based on the declaring the noise segments.

Abstract: 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.

Abstract: A lens assembly includes a lens including an optical portion refracting light and a flange portion extended along a periphery of at least a portion of the optical portion, and a lens barrel accommodating the lens. The lens includes a first D-cut portion on one side surface of the flange portion spaced apart from the lens barrel and a second D-cut portion on another side surface of the flange portion spaced apart from the lens barrel, wherein the first D-cut portion and the second D-cut portion each include first inclined surfaces, and the first inclined surfaces are spaced apart from respective ends of the first D-cut portion and the second D-cut portion by a predetermined interval.

Abstract: During cross-chamber pacing, where anodal capture may not be desirable, pulses are applied between a cathode electrode in a first chamber and an anode electrode in a second chamber. A capture detector detects for capture of the second chamber by the pacing pulses. If capture of the second chamber persists, another electrode is selected as the anodal electrode. During single-chamber pacing, where anodal capture may be desirable, pulses are applied between a cathode electrode and an anode electrode associated with the same chamber. A capture detector detects for capture at both electrodes. If anodal capture is not detected, the energy of the pacing pulse is increased, until anodal capture is detected.

Abstract: In specific embodiments, a method for estimating central arterial blood pressure (CBP), comprises determining a time t1 from a predetermined feature of a signal indicative of electrical activity to a predetermined feature of one of a first and second signals, the time t1 being a first pulse arrival time (PAT1) indicative of how long it takes a pulse wave to travel from the aorta to one of a first and second sites, determining a time t2, the time t2 being a second pulse arrival time (PAT2) indicative of how long it takes a pulse wave to travel from the aorta to the other of the first and second sites, and (f) estimating the patient's central arterial blood pressure (CBP) based on the first pulse arrival time (PAT1) and the second pulse arrival time (PAT2).

Abstract: In specific embodiments, a method for estimating central arterial blood pressure (CBP), comprises determining a time t1 from a predetermined feature of a signal indicative of electrical activity to a predetermined feature of one of a first and second signals, the time t1 being a first pulse arrival time (PAT1) indicative of how long it takes a pulse wave to travel from the aorta to one of a first and second sites, determining a time t2, the time t2 being a second pulse arrival time (PAT2) indicative of how long it takes a pulse wave to travel from the aorta to the other of the first and second sites, and (f) estimating the patient's central arterial blood pressure (CBP) based on the first pulse arrival time (PAT1) and the second pulse arrival time (PAT2).

Abstract: Techniques are provided for use with an implantable medical device for assessing left ventricular (LV) sphericity and atrial dimensional extent based on impedance measurements for the purposes of detecting and tracking heart failure and related conditions such as volume overload or mitral regurgitation. In some examples described herein, various short-axis and long-axis impedance vectors are exploited that pass through portions of the LV for the purposes of assessing LV sphericity. In other examples, impedance measurements taken along a vector between a right atrial (RA) ring electrode and an LV electrode implanted near the atrioventricular (AV) groove are exploited to assess LA extent, biatrial extent or mitral annular diameter. The assessment techniques can be employed alone or in conjunction with other heart failure detection techniques, such as those based on left atrial pressure (LAP.

Abstract: Techniques are provided for detecting and distinguishing stroke and cardiac ischemia based on electrocardiac signals. In one example, the device senses atrial and ventricular signals within the patient along a set of unipolar sensing vectors and identifies certain morphological features within the signals such as PR intervals, ST intervals, QT intervals, T-waves, etc. The device detects changes, if any, within the morphological features such as significant shifts in ST interval elevation or an inversion in T-wave shape, which are indicative of stroke or cardiac ischemia. By selectively comparing changes detected along different unipolar sensing vectors, the device distinguishes or discriminates stroke from cardiac ischemia within the patient. The discrimination may be corroborated using various physiological and hemodynamic parameters. In some examples, the device further identifies the location of the ischemia within the heart.

Abstract: A method for trending heart failure measures cardiogenic impedance (CI) and obtains signals representing estimates for or direct measurements of at least one of cardiac volume and pressure of the heart when the CI measurements were obtained. The method identifies correction factors based on the signals and applies the correction factors to the contractility estimates. A system for trending heart failure includes a contractility module to determine contractility estimates from CI measurements taken along at least a first vector through a heart, and a collection module to receive signals representing estimates for or direct measurements of at least one of cardiac volume and pressure of the heart when the CI measurements were obtained. The system further includes a factor module to identify correction factors based on the signals and a correction module to apply the correction factors to the contractility estimates.

Abstract: Tachyarrhythmia is treated by applying anti-tachycardia pacing through at least one multi-site electrode set located on, in or around the heart. The electrode set is arranged and located such that an electrical activation pattern having a wave-front between substantially flat and concave is generated through a reentrant circuit associated with the tachyarrhythmia. The electrode set may be one of a plurality of predefined, multi-site electrode sets located on, in or around the atria. Alternatively, the electrode set may be formed using at least two selectable electrodes located on, in or around the atria.

Abstract: An exemplary method includes detecting a change in state of a cardiac valve, detecting elongation of the left ventricle substantially along its major axis, determining a time difference between the change in state of the cardiac valve and the elongation of the left ventricle and, based at least in part on the time difference, deciding whether a diastolic abnormality exists. Other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: An exemplary method includes delivering a cardiac pacing therapy using an electrode configuration for left ventricular, single site pacing or left ventricular, multi-site pacing, measuring a series of interventricular conduction delays using the left ventricular pacing and right ventricular sensing (IVCD-LR), comparing the interventricular conduction delay values to a limit and, based on the comparison, deciding whether to change the electrode configuration for the left ventricular pacing. Other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: Provided herein are implantable systems, and methods for use therewith, for monitoring a patient's pre-ejection interval (PEI). A signal indicative of cardiac electrical activity and a signal indicative of changes in arterial blood volume are obtained. One or more predetermined features of the signal indicative of cardiac electrical activity and the signal indicative of changes in arterial blood volume are detected. The patient's PEI is determined by determining an interval between the predetermined feature of the signal indicative of cardiac electrical activity and the predetermined feature of the signal indicative of changes in arterial blood volume.

Abstract: Techniques are provided for use by an implantable medical device for optimizing the amount of ventricular dyssynchrony induced within a patient during protective pacing. In one example, the device analyzes intracardiac electrogram signals to detect an ischemic event within the heart. The device then delivers pacing stimulus in accordance with adjustable pacing parameters to induce ventricular dyssynchrony within the heart and adjusts the pacing parameters within a range of permissible values to achieve a preferred degree of ventricular dyssynchrony within the patient, so long as there is no significant reduction in left ventricular pumping functionality. Preferably, the pacing parameters are adjusted to maximize or otherwise optimize the degree of dyssynchrony induced within the patient. If a significant reduction in LV pumping functionality is detected, the dyssynchrony-inducing pacing is preferably suspended to avoid any deterioration in the condition of the heart.

Abstract: Embodiments of the present invention are directed to implantable systems, and methods for use therewith, that monitor and modify a patient's arterial blood pressure without requiring an intravascular pressure transducer. In accordance with an embodiment, for each of a plurality of periods of time, there is a determination one or more metrics indicative of pulse arrival time (PAT), each of which are indicative of how long it takes for the left ventricle to generate a pressure pulsation that travels from the patient's aorta to a location remote from the patient's aorta. Based on the one or more metrics indicative of PAT, the patient's arterial blood pressure is estimated. Changes in the arterial blood pressure are monitored over time. Additionally, the patient's arterial blood pressure can be modified by initiating and/or adjusting pacing and/or other therapy based on the estimates of the patient's arterial blood pressure and/or monitored changes therein.

Abstract: An implantable system terminates atrial fibrillation by applying optimized anti-tachycardia pacing (ATP). In one implementation, the system senses and paces at multiple sites on the left atrium. At each site, the system senses reentrant circuits causing the atrial fibrillation. In one implementation, the system applies ATP tuned to the frequency of the reentrant circuit at the electrode that senses the most regular reentrant circuit. In another implementation, the system applies ATP at multiple electrodes, delivering each pulse at each site when the excitable gap is near the site. In other variations, the ATP is optimized for different patterns of sequential, simultaneous, or syncopated delivery to terminate the atrial fibrillation. The system can also monitor multiple heart chambers for cardiac events that favor terminating atrial fibrillation via ATP. The system then times delivery of the ATP according to these cardiac events.

Abstract: A method of calculating a timing delay for an implantable medical device based on cardiogenic impedance estimates cardiogenic impedance from a signal between a first electrode and a second electrode positioned in at least one chamber of a heart. The method also determines the timing delay based on the estimated cardiogenic impedance.

Abstract: Implantable systems and method for use therewith are provided that take advantage of various neuromodulation and neurosensing techniques for either preventing atrial fibrillation (AF) or terminating AF. Specific embodiments are for use with an implantable device that includes one or more atrial electrode for sensing atrial fibrillation (AF) and/or delivering Atrial Anti-Tachycardia Pacing (AATP) and one or more electrode for monitoring and/or stimulating atrial vagal fat pads.

Abstract: Techniques are provided for use with implantable medical devices for addressing encapsulation effects, particularly in the detection of cardiac decompensation events such as heart failure (HF) or cardiogenic pulmonary edema (PE.) In one example, during an acute interval following device implant, cardiac decompensation is detected using heart rate variability (HRV), ventricular evoked response (ER) or various other non-impedance-based parameters that are insensitive to component encapsulation effects. During the subsequent chronic interval, decompensation is detected using intracardiac or transthoracic impedance signals. In another example, the degree of maturation of encapsulation of implanted components is assessed using impedance frequency-response measurements or based on the frequency bandwidth of heart sounds or other physiological signals.

Abstract: Techniques are provided for detecting and distinguishing stroke and cardiac ischemia based on electrocardiac signals. In one example, the device senses atrial and ventricular signals within the patient along a set of unipolar sensing vectors and identifies certain morphological features within the signals such as PR intervals, ST intervals, QT intervals, T-waves, etc. The device detects changes, if any, within the morphological features such as significant shifts in ST interval elevation or an inversion in T-wave shape, which are indicative of stroke or cardiac ischemia. By selectively comparing changes detected along different unipolar sensing vectors, the device distinguishes or discriminates stroke from cardiac ischemia within the patient. The discrimination may be corroborated using various physiological and hemodynamic parameters. In some examples, the device further identifies the location of the ischemia within the heart.