Abstract: A method of etching a foil for use in an electrolytic capacitor utilizes a nanoimprinted optic to control the etch pattern. The optic is formed by creating a self-assembled monolayer (SAM) of hemispheres onto the surface of an optical quartz substrate. A laser is directed onto the optic while the foil underlies the optic, and the concentrated light source is used to effectively image an array of submicron spots. The resulting spots allow for controlled initiation of etch tunnels during a subsequent electrochemical etch of the foil, with the purpose of ultimately increasing foil capacitance through the increased surface area.

Abstract: An exemplary method includes receiving a signal from an intrathoracic vibration sensor, analyzing the signal for vibration associated with deceleration of blood flow into the left ventricle, based at least in part on the analyzing, deciding whether to call for adjustment to one or more parameters of a bi-ventricular pacing therapy. Other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: Techniques are provided for estimating optimal atrioventricular pacing delay values for use in pacing the ventricles based on features of an intracardiac electrogram (IEGM) signal. Briefly, atrioventricular pacing delay pacing values are set based upon the location of atrial repolarization events within the IEGM. In one example, the end of an atrial repolarization is identified, then the interval from the atrial depolarization to the end of the atrial repolarization is measured. The atrioventricular pacing delay is then set by subtracting an offset value from that interval so as to time delivery of V-pulses prior the end of atrial repolarization. In this manner, atrioventricular pacing delay values are set based only IEGM signals and hence can be set to optimal/preferred values by the device itself without requiring surface electrocardiogram (EKG) signals and Doppler echocardiography or other cardiac performance monitoring techniques.

Abstract: Systems and methods for penetrating a tissue membrane to gain access to a target site are disclosed. In some examples, systems and methods for accessing the left atrium from the right atrium of a patient's heart are carried out by puncturing the intra-atrial septal wall. One embodiment provides a system for transseptal cardiac access that includes a guiding catheter, an access catheter and a guidewire. The access catheter may include a tissue penetration member disposed within a housing wherein the tissue penetration member is substantially contained within the housing when in a retracted configuration. When the distal end of the access catheter is disposed adjacent the septal wall, the user can initiate an actuator switch, which may be in a proximal portion of the system, to cause the tissue penetration member to extend through the septal wall.

Abstract: A lead for connecting to a pacing and/or defibrillation power source is disclosed herein. The lead includes a lead tubular body, a connector for connecting the lead to the power source, and a strain-flex relief assembly joining the lead tubular body to the connector assembly and including a helical multi-strand cable conductor configuration.

Abstract: T-wave amplitude and QT interval are derived from patient cardiac signals. Then blood glucose levels are determined based on a combination of the T-wave amplitude and the QT interval. By using a combination of both T-wave-based and QT interval-based signals, blood glucose levels can be reliably detected throughout a wide range of blood glucose levels. Once the blood glucose level has been detected, the implanted device compares the blood glucose level against upper and lower acceptable bounds and appropriate warning signals are generated if the level falls outside the bounds. In one example, wherein an implantable insulin pump is additionally provided, the pump is controlled based on the detected blood glucose level to maintain glucose levels within an acceptable range. A calibration technique is also provided for determining patient-specific parameters for use in the detection of blood glucose levels.

Abstract: A plurality of electrodes are implanted in, on or near the patient's heart and initially configured to define first circuits or vectors enabled for at least one of sensing and stimulating and second circuits or vectors which are idle for at least one of sensing and stimulating. Selected first circuits or second circuits are tested for fault indications related to one or both of sensing and stimulating and a status record is updated to indicate corresponding sensing fault indications and stimulating fault indications. If a sensing fault is found in one of the first circuits, the first circuit is redefined when enabled for sensing to include at least one electrode of a second circuit that does not have a record of a sensing fault indication. Likewise, if a stimulating fault is found in one of the first circuits, the first circuit is redefined when enabled for stimulating to include at least one electrode of a second circuit that does not have a record of a stimulating fault indication.

Abstract: A method of forming a tubular body for a catheter, sheath or lead comprises extruding a polymer core having an integrally formed core wall, first lumen, and second lumen, placing a first layer over an outer circumferential surface of the extruded polymer core, and bonding the first layer to the circumferential surface of the extruded polymer cover via a reflow process. The first and second lumens are mandrel free during the reflow process, and a temperature of the reflow process is below a softening point of the polymer core to maintain a collapse free first and second lumen.

Abstract: Techniques are provided for detecting and evaluating ventricular dyssynchrony based on morphological features of the T-wave and for controlling therapy in response thereto. For example, the number of peaks in the T-wave, the area under the peaks, the number of points of inflection, and the slope of the T-wave can be used to detect ventricular dyssynchrony and evaluate its severity. As ventricular dyssynchrony often arises due to heart failure, the degree of dyssynchrony may also be used as a proxy for tracking the progression of heart failure. Pacing therapy is automatically and adaptively adjusted based on the degree of ventricular dyssynchrony so as to reduce the dyssynchrony and thereby improve cardiac function.

Abstract: An implantable cardiac stimulation device provides bichamber pacing and dynamic bichamber and single chamber sensing. The device includes a sensing circuit that senses activity of a heart, a lead system coupled to a plurality of chambers of the heart, and a cardiac rate circuit that determines a cardiac rate of the heart. A control circuit causes the lead system to couple the sensing circuit to corresponding chambers of the heart to enable bichamber trigger pacing when the cardiac rate is below a given rate and to a single chamber of the heart when the cardiac rate is above the given rate to enable enhanced tachycardia sensing.

Abstract: An implantable cardiac stimulation device monitors the progression and/or regression of heart disease. The device comprises a sensing circuit that senses activity of a heart and provides an electrogram for each one of a plurality of cardiac cycles, an averaging circuit that averages a number of the plurality of electrograms at spaced apart intervals to provide averaged trend electrograms, and a data generator that provides a metric reflective of progression or regression of heart failure responsive to a difference between a current averaged trend electrogram and a previous averaged trend electrogram.

Abstract: An exemplary method includes providing a maximum right ventricular systolic pressure value and corresponding time during a cardiac cycle, providing a left ventricular displacement value for the corresponding time, determining a product of the maximum right ventricular systolic pressure value and the magnitude of the left ventricular displacement value and assessing ventricular synchrony for the cardiac cycle based at least in part on the product. Such a method may include adjusting one or more cardiac pacing parameters based at least in part on the product. Other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: A lead of the present invention comprises an electrode array adapted to be stably anchored at a selected location within the vena cava of a human patient. The electrode array may take various shapes, including helical, annular and linear. The electrode array is connectable to an electrical stimulation means such as an implantable pulse or signal generator. Electrical stimulation applied to a selected region of the vena cava and across the wall of the vein, that is, transvascularly, to the vagus nerve or branches thereof, depolarizes the nerve to thereby effect control of the heart rate.

Abstract: One or more sensors sense patient heart rate and patient activity and provide related signals to a processor. The processor is responsive to sensor signals and obtains an activity threshold based on historical patient heart-rate signals and historical patient activity signals. The processor periodically derives a correlation value from current patient heart-rate signals and current patient activity signals and compares the correlation values to the activity threshold. A start of activity is noted when a correlation value exceeds the activity threshold; while an end of activity is noted when a correlation value fails to exceed the activity threshold. Activity is identified as exercise when correlation values continue to exceed the activity threshold for a predetermine amount of time, while an end of exercise is noted when correlation values fall below the activity threshold for a predetermined amount of time.

Abstract: A bioelectric battery used to power an implantable device comprises an anode electrode and a cathode electrode separated by an insulating member. The anode is formed from a nanocrystalline or ultra fine grain sized magnesium alloy. The magnesium alloy can be formed by subjecting a starting magnesium alloy to one or more plastic deformation treatments to reduce grain size and improve uniform material distribution, thereby reducing corrosion loss and improving service life.

Abstract: A glycemic condition is indicated based on variance of a feature derived from cardiac electrogram data. Neurostimulation is then used to counteract a cardiac-related autonomic response to the glycemic condition. For example, stimulation of parasympathetic innervation may be used to counteract an autonomic sympathetic response that is associated with hypoglycemia or hyperglycemia. In addition, stimulation of sympathetic innervation may be used to counteract an autonomic parasympathetic response that is associated with hypoglycemia or hyperglycemia.

Abstract: Embodiments of the present invention relate to monitoring a patient's atrial stretch, heart failure (HF) condition, and/or risk of atrial fibrillation (AF), as well as methods for estimating a change in at least one of a patient's left atrial pressure (LAP), pulmonary capillary wedge pressure (PCWP), and right pulmonary artery pressure (RPAP). Embodiments of the present invention also relate to selecting a pacing energy level. Such embodiments involve determining atrial evoked response metrics when a patient's atrium is paced, and monitoring changes in such metrics.

Abstract: A hardware-based state machine is provided for use in a pacemaker or other implantable cardiac stimulation device for use in discriminating near field signals sensed in the atria from far field signals emanating from the ventricles. The state machine is interposed between atrial/ventricular channel sense amplifiers and a main microcontroller of the device. The state machine operates to quarantine each P-wave interrupt received from the atrial channel sense amplifier to determine whether the P-wave interrupt corresponds to a true P-wave (i.e. a near field P-wave) as opposed to a false P-wave (i.e. a far field R-wave). Interrupts corresponding to true P-waves are forwarded by the quarantine circuit to the microcontroller after a short time delay. Interrupts corresponding to false P-waves are not forwarded. Hence, the microcontroller receives only true P-wave interrupts and therefore does not need to devote processing resources to distinguishing between true P-waves and false P-waves.

Abstract: An exemplary method includes delivering stimulation according to one or more stimulation parameters to cause contraction of the diaphragm, monitoring chest activity related to respiration and, in response to the monitoring, adjusting one or more of the one or more stimulation parameters during contraction of the diaphragm and continuing the delivering. Various other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: Techniques are provided for detecting dilated cardiomyopathy within a patient using a pacemaker or other implantable medical device. Briefly, values representative of QT duration and QT dispersion are detected within the patient and then the risk of dilated cardiomyopathy is evaluated based on the values of QT duration and QT dispersion. In one particular example, the implanted device calculates an index representative of the extent to which individual QT duration and QT dispersion values deviate from a daily mean. The device then compares the index against a threshold indicative of a substantial likelihood of the presence of dilated cardiomyopathy within the patient. Additional techniques described herein relate to distinguishing dilated cardiomyopathy from heart failure within patients that may have one or both conditions.