Abstract: In one embodiment an implantable cardiac device is provided that includes an implantable cardiac stimulation device with an implantable satellite device coupled to it. The implantable satellite device has a charge storage device. The implantable stimulation device having a refresh generator configured to generate a charge and voltage balanced multi-phasic refresh signal with a duration less than a capacitive time constant of an electrode-electrolyte interface of the implantable cardiac device and transmit the charge and voltage balanced multi-phasic refresh signal to the implantable satellite device for charging the charge storage device. In various embodiments, the charge and voltage balanced multi-phasic refresh signal having alternating phase signs and null durations between the alternating phases. In some embodiments, the refresh generator is configured to modulate the multi-phasic waveform refresh signal.

Abstract: A communication device for an implantable medical device may include: an input/output interface configured to communicate with a wireless communication device; a communication interface configured to communicate with a remote system; and a processor configured to perform an analysis of data received from the wireless communication device via the input/output interface and associated with the implantable medical device. The communication device may include a user interface configured to receive data input by a user. A communication system may include a wireless communication device and the aforementioned communication device.

Abstract: A communication wake-up scheme for an implantable medical device may involve repeatedly activating a receiver to determine whether an external device is attempting to establish communication with the implantable device. To reduce the amount of power consumed by the implantable device in conjunction with the wake-up scheme, the scheme may involve conducting preliminary radio frequency signal detections as a precursor to conducting a full scan. In this way, power may be conserved since the more power intensive full scans may be performed less frequently. This preliminary detection of radio frequency signals also may be adapted to reduce the number of full scans performed by the implantable device that do not result in communication with the external device. In some embodiments the adaptation involves adjusting one or more thresholds that are used in conjunction with the preliminary detection of radio frequency signals.

Abstract: The present invention is a method for the production of a high capacitance foil for use as a cathode in an electrolytic capacitor by forming a nitride layer on at least one surface of the foil by annealing the foil at an elevated temperature in the presence of nitrogen gas (N2). By this method, an enhanced foil surface area can be achieved. Since the double layer capacitance of a cathode is proportional to the effective surface area of the cathode, the annealing process increases the cathode capacitance such that it can be effectively used in a high-gain multiple stacked anode electrolytic capacitor. After production of the foil by said method, the foil is cut into a shape that is suitable for assembly in such an electrolytic capacitor, which is commonly used in an implantable cardiac defibrillator (ICD).

Abstract: Embodiments of the present invention relate to implantable systems, and methods for use therewith, for monitoring myocardial electrical stability. A patient's heart is paced for a period of time using a patterned pacing sequence that repeats every N beats, and an electrical signal is obtained that is representative of a plurality of consecutive beats of the patient's heart while it is being paced using the patterned pacing sequence that repeats every N beats. Myocardial electrical stability is then analyzed using time domain techniques that are tailored to the patterned pacing sequence used to pace the patient's heart. In other embodiments, the patient's heart need not be paced. This abstract is not intended to be a complete description of, or limit the scope of, the invention.

Abstract: A method and system are provided for trending variation in coronary burden across multiple heart rate ranges. The method and system include obtaining cardiac signals having a segment of interest over a period of time where each cardiac signal has an associated heart rate that falls within at least one heart rate range. Segment variations of the segment of interest are determined and grouped based on the associated heart rates to produce distributions of segment variations that are associated with the heart rate ranges. Trending information is produced by automatically comparing the distributions of segment variations between different heart rate ranges.

Abstract: Provided herein are implantable systems, and methods for use therewith, that increase the accuracy of measurements produced using an implanted sensor, where the measurements are affected by cycles of a cyclical body function (e.g., heart beat and/or respiration). In accordance with specific embodiments of system, a measurement that is presumed to be accurate is obtained. The measurement can be of a physiologic property, such as, but not limited to, blood oxygen saturation, hematocrit, or blood glucose concentration. Additionally, the implanted is used to produce a plurality of measurements of the physiologic property. Such measurements, produced using the implanted sensor, are compared to the measurement presumed to be accurate to thereby identify when the measurements produced using the implanted sensor are most accurate. Thereafter, the implanted system is configured to use the implanted sensor to produce measurements when the measurements produced using the implanted sensor are most accurate.

Abstract: Provided herein are implantable systems, and methods for use therewith, for estimating a level of noise in a signal produced by an implantable sensor that is sensitive to motion induced noise. Sample data is obtained that is representative of a signal produced by the implantable sensor that is sensitive to motion induced noise. Such a sensor signal has a corresponding morphology. The morphology of a portion of the sensor signal is compared to a template, and a level of motion induced noise in the sensor signal is estimated, based on results of the morphology comparison.

Abstract: Methods and system are provided for monitoring a patients venous blood oxygen saturation (SvO2). At least one signal indicative of electrical activity of a patient's heart is obtained. Such a signal can be, e.g., an IEGM or ECG signal. In specific embodiments, such a signal(s) can be obtained from implanted electrodes, and thus, embodiments of the present invention can be implemented by an implantable system. Additionally, there are measurements of at least one metric of cardiac cycles represented in the at least one signal indicative of electrical activity of the patient's heart, where the metric changes with changes in SvO2. Examples of such metric include T-wave metrics and PR intervals. SvO2, and changes therein, are monitored based on the measured metric(s).

Abstract: Hemodynamic signals, such as photoplethysmography (PPG) signals, pressure signals, and impedance signals, are sampled once per cyclical body cycle to reduce the amount of data, processing and/or power required to analyze the hemodynamic signals.

Abstract: Embodiments of the present invention relate to implantable systems, and method for use therein, that can detect T-wave alternans. In accordance with specific embodiments of the present invention, intrinsic premature contractions of the ventricles are detected, and at least one metric of T-waves is measured in a specified number of beats that follow each detected intrinsic premature contraction of the ventricles. A determination of whether T-wave alternans are present is made based on the measured T-wave metrics. In alternative embodiments, rather than waiting for intrinsic premature contractions of the ventricles, premature contractions of the ventricles are caused on demand by inducing premature atrial contractions. In still other embodiments, a patient's vagus nerve is stimulated to simulate premature contractions of the ventricles. This abstract is not intended to be a complete description of, or limit the scope of, the invention.

Abstract: A method and apparatus for using vagal stimulation to detect autonomic tone and assess a patient's risk of sudden cardiac death (SCD) are presented. The method involves stimulating the patient's vagus nerve in order to induce a drop in arterial blood pressure, which simulates the patient's cardiovascular response to a premature ventricular contraction (PVC). Sinus rhythm data just before and immediately following the stimulation is recorded and analyzed for a degree of heart rate turbulence (HRT) in order to detect abnormalities in autonomic tone and assess the risk of SCD. In an embodiment, the method is implemented in an implantable cardiac device (ICD), which can deliver arrhythmia prevention therapy based on the risk of SCD. The method can assess the patient's vagal activity on-demand by measuring HRT without relying on naturally occurring PVCs and eliminates the risk of causing arrhythmia associated with artificially inducing PVCs in order to measure HRT.

Abstract: Implantable systems, and methods for use therein, for monitoring for mitral valve regurgitation (MR) are provided. An electrogram (EGM) signal and a corresponding pressure signal are obtained, where the EGM signal is representative of electrical functioning of the patient's heart during a plurality of cardiac cycles, and the corresponding pressure signal is representative of pressure within the left atrium the patient's heart during the cardiac cycles. Windows of the pressure signal are defined, based on events detected in the EGM signal, and measurements from the windows are used to monitor for MR.

Abstract: Implantable systems, and methods for use therewith, are provided for using an implantable sensor for detecting body position and/or body movement, and using what is learned therefrom to improve accuracy of an implantable sensor that is sensitive to at least one of body position and/or body movement. Also provided are implantable systems, and methods for use therewith, that detect body position and/or body movement in order to monitor a condition and/or detect specific episodes. Other embodiments are also provided.

Abstract: Techniques are provided for estimating left atrial pressure (LAP) or other cardiac pressure parameters based on various parameters derived from impedance signals. In particular, effective LAP is estimated based on one or more of: electrical conductance values, cardiogenic pulse amplitudes, circadian rhythm pulse amplitudes, or signal morphology fractionation values, each derived from the impedance signals detected by the implantable device. Predetermined conversion factors stored within the device are used to convert the various parameters derived from the electrical impedance signal into LAP values or other appropriate cardiac pressure values. The conversion factors may be, for example, slope and baseline values derived during an initial calibration procedure performed by an external system, such as an external programmer. In some examples, the slope and baseline values may be periodically re-calibrated by the implantable device itself.

Abstract: Methods and systems are provided for expediting set-up of a multi-electrode lead (MEL). In accordance with specific embodiments, such an MEL includes N groups of electrodes, with each of the N groups including at least M electrodes, where N?2 and M is ?2. Electrodes in a same group are within 5 mm of one another. Electrodes in separate groups are at least 10 mm from one another. Specific embodiments relate to methods for identifying cathode-anode electrode configurations that can be used to not exceed a maximum acceptable capture threshold, and that provide a sensed intrinsic R-wave amplitude of at least a minimum acceptable sensing threshold. Such thresholds can be default values, or can be defined by a user (e.g., clinician, physician, nurse, or the like).

Abstract: Methods and systems for performing pacing interval optimization are provided. One or more optimum pacing interval is determined for each of a plurality of different ranges of heart rate, different levels of autonomic tone, different body temperature ranges, or combinations thereof. The information (e.g., measures of hemodynamic response) collected to perform pacing interval optimization can be collected and stored in a table over disjoint periods of time. Such measures of hemodynamic performance are preferably relative measures, but can alternatively be absolute measures.

Abstract: Embodiments of the present invention relate to implantable systems, and method for use therein, that can detect T-wave alternans. In accordance with specific embodiments of the present invention, intrinsic premature contractions of the ventricles are detected, and at least one metric of T-waves is measured in a specified number of beats that follow each detected intrinsic premature contraction of the ventricles. A determination of whether T-wave alternans are present is made based on the measured T-wave metrics. In alternative embodiments, rather than waiting for intrinsic premature contractions of the ventricles, premature contractions of the ventricles are caused on demand by inducing premature atrial contractions. In still other embodiments, a patient's vagus nerve is stimulated to simulate premature contractions of the ventricles. This abstract is not intended to be a complete description of, or limit the scope of, the invention.

Abstract: An implantable stimulation device that maps the location of irritable foci causing an atrial arrhythmia is provided by certain embodiments disclosed herein. The device may, for example, collect intra-cardiac data from a plurality of electrodes spatially distributed throughout a chamber of the heart. This data may be compared with data related to the location of each electrode and the electrical properties of the heart to approximate a point of origin for the atrial arrhythmia. Further embodiments may provide methods and systems for using this information to provide more efficient treatment of the atrial arrhythmia. For example, an optimized ATP pulse train may be determined based on the location of one or more irritable foci. Such an ATP pulse train may be applied to more efficiently terminate the atrial arrhythmia.

Abstract: Methods and devices are provided for reducing motion artifacts when measuring blood oxygen saturation. A portion of the light having the first wavelength, a portion of light having the second wavelength and a portion of the light having the third wavelength are received. A first signal is produced based on the received portion of light having the first wavelength. Similarly, a second signal is produced based on the received portion of light having the second wavelength, and a third signal is produced based on the received portion of light having the third wavelength. A difference between the second signal and the first signal is determined, wherein the difference signal is first plethysmography signal. Similarly, a difference is determined between the third signal and the first signal to produce a second plethysmography signal. Blood oxygen saturation is then estimated using the first and second plethysmography signals.