摘要:
An implantable medical device delivers anti-tachyarrhythmia therapies including anti-tachyarrhythmia pacing (ATP). When a tachyarrhythmia episode is detected, the implantable medical device analyzes cardiac cycle length stability to determine whether and/or when to deliver an ATP. In one embodiment, the cardiac cycle length stability is measured by existence of stable ventricular tachyarrhythmia clusters (SVTCs) during the tachyarrhythmia episode. Each SVTC includes at least a specified minimum number of heart beats over which the cardiac cycle lengths meet a stability criterion.
摘要:
A cardiac rhythm management (CRM) system includes an implantable medical device that delivers anti-tachyarrhythmia therapies including anti-tachyarrhythmia pacing (ATP) and a hemodynamic sensor that senses a hemodynamic signal. The implantable medical device includes a hemodynamic sensor-controlled closed-loop ATP system that uses the hemodynamic signal for ATP capture verification. When ATP pulses are delivered according to a selected ATP protocol to terminate a tachyarrhythmia episode, the implantable medical device performs the ATP capture verification by detecting an effective cardiac contraction from the hemodynamic signal. The ATP protocol is adjusted using an outcome of the ATP capture verification.
摘要:
A geographic location of a network device is determined using response delay times from internet servers used as landmarks. A coordination server provides to a client a list of area landmark servers (ALS) with known geographic locations. The client probes ALSs, measures response delays, and provides results to the coordination server. The coordination server then provides to the client a list of additional city landmark servers (CLS) within the area. The client probes the CLSs and provides results to the coordination server which then determines the geographic location of the client.
摘要:
An apparatus comprises an implantable sensor, which provides a plurality of physiologic sensor signals of a subject, and a processor. The processor includes a feature module and a detection module. The feature module is configured to identify a feature in the sensor signals and to determine a measure of quality of the feature in the sensor signals. The detection module is configured to perform a morphology analysis of a subsequent portion of at least one of the sensor signals using the feature when the measure of quality of the feature satisfies a quality measure threshold.
摘要:
This document discusses, among other things, an apparatus comprising an implantable hemodynamic sensor circuit that provides a hemodynamic signal representative of mechanical function of a cardiovascular system of a subject and a controller circuit communicatively coupled to the hemodynamic sensor circuit. The controller circuit includes a detection module configured to detect an onset of tachyarrhythmia, a signal analyzer module configured to determine a measure of morphological variability of the hemodynamic signal during the episode of tachyarrhythmia, and a rhythm discrimination module configured to deem whether the tachyarrhythmia episode is indicative of ventricular tachycardia (VT) according to the measure of morphological variability.
摘要:
Various implantable medical device embodiments stimulate an autonomic neural target from within a pulmonary artery, and comprise at least one electrode, a power supply, a neural stimulator connected to the power supply, and an anchor structure. The neural stimulator is configured to generate a neural stimulation signal for delivery to the neural stimulation target through the at least one electrode. The anchor structure is configured to chronically and securely implant the neural stimulator, the power supply and the at least one electrode within the pulmonary artery. The anchor structure, the neural stimulator, the power supply and the at least one electrode are configured to be implanted through a pulmonary valve into the pulmonary artery. In various embodiments, the neural stimulator is configured to be operational to implement a neural stimulation protocol when chronically implanted within the pulmonary artery without a wired connection through the pulmonary valve.
摘要:
A method for electrospinning nanofibers having a core-sheath, tubular, or composite structure is disclosed. The process uses a spinneret having first and second capillaries that channel first and second fluids in the spinneret, the second capillary surrounding the first. A high voltage is applied between the spinneret and a spaced conductive collector. In one embodiment, the first fluid is a mineral oil and the second fluid is a polymeric solution that may include a polymer, a catalyst, a solvent, and a sol-gel precursor. The as-spun nanofiber includes an oil core and a composite sheath. The oil may be removed to produce a composite tubular fiber or the polymer and oil may be removed by calcination to produce a ceramic tubular fiber. In other embodiments, miscible fluids are used to produce porous nanofibers, selected additives functionalize the surfaces of the nanofibers and/or conjugated polymers are used.
摘要:
A system evaluates the performance of an implantable medical device, such as by using a remote external server and a user interface and stored historical physiological data of a population of congestive heart failure (CHF) patients. A processor is coupled to a patient data storage device to apply multiple algorithm variations against the same implantable physiological data from the patient to produce corresponding resulting CHF indicators. The user interface includes a display that is configured to display to a user information allowing comparison between the resulting CHF indicators from the multiple algorithm variations. The display also includes a population data selector to permit the user to select physiological data from a population that includes a different set of one or more patients or physiological data collected over a period of time from the patient. This permits optimization of an algorithm parameter or selection of a best performing algorithm.
摘要:
An implantable cardioverter/defibrillator (ICD) includes a tachyarrhythmia detection and classification system that classifies tachyarrhythmias based on a morphological analysis of arrhythmic waveforms and a template waveform. Correlation coefficients each computed between morphological features of an arrhythmic waveform and morphological features of the template waveform provide for the basis for classifying the tachyarrhythmia. In one embodiment, a correlation analysis takes into account the uncertainty associated with the production of the template waveform by using a template band that includes confidence intervals.
摘要:
A system including at least one implantable sensor circuit adapted to produce an electrical sensor signal related to one or more physiologic cardiovascular events of a subject, a therapy circuit configured to provide anti-tachycardia pacing (ATP) therapy, and a controller. The controller includes a tachyarrhythmia detection circuit and an efficacy circuit. The tachyarrhythmia detection circuit is configured to detect a tachyarrhythmia episode in the subject using the electrical sensor signal, and to determine whether the tachyarrhythmia episode is of a type that is treatable with ATP. The efficacy circuit is configured to estimate an efficacy of a currently configured ATP therapy for the subject, and the controller is configured to alter a delivery regimen of the currently configured ATP therapy when the estimated ATP therapy efficacy is deemed insufficient. Other systems and methods are described.