Abstract: Methods and process for detection of myocardial ischemia involve detection and analysis of changes in electrical conduction velocity within the heart to monitor changes in the condition of the cardiac muscle and indicate possible ischemia. Conduction velocity slows considerably when oxygen supply to the heart is reduced. Analysis of electrical conduction velocity can be used to verify the occurrence of myocardial ischemia in a more reliable manner. Changes in conduction velocity may be monitored based on conduction time between electrodes positioned in the left and right ventricles of the heart. The electrodes may be endocardial or epicardial electrodes. In general, the techniques may involve launching a stimulation waveform at one electrode and sensing a local cardiac depolarization at another electrode to assess conduction time.

Abstract: A method for detecting a cardiac arrhythmia from an electrocardiogram includes the steps of identifying a plurality of R-waves in the electrocardiogram during a predetermined time interval; extracting heartbeat complexes corresponding to the identified R-waves; identifying a key region within each heartbeat complex that is morphologically altered in the event of the cardiac arrhythmia; calculating a statistical measurement of an ensemble of the key regions from each of the heartbeat complexes; and determining from the statistical measurement whether the cardiac arrhythmia occurred during the predetermined time interval. An apparatus is also provided that includes a processor that is coupled to receive an electrocardiogram, and is configured in response thereof to perform the method for detecting a cardiac arrhythmia.

Abstract: Techniques for pacing the heart of a patient as a function of a pressure value make use of a pressure monitor that receives a signal from a pressure sensor in the heart. The pressure monitor measures a pressure value. The pressure monitor may, for example, estimate the pulmonary artery diastolic pressure if the pressure sensor is located in the right ventricle, or calculate the mean central venous pressure if pressure sensor is located in the right atrium. The energy level of the pacing pulses delivered to the patient's heart by a pacemaker is modulated as a function of the pressure value. Modulating the energy level of the pacing pulses modulates the cardiac output of the patient's heart.

Abstract: Devices and methods for measuring a target ion concentration uses an electrode pair. The pair includes a working electrode and a reference electrode. The working and reference electrodes are ion-selective electrodes (ISEs). The reference ISE can include a sodium ISE. The ISE pair interacts with body fluids where a target ion concentration changes more than sodium ion concentration over time. Some ISE membranes of a pair vary essentially only in the ionophore. An ISE pair can determine the ratio of a target ion concentration to sodium ion concentration in vivo. Periodic measurement of sodium concentration in drawn blood can be used to calibrate an ISE pair and provide target ion concentration as an output. Or, a potassium/sodium ISE pair beneficially monitors potassium concentration changes over time in heart- or kidney-failure patients. Then, manual or automatic titration of a diuretic material can be implemented to maintain a desired potassium concentration.

Abstract: A cardiovascular analysis system and method includes an implantable medical device with a sensor positioned to sense a hemodynamic pressure over time. The implantable medical device generates hemodynamic pressure waveform data based upon the hemodynamic pressure sensed. A processor analyzes the hemodynamic waveform data to provide an indication of cardiovascular health based upon prominent peaks in the hemodynamic waveform data.

Abstract: An implantable medical device system for detecting cardiac conditions such the long-term ischemic heart disease, an occlusion of a coronary artery by a thrombus or an impending as a myocardial infarction. The implantable medical device (IMD) system includes a sensor that outputs a blood flow rate signal representing a rate of blood flow through a coronary sinus of a patient's heart. An implantable medical device (IMD) includes a microcomputer circuit configured to analyze the blood flow rate signal and detect a cardiac condition as a function of the blood flow rate signal. The system can also includes an implantable lead that senses electrical activity from the patient's heart. The microcomputer circuit monitors an ST segment of the electrical activity signal and detects a cardiac condition as a function of blood flow rate signal in conjunction with the electrical activity signal.

Abstract: An insulative feedthrough receives an electrical lead therethrough and includes a ferrule having fist and second open ends and an interior surface. At least one polymeric guide member is positioned substantially within the first end of the ferrule and has an aperture therethrough for receiving the lead. An insulating material is deposited in the ferrule through the second end for sealingly engaging the lead and the interior surface of the ferrule.

Abstract: The present invention generally relates to improved capacitors; in particular, the present invention provides advanced valve metal (AVM) anodes and methods for fabricating AVM anodes having complex surface and interior features for use in high energy density capacitors. Such anodes find use in high voltage capacitors incorporated into implantable medical devices (IMDs), among other uses. The AVM anodes may be pressed into virtually any arbitrary shape and may have a gradually changing (or substantially constant) density profile throughout the AVM anode. Such AVM anodes may also be perforated or shaped to receive one or more cathode members. The AVM anodes enhance packaging efficiency for compact high energy density capacitors.

Abstract: An anode subassembly for use in an implantable electrochemical cell includes a solid anode current collector and an alkali metal anode pressed onto the solid anode current collector such that the solid anode current collector is located on the outer side of the outermost winding of a coiled electrode assembly formed when the anode subassembly is wound with a cathode subassembly. The anode subassembly may further include a spacer formed from a microporous, non-conductive material pressed onto the alkali metal anode on the opposite side from the solid anode current collector.

Abstract: An anode subassembly is provided for use in an implantable electrochemical cell wherein the anode subassembly includes an anode current collector designed to eliminate perforation edges in the final, outermost turn of a coiled electrode assembly. The anode current collector may be of a reduced size, discontinuous, or formed from alternating perforated and solid areas. The anode subassembly may further include reinforcing elements to support a thin anode layer in the outermost coil of a coiled, anode-limited cell. Reinforcing elements may take the form of a spacer, extensions extending from a reduced-size anode current collector, or strips of alkali metal.

Abstract: A medical device, e.g., an implantable medical device, delivers one or more neurally-excitable stimulation pulses to myocardial tissue during a period when the tissue is refractory. The width of the pulses is less than or equal to approximately one half millisecond. In some embodiments, the current amplitude of the pulses is less than or equal to approximately twenty milliamps. In exemplary embodiments, the medical device delivers a pulse train of six or fewer pulses separated from each other by an interval that is greater than or equal to approximately ten milliseconds. In some embodiments, the medical device delivers pulses according to a schedule stored in a memory, or as a function of a monitored physiological parameter of a patient, such as an intracardiac pressure. In some embodiments, the medical device suspends or withholds delivery of neurally-excitable based on detection of cardiac ischemia.

Abstract: A conductor assembly and methods for mechanically and electrically coupling a small diameter conductor to a lead component having a relatively larger sized conductor bore is provided. The assembly includes a sizing member sized to fit securely around a relatively small diameter conductor and to further fit within a conductor bore so that temporary compression (e.g., crimping, crushing, or staking) of a discrete portion of the conductor bore mechanically couples, and establishes electrical communication between, the conductor and the lead component. Alternately, a conductive sleeve member having a relatively large diameter conductor bore is adapted to receive a sizing unit to downsize one side of the sleeve member in a manner similar to the foregoing. In this case, a relatively smaller diameter one of a pair of different diameter elongated conductors is firmly mechanically coupled and in electrical communication with a relatively larger diameter conductor.

Abstract: A method of connecting two components includes providing an assembly including a first component and a second component, optically sensing a connection region between the first component and the second component to produce an image, defining a substantially elliptical path in a three-dimensional space based on the image, and initiating relative movement between the assembly and welding means such that the welding means is positioned, by relative movement, along the substantially elliptical path to produce a weld between the first component and the second component.

Abstract: A method of operating a cardiac pacing device that optimizes the mechanical heart rate using coordinated potentiation therapy while maximizing the opportunity for intrinsic AV conduction to occur. The method may include adjusting the timing of extra stimulus intervals during coupled or paired pacing to promote AV conduction and to effect changes in rate according to certain embodiments of the invention. Other embodiments may include adjusting the atrial pacing rate to achieve a desired target rate consistent with AV conduction. A mode switch to a dual-chamber pacing mode may be provided according to certain embodiments of the invention to ensure a ventricular rate that meets or exceeds a minimum mechanical rate.

Abstract: A method and apparatus for determining a metric of cardiac ventricular synchronization and optimizing a cardiac therapy based on the ventricular synchronization metric are provided. A ventricular synchronization metric is determined by: monitoring right and left ventricular pressure; plotting right ventricular pressure as a function of left ventricular pressure to form an RVP-LVP loop; and integrating with respect to direction to determine an area of the RVP-LVP loop which, according to one convention, is mathematically negative during left ventricular led pressure development and is mathematically positive during right ventricular led pressure development. Timing parameters used to control the delivery of cardiac resynchronization therapy or ventricular assist device therapy are adjusted as needed according to the ventricular synchronization metric.

Abstract: An alert system for alerting a clinician to an occurrence of an event detected by an implantable medical device includes a monitor and a patient management network. The implantable medical device includes a means for detecting the occurrence of the event and initiating a wireless transmission of data related to the event. The monitor is configured to receive the wireless transmission of data and transfer the data. The patient management network is configured to receive the data and store the data on a data storage device. The patient management network includes a web presentation service for creating a website from the data stored on the data storage device, the website configured to alert the clinician to the occurrence of the event.

Abstract: Efficient provision of hemodynamic benefits and therapy for patients suffering from intraventricular conduction delays or conduction blockage. By effectively measuring conduction delay or block (e.g., left bundle branch block or “LBBB”) and enhancing delivery of a novel form of left ventricle-only cardiac resynchronization therapy. Accordingly, a single LV fusion pacing stimulus is triggered from an atrial event (e.g., intrinsic or evoked depolarization). The triggering event can emanate from the right atrium (RA) or the left atrium (LA). The single LV fusion pacing stimulus is delivered prior to the intrinsic depolarization of the RV—upon expiration of a “LEPARS interval”—thus efficiently providing intraventricular electromechanical synchrony by fusion. During variations in heart rate the operating AV interval (herein A-LVp interval) is varied while the LEPARS interval is substantially essentially constant, thereby preserving the enhanced hemodynamics resulting from the fusion depolarization.

Abstract: A method and apparatus exercise a battery of an implantable medical device by determining whether a film is disposed on a portion of an electrode of a battery, discharging the battery a sufficient amount to reduce the film, and optimizing energy used during exercising the battery. The apparatus includes a battery having an electrode that develops a resistive film and a low deformation rate capacitor capable of storing a charge from the battery, the capacitor requiring few or no periodic discharges of the battery for reformation. The energy from the battery is periodically discharged into the low deformation-rate capacitor to reduce film buildup on the electrode.

Abstract: A sealed electrode enclosed in separator material is provided for use in a capacitor cell. The separator may either be adhered to the electrode in sheets, or may be formed into a pouch, which is used to enclose the electrode. A method of preparing the electrode sealed with separator is described in which an adhesive is used to secure the pouch to the electrode before sealing it. The prefabricated electrode and separator combination may be used in both coiled capacitor cells and flat capacitor cells that are often used in implantable medical devices. Electrodes prepared in this fashion can be efficiently and reliably aligned within the case of a capacitor cell, and have no exposed electrode surfaces that could lead to short-circuiting within the cell.

Abstract: A system for monitoring a patient and treating the malfunctioning heart of the patient, either in an automatic mode or in a semiautomatic mode, includes means which derive at least one physiologic signal from or related to the patient's circulatory system representative of hemodynamic status. A feedback loop is implemented in a biventricular implant, in order to automatically or selectively optimize the patient's clinical hemodynamic status. Accordingly, the biventricular implant will be programmed to go through a series of AV delay, RV-LV timing and heart rate sequences which scan a preselected range of programmable values and apply those values to the patient's heart. Hemodynamic patient measurements will be recorded and preferably graphed over those applied values.