Abstract: Improved methods and apparatus for providing optimal anti-tachycardia pacing (ATP) regimens in response to the return cycle length (RCL) exhibited by an exploratory ATP sequence initially applied upon detection of the tachycardia episode are disclosed. When a tachycardia episode is detected, an exploratory ATP sequence comprising a burst of pacing pulses is delivered, and an exploratory RCL is measured following delivery of the exploratory ATP sequence. A database of successful and unsuccessful ATP regimens associated with stored exploratory RCL values. The measured exploratory RCL and database are utilized to formulate an ATP regimen that is more likely than not to convert the tachycardia episode to NSR.

Abstract: A medical electrical lead, which may be useful in coupling an implantable medical device, is comprised of a first and second lead. The first lead has a first electrode coupled adjacent a distal end portion thereof. The distal end portion of the first lead is anchorable in the coronary sinus of a patient. The second lead is coupled with and moveable along the first lead. The second lead has a second electrode located thereon wherein the position of the first and second electrodes may be varied relative to one another by movement of the second lead along the first lead. A rubber tip holds the relative position of each electrode.

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: A cardiac rhythm management system recognizes patterns of interval durations, distinguishing between events in different heart chambers even though signals associated with those different heart chambers are processed using a commonly shared sensing circuit. A therapy delivery algorithm ignores intervals between cardiac events occurring in different heart chambers when determining a cardiac rate upon which the delivery of therapy is based. This reduces the risk of inappropriate delivery of therapy to the patient. Delayed conduction left ventricular beats are not erroneously recognized as a subsequent right ventricular beat, preventing such short intervals from inappropriately triggering a defibrillation countershock.

Abstract: A system and method for discriminating cardiac rhythms in sensed cardiac complexes associated with at least two cardiac signals, which includes at least two electrodes disposed at different locations in a heart for sensing at least two cardiac signals. A controller through a sensing circuit receives the sensed at least two cardiac signals from the electrodes and processes the sensed at least two cardiac signals to compute interelectrode time differences between the cardiac complexes associated with one of the at least two sensed cardiac signals, and corresponding cardiac complexes associated with the other of the at least two sensed cardiac signals. The controller further computes a detection time difference variability from the computed interelectrode detection time difference variabilities.

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: In an exercise machine, when a measurement starts, an electrocardiographic signal is detected by an electrocardiographic sensor 1 (ST33), a load drive is started (ST4), and heartbeat rate intervals of the electrocardiographic signal are sequentially obtained. A fluctuation of heartbeat rate intervals PI(n) % is obtained from a calculation formula in which the RR interval RR(n+1) of the current heartbeat is subtracted from the RR interval RR(n) of the previous heartbeat, which is then divided by RR(n) and multiplied by 100% (ST5). Entropy is calculated from 128 pieces of such PI (ST6). From the change of the entropy under the gradually increasing load (ST8), a minimum point of the entropy is obtained, which point is designated as an anaerobic threshold point (ST7). The load of the exercise machine is controlled employing this anaerobic threshold.

Abstract: A subcutaneous cardiac device includes a subcutaneous electrode and a housing coupled to the subcutaneous electrode by a lead with a lead wire. The subcutaneous electrode is adapted to be implanted in a frontal region of the patient so as to overlap a portion of the patient's heart.

Abstract: A medical electrode includes a moderately conductive flexible member having a top side and a bottom side with a connector and contact with a flexible member top side for establishing electrical contact with an external apparatus. A non-conductive flexible sheet covers the conductive flexible member top and the connector and a highly conductive ink pattern is disposed on a conductive flexible member bottom side. A moderately high conductive hydrogel adhesive disposed on the conductive flexible member bottom side and cover the conductive ink pattern is provided for adhering electrode to a patients' skin.

Abstract: Techniques are provided for overdrive pacing the ventricles using a pacemaker wherein an increase in an overdrive pacing rate is performed primarily to achieve a high degree of rate smoothing. The ventricles are paced at an overdrive pacing rate selected to permit the detection of the least some intrinsic ventricular pulses and then the overdrive pacing rate is dynamically adjusted based on the detected intrinsic ventricular pulses. In one example, an increase in the ventricular overdrive rate is performed only in response to detection of at least two intrinsic ventricular beats within a predetermined search period. If at least two intrinsic ventricular beats are not detected within the search period, the overdrive pacing rate is decreased.

Abstract: An apparatus and method for verifying capture by first and second pacing pulses in which an evoked response waveform recorded during a pacing event is compared with template waveforms representing capture by the first, second, and both pacing pulses. The evoked response is then classified as representing a type of capture represented by a template waveform if the evoked response waveform highly correlates with one template waveform and has correlation values with the other template waveforms within specified bounds.

Abstract: A cardiac transvenous defibrillation lead has a continuous coil conductor within a layer of insulation. A portion of the coil conductor is exposed as a defibrillation electrode. In order to enhance fluoroscopic visualization of the exposed electrode during implant, the end of the exposed electrode is marked with a radiopaque element. The element may be in the form of an adhesive filled with radiopaque material that is used to backfill under the layer of insulation. Alternatively, a tube made of radiopaque material may be installed between the layer of insulation and the coil conductor.

Abstract: A minute ventilation sensing device in which transthoracic impedance is measured with voltage sense electrodes during injection of current by excitation current electrodes. The device is capable of operating with different configurations of voltage sense and excitation current electrodes. By computing a signal and/or noise level for a number of available configurations, the electrodes resulting in the highest signal-to-noise ratio may be selected for use by the device.

Abstract: A method and apparatus for analyzing a physiological waveform. The apparatus comprising an input terminal for connection to a patient to acquire the physiological waveform from a patient, an instrumentation amplifier connected to the input terminal to filter the physiological waveform, and an analysis module including a processor and software for operating the processor to detect cyclic artifact in the physiological waveform. The method comprising the acts of obtaining the physiological waveform and determining whether there is more than one independent complex rhythm within the digital physiological waveform.

Abstract: The present invention relates to identifying and using groups of cardiac events associated with depolarization wavefronts to coordinate the delivery of pacing therapy to the heart. According to one aspect of the invention, cardiac events associated with a plurality of cardiac sites are detected. The cardiac sites may be located in a single heart chamber or in bilateral heart chambers. A group of detected cardiac events associated with a depolarization wavefront is identified. According to another aspect of the invention, a particular cardiac event of an identified group associated with a depolarization wavefront may be used to synchronize pacing therapy delivered to the heart. According to yet another aspect, premature ventricular contractions may be classified using the identified groups.

Abstract: A lead assembly includes a flexible lead body extending from a proximal end to a distal end, and the lead body includes two or more conductors disposed therein. The second conductor is disposed within the first conductor, and the second conductor has a coating of insulation on the second conductor. In another option, a sleeve of insulative material is disposed between the first conductor and the second conductor.

Abstract: The present invention is an implantable electronic device formed within a biocompatible hermetic package. Preferably the implantable electronic device is used for a visual prosthesis for the restoration of sight in patients with lost or degraded visual function. The package may include a hard hermetic box, a thin film hermetic coating, or both.

Abstract: In a small sized pump driving unit, a fluid pump is used for driving the pump for supporting of substituting of cardiac function. The fluid pump can generate pressure fluctuations that can generate pulsation of the pump for supporting or substituting of cardiac function and produces sufficient performance to drive the pump unit.

Abstract: A method for the treatment of obesity or other disorders, by electrical activation or inhibition of the sympathetic nervous system. This activation or inhibition can be accomplished by electrically stimulating the greater splanchnic nerve or other portion of the sympathetic nervous system using an implantable pulse generator. This nerve activation can result in reduced food intake and increased energy expenditure. Reduced food intake may occur through a variety of mechanisms that reduce appetite and cause satiety. Increased adrenal gland hormone levels will result in increased energy expenditure. Fat and carbohydrate metabolism, which are also increased by sympathetic nerve activation, will accompany the increased energy expenditure.

Abstract: A hand-held electrocardiograph system with automatic analysis and interpretation is provided. The electrocardiograph includes an acquisition element adapted to be coupled to a patient through a set of relatively short leadwires and a hand-held, battery powered portable processing and display element coupled to the acquisition element and controlled through a graphical user interface.