Abstract: The present invention provides an apparatus for detecting and monitoring obstructive sleep apnea. The apparatus measures sinus tachycardia and a change in the atrial-ventricular conduction, and includes a controller for receiving the measurement of the sinus tachycardia and the change in the atrial-ventricular conduction to detect obstructive sleep apnea based upon the sinus tachycardia and the change in the atrial-ventricular conduction.

Abstract: A method of ablating an epicardial tissue region, including positioning a medical device adjacent the epicardial tissue region, the medical device having a first electrode, a second electrode, and a third electrode located in between the first and second electrodes; delivering an irrigation fluid to the tissue region; and ablating at least a portion of the tissue region by sequentially activating the third electrode in a monopolar radiofrequency delivery mode and activating the first and second electrodes in a bipolar radiofrequency delivery mode.

Abstract: A method and system for detecting microbubble formation during a radiofrequency ablation procedure. The method includes measuring an impedance of a pair of electrodes, at least one electrode in the pair of electrodes being coupled to a treatment assembly of a medical device. Radiofrequency ablation energy is transmitted between the pair of electrodes. The transmission of radiofrequency ablation energy between the pair of electrodes is terminated when after a predetermined period of time the measured impedance in either of the electrodes in the pair of electrodes is a predetermined percentage above a measured minimum impedance and a measured power is above a predetermined power threshold. An alert is generated indicating at least one of the formation and release of microbubbles proximate the pair of electrodes.

Abstract: Systems and methods for assessing tissue contact, including positioning an electrode adjacent a tissue region; delivering radiofrequency energy to the electrode, wherein the delivered radiofrequency energy is sufficient to ablate at least a portion of the tissue region; obtaining a plurality of impedance measurements from the electrode during the delivery of the radiofrequency energy; calculating a change in the impedance measurements over a pre-determined time period; and generating an alert if the calculated change is less than a pre-defined value.

Abstract: Systems and methods for assessing electrode position, including positioning a plurality of electrodes within a heart and proximate a pulmonary vein; obtaining an impedance measurement from each of the plurality of electrodes; determining whether any of the plurality of electrodes is located within the pulmonary vein based at least in part on the obtained impedance measurements; and generating an indication if at least one of the plurality of electrodes is determined to be located within the pulmonary vein.

Abstract: A method and system for detecting a short circuit during a radiofrequency ablation procedure. The method includes measuring an impedance of a pair of electrodes coupled to a treatment assembly of a medical device. Radiofrequency ablation energy is transmitted between the pair of electrodes. The transmission of radiofrequency ablation energy between the pair of electrodes is terminated when after a predetermined period of time the measured impedance in either of the electrodes in the pair of electrodes is below a predetermined threshold impedance value. An alert is generated indicating a short circuit between the pair of electrodes.

Abstract: The present invention provides a method and apparatus for detecting and monitoring obstructive sleep apnea. The apparatus measures sinus tachycardia and a change in the atrial-ventricular conduction, and includes a controller for receiving the measurement of the sinus tachycardia and the change in the atrial-ventricular conduction to detect obstructive sleep apnea based upon the sinus tachycardia and the change in the atrial-ventricular conduction.

Abstract: A method of assessing a tissue ablation treatment, including positioning a medical device adjacent a target tissue; measuring a first impedance magnitude a first frequency with the medical device; measuring a first impedance phase at a second frequency with the medical device; ablating at least a portion of the target tissue with the medical device; measuring at second impedance magnitude at a third frequency with the medical device; measuring a second impedance phase at a fourth frequency with the medical device; comparing at least one of (i) the first and second impedance magnitudes and (ii) the first and second impedance phases; and providing an indication of the efficacy of the ablation treatment based at least in part on the comparison.

Abstract: In an implantable medical device that provides atrial and ventricular pacing in an atrial-based pacing mode, longer periods of time are permitted for intrinsic AV conduction to occur. By monitoring the patient's AV delay under these circumstances, useful information is obtained that can be correlated to other patient conditions or symptoms.

Abstract: A method of ablating an epicardial tissue region, including positioning a medical device adjacent the epicardial tissue region, the medical device having a first electrode, a second electrode, and a third electrode located in between the first and second electrodes; delivering an irrigation fluid to the tissue region; and ablating at least a portion of the tissue region by sequentially activating the third electrode in a monopolar radiofrequency delivery mode and activating the first and second electrodes in a bipolar radiofrequency delivery mode.

Abstract: Techniques for storing electrograms (EGMS) that are associated with sensed episodes or events that may be non-physiological and, instead, associated with a sensing integrity condition are described. In some examples, a device or system identifies suspected non-physiological NSTs, and stores an EGM for the suspected non-physiological NSTs within an episode log. In some examples, a device or system determines whether to store an EGM for a suspected non-physiological episode or event based on whether an impedance integrity criterion has been satisfied. For example, a device or system may store an EGM for a detected short interval if the impedance integrity criterion has been met. In some examples, a device or system determines whether to buffer EGM data based on whether an impedance integrity criterion or other sensing integrity criterion has been met.

Abstract: A medical method, device, and system are provided, including advancing an ablation element of a medical device into contact with tissue to be treated, selecting a power level of energy to ablate the tissue, delivering energy at the selected power level to the ablation element, determining whether the ablation element is in continuous contact with the tissue, and reducing the selected power level when the ablation element ceases to be in continuous contact with the tissue.

Abstract: A medical method, device, and system are provided, including advancing an ablation element of a medical device into contact with tissue to be treated, selecting a power level of energy to ablate the tissue, delivering energy at the selected power level to the ablation element, determining whether the ablation element is in continuous contact with the tissue, and reducing the selected power level when the ablation element ceases to be in continuous contact with the tissue.

Abstract: The present invention provides a method and apparatus for detecting and monitoring obstructive sleep apnea. The apparatus includes an intracardiac impedance sensor to measure intracardiac impedance, a movement sensor to measure an amount of movement of a patient, and a controller operatively coupled to said intracardiac impedance sensor and said movement sensor, said controller adapted to receive at least one of an intracardiac impedance and the amount of movement of the patient and detect obstructive sleep apnea based upon said intracardiac impedance and said movement.

Abstract: System and method for ablating tissue of a heart of a patient. The tissue is characterized, then a predetermined ablation procedure is selected based on the characterization, ablation energy is delivered according to procedure with the ablation device, and a temperature of the tissue and an impedance of the tissue are determined. Delivery of ablation energy is ceased at a time based, at least in part, on when at least one of an accumulated effective temperature of the tissue over time exceeds a thermal dose threshold and an accumulated effective energy of the tissue over time exceeds an effective energy threshold. Else, the ablation energy delivered is modified by adjusting the energy level based, at least in part, on at least one of the temperature being outside of a predetermined temperature range and the impedance being outside of an impedance range.

Abstract: A method of assessing lesion quality of an ablated tissue region comprising ablating at least a portion of the tissue region. The reactance of the ablated tissue region is measured. The lesion quality of the ablated tissue region is determined based on the measured reactance.

Abstract: A medical treatment system, including a catheter body defining a fluid flow path therethrough; an expandable element disposed on the catheter body, the expandable element defining a cooling chamber therein in fluid communication with the fluid flow path; a plurality of electrodes disposed on the expandable element; a cryogenic fluid source in fluid communication with the fluid flow path; and a radiofrequency energy source in electrical communication with the plurality of electrodes. A method of treating a cardiac tissue site proximate an orifice, including substantially occluding the orifice with an expandable element; powering a plurality of electrodes coupled to the expandable element to reach a predetermined target temperature; circulating a coolant through the expandable element to freeze portions of the cardiac tissue site located between the plurality of electrodes; and ablating the non-frozen portions of the tissue site with the plurality of electrodes.

Abstract: In an implantable medical device that provides atrial and ventricular pacing in an atrial-based pacing mode, longer periods of time are permitted for intrinsic AV conduction to occur. By monitoring the patient's AV delay under these circumstances, useful information is obtained that can be correlated to other patient conditions or symptoms.

Abstract: Multiple sensing configurations may be qualified based on one induced tachyarrhythmia, e.g., ventricular fibrillation, or other qualification event during an implantation procedure. Each sensing configuration comprises a different combination of two or more electrodes used for sensing electrical signals of the heart of the patient. In some examples, an implantable medical device or other device generates qualification information for each sensing configuration, which may indicate whether the sensing configuration is qualified for subsequent cardiac event detection based on an accuracy of the cardiac event detection for the sensing configuration during the qualification event. One of the qualified configurations may initially be selected as a primary sensing configuration for subsequent cardiac event detection. Switching to an alternate sensing configuration, e.g.

Abstract: In an implantable medical device that provides atrial and ventricular pacing in an atrial-based pacing mode, longer periods of time are permitted for intrinsic AV conduction to occur. By monitoring the patient's AV delay under these circumstances, useful information is obtained that can be correlated to other patient conditions or symptoms.