Abstract: Embodiments of the invention provide an ablation apparatus for ablating target tissue adjacent pulmonary veins of a patient. The ablation apparatus can include a tube capable of being advanced around the pulmonary veins to form a loop. The tube can receive or include electrodes to ablate target tissue. Some embodiments provide a loop ablation device, which may include a cannula and two or more electrode rods carrying two or more bipolar electrodes. The electrode rods can be advanced through the distal ends toward the proximal ends of the loop and toward the target tissue. The bipolar electrodes can receive energy to ablate the target tissue. The bipolar electrodes may be surrounded by the liquid within the cannula while ablating the target tissue. The loop ablation device can further include a rotating grasping mechanism coupled to the electrode rods.

Abstract: Apparatus and method for ablating target tissue including a non-linear area of tissue in the left atrium of a patient. The method can include selecting an ablation apparatus having an ablator with a tissue engagement section, penetrating a chest cavity of the patient, and identifying the target tissue. The method can also include positioning the ablation apparatus adjacent to the target tissue so that the tissue engagement section can transfer ablation energy to the target tissue. The method can further include energizing the tissue engagement section with ablation energy in order to create a footprint on the non-linear area of tissue in the left atrium and to reduce an overall mass of excitable tissue in the left atrium.

Abstract: A tissue ablation device has a handle and an ablation head coupled to the handle. The ablation head has a first jaw, a second jaw, and an ablative element coupled to at least one of the first and second jaws. A thickness measurement device may be coupled to the ablation device to indicate the distance separating the first and second jaws. Further, a force measurement device may be coupled to the ablation device to measure the force being applied by the first and second jaws to a piece of tissue. Further, a strain measurement device may be coupled to the ablation device to indicate the strain resulting in a piece of tissue disposed between the first and second jaws when a stress is applied to the tissue.

Abstract: A system and method of making a lesion on living tissue including providing an electrosurgical system, determining a desired lesion depth, selecting a power setting, and applying electrical energy to the living tissue. The system includes an instrument having an electrode at a distal portion thereof, and a power source having multiple available power settings. The power source is electrically connected to the electrode. The step of applying electrical energy includes energizing the electrode at the selected power setting for a recommended energization time period that is determined by reference to predetermined length of time information and based upon the desired lesion depth and the selected power setting. The system preferably further includes a fluid source for irrigating the electrode at an irrigation rate. In this regard, the predetermined length of time information is generated as a function of irrigation rate.

Abstract: A device for ablating tissue is provided. The device comprises a conductive element with a channel for irrigating fluid formed therein, which is in contact with a non-conductive microporous interface. All or a portion of the interface may be removable. When the interface is removed, a portion of the conductive element is exposed for use in ablating tissue. Methods of using the device and of removing the interface are also provided.

Abstract: A system and method for creating lesions and assessing their completeness or transmurality. Assessment of transmurality of a lesion is accomplished by monitoring the impedance of the tissue to be ablated. Rather than attempting to detect a desired drop or a desired increase impedance, completeness of a lesion is detected in response to the measured impedance remaining at a stable level for a desired period of time, referred to as an impedance plateau. The mechanism for determining transmurality of lesions adjacent individual electrodes or pairs may be used to deactivate individual electrodes or electrode pairs, when the lesions in tissue adjacent these individual electrodes or electrode pairs are complete, to create an essentially uniform lesion along the line of electrodes or electrode pairs, regardless of differences in tissue thickness adjacent the individual electrodes or electrode pairs.

Abstract: A method of and a system for treatment of atrial tachyarrhythmias. The system includes a set of hemostats having elongated opposing jaws carrying mechanisms for applying ablation energy along the jaws. The jaws having straight and curved configurations selected to allow arrangement of the jaws of along opposite sides of walls of a patient's atrium. Treatment is accomplished by applying of ablation energy to the walls of a patient's artria to create lines of lesion corresponding generally to incisions employed in a Maze type procedure.

Abstract: A system and method of making a lesion on living tissue including providing an electrosurgical system, determining a desired lesion depth, selecting a power setting, and applying electrical energy to the living tissue. The system includes an instrument having an electrode at a distal portion thereof, and a power source having multiple available power settings. The power source is electrically connected to the electrode. The step of applying electrical energy includes energizing the electrode at the selected power setting for a recommended energization time period that is determined by reference to predetermined length of time information and based upon the desired lesion depth and the selected power setting. The system preferably further includes a fluid source for irrigating the electrode at an irrigation rate. In this regard, the predetermined length of time information is generated as a function of irrigation rate.

Abstract: An electrosurgical instrument including an elongated shaft and a non-conductive handle. The shaft defines a proximal section, a distal section, and an internal lumen extending from the proximal section. The distal section forms an electrically conductive tip and defines at least one passage for distributing fluid. Further, the shaft is adapted to be transitionable from a straight state to a first bent state. The shaft is capable of independently maintaining the distinct shapes associated with the straight state and the first bent state. The handle is rigidly coupled to the proximal section of the shaft. With this in mind, an exterior surface of the shaft distal the handle and proximal the distal section is electrically non-conductive. In one preferred embodiment, the shaft is comprised of an elongated electrode body surrounded by an electrical insulator.

Abstract: A system and method of making a lesion on living tissue including providing an electrosurgical system, determining a desired lesion depth, selecting a power setting, and applying electrical energy to the living tissue. The system includes an instrument having an electrode at a distal portion thereof, and a power source having multiple available power settings. The power source is electrically connected to the electrode. The step of applying electrical energy includes energizing the electrode at the selected power setting for a recommended energization time period that is determined by reference to predetermined length of time information and based upon the desired lesion depth and the selected power setting. The system preferably further includes a fluid source for irrigating the electrode at an irrigation rate. In this regard, the predetermined length of time information is generated as a function of irrigation rate.

Abstract: A system to provide cardiac assistance to a patient's heart. The system includes a pulse generator adapted to be coupled to patient's heart and adapted to be coupled to a skeletal muscle ventricle (SMV). The system further includes a sewing ring adapted to be coupled to the SMV and adapted to be coupled to the patient's circulatory system, the sewing ring has a flexible cylindrical sleeve having a distal end and a proximal end, the flexible cylindrical sleeve defining a lumen therewithin, the ring further features a means for maintaining the patency of the lumen, the means for maintaining the patency positioned on the proximal end. In the preferred embodiment the means for maintaining the patency of the lumen is a reinforcing ring mounted to the proximal end of the flexible cylindrical sleeve, preferably a silicone ring.

Abstract: A cardiac assist device having muscle augmentation after a confirmed arrhythmia. In particular the present invention operates, in a first embodiment, to sense a cardiac event, next it determines whether the cardiac event is a cardiac arrhythmia, if the event is not a cardiac arrhythmia the devices delivers stimulation to a skeletal muscle grafted about a heart, but if the event is a cardiac arrhythmia the device inhibits delivery of skeletal muscle stimulation and once the arrhythmia is confirmed, then delivers therapeutic stimulation to the heart. In a second embodiment the present invention operates to re-initiate skeletal muscle stimulation once the arrhythmia is confirmed but prior to the delivery of the therapeutic stimulation to the heart.

Abstract: A cardiac assist device having circadian muscle stimulation. In particular the present invention operates in one of two states, either day mode or night mode. During the day mode, muscle stimulation and conditioning are performed according to a first schedule. During the night mode, muscle stimulation and conditioning are performed according to a second schedule. In addition, the night mode is only reached if the night mode is permitted, a set number of sensed beats are less than the night mode rate, and the time of day is nighttime. The night mode is interrupted if the night mode is turned off, the time of day is daytime, or a set number of beats are greater than the night rate. In short, the present invention provides for skeletal muscle stimulation at a less fatiguing level during the night than during the day.

Abstract: A cardiac assist device which provides an improved method of conditioning a skeletal muscle graft. In particular the present invention features a memory. The memory contains a regime to transform the muscle. Typically the regime has a schedule of various muscle stimulation parameters which may be varied during the muscle training period. When the memory is activated the muscle conditioning regime is automatically altered during the desired time period. In the preferred embodiment the memory features several training schedules, any one of which may be selected. The present invention further features an interrupt to temporarily disable the muscle training regime in the event the onset of a cardiac arrythmia is detected. Once the arrythmia is confirmed, then the cardiac assist device delivers therapeutic stimulation to the heart. After the termination of the arrythmia is confirmed the muscle training regime is re-initiated at the point in the therapy it would have been if it had not been inhibited.

Abstract: A device and algorithm for a combined cardiomyostimulator and a cardiac pacer-cardioverter-defibrillator.