Abstract: A catheter includes a fluid network for cooling the ablation electrode, surrounding blood and tissue. The fluid network comprises a circumferential channel having an annular shape and fluidly coupled to at least one proximal longitudinal channel configured to conduct fluid along a proximal length of the catheter. The circumferential channel is configured to conduct fluid about at least a circumferential portion of the catheter. The fluid network further comprises a plurality of distal longitudinal channels fluidly coupled to the circumferential channel, with the plurality of distal longitudinal channels being configured to conduct fluid a long a distal length of the catheter. The fluid network occupies a region of the catheter peripheral to a central longitudinal axis of the catheter such that other components of the irrigated catheter, including at least one imaging sensor, is disposed within the central region of the ablation electrode.

Abstract: Methods of selecting operating parameter values for tissue ablation procedures are disclosed. Energy supply parameters may be selected based on inputs such as fluid flow rate, impedance, and the distance from an ablation electrode surface to a target tissue surface. The distance to place an ablation electrode surface from a target tissue surface may be selected based on various operating parameter values and/or operating condition values. Operating curves, lookup tables, or processors may be used to select operating parameter values.

Abstract: Junctions of ablation electrodes and catheters are disclosed. Electrophysiology catheter systems include a recessed region such as a channel at a junction of an electrode and a catheter shaft. The channel can help to reduce electrode hotspots, energy density and/or blood coagulation at the junction. The channel may be incorporated in a distal tip electrode or a ring electrode.

Abstract: Extendable and expandable ablation electrodes are disclosed. Electrophysiology catheter systems include ablation electrodes that maintain a reduced cross-sectional profile during introduction into a patient and are extendable and/or expandable once positioned at a lesion site. The expanded electrodes having a larger length or and/or diameter can help to produce large lesions. Controllability of the dimensions of the ablation electrodes may be improved.

Abstract: Methods of selecting operating parameter values for tissue ablation procedures are disclosed. Energy supply parameters may be selected based on inputs such as fluid flow rate, impedance, and the distance from an ablation electrode surface to a target tissue surface. The distance to place an ablation electrode surface from a target tissue surface may be selected based on various operating parameter values and/or operating condition values. Operating curves, lookup tables, or processors may be used to select operating parameter values.

Abstract: Junctions of ablation electrodes and catheters are disclosed. Electrophysiology catheter systems include a recessed region such as a channel at a junction of an electrode and a catheter shaft. The channel can help to reduce electrode hotspots, energy density and/or blood coagulation at the junction. The channel may be incorporated in a distal tip electrode or a ring electrode.

Abstract: A handle/actuator for use with a steerable catheter having a tip assembly and four pull cables for bending said tip assembly, comprises a housing containing rotary and linear actuators. The rotary actuator is in the form of a wheel rotatably supported in said housing with a portion of said wheel being accessible from the exterior of said housing. Two of the pull cables are anchored to the wheel such that clockwise rotation of the wheel applies tension to one pull cable and counter-clockwise rotation of the wheel applies tension to the second pull cable. The linear actuator comprises a slider mounted in said housing and means exterior of the housing for moving the slider linearly. The third and fourth pull cables are anchored to the slider such that linear movement of the slider in one direction applies tension to the third cable and linear movement of the slider in the opposite direction applies tension to the fourth cable.

Abstract: A steerable electrocardial catheter comprises an elongated flexible shaft and a flexible tip assembly connected to the distal end of the shaft. The tip assembly comprises a distal section and a proximal section coaxial with the shaft, the stiffness and length of the distal and proximal sections being selected to provide a predetermined curve configuration of the tip assembly when the distal section and/or proximal section is bent. A first pair of pull cables extending through the catheter is anchored at a first point in the tip assembly for bending the proximal section in a predetermined plane. A second pair of pull cables extending through the catheter is anchored at a second point in the tip assembly for bending the distal section in a predetermined plane. Any desired orientation of the bending planes is possible with the invention. A handle/actuator is also disclosed for applying tension to selected ones of the pull cables for controlling the deflection of the tip assembly.