Abstract: A catheter used for diagnosing and treating, for example, atrial fibrillation. The catheter includes a catheter shaft that has a proximal portion and a distal portion. The distal portion is adapted to be inserted into a body cavity having tissue to be diagnosed or treated and is disposed remotely from the proximal portion. The distal portion, which may be curved or straight, comprises an outer peripheral wall having an active region, and the distal portion has a cross-sectional configuration along the active region. The cross-sectional configuration is adapted to bias the active region against the tissue to be diagnosed or treated.

Abstract: An ablation catheter having a catheter shaft and a virtual electrode, the virtual electrode comprising portholes through an outer peripheral wall of the catheter shaft and a metal electrode, the catheter being used for treatment of cardiac arrhythmia, for example, atrial fibrillation, by electrically isolating a vessel, such as a pulmonary vein, from a chamber, such as the left atrium. The catheter shaft includes a proximal portion and a distal portion. The distal portion includes an active region, which is either a looped structure transverse to the longitudinal axis of the catheter shaft, or a linear structure that extends parallel to the longitudinal axis of the catheter shaft. During use, the active region is directed into contact with, for example, the wall of a pulmonary vein. Upon energization, the virtual electrode creates a continuous lesion on an inner wall of the pulmonary vein, thereby electrically isolating the pulmonary vein from the left atrium.

Abstract: The invention relates to an ablation catheter which controls the temperature and reduces the coagulation of biological fluids on an electrode of a catheter, prevents the impedance rise of tissue in contact with the electrode, and maximizes the potential energy transfer to the tissue, thereby allowing an increase in the lesion size produced by the ablation. The electrode includes passages positioned to allow saline flow out of an inner cavity of the electrode. This fluid flow produces the desired cooling effect and is accomplished, for example, by saline irrigation flow with a valve element to block flow of blood into the inner cavity of the electrode.

Abstract: The invention relates to an ablation catheter which controls the temperature and reduces the coagulation of biological fluids on an electrode of a catheter, prevents the impedance rise of tissue in contact with the electrode, and maximizes the potential energy transfer to the tissue, thereby allowing an increase in the lesion size produced by the ablation. The electrode includes passages positioned to allow blood and other biological fluids to flow into and out of an inner cavity of the electrode. This fluid flow produced the desired cooling effect and is accomplished, for example, by a reciprocating plunger or piston, or by a balloon that is alternately inflated and deflated.

Abstract: The invention relates to an ablation catheter which controls the temperature and reduces the coagulation of biological fluids on an electrode of a catheter, prevents the impedance rise of tissue in contact with the electrode, and maximizes the potential energy transfer to the tissue, thereby allowing an increase in the lesion size produced by the ablation. The electrode includes passages positioned to allow saline flow out of an inner cavity of the electrode. This fluid flow is pulsatile to increase turbulence, reducing areas of stagnant flow, and produces a desired cooling effect.

Abstract: The invention relates to electrodes used in ablation catheter devices, where the electrodes contain two or more thermal sensors at different positions within the electrode that are capable of detecting temperature differences along the external surface of the electrode. In preferred embodiments, the thermal sensors are separated by one or more thermal insulating members and the thermal sensors are positioned near the external surface of the electrode at about the same distance from the end of the electrode, so that temperature measurements can indicate the position of the electrode with respect to the tissue desired to be ablated.

Abstract: A cardiac ablation catheter system incorporates several different, but complementary features. The catheter includes a virtual electrode section for transferring ablation energy to form a linear lesion in cardiac tissue. The distal tip of the catheter shaft is provided with a tip electrode to perform spot ablations. The distal end of the catheter, generally including the virtual electrode section, may be operably formed into a curve with a variable radius of curvature.

Abstract: A catheter is designed with a virtual electrode structure for creating a linear lesion. The catheter includes a sensor array that measures temperatures of adjacent tissue along the length of the virtual electrode section. The sensors in the sensor array include a conductive material that is substantially coated with an electrically and thermally insulating material. An aperture is formed in the insulating coating to expose an area of the conductive material. Leads are coupled with each sensor and are connected at their opposite, proximal ends with a discrimination circuit. The circuit processes the signals induced in the sensors to output a single temperature measurement, for example, the highest temperature, the lowest temperature, or the average temperature. The sensors also measure cardiac electrical activity and the leads are further connected to an electrocardiograph monitor to determine the efficacy of treatment.

Abstract: The present invention provides an ablation catheter tip for use with an irrigated catheter device comprising an inner cavity and at least one passageway that leads to an orifice, wherein the fluid flow from the orifice promotes a circular, vortex, or spiral flow around the catheter tip from the acute angle formed at the orifice with respect to a line tangent to the surface of the ablation electrode at the orifice. The present invention further provides for an ablation catheter tip, for use with an irrigated catheter device, comprising an inner cavity and at least one curved passageway that leads to an orifice, wherein a line drawn tangent to the arc of the curve forms an acute angle measured with respect to a line drawn tangent to surface of the ablation electrode at the orifice of the passageway.

Abstract: A catheter used for diagnosing and treating, for example, atrial fibrillation. The catheter includes a catheter shaft that has a proximal portion and a distal portion. The distal portion is adapted to be inserted into a body cavity having tissue to be diagnosed or treated and is disposed remotely from the proximal portion. The distal portion, which may be curved or straight, comprises an outer peripheral wall having an active region, and the distal portion has a cross-sectional configuration along the active region. The cross-sectional configuration is adapted to bias the active region against the tissue to be diagnosed or treated.

Abstract: An ablation catheter used for treatment of, for example, atrial fibrillation by electrically isolating a vessel, such as a pulmonary vein, from a chamber, such as the left atrium. The ablation catheter has a virtual electrode and a catheter shaft. The virtual electrode comprises a porous conductor. The catheter shaft includes a proximal portion and a distal portion. The distal portion includes an active region, which is either a looped structure transverse to the longitudinal axis of the catheter shaft, or a linear structure that extends parallel to the longitudinal axis of the catheter shaft. During use, the active region is directed into contact with, for example, the wall of a pulmonary vein and, upon energization, the virtual electrode creates a continuous lesion at or near the ostium of the pulmonary vein, thereby electrically isolating the pulmonary vein from the left atrium.

Abstract: The present invention pertains to multiple piece irrigated ablation electrode assemblies wherein the irrigation channels are insulated or separated from at least one temperature sensing mechanism within the distal portion of the electrode assembly. The present invention further pertains to methods for improved assembly and accurate measurement and control of the electrode temperatures while effectively irrigating the device and target areas.

Abstract: An ablation catheter having a catheter shaft and a virtual electrode, the virtual electrode comprising portholes through an outer peripheral wall of the catheter shaft and a metal electrode, the catheter being used for treatment of cardiac arrhythmia, for example, atrial fibrillation, by electrically isolating a vessel, such as a pulmonary vein, from a chamber, such as the left atrium. The catheter shaft includes a proximal portion and a distal portion. The distal portion includes an active region, which is either a looped structure transverse to the longitudinal axis of the catheter shaft, or a linear structure that extends parallel to the longitudinal axis of the catheter shaft. During use, the active region is directed into contact with, for example, the wall of a pulmonary vein. Upon energization, the virtual electrode creates a continuous lesion on an inner wall of the pulmonary vein, thereby electrically isolating the pulmonary vein from the left atrium.

Abstract: An ablation catheter used for treatment of, for example, atrial fibrillation by electrically isolating a vessel, such as a pulmonary vein, from a chamber, such as the left atrium. The ablation catheter has a virtual electrode and a catheter shaft. The virtual electrode comprises a porous conductor. The catheter shaft includes a proximal portion and a distal portion. The distal portion includes an active region, which is either a looped structure transverse to the longitudinal axis of the catheter shaft, or a linear structure that extends parallel to the longitudinal axis of the catheter shaft. During use, the active region is directed into contact with, for example, the wall of a pulmonary vein and, upon energization, the virtual electrode creates a continuous lesion at or near the ostium of the pulmonary vein, thereby electrically isolating the pulmonary vein from the left atrium.

Abstract: An ablation catheter having a catheter shaft and a virtual electrode, the virtual electrode comprising portholes through an outer peripheral wall of the catheter shaft and a metal electrode, the catheter being used for treatment of cardiac arrhythmia, for example, atrial fibrillation, by electrically isolating a vessel, such as a pulmonary vein, from a chamber, such as the left atrium. The catheter shaft includes a proximal portion and a distal portion. The distal portion includes an active region, which is either a looped structure transverse to the longitudinal axis of the catheter shaft, or a linear structure that extends parallel to the longitudinal axis of the catheter shaft. During use, the active region is directed into contact with, for example, the wall of a pulmonary vein. Upon energization, the virtual electrode creates a continuous lesion on an inner wall of the pulmonary vein, thereby electrically isolating the pulmonary vein from the left atrium.

Abstract: A catheter used for diagnosing and treating, for example, atrial fibrillation. The catheter includes a catheter shaft that has a proximal portion and a distal portion. The distal portion is adapted to be inserted into a body cavity having tissue to be diagnosed or treated and is disposed remotely from the proximal portion. The distal portion, which may be curved or straight, comprises an outer peripheral wall having an active region, and the distal portion has a cross-sectional configuration along the active region. The cross-sectional configuration is adapted to bias the active region against the tissue to be diagnosed or treated.

Abstract: An ablation catheter used for treatment of, for example, atrial fibrillation by electrically isolating a vessel, such as a pulmonary vein, from a chamber, such as the left atrium. The ablation catheter has a virtual electrode and a catheter shaft. The virtual electrode comprises a porous conductor. The catheter shaft includes a proximal portion and a distal portion. The distal portion includes an active region, which is either a looped structure transverse to the longitudinal axis of the catheter shaft, or a linear structure that extends parallel to the longitudinal axis of the catheter shaft. During use, the active region is directed into contact with, for example, the wall of a pulmonary vein and, upon energization, the virtual electrode creates a continuous lesion at or near the ostium of the pulmonary vein, thereby electrically isolating the pulmonary vein from the left atrium.

Abstract: A reservoir for use in an extracorporeal blood circuit including a rigid shell forming an enclosed reservoir. A filter unit divides the reservoir into an inlet chamber and outlet chamber. Cardiotomy blood filtering and defoaming means and venous blood filtering and defoaming means are located within the inlet chamber.