Abstract: A medical apparatus and system for determining contact assessment includes a catheter having an elongate body having a proximal end, a distal end opposite the proximal end, and defining an injection lumen and an exhaust lumen, an expandable membrane defining a cooling chamber disposed at a point along the elongate body, the cooling chamber in fluid communication with the injection lumen and the exhaust lumen, and a contact assessment element which may be a temperature sensor located proximate the coolant return lumen for measuring an internal temperature of the chamber. The system may include the catheter, a console having a fluid supply, an exhaust path and at least one control mechanism operationally coupled to the temperature sensor for processing a temperature signal received from the temperature sensor. The apparatus and system can also have multiple electrodes to measure and process various impedances to determine contact assessment.

Abstract: A method of treating tissue is provided, including positioning a portion of a catheter in proximity to cardiac tissue; measuring an impedance value with the catheter; determining a respiratory rate based at least in part on the measured impedance value; and thermally treating the cardiac tissue with the catheter.

Abstract: A medical device having enhanced steerability for navigation through a patient's vasculature and for positioning the device for performing a medical procedure, such as pulmonary vein isolation. The device generally includes an elongate body, a balloon defining a proximal neck that is affixed to the distal end of the elongate body such that the neck and elongate body are coterminous, a shaft disposed at least partially within the elongate body and at least partially within the balloon, and a pull wire affixed to a distal portion of the shaft, such that pulling the pull wire will cause deflection of the balloon at a point that is immediately distal of the proximal neck of the balloon. Further, the shape of the balloon when deflected and when in a neutral configuration may be substantially the same.

Abstract: A method of treating tissue is provided, including positioning a portion of a catheter in proximity to cardiac tissue; measuring an impedance value with the catheter; determining a respiratory rate based at least in part on the measured impedance value; and thermally treating the cardiac tissue with the catheter.

Abstract: A method of treating tissue is provided, including positioning a stimulation device proximate a phrenic nerve; stimulating the phrenic nerve with the stimulation device; measuring a physiological response to the stimulation; defining a threshold physiological response value based at least in part on the measured physiological response; positioning a thermal treatment element proximate to an arrhythmogenic cardiac tissue region; applying a thermal treatment regimen to the cardiac tissue region with the medical device; measuring a physiological parameter during the thermal treatment regimen application; and conveying the measured physiological parameter to a controller, the controller comparing the measured physiological parameter to the defined physiological response value threshold, the controller adjusting the thermal treatment regimen in response to the comparison of the measured physiological parameter to the defined physiological response value threshold.

Abstract: The present invention advantageously provides a method and system for cryogenically ablating large areas of tissue within the left atrium. In an exemplary embodiment a cryotherapy device includes a catheter body having a substantially fixed diameter, a proximal end and a distal end; a first lumen for permitting passage of a cooling fluid from the proximal end to the distal end; a second lumen permitting return of the cooling fluid from the distal end to the proximal end; and an ablation element expandable from a first diameter that is substantially the same as the diameter of the catheter body to a second diameter that is at least twice the diameter of the catheter body, the ablation element having a surface portion that conforms to the uneven surface topography of the cardiac tissue. The ablation element can include one or more balloon and/or a flexible element that is deformed by moving the distal end of the catheter toward the proximal end of the catheter.

Abstract: An intravascular catheter is provided, including a flexible elongate body; an expandable element positioned on the elongate body; a substantially linear thermal segment located distally of the expandable element; a first fluid flow path in fluid communication with the expandable element; and a second fluid flow path in fluid communication with the substantially linear thermal segment.

Abstract: A method is disclosed for cooling a limited portion of a body organ by placing a cooling device into a blood vessel within a target organ; and activating the cooling device to cool tissue proximate the cooling device to a temperature below +34 degrees Centigrade. The blood vessel can be a vein or an artery and the cooling device can be a fixed diameter catheter or it can include a balloon. More particularly, the method of cooling can provide a method for treating injured ischemic and infarcted tissue by placing a device capable of passage through the vasculature into a target organ, wherein the device is capable of providing sufficient thermal exchange at a working region thereof to cool adjacent tissue; and activating the device to cool adjacent tissue to a temperature in the range of 0 degrees Centigrade to +36 degrees Centigrade.

Abstract: A method of ablating tissue is provided, including positioning an expandable element of a catheter in a blood vessel; inflating the expandable element with a volume of refrigerant to substantially occlude the blood vessel; measuring the volume of refrigerant used to inflate the expandable element; correlating the measured volume to an inflated dimension of the expandable element; defining at least one of a target pressure within the expandable element and a target flow rate for refrigerant delivery to the expandable element based at least in part on the inflated dimension; regulating refrigerant delivery to the expandable element to attain the at least one defined target pressure within the expandable element or defined target flow rate for fluid delivery to the expandable element; and ablating at least a portion of the blood vessel with the expandable element.

Abstract: A method and system for ablating a tissue region. In an exemplary embodiment, the method includes positioning a medical device including a deformable and helical distal portion in contact with a tissue region, the a helical distal portion including a plurality of turns each having a diameter, the diameter of each turn being greater than the diameter of the next distal turn, compressing the helical distal portion against the tissue region, deforming the distal portion into a substantially concentric spiral, and activating one or more treatment elements and ablating the target tissue. The method may further include advancing the uncompressed helical distal portion into a hollow anatomical feature, such as a pulmonary vein, and activating one or more treatment elements and ablating the target tissue.

Abstract: A method of treating tissue is provided, including positioning a stimulation device proximate a phrenic nerve; stimulating the phrenic nerve with the stimulation device; measuring a physiological response to the stimulation; defining a threshold physiological response value based at least in part on the measured physiological response; positioning a thermal treatment element proximate to an arrhythmogenic cardiac tissue region; applying a thermal treatment regimen to the cardiac tissue region with the medical device; measuring a physiological parameter during the thermal treatment regimen application; and conveying the measured physiological parameter to a controller, the controller comparing the measured physiological parameter to the defined physiological response value threshold, the controller adjusting the thermal treatment regimen in response to the comparison of the measured physiological parameter to the defined physiological response value threshold.

Abstract: A thermal treatment medical system including an umbilical having a first portion and a second portion, and a connector including a male coupling body connected to the first portion, the male coupling body having a central shank defining first and second lumens, a female coupling body connected to the second portion, the female coupling body, matable with the male coupling body and defining third and fourth lumens matable to be in fluid communication with the first and second lumens, respectively, to define first and second fluid flow pathways, respectively, through the connector when the male coupling body is mated with the female coupling body. The second fluid flow pathway is co-axially disposed about a central axis coincident with the first fluid flow pathway. The connector includes a mating mechanism for spatially locking the male and female coupling bodies with respect to each other.

Abstract: A cryogenic catheter includes an elongate, contiguous, thermally-transmissive region coupled to the catheter, the thermally-transmissive region being sufficiently flexible to change from a linear configuration to an arcuate configuration. The thermally-transmissive region may include a plurality of interconnected thermally-transmissive segments that are generally cylindrical in shape. The cryogenic catheter may be in fluid communication with a fluid source, and may include one or more fluid injection tubes. Further, an injection tube may be slidably disposed within the catheter so that the injection tube is longitudinally movable relative to an outer surface of the catheter. The cryogenic catheter may also be in communication with a controller programmed to regulate delivery of a cryogenic fluid from the fluid source to the medical device.

Abstract: A resilient model of a heart's atria and associated vasculature is disclosed. The model is generated from CT scans of patients' with varying cardiac anatomies. The model is connected to a temperature-controlled fluid reservoir and a pump that periodically circulates fluid through the cardiac model. The model provides a visual indication of temperature change. The model may be used to simulate endocardial procedures such as pulmonary vein isolation for treatment of atrial fibrillation.

Abstract: A method and system for treating ventricular tachycardia (VT) by ablating scarred myocardial tissue containing a reentrant VT circuit. The method generally includes measuring electrical activity at a plurality of sites within a heart, identifying an area of scarred myocardial tissue based at least in part on the electrical activity measurements, and ablating substantially all of the scarred area. The system generally includes a medical device having a distal end, a plurality of electrical conduction sensors coupled to the distal end, and a console in communication with the distal end of the device, the console including a computer with display. The computer may be programmed to identify optimal ablation sites within a target tissue and the location of an isthmus associated with a reentrant VT circuit within a target tissue, the identifications being based at least in part on the measurements of the electrical conduction sensors.

Abstract: A system and method for controlling the inflation, ablation, and deflation of a balloon catheter. The system includes a balloon catheter, a console, having a pressurized gas or liquid inflation source, and an umbilical system to deliver pressurized coolant to the balloon catheter. The system comprises a PID (Proportional Integral Derivative) controller or other pressure-sensing device that monitors the amount of pressure and volume within the balloon catheter. During inflation, the pressure and/or volume of fluid within the balloon is maintained at a target amount in order to provide sufficient mechanized pressure against the desired target region. The system limits the inflation pressure such that a safe quantity of gas would be released should a leak occur. If the amount falls below a certain threshold level, gas or fluid egress is presumed and the inflation process is halted. In one embodiment, an intermediate console is placed between the console and the balloon catheter and coupled thereto.

Abstract: A catheter includes a first expandable membrane having a first pressurization limit and a second expandable membrane, having a second pressurization limit, wherein the second pressurization limit is greater than the first pressurization limit, the first expandable membrane defines a cooling chamber, the second expandable membrane being disposed around the first expandable membrane to define an junction therebetween. The catheter includes a coolant injection lumen in fluid communication with the at least one fluid inlet port and the cooling chamber, and a primary coolant return lumen in fluid communication with the at least one fluid outlet port and the cooling chamber. The coolant injection tube, the cooling chamber, and the primary coolant return lumen define a first fluid pathway. The catheter further includes a secondary coolant return lumen in fluid communication with the at least one fluid outlet port and the junction. The junction and the secondary coolant return lumen define a second fluid pathway.

Abstract: The present invention advantageously provides a method and system for cryogenically ablating large areas of tissue within the left atrium. In an exemplary embodiment a cryotherapy device includes a catheter body having a substantially fixed diameter, a proximal end and a distal end; a first lumen for permitting passage of a cooling fluid from the proximal end to the distal end; a second lumen permitting return of the cooling fluid from the distal end to the proximal end; and an ablation element expandable from a first diameter that is substantially the same as the diameter of the catheter body to a second diameter that is at least twice the diameter of the catheter body, the ablation element having a surface portion that conforms to the uneven surface topography of the cardiac tissue. The ablation element can include one or more balloon and/or a flexible element that is deformed by moving the distal end of the catheter toward the proximal end of the catheter.

Abstract: A device, system, and method for enhancing cooling uniformity and efficiency of cryogenic fluids and providing a treatment element the shape of which can be adjusted for multiple purposes. The device may include a balloon catheter and fluid dispersion element, the fluid dispersion element directing the flow of coolant from a fluid injection element the interior wall of the balloon. The method of changing the shape of the treatment element may include retracting and extending a shaft to which the distal neck of a balloon is coupled, so that the balloon goes from a first shape to a second shape.

Abstract: A system and method is disclosed for cryogenic medical treatment, having a stabilizer for a reservoir of cryogenic fluid. Accordingly, the stabilizer allows the reservoir some limited range of motion to enhance accuracy of a load sensor engaged by the reservoir, and to resist tipping or other undesirable movement by the reservoir. The stabilizer may allow the reservoir a range of vertical movement, and may limit the reservoir to a range of positions or alignments relative to the load sensor. Additional configurations are disclosed, providing stabilizers of various types and features.