Abstract: A system and method for diagnosis or treatment of tissue is provided. One or more optic fibers are disposed within a deformable, tubular body. An electronic control unit activates an electromagnetic radiation source to direct a first set of electromagnetic radiation through a first optic fiber to the tissue. The unit also receives a signal generated by an electromagnetic radiation sensor in response to a second set of electromagnetic radiation received through the first optic or a second fiber. The second set of electromagnetic radiation originates from the tissue in response to the first set of electromagnetic radiation and may be reflected or emitted by a substance contained in the tissue that alters radiation characteristics of the tissue. Finally, the unit is configured to determine a characteristic of the tissue (e.g. the distance from the tissue to the tubular body) responsive to the signal.

Abstract: An electrode catheter and a method for assessing electrode-tissue contact and coupling are disclosed. An exemplary electrode catheter comprises an electrode adapted to apply electrical energy. A measurement circuit is adapted to measure impedance between the electrode and ground as the electrode approaches a target tissue. A processor determines a contact and coupling condition for the target tissue based at least in part on reactance of the impedance measured by the measurement circuit. In another exemplary embodiment, the electrode catheter determines the contact and coupling condition based at least in part on a phase angle of the impedance.

Abstract: Catheter systems and methods are disclosed for anchoring the catheter system to tissue, e.g., for delivery of biologic or chemical agents, or other therapeutic fluid during various procedures. An exemplary tissue anchoring catheter comprises an outer catheter shaft connected to a catheter handle. A delivery sheath is provided within the outer catheter shaft, the delivery sheath housing a needle. At least one anchor is operatively associated with the delivery sheath, the at least one anchor operable at the catheter handle to secure the delivery sheath to tissue for conveying biologic or chemical agents, or other therapeutic fluid from the needle to the tissue. The tissue anchoring catheter may further comprise sensing means such as piezoelectric, pressure, thermistor, thermocouple, or ultrasound sensors.

Abstract: Disclosed herein are ablation systems and methods for providing feedback on lesion formation in real-time. The methods and systems assess absorptivity of tissue based on a degree of electric coupling or contact between an ablation electrode and the tissue. The absorptivity can then be used, along with other information, including, power levels and activation times, to provide real-time feedback on the lesions being created. Feedback may be provided, for example, in the form of estimated lesion volumes and other lesion characteristics. The methods and systems can provide estimated treatment times to achieve a desired lesion characteristic for a given degree of contact, as well as depth of a lesion being created. The degree of contact may be measured using different techniques, including the phase angle techniques and a coupling index.

Abstract: Side-port sheaths for catheter placement and translation are disclosed. The sheaths include a side-port opening through which a gliding catheter may be deployed during diagnosis or treatment of tissue. The side-port sheath may include a suspension ribbon used to deploy, or that aids in the deployment of, the embedded gliding catheter. The suspension ribbon may be slideably or fixably engaged with an outer surface of the sheath of the gliding catheter.

Abstract: System and methods are disclosed for tissue contact and thermal assessment, e.g. for tissue ablation procedures. An exemplary brush electrode comprises a plurality of flexible filaments adapted to transfer electrical energy to a tissue. At least one piezoelectric sensor is embedded among the plurality of flexible filaments. The at least one piezoelectric sensor is responsive to contact stress of the flexible filaments by generating electrical signals corresponding to the amount of contact stress. An output device is electrically connected to the at least one piezoelectric sensor. The output device receives the electrical signal for assessing tissue contact by the flexible filaments. The brush electrode may further comprise a sensing device mounted adjacent the at least one piezoelectric sensor, wherein the sensing device is a pressure sensor, a thermistor, a thermocouple, or an ultrasound sensor.

Abstract: An ablation catheter has improved fluid distribution structures. An ablation section at a distal end of the catheter is designed to provide a more uniform fluid flow emanating from the catheter. By creating a uniform fluid flow, a more uniform tissue lesion results and the possibility of charring the tissue is reduced. A combination of mesh material layers, porous materials, and dispersion channels or openings are used to achieve the uniform flow. The amount of fluid used as a virtual electrode to ablate the tissue is greatly reduced with the present invention. Further, the catheter may be used to create a single, uniform linear lesion by successive application of energy to adjacent portions of the ablation section, thus reducing the power required to create the desired lesion.

Abstract: An electrode catheter and a method for assessing electrode-tissue contact and coupling are disclosed. An exemplary electrode catheter comprises an electrode adapted to apply electrical energy. A measurement circuit is adapted to measure impedance between the electrode and ground as the electrode approaches a target tissue. A processor determines a contact and coupling condition for the target tissue based at least in part on reactance of the impedance measured by the measurement circuit. In another exemplary embodiment, the electrode catheter determines the contact and coupling condition based at least in part on a phase angle of the impedance.

Abstract: An electrode catheter and a method for assessing electrode-tissue contact and coupling are disclosed. An exemplary electrode catheter comprises an electrode adapted to apply electrical energy. A measurement circuit is adapted to measure impedance between the electrode and ground as the electrode approaches a target tissue. A processor determines a contact and coupling condition for the target tissue based at least in part on reactance of the impedance measured by the measurement circuit. In another exemplary embodiment, the electrode catheter determines the contact and coupling condition based at least in part on a phase angle of the impedance.

Abstract: A medical device utilizing temperature sensing to identify or assess anatomical bodies or structures includes an elongate tubular member, at least one electrode, a thermal sensor, and a temperature response assessment system or component. The at least one electrode may be connected to the distal portion of the elongate tubular member, and the one or more electrode can be configured to provide energy or heat to a portion of an anatomical body or structure. The thermal sensor may be configured to measure the thermal response of the portion of an anatomical body or structure, e.g., tissue or blood pools. The temperature response assessment system or component can be coupled to the thermal sensor. In embodiments, the device may include a lumen and port opening, which may accommodate a tool, such as a needle. Methods for using temperature sensing to identify an anatomical body or structure are also disclosed.

Abstract: A tissue puncture assembly includes an elongate tubular member having a lumen, a distal portion having a side wall, a side port opening extending through the side wall and, and a guiding surface having a distal end that extends adjacent to a distal edge of the side port opening. The tissue puncture assembly further includes a flexible puncture member insertable through the lumen of the elongate tubular member. The flexible puncture member deflects upon contacting the guiding surface to exit the elongate tubular member through the side port in a lateral direction relative to a longitudinal direction of the elongate tubular member. The tissue puncture member is capable of puncturing tissue at an oblique angle. The tissue puncture member may further adopt a pre-formed shape at its distal end to prevent inadvertent puncture of tissue and to maintain access to the puncture site.

Abstract: A catheter system including an accelerometer-based sensing assembly is provided. In particular the present teachings relate to an accelerometer based assembly used to determine contact between a catheter and surrounding proximate tissue, such as cardiac tissue. An embodiment of such a system may, for example, be used for visualization, mapping, ablation, or other methods of diagnosis and treatment of tissue and/or surrounding areas.

Abstract: Coupler assemblies and methods are disclosed as the coupler assemblies may be used with a catheter. An exemplary coupler assembly includes a spherical linkage coupler for a catheter. The coupler comprises a first cylinder portion for connecting to a structure, and a second cylinder portion for connecting to a distal end of a body of the catheter. The coupler also comprises a spherical linkage including at least two link arms. Each of the two link arms are connected on one end to the first cylinder portion and on the other end to the second cylinder portion. The two link arms connect a portion of the structure to the distal end of the catheter and enable the structure to move relative to the distal end of the catheter in response to an external force exerted on the structure.

Abstract: A method and system for assessing lesion formation in tissue is provided. The system includes an electronic control unit (ECU). The ECU is configured to acquire values for first and second components of a complex impedance between the electrode and the tissue, and to calculate an index responsive to the first and second values. The ECU is further configured to process the ECI to assess lesion formation in the tissue.

Abstract: A system and method for assessing and displaying a degree of contact between a sensor, an electrode, and tissue in a body is provided. Values for the sensor are read, and a degree of contact is calculated. This degree of contact is displayed to a clinician in a variety of ways to indicate the degree of contact to the clinician. The system and method find particular application in ablation of tissue by permitting a clinician to create lesions in the tissue more effectively and safely.

Abstract: An electrode for use on a medical device is disclosed. The electrode may have a main body of electrically conductive material extending along an axis and may have a proximal end and a distal end. The electrode may also include a magnetic resonance imaging (MRI) tracking coil disposed in the body. The MRI tracking coil may comprise electrically insulated wire. A catheter including an electrode, as well as a method for determining the location of an electrode, are also disclosed.

Abstract: A method and system for ablation of cardiac tissue in a living being via the esophagus is provided. The method includes the step of introducing a photodynamic substance to the cardiac tissue. A deformable, elongated body defining a proximal end and a distal end is inserted into an esophagus of the living being. The distal end of the elongated body is located proximate the cardiac tissue. A first set of electromagnetic radiation is then directed from the distal end of the elongated body towards the cardiac tissue. Reflective and opaque surfaces at the distal end of the elongated body may be used to direct the electromagnetic radiation and an expandable membrane at the distal end may be used to urge the distal end of the elongated body to a predetermined position within the esophagus.

Abstract: A needle for a medical procedure includes a shaft with an inner surface, an outer surface, a proximal section, and a distal section. The distal section has a conductive tip configured to be a first electrode for voltage measurement. The needle further includes a first electrically insulative outer layer over a portion of the outer surface of the shaft. The conductive tip is adapted for insertion through tissue into, for example, a pericardial space of a patient. A system for determining the location of a needle during a medical procedure includes the needle and an anatomical mapping and localization system electrically coupled to the needle and adapted to measure voltage at the conductive tip.

Abstract: Systems and methods for photodynamic ablation of cardiac tissue via an esophagus are disclosed. An exemplary system includes an ablation catheter having an expandable distal end for securing the ablation catheter in the esophagus. The distal end of the ablation catheter contains at least one light source operable to activate a photodynamic substance delivered to the target area of the cardiac tissue to be ablated and form a lesion. The system also includes at least one feedback device contained in the distal end of the ablation catheter. The at least one feedback device provides feedback for at least one of: positioning a distal end of an ablation catheter in a desired position in the esophagus adjacent a target area of the cardiac tissue to be ablated, forming an adequate lesion, and assessing lesion formation.

Abstract: An ablation catheter includes a flexible elongated shaft having a flexible electrode at its distal end. The flexible electrode includes an inner, flexible, electrically-conductive element and an outer, flexible, electrically-conductive polymer layer in electrical contact with the inner, flexible, electrically-conductive element. The catheter further includes an electrically insulative sheath surrounding at least a portion of the flexible electrode and a linear displacement mechanism capable of adjusting at least one of the electrically insulative sheath and the flexible electrode to vary a length of the flexible electrode exposed at the distal end of the shaft. Also disclosed is an adjustable length ablation electrode and methods of ablating tissue.