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 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: The present invention is directed to bipolar ablation systems. A bipolar electrode system for ablation therapy is disclosed, including a pressure-sensitive conducting composite layer and a pair of electrodes in electrical conductive contact or communication with the pressure-sensitive conducting composite layer. Energy (e.g., ablation energy) is delivered via the pressure-sensitive conductive composition when sufficient pressure is applied to transform the pressure-sensitive conductive composite to an electrical conductor. An electrically insulative flexible layer, which may include a passageway for a fill material is also disclosed. In some embodiments, the systems can also be used for targeted delivery of compounds, such as drugs, using a bipolar electrode.

Abstract: A contact sensing catheter system includes a catheter shaft having a distal end; a flexible conductive polymer electrode located at the distal end of the shaft; and an electro-mechanical contact sensor positioned at least partially within the electrode. The sensor outputs an electrical signal in response to a mechanical force acting thereon. The sensor may be a piezoelectric sensor, a strain gauge, a fiber optic sensor, or another suitable electro-mechanical contact sensor. The electrical signal output by the sensor typically varies in response to variations in the mechanical force acting on the sensor. An output device may receive the signal output by the contact sensor and present to a user of the system an indicator of contact between the electrode and a tissue by assessing, for example, the amplitude or periodicity of the signal.

Abstract: Systems and methods are disclosed for assessing electrode-tissue contact for tissue ablation. An exemplary electrode contact sensing system comprises an electrode 10 housed within a distal portion of a catheter shaft 14. At least one electro-mechanical sensor 20 is operatively associated with the electrode 10 within the catheter shaft 14. The at least one electro-mechanical sensor 20 is responsive to movement of the electrode 10 by generating electrical signals corresponding to the amount of movement. The system may also include an output device electrically connected to the at least one electro-mechanical sensor 20. The output device receives the electrical signals for assessing a level of contact between the electrode 10 and a tissue 12.

Abstract: An electrode for ablation therapy includes a flexible conductive element for conducting electrical energy and a flexible conductive polymer member in electrically conductive contact with the conductive element. A catheter shaft may be coupled to the conductive element and/or the flexible conductive polymer member. The flexible conductive element may be formed as a helical coil, a mesh coating or wrap, or any other suitable form, and may surround (wholly or partially) a flexible electrically insulative, and optionally thermally conductive, member. A heat sink may be thermally coupled to at least one of the flexible conductive polymer member and the flexible electrically insulative member. The flexible electrically insulative member may include a passageway for coolant fluid to cool the electrode during ablation. The passageway may include at least one efflux hole to permit coolant fluid to flow from the passageway, or may define a closed loop.

Abstract: A contact sensing assembly including a catheter and an electrode including a tip portion and a base portion, and a generally central axis, with the electrode being connected to a distal end of the catheter. Optical sensor(s) may be provided for emitting and/or receiving an optical signal, with a part of the optical signal being transverse to the central axis. Optical interference member(s) may be provided for interfering with the optical signal. A method for sensing contact force exerted by an electrode on a tissue includes directing an optical signal along a portion of a catheter, emitting and/or receiving an optical signal, with a part of the optical signal being at a predetermined angle relative to the central axis, and sensing changes in intensity of the optical signal based on displacement associated with the electrode tip portion based on the contact force exerted by the electrode on the tissue.

Abstract: Systems and methods are disclosed for assessing electrode-tissue contact for tissue ablation. An exemplary electrode contact sensing system comprises an electrode housed within a distal portion of a catheter shaft. At least one electro-mechanical sensor is operatively associated with the electrode within the catheter shaft. The at least one electro-mechanical sensor is responsive to movement of the electrode by generating electrical signals corresponding to the amount of movement. The system may also include an output device electrically connected to the at least one electro-mechanical sensor. The output device receives the electrical signals for assessing a level of contact between the electrode and a tissue.

Abstract: A three dimensional physiological mapping system utilizing an intracardiac echo catheter capable of being located in six degrees of freedom by a visualization, navigation, or mapping system. An echocardiography image of the intracardiac echo catheter may be projected within a geometric model of the visualization, navigation, or mapping system where the location of the projected image is adjusted in response to user input identifying a structure present in the echocardiography image and the geometric model.

Abstract: The present invention is directed to ablation devices and methods utilizing pressure sensitive conductive composites, such as quantum tunneling composites, or other contact-sensitive, conductive polymers. The materials provide for electrodes and methods capable of differentiating between a soft and a hard push. The present invention thus provides an electrode for delivering selective electrical energy for ablation that may be varied based upon the pressure exerted on the surface area of the targeted tissue.

Abstract: A catheter assembly for pressure-sensitive control of ablation treatment is disclosed. The assembly includes a conductive element, an electrode, and a pressure sensitive conductive composite member positioned between the conductive element and the electrode. At least one of the conductive pin, the pressure sensitive conductive composite element and the ablation electrode are moveable to create an engagement position and a non-engagement position. In the engagement position, the elements are electrically coupled such that ablation energy may be delivered from the conductive pin to the ablation electrode via the pressure sensitive conductive composite element. In the non-engagement position, the elements are electrically decoupled such that ablation energy is not delivered to the ablation electrode. A related method for pressure-sensitive control of ablation is also disclosed.

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 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: 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: 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: 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 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: 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.