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 electromechanical 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 electromechanical 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: 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: 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 coupling output system provides indication to the physician, via electrode guidance instrumentation, concerning the electrical coupling of an electrode, such as an ablative or mapping electrode, with a patient. The output can be provided to the physician via an output device incorporated into the handle set of the electrode catheter. For example, a visual, audio or mechanical output can be provided via the handle set. Additionally or alternatively, the output can be provided to the physician via a navigation system. The indication may be provided by changing the color or other display characteristics of the electrode on the navigation system display or by way of providing a waveform indicating the electrode coupling. In this manner, electrode coupling information is provided to a physician in a manner that minimizes physician distraction.

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 electromechanical sensor 20 is operatively associated with the electrode 10 within the catheter shaft 14. The at least one electromechanical 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 electromechanical 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 head is disclosed that utilizes electrically conductive or dissipative fabric to exchange electrical energy with tissue. This electrode head may be used for any appropriate application, such as a catheter electrode, a return electrode, or the like. Any appropriate function may be provided by this electrode head, such as tissue ablation, tissue mapping, or providing an electrical ground.

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: A catheter assembly for assessing contact between the catheter assembly and tissue is disclosed. The assembly includes a catheter shaft and a pressure sensitive conductive composite member whose electrical resistance varies with pressure applied to the catheter assembly. The assembly also includes at least one measurement terminal to permit the measurement of changes in the electrical characteristics of the pressure sensitive conductive composite member. The assembly may optionally include a measurement device to measure resistance, impedance and/or other electrical characteristics. The assembly may utilize a reference electrode secured to the patient's tissue, which permits the measurement device to measure changes between the reference electrode and the at least one measurement terminal. Optionally, the assembly may include a conductive outer layer.

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: An ablation catheter is provided for ablating internal tissue of a patient. The catheter includes a distal end that is adapted to be inserted into a body cavity relative to a desired location therein (e.g., within the heart). An ablation electrode is connected relative to the distal end of the catheter for providing ablation energy to patient tissue. A heat sink is provided that is in thermal contact with the ablation electrode. The heat sink, in addition to being in thermal contact with the ablation electrode, is electrically isolated from the ablation electrode. This allows the heat sink to conduct heat away from the ablation electrode without dissipating electrical energy from the electrode. In this regard, the heat sink may prevent build-up of excess heat within the electrode that may result in blood coagulation and/or tissue charring.

Abstract: A brush electrode and a method for using the brush electrode for tissue ablation are disclosed. The brush electrode comprises a plurality of flexible filaments or bristles for applying ablative energy (e.g., RF energy) to target tissue during the formation of spot or continuous linear lesions. Interstitial spaces are defined among the filaments of the brush electrode, and the interstitial spaces are adapted to direct conductive or nonconductive fluid, when present, toward the distal ends of the brush filaments. The brush electrode facilitates electrode-tissue contact in target tissue having flat or contoured surfaces. The flexible filaments may be selectively trimmed to give a desired tip configuration or a desired standoff distance between the tissue and the conductive filaments in the brush electrode. Also, the filaments may be grouped into clusters. A shielded-tip brush electrode, including a flexible boot, is also disclosed.

Abstract: A surgical device incorporates a brush electrode for tissue ablation and other forms of electrosurgical treatment. A plurality of flexible filaments compose the brush electrode, through which therapeutic energy (e.g., RF energy) is applied to target tissue for the formation of spot or continuous linear lesions, cauterization, incision, and desiccation. A fluid delivery system is used in conjunction with the brush electrode to apply fluid to the filaments and surgical site.

Abstract: A brush electrode and a method for using the brush electrode for tissue ablation are disclosed. The brush electrode comprises a plurality of flexible filaments or bristles for applying ablative energy (e.g., RF energy) to target tissue during the formation of spot or continuous linear lesions. Interstitial spaces are defined among the filaments of the brush electrode, and the interstitial spaces are adapted to direct conductive or nonconductive fluid, when present, toward the distal ends of the brush filaments. The brush electrode facilitates electrode-tissue contact in target tissue having flat or contoured surfaces. The flexible filaments may be selectively trimmed to give a desired tip configuration or a desired standoff distance between the tissue and the conductive filaments in the brush electrode. Also, the filaments may be grouped into clusters. A shielded-tip brush electrode, including a flexible boot, is also disclosed.

Abstract: A brush electrode catheter and a method for using the brush electrode catheter for tissue ablation are disclosed. The brush electrode catheter comprises a plurality of flexible filaments or bristles for applying ablative energy (e.g., RF energy) to target tissue during the formation of spot or continuous linear lesions. Interstitial spaces are defined among the filaments of the brush electrode, and the interstitial spaces are adapted to direct conductive or nonconductive fluid, when present, toward the distal ends of the brush filaments. The brush electrode facilitates electrode-tissue contact in target tissue having flat or contoured surfaces. The flexible filaments may be selectively trimmed to give a desired tip configuration or a desired standoff distance between the tissue and the conductive filaments in the brush electrode. Also, the filaments may be grouped into clusters. A shielded-tip brush electrode, including a flexible boot, is also disclosed.

Abstract: An electrode catheter and a method for assessing catheter-tissue contact for tissue ablation are disclosed. An exemplary electrode catheter comprises a flexible catheter shaft. At least one piezoelectric sensor is oriented coaxial to the flexible catheter shaft. The at least one piezoelectric sensor is responsive to movement of the flexible catheter shaft 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 piezoelectric sensor. The output device receives the electrical signals for dynamically assessing a level of contact between the flexible catheter shaft and a moving tissue. In another exemplary embodiment, the system may be implemented in a hydrodynamic environment.

Abstract: A spring-tip, flexible electrode, and a method for using that electrode for tissue ablation, are disclosed. The spring-tip, flexible electrode comprises an enshrouded flexible electrode (e.g., an enshrouded plurality of flexible brush filaments or bristles) for applying ablative energy (e.g., RF energy) to target tissue during the formation of spot or continuous linear lesions. The spring of the spring tip may comprise compressible coils, compressible mesh, or compressible bellows, among other things. The spring provides axial suspension and is capable of axial compression and extension, and is flexible enough for deflection and bending. The axial suspension of the spring tip facilitates the desired contact between the electrode and the tissue surface. A shielded, spring-tip, flexible electrode is also disclosed, and includes a flexible nipple or shield. The spring-tip, flexible electrode facilitates enhanced tissue contact in difficult environments (e.g.

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: 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: Systems and methods are disclosed for assessing tissue contact, e.g., for mapping tissue ablation or other procedures. An exemplary tissue contact sensing system comprises a flexible tip device. At least one piezoelectric sensor is housed within the flexible tip device. The at least one piezoelectric sensor is responsive to contact stress of the flexible tip device 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 signals for assessing tissue contact by the flexible tip device. Methods for assembling and using the flexible tip device are also disclosed.