Abstract: Systems and methods examine heart tissue morphology using three or more spaced apart electrodes, at least two of which are located within the heart in contact with endocardial tissue. The systems and methods transmit electrical current through a region of heart tissue lying between selected pairs of the electrodes, at least one of the electrodes in each pair being located within the heart. The systems and methods derive the electrical characteristic of tissue lying between the electrode pairs based, at least in part, upon sensing tissue impedances. The systems and methods arrange the derived tissue electrical characteristics into groups of equal electrical characteristics. The systems and methods display the groups of equal electrical characteristics in spatial relation to the location of the examined tissue regions. The systems and methods make possible the use of multiple endocardial electrodes for taking multiple measurements of the electrical characteristics of heart tissue.

Abstract: A catheter assembly which has a distal end adapted for insertion into a living body and a proximal end adapted to remain external to said body or a cable for use in such an assembly includes a cylindrical surface on which are inscribed a plurality of markings. Each of the markings indicates one of the specific locations within the living body at which the distal end may be placed during insertion. The markings are positioned at spaced intervals around the circumference of the cylindrical surface. A sleeve is rotatably and/or axially movable around the cylindrical surface, the sleeve being provided with at least one window adapted to be moved into alignment with a selected one of the markings.

Abstract: Systems and methods examine heart tissue morphology by locating electrodes in contact with a region of heart tissue to sense the timing of a local depolarization events. From this, the systems and methods derive the propagation velocities of the depolarization events and create an output that displays the derived propagation velocities in spatial relation to sensing electrode. The systems and methods can arrange the derived propagation velocities into groups of equal propagation velocities and generate in three dimensions an output of the groups of equal propagation velocities in spatial relation to the location of the sensing electrodes. The iso-conduction display more rapidly identifies the regions of slow conduction which are candidate ablation sites, than an iso-chronal or iso-delay display.

Abstract: Systems and methods examine heart tissue morphology using three or more spaced apart electrodes, at least two of which are located within the heart in contact with endocardial tissue. The systems and methods transmit electrical current through a region of heart tissue lying between selected pairs of the electrodes, at least one of the electrodes in each pair being located within the heart. The systems and methods derive the electrical characteristic of tissue lying between the electrode pairs based, at least in part, upon sensing tissue impedances. The systems and methods also sense the timing of local depolarization events in the tissue in which impedance is sensed and derive therefrom the propagation velocities of the sensed depolarization events. The systems and methods match the derived tissue electrical characteristics with the derived propagation velocities in spatial relation to the electrodes to characterize the morphology of the contacted heart tissue.

Abstract: A probe for cardiac diagnosis and/or treatment has a catheter tube. The distal end of the catheter tube carries first and second electrode elements. The probe includes a mechanism for steering the first electrode element relative to the second electrode element in multiple directions.

Abstract: An improved probe for cardiac diagnosis and/or treatment includes a control handle and a catheter for insertion into the heart. The catheter has a distal end, a proximal end and at least one lumen connecting said distal and proximal ends. It also includes a flexible inner tube and an outer sheath enveloping said tube. At least one measuring electrode or ablation device is attached to the distal end of the tube. The outer sheath and the inner tube are rotatable relative to each other so that the electrode or device can be rotated within the heart without rotating the outer sheath. The sheath is also axially movable relative to the tube to selectively enclose or expose the electrode or device for use.

Abstract: The invention provides an improved catheter steering mechanism for pulling a first catheter steering wire while simultaneously allowing a second catheter steering wire to remain static, and vice versa. The mechanism includes at least one rotatable gear and means, such as a rotatable knob, for manually rotating the gear. A first linearly slidable toothed rack is attached to the proximal end of one steering wire, and a second linearly slidable toothed rack is attached to the proximal end of the other steering wire. A toothed gear rotatable by rotation of the knob engages each of the toothed racks to move them linearly in opposite directions in response to rotation of said gear. Preferably three intermeshing gears are used so that movements of the racks are in the same direction as the rotation of the knob.

Abstract: An ablation electrode carries a temperature sensing element for measuring the temperature of the tissue being ablated. A thermal insulating element associated with the sensing element blocks the transfer of heat energy from between the temperature sensing element and the body. The temperature sensing element therefore measures temperature without being affected by the surrounding thermal mass of the electrode.

Abstract: Systems for ablating tissue control radiofrequency power to an ablation electrode by relying upon actual phase sensitive power measurements, unaffected by phase shifts between radiofrequency voltage and current. The systems also detect these phase differences, if they develop, and integrate this factor in making their control decisions.

Abstract: The apparatus comprises a probe having a tip portion, a first electrode mounted on a terminal free end of the tip portion and a second electrode spaced along the tip portion from the first electrode for supplying a reference potential. The probe is constructed so as to hold the first electrode in contact with tissue of an in vivo beating heart with a positive pressure without causing macroscopic damage to the heart tissue while orienting the probe such that the second electrode is spaced from the heart tissue. A stylet is retractably mounted within the probe, for allowing a physician to maneuver the probe through a vein or the like. Once the probe is in position, it may be replaced by a probe of a different shape. The probe may also be retracted while being inserted, for preventing internal injury to the patient. The stylet may have a noncircular cross-section for restricting directions in which it can bend.

Abstract: A combination catheter for both detecting monophasic action potentials and ablating surface tissue in an in vivo heart of a patient is provided. The apparatus includes a catheter probe having a terminal tip portion and an electrode carried on the tip such that a portion of the tip electrode is exposed to ambient. A reference electrode is spaced along the tip from the first electrode for supplying a reference potential signal. An ablating electrode is located adjacent to but electrically insulated from both the tip and reference electrodes for providing electromagnetic energy to the tip. The electrodes are electrically connected to the proximal end of the catheter through individual conductors or wires that run through an insulated cable. An electronic filter is provided to permit the recording of MAPs during ablation without radiofrequency interference. The catheter may also include standard mapping and/or pacing electrodes.

Abstract: An electrode tip assembly attachable to the end of a catheter for supporting a tip electrode for percutaneous insertion into a living body having a steering mechanism includes an elongated body bendable in response to external forces to steer the tip electrode. The body is connected at its distal end to the tip electrode. At least one steering wire is attached to the elongated body for transmitting bending force to the body from a remote control mechanism. An movable stiffening member, preferably in the form of a sleeve or rod provides a variable fulcrum for bending of the body in response to an applied bending force. A control stylet or sleeve extends through the catheter and is attached to the stiffening member for moving the stiffening member in a distal/proximal direction or for rotating it relative to the body.

Abstract: A steering mechanism including a steering shaft coupled to a controller which includes a handle and apparatus for manipulating the distal end of the steering shaft. The steering shaft includes a flexible coiled spring having a lead spring fixed in position with respect to a distal end thereof in the distal end of the steering shaft. One or more steering wires is affixed at the distal ends thereof to the lead spring. The steering wires extend through the steering shaft to the controller, and the steering apparatus of the controller is used to place tension on one or both of the steering wires. The attachment of the distal ends of the steering wires to the lead spring may be opposite one another or may be offset for providing greater maneuverability.

Abstract: A catheter carries a functional component, like an ablating electrode, having a predetermined operating characteristic. The catheter also electronically retains an identification code that uniquely identifies the predetermined operating characteristic. The catheter is capable of transmitting the identification code to an external reader in response to a predetermined prompt. An associated apparatus, like an ablating energy source, reads the identification code and compares it to predetermined operating criteria. The apparatus will not permit interaction with the functional catheter component, if the identification code indicates that the functional characteristics of the catheter are not suited for the intended interaction. The catheter can also store usage information, to prevent reuse.

Abstract: An antenna assembly has an energy propagating region that is encapsulated in a material having a high dielectric constant for minimizing the loss of energy while having a high thermal conductivity for dissipating conductive heat patterns about the energy propagating region.

Abstract: An improved assembly for steering and orienting a functional element at the distal end of a catheter tube holds the functional element with its major axis aligned with the axis of the catheter tube for convenient steering to a tissue site. The mechanism can also pivot the functional element in response to an external force to orient the major axis of the functional element generally parallel to the plane of the tissue site, without bending the catheter tube.

Abstract: The invention provides an improved catheter steering mechanism for pulling a first catheter steering wire while simultaneously allowing a second catheter steering wire to remain static, and vice versa. The mechanism includes at least one rotatable gear and means, such as a rotatable knob, for manually rotating the gear. A first linearly slidable toothed rack is attached to the proximal end of one steering wire, and a second linearly slidable toothed rack is attached to the proximal end of the other steering wire. A toothed gear rotatable by rotation of the knob engages each of the toothed racks to move them linearly in opposite directions in response to rotation of said gear. Preferably three intermeshing gears are used so that movements of the racks are in the same direction as the rotation of the knob.

Abstract: An electrode tip assembly for a catheter is bendable under the control of the user. One portion of the assembly is more resistant to bending than the remaining portions. The variable stiffness directs and concentrates the applied bending forces in the particular region where maximum bending is desired.

Abstract: A catheter has an electrode tip assembly that is bendable at the selection of the user in two different directions. The electrode tip assembly assumes different asymmetric predetermined curve configurations when bent in the two directions and is manipulated by means of steering wires adjustably connected tangentially to the lateral edges of a rotatable cam located in the catheter handle.