Abstract: A method is provided for ablating tissue in a heart of a subject during an ablation procedure. The method includes applying a local treatment to the heart at a plurality of sites designated for ablation. At each respective site, a parameter is sensed that is indicative of a level of ablation at the site. The method preferably includes displaying a map of the heart, and designating, on the map, during the ablation procedure, indications of the respective levels of ablation at the sites, responsive to the respective sensed parameters.

Abstract: A catheter introduction apparatus provides an optical assembly for emission of laser light energy. In one application, the catheter and the optical assembly are introduced percutaneously, and transseptally advanced to the ostium of a pulmonary vein. An anchoring balloon is expanded to position a mirror near the ostium of the pulmonary vein, such that light energy is reflected and directed circumferentially around the ostium of the pulmonary vein when a laser light source is energized. A circumferential ablation lesion is thereby produced, which effectively blocks electrical propagation between the pulmonary vein and the left atrium.

Abstract: A method for performing a procedure at the fossa ovalis in the septal wall of the heart includes the steps of providing a sheath having a body wherein the body has a lumen extending therethrough and an open end at the distal end of the body. The body also has at least one electrode and a position sensor at the distal end of the body. The position sensor generates signals indicative of the location of the distal end of the body. The sheath is navigated to the septal wall using the position sensor and the fossa ovalis in the septal wall is identified using the at least one electrode of the sheath.

Abstract: A medical location system includes a medical device having a body and a position sensor at a portion of the body. The position sensor has a core made of a Wiegand effect material and a winding circumferentially positioned around the core. The position sensor provides signals that are used to determine temperature at the position sensor and location information of the portion of the body of the medical device. A signal processor is coupled to receive the signals from the position sensor and the signal processor determines the temperature at the position sensor and location information of the portion of the body of the medical device based on the signals received from the position sensor.

Abstract: A method for mapping a heart comprises the steps of inserting a mapping catheter having an ultrasonic position sensor into the heart. At least one reference catheter having an ultrasonic position sensor is also inserted into the heart. The position of the mapping catheter is determined relative to the at least one reference catheter and a portion of the heart is mapped with the mapping catheter. Additionally, the at least one reference catheter may be provided outside of the heart.

Abstract: A method is provided for electrical mapping of a pulmonary vein of a heart, including introducing into the heart a catheter having a curved section and a base section, the base section having a distal end attached to a proximal end of the curved section. At a location on the curved section, a first position signal is generated having fewer than six dimensions of position and orientation information. At a vicinity of the distal end of the base section, a second position signal is generated having six dimensions of position and orientation information. The method also includes measuring, at one or more locations on the curved section, an electrical property of the pulmonary vein.

Abstract: A method of determining an optimal location for implanting a pacemaker electrode includes the steps of pacing a heart from a first location and generating a first map of the heart associated with pacing at the first location. The heart is paced from a second location and a second map is generated of the heart associated with pacing at the second location. The first and second maps are compared in order to diagnose the effect of the pacing and an optimal location for implanting the pacemaker electrode based on the comparison of the maps is selected.

Abstract: A novel apparatus and method for rapidly generating an electrical map of a chamber of a heart utilizes a catheter including a body having a proximal end and a distal end. The distal end has a distal tip and an array of non-contact electrodes having a proximal end and a distal end and at least one location sensor. Preferably, two location sensors are utilized. The first location sensor is preferably proximate to the catheter distal tip and the second location sensor is preferably proximate to the proximal end of the non-contact electrode array. The catheter distal end further preferably includes a contact electrode at its distal tip. Preferably, at least one and preferably both of the location sensors provide six degrees of location information. The location sensor is preferably an electromagnetic location sensor. The catheter is used for rapidly generating an electrical map of the heart within at least one cardiac cycle and preferably includes cardiac ablation and post-ablation validation.

Abstract: A catheter introduction apparatus provides a radially expandable helical coil as a radiofrequency emitter. In one application the emitter is introduced percutaneously, and transseptally advanced to the ostium of a pulmonary vein. The emitter is radially expanded, which can be accomplished by inflating an anchoring balloon about which the emitter is wrapped, in order to cause the emitter to make circumferential contact with the inner wall of the pulmonary vein. The coil is energized by a radiofrequency generator, and a circumferential ablation lesion is produced in the myocardial sleeve of the pulmonary vein, which effectively blocks electrical propagation between the pulmonary vein and the left atrium.

Abstract: A locating system for determining the location and orientation of an invasive medical instrument, for example a catheter or endoscope, relative to a reference frame, comprising: a plurality of field generators which generate known, distinguishable fields, preferably continuous AC magnetic fields, in response to drive signals; a plurality of sensors situated in the invasive medical instrument proximate distal end thereof which generate sensor signals in response to said fields; and a signal processor which has an input for a plurality of signals corresponding to said drive signals and said sensor signals and which produces the three location coordinates and three orientation coordinates of a point on the invasive medical instrument.

Abstract: An implantable medical device comprises a housing having a proximal end and a distal end and a longitudinal axis. A first set of anchoring members are operatively connected to the proximal end of the housing. A second set of anchoring members are operatively connected to the distal end of the housing. The first set of anchoring members and the second set of anchoring members are movable between a collapsed position and a deployed position. The collapsed position is defined as a position whereby the first set of anchoring members and the second set of anchoring members are substantially parallel to the longitudinal axis of the housing. The deployed position is defined as a position whereby the first set of anchoring members and the second set of anchoring members are substantially perpendicular to the longitudinal axis of the housing.

Abstract: Apparatus for mapping a surface of a cavity within a body of a subject includes an elongate probe, having a longitudinal axis and including a distal portion adapted for insertion into the cavity. A primary acoustic transducer on the distal portion of the probe is adapted to emit acoustic waves while the probe is in the cavity. A plurality of secondary acoustic transducers, distributed along the longitudinal axis over the distal portion of the probe, are adapted to receive the acoustic waves after reflection of the waves from the surface of the cavity and to generate, responsive to the received waves, electrical signals indicative of times of flight of the waves.

Abstract: A system for mapping a heart comprises a mapping catheter having an ultrasonic position sensor for insertion into the heart. The system also comprises at least one reference catheter having an ultrasonic position sensor placeable in a fixed position relative to the heart. The position of the mapping catheter is determined relative to the at least one reference catheter. The ultrasonic position sensor of the mapping catheter is located at the tip of the mapping catheter. The ultrasonic position sensor for the at least one reference catheter is located at the tip of the at least one reference catheter.

Abstract: A method for implanting a medical device between tissue comprises the steps of providing a catheter having a body and a distal end thereof wherein the catheter includes an implantable device comprising a housing having a proximal end and a distal end and a longitudinal axis. The implantable device further includes a first set of anchoring members operatively connected to the proximal end of the housing and a second set of anchoring members operatively connected to the distal end of the housing. Both sets of anchoring members are movable between a collapsed position and a deployed position. Each set of anchoring members includes ring members connected to a housing of the device. Further steps of the method include inserting the distal end of the catheter into tissue and disposing the medical device at least partially from the distal end of the catheter.

Abstract: Apparatus for mapping a surface of a cavity within a body of a subject includes an elongate probe, having a longitudinal axis and including a distal portion adapted for insertion into the cavity. A plurality of acoustic transducers are distributed along the longitudinal axis over the distal portion of the probe, which transducers are adapted to be actuated individually to emit acoustic waves while the probe is in the cavity, and are further adapted to receive the acoustic waves after reflection of the waves from the surface of the cavity and to generate, responsive to the received waves, electrical signals indicative of times of flight of the waves.

Abstract: Apparatus for intracardiac drug administration, including a catheter which is inserted into a chamber of the heart and brought into engagement with a site in the heart wall. The catheter includes at least one position sensor, which generates signals responsive to the position of the catheter within the heart, and a drug delivery device, which administers a desired dose of a therapeutic drug at the site determined responsive to the signals from the position sensor.

Abstract: A locating system for determining the location and orientation of an invasive medical instrument, for example a catheter (10) or endoscope, relative to a reference frame, comprising: a plurality of field generators (18, 20, 22) which generate known, distinguishable fields, preferably continuous AC magnetic fields, in response to drive signals; a plurality of sensors (30, 32, 34) situated in the invasive medical instrument (10) proximate the distal end thereof which generate sensor signals in response to said fields; and a signal processor (26) which has an input for a plurality of signals corresponding to said drive signals and said sensor signals and which produces the three location coordinates and three orientation coordinates of a point on the invasive medical instrument.

Abstract: A method for measuring near-field electrical activity at a location in a heart comprising introducing into the heart a catheter. The catheter comprises an elongated tubular body having a distal region and a circumferential recess along the length of the distal region, a first electrode mounted on the distal region in close proximity to the circumferential recess, and a second electrode mounted within the circumferential recess. The distal region is positioned at the location in the heart so that the first electrode is in direct contact with heart tissue and the second electrode is not in direct contact with heart tissue but is in contact with blood. A first signal is obtained with the first electrode, and a second signal is obtained with the second electrode. The first signal and the second signal are compared to obtain the near-field electrical activity at the location in the heart.

Abstract: A signal reading and charging device for use with an implantable telemetric medical sensor comprises a casing and a circuit within the casing comprising a logic control unit and a processing unit. The logic control unit sends a powering signal to the telemetric medical sensor for remotely powering the sensor. The logic control unit also receives a transmitted signal from the sensor. The processing unit is operatively connected to the control unit for converting the transmitted signal by the sensor into a measured parameter. An antenna coil is used for sending the powering signal and receiving the transmitted signal from the sensor. The device also includes a display for displaying the measured parameter.

Abstract: A method for telemetrically measuring a parameter in a patient's heart comprises the steps of imaging the heart and identifying an implantation site in the heart. An opening is created in the tissue at the implantation site. A sensor comprising a housing, a membrane at one end of the housing wherein the membrane is deformable in response to the parameter, and a microchip positioned within the housing and operatively communicating with the membrane for transmitting a signal indicative of the parameter is provided. The sensor is placed in the opening and the parameter is telemetrically measured from outside of the patient's body based on the transmitted signal by the sensor. The sensor is also telemetrically powered from outside of the patient's body. A signal charging and reading device is placed outside of the patient's body for telemetric powering and signal reading with respect to the sensor.