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 method for mapping electrical activity of a heart includes inserting a probe into a chamber of the heart, the probe including at least one position sensing device and a plurality of non-contact electrodes. Position coordinates of the electrodes are determined relative to an endocardial surface of the chamber, using the at least one position sensing device, and electrical potentials are measured at the determined position coordinates using the electrodes. Electrical potentials are computed at a plurality of points on the endocardial surface, using the measured potentials and the position coordinates, so as to generate a map of electrical activity over the endocardial surface based on the computed potentials.

Abstract: A method of treating a patient's heart comprises the steps of identifying an ischemic area of the heart. A plurality of cells are provided and the cells are irradiated in vitro with electromagnetic radiation. The irradiated cells are then implanted into the ischemic area of the heart. The electromagnetic radiation provides biostimulation of the cells. The treated cells are cardio myocetes such as from embrionic heart muscle or skeletal muscle cells. The electromagnetic radiation is in the infrared (IR) range, visible light range, or ultraviolet (UV) range.

Abstract: A condition, such as an electrical property, of a chamber of a heart is surveyed with a catheter having a condition sensor at its distal tip. A method for surveying the chamber includes the steps of acquiring a first image of the chamber containing topographical information, advancing the distal tip of the catheter into the chamber, acquiring a second image including a representation of the catheter distal tip in the chamber, displaying a superposition of the topographical information extracted from the first image with the second image to generate a displayed superimposed image, acquiring condition information at a point on the chamber displayed on the superimposed image on or near the topographical information, and acquiring condition information at one or more additional points sufficient in number and spacing to permit the generation of a survey map of the condition in the chamber.

Abstract: A method for tracking an object, including producing an unperturbed energy field at a plurality of predetermined frequencies in the vicinity of the object and determining a characteristic of a perturbing energy field induced responsive to the unperturbed field, due to introduction of an article, responsive to the unperturbed field, into the vicinity of the object. The method further includes receiving a plurality of resultant signals responsive to the unperturbed and perturbing energy fields generated at a location of the object after introduction of the article, determining an optimal frequency for the unperturbed energy field from amongst the plurality of predetermined frequencies responsive to a parameter of the resultant signals, and determining spatial coordinates of the object responsive to the resultant signal at the optimal frequency.

Abstract: A method for intracardially mapping a condition such as an electrical or mechanical property of a chamber of a heart uses a catheter having a distal tip and at least one condition sensor contained therein or proximate thereto. The at least one sensor is capable of sensing condition information in the chamber and provides the three-dimensional position of the catheter tip in a positional frame of reference. The method includes the steps of acquiring first and second images of the chamber. The images are acquired from different projections and contain topological information of the chamber. The chamber images are registered with the positional frame of reference. The catheter distal tip is advanced into the catheter and is navigated to acquisition points under the guidance of topological information contained in or derived from the images.

Abstract: A probe assembly (18) for connection to a console (34) including a problem (20) for insertion into the body of a subject and a cable (21) for connecting the problem (20) to the console (34), the problem (20) having distal (22) and proximal ends and including a microcircuit (90) which stores information relating to the probe (20), and the cable (21) including access circuitry for accessing the microcircuit in the probe.

Abstract: A system for determining the disposition of a probe within the body of a patient includes a probe having probe field transducers and one or more reference field transducers. The reference field transducers are affixed to a rigid but repositionable frame constructed to allow the transducers to be positioned in close proximity to the body. Non-ionizing fields are transmitted and detected between the probe and reference field transducers, and from the detected fields the relative disposition of the probe with respect to the reference field transducers is determined.

Abstract: A method for calibrating a magnetic field generator, including fixing one or more magnetic field sensors to a probe in known positions and orientations and selecting one or more known locations in the vicinity of the magnetic field generator. The magnetic field generator is driven so as to generate a magnetic field. The probe is moved in a predetermined, known orientation to each of the one or more locations, and signals are received from the one or more sensors at each of the one or more locations. The signals are processed to measure the amplitude and direction of the magnetic field, at the respective positions of the one or more sensors and to determine calibration factors relating to the amplitude and direction of the magnetic field in the vicinity of the magnetic field generator.

Abstract: A medical probe such as a catheter (20) is guided within the body of a patient by determining the relative positions of the probe relative to another probe, as by transmitting non-ionizing radiation to or from field transducers (30, 230) mounted on both probes. In one embodiment, a site probe (28) is secured to a lesion within the body, and an instrument probe (200) for treating the lesion may be guided to the lesion by monitoring relative positions of the probes. Two or more probes may be coordinated with one another to perform a medical procedure.

Abstract: A method of excavating tissue in the body, including bringing a catheter (60) to a location, injecting microbubbles (84) at the location and causing cavitation of tissue (76) at the location using ultrasound. Preferably, the microbubbles (84) are injected directly into the tissue, such as by using a hollow needle (62). Alternatively, microbubbles (84) are injected into the vascular bed of the tissue at the location, so that the capillaries (86) are infused with microbubbles (84).

Abstract: Apparatus for X-ray guided surgery, including a reference element (20), which is placed in contact with the body (32) of a subject. The element includes a plurality of fiducial marks (22a, 22b, 22c) and a first coordinate sensing device (24), in predetermined, fixed positions in the element (20). A surgical tool (36), having a distal end for insertion into the body (32), includes a second coordinate sensing device (40) fixed thereto. A fluoroscope (54) forms an X-ray image of the body, including the fiducial marks. A computer analyzes the image to determine the position of the reference element in the image, so as to find coordinates of the first coordinate sensing device relative to the image, and registers the position of the tool with the X-ray image by referring coordinates of the second coordinate sensing device to the known coordinates of the first position sensor.

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 method of diagnosing an abnormal condition in a biological structure, such as the heart, including the steps of measuring a physiological response at at least three sampled points on a surface of the biological structure, calculating a vector function related to the response, displaying a representation of the vector function, and inferring the abnormal condition from the representation. The present invention is particularly useful for diagnosing cardiac arrhythmias, in which case the physiological response is a voltage, from which is inferred a local activation time and the vector function is a gradient of the local activation time, specifically, a conduction velocity.

Abstract: A method of constructing a cardiac map of a heart having a heart cycle including; bringing an invasive probe into contact with a location on a wall of the heart; determining, at at least two different phases of the heart cycle, a position of the invasive probe; and determining a local non-electrical physiological value at the location. The method is repeated for a plurality of locations in the heart The positions are combined to form a time-dependent map of at least a portion of the heart and local relationships between changes in positions of the invasive probe and determined local non-electrical physiological values are determined. Preferably, local electrical activity at the plurality of locations is also acquired.

Abstract: This invention is an invasive probe apparatus including flexible elongate probe (20) having a distal portion adjacent to a distal end (22) thereof for insertion into the body of a subject, which portion assumes a predetermined curve form when a force is applied thereto. First and second sensors (28, 30) are fixed to the distal portion of the probe (20) in known positions relative to the distal end (22), which sensors generate signals responsive to bending of the probe. Signal processing circuitry (36) receives the bend responsive signals and processes them to find position and orientation coordinates of at least the first sensor (28), and to determine the locations of a plurality of points along the length of the distal portion of the probe.

Abstract: A probe (20) for insertion into the body of a subject, the probe (20) having distal (22) and proximal ends, and including an electronic microcircuit (90), which stores information relating to calibration of the probe (20). Preferably, the microcircuit (90) stores a calibration code, which is encrypted. Alternatively or additionally, the microcircuit (90) stores a usage code, which controls availability of the probe (20) to a user thereof. Preferably, the probe (20) includes access control circuitry (90) that allows the usage code to be changed so as to reduce the availability of the probe (20), but not to increase the availability thereof.

Abstract: The invention is a catheter (20) with a lumen (24) wherein the lumen is obstructed by a portion of the catheter (50). The catheter (20) includes a position detector (22) at the tip of the catheter (20).

Abstract: An apparatus for intracardiac drug administration of a therapeutic drug comprises a catheter having a distal end and a drug delivery device which is driveable from the distal end. The drug delivery device includes a needle and a spring-loaded mechanism operatively connected to the needle. The spring-loaded mechanism drives the needle out of the distal end of the catheter upon administering of the therapeutic drug. The spring-loaded mechanism returns the needle within the distal end of the catheter after the administering of the therapeutic drug.

Abstract: A method of reconstructing a map of a volume, including determining coordinates of a plurality of locations on a surface of the volume having a configuration, generating a grid of points defining a reconstruction surface in 3D space in proximity to the determined locations, for each of the points on the grid, defining a respective vector, dependent on a displacement between one or more of the points on the grid and one or more of the locations, and adjusting the reconstruction surface by moving substantially each of the points on the grid responsive to the respective vector, so that the reconstruction surface is deformed to resemble the configuration of the surface.