A temperature probe for monitoring temperatures of a surface of a tissue or organ within the body of a subject includes a section with a substantially two-dimensional arrangement and a plurality of temperature sensors positioned across an area defined by the substantially two-dimensional arrangement. Such an apparatus may be used in conjunction with procedures in which thermal techniques are used to diagnose a disease state or treat diseased tissue. Specifically, a temperature probe may be used to monitor temperatures across an area of a surface of a tissue or organ located close to the treated tissue to prevent subjection of the monitored tissue or organ to potentially damaging temperatures.

Aspects of the present disclosure are directed to flexible catheters for both electrophysiology mapping and ablation using a high-density array of electrodes. These catheters may be used to detect electrophysiological characteristics of tissue in contact with the electrodes, and conduct monopolar and bipolar ablations of the tissue.

Systems and methods for quantifying cardiac electrophysiologic signals. An electronic processor receives a unipolar electrogram signal from each of a plurality of electrodes positioned at different locations of a heart. The electronic processor then calculates or measures a bipolar electrogram signal based on a difference between the unipolar electrogram signal for a first electrode and the unipolar electrogram signal for a second electrode. A local activation time (LAT) difference between a location of the first electrode and a local of the second electrode is then determined based on a voltage amplitude of the bipolar electrogram signal. The LAT difference is indicative of an amount of time between a local activation of a propagating wavefront at the location of the first electrode and a local activation of the propagating wavefront at the location of the second electrode.

A system comprises a catheter configured for delivery to a body cavity defined by surrounding tissue; a plurality of ultrasound transducers coupled to a distal end of the catheter; and an electronics module configured to selectively turn on/off each ultrasound transducer according to a predetermined activation sequence and to process signals received from each ultrasound transducer to produce at least a 2D display of the surrounding tissue. A user can selectively calculate and display various aspects of cardiac activity. The user can display Dipole Density (DDM), Charge Density (CDM), or Voltage (V-V). The shape and location of the chamber (surface), and the potentials recorded at electrodes can be displayed. The system can also change back and forth between the different display modes, and with post processing tools, can change how various types of information is displayed. Methods are also provided.

A system includes an expandable distal-end assembly, a proximal position sensor, a distal position sensor, and a processor. The expandable distal-end assembly is coupled to a distal end of a shaft for insertion into a cavity of an organ of a patient. The proximal and distal position sensors are located at a proximal end and a distal end of the distal-end assembly, respectively. The processor is configured to estimate a position and a longitudinal direction of the proximal sensor, and a position of the distal sensor, all in a coordinate system used by the processor. The processor is further configured to project the estimated position of the distal sensor on an axis defined by the estimated longitudinal direction, and calculate an elongation of the distal-end assembly by calculating a distance between the estimated position of the proximal sensor and the projected position of the distal sensor.

A method includes receiving multiple electrophysiological (EP) signals acquired by multiple electrodes of a multi-electrode catheter that are in contact with tissue in a region of a cardiac chamber, and respective tissue locations at which the electrodes acquired the EP signals. The region is divided into two sections. Using the EP signals acquired by the electrodes, local activation times (LAT) are calculated for the respective tissue locations, and found are: a first section of the two sections having a smaller average LAT value, and a second section of the two sections having a higher average value. Determined are a first representative location in the first section, and a second representative location in the second section. A propagation vector is calculated between the first and second representative locations, that is indicative of propagation of an EP wave that has generated the EP signals. The propagation vector is presented to a user.

An apparatus includes a shaft, configured for insertion into a body of a subject, and an expandable element coupled to a distal end of the shaft. The expandable element includes multiple electrodes arranged in a hexagonal grid when the expandable element is expanded. Other embodiments are also described.

A medical apparatus includes a shaft, an expandable frame, a membrane, a diagnostic electrode, a reference electrode, and a processor. The shaft is configured for insertion into an organ of a patient. The expandable frame is coupled to a distal end of the shaft. The diagnostic electrode, which is disposed on an external surface of the expandable frame, is configured to sense diagnostic signals when in contact with tissue. The reference electrode is disposed on a surface of the expandable frame directly opposite the diagnostic electrode, wherein the reference electrode is electrically insulated from the tissue and is configured to sense interfering signals.