Computing local propagation velocities in real-time

Abstract

A method includes, based on respective signals acquired by a plurality of electrodes on an anatomical surface of a heart, computing respective local activation times (LATs) at respective locations of the electrodes. The method further includes, based on the LATs, computing respective directions of electrical propagation at the locations. The method further includes selecting pairs of adjacent ones of the electrodes such that, for each of the pairs, a vector joining the pair is aligned, to within a predefined threshold degree of alignment, with the direction of electrical propagation at the location of one of the electrodes belonging to the pair. The method further includes associating respective bipolar voltages measured by the pairs of electrodes with a digital model of the anatomical surface. Other examples are also described.

1 .- 6 . (canceled) 
     
     
         7 . A system for real-time computing of local signal propagation velocities in a heart of a patient, comprising:
 a display;   a probe carrying a plurality of electrodes, the probe being inserted into the heart of the patient and configured to measure electrical signals during an electroanatomical mapping procedure;   and   a processor connected to the probe and to the display, configured to:
 generate a digital electro-anatomical (EA) map of the heart by associating spatial coordinates for each electrode of the plurality of electrodes, with the respective signals received from the plurality of electrodes; 
 display the digital EA map on the display; 
 based on respective signals acquired by the electrodes, on an anatomical surface of the heart, compute respective local activation times (LATs) at respective locations of the electrodes, 
 based on the LATs, compute respective directions of, and speeds of, electrical propagation at the locations, 
 while the electrodes are at the locations, respectively, display an icon of the probe on the digital EA map on the display, and 
 place, at portions of the icon corresponding to the electrodes, respective markers oriented in the directions of electrical propagation, respectively, and having at least one property that varies in accordance with the speeds. 
   
     
     
         8 . The system according to  claim 7 , wherein the processor is configured to compute the LAT at the location of each first electrode of the electrodes by:
 obtaining multiple candidate sets of LATs for the location, by, for each second electrode of the electrodes that is adjacent to the first electrode:
 providing, as input to a function, (i) a unipolar voltage signal, which represents a unipolar voltage between the first electrode and a reference electrode, and (ii) a bipolar voltage signal, which represents a bipolar voltage between the first electrode and the second electrode, and 
 receiving, as output from the function, a respective one of the candidate sets, and 
   choosing the LAT from the candidate sets.   
     
     
         9 . The system according to  claim 7 , wherein the property varies in accordance with the speeds by virtue of the markers:
 having a first shape and a first thickness for those of the speeds that belong to a first range,   having the first shape and a second thickness for those of the speeds that belong to a second range that is lower than the first range, and   having a second shape for those of the speeds that belong to a third range that is lower than the second range.   
     
     
         10 . The system according to  claim 9 , wherein the markers have at least one other property that varies in accordance with the LATs. 
     
     
         11 . The system according to  claim 10 , wherein the markers are colored in accordance with a color scale based on the LATs. 
     
     
         12 . A method, executed by a processor, for real-time computing of local signal propagation velocities in a heart of a patient, the processor being connected to a probe carrying a plurality of electrodes, the probe being inserted into the heart of the patient and configured to measure electrical signals during an electroanatomical mapping procedure, the method comprising:
 generating a digital electro-anatomical (EA) map of the heart by associating spatial coordinates for each electrode of the plurality of electrodes, with the respective signals received from the plurality of electrodes;   displaying the digital EA map on the display;   based on respective signals acquired by the electrodes, on an anatomical surface of the heart, computing respective local activation times (LATs) at respective locations of the electrodes;   based on the LATs, computing respective directions of, and speeds of, electrical propagation at the locations;   while the electrodes are at the locations, respectively, displaying an icon of the probe on the digital EA map; and   placing, at portions of the icon corresponding to the electrodes, respective markers oriented in the directions of electrical propagation, respectively, and having at least one property that varies in accordance with the speeds.   
     
     
         13 . The method according to  claim 12 , wherein computing the LATs comprises computing the LAT at the location of each first electrode of the electrodes by:
 obtaining multiple candidate sets of LATs for the location, by, for each second electrode of the electrodes that is adjacent to the first electrode:
 providing, as input to a function, (i) a unipolar voltage signal, which represents a unipolar voltage between the first electrode and a reference electrode, and (ii) a bipolar voltage signal, which represents a bipolar voltage between the first electrode and the second electrode, and 
 receiving, as output from the function, a respective one of the candidate sets; and 
   choosing the LAT from the candidate sets.   
     
     
         14 . The method according to  claim 12 , wherein the property varies in accordance with the speeds by virtue of the markers:
 having a first shape and a first thickness for those of the speeds that belong to a first range,   having the first shape and a second thickness for those of the speeds that belong to a second range that is lower than the first range, and   having a second shape for those of the speeds that belong to a third range that is lower than the second range.   
     
     
         15 . The method according to  claim 14 , wherein the markers have at least one other property that varies in accordance with the LATs. 
     
     
         16 . The method according to  claim 15 , wherein the markers are colored in accordance with a color scale based on the LATs. 
     
     
         17 .- 20 . (canceled)