System and method for assessing lesions in tissue

Abstract

A method and system for assessing lesion formation in tissue is provided. The system includes an electronic control unit (ECU). The ECU is configured to acquire values for first and second components of a complex impedance between the electrode and the tissue, and to calculate an index responsive to the first and second values. The ECU is further configured to process the ECI to assess lesion formation in the tissue.

What is claimed is: 
     
         1 . A guidance system for a catheter, comprising:
 an electronic control unit (ECU) configured to:
 analyze first and second components of a complex impedance between an electrode and tissue; 
 analyze a state of contact between the electrode and the tissue; and 
 assess at least one lesion site on the tissue according to the first and second complex impedance components and according to the state of contact; and 
   a display device, electrically coupled with said ECU, configured to provide feedback to a user for manipulating the catheter according to said lesion site assessment.   
     
     
         2 . The guidance system of  claim 1 , wherein the state of contact comprises one or more of a contact pressure, a contact force, a temperature, a change in temperature, and a fluid flow rate. 
     
     
         3 . The guidance system of  claim 1 , wherein said ECU is configured to assess the at least one lesion site by calculating an index responsive to at least the first and second complex impedance components and to the state of contact. 
     
     
         4 . The guidance system of  claim 3 , wherein said ECU is configured to assess the at least one lesion site by calculating an index rate by:
 receiving first location coordinates corresponding to a first location of the electrode and second location coordinates corresponding to a second location of the electrode;   calculating an index change between a first index calculated responsive to first and second components of a first complex impedance acquired while said electrode is located at said first location and a second index calculated responsive to first and second components of a second complex impedance acquired while said electrode is located at said second location over a predetermined time interval;   calculating a change in said location coordinates; and   calculating an index rate by dividing said index change by said change in said location coordinates of said electrode.