System and methods for identifying tissue and vessels

Abstract

A surgical system and corresponding methods for identifying tissue or vessels and assessing their conditions includes a probing signal source for applying a probing signal to the tissue and a response signal monitor for monitoring a response signal that varies according to the level of blood circulation in the tissue or vessels. The response signal monitor monitors the response signal over an interval equal to or longer than air interval between two successive cardiac contractions. The surgical system includes a microprocessor that analyzes the amplitude and/or phase of the response signal to determine the level of blood circulation in the tissue or in different portions of the tissue, and determines a tissue parameter based upon the level of blood circulation. The surgical system may monitor a cardiac signal related to cardiac contractions and correlate the response signal and the cardiac signal to determine a level of blood circulation in the tissue.

1 - 14 . (canceled) 
     
     
         15 . A method of determining a tissue parameter, comprising:
 applying a probing signal to tissue, the probing signal being configured to interact with the tissue;   monitoring a response signal that has interacted with the tissue over an interval longer than an interval between two successive cardiac contractions;   monitoring a cardiac signal related to cardiac contractions;   correlating the response signal and the cardiac signal;   determining a level of blood circulation in the tissue based upon the result of correlating the response signal and the cardiac signal; and   determining a parameter of the tissue based upon the result of determining the level of blood circulation in the tissue.   
     
     
         16 . The method of  claim 15 , wherein the parameter of the tissue is a type of the tissue. 
     
     
         17 . The method of  claim 16 , wherein the type of the tissue is selected from the group consisting of connective tissue, muscle tissue, nervous tissue, and epithelial tissue. 
     
     
         18 . A system for determining a tissue parameter, comprising:
 a probing signal source configured to apply a probing signal to tissue;   a response signal monitor configured to monitor a response signal over an interval longer than an interval between two successive cardiac contractions; and   a processor configured to analyze the amplitude of the response signal to determine a level of blood circulation in the tissue, the processor further configured to determine a tissue parameter based on the level of blood circulation.   
     
     
         19 . The system of  claim 18 , further comprising an electrosurgical energy source configured to apply electrosurgical energy to tissue during an electrosurgical procedure, wherein the probing signal source is the same source as the electrosurgical energy source.