Methods and systems for determining physiologic characteristics for treatment of the esophagus

Abstract

A method and apparatus for treating abnormal mucosa in the esophagus is disclosed, such that the depth of the treated tissue is controlled. The depth of ablation is controlled by monitoring the tissue impedance and/or the tissue temperature. A desired ablation depth is also achieved by controlling the energy density or power density, and the amount of time required for energy delivery. A method and apparatus is disclosed for measuring an inner diameter of a body lumen, where a balloon is inflated inside the body lumen at a fixed pressure.

1 . A method for measuring an inner diameter of a body lumen comprising: 
 inserting a balloon in the body lumen;    inflating the balloon inside the body lumen using an expansion medium; and    monitoring a mass of the expansion medium inside the balloon.    
   
   
       2 . The method of  claim 1 , wherein monitoring the mass of the expansion medium is performed using a mass flow sensor.  
   
   
       3 . The method of  claim 1 , wherein the expansion medium is a gas.  
   
   
       4 . The method of  claim 1 , wherein the expansion medium is a liquid.  
   
   
       5 . The method of  claim 1 , wherein the balloon is inflated at a fixed pressure.  
   
   
       6 . The method of  claim 1 , wherein the fixed pressure is approximately 4 psig.  
   
   
       7 .- 17 . (canceled)  
   
   
       18 . A method for treating abnormal tissue inside a body lumen, the method comprising: 
 automatically determining an inner diameter of the body lumen at a location proximal to the abnormal tissue;    deploying an electrode structure at a surface of the tissue at the proximal location; and    delivering energy to the electrode structure for treating the tissue.    
   
   
       19 . The method of  claim 18 , wherein the inner diameter is determined by automatically inflating and deflating a balloon inside the body lumen using an expansion medium.  
   
   
       20 . The method of  claim 19 , further comprising monitoring a mass of the expansion medium inside the balloon.  
   
   
       21 . The method of  claim 18 , further comprising controlling a depth of treated tissue.  
   
   
       22 . The method of  claim 21 , wherein controlling the depth of treated tissue comprises controlling an amount of power delivered to the tissue over time.  
   
   
       23 . The method of  claim 21 , wherein controlling the depth of treated tissue comprises normalizing power delivered to the tissue over time.  
   
   
       24 . The method of  claim 21 , wherein controlling the depth of treated tissue comprises controlling an amount of energy delivered to the tissue over time.  
   
   
       25 . The method of  claim 21 , wherein controlling the depth of treated tissue comprises controlling delivered energy density.  
   
   
       26 . The method of  claim 21 , wherein controlling the depth of treated tissue comprises monitoring and controlling tissue impedance over time.  
   
   
       27 . The method of  claim 21 , wherein controlling the depth of treated tissue comprises monitoring and controlling tissue temperature over time.  
   
   
       28 . The method of  claim 18 , further comprising controlling an amount of power delivered to the tissue by rapidly increasing the power until it reaches a set target value.  
   
   
       29 . The method of  claim 28 , wherein controlling the amount of power delivered is performed using a proportional integral derivative controller.  
   
   
       30 . An apparatus for treating a tissue inside a body lumen comprising: 
 an electrode structure adapted to be positioned at a surface of the tissue inside the body lumen, wherein the electrode structure is coupled to an expansion member; and    a generator for producing and delivering energy to the electrode structure;    wherein the generator is adapted to automatically inflate the expansion member inside the body lumen and control the pressure inside the expansion member during treatment of the tissue.    
   
   
       31 . The apparatus of  claim 30 , wherein the expansion member is a balloon coupled to a catheter.  
   
   
       32 . The apparatus of  claim 30 , further comprising a storage device for storing generator settings.  
   
   
       33 . The apparatus of  claim 32 , wherein the storage device is an EEPROM.  
   
   
       34 . The apparatus of  claim 30 , further comprising a pump for automatically inflating and deflating the expansion member.  
   
   
       35 . The apparatus of  claim 30 , wherein the generator is adapted to determine an inner diameter of the body lumen using an inflatable balloon.  
   
   
       36 . The apparatus of  claim 35 , wherein the generator is adapted to control the amount of energy delivered to the tissue over time based on the measured diameter of the esophagus.  
   
   
       37 . The apparatus of  claim 35 , wherein the generator is adapted to normalize the density of energy delivered to the tissue based on the measured diameter of the esophagus.  
   
   
       38 . The apparatus of  claim 35 , wherein the generator is adapted to control the amount of power delivered to the tissue over time based on the measured diameter of the esophagus.  
   
   
       39 . The apparatus of  claim 30 , wherein the generator is adapted to control the energy delivered to the electrode structure.  
   
   
       40 . The apparatus of  claim 30 , wherein the generator is adapted to control the power delivered to the electrode structure.  
   
   
       41 . The apparatus of  claim 30 , wherein the generator is adapted to normalize the amount of power delivered to the tissue over time based on the measure diameter of the esophagus.  
   
   
       42 . The apparatus of  claim 30 , wherein the generator is adapted to detect whether a catheter is attached thereto and to identify a characteristic of the attached catheter.  
   
   
       43 . The apparatus of  claim 42 , further comprising a storage device adapted to store information about the attached catheter.  
   
   
       44 . The apparatus of  claim 30 , further comprising a footswitch coupled to the generator and adapted to control the energy delivered to the electrode structure.  
   
   
       45 . The apparatus of  claim 30 , further comprising a display for displaying information to a user.  
   
   
       46 . The apparatus of  claim 30 , wherein the generator is adapted to be manually controlled by a user such that the user controls the energy delivered to the electrode structure over time.  
   
   
       47 . The apparatus of  claim 30 , further comprising a proportional integral derivative controller adapted to gradually increase power delivered to the electrode structure until it reaches a set target value.  
   
   
       48 . An apparatus for treating a tissue inside a body lumen comprising: 
 an electrode structure adapted to be positioned at a surface of the tissue inside the body lumen, wherein the electrode structure is coupled to an expansion member; and    a generator for producing, delivering and controlling energy delivered to the electrode structure;    wherein the generator is adapted to determine an inner diameter of the body lumen.