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

Abstract

A system for measuring physiologic characteristics for treating abnormal mucosa in the esophagus comprises a sizing device having an inflatable balloon on a distal end of a catheter that is inflated with an expansion medium to expand the balloon to engage the wall of the esophagus so that the internal cross-section can be calculated or measured. The sizing device may also include an infusion source for delivering the expansion medium and means for measuring the amount and pressure of the expansion medium inside the catheter. The system also comprises one or more energy delivery devices for injuring or ablating the mucosal layer of the esophageal wall, the energy delivery devices having an expandable member selected to engage the esophageal wall to the appropriate dimension as determined by the sizing device.

What is claimed is:  
     
         1 . A method for treating the tissue of a body lumen at a treatment location, the method comprising: 
 measuring a luminal dimension at the treatment location of the lumen;    selecting an electrode deployment device having an electrode structure with a pre-selected deployed size which corresponds to the measured dimension;    deploying the selected electrode structure to the pre-selected deployed state to engage a wall of the lumen at a treatment location; and    delivering energy to the electrodes for treatment of the luminal tissue.    
     
     
         2 . A method as in  claim 1 , wherein measuring comprises: 
 positioning a sizing member at the treatment location within the lumen;    expanding the sizing member until it engages an inside wall of the lumen;    calculating the luminal dimension at the treatment location of the lumen based on the expansion of the sizing member.    
     
     
         3 . A method as in  claim 2 , wherein expanding the sizing member comprises inflating a sizing balloon by introducing an expansion medium.  
     
     
         4 . A method as in  claim 3 , wherein the expansion medium is a compressible fluid.  
     
     
         5 . A method as in  claim 3 , wherein the expansion medium is an incompressible fluid.  
     
     
         6 . A method as in  claim 4 , wherein the sizing balloon is generally cylindrical and has a known length and a diameter that is greater than the diameter of the target lumen.  
     
     
         7 . A method as in  claim 6 , wherein the sizing balloon is noncompliant.  
     
     
         8 . A method as in  claim 3 , wherein calculating comprises determining the amount of the expansion medium introduced to the sizing balloon while it is inflated.  
     
     
         9 . A method as in  claim 8 , wherein determining the amount of expansion medium comprises measuring the mass of the expansion medium introduced to the sizing balloon.  
     
     
         10 . A method as in  claim 8 , wherein determining the amount of expansion medium comprises measuring the volume of the expansion medium introduced to the sizing balloon.  
     
     
         11 . A method as in  claim 8 , further comprising a pressure sensor coupled to the sizing balloon, wherein the pressure sensor measures an internal pressure exerted from the expansion medium.  
     
     
         12 . A method as in  claim 11 , wherein calculating further comprises determining the luminal dimension based on the measured amount of expansion medium introduced to the balloon at a given pressure.  
     
     
         13 . A method as in  claim 1 , wherein measuring comprises determining the luminal dimension with ultrasound imaging.  
     
     
         14 . A method as in  claim 1 , wherein measuring comprises determining the luminal dimension with infrared imaging.  
     
     
         15 . A method as in  claim 1 , wherein measuring comprises determining the luminal dimension with calipers.  
     
     
         16 . A method as in  claim 3 , wherein the inflation medium comprises a contrast medium, and wherein measuring comprises determining the luminal dimension with a fluoroscope.  
     
     
         17 . A method as in  claim 2 , further comprising a measuring strip surrounding the sizing member, and wherein measuring comprises determining the luminal dimension by measuring the expansion of the measuring strip.  
     
     
         18 . A method as in  claim 1 , wherein selecting comprises choosing one electrode deployment device from an inventory of devices having different electrode deployment sizes.  
     
     
         19 . A method as in  claim 1 , wherein positioning the electrode deployment device comprises transesophageally delivering the device to a treatment area within the esophagus.  
     
     
         20 . A method as in  claim 19 , wherein transesophageally delivering the device comprises advancing a catheter through the esophagus, wherein the catheter carries the electrode array and an expansion member.  
     
     
         21 . A method as in  claim 20 , wherein the expansion member is an inflatable balloon, and wherein the balloon is generally cylindrical and has an outer diameter sized to match the value of the measured luminal dimension.  
     
     
         22 . A method as in  claim 21 , wherein deploying the electrode array comprises inflating the balloon with an expansion medium.  
     
     
         23 . A method as in  claim 22 , wherein the electrode deployment device further includes a pressure sensor, and wherein the balloon is inflated to a pressure no greater than 7 psig.  
     
     
         24 . A method as in  claim 23 , wherein the balloon is inflated to a pressure between 4 psig and 7 psig.  
     
     
         25 . A method as in  claim 20 , further comprising a dimensionally stable support, wherein the array of electrodes are arranged on a surface of the support.  
     
     
         26 . A method as in  claim 25 , wherein the support comprises a non-distensible, electrode backing.  
     
     
         27 . A method as in any one of  claims 19  to  26 , wherein delivering energy comprises applying radiofrequency energy to tissue of the body lumen through the electrodes.  
     
     
         28 . A method as in  claim 27 , wherein the radiofrequency is applied through a multiplicity of bipolar electrode pairs in the array.  
     
     
         29 . A method as in  claim 28 , wherein the electrodes are parallel, have a width in the range from 0.1 mm to 3 mm, and are spaced-apart by a distance in the range from 0.1 mm to 3 mm.  
     
     
         30 . A method for treating the tissue of a body lumen at a treatment location, the method comprising: 
 measuring a luminal dimension at a location of the lumen;    positioning an electrode deployment device at a treatment location within the lumen, wherein the electrode deployment device has an electrode structure coupled to an expansion member;    deploying the expansion member to engage the electrode structure against a wall of the lumen; and    delivering sufficient energy to the electrode structure for treatment of the luminal tissue based on the measured dimension of the lumen.    
     
     
         31 . A method as in  claim 30 , wherein measuring comprises: 
 positioning a sizing member at the treatment location within the lumen;    expanding the sizing member until it engages an inside wall of the lumen;    calculating the luminal dimension at the treatment location of the lumen based on the expansion of the sizing member.    
     
     
         32 . A method as in  claim 31 , wherein expanding the sizing member comprises inflating a sizing balloon by introducing an expansion medium.  
     
     
         33 . A method as in  claim 32 , wherein the expansion medium is a compressible fluid.  
     
     
         34 . A method as in  claim 32 , wherein the expansion medium is an incompressible fluid  
     
     
         35 . A method as in  claim 33 , wherein the sizing balloon is generally cylindrical and has a known length and a diameter that is greater than the diameter of the target lumen.  
     
     
         36 . A method as in  claim 35 , wherein the sizing balloon is noncompliant.  
     
     
         37 . A method as in  claim 32 , wherein calculating comprises determining the amount of the expansion medium introduced to the sizing balloon while it is inflated.  
     
     
         38 . A method as in  claim 37 , wherein determining the amount of expansion medium comprises measuring the mass of the expansion medium introduced to the sizing balloon.  
     
     
         39 . A method as in  claim 37 , wherein determining the amount of expansion medium comprises measuring the volume of the expansion medium introduced to the sizing balloon.  
     
     
         40 . A method as in  claim 37 , further comprising a pressure sensor coupled to the sizing balloon, wherein the pressure sensor measures an internal pressure exerted from the expansion medium.  
     
     
         41 . A method as in  claim 40 , wherein calculating further comprises determining the luminal dimension based on the measured amount of expansion medium inside the balloon at a given pressure.  
     
     
         42 . A method as in  claim 30 , wherein positioning the electrode deployment device comprises transesophageally delivering the device to a treatment area within the esophagus.  
     
     
         43 . A method as in  claim 42 , wherein transesophageally delivering the array comprises advancing a catheter through the esophagus, wherein the catheter carries the electrode array and the expansion member.  
     
     
         44 . A method as in  claim 43 , wherein the expansion member can variably expand to engage the wall of the esophagus independent of the size of the esophagus.  
     
     
         45 . A method as in  claim 44 , wherein the expansion member is an inflatable balloon, and wherein the balloon is generally cylindrical.  
     
     
         46 . A method as in  claim 45 , wherein the balloon can expand to a range of diameters between 12 mm and 50 mm.  
     
     
         47 . A method as in  claim 46 , wherein deploying the expansion member comprises inflating the balloon with an expansion medium.  
     
     
         48 . A method as in  claim 47 , wherein the electrode deployment device further includes a pressure sensor, and wherein the balloon is inflated to a pressure no greater than 10 psig.  
     
     
         49 . A method as in  claim 48 , wherein the balloon is inflated to a pressure between 4 psig and 7 psig.  
     
     
         50 . A method as in  claim 44 , further comprising a dimensionally stable support, wherein the array has a pre-selected density of electrodes and is arranged on a surface of the support.  
     
     
         51 . A method as in  claim 50 , wherein the support comprises a non-distensible, electrode backing.  
     
     
         52 . A method as in  claim 51 , wherein the electrode array surface area enlarges as the expansion member expands while maintaining the pre-selected electrode density.  
     
     
         53 . A method as in any one of  claims 42  to  53 , wherein delivering energy comprises applying radiofrequency energy to tissue of the body lumen through the electrodes  
     
     
         54 . A method as in  claim 53 , wherein the radiofrequency energy is applied through a multiplicity of bipolar electrode pairs in the array.  
     
     
         55 . A method as in  claim 54 , wherein the electrodes are parallel, have a width in the range from 0.1 mm to 3 mm, and are spaced-apart by a distance in the range from 0.1 mm to 3 mm.  
     
     
         56 . A method as in  claim 53 , wherein the radiofrequency energy density is delivered at a total dosage in the range from 1 joules/cm 2  to 50 joules/cm 2 .  
     
     
         57 . A method as in  claim 56 , wherein the radiofrequency energy is delivered over a time period below 5 seconds.  
     
     
         58 . A method for measuring an internal dimension at a location in a body lumen, the method comprising: 
 positioning a balloon at a location within the lumen, wherein the balloon is generally cylindrical and has a known length;    inflating the balloon with an expansion medium to expand the balloon to engage an inside wall of the lumen;    monitoring the extent of engagement of the balloon with the wall of the lumen;    determining the amount of expansion medium in the balloon while inflated at the location; and    calculating the internal dimension of the esophagus based on the length of the balloon and the measured amount of expansion medium inside the balloon.    
     
     
         59 . A method as in  claim 58 , wherein positioning comprises transesophageally delivering the balloon to a treatment area within the esophagus.  
     
     
         60 . A method as in  claim 59 , wherein transesophageally delivering the balloon comprises advancing a catheter through the esophagus, wherein the catheter carries the balloon.  
     
     
         61 . A method as in  claim 60 , wherein the balloon is non-distensible.  
     
     
         62 . A method as in  claim 61 , wherein the balloon has a diameter that is greater than the diameter of the inside wall of the lumen.  
     
     
         63 . A method as in  claim 62 , wherein the expansion medium is a compressible fluid.  
     
     
         64 . A method as in  claim 63 , wherein the expansion medium is air.  
     
     
         65 . A method as in  claim 60 , wherein monitoring the extent of engagement comprises determining the expansion of the balloon via visual inspection.  
     
     
         66 . A method as in  claim 63 , further comprising a pressure sensor coupled to the balloon, wherein the pressure sensor measures an internal pressure exerted from the expansion medium, and wherein monitoring the extent of engagement comprises determining internal pressure.  
     
     
         67 . A method as in  claim 66 , wherein the pressure sensor is a strain gauge.  
     
     
         68 . A method as in  claim 66 , wherein the balloon is expanded to apply pressure to the inside wall of the lumen, thereby causing the lumen to stretch.  
     
     
         69 . A method as in  claim 68 , wherein the balloon is expanded to a pressure no greater than 7 psig.  
     
     
         70 . A method as in  claim 69 , wherein the balloon is expanded to a pressure between 4 psig and 7 psig.  
     
     
         71 . A method for determining wall compliance of an esophagus, the method comprising: 
 positioning a balloon at a location within the esophagus;    inflating the balloon with a compressible fluid;    measuring the static pressure within the balloon;    measuring the total amount of fluid within the balloon at at least two static pressure values;    calculating the diameter at the two static pressure values;    calculating the wall compliance based on the variation in the calculated diameters between a first measured pressure and a second measured pressure.    
     
     
         72 . A method as in  claim 71 , wherein the compressible fluid is air.  
     
     
         73 . A method as in  claim 71 , wherein the at least two static pressure values are below 10 psig.  
     
     
         74 . A system for treating tissue of a body lumen, the system comprising: 
 a sizing member for measuring the cross section at a location of the lumen;    one or more individual treatment devices, each device comprising an electrode structure adapted to treat a target location, wherein at least some of the structures are adapted to treat locations having different sizes determined by the sizing member.    
     
     
         75 . A system as in  claim 74 , wherein the sizing member is an inflatable sizing balloon.  
     
     
         76 . A system as in  claim 75 , wherein the sizing balloon is generally cylindrical and has a known length.  
     
     
         77 . A system as in  claim 76 , wherein the sizing balloon is noncompliant.  
     
     
         78 . A system as in  claim 77 , wherein the sizing balloon has a diameter that is larger than the diameter of the inside wall of the lumen.  
     
     
         79 . A system as in  claim 75 , wherein the sizing balloon is inflated with a compressible fluid.  
     
     
         80 . A system as in  claim 79 , further comprising a pressure sensor coupled to the sizing balloon.  
     
     
         81 . A system as in  claim 80 , further comprising a measuring means for determining the amount of fluid in the sizing balloon.  
     
     
         82 . A system as in  claim 81 , wherein the measuring means comprises a mass-flow meter.  
     
     
         83 . A system as in  claim 81 , wherein the measuring means comprises a volume-flow meter.  
     
     
         84 . A system as in  claim 80 , wherein the fluid expands the sizing balloon to a pre-selected pressure, and wherein the measuring means determines the amount of fluid in the balloon at the pre-selected pressure.  
     
     
         85 . A system as in  claim 84 , wherein the sizing balloon is calibrated so that the diameter of the balloon can be calculated from the value of the amount of fluid measured.  
     
     
         86 . A system as in  claim 74 , wherein each device comprises an expansion member coupled to the electrode structure.  
     
     
         87 . A system as in  claim 86 , wherein the expansion member is an inflatable balloon.  
     
     
         88 . A system as in  claim 87 , wherein each balloon are cylindrical and range in diameter from 12 mm to 50 mm when expanded.  
     
     
         89 . A system as in  claim 88 , wherein the individual treatment device and the sizing member are both inflated with the same expansion medium.