Systems and methods for locating and/or characterizing intragastric devices

Abstract

Devices and methods for treating obesity are provided. More particularly, intragastric devices and methods of fabricating, deploying, inflating, locating, tracking, monitoring, deflating, and retrieving the same are provided.

What is claimed is: 
     
         1 . A magnetic system for locating an intragastric device inside the body, the system comprising:
 a magnetic field sensor configured to sense a magnetic field;   a swallowable magnetic marker configured to couple with the system and further configured to produce a local magnetic field in an in vivo gastric environment; and   a valve system configured for introducing an initial fill fluid into a volume occupying intragastric device when the intragastric device is in the in vivo gastric environment, the valve system comprising a swallowable catheter configured to releasably couple with the intragastric device.   
     
     
         2 . The system of  claim 1 , wherein the magnetic marker is configured to couple with a distal end of the swallowable catheter. 
     
     
         3 . The system of  claim 1 , wherein the magnetic marker is configured to couple with the intragastric device. 
     
     
         4 . The system of  claim 1 , further comprising at least one external reference sensor configured to be placed outside the body and to sense a local magnetic field. 
     
     
         5 . The system of  claim 1 , further comprising a sensor interface unit configured to electrically communicate with the magnetic marker. 
     
     
         6 . The system of  claim 5 , further comprising a system control unit configured to electrically communicate with the sensor interface unit and with the magnetic field sensor. 
     
     
         7 . The system of  claim 6 , further comprising a computer configured to electrically communicate with the system control unit and to display an identifier indicating the location of the magnetic marker inside the body. 
     
     
         8 . The system of any of  claim 7 , wherein the computer is further configured to display a trace indicating a path travelled by the magnetic marker inside the body. 
     
     
         9 . The system of  claim 1 , further comprising the intragastric device, wherein the intragastric device is a balloon. 
     
     
         10 . The system of  claim 9 , further comprising the initial fill fluid, wherein the intragastric device comprises a polymeric wall configured to have, under conditions of the in vivo gastric environment, a permeability to CO 2  of more than 10 cc/m 2 /day, such that a rate and an amount of diffusion of CO 2  from the in vivo gastric environment into a lumen of the intragastric device through the polymeric wall is controlled, at least in part, by a concentration of an inert gas in the initial fill fluid. 
     
     
         11 . The system of  claim 10 , wherein the initial fill fluid comprises SF 6  in one or more of liquid form, vapor form, or gaseous form. 
     
     
         12 . The system of  claim 10 , wherein the initial fill fluid comprises gaseous N 2  and gaseous SF 6 . 
     
     
         13 . A method for magnetically locating an intragastric device inside the body of a patient, the method comprising:
 introducing into the body of the patient, via swallowing, the intragastric device comprising an uninflated gastric balloon, the intragastric device releasably coupled with a catheter and coupled with a magnetic marker, the magnetic marker configured to be sensed by the magnetic field sensor;   sensing the magnetic field with the magnetic field sensor; and   confirming a location of the uninflated gastric balloon inside the patient based on sensing the magnetic field.   
     
     
         14 . The method of  claim 13 , wherein the location of the uninflated gastric balloon inside the patient is the patient's stomach. 
     
     
         15 . The method of  claim 13 , further comprising:
 introducing an initial fill fluid into a lumen of the uninflated gastric balloon through the catheter, the intragastric balloon comprising a polymeric wall configured to have, under conditions of an in vivo gastric environment, a permeability to CO 2  of more than 10 cc/m 2 /day; and   exposing the inflated intragastric balloon to the in vivo intragastric environment for a useful life of at least 30 days, wherein a rate and an amount of diffusion of CO 2  from the in vivo gastric environment into the lumen of the balloon through the polymeric wall is controlled, at least in part, by a concentration of an inert gas in the initial fill fluid.   
     
     
         16 . The method of  claim 15 , wherein the initial fill fluid comprises SF 6  in one or more of liquid form, vapor form, or gaseous form. 
     
     
         17 . The method of  claim 15 , wherein the initial fill fluid comprises gaseous N 2  and gaseous SF 6 . 
     
     
         18 . The method of  claim 13 , wherein confirming a location of the uninflated gastric balloon inside the patient based on sensing the magnetic field generated by the magnetic marker comprises displaying on a computer an identifier indicating the location of the magnetic marker. 
     
     
         19 . The method of  claim 13 , wherein the magnetic marker is coupled with the catheter. 
     
     
         20 . The method of  claim 13 , wherein the electromagnetic sensor is coupled with the intragastric device.