Methods and apparatus for locating a surface of a body lumen

Abstract

An embodiment of an apparatus for locating a surface of a body lumen is disclosed. The apparatus includes a locator assembly that has a distal end region configured to extend into an opening of the body lumen and to selectably engage at least a portion of the body lumen adjacent to the opening. The distal end region includes at least one surface engaging element that is configured to engage the surface of the body lumen. The apparatus includes a measuring device that is in electrical communication with the surface engaging element. The measuring device is configured to determine changes in measurable characteristics of the surface engaging element. Methods and apparatus for locating a surface of a body lumen are also disclosed.

1 . An apparatus for locating a surface of a body lumen, comprising:
 a locator assembly including a distal end region configured to extend into an opening of the body lumen and to selectably engage at least a portion of the body lumen adjacent to the opening, said distal end region including at least one surface engaging element configured to engage the surface of the body lumen; and   a measuring device in electrical communication with said surface engaging element, said measuring device configured to determine changes in measurable characteristics of said surface engaging element.   
     
     
         2 . The apparatus of  claim 1 , said locator assembly further comprising a control member and said control member being in electrical communication with said measuring device and a distal end of said surface engaging element. 
     
     
         3 . The apparatus of  claim 2 , said locator assembly further comprising a tubular body and wherein said tubular body is in electrical communication with said measuring device and a proximal end of said surface engaging element and said tubular body being in indirect electrical communication with said control member. 
     
     
         4 . The apparatus of  claim 2 , further comprising a cover member, wherein said cover member is in electrical communication with said measuring device, said cover member being selectively electrically isolated from said tubular body. 
     
     
         5 . The apparatus of  claim 1 , said locator assembly further comprising a plurality of engaging members configured to engage the surface of the body lumen. 
     
     
         6 . The apparatus of  claim 5 , a first engaging member being selectively electrically isolated from a second engaging member. 
     
     
         7 . The apparatus of  claim 5 , said distal end region being selectably controllable between an unexpanded state and an expanded state for engaging the body lumen. 
     
     
         8 . The apparatus of  claim 7 , said plurality of engaging members being configured to expand substantially transversely with respect to a longitudinal axis of said locator assembly. 
     
     
         9 . The apparatus of  claim 6 , said first engaging member being in electrical communication with a third engaging member that is selectively electrically isolated from said second engaging member. 
     
     
         10 . The apparatus of  claim 1 , said measurable characteristics of said surface engaging element that change are selected from the group consisting of an impedance of said surface engaging element, a pressure on said surface engaging element, changes ultrasonic data near said surface engaging element, and combinations thereof. 
     
     
         11 . A method for locating a surface of a body lumen, comprising:
 inserting a locator assembly through an opening of the body lumen, said locator assembly comprising a distal end region including a surface engaging element configured to selectively engage the surface of the body lumen;   positioning said locator assembly in close proximity to the opening of the body lumen;   measuring a measurable characteristic of said surface engaging element within the body lumen; and   determining whether said measurable characteristic of said surface engaging element indicates that said surface engaging element has engaged the surface of the body lumen.   
     
     
         12 . The method of  claim 11 , said measurable characteristic including an opening electrical characteristic and the method further comprising after positioning said locator assembly within the body lumen, measuring an initial electrical characteristic of said surface engaging element. 
     
     
         13 . The method of  claim 12 , wherein determining whether said measurable characteristic of said surface engaging element indicates that said surface engaging element has engaged the surface of the body lumen further comprises comparing said measured initial electrical characteristic of said surface engaging element with said measured opening electrical characteristic of said surface engaging element. 
     
     
         14 . The method of  claim 11 , said locator assembly further comprising a control member and said control member being in electrical communication with said measuring device and a distal end of said surface engaging element. 
     
     
         15 . The method of  claim 14 , said locator assembly further comprising a cover member, said cover member being in electrical communication with said measuring device, and said cover member being selectively electrically isolated from said control member. 
     
     
         16 . The method of  claim 15 , wherein determining whether said opening electrical characteristic of said surface engaging element indicates that said surface engaging element has engaged the surface of the body lumen further comprises determining whether said cover member and said control member are in electrical communication. 
     
     
         17 . A surface engaging element comprising:
 a proximal end portion including at least one retaining portion;   a distal end portion including at least one retaining portion; and   at least one engaging member extending toward said proximal end portion and extending toward said distal end portion, said at least one engaging member configured to engage a surface of a body lumen.   
     
     
         18 . The surface engaging element of  claim 17 , said surface engaging element being formed from a unitary base material. 
     
     
         19 . The surface engaging element of  claim 18 , said surface engaging element being formed by a laser cutting process from said unitary base material. 
     
     
         20 . The surface engaging element of  claim 18 , said unitary base material including nickel-titanium. 
     
     
         21 - 24 . (canceled)