Catheter with an expandable end portion

Abstract

A catheter ( 2 ) is used in medical applications, for example for the retrieval of a sample from a patient or the insertion or retrieval of medical devices such as filters, stents ( 3 ) to and from the patient. The catheter ( 2 ) includes an expandable tip ( 6 ) at a leading portion of a catheter tube portion ( 5 ). This expandable tip ( 6 ) can retrieve or deliver samples, medical devices, etc. ( 3 ), which are slightly larger than the dimensions of a main catheter tube ( 5 ) inserted into the patient. The expandable tip ( 6 ) can also include extension members ( 10 ) which provide axial support to the expandable tip ( 6 ) but which still allow expansion in the radial direction.

1 . A catheter comprising a catheter tube portion and a tip extending axially from the catheter tube portion, the tip being flexible relative to the catheter tube portion, characterised in that the catheter includes reinforcement means to enhance the axial strength of the tip while facilitating radial expansion of the tip to accommodate an article in the tip.  
     
     
         2 . A catheter as claimed in  claim 1  wherein the tip is a soft tip of flexible material.  
     
     
         3 . A catheter as claimed in  claim 1  or  2  wherein the reinforcement means comprises an extension means extending from the catheter tube portion.  
     
     
         4 . A catheter as claimed in  claim 3  wherein the tip includes a free distal end and the extension means terminates at a position that is axially spaced back from the free end of the tip.  
     
     
         5 . A catheter as claimed in  claim 3  or  4  wherein the extension means comprises at least one extension member extending from said catheter tube portion into said expandable tip.  
     
     
         6 . A catheter as claimed in any of  claims 3  to  5  wherein the extension means comprises a plurality of extension members extending from said catheter tube portion into said expandable tip.  
     
     
         7 . A catheter as claimed in  claim 6  wherein said at least one extension member is tapered toward a leading portion of said expandable tip.  
     
     
         8 . A catheter as claimed in  claim 6  or  7  wherein said plurality of extension members are equi-spaced in the direction of said expandable tip.  
     
     
         9 . A catheter as claimed in any of  claims 6  to  8  wherein said plurality of extension members are tapered toward a leading portion of said expandable tip.  
     
     
         10 . A catheter as claimed in any of  claims 6  to  9  wherein the number of said plurality of extension members is four.  
     
     
         11 . A catheter as claimed in any of  claims 6  to  10  wherein said at least one extension member includes a radiused tip.  
     
     
         12 . A catheter as claimed in  claim 9  wherein said plurality of extension members each include a radiused tip.  
     
     
         13 . A catheter as claimed in any preceding claim wherein the tip has a free end which is rounded for ease of passage of an article.  
     
     
         14 . A catheter as claimed in any preceding claim wherein the tip has a free end which is rounded for ease of passage of the tip through the vasculature.  
     
     
         15 . A catheter as claimed in any preceding claim wherein the tip comprises a tubular sleeve of flexible material.  
     
     
         16 . A catheter as claimed in  claim 15  wherein the sleeve is attached to the catheter tube portion by heating.  
     
     
         17 . A catheter as claimed in any preceding claim wherein the tip has an outer diameter which is approximately the same dimension as the outer diameter of the catheter tube portion.  
     
     
         18 . A retrieval catheter for retrieving an article comprising a catheter tube portion and a tip extending axially from the catheter tube portion, the tip being flexible relative to the catheter tube portion, characterised in that the catheter includes reinforcement means to enhance the axial strength of the tip while facilitating radial expansion of the tip to accommodate an article in the tip.  
     
     
         19 . A retrieval catheter as claimed in  claim 18  wherein the article to be retrieved has a larger dimension then that of the normal internal dimension of the tip.  
     
     
         20 . A catheter as claimed in any preceding claim wherein the tip is movable from a delivery configuration in which the outer diameter of the tip is approximately of the same dimension as the outer diameter of the catheter portion to which it is attached, to an expandable position as an article is received in the tip.  
     
     
         21 . A catheter as claimed in any preceding claim wherein the tip is progressively movable to an expanded position in response to receiving an article in the tip.  
     
     
         22 . A catheter tube portion having a tip extending axially from the catheter tube portion, characterised in that the catheter tube portion includes reinforcement means to enhance the axial strength of the tip while facilitating radial expansion of the tip to accommodate an article in the tip.