Medical tube, catheter and method of manufacturing medical tube

Abstract

A medical tube includes a distal portion provided on one end side having a first outer diameter, a first inner diameter, and a first thickness; a proximal portion provided on the other end side having a second outer diameter greater than the first outer diameter, a second inner diameter greater than the first inner diameter, and a second thickness greater than the first thickness; and an intermediate portion provided between the distal portion and the proximal portion and having an outer diameter, an inner diameter, and a thickness which gradually vary. Thus, a medical tube is provided having improved operability and which reduces the likelihood of bending during an operation.

What is claimed is: 
     
         1 . A medical tube comprising:
 a distal portion provided on one end side having a first outer diameter, a first inner diameter, and a first thickness;   a proximal portion provided on an other end side having a second outer diameter greater than the first outer diameter, a second inner diameter greater than the first inner diameter, and a second thickness greater than the first thickness; and   an intermediate portion provided between the distal portion and the proximal portion and having an outer diameter, an inner diameter, and a thickness which gradually vary.   
     
     
         2 . The medical tube according to  claim 1 ,
 wherein the outer diameter, the inner diameter, and the thickness in the intermediate portion gradually vary to be smaller from the proximal portion toward the distal portion.   
     
     
         3 . The medical tube according to  claim 1 ,
 wherein the medical tube is made of a crystalline resin.   
     
     
         4 . The medical tube according to  claim 3 ,
 wherein the distal portion has lower crystallinity than the proximal portion.   
     
     
         5 . A catheter comprising:
 a sheath connected with the medical tube according to  claim 1  and configured to be inserted into a lumen;   a hub configured to be connected to a proximal side of the sheath and to be arranged on a hand side of a user; and   an imaging core configured to advance and retreat inside the sheath and to create an image inside the lumen.   
     
     
         6 . The catheter according to  claim 5 ,
 wherein the imaging core passes through the hub.   
     
     
         7 . The catheter according to  claim 6 ,
 wherein the sheath includes a sheath main body portion connected to the hub, a distal tube connected to a distal side of the sheath main body portion, and an intermediate tube connected to the sheath main body portion closer to a proximal side than the distal tube.   
     
     
         8 . The catheter according to  claim 7 ,
 wherein the sheath main body portion includes a first guide wire lumen and the intermediate tube includes a second guide wire lumen.   
     
     
         9 . The catheter according to  claim 8 ,
 wherein the sheath main body portion includes the medical tube connected to the hub, a distal outer tube bonded to an outer side surface of the medical tube, and a distal inner tube arranged inside the distal outer tube.   
     
     
         10 . The catheter according to  claim 9 ,
 wherein the distal inner tube and the medical tube include observation portion lumens, the imaging core being arranged inside the observation portion lumens.   
     
     
         11 . A method of manufacturing a medical tube comprising:
 a molding step of molding a tubular intermediate body with a crystalline resin in which a thickness of a first section on one side is less than a thickness of a second section on the other side, an outer diameter of the first section is equal to or less than an outer diameter of the second section, and a third section is formed as gradually varying in thickness between the first section and the second section; and   an annealing step of forming a distal portion which is provided on one end side and has a first outer diameter, a first inner diameter, and a first thickness, a proximal portion which is provided on the other end side and has a second outer diameter greater than the first outer diameter, a second inner diameter greater than the first inner diameter, and a second thickness greater than the first thickness, and an intermediate portion which is provided between the distal portion and the proximal portion and has an outer diameter, an inner diameter, and a thickness which gradually vary by annealing the intermediate body to promote crystallization.   
     
     
         12 . The method of manufacturing a medical tube according to  claim 11 ,
 wherein an inner diameter of the intermediate body is constant from the first section to the second section.   
     
     
         13 . The method of manufacturing a medical tube according to  claim 11 ,
 wherein the intermediate body is molded by extrusion molding in the molding step.   
     
     
         14 . The method of manufacturing a medical tube according to  claim 11 ,
 wherein time for annealing the first section is shorter than time for annealing the second section in the annealing step.   
     
     
         15 . The method of manufacturing a medical tube according to  claim 11 ,
 wherein said annealing step lowers crystallinity of the distal portion to be less than that of the proximal portion.