Medical tubing having variable characteristics and method of making same

Abstract

The invention primarily is directed to a medical tubing adapted for insertion into a body tissue or cavity and method of manufacturing different variations of the tubing along a length of the tubing. The tubing comprises a plurality of individual, discrete, generally ring-shaped elements arranged in series and fused or bonded together forming a continuous tubular structure. The ring-shaped elements may be formed of a thermoplastic or a thermoset material. The ring-shaped elements may include plastic rings, metallic rings, un-reinforced plastic rings and/or metal reinforced plastic rings assembled along the length of the tubular structure to provide variable flexibility and kink-resistance. The tubular structure may have a cross-section of any geometric shape and it may be bent, twisted or curved without kinking. The ring-shaped elements may have different flexural modulus. The ring-shaped elements may include a combination of flexible and rigid ring-shaped elements assembled along different portions or sections of the tubular structure. The ring-shaped elements may be metallic and may be bonded with a resilient, flexible elastomeric adhesive, wherein the ring-shaped elements may have different lengths and may be fused closer or further apart to one another depending on the characteristics of a portion or section of the tubing. In another aspect of the invention, the medical tubing may further comprise a secondary lumen and a pull wire to control the tubular structure. The ring-shaped elements may be truncated to provide a bending bias. In another aspect of the invention, the ring-shaped elements may vary in diameter and/or composition in different portions or sections of the tubular structure. In yet another aspect of the invention, some of the ring-shaped elements may be radiopaque, or the ring-shaped elements may comprise of different colors to operate as indicators along the tubular structure.

1 . A medical tubing adapted for insertion into a body tissue or cavity having a length with variable characteristics, comprising: 
 a plurality of individual, discrete, generally ring-shaped elements arranged in series and fused or bonded together forming a continuous tubular structure.    
     
     
         2 . The medical tubing of  claim 1 , wherein the ring-shaped elements are formed of a thermoplastic material.  
     
     
         3 . The medical tubing of  claim 1 , wherein the ring-shaped elements are formed of a thermoset material.  
     
     
         4 . The medical tubing of  claim 1 , wherein the ring-shaped elements include at least one of plastic rings, metallic rings, un-reinforced plastic rings and metal reinforced plastic rings assembled along the length of the tubular structure to provide variable flexibility and kink-resistance.  
     
     
         5 . The medical tubing of  claim 1 , wherein the tubular structure may be bent, twisted or curved without kinking.  
     
     
         6 . The medical tubing of  claim 1 , wherein the tubular structure has a cross-structure including circular, oval, rectangular, triangular, hexagonal and any geometric shape.  
     
     
         7 . The medical tubing of  claim 1 , wherein the ring-shaped elements have different flexural modulus.  
     
     
         8 . The medical tubing of  claim 1 , wherein the ring-shaped elements include a combination of flexible and rigid ring-shaped elements assembled along different portions or sections of the tubular structure.  
     
     
         9 . The medical tubing of  claim 4 , wherein the metallic rings are coated with plastic and are assembled with alternating elastomeric rings.  
     
     
         10 . The medical tubing of  claim 8 , wherein as the tubular structure is bent, twisted or curved, the rigid ring-shaped elements provide reinforcement to maintain the size and shape of the lumen and the flexible ring-shaped elements operate to stretch and compress to prevent kinking.  
     
     
         11 . The medical tubing of  claim 1 , wherein the ring-shaped elements are metallic and are bonded with a resilient, flexible elastomeric adhesive.  
     
     
         12 . The medical tubing of  claim 11 , wherein the ring-shaped elements have different lengths and are fused closer or further apart to one another depending on the characteristics of a portion or section of the tubing.  
     
     
         13 . The medical tubing of  claim 1 , further comprising a secondary lumen and a pull wire to control the tubular structure.  
     
     
         14 . The medical tubing of  claim 1 , wherein at least one of the ring-shaped elements is truncated to provide a bending bias.  
     
     
         15 . The medical tubing of  claim 14 , wherein the truncated elements comprise of alternating flexible ring-shaped elements and rigid ring-shaped elements.  
     
     
         16 . The medical tubing of  claim 1 , wherein the ring-shaped elements vary in diameter in different portions or sections of the tubular structure.  
     
     
         17 . The medical tubing of  claim 16 , wherein the composition of the ring-shaped elements vary in the different portions or sections of the tubular structure.  
     
     
         18 . The medical tubing of  claim 17 , wherein the ring-shaped elements are assembled in accordance with a preferred modulus within portions or sections of the tubular structure.  
     
     
         19 . The medical tubing of  claim 1 , wherein at least one of the ring-shaped elements is radiopaque.  
     
     
         20 . The medical tubing of  claim 1 , wherein the ring-shaped elements comprise of different colors to operate as indicators along the tubular structure  
     
     
         21 . A method of manufacturing a medical tubing having a length with variable characteristics, the medical tubing comprising a plurality of individual, discrete, generally ring-shaped elements arranged in series and fused together to form a continuous tubular structure, the method comprising the steps of: 
 placing the plurality of ring-shaped elements upon a support member or mandrel in a series arrangement; and    heating the plurality of ring-shaped elements to fuse them together over the support member or mandrel    
     
     
         22 . The method of  claim 21 , further comprising placing the plurality of ring-shaped elements upon a second support member or mandrel before the heating step to subsequently form a second lumen or control tube to the tubular structure.  
     
     
         23 . The method of  claim 21 , further comprising forming a control tube over the assembled ring-shaped elements prior to the heating step.  
     
     
         24 . The method of  claim 23 , wherein the control tube comprises at least one of glass, silicone, heat shrinkable polyolefin, PTFE, FEP, metallic or other tubing that has a higher melting temperature than the assembled ring-shaped elements.  
     
     
         25 . A method of manufacturing a medical tubing having a length with variable characteristics, the medical tubing comprising a plurality of individual, discrete, generally ring-shaped elements arranged in series and fused together to form a continuous tubular structure, the method comprising the steps of: 
 placing the plurality of ring-shaped elements upon a support member or mandrel in a series arrangement; and    fusing the plurality of ring-shaped elements together over the support member or mandrel with a solvent or other chemical compound.    
     
     
         26 . The method of  claim 25 , wherein the fusing step further comprises immersing the ring-shaped elements into the solvent to fuse the elements  
     
     
         27 . A method of manufacturing a medical tubing having a length with variable characteristics, the medical tubing comprising a plurality of individual, discrete, generally ring-shaped elements arranged in series and bonded together to form a continuous tubular structure, the method comprising the steps of: 
 placing the plurality of ring-shaped elements upon a support member or mandrel in a series arrangement; and    bonding together the plurality of ring-shaped elements upon a support member or mandrel with an adhesive.    
     
     
         28 . The method of  claim 27 , wherein the adhesive is photodynamic or heat-activated.  
     
     
         29 . The method of  claim 21 , further comprising coating the tubular structure with an elastomeric adhesive or dispersion.  
     
     
         30 . The method of  claim 21 , wherein the mandrel has a pre-formed curvature for accessing a specific region of a body cavity.  
     
     
         31 . The method of  claim 21 , wherein the mandrel includes a collapsible, inflatable or dissolvable mandrel allowing the tubular structure to vary in diameter and lumen size.  
     
     
         32 . The method of  claim 31 , wherein the mandrel is formed of an electrically dissolvable epoxy resin.  
     
     
         33 . The medical tubing of  claim 1 , wherein the tubing is used as an AV introducer, a urological sheath, a ureteral access sheath, a urethral and bladder access sheath, a kidney access sheath, a ureteral stent, a trocar cannula, a suction/irrigation tubing, an insufflation tubing, a vacuum tubing, a split sheath introducer, a tracheostomy tube, an intubation tube, a gastronomy tube, a jujenostomy tube, an extracorporeal retrograde cholangeopancreatography catheter, an endoscope shaft, a drainage tube, a guide catheter, a hydrocephalic shunt, a guidewire, an angioplasty and dilation balloon, a vascular graft, a cholangiography catheter, a vascular embolectomy/thrombectomy catheter, or a central venous catheter.  
     
     
         34 . A method of manufacturing a thin-walled tube, comprising: 
 coating a wire with a plastic material;    wrapping the coated wire around a mandrel forming a plurality of windings; and    heating the wound coated wire until the plastic material melts and bonds the windings forming a wire-reinforced tube.    
     
     
         35 . The method of  claim 34 , wherein the plastic material comprises at least one of polyurethane, a thermoplastic material and a thermoset material.  
     
     
         36 . The method recited of  claim 34 , wherein the wire comprises at least one of a metallic material and a second plastic material.  
     
     
         37 . The method of  claim 34 , wherein the wire is coated with the plastic material in a coextrusion process.  
     
     
         38 . The method of  claim 34 , wherein the tube has a wall thickness of about 0.015″ or less.  
     
     
         39 . The method of  claim 34 , wherein the tube has an inner diameter that ranges from about 0.026″ to about 0.75″.  
     
     
         40 . The method of  claim 39 , wherein the tolerance on the inner diameter is on the order of 0.001″ or less.  
     
     
         41 . The method of  claim 34 , further comprising compressing the windings as the coated wire is being heated  
     
     
         42 . The method of  claim 34 , further comprising providing a mold to compress the windings.  
     
     
         43 . The method of  claim 34 , further comprising removing the wire-reinforced tube from the mandrel after the tube is cooled.  
     
     
         44 . The method of  claim 34 , wherein the wound coated tube is heated until the plastic material is formed above, below and between all the windings.  
     
     
         45 . The method of  claim 34 , further comprising dipping the tube in a solvent based solution forming an outer layer of the tube.  
     
     
         46 . The method of  claim 34 , wherein the mandrel is tapered to provide the tube with varying diameter throughout the length of the tube.  
     
     
         47 . The method of  claim 34 , further comprising providing a filament comprising a material different from the coating of the wire.  
     
     
         48 . The method of  claim 47 , wherein the coated wire is alternatively wound with the filament around the mandrel.  
     
     
         49 . The method of  claim 34 , wherein the mandrel may be any shape such that the resultant shape of the tube can be removed from the mandrel after the heating step.  
     
     
         50 . The method of  claim 49 , wherein the mandrel is a multiple-part mandrel.  
     
     
         51 . A method of manufacturing a kink-resistant thin-walled tube having a length with different characteristics, comprising: 
 coating a mandrel with a first layer of plastic material;    placing a spring reinforcement over the first layer; and    coating the spring reinforcement with a second layer of plastic material to form a spring-reinforced tube.    
     
     
         52 . The method of  claim 51 , wherein the first layer is formed in an extrusion process.  
     
     
         53 . The method of  claim 51 , wherein the first layer is formed in a molding process.  
     
     
         54 . The method of  claim 51 , wherein the second layer is formed in an extrusion process.  
     
     
         55 . The method of  claim 51 , wherein the second layer is formed in a molding process.  
     
     
         56 . The method of  claim 51 , wherein the spring reinforcement is a pre-wound wire comprising at least one of a metallic material and a second plastic material.  
     
     
         57 . The method of  claim 51 , wherein the spring reinforcement is a wire comprising at least one of a metallic material and a second plastic material wound around the first layer.  
     
     
         58 . The method of  claim 51 , further comprising dipping the tube in a solvent based solution forming an outer layer of the tube.  
     
     
         59 . The method of  claim 51 , wherein the mandrel is tapered to provide the tube with varying diameter throughout the length of the tube.  
     
     
         60 . The method of  claim 51 , wherein the mandrel may be any shape such that the resultant shape of the tube can be removed from the mandrel.  
     
     
         61 . The method of  claim 60 , wherein the mandrel is a multiple-part mandrel.  
     
     
         62 . A method of manufacturing a kink-resistant thin-walled tube having a length with different characteristics, comprising: 
 coating a mandrel with a first layer of plastic material;    placing a spring reinforcement over the first layer; and    dipping the spring-reinforced first layer in a solvent based solution to form a second layer of the tube.    
     
     
         63 . The method of  claim 62 , wherein the second layer is impervious.  
     
     
         64 . The method of  claim 62 , wherein the mandrel is tapered to provide the tube with varying diameter throughout the length of the tube.  
     
     
         65 . The method of  claim 62 , wherein the mandrel may be any shape such that the resultant shape of the tube can be removed from the mandrel.  
     
     
         66 . The method of  claim 65 , wherein the mandrel is a multiple-part mandrel.