Surgical device with tack-free gel and method of manufacture

Abstract

A process of making a tack-free gel is disclosed comprising the steps of providing a mold defining a mold cavity, the mold cavity comprising a plastic material; pouring or injecting a molten gel having a high molding temperature into the mold cavity; and forming the tack-free gel as a thin layer of plastic of the mold cavity is melted over the gel. The forming step further comprises cooling the gel from the molten state to a solidified state. The melting temperature of the plastic material is lower than the molding temperature of the gel; and the higher the temperature differential, the greater the melting of the plastic material and the thicker the layer of the plastic material on the surface of the gel. The mold may be formed of low-density polyethylene (LDPE). With the process of the invention, the heat of the molten gel at its molding temperature is transferred to the surface of the LDPE mold so as to melt a thin layer of the LDPE. The mold may comprise a mold base having a plurality of mold holes forming a plurality of mold cavities, each of the mold holes comprising an axial pin to mold an axial hole through a center of the gel, an LDPE cylinder providing a predetermined inside diameter for the mold, and an LDPE disc mounted on the axial pin and disposed at the bottom of each mold cavity in the mold base. The process may further comprise the step of dabbing the gel in a low-friction powder such as polytetrafluoroethylene (PTFE) and a lubricant. The mold may further comprise a mold top disposed axially of the mold base and comprises a plurality of holes forming a plurality of cavities, each of the mold top holes is adapted to receive the LDPE cylinder, and a second LDPE disc disposed at the top of each mold cavity of the mold top.

1 . A method of making a tack-free gel, comprising the steps of: 
 providing a mold defining a mold cavity, the mold cavity comprising a plastic material;    pouring or injecting a molten gel having a high molding temperature into the mold cavity; and    forming the tack-free gel as a thin layer of plastic of the mold cavity is melted over the gel.    
   
   
       2 . The method of  claim 1 , wherein the mold providing step further comprises the step of injecting or spraying the mold cavity with the plastic material.  
   
   
       3 . The method of  claim 1 , wherein the forming step further comprises cooling the gel from the molten state to a solidified state.  
   
   
       4 . The method of  claim 1 , wherein a melting temperature of the plastic material is lower than the molding temperature of the gel.  
   
   
       5 . The method of  claim 4 , wherein the difference in the melting temperature of the plastic material and the molding temperature of the gel is in a range of about 20° F. to about 100° F.  
   
   
       6 . The method of  claim 4 , wherein the higher the temperature differential, the greater the melting of the plastic material and the thicker the melted layer of the plastic material on the surface of the gel.  
   
   
       7 . The method of  claim 1 , wherein the gel molding temperature is about 450° F.  
   
   
       8 . The method of  claim 1 , wherein the mold is formed of low-density polyethylene (LDPE) and having a melting temperature of about 240° F.  
   
   
       9 . The method of  claim 8 , wherein the heat of the molten gel at its molding temperature is transferred to a surface of the LDPE mold so as to melt a thin layer of the LDPE.  
   
   
       10 . The method of  claim 9 , further comprising the step of cooling the molten gel and melted LDPE so as to form a non-tacky surface on the solidified gel.  
   
   
       11 . The method of  claim 10 , wherein the solidified gel has a cylindrical shape having a first opposing end, a second opposing end and a cylindrical body.  
   
   
       12 . The method of  claim 1 , wherein the mold comprises a mold base having: 
 a plurality of mold holes forming a plurality of mold cavities, each of the mold holes comprising an axial pin to mold an axial hole through a center of the gel;    a low-density polyethylene (LDPE) cylinder providing a predetermined inside diameter for the mold; and    an LDPE disc mounted on the axial pin and disposed at the bottom of each mold cavity in the mold base.    
   
   
       13 . The method of  claim 12 , wherein each of the mold cavities includes a disposable plastic liner.  
   
   
       14 . The method of  claim 12 , wherein the LPDE cylinder is replaced after each molding process.  
   
   
       15 . The method of  claim 11 , further comprising the step of dabbing at least one of the opposing ends in a low-friction powder.  
   
   
       16 . The method of  claim 15 , wherein the low-friction powder includes at least one of polytetrafluoroethylene (PTFE) and a lubricant.  
   
   
       17 . The method of  claim 12 , wherein the mold further comprises a mold top disposed axially of the mold base and comprising: 
 a plurality of holes forming a plurality of cavities, each of the mold top holes is adapted to receive the LDPE cylinder; and    a second LDPE disc disposed at the top of each mold cavity of the mold top.    
   
   
       18 . The method of  claim 1 , wherein the plastic is formed from at least one of PVC, ABS, acrylic, polycarbonate, clear polycarbonate, Delrin, acetal, polypropylene and high-density polyethylene (HDPE).  
   
   
       19 . The method of  claim 1 , further comprising the step of tumbling or coating the gel in a lubricious material.  
   
   
       20 . The method of  claim 1 , further comprising the step of applying a lubricious coating to the gel in a vacuum deposition process.  
   
   
       21 . The method of  claim 1 , further comprising the step of dipping the gel in a lubricious material.  
   
   
       22 . The method of  claim 1 , further comprising the step of spraying the solidified gel with a lubricious material.  
   
   
       23 . The method of any one of claims  19 - 22 , wherein the lubricious material includes Parylene.  
   
   
       24 . A method of making a tack-free gel by co-extrusion, comprising the steps of: 
 extruding an elongate sleeve formed of a plastic material around a molten gel having a high molding temperature, the elongate sleeve having an axis and a diameter;    pressurizing the molten gel to control the diameter of the filled elongate sleeve; and    cooling the filled elongate sleeve to form the tack-free gel.    
   
   
       25 . The method of  claim 24 , wherein the plastic material is low-density polyethylene (LDPE).  
   
   
       26 . The method of  claim 24 , further comprising the step of radially cutting the elongate sleeve into individual segments having predetermined lengths.  
   
   
       27 . The method of  claim 24 , further comprising the step of removing the gel by squeezing the sleeve and pulling the gel from the sleeve.  
   
   
       28 . The method of  claim 27 , wherein the gel has a cylindrical shape having a first opposing end, a second opposing end and a cylindrical body.  
   
   
       29 . The method of  claim 28 , further comprising the step of dabbing at least one of the opposing ends in a low-friction powder.  
   
   
       30 . The method of  claim 29 , wherein the low-friction powder includes at least one of polytetrafluoroethylene (PTFE) and a lubricant.  
   
   
       31 . The method of  claim 24 , further comprising the step of tumbling or coating the gel in a lubricious material.  
   
   
       32 . The method of  claim 24 , further comprising the step of applying a lubricious coating to the gel in a vacuum deposition process.  
   
   
       33 . The method of  claim 24 , further comprising the step of dipping the gel in a lubricious material.  
   
   
       34 . The method of  claim 24 , further comprising the step of spraying the gel with a lubricious material.  
   
   
       35 . The method of any one of claims  31 - 34 , wherein the lubricious material includes Parylene.  
   
   
       36 . A trocar adapted to provide access for a surgical instrument through a body wall and into a body cavity, comprising: 
 a cannula having a proximal end and a distal end;    a seal housing communicating with the cannula to define a working channel;    a seal assembly disposed within the seal housing;    at least one roller included in the seal assembly and having an axle supported by the seal housing; and    the roller having a tack-free surface and properties for forming a zero seal in the absence of the instrument, and an instrument seal in the presence of the instrument.    
   
   
       37 . The trocar recited of  claim 36 , wherein the roller is pivotal with the axle relative to the seal housing.  
   
   
       38 . The trocar recited of  claim 36 , wherein the tack-free surface is formed of LDPE.  
   
   
       39 . The trocar recited of  claim 38 , wherein the roller further comprises a lubricious coating.  
   
   
       40 . The trocar recited of  claim 39 , wherein the lubricious coating includes at least one of polytetrafluoroethylene (PTFE) low-friction powder or a lubricant including Parylene.  
   
   
       41 . A medical access device, comprising: 
 a tubular member having an elongate configuration;    at least one wall defining with the tubular member a working channel sized and configured to receive an instrument; and    a gel disposed in the working channel and being adapted to form a seal with any instrument disposed in the working channel,    wherein the gel includes a non-tacky film to facilitate movement of any instrument through the working channel.    
   
   
       42 . The medical access device of  claim 41 , wherein the film is formed by a fluoropolymer including polytetrafluoroethylene (PTFE).  
   
   
       43 . The medical access device of  claim 42 , wherein the non-tacky film is applied as a powder or as a tape over the gel.  
   
   
       44 . The medical access device of  claim 41 , wherein the gel and non-tacky film have properties including an elongation up to about 1500 percent.  
   
   
       45 . The medical access device of  claim 41 , wherein the gel is coated with a lubricant including Parylene.  
   
   
       46 . A surgical handport facilitating a sealing relationship with a surgeon's arm extending through the handport and into an incision in an abdominal wall of a patient, comprising: 
 a valve structure comprising only a single valve disposed relative to the incision in the abdominal wall, the single valve having a first state in the absence of the arm of the surgeon extending through the valve structure, and a second state in the presence of the arm of the surgeon extending through the valve structure;    means for coupling the valve structure to the abdominal wall in a sealing relationship with the abdominal wall around the incision;    the single valve in the first state forming a zero seal in the absence of the arm of the surgeon extending through the valve structure; and    the single valve structure in the second state forming an arm seal with the arm of the surgeon in the presence of the arm of the surgeon extending through the handport,    wherein the single valve includes a non-tacky film to facilitate movement of the arm of the surgeon through the handport.    
   
   
       47 . The surgical handport of  claim 46 , wherein the valve structure further comprises: 
 a gel;    at least portions of the gel partially define an opening through the valve structure; and    the opening defining portions of the gel having properties in the first state for sealing the opening in the absence of the arm of the surgeon extending through the opening.    
   
   
       48 . The surgical handport of  claim 46 , wherein the zero seal and the arm seal have properties for inhibiting the escape of liquids and gases through the single seal.  
   
   
       49 . The surgical handport of  claim 46 , wherein the coupling means includes an adhesive having properties for attaching the valve structure to the abdominal wall.