Tungsten alloy suture needles with surface coloration

Abstract

A medical device, particularly a suture needle, comprising a tungsten alloy and having a blue, yellow or black surface coloration.

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         9 . A method for making a suture needle comprising the steps of (1) forming needle blanks comprising up to 30 weight percent rhenium, and the balance tungsten, into a suture needle; and (2) subjecting the suture needle to a DC or AC potential ranging from 1 to 40 VDC while submerged in an aqueous solution with a pH of 7 or less, to impart a yellow, blue or black surface coloration to the needle. 
     
     
         10 . The method of  claim 9 , wherein the potential is greater than about 20 volts and the surface coloration is blue. 
     
     
         11 . The method of  claim 9 , wherein the potential is less than about 20 volts and the surface coloration is yellow. 
     
     
         12 . The method of  claim 9 , wherein the potential is about 20 volts and the surface coloration is black. 
     
     
         13 . The method of  claim 9 , where the solution comprises one or more of the group consisting of hydrochloric acid, phosphoric acid, sulfuric acid, nitric acid, oxalic acid, acetic acid, water, or salt water. 
     
     
         14 . A method of polishing and sharpening the point of a suture needle comprising the steps of (1) forming needle blanks comprising up to 30 weight percent rhenium, and the balance tungsten, into a suture needle; and (2) subjecting the suture needle to a DC or AC potential while submerged in an aqueous solution with a pH of 7 or greater.