Electrically weldable suture material, and apparatus and method for forming welded suture loops and other welded structures

A method for forming a weld between two portions of a biocompatible conductive thermoplastic material configured to be placed in a body of an animal, wherein the method comprises:

• positioning first and second portions of a biocompatible conductive thermoplastic material in the body of an animal between first and second electrodes so that said first portion is in contact with said first electrode, said second portion is in contact with said second electrode, and said first and second portions of the biocompatible conductive thermoplastic material are in contact with one another, said first portion and said second portion each being a length of suture material comprising a substantially round cross-section, with said first portion and said second portion being disposed substantially parallel to one another, resulting in line contact between said first portion and said second portion;
• applying a selected amount of electrical current across said first and second electrodes so as to generate a selected amount of heat by electric resistance at the line contact between said first and second portions so as to create localized melting of regions of said first and second portions adjacent to the line contact;
• and
• terminating the electrical current across said first and second electrodes so that the melted regions of said first and second portions re-solidify so that a weld is formed at the line contact.