Abstract: An implanted catheter suppresses tunnel infection by having its surface temperature raised to a point above which the bacteria residing on the surface cannot survive. The temperature is held at that temperature level for 20 milliseconds whereby the catheter can be cleaned of the bio-burden.

Abstract: Two thermoplastic tubes are welded together by pre-cutting the tubes to create two ends which are axially aligned when placed in a holding device. A wafer is inserted in the space between the cut ends and the wafer is heated to melt the cut ends while the cut ends are in a non-flattened condition. After the wafer is removed the melted cut ends are pressed against each other to weld the cut ends together.

Abstract: Two thermoplastic tubes are welded together in a process which includes severing the tubes by a severing wafer having a temperature of about 350.degree. F. to create two cut sections. The severing wafer is removed from the space between the tubes and a hot wafer having a temperature of 500.degree.-1200.degree. F. is inserted in the space to radiantly heat the tube ends so that they are welded when pressed-together while in an unflattened and open condition.

Abstract: A plastic tube is sealed at its end by placing the tube in a pair of spaced apart tube holders having tube receiving pockets. The tube is cut by a cutting device movable into and out of the space between the pockets to form two distinct tube sections which are melted at their ends while in the clamped condition. The cut ends are then brought into contact with each other in a mis-aligned condition offset by one-half the thickness of a tube wall to seal the tube end.

Abstract: A thin wafer for cutting plastic tubes which are to be butt welded together includes a high temperature insulated plate-like core with a resistance circuit on the core for heating the wafer to a temperature sufficiently high to melt through the tubes. A glass layer may be on the outer surface of the water, particularly in the contact area with the tube. The wafer may be used in an arrangement wherein residue is removed from the water by having the residue adhere to unused portions or stubs of the tubes which then would be stripped from the wafer.

Abstract: Thermoplastic tubes are welded together in a dry condition with the tubes being open and maintained in their undistorted condition during the welding step. In an alternative technique a branch tube is welded to a main tube by placing the tubes in a non-parallel orientation in a holding device. A wafer cuts completely through one tube to form two tube sections. The wafer also cuts a notch from the other tube. One of the tube sections is shifted to become aligned with the notched other tube and welded thereto. A further technique includes placing at least one tube in a holding device which has a false floor for pressing against an area of the tube while the tube is being flattened at two spaced locations on opposite sides of the area. When the false floor is moved away from the tube a partial vacuum results. An air pocket is formed when the tube is severed by a wafer by air flowing into the cut tube.

Abstract: A linear welding process and apparatus connects fluid-filled tubes in a sterile manner. The linear welder includes a base on which a carriage is slidably mounted. A pair of side by side arms are secured to the carriage as are a pair of tube holders. A pair of clamping jaws are mounted on the arms to clamp a pair of tubes in the holders. The arms are movable for passing the clamped tubes into contact with a heated wafer which cuts the tubes into tube sections. The tube sections are realigned and a pair of sections are butt welded together.

Abstract: Thermoplastic tubes are welded together in a dry condition with the tubes being open and maintained in their undistorted condition during the welding step. In an alternative technique a branch tube is welded to a main tube by placing the tubes in a non-parallel orientation in a holding device. A wafer cuts completely through one tube to form two tube sections. The wafer also cuts a notch from the other tube. One of the tube sections is shifted to become aligned with the notched other tube and welded thereto. A further technique includes placing at least one tube in a holding device which has a false floor for pressing against an area of the tube while the tube is being flattened at two spaced locations on opposite sides of the area. When the false floor is moved away from the tube a partial vacuum results. An air pocket is formed when the tube is severed by a wafer by air flowing into the cut tube.

Abstract: A process and system is provided for making a connection between two fluid-filled plastic tubes that ensures total containment of potentially dangerous fluids and maintaining sterility of the connection. The tubes are folded to remove all fluid from the weld site and positioned to cause the connection to take place in this fluid free zone. Each folded section is first cauterized to create a bacteria free zone, the tubes are slit in the zone, and cauterized a second time to insure sterility and melt the tube ends. The tubes are urged together and as the thermoplastic resin cools, a totally contained, sterile weld is formed.