Davis-Standard, Conair, Zumbach demonstrate catheter production at MD&M West

Davis-Standard, Conair and Zumbach Electronics are once again teaming up at this week's MD&M West trade show to demonstrate technically difficult production of an extremely small, tapered, three-lumen surgical catheter. 

The companies have produced similar medical tubing at past MD&M shows. However, the multi-lumen catheter segments at the show Feb. 4-6 in Anaheim, Calif., are particularly challenging to produce. 

Each segment requires continuous and precise dimensional control of a constantly changing and tapering tube profile as well as for each of the three internal lumen profiles. A segment that is about 24 inches long has an external tube profile that tapers from a maximum of 0.14inch at the catheter body to a minimum of 0.11 inch at the tip. 

There are three lumens inside each tapered catheter segment: Two crescent-shaped lumens surround a central lumen with an inside diameter of 0.005 inch. The internal dimensions of all three lumens vary with the taper of the outside diameter of the tube. The three lumens provide passageways for surgical tools, cameras, air injection, drug delivery, irrigation and fluid evacuation. 

The tubing is made from medical-grade thermoplastic elastomer (TPE).  

Conair equipment in the production cell includes AL-2 and TLM loaders, TrueBlend TB45 blender, EP1A-02 portable two-ton, air-cooled chiller and a TW-T temperature control unit.  

The 1-inch Davis-Standard extruder is equipped with a Guill crosshead die. Within the die, air inputs from the Zumbach SPV-1 digital airboxes inflate the extrudate and maintain each lumen inside the hot tube. 

The three-lumen tube production will take place in Booth 4320. Davis-Standard, along with subsidiary Maillefer, will produce four-lumen Pebax tubing at Booth 4011. Pebax is an engineered high-performance polyether block amide used by medical device designers for its strength and flexibility. It is widely used for fluid transfer, catheters and balloon tubing.  

The Pebax production line consists of a Davis-Standard HPE extruder, Maillefer die, vacuum tank, puller/cutter and conveyor. A Zumbach gauge system and servo air controllers, along with a Conair chiller and drying system, also will operate as part of the line.