Originally Published EMDM November/December 2002
TECHNOLOGY NEWS
Catheter ProductionUV Laser Machining Improves Catheter Flexibility
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| NanoVia reports that flexibility in guide catheters can be increased by using UV laser machining. Here, an SEM image shows the removed material down to the braid. |
In order to be flexible enough to navigate the narrow curves of the human body, guide catheters traditionally have been crafted of laminated layers of braided steel or cross-spiraled wires in between layers of polymer and elastomer jacketing. While the braids provide torque and tensile strength, their density at certain points, along with the types of elastomers or polymers used in the inner and outer jackets, helps to determine the catheters' flexibility. NanoVia (Londonderry, NH, USA) is now testing alternative designs that involve excimer laser machining and patterning of the outer surface of guide catheters in order to improve the standard catheter design.
The company reports that excimer micromachining technology applied to a guide catheter can improve the flexibility of the catheter. As an example, experts machined the outer jackets of guide catheters made from a nylon material with three patterns: spiral, cross-cut, and removal of specific zones of material. In all cases, flexibility was increased.
The tests support NanoVia's claim that short-pulsed (20–30-nanosecond) ultraviolet (UV) lasers, such as excimer and diode-pumped YAG lasers operating at 266-nm and 355-nm UV output, can micromachine or mill structures into catheters, and can remove the material to specific depths yet not disturb the underlying metal braid. This UV laser technology, called laser photoablation, breaks down the chemical bond in the material and expels the fragmented material.
"Although more research is needed, current results demonstrate promise and increased opportunities to use these techniques to create channels for embedding wires for sensors or electrodes, or fluid paths for drug delivery," says Todd Lizotte, chief development officer and vice president of research and development for NanoVia. "In any case, it is evident that UV lasers still offer clear advantages for creating unique medical devices."
Copyright ©2002 European Medical Device Manufacturer
