Ultrafast-pulse laser machining enables high quality for catheter marker bands

A major breakthrough in marker band manufacturing has taken place with the advent of commercial-grade femtosecond laser technology.

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CHICAGO, IL – Marker bands are small metal bands attached to catheters for minimally invasive medical procedures. The bands are radio-opaque (highly visible under x-ray), giving physicians much-needed visibility of the catheter location during procedures (FIGURE).

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Marker bands enhance the ability to view catheters when performing noninvasive procedures.

Manufacturing surgical marker bands is challenging because of the precision required to create a tiny metal ring that will slide smoothly along the outer diameter of the catheter and remain in place during the procedure. The outer diameter of a catheter can be as small as 100μm, meaning the marker band must be slightly larger to fit over the catheter, with surface and edge smoothness to allow it to be accurately placed without damaging the catheter.

Another challenge associated with marker bands is that the materials involved are expensive—typically gold, platinum, or palladium. This makes precision machining even more important, as material loss can be very costly.

In traditional marker band manufacturing, the bands are cut roughly and then finished in post-processing. Typical post-processing steps include cleaning, deburring, honing, and chemical etching. Post-processing adds time and material loss to the manufacturing process.

A major breakthrough in marker band manufacturing has taken place with the advent of commercial-grade femtosecond laser technology. Ultrafast-pulse (UFP) lasers matter because they are able to remove material faster than the material can absorb heat. Heat damage—melting, burring, and recast—is one of the primary sources of cost and failure in marker band manufacturing. The heat-affected zone must be reworked with extensive post-processing (deburring, polishing), often manually, resulting in lower yields and longer cycle times.

Even with the promise of UFP lasers, the raw material of the marker band—a metal tube—must be accurately held and moved through the machining processes. The pulse delivery must be synchronized with the motion of the material. The margin for error in marker band manufacturing is pretty close to zero. Each part must meet specification, and part-to-part consistency is also critical.

A UFP laser machining system achieves unprecedented accuracy in a single process, with surface and edge quality ensuring part performance. The MLTC tube cutting platform from Microlution Inc. (Chicago, IL) features integrated metrology, with a laser micrometer that measures tube length and an optical camera that measures inner and outer tube diameters. Every part is validated, any parts that don't meet specifications can be separated out of the batch, and all measurements are stored for each part for traceability.

The cutting platform delivers part-to-part accuracy and consistency in metal and metal marker bands without the need for post-processing. It also eliminates the need for interior dimension honing, acid etch, and bead blasting steps typical of other manufacturing processes.

This story was contributed by Microlution Inc.

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