Tech Briefs

Rolled tube technology offers a cost-effective alternative for high-volume disposables.

Traditional handheld surgical tools continue to provide benefits where surgeons need instruments to be more rigid and have strong holding power to withstand complex procedures. The majority of these small handheld devices include tubing technology. Those made with metal can be formed to meet specific needs. Base tubing can be created from drawn tubing or from flat sheets of metal in a patented technique known as rolled-tube technology, which is ideal for creating high volume disposable devices.

Medical instruments made from metal tubing. (Credit: MICRO)

Some tubes are relatively simple to create while others require more intricate details. Depending on the complexity of the device, tubes can undergo many different processes: They can be manipulated through flaring and flanging, expansions and reductions, piercing and slotting, precision sharpening, electropolishing, and laser cutting, welding, and marking.

Large-volume medical devices that require basic features can be created using rolled tube technology, which makes it possible to stamp and roll a finished tube off of a power press in one second. This represents a dramatic time savings compared with the traditional process of drawing raw tubing, cleaning it, cutting it to length, and putting in secondary features following. Rolled-tube technology is better suited for high volume runs of several hundred thousand units per year. Products that tend to fall into this category include single-use endoscopic scissors, graspers, dissectors, and tissue-holding forceps. Using a “rolled” tube in a progressive die to replace traditional drawn tubing can reduce component costs by creating critical features in-die, eliminating costly secondary operations.

Examples of rolled tubes and seamless and drawn tubes. (Credit: MICRO)

As it relates to design, flexibility can impact how a device is made. Not all tubes have to be round, for example. They can be rectangular, D-shaped, octagonal, or even have a dog bone or figure eight cross section. Tolerance and thickness of tubes need to be factored in as well. Tighter tolerances, for example, are necessary to avoid flashing if the tube is too over-molded. If the diameter varies too much, the molding operation will cause flash, and tooling may need to be changed to avoid this. Flash around critical features must be controlled to minimize fit and function issues in the final device assembly. Regarding thickness, if a tube surface needs to be machined, a thicker wall will be required.

When choosing a CMO partner for the development of tubing technology for medical devices, whether it be parts, or a complete product, consider the following in decision-making process:

  • Material type (metal versus plastic).

  • Design type (disposable versus reusable).

  • Features (basic versus intricate).

  • Flexibility (rigid versus articulating).

  • Volume (low versus high).

  • Cost (as determined by the above requirements).

This article was written by Jim Jock, Marketing Coordinator, MICRO, Somerset, NJ. For more information, visit here.